Patent Application
20220259460
The present invention relates to a two-component curing adhesive, a laminated film, a laminated film-manufacturing apparatus, and a method for manufacturing a laminated film.
In some of laminated films each composed of two films bonded to each other with an adhesive, a two-component curing adhesive using a curing reaction between a polyisocyanate composition and a polyol composition has been used as the adhesive.
As methods for manufacturing a laminated film by using a two-component curing adhesive, there are a method including a two-component mixing application process that has been used for a long time and a method including a two-component separate application process that has been attracting attention in recent years.
In the method including a two-component mixing application process, a method including a two-component mixing application process of mixing a polyisocyanate composition and a polyol composition to prepare a mixture solution and applying this mixture solution onto a film and an adhesive layer forming process of bonding another film on the coated film formed on the above film and performing curing is used.
As the method including a two-component separate application process, there is a method including a two-component separate application process consisting of a first application step of applying a polyisocyanate composition to a first film and a second application step of applying a polyol composition to a second film and an adhesive layer forming process of bring the polyisocyanate composition applied on the first film and the polyol composition applied on the second film into contact with each other by laminating the first film and the second film to cause a curing reaction.
Recently, from the viewpoint of reducing the environmental loading and improving the working environment, a demand for a solvent-free two-component curing adhesive not using an organic solvent is increasing.
For example, PTLs 1 to 3 describe two-component separate application-type adhesives that start a curing reaction when a solvent-free agent A in a liquid form at ordinary temperature applied to one adherend and a solvent-free agent B in a liquid from at ordinary temperature applied to the other adherend come into contact with each other.
PTL 1 describes a two-component separate application-type urethane-based adhesive containing the agent A that is mainly composed of a compound having isocyanate groups at both ends of the molecule and the agent B that is composed of a compound having amino groups at both ends of the molecule, a compound having a tertiary amine in the molecule, and a tackifier resin.
PTL 2 describes a two-component separate application-type urethane-based adhesive composed of the agent A that is mainly composed of a compound having isocyanate groups at both ends of the molecule and the agent B that is mainly composed of a compound having amino groups at both ends of the molecule.
PTL 3 describes a two-component separate application-type urethane-based adhesive in which the agent A is mainly composed of a compound having isocyanate groups at both ends of the molecule and the agent B is mainly composed of a compound having a hydroxy group in the molecule.
In laminated films including an adhesive layer formed between a first film and a second film by using a two-component curing adhesive using a curing reaction between a polyisocyanate composition and a polyol composition, the laminated films or the laminated film and another film are heat sealed (fusion bond) in many cases. For example, the laminated film can be used as a packaging material for food and daily necessities (such as detergent and medicine) by heat sealing the ends of the laminated film to form into a bag shape. In such a packaging material, it is demanded to express a high bond strength by heat sealing for maintaining an excellent bag making property. However, in a laminated film formed using a known two-component curing adhesive, there is still room for improvement in the heat seal strength.
The heat sealing property of a laminated film is evaluated after heat sealing of the laminated film with a laminating device. Accordingly, evaluation of the heat sealing property of a laminated film requires time and labor. Consequently, a simple parameter that can estimate the heat seal strength of a laminated film from a physical property value of the two-component curing adhesive itself that is used as a material for the adhesive layer of the laminated film is required.
The present invention was made in view of the above circumferences, and it is an object to provide a two-component curing adhesive that uses a curing reaction between a polyisocyanate composition and a polyol composition and can give a laminated film having a good heat sealing property by being formed into an adhesive layer between a first film and a second film.
It is an object of the present invention to provide a laminated film including an adhesive layer between a first film and a second film and having a good heat sealing property that gives an excellent bond strength by heat sealing.
It is an object of the present invention to provide a laminated film-manufacturing apparatus that can be suitably used when a laminated film including an adhesive layer between a first film and a second film and obtaining an excellent bond strength by heat sealing is manufactured using a two-component curing adhesive using a curing reaction between a polyisocyanate composition and a polyol composition.
It is an object of the present invention to provide a method for manufacturing a laminated film including an adhesive layer between a first film and a second film and obtaining an excellent bond strength by heat sealing by using a two-component curing adhesive using a curing reaction between a polyisocyanate composition and a polyol composition.
In order to solve the above problems, the present inventors have made extensive studies for improving the bond strength by heat sealing of a laminated film including an adhesive layer formed between a first film and a second film by using a two-component curing adhesive using a curing reaction between a polyisocyanate composition and a polyol composition.
As a result, it was found that the bond strength is improved in a laminated film including an adhesive layer formed by a two-component curing adhesive including a polyisocyanate composition and a polyol composition each having a Trouton ratio, which is a ratio of the elongational viscosity to the shear viscosity (elongational viscosity/shear viscosity), within a range of 4.0 to 8.0. Furthermore, the present inventors have made extensive studies and confirmed that the bond strength by heat sealing of a laminated film in which a two-component curing adhesive is used as a material of the adhesive layer can be estimated with high accuracy by the Trouton ratios of the polyisocyanate composition and the polyol composition of the two-component curing adhesive and arrived at the present invention.
That is, the present invention relates to the following aspects:
[1] A two-component curing adhesive using a curing reaction between a polyisocyanate composition (X) and a polyol composition (Y), wherein
the polyisocyanate composition (X) includes a polyisocyanate (A),
the polyol composition (Y) includes a polyol (B), and
the polyisocyanate composition (X) and the polyol composition (Y) each have a Trouton ratio within a range of 4.0 to 8.0;
[2] A laminated film including an adhesive layer between a first film and a second film, wherein the adhesive layer is made of a cured product of the two-component curing adhesive according to aspect [1];
[3] A laminated film-manufacturing apparatus including:
a first coating unit for applying a polyisocyanate composition (X) including a polyisocyanate (A) and having a Trouton ratio within a range of 4.0 to 8.0 to a first film;
a second coating unit for applying a polyol composition (Y) including a polyol (B) and having a Trouton ratio within a range of 4.0 to 8.0 to a second film; and
a bonding device for bonding the polyisocyanate composition (X)-coated surface of the first film and the polyol composition (Y)-coated surface of the second film; and
[4] A method for manufacturing a laminated film, including:
a two-component separate application process composed of a first application step of applying a polyisocyanate composition (X) including a polyisocyanate (A) and having a Trouton ratio within a range of 4.0 to 8.0 to a first film, and
a second application step of applying a polyol composition (Y) including a polyol (B) and having a Trouton ratio within a range of 4.0 to 8.0 to a second film; and
an adhesive layer forming process of bringing the polyisocyanate composition (X) applied on the first film and the polyol composition (Y) applied on the second film into contact with each other by laminating the first film and the second film to cause a curing reaction.
In the two-component curing adhesive of the present invention, the Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) are within a range of 4.0 to 8.0. Consequently, a laminated film including an adhesive layer formed between a first film and a second film by using the two-component curing adhesive of the present invention can obtain an excellent bond strength by heat sealing. Accordingly, the two-component curing adhesive of the present invention can be suitably used when a laminated film is manufactured.
The laminated film of the present invention includes an adhesive layer between a first film and a second film, and the adhesive layer is made of a cured product of the two-component curing adhesive of the present invention. Accordingly, the laminated film of the present invention has a good heat sealing property that gives an excellent bond strength by heat; sealing.
The laminated film-manufacturing apparatus of the present invention applies a polyisocyanate composition (X) having a Trouton ratio within a range of 4.0 to 8.0 to a first film by a first coating unit and applies a polyol composition (Y) having a Trouton ratio within a range of 4.0 to 8.0 to a second film by a second coating unit. Consequently, the laminated film-manufacturing apparatus of the present invention can be suitably used when manufacturing a laminated film of the present invention by a manufacturing method including a two-component separate application process using a two-component curing adhesive of the present invention.
The method for manufacturing a laminated film of the present invention includes a two-component separate application process and applies a polyisocyanate composition (X) having a Trouton ratio within a range of 4.0 to 8.0 to a first film in a first application step and applies a polyol composition (Y) having a Trouton ratio within a range of 4.0 to 8.0 to a second film in a second application step. Consequently, according to the method for manufacturing a laminated film of the present invention, a laminated film of the present invention can be manufactured using a two-component curing adhesive of the present invention.
The two-component curing adhesive, the laminated film, the laminated film-manufacturing apparatus, and the method for manufacturing a laminated film of the present invention will now be described in detail using the drawings. Incidentally, the drawings used in the following description may be enlarged to show the characteristic parts for convenience in order to make the characteristics of the present invention easy to understand. Accordingly, for example, the dimensional ratio of each component may differ from the actual one.
[Two-Component Curing Adhesive]
The two-component curing adhesive of the present embodiment is a two-component curing adhesive using a curing reaction between a polyisocyanate composition (Y) and a polyol composition (Y).
The polyisocyanate composition (X) in the two-component curing adhesive of the present embodiment includes a polyisocyanate (A) and has a Trouton ratio within a range of 4.0 to 8.0. The polyol composition (Y) includes a polyol (B) and has a Trouton ratio within a range of 4.0 to 8.0. The polyisocyanate composition (X) may include a part of the polyol (B) included in the two-component curing adhesive as needed.
The two-component curing adhesive of the present embodiment cures by a chemical reaction between a isocyanate group in the polyisocyanate composition (X) and a hydroxy group (or a hydroxy group and an amino group) in the polyol composition (Y).
The “Trouton ratio” in the present embodiment is a ratio of an elongational viscosity at 40° C. to a shear viscosity at 40° C. (elongational viscosity/shear viscosity).
In the two-component curing adhesive of the present embodiment, the polyisocyanate composition (X) and the polyol composition (Y) each have a Trouton ratio within a range of 4.0 to 8.0. Since the Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) in the two-component curing adhesive of the present embodiment are each 4.0 or more, the laminated film including an adhesive layer formed between a first film and a second film by using the two-component curing adhesive obtains an excellent bond strength by heat sealing. The Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) are each preferably 4.2 or more, more preferably 4.5 or more, and further preferably 5.0 or more for further improving the heat sealing property of a laminated film.
In the two-component curing adhesive of the present embodiment, since the Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) are each 8.0 or less, an excellent heat sealing property is obtained, and the fluidity of the polyisocyanate composition (X) and the polyol composition (Y) can be also maintained. The Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) are each preferably 7.0 or less and more preferably 6.5 or less for having a viscosity that allows easy application to a roll coater or a gravure coater.
The Trouton ratio of the polyisocyanate composition (X) can be controlled by adjusting the elongational viscosity and/or the shear viscosity through adjustment of the ratio of a low-viscosity material and a high-viscosity material included in the material (compound) used in the polyisocyanate composition (X).
The Trouton ratio of the polyol composition (Y) can be controlled by adjusting the elongational viscosity and/or the shear viscosity through adjustment of the ratio of a low-viscosity material and a high-viscosity material included in the material (compound) used in the polyol composition (Y).
Incidentally, the viscosity of a material (compound) that is used in the polyisocyanate composition (X) or the polyol composition (Y) can be grasped by those skilled in the art. In addition, it is possible for those skilled in the art to obtain a polyisocyanate composition (X) and a polyol composition (Y) each having a Trouton ratio within a desired range by combining materials (compounds) that are used in the polyisocyanate composition (X) or polyol composition (Y) and appropriately adjusting the compounding ratio within the range of normal experiments based on a known technology.
(Polyisocyanate (A))
As the polyisocyanate (A), a known polyisocyanate can be used without particular limitation.
Examples of the polyisocyanate (A) include:
aromatic polyisocyanates, such as tolylene diisocyanate, 2,4′-diphenylmethane diisocyanate (hereinafter, diphenylmethane diisocyanate may be simply mentioned as “MD1”), 2,2′-MDI, 4,4′-MDI, 1,5-naphthalene diisocyanate, and triphenylmethane triisocyanate;
aliphatic polyisocyanates, such as xylene diisocyanate, isophorone diisocyanate, 4,4′-methylenebis(cyclohexylisocyanate), 3,3-(isocyanatomethyl)cyclohexane, 1,6-hexamethylene diisocyanate, lysine diisocyanate, and trimethyl hexamethylene diisocyanate;
compounds in which some of the isocyanate groups of these polyisocyanates (hereinafter, may be referred to as “NCO group”) are modified with carbodiimide;
isocyanurates derived from these polyisocyanates; allophanates derived from these polyisocyanates; biurets derived from these polyisocyanates; adducts obtained by modifying these polyisocyanates with trimethylolpropane; and
polyisocyanates (A1) as reaction products (prepolymers) of various polyisocyanates and polyol components (hereinafter, the polyisocyanate as a prepolymer may be referred to as “polyisocyanate (A1)”).
In the polyisocyanate (A1), examples of the polyol component that is reacted with an aromatic polyisocyanate or an aliphatic polyisocyanate specifically include chain aliphatic glycols, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3 methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl, glycol, methyl pentanediol, dimethyl butanediol, butyl ethyl propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, and bishydroxyethoxybenzene; alicyclic glycols, such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol; trifunctional or tetrafunctional aliphatic alcohols, such as glycerol, trimethylolpropane, and pentaerythritol; bisphenols, such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimer diol; a polyether polyol obtained by addition polymerization of an alkylene oxide, such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, or cyclohexylene, in the presence of a polymerization initiator, such as the glycol or the trifunctional or tetrafunctional aliphatic alcohol mentioned above; and a polyester polyol (1) that is a reaction product of a polyester obtained by a ring-opening polymerization reaction of a cyclic ester compound, such as propiolactone, butyrolactone, ε-caprolactone, α-valerolactone, or β-methyl-σ-valerolactone, and the glycol or the trifunctional or tetrafunctional aliphatic alcohol mentioned above;
A polyester polyol (2) obtained by reacting a polyol, such as the above-mentioned chain aliphatic glycol, alicyclic glycol, dimer diol, bisphenol, or polyether polyol, and a polyvalent carboxylic acid;
a polyester polyol (3) obtained by reacting the above-mentioned trifunctional or tetrafunctional aliphatic alcohol and a polyvalent carboxylic acid;
a polyester polyol (4) obtained by reacting a polyol, such as the above-mentioned chain aliphatic glycol, alicyclic glycol, dimer diol, bisphenol, or polyether polyol, the above-mentioned trifunctional or tetrafunctional aliphatic alcohol, and a polyvalent carboxylic acid;
a polyester polyol (5) that is a polymer of a hydroxy acid, such as dimethylol propionic acid and castor oil fatty acid; and
castor oil, dehydrated castor oil, hydrogenated castor oil, which is a hydrogen additive of castor oil, castor oil-based polyols such as a 5 to 50 mol alkylene oxide adduct of castor oil, and a mixture thereof.
Examples of the polyvalent carboxylic acid that is used for manufacturing the polyester polyol (2), (3), or (4) include acyclic aliphatic dicarboxylic acids, such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, and fumaric acid; alicyclic dicarboxylic acids, such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids, such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphtlhaienedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p′-dicarboxylic acid; anhydrides or ester-forming derivatives of these aliphatic or aromatic dicarboxylic acids; and polybasic acids, such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acid.
Among these polyisocyanates (A), the polyisocyanates (A1) are preferable, in particular, polyisocyanate obtained by reacting the polyether polyol and the polyisocyanate is preferable from the viewpoint of wettability.
Furthermore, it is preferable to use a polyol having a polypropylene skeleton as the polyol component to be reacted with polyisocyanate, because the obtained polyisocyanate (A1) has a low viscosity and can be easily handled at low temperature.
From the viewpoint of flexibility of the coated film after curing of the polyisocyanate (A1), it is preferable to use a polyether polyol having a number average molecular weight (Mn) of 300 to 5,000, more preferably, 350 to 3,000, as the polyol component to be reacted with polyisocyanate.
The proportion of the polyether polyol having a number average molecular weight (Mn) of 300 to 5,000 in the polyol component is preferably 50 mass % or more as an example. The whole polyol component may be a polyether polyol having a number average molecular weight (Mn) of 300 to 5,000.
In the present specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are values measured by gel permeation chromatography (GPC) under the following conditions:
Measurement apparatus: HLC-8320 GPC manufactured by TOSOH Corporation;
Column: TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, and TSKgel 1000HXL manufactured by TOSOH Corporation;
Detector: RI (differential refractometer);
Data processing: Multistation GPC-8020 model IT manufactured by TOSOH Corporation;
Measurement condition: column temperature of 40° C.
Solvent: tetrahydrofuran;
Flow rate: 0.35 mL/min;
Standard: monodisperse polystyrene; and
Sample: product (100 μL) obtained by filtrating a tetrahydrofuran solution of 0.2 mass % in terms of resin solid content through a microfilter.
In the polyisocyanate (A1), it is preferable to include an aromatic polyisocyanate as the polyisocyanate to be reacted with the polyol component, because of excellent reactivity with polyamine (C) described later. The amount of the aromatic polyisocyanate is, for example, preferably 30 parts by mass or more based on the total charged amount of 100 parts by mass at the time of synthesis of the polyisocyanate (A1), and more preferably 40 parts by mass or more. The upper limit of the amount of the aromatic polyisocyanate is preferably 60 parts by mass or less and more preferably 55 parts by mass or less from the viewpoint of storage stability.
As the polyisocyanate to be reacted with the polyol component, at least one of aliphatic polyisocyanates and derivatives of aliphatic polyisocyanates is preferably used in combination with an aromatic polyisocyanate from the viewpoint of storage stability.
The reaction ratio of the polyisocyanate and the polyol component in the polyisocyanate (A1) is preferably within a range of 1.5 to 5.0 as the equivalent ratio of the isocyanate group in the polyisocyanate and the hydroxy group in the polyol component (isocyanate group/hydroxy group). A polyisocyanate composition (X) including the polyisocyanate (A) adopting such a polyisocyanate (A1) has a viscosity within an appropriate range and is preferable because the coating properties are improved, and the cohesive force of the coated film made of a two-component curing adhesive including the polyisocyanate (A) is improved.
The polyisocyanate (A) preferably has a weight average molecular weight (Mw) within a range of 100 to 10,000 from the viewpoint of ensuring proper packaging properties while shortening the aging time and more preferably within a range of 200 to 5,000.
When the polyisocyanate (A) is the polyisocyanate (A1), it is preferable that the weight average molecular weight (Mw) is within a range of 300 to 10,000.
The isocyanate content of the polyisocyanate (A) is preferably 5 to 20 mass %. A polyisocyanate composition (X) including such a polyisocyanate (A) is preferred from the viewpoint of a proper resin viscosity and excellent coating properties.
The isocyanate content of the polyisocyanate (A) is a value determined by a titration method using di-n-butylamine.
(Polyol (B))
Examples of the polyol (B) include glycols, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methyl pentanediol, dimethyl butanediol, butyl ethyl propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol;
Trifunctional or tetrafunctional aliphatic alcohols, such as glycerol, trimethylolpropane, and pentaerythritol; bisphenols, such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimer diol; a polyether polyol obtained by addition polymerization of an alkylene oxide, such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, or cyclohexylene, in the presence of a polymerization initiator, such as the glycol or the trifunctional or tetrafunctional aliphatic alcohol mentioned above; a polyether urethane polyol obtained by further increasing the molecular weight of the polyether polyol with the aromatic or aliphatic polyisocyanate; and a polyester polyol (1) that is a reaction product of a polyester obtained by a ring-opening polymerization reaction of a cyclic ester compound, such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, or β-methyl-σ-valerolactone, and the glycol or the trifunctional or tetrafunctional aliphatic alcohol mentioned above;
A polyester polyol (2) obtained by reacting a bifunctional polyol, such as the glycol, dimer diol, or bisphenol, and a polyvalent carboxylic acid;
a polyester polyol (3) obtained by reacting the trifunctional or tetrafunctional aliphatic alcohol mentioned above and a polyvalent carboxylic acid;
a polyester polyol (4) obtained by reacting a bifunctional polyol, the trifunctional or tetrafunctional aliphatic alcohol mentioned above, and a polyvalent carboxylic acid;
a polyester polyol (5) that is a polymer of a hydroxy acid, such as dimethylol propionic acid and castor oil fatty acid;
a polyester polyether polyol obtained by reacting any of the polyester polyols (1) to (5), the polyether polyol, and an aromatic or aliphatic polyisocyanate;
a polyester polyurethane polyol obtained by increasing the molecular weight of any of the polyester polyols (1) to (5) with an aromatic or aliphatic polyisocyanate; and
castor oil, dehydrated castor oil, hydrogenated castor oil, which is a hydrogen additive of castor oil, castor oil-based polyol such as a 5 to 50 mol alkylene oxide adduct of castor oil, and a mixture thereof.
Examples of the polyvalent carboxylic acid that is used for manufacturing of the polyester polyol (2), (3), or (4) include aliphatic dicarboxylic acids, such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids, such as terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p′-dicarboxylic acid; anhydrides or ester-forming derivatives of these aliphatic or dicarboxylic acids; and polybasic acids, such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acid.
As the polyol (B), a tertiary amine compound having multiple hydroxy groups may be used. The tertiary amine compound having multiple hydroxy groups not only cures by a reaction of the hydroxy groups with a polyisocyanate (A) but also promotes the curing reaction by the amine structure and therefore also functions as a curing accelerator.
In the tertiary amine compound having multiple hydroxy groups, the number of the hydroxy groups is two or more and is preferably two to six. The tertiary amine compound having multiple hydroxy groups may have one or more tertiary amino groups and preferably one or two.
Examples of the tertiary amine compound having multiple hydroxy groups include polypropylene glycol ethylenediamine ether, tri (1,2-polypropylene glycol)amine, N-ethyldiethanolamine, N-methyl-N-hydroxyethyl-N-hydroxyethoxyethylamine, pentakishydroxypropyldiethylenetriamine, tetrakishydroxypropylethylenediamine, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine, triethanolamine, and triethanolamine propoxylated.
As the tertiary amine compound having multiple hydroxy groups, a commercially available product may be used. Examples of the commercially available product include EDP-300 manufactured by ADEKA Corporation, ED-500 and TE-360 manufactured by Kukdo Chemical Co., Ltd., and VORANOL™ 800 Polyol manufactured by DOW Chemical Company.
When the polyol (B) includes the tertiary amine compound having multiple hydroxy groups, the mixing ratio of the polyol other than the tertiary amine compound in the polyol (B) and the tertiary amine compound (polyol other than tertiary amine compound/tertiary amine compound (mass ratio)) is preferably 100/5 to 100/70 and more preferably 100/10 to 100/70.
As the polyol (B), these compounds can be used alone or in combination.
The polyol (B) preferably includes a polyol having a polyether skeleton, in particular, a polyol having a polypropylene skeleton. Such a polyol (B) has a viscosity that allows coating at a temperature of 25° C. to 60° C. even in a solvent-free type. A two-component curing adhesive including such a polyol (B) is preferable because it has excellent adhesion strength with a metal oxide such as silica and/or alumina, a metal such as aluminum, and a resin film.
The content of the polyol having a polyether skeleton is preferably 5 mass % or more, more preferably 10 mass % or more, and more preferably 15 mass % or more based on the total amount of the polyol (B) from the viewpoint of coatability. The upper limit of the content of the polyol having a polyether skeleton is not particularly limited, and the whole polyol (B) may be a polyol having a polyether skeleton, but the upper limit is preferably 95 mass % or less from the viewpoint of initial cohesive force of the two-component curing adhesive.
The polyol (B) preferably includes, from the viewpoint of the initial cohesive force and the coatability of the two-component curing adhesive, at least one castor oil-based compound selected from the group consisting of castor oil, dehydrated castor oil, hydrogenated castor oil, which is a hydrogen additive of castor oil, castor oil-based polyol such as a 5 to 50 mol alkylene oxide adduct of castor oil. The content of these castor oil-based compounds is preferably 5 mass % or more, more preferably 10 mass % or more, more preferably 15 mass % or more, and more preferably 20 mass % or more based on the total amount of the polyol (B). The upper limit of the castor oil-based compound is not particularly limited, and the whole polyol (B) may be a castor oil-based compound, but the upper limit is preferably 95 mass % or less from the viewpoint of the coatability.
The polyol (B) may include a highly reactive low molecular weight polyol (one that is a liquid at ordinary temperature and has a molecular weight of about 150 or less). The reaction with the polyisocyanate (A) can be quickened by including such a low molecular weight polyol. In contrast, if the amount of the low molecular weight polyol is too large, the reaction with the polyisocyanate (A) may be too quickened. Accordingly, the content of the low molecular weight polyol is preferably 5 mass % or less, more preferably 3 mass % or less, of the polyol (B).
A polyol (B) having a weight average molecular weight (Mw) of 400 to 5,000 is preferred because it has a viscosity within a proper range to improve not only the coating properties but also the cohesive force of the two-component curing adhesive.
The polyol (B) preferably has a hydroxy value of 50 mg KOH/q or more and 300 mg KOH/g or less and more preferably 100 mg KOH/g or more and 250 mg KOH/g or less.
The hydroxy value of the polyol (B) can be measured by the hydroxy value measurement method described in JIS-K0070.
(Polyamine (C))
The polyol composition (Y) preferably includes a polyamine (C). The polyamine (C) functions as a curing accelerator.
As the polyamine (C), a known polyamine can be used without particular limitation. The polyamine (C) is desirably a compound having two or more amino groups (NH2 group or NHR group (R represents an alkyl group)) in the molecule in order to keep the strength of a coated film made of the two-component curing adhesive.
Examples of the polyamine (C) include methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropaneamine-2,4,8,10-tetraoxaspiro undecane, lysine, phenylenediamine, 2,2,4-trimethylhexamethylenediamine, tolylenediamine, hydrazine, piperazine, hexamethylenediamine, propylenediamine, dicyclohexylmethane-4,4-diamine, 2-hydroxyethylethylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, and 1,3-diaminopropane;
1,4-Diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, etc., benzylamine, diethyleretriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, etc., tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2′-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bishexamethylenetriamine, etc., 1,4-cyclohexanediamine, 4,4′-methylenebiscyclohexylaamine, 4,4′-isopropylidenebiscyclohexylamine, and norbornadiamine;
Bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, mensendiamine, etc., bis(aminoalkyl)benzene, bis(aminoalkyl) naphthalene, bis(cyanoethyl)diethylenetriamine, ortho-xylenediamine, meta-xylenediamine, para-xylenediamine, phenylenediamine, naphthylenediamine, diaminodiphenylnethane, diaminodiethylphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 2,2′-dimethyl-4,4′-diaminodiphenylethane, 2,4-diaminobiphenyl, 2,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, bis(aminomethyl)naphthalene, bis(aminoethyl)naphthalene, etc., N-methylpiperazine, morpholine, 1,4-bis-(8-aminopropyl)-piperazine, piperazine-1,4-diazacycloheptane, 1-(2′-aminoethylpiperazine), 1-[2′-(2″-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyureaamines as reaction products of the above-mentioned various polyamines and the above-mentioned various isocyanate components.
As the polyamine (C), it is preferably to use a polyether amine having a polyether structure in the main chain in order to keep the flexibility of a coated film made of the two-component curing adhesive.
These polyamines (C) may be used alone or in combination of two or more thereof.
As the polyamine (C), a commercially available product may be used. Examples of the commercially available product include EC-310 and EC-303 manufactured by BASF SE.
The molar ratio of the functional group (the isocyanate group possessed by the polyisocyanate (A)) in the polyisocyanate composition (X) and the functional groups (the hydroxy group possessed by the polyol (B) and the amino group possessed by the polyamine (C)) in the polyol composition (Y), [isocyanate group/(hydroxy group and amino group)], is desirably 0.5 to 5.0 and is further desirably within a range of 1.0 to 3.0 from the viewpoint of the adhesion performance of the two-component curing adhesive.
As the proportions of the polyol (B) and the polyamine (C) in the polyol composition (Y), the molar ratio of the amino group derived from the polyamine (C) and the hydroxy group derived from the polyol (B), [amino group/hydroxy group], is desirably 0.001 to 2.0 and more preferably within a range of 0.1 to 1.0 from the viewpoint of establishing the adhesion strength, the processed appearance, and the practicability of processability of the two-component curing adhesive. When the molar ratio is 0.001 or more, the laminated film manufactured using the two-component curing adhesive has good processability. When the molar ratio is 2.0 or less, the two-component curing adhesive has good adhesion strength.
(Solvent)
Although the two-component curing adhesive of the present embodiment can be used as a solvent-free adhesive, the two-component curing adhesive of the present embodiment may contain a solvent as needed.
The term “solvent” in the present embodiment refers to an organic solvent having high solubility that can dissolve the polyisocyanate composition (X) and/or the polyol composition (Y). The term “solvent-free” in the present embodiment refers to that these organic solvents with high solubility are not included.
Examples of the organic solvent (solvent) with high solubility include toluene, xylene, methylene chloride, tetrahydrofuran, methanol, ethanol, isopropyl alcohol, methyl acetate, ethyl, acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, n-hexane, and cyclohexane. Among these examples, toluene, xylene, methylene chloride, tetrahydrofuran, methyl acetate, and ethyl acetate are organic solvents having particularly high solubility.
When the two-component curing adhesive of the present embodiment is demanded to reduce the viscosity, it can be used by being diluted with a solvent to a desired viscosity. In such a case, only one of the polyisocyanate composition (X) and the polyol composition (Y) may be diluted with a solvent, or both may be diluted.
Examples of the organic solvent that may be contained in the two-component curing adhesive of the present embodiment include methanol, ethanol, isopropyl alcohol, methyl acetate, ethyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylene, n-hexane, and cyclohexane. Among these examples, it is preferable to use ethyl acetate and/or methyl ethyl ketone (MEK), in particular, ethyl acetate from the viewpoint of solubility of the polyisocyanate composition (X) and the polyol composition (Y).
The content of the organic solvent in the two-component curing adhesive of the present embodiment can be appropriately determined based on the required viscosity and can be, for example, 20 to 50 mass %.
(Catalyst)
The two-component curing adhesive of the present embodiment may contain a catalyst. The catalyst may be included in only one of the polyisocyanate composition (X) and the polyol composition (Y) or may be included in both. The catalyst is preferably included only in the polyol composition (Y) from the viewpoint of generally high reactivity with a polyisocyanate composition and of effectively applying the catalyst after the contact between the polyisocyanate composition (X) and the polyol composition (Y). The catalyst may be added to the polyisocyanate composition (X) and/or the polyol composition (Y) at the time of coating of the two-component curing adhesive.
When the two-component curing adhesive includes a catalyst, the curing of the two-component curing adhesive is promoted, and a harmful low molecular weight chemical material represented by an aromatic amine is prevented from flowing out from the laminated film manufactured using the two-component curing adhesive. That is, the catalyst also functions as a curing accelerator as in the polyamine (C).
The catalyst is not particularly limited as long as the urethanization reaction between the polyisocyanate composition (X) and the polyol composition (Y) is promoted. As the catalyst, for example, a metal-based catalyst, an amine-based catalyst, diazabicycloundecene (DBU), an alicyclic amide compound, or a titanium chelate complex can be used.
Examples of the metal-based catalyst include a metal complex-based catalyst, an inorganic metal-based catalyst, and an organic metal-based catalyst.
Examples of the metal complex-based catalyst include acetylacetonate salts of a metal, selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt). Specifically, for example, iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconium acetylacetonate are mentioned. Among these metal complex-based catalysts, from the viewpoint of toxicity and catalyst activity, iron acetylacetonate (Fe(acac)3) and/or manganese acetylacetonate (Mn(acac)2) are preferable.
Examples of the organic metal-based catalyst include stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyl tin oxide, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin dichloride, dioctyl tin dilaurate, nickel octylate, nickel naphthenate, cobalt octylate, cobalt naphthenate, bismuth octylate, bismuth naphthenate, bismuth neodecanoate, and zinc neodecanoate. Among these examples, preferable organic metal-based catalysts are stannous dioctate, dibutyl tin dilaurate, bismuth neodecanoate, zinc neodecanoate, and mixture thereof.
Examples of the amine-based catalyst include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, and 2-methylquinuclidine. Among these examples, since triethylenediamine and/or 2-methyltriethylenediamine has excellent catalyst activity and is industrially available, it is preferable to use them as the amine-based catalyst.
As other tertiary amine catalysts, examples thereof include N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylpropylenediamine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N″,N″-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N′,N″,N″-pentamethyldipropylenetriamine, N,N,N′,N′-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl) ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N′-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N′-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl)isopropanolamine, 3-quinuclidinol, N, N, N′,N′ tetramethylquanidine, 1,3,5-tris(N, N-dimethylaminopropyl) hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N′-(2-dimethylamimoethyl)piperazine, N,N′-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N methyl-N′-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, and 1-(2-hydroxypropyl)-2-methylimidazole.
Examples of the alicyclic amide compound that is used as the catalyst include δ-valerolactam, ε-caprolactam, ω-enanthollactam, η-capryllactam, and β-propiolactam. Among these alicyclic amide compounds, ε-caprolactam can effectively promote curing of the two-component curing adhesive.
The content of the catalyst in the two-component curing adhesive of the present embodiment is not particularly limited and may be a known amount. The content of the catalyst can be, for example, 0.001 to 5.0 mass % based on the total solid content of the two-component curing adhesive.
(Adhesion Promoter)
The two-component curing adhesive of the present embodiment may contain an adhesion promoter. The adhesion promoter may be included in only one of the polyisocyanate composition (X) and the polyol composition (Y) or may be included in both. The adhesion promoter is highly reactive with the polyisocyanate composition (X) and is therefore preferably applied after the contact between the polyisocyanate composition (X) and the polyol composition (Y). Accordingly, the adhesion promoter is preferably included in only the polyol composition (Y). The adhesion promoter may be added to the polyisocyanate composition (X) and/or the polyol composition (Y) at the time of coating of the two-component curing adhesive.
Examples of the adhesion promoter include a silane coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, and an epoxy resin.
Examples of the silane coupling agent include aminosilanes, such as γ-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes, such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane; vinylsilanes, such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; and hexamethyldisilazane and γ-mercaptopropyltrimethoxysilane.
Examples of the titanate-based coupling agent include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.
Examples of the aluminum-based coupling agent include acetoalkoxyaluminum diisopropylate.
Examples of the epoxy resin include generally commercially available various epoxy resins, such as epi-bis type, novolak type, β-methylepichloro type, cyclic oxirane type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, epoxidized fatty acid ester type, polyvalent carboxylic acid ester type, aminoglycidyl type, and resorcin type epoxy resins.
The content of the adhesion promoter in the two-component curing adhesive of the present embodiment is not particularly limited and may be a known amount. The content of the adhesion promoter can be, for example, 0 to 50 mass % based on the total solid content of the two-component curing adhesive.
(Pigment)
The two-component curing adhesive of the present embodiment may include a pigment as needed. The pigment may be included in only one of the polyisocyanate composition (X) and the polyol composition (Y) or may be included in both. The pigment may be added to the polyisocyanate composition (X) and/or the polyol composition (Y) at the time of coating of the two-component curing adhesive.
The pigment is not particularly limited, and various pigments are mentioned. Examples of the pigment include organic pigments, such as an extender pigment, a white pigment, a black pigment, a gray pigment, a red pigment, a brown pigment, a green pigment, a blue pigment, a metal powder pigment, a luminescent pigment, and a pearl pigment; organic pigments; and plastic pigments described in Paint Raw Material Handbook, 1970 edition (edited by Japan Paint Manufacturers Association).
Examples of the organic pigment include various insoluble azo pigments, such as Benzidine yellow, Hansa yellow, and lake red 4R; soluble azo pigments, such as lake red C, carmine 6B, and Bordeaux 10; various (copper) phthalocyanine based pigments, such as phthalocyanine blue and phthalocyanine green; various chlorine dyeing lakes, such as rhodamine lake and methyl violet lake; various mordant dye pigments, such as quinoline lake and fast sky blue; various vat dye pigments, such as an anthraquinone pigment, a thioindigo pigment, and a perinone pigment; various quinacridone pigments, such as Cinquasia Red B; various dioxazine pigments, such as dioxazine violet; various condensed azo pigments, such as Cromophtal; and aniline black.
Examples of the inorganic pigment include various chromates, such as chrome yellow, zinc chromate, and molybdate orange; various ferrocyanide compounds, such as Prussian blue; various metal oxides, such as titanium oxide, zinc oxide, Mapico yellow, iron oxide, red iron oxide, chrome oxide green, and zirconium oxide; various sulfides and selenides, such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates, such as barium sulfate and lead sulfate; various silicates, such as calcium silicate and ultramarine blue; various carbonates, such as calcium carbonate and magnesium carbonate; various phosphates, such as cobalt violet and manganese violet; various metal powder pigments, such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; flake pigments of these metals and a mica flake pigment; metallic pigments and pearl pigments, such as a mica flake pigment coated with a metal oxide and a micaceous iron oxide pigment; and graphite and carbon black.
Examples of the extender pigment include sedimentary barium sulfate, gohun, sedimentary calcium carbonate, calcium bicarbonate, white limestone, alumina white, silica, fine hydrous silica powder (white carbon), ultrafine anhydrous silica powder (aerosil), silica sand, talc, sedimentary magnesium carbonate, bentonite, clay, kaolin, and yellow ocher.
Examples of the plastic pigment include “GRANDOLL PP-1000” and “PP-2000S” manufactured by DIC Corporation.
As the pigment, it is preferable to use an inorganic oxide, such as titanium oxide and zinc oxide, as a white pigment and carbon black as a black pigment, because they are excellent in durability, weather resistance, and designability.
The content of the pigment in the two-component curing adhesive of the present embodiment is preferably 1 to 400 parts by mass, more preferably 10 to 300 parts by mass, based on 100 parts by mass of the total solid content of the polyisocyanate composition (X) of the polyol composition (Y). When the content of the pigment is 1 to 400 parts by mass, the two-component curing adhesive has excellent adhesive properties and blocking resistance.
(Additive)
The two-component curing adhesive of the present invention may contain an additive, in addition to the above-described components, as needed. The additive may be included in only one of the polyisocyanate composition (X) and the polyol composition (Y) or may be included in both. The additive may be added to the polyisocyanate composition (X) and/or the polyol composition (Y) at the time of coating of the two-component curing adhesive.
Examples of the additive include a leveling agent; inorganic fine particles, such as colloidal silica and alumina sol; polymethyl methacrylate-based organic fine particles; an antifoaming agent; an anti-dripping agent; a wetting and dispersing agent; a viscosity modifier; an UV absorber; a metal inactivating agent; a peroxide decomposing agent; a flame retardant; a reinforcing agent; a plasticizer; a lubricant; an anticorrosive; a fluorescent brightening agent; an inorganic heat ray absorber; a fire-extinguishing agent; an antistatic agent; and a dehydrating agent.
The two-component curing adhesive of the present embodiment is a two-component curing adhesive using a curing reaction between a polyisocyanate composition (X) and a polyol composition (Y), wherein the polyisocyanate composition (X) includes a polyisocyanate (A), the polyol composition (Y) includes a polyol (B), and the polyisocyanate composition (X) and the polyol composition (Y) each have a Trouton ratio within a range of 4.0 to 8.0.
Accordingly, a laminated film including an adhesive layer formed between a first film and a second film by using the two-component curing adhesive of the present embodiment obtains an excellent bond strength by heat sealing. Accordingly, the two-component curing adhesive of the present invention can be suitably used when manufacturing a laminated film.
[Laminated Film]
A laminated film of the present embodiment will then be described in detail using a drawing.
(Film)
In the laminated film 11a of the present embodiment, the films used as the first film W1 and the second film W2 are preferably plastic films that are used in known laminated films.
As the first film W1, for example, a base film, such as a polyethylene terephthalate (hereinafter, may be abbreviated to “PET”) film, a nylon (OPA) film, a biaxially oriented polypropylene (OPP) film, and various vapor deposited films, or aluminum foil can be used.
As the second film W2, for example, a sealant film, such as a cast polypropylene (CPP) film and a linear low-density polyethylene (LLDPE) film, can be used.
As the first film W1 and the second film W2, paper, such as natural paper, synthetic paper, and coating paper, may be used.
A printing layer may be provided on the outer surface or the inner surface of the first film W1 and/or the second film W2 as needed.
The laminated film 11a of the present embodiment can be industrially used as, for example, a flexible packaging film, a flexible packaging (packaging whose shape is formed by putting a content therein) material, or a packaging material to be filled with detergent, medicine, food, a beverage, etc. Examples of the detergent and medicine include liquid detergent for laundry, liquid detergent for kitchen, liquid detergent for bath, liquid soap for bath, liquid shampoo, and liquid conditioner. The food and the beverage are not particularly limited.
The laminated film 11a of the present embodiment can be used as a package by being formed into a bag shape.
The laminated film 11a of the present embodiment includes an adhesive layer 10 between a first film W1 and a second film W2, and the adhesive layer 10 is made of a cured product of the two-component curing adhesive of the above-described embodiment. Consequently, the laminated film 11a of the present embodiment has a good heat sealing property that gives an excellent bond strength by heat sealing.
[Laminated Film-Manufacturing Apparatus]
An apparatus for manufacturing the laminated film 11a of the present embodiment will then be described in detail with reference to the drawings.
The laminated film-manufacturing apparatus 1 shown in
The laminated film-manufacturing apparatus 1 of the present embodiment includes, as shown in
The first unwinding unit 11 sends out a first film W1 to the polyisocyanate coating unit 12. The first film W1 is rotatably mounted on the film mounting unit 111 of the first unwinding unit 11.
The polyisocyanate coating unit 12 applies the polyisocyanate composition (X) of the two-component curing adhesive of the present embodiment to the first film W1 sent out from the first unwinding unit 11.
The polyisocyanate coating unit 12 is a roll coater of a four-roller squeeze system, as shown in
The application roller 121 is a roller having an outer peripheral surface made of an elastic material such as rubber. The doctor roller 122 is a roller having an outer peripheral surface made of a metal (non-elastic material). As shown in
In the upper part of the facing portion of the application roller 121 and the doctor roller 122, a pair of weir plates 126 is installed with a predetermined space in the direction of the rotating shafts of the application roller 121 and the doctor roller 122. The pair of weir plates 126, the outer peripheral surface of the application roller 121, and the outer peripheral surface of the doctor roller 122 form a liquid reservoir unit 120.
The Liquid reservoir unit 120 temporarily stores the polyisocyanate composition (X). The polyisocyanate composition (X) is supplied to the liquid reservoir unit 120 from a polyisocyanate supply portion (not shown). Consequently, the amount of the polyisocyanate composition (X) stored in the liquid reservoir unit 120 is maintained constant.
The doctor roller 122 is preferably provided with a temperature controller (not shown). The temperature controller keeps the temperature of the polyisocyanate composition (X) stored in the liquid reservoir unit 120 constant to stabilize the viscosity of the polyisocyanate composition (X). Consequently, the temperature of the outer peripheral surface of the doctor roller 122 is kept certain.
As shown in
As shown in
The polyisocyanate composition (X) applied to the outer peripheral surface of the doctor roller 122 is transferred to the metering roller 123. The rotating shaft of the metering roller 123 is disposed parallel to the rotating shaft of the doctor roller 122. The outer peripheral surface of the metering roller 123 is made of an elastic material such as rubber. The outer peripheral surface of the metering roller 123 is in pressure contact with the outer peripheral surface of the doctor roller 122.
The polyisocyanate composition (X) applied to the outer peripheral surface of the metering roller 123 is transferred to the coating roller 124. The rotating shaft of the coating roller 124 is disposed parallel to the rotating shaft of the metering roller 123. The outer peripheral surface of the coating roller 124 is formed of a metal material. The outer peripheral surface of the coating roller 124 is in pressure contact with the outer peripheral surface of the metering roller 123.
The backing roller 125 is disposed such that the rotating shaft is parallel to the rotating shaft of the coating roller 124. The second film W2 is sandwiched between the backing roller 125 and the coating roller 124 and is transported. The backing roller 125 helps the transfer of the polyisocyanate composition (X) applied to the outer peripheral surface of the coating roller 124 to the first film W1. The outer peripheral surface of the backing roller 125 is formed of an elastic material such as rubber.
The temperature of the outer peripheral surface of the coating roller 124 is preferably kept constant by a temperature controller (not shown) as in the doctor roller 122. Consequently, the viscosity of the polyisocyanate composition (X) applied to the first film W1 is stabilized.
The second unwinding unit 13 sends out the second film W2 to the polyol coating unit 14. The second film W2 is rotatably mounted on the film mounting unit 131 of the second unwinding unit 13.
The polyol coating unit 14 applies the polyol composition (Y) of the two-component curing adhesive of the present embodiment to the second film W2 sent out from the second unwinding unit 13.
The polyol coating unit 14 is a gravure coater for applying the polyol composition (Y) by gravure printing as shown in
The gravure roller 141 is a metal roller rotatably supported by the polyol coating unit 14. The surface of the gravure roller 141 is provided with a plurality of concavities (gravure pattern) by, for example, laser engraving. The amount of the coating liquid to be applied to the surface of the gravure roller 141 can be adjusted by changing, for example, the volume, the opening ratio, and the depth of the concavities. The gravure pattern formed on the surface of the gravure roller 141 is not particularly limited and can be, for example, a honeycomb pattern.
As shown in
The chamber 142 includes a reservoir 142a for storing the polyol composition (Y). The reservoir 142a is opened on the gravure roller 141 side. The outer peripheral surface of the gravure roller 141 is partially immersed in the polyol composition (Y) stored in the reservoir 142a.
The reservoir 142a is sealed by a doctor blade 142b, a seal plate 142c, and a pair of side plates 142d.
The chamber 142 includes a plate-like doctor blade 1421b. The doctor blade 142b is arranged so as to protrude from the top end of the opening of the reservoir 142a toward the gravure roller 141. The material of the doctor blade 142b is not particularly limited and may be a metal or a resin and can be, for example, stainless steel.
The distal portion of the doctor blade 142b is in pressure contact with the outer peripheral surface of the gravure roller 141. The distal portion of the doctor blade 142b seals the reservoir 142a at the downstream side in the roller rotation direction. The doctor blade 142b scrapes the excess polyol composition (Y) adhering to the outer peripheral surface of the gravure roller 141 by the rotation operation of the gravure roller 141 and measures the amount.
The chamber 142 includes a plate-like seal plate 142c. The seal plate 142c is made of a resin. The seal plate 142c is arranged so as to protrude from the bottom end of the opening of the reservoir 142a toward the gravure roller 141.
The distal portion of the seal plate 142c is in pressure contact with the outer peripheral surface of the gravure roller 141. The distal portion of the seal plate 142c seals the reservoir 142a a the upstream side in the roller rotation direction.
The chamber 142 includes side plates 142d made of a resin. The side plates 142d are installed on both side surfaces of the chamber 142, that is, on both ends of the gravure roller 141 in the rotating shaft direction.
As shown in
The second film W2 is sandwiched between the impression drum 143 and the gravure roller 141 as shown in
The coating liquid tank 144 is a container for storing the polyol composition (Y). As shown in
The pump 145 is connected to the coating liquid tank 144 and the chamber 142 via piping. The pump 145 supplies the polyol composition (Y) stored in the coating liquid tank 144 to the reservoir 142a of the chamber 142. As the pump 145, for example, a sine pump can be used.
The temperature controller 146 controls the temperature of the polyol composition (Y) stored in the coating liquid tank 144. Consequently, the temperature of the polyol composition (Y) is kept constant, and the viscosity of the polyol composition (Y) is stabilized. The temperature controller 146 is, for example, a water temperature adjuster that heats water as a heat transfer medium with a heater and allows the water to circulate in the periphery of the polyol composition (Y) stored in the coating liquid tank 144.
As shown in
The bonding unit 151 bonds the polyisocyanate composition (X)-coated surface of the first film W1 sent out from the polyisocyanate coating unit 12 and the polyol composition (Y)-coated surface of the second film W2 sent out from the polyol coating unit 14. The winding unit 152 winds the laminated film 11a bonded by the bonding unit 151.
The bonding unit 151 includes, as shown in
As shown in
The winding unit 152 winds the laminated film 11a formed by bonding the first film W1 and the second film W2 in the bonding unit 151.
[Method for Manufacturing Laminated Film]
As a method for manufacturing a laminated film of the present embodiment, a case of manufacturing the laminated film 11a shown in
The method for manufacturing a laminated film 11a of the present embodiment includes a two-component separate application process and an adhesive layer forming process. In the present embodiment, the two-component separate application process and the adhesive layer forming process are continuously performed.
(Two-Component Separate Application Process)
The two-component separate application process; is composed of a first application step of applying a polyisocyanate composition (X) that includes a polyisocyanate (A) and has a Trouton ratio within a range of 4.0 to 8.0 to a first film W1 and a second application step of applying a polyol composition (Y) that includes a polyol (B) and has a Trouton ratio within a range of 4.0 to 8.0 to a second film W2. In the present embodiment, the first application step and the second application step are simultaneously performed.
“First Application Step” A method of performing the first application step using the laminated film-manufacturing apparatus 1 shown in
First, the first film W1 is sent out from the first unwinding unit 11 to the polyisocyanate coating unit 12. In the polyisocyanate coating unit 12, each roller is rotated in the direction indicated by the arrow mark in
In the present embodiment, the temperature of the polyisocyanate composition (X) stored in the liquid reservoir unit 120 is preferably set to 25° C. to 80° C., more preferably 25° C. to 40° C., by the temperature controller (not shown).
In the present embodiment, the shear viscosity of the polyisocyanate composition (X) at 40° C. is preferably 5,000 mPa·s or less and more preferably 4,000 mPa·s or less.
The polyisocyanate composition (X) applied to the doctor roller 122 is transferred to the metering roller 123 and the coating roller 124 sequentially. The rotation speeds of the rollers of the polyisocyanate coating unit 12 are set such that the rotation speeds sequentially increase. Consequently, the thickness of the coated film of the polyisocyanate composition (X) is gradually decreased, and the coating roller 124 adjusts the thickness of the coated film (application amount) to a certain level.
The polyisocyanate composition (X) transferred to the coating roller 124 is transferred to the first film W1 that is transported between the coating roller 124 and the backing roller 125. Consequently, the polyisocyanate composition (X) is applied to the first film W1.
In the present embodiment, the application amount of the polyisocyanate composition (X) to be applied to the first film W1 is preferably 0.5 to 3.0 g/m2 and more preferably 0.5 to 2.0 g/m2.
In the polyisocyanate coating unit 12, the first film W1 coated with the polyisocyanate composition (X) is sent out to the bonding device 15.
“Second Application Step”
A method of performing the second application step using the laminated film-manufacturing apparatus 1 shown in
First, the second film W2 is sent out from the second unwinding unit 13 to the polyol coating unit 14. In the polyol coating unit 14, the gravure roller 141 and the impression drum 143 are rotated in the direction indicated by the arrow mark in
In the present embodiment, the application amount of the polyol composition (Y) to be applied to the second film W2 is preferably 0.5 to 3.0 g/m2 and more preferably 0.5 to 2.0 g/m2.
In the present embodiment, the temperature of the polyol composition (Y) stored in the coating liquid tank 144 is preferably set to 25° C. to 80° C., more preferably 25° C. to 40° C., by the temperature controller 146.
In the present embodiment, the viscosity of the polyol composition (Y) is adjusted to a viscosity suitable for a gravure coater.
The rotation direction of the gravure roller 141 may be the positive rotation that is the same direction as the transport direction of the second film W2 or may be a reverse rotation that is the opposite direction to the transport direction of the second film W2. In the present embodiment, as shown in
In the polyol coating unit 14, the second film W2 coated with the polyol composition (Y) is sent out to the bonding device 15.
(Adhesive Layer Forming Process)
In the adhesive layer forming process, the polyisocyanate composition (X) applied on the first film W1 and the polyol composition (Y) applied on the second film are brought into contact with each other by laminating the first film W1 and the second film W2 to cause a curing reaction.
In the bonding unit 151 of the bonding device 15, as shown in
In the present embodiment, the temperature of the outer peripheral surfaces of the two lamination rollers R1 and R2 is preferably set to 40° C. to 80° C. and more preferably 40° C. to 60° C.
The pressure from the two lamination rollers R1 and R2 to the first film W1 and the second film W2 can be, for example, 3 to 300 kg/cm2.
In the present embodiment, the coated surface of the first film W1 sent out from the polyisocyanate coating unit 12 and the coated surface of the second film W2 sent out from the polyol coating unit 14 are brought into contact with each other by being sandwiched between the two lamination rollers R1 and R2. As a result, the polyisocyanate composition (X) applied to the first film W1 and the polyol composition (Y) applied to the second film W2 are mixed to start the curing of the two-component curing adhesive.
A laminated film 11a including an adhesive layer 10 between the first film W1 and the second film W2 is obtained by curing the two-component curing adhesive.
The laminated film 11a produced by bonding the first film W1 and the second film W2 in the bonding unit 151 is transported to the winding unit 152. The laminated film 11a transported to the winding unit 152 is wound by the winding unit 152.
In the method for manufacturing the laminated film 11a of the present embodiment, the film transport speed (winding speed of the laminated film 11a in the winding unit 152) when the laminated film 11a is manufactured can be, for example, 30 to 0.300 m/min and is preferably 100 to 250 m/min. When the film transport speed is 30 m/min or more, a laminated film can be efficiently manufactured. When the film transport speed exceeds 300 m/min, a coating defect, a defect in transportation itself, a defect at the time of bonding, etc. may occur. Accordingly, the film transport speed is preferably 300 m/min or less.
The laminated film 11a obtained by the manufacturing method of the present embodiment may be, after bonding between the first film W1 and the second film W2 in the bonding unit 151 and winding by the winding unit 152, stored at ordinary temperature or under warming for 3 to 48 hours for aging as needed. The two-component curing adhesive is sufficiently cured by performing aging, and practical physical properties as an adhesive layer 10 may be expressed.
The laminated film 11a-manufacturing apparatus 1 of the present embodiment includes a polyisocyanate coating unit 12 for applying a polyisocyanate composition (X) having a Trouton ratio within a range of 4.0 to 8.0 to a first film W1, a polyol coating unit 14 for applying a polyol composition (Y) having a Trouton ratio within a range of 4.0 to 8.0 to a second film W2, and bonding device 15 for bonding the polyisocyanate composition (X)-coated surface of the first film W1 and the polyol composition (Y)-coated surface of the second film W2. Accordingly, the laminated film 11a-manufacturing apparatus 1 of the present embodiment can be suitably used when the laminated film 11a is manufactured by the manufacturing method of the present embodiment including a two-component separate application process using a two-component curing adhesive of the present embodiment.
In the laminated film 11a-manufacturing apparatus 1 of the present embodiment, as the polyol coating unit 14, a gravure coater that gives a wide range of choices in, for example, viscosity of the polyol, composition (Y) may be provided, or a roll coater may be provided. When a gravure coater is selected as the polyol composition (Y) application device of the polyol coating unit 14, even if the viscosity of the polyol composition (Y) is low to cause defects, such as dripping, when a roll coater is used, dripping does not occur, and a high quality laminated film 11a having improved application quality can be manufactured. In addition, the configuration of the polyol coating unit 14 can be simplified by using a gravure coater, and the laminated film 11a-manufacturing apparatus can be miniaturized.
In the laminated film 11a-manufacturing apparatus 1 of the present embodiment, a roll coater is used in the polyisocyanate coating unit 12 that applies a polyisocyanate composition (X) having a relatively high viscosity to a first film W1. Even if the viscosity of the polyisocyanate composition (X) is relatively high, application can be performed by using a roll coater, resulting in a wider choice of materials for the polyisocyanate composition (X).
The method for manufacturing the laminated film 11a of the present embodiment includes a two-component separate application process consisting of a first application step of applying a polyisocyanate composition (X) having a Trouton ratio within a range of 4.0 to 8.0 to a first film W1 and a second application step of applying a polyol composition (Y) having a Trouton ratio within a range of 4.0 to 8.0 to a second film W2; and an adhesive layer forming process of bringing the polyisocyanate composition (X) applied on the first film W1 and the polyol composition (Y) applied on the second film W2 into contact with each other by laminating the first film W1 and the second film W2 to cause a curing reaction.
Since the method for manufacturing the laminated film 11a of the present embodiment includes a two-component separate application process, a step of mixing the polyisocyanate composition (X) and the polyol composition (Y) is not necessary. Consequently, compared to the case of including a step of mixing the polyisocyanate composition (X) and the polyol composition (Y), the workability is excellent. In addition, since the polyisocyanate composition (X) and the polyol composition (Y) are not mixed, the two-component curing adhesive of the present embodiment that cures quickly can be used without being limited by the pot life of the two-component curing adhesive.
In the method for manufacturing the laminated film 11a of the present embodiment, a polyisocyanate composition (X) having a Trouton ratio within a range of 4.0 to 8.0 is applied to a first film in the first application step, and a polyol composition (Y) having a Trouton ratio within a range of 4.0 to 8.0 is applied to a second film W2 in the second application step. Consequently, according to the laminated film 11a-manufacturing method of the present embodiment, the laminated film 11a of the present embodiment that can obtain an excellent bond strength by heat sealing can be manufactured using a two-component curing adhesive of the present embodiment.
In the above-described embodiment, a roll coater is used as the polyisocyanate coating unit 12. However, for example, when the polyisocyanate composition (X) has a low viscosity, a gravure coater may be used as the polyisocyanate coating unit 12.
In addition, in the above-described embodiment, a gravure coater is used as the polyol coating unit 14. However, a roll coater may be used as the polyol coating unit 14 when application of the polyol composition (Y) is possible.
In the polyol coating unit 14 of the laminated film 11a-manufacturing apparatus 1 of the embodiment above, although the temperature of the polyol composition (Y) stored in the coating liquid tank 144 is controlled by the temperature controller 146, the temperature of the polyol composition (Y) stored in the reservoir 142a of the chamber 142 and/or the temperature of the gravure roller 141 may also be controlled. Consequently, the viscosity of the polyol composition (Y) at the time of coating can be further stabilized, and the application quality and the quality of the laminated film 11a can be further improved.
The present embodiment has described an example of a case of manufacturing a laminated film 11a by a manufacturing method including a two-component separate application process using a laminated film 11a-manufacturing apparatus 1 including a polyisocyanate coating unit 12 for applying a polyisocyanate composition (X) to a first film W1, a polyol coating unit 14 for applying a polyol composition (Y) to a second film W2, and a bonding device 15 for bonding the first film W1 and the second film W2. However, the laminated film 11a may be manufactured by, for example, a manufacturing method including a two-component mixing application process using a manufacturing apparatus shown below.
The laminated film-manufacturing apparatus 1A shown in
The laminated film-manufacturing apparatus 1A shown in
The laminated film-manufacturing apparatus 1A shown in
In the laminated film-manufacturing apparatus 1A shown in
The mixture solution coating unit 12A in the laminated film-manufacturing apparatus 1A shown in
In the laminated film-manufacturing apparatus 1A shown in
As a method for manufacturing the laminated film 11a of the present embodiment using the laminated film-manufacturing apparatus 1A shown in
First, a first film W1 is sent out from the first unwinding unit 11 to the mixture solution coating unit 12A. In the mixture solution coating unit 12A, each roller is rotated in the direction indicated by the arrow mark in
In the present embodiment, the temperature of the mixture solution stored in the liquid reservoir unit 120 is preferably set to 25° C. to 80° C., more preferably 25° C. to 40° C., by a temperature controller (not shown).
In the present embodiment, the shear viscosity of the mixture solution at 40° C. is preferably 2,000 mPa·s or less and more preferably 1,800 mPa·s or less.
In the present embodiment, the polyol composition (Y) and the polyisocyanate composition (X) are mixed in the mixer to start the curing of the two-component curing adhesive.
The mixture solution applied to the doctor roller 122 is transferred to the metering roller 123 and the coating roller 124 sequentially. The mixture solution transferred to the coating roller 124 is transferred to the first film W1 transported between the coating roller 124 and the backing roller 125. Consequently, the mixture solution is applied to the first film W1.
In the present embodiment, the application amount of the mixture solution to be applied to the first film W1 is preferably 0.5 to 3.0 g/m2 and more preferably 0.5 to 2.0 g/m2.
In the mixture solution coating unit 12A, the first film W1 coated with the mixture solution is sent out to the bonding device 15 as shown in
As shown in
In the present embodiment, the temperature of the outer peripheral surfaces of the two lamination rollers R1 and R2 is preferably 40° C. to 80° C. and more preferably 40° C. to 60° C.
The pressure from the two lamination rollers R1 and R2 to the first film W1 and the second film W2 can be, for example, 3 to 0.300 kg/cm2.
A laminated film 11a including an adhesive layer 10 between the first film W1 and the second film W2 is obtained by curing the two-component curing adhesive.
The laminated film 11a produced by bonding the first film W1 and the second film W2 in the bonding unit 151 is transported to the winding unit 152. The laminated film 11a transported to the winding unit 152 is wound by the winding unit 152.
In the laminated film 11a-manufacturing method of the present embodiment, the film transport speed (the winding speed of the laminated film 11a in the winding unit 152) when manufactures the laminated film 11a can be, for example, 30 to 300 m/min and is preferably 100 to 250 m/min. When the film transport speed is 30 m/min or more, a laminated film can be efficiently manufactured. When the film transport speed exceeds 300 m/min, a coating defect, a defect in transportation itself, a defect at the time of bonding, etc. may occur. Accordingly, the film transport speed is preferably 300 m/min or less.
In also a method manufacturing laminated film 11a using the laminated film-manufacturing apparatus 1A shown in
The above-described embodiment has described an example of a case of manufacturing a laminated film 11a using a manufacturing method including a two-component separate application process including a step of applying only a polyol composition (Y) onto a film as a manufacturing method including a two-component separate application process. However, as the manufacturing method including a two-component separate application process, for example, the following method (1) or method (2) may be used.
(1) A mixture solution of a polyisocyanate composition and a polyol composition is applied onto a first film in a first application step, and a solution including a curing accelerator is applied to a second film in a second application step.
(2) A mixture solution of a part of a polyol composition and a polyisocyanate composition is applied onto a first film in a first application step, and a solution including the residue of the polyol composition and a curing accelerator is applied to a second film in a second application step.
The present invention will now be further specifically described by examples. Incidentally, the present invention is not limited only to the following examples. In the following examples, the “part” and “%” are based on mass, unless specified otherwise.
(Polyisocyanate Composition (X-1))
(Manufacturing of Polyisocyanate (A))
4,4-Diphenylmethane diisocyanate (hereinafter, abbreviated to “MDI”): 41.9 parts, 2,4′-MDI: 13.0 parts, and xylene diisocyanate: 0.1 parts were fed in a reaction container being a flask equipped with a stirrer, a thermometer, and a nitrogen gas introduction pipe and were stirred in a nitrogen gas and heated to 60° C. Furthermore, a bifunctional polypropylene glycol (hereinafter, abbreviated to “PPG”) having a number average molecular weight of 400:20.0 parts and a bifunctional PPG having a number average molecular weight of 2,000:25.0 parts were dropwise added to the flask in several divided times, followed by stirring at 80° C. for 5 to 6 hours fox a urethanization reaction to obtain a polyisocyanate composition (X-1) consisting of a polyisocyanate (A).
The isocyanate content of the polyisocyanate (A) was measured by a titration method using di-n-butylamine. As a result, it was 14 mass %.
In addition, the melt viscosity of the polyisocyanate (A) at 40° C. was measured. As a result, it was 1,500 mPa·s.
(Polyisocyanate Compositions (X-2) to (X-4))
As polyisocyanate compositions (X-2) to (X-4), the followings were prepared.
X-2: 2K-SF-220A (manufactured by DIC Corporation)
X-3: 2K-SF-700A (manufactured by DIC Corporation)
X-4: TAKENATE 500, isocyanate content: 44.7 mass % (manufactured by Mitsui Chemicals, Inc.)
The isocyanate content each of the polyisocyanate compositions (X-2) to (X-4) was measured by a titration method using di-n-butylamine. The results are shown in Tables 3 and 4 as the functional group amounts together with the results of the polyisocyanate composition (X-1) (isocyanate content of polyisocyanate (A)).
(Polyol Composition (Y-1))
Castor oil as a polyol: 70 parts, D-1000 as a polyol: 15.8 parts, EXCENOL 430 as a polyol: 6.6 parts, EC 310 as a polyamine: 6.6 parts, and ε-caprolactam as a catalyst: 1.0 parts were fed in a flask equipped with a stirrer, a thermometer, and a nitrogen gas introduction pipe and were heated to 80° C. in a nitrogen gas and stirred. It was confirmed that the solution was uniform to obtain a polyol composition (Y-1) including polyol.
The hydroxy values of the materials used for the polyol composition (Y-1) were measured. The hydroxy value means the number of milligrams of potassium hydroxide corresponding to the hydroxy groups in 1 g of a sample. The method for measuring the hydroxy value is not particularly limited, and the hydroxy value can be calculated by a known method. In the present embodiment, the hydroxy value was determined in accordance with the hydroxy value measurement method of JIS-K0070.
The amine values of the materials used for the polyol composition (Y-1) were measured. The amine value means the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1 g of a sample. The method for measuring the amine value is not particularly limited, and the amine value can be calculated using a known method. In the present embodiment, the amine value was measured in accordance with the amine value standard testing method of ASTM D2073.
The sum of the hydroxy value and the amine value included in the polyol composition (Y-1) was then determined. The result was 179.2 mg KOH/g.
(Polyol Compositions (Y-2) to (Y-4))
Polyol compositions (Y-2) to (Y-4) were prepared as in the polyol composition (Y-1) except that a polyol. (B), a polyamine (C), and an additive shown in Table 1 were used at the proportions shown in Table 1.
The hydroxy value and the amine value of each of the polyol compositions (Y-2) to (Y-4) were measured as in the polyol composition (Y-1), and the sum thereof was determined. The results are also shown in Table 1.
(Polyol Composition (Y-5) to (Y-7))
As polyol compositions (Y-5) to (Y-7), the followings were prepared.
Y-5: HA-234B, hydroxy value: 90 mg KOH/g (manufactured by DIC Corporation)
Y-6: HA-700B, hydroxy value: 120 mg KOH/g (manufactured by DIC Corporation)
Y-7: D-1000 (bifunctional polypropylene glycol, manufactured by Mitsui Chemicals Polyuxethanes, Inc., number average molecular weight: about 1,000), hydroxy value: 112 mg KOH/g, 40° C. melt shear viscosity: 150 mPa·s)
Regarding the polyisocyanate compositions (X-1) to (X-4) and the polyol compositions (Y-1) to (Y-7), the elongational viscosity at an elongation rate of 4,000 s−1 and the shear viscosity at a shear rate of 4,000 s−1 were measured respectively by the following methods, and the ratio thereof (elongational viscosity/shear viscosity), i.e., the Trouton ratio, was determined.
The elongational viscosity was measured in accordance with the capillary rheometer evaluation method described in JIS-7199 (ISO 11443, ASTM D 3835).
Specifically, a twin capillary-type apparatus (manufactured by Goettfert Inc., RHEOGRAPH 20) was used. In the polyisocyanate compositions (X-4) and the polyol composition (Y-1), a combination of a capillary die having a length of 30 mm and a diameter of 0.3 mm and a capillary die having a length of 0.25 mm and a diameter of 0.3 mm was used. In the polyisocyanate compositions (X-1) to (X-3) and the polyol compositions (Y-2) to (Y-7), a combination of a capillary die having a length of 10 mm and a diameter of 0.5 mm and a capillary die having a length of 0.25 mm and a diameter of 0.5 mm was used.
The true shear viscosity was then obtained by removing the pressure loss from an apparent shear viscosity (pressure) measured at a temperature of 40° C. and a shear rate of 1,000 to 300,000 s−1 by Bargley correction. The elongational viscosity corresponding to the elongation rate was determined using a Cogswell model from the resulting true shear viscosity and the pressure loss.
The elongational viscosity at an elongation rate of 4,000 s−1, the shear viscosity at a shear rate of 4,000 s−1, and the Trouton ratio values are shown in Tables 2 and 3.
The polyisocyanate compositions (X-1) to (X-4) and the polyol compositions (Y-1) to (Y-7) were used at the proportions shown in Table 4, and laminated films of Examples 1 to 6 and Comparative Examples 1 to 3 were produced respectively by the method shown below using the manufacturing apparatus shown in
Any of the polyisocyanates (X-1) to (X-4) was applied to a corona treated polyamide film (first film) having a thickness of 15 μm (first application step). The first application step was performed by adjusting the temperature of the polyisocyanate compositions (X-1) to (X-4) stored in the coating liquid tank to 40° C.
Simultaneously with the first application step, any of the polyol compositions (Y-1) to (Y-7) was applied to a linear low-density polyethylene (LLDPE) film (second film) having a thickness of 60 μm (second application step).
The first application step and the second application step were performed such that the total application amount of the polyisocyanate compositions (X-1) to (X-4) and the polyol compositions (Y-1) to (Y-7) was 2.0 g/m2.
The adhesive layer forming process was then performed continuously from the first application step and the second application step. The adhesive layer forming process was performed by laminating the first film and the second film to bring any of the polyisocyanate compositions (X-1) to (X-4) applied on the first film and any of the polyol compositions (Y-1) to (Y-7) applied on the second film into contact with each other and to cause a curing reaction.
The proportions of the polyisocyanate compositions (X-1) to (X-4) and the polyol compositions (Y-1) to (Y-4) were determined such that the molar ratio of the isocyanate groups possessed by the polyisocyanate (A) in the compositions (X-1) to (X-4) to the sum of the hydroxy group and the amino group in the polyol compositions (Y-1) to (Y-7) [isocyanate group/(hydroxy group+amino group)] was within a range of 1.4 to 1.6. In Table 4, the molar ratio is shown as an NCO excess ratio.
The functional group amounts of the polyisocyanate compositions shown in Table 4 are isocyanate contents (%) of the polyisocyanate compositions. The functional group amounts of the polyol compositions shown in Table 4 are each the sum (mg KOH/g) of the hydroxy value and the amine value of the polyol composition.
The thus obtained laminated films of Examples 1 to 6 and Comparative Examples 1 to 3 were each subjected to aging at 40° C. for 48 hours.
Subsequently, two test pieces having a length of 200 mm and a width of 15 mm were cut out from the laminated film and were laminated such that the surfaces on the linear low-density polyethylene (LLDPE) film sides face to each other. The laminated two test pieces were heated and pressed from the outer (polyamide films) sides using a heat seal bar having a width of 1 cm under conditions of a temperature of 180° C. and a pressure of 0.1 bar for 1 second for heat sealing (fusion bond). The heat sealed test pieces were cut such that the length of the heat sealed portion was 15 mm and were peeled off from each other at a rate of 300 mm/min to measure the heat seal strength.
“Criteria”
As for the heat seal strength, the maximum load at which the heat-sealed portion breaks was evaluated by five grades of the following criteria, and 4 or above was judged to be acceptable. The evaluation results of the heat seal strength are shown in Table 4.
5: 50 N/15 mm or more;
4: 40 N/15 mm to 49 N/15 mm;
3: 30 N/15 mm to 39 N/15 mm;
2: 20 N/15 mm to 29 N/15 mm; and
1: 0 to 19 N/15 mm.
As shown in Table 4, in Examples 1 to 6 in which the Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) were within a range of 4.0 to 8.0, in the peeling test, edge break and film rupture did not occur up to 50 N/15 mm or more. As a result, the heat seal strength was evaluated as “5” in Examples 1 to 5, and the heat seal strength was evaluated as “4” in Example 6. Thus, good heat sealing properties were obtained.
In contrast, as shown in Table 4, in Comparative Example 1 in which the Trouton ratio of the polyisocyanate composition (X) was lower than 4.0, in the peeling test, triangular peeling occurred at 19 N/15 mm or less. As a result, the heat seal strength was evaluated as “1”, and the heat sealing property was insufficient. Also in Comparative Example 2 in which the Trouton ratio of the polyol composition (Y) was less than 4.0 and Comparative Example 3 in which the Trouton ratios of the polyisocyanate composition (X) and the polyol composition (Y) were less than 4.0, triangular peeling occurred at 19 N/15 mm or less as in Comparative Example 1. As a result, the heat seal strength was evaluated as “1”, and the heat sealing property was insufficient. It was inferred that in Comparative Examples 1 to 3, the adhesive layer had insufficient flexibility and could not follow the elongation of the first film and the second film, resulting in occurrence of breakage due to triangular peeling.
These results demonstrated that a laminated film including an adhesive layer formed using a two-component curing adhesive in which the polyisocyanate composition (X) and the polyol composition (Y) each have a Trouton ratio within a range of 4.0 to 8.0 has a good heat sealing property.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/005468 | 2/15/2021 | WO |
