Patent Application
20240117099
The present invention relates to a polyurethane resin composition, a cured product, a fiber laminate, and an artificial leather.
Aqueous polyurethane resin compositions, which can impart durability, have been used for leather-like sheets such as suede-like artificial leather (for example, Patent Literature 1).
Patent Literature 1 describes an aqueous-dispersion polycarbonate-based polyurethane resin composition produced by chain-extending, using a polyamine compound containing, in a single molecule, two or more amino groups of at least one selected from the group consisting of a primary amino group and a secondary amino group, a urethane prepolymer that is a reaction product between a polyol including a polycarbonatediol containing a structural unit derived from 1,10-decanediol and a polyhydric alcohol containing, as a functional group, a hydroxy group alone and having a molecular weight of 400 or less, and an organic polyisocyanate, and that has, at an end, an isocyanate group.
However, the inventors of the present invention have found that the polyurethane resin described in PTL 1 undergoes degradation of the flexibility at low temperatures, which is problematic. Thus, development of a technique that provides high durability and high flexibility at low temperatures is desirable.
In order to address the problem, the present invention has been made and can be carried out as the following embodiments.
The polyurethane resin composition according to this embodiment provides high durability and high flexibility at low temperatures.
The polyurethane resin composition according to this embodiment can provide a stable emulsion.
The polyurethane resin composition according to this embodiment provides higher durability and higher flexibility at low temperatures.
The polyurethane resin composition according to this embodiment provides higher durability and higher flexibility at low temperatures.
The polyurethane resin composition according to this embodiment provides higher durability and higher flexibility at low temperatures.
A polyurethane resin composition according to an embodiment of the present invention is produced by chain-extending, using polyamine, a reaction product between a polyol including a polycarbonate polyol including a structural unit derived from 1,10-decanediol, a polyhydric alcohol including, as functional groups, three or more hydroxy groups alone and having a number-average molecular weight of 420 or more and 2000 or less (hereafter, also simply referred to as “polyhydric alcohol”), and a polyol including an anionic hydrophilic group, and polyisocyanate. The polyurethane resin composition according to this embodiment can be present in the form of an aqueous dispersion. The polyurethane resin composition according to this embodiment provides high durability and high flexibility at low temperatures.
A polyol component (A) used for the polyurethane resin composition according to this embodiment includes a polycarbonate polyol including a structural unit derived from 1,10-decanediol (hereafter, also referred to as “decanediol-derived polycarbonate polyol”), a polyhydric alcohol including, as functional groups, three or more hydroxy groups alone and having a number-average molecular weight of 420 or more and 2000 or less, and a polyol including an anionic hydrophilic group.
The number-average molecular weight of the decanediol-derived polycarbonate polyol is not particularly limited, and is, from the viewpoint of providing high flexibility at low temperatures, preferably 800 or more, more preferably 900 or more, still more preferably 950 or more. On the other hand, the number-average molecular weight of the decanediol-derived polycarbonate polyol is, from the viewpoint of providing high handleability, preferably 3400 or less, more preferably 3200 or less, still more preferably 3100 or less.
The decanediol-derived polycarbonate polyol is not particularly limited and examples include products manufactured by Mitsubishi Chemical Corporation such as BENEBiOL (registered trademark) NL1010DB, BENEBiOL (registered trademark) NL2010DB, and BENEBiOL (registered trademark) NL3010DB.
The polyhydric alcohol including, as functional groups, three or more hydroxy groups alone and having a number-average molecular weight of 420 or more and 2000 or less is not particularly limited and examples include polyether polyol and polyester polyol. The polyhydric alcohol according to this embodiment is preferably, from the viewpoint of providing high durability and high flexibility at low temperatures, polyether polyol.
The polyhydric alcohol according to this embodiment includes three or more hydroxy groups. The number of hydroxy groups of the polyhydric alcohol is, from the viewpoint of providing high durability and high flexibility at low temperatures, preferably 4 or more, or preferably 8 or less, more preferably 7 or less, still more preferably 6 or less.
The polyhydric alcohol according to this embodiment has a number-average molecular weight of 420 or more and 2000 or less. The number-average molecular weight of the polyhydric alcohol is, from the viewpoint of providing high durability and high flexibility at low temperatures, preferably 450 or more, more preferably 500 or more, still more preferably 520 or more, or preferably 1500 or less, more preferably 1000 or less, still more preferably 800 or less.
The polyhydric alcohol according to this embodiment is not particularly limited and examples include SANNIX GP-600 manufactured by Sanyo Chemical Industries, Ltd. and EXCENOL 430, EXCENOL 1030, EXCENOL 410NE, and EXCENOL 3030 manufactured by Asahi Glass Co., Ltd.
In this Description, the anionic hydrophilic group refers to a carboxy group or a salt thereof or a sulfonic group or a salt thereof.
Examples of the polyol including a carboxy group include carboxylic acid-containing compounds such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, dioxymaleic acid, 2,6-dioxybenzoic acid, and 3,4-diaminobenzoic acid, derivatives of the foregoing, salts of the foregoing, and polyester polyols formed from the foregoing.
Examples of the polyol including a sulfonic group include sulfonic acid-containing compounds such as 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid, sulfanilic acid, 1,3-phenylenediamine-4,6-disulfonic acid, and 2,4-diaminotoluene-5-sulfonic acid, derivatives of the foregoing, salts of the foregoing, and polyester polyols, polyamide polyols, and polyamide polyester polyols formed from the foregoing.
Such carboxy groups or sulfonic groups are neutralized into salts, to thereby provide high aqueous dispersibility of the finally obtained polyurethane, which is preferred. Examples of the neutralizer include nonvolatile bases such as sodium hydroxide and potassium hydroxide, tertiary amines such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine, and triethanolamine, and volatile bases such as ammonia. The neutralization can be performed before, during, or after the urethane-forming reaction.
The polyol including an anionic hydrophilic group is, from the viewpoint of improving the storage stability of the polyurethane aqueous dispersion, preferably polyols including a carboxy group, more preferably 2,2-dimethylolpropionic acid.
The polyol preferably includes, as a polyol other than the decanediol-derived polycarbonate polyol, the polyhydric alcohol, and the polyol including an anionic hydrophilic group, from the viewpoint of providing a stable emulsion, a polyether polyol including a structural unit derived from ethylene glycol. The polyether polyol including a structural unit derived from ethylene glycol is not particularly limited and examples include polyoxyethylene-polyoxypropylene random copolymer glycol and polyethylene glycol. Examples of the polyoxyethylene-polyoxypropylene random copolymer glycol include ADEKA POLYETHER PR-3007 (manufactured by ADEKA CORPORATION, molecular weight: 3000, oxyethylene group content: 70%). Examples of the polyethylene glycol include PEG-600S (manufactured by DAI-ICHI KOGYO SEIYAKU CO., LTD., molecular weight: 600).
The formulation ratio of the decanediol-derived polycarbonate polyol to the entirety of the polyol is not particularly limited, and is, from the viewpoint of providing high abrasion resistance and high flexibility at low temperatures, preferably 50 mass % or more, more preferably 60 mass % or more, still more preferably 70 mass % or more. On the other hand, the formulation ratio of the decanediol-derived polycarbonate polyol to the entirety of the polyol is preferably 97 mass % or less, more preferably 93 mass % or less, still more preferably 88 mass % or less.
The formulation ratio of the polyhydric alcohol to the entirety of the polyol is not particularly limited, and is, from the viewpoint of providing high abrasion resistance and high flexibility at low temperatures, preferably 1 mass % or more, more preferably 3 mass % or more, still more preferably 5 mass % or more. On the other hand, the formulation ratio of the polyhydric alcohol to the entirety of the polyol is preferably 22 mass % or less, more preferably 20 mass % or less, still more preferably 18 mass % or less.
The polyisocyanate used for the polyurethane resin composition according to this embodiment is not particularly limited and examples include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and aromatic-aliphatic polyisocyanates. From the viewpoint of providing high abrasion resistance and high flexibility at low temperatures, as the polyisocyanate, an alicyclic polyisocyanate is preferably included.
The aliphatic polyisocyanates are not particularly limited and examples include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate.
The alicyclic polyisocyanates are not particularly limited and examples include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate (hereafter, also referred to as “H12MDI”), 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane.
The aromatic polyisocyanates are not particularly limited and examples include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, 4,4′-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate.
The aromatic-aliphatic polyisocyanates are not particularly limited and examples include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, and α,α,α,α-tetramethylxylylene diisocyanate.
As the polyisocyanate, modified products of the above-described organic polyisocyanates may be used. Such modified products of the organic polyisocyanates are not particularly limited and examples include carbodiimides, allophanates, biurets, isocyanurates, and adducts. Note that such polyisocyanates can be used alone or in combination of two or more thereof.
From the viewpoint of providing high abrasion resistance and high flexibility at low temperatures, the polyisocyanate is preferably 4,4′-dicyclohexylmethane diisocyanate (H12MDI).
The number-average molecular weight of the polyisocyanate is not particularly limited, and is preferably 100 or more and 400 or less, more preferably 120 or more and 300 or less, more preferably 150 or more and 280 or less.
The polyamine used for the polyurethane resin composition according to this embodiment is not particularly limited and examples include chain extenders ordinarily used in the technical field. Examples of the polyamine include diamines, triamines, and tetramines. Examples of the diamines include ethylenediamine, trimethylenediamine, piperazine, and isophoronediamine. Examples of the triamines include diethylenetriamine and dipropylenetriamine. Examples of the tetramines include triethylenetetramine.
The polyurethane resin composition according to this embodiment may include other materials as long as they do not impair advantages of the present invention. The other materials are not particularly limited and examples include chain extenders other than the above-described polyamine, crosslinking agents, and catalysts.
The chain extenders other than the above-described polyamine are not particularly limited and examples include ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,3-propylene glycol, 1,2-propylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and neopentyl glycol. The crosslinking agents are not particularly limited and examples include aminoplast compounds, epoxy compounds, carbodiimide compounds, and glycerol.
The catalysts are not particularly limited and examples include metallic catalysts and amine-based catalysts. The metallic catalysts are not particularly limited and examples include tin catalysts such as dibutyl tin dilaurate, dioctyl tin dilaurate, and dibutyl tin dioctate, lead catalysts such as lead octylate, lead octenoate, and lead naphthenate, and bismuth catalysts such as bismuth octylate and bismuth neodecanoate. The amine-based catalysts are not particularly limited and examples include tertiary amine compounds such as triethylenediamine.
The polyurethane resin composition is not particularly limited in terms of the production method and can be produced by publicly known methods. For example, first, the decanediol-derived polycarbonate polyol, the polyhydric alcohol, the polyol including an anionic hydrophilic group, the other polyol, and polyisocyanate are caused to react, to thereby synthesize an isocyanate-terminated urethane prepolymer. This reaction is performed without solvents or in an organic solvent not having active hydrogen groups. Subsequently, as needed, the anionic hydrophilic group is neutralized and then dispersion-emulsification is performed in water. Subsequently, a small equivalent of a chain extender relative to the remaining isocyanate groups in the urethane prepolymer (for example, an equivalent ratio of isocyanate groups to amino groups in the chain extender=1:0.5 to 0.95) is added, and subsequently an interfacial polymerization reaction is caused between the chain extender and isocyanate groups within emulsification micelles, to thereby form urea bonds. This reaction causes polymerization within emulsification micelles, to provide a polyurethane resin aqueous dispersion. Subsequently, as needed, the used solvent is removed, to thereby obtain an aqueous dispersion of the polyurethane resin composition. In this method, the equivalent ratio of the isocyanate groups of the polyisocyanate to the total of the hydroxy groups of the polyol and the amino groups of the chain extender is preferably 1:0.85 to 1.1.
In the case of dispersion emulsification of the isocyanate-terminated urethane prepolymer in water, a surfactant may be used as an emulsifier. The surfactant is not particularly limited and examples include nonionic surfactants, anionic surfactants, and cationic surfactants. Such surfactants may be used alone or in combination of two or more thereof.
The nonionic surfactants are not particularly limited and examples include alcohols having 8 to 24 carbon atoms, alkenols having 8 to 24 carbon atoms, polycyclic phenols, amines having 8 to 44 carbon atoms, amides having 8 to 44 carbon atoms, fatty acids having 8 to 24 carbon atoms, fatty acid esters of polyhydric alcohols, fats and oils, alkylene oxide adducts of polypropylene glycol, alkylene oxide adducts of polycyclic phenols, and PLURONIC (registered trademark) nonionic surfactants. The alkylene oxide adducts of polycyclic phenols are not particularly limited and examples include polyoxyethylene distyrylphenyl ether-based nonionic surfactants, polyoxyethylene polyoxypropylene distyrylphenyl ether-based nonionic surfactants, polyoxyethylene tristyrylphenyl ether-based nonionic surfactants, and polyoxyethylene polyoxypropylene tristyrylphenyl ether-based nonionic surfactants. When two or more alkylene oxides are added to such a nonionic surfactant, such addition may be block addition or random addition.
The anionic surfactants are not particularly limited and examples include alcohols, alkenols, and anionized products of alkylene oxide adducts of the above-described nonionic surfactants.
The cationic surfactants are not particularly limited and examples include monoalkyltrimethyl ammonium salts having 8 to 24 carbon atoms, dialkyldimethyl ammonium salts having 8 to 24 carbon atoms, monoalkylamine acetates having 8 to 24 carbon atoms, dialkylamine acetates having 8 to 24 carbon atoms, and alkylimidazoline quaternary salts having 8 to 24 carbon atoms.
As the surfactant, from the viewpoint of having high compatibility with other components, preferred are nonionic surfactants and more preferred are alkylene oxide adducts of polycyclic phenols and PLURONIC (registered trademark) nonionic surfactants.
The amount of surfactant used is, relative to 100 parts by mass of the solid content of the isocyanate-terminated urethane prepolymer, preferably 0.5 parts by mass or more, more preferably 2 parts by mass or more, or preferably 10 parts by mass or less, more preferably 8 parts by mass or less. When the amount of surfactant used is in such a range, a polyurethane resin composition that provides higher abrasion resistance and higher flexibility at low temperatures can be obtained.
The molecular weight of the polyurethane resin composition is not particularly limited; for example, the weight-average molecular weight is preferably 5000 to 500000, more preferably 10000 to 300000. The weight-average molecular weight is measured using a GPC apparatus using tetrahydrofuran (THF) as the solvent and is determined as a polystyrene-equivalent value. Specific measurement conditions are as follows.
Columns: polystyrene gel columns manufactured by Tosoh Corporation (TSK gel G4000HXL+TSK gel G3000HXL+TSK gel G2000HXL+two TSK gel G1000HXL are connected in series in this order)
Column temperature: 40° C.
Detector: differential refractive index detector (manufactured by SHIMADZU CORPORATION, RID-6A) Flow rate: 1 ml/min
The acid value of the polyurethane resin composition is not particularly limited and is, for example, preferably 0.1 mgKOH/g to 20 mgKOH/g, more preferably 0.3 mgKOH/g to 15 mgKOH/g. Such acid values used herein refer to acid values measured in accordance with JIS K0070-1992.
The polyurethane resin composition according to this embodiment provides high abrasion resistance and high flexibility at low temperatures and hence is effectively applicable to artificial leathers, for example. The method of using the polyurethane resin composition according to this embodiment to produce an artificial leather is not particularly limited and existing methods can be used. For example, the polyurethane resin composition is applied to a release paper sheet and subsequently subjected to evaporation of water to thereby form a surface layer; this surface layer is coated with an adhesive, subsequently bonded to a fiber fabric layer, and subjected to evaporation of water, to thereby produce an artificial leather. This method is a method for producing a fiber laminate including a surface layer formed from the polyurethane resin composition according to this embodiment and a fiber fabric layer, and this fiber laminate corresponds to an artificial leather. The obtained artificial leather is used for, for example, vehicles, furniture, clothing, shoes, bags, pouches, sandals, and sundry goods. The artificial leather may further include, in addition to the surface layer and the fiber fabric layer, another layer (for example, a metallic layer). The adhesive used in the method is not particularly limited as long as it bonds together the surface layer and the fiber base member and examples include polyurethane adhesives. The polyurethane resin composition according to this embodiment can be dried to thereby provide a cured product. The cured product and the fiber laminate obtained in this embodiment may further be subjected to post-processing such as surface treatment and boarding.
Hereinafter, the present invention will be described further in detail with reference to Examples; however, the present invention is not limited to the following Examples.
Note that, in the following Examples and Comparative Examples, “parts” are based on mass unless otherwise specified.
(Polycarbonatediol including structural unit derived from 1,10-decanediol)
Polyurethane resin compositions of Examples and Comparative Examples were produced in accordance with formulations (parts by mass) described in Table below. Note that, in Example 8, isophoronediamine used in Example 1 was replaced by diethylenetriamine.
A polycarbonatediol including a structural unit derived from 1,10-decanediol, 4,4′-dicyclohexylmethane diisocyanate, a polyhydric alcohol including, as functional groups, three or more hydroxy groups, dimethylolpropionic acid, and methyl ethyl ketone were added and caused to react at 70 to 75° C. for 120 minutes. At this time, the free isocyanate group content (in terms of solid content) was 1.8 mass %. The prepolymer was cooled to 35° C. and neutralized by adding triethylamine. Subsequently, while water was gradually added to this solution, a homogenizer was used to achieve emulsification. To the resultant emulsification dispersion, an aqueous solution in which isophoronediamine was dissolved was added; after disappearance of free isocyanate groups was confirmed, methyl ethyl ketone was distilled off to provide an aqueous dispersion of a polyurethane resin composition having a solid content of 40 mass % and an acid value of 4.2 mgKOH/g.
The obtained aqueous dispersion of the polyurethane resin composition was cast on a release paper sheet so as to have a dry film thickness of 200 μm and subsequently dried at 80° C. for 6 hours, to thereby produce a film.
The obtained film was cut into a predetermined size. The resultant sample was subjected to, in accordance with JIS K 6301, tension at a tensile speed of 200 mm/min to a predetermined elongation, at which time the stress (100% modulus) was measured. The evaluation of flexibility was performed three times: immediately after preparation of the sample, after storage at 5° C. for 2 weeks, and after storage at 5° C. for 4 weeks. The lower the stress, the higher the flexibility.
For the flexibility, evaluation was performed in the following manner.
A plane abrasion tester (manufactured by DAIEI KAGAKU SEIKI MFG. CO., LTD., PA-300A) was used to rub, under a load of 500 g/cm2 at 60 times/min, the surface of the obtained film 2000 times and whether or not scratching occurred was visually observed. The less the occurrence of scratching or separation, the higher the abrasion resistance.
For the abrasion resistance, evaluation was performed in the following manner.
The results in Table have demonstrated the following. Examples including a polyhydric alcohol including three or more hydroxy groups and having a number-average molecular weight of 420 or more and 2000 or less have been demonstrated to provide high abrasion resistance and high flexibility at low temperatures, compared with Comparative Example 1 including the polyhydric alcohol including three or more hydroxy groups but having a number-average molecular weight of less than 420 and Comparative Example 2 including the polyhydric alcohol including three or more hydroxy groups but having a number-average molecular weight of more than 2000.
The present invention is not limited to the above-described embodiments and can be carried out in various embodiments without departing from the spirit and scope thereof. For example, technical features in embodiments and Examples corresponding to technical features in embodiments in Summary of Invention can be appropriately replaced or combined in order to achieve a portion of or the entirety of the above-described object or in order to provide a portion of or the entirety of the above-described advantages. As long as such technical features are not described as essential features in this Description, the features can be appropriately removed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-023106 | Feb 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/003481 | 1/31/2022 | WO |
