Patent Application
20180297410
The present invention relates to a tire.
In recent years, from the viewpoints of weight reduction and ease of recycling, it is known that a thermoplastic polymer material such as a thermoplastic elastomer (TPE) or a thermoplastic resin is used as a tire frame member. Such a tire is economical and highly recyclable. From the viewpoint of increasing the strength of the tire, it is conceivable to dispose a reinforcing layer on a framework member. A cord member made of an inorganic material or an organic material is used as the reinforcing layer, and a specific organic fiber is particularly advantageous from the viewpoints of light weight, economic efficiency, and strength. In the reinforcing layer, by coating the cord member with rubber or a resin material, rigidity in a tire radial direction can be maintained.
In this regard, as a technique for adhering an organic fiber and rubber, for example, there is a technique of adhering a fiber with an epoxy compound or an isocyanate compound (for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-339299 and International Publication (WO) No. 2014/074404). An adhering method using a resorcinol-formaldehyde-latex resin in the case of adhering rubber and a fiber is known (for example, JP-A No. 2001-73247).
The methods according to the above patent documents assume the adhesiveness between an organic fiber and rubber, and do not assume the case of adhering an organic fiber and a resin material.
There is still room for improvement in adhesion between a resin material and a cord member in the case of coating the cord member used for the reinforcing layer with the resin material.
Therefore, development of a tire including a reinforcing layer sufficiently adhering a cord member and a resin material is awaited.
A tire includes: a tire frame member made of resin and including a bead portion and a side portion positioned on a tire radial direction outer side of the bead portion; and a reinforcing layer including an organic fiber and a resin material with which the organic fiber is coated, wherein the organic fiber includes: a cord member including at least one of an aramid fiber material or a polyester fiber material; an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin.
According to the present disclosure, there is provided a tire including a reinforcing layer in which a cord member and a resin material are sufficiently adhered.
Tire
A tire according to the present disclosure includes: a tire frame member made of resin and including a bead portion and a side portion positioned on a tire radial direction outer side of the bead portion; and a reinforcing layer including an organic fiber and a resin material with which the organic fiber is coated, wherein the organic fiber includes: a cord member including at least one of an aramid fiber material or a polyester fiber material; an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer (hereinafter, referred to as an “RF layer” if appropriate) provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin.
As described above, the organic fiber including the cord member in the reinforcing layer is configured so as to include three constituent elements of the specific cord member, the undercoat layer, and the RF layer, and the respective constituent elements are adhered, whereby the organic fiber is strongly adhered to the resin material included in the reinforcing layer and is fixed in a case in which the organic fiber is coated with the resin material included in the reinforcing layer. Since the reinforcing layer is formed from the resin material, an adhesive force between the reinforcing layer and the tire frame member can be increased as compared with the case of using rubber.
In the present specification and the like, “to” representing a range including numerical values of the upper and lower limit thereof.
The value of the adhesive strength between the organic fiber and the resin material can be determined using a method of measuring an adhesive force between vulcanized rubber and an organic fiber cord in a test piece as described in International Publication (WO) No. 2010/125992, for example. That is, the adhesive strength between the organic fiber and the resin material included in the test piece is determined by a test method in accordance with “7. Peeling Test” as defined in JIS K6301: 1995.
The details of the present disclosure are described below.
Reinforcing Layer
A reinforcing layer according to the present disclosure includes an organic fiber and a resin material with which the organic fiber is coated. The position at which the reinforcing layer is disposed is not particularly limited, and the reinforcing layer may be disposed at the side portion of the tire frame member. Here, “the reinforcing layer is disposed at the side portion” includes an aspect in which the reinforcing layer is provided inside the tire frame member itself, and an aspect in which the reinforcing layer is arranged on the inner surface or the outer surface of the tire frame member.
As described above, the reinforcing layer is configured so as to include the organic fiber and the resin material with which the organic fiber is coated. Here, the organic fiber may be fully coated with the resin material, or the reinforcing layer may have a portion where the organic fiber is not coated with the resin material. The reinforcing layer may be, for example, a layer extending from the bead portion of the tire to the side portion and disposed side by side at intervals in a tire circumferential direction.
It is preferable to adjust the thickness of the reinforcing layer appropriately according to the purpose, such as the material or thickness of the organic fiber.
Hereinbelow, a specific example of the structure of the reinforcing layer is described below with reference to
Organic Fiber
The organic fiber according to the present disclosure includes a cord member including at least one of an aramid fiber material or a polyester fiber material (hereinafter referred to as a cord member); an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin. It is preferable that the cord member included in the organic fiber is a single twisted multifilament obtained by twisting a plurality of monofilaments, or is obtained by twisting two or more of the multifilaments. Depending on the purpose, for example, only one multifilament may be used, or only a monofilament may be used without using a multifilament. Here, “a plurality of” means ten or more.
Here, “including at least one of an aramid fiber material or a polyester fiber material” means that the cord member may be a cord-like member including a fiber material of at least one of an aramid fiber material or a polyester fiber material, or may be a member including both the members. For example, a multifilament including at least one of an aramid fiber material or a polyester fiber material can be used as the cord member.
The structure of the organic fiber is specifically described with reference to
The fineness of all the filaments included in the cord member 1 is not particularly limited. For example, from the viewpoint of further improving the adhesive strength between the organic fiber and the resin material, the fineness may be from 500 dtex/2 to 3000 dtex/2.
In the organic fiber 4, between the cord member 1 and the undercoat layer 2, and between the undercoat layer 2 and the RF layer 3, materials for forming respective layers are adhered to each other. The organic fiber 4 can be used as a reinforcing layer in a state in which the organic fiber 4 is partially or entirely coated with the resin material as described later.
As shown in
The RF layer 3 is provided on the undercoat layer 2, and covers the surface of the undercoat layer 2. One surface of the RF layer 3 may be adhered onto the undercoat layer 2. It is preferable that the RF layer 3 is adhered and provided so as to cover the entire surface of the undercoat layer 2. However, as long as the effects of the tire according to the present disclosure are not impaired, the RF layer 3 may have an area not adhered to the surface of the undercoat layer 2 in a part of the surface. As described above, the outer circumferential surface of the RF layer 3 is covered with the resin material, and is adhered to the resin material in a case in which the organic fiber 4 is coated with the resin material in order to form the reinforcing layer.
It is preferable to appropriately set the count of the organic fibers depending on the type of the cord member to be used and the type of the tire. For example, preferable aspects of the reinforcing layer include one in which the organic fibers obtained by twisting the cord member are disposed side by side in a row at regular intervals with the count of about 50 per 50 mm in a case in which the diameter of the cord member is 0.5 mm. Even though the counting of the organic fibers is uniform over the reinforcing layer, the cord member may be provided with spacing below tread grooves according to the shape of the tread.
Examples of the aramid fiber material for forming the cord member include a para-aramid fiber and a meta-aramid fiber. Examples of the para-aramid fiber include m-phenylene isophthalamide, and examples of the meta-aramid fiber include p-phenylene terephthalamide. Examples of m-phenylene isophthalamide include “KEVLAR” manufactured by Du Pont-Toray Co., Ltd., and “TWARON” and “TECHNORA” manufactured by Teijin Techno Products Limited. Examples of p-phenylene terephthalamide include “NOMEX” manufactured by Du Pont Co., Ltd., and “CONEX” manufactured by Teijin Techno Products Limited. These fiber materials may be used singly as the cord member, or two or more of these fiber materials may be used in combination.
Among them, a para-aramid fiber is preferably used from the viewpoint of an adhesive strength between the cord member and the undercoat layer.
Examples of the polyester fiber material for forming the cord member include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polytrimethylene terephthalate (PTT). These fiber materials may be used singly as the cord member, or two or more of the fiber materials may be used in combination. Among them, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is preferably used from the viewpoint of the adhesive strength between the cord member and the undercoat layer.
Either of the aramid fiber material or the polyester fiber material may be used singly as the cord member, or the respective fiber materials may be mixed for use. In this case, either of these fiber materials may be used singly in a single cord member, or the respective fiber materials may be mixed for use. Furthermore, all of the cord members included in the large number of organic fibers used for the reinforcing layer may be made of a single type of fiber material, or different types of fiber materials may be used between the organic fibers.
The cord member may include other fiber materials other than the aramid fiber material and the polyester fiber material. For example, plural monofilaments composed of at least one of the aramid fiber material or the polyester fiber material and plural monofilaments composed of other type of fiber material are assembled, and a predetermined number of twists are applied to the assembled article, thereby obtaining a multifilament.
In addition to the aramid fiber material and the polyester fiber material, the cord member may include an additive such as an antioxidant such as a styrenated phenol or a hindered phenol, an antifoaming agent such as a silicone antifoaming agent, higher alcohol antifoaming agent or mineral oil antifoaming agent, a reaction terminator, or an anti-freezing agent, if necessary.
Undercoat Layer
The undercoat layer is a layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound. The “layer formed from a first composition” means a layer formed by reacting a compound included in the first composition, for example, a layer formed from a compound derived from at least one of an epoxy compound or an isocyanate compound. The epoxy compound and the isocyanate compound included in the first composition are described below.
Examples of the epoxy compound include a reaction product of a polyhydric alcohol and epichlorohydrin such as diethylene glycol diglycidyl ether, polyethylene diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythiol polyglycidyl ether, diglycerol polyglycidyl ether, or sorbitol polyglycidyl ether; a novolac epoxy resin such as a phenol novolac epoxy resin or a cresol novolac epoxy resin; and a bisphenol A epoxy resin.
Examples of the isocyanate compound include a blocked isocyanate group-containing compound, and examples thereof include a compound having a blocked isocyanate group produced by reaction with a blocking agent for an isocyanate group, a compound having an isocyanate group which is unreacted with a blocking agent for an isocyanate group, and a compound having an isocyanate group generated by dissociation of the blocking agent of the blocked isocyanate group.
A blocked isocyanate compound obtained by blocking an organic polyisocyanate compound such as diphenylmethane diisocyanate (MDI) or tolylene diisocyanate (TDI) with a blocking agent is preferably used as the blocked isocyanate compound. Examples of the blocking agent include phenols such as phenol, thiophenol, chlorophenol, cresol, resorcinol, p-sec-butylphenol, p-tert-butylphenol, p-sec-amylphenol, p-octylphenol, or p-nonylphenol; secondary or tertiary alcohols such as isopropyl alcohol or tert-butyl alcohol; aromatic secondary amines such as diphenylamine; phthalic acid imides; lactams such as δ-valerolactam; caprolactams such as ε-caprolactam; active methylene compounds such as dialkyl malonate, acetylacetone, or acetoacetate alkyl ester; ketoximes such as acetoxime, methyl ethyl ketoxime, or cyclohexanone oxime; and basic nitrogen compounds such as 3-hydroxypyridine, and acidic sodium sulfites.
Phenol, ε-caprolactam, and ketoxime can be preferably used as the blocking agent.
Examples of a water dispersible compound containing a component obtained by blocking the diphenylmethane diisocyanate with a thermally dissociable blocking agent include a reaction product obtained by blocking diphenylmethane diisocyanate with a known blocking agent which blocks an isocyanate group. Specifically, a commercially available blocked polyisocyanate compound such as ELASTRON BN 69 or BN-27 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. can be used.
The undercoat layer can be formed by polymerizing the first composition. The first composition for forming the undercoat layer may further include, as a component other than the epoxy compound and the isocyanate compound, a water-soluble polymer or a thermoplastic high molecular weight polymer as long as the effects of the tire according to the present disclosure are not impaired. In a case in which these polymers or the like are appropriately added to the first composition, brittleness and easiness of breakage of the undercoat layer is improved, and further adhesiveness to the cord member and the RF layer is enhanced.
The number average molecular weight of each of the epoxy compound and the isocyanate compound in the first composition is not particularly limited, and it is preferably from 100 to 10000, more preferably from 300 to 5000, and still more preferably from 1000 to 3000.
The content of the compound derived from at least one of the epoxy compound or the isocyanate compound included in the undercoat layer is not particularly limited, and it is preferably from 2% by mass to 20% by mass and more preferably from 3% by mass to 10% by mass in terms of solid content.
Adhesive Layer
The adhesive layer (RF layer) is a layer provided on the undercoat layer, and is a layer formed from a second composition including a resorcinol-formaldehyde resin. The “layer formed from a second composition including a resorcinol-formaldehyde resin” is a layer formed by reacting the resorcinol-formaldehyde resin included in the second composition.
The resorcinol-formaldehyde resin for forming the RF layer (hereinafter also referred to as a resorcinol-formaldehyde condensate) is a compound obtained by condensation of formaldehyde with a phenol compound partially including at least resorcinol.
The resorcinol-formaldehyde condensate is preferably a resol resin having few branches (the form of a general phenol resin used as an adhesive). The resorcinol-formaldehyde condensate in which a methylol group and a dimethylene ether bond (dibenzyl ether bond) do not remain and a condensation reaction does not almost proceed by itself even though receiving heating, that is, stability is high, is preferable. For example, a percentage of a methylene bond in the total number of bonding sites between phenolic compounds can be preferably 90% or more, more preferably 95% or more, and still more preferably 97% or more. That is, it is considered that the resorcinol-formaldehyde condensate in which several phenolic compound molecules are almost linearly bonded by nearly only methylene bonds is preferable.
The resorcinol-formaldehyde condensate is that a part or the whole of the phenolic compounds to be bonded by a portion derived from formaldehyde is resorcinol. The resorcinol-formaldehyde condensate may be modified as described in JP-A No. 2014-001270.
The molar ratio (F/R) of formaldehyde (F) and resorcinol (R) used for forming the RF layer can be appropriately selected according to the purpose.
The resorcinol-formaldehyde condensate can be obtained by adding formaldehyde to resorcinol dissolved in a solvent and stirring and mixing the resultant at a predetermined temperature for a predetermined time. As the solution used in this case, acidic, neutral or alkaline water, or an organic solvent such as acetone or alcohol can be used. It is preferable to use alkaline or neutral water in order to sufficiently carry out a resorcinol-formaldehyde condensation reaction (resol formation reaction). This resol formation reaction is usually carried out preferably at pH 8.0 or higher, and more preferably from 8.5 to 10.0.
Here, the alkaline water is prepared by dissolving sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonium hydroxide, or an organic amine such as monomethylamine or ammonia in water.
The alkaline water can also be used in a state where the alkaline water is dispersed in neutral water with a ball mill or a sand mill using an arbitrary anionic surfactant. In this case, in order to effectively develop an adhesive force, it is preferable to reduce the amount of the surfactant to such an extent that the dispersed state does not deteriorate.
The RF layer can be formed by, for example, applying a second composition onto the undercoat layer and reacting the second composition with the undercoat layer to form an adhesive layer (RF layer) adhered to the undercoat layer. In this reaction, the resorcinol-formaldehyde condensate reacts with a functional group on the surface of the undercoat layer. Furthermore, the condensates sterically entangled with each other and firmly form the RF layer adhered to the undercoat layer. In this case, the reaction of the second composition is preferably carried out by heating, and a reaction temperature during heating is preferably from 160° C. to 180° C.
The content of the resorcinol-formaldehyde resin included in the RF layer is not particularly limited, and it is preferably from 2% by mass to 20% by mass, and more preferably from 3% by mass to 10% by mass in terms of solid content.
The total content of the undercoat layer and the adhesive layer in the organic fiber is preferably from 0.5% by mass to 3.0% by mass with respect to the total mass of the organic fiber. In a case in which the content is 0.5% by mass or more, the adhesiveness between the cord member 1 and the undercoat layer 2 can be further improved, and the adhesion strength between the organic fiber and the resin material can be further enhanced. In a case in which the content is 3.0% by mass or less, the reinforcing layer can be made lighter, which provides excellent economic efficiency. Here, the total content of the undercoat layer and the adhesive layer can be calculated, for example, by subtracting the mass of the organic fiber before adhesion and impregnation of the first composition and the second composition as described below, from the mass of the organic fiber after adhesion and impregnation of each of the first composition and the second composition to the cord member 1, followed by drying.
Resin Material
The resin material is included in the reinforcing layer, and is a material with which the organic fiber is coated. It is intended that the resin material does not include conventional natural rubber or vulcanized rubber such as synthetic rubber.
Both a thermoplastic resin and a thermosetting resin can be used as the resin material. Here, the thermoplastic resin (including a thermoplastic elastomer) refers to a polymer compound which softens and flows with increased temperature, and becomes relatively hard and strong in the case of being cooled. In the present specification, a polymer compound which softens and flows with increased temperature, becomes relatively hard and strong in the case of being cooled, and has a rubber-like elasticity, is defined as a thermoplastic elastomer, which is distinguished from a polymer compound which softens and flows with increased temperature, becomes relatively hard and strong in the case of being cooled, and has no rubber-like elasticity, defined as a non-elastomer thermoplastic resin.
The thermosetting resin refers to a polymer compound which is cured to form a three-dimensional network structure with increased temperature.
Examples of the thermoplastic resin include a polyurethane resin, a polyolefin resin, a polyvinyl chloride resin, and a polyamide resin. Examples of the thermoplastic resin include a thermoplastic polyolefin elastomer (TPO), a thermoplastic polystyrene elastomer (TPS), a thermoplastic polyamide elastomer (TPA), a thermoplastic polyurethane elastomer (TPU), a thermoplastic polyester elastomer (TPC), and a thermoplastic vulcanizate (TPV).
For example, as the thermoplastic material, a thermoplastic material having a temperature of deflection under load (loading 0.45 MPa) defined by ISO 75-2 or ASTM D648 of 78° C. or more, a tensile strength at yield defined by JIS K7113 of 10 MPa or more; a tensile elongation at break defined by JIS K7113 of 50% or more; and a Vicat softening temperature defined by JIS K7206 (method A) of 130° C. or more can be used.
Examples of the thermosetting resin include a phenol resin, a urea resin, a melamine resin, an epoxy resin, and a polyamide resin.
Among these, from the viewpoint of adhesiveness with the organic fiber, a thermoplastic resin is preferably used; a thermoplastic polyamide resin or a thermoplastic polyurethane resin is more preferably used; and a thermoplastic polyamide elastomer (TPA) is still more preferably used.
Other than the thermoplastic resin (including a thermoplastic elastomer) and thermosetting resin described above, a general-use resin such as a (meth)acrylic resin, an EVA resin, a vinyl chloride resin, a fluorine resin, or a silicone resin may also be used as the resin material.
In a case in which the thermoplastic polyamide resin is used as the resin material, the modulus of elasticity (modulus of elasticity in tension of elasticity as defined in JIS K7113: 1995) of the thermoplastic polyamide resin material is preferably set within a range of from 0.1 times to 10 times the modulus of elasticity of the thermoplastic resin for forming a tire frame member. In a case in which the modulus of elasticity of the thermoplastic polyamide resin material is not more than 10 times the modulus of elasticity of the thermoplastic polyamide resin material for forming the tire frame member, the crown portion does not become too hard, facilitating the rim assembling. In a case in which the modulus of elasticity of the thermoplastic polyamide resin material is 0.1 times or more the modulus of elasticity of the thermoplastic resin material for forming the tire frame member, a resin constituting the reinforcing layer is not too soft, the in-plane shear stiffness of the belt is high, and cornering power is improved.
In a case in which the thermoplastic polyamide resin material is included in the resin material, from the viewpoint of increasing pull-out property (difficulty to pull out) of the organic fiber, the surface of the organic fiber is preferably coated with the thermoplastic polyamide resin material by 20% or more, and more preferably by 50% or more. The content of the thermoplastic polyamide resin material included in the reinforcing layer is preferably 20% by mass or more, and more preferably 50% by mass or more, from the viewpoint of increasing pull-out property of the organic fiber with respect to the total amount of the materials constituting the reinforcing layer excluding the organic fiber.
In order to configure the reinforcing layer to include the resin material, for example, the reinforcing layer can be formed by configuring such that at least a part of the organic fiber is embedded in the outer circumference of the tire frame member formed of the thermoplastic polyamide resin material in a cross sectional view along the axial direction of the tire frame member. In this case, the resin material including the thermoplastic polyamide resin at the outer circumference of the tire frame member with which the organic fiber is coated corresponds to the resin material constituting the reinforcing layer, and the reinforcing layer is constituted by the thermoplastic polyamide resin material forming the tire frame member and the organic fiber.
Exemplary Method of Producing for Reinforcing Layer
The reinforcing layer can be produced, for example, by a method having the following steps (1) to (3):
(1) an undercoating treatment step of applying a first composition including at least one of an epoxy compound or an isocyanate compound to the surface of a cord member including at least one of an aramid fiber material or a polyester fiber material, to form an undercoat layer;
(2) an RF treatment step of applying a second composition including a resorcinol-formaldehyde resin to the surface of the undercoat layer after the undercoating treatment step, and thereafter heating the second composition to from 160° C. to 180° C. to form an adhesive layer (RF layer), thereby obtaining an organic fiber; and
(3) a resin coating treatment step of juxtaposing the plural organic fibers at desired intervals on a tire frame member after the RF treatment step, applying a resin material to the surface of the adhesive layer (RF layer) on which the organic fibers are juxtaposed, and thereafter heating the resin material to form a reinforcing layer.
In the undercoating treatment step, the first composition including at least one of the epoxy compound and the isocyanate compound is applied to the surface of the cord member including at least one of the aramid fiber material or the polyester fiber material. The first composition may be applied to the surface of the cord member, followed by heating at a predetermined temperature for a predetermined time, to form the undercoat layer, or the undercoat layer and the RF layer may be simultaneously formed by applying the second composition, followed by heating. From the viewpoint of adhesiveness to the cord member, a drying step of drying the coating film immediately after application of the first composition may be provided, and a baking step of baking after the drying step may be provided. By providing the drying step, the solvent in the first composition can be sufficiently removed, which can provide the subsequent efficient baking step. In the drying step, the temperature and drying time are set if appropriate, but it is preferable to dry at from 150° C. to 200° C. for from 60 seconds to 100 seconds, and more preferable to dry at from 160° C. to 180° C. for from 70 seconds to 90 seconds. In the baking step, it is preferable to bake at, for example, from 220° C. to 280° C. for from 40 seconds to 80 seconds, and more preferable to bake at from 230° C. to 260° C. for from 50 seconds to 70 seconds.
A known method such as coating, dipping, or extrusion molding can be used if appropriate as the method of applying the first composition to the cord member. For example, the undercoat layer can be efficiently formed by impregnating the cord member with the first composition and baking after drying as described above.
In the RF treatment step, the second composition including the resorcinol-formaldehyde condensate is applied to the surface of the undercoat layer obtained in the undercoat step, and heated at a temperature of from 160° C. to 180° C., to form the RF layer.
In the RF treatment step, from the viewpoint of further enhancing the adhesiveness between the RF layer and the undercoat layer, the drying step of drying the coating film of the second composition may be provided, and the baking step of baking the coating film of the second composition may be then provided. By providing the drying step, the solvent in the second composition can be sufficiently removed, which can provide the subsequent efficient baking step. In the RF treatment step, in a case in which the drying step and the baking step are performed, the heating temperature is preferably in the range of from 160° C. to 180° C. in both the steps. In the drying step, for example, it is preferable to dry at from 160° C. to 180° C. for from 70 seconds to 90 seconds. In the baking step, for example, it is preferable to bake at from 160° C. to 170° C. for from 50 seconds to 70 seconds.
A known method such as coating, dipping, or extrusion molding can be used if appropriate as the method of applying the second composition. For example, the cord member having the undercoat layer formed thereon is impregnated with the second composition and baked after drying as described above, whereby the RF layer can be efficiently formed.
In the resin coating treatment step, by coating the cord member (that is, the organic fiber) on which the undercoat layer and the RF layer obtained in the RF treatment step after the undercoat treatment are formed with the resin, and heating at a predetermined temperature for a predetermined time, the reinforcing layer in which the organic fiber is coated with the resin material can be produced. The heating temperature in the resin coating treatment step is preferably adjusted if appropriate depending on the resin material to be used. For example, in a case in which the thermoplastic polyamide resin is used as the resin material, the heating temperature is preferably from 220° C. to 280° C. A method of coating the organic fiber with the resin material is not particularly limited. For example, the organic fiber is placed in a general laminator (coating apparatus), extruded at a resin extrusion temperature of from 220° C. to 280° C., and laminated at a laminator press temperature of from 200° C. to 250° C., whereby the reinforcing layer in which the organic fiber is coated with the resin material can be produced.
Hereinbelow, specific embodiments according to the present disclosure are described with reference to the drawings. However, the present disclosure is not limited to these embodiments.
In the drawings, the arrow C direction indicates the tire circumferential direction, the arrow R direction indicates the tire radial direction, and the arrow W direction indicates the tire width direction. The tire radial direction means a direction orthogonal to the tire axis (not shown). The tire width direction means a direction parallel to the tire rotation axis. The tire width direction can also be referred to as the tire axial direction.
Dimensions of each part are measured by the method described in the 2013 version YEAR BOOK issued by JATMA (Japan Automobile Tire Association).
Subsequently, a specific embodiment of a tire of the present disclosure is described below with reference to the drawings. In
The tire frame member 12 is made of a resin and includes a bead portion 16, a side portion 18 positioned on a tire radial direction outer side of the bead portion 16, and a crown portion 26 positioned on a tire width direction inner side of the side portion 18. A tread 32 is disposed on the crown portion 26. Here, the bead portion 16 means a range from the tire radial direction inner side end of the tire frame member 12 to 30% of the cross-sectional height of the tire frame member 12. The tire frame member 12 has an annular shape about a tire axis. Examples of the resin included in the tire frame member 12 include a thermoplastic resin (including a thermoplastic elastomer), a thermosetting resin, and other general-use resins, as well as an engineering plastic (including a super engineering plastic). Vulcanized rubber is not included in the resin here.
Examples of the resin used in the first embodiment include a thermoplastic resin (including a thermoplastic elastomer) and a thermosetting resin, and their definitions are the same as described above.
Examples of the thermoplastic resin (including a thermoplastic elastomer) used for the tire frame member 12 include a thermoplastic polyolefin elastomer (TPO), a thermoplastic polystyrene elastomer (TPS), a thermoplastic polyamide elastomer (TPA), a thermoplastic polyurethane elastomer (TPU), a thermoplastic polyester elastomer (TPC), a dynamically thermoplastic vulcanizate (TPV), a thermoplastic polyolefin resin, a thermoplastic polystyrene resin, a thermoplastic polyamide resin, and a thermoplastic polyester resin.
For example, as the thermoplastic material, a thermoplastic material having a temperature of deflection under load (loading 0.45 MPa) defined by ISO 75-2 or ASTM D648 of 78° C. or more, a tensile strength at yield defined by JIS K7113 of 10 MPa or more; a tensile elongation at break defined by JIS K7113 of 50% or more; and a Vicat softening temperature defined by JIS K7206 (method A) of 130° C. or more can be used.
Examples of the thermosetting resin include a phenol resin, an epoxy resin, melamine resin, and a urea resin.
Other than the thermoplastic resin (including a thermoplastic elastomer) and the thermosetting resin, a general-use resin such as a (meth)acrylic resin, an EVA resin, a vinyl chloride resin, a fluorine resin, or a silicone resin may also be used as the resin material.
A bead core 22 is embedded in the bead portion 16. The thermoplastic material included in the bead core 22 is preferably an olefin type TPE, ester type TPE, amide type TPE, or urethane type TPE, or a TPV which is a mixed, partly rubber-based resin. The thermoplastic material preferably has, for example, a temperature of deflection under load (loading 0.45 MPa) defined by ISO 75-2 or ASTM D648 of 75° C. or more, a tensile elongation at yield by JIS K7113 of 10% or more; a tensile elongation at break defined by JIS K7113 of 50% or more; and a Vicat softening temperature defined by JIS K7113 (method A) of 130° C. or more.
As shown in
As shown in
In the tire frame member 12, the crown portion 26 is connected to the tire radial direction outer side of the side portion 18. On the outer circumference surface of the crown portion 26, a belt layer 28 is provided. The belt layer 28 is configured by winding a resin-coated cord in a spiral shape in the tire circumferential direction, for example.
A tread 32 is provided on the tire radial direction outer side of the crown portion 26 and the belt layer 28. The tread 32 is, for example, a pre-cured tread (PCT) formed using rubber. The tread 32 is formed from rubber having more excellent abrasion resistance than that of the resin material for forming the tire frame member 12. The same types of tread rubber used for conventional rubber-made pneumatic tires, for example, styrene-butadiene rubber (SBR) may be used as the rubber. Other type of resin material having more excellent abrasion resistance than that of the resin material forming the tire frame member 12 may be used as the tread 32.
In the reinforcing layer 14, an organic fiber 30 is coated with a resin material. The reinforcing layer 14 extends from the bead portion 16 to the side portion 18. The reinforcing layers 14 are disposed side by side at intervals in the tire circumferential direction. The reinforcing layer 14 is formed to be longer in a tire radial direction than in the tire circumferential direction in a state where it is extended in a plane. For example, the same resin material as the resin material included in the tire frame member 12 is used as the resin material. One surface, or both surfaces of the organic fiber 30 may be coated with the resin material. In a case in which both the surfaces of the organic fiber 30 are coated with the resin material, the organic fiber 30 can be disposed at the thickness direction center of the reinforcing layer 14. In a case in which both surfaces are coated, different resin materials may be used for one surface and the other surface.
The organic fiber 30 is configured so as to include three constituent elements: a cord member including at least one of an aramid fiber material or a polyester fiber material; an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer (RF layer) provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin. In the reinforcing layer 14, the organic fiber 30 extends at least along the tire radial direction. An organic fiber 30 extending in the tire circumferential direction may be combined with the organic fiber 30 so that the organic fibers 30 are overlapped with each other so as to cross each other. In this case, the organic fibers 30 may be woven or knitted to form a cloth shape. Note that the organic fiber 30 may be inclined with respect to the tire radial direction and the tire circumferential direction.
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The position of the outer surface 14B of the reinforcing layer 14 is not limited thereto. For example, the outer surface 14B may be positioned at the half of the thickness of the tire frame member 12 (the position of the line H), or may be positioned on the tire inner side with respect to the half of the thickness of the tire frame member 12.
Effects
The tire 10 according to the present embodiment includes at least the tire frame member 12 made of resin and the reinforcing layer 14. The tire frame member 12 includes the bead portion 16, the side portion 18 positioned on the tire radial direction outer side of the bead portion, and the crown portion 26 positioned on the tire width direction inner side of the side portion. The tread is disposed on the crown portion 26. The reinforcing layers 14, in which the organic fiber is coated with the resin material, extend from the bead portion 16 to the side portion 18, and are disposed side by side in the tire circumferential direction. Hereinbelow, the effects are described.
In
The outer surface 14B of the reinforcing layer 14 is positioned on the tire outer side with respect to the half of the thickness of the tire frame member 12. That is, the outer surface 14B of the reinforcing layer 14 is positioned on the outer surface side of the tire frame member 12, so that durability with respect to bending deformation of the tire is improved.
Furthermore, the tire radial direction inner side end 14A of the reinforcing layer 14 is positioned on the tire radial direction inner side with respect to the rim separation point P of the bead portion 16, so that pinch cut can be suppressed in a case in which a vehicle runs on a curb or the like, for example.
The reinforcing layer 14 is engaged with the bead core 22 embedded in the bead portion 16, and wound with the bead core 22, so that the reinforcing layer 14 can bear most of a tensile force occurring in the tire. Therefore, resistance with respect to internal pressure is remarkably improved. As a result of which the thickness of the tire frame member 12 can be reduced, and ride comfort can be improved.
As described above, the tire 10 according to the present embodiment, the cut resistance performance can be improved while considering the balance between the rigidity in the tire circumferential direction and the rigidity in the tire radial direction, and thus the ride comfort can be improved.
In the tire 10, by configuring the organic fiber of the reinforcing layer 14 disposed at the side portion so as to include three layers of the cord member, the undercoat layer, and the adhesive layer (RF layer), the organic layer can be strongly adhered to not only the reinforcing layer 14 but also the tire frame member 12.
In
In the reinforcing layer 14, a wide portion 14W located on a tire radial direction outer side and a narrow portion 14S located on a tire radial direction inner side are formed. The wide portion 14W includes the tire maximum width position of a side portion 18. The wide portions 14W come into contact with each other. The narrow portions 14S are separated from each other in the tire circumferential direction.
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According to the tire 20 of the present embodiment, the reinforcing layers 14 are disposed so as to be in contact with each other in the tire circumferential direction, so that cut resistance performance can be further improved.
The other parts are the same as those in the first embodiment, so that the same elements are denoted by the same reference numerals in the drawings, and the description thereof is omitted.
Other reinforcing layers (not shown) may be disposed between reinforcing layers 14 according to the first embodiment which are adjacent to each other in a tire circumferential direction. In this case, the other reinforcing layers and the reinforcing layers 14 may be partially overlapped with each other. Configuration may also be such that one tire circumferential direction side of the other reinforcing layer is partially overlapped with the adjacent reinforcing layer 14, and the other tire circumferential direction side is provided with a gap of 0.1 mm or greater, for example, without being overlapped with the adjacent reinforcing layer 14. In the second embodiment, the reinforcing layers 14 which are adjacent to each other in the tire circumferential direction may be partially overlapped with each other.
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In
The tire frame member 112 is made of a resin and includes a bead portion 116, a side portion 118 positioned on a tire radial direction outer side of the bead portion 116, and a crown portion 126 positioned on a tire width direction inner side of the side portion 118. A tread 132 is disposed on the crown portion 126. Here, the bead portion 116 means a range from the tire radial direction inner side end of the tire frame member 112 to 30% of the cross-sectional height of the tire frame member 112. The tire frame member 112 has an annular shape about a tire axis. Examples of the resin included in the tire frame member 112 include a thermoplastic resin (including a thermoplastic elastomer), a thermosetting resin, and other general-use resins, as well as an engineering plastic (including a super engineering plastic). Vulcanized rubber is not included in the resin here.
The thermoplastic resin (including a thermoplastic elastomer) referred to herein refers to the same polymer compound as that defined in the first embodiment, and examples of the thermoplastic resin (including a thermoplastic elastomer) include the same resins as the resins or the like mentioned in the first embodiment. Furthermore, as the thermoplastic resin, for example, there can be used thermoplastic resins having the same temperature of deflection under load, tensile strength at yield, tensile elongation at break, and Vicat softening temperature as those of the thermoplastic resins mentioned in the first embodiment.
The thermosetting resin refers to the same polymer compound as that defined in the first embodiment, and examples of the thermosetting resin include the same resins as those mentioned in the first embodiment. Furthermore, other resin materials which can be used are also the same as those described in the first embodiment.
An annular-shaped bead core 122 formed from resin-coated cords 120 is embedded in the bead portion 116. The material of the cord 120 may be steel, an organic fiber, a resin, or the like. The bead core 122 is, for example, a strand bead formed by stacking plural (for example, three) resin-coated cords 120 on each other while winding the plural resin-coated cords 120 in the tire circumferential direction. In the cross section of the strand bead in the tire width direction, plural resin-coated cords 120 are arranged. For example, three layers of cords 120 are stacked on each other.
The stacked direction of the cords 120 may be the tire radial direction as shown in
The resin material with which the cord 120 is coated is preferably an olefin type TPE, ester type TPE, amide type TPE, or urethane type TPE, or a TPV which is a mixed, partly rubber-based resin. The thermoplastic material preferably has, for example, a temperature of deflection under load (loading 0.45 MPa) defined by ISO 75-2 or ASTM D648 of 75° C. or more, a tensile elongation at yield by JIS K7113 of 10% or more; a tensile elongation at break defined by JIS K7113 of 50% or more; and a Vicat softening temperature defined by JIS K7113 (method A) of 130° C. or more.
In the tire frame member 112, the crown portion 126 is connected to the tire radial direction outer side of the side portion 118. On the outer circumference surface of the crown portion 126, a belt layer 128 is provided. The belt layer 128 is configured by winding a resin-coated cord in a spiral shape in the tire circumferential direction, for example.
A tread 132 is provided on the tire radial direction outer side of the crown portion 126 and the belt layer 128. The tread 132 is formed from rubber having more excellent abrasion resistance than that of the resin material for forming the tire frame member 112. The same types of tread rubber used for conventional rubber-made pneumatic tires, for example, styrene-butadiene rubber (SBR) may be used as the rubber. Other type of resin material having more excellent abrasion resistance than that of the resin material forming the tire frame member 112 may be used as the tread 132.
In the reinforcing layer 114, an organic fiber 130 is coated with a resin material. The reinforcing layer 114 is thermally welded to the bead core 122. Thermal welding refers to using heat to melt and join the resin material of the reinforcing layer 114 and the resin material of the bead core 122. The reinforcing layer 114 is thermally welded to the bead core 122.
For example, the same resin material as the resin material included in the tire frame member 112 is used as the resin material with which the organic fiber 130 is coated. One surface, or both surfaces of the organic fiber 130 may be coated with the resin material. In a case in which both the surfaces of the organic fiber 130 are coated with the resin material, the organic fiber 130 can be disposed at the thickness direction center of the reinforcing layer 114. In a case in which both surfaces are coated, different resin materials may be used for one surface and the other surface.
The organic fiber 130 is configured so as to include three constituent elements: a cord member including at least one of an aramid fiber material or a polyester fiber material; an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin. In the reinforcing layer 114, the organic fiber 130 extends at least along the tire radial direction. An organic fiber 130 extending in the tire circumferential direction may be combined with the organic fiber 130 so that the organic fibers 130 are overlapped with each other so as to cross each other. In this case, the organic fibers 130 may be woven or knitted to form a cloth shape. Note that the organic fiber 130 may be inclined with respect to the tire radial direction and the tire circumferential direction.
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Here, the manufacturing process of the tire 110 is briefly described. First, the integrally-formed bead core 122 and the reinforcing layer 114 are disposed in a mold (not shown), and a resin material is supplied into a cavity inside the mold, thereby molding the tire frame member 112 made of a resin material integrally with the bead core 122 and the reinforcing layer 114 as shown in
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For example, a tire radial direction outer side end 114C of the reinforcing layer 114 extends from the crown portion 126 of the tire frame member 112, and is overlapped with the belt layer 128. The overlapping with the belt layer 128 is preferably 5 mm or more from a tire width direction end portion of the belt layer 128 to a tire width direction center side. The reinforcing layer 114 may extend to the tire width direction center. The position of the tire radial direction outer side end 114C of the reinforcing layer 114 may be terminated in the vicinity of the maximum width position of the tire in the side portion 118, or may be terminated just before reaching the crown portion 126 (so-called buttress portion).
Effects
The tire 110 according to the present embodiment includes: the tire frame member made of resin and including the bead portion, in which at least the bead core formed from the resin-coated cords is embedded, and the side portion positioned on the tire radial direction outer side of the bead portion; and the reinforcing layer in which the organic fiber is coated with the resin material, is thermally welded to the bead core, and extends from the bead portion to the side portion. The effects are described below.
In
The outer surface of the reinforcing layer 114 is positioned on the outer surface of the tire frame member 112, so that the durability with respect to bending deformation of the tire 110 is improved. The reinforcing layer 114 is joined to the bead core 122, so that the reinforcing layer 114 can bear a tensile force occurring in the tire 110. Therefore, resistance with respect to internal pressure (pressure resistance) can be improved. As a result of which the thickness of the tire frame member 112 can be reduced, and ride comfort can be improved.
In
In particular, in the example shown in
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In the tire 110, the organic fiber of the reinforcing layer 114 disposed at the side portion is configured by three layers, that is, the cord member, the undercoat layer, and the adhesive layer, so that the organic layer can be strongly adhered to not only the reinforcing layer 114 but also the tire frame member 112.
As described above, according to the tire 110 of the present embodiment, due to the reinforcing layer 114 extending from the bead portion 116 to the side portion 118, both the pressure resistance and the cut resistance performance can be improved while reducing the weight of the tire 110.
In the fourth embodiment, the reinforcing layers 114 are disposed side by side in the tire circumferential direction. However, the reinforcing layers 114 may be integrally formed. The reinforcing layers 114 which are adjacent to each other in the tire circumferential direction may be partially overlapped with each other. Furthermore, other reinforcing layers (not shown) may be disposed between the reinforcing layers 114 which are adjacent to each other in the tire circumferential direction. In this case, the other reinforcing layers and the reinforcing layers 114 may be partially overlapped with each other. Configuration may also be such that one tire circumferential direction side of the other reinforcing layer is partially overlapped with the adjacent reinforcing layer 114, and the other tire circumferential direction side is provided with a gap of 0.1 mm or greater, for example, without being overlapped with the adjacent reinforcing layer 114.
The tire according to the present disclosure includes the following aspects.
<1> A tire including:
a tire frame member made of resin and including a bead portion and a side portion positioned on a tire radial direction outer side of the bead portion; and
a reinforcing layer including an organic fiber and a resin material with which the organic fiber is coated,
wherein the organic fiber includes: a cord member including at least one of an aramid fiber material or a polyester fiber material; an undercoat layer provided on the cord member and formed from a first composition including at least one of an epoxy compound or an isocyanate compound; and an adhesive layer provided on the undercoat layer and formed from a second composition including a resorcinol-formaldehyde resin.
<2> The tire according to <1>, wherein the resin material included in the reinforcing layer includes a thermoplastic polyamide resin or a thermoplastic polyurethane resin.
<3> The tire according to <2>, wherein the thermoplastic polyamide resin is a thermoplastic polyamide elastomer.
<4> The tire according to any one of <1> to <3>, wherein the cord member is a single twisted multifilament obtained by twisting a plurality of monofilaments, or is obtained by twisting two or more of the multifilaments.
<5> The tire according to any one of <1> to <4>, wherein the reinforcing layer is disposed at the side portion.
Hereinbelow, the present disclosure is further described by way of Examples, but the present disclosure is not limited to the following examples. Hereinbelow, a treatment of forming an undercoat layer on a cord member is referred to as an undercoating treatment; a treatment of forming an adhesive layer (RF layer) is referred to as an RF treatment; and a treatment of coating with a resin is referred to as a resin coating treatment.
Cord Member
As the cord member, two yarn bundles of 1100 dtex which were multifilaments of a polyester fiber were twisted with 47 turns per 10 cm of a length to make a first twist and a second twist, thereby obtaining a cord member formed from a polyester fiber having a structure represented by 1670 dtex/2 and twist number of 47×47 (turn/10 cm).
As the cord member, two yarn bundles of 1670 dtex which were multifilaments of an aramid fiber were twisted with 47 turns per 10 cm of a length to make a first twist and a second twist, thereby obtaining a cord member formed from an aramid fiber having a structure represented by 1670 dtex/2 and twist number of 39×39 (turn/10 cm).
First Composition
A first composition for forming an undercoat layer was prepared with a formulation shown in the following condition 1.
Sorbitol polyglycidyl ether (DENACOL EX-614B, manufactured by Nagase ChemteX Corporation): 7.8 parts by mass
Copolymer of isobutylene and maleic anhydride (ISOBAM, manufactured by Kuraray Co., Ltd.): 60.7 parts by mass
Aqueous solution of blocked isocyanate (BN-27, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 41.5 parts by mass
Water: 889.9 parts by mass
Second Composition
A second composition for forming an adhesive layer was prepared with a formulation shown in the following condition 2.
Sodium hydroxide solution (10% by mass aqueous solution) (manufactured by Tosoh Corporation): 33.3 parts by mass
Formaldehyde (37% by mass aqueous solution) (ISOBAM, manufactured by Nippon Kasei Chemical Co., Ltd.): 34.8 parts by mass
Resorcinol (manufactured by Sumitomo Chemical Co., Ltd.): 27.1 parts by mass
Water: 904.8 parts by mass
The cord member formed from the polyester fiber prepared above was impregnated and coated with the first composition prepared above, using a general dipping treatment apparatus, and dried and baked at from 160° C. to 180° C.
RF Treatment
The cord member after the undercoating treatment was impregnated and coated with the second composition prepared above, and dried and baked at from 160° C. to 180° C., thereby obtaining an organic fiber in which the cord member, the undercoat layer, and an RF adhesive layer were laminated in this order.
Resin Coating Treatment
The organic fiber was placed in a general laminator (coating apparatus), and coated with a thermoplastic polyamide elastomer (TPA) as a resin material at a die temperature of 245° C. during resin extrusion and a laminator press temperature of 230° C., thereby preparing a laminate plate having a width of 13 cm, a length of 100 mm, and a thickness of 0.8 mm, as a test piece 1. The test piece 1 includes 100 organic fibers at intervals of 1 mm only in a lateral row.
The preparation of a thermoplastic polyamide elastomer (TPA) is described below.
Preparation of Thermoplastic Polyamide Elastomer (TPA)
The TPA was prepared by a treatment step including the following two-step polymerization reaction, i.e., polymerization reaction A and polymerization reaction B.
43.7 g of 1,2-aminododecanoic acid (manufactured by Aldrich), 601 g of aminododecanolactam (manufactured by Aldrich), and 15.5 g of adipic acid (manufactured by Aldrich) were placed in a reaction vessel having a capacity of 2 L and equipped with a stirrer, a nitrogen gas inlet, and a condensed water discharge port. The air in the reaction vessel was sufficiently replaced by nitrogen, and then the temperature was raised to 280° C. The mixture was reacted (polymerization reaction A) while stirring under a pressure of 0.6 MPa for 4 hours. After the pressure was released, the mixture was further reacted for 1 hour under a nitrogen stream to obtain a white solid which was a nylon 12 polymer having a weight average molecular weight of 6000 (hard segment [PA 12] having a chain extender attached to the end thereof).
70.9 g of Polyoxypropylene-polytetramethylene glycol-polyoxypropylenediamine (PPG-PTMG-PPG) (manufactured by HUNTSMAN, JEFFAMINE XTJ-548, weight average molecular weight: 1700) as a soft segment, and 71 mg of tetra-tert-butoxyzirconium were added to 250 g of the nylon 12 polymer obtained as described above, and the reaction of the mixture (polymerization reaction B) was performed while stirring at 230° C. for 6 hours. Then 1 g of IRGANOX 1010 was added to the reaction product obtained by this reaction, and mixed, thereby obtaining a white thermoplastic polyamide elastomer (weight average molecular weight: 75,000) as a resin material.
In Example 2, an organic fiber was prepared under the same conditions as those of Example 1 except that the cord member of Example 1 was changed to an aramid fiber, and the organic fiber was coated with a resin material in the same manner as in Example 1, thereby preparing a laminate plate as a test piece 2.
In Example 3, a resin coating treatment was performed in the same manner as in Example 1 except that TPA as the coating material of Example 1 was changed to a thermoplastic polyurethane elastomer (TPU), thereby preparing a laminate plate as a test piece 3. In Example 4, a resin coating treatment was performed in the same manner as in Example 1 except that TPA as the coating material of Example 2 was changed to a TPU, thereby preparing a laminate plate as a test piece 4.
As the TPU, ELASTOLLAN (ET 680) manufactured by BASF Co. was used as it was.
In Comparative Example 1, a cord member formed from a polyester fiber was placed in the coating apparatus as it was without an undercoating treatment and an RF treatment, and a resin coating treatment was performed in the same manner as in Example 1, thereby preparing a laminate plate as a test piece 5.
In Comparative Example 2, a cord member formed from an aramid fiber was placed in the coating apparatus as it was without an undercoating treatment and an RF treatment, and a resin coating treatment was performed in the same manner as in Example 1, thereby preparing a laminate plate as a test piece 6.
In Comparative Example 3, a polyester fiber obtained by a undercoating treatment performed in the same manner as in Example 1 was placed in the coating apparatus as it was without an RF treatment, and a resin coating treatment was performed in the same manner as in Example 2, thereby preparing a laminate plate as a test piece 7.
In Comparative Example 4, an aramid fiber obtained by an undercoating treatment performed in the same manner as Example 2 was placed in the coating apparatus as it was without an RF treatment, and a resin coating treatment was performed in the same manner as in Example 2, thereby preparing a laminate plate as a test piece 8.
In Comparative Example 5, a cord member formed from a polyester fiber obtained in the same manner as Example 1 was subjected to an RF treatment without an undercoating treatment, and then subjected to a resin coating treatment in the same manner as in Example 1, thereby preparing a laminate plate as a test piece 9.
In Comparative Example 6, a cord member formed from a aramid fiber obtained in the same manner as Example 2 was subjected to an RF treatment without an undercoating treatment, and then subjected to a resin coating treatment in the same manner as in Example 2, thereby preparing a laminate plate as a test piece 10.
In Comparative Example 7, a resin coating treatment was performed in the same manner as in Example 1 except that the TPA as the resin material of Comparative Example 1 was changed to a TPU, thereby preparing a laminate plate as a test piece 11. Similarly, as shown in Table 1 below, each of laminate plates as test pieces 12 to 16 in Comparative Examples 8 to 12 was prepared in the same manner as in Comparative Examples 2 to 6 except that the TPA used in the resin coating treatment in Comparative Examples 2, 3, 4, 5, and 6 were changed to a TPU in Comparative Examples 8, 9, 10, 11, and 12, respectively.
Measurement of Adhesive Strength
The adhesive strength of each of the test pieces in Examples and Comparative Examples prepared above was determined by using a method of measuring an adhesive force of vulcanized rubber in a test piece described in International Publication (WO) No. 2010/125992. That is, for each of the test pieces, the adhesive strength between the organic fiber and the resin material was determined by a test method in accordance with “7. Peeling test” as defined in JIS K6301:1995. In the measurement, the organic fiber embedded in the laminate plate as the test piece was pulled out from the laminate plate at a constant tensile rate, and a force required to pull out one organic fiber from the laminate plate was represented as an adhesive strength (N/yarn).
The results of Tables 1 and 2 showed that, in both cases using the polyester fiber and the aramid fiber, a test piece (reinforcing layer) having a high peel strength can be obtained by performing the undercoating treatment and the RF treatment. Among them, it was shown that the undercoating treatment is important for improving the peel strength of the obtained member.
Thus, it was shown that the reinforcing layer in which the cord member and the resin material are sufficiently adhered can be obtained in a case in which the organic fiber is configured to include the cord member, the undercoat layer, and the RF layer, and the organic fiber is coated with the resin material.
The disclosure of Japanese Patent Application No. 2015-199628 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described in the present specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-199628 | Oct 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/078304 | 9/26/2016 | WO | 00 |
