JP7101022B2 - Organic fiber / rubber composition complex and tire - Google Patents

Description

The present invention relates to an organic fiber / rubber composition complex and a tire.

Various fibers such as polyester fiber and nylon fiber have been widely used as reinforcing materials for tires, and are properly used to meet the required performance and various members. For example, polyester fibers have excellent mechanical properties (eg, high elastic modulus) and excellent dimensional stability. However, on the other hand, it has the disadvantage that the adhesiveness to rubber, which is the material of the tire, is significantly reduced compared to nylon fiber, especially when the tire is embedded in a rubber compound and exposed to high temperature for a long time. ..

In Patent Document 1, the heat-resistant adhesiveness is improved by treating the polyester fiber with a treatment liquid containing a carrier, a blocked isocyanate aqueous solution, an epoxy resin dispersion liquid, and a resorcin formalin latex (RFL) adhesive. It is proposed that.

Further, in Patent Document 2, the polyester fiber is treated with an adhesive treatment agent containing a polyepoxide compound, a blocked polyisocyanate compound, a silicate compound, and an ethylene-based unsaturated acid-modified styrene-butadiene rubber latex. It has been proposed that adhesion deterioration at high temperatures is reduced.

Japanese Unexamined Patent Publication No. 2000-21285 Japanese Unexamined Patent Publication No. 2008-169504

However, none of them can be said to have sufficient heat-resistant adhesiveness as compared with nylon fibers. Under such circumstances, the present invention is a composite of an organic fiber / rubber composition having excellent heat-resistant adhesiveness, in which the organic fiber and the rubber composition can maintain a high adhesive force even when exposed to a high temperature. The challenge is to provide.

The first aspect of the present invention relates to an organic fiber / rubber composition composite in which an organic fiber and a rubber composition are integrated, and the pull-out adhesive force by the following measuring method is 120 N / cm or more.
The organic fiber / rubber composition composite is heat-treated at 180 ° C. for 60 minutes, and the organic fiber embedded at a depth of 1 cm from the surface of the composite is removed from the composite at a rate of 100 mm / min. It is pulled until it comes off, and the force required for the pull is defined as the pull-out adhesive force (N / cm).

In the organic fiber / rubber composition composite, at least one selected from the group consisting of polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber. May be.

In the organic fiber / rubber composition composite, the organic fiber is selected from the group consisting of polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber alone. Alternatively, it may be two or more kinds of composite organic fibers.

In the organic fiber / rubber composition composite, the organic fiber is (a) a sorbitol polyglycidyl ether and an epoxy compound having a chlorine content of 9.6% by mass or less, and (b) a blocked isocyanate. It may be one that has been immersed in an adhesive composition for organic fibers containing the mixture.

In the organic fiber / rubber composition composite, the rubber composition contains a rubber component, and the content of polyisoprene-based rubber may be 0 to 70% by mass in 100% by mass of the rubber component.

The second aspect of the present invention relates to a tire using the organic fiber / rubber composition composite as a jointless band, a carcass ply, or a filler.

According to the present invention, it is possible to obtain an organic fiber / rubber composition composite having excellent heat-resistant adhesiveness, in which the organic fiber and the rubber composition can maintain a high adhesive force even when exposed to a high temperature.

It is a figure which shows an example of the embodiment of a tire. It is a figure which shows an example of embodiment of a jointless band.

[Organic fiber / rubber composition complex]
Hereinafter, an example of a preferred embodiment of the present invention will be specifically described. The organic fiber / rubber composition composite of the present disclosure has a pull-out adhesive force of 120 N / cm or more by the following measuring method. The pull-out adhesive force is preferably 122 N / cm or more, more preferably 123 N / cm or more, and even more preferably 125 N / cm or more. The upper limit is not particularly limited, but is the pull-out adhesive force obtained when a relatively low-temperature heat treatment such as at 150 ° C. for 30 minutes is performed instead of a high-heat long-term heat treatment such as at 180 ° C. for 60 minutes. It may be about 150 N / cm or less.

The organic fiber / rubber composition composite is heat-treated at 180 ° C. for 60 minutes, and the organic fiber embedded at a depth of 1 cm from the surface of the composite is removed from the composite at a rate of 100 mm / min. It is pulled until it comes off, and the force required for the pull is defined as the pull-out adhesive force (N / cm).

Specifically, first, the organic fiber / rubber composition complex can be heat-treated at 180 ° C. for 60 minutes using a heating oven. Next, the end of the organic fiber embedded at a depth of 1 cm from the surface of the organic fiber / rubber composition composite is exposed from the composite, and the end of the organic fiber is grasped by a gripper on one side of the tensile tester. , The composite is grabbed by the other grip and pulled at a rate of 100 mm / min until the organic fibers come out of the composite. The force required for the tension is shown as the force per unit length of the organic fiber (N / cm), and this is referred to as the pull-out adhesive force (N / cm).

Further, the organic fiber / rubber composition composite means a state in which the organic fiber and the rubber composition are integrated by adhesion or the like. The state includes, for example, a state in which a plurality of organic fibers twisted together (may be one in which one or more filament yarns are twisted) arranged in a rubber composition, and a state in which the organic fibers are short. Examples thereof include a state in which the fibers are dispersed in the rubber composition, but the present invention is not particularly limited as long as the organic fibers and the rubber composition are integrated.

(Rubber composition)
The rubber composition used in the organic fiber / rubber composition complex of the present disclosure is not particularly limited as long as it contains a rubber component.

As the rubber component, a conjugated diene-based weight such as polyisoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR) Combined; and non-diene polymers such as ethylene propylene diene rubber (EPDM), butyl rubber (IIR), halogenated butyl rubber (X-IIR) and the like can be mentioned. The various rubber components may be used alone or in combination of two or more. Among them, SBR and / or polyisoprene-based rubber is preferably contained because it is excellent in mechanical strength, reversion resistance, heat resistance, and crack growth resistance.

Examples of the polyisoprene-based rubber include isoprene rubber (IR), natural rubber (NR), modified natural rubber and the like. NR also includes deproteinized natural rubber (DPNR) and high-purity natural rubber (HPNR), and the modified natural rubber includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. And so on. Further, as the NR, for example, SIR20, RSS # 3, TSR20 and the like, which are common in the tire industry, can be used. Among them, NR and IR are preferable, and NR is more preferable because they are excellent in breaking elongation and breaking strength.

The butadiene rubber (BR) is not particularly limited, and for example, BR1220 manufactured by Nippon Zeon Co., Ltd., BR150B manufactured by Ube Kosan Co., Ltd., and the like, BR with a high cis content, VCR412, VCR617 manufactured by Ube Kosan Co., Ltd. BRs containing 1,2-synthiotactic polybutadiene crystals (SPB), BR synthesized using Nd catalysts such as BUNA CB 25 and BUNA CB 24 manufactured by LANXESS, etc., which are common in the tire industry. Can be used. Further, a tin-modified butadiene rubber modified with a tin compound (tin-modified BR) can also be used.

The styrene-butadiene rubber (SBR) is not particularly limited, and is modified with emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), 3-aminopropyldimethylmethoxysilane, or the like. Can be mentioned. Among them, E-SBR is preferable because it has a large amount of high molecular weight polymer component and is excellent in elongation at break.

The rubber component preferably contains a conjugated diene-based polymer in 100% by mass of the rubber component, but the content is not particularly limited.

The content of the conjugated diene polymer in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 80% by mass or more. The upper limit is not particularly limited and may be 100% by mass.

The content of the polyisoprene-based rubber in 100% by mass of the rubber component may be 0% by mass, but is preferably 10% by mass or more, more preferably 30% by mass or more. The content of the polyisoprene-based rubber is preferably 90% by mass or less, more preferably 70% by mass or less. This is because, by being in these ranges, the adhesiveness to the organic fiber (particularly, the cord) and the breaking strength can be enhanced.

The content of the conjugated diene polymer other than the polyisoprene rubber is preferably 10% by mass or more, more preferably 30% by mass or more. The conjugated diene polymer other than the polyisoprene rubber is preferably 90% by mass or less, more preferably 70% by mass or less. This is because the tear strength can be increased and the heat generation of the rubber can be suppressed by being in these ranges.

It is preferable that the content of the polyisoprene-based rubber is 0 to 70% by mass and the conjugated diene polymer other than the polyisoprene-based rubber is 30 to 70% by mass in 100% by mass of the rubber component. Further, it is more preferable that the content of the polyisoprene-based rubber is 50 to 70% by mass, and the conjugated diene-based polymer other than the polyisoprene-based rubber is 30 to 50% by mass. This is because, by being in these ranges, the adhesiveness to organic fibers (particularly, cord) and the crack growth resistance can be enhanced.

The conjugated diene-based copolymer other than the polyisoprene-based rubber is preferably SBR and / or BR, and more preferably SBR.

(Optional component of rubber composition)
The rubber composition may contain, if necessary, a compounding agent generally used for producing the rubber composition, for example, a strength improver such as sulfur, carbon black and silica, as long as the object and effect of the present invention are not impaired. ; Reinforcing fillers such as clay, silane coupling agents, stearic acid, zinc oxide, various anti-aging agents, oils such as aroma oil, waxes, vulcanization accelerators, vulcanization accelerators, etc. may be appropriately added. can.

By blending carbon black in the rubber composition, better reinforcing properties can be obtained, and complex elastic modulus, low heat generation property, elongation at break, and durability can be improved in a well-balanced manner.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 38 m ² / g or more, more preferably 60 m ² / g or more, and even more preferably 90 m ² / g or more. When the N ₂ SA of carbon black is less than 38 m ² / g, sufficient reinforcing properties cannot be obtained, and the hardness and elongation at break (when new, after thermal oxidation deterioration) tend to decrease. The N ₂ SA of carbon black is preferably 125 m ² / g or less, more preferably 115 m ² / g or less. If it exceeds 125 m ² / g, fuel efficiency and workability (sheet rollability) tend to decrease. The nitrogen adsorption specific surface area of carbon black is a value measured by the method A on page 7, JIS K6217.

The content of the carbon black is preferably 10 parts by mass or more, and more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. When the content of carbon black is less than 10 parts by mass, the rubber composition does not have sufficient reinforcing properties and tends to have a low complex elastic modulus, and sufficient elongation at break cannot be obtained and the durability is lowered. Tend to do. The carbon black content is preferably 55 parts by mass or less, more preferably 50 parts by mass or less. When the content of carbon black exceeds 55 parts by mass, the rubber composition tends to have low heat generation property, elongation at break, processability (sheet rollability), and durability.

By blending silica with the rubber composition, it is possible to improve the elongation at break and the adhesiveness with organic fibers (particularly, cord).

The silica is not particularly limited, and examples thereof include dry silica (silicic anhydride) and wet silica (hydrous silicic acid), but wet silica is preferable because it has many silanol groups.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 80 m ² / g or more, more preferably 100 m ² / g or more, and further preferably 110 m ² / g or more. When the N ₂ SA of silica is less than 80 m ² / g, the elongation at break tends to decrease and the durability tends to decrease. Further, the N ₂ SA of silica is preferably 250 m ² / g or less, more preferably 235 m ² / g or less, and further preferably 220 m ² / g or less. If it exceeds 250 m ² / g, fuel efficiency and workability (sheet rollability) tend to decrease. The nitrogen adsorption specific surface area of silica is a value measured by the BET method according to ASTM D3037-81.

When the silica is contained, the content is preferably 5 parts by mass or more, and more preferably 7 parts by mass or more with respect to 100 parts by mass of the rubber component. When the silica content is less than 5 parts by mass, the elongation at break is lowered and the durability tends to be lowered. In addition, fuel efficiency tends to deteriorate. The silica content is preferably 17 parts by mass or less, more preferably 15 parts by mass or less, and further preferably 13 parts by mass or less. When the silica content exceeds 17 parts by mass, the dispersibility tends to decrease and the complex elastic modulus E * tends to decrease. In addition, silica tends to reaggregate during heating during rolling and during storage after rolling, resulting in deterioration of workability.

(Organic fiber)
The various organic fibers used in the organic fiber / rubber composition composite of the present disclosure include tires; various hoses; and reinforcing materials such as belts for transmitting rotation of timing belts, conveyor belts, V-belts and the like. Examples include commonly used fibers. Examples of the fiber type include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; vinylon fibers; aramid fibers; and polyurethane fibers.

Among these organic fibers, since the organic fiber / rubber composition composite has excellent resistance to load and impact, polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber are selected. It is preferable to use at least one selected from the group.

Among these organic fibers, since the organic fiber / rubber composition composite has excellent resistance to load and impact, polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber are selected. It is preferable to use one kind alone or two or more kinds of composite organic fibers selected from the group. In particular, from the viewpoint of ensuring workability when molding an organic fiber / rubber composition composite or a tire using the organic fiber / rubber composition composite, it is possible to use two or more kinds of composite organic fibers. preferable.

The form of these organic fibers is not particularly limited, and examples thereof include filament yarns, cords, woven fabrics, and woven fabrics. The cord may be formed by twisting one or more filament yarns together.

As the cord made of polyester fiber (polyester cord), for example, i) 2 or 3 multifilaments of 1100 decitex are combined (in other words, 1100/2 decitex or 1100/3 decitex), 10 to 60 times. After twisting / 10 cm, the two lower twist cords are combined and the same number of upper twists are applied in the opposite direction to the lower twist (intermediate elongation 4.30% when a constant load of 44 N is applied). , Ii) Two 1670 decitex multifilaments are combined (in other words, 1670/2 decitex), twisted 20 to 50 times / 10 cm, and then the two lower twist cords are combined to oppose the lower twist. The same number of upper twists in the direction (intermediate elongation 4.30% when a constant load of 66 N is applied) can be used. The intermediate elongation can be determined in accordance with the test method of "elongation rate under constant load" of JIS L1017.

As a cord made of nylon fiber (nylon cord), for example, i) two 940 decitex multifilaments are combined (in other words, 940/2 decitex), twisted 31 to 48 times / 10 cm, and then twisted. These two lower twist cords are combined and the same number of upper twists are applied in the opposite direction to the lower twist (intermediate elongation 8.80% when a constant load of 44 N is applied), or ii) 1400 decitex multifilament. Two of each are combined (in other words, 1400/2 decitex), twisted 30 to 51 times / 10 cm, and then the two lower twist cords are combined and the same number of upper twists are applied in the opposite direction to the lower twist. (Intermediate elongation 8.80% when a constant load of 66 N is applied) can be used.

As a cord made of rayon fiber (rayon cord), for example, two 1840 decitex multifilaments are combined (in other words, 1840/2 decitex), twisted 20 to 50 times / 10 cm, and then twisted. A combination of two lower twist cords and the same number of upper twists in the opposite direction to the lower twist (intermediate elongation 4.80% when a constant load of 44 N is applied) can be used.

As the cord made of aramid fiber (aramid cord), for example, two or three aromatic polyamide multifilaments (Kevlar manufactured by DuPont) of 1670 decitex are combined (in other words, 1670/2 decitex or 1670 /). (3 decitex), after twisting 30 to 78 times / 10 cm, the two lower twist cords are combined and the same number of upper twists are applied in the opposite direction to the lower twist (intermediate when a constant load of 44 N is applied). Elongation 0.7-1.5%) can be used.

As the cord composed of polyester fiber and nylon fiber (polyester-nylon hybrid cord), for example, two 1440 decitex polyester multifilaments and 1440 decitex nylon multifilaments are combined (in other words, 1440-P / 1400-N decitex). ), After twisting 30 to 38 times / 10 cm, the two lower twist cords are combined and the same number of upper twists are applied in the opposite direction to the lower twist (intermediate elongation when a constant load of 44 N is applied). 4.40%, intermediate elongation 6.30% when a constant load of 66N is applied) can be used.

As the cord composed of aramid fiber and nylon fiber (aramid-nylon hybrid cord), for example, two 1100 decitex aramid multifilaments and 940 decitex nylon multifilaments are combined (in other words, 1100-K / 940-N decitex). ), After twisting 42 times / 10 cm, the two lower twist cords are combined and the same number of upper twists are applied in the direction opposite to the lower twist (intermediate elongation when a constant load of 44 N is applied). 60%) can be used.

[Production method]
In the organic fiber / rubber composition composite of the present disclosure, the organic fiber is composed of (a) a sorbitol polyglycidyl ether and an epoxy compound having a chlorine content of 9.6% by mass or less, and (b) a blocked isocyanate. It can be obtained by treating with the containing organic fiber adhesive composition and adhering to the rubber composition.

(Treatment with an adhesive composition for organic fibers)
The treatment of organic fibers with the organic fiber adhesive composition includes a treatment performed for adhering various components contained in the organic fiber adhesive composition to the organic fibers and a subsequent heat treatment.

As the adhesion method, for example, any method such as coating using a roller, spraying from a nozzle, or immersing in a bath liquid (adhesive composition for organic fibers) can be used. Immersion is preferable from the viewpoint of evenly adhering and removing excess adhesive. In other words, as a method for treating the organic fiber with the organic fiber adhesive composition, a dipping treatment is preferable.

Further, in order to adjust the amount of adhesion to the organic fiber, means such as squeezing with a pressure welding roller, scraping with a scraper, blowing off with air blowing, suction, and beating with a beater may be further adopted. In particular, it is preferable to further perform a drawing step using a pressure welding roller after the immersion.

As a heating method, for example, the organic fiber to which the adhesive composition for organic fibers is attached is dried at 100 ° C. or higher and 250 ° C. or lower for 1 minute or longer and 5 minutes or shorter, and then further dried at 150 ° C. or higher and 250 ° C. or lower for 1 minute or longer. A method of performing heat treatment in 5 minutes or less can be mentioned. The conditions for the heat treatment after the drying treatment are preferably 180 ° C. or higher and 240 ° C. or lower for 1 minute or longer and 2 minutes or shorter. In particular, in the heat treatment after the drying treatment, if the temperature is too low, the adhesive force to the rubber composition may be insufficient, and if it is too high, the organic fibers may be deteriorated, which may cause a decrease in strength. be.

The amount of the adhesive composition for organic fibers attached to the organic fibers is preferably 0.2% by mass or more and 1.8% by mass or less, and more preferably 0.5% by mass or more and 1.5% by mass or less. If it is less than 0.2% by mass, the amount of adhesion may be insufficient and sufficient adhesive strength may not be obtained. If it exceeds 1.8% by mass, the fibers become hard and the bending fatigue strength and the like become low. Because there is. Here, the unit [mass%] of the adhered amount is the mass of the solid content in the composition obtained with the mass of the organic fiber as 100.

The total solid content concentration of the adhesive composition for organic fibers is preferably 0.9% by mass or more and 8.1% by mass or less in order to prevent the obtained fibers from becoming too hard while obtaining sufficient adhesive strength. More preferably, it is 2.3% by mass or more and 6.5% by mass or less.

Further, in order to adjust the amount of adhesion to the organic fiber, means such as squeezing with a pressure welding roller, scraping with a scraper, blowing off with air blowing, suction, and beating with a beater may be further adopted.

(Adhesion with rubber composition)
In the adhesion between the organic fiber treated with the adhesive composition for organic fiber and the rubber composition, the organic fiber treated with the adhesive composition for organic fiber and the rubber composition are brought into contact with each other and heat-treated to obtain the rubber composition. It can be carried out by a cross-linking reaction. Examples of the conditions for this heat treatment include 1 minute or more and 15 minutes or less at 150 ° C. or higher and 200 ° C. or lower, 12 minutes or lower at 170 ° C. or the like.

(Epoxy compound)
The epoxy compound contained in the adhesive composition for organic fibers is a compound having an epoxy group in the molecule. Sorbitol polyglycidyl ether is used as the epoxy compound. As the sorbitol polyglycidyl ether, sorbitol diglycidyl ether, sorbitol triglycidyl ether, sorbitol tetraglycidyl ether, sorbitol pentaglycidyl ether, sorbitol hexaglycidyl ether, or a mixture thereof can be used, and sorbitol monoglycidyl ether is included. May be. Since the sorbitol polyglycidyl ether has a large number of epoxy groups in one molecule and can form a high crosslinked structure, the adhesive composition for organic fibers has excellent adhesiveness.

The epoxy compound has a chlorine content of 9.6% by mass or less, preferably 9.5% by mass or less, more preferably 9.4% by mass or less, and further preferably 9.3% by mass or less. The lower limit value is not particularly limited, but may be, for example, 1% by mass or more.

The lower chlorine content in the epoxy compound increases the purity of the epoxy groups in the epoxy compound and enhances the reactivity of the epoxy compound with isocyanates. Therefore, more excellent heat-resistant adhesiveness can be obtained.

Further, by increasing the purity of the epoxy group in the epoxy compound, the viscosity of the adhesive composition for organic fibers is lowered, so that the permeability to the organic fibers is enhanced. Therefore, when the organic fiber is to be adhered to the rubber composition, the contact between the amine compound contained in the rubber composition and the organic fiber, which is one of the causes of the decrease in the adhesive force at high temperature, can be reduced, and the organic fiber can be organic. Deterioration of fibers can be suppressed. As a result, more excellent heat-resistant adhesiveness can be obtained.

The chlorine content in the epoxy compound can be determined by the method described in JIS K 7243-3 or the like.

The chlorine content of the epoxy compound can be reduced by reducing the amount of epichlorohydrin used when synthesizing the epoxy compound.

(Blocked isocyanate)
The blocked isocyanate contained in the adhesive composition for organic fibers is a compound produced by a reaction between an isocyanate compound and a blocking agent and temporarily inactivated by a group derived from the blocking agent, and is heated at a predetermined temperature. Then, the group derived from the blocking agent is dissociated to generate an isocyanate group.

As the isocyanate compound, a compound having two or more isocyanate groups in the molecule can be used. Examples of the diisocyanates having two isocyanate groups include hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, phenylenedi isocyanate, tolylene diisocyanate, trimethylhexamethylene diisocyanate, metaphenylenedi isocyanate, naphthalenedi isocyanate, and diphenyl ether diisocyanate. Diphenylpropane diisocyanate, biphenyldiisocyanate, isomers thereof, alkyl substituents, halides, hydrogenated additives to the benzene ring and the like can be used. Further, triisocyanates having three isocyanate groups, tetraisocyanates having four isocyanate groups, polymethylenepolyphenylpolyisocyanate and the like can also be used. These isocyanate compounds can be used alone or in combination of two or more.

Among these, tolylene diisocyanate, metaphenylenedi isocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate are particularly easy to obtain industrially and have good heat-resistant adhesiveness of the obtained adhesive composition for organic fibers after treatment. , Polymethylene polyphenyl polyisocyanate is preferred.

Examples of the blocking agent include lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-propiolactam; phenol-based agents such as phenol, cresol, resorcinol and xylenol; methanol, ethanol, n-propyl alcohol and isopropyl. Alcohols such as alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and benzyl alcohol; Oxime-based substances such as acetoxime, methylethylketoxim, diacetylmonooxime, benzophenone oxime, and cyclohexanone oxime; active methylene-based substances such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, and acetylacetone can be mentioned. Of these, lactam-based, phenol-based, and oxime-based blocking agents are preferable because they rapidly dissociate from the isocyanate compound at a relatively low temperature.

The content of blocked isocyanate in the adhesive composition for organic fibers is preferably 50 parts by mass or more and 500 parts by mass or less, and more preferably 200 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the epoxy compound. Within this range, better heat-resistant adhesiveness between the organic fiber and the rubber composition can be obtained. If it is less than 50 parts by mass, the cross-linking may be insufficient, which may cause deterioration of adhesive strength and heat resistance, and if it exceeds 500 parts by mass, the fiber may become too hard or the fatigue resistance may be lowered. Therefore, it is not preferable. The content of the blocked isocyanate can be appropriately adjusted depending on the type of the rubber composition to which the organic fiber is to be adhered.

(Optional component of adhesive composition for organic fibers)
The adhesive composition for organic fibers may contain the following optional components, if necessary, within a range that does not interfere with the object and effect of the present invention. For example, epoxy compounds other than sorbitol polyglycidyl ether, resins copolymerizable with sorbitol polyglycidyl ether, curing agents other than blocked isocyanate, organic thickeners, antioxidants, light stabilizers, adhesive enhancers, reinforcing agents. , Softeners, colorants, leveling agents, flame retardants, antistatic agents and the like.

Examples of epoxy compounds other than sorbitol polyglycidyl ether include ethylene glycol glycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, novolak glycidyl ether, and the like. And glycidyl ethers such as brominated bisphenol A diglycidyl ether; glycidyl esters such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester; triglycidyl isocyanurate, glycidyl hindantin, tetraglycidyl diaminodiphenylmethane, triglycidyl paraaminophenol, Glycidyl amines such as triglycidyl metaaminophenol, diglycidyl aniline, diglycidyl toluidin, tetraglycidyl metaxylene diamine, diglycidyl tribromaniline, and tetraglycidyl bisaminomethylcyclohexane; and 3,4-epoxycyclohexylmethylcarboxylate, epoxy. Examples thereof include alicyclic groups such as polybutadiene and epoxidized soybean oil, or aliphatic epoxisides.

(Treatment with a second treatment agent)
In the organic fiber / rubber composition composite of the present disclosure, as described above, the organic fiber is (a) an epoxy compound which is a sorbitol polyglycidyl ether and has a chlorine content of 9.6% by mass or less, and (b) a block. It is obtained by treating with an adhesive composition for organic fibers containing diisocyanate and adhering to a rubber composition. In the treatment, the adhesive composition for organic fibers is used as a first treatment agent, and further, the first treatment agent is used. (Ii) It may be treated with a treatment agent.

The processing method in that case can be shown as follows. (1) A step of treating the organic fiber with the adhesive composition for organic fiber as the first treatment agent; and (2) the organic fiber treated with the first treatment agent containing resorcin, formalin, and rubber latex (RFL). (2) The process of treating with a treatment agent.

(1) The step of treating the organic fiber with the organic fiber adhesive composition as the first treatment agent is as described above.

(2) The step of treating the organic fiber treated with the first treatment agent with the second treatment agent containing resorcin, formalin, and rubber latex (RFL) will be described in detail.

The second treatment agent is a composition containing resorcin, formalin, and rubber latex (RFL).

Resorcin formalin rubber latex (RFL) can be prepared by mixing and aging an initial condensate of resorcin and formalin and rubber latex.

The initial condensate of resorcin and formalin is obtained by reacting resorcin monomer and formaldehyde monomer in water in the presence of an acidic catalyst such as hydrochloric acid or sulfuric acid, an alkali metal hydroxide such as sodium hydroxide, or ammonia to condense them. can get.

As the initial condensate, the molar ratio of resorcin monomer to formaldehyde monomer is preferably 1: 0.1 to 1: 8, more preferably 1: 0.5 to 1: 5, and even more preferably 1: 1 to 1: 4. ..

As the rubber latex, natural rubber latex, styrene / butadiene copolymer latex, styrene / butadiene / vinylpyridine copolymer latex and the like can be used. In resorcin / formalin / rubber latex (RFL), the ratio of the initial condensate of resorcin and formalin to the rubber latex is preferably 1: 1 to 1:15, more preferably 1: 3 to 1:12 in terms of solid content ratio. preferable.

These can be used alone or as a mixture of two or more. In particular, styrene-butadiene-vinylpyridine copolymer latex is preferable because high adhesive strength can be obtained for natural rubber and SBR (styrene-butadiene rubber).

The initial condensate of resorcin and formalin can contain a resorcin monomer, a formaldehyde monomer, a trace amount of a molecular weight modifier (for example, calcium chloride, etc.), a solvent (for example, MEK: methyl ethyl ketone, etc.) and the like.

Treatment of organic fibers treated with the first treatment agent with a second treatment agent containing resorcin, formalin, and rubber latex (RFL) is to attach the second treatment agent to the organic fibers treated with the first treatment agent. This treatment can be performed by the same means and conditions as when treating organic fibers with the first treatment agent. Even in the case of treatment with the second treatment agent, as an adhesion method, adhesion by immersion is preferable from the viewpoint of uniformly adhering and removing excess adhesive.

Further, in order to adjust the amount of adhesion to the cord, means such as squeezing with a pressure welding roller, scraping with a scraper, blowing off with air blowing, suction, and beating with a beater may be further adopted. In particular, it is preferable to further perform a drawing step using a pressure welding roller after the immersion.

The amount of the second treatment agent attached to the organic fiber is preferably 1.0% by mass or more and 3.0% by mass or less, and more preferably 1.5% by mass or more and 2.5% by mass or less. If it is less than 1.0% by mass, the amount of adhesion is small and the adhesive strength may be insufficient, and if it exceeds 3.0% by mass, the fibers may become hard and the bending fatigue strength may decrease. be. The amount [mass%] of the second treatment agent attached to the organic fiber indicates the mass of the solid content in the second treatment agent obtained with the mass of the organic fiber as 100.

The total solid content concentration of the second treatment agent is preferably 0.9% by mass or more and 29% by mass or less, preferably 14% by mass or more, in order to prevent the obtained fibers from becoming too hard while obtaining sufficient adhesive strength. More preferably, it is 23% by mass or less.

In addition to the initial condensate of resorcin and formalin and rubber latex, a vulcanization adjuster, zinc oxide, an antioxidant, an antifoaming agent and the like may be added to the second treatment agent.

[Use]
The organic fiber / rubber composition composite of the present disclosure can be used as a tire, various hoses, belts for transmitting rotation, and the like. Specifically, for example, the organic fiber may be provided inside a tire, various hoses, or belts for transmitting rotation. Organic fibers can be used as these reinforcing materials.

The organic fiber / rubber composition composite of the present disclosure is exposed to high temperature for a long time because the organic fiber and rubber composition can maintain high adhesive strength and have excellent heat-resistant adhesiveness even when exposed to high temperature. It can be preferably used for tires used in the environment. In particular, it is preferably used as a jointless band, carcass ply, filler or the like of a tire.

As will be described later, the jointless band is a member provided on the outer side of the breaker in the radial direction of the tire in order to prevent the breaker (also referred to as a belt) from floating from the carcass due to the centrifugal force caused by the rotation of the tire when the vehicle is running. .. The breaker is a member arranged inside the tread of the tire and outside the radial direction of the carcass.

The carcass ply or carcass is a member arranged inside the tread of a tire and outside in the radial direction of the inner liner. Here, in particular, a carcass composed of one or more carcass plies is referred to as a carcass. The inner liner is a member formed so as to form a tire lumen surface, and this member can reduce the amount of air permeation and maintain the tire internal pressure.

The chafer is a member located at the bead portion of the tire, which abuts on the rim of the wheel and protects the carcass ply or carcass inside the tire from friction with the rim.

The filler is a member arranged on the bead portion of the tire to increase the rigidity of the bead portion.

An example of the embodiment of the tire using the organic fiber of the present disclosure will be described in detail with reference to the drawings. FIG. 1 shows a pneumatic tire 2. In FIG. 1, the vertical direction is the radial direction of the tire 2, the left-right direction is the rotation axis direction of the tire 2, and the direction perpendicular to the paper surface is the circumferential direction of the tire 2. In FIG. 1, the alternate long and short dash line CL represents the equatorial plane of the tire 2. The shape of the tire 2 is symmetrical with respect to the equatorial plane except for the tread pattern.

The tire 2 includes a tread 4, a pair of sidewalls 6, a pair of chafers 7, a pair of beads 8, an inner liner 9, a carcass 10, a breaker (also called a belt) 12, a pair of fillers 13, and a jointless band 14. It is equipped with. This tire 2 is a tubeless type. The tire 2 is mounted on a passenger car.

The tread 4 has a shape that is convex outward in the radial direction. The tread 4 forms a tread surface 16 that is in contact with the road surface. A groove 18 is carved in the tread 4. The tread pattern is formed by the groove 18. The tread 4 is made of crosslinked rubber having excellent wear resistance and grip.

Each sidewall 6 extends substantially inward in the radial direction from the end of the tread 4. The radial outer edge of the sidewall 6 is joined to the tread 4. The sidewall 6 is made of crosslinked rubber having excellent cut resistance and weather resistance.

Each chafer 7 is located in the vicinity of the bead 8. When the tire 2 is incorporated into the rim (which is part of the wheel and where the tires are combined, not shown), the chafer 7 comes into contact with the rim. This contact protects the vicinity of the bead 8.

The form of the organic fiber used in the chafer 7 is a cord. The chafer 7 is configured by treating the cord with an organic fiber adhesive composition and adhering it to the rubber composition. Preferred organic fibers include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

Each bead 8 is located axially inside the sidewall 6. The bead 8 has a core 20 and an apex 22 extending radially outward from the core 20. The core 20 is ring-shaped and contains a wound non-stretchable wire. A typical material for wire is steel. Apex 22 is tapered outward in the radial direction. Apex 22 is made of high hardness crosslinked rubber.

The inner liner 9 is formed so as to form a tire lumen surface. The inner liner 9 is formed of a crosslinked rubber that suppresses air permeability.

The carcass 10 is composed of two plies, a carcass ply 10a and a carcass ply 10b. The carcass ply 10a and the carcass ply 10b are bridged between the beads 8 on both sides and run along the tread 4 and the sidewall 6. The carcass ply 10a and the carcass ply 10b are folded back from the inside to the outside in the axial direction around the core 20. The carcass ply 10a and the carcass ply 10b are each composed of a large number of cords and topping rubbers arranged in parallel in the circumferential direction. The absolute value of the angle each code makes with respect to the equatorial plane is 75 ° to 90 °. In other words, the carcass ply 10a and the carcass ply 10b have a radial structure. Further, the carcass 10 may be formed of one or three or more carcass plies in addition to the two.

The form of the organic fiber used in the carcass ply 10a and the carcass ply 10b is a cord. The carcass ply 10a and the carcass ply 10b are each composed by treating the cord with an adhesive composition for organic fibers and adhering the cord to the rubber composition. Preferred organic fibers include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

Even when the organic fiber / rubber composition composite is used as the carcass ply 10a and the carcass ply 10b of the tire, the pull-out adhesive force has 120 N / cm or more.

When the organic fiber / rubber composition composite is used as the carcass ply 10a and the carcass ply 10b of the tire, the organic fibers of the carcass ply 10a and the carcass ply 10b are cut out or not cut out. The edge can be exposed and the pull-out adhesive force (N / cm) can be measured.

The breaker (also referred to as a belt) 12 is located inside the tread 4 in the radial direction. The belt 12 is laminated with the carcass 10. The breaker (also referred to as a belt) 12 reinforces the carcass 10. The breaker (also referred to as a belt) 12 is composed of an inner layer 24 and an outer layer 26. As is clear from FIG. 1, the width of the inner layer 24 is slightly larger than the width of the outer layer 26 in the axial direction. Although not shown, each of the inner layer 24 and the outer layer 26 consists of a large number of parallel cords and topping rubbers. Each code is tilted with respect to the equatorial plane. The general absolute value of the tilt angle is 10 ° or more and 35 ° or less. The direction of inclination of the cord of the inner layer 24 with respect to the equatorial plane is opposite to the direction of inclination of the cord of the outer layer 26 with respect to the equatorial plane. As the cord, an organic fiber may be used in addition to the steel cord.

Each filler 13 is arranged on the bead portion of the tire. Each filler consists of a number of parallel cords and topping rubber.

The form of the organic fiber used in the filler 13 is a cord. The filler 13 is configured by treating the cord with an organic fiber adhesive composition and adhering it to the rubber composition. Preferred organic fibers include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

Even when the organic fiber / rubber composition composite is used as the filler 13 of the tire, the pull-out adhesive force has 120 N / cm or more.

When the organic fiber / rubber composition composite is used as the filler 13 of the tire, the end of the organic fiber of the filler 13 is exposed without cutting out a part of the tire or cutting it out, and the pull-out adhesive force (N). / Cm) can be measured.

The jointless band 14 is located radially outside the breaker (also referred to as a belt) 12. In the axial direction, the width of the jointless band 14 is larger than the width of the breaker (also referred to as a belt) 12. The jointless band 14 reinforces the breaker (also referred to as a belt) 12.

FIG. 2 shows the ribbon 28 constituting the jointless band 14. The ribbon 28 has two cords 30 and a topping rubber 32. The ribbon 28 is configured by treating the cord 30 with an organic fiber adhesive composition and adhering it to the topping rubber 32. The ribbon 28 is spirally wound in the circumferential direction to form a jointless band 14. The jointless band 14 has a so-called jointless structure. Each cord 30 extends substantially in the circumferential direction. The angle of the cord 30 with respect to the circumferential direction is preferably 5 ° or less, and particularly preferably 2 ° or less. Since the breaker (also referred to as a belt) 12 is restrained by this code 30, the lifting of the breaker (also referred to as a belt) 12 is suppressed. The number of cords 30 in the ribbon 28 may be one or three or more.

Each cord 30 is formed by twisting a plurality of organic fibers. The tire including this code 30 is excellent in heat resistance and durability. Preferred organic fibers forming the cord 30 include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

Even when the organic fiber / rubber composition complex is used as the jointless band 14, the pull-out adhesive force has 120 N / cm or more.

When the organic fiber / rubber composition composite is used as the jointless band 14, the end of the organic fiber of the jointless band 14 is exposed without cutting out or cutting out a part of the tire, and the pull-out adhesive force is obtained. (N / cm) can be measured.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The adhesiveness in the examples and comparative examples was evaluated by the following method.
<Pull-out adhesive strength>
The treated organic fiber was embedded in uncrosslinked rubber containing natural rubber as a main component at a depth of 1 cm from the surface, and press-crosslinked at 170 ° C. for 12 minutes. The obtained organic fiber / rubber composition composite is heat-treated at 180 ° C. for 60 minutes using a heating oven to expose the ends of the organic fibers from the composite, and the ends of the organic fibers are exposed on one side of the tensile tester. The composite was grabbed by a gripper and the composite was grabbed by the other gripper and pulled at a rate of 100 mm / min until the organic fibers were removed from the composite. The force required for the tension was shown as the force per unit length of the organic fiber (N / cm), and this was taken as the pull-out adhesive force (N / cm).

The composition of the uncrosslinked rubber containing the natural rubber as a main component is as follows.
TSR20 as natural rubber (TSR is an abbreviation for Technically Specitied Rubber): 60 parts by mass SBR 1502: 40 parts by mass as styrene-butadiene rubber "Cist 300" as a reinforcing agent (manufactured by Tokai Carbon Co., Ltd.): 50 parts by mass Mineral oil as a softener : 2 parts by mass "ROBO RD" (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.): 1 part by mass Stealic acid: 3 parts by mass Zinc oxide: 6 parts by mass Powdered sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd.): 4 Parts by mass "Noxeller NS" (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd .: N-tert-butyl-2-benzothiazolyl sulphenamide): 1.0 part by mass

(Example 1)
As an epoxy compound, add 11.8 g of ETC-N615 (sorbitol polyglycidyl ether, chlorine content: 9.3% by mass, epoxy equivalent: 163, manufactured by Nagase ChemteX Corporation) to 920 g of water with stirring, and block there. As a diisocyanate, 72.1 g of an aqueous dispersion of ε-caprolactam block diphenylmethane diisocyanate (54% concentration) was added to prepare an adhesive composition for organic fibers as a first treatment agent.

As rubber latex, 172 g of Nipponol 2518FS (Nippon Zeon Co., Ltd., vinyl pyridine, styrene, butadiene tarpolymer water emulsion, total solid content concentration 40.5%) and Nippon Zeon LX-112 (Nippon Zeon Co., Ltd., styrene, butadiene) 73 g of copolymer 41% hydroemulsified solution, total solid content concentration 40.5%) was diluted with 76 g of water, and 270 g of resorcin formalin initial condensation dispersion (molar ratio of resorcin and formaldehyde) was added to this diluted solution as resorcin formarin. 1: 1.5, total solid content concentration 6.5%) was added while slowly stirring to prepare an RFL solution. The obtained RFL solution was diluted with 591 g of water to obtain a second treatment agent (total solid content concentration: 10%).

Polyester (polyethylene terephthalate (PET)) cord as organic fiber (cord composition: 1100/2 (decitex), number of twists of cord: 26 (times / 10 cm), wire diameter: 0.54 mm, ends: 49/5 cm) Was dipped in the first treatment agent, dried at 150 ° C. for 130 seconds, and subsequently heat-treated at 240 ° C. for 130 seconds. Then, after immersing in the second treatment agent, it was dried at 150 ° C. for 130 seconds, and then heat-treated at 240 ° C. for 70 seconds. The pull-out adhesive strength of the treated polyester cord (organic fiber) was measured. The results are shown in Table 1. In addition, the end means the number of cords (number of drives) arranged in the arrangement direction when the cords are arranged in parallel within a certain width, and the unit [book / 5 cm] is the fixed number. It is a unit indicating the number of cords when the width is 5 cm.

(Comparative Example 1)
Organic as in Example 1 except that EX-614B (sorbitol polyglycidyl ether, chlorine content: 10.1% by mass, epoxy equivalent: 173, manufactured by Nagase ChemteX Corporation) was used as the epoxy compound. The fibers were processed. The pull-out adhesive strength of the treated polyester cord (organic fiber) was measured. The results are shown in Table 1.

(Comparative Example 2)
Nylon cord (cord composition: 940 (decitex), cord twist number: 31 to 48 (times / 10 cm), wire diameter: 0.95 mm, ends: 43 to 49 lines / 5 cm) is used as the organic fiber as the second treatment agent. After soaking in, it was dried at 150 ° C. for 130 seconds and heat-treated at 240 ° C. for 70 seconds. The pull-out adhesive strength of the treated nylon cord (organic fiber) was measured. The results are shown in Table 1.

As shown in Comparative Examples 1 and 2, the conventional organic fiber / rubber composition complex has a low pull-out adhesive force (Comparative Example 1: 105 N / cm, Comparative Example 2: 110 N / cm). On the other hand, as shown in Example 1, the organic fiber / rubber composition complex of the present disclosure has a very excellent pull-out adhesive force even when exposed to a high temperature (Example 1: 125 N / cm).

Claims (5)

The pull-out adhesive force by the following measurement method is 120 N / cm or more, and the organic fiber and the rubber composition are integrated .
The organic fiber is immersed in an adhesive composition for organic fiber containing (a) a sorbitol polyglycidyl ether and an epoxy compound having a chlorine content of 9.6% by mass or less, and (b) a blocked isocyanate. Organic fiber / rubber composition composite .
The organic fiber / rubber composition composite is heat-treated at 180 ° C. for 60 minutes, and the organic fibers embedded at a depth of 1 cm from the surface of the composite are removed from the composite at a rate of 100 mm / min. It is pulled until it comes off, and the force required for the pull is defined as the pull-out adhesive force (N / cm). The organic fiber according to claim 1, wherein the organic fiber is at least one selected from the group consisting of polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber. -Rubber composition composite. The organic fiber is one or more composite organic fibers selected from the group consisting of polyethylene terephthalate (PET) fiber, polyethylene naphthalate (PEN) fiber, nylon fiber, aramid fiber, and rayon fiber. The organic fiber / rubber composition composite according to claim 1 or 2. The rubber composition contains a rubber component and contains a rubber component.
The organic fiber / rubber composition composite according to any one of claims 1 to 3 , wherein the content of the polyisoprene-based rubber is 0 to 70% by mass in 100% by mass of the rubber component. A tire using the organic fiber / rubber composition complex according to any one of claims 1 to 4 as a jointless band, a carcass ply, or a filler.

Images