JP7087586B2 - Method for manufacturing cord / rubber composition complex, tire and cord / rubber composition complex - Google Patents

Description

The present invention relates to a cord-rubber composition complex, a tire, and a method for producing a cord-rubber composition composite.

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

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. Under such circumstances, the present invention provides a cord-rubber composition composite having excellent heat-resistant adhesiveness, in which the cord and the rubber composition can maintain high adhesive strength even when exposed to high temperatures. The task is to do.

The first of the present invention is to treat a cord made of organic fibers with an adhesive composition while applying a tension of 6.8 × ^10-2 N / tex or less, and to treat with the adhesive composition. The cord obtained by coating the cord with a rubber composition and treated with the adhesive composition has a cord made of organic fibers and a rubber composition having an elastic modulus of 6000 MPa or more at 2% elongation. It relates to a cord-rubber composition composite in which an object is integrated.

The adhesive composition preferably contains an epoxy compound having a weight average molecular weight of 600 or more.

It is preferable that the organic fiber is a polyester fiber.

The second aspect of the present invention relates to a tire using the cord-rubber composition complex as a jointless band.

The third aspect of the present invention is to treat a cord made of organic fibers with an adhesive composition while applying a tension of 6.8 × ^10-2 N / tex or less, and to treat with the adhesive composition. The cord having the cord coated with a rubber composition and having been treated with the adhesive composition has a cord made of organic fibers and a rubber composition having an elastic modulus of 6000 MPa or more at the time of 2% elongation. A method for producing an integrated cord / rubber composition composite.

The treatment with the adhesive composition is preferably to treat the cord composed of the organic fiber with an adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate. ..

The treatment with the adhesive composition is an adhesive composition containing (1) a first treatment agent, (a) a sorbitol polyglycidyl ether as an epoxy compound, and (b) a blocked isocyanate, and is a cord composed of the organic fibers. It is preferable that the cord made of the organic fiber treated with (2) the first treatment agent is treated with a second treatment agent containing a isocyanate, formalin, and rubber latex (RFL).

According to the present invention, it is possible to obtain a cord-rubber composition complex having excellent heat-resistant adhesiveness, in which the cord and the rubber composition can maintain a high adhesive strength even when exposed to a high temperature.

It is a figure which shows an example of the processing method by the adhesive composition of the cord made of organic fibers. 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.

[Cord / rubber composition complex]
Hereinafter, an example of a preferred embodiment of the present invention will be specifically described. In the cord-rubber composition composite of the present disclosure, a cord made of organic fibers is treated with an adhesive composition while applying a tension of 6.8 × 10 ^-2- N / tex or less, and the adhesive composition is described. The cord treated with the above-mentioned adhesive composition is obtained by coating the cord with a rubber composition, and the cord treated with the adhesive composition has an elastic modulus of 6000 MPa or more at 2% elongation.

The elastic modulus at 2% elongation can be measured by the following method. The test is carried out by the same method as the measurement of the tensile strength and the elongation rate specified in JIS L 1017, and the tangential slope at the time of 2% elongation is calculated in the obtained load-elongation curve.

Further, the cord / rubber composition composite means a cord made of organic fibers and a rubber composition in a state of being integrated by adhesion or the like.

(code)
The cord used in the cord-rubber composition complex of the present disclosure consists of organic fibers. The cord refers to a cord obtained by twisting one or more filament yarns, for example, tires; various hoses; and belts for transmitting rotation of timing belts, conveyor belts, V-belts, etc. Examples include cords commonly used as reinforcements.

Examples of the type of organic fiber fiber include polyester fiber such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fiber; rayon fiber; vinylon fiber; aramid fiber; and polyurethane fiber.

Among these organic fibers, polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferably used because of their relatively high elastic modulus.

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 44N 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.

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

As the rubber component, a conjugate of natural rubber, polyisoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR) and the like. Diene-based polymers; and non-diene-based polymers such as ethylenepropylene diene rubber (EPDM), butyl rubber (IIR), and halide butyl rubber (X-IIR) 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 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) such as BR, 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, 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.

(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 enhancer such as sulfur and carbon black; clay, as long as the object and effect of the present invention are not impaired. Reinforcing fillers such as, silane coupling agents, stearic acid, zinc oxide, various antioxidants, oils such as aroma oils, waxes, vulcanization accelerators, vulcanization accelerator aids and the like can be appropriately blended.

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 carbon black N ₂ SA 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 reduced complex elastic modulus, and sufficient elongation at break cannot be obtained and 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.

(Treatment with adhesive composition)
First, the treatment with the adhesive composition while applying a tension of 6.8 × 10 ^-2- N / tex or less to the cord made of organic fibers will be described in detail.

The tension applied to the cord is 6.8 × 10 ^-2 N / tex or less, preferably 6.5 × 10 ^-2 N / tex or less, and more preferably 6.0 × 10 ^-2 N / tex or less. It is more preferably 5.7 × 10 ^-2 N / tex or less, and most preferably 4.5 × 10 ^-2 N / tex or less. The lower limit is not particularly limited, but may be, for example, 3.5 × ^10-2 N / tex or more from the viewpoint of stabilizing the blind shape during cord manufacturing.

By applying such tension to the cord, the degree of penetration of the adhesive composition into the cord can be increased, so that the cord and the rubber composition have high adhesive strength and also have excellent heat-resistant adhesiveness. -A rubber composition composite can be obtained.

As a method of applying tension to the cord, for example, a speed difference may be applied to a plurality of rollers.

The treatment with the adhesive composition includes a treatment performed for adhering various components contained in the adhesive composition to a cord made of 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) can be used. Adhesion by immersion is preferable from the viewpoint of evenly 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.

As a heating method, for example, the cord to which the adhesive composition is attached is dried at 100 ° C. or higher and 250 ° C. or lower for 1 minute or more and 5 minutes or less, and then further dried at 150 ° C. or higher and 250 ° C. or lower for 1 minute or longer and 5 minutes or shorter. Examples thereof include a method of performing heat treatment. 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 may be insufficient, and if it is too high, the cord may be deteriorated, which may cause a decrease in strength.

(Adhesive composition)
The adhesive composition is not particularly limited, but preferably contains an epoxy compound having a weight average molecular weight of 600 or more. This is because a cord having a high elastic modulus can be obtained by using a high molecular weight epoxy.

The weight average molecular weight of the epoxy compound is preferably 900 or more, more preferably 1000 or more. The upper limit of the weight average molecular weight is not particularly limited, but it may be 3000 or less because the viscosity of the aqueous solution increases with the increase in molecular weight and it becomes difficult to control the adhered amount and clean the equipment. Within this range, the elastic modulus of the cord treated with the adhesive composition at 2% elongation can be increased.

The weight average molecular weight of the epoxy compound can be measured by polystyrene conversion gel permeation chromatography (GPC).

The epoxy compound 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. Sorbitol polyglycidyl ether has a large number of epoxy groups in one molecule and can form a high crosslinked structure, so that it has excellent adhesiveness.

The treatment with the adhesive composition may be to treat a cord composed of organic fibers with an adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate.

Blocked isocyanate is a compound that is produced by the reaction of an isocyanate compound and a blocking agent and is temporarily inactivated by a group derived from the blocking agent. When heated at a predetermined temperature, the group derived from the blocking agent dissociates. , Produces an isocyanate group.

As the isocyanate compound, a compound having two or more isocyanate groups in the molecule can be used. Examples of 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, hexamethylene diisocyanate, and polymethylene are particularly easy to obtain industrially and have good heat-resistant adhesiveness of the obtained adhesive composition after treatment. Polyphenylpolyisocyanate 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 the blocked isocyanate in the adhesive composition of the present disclosure 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, excellent heat-resistant adhesiveness between the cord and rubber can be obtained. If it is less than 50 parts by mass, the cross-linking may be insufficient, which may cause a decrease in adhesive strength and heat resistance, and if it exceeds 500 parts by mass, the cord may become too hard or the fatigue resistance may decrease. Therefore, it is not preferable. The content of the blocked isocyanate can be appropriately adjusted depending on the type of rubber to which the cord is to be adhered.

The adhesive composition 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.

The amount of the adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate is preferably 0.2% by mass or more and 1.8% by mass or less, preferably 0. More preferably, it is 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 amount of adhesion of the adhesive composition to the cord may increase. This is because the cord may become too hard, or gel may form on the cord or processing device. Here, the unit [mass%] of the adhered amount is the mass of the solid content in the composition obtained with the mass of the cord as 100.

The total solid content concentration of the adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate is such that the obtained cord does not become too hard while obtaining sufficient adhesive strength. Therefore, it is preferably 0.9% by mass or more and 8.1% by mass or less, and more preferably 2.3% by mass or more and 6.5% by mass or less.

The treatment with the adhesive composition is carried out after treating the code with an adhesive composition containing (1) a first treatment agent, (a) a sorbitol polyglycidyl ether as an epoxy compound, and (b) a blocked isocyanate. (2) The code treated with the first treatment agent may be treated with a second treatment agent containing resorcin, formarin, and rubber latex (RFL).

(1) As described above, the above-mentioned code is treated with an adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate as the first treatment agent.

(2) The step of treating the cord 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 formaldehyde 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.

Treating a cord treated with a first treatment agent with a second treatment agent containing resorcin, formalin, and rubber latex (RFL) is a treatment performed to attach the second treatment agent to the cord treated with the first treatment agent. Therefore, it can be carried out by the same means and conditions as when treating the cord 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 cord is preferably 1.0% by mass or more and 5.0% by mass or less, and more preferably 1.5% by mass or more and 3.5% 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 5.0% by mass, the cord may become hard and the bending fatigue strength may decrease. be. The amount [mass%] of the second treatment agent attached to the cord indicates the mass of the solid content in the second treatment agent obtained with the mass of the cord 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 cord 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.

An example of a treatment method using the adhesive composition of the cord made of the organic fiber of the present disclosure will be described in detail with reference to the drawings. FIG. 1 shows a series of steps for treating a cord made of organic fibers with an adhesive composition. In FIG. 1, while tensioning the cord by rollers r2 and roller r5 having different rotation speeds, the cord was put into the first dip bathtub DP1 as (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate. Immerse in an adhesive composition (first treatment agent) containing and. Next, the cord to which the adhesive composition (first treatment agent) is attached is dried and heat-treated by heaters (oven) H1 to H3.

After that, while tensioning the cord with rollers r27 and roller r46 having different rotation speeds, the cord is applied to a treatment agent (second treatment agent) containing resorcin, formalin, and rubber latex (RFL) in the second dip bathtub DP2. Soak. Next, the cord to which the treatment agent (second treatment agent) is attached is dried and heat-treated by heaters (oven) H4 to H6.

[Use]
The cord-rubber composition complex of the present disclosure can be used as a tire, various hoses, belts for transmitting rotation, and the like. Specifically, for example, the cord may be provided inside a tire, various hoses, or belts for transmitting rotation. The cord can be used as a reinforcing material for these.

The cord-rubber composition composite of the present disclosure is an environment exposed to high temperature for a long time because the cord and the 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. 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 carcass in the radial direction.

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 two or more carcass plies is called 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 an embodiment of a tire using the code of the present disclosure will be described in detail with reference to the drawings. FIG. 2 shows the pneumatic tire 2. In FIG. 2, 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. 2, 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 belt 12, a pair of fillers 13, and a jointless band 14. 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 (part of the wheel, 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 cord used for the chafer 7 consists of a cord treated with an adhesive composition. Preferred organic fibers used in the cord 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. The carcass 10 may be formed of one or three or more carcass plies in addition to the two.

The cord used for the carcass ply 10a and the carcass ply 10b consists of a cord treated with an adhesive composition. Preferred organic fibers used in the cord include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

The belt 12 is located inside the tread 4 in the radial direction. The belt 12 is laminated with the carcass 10. The belt 12 reinforces the carcass 10. The belt 12 is composed of an inner layer 24 and an outer layer 26. As is clear from FIG. 2, in the axial direction, the width of the inner layer 24 is slightly larger than the width of the outer layer 26. Although not shown, each of the inner layer 24 and the outer layer 26 consists of a 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 cord used for the filler 13 consists of a cord treated with an adhesive composition. A cord is formed by twisting a plurality of organic fibers. Preferred organic fibers used in the cord include polyester fibers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); nylon fibers; rayon fibers; and aramid fibers.

The jointless band 14 is located on the outer side in the radial direction of the belt 12. In the axial direction, the width of the jointless band 14 is larger than the width of the belt 12. The jointless band 14 reinforces the belt 12.

FIG. 3 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 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 belt 12 is restrained by this code 30, the lifting of the belt 12 is suppressed. The number of cords 30 in the ribbon 28 may be one or three or more.

Each cord 30 consists of a cord treated with an adhesive composition. The cord 30 is formed by twisting a plurality of organic fibers. The tire including the code 30 is excellent in heat resistance and durability. Preferred organic fibers forming the cord 30 include polyester fibers such as polyethylene naphthalate; nylon fibers; rayon fibers; and aramid fibers.

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.
<Initial adhesive strength>
The treated cord is embedded in unvulcanized rubber containing natural rubber as the main component, press vulcanized at 150 ° C. for 30 minutes, and then the cord is pulled out from the rubber block at a speed of 100 mm / min, and the force required for pulling out ( N / cm) was measured. The results were displayed as relative values (exponential) with the initial adhesive force (N / cm) of Comparative Example 1 as 100, and the adhesiveness was evaluated.

The composition of unvulcanized rubber containing natural rubber as a main component is as follows.
TSR20 as natural rubber (TSR is an abbreviation for Chemically Specialized Rubber): 60 parts by mass SBR 1502: 40 parts by mass as styrene-butadiene rubber "Seast 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

<Heat-resistant adhesive strength>
The treated cord is embedded in unvulcanized rubber containing natural rubber as the main component, press vulcanized at 170 ° C for 90 minutes, and then the cord is pulled out from the rubber block at a speed of 100 mm / min, and the force required for pulling out ( N / cm) was measured. The results were displayed as relative values (exponential) with the initial adhesive force (N / cm) of Comparative Example 1 as 100, and the adhesiveness was evaluated.

The composition of unvulcanized rubber containing natural rubber as a main component is as follows. TSR20 as natural rubber (TSR is an abbreviation for Chemically Specialized Rubber): 60 parts by mass SBR 1502: 40 parts by mass as styrene-butadiene rubber "Seast 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

<Elastic modulus at 2% elongation>
The test was carried out by the same method as the measurement of the tensile strength and the elongation rate specified in JIS L 1017, and the tangential slope at the time of 2% elongation was calculated in the obtained load-elongation curve.

(Example 1)
As an epoxy compound, 11.8 g of ETC-N615 (sorbitol polyglycidyl ether, weight average molecular weight 950, epoxy equivalent: 163, manufactured by Nagase ChemteX Corporation) was added to 920 g of water with stirring, and the blocked isocyanate was added thereto. 72.1 g of an aqueous dispersion of ε-caprolactam block diphenylmethane diisocyanate (54% concentration) was added to prepare an adhesive composition as a first treatment agent.

As rubber latex, 172 g of Nipponol 2518FS (Nippon Zeon Co., Ltd., vinyl pyridine, styrene, butadiene terpolymer hydroemulsified solution, 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 used as resorcin formalin in this diluted solution. 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 (cord configuration: 1100/2 (decitex), number of twists of cord: 26 (times / 10 cm), wire diameter: 0.54 mm, ends: 49/5 cm) as the cord After soaking in the first treatment agent, it was dried at 150 ° C. for 130 seconds and then 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. Adhesion of organic fiber cords with a tension of 5.7 × ^10-2 N / tex throughout the entire process of immersion in the first treatment agent, drying, heat treatment, immersion in the second treatment agent, drying, and heat treatment. Treatment with the agent composition was performed. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Example 2)
A cord made of organic fibers in the same manner as in Example 1 except that EX-614B (sorbitol polyglycidyl ether, weight average molecular weight 1020, epoxy equivalent: 173, manufactured by Nagase ChemteX Corporation) was used as the epoxy compound. Was processed. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Example 3)
Through the whole of immersion in the first treatment agent, drying, heat treatment, immersion in the second treatment agent, drying, and heat treatment, the cord made of organic fibers is adhered while applying a tension of 2.7 × ^10-2 N / tex. A cord made of organic fibers was treated in the same manner as in Example 1 except that the treatment with the agent composition was performed. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Comparative Example 1)
A cord made of organic fibers in the same manner as in Example 1 except that EX-313 (glycerol polyglycidyl ether, weight average molecular weight 540, epoxy equivalent: 141, manufactured by Nagase ChemteX Corporation) was used as the epoxy compound. Was processed. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Comparative Example 2)
Through the whole of immersion in the first treatment agent, drying, heat treatment, immersion in the second treatment agent, drying, and heat treatment, the cord made of organic fibers is adhered while applying a tension of 7.0 × ^10-2 N / tex. A cord made of organic fibers was treated in the same manner as in Example 1 except that the treatment with the agent composition was performed. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Comparative Example 3)
EX-313 (glycerol polyglycidyl ether, weight average molecular weight 540, epoxy equivalent: 141, manufactured by Nagase ChemteX Corporation) is used as the epoxy compound, and is immersed in the first treatment agent, dried, heat-treated, and the second treatment agent. Same as Example 1 except that the cord made of organic fibers was treated with the adhesive composition while applying a tension of 7.0 × ^10-2 N / tex throughout the immersion, drying, and heat treatment. And treated the cord made of organic fiber. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

(Comparative Example 4)
As an epoxy compound, EX-614B (sorbitol polyglycidyl ether, weight average molecular weight 1020, epoxy equivalent: 173, manufactured by Nagase ChemteX Corporation) is used, and it is immersed in a first treatment agent, dried, heat-treated, and used as a second treatment agent. The same as in Example 1 except that the cord made of organic fibers was treated with the adhesive composition while applying a tension of 7.0 × 10 ^-2 N / tex throughout the dipping, drying, and heat treatment. And treated the cord made of organic fiber. The initial adhesive strength, heat-resistant adhesive strength and elastic modulus at 2% elongation were measured for the treated polyester cord. The results are shown in Table 1.

In Comparative Example 1, since a polyester cord having an elastic modulus of less than 6000 MPa at the time of 2% elongation was used, the obtained cord-rubber composition composite had initial adhesive strength and heat resistance as compared with Examples 1 to 3. Both adhesive strengths are low.

In Comparative Examples 2 to 4, the polyester cord was treated with the adhesive composition while applying a tension exceeding 6.8 × ^10-2 N / tex, so that the cords obtained as compared with Examples 1 to 3 were obtained. The rubber composition composite has low initial adhesive strength and heat-resistant adhesive strength.

On the other hand, it was confirmed that the cord-rubber composition complex of the present disclosure has high initial adhesive strength and heat-resistant adhesive strength, and is excellent in heat-resistant adhesive strength.

Claims (7)

The cord made of organic fibers is treated with an adhesive composition while applying a tension of 6.8 × 10 ^-2 N / tex or less, and the cord treated with the adhesive composition is coated with a rubber composition. Obtained by the method of having to
The cord treated with the adhesive composition has an elastic modulus of 6000 MPa or more at 2% elongation .
The treatment with the adhesive composition is
(1) After treating the cord composed of the organic fiber with an adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate as the first treatment agent,
(2) The cord made of organic fibers and the rubber composition obtained by treating the cord made of the organic fiber treated with the first treatment agent with a second treatment agent containing resorcin, formalin, and rubber latex (RFL). An integrated cord-rubber composition composite. The cord-rubber composition composite according to claim 1, wherein the adhesive composition contains an epoxy compound having a weight average molecular weight of 600 or more. The cord-rubber composition complex according to claim 1 or 2, wherein the organic fiber is a polyester fiber. A tire using the cord-rubber composition complex according to any one of claims 1 to 3 as a jointless band. The cord made of organic fibers is treated with an adhesive composition while applying a tension of 6.8 × 10 ^-2 N / tex or less, and the cord treated with the adhesive composition is coated with a rubber composition. Have to do
The cord treated with the adhesive composition has an elastic modulus of 6000 MPa or more at 2% elongation .
The treatment with the adhesive composition is
(1) After treating the cord composed of the organic fiber with an adhesive composition containing (a) sorbitol polyglycidyl ether as an epoxy compound and (b) blocked isocyanate as the first treatment agent,
(2) The cord made of organic fibers and the rubber composition obtained by treating the cord made of the organic fiber treated with the first treatment agent with a second treatment agent containing resorcin, formalin, and rubber latex (RFL). A method for producing an integrated cord / rubber composition composite. The method for producing a cord-rubber composition complex according to claim 5, wherein the epoxy compound has a weight average molecular weight of 600 or more. The method for producing a cord-rubber composition complex according to claim 5, wherein the organic fiber is a polyester fiber.

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