JP2003306871A - Treating liquid for fiber, and cord for rubber reinforcement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treating liquid for a fiber, stable even in a high concentration at a process for imparting the treating liquid for the fiber, and to provide a cord for rubber reinforcement having excellent adhesiveness to a base material containing a rubber, and having excellent fatigue resistance against bending deformation. <P>SOLUTION: The treating liquid for the fiber comprising an epoxy resin and a rubber latex contains 0.1-20 pts.wt. surfactant based on 100 pts.wt. epoxy resin. The cord for the rubber reinforcement is obtained by impregnating a carbon fiber bundle with the treating liquid for the fiber. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-reinforcing cord suitable for industrial rubber products and a fiber treating liquid for obtaining the same. More specifically, the present invention relates to a rubber-reinforcing cord excellent in adhesiveness to a rubber base material and fatigue resistance.

[0002]

2. Description of the Related Art Industrial rubber products such as tires, belts and hoses are usually composites reinforced with a fiber material, and strong adhesion is required between the fiber and the rubber base material.
Conventionally, the method of adhering fibers and rubber has been resorcin
It is well known that a fiber is previously treated with a formalin / rubber latex mixed liquid (hereinafter referred to as RFL liquid), and then the fiber is adhered and vulcanized with unvulcanized rubber.

The fiber material is required to have excellent properties such as tensile strength, tensile elastic modulus, heat resistance, water resistance, and fatigue resistance. Above all, in order to endure deformation by external force, fatigue resistance, The adhesion between the fiber and the rubber substrate is important.

Under such circumstances, carbon fiber has a tensile elastic modulus,
The tensile strength, heat resistance, and water resistance are good, and the fiber-reinforced rubber material using this is excellent in dimensional stability and weather resistance. However, there is a problem that the carbon fiber cord is apt to be broken due to the rubbing of the single fibers and peeling is likely to occur at the interface between the carbon fiber cord and the rubber substrate, resulting in poor fatigue resistance.

For example, US Pat. No. 3,648,452 and Japanese Patent Publication No. 53-30757 disclose a method of applying a water-insoluble epoxy resin to a carbon fiber bundle and attaching RFL thereto. Further, JP-A-60-181369 proposes a method in which a treatment liquid containing an epoxy resin and a rubber latex is applied to a carbon fiber bundle, followed by heat treatment, and then an RFL liquid is applied, followed by heat treatment. However, this method was insufficient because the fatigue resistance did not reach a practical level. Further, since the stability of the processing liquid containing the epoxy resin and the rubber latex is insufficient, there is a problem in the manufacturing efficiency in the processing. Specifically, the treatment liquid by the method is
Aggregation of solids begins within a few hours after mixing, resulting in a change in the concentration of the treatment liquid, and finally complete solidification, making dipping treatment impossible. Therefore, it is essential to replace the processing liquid within a few hours, which causes a problem in economic efficiency. Furthermore, when the concentration of the treatment liquid was high, the pot life was further shortened, and it was completely unusable for practical use.

[0006]

Therefore, an object of the present invention is to provide a treatment liquid for fibers which is stable even at a high concentration, and which is excellent in adhesiveness between carbon fibers and a rubber compound, and is also capable of flexural deformation. It is intended to provide a rubber-reinforcing cord excellent in fatigue resistance against.

[0007]

In order to solve the above problems, the present invention has the following constitution. That is, a fiber treatment liquid containing an epoxy resin, a rubber latex and a surfactant, wherein the fiber treatment liquid contains 0.1 to 20 parts by weight of the surfactant per 100 parts by weight of the epoxy resin. It is a liquid. A rubber-reinforcing cord is obtained by impregnating a carbon fiber bundle with the fiber treatment liquid.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that a stable treating agent can be obtained even at a high concentration by adding a certain amount of a surfactant to a treating solution for fibers composed of an epoxy resin and a rubber latex. It is a thing.

Since the treatment liquid for fibers (hereinafter, treatment liquid) can be used even at a high concentration, a rubber-reinforcing cord (hereinafter, simply referred to as cord) obtained by treating carbon fibers with this treatment liquid. Is capable of adhering a large amount of solids such as epoxy resin and rubber component contained in the processing liquid (excluding water content of the processing liquid, hereinafter referred to as solid content of the processing liquid), resulting in bending deformation. It has been found that the fatigue resistance against (hereinafter, simply referred to as flexural deformation) is superior to that of the prior art.

The treatment liquid in the present invention is an epoxy resin,
A rubber latex and a surfactant are contained, but the surfactant used in the present invention needs to be 0.1 to 20 parts by weight, preferably 1 to 18 parts by weight, based on 100 parts by weight of the epoxy resin. , And more preferably 2 to 15 parts by weight. If it is less than 0.1 parts by weight, the stability of the treatment liquid may be insufficient, and if it exceeds 20 parts by weight, the adhesion between the cord and the adherend rubber may be insufficient.

The mechanism by which the stability of the treatment liquid is improved by adding a surfactant is not clear, but it is presumed that the reaction between the rubber latex and the epoxy resin is the cause of poor stability of the treatment liquid. It is considered that by emulsifying and dispersing the epoxy resin with a surfactant, the reaction with the rubber latex is blocked, and as a result, the stability of the treatment liquid is improved.

As the epoxy resin which can be used in the treatment liquid of the present invention, any compound may be used as long as it has two or more epoxy groups in one molecule.

The compound having two or more epoxy groups in the molecule is not particularly limited. For example, a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule, glycidyl obtained from a compound having an amino group in the molecule. Amine type epoxy resin, glycidyl ester type epoxy resin obtained from compound having carboxyl group in molecule, cycloaliphatic epoxy resin obtained from compound having unsaturated bond in molecule, heterocyclic epoxy such as triglycidyl isocyanate A resin or an epoxy resin in which two or more types selected from these are mixed in the molecule can be used.

Specific examples of the glycidyl ether type epoxy resin include a bisphenol A type epoxy resin obtained by reacting bisphenol A with a halogen-containing epoxide such as epichlorohydrin, and bisphenol F.
And a bisphenol F type epoxy resin obtained by the reaction of the halogen-containing epoxides, a biphenyl type epoxy resin obtained by the reaction of biphenyl and the halogen-containing epoxides, and a resorcinol obtained by the reaction of resorcinol and the halogen-containing epoxides -Type epoxy resin, bisphenol S-type epoxy resin obtained by the reaction of bisphenol S and the halogen-containing epoxides, polyethylene glycol-type epoxy resin which is a reaction product of polyhydric alcohols and the halogen-containing epoxide, polypropylene glycol-type Epoxy resin, bis- (3,4-epoxy-6-methyl-
Dicyclohexylmethyl) adipate, epoxy resins obtained by oxidizing unsaturated bond moieties such as 3,4-epoxycyclohexene epoxide, other naphthalene type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and halogens thereof or Examples include alkyl-substituted compounds.

Of these, aliphatic epoxy resins having no cyclic structure are preferable from the viewpoint of cord flexibility, and include glycerol polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether, hexanediol diglycidyl ether, and polyethylene. A reaction product of a polyhydric alcohol such as glycol diglycidyl ether or polypropylene glycol diglycidyl ether and epichlorohydrin can be preferably used.

Among them, glycerol polyglycidyl ether and sorbitol polyglycidyl ether are particularly effective in improving fatigue resistance and are preferably used.

The epoxy resin used in the present invention has an epoxy equivalent of 50 to 500, preferably 70 to 400, more preferably 100 to 300. If it is less than 50, the cord formed by impregnating carbon fibers with this treatment liquid tends to be too rigid, and buckling is likely to occur due to bending deformation, resulting in reduced fatigue resistance. If it exceeds 500, the adhesion between the cord and the rubber substrate may become insufficient. When using a plurality of types of epoxy resins, it is preferable that the epoxy equivalent of at least one type of the epoxy resins satisfies the above range, and it is more preferable that all of the epoxy resins used be in the above range.

The epoxy resin may be contained in an amount of 20 to 80% by weight, preferably 30 to 70% by weight, and more preferably 40 to 60% by weight based on 100% by weight of the solid content of the treatment liquid. If it is less than 20% by weight, the adhesiveness with the cord may be insufficient at the interface with the rubber substrate, and if it is less than 80% by weight, the flexibility of the cord may be lowered and fatigue resistance may be insufficient. There is.

The surfactant used in the present invention is not particularly limited, and an ionic surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant can be used. . Among them, the stability of the processing liquid,
A nonionic surfactant is preferable from the viewpoint of the adhesiveness between the cord and the rubber substrate. When an ionic surfactant is used, the emulsion stability of the rubber latex is destroyed, the stability of the processing liquid becomes poor, and it reacts with the epoxy group, which is the active ingredient for adhesiveness, and the reactive epoxy group is insufficient. Therefore, the adhesion between the cord and the rubber base material may be poor.

As the anionic surfactant, higher alcohol sulfate ester salt, higher alkyl ether sulfate ester salt, sulfated fatty acid ester, sulfated olefin, alkylbenzene sulfonate, alkylnaphthalene salt,
Paraffin sulfonate, higher alcohol phosphate ester salt and the like can be used.

As the cationic surfactant, higher alkyl amine salt, higher alkyl amine ethylene oxide adduct, alkyl trimethyl ammonium salt, alkyl dimethyl benzyl ammonium salt and the like can be used.

As the amphoteric surfactant, coconut oil fatty acid amide propyl betaine solution, lauric acid amide propyl betaine solution, lauryl dimethylamino acetic acid betaine and the like can be used.

As the nonionic surfactant, higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct,
Ethylene oxide adducts of fats and oils, polypropylene glycol ethylene oxide adducts, glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, sorbitan fatty acid esters, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines, fatty acid esters of sucrose, etc. Can be used. Among them, higher alcohol ethylene oxide adduct,
Ethylene oxide adducts of fats and oils are particularly effective for the stability of the treatment liquid and are preferably used.

When a nonionic surfactant is used, the surfactant HLB (Hydrophile-Lipophi) is used.
le Balance) is preferably 3 to 15 and 4 to 1
4 is more preferable. When it is less than 3, the surfactant may be difficult to dissolve in water, and when it exceeds 15, the emulsifying effect of the epoxy resin may be poor and, as a result, the stability of the treatment liquid may be poor.

The processing liquid of the present invention has a solid content of 10%.
It is preferable to contain 20 to 80% by weight of the rubber component with respect to 0% by weight. If it is less than 20% by weight, when subjected to stress deformation such as bending deformation, the cord may be broken due to rubbing of the single fibers, or peeling from the cord may occur at the rubber interface. On the other hand, if it exceeds 80% by weight, the adhesiveness of the cord becomes excessive and the handleability may deteriorate.

The rubber component can be added to the processing liquid as a rubber latex. By using the rubber latex, the viscosity of the entire treatment liquid is lowered, the impregnation of the treatment liquid into the inside of the carbon fiber bundle is facilitated, and the solid content of the treatment liquid facilitates the function of suppressing single fiber rubbing.

The rubber latex is generally one in which a polymer is stably dispersed in water. After impregnating a carbon fiber bundle, water remaining in the cord is removed by heating and drying. Is preferred. If water remains in the cord, it may cause voids that impair the fatigue resistance of the cord. The temperature for heating and drying is 100 to 270 ° C.
Is preferable, and a range of 150 to 240 ° C. is more preferable.

Examples of the rubber latex include butadiene rubber latex, isoprene rubber latex, urethane rubber latex, natural rubber latex, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, chloroprene rubber latex and vinylpyridine-styrene-butadiene rubber latex. Can be used. Among them, acrylonitrile-butadiene rubber latex and vinylpyridine-styrene-butadiene rubber latex are particularly effective in improving fatigue resistance and are preferably used. These can be used alone or in a mixture.

The type of rubber latex can be appropriately selected depending on the compatibility with the rubber substrate used. For example, when natural rubber is used as the rubber base material, the rubber component derived from the vinylpyridine-styrene-butadiene rubber latex is 50% in 100% by weight of the total rubber component in the treatment liquid.
It is preferable to occupy at least wt%. When acrylonitrile-butadiene rubber is used as the rubber base material, it is preferable that the rubber component derived from the acrylonitrile-butadiene rubber latex accounts for 50% by weight or more in 100% by weight of all rubber components in the treatment liquid. .

The average particle size of the rubber latex used in the present invention is 0.3 μm or less, preferably 0.2 μm or less, more preferably 0.1 μm or less. If it exceeds 0.3 μm, the impregnation property into the carbon fiber bundle may be deteriorated, and rubbing between the single fibers may occur, so that the fatigue resistance of the cord may be deteriorated. Further, the smaller the average particle size of the rubber latex is, the more preferable. However, if it is 0.05 μm, the object of the present invention can be achieved. The average particle size in the present invention means a method using a standard sieve, a microscope method, an optical path shielding method, a laser forward scattering method, a light scattering method, an electrical method (a coulter counter for measuring the electric capacity of a suspension). , The sedimentation velocity method, the X-ray small angle scattering method, the cascade impactor method, or the like.

The dry weight ratio of the epoxy resin and the rubber latex contained in the treatment liquid of the present invention is 10/90 to 90/1.
It is 0, preferably 20/80 to 80/20, and more preferably 30/70 to 70/30. October 9
If it is less than 0, the adhesion between the cord and the rubber base material may be insufficient, and if it is 90/10 or more, the cord tends to be too rigid, and buckling due to bending deformation tends to occur. As a result, fatigue resistance may decrease. The dry weight ratio of the epoxy resin and the rubber latex can be adjusted by blending the treatment liquid from the calculated values of the weight of the epoxy resin and the solid content of the rubber latex (rubber component derived from the rubber latex).

The treatment liquid of the present invention may contain an epoxy compound having one epoxy group in one molecule, if necessary.

Further, the present invention is a rubber-reinforcing cord obtained by impregnating a carbon fiber bundle with the treatment liquid. Specifically, the inside of the carbon fiber bundle is impregnated with the treatment liquid to remove water, and the solid content of the treatment liquid is adhered to the inside of the fiber bundle and the entire surface of the fiber bundle to form a cord-shaped material.

If the solid content of the treatment liquid is not sufficiently adhered to the inside of the carbon fiber bundle, the cords often break due to the rubbing of the single fibers when subjected to stress deformation such as bending deformation. Further, if the solid content of the treatment liquid does not adhere to the surface of the cord, the cord may peel off at the interface with the rubber base material described later.

The rubber-reinforcing cord of the present invention preferably has 20 to 80 parts by weight of the solid content of the treatment liquid adhered to 100 parts by weight of the carbon fiber bundle. If the solid content of the treatment liquid is less than 20 parts by weight with respect to 100 parts by weight of the carbon fiber bundle, the fatigue resistance of the cord may decrease due to the rubbing of the single fibers. On the other hand, if the solid content of the treatment liquid exceeds 80 parts by weight, the cord tends to be too rigid, and buckling due to bending deformation tends to occur, resulting in reduced fatigue resistance.

In the present invention, in order to further improve the adhesiveness of the cord / rubber substrate, it is preferable to attach resorcin / formalin / rubber latex (hereinafter, RFL) to the cord surface. That is, it is preferable to have the RFL layer on the code surface layer. Here, “attached to the surface of the cord” or “having an RFL layer on the surface of the cord” means that the total R is within the outer peripheral area corresponding to 10% of the total cross-sectional area of the cord.
90% or more of FL is unevenly distributed. code/
The uneven distribution of RFL at the rubber substrate interface further enhances the adhesiveness at the cord / rubber substrate interface.

The method of unevenly distributing RFL on the surface of the rubber-reinforcing cord is not particularly limited, but the carbon-fiber bundle is impregnated with the treatment liquid to form a cord-shaped material, and the RFL is further provided on the surface of the rubber-reinforcing cord. It is also possible to use a method of giving.

For example, it can be manufactured by the following method. That is, the carbon fiber bundle is passed through a treatment liquid tank containing the treatment liquid, heated and dried, and then RF.
It is a method of passing water through a treatment liquid tank containing L and then further passing through a heating and drying furnace to remove water in the cord.

All RFLs included in the rubber reinforcing cord
The amount of adhered to the carbon fiber bundle is preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight after drying.
Parts by weight, particularly preferably 3 to 10 parts by weight. If it is less than 1 part by weight, the adhesiveness of the cord / rubber substrate interface may be reduced, and if it exceeds 20 parts by weight, the flexibility of the cord may be reduced and the adhesion to the roll (gum in the cord production process Up) and quality stability may be impaired.

The manufacturing method of RFL is not particularly limited,
It can be prepared using an initial condensation product of resorcin and formalin. Particularly, RFL can be preferably prepared using a resorcin-formalin initial condensation product obtained by initial condensation under an alkali catalyst. For example, by adding and mixing resorcinol and formalin in an alkaline aqueous solution containing an alkaline compound such as sodium hydroxide,
The mixture is left standing at room temperature for several hours to initially condense resorcin and formaldehyde, and then rubber latex is added to prepare a mixed emulsion.

The resorcin-formalin initial condensate preferably has a molar ratio of resorcin and formalin of 1: 0.3.
˜1: 5, more preferably 1: 0.75 to 1: 2.0
The thing of the range of can be used. Outside this range, the adhesiveness at the cord / rubber substrate interface may become insufficient.

The rubber latex used for the preparation of RFL is acrylonitrile-butadiene rubber latex, isoprene rubber latex, urethane rubber latex, chloroprene rubber latex, styrene-butadiene rubber latex, vinylpyridine-styrene-butadiene rubber latex, hydrogenated nitrile rubber latex. And synthetic rubber latex.

The type of rubber latex can be appropriately selected depending on the compatibility with the rubber base material used. For example, when natural rubber is used as the rubber base material, the rubber component derived from the vinylpyridine-styrene-butadiene rubber latex is 50% in 100% by weight of the total rubber component in the treatment liquid.
It is preferable to occupy at least wt%. When acrylonitrile-butadiene rubber is used as the rubber base material, it is preferable that the rubber component derived from the acrylonitrile-butadiene rubber latex accounts for 50% by weight or more in 100% by weight of all rubber components in the treatment liquid. .

The compounding ratio of the resorcinol formalin initial condensate and the rubber latex in the RFL is preferably 1: 3 to 1: 8 in terms of solid content weight ratio, and 1: 4 to 1: 6.
It is more preferable that the range is If it is out of this range, the adhesiveness may be insufficient.

The treatment liquid of the present invention can be adjusted to an appropriate concentration and used for treating carbon fiber bundles. The concentration of the treatment liquid can be adjusted by adding water in order to enhance the impregnation property into the carbon fiber bundle. Here, it is preferable to use ion-exchanged water as the water because the stability of the treatment liquid is improved. The concentration of the treatment liquid is preferably 20 to 80% by weight, more preferably 30 to 70% by weight.
Is preferred. If it is less than 20% by weight, impregnation of the carbon fiber bundle with the solid content of the treatment liquid may be insufficient and the fatigue resistance may be deteriorated. If it exceeds 80% by weight, the stability of the treatment liquid may be deteriorated, and the solid content may be aggregated or settled, so that the dipping treatment may be impossible. Here, the concentration of the treatment liquid is a value obtained by dividing the weight of the dried solid content contained in the treatment liquid by the weight of the treatment liquid before drying.

In the present invention, the treatment of the carbon fiber bundle with the treatment liquid can be carried out by immersing the carbon fiber bundle in the treatment liquid and then subjecting it to heat treatment. This heat treatment may be carried out at a temperature sufficient to fix the solid content of the treatment liquid impregnated or adhered to the carbon fiber bundle and remove water.
The treatment may be performed at 100 to 270 ° C. for several minutes.

Further, it is preferable to add a solvent such as water to the above-mentioned RFL and use it as an RFL liquid from the viewpoint of uniformly applying it on the carbon fiber bundle. As the water, it is preferable to use ion-exchanged water from the viewpoint of improving the stability of the RFL solution.

If necessary, a chlorophenol compound obtained by co-condensing parachlorophenol and resorcin with formaldehyde, a blocked isocyanate compound which is an adduct of a polyisocyanate compound and a block compound, or the like may be added to the RFL liquid. it can.

The concentration of the RFL liquid is preferably 10 to 40% by weight, more preferably 15 to 30% by weight. If it is less than 10% by weight, the amount of RFL attached may be insufficient and the adhesive strength may be insufficient. When the concentration of the RFL liquid exceeds 40% by weight, the storage stability of the RFL liquid may be deteriorated, and the solid content may agglomerate to lower the concentration, which makes it difficult to uniformly attach the RFL. here,
The concentration of the RFL liquid is a value obtained by dividing the weight of the dried solid substance contained in the RFL liquid by the weight of the RFL liquid before drying.

The rubber-reinforcing cord of the present invention is preferably twisted. The twist number is 100 times / m or less, preferably 10 times / m to 80 times / m, and more preferably 20 times / m to 60 times / m. 100 times / m
If it exceeds, kink is likely to occur, which may lead to deterioration of strength and deterioration of operability. In addition, the twist is given
It may be performed before the treatment liquid is impregnated, or after the treatment liquid is impregnated / heat treated, but in order to promote the impregnation of the treatment liquid into the inside of the carbon fiber bundle, the treatment liquid is impregnated in the opened state and the twist is applied after the heat treatment. Is more preferable.

The twisted structure may be a single twisted structure in which a single cord is twisted. A so-called twisted structure in which a twisted cord is first added to several cords, and then several cords are combined to add a twisted cord. It may have a twisted structure.

The rubber-reinforcing cord treated as described above is brought into close contact with a base material (hereinafter, rubber base material) containing rubber,
By performing vulcanization adhesion under the usual processing conditions known for the rubber base material, it becomes possible to achieve strong adhesion between the carbon fiber and the rubber base material.

The fiber reinforced rubber material of the present invention comprises a rubber base material reinforced by the cord.

Here, the rubber is 5% in 100% by weight of the rubber base material.
It is preferably contained in an amount of 0 to 100% by weight.

Specific examples of the rubber contained in the base material include acrylic rubber, acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, isoprene rubber, urethane rubber, ethylene-propylene rubber, epichlorohydrin rubber and chlorosulfonated rubber. Polyethylene rubber, chloroprene rubber, silicone rubber, styrene-butadiene rubber, polysulfide rubber, natural rubber, butadiene rubber, butyl rubber, fluororubber and the like can be used.

In addition to rubber as the main component, the base material includes inorganic fillers such as carbon black and silica, organic fillers such as coumarone resin and phenol resin, softening agents such as naphthenic oil, and antiaging agents. A vulcanization aid, a processing aid and the like may be included as necessary.

The fiber reinforced rubber material of the present invention can be produced, for example, by the following method. That is, the cords aligned in one direction are sandwiched from both sides by a sheet-like base material containing rubber as a main component, and then the cord / rubber composite is heated / pressurized in a press machine to vulcanize the rubber,
It is a molding method.

The rubber material according to the present invention can be suitably used for any of tires, belts and hoses. In the case of tires, natural rubber and styrene-butadiene rubber are particularly suitable. For power transmission belts, the use of hydrogenated acrylonitrile-butadiene rubber is particularly suitable.

Depending on the type of rubber used for such a base material, it is preferable to include the same type of rubber component in the treatment liquid used for the above-mentioned rubber-reinforcing cord, as a good fiber-reinforced rubber material having good adhesiveness and bending fatigue resistance. To obtain.

[0060]

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

In this example, the following raw materials were used for producing the treatment liquid and the rubber-reinforcing cord. <Raw material> (Rubber latex) -Vinylpyridine-styrene-butadiene rubber latex: Pylatex (registered trademark) FS (Japan A & L Co., Ltd.)
Manufactured), solid content concentration 40.5%, average particle size 0.09 μm
(Measurement by Microscopic Method) Styrene-butadiene rubber latex: Nippole (registered trademark) LX110 (manufactured by Nippon Zeon Co., Ltd.), solid content concentration 40.5%, average particle size 0.05 μm (measured by microscopic method) -Butadiene rubber latex: Nippon (registered trademark)
LX111K (manufactured by Nippon Zeon Co., Ltd.), solid content concentration 55
%, Average particle size 0.35 μm (measured by microscope) (epoxy resin) -sorbitol polyglycidyl ether: Denacol (registered trademark) EX-614 (Nagase Kasei Co., Ltd.)
), Epoxy equivalent 167-cresol novolac type epoxy resin: Denacol (registered trademark) EM-150 (Nagase Kasei Co., Ltd.)
Manufactured), epoxy equivalent 450, solid content concentration 50% Lauryl alcohol glycidyl ether: Denacol (registered trademark) EX-171 (Nagase Chemical Industry Co., Ltd.)
Manufactured), epoxy equivalent 971 (surfactant) -polyoxyethylene castor oil ether: GS-2 (manufactured by Sanyo Kasei Co., Ltd.), nonionic surfactant, HLB =
13.8 ・ Polyoxyethylene alkyl ether: Sanmorin 1
1 (manufactured by Sanyo Kasei Co., Ltd.), nonionic surfactant, H
LB = 15.1 Sodium dioctyl sulfosuccinate: Sanmorin (registered trademark) OT-70 (manufactured by Sanyo Kasei Co., Ltd.), anionic surfactant (carbon fiber bundle) -Torayca (registered trademark) T700S-12K-50C ( Toray Industries, Inc .: Tensile strength 4900 MPa, fineness 8000
dtex Moreover, the evaluation method of each physical property used in this example is as follows. <Stability of treatment liquid (life)> After preparing the treatment liquid, 25
The sample was allowed to stand in a room at 50 ° C and a humidity of 50%, and the time until the solid content was agglomerated (pudding-like mass) was measured. <Cord production / evaluation> (1) Resin impregnation (cord production) The carbon fiber bundle was conveyed at a speed of 10 m / min, passed through a treatment liquid tank (first bath) containing the treatment liquid, and then heated at 200 ° C. The water was removed by passing through a heating furnace.

Next, a processing liquid tank (2 containing the RFL liquid is used.
Bath). Dripping is performed under the condition of an air wiper pressure of 9.8 kPa, and the liquid is passed through a heating furnace at 200 ° C.
Water was removed to obtain a rubber reinforcing cord.

It should be noted that the amount of solids deposited on the treatment liquid in the first bath of the dried cord is the amount of solids deposited on the second bath RFL as the carbon fiber bundle 1
As a standard, 45 parts by weight and 5 parts by weight with respect to 00 parts by weight, respectively.

Here, in this embodiment, as an apparatus for conveying carbon fibers when the carbon fibers are immersed in the treatment liquid tank,
A computer treating single dipping machine (manufactured by Ritzler Co., USA) was used.

In each of the examples, the treatment liquid for fibers having the composition shown in Table 1 was used as the treatment liquid for the first bath, and the RFL liquid having the composition shown in Table 2 was used as the treatment liquid for the second bath. (2) Treatment liquid solid content adhesion amount The treatment liquid solid content adhesion amount is measured in advance by measuring the weight of the carbon fiber bundle per a certain length, and using the cord weight of the same length after the treatment liquid impregnation and heat treatment. By measuring, the adhesion amount (parts) of the treatment liquid solid content as a difference was calculated. (3) T-Adhesive Strength The adhesive strength between the rubber base material and the cord is JIS L-1017 (1
983) Adhesive strength T test (method A). Embed the rubber reinforcement cord in the sheet-shaped rubber base material,
A rubber block was obtained by press vulcanization at 150 ° C. for 30 minutes under pressure. After left to cool, pull the cord from the rubber block 30c
Pull out at a speed of m / min, and pull out the load N /
It was expressed in cm and was designated as T-adhesion.

In this example, a base material having the composition shown in Table 3 was used as the sheet-shaped rubber base material. (4) Flexural fatigue resistance of rubber-reinforcing cord In accordance with the Goodyear method described in JIS L1017, the time until the tube breaks (breaking life) is measured using a tube test piece, and this is measured for flexural fatigue resistance. Was used as an index.

In this example, a sheet-shaped rubber base material having the composition shown in Table 3 was wound on a drum, and the rubber-reinforcing cords of each example were wound on the drum at an interval of 55 pieces / 10 cm. From there, the same sheet-shaped rubber substrate was wound.

The thus obtained three-layered body of rubber substrate / cord / rubber substrate was removed from the drum and wound around a mandrel to form a tube. Furthermore, the rubber is heated to a temperature of 1 in the press.
Vulcanization was performed under the conditions of 60 ° C., pressure of 9.8 MPa and time of 30 minutes to prepare a tube test piece. Thus, a fiber reinforced rubber material (outer diameter 27 mm, inner diameter 13 mm, length 24 cm) in which the axial direction of the rubber tube and the orientation of the cord were the same was obtained.

The central portion of the fiber reinforced rubber material was bent at 90 °, air with a pressure of 0.3 MPa was fed into the tube, and both ends of the tube were moved in the same direction at a speed of 850 times / minute in an atmosphere at a temperature of 25 ° C. The tube was rotated and the time until the tube was broken was measured. (Examples 1 to 7 and Comparative Examples 1 to 4) A treatment liquid, a rubber-reinforcing cord, and a fiber-reinforced rubber material were obtained according to the methods described above. The composition of the treatment liquid used in each example is shown in Table 1 and RF
The composition of the L liquid is shown in Table 2, and the composition of the sheet-shaped rubber substrate is shown in Table 3.

Table 4 summarizes the stability (life) of the treatment liquid of each example, the adhesive strength between the rubber-reinforcing cord and the rubber base material, and the evaluation result of the tube breaking life which is an index of flex fatigue resistance. Showed.

As can be seen from the evaluation results shown in Table 4, the treatment liquid according to the present invention exhibits high stability even at high concentrations. Further, it is understood that the rubber-reinforcing cord according to the present invention exhibits extremely excellent fatigue resistance against repeated bending deformation.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a treatment liquid for fibers which has good stability even in a high concentration in the treatment liquid application process (dipping) for fibers. In addition, tires
It is possible to provide a rubber-reinforcing cord having excellent adhesion to rubber products represented by belts and excellent fatigue resistance in rubber.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D06M 15/693 D06M 15/693 // B29K 221: 00 B29K 221: 00 263: 00 263: 00

Claims (11)

[Claims] 1. A treatment liquid for fibers comprising an epoxy resin, a rubber latex and a surfactant, which comprises an epoxy resin 10
A treatment liquid for fibers, characterized in that 0.1 to 20 parts by weight of a surfactant is contained with respect to 0 parts by weight. 2. The treatment liquid for fibers according to claim 1, wherein at least one of the epoxy resins is an aliphatic epoxy resin. 3. At least one epoxy resin having an epoxy equivalent of 50 to 500 is contained.
Or the treatment liquid for fibers according to 2. 4. The treatment liquid for fibers according to claim 1, wherein the surfactant is a nonionic surfactant. 5. The treatment liquid for fibers according to claim 4, wherein the nonionic surfactant has an HLB of 3 to 15. 6. The treatment liquid for fibers according to claim 1, wherein the rubber latex has an average particle diameter of 0.3 μm or less. 7. The treatment liquid for fibers according to claim 1, wherein the dry weight ratio of the epoxy resin and the rubber latex is 10/90 to 90/10. 8. The treatment liquid for fibers according to claim 1, wherein the concentration of the treatment liquid for fibers containing the epoxy resin and the rubber latex is 20 to 80% by weight. 9. A rubber-reinforcing cord obtained by impregnating a carbon fiber bundle with the treatment liquid for fibers according to any one of claims 1 to 8. 10. The rubber reinforcing cord according to claim 9, wherein the solid content of the treatment liquid for fibers is 20 to 80 parts by weight with respect to 100 parts by weight of the carbon fiber bundle. 11. The rubber-reinforcing cord according to claim 9, which has an RFL layer on the cord surface layer portion.