JPH0457833A - Method of treatment of glass fiber for reinforcing rubber - Google Patents

Abstract

PURPOSE:To improve the resistance to heat, water, and flex fatigue of a rubber compsn. compounded with a glass fiber by treating the fiber with two specific liqs. successively. CONSTITUTION:100 pts. wt. rubber latex (e.g. a vinylpyridine-butadiene-styrene terpolymer latex), 0.1-15 pts. wt. water-sol. resolcin-formaldehyde condensate, 0.1-1.5 pts. wt. water- and oil-repellent comprising an aq. dispersion of a water- insol. fluorocompd. having a 3-20C perfluoroalkyl group an m.p. or glass transition point or softening point of 20 deg.C of higher and a mol. wt. of 700-200000, and a solvent are compounded to give a first liq. Separately 5-15 wt.% mixture of the agent with a halogenated polymer adhesive is mixed with the solvent to give a second liq. A glass fiber is treated with the first liq., thermally treated, treated with the second liq., and dried to give the title fiber of which the surface is covered with the first layer contg. the rubber, the condensate, the repellent, and with the second layer contg. the repellent and the adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for treating rubber reinforcing glass fibers used for reinforcing rubber products such as rubber belts and tires. More specifically, the present invention relates to a method for treating glass fibers used as reinforcing agents for products such as toothed belts that are subjected to both heat and bending stress during running.

<Prior Art> Reinforcing fibers such as glass fiber cords are widely used as reinforcing materials for rubber products such as rubber belts and tires. Rubber products such as rubber belts are subject to repeated bending stress, resulting in bending fatigue and performance deterioration. Peeling occurs between the reinforcing material and the rubber matrix, and reinforcing fibers wear out, resulting in a decrease in strength. Such phenomena tend to be particularly accelerated by heat and moisture. In order to prevent such peeling due to bending fatigue and obtain a sufficient reinforcing effect, it is necessary to increase the compatibility between reinforcing fibers and rubber, increase adhesive strength, and provide heat and water resistance. Various treatment agents are applied to the fiber surface.

Various types of processing agents have been proposed.

For example, in JP-A-1-221433, a resorcinol-formaldehyde water-soluble condensate, a vinylpyridine-butadiene-styrene copolymer latex, a dicarboxylated butadiene-styrene copolymer latex, and a chlorosulfonated polyethylene latex are used in combination. Various processing agents such as processing agents have been proposed.

<Problems to be Solved by the Invention> By using such a treatment agent, it is possible to satisfy the adhesion between the reinforcing fibers and the rubber matrix and the heat resistance, bending fatigue resistance, and resistance of the treatment agent itself. Due to insufficient properties, when reinforcing fibers treated with these processing agents are used, it is difficult to obtain rubber products with excellent heat resistance, water resistance, bending fatigue resistance, and so on. This tendency is particularly remarkable when used for reinforcing heat-resistant rubbers with poor adhesion such as chlorosulfonated polyethylene and hydrogenated nitrile rubber. The present invention aims to overcome the aforementioned drawbacks of the prior art.

Means for Solving the Problems> The present invention has been made with the aim of solving the above-mentioned drawbacks, and it combines glass fibers with rubber latex and resorcinol.
After treatment with a first liquid containing a formaldehyde water-soluble condensate and a fluorine-based water and oil repellent and heat treatment, treatment with a second liquid containing a fluorine-based water and oil repellent and a halogen-containing polymer adhesive and drying. A method for processing glass fiber for rubber reinforcement, characterized by:

Next, the present invention will be explained in more detail.

As for the rubber latex, butadiene-styrene copolymer latex, dicarboxylated butadiene-styrene copolymer latex, vinylpyridine-butadiene-styrene terpolymer latex, chlorosulfonated polyethylene latex, etc. can be suitably used as the rubber latex. Among these, dicarboxylated butadiene
In the case of a mixture of styrene copolymer latex, vinylpyridine-butadiene-styrene terpolymer latex, and chlorosulfonated polyethylene latex, for example, a mixture of two or three, one component is
Particularly suitable results can be obtained with mixtures containing 80% by weight. As the dicarboxylated butadiene-styrene copolymer latex, butadiene 20 to 80 wt%
, 5 to 70 wt% of styrene and 1 to 10 wt% of ethylenically unsaturated dicarboxylic acid are particularly suitable, such as N1pol 2570X5 (trade name, manufactured by Nippon Zeon Co., Ltd.), JSR0668 (trade name, manufactured by Nippon Gosei Rubber Co., Ltd.). ) etc. can be suitably used. As the vinylpyridine-butadiene-styrene turbopolymer latex, a large number of such terpolymers known to those skilled in the art can be used. For example, the polymerization ratio of vinylpyridine, butadiene, and styrene is 10 to 2060 to 8010 to
2o is particularly suitable, N1pol 2518F
S (trade name, manufactured by Nippon Zeon Co., Ltd.), Pyratex (trade name, manufactured by Susumu Naugatuck Co., Ltd.), etc. can be suitably used.

The chlorosulfonated polyethylene latex has a chlorine content of 1125 to 43 wt% and a sulfur content of 1.0 to 1.5.
wt% is particularly suitable, and Esprene (trade name, manufactured by Susumu Kagaku Co., Ltd.) and the like can be suitably used.

Resorcinol-formaldehyde water-soluble condensate (hereinafter referred to as RF)
A resol-type water-soluble addition condensate obtained by reacting resorcinol and formaldehyde in the presence of an alkaline catalyst such as an alkali hydroxide or an amine can be suitably used. Particularly preferred is one in which resorcinol and formaldehyde are reacted at a reaction molar ratio of 1+0.5 to 3.

The fluoro-based water and oil repellent has a perfluoroalkyl group having 3 to 20 carbon atoms, preferably 6 to 12 carbon atoms, is insoluble in water, has a melting point, glass transition point or softening point of 20°C or higher, and has a molecular weight of 20°C or higher. Aqueous dispersions of compounds having a molecular weight of about 700 to about 200,000 are preferably used.

Examples of such perfluoroalkyl group-containing organic fluorine compounds include the following.

(1) A homopolymer of a vinyl monomer having a perfluoroalkyl group having 3 to 20 carbon atoms or a copolymer with a vinyl monomer containing no fluoroalkyl group.

Examples of vinyl monomers having perfluoroalkyl groups include the following.

CF (CF2)7(CH2)1.0COCH-CH2
CF (CF)CH0COC(CH3) -CH2
(CF3)20F(CF2)6(CH2)30COCH
=CH2 CF (CF) (CH2) 20COC(CH
3)=CH2 CF (CF)SON(C3H7)(CH2)20CO
CH-CH2 CF (CF) So N (CH2CH20COC
H=CH2)2 Examples of vinyl monomers that do not contain perfluoroalkyl groups include vinyl chloride, ethylene, vinyl acetate, vinylidene fluoride, acrylonitrile, styrene, acrylic acid and its alkyl esters, acrylamide, butadiene, and chlorobrene. Two or more of these may be used in combination.

(2) Ester of a monohydric or polyhydric alcohol containing a perfluoroalkyl group having 3 to 20 carbon atoms and a monohydric or polyhydric carboxylic acid which may be fluorinated.

A monohydric or polyhydric alcohol which may be fluorinated and a perfluoroalkyl group containing 3 to 20 carbon atoms
Esters with monovalent or polyvalent carboxylic acids.

Examples of components that form these esters include the following compounds.

CF (CF) 5ON(C3H7)CH2CH20C
F (CF)SON(C2H5)CH2CH(0H)C
H20H CF (CF2)7S02N(C3H7)CH2COO
H1 Benzoic acid, adipic acid, phthalic acid, maleic acid, ethylene glycol, propylene glycol, glycerin, ethylene glycol monoethyl ether.

(3) Urethane made of a monohydric or polyhydric alcohol having a perfluoroalkyl group having 3 to 20 carbon atoms and a monohydric or polyhydric isocyanate.

Examples of this are urethanes with phenyl isocyanate, tolylene diisocyanate, hexamethylene diisocyanate.

Examples of these water dispersions include Dicguard F-7
0 and F-60 (trade name, manufactured by Dainippon Ink Chemical Co., Ltd.), etc. can be suitably used.

The concentration of the second liquid of the present invention mentioned above is suitably 5 to 15 wt%, preferably 7 to 10 wt%. If the concentration is too low, adhesion to glass fibers will be insufficient, and if the concentration is too high, uneven adhesion will likely occur. The amount of the second liquid attached is 1.5 to 7.0 wt% of the weight of the glass fiber as a solid content.
, preferably 2.5 to 5.0 wt %; if this amount is too small, the effect of the present invention will not be sufficient, and if this amount is too large, the flexibility of the fiber will decrease.

The glass fiber to which the second liquid has been applied is dried at 80 to 150°C, preferably 100 to 120°C. It is appropriate to set the drying time so that the remaining amount of solvent is 0.5 wt% or less.

There is no particular limitation on the type of rubber to be reinforced with the glass fibers of the present invention, but chlorosulfonated polyethylene rubber, hydrogenated nitrile rubber, etc. can be used as examples, and very suitable results can be obtained, with excellent heat resistance, water resistance, and bending resistance. Excellent reinforced rubber products such as timing belts can be obtained.

<Function> Since both the first and second liquids of the treatment agent of the present invention contain a fluorine-based water and oil repellent, water resistance and oil resistance are improved and the glass fibers treated with the treatment agent of the present invention are reinforced. When used as a material, even if subjected to bending stress in a high temperature, high humidity, and oily environment such as an automobile engine compartment, the adhesive strength between the glass fiber and the rubber matrix does not decrease, causing fatigue. I think it will become difficult.

The present invention will be explained in more detail with reference to Examples below.

<Example> 3 parts by weight of resorcinol-formaldehyde water-soluble condensate (solid content 8 wt%, reaction molar ratio of resorcinol and formaldehyde 1:1.5), vinylpyridine-butadiene-styrene terpolymer latex (N1pol 2
518FS product name, manufactured by Nippon Zeon, solid content 40w
t%) 30 parts by weight, dicarboxylated butadiene-styrene copolymer latex (Nipol 2570
rene 200 product name, made by Juju Chemical, solid content: 14
0wt%) 20 parts by weight, 1 part by weight of 25% ammonia water,
Fluorine-based water and oil repellent (Dicguard F-70 trade name, manufactured by Dainippon Ink Chemical, solid content included! 20wt%) 1
A first liquid consisting of 4 parts by weight and 4 parts by weight of water was applied in accordance with a conventional method to three glass fiber bundles made of 200 9 μm glass fibers, and heat treated at a temperature of 250°C for 2 minutes. The amount of the first liquid attached to the glass fiber is 20wt.
% glass fiber bundles were obtained.

Next, this glass fiber bundle is first twisted in the Z direction (S direction) 2.1 times per inch, and then 13 fiber bundles that have been given this first twist are twisted together 2.1 times per inch. S direction (
Z-direction) with upper twist, ECG150 3/13 2
．． A glass fiber cord of 15 (Z) was obtained.

Next, a halogen-containing polymer adhesive solution (Chemlock 402 trade name,
Manufactured by Lord Corporation Rayon, solid content 15wt%)
50 parts by weight, 0.8 parts by weight of perfluoroalkyl group-containing acrylic copolymer (Dieguard F-327 trade name, manufactured by Dainippon Ink Chemical, solid content 7.5 wt%), and 50 parts by weight of trichlorethylene. was applied by a conventional method and dried at a temperature of 110'C for 1 minute to reduce the amount of the second liquid deposited to 3.5 wt% based on the glass fiber cord.
obtained glass fiber cord.

A toothed belt having a width of 19 mm and a length of 980 mm was prepared using this cord as a reinforcing fiber and rubber having the composition shown in Table 1.

This toothed belt was attached to a water injection running test machine equipped with a 6000 rpm drive motor, and the belt was run for 24 hours while water was dripped at the part where the belt tooth surface and the pulley tooth surface begin to mesh at a speed of IL/Hr. The tensile strength retention rate was determined.

The results are shown in Table-2.

Comparative Example> A test was carried out in exactly the same manner as in the example except that the fluorine-based water and oil repellent was not used. The results are shown in Table-2.

<Effects of the Invention> Rubber products reinforced with glass fibers treated by the treatment method of the present invention have a large bonding force between the reinforcing fibers and the matrix rubber, and their strength does not decrease even when subjected to repeated bending stress, and they have low water resistance. It is large, so even if repeated bending stress is applied in a high humidity environment, the strength will only decrease.

(blank below) Table-1 rubber compound Distribution Mu medicine Weight part hydrogenated nitrile rubber (Zetpo Le 2020) mosquito bomb black acid transformation sub lead stearic acid blood Ocol sulfur yellow 0.

Tetramethylthiuram Disulfy de 1.

cyclohexylbenzo Thiadylsulfenamide de 1, Table-X Example Comparative example belt strength Retention rate (%)

Claims (4)

[Claims] (1) After being treated with a first liquid containing rubber latex, a resorcinol-formaldehyde water-soluble condensate, and a fluorine-based water and oil repellent and heat-treated, a second liquid containing a fluorine-based water and oil repellent and a halogen-containing polymer adhesive is applied. A method for processing glass fiber for rubber reinforcement, which is characterized by processing with a liquid and drying. (2) A patent claim in which the resorcinol-formaldehyde water-soluble condensate and the fluorine-based water/oil repellent in the first liquid are contained in amounts of 5 to 15 wt% and 0.1 to 1.5 wt%, respectively, based on the rubber latex. A method for treating glass fibers for rubber reinforcement according to item 1. (3) The fluorine-based water and oil repellent in the first liquid and the second liquid are both a water dispersion of a water-insoluble compound having a perfluoroalkyl group, according to claim 1 or 2. A method of processing glass fiber for rubber reinforcement. (4) A first coating containing rubber latex, a water-soluble condensate of resorcinol-formaldehyde, and a fluorine-based water and oil repellent on the surface of the glass fiber, and a fluorine-based water and oil repellent and a halogen-containing polymer adhesive on top of the first coating. and a second coating containing a rubber reinforcing glass fiber.