JPH0567652B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Application Field) The present invention relates to a method for processing rubber reinforcing glass fibers used for reinforcing rubber products such as rubber belts and tires, and a method for producing reinforced rubber products. (Prior Art) Reinforcing glass fibers such as glass fiber yarns are widely used to increase the strength of rubber products such as rubber belts and tires. Rubber products such as rubber belts are subjected to repeated bending stress, resulting in bending fatigue, resulting in a decrease in performance, and peeling between the reinforcing material and the rubber matrix is likely to occur. In order to prevent such peeling or deterioration of performance and obtain a sufficient reinforcing effect, it is necessary to increase the compatibility between the reinforcing glass fiber and the rubber and increase the adhesive strength. is applied. Various compositions of treatment materials have been proposed. For example, various processing agents have been proposed, such as a processing agent using a combination of a vinylpyridine-styrene-butadiene terpolymer latex and a water-soluble condensate of resorcinol and formalin, or a processing agent containing rubber latex. (See JP-A No. 55-114551.) Treatment liquids containing polyisocyanates, polynitrone aromatic compounds, and acidic halogen-containing polymers have also been proposed. (Refer to JP-A-49-14546) However, when the treatment methods using these treatment liquids are applied to glass fibers, (1) Sufficient adhesive strength cannot be obtained. (2) It is difficult to obtain rubber products with sufficient bending strength. It had the following drawbacks. Recently, with the rise in temperature near automatic engines, heat-resistant rubbers such as chloroprene rubber, chlorosulfonated polyethylene, and hydrogenated nitrile rubber have come to be used as rubber for timing belts. However, since the adhesion of such heat-resistant rubber, especially hydrogenated nitrile rubber, is lower than that of ordinary rubber, the above-mentioned drawbacks tend to be greater than that of ordinary rubber, and it is difficult to achieve industrially satisfactory rubber reinforcement. There was no known method for processing glass fiber for industrial use or for manufacturing reinforced rubber products. For example, glass fibers treated with the treatment agent described in JP-A-55-114551 have extremely low adhesion to hydrogenated nitrile rubber. Furthermore, the treatment liquid described in JP-A-49-14546 adheres well to organic fibers, but has extremely low adhesion to glass fibers and has a short pot life. (Problems to be Solved by the Invention) The present invention aims to solve the above-mentioned drawbacks of the prior art. [Structure of the Invention] (Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and is intended to solve the above-mentioned problems. A method for treating glass fibers for rubber reinforcement, which comprises treating with a first liquid containing a water-soluble condensate and then a second liquid containing a halogen-containing polymer and an isocyanate, and a vinyl pyridine-styrene-butadiene terpolymer. The hydrogenated nitrile rubber is reinforced with glass fibers treated with a first liquid containing latex, rubber latex, and a water-soluble condensate of resordin-formaldehyde, and then treated with a second liquid containing a halogen-containing polymer and an isocyanate. The present invention provides a method for manufacturing reinforced rubber products. Next, the invention described in claim 1 (the first
invention) will be explained in more detail. First, the first liquid will be explained. Vinylpyridine-styrene-butadiene terpolymer latex (hereinafter referred to as terpolymer latex) is one in which vinylpyridine, styrene, and butadiene are copolymerized in a weight ratio of 10 to 20:10 to 20:60 to 80. It is particularly appropriate to use Examples of such terpolymer latexes include pyratex (trade name, manufactured by Sumitomo Naugatatsu Co., Ltd.), 0650 (trade name, manufactured by Japan Synthetic Rubber Co., Ltd.), and Nipol.
2518FS (trade name, manufactured by Nippon Zeon) etc. can be suitably used. As the rubber latex, a latex with a relatively low degree of polymerization used as a treatment agent for rubber reinforcing fibers, particularly a butadiene rubber latex, is suitable. 0700 (Product name, Japan Synthetic Rubber, Nipol LX111
(manufactured by Nippon Zeon) etc. can be suitably used. A water-soluble condensate of resorcinol-formaldehyde (hereinafter simply referred to as a condensate) is obtained by reacting resorcinol and formaldehyde in the presence of an alkaline catalyst such as an alkali hydroxide, ammonia, or an amine. Water-soluble initial addition condensates of resorcinol and formaldehyde (resols) rich in oxymethyl groups can be preferably used. In particular, the molar ratio of resorcin and formaldehyde is 1:0.3.
It is preferable to react at a ratio of ~2.5. In the first liquid, the three components are mixed so that the ratio of latex to the total amount of terpolymer latex and latex (referred to as total latex) is between 2.5 and 50 wt%, and the ratio of condensate to the total latex is between 2.5 and 25 wt%. Mix uniformly according to the usual method. Note that the above ratios are all based on solid content. If the ratio of latex to total latex is too large, the adhesive strength of reinforcing glass fibers treated with the treatment agent of the present invention becomes excessive, which tends to cause trouble in the yarn twisting process, and also reduces heat resistance. If the above ratio is too small, the effect of preventing peeling when subjected to repeated stress will be insufficient, and peeling will easily occur especially when used in a high temperature and humid environment. If the ratio of the condensate to the total latex is too large, the reinforcing glass fibers treated with the treatment agent of the present invention will become hard and prone to bending fatigue. In addition, if this value is too small, the adhesive force with the rubber matrix tends to decrease. The concentration of the first liquid mixture, ie, the weight percent of the total amount of the terpolymer latex, latex, and condensate in the processing agent, is suitably from 10 to 50%, preferably from 20 to 40%. If the concentration is too low, adhesion to reinforcing glass fibers will be insufficient, and if the concentration is too high, stability will deteriorate and gelation will occur easily. The first liquid contains the above-mentioned terpolymer latex, latex, and condensate as essential components, but a latex stabilizer, anti-aging agent, etc. may be added as necessary. Next, the second liquid will be explained. As the isocyanate, methylene di(phenyl isocyanate) (MDI), toluene diisocyanate (TDI), triphenylmethane triisocyanate, naphthalene diisocyanate, etc. can be suitably used. Since the isocyanate monomer has high volatility, polyisocyanate such as a dimer having a relatively small molecular weight and high reactivity can be suitably used. The preferred degree of polymerization is 2-10. Examples of halogen-containing polymers include chlorinated rubber,
Chloroprene, chlorinated polyethylene, chlorinated ethylene-propylene copolymer, chlorinated polyvinyl chloride, chlorosulfonated polyethylene, etc. can be used, but chlorosulfonated polyethylene gives particularly favorable results. It is appropriate that the ratio of isocyanate to halogen-containing polymer is 10 to 100:100; if the ratio of isocyanate is too large, bending fatigue resistance and heat resistance will deteriorate. Furthermore, if the proportion of isocyanate is too small, the adhesiveness will decrease. The concentration of the second liquid (wt% of the total amount of isocyanate and halogen-containing polymer) is suitably 3 to 15 wt%, preferably 5 to 10 wt%; if this concentration is too large, the viscosity of the liquid will increase. Then,
Unevenness tends to occur, and if this concentration is too low, the amount of adhesion decreases, making it impossible to obtain sufficient effects. Note that the second liquid can further contain a lead compound to improve water resistance. Lead compounds include litharge, lead maleate,
Particularly preferred is lead phthalate. The amount of lead compound in the second liquid is suitably 0.5 to 5 wt%, preferably 1 to 3 wt%. Although there are no particular limitations on the reinforcing glass fibers to be treated by the method of the present invention, for example, glass fibers with a thickness of 9 μm added with a sizing agent and bundled in about 200 glass fibers can be suitably used. Arrange three such reinforcing glass fibers and add 12 to 22 wt% of the first liquid, preferably 16 to 20 wt%.
%Apply according to the usual method. After applying the first liquid, preferably after sufficiently drying, the second liquid is applied according to a conventional method. It is desirable to dry the first liquid at a temperature of 200 to 350°C. The amount of the second liquid applied is based on the reinforcing glass fiber.
A suitable content is 0.5 to 5 wt%, preferably 2 to 4 wt%. After applying the second liquid, preferably 120~
Dry at 200°C. In addition, about 0.5 to 4.0 S per 2.54 cm (1 inch) was added to the reinforcing glass fiber coated with the above-mentioned first liquid.
Or, add Z-twist (pre-twist) and add 2~
About 13 pieces lined up, about 0.5 to 3.0 per 2.54cm,
It is preferable to give a twist in the opposite direction to the first twist (first twist) to form a yarn, and then apply the second liquid to the yarn. There is no particular limitation on the type of rubber to be reinforced with the reinforcing glass fibers treated by the method of the present invention, but Hybaron, nitrile rubber, hydrogenated nitrile rubber, etc. can be exemplified, and very suitable results can be obtained.
Reinforced rubber products such as timing belts with good heat resistance and durability can be obtained. Furthermore, even when hydrogenated nitrile rubber is used as the rubber, the adhesion is extremely good, and even when subjected to repeated bending stress at high temperatures, bending fatigue will not occur and performance will not deteriorate or peeling will occur. Next, the invention described in claim 3 (second claim)
invention) will be explained in more detail. In the second invention, a reinforced rubber product is manufactured by reinforcing hydrogenated nitrile rubber with the rubber reinforcing fibers obtained in the first invention (referred to as main reinforcing fibers). As the hydrogenated nitrile rubber, there are known ones such as Zetpole2020 (trade name, manufactured by Nippon Zeon),
Tornacc3830 (trade name, manufactured by NOVA) can be suitably used. There are no particular limitations on the manufacturing method of the reinforced rubber product, and conventional methods can be used. For example, a hydrogenated nitrile rubber compound containing carbon black, zinc white, anti-aging agents, vulcanization accelerators, plasticizers, etc. is formed into a sheet, and the reinforcing fibers are placed between the sheets. A sheet-shaped reinforced rubber product can be obtained by sandwiching and pressing while heating. In addition, according to the usual method, an organic fiber woven fabric (teeth cloth) is wound around a cylindrical mold, the reinforcing fiber is wound on top of this in a spiral shape, the above-mentioned sheet is further wrapped, and the mold cut in half is covered. It is also possible to manufacture an endless belt by manufacturing a cylindrical reinforcing rubber product by pressing while heating and cutting the product into a predetermined width perpendicular to the cylindrical axis. (Function) The first liquid of the present invention has good affinity with the reinforcing glass fibers, and forms a first layer firmly adhered to the reinforcing glass fibers. The second liquid has insufficient adhesion to the reinforcing glass fibers, but is reactive with the first liquid, and the second layer formed by the second liquid is integrated with the first layer, 2
The layers are firmly bonded to the reinforcing glass fibers via the first layer. The second layer is compatible with the rubber matrix and is strongly bonded to the rubber matrix.
It seems that suitable results can be obtained. Although the mechanism of this is not clear, it is thought that the reaction between some moisture remaining in the first layer and isocyanate in the second liquid also contributes. Example 1 Vinylpyridine, styrene and butadiene
Vinylpyridine-styrene-butadiene terpolymer latex copolymerized in a ratio of 15:15:70 (Pyratex, trade name, manufactured by Sumitomo Naugatatsu Co., Ltd.)
terpolymer content: 41 wt%), 65 parts by weight, butadiene latex (0700, trade name, made by Japan Synthetic Rubber, butadiene content: 57 wt%), 8 parts by weight, addition condensate of resorcinol and formaldehyde (resol). Aqueous solution containing 20wt%, 15 parts by weight, water, 12
To the mixture of parts by weight, 1 part by weight of an emulsion of mineral oil (mineral oil content 55 wt%) and 1 part by weight of aqueous ammonia (concentration 18 wt%) as anti-aging agents were added.
I got the liquid. Chlorosulfonated polyethylene (Hypalon)
Toluene was added to 10 parts by weight of polyisocyanate (MR-200, trade name, manufactured by Nippon Polyurethane Co., Ltd.) and 5 parts by weight of polyisocyanate (MR-200, manufactured by Nippon Polyurethane Co., Ltd.).
A second solution with a concentration of 10 wt% was obtained. Three glass fiber bundles made of 200 9μ glass fibers were arranged and the first liquid was applied in accordance with a conventional method. (Solid content 17wt%). After drying at 250°C for 1 minute, this glass fiber bundle was given 4.0 Z twists (first twist) per 2.54 cm, and the fiber bundle that had been given this first twist was further
The second liquid was applied to the 13 fibers that had been twisted 2.1 times per 2.54 cm (first twist). (solid content 3wt%) This was dried at 130℃ for 1 minute,
A test piece was created using it as a reinforcing glass fiber. Rubber type Carbon black, 40 parts by weight, zinc white, 5 parts by weight, stearic acid, 1 part by weight, anti-aging agent, 2 parts by weight, vulcanization accelerator, 3 parts by weight, per 100 parts by weight of hydrogenated nitrile rubber. Contains 5 parts by weight of plasticizer. Test piece 1 Two of the above reinforcing fibers were sandwiched between rubber sheets with a thickness of 1 mm, a width of 5 mm, and a length of 300 mm, pressed, and heated at 150°C.
Test piece 2 Vulcanized for 20 minutes at 150℃ Test piece 2 The reinforcing glass fibers were lined up without gaps between rubber sheets with a thickness of 3 mm, width of 25.4 mm, and length of 100 mm, pressed, and vulcanized for 20 minutes at 150°C. The tensile strength of the test piece 1 was measured, as well as the tensile strength of the test piece 1 after being left in an oven at 120° C. for 24 hours and subjected to bending stress 3000 times using an MIT tester. Using an autograph, this test piece 2 and the test piece 2 after being left in hot water at 100°C for 1 hour,
The adhesive force was measured by peeling at a tensile speed of 50 mm/min. The above test results are shown in the attached table. Example 2 Instead of the rubber in Example 1, 100 parts by weight of Hypalon, 50 parts by weight of carbon black, MgO,
The results of a test similar to Example 1 using a mixture of 10 parts by weight, 10 parts by weight of plasticizer, 1 part by weight of anti-aging agent, and 2 parts by weight of vulcanization accelerator are shown in the attached table. . Comparative Examples 1 and 2 Using reinforcing glass fibers coated with 20wt% of the same first liquid as in Example 1, test pieces similar to those in Examples 1 and 2 were prepared and the same tests were conducted. The results are shown in the attached table. Comparative Examples 3 and 4 In place of the first liquid in Comparative Examples 1 and 2, the same second liquid as in Example 1 was used, test pieces similar to those in Examples 1 and 2 were prepared, and the same tests were conducted. The results are shown in the attached table. (Effects of the Invention) The reinforcing glass fibers treated by the method of the present invention have high adhesion to heat-resistant rubbers such as Hypalon and hydrogenated nitrile rubber, especially hydrogenated nitrile rubber, and can be used as rubber products with high bending strength. obtained,
There is little loss of performance even when used in high temperature and high humidity conditions. Furthermore, the treatment solution of the present invention has an extremely long pot life of about 30 days.

[Table] Shows hydrogenated nitrile rubber, Hypalon.

Claims (1)

[Scope of Claims] 1. After being treated with a first liquid containing a terpolymer latex of vinyl pyridine-styrene-butadiene, a rubber latex and a water-soluble condensate of resordine-formaldehyde, a second liquid containing a halogen-containing polymer and an isocyanate is treated. 1. A method of processing glass fiber for rubber reinforcement, the method comprising: processing. 2. The method for treating glass fibers for rubber reinforcement according to claim 1, wherein the rubber latex is butadiene latex. 3. After treatment with a first liquid containing a terpolymer latex of vinyl pyridine-styrene-butadiene, a rubber latex and a water-soluble condensate of resordine-formaldehyde, hydrogen is applied to glass fibers treated with a second liquid containing a halogen-containing polymer and an isocyanate. A method for producing a reinforced rubber product characterized by reinforcing nitrile rubber. 4. The method for producing a reinforced rubber product according to claim 3, wherein the rubber latex is butadiene latex.