JPH04126877A - Glass fiber for rubber reinforcement - Google Patents

Abstract

PURPOSE:To obtain glass fiber for reinforcement having improved adhesiveness to rubber matrix by treating a glass fiber with a liquid containing an RF precondensate, a nitrile rubber, etc., and, as necessary, further treating the fiber with a liquid containing a nitrile rubber, etc. CONSTITUTION:Adhesiveness of glass fiber to various rubbers, especially heat- resistant rubbers such as hydrogenated nitrile rubber can remarkably be improved by treating a glass fiber with a treating liquid produced by using an RF precondensate, nitrile rubber, chlorosulfonated polyethylene and vinylpyridine- styrene-butadiene as main components and, as necessary, further treating the treated fiber with the 2nd treating liquid containing a nitrile rubber or a hydrogenated nitrile rubber, an isocyanate and a chlorinated rubber. The fiber can be used in various uses.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to rubber reinforcing glass fibers used for reinforcing various rubber products, and more specifically, to a unique method for better adhesion between glass fibers and rubber. This relates to surface-treated glass fibers.

[Prior Art] Rubber products such as rubber belts and tires are widely reinforced with glass fibers in order to improve their strength, toughness, dimensional stability, etc. However, in these applications, they are subjected to repeated bending stress, resulting in bending fatigue, resulting in decreased performance, and peeling between the glass fiber and the rubber matrix is likely to occur.

In order to prevent this peeling and the deterioration of performance, it is necessary to increase the compatibility and adhesive strength between the glass fiber and the rubber matrix, and various treatment agents have been proposed to be applied to the surface of the glass fiber. The most common method is to use a dispersion of resorcinol/formaldehyde resin and various Latinxes. However, even with glass fiber-reinforced rubber bodies that have undergone this treatment, the adhesive strength is not necessarily sufficient, and products with high adhesive strength have the problem that it is difficult to obtain satisfactory water resistance. be. In addition, in recent years, rubber materials with higher physical properties have been used in various applications, and in this case, depending on the rubber material, adhesive strength may not be fully demonstrated only by treatment with these chemicals. Various methods have been proposed in which, after treatment with a chemical, treatment is performed with a different chemical. However, even in this case, the adhesive strength is not necessarily sufficient, and this tendency is particularly strong when hydrogenated nitrile rubber, chlorosulfonated polyethylene, etc. are used as the rubber matrix.

[Means for Solving the Problems 1] In view of the problems of the prior art, the present inventors have arrived at the present invention as a result of intensive studies.

That is, the first aspect of the present invention is a resorcinol-formaldehyde initial condensate, nitrile rubber (hereinafter abbreviated as NBR), chlorosulfonated polyethylene (hereinafter abbreviated as C3M), and vinylpyridine-styrene-butadiene (hereinafter abbreviated as V
This glass fiber for rubber reinforcement is characterized by being treated with a liquid containing P as its main component.

The NBR used in the present invention has a nitrile bond amount of 20 to 4
0% is preferred.

Moreover, there are no particular limitations on C3M, and various commercially available -C compounds can be used as appropriate.

As for Vp, the weight ratio of vinylpyridine:styrene:butadiene is 10-20:10-20:60-8o
Viratex (trade name, manufactured by Sumitomo Nogatta Co., Ltd.), 0650 (trade name, manufactured by Japan Synthetic Rubber Co., Ltd.), Nirapol 1218FS (trade name, manufactured by Nippon Zeon Co., Ltd.), etc. can be suitably used.

In addition, the first MJIm compound of resorcin and formaldehyde is a water-soluble initial compound rich in oxymethyl groups of resorcin and formaldehyde obtained by reacting resorcin and formaldehyde in the presence of an alkaline catalyst such as an alkali hydroxide, ammonia, or an amine. Additional fasteners can be advantageously used. The weight of the pure resorcinol/formaldehyde is preferably within a range of 15 times or less relative to the solid weight of NBR, C3M and Vp. Moreover, it is preferable that the molar ratio of resorcinol and formaldehyde is in the range of 1:05 to 25.

In the present invention, the amount of NBR is NBR, C3M and V
It is preferably in the range of 10 to 70% by weight based on the total solid weight of p. If it is less than this range, the adhesiveness will not be sufficient, and if it exceeds this range, the water resistance will be poor.

The amount of C3M ranges from 0 to 40% by weight based on the total solid weight of NBR, C3M and Vp. If it is less than this range, there will be a problem in heat resistance, and if it is more than this range, there will be a problem in adhesiveness.

The preferred range for Vp is 10 to 70% by weight based on the total weight of NBR, C3M and Vp; below this range, water resistance is poor, and above this range, NBR, C3M and Vp are relatively
Since the amount of 3M is reduced, the adhesiveness and heat resistance are inferior.

In the treatment with the chemical solution of the present invention, the amount of solid content deposited is preferably in the range of 15 to 25% by weight based on the glass fiber,
If it is less than this range, the fatigue performance will not be sufficient, and if it exceeds this range, the adhesiveness will become unstable, which is not preferable. In this process, drying is usually performed at a temperature in the range of 200 to 350°C. When applying such glass fibers as they are to various rubber materials, as is generally done, first twist is added to the glass fiber bundle, then several fibers are pulled together and further twisted to form a glass cord. It is what you use. The glass fibers treated in this way can be applied as they are to various rubber materials and exhibit good physical properties as glass fiber-reinforced rubber bodies.

The glass cord according to the present invention also has excellent heat resistance, and in order to fully demonstrate its characteristics, it is necessary to use a heat-resistant rubber material as the target rubber material, specifically hydrogenated nitrile rubber (hereinafter referred to as H-
It is preferable to choose NBR) or C3M. In this case, since the glass cord as it is has difficulty in adhesion, it is preferable to further treat it with a second chemical solution, and the chemicals normally used for this type of treatment can be widely applied. Specifically, the treatment is performed with a chemical solution containing chlorosulfonated polyethylene, chlorinated rubber, isocyanate, or the like.

The second treatment with such a chemical solution can improve the adhesion with the rubber matrix, but the present inventors have found that in particular NBR
Alternatively, it has been found that the adhesion can be significantly improved by treating with a second liquid containing H-NBR, an isocyanate, and a chlorinated rubber.

Examples of the isocyanate used in this second liquid include methylene diphenyl diisocyanate, tolylene diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, etc. Among these, methylene diphenyl diisocyanate is the most suitable because it has a moderate film hardness and good adhesive properties. preferable.

As NBR, commonly available commercially available NBRs having a nitrile bond content in the range of 20 to 40% can be used. Moreover, H-NBR can be used instead of NBRO. By using this H-NBR, it has excellent adhesion and extremely good heat resistance, and is suitable for applications requiring particularly high heat resistance. The H-NBR preferably has an unsaturation degree of 14 to 28. If the degree of unsaturation is lower than this, the heat resistance will be further improved, but the adhesiveness will be inferior, which is not preferable.

The chlorinated rubber preferably has a chlorination degree of 40 to 80.

The ratio of isocyanate-1- to NBR or H-NBR is preferably in the range of 085 to 3 to 1 isocyanate. If it is less than this range, the film will become too hard, and if it exceeds this range, the adhesion and adhesion will become unstable, which is not preferable. In addition, this isocyanate and NB in the second liquid
The amount of R or H-NBR is preferably in the range of 5 to 15% by weight on a solid basis, and if it is less than this range, sufficient adhesive strength cannot be obtained.

Moreover, if it exceeds this range, the adhesion becomes unstable, which is not preferable. Moreover, it goes without saying that NBR and H-N I3 R can be used in combination, and there is no restriction on their quantitative range. Furthermore, since the second liquid uses chlorinated rubber and has excellent film-forming ability, a rubber reinforcing material with higher adhesive strength can be obtained. The amount of chlorinated rubber is preferably in the range of 10 to 100% by weight based on NBR or H-NBR. Furthermore, various commonly used additives such as zinc white, magnesium oxide, sulfur, and litharge can also be used as vulcanizing agents.

After the coating treatment with the second liquid, drying is performed, but the drying conditions are not particularly limited, and are carried out under boat-like conditions, specifically, at 120 to 200 DEG C. Cl2O to 60 seconds. The glass fibers used in the present invention are not particularly limited, but usually about 200 glass fibers with a thickness of 5 to 1311 m are coated with a binding agent consisting of an anchor agent, an adhesive, a surfactant, etc. Glass fiber is used.

The glass fibers treated according to the present invention are applied to various rubbers, and the types of target rubbers are not particularly limited, but when applied to rubbers with excellent heat resistance such as H-NBR and C3M rubbers, The glass fiber of the present invention significantly exhibits its characteristics.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example: Acrylonitrile butadiene latex (Nippol 1562 manufactured by Nippon Zeon Co., Ltd.
, 447 parts by weight of chlorosulfonated polyethylene (Sumitomo Seika C3M450, solid content 40% by weight), Vp(
Manufactured by Sumitomo Noga Tatsuta Co., Ltd., product name Viratex, solid content 4
1% by weight) to 64 parts by weight of ammonia water (solid content:
25% by weight) was added with stirring to prepare a first liquid.

Three glass fiber bundles, each consisting of 200 glass fibers of 9 μm, were aligned and treated with the first solution according to a conventional method. The solid content adhesion rate at this time was 19% by weight. 280
After drying at °C for 22 seconds, the glass fiber bundles were twisted 8 times per 10 cm and made into 11 fiber bundles.
Furthermore, the reinforcing glass cord was made by ply-twisting it 8 times per Ocm. Various physical properties were evaluated using this glass cord.

The results are shown in Table 1.

In addition, each measurement method is as follows.

Tensile strong wind - speed i 300mm/min, clamp interval: 250mm
, Clamp; Winding method measures the tensile strength of glass cord.

The water-resistant strength test piece was made by applying a tension of 5 kg to the treated glass cord at 1.5 mm intervals, 2 wooden pulls aligned, cotton cloth on the bottom, and chloroprene rubber on the back, preheating for 5 minutes, and then heating to 140°C.
- Pressure molding was carried out for 30 minutes to obtain a product measuring 5 x 300 x 3 mm. Two of these were combined to form one belt. This belt was put on a combination of pulleys of 100 mmφ and 25 mmφ, and the 25 mmφ pulley was immersed in water, and after running at a rotation speed of 1000 r, p, m for 24 hours, a test piece was taken out and the tensile strength was measured. The strength per nid was obtained.

Heat retention rate In the MIT bending tester, the treated glass cord was attached to the adhesive tape from both sides with the paper adhesive tape: 72] 0.18
mm width), attached to a testing machine, subjected to a load of 3 kg, repeated bending (at an angle of 20°) at a rate of 120 times/minute, and read the number of times it took to cut, and the value was set as 8. .

On the other hand, after the treated glass cord was heated and left for 140'-7 days, the number of times until it was cut was read using the same method, and the value was designated as B.

Then, B/AX100 was taken as the heat resistance retention rate.

In addition, using this glass cord, polyisocyanate (
Mitsui Toatsu Co., Ltd., MDI-PH, metaphenylene diisocyanate type) 36 parts by weight, H-NBR compound (Nippon Zeon Co., Ltd., 2020) 60 parts by weight, chlorinated rubber (Asahi Denka Co., Ltd., CR-15) 12 parts by weight , treated with a second liquid containing 1 part by weight of Zinc White No. 3 as a vulcanizing agent and 891 parts by weight of a solvent consisting of methyl ethyl ketone and toluene,
Drying was performed at 155°C for 148 seconds.

The solid content adhesion rate by this second liquid treatment was 2.3% by weight. Using this reinforcing glass cord, the adhesive strength with various rubber matrices was measured. The results are shown in Table 1 along with the rubber used.

In addition, the second liquid was metaphenylene diisocyanate (MD
I-PH2 manufactured by Mitsui Toatsu Co., Ltd.) 50 parts by weight, chlorinated rubber (manufactured by Asahi Denka Co., Ltd., CR-1,5 > 80 parts by weight, chlorosulfonated polymethylene 40 (manufactured by Showa Denko/DuPont) 12
The adhesive strength was also measured for a second solution which was treated in the same manner as above, consisting of 0 parts by weight, 50 parts by weight of carbon black, 5 parts by weight of zinc white, and 1,695 parts by weight of toluene.

For 100 parts by weight of JYU H-NBR (Nippon Zeon Co., Ltd., 2020), 50 parts by weight of carbon black HA F, 5 parts by weight of zinc white, 3 parts by weight of plasticizer, 2 parts by weight of anti-aging agent. parts, and 3 parts by weight of a vulcanization accelerator.

■C3M (manufactured by Showa Denko/DuPont, C3M40)
Carbon black S RF 50 per 100 parts by weight
parts by weight, 5 parts by weight of magnesium oxide, 3 parts by weight of pentaerythritol, 4 parts by weight of a plasticizer, 3 parts by weight of an anti-aging agent, and 2 parts by weight of a vulcanization accelerator.

Adhesive strength: Arrange 21-22/25mm of treated glass cord on a rubber sheet (approx. 3mm thick) with the composition described in "Adhesive Strength", cover it with a cloth, and heat it at 150°C for 25 minutes at 20Kg/cn.
It was created by vulcanization molding at a pressure of 300 ft. This material was cut to obtain a sample piece with a width of 25 mm and a length of 120 mm.

Then, the adhesive strength was obtained by peeling the cord side and the rubber side at a speed of 50 mm/min.

Examples 2 to 5, Comparative Examples 1 to 7 Using the same treatment liquid as in Example 1 and changing the amount of treatment liquid as shown in Table 1, the same operations were performed to evaluate various physical properties. The results are also shown in Table 1.

As is clear from Table 1, the physical properties of the comparative example, such as water resistance strength, heat resistance retention rate, and adhesive strength, are good, but it is difficult to maintain the necessary balance between the three for practical use as glass fiber for rubber reinforcement. Can not.

On the other hand, according to the embodiment, a balance between the three can be achieved, and a practically excellent glass cord can be obtained.

[Effect of the invention 1 The glass fiber of the present invention has excellent adhesion to various rubbers,
In particular, it has excellent adhesion to heat-resistant rubbers such as H-NBR and C3M, and can be used in a wide range of applications.

■

Claims (2)

[Claims] (1) A glass fiber for rubber reinforcement, characterized in that it has been treated with a liquid whose main components are a resorcinol-formaldehyde initial condensate, nitrile rubber, chlorosulfonated polyethylene, and vinylpyridine-styrene-butadiene. (2) After treatment with the first liquid mainly consisting of resorcinol/formaldehyde initial condensate, nitrile rubber, chlorosulfonated polyethylene, and vinylpyridine-styrene-butadiene, nitrile rubber or hydrogenated nitrile rubber, isocyanate, and chlorinated rubber A glass fiber for rubber reinforcement, characterized in that it is treated with a second liquid containing.