JPH02167845A - Glass fiber for rubber reinforcing - Google Patents

Abstract

PURPOSE:To improve adhesion and fatigue resistance at high temperature by treating with a liquid comprising resorcin formaldehyde initial condensate, etc., as a main component and a natural rubber, etc., as an adding component. CONSTITUTION:Resorcin is reacted with formaldehyde in a weight ratio of 1:0.5-2.5 in the presence of an alkali catalyst to obtain a resorcin formaldehyde initial condensate (A). Next, vinylpyridine, styrene and butadiene are mixed in a weight ration of 10-20:10-20:60-80 to obtain vinylpyridine-styrene-butadiene (B). Then, component B is mixed with chlorosulfonated polyethylene (C) in a weight ratio of 9-5:1-5 and resultant mixture is mixed with component A in an amount of <=15wt.% of solid weight of the resultant mixture calculated as pure resorcin formaldehyde to obtain a main component material (D). Next, a natural rubber or isoprene rubber of 5-20wt.% of total solid of component B and C in the main component D is added to the component D to obtain a liquid-like material (E), then glass fiber is treated with the component E and dried at 200-350 deg.C to produce the rubber-reinforcing glass fiber.

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 + d fat 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 is used as the rubber matrix. The problem was that it was difficult to obtain.

[Means for Solving the Problems] 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, vinylpyridine-styrene-butadiene (hereinafter abbreviated as Vp) and chlorosulfonated polyethylene (hereinafter referred to as C3
This glass fiber for rubber reinforcement is characterized by being treated with a liquid containing M) as a main component and further adding natural rubber or isoprene rubber.

As Vp used in the present invention, the ratio of vinylpyridine:styrene:butadiene is 10 to 20:10 to 20 by weight.
: 60 to 80 is suitable, such as Viratex (product name, manufactured by Sumitomo Nogatta Co., Ltd.), 0650 (product name,
Nippon Synthetic Rubber Co., Ltd.), Nirapol 1218FS (trade name, Nippon Zeon Co., Ltd.), etc. can be suitably used.

Moreover, there are no particular restrictions on the C3M, and various types of C3M commercially available for boat fishing can be used as appropriate.

The resorcinol/formaldehyde initial condensate is a water-soluble initial addition line enriched in the oxymethyl group of resorcinol and formaldehyde obtained by reacting resorcinol and formaldehyde in the presence of an alkaline catalyst such as alkali hydroxide, ammonia, or amine. Hardware can be suitably used.

The weight of pure resorcinol/formaldehyde is preferably 15% by weight or less based on the solid weight of Vp and C3M, and the ratio of resorcinol and formaldehyde is 1:0.5 to 2.5. In the present invention, the ratio of Vp and C3M is preferably 9:1 by weight.
The range of Vp to 5:5 is preferred.

If the amount is less than this, the adhesion will not be sufficient, and if it is more than this, the fatigue resistance will be poor.

In the present invention, in addition to these main components, natural rubber or isoprene rubber is further added, and the amount added is 5 to 5% based on the total solid content of Vp and C5M.
The content is preferably in the range of 20% by weight; if it is less than this range, the fatigue resistance at high temperatures will not be sufficiently improved, and if it exceeds this range, the adhesive strength will decrease, so it is preferable to avoid it.

On the other hand, in order to improve adhesion, nitrile rubber (hereinafter N
It is effective to add a small amount of BR (referred to as BR), and can improve the decrease in adhesion caused by the addition of natural rubber or isoprene rubber.

The type of natural rubber is not particularly limited, and commercially available natural rubber can be used. Further, as the isoprene rubber, CARIFLEX IR-700 (manufactured by Shell Chemical Co., Ltd.) and MaxRen IR-900 (manufactured by Seitetsu Kagaku Kogyo Co., Ltd.) can be suitably used.

The amount of solid content deposited by this treatment is 1% per glass fiber.
It is preferably in the range of 5 to 25% by weight; 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 preferred.

After this treatment, the glass fibers are usually dried at a temperature in the range of 200 to 350°C. When applying the glass fibers as they are to various rubber materials, the glass fiber bundles are first twisted as is generally done. Afterwards, multiple cords are tied together and further twisted to form a glass cord. 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 select NBR) or C3M; in this case, since the glass cord has poor adhesion as it is, it is preferable to further treat it with a second chemical solution, and the second invention was made from this point of view. be. That is, resorcinol formaldehyde initial condensate and Vp and C
A rubber characterized by being treated with a first liquid containing SM as a main component and further adding natural rubber or isoprene rubber, and then treated with a second liquid containing NBR or H-NBR, isocyanate, and chlorinated rubber. Glass fiber for reinforcement.

Isocyanates used in the present invention include methylene diphenyl diisocyanate, toluene diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, etc. Among these, methylene diphenyl diisocyanate, which has appropriate film hardness and good adhesiveness, is most preferred.

As NBR, commonly available commercially available ones having a nitrile bond content in the range of 20 to 40% can be used.

Moreover, H-NBR can be used instead of NBR. By using this H-NBR, it has excellent adhesion and extremely good heat resistance, and is particularly suitable for applications requiring high heat resistance. The H-NBR preferably has an unsaturation degree in the range of 14 to 28. If the unsaturation degree is lower than this, the heat resistance will be further improved, but the adhesiveness will be poor, which is not preferable.

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

The ratio of isocyanate to NBR or H-NBR is preferably in the range of 0.5 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 adhesiveness and adhesion will become unstable, which is undesirable.
Alternatively, the amount of H-NBRO 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.

In addition, if it exceeds this range, the adhesion becomes unstable, which is not preferable.Also, it goes without saying that NBR and H-NBR can be used in combination, and there is no restriction on the quantitative range. In addition, the second liquid uses chlorinated rubber, which has excellent film-forming ability.
A rubber reinforcing material with higher adhesive strength can be obtained.

The amount of chlorinated rubber is 10% for NBR or H-NBR.
The range of 1001% to 100% is preferable, and various commonly used additives such as zinc white, magnesium oxide, sulfur, litharge, etc. can also be used as the vulcanizing agent.

After treatment with the second liquid, drying is performed, but the drying conditions are not particularly limited.
The glass fiber used in the present invention is not particularly limited, but it is usually a glass fiber with a thickness of 5 to 13 μm that is coated with an anchoring agent, an adhesive, a surfactant, etc. Apply a sizing agent consisting of 20
About 0 glass fibers are used.

The glass fibers treated according to the present invention can be used in various rubbers, and the target rubber type is 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 1 Vp containing vinylpyridine, styrene, and butadiene at a ratio of 1515 to 0 to 320 parts by weight of an addition condensate of resorcinol and formaldehyde (manufactured by Sumitomo Nogatta, trade name Viratex, solid content 41% by weight) 4
24 parts by weight, 188 parts by weight of chlorosulfonated polyethylene (C3M450 manufactured by Steel Chemical Co., Ltd., solid content 40% by weight),
Natural rubber (l (A latex, solid content 60% by weight) 22
22 parts by weight of aqueous ammonia (25%) were added with stirring, and water was added to give a total of 1000 parts by weight to prepare a first liquid.

Three glass fiber bundles made of 200 glass fibers of 9μ are aligned and prepared according to a conventional method. fi. At this time, the solid content adhesion rate was 19 weight 1% tear.
After drying at 280'C for 22 seconds, 13 fiber bundles of this glass woven Rikyo were twisted 16 times per 10cm and then twisted 8 times per 10cm to form a reinforcing glass cord. . Various physical properties were evaluated using this glass cord. The results are shown in Table 1.

Okai 11 chloroprene rubber (manufactured by Showa Den Epon Co., Ltd., Neo 7”
Ren GRT60. 17”: zWRT40)
Carbon black HAF per 100 parts by weight
45 parts by weight, 5 parts by weight of zinc white, 5 parts by weight of anti-aging agent,
5 parts by weight of process oil, 4 parts by weight of magnesium oxide,
Contains 1 part by weight of stearic acid, 0.5 part by weight of sulfur, 0.5 part by weight of paraffin wax, and 1 part by weight of NA-22.

In addition, each measurement method is as follows.

Hair drying speed i: 300ts/min, clamp interval: 250mm
, Clamp; Measuring the tensile strength of glass cord using the winding method.

The shoe tying test specimen was made by arranging 19 to 20 treated reinforced glass cords/25 wires on rubber seams (3 mm thick), covering them with a cloth, and heating them at 150°C for 30 minutes at 20 kg/cd.
It was prepared by vulcanization molding at a pressure of . Peel this thing at a rate of 5
Measurement was made at 0 mm/min.

The barge test piece is 5kg of treated glass cord at 1mm intervals.
Apply tension, align the two, cotton cloth on the bottom, chloroprene rubber on the back, preheat for 5 minutes, pressurize at 140℃ for 30 minutes,
Two molded bodies measuring 5 x 300 x 3 mm were combined to form one belt.

A belt was applied to two pulleys of 100 amφ and 25 mmφ, and a part of the 25 mmφ pulley was immersed in water, and the test piece was rotated for 24 hours at a rotation speed of 100 Or, p, -. It was taken out and its tensile strength was measured.

The MIT glued glass cord was attached to a lamination testing machine from both sides with adhesive tape (Ttogi adhesive tape, 7210.18 mm width), a load of 3 kg was applied, and the cord was bent at 120 times/min (120° angle) and cut. I read the number of times I got there. (Normal temperature) On the other hand, the glass fibers left at 120°C for 7 days were similarly measured. (Heat resistance) Examples 2 to 6 #JLtc of the first liquid was as shown in Table 1, and the whole was 100
A glass cord was obtained in the same manner as in Example 1, except that the amount was 0 parts by weight, and various physical properties were evaluated in the same manner. The results are shown in Table 1. The isoprene rubber used in Example 4.5 was Max 7 Fluorene IR-900 (manufactured by Steel Chemical Industry Co., Ltd., solid content: 66.5% by weight).

The nitrile rubber added in Example 6 is Nilapol 1562 manufactured by Nippon Zeon Co., Ltd. and has a solid content of 41% by weight.

Comparative Example 1.2 As shown in Table 1, C3M-free (Comparative Example 1) 1st
Liquid, Contains No Vp (Comparative Example 2) A glass cord was prepared and evaluated in the same manner as in Example 1, except that the first liquid was used. The results are shown in Table 1.

Comparative Example 3 A glass cord was prepared in the same manner using a liquid containing no natural rubber as the first liquid, and evaluated. The results are shown in Table 1.

Comparative Examples 4 to 6 Carboxylated SBR (
Manufactured by Asahi Kakai Kogyo Co., Ltd., L-5702, solid content 48% by weight) (
Comparative Example 4), butadiene rubber (manufactured by Japan Synthetic Rubber Co., Ltd., 07
00, solid content 57%) (Comparative Example 5), carboxylated NBR (manufactured by Nippon Zeon Co., Ltd., Nilapol 15F 1. Solid content 40%) (Comparative Example 6) to have the composition shown in Table 1. A glass cord was otherwise prepared in the same manner as in Example 1,
We conducted the evaluation.

The results are shown in Table 1.

As is clear from Table 1, the addition of NR or ■R significantly improves fatigue resistance, especially thermal fatigue resistance.
If a large amount is added, a decrease in adhesiveness is observed (Example 3), but when NBR is added to this system, the effect of suppressing the decrease in adhesiveness is large (Example 6).

Example 7 Using the glass cord treated in Example 1, 36 parts by weight of polyisocyanate (manufactured by Mitsui Toatsu Co., Ltd., MDI-PH, metaphenylene diisocyanate type), 60 parts by weight of H-NBR compound (manufactured by Nippon Zeon Co., Ltd., 2020) 12 parts by weight of chlorinated rubber (manufactured by Asahi Denka Co., Ltd., CR-15), 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 carried out for C148 seconds.The solid content adhesion rate by this second liquid treatment was 2.3% by weight.Various physical properties were evaluated using this reinforcing glass cord.The results were used to evaluate the treatment liquid composition. , and the rubber used are shown in Table 2.

Oi≦Ramura■H-NBR (manufactured by Nippon Zeon Co., Ltd., 2020) 100
! For 1 part, 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, and 3 parts by weight of vulcanization accelerator were blended.

■C3M (manufactured by Showa Denko/DuPont, C3M40)
Carbon black S RF 5 per 100 parts by weight
0 parts by weight, 5 parts by weight of magnesium oxide, 1 part by weight of pentaerythritol, 4 parts by weight of a plasticizer, 3 parts by weight of an anti-aging agent, and 1 part by weight of a vulcanization accelerator.

Examples 8 to 14 The glass cords of Examples 2 to 6 were treated in the same manner as in Example 7, except that the composition of No. 2'/& was as shown in Table 2, and the reinforcing glass glue fiber cords were obtained, and its physical properties were evaluated.

In addition, the same treatment was performed using an NBR compound (manufactured by Nippon Zeon Co., Ltd., 1042) instead of the H-NBR compound as the second liquid, and the physical properties were evaluated. The results are shown in Table 2.

Comparative Examples 7 to 12 The glass cords obtained in Comparative Examples 1 to 6 were treated with the second liquid in the same manner as in Example 7.

The physical properties of this product were evaluated and the results are shown in Table 2.

As is clear from Table 2, by adding NRS IR to the first liquid, fatigue resistance, especially thermal fatigue resistance, is significantly improved, but when a large amount is added, a decrease in adhesiveness is observed (Example 9), on the other hand, by adding NBR to this system, the decrease in adhesiveness can be suppressed (Example 12).

[Effects of the Invention] The glass fiber of the present invention has excellent adhesion to various rubbers and has excellent fatigue resistance at high temperatures, and in particular has excellent adhesion to heat-resistant rubbers such as H-NBR and C3M. It is large and can be used for a wide range of purposes.

Claims (2)

[Claims] (1) Rubber reinforcing glass characterized by being treated with a liquid consisting mainly of a resorcinol-formaldehyde initial condensate, vinylpyridine-styrene-butadiene and chlorosulfonated polyethylene, with the addition of natural rubber or isoprene rubber. fiber. (2) After treatment with a first liquid consisting of a resorcinol-formaldehyde initial condensate, vinylpyridine-styrene-butadiene and chlorosulfonated polyethylene as main components, and further adding natural rubber or isoprene rubber,
A glass fiber for reinforcing rubber, characterized in that it has been treated with a second liquid containing nitrile rubber or hydrogenated nitrile rubber, an isocyanate, and a chlorinated rubber.