JPH0459640A - Glass fiber for reinforcing rubber - Google Patents

Abstract

PURPOSE:To improve adhesiveness of rubber to glass fiber and heat resistance of adhesive, by treating glass fibers for reinforcing rubber with a solution consisting essentially of resorcinolformaldehyde precondensate, a latex and free resorcinol. CONSTITUTION:A latex (e.g. vinylpyridine-styrene-butadiene latex) is blended with 5-15wt.% based on solid content of the latex of resorcinol-formaldehyde precondensate, aged for 24 hours and mixed with water containing 3-40wt.% free resorcinol to give 20-40wt.% treating solution. Glass fibers of about 200 fibers bundled with a bundling agent are coated with 15-25wt.% calculated as solid content of the treating solution and dried at 200350 deg.C.

Description

[Detailed Description of the Invention] [Field of Industrial Application] 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 strength, toughness, dimensional stability, etc. However, in these applications, the glass fibers are subjected to repeated bending stress, resulting in bending fatigue, resulting in decreased performance, and peeling between the glass fibers 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 between the glass fiber and the rubber matrix and the adhesive strength. The most common method is to use a dispersion of resorcinol/formaldehyde resin and various latexes.

Generally, the molar ratio of formalin to resorcin in this resorcinol/.decalumaldehyde resin is in the range of 0.5 to 20, and if it is smaller than this range, the liquid phase becomes unstable. In addition, in order to reduce instability factors, it is necessary to add various additives such as stabilizers, but depending on the addition of these additives, it may cause various undesirable effects when used as a surface treatment agent. This is the result.

However, if it is larger than this range, the migration will increase during curing after treatment with a treatment agent, and
Water resistance also decreases.

In recent years, rubber-glass fiber composite materials have been increasingly used in environments with severe temperature conditions.

In order to create a glass fiber-rubber composite material that can withstand use in such environments, it goes without saying that the rubber material itself must have heat resistance, but it is also important to improve the adhesion between the rubber material and glass fiber. Of course, it is also necessary to add heat resistance to the adhesive. In this case, it is possible to use a material with excellent heat resistance as latex, and it can be expected to have some effect, but the use of special latex materials is not recommended due to price, availability of raw materials, ease of use, etc. It was limited.

[Specific means for solving the problem] The present inventors
As a result of intensive studies on a glass fiber treatment agent consisting of an initial condensate of resorcinol/decalumaldehyde resin and latex, we have obtained glass fibers that can provide a rubber-glass fiber composite material with excellent heat resistance without using special latex. This is what led to the present invention. That is, the present invention provides rubber-reinforcing glass 46, which is treated with a liquid whose main components are a resorcinol-formaldehyde initial condensate, latex, and free resorcinol! Glass for rubber reinforcement, characterized in that the initial condensate of resorcinol/formaldehyde and latex are mixed and aged to stabilize the liquid phase, and then treated with a liquid obtained by dissolving in water and adding and mixing lucin. It is a fiber.

The present invention has been achieved by making it possible to reduce the formalin/resorcinol molar ratio without using additives such as stabilizers, and to obtain a processing solution with extremely good stability. That is, the present invention is a rubber-reinforcing glass fiber characterized by being treated with a liquid containing a resorcinol/formaldehyde initial condensate and latex and free resorcinol as the main components. Glass fibers for rubber reinforcement are mixed and aged to stabilize the liquid phase, and then treated with a mixture of resorcinol dissolved in water.

The present invention is characterized in that the formalin/resorcinol molar ratio in the adhesive treatment liquid is extremely lower than the normal range; No liquid was obtained.

The present inventors have found that in the preparation process of a mixed dispersion of resorcin-formalin initial condensate and latex, it is almost impossible to add an excess of resorcin to formalin from the viewpoint of liquid stability. This is not possible, and if free resorcin is added to an aged and stabilized solution of resorcin-formalin initial condensate (molar ratio approximately 1:1) and latex, the stability of the solution may be impaired. Without,
This confirms that a uniform dispersion can be obtained.

The resorcinol/formaldehyde initial condensate used in the present invention is an initial aqueous solution rich in oxy/methyl groups of resorcinol and formaldehyde obtained by reacting resorcinol and formaldehyde in the presence of an alkaline catalyst such as an alkali hydroxide, ammonia, or an amine. Addition condensates of can be suitably used.

The molar ratio of formalin/resorcin is approximately 1, which allows a uniform and stable dispersion to be obtained by mixing with latex.
Preferably, at least one.

As the latex, various types of latex commonly used in this type of treatment liquid can be used, such as vinylpyridine-styrene-butadiene (hereinafter abbreviated as Vp), chlorosulfonated polyethylene (hereinafter abbreviated as C3M), Acrylic color butadiene latex (hereinafter referred to as MBR), styrene butadiene latex (hereinafter referred to as SBR)
(abbreviated as ), and of course, these can also be used in combination.

There is no particular restriction on the type of Vp, but the weight ratio of vinylpyridine:styrene:butanoene is 10 to 20:1.
0 to 20: 60 to 80 is more preferable, and Viratex (trade name, manufactured by Sumitomo Noganota), 0650 (
Product name: Made by Japan Synthetic Rubber Co., Ltd.) 2. Ball 1218FS
(trade name, manufactured by Nippon Zeon Co., Ltd.), etc. can be suitably used.

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

The weight of pure resorcinol/formaldehyde is preferably in the range of 5 to 15% based on the solid weight of the latex component. If it is less than this range, the obtained glass cord will have unstable strength in terms of adhesion and fatigue, and if it exceeds this range, the liquid phase of the treatment liquid will become unstable, which is not preferable.

In the present invention, the initial condensate of formalin/resorcin and latex are mixed, sufficiently aged to stabilize the liquid phase, preferably aged for 24 hours or more, and then resorcin dissolved in water is added to the liquid phase. It is added and mixed.

The amount of free resorcinol added is latte.

The amount can be in the range of 3 to 40% by weight based on the solid content of the wood, but from the viewpoint of heat resistance and bending fatigue, the amount is preferably in the range of 8 to 35%. Further, at this time, a stabilized liquid phase can be obtained by gradually adding an aqueous solution of resorcinol dissolved in water in advance. The resorcinol component to be added is preferably in a free form, so the use of acids, alkalis, other hydrates, etc. is not preferred, and water is most preferred as the solvent.

Like this! The concentration of the treatment solution prepared by i is 20 to 40%.
A range of is preferred. If it is less than this range, the bending fatigue resistance will be insufficient, and if it exceeds this range, uneven adhesion of the treatment liquid will likely occur, and the adhesiveness will be unstable, which is undesirable.

Naturally, the solid content concentration of the liquid to which resorcin was added increases, but surprisingly, there is almost no difference in the amount of solid content adhering to the glass cord compared to the liquid before addition.
It does not change even if the amount added increases.

The glass fiber used in the present invention is not particularly limited, but usually, glass raw materials of various compositions are melted and formed into a filament, and when wound up, z.

Make a bundle of about O pieces and apply a sizing agent. The wound strands are dried at room temperature. The basic composition of a sizing agent is usually an anchor agent, an adhesive, and an auxiliary material (activator, lubricant, etc.), but the most widely used annoker agents are those based on polymers, vinyl silane, epoxy resin, etc. /silane, mercapto7rane, amino/rane, etc. are common. Among these, aminolan has the best focusing ability. Various types of adhesives are known, such as latex such as natural rubber, synthetic rubber, or modified rubber, and resin-based adhesives such as vinyl-based, vinyl-acetate-based, etc.
Examples include acrylic, ebony/urethane, and modified products thereof. Further, when an aminosilane type anchor agent is used, a cationic emulsion such as a quaternary ammonium salt polymer is preferably used as the adhesive.

Glass fibers coated with such a sizing agent are treated with a treatment solution to improve adhesion to rubber materials, but the amount of solid matter deposited by this treatment is 15 to 25% by weight based on the glass fibers. % range is preferred; 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, 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, and then multiple fibers are tied together and further twisted to form a glass cord. It is what you use. The glass fibers treated in this manner can be applied as they are to various rubber materials and exhibit good physical properties as glass fiber-reinforced rubber bodies.

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

Example 1 Vp containing vinylpyridine, styrene and butadiene in a ratio of 15:15 to 0 to 320 parts by weight (mole ratio) of an addition condensate of resorcinol and formaldehyde.
(Manufactured by Sumitomo Noganota Co., Ltd., product name Viratex, solid content 4
1% by weight) 6391i parts, ammonia water (25%) 2
2 parts by weight were added with stirring, and water was added to make a total of 1000 parts by weight to prepare a treatment liquid. RF/L in this case was 7.5%, and after being left at room temperature for 24 hours, 30 parts by weight of an aqueous solution of zorcin SO% was gradually added to the treated solution. After that, it was left for another 2 hours.

Three bundles of glass fibers, each consisting of 200 9μ E glass fibers, were arranged and treated with this treatment solution in accordance with a conventional method. The solid content adhesion rate at this time was 191% by weight.

After drying at 280°C for 22 seconds, this glass fiber bundle was
11 fiber bundles that have been given 8 ply twists are pulled together and 1
The reinforcing glass cord was made by ply-twisting it 8 times per 0c++. A bending fatigue test was conducted using this glass cord. The MIT method was used for the bending fatigue test. The results are shown in Table 1.

Note that MIT bending was evaluated as follows.

The treated glass cord was attached to a lamination testing machine from both sides with adhesive tape and Soto paper adhesive tape (7210118m+U width), a load of 3 kg was applied, and the cord was bent at 120 times/min (120° angle) to measure the number of times it took to break. I read it. (Room Temperature) On the other hand, a glass hood that had been left at 140°C for 7 days was similarly measured. (Heat resistance) Examples 2 to 12, Comparative Examples 1 to 5 In the same manner as in Example 1, glass needles were obtained by treatment with the treatment liquid having the composition shown in Table 1, and the MfT bending thereof was measured. The results are shown in Table 1.

As is clear from Table 1, the glass fibers of the present invention have MIT bending values at room temperature that are not significantly different from those treated with the same resorcinol-polmarine latex treatment solution, but The value was about 20 to 40% the same as above, and an excellent effect was exhibited.

[Effects of the Invention] The glass fiber of the present invention can improve heat resistance when made into a rubber-glass fiber composite material without using special latex, and can be used in various applications requiring heat resistance. It is possible to provide glass fibers that can be used for various purposes.

Claims (2)

[Claims] (1) A glass fiber for rubber reinforcement, characterized in that it has been treated with a liquid containing an initial condensate of resorcinol/formaldehyde, latex, and free resorcinol. (2) Glass fiber for rubber reinforcement, characterized in that the initial condensate of resorcinol/formaldehyde and latex are mixed and aged to stabilize the liquid phase, and then treated with a mixture of resorcinol dissolved in water.