JPS6022105B2 - Method for improving adhesion of synthetic fiber materials for elastomer reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the adhesion of synthetic fiber materials for elastomer reinforcement.
A first treatment step of impregnating a compound selected from an epoxy compound, an isocyanate compound, an oxazoline compound, and a methylolmelamine compound, and further impregnating the fiber aggregate with a treatment liquid containing a triazine compound and an elastomer aqueous dispersion. The present invention relates to a method for improving the adhesion of a synthetic fiber material for reinforcing an elastomer, which comprises a second treatment step, and provides a synthetic fiber material that has excellent adhesion to elastomers.

Composites made of synthetic fiber materials and elastomers are used in a wide variety of applications due to their excellent performance, such as tires, various belts, and canvas, but nylon 6 and nylon 6
Compared to the polyamide synthetic fibers represented by 6,
Polyester-based synthetic woven fabrics represented by polyethylene terephthalate and aromatic polyamide (hereinafter referred to as aramid) synthetic fibers represented by paraphenylene phthalamide, which has been developed in recent years, are strong, modulus, and heat-resistant. Although it has excellent performance in elastomers, etc., it has poor adhesion with elastomers, and as a result, the lifespan of elastomer products containing the above synthetic fiber materials has been significantly shortened.

For this reason, various formulations for improving adhesion have been studied for the synthetic fiber materials mentioned above, but the treatment agent used in most of them is a so-called RF/ It was an L-based adhesive. For example, as such a processing agent, i) one using halogenated phenol, hydroxybenzoic acid, furfuryl alcohol, etc. as a part of the constituent components of RF/L. i
i) Those to which a third component such as an epoxy compound, melamine compound, or isocyanate compound is added are included. Furthermore, in order to improve the adhesion of synthetic fiber materials, a two-stage treatment method is known in which the material is first treated with an epoxy resin and then further treated with RF/L. However, RF/L adhesives
Although it shows relatively excellent adhesive strength, the adhesive strength varies depending on the condensation conditions of resorcin and formalin. ii) Condensation requires several to 20 hours of preparation. Bait RF/
Adhesive strength varies depending on the time elapsed since L was created. The adhesion strength of the iv-treated fiber material deteriorates over time and over time due to heat aging. It has drawbacks such as: In order to solve the above-mentioned shortcomings of the prior art, the present inventors investigated various treatment methods that provide excellent adhesion to synthetic fiber materials without using R/F initial condensates.
A method of the present invention has been developed in which treatment is performed with a compound selected from isocyanate compounds, oxazoline compounds, and methylolmelamine compounds, followed by treatment with a solution containing a triazine compound and an elastomer aqueous dispersion as described below.

The method of the present invention not only can impart adhesion strength greater than that of conventional RF/L to synthetic fiber materials, but also: i) does not require training time for adjusting adhesive solution; ii) Excellent heat-resistant adhesive strength. Bait) Do not use formalin and have a good working environment. It has the following advantages. As mentioned above, synthetic fiber materials that are considered preferable for the application of the present invention include those that have poor post-adhesiveness with rubber, such as
There are polyester synthetic fibers, aramid synthetic fibers, etc.

Good results can also be obtained when applied to polyamide synthetic fibers such as nylon 6 and 66, and polyvinyl acetal synthetic fibers such as vinylon. These fibrous materials may be in any aggregate form, such as tow, sliver, net, tire cord, drapery, web. The synthetic fiber material obtained by the method of the present invention can also be used as elastomers such as natural rubber, styrene-butadiene copolymer rubber, nitrile-butadiene copolymer rubber, isopten-isoprene copolymer rubber, butadiene rubber, etc.: ethylene propylene Various rubbers such as ternary copolymer rubber, olefin rubber such as chlorosulfonated polyethylene; chlorohydrin rubber; chloroprene rubber; and vinyl chloride graft of polyvinyl chloride, chlorinated polyolefin, and ethylene/vinyl acetate copolymer. It can be advantageously used for halogen-containing thermoplastic resins such as elastomers, mixtures of two or more of the above elastomers, and mixtures of elastomers other than those mentioned above.

The method of the present invention will be explained below.

The method of the present invention includes a first step using a treatment liquid containing at least one compound selected from epoxy compounds, isocyanate compounds, oxazoline compounds, and methylolmelamine compounds, and a thiol-S-triazine compound of the general formula {11 and an elastomer. The second step uses a treatment liquid containing an aqueous dispersion.

The treatment liquid in the first step may contain any of the above four types of compounds, or may contain two or more of these compounds.

As epoxy compounds, polyfunctional ones having two or more glycidyl groups are effective, and typical examples include bisphenol A type diglycidyl ether, polyalkylene glycol diglycidyl ether, glycerin, di- or triglycidyl. Ether, hexanediol diglycidyl ether, sorbitol polyglycidyl ether,
and so on.

Examples of the isocyanate compound include methylene diisocyanate, tolylene diisocyanate, and metaphenylene diisocyanate, and these isocyanate compounds are blocked with at least a species selected from phenol, chloride, and ethyleneimine.

There are blocked disocyanates. Examples of oxazoline compounds include those represented by the following formula.

R: lower alkyl group As the methylol melamine compound, polyfunctional compounds represented by di-, tri-, tetra-, venter or hexer-methylol melamine are preferred.

The treatment liquid in the first step may be either solvent-based or water-based, but from the viewpoint of working environment hygiene, water-based is preferable, but it should be judged comprehensively from the solution stability of the compound, treatment effect, etc. be. In addition to the compounds selected from the above four types, the solution contains a solubilizing agent, a dispersing agent, a penetrating agent for the compound, a swelling agent for the fiber material to be treated, etc., without reducing the adhesive properties. It may also contain compounds that smooth the process.

The content of the compound used in the first treatment step can be appropriately selected depending on the treatment conditions, the fiber material to be treated, etc., but is usually preferably 0.5 to 1%.

This treatment includes the steps of immersion in an adhesive treatment solution, drying, and heat treatment, but in order to obtain high adhesive strength, it is necessary to
A temperature range of is preferred. The treatment liquid in the second step is the above-mentioned 01
This is an aqueous treatment liquid containing a thiol-S triazine compound of the formula and an aqueous elastomer dispersion as main components.

Thiol-S-triazine is a compound represented by the following formula, where R,, R2 and R3 are as shown below.

Others' ears, scales, fake brains. Fat equipment chicken seaweed” In the formula, R4, R5, R6, R7 are and so on.

Preferable compounds of the formula '1} used in the present invention include trithiol-S-triazine and its alkali metal salts, dithiolani-IJ-no-S-triazine, and
Its alkali metal salt, dithiol dibutylamino S-
*These include triazine and its alkali metal salts, dithioldicyclohexylamino-S-triazine and its alkali metal salts, and the like.

The above-mentioned alkali metal imitation material of the triazine compound is convenient for improving the water-removal properties of the triazine compound.

Among the triazine compounds, water-soluble ones can be dissolved in a water-soluble solvent such as polyalkylene glycol or its ethers, or if an aqueous solution containing an alkali metal hydroxide is used. can be water-soluble or easily dispersible. Further, the triazine compound is preferably a dithiol type triazine compound, and the dithiol type triazine compound reacts with the treatment compound used in the first step, such as an eboxy compound, as described below to enable a crosslinking reaction with the elastomer. , can maintain strong adhesive strength.

The aqueous elastomer dispersion, which is the second element constituting the treatment liquid in the second step, may be a natural or synthetic rubber latex, a thermoplastic resin latex, or a mixture thereof.

This elastomer is usually preferably the same as the elastomer to which the loom material produced by the method of the invention is bonded, such as natural rubber latex, styrene/
Ptadiene copolymer latex styrene/butadiene/
Vinylpyridine copolymer latex, nitrile/butadiene copolymer latex, chloroprene latex, polyvinyl chloride latex, polyvinylidene chloride latex, vinyl chloride/vinyl acetate copolymer latex, etc. can be used. The contents of the triazine compound of formula {1- and the aqueous elastomer dispersion may be selected as appropriate, but are 0.5 to 5 wt% and 2 to 2 wt%, respectively.
0 Wt% (all calculated by Sono Kata Molecule) is preferable.

The treatment temperature is preferably 140 to 220°C in order to obtain good adhesive strength.

In addition, the treatment liquid contains a pH adjuster to improve the stability of the liquid,
It may contain any compound that does not affect adhesiveness, liquid stability, workability, etc., such as solubilizers and thickeners for triazine derivatives.

The treatment liquid used in the second step can be adjusted within a short period of time by simply using a mechanical filter.

Therefore, there is no need for the long-time process of preparing conventional RF/L adhesives. As described above, the present invention relates to a method for producing synthetic fibers with improved adhesion that are useful as reinforcing materials for elastomers, and provides a fiber material that has extremely excellent adhesion to elastomers. It is also an excellent adhesion-improving treatment method that can not only improve the adhesive properties but also solve various drawbacks found in conventional RF/L adhesives.

The method of the present invention will be explained in more detail with reference to the following examples.

Example 1 Kepler T-950 (DuPont product aramid fiber)
A cord obtained by twisting two 150/100 filaments was immersed in a first step treatment solution having the following composition and subjected to heat treatment at 24 pcs x 3 min.

[1st step treatment liquid] Next, it was immersed in a 2nd step treatment liquid consisting of the following composition, and
00qo×3hin. Heat treatment was performed.

[Second process treatment solution] Furthermore, a cord was placed between the unvulcanized rubber sheets at 150°C for 3 minutes. Vulcanization was performed.

The adhesion strength was measured by pulling out the cord from between the sheets, a so-called "strike" method.
The measured initial adhesion force and the adhesion force when used after 3 weeks of preparing the second process treatment solution were 13.8[9], respectively.
/1/4'', i2.6kQ/1/4''.

Example 2 In Example 1, the adhesive strength was determined when the second process treatment liquid was changed as follows.

[Second Step Treatment Liquid] The RF/L adhesive was separately prepared using the following formulation.

For each adhesive formulation, the treatment liquid preparation time, initial adhesive strength, and adhesive strength when using the treatment liquid 3 weeks after preparation of the adhesive treatment liquid are shown.

The formulation of the present invention not only requires about 1/20 the adjustment time compared to conventional RF/L adhesives, but also has excellent adhesive strength. Example 3 Polyester filament fabric (100M density 28×2
160°C x 23mm x 3min using the first and second process treatment solutions consisting of the following compositions:
Heat treatment was performed for 3 minutes.

[First step treatment liquid] Next, the treated fabric and an unvulcanized chloroprene rubber sheet with a thickness of about 0.8 ribs were combined and heated at 50°C for 3 hours in a pressure press 1.
in. Vulcanized.

The obtained sample was cut into 3 skin widths and peeled at 180o.
The adhesive force between rubber/fabric was measured. Using the same machine, the adhesive force was also measured for fabrics treated with the RF/L adhesive only in the second step.

The adhesive strength between the two is as follows, and it is clear that the treatment method of the present invention is superior.

Example 4 In Example 2, the treatment liquid composition of the second step
After the treatment with (1) and (2), before vulcanization by integrating with the unvulcanized rubber, only the treatment code was further treated with 140 qo x 1 rule rs.
After heat treatment, it was heated and the adhesive strength was measured.

The adhesive strength was 12.1k9/1/4'' for the composition (invention), and 8.2k9/1/4'' for the composition (RF/L), compared to the conventional RF/L adhesive. Less decrease in adhesive strength,
It is clear that the formulation also has excellent heat resistance. Example 5 In Example 1, the sample was immersed in the first step treatment liquid having the following composition, 220qC x 3h. Heat treated.

The adhesive strength of each formulation was as follows. Example 6 66 nylon fabric (84, density 28 x 28 pieces/0 dimension)
were treated at 230 qo x 3 min. using the first and second process treatment liquids having the following compositions. , 180×3min. Heat treated.

Next, the treated fabric was combined with a soft polysalt vinyl sheet (containing 6 hours of plasticizer) having a thickness of about 0.6, and pressed to 180 qo x 5 h with a pressure press. Heated.

The obtained sample was cut into 3 side widths and peeled at 180°.
The adhesive force between the vinyl sheet/fabric was measured. Similarly, in the second step, the adhesive strength of the fabric treated with the RF/L adhesive was also measured. The initial adhesive strength of both and the adhesive strength of the treatment solution 3 weeks after preparation of the treatment solution are as follows. Example 7 In Example 7, the second
Soaked in process treatment solution, 210oo x 2.8hin. Heat treated.

[Second process treatment liquid] Based on Example 1, initial adhesive strength and 3
After a week, the adhesive strength was measured using the treatment solution.

In both cases, excellent adhesion was exhibited.

As described above, the method of the present invention is an epoch-making method that can eliminate the drawbacks of the previously used method using an RF/L adhesive and provide a fiber material with excellent adhesive strength.

Claims (1)

[Scope of Claims] 1. A first step of impregnating a synthetic fiber aggregate with a treatment liquid containing at least one compound selected from an epoxy compound, an isocyanate compound, an oxazoline compound, and a methylolmelamine compound; In addition, the synthetic fiber aggregate has the following formula (1); ▲ mathematical formula, chemical formula, table, etc. ▼ [However, in the above formula, R_1 is SH, NHR_4, NR
_5R_6 or OR_7 group, R_4, R_5
, R_6, R_7 each represent a hydrocarbon residue,
R_2 and R_3 each represent SH or SM, and M represents an alkali metal atom. have,
Method for improving adhesion of synthetic fiber materials for elastomer reinforcement. 2. The method according to claim 1, wherein the epoxy compound contains two or more glycidyl groups. 3. A patent claim in which the isocyanate compound is selected from methylene diisocyanate, tricyne diisocyanate, metaphenylene diisocyanate, and a blocked isocyanate obtained by blocking the isocyanate compound with at least one selected from phenol, cresol, and ethyleneimine. The method described in item 1. 4 The oxazoline compound has the following general formula; ▲ mathematical formula,
There are chemical formulas, tables, etc.▼ [However, in the above formula, R represents a hydrogen atom or a lower alkyl group.] The method according to claim 1. 5 The methylolmelamine compound is di-, tri-,
2. The method of claim 1, wherein the melamine is tetra-, penda- or hexa-methylolmelamine. 6 The treatment liquid in the first step is 0.5 to 10% by weight.
2. The method of claim 1, wherein the treatment compound comprises: 7. The method according to claim 1, comprising treating the fiber aggregate impregnated with the treatment compound of the first step at a temperature of 180 to 250°C. 8 The compound of general formula (1) is trithiol-S-triazine, dithiolanilino-S-triazine, dithioldibutylamine-S-triazine, dithioldicyclohexylamino-S-triazine, and alkali metal salts of the above triazine compounds. A method according to selected claim 1. 9. The method of claim 1, wherein the aqueous elastomer dispersion is a latex of natural or synthetic rubber or a latex of thermoplastic elastomer resin. 10 The treatment liquid in the second step is 0.5 to 5% by weight.
The method according to claim 1, comprising the triazine compound of formula (1). 11. The method according to claim 1, wherein the treatment liquid in the second step contains 2 to 20% by weight of elastomer. 12 The impregnated fiber material obtained in the second step is
The method according to claim 1, wherein the method is heat-treated to a temperature of 140 to 220°C.