JP3793931B2 - Method for producing aromatic polyamide fiber for rubber reinforcement - Google Patents

Description

［比較例１〜８］
上記実施例において、ビニルピリジン−スチレン−ブタジエン系ラテックス１００重量部に対し、レゾルシン−ホルムアデヒド初期縮合物、ポリエポキシ化合物、トリアジン化合物、エチレンイミン化合物の各配合割合を、表２に示したように変更し、さらに、レゾルシン−ホルムアデヒド初期縮合物におけるホルムアデヒド／レゾルシンモル比（Ｘ）を表２に示したように変更した以外は、実施例と同一の条件で芳香族ポリアミド繊維を処理した。
【００４６】
得られた各コードの評価結果を表２に併せて示した。なお、記号内容，各特性の単位は表１と同一である。
【００４７】
【表２】

【００４８】
【発明の効果】
以上説明したように、本発明の方法によれば、ゴムとの初期接着性および耐水接着性にすぐれ、長時間の水浸漬によっても接着力の低下が小さい補強ゴム構造物を与えることが可能なゴム補強用芳香族ポリアミド繊維を効率的に製造することができる。[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for producing an aromatic polyamide fiber for rubber reinforcement, and more specifically, for rubber reinforcement capable of providing a reinforced rubber structure having excellent water resistance and low adhesion deterioration even when immersed in water for a long time. The present invention relates to a method for efficiently producing an aromatic polyamide fiber.
[0002]
[Prior art]
In recent years, aromatic polyamide fibers have been widely used as rubber reinforcing fibers for tires, belts, hoses and the like because they have high strength and high modulus characteristics and excellent heat resistance of the fibers themselves.
[0003]
However, since aromatic polyamide fibers have poorer adhesion to rubber than nylon fibers and polyester fibers, various methods for improving the adhesion between aromatic polyamide fibers and rubber have been proposed.
[0004]
For example, Japanese Patent Application Laid-Open No. 2-20269 proposes a method in which an aromatic polyamide fiber is treated with an epoxy compound having two or more epoxy groups in one molecule and then treated with resorcin / formaldehyde / rubber latex. Yes.
[0005]
JP-A-3-40875 discloses a treatment liquid in which an aromatic polyamide fiber is treated with a mixture of a polyepoxide compound, a blocked isocyanate compound, and a rubber latex, and then a special chlorophenol compound is blended with resorcin, formaldehyde, and rubber latex. The processing method is proposed.
[0006]
However, according to the conventional adhesion improving method, although almost satisfactory in terms of improving the adhesion between the aromatic polyamide fiber and the rubber, when the reinforced rubber composition is used in contact with water, There was a problem that the adhesiveness was significantly lowered, that is, the water resistance was poor.
[0007]
[Problems to be solved by the invention]
The present invention has been achieved as a result of examining the solution of the problems in the above-described prior art as an object.
[0008]
Therefore, an object of the present invention is to provide a method for efficiently producing an aromatic polyamide fiber for rubber reinforcement excellent in initial adhesion to water and water-resistant adhesion.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the method for producing an aromatic polyamide fiber for reinforcing rubber according to the present invention comprises: resorcinol-based on 100 parts by weight of vinylpyridine-styrene-butadiene copolymer latex on the surface of the aromatic polyamide fiber. Mixture mixture (A) 100 parts by weight of formaldehyde precondensate mixed with 10 to 10 parts by weight, polyepoxide compound (B) 10 to 20 parts by weight, triazine compound (C) 5 to 15 parts by weight, and ethyleneimine compound (D ) 100 wt. Of a mixture (E) obtained by treating with the first treatment liquid containing 20-40 wt. Parts and then heat-treating, and then mixing 12-25 wt. Parts of resorcin-formaldehyde precondensate with 100 wt. Parts of rubber latex. Parts, triazine compound (F) 5 to 15 parts by weight, and ethyleneimine compound (G) 5 to 20 A second treatment liquid by a method of applying a heat treatment after the process of containing an amount unit and resorcinol in the first treatment liquid and second treatment liquid - the molar ratio of formaldehyde / resorcinol in formaldehyde precondensate is 0 .20 to 0.50 .
[0010]
In the production method of the present invention, after the heat treatment after the treatment with the first treatment liquid is dried at 100 ° C. to 150 ° C., the heat treatment is carried out at 200 ° C. to 260 ° C. and the heat treatment after the treatment with the second treatment liquid is 100. After drying at 150 ° C. to 150 ° C., heat treatment at 200 ° C. to 260 ° C., and the amount of mixture applied when treating with the first treatment liquid is 6.0 to 15.0% by weight with respect to the aromatic polyamide fiber. The amount of the mixture applied in the treatment with the second treatment liquid is preferably 0.5 to 4.0% by weight with respect to the aromatic polyamide fiber. When these conditions are applied, a more preferable effect is obtained. Obtainable.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The aromatic polyamide fiber in the present invention is not particularly limited as long as it is a polyamide containing an aromatic diamine residue and an aromatic dicarboxylic acid residue, but aromatic poly-p-phenylene terephthalamide and poly-p-phenylene terephthalamide. -A 3-4 'diphenyl ether terephthalamide copolymer is preferable, and the form of fiber includes filament yarn, cord, fabric and the like.
[0012]
The rubber latex contained in the treatment liquid of the present invention includes vinylpyridine-styrene-butadiene copolymer rubber latex, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, chloroprene rubber latex, chlorosulfonated polyethylene rubber latex. Acrylate rubber latex and natural rubber latex are suitably used, and vinylpyridine-styrene-butadiene copolymer rubber latex is preferred.
[0014]
The polyepoxide compound (B) contained in the treatment liquid of the present invention is a compound containing two or more epoxy groups in one molecule, specifically, glycerol, pentaerythritol, sorbitol, ethylene glycol, polyethylene glycol, Reaction products of polyhydric alcohols such as propylene glycol and polypropylene glycol with halogen-containing epoxides such as epichlorohydrin, resorcinol, bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resin, resorcin / formaldehyde resin, etc. Reactive products of valent phenols with the halogen-containing epoxides, unsaturated compounds such as bis- (3,4-epoxy-6-methyl-dicyclohexylmethyl) adipate and 3,4-epoxycyclohexene epoxide Such polyepoxide compounds obtained a binding moiety with oxide. Preferably, sorbitol-polyglycidyl ether of polyhydric alcohol is used.
[0015]
Next, the triazine compound (C, F) used in the treatment liquid of the present invention is cyanuric acid, isocyanuric acid, 2.4.6-ethyloyl-S-triazine, triallyl isocyanurate, trihydroxyethyl. One kind or a mixture of plural kinds selected from isocyanurates can be used.
[0016]
Examples of the ethyleneimine compound (D, G) include diphenylmethane-bis-4,4′-N, N′-diethyleneimine, 1,6-hexamethylenediethyleneimine, octadecyldiethyleneimine, tolylenediamineimine, and naphthylene. Examples include reaction products of aromatic and aliphatic isocyanates and ethyleneimine such as ethyleneimine and triphenylmethanediethyleneimine, and particularly aromatic ethyleneimine compounds give good results.
[0017]
In the first treatment liquid of the present invention, a mixture (A) containing 2 to 10 parts by weight of a resorcin-formaldehyde initial condensate with respect to 100 parts by weight of the rubber latex is used. And it is a ratio of 3-8 weight part preferably resorcinol-formaldehyde initial stage condensate.
[0018]
In the above mixture (A), if the resorcin-formaldehyde condensate is less than 2 parts by weight, the processing machine is contaminated, and if it is more than 10 parts by weight, the adhesive strength is lowered, which is not preferable.
[0019]
Furthermore, resorcin - formaldehyde precondensate, arbitrary preferable those obtained under the alkaline catalyst. Further, resorcinol - the molar ratio of formaldehyde is in the range of formaldehyde from 0.20 to 0.50 molar with respect to resorcinol mole. When this molar ratio is less than 0.20, the processing machine may be soiled.
[0020]
The 1st process liquid used by this invention is a polyepoxide compound (B) 10-20 weight part, a triazine compound (C) 5-15 weight part, and an ethyleneimine compound (D) with respect to 100 weight part of said mixtures (A). ) 20 to 40 parts by weight are contained.
[0021]
In the first treatment liquid, if the components (A), (B), (C) and (D) are out of the above range, the object of the present invention cannot be achieved. That is, when the polyepoxide compound (A) and the ethyleneimine compound (D) are each less than the above ratio, the initial adhesive strength of the fiber obtained by the treatment is low, and conversely when the ratio is higher than the above ratio, the cord becomes hard. Therefore, it is not preferable. On the other hand, if the triazine compound (C) is less than 5 parts by weight, high heat-resistant adhesive strength cannot be obtained, and if it is more than 15 parts by weight, the rubber adhesion rate of inter-ply peeling is lowered, which is not preferable.
[0022]
The first bath treatment liquid is usually used at a solid concentration of 10 to 25%, and is treated so that the amount of adhesion to the aromatic polyamide fiber is 6.0 to 15.0% by weight. If the amount of the second treatment liquid attached to the aromatic polyamide fiber is too small, the peel strength between the plies and the rubber adhesion rate will decrease, and conversely, even if a large amount is applied, the rubber adhesion rate will not be greatly improved and the cost will increase. This is not preferable.
[0023]
In addition, the heat treatment after the application of the first treatment liquid is not particularly limited, but it is preferable that the heat treatment is usually performed at 200 to 260 ° C. for 0.5 to 5 minutes after drying at 100 to 150 ° C. for 0.5 to 5 minutes. However, the above drying can be omitted.
[0024]
Next, the rubber latex and the resorcin-formaldehyde initial condensate contained in the second bath treatment liquid may be the same as or different from those contained in the first treatment liquid. In the treatment liquid, a mixture (E) containing 12 to 25 parts by weight of a resorcin-formaldehyde initial condensate with respect to 100 parts by weight of rubber latex is used. And preferably a resorcinol-formaldehyde initial condensate is a ratio of 14-22 weight part.
[0025]
The second treatment liquid is constituted by adding 5 to 15 parts by weight of the triazine compound (F) and 5 to 20 parts by weight of the ethyleneimine compound (G) with respect to 100 parts by weight of the mixture (E). High adhesion can be obtained by adding the components (F) and (G). The triazine compound (F) and the ethyleneimine compound (G) in the second treatment liquid are the same as or different from the triazine compound (C) and the ethyleneimine compound (D) contained in the first treatment liquid. It may be.
[0026]
The second bath treatment liquid is usually used at a solid content concentration of 5 to 15%, and is treated so that the amount of adhesion to the aromatic polyamide fiber is 0.5 to 4.0% by weight. If the amount of the second treatment liquid attached to the aromatic polyamide fiber is too small, the peel strength between the plies and the rubber adhesion rate will decrease, and conversely, even if a large amount is applied, the rubber adhesion rate will not be greatly improved and the cost will increase. This is not preferable.
[0027]
Moreover, although the heat processing after 1st process liquid provision is not specifically limited, After drying at 100-150 degreeC for 0.5-5 minutes, it is performed by heat-processing at 200-260 degreeC for 0.5-5 minutes. However, the above drying can be omitted.
[0028]
Thus, the aromatic polyamide fiber that has been subjected to the adhesive treatment liquid treatment and heat treatment with the two-component components is then embedded in a rubber composition mainly composed of natural rubber or synthetic rubber and vulcanized under pressure. As a result, it is firmly bonded to the rubber.
[0029]
The rubber-reinforcing aromatic polyamide obtained by the method of the present invention is excellent in water resistance, and can provide a reinforced rubber structure with little decrease in adhesion even when immersed in water for a long time.
[0030]
【Example】
Next, the present invention will be described more specifically with reference to examples. Each measured value in the examples is obtained by the following method.
[0031]
[T-Pulling force (initial and heat resistance)]
Adhesive strength of JIS L-1017 (1983)-The treated cord was embedded in unvulcanized rubber under the following conditions in accordance with the A method, the initial pulling force was 150 ° C for 30 minutes under pressure, and the heat pulling force was 170. Press vulcanization was carried out at 0 ° C. for 16 hours, and after cooling, the cord was pulled out from the rubber block at a speed of 30 cm / min, and the pulling load was displayed in Kg / cm.
[0032]
[Ply peel adhesion (rubber adhesion rate, peel force)]
Two rubber sheets topped with 18 cords / inch of processing code are bonded together so that the processing cords are parallel, press vulcanization is performed at 150 ° C. for 30 minutes under pressure, and both are left to cool. The peeling force when peeling the ply at a pulling speed of 10 cm / min is measured. The rubber adhesion rate is obtained by observing the cord peeled off from the rubber with the naked eye and expressing the percentage of the portion where the rubber adheres to the cord surface. The peeling force is expressed in Kg / inch. did.
[0033]
As the rubber compound in the adhesion evaluation, an unvulcanized rubber containing a carcass composed mainly of natural rubber was used.
[0034]
[Strong code]
It measured according to JISl L-1017 (1983) using Tensilon.
[0035]
[Examples 1 to 3]
For the first bath treatment liquid, a resorcin-formaldehyde initial condensate obtained by reacting 0.20 to 0.50 mol of formaldehyde with 1 mol of resorcin in the presence of caustic soda was used as a vinylpyridine-styrene-butadiene latex. A mixture (A) prepared by mixing at a predetermined ratio shown in Table 1 and aging for 24 hours with respect to 100 parts by weight was prepared.
[0036]
Next, an aqueous dispersion of diphenylmethane-bis-4,4′-N, N′-diethylemin and water obtained by adding water to sorbitol polyglycidyl ether and emulsifying the mixture (A) with a homogenizer A solution (D) and trihydroxyethyl isocyanurate dissolved in water (C) were mixed at a predetermined ratio shown in Table 1 to obtain a first bath treatment liquid having a solid content concentration of 20%.
[0037]
For the second bath treatment liquid, as in the first bath treatment liquid, an initial condensate obtained by reacting 0.20 to 0.50 mol of formaldehyde with 1 mol of resorcin in the presence of caustic soda is used as vinyl. A mixture (E) prepared by mixing at a predetermined ratio shown in Table 1 and aging for 24 hours with respect to 100 parts by weight of pyridine-styrene-butadiene latex was prepared.
[0038]
Next, a solution obtained by dissolving trihydroxyethyl isocyanurate (F) in water in the aqueous dispersion (G) of diphenylmethane-bis-4,4′-N, N′-diethylamine in the above mixture (E) By mixing at a predetermined ratio shown in 1, a second treatment liquid having a solid content concentration of 12% was obtained.
[0039]
Meanwhile, two DuPont Kevlar 1500 denier multifilaments are twisted into a cord with a lower twist of 15.7 times / 10 cm and an upper twist of 15.7 times / 10 cm. The product was immersed in the first bath treatment solution (solid content 7.8 to 8.3% by weight), dried at 140 ° C. for 150 seconds, and then heat-treated at 245 ° C. for 60 seconds.
[0040]
Next, the cord treated with the first treatment liquid, dried and heat-treated is immersed in the second treatment liquid (solid content: 0.6 to 2.1% by weight) and dried at 120 ° C. for 150 seconds, Subsequently, the cord of the present invention was manufactured by heat treatment at 240 ° C. for 60 seconds.
[0041]
Table 1 shows the evaluation results of the cords thus obtained.
[0042]
The symbol contents in Table 1 are as follows.
[0043]
X: molar ratio of formaldehyde (F) / resorcin (R) Y: RF amount (parts by weight)
B: Epoxy compound (parts by weight)
C or F: Triazine compound (parts by weight)
D or G: ethylene urea compound (parts by weight)
Y is a weight ratio with respect to 100 parts by weight of vinylpyridine-styrene-butadiene latex, and B, C, F, D, and G are weight ratios with respect to 100 parts by weight of RFL (symbol: A, E).
[0044]
The unit of each characteristic is as follows.
[0045]
T-pull force: Kg / cm
Rubber adhesion rate at the time of peeling away:%
Peel strength: Kg / inch Cord strength: Kg
[Table 1]

[Comparative Examples 1 to 8]
In the above examples, the mixing proportions of resorcin-formaldehyde initial condensate, polyepoxy compound, triazine compound, and ethyleneimine compound were changed as shown in Table 2 with respect to 100 parts by weight of vinylpyridine-styrene-butadiene latex. Furthermore, the aromatic polyamide fiber was treated under the same conditions as in the Examples except that the formaldehyde / resorcin molar ratio (X) in the resorcin-formaldehyde initial condensate was changed as shown in Table 2 .
[0046]
The evaluation results of the obtained codes are shown together in Table 2. The symbol content and the unit of each characteristic are the same as in Table 1.
[0047]
[Table 2]

[0048]
【The invention's effect】
As described above, according to the method of the present invention, it is possible to provide a reinforced rubber structure that is excellent in initial adhesion to water and water-resistant adhesion, and that has a small decrease in adhesion even when immersed in water for a long time. An aromatic polyamide fiber for rubber reinforcement can be produced efficiently.

Claims (3)

A mixture of 2 to 10 parts by weight of resorcin-formaldehyde initial condensate with 100 parts by weight of vinylpyridine-styrene-butadiene copolymer latex on the surface of an aromatic polyamide fiber ( A) 100 parts by weight, polyepoxide compound (B) 10-20 parts by weight, a triazine compound (C) 5-15 parts by weight, and an ethyleneimine compound (D) 20-40 parts by weight. 100 parts by weight of a mixture of resorcin-formaldehyde initial condensate 12-25 parts by weight with respect to 100 parts by weight (E) 100 parts by weight, triazine compound (F) 5-15 parts by weight, and ethyleneimine compound (G) 5-20 parts by weight part a facilities to method a heat treatment after treatment with the second treatment liquid containing, and, in the first processing liquid及Beauty resorcinol second processing liquid - method of manufacturing a rubber-reinforcing aromatic polyamide fibers molar ratio of formaldehyde / resorcinol in formaldehyde initial condensation product is characterized and Dearuko 0.20 to 0.50. Heat treatment after processing in the first processing liquid, dried at 100 ° C. to 150 DEG ° C., carried out by Netsusho sense at 200 ° C. to 260 ° C., and heat treatment after the treatment with the second treatment liquid, The method for producing an aromatic polyamide fiber for rubber reinforcement according to claim 1, wherein the method is carried out by heat treatment at 200 ° C to 260 ° C after drying at 100 ° C to 150 ° C.   The amount of mixture applied when treating with the first treatment liquid is 6.0 to 15.0% by weight with respect to the aromatic polyamide fiber, and the amount of mixture applied when treating with the second treatment liquid is aromatic polyamide. The method for producing an aromatic polyamide fiber for rubber reinforcement according to claim 1 or 2, wherein the content is 0.5 to 4.0% by weight based on the fiber.