JPH0370037B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for treating polyester fibers for rubber reinforcement with improved adhesion to rubber compounds. <Prior art> Polyester fibers, typified by polyethylene terephthalate fibers, have physical properties such as high strength and Young's modulus, low elongation and creep, and excellent fatigue resistance, and are suitable for rubber reinforcement. It is widely used for composites, etc. However, polyester fibers have poor adhesion to rubber materials compared to polyamide fibers such as nylon 6 and nylon 6,6, and ordinary adhesive treatment is insufficient to fully demonstrate the separation properties of the polyester fibers. Strong adhesion performance cannot be obtained. The main reason for this is thought to be that the hydrogen bonding capacity of ester bonds in polyester is smaller than that of amide bonds in nylon. For this reason, a method has been proposed in which the surface of polyester fibers is treated with highly reactive substances such as epoxy compounds and isocyanate compounds to impart adhesive properties. (For example, Japanese Patent Publication No. 60-55632, Japanese Patent Publication No. 47-49768 [Japanese Patent No. 692769], etc.) However, when trying to improve the adhesion of polyester fiber to rubber, the treated fiber material becomes hard. As a result, molding becomes difficult and fatigue resistance decreases. <Object of the invention> The present invention has been made against the background of the above-mentioned circumstances, and the purpose of the present invention is to provide excellent performance in adhesion between polyester fiber and rubber, particularly in heat-resistant adhesion. It is in. <Structure of the Invention> That is, the present invention comprises (1) pre-treating a linear aromatic polyester fiber with a treatment liquid containing 2,6-dimethylol-4-chlorophenol and a polyepoxide compound (A), and then treated with a first treatment agent containing a polyepoxide compound (B), a blocked polyisocyanate compound (C) and a rubber latex (D),
Next, an ethylene urea compound represented by the following general formula (E) and an epoxy cresol novolac condensate represented by the following general formula (F) were added to resorcinol-formalin-rubber latex (RFL) (E)/(F).
A method for treating polyester fibers, characterized by treating with a second treating agent added at a weight ratio of =0/100 to 80/20. [Here, R is an aromatic or aliphatic hydrocarbon residue, and n is 0, 1 or 2. When n=0, the terminal group is hydrogen. ] [Here, R' is -O(-CH ₂ ) _-k Cl, -O(-CH ₂ ) _-l
OH or [-O( _-CH2 ) _-n ] _-n OH, R'' is -H, -
CH ₃ , -C ₂ H ₅ , k, l, m are integers of 1 to 4, m' is an integer of 1 to 5, a, b are integers of 1 to 5, a+b≦6 It is. 2,6-dimethylol-4-chlorophenol used as the pretreatment agent of the present invention is produced as an intermediate during the reaction of resorcinol, p-chlorophenol, and formaldehyde. Next, the polyepoxide compound used in the pretreatment agent and first treatment agent of the present invention is a compound containing at least two or more epoxy groups in one molecule in an amount of 0.2 g or more per 100 g of the compound, such as ethylene glycol, glycerol, sorbitol, etc. , reaction products of polyhydric alcohols such as pentaerythritol and polyethylene glycol and halogen-containing epoxides such as epichlorohydrin, resorcinol, bis(4-hydroxyphenyl)dimethylmethane, phenol-formaldehyde resin, resorcinol-formaldehyde resin, etc. A reaction product of polyhydric phenols and the halogen-containing epoxides, a polyepoxide compound obtained by oxidizing an unsaturated compound with peracetic acid or hydrogen peroxide, i.e., 3,4-epoxycyclohexene epoxide,
3,4-epoxycyclohexylmethyl-3,4
-epoxycyclohexenecarboxylate, bis(3,4-epoxy-6-methyl-cyclohexylmethyl)adipate, and the like. Among these, reaction products of polyhydric alcohols and epichlorohydrin, ie, polyglycidyl ether compounds of polyhydric alcohols, are particularly preferred because they exhibit excellent performance. Such polyepoxide compounds are usually used as emulsions. To make an emulsion or solution, for example, such a polyepoxide compound as it is or dissolved in a small amount of a solvent as necessary may be mixed with a known emulsifier such as sodium alkylbenzene sulfonate, dioctyl sulfosuccinate sodium salt, nonylphenol ethylene. Emulsify or dissolve using oxide adducts, etc. Next, the blocked polyisocyanate compound used in the first treatment agent of the present invention is an addition compound of a polyisocyanate compound and a blocking agent, and the blocking component is liberated by heating to produce an active polyisocyanate compound. be. Examples of the polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, and triphenylmethane triisocyanate, or these polyisocyanates with two active hydrogen atoms.
A polyalkylene glycol containing a terminal isocyanate group obtained by reacting a compound having at least 1 group of isocyanate groups, such as trimethylolpropane, pentaerythritol, etc., at a molar ratio of isocyanate group (-NCO) to hydroxyl group (-OH) exceeding 1. Examples include adduct polyisocyanate. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl isocyanate are preferred because they exhibit excellent performance. Examples of blocking agents include phenols such as phenol, thiophenol, cresol, and resorcinol; aromatic secondary amines such as diphenylamine and xylidine; phthalic acid imides; lactams such as caprolactam and valerolactam;
Examples include oximes such as acetoxime, methyl ethyl ketone oxime, and cyclohexane oxime, and acidic sodium sulfite. Examples of the rubber latex used in the first treatment agent of the present invention include natural rubber latex, styrene-butadiene copolymer latex, vinylpyridine-styrene-butadiene terpolymer latex, nitrile rubber latex, and chloroprene rubber latex. , these can be used alone or in combination. Among these, vinylpyridine-styrene-butadiene terpolymer latex shows excellent performance when used alone or when used in an amount of 1/2 or more. The pretreatment agent is the above-mentioned 2,6-dimethylol-4
- It is desirable to use the compound so that the blending weight ratio of chlorophenol and polyepoxide compound (A) ((A)/2,6 dimethylol-4-chlorophenol) is 0.05 to 1.0. The first treatment agent is the above polyepoxide compound (B),
Contains a blocked polyisocyanate compound (C) and a rubber laxative (D), and the blending weight ratio of each component (B), (C), and (D) is (B)/[(B)+(C)] from 0.05 to 0.9, (D)/[(B)+(C)
]
It is desirable to use it so that it is between 0.5 and 15. In particular, (B)/[(B)+(C)] is 0.1 to 0.5, (D)/[(B)+
(C)] is preferably in the range of 1 to 10. If (B)/[(B)+(C)] is out of the above range, the rate of rubber adhesion to polyester fibers tends to be poor, and the adhesiveness tends to decrease.
If [(B)+(C)] is smaller than the above range, the treated polyester fiber will become hard, which may lead to a decrease in fatigue resistance, while if it is larger than the above range, adhesiveness will be reduced. The total solid content including the polyoxide compound (B), blocked polyisocyanate compound (C) and rubber latex (D) is used in an amount of 1 to 30 wt%, preferably 3 to 20 wt%, based on the weight of the fiber.
If the concentration is too low, the adhesion will decrease, and if the concentration is too high, it will become hard and the fatigue resistance will decrease. When the first treatment agent composition is used as an aqueous dispersion, the appropriate amount of the dispersant, that is, the surfactant, is 0 to 15 wt%, preferably 0 to 15 wt%, based on the total solid content of the first treatment agent.
The content is 10wt% or less, and if it exceeds the above range, the adhesiveness tends to decrease slightly. The second treatment agent of the present invention is a composition containing resorcinol, formalin, and rubber latex, and the resorcinol, formalin, and rubber latex used here is usually called RFL, and the molar ratio of resorcinol to formaldehyde is is 1:01
-1:8, preferably 1:05-1:5, more preferably 1:1-1:4. Examples of rubber latex include natural rubber latex, styrene-butadiene copolymer latex, vinylpyridine-styrene-butadiene terpolymer latex, nitrile rubber latex, chloroprene rubber latex, etc.
These may be used alone or in combination. Among these, vinylpyridine-styrene-butadiene terpolymer latex shows excellent performance when used alone or when used in an amount of 1/2 or more. The blending ratio of resorcinol/formalin and rubber latex is 1:1 in terms of solid content, although it depends on the addition ratio of the ethylene urea compound (E) and the epoxy-modified phenol/formalin resin condensate (F), which will be described later.
-1:15, preferably in the range of 1:3-1:12. If the proportion of rubber latex is too small, the treated polyester fiber material will become hard and have poor fatigue resistance. On the other hand, if the amount is too large, satisfactory adhesive strength and rubber adhesion rate cannot be obtained. The mixing ratio of ethylene urea compound (E) and epoxy-modified phenol formalin condensate (F) is 50/50 ~
80/20 (weight ratio) is preferred, and the mixture is
0.5 to 30wt%, preferably 1.0 to RFL
Added at 20wt%. If the amount of the mixture added is too small, good adhesion and rubber adhesion cannot be obtained.
On the other hand, if the amount added is too large, the viscosity of the processing agent will increase significantly, making it difficult to process the fiber material. Moreover, the adhesion force and rubber adhesion rate reach a saturation value, and the effect of eliminating the amount of the mixture added does not increase, and the cost only increases, and the fiber material after treatment becomes extremely hard and loses strength. The disadvantage is that The ethylene urea compound added to the second treatment agent is represented by the following general formula (E). [R is an aromatic or resinous hydrocarbon residue.
n is an integer of 0 to 2, and when n=0, the terminal group is hydrogen. ] Representative compounds include aromatic and aliphatic isocyanates such as octadecyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, metaxylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, triphenylmethane triisocyanate, and ethylene. Reaction products with imines are mentioned, and in particular aromatic ethylene urea compounds such as diphenylmethane diethylene urea give good results. Similarly, the epoxy-modified phenol-formalin condensate added to the second processing agent is represented by the following general formula (F). [Here, R' is -O-(CH ₂ )k-Cl, -O-(CH ₂ )
l-OH or [-O( _-CH2 )m] _-n OH, R″ is-
H, _-CH2 , _-C2H5 , k, l _,
m is an integer from 1 to 4, m' is an integer from 1 to 5, a, b
is an integer from 1 to 5, and a+b≦6. ] Various compounds that satisfy the above (F) can be considered, but
Good results are obtained by using a material with a molecular weight of 1200 to 1300 and an epoxy value of 4.0 to 4.5 eq/Kg. In the present invention, the ethylene urea compound (E) and the epoxy-modified phenol-formalin condensate (F) have a catalytic effect on each other, and the ethylene urea compound has an ethylene imine ring that is opened and an epoxy-modified phenol-formalin condensate. In products, the epoxy ring opens and reacts, increasing adhesive properties and at the same time increasing the cohesive force of the adhesive itself.As a result, strong chemical bonds are created with amines generated in rubber, preventing adhesive deterioration. It is something to do. The above-mentioned second processing agent is usually adjusted to contain a solid content of 10 to 25% by weight. In order to attach the first treatment agent and the second treatment agent to the polyester fiber material, any method such as contact with a roller, application by spraying from a nozzle, or immersion in a solution can be adopted. The amount of solid content deposited on the polyester fiber is 0.1 to 10% by weight, preferably 0.5% by weight as the first treatment agent composition.
~5% by weight, 0.5~10 as the second treatment agent composition
It is preferable to apply it in an amount of 1 to 5% by weight, preferably 1 to 5% by weight. In order to control the amount of solid content attached to the fibers, means such as squeezing with a pressure roller, scraping with a scraper, blowing off with air, suction, and beating with a beater may be used. In the present invention, 2,6-dimethylol-4
- After pre-treatment with a treatment solution containing chlorophenol and a polyepoxide compound, the polyester fiber is dried and heat-treated at a temperature of 160°C or higher and at least 10°C lower than the melting point of the polyester fiber, and subsequently treated with a first treatment agent and then heated at 50°C or higher. The polyester fibers are dried and heat treated at a temperature of 10°C or more lower than the melting point of the fiber, preferably 220 to 250°C, and then treated with a second treatment agent to a temperature of 120°C or higher and below the melting point of the polyester fiber, preferably 180°C. Dry and heat treat at temperatures of ~250℃. Drying/
If the heat treatment temperature is too low, adhesion to the rubber will be insufficient, while if the temperature is too high, the polyester fibers will melt or fuse, or the strength will be significantly reduced, making it impossible to put it to practical use. <Effects of the Invention> Compared to conventional methods, fibers treated by the method of the present invention have improved heat-resistant adhesion and improved peel strength and durability without impairing moldability with rubber. <Example> Hereinafter, the present invention will be specifically described with reference to Examples. In the Examples, the heat resistance in rubber, cord peeling adhesive strength, T adhesive strength, and inter-ply peeling force were determined as follows. <Heat resistance in rubber> This indicates the strength retention rate after vulcanization in rubber. After vulcanization in rubber at 170°C for 3 hours, the cord was taken out from the rubber, the tensile strength at break was determined at a speed of 200 mm/min, and the retention rate was determined by comparing it with the initial strength. <Cord Peel Adhesive Strength> This indicates the adhesive strength between the treated cord and rubber. Five cords were buried under the surface layer of the rubber sheet, vulcanized at 150℃ for 30 minutes under pressure, and then the force required to peel the five cords from the rubber sheet at a speed of 200 mm/min was calculated in kg/5 cords. This is what is displayed. <T adhesive strength> This indicates the adhesive strength between the treated cord and the rubber. The cord was embedded in a rubber block, cured under pressure at 150°C for 30 minutes, and then pulled out from the rubber block at a speed of 200 mm/min. The force required for pulling out is expressed in kg/cm. <Peeling force between plies> This indicates the adhesive force with the treated cord. After embedding 2 plies of treated cord in rubber as a cross ply (cord density: 27 cords/inch) at a 90 degree angle and vulcanizing at 150℃ for 30 minutes, both plies were peeled off at a tensile speed of 200 mm/min. The force required to do so is expressed in kg/inch. <Rubber adhesion rate> This is a measure of the adhesion of rubber to fibers.
The cord peeled off from the rubber during the inter-ply peel force measurement described above was observed with the naked eye, and the portion of the cord surface to which the rubber was attached is expressed as a percentage. Examples 1 to 3, Comparative Examples 1 to 6 Denacol was added to 100 g of a 20 wt% ammonia aqueous solution of 2,6-dimethylol-4-chlorophenol.
6 g of EX-611 (manufactured by Nagase Sangyo Co., Ltd., sorbitol polyglycidyl ether) and 4 g of Neocol SW-30 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., 30% aqueous solution of dioctyl sulfosuccinate sodium salt) as a surfactant. Add and dissolve uniformly. water 805
g while stirring to uniformly dissolve Denacol EX-611 in water. Next, Hiren MP
A dispersion obtained by mixing 14 g (phenol block of 4,4-diphenylmethane diisocyanate manufactured by Dupont Co., Ltd.), 4 g Neocol SW-30, and 42 g water in a ball mill for 24 hours, and a dispersion obtained by mixing Nitzpol 2518FS (Nippon Zeon Co., Ltd.) for 24 hours. Add 125 g of a 40% water emulsion of vinylpyridine-styrene-butadiene terpolymer (manufactured by Co., Ltd.) and mix uniformly. The obtained liquid mixture is used as a first treatment agent. In addition, 10 g of a 10% caustic soda aqueous solution and 30 g of a 28% ammonia aqueous solution were added to 260 g of water, and stirred well. Into the resulting aqueous solution, 60 g of a resorcinol-formalin initial condensate (40% acetone solution) reacted with an acidic catalyst was added. Add and stir thoroughly to disperse.
Next, 240 g of Nitzpol 2518GL (manufactured by Nippon Zeon Co., Ltd., vinylpyridine-styrene-butadiene-terpolymer latex 40% water emulsion) and Nitzpol LX-112 (manufactured by Nippon Zeon Co., Ltd., styrene-butadiene copolymer 40%). % water emulsion) 100g to 200% water
Dilute with g. The resorcinol/formalin initial condensation dispersion was slowly stirred into this diluted solution, and 20 g of formalin (37% aqueous solution) was added and mixed uniformly. Next, add 14 g of diphenylmethane diethylene urea to this mixture.
Add and mix an aqueous dispersion obtained by stirring and mixing Neocol SW-305g and water 36g in a ball mill for 24 hours. Next, 7.2 g of ECN1299 (epoxy compound of phenol formalin resin condensate manufactured by Ciba Geigy Co., Ltd.) was dissolved in toluene in advance, and Neocol P (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., dioctylsulfosuccinate sodium salt) was dissolved in toluene. An aqueous solution in which 0.1g and 0.6g of methyl cellulose were added and dissolved.
Add the dispersed solution to 28 g with stirring and mix, and use the obtained liquid mixture as the second treatment agent. [n] = 0.89 polyethylene terephthalate was melt-spun and stretched according to a conventional method to obtain a 1500 denier/
After obtaining a multifilament of 192 filaments, continue to combine the two multifilaments with 40×
A 3000 denier/384 filament cord was obtained by twisting 40T/10cm. The above-mentioned cord was previously dipped in a pretreatment agent and then heat-treated at 180°C for 3 minutes using a cord processing machine (at this time, heat setting may be added at 180°C after stretching). These cords were immersed in the first treatment using a computer treater (tire cord processor manufactured by CA Ritzler Co., Ltd.), dried at 150°C for 2 minutes, and then dried at 230°C for 1 minute. Heat treatment. Next, after immersing in the second treatment agent, it was heated at 150℃ for 2 hours.
Dry for 1 minute, then heat treat at 230°C for 1 minute. In the treated polyester tire cord, the solid content of the first treatment agent is 2.2wt%, and the solid content of the second treatment agent is 2.5wt%.
% was attached. The treated cord thus obtained was embedded in an unvulcanized rubber containing a carcass containing natural rubber as the main component, and vulcanized at 150°C for 30 minutes (initial value) and at 170°C for 90 minutes (heat resistance value). The above experiment was carried out by variously changing the weight ratio of 2,6-dimethylol-4-chlorophenol to the polyepoxide compound and the weight ratio of compound (E) to the epoxy-modified phenol formalin condensate (F) as shown in Table 1. repeated. The experimental results are shown in Table 1.

【table】

【table】

Claims (1)

[Scope of Claims] 1 Linear aromatic polyester fibers pretreated with a treatment solution containing 2,6-dimethylol-4-chlorophenol and a polyepoxide compound (A) are treated with a polyepoxide compound (B) and a blocked polyester fiber. It is treated with a first treatment agent containing an isocyanate compound (C) and a rubber latex (D), and then an ethylene urea compound represented by the following general formula (E) and an ethylene urea compound represented by the following general formula (F) are added to the resorcinol formalin rubber latex (RFL). A method for treating polyester fibers, which comprises treating the polyester fibers with a second treatment agent added to the epoxy cresol novolak condensate represented by the formula (E)/(F) in a weight ratio of 20/80 to 80/20. [Here, R is an aromatic or aliphatic hydrocarbon residue,
n is 0, 1 or 2. When n=0, the terminal group is hydrogen. ] [Here, R' is -O(-CH ₂ ) _-k Cl, -O(-CH ₂ )- _l O
H
or [-O( _-CH2 ) _-n ] _-n OH, R'' is -H, _-CH2
,
-C ₂ H ₅ , where k, l, m are 1 to 4
m' is an integer of 1 to 5, a and b are integers of 1 to 5, and a+b≦6. ]