JPS6254911B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for treating polyester fibers, and its purpose is to provide a method for treating polyester fibers that dramatically improves the heat-resistant adhesion between the fibers and rubber. In particular, the present invention is a process that improves the rate of rubber adhesion to polyester fibers (rubber coverage) when peeling polyester fibers from a composite molded product with rubber, and also makes the polyester fibers flexible and has excellent fatigue resistance. It is about the method. Prior Art Polyester fibers, typified by polyethylene terephthalate fibers, have physical properties such as high strength and Young's modulus, low elongation, low creep, and excellent fatigue resistance, and are used as composites for rubber reinforcement. It is widely used for such purposes. However, polyester fibers have poor adhesion to rubber compared to polyamide fibers such as nylon 6 and nylon 6/6, and ordinary adhesive treatment does not allow the polyester fibers to fully exhibit their physical properties. 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 purpose, the surface of polyester fibers is coated with, for example, epoxy compounds,
A method of imparting adhesive properties by treating with a highly reactive substance such as an isocyanate compound has been proposed. However, when trying to improve the adhesion of polyester fibers to rubber, the treated fiber material becomes hard, making molding difficult and reducing fatigue resistance. Purpose of the Invention The present invention has been made against the background of the above circumstances, and the purpose of the present invention is to provide excellent performance in adhesive properties, particularly heat-resistant adhesive properties, between polyester fibers and rubbers. In order to achieve this object, the present invention has been devised as a treatment method for imparting adhesive properties, particularly excellent heat-resistant adhesive properties, between polyester fibers and rubbers. Structure of the Invention That is, the present invention provides (1) treating linear aromatic polyester fibers with a first treatment agent containing a polyepoxide compound (A), a blocked polyisocyanate compound (B), and a rubber latex (C), and then treating the linear aromatic polyester fiber with a first treatment agent containing a polyepoxide compound (A), a blocked polyisocyanate compound (B), and a rubber latex (C), and then treating the linear aromatic polyester fiber with a first treatment agent containing a polyepoxide compound (A), a blocked polyisocyanate compound (B), and a rubber latex (C).・
An ethylene urea compound represented by the following general formula (D) and the following general formula (E) are added to rubber latex (RFL).
This is a method for treating polyester fibers, which is characterized by treating with a second treating agent containing an epoxy-modified phenol-formalin condensate represented by the formula D/E in a weight ratio of 50/50 to 80/20. [In the formula, R is an aromatic or aliphatic hydrocarbon group, 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(-CH ₂ )- _n ]- _n ′
OH, R″ is either H, CH ₃ or C ₂ H ₅ ,
k, l, m are integers from 1 to 4, m' is an integer from 1 to 5, a, b are integers from 1 to 5, and a+b≦6
It is. (2) The linear aromatic polyester has the general formula (n' is an integer from 2 to 6) A method for treating a polyester fiber according to claim 1, which is a polyester whose main constituent is a repeating unit represented by: The present invention can be applied to any linear aromatic polyester, especially the general formula (n' is an integer from 2 to 6) Preferably used is a polyester whose main constituent is a repeating unit represented by Preferably, polyester is used. Polyester fiber molecular weight, denier, number of filaments, cross-sectional shape, fiber physical properties, microstructure,
Needless to say, there are no limitations on the presence or absence of additives and the polymer properties (terminal carboxyl group concentration, etc.). The polyepoxide compound used in the 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 equivalent or more per 100 g of the compound, and includes ethylene glycol, glycerol, sorbitol, pentaerythritol, polyethylene Resorcinol bis(4
-Hydroxyphenyl)dimethylmethane, phenol/formaldehyde resin, resorcinol/formaldehyde resin, and other reaction products of polyhydric phenols and the above-mentioned halogen-containing epoxides, oxidizing unsaturated compounds with peracetic acid, hydrogen peroxide, etc. Examples of the resulting polyepoxide compounds include 3,4-epoxycyclohexene epoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexenecarboxylate, and bis(3,4-epoxy-6-methyl-cyclohexylmethyl)adipate. be able to. 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 and active hydrogen atoms. A polyalkylene glycol containing terminal isocyanate groups obtained by reacting a compound having two or more such as trimethylolpropane, pentaerythritol, etc. at a molar ratio of isocyanate groups (-NCO) to hydroxyl groups (-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, chlorolene rubber latex, etc. 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 first treatment agent is the above polyepoxide compound (A),
Contains a blocked polyisocyanate compound (B) and rubber latex (C), and the weight ratio of each component (A), (B), and (C) is (A)/[(A)+(B)] is 0.05 to 0.9 , (C)/[(A)+
(B)] is preferably used in a range of 0.5 to 15. Especially (A)/[(A)+(B)] is 0.1 to 0.5, (C)/
It is preferable to blend them so that [(A)+(B)] is in the range of 1 to 10. If (A)/[(A)+(B)] is out of the above range, the rate of rubber adhesion to polyester fibers tends to deteriorate, and the adhesiveness tends to decrease.
If (C)/[(A)+(B)] is smaller than the above range, the treated polyester fiber will become hard and may lead to a decrease in fatigue resistance, while if it is larger than the above range, adhesiveness may decrease. come. The total solid content including the polyoxide compound (A), blocked polyisocyanate compound (B) and rubber latex (C) 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 and formaldehyde is 1:01~
The ratio is preferably 1:8, preferably 1:05 to 1:5, and more preferably 1:1 to 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 as follows: ethylene urea compound (D) and epoxy-modified phenol/formalin resin condensate.
Depending on the addition ratio of (E), the solid content ratio is 1:1 to 1:1.
The ratio is desirably 1:15, preferably in the range of 1:3 to 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 (D) and epoxy-modified phenol formalin condensate (E) 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 processing agent is represented by the following general formula (D). [R is an aromatic or aliphatic 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 (E). [Here, R' is -O-(CH ₂ )k-Cl, -O-
(CH ₂ )l—OH or [—O—(—CH ₂ ) _n ]— _n ′OH,
R″ is either H, CH ₃ or C ₂ H ₅ , k,
l, m are integers from 1 to 4, m' is an integer from 1 to 5,
a and b are integers of 1 to 5, and a+b≦6. ] Various compounds that satisfy the above (E) 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 (D) and the epoxy-modified phenol-formalin condensate (E) have a catalytic effect on each other, and the ethylene urea compound has an ethylene imine ring 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 to 10% by weight as the first treatment agent composition.
The amount of the second treating agent composition is preferably 0.5 to 10% 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, after the polyester fiber is treated with the first treatment agent, the temperature is 50°C or more and 10°C or more lower than the melting point of the polyester fiber, preferably 220°C or more.
It is dried and heat-treated at a temperature of 250°C, then treated with a second treatment agent, and then dried and heat-treated at a temperature of 120°C or higher and below the melting point of the polyester fiber, preferably 180 to 250°C. If the drying/heat treatment temperature is too low, adhesion with 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. EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples. In the examples, the heat resistance in rubber, CRA adhesive strength, T adhesive strength, and inter-ply peeling force are values determined as follows. <Heat resistance in rubber> Shows strong retention after vulcanization in rubber. After heating the cord in the 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. <CRA adhesive strength> Indicates the adhesive strength between the treated cord and rubber. Five cords are buried near the surface layer of the rubber sheet,
The force required to peel five cords from the rubber sheet at a speed of 200 mm/min after vulcanization at 150°C for 30 minutes under pressure is expressed in kg/5 cords. <T adhesive strength> This indicates the adhesive strength between the treated cord and rubber. The cord was embedded in a rubber block and vulcanized under pressure at 150°C for 30 minutes, and then the cord was pulled out from the rubber block at a speed of 200 mm/min. The force required for pulling out was expressed in kg/cm. <Peeling force between plies> 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 4 Neocol SW-30 (Daiichi Kogyo Pharmaceutical
Add 4 g of dioctyl sulfosuccinate sodium salt 30% aqueous solution (manufactured by Co., Ltd.) and dissolve uniformly. Add this to 805g of water while stirring, and add Denacol to 805g of water.
Dissolve Ex-611 uniformly in water. Next, Hiren MP (a phenol block of 4,4-diphenylmethane diisocyanate manufactured by Dupont Co., Ltd.)
A dispersion obtained by mixing 14 g of Neocol SW-30, 4 g of Neocol SW-30, and 42 g of water in a ball mill for 24 hours, and Nitzpol 2518FS (manufactured by Nippon Zeon Co., Ltd., a 40% water emulsion of vinylpyridine-styrene-butadiene terpolymer) ) Add 125g and mix evenly. 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 2518FS (manufactured by Nippon Zeon Co., Ltd., vinylpyridine-styrene-butadiene-terpolymer latex 40% water emulsion) and Nitzpol Lx-112 (manufactured by Nippon Zeon Co., Ltd., 40% styrene-butadiene copolymer) water emulsion) 100g with water
Dilute with 200g. The resorcinol-formalin initial condensation dispersion was added to this diluted solution while stirring slowly, and 20 g of formalin (37% aqueous solution) was added and mixed uniformly. Next, add 14 diphenylmethane diethylene urea to this mixture.
g, 5 g of Neocol SW-30, and 36 g of water were stirred and mixed in a ball mill for 24 hours, and an aqueous dispersion obtained was added and mixed. 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., dioctyl sulfosuccinate sodium salt) was dissolved in toluene. 0.1g
Add and dissolve 0.6 g of methyl cellulose, add to 28 g of water with stirring, and mix. The resulting liquid mixture is used as a second treatment agent. [η] = 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. After immersing these cords in the first treatment agent using a computer treater (tire cord treatment machine manufactured by CA Ritzler Co., Ltd.), the cords were heated at 150°C.
The sample was dried for 2 minutes at 230°C, and then heat treated at 230°C for 1 minute. Next, after being immersed in a second treatment agent, it is dried at 150°C for 2 minutes, and then heat treated at 30°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 repeated by varying the weight ratio of the ethylene urea compound (D) and the epoxy-modified phenol formalin condensate (E) as shown in Table 1. The experimental results are shown in Table 1.

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Claims (1)

[Scope of Claims] 1. Linear aromatic polyester fibers are treated with a first treatment agent containing a polyepoxide compound (A), a blocked polyisocyanate compound (B) and a rubber latex (C), and then treated with a resorcinol formalin rubber latex. Add an ethylene urea compound represented by the following general formula (D) and an epoxy-modified phenol formalin condensate represented by the following general formula (E) to (RFL) at a weight ratio of D/E = 50/50 to 80/20. The second
A method for treating polyester fibers, which comprises treating with a treatment agent. [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-
( _CH2 )l-OH or [-O( _-CH2 ) _-n ] _-n'OH ,
R″ is either H, CH ₃ or C ₂ H ₅ , k,
l, m are integers from 1 to 4, m' is an integer from 1 to 5,
a and b are integers of 1 to 5, and a+b≦6. ] 2 The linear aromatic polyester has the general formula (n' is an integer of 2 to 6) A method for treating polyester fibers according to claim 1, which is a polyester whose main constituent is a repeating unit represented by: (n' is an integer of 2 to 6)