JPH0112870B2 - - 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. be. In particular, the present invention relates to a novel treatment method for improving the adhesion performance between the reinforced polyester fiber and rubber and providing excellent fatigue resistance when the polyester fiber reinforced rubber composite is used under high load and high temperature conditions. It is. <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 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 physical 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 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. <Object of the invention> The present invention was made against the background of the above 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. be. 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 (1) converts linear aromatic polyester fibers whose surface has been previously treated with a polyepoxide compound into polyepoxide compound (A) and N-methoxymethyl nylon.
(B), and then add an ethylene urea compound represented by the following general formula (C) and a cresol novolac type epoxy represented by the following general formula (D) to resorcin formalin rubber latex (RFL). This is a method for treating polyester fibers, which is characterized by treating with a second treating agent to which a compound is added in a weight ratio of C/D = 40/60 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 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. . ] (2) Linear aromatic polyester has the general formula (n' is an integer from 2 to 6.) A method for treating polyester fiber according to claim 1, which is a polyester whose main constituent is a repeating unit represented by the following. The present invention can be applied to any linear aromatic polyester, especially the general formula (n' represents an integer of 2 to 6) Preferably used is a polyester whose main constituent is a repeating unit represented by A polyester having the following properties is preferably 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 surface treatment of polyester fibers and 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, such as ethylene glycol, glycerol, Reaction products of polyhydric alcohols such as sorbitol, pentaerythritol, and polyethylene glycol and halogen-containing epoxides such as epichlorohydrin, resorcinol, bis(4-hydroxyphenyl)dimethylmethane, phenol/formaldehyde resin, resorcinol/formaldehyde resin, etc. reaction products of polyhydric phenols and the halogen-containing epoxides, polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide, i.e., 3,4-epoxycyclohexene epoxide, 3,4- Examples include epoxycyclohexylmethyl-3,4-epoxycyclohexenecarboxylate and bis(3,4-epoxy-6-methyl-cyclohexylmethyl)adipate. 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 N-methoxymethyl nylon used in the first treatment agent of the present invention is a nylon made from nylon resin and chemically modified by reacting formaldehyde and methanol to make it soluble in alcohol. The hydrogen of -NHCO- is replaced with a methoxymethyl group -CH ₂ OCH ₃ and is represented by the following chemical formula. This may be further grafted with acrylic acid, acrylamide, etc. to add a carboxyl group to make it water-soluble. The above-mentioned polyepoxide compound is added to this, and the weight ratio (B)/N-methoxymethyl nylon (B)/polyepoxide compound (A) is
(A) Blend at 100/10 to 100/80. Especially 100/10~
It is preferable to mix them at a ratio of 100/50 (weight ratio). If (B)/(A) is out of the above range, the adhesion of N-methoxymethyl nylon to polyester fibers will be poor, resulting in decreased adhesion or hardness, resulting in decreased fatigue resistance. The total solid content concentration including N-methoxymethyl nylon (B) and polyepoxide compound (A) is 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 is 1:
It is used in a range of 0.1 to 1:8, preferably 1:0.5 to 1:5, 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 1:1 to 1:15 in terms of solid content, depending on the addition ratio of the ethylene urea compound (C) and the cresol novolak type epoxy compound (D), which will be described later.
Preferably, the ratio is 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 there is too much adhesive strength,
Rubber adhesion rate cannot be obtained. The mixing ratio of the ethylene urea compound (C) and the cresol novolak type epoxy compound (D) is 40/60 to 80/
20 (weight ratio), and the mixture is added in an amount of 0.5 to 30 wt%, preferably 1.0 to 20 wt%, based on the RFL. 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, adhesive strength,
The disadvantage is that the rubber adhesion rate reaches 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 its strength. occurs. The ethylene urea compound added to the second treatment agent is represented by the following general formula (C). [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 ocdadecyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, metaxylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, and triphenylmethane triisocyanate. Examples include reaction products with ethyleneimine, and aromatic ethylene urea compounds such as diphenylmethane diethylene urea give particularly good results. Similarly, the cresol novolak type epoxy compound added to the second treatment agent is represented by the following general formula (D). (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 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 (D) can be considered, but
Good results are obtained by using one with a molecular weight of 1200-1300 and an epoxy value of 4.0-4.5oq/Kg. In the present invention, the ethylene urea compound (C) and the cresol novolak type epoxy compound (D) have a catalytic effect on each other. , the epoxy ring opens and reacts to improve adhesion, while also increasing the cohesive force of the adhesive itself.As a result, it creates a strong chemical bond with the amines generated in the rubber, preventing adhesive deterioration. It is. Furthermore, due to the synergistic effect with the heat resistance of the nylon resin applied as the first treatment agent, adhesive deterioration is suppressed to a minimum, thereby exhibiting good heat-resistant adhesive properties. 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, 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 260°C, then treated with a second treatment agent, and dried and heat-treated at a temperature of 120°C or higher and below the melting point of the polyester fiber, preferably 180-250°C. If the drying/heat treatment temperature is too low, the adhesion with the rubber will be insufficient, while if the temperature is too high, the polyester fibers may melt or fuse.
This may cause a significant decrease in strength, 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 pull-out strength 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 are values 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 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 the rubber. Rubber is embedded in a rubber block and under pressure
After vulcanization at 150°C for 30 minutes, 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> 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 6, Comparative Examples 1 to 7 6 g of Denacol Ex-611 (manufactured by Nagase Sangyo Co., Ltd., sorbitol polyglycidyl ether) and Neocol SW-30 (Daiichi Kogyo Seiyaku Co., Ltd.) as a surfactant.
Add 4 g of 30% aqueous solution of dioctyl sulfosuccinate sodium salt (manufactured by Manufacturer, Inc.) and dissolve uniformly. Add this to 805g of water while stirring, and add Denacol Ex.
- Dissolve 611 uniformly in water. Next, 1 g of piperazine as a reaction catalyst is added and mixed uniformly to form a fiber surface treatment agent. Next, Torezin FS-500 (manufactured by Teikoku Kagaku Sangyo Co., Ltd.,
Acrylamide graft compound of N-methoxymethylated nylon) Add Denacol to 100g of 30% solution.
Add 5 g of Ex-421 (manufactured by Nagase Sangyo Co., Ltd., diglycerol polyglycidyl ether), and dissolve and mix uniformly. Add this to 150 g of water while stirring and dissolve uniformly to form the 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, 240g of Nitzpol 2518GL (manufactured by Nippon Zeon Co., Ltd., vinylpyridine/styrene/butadiene-terpolymer latex 40% water emulsion) and Nitzpol
100g of Lx-112 (manufactured by Nippon Zeon Co., Ltd., 40% water emulsion of styrene-butadiene copolymer) and 200g of water.
Dilute with This diluted solution contains the above resorcinol.
Add formalin initial condensation dispersion while stirring slowly, and then add formalin (37% aqueous solution).
Add 20g and mix evenly. Next, add 14 g of diphenylmethane diethylene urea, 50 g of Neocol SW-30, and 36 g of water to this mixture in a ball mill.
Add and mix the aqueous dispersion obtained by stirring and mixing for 24 hours. Next, 7.2 g of ECN1299 (manufactured by Ciba Geigy Co., Ltd., an epoxy compound of phenol-formalin resin condensate) was dissolved in toluene in advance, and Neocol P (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., dioctyl sulfosuccinate sodium salt) was dissolved in toluene. ) and 0.6 g of methylcellulose were added and dissolved in 28 g of water with stirring, and the dispersed mixture was added and mixed, and the resulting liquid mixture was used as the second treatment agent. [η] = 0.89 polyethylene terephthalate was melt-spun and stretched according to a conventional method to obtain a 1500 denier/
A multifilament of 192 filaments was obtained.
During spinning, a surface treatment agent having the composition shown above was applied. Continue to apply the two multifilaments 40x.
A 3000 denier/384 filament cord was obtained by twisting 40T/10cm. These cords were immersed in the first treatment agent using a computer treater (tire cord treatment machine manufactured by CA Ritzler Co., Ltd.), and then 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 230°C for 1 minute.
The treated polyester tire cord has a solid content of 2.2wt% of the first treatment agent and a solid content of the second treatment agent.
2.5wt% was attached. The treated cord thus obtained was embedded in unvulcanized rubber with a carcass composition mainly composed of natural rubber, and vulcanized at 150°C for 30 minutes (initial value) and at 170°C for 90 minutes (heat resistance value). As shown in Table 1, the above experiment was performed by variously changing the weight ratio of the N-methoxymethylated nylon acrylamide graft compound (B) and the polyepoxy compound (A) as the first treatment agent, and ethylene urea as the second treatment agent. The experiments were repeated while varying the weight ratio of the compound (C) and the cresol novolak type epoxy compound (D). The experimental results are shown in Table 1.

【table】

【table】

Claims (1)

[Claims] 1. A linear aromatic polyester fiber whose surface has been previously treated with a polyepoxide compound is treated with a first treatment agent containing a polyepoxide compound (A) and N-methoxymethyl nylon (B), and then treated with resorcin formalin. The following general formula (C) is applied to rubber latex (RFL).
Ethylene urea compound represented by and the following general formula
A method for treating polyester fibers, which comprises treating with a second treatment agent containing a cresol novolak type epoxy compound represented by (D) in a weight ratio of D/D=40/60 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,
Either CH ₃ or C ₂ H ₅ , and k, l, and m are 1
An integer of ~4, m' is an integer of 1 to 5, a, b are an integer of 1 to 5.
It is an integer of 5 and a+b≦6. ] 2 Linear aromatic polyester has the general formula (n' is an integer from 2 to 6.) The method for treating polyester fibers according to claim 1, which is a polyester whose main constituent is a repeating unit represented by the following.