JPH0112868B2 - - 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 improves the rate of rubber adhesion to polyester fibers (Rubbor coverage) when peeling polyester fibers from a composite molded product with rubber,
The present invention also relates to a processing method for making polyester fibers flexible and having excellent fatigue resistance. <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 compared to polyamide fibers such as nylon 6 and nylon 6/6, and normal adhesive treatment is difficult to achieve in order to fully demonstrate the physical properties of 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 attempting 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 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. be. In order to achieve this object, the present invention has been made as a treatment method for imparting adhesion between polyester fibers and rubber, particularly excellent heat-resistant adhesion, and as a treatment method for improving fatigue resistance. <Structure of the Invention> That is, the present invention provides the following steps: (1) After treating a linear aromatic polyester fiber in an ionized active gas atmosphere (plasma treatment),
It is 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.
This method of treating polyester fibers is characterized by treating formalin rubber latex (RFL) with a second treating agent in which an ethylene urea compound represented by the following general formula (D) is added. [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. ] (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 of 2 to 6) Preferably used is a polyester whose main constituent is a repeating unit represented by: Polyester is preferably used. Polyester fiber molecular weight, denier,
Needless to say, there are no limitations on the number of filaments, cross-sectional shape, fiber physical properties, microstructure, presence or absence of additives, and polymer properties (terminal carboxyl group concentration, etc.). The plasma treatment in the present invention includes oxygen, nitrogen,
The polyester fiber is treated in an ionized atmosphere using gases such as ammonia, carbon monoxide, nitrogen monoxide, argon, helium, etc. alone or in a mixture of two or more gases to increase the reactivity of the fiber surface. be. The reason for the improvement in heat-resistant adhesion and fatigue resistance is
Although it is not clear, it is thought that plasma treatment of the polyester cord improves wetting with the treatment agent due to the generation of functional groups on the fiber surface or the formation of irregularities on the fiber surface. This allows the treatment agent to be applied uniformly to the cord surface, making it possible to uniformly disperse external stress during adhesive failure and fatigue failure.
This is thought to be due to the fact that stress concentration becomes less likely to occur. In order to form an ionized state of active gas, a so-called plasma processing apparatus is used. Plasma processing apparatuses include external polarity, internal polarity, capacitive coupling type, inductive coupling type, etc., and any type may be used. The operating processing conditions vary depending on the time, but
For example, a high frequency glow discharge of 10 ^-3 Torr to several Torr is suitable. By using plasma treatment, the surface of polyester fibers can be treated at low temperatures and in a short time without impairing the mechanical properties of the fibers. 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 Reaction products of polyhydric alcohols such as glycols and halogen-containing epoxides such as epichlorohydrin, 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 polyepoxide compounds obtained 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 is 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 containing terminal isocyanate groups obtained by reacting a compound having two or more such groups, such as trimethylolpropane, pentaerythritol, etc., at a molar ratio of isocyanate groups (-NCO) to hydroxyl groups (-OH) exceeding 1. Examples include glycol 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 rubber latex,
There are butadiene copolymer latex, vinylpyridine-styrene-butadiene terpolymer latex, nitrile rubber latex, chloroprene rubber latex, etc., and these can be used alone or in combination. Among these, vinylpyridine
Excellent performance is shown when styrene-butadiene-terpolymer latex is used alone or 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)
]
It is desirable to use it so that it is between 0.5 and 15. In particular, (A)/[(A)+(B)] is 0.1 to 0.5, (C)/[(A)+
(B)] is preferably in the range of 1 to 10. If (A)/[(A)+(B)] is out of the above range, the adhesion rate of rubber to polyester fibers tends to be poor, and the adhesiveness tends to decrease.
If [(A)+(B)] 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 concentration including the polyepoxide 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 fibers.
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 1:0.1
-1:8, preferably 1:0.5-1:5, 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 alone or in use of 1/2 or more shows excellent performance. The blending ratio of resorcinol/formalin and rubber latex is 1:1 to 1:15 in solid weight ratio, depending on the addition ratio of ethylene urea compound (D) described below.
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. Ethylene urea compound (D) is 0.5 to the above RFL.
~30 wt%, preferably 1.0 to 20 wt%.
If the amount of the mixture added is too small, good adhesion,
Rubber adhesion rate 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 effect of eliminating the amount of the mixture added to the saturated value of adhesive strength and rubber adhesion rate is not increased, and the cost only increases, and the fiber material after treatment becomes extremely hard and loses its 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. ] Typical 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. Examples include reaction products with imines, and aromatic ethylene urea compounds such as diphenylmethane diethylene urea give particularly good results. In the ethylene urea compound used in the second treatment bath in the present invention, when heated, the ethyleneimine ring opens and reacts, increasing adhesiveness. The reaction mechanism is completely different from that of the blocked isocyanate compound which becomes the isocyanate compound. When such an ethylene urea compound is added to the second treatment bath and treated, a polyester fiber material for rubber reinforcement with excellent adhesion and flexibility can be obtained.Furthermore, like a blocked isocyanate compound, the blocking component is released during heating. It does not pollute the environment. For the second treatment bath, it is possible to use an RFL solution that has been aged after adding an ethylene urea compound, or it is also possible to use an RFL solution that has been aged in advance and then added an ethylene urea compound immediately before treating the textile material in the second treatment bath. It can also be used by adding it. RFL
Aging during liquid preparation is usually carried out at 15-25℃ for 15 hours or more, but when an ethylene urea compound is added,
RFL liquid can be used even if it is not matured. The second treatment bath containing the ethylene urea compound and RFL is usually adjusted to have a solids 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 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, fuse, or significantly 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 peel strength durability without impairing moldability with rubber. In addition, the fatigue resistance of the cord in the rubber is improved,
Deterioration of code strength is reduced. <Example> Hereinafter, the present invention will be specifically described with reference to Examples. In the Examples, the cord peeling adhesive strength, T adhesive strength, and strength retention rate during fatigue were determined as follows. Cord peel adhesion 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 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 to pull it out is expressed in kg/cm. Tensile strength retention rate at fatigue This is a measure of fatigue resistance, measured by a Gutdoritsu type disk tester, which shows the elongation of 6 between rotating disks.
%, the remaining strength expressed in parts per million after applying cyclic fatigue to the cord 3.5 million times at a compression setting of 18%. Example 1, Comparative Examples 1 to 2 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 a 30% by weight aqueous solution of dioctyl sulfosuccinate sodium salt, manufactured by Manufacturer, Inc., and dissolve uniformly. Add this to 805g of water while stirring vigorously,
Dissolve Denacol EX-611 uniformly in water. Next, a dispersion obtained by mixing 14 g of Hiren MP (manufactured by Dupont Co., Ltd., a phenol block of 4,4'-diphenylmethane diisocyanate), 4 g of Neocol SW-30, and 42 g of water in a ball mill for 24 hours, and Nitzpol 2518FS. (Nippon Zeon
Add 125 g of a 40% by weight water emulsion of vinylpyridine-styrene-butadiene terpolymer (Co., Ltd.) and mix uniformly. The obtained liquid mixture is used as a first treatment bath. On the other hand, 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. The resulting aqueous solution was then reacted with an acidic catalyst to form a resorcinol/formalin initial condensate (40% acetone solution).
Add 60g 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., styrene, butadiene,
Dilute 100g of copolymer (40% water emulsion) with 200g of water. The resorcinol/formalin initial condensate dispersion is slowly stirred into this diluted solution, and 20 g of formalin (37%) is further added and mixed uniformly. Finally, add 20g of diphenylmethane diethylene urea and Neocol to this mixture.
An aqueous dispersion obtained by stirring and mixing 7 g of SW-30 and 53 g of water in a ball mill for 24 hours is added and mixed.
The obtained liquid mixture is used as a second treatment bath. [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. The code obtained in this way is made by JEOL Ltd.
It was set in a plasma processing apparatus using a 13.56 MHz oscillator, and processed at 200 W for 1 minute under a reduced pressure of 1 Torr in an oxygen gas atmosphere to obtain a code with an activated surface. 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 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 cord peel adhesion strength, T-adhesion strength, and strength retention rate during fatigue of the obtained treated cords were measured. The results are shown in Table 1. For comparison, a sample without plasma treatment (Comparative Example 1) and a sample with diphenylmethane diethylene urea removed from the second treatment bath (Comparative Example 2) were used, and the other conditions were exactly the same as in Example 1. A processed code was created and various characteristics of the resulting code were measured. The results are also shown in Table 1.

[Table] When using a cord that is not plasma treated or when diphenylmethane diethylene urea is removed from the second treatment bath, the adhesive force is inferior to that of the method of the present invention. Examples 2 to 5 Cords were processed in the same manner as in Example 1, except that the plasma treatment conditions in Example 1 were changed to those shown in Table 2. All of the processed codes showed excellent performance as shown in Table 2.

【table】

Claims (1)

[Claims] 1. After treating a linear aromatic polyester fiber in an atmosphere of ionized active gas (plasma treatment), it is subsequently treated with a polyepoxide compound (A), a blocked polyisocyanate compound (B), and a rubber latex (C). and then treated with a first treatment agent containing resorcinol formalin rubber latex (RFL).
A method for treating polyester fibers, which comprises treating the fibers with a second treating agent to which an ethylene urea compound represented by the following general formula (D) is added. [Here, R is an aromatic or aliphatic hydrocarbon residue,
n is 0, 1 or 2. When n=0, the terminal group is hydrogen. ] 2 The 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: (n' is an integer of 2 to 6)