JPS649349B2 - - Google Patents

Description

[Detailed description of the invention]

<Technical field to which the invention pertains> The present invention relates to a method for improving the adhesion of polyester-based synthetic fiber materials, and specifically relates to an ethylene-propylene-based copolymer rubber composition, particularly an ethylene-propylene-diene terpolymer rubber. The present invention relates to a method for improving the adhesion between a composition (abbreviated as EPDM) and a polyester synthetic fiber material used for reinforcing the composition. <Technical Background and Problems of the Invention> Polyester-based synthetic fiber materials generally have excellent properties such as tensile strength, impact resistance, and dimensional stability, so they can be used as rubber for automobile tires, conveyor belts, V-belts, hoses, etc. It is suitable as a reinforcing material. On the other hand, ethylene-propylene copolymer rubber compositions, especially ethylene-propylene-diene terpolymer rubber compositions,
It has superior ozone resistance, weather resistance, heat resistance, steam resistance, chemical resistance, oil resistance, etc. compared to other synthetic rubbers, making it suitable for general industrial use, and furthermore, it has a low specific gravity. (0.865), it is attracting attention as a lightweight material. However, since ethylene/propylene copolymer rubber compositions are chemically inert,
When polyester-based synthetic fiber materials are used in combination as reinforcing materials, their adhesiveness is extremely low compared to other synthetic rubbers, and therefore their use is currently limited. Therefore, various methods have been tried in the past in order to improve the above-mentioned adhesiveness. For example, ethylene propylene diene terpolymer (EPDM) halogen compound aqueous dispersion and resorcinol formaldehyde latex liquid (RFL).
A method using an adhesive liquid consisting of
22358), a method using an adhesive liquid consisting of an aqueous dispersion of ethylene diene terpolymer (EPDM) and a resorcinol formaldehyde latex liquid (RFL) (Japanese Patent Publication No. 47-43630).
Method using resorcinol formaldehyde latex liquid (RFL) and organic solvent liquid or water dispersion of sulfohalogenated polymer (Japanese Patent Application Laid-Open No. 57-705476
) etc. have been proposed. Although these methods may have a certain effect on improving adhesive strength, they are still insufficient for use in V-belts, etc., and furthermore, the stability of the adhesive is poor. There were various problems such as inferiority and cost increase compared to conventional methods, and there were many cases where it could not be put to practical use. In addition, a method of adding a methylene group generator to an ethylene/propylene copolymer rubber composition (Japanese Patent Application Laid-open No.
55-59950) has also been proposed, and although this method provides a fairly high level of adhesive strength,
Since additives must be added to areas that do not come into contact with the fibers, there are problems in that the properties of the rubber composition deteriorate and the cost increases. Furthermore, polybutadiene latex or styrene-butadiene copolymer latex and styrene-butadiene copolymer latex
A phenolic compound such as 2,6-bis(2',4'dihydroxy-phenyl)-4-chlorophenol is added to a resorcinol/formaldehyde latex using a rubber latex containing a butadiene/vinylpyridine terpolymer latex. It has also been proposed to use this adhesive to bond ethylene-propylene copolymer rubber compositions and synthetic fibers (Japanese Patent Application Laid-Open No. 19375/1983), but this adhesive has a sufficiently high level of adhesion. It is difficult to obtain sex. <Object of the invention> The object of the invention is to provide an adhesive treatment method that solves the above problems and improves the adhesive performance between a polyester synthetic fiber material and an ethylene/propylene copolymer rubber composition. It is in. <Structure of the Invention> The present invention provides a method of attaching an epoxy compound having at least two or more epoxy groups to a polyester synthetic fiber material, and then heat-treating the material at 150 to 260°C.
In the subsequent process, the general formula (In the formula, R' is an aromatic or aliphatic hydrocarbon residue, n is 0, 1 or 2), and the main components are polybutadiene latex or butadiene, and the styrene component is 30% by weight. %
A styrene-butadiene copolymer latex made by copolymerizing up to An ethylene-propylene copolymer rubber composition, particularly an ethylene-propylene-dien terpolymer rubber composition (EPDM), characterized in that it is treated with an adhesive solution containing the compound and then heat-treated at 150 to 260°C.
This is a method for improving the adhesion between the fiber and the reinforcing polyester synthetic fiber material. The polyester synthetic fiber used in the present invention is
For example, one or more glycols such as ethylene glycol and propylene glycol, and an aromatic or aliphatic dicarboxylic acid such as terephthalic acid, isophthalic acid, naphthalic acid 2,6 dicarboxylic acid, adipic acid, or It is a fiber made from linear polyester obtained by reaction with one or more of these derivatives. A typical example thereof is high molecular weight polyethylene terephthalate fiber obtained by the reaction of ethylene glycol and terephthalic acid. The first treatment step of the present invention, treatment with an epoxy compound, can be applied to any form of fibrous material. For example, it may be treated by being mixed with an oil agent in the spinning process, or it may be treated after stretching and before winding up. Alternatively, it may be treated after being made into a cord woven fabric. In either case, the epoxy compound may be treated in combination with an epoxy curing agent. In this case, it may be applied to the fiber material at the same time in the same bath as the epoxy compound, or in separate baths, for example, the epoxy curing agent is applied during the spinning process, and the epoxy compound is applied after stretching. You may also do so. As an epoxy curing agent,
Typical examples include higher aliphatic tertiary amines represented by the following general formula as shown in No. 53912. (In the formula, R is a saturated or unsaturated alkyl group having 8 to 22 carbon atoms, n is 2 or 3, and p and q are integers of 1 to 30.) After treating the polyester synthetic fiber material with an epoxy compound, for example, Heat treatment is performed at 150 to 260°C using any heating means such as a slit heater, oven, or heating roller. When producing polyester synthetic fibers for rubber reinforcement, it is common to heat-treat at around 200°C after spinning and drawing.If an epoxy compound is applied before this heat treatment, the heat treatment of the present invention can It can also be used in the post-stretching heat treatment step. The time required for heat treatment depends on the treatment temperature,
In a temperature range of 150 to 260°C, a time of 1 to 240 seconds is appropriate. Epoxy compounds are usually 0.05 for textile materials
Adjust to adhere at ~2.0% by weight. When using epoxy hardener together, use epoxy compound 100
It is appropriate to use it in a proportion of 5 to 30 parts by weight. The epoxy compound used in the present invention is a compound having two or more epoxy groups in one molecule, and specifically, a compound having a glycidyl group, such as a compound having an alcoholic or phenolic hydroxyl group. Examples include reaction products with epihalohydrin. As a compound having an alcoholic hydroxyl group,
These include ethylene glycol, glycerin, diglycerin, diethylene glycol, sorbitol, pentaerythritol, trimethylolpropane, polyethylene glycol, polypropylene glycol, etc. Compounds with phenolic hydroxyl groups include resorcinol, catechol, 2,2-bis(4-hydroxy) (phenyl)propane, and further phenol derivatives, such as condensates of phenols such as phenol, cresol, and resorcinol, and formaldehyde. As mentioned above, after treating the polyester synthetic fiber material with an epoxy compound and applying heat treatment,
Furthermore, a copolymerized butadiene latex (SBR) made by copolymerizing an ethylene urea compound and a polybutadiene latex, or a butadiene component and a styrene component up to 30% by weight, and a copolymerized butadiene latex (SBR) made by copolymerizing each component of styrene, butadiene, and vinylpyridine. A rubber latex blended with a terpolymer latex is treated with an adhesive solution containing resorcinol/formaldehyde latex. The resorcinol/formaldehyde latex used in the present invention is a mixture of the above latex and an initial condensate obtained by reacting resorcinol and formaldehyde under an alkaline or acidic catalyst, and the molar ratio of resorcinol/formaldehyde is 1/
Used in the range of 0.1 to 1/8, preferably 1/0.5
~1/5, more preferably 1/1 to 1/4. The rubber latex used in the present invention is a combination of polybutadiene latex, styrene-butadiene latex, and styrene-butadiene-vinylpyridine latex, but in addition, butadiene-vinylpyridine latex, acrylonitrile latex, Acrylonitrile-butadiene latex, natural rubber latex, etc. can be mixed and used. In particular, the mixing ratio of polybutadiene latex or styrene-butadiene latex and styrene-butadiene-vinylpyridine latex should be 1/0.1 to 1/9 (weight ratio) to improve adhesion.
The range used is preferably 1/0.5 to 1/6, more preferably 1/0.7 to 1/4. The above polybutadiene latex is cis-
It consists of 1,4-polybutadiene, trans-1,4-polybutadiene, and vinyl-1,2-polybutadiene, and there are no restrictions on the composition ratio and gel content thereof. Styrene-butadiene-vinylpyridine latex has a copolymerization ratio of each component (S+
Vp)/B(S: styrene, B: butadiene,
A terpolymer having Vp (vinylpyridine) in a range of 30/60 (weight ratio) or less is desirable. The mixing ratio of the resorcinol/formaldehyde initial condensate and the rubber latex is 1/2 to 1/16 (weight ratio), preferably 1/4 to 1/13, depending on the addition rate of the ethylene urea compound described below. . If the ratio of rubber latex is too low, the treated cord will become hard, and if it is too high, satisfactory adhesion performance will not be obtained and the adhesiveness will increase, resulting in poor hose formability when used as a hose cord, so it is preferable. do not have. The ethylene urea compound added to the resorcinol/formaldehyde latex is 0.5% of the resorcinol/formaldehyde latex.
-30% by weight, preferably 1.0-20% by weight.
If the amount added is small, it is difficult to achieve the effect of improving the adhesive strength, while if the amount added exceeds 30% by weight, the adhesive strength reaches saturation and the treated cord or sag becomes extremely hard, resulting in poor workability in subsequent processes. tends to worsen. The ethylene urea compound used in the present invention is represented by the general formula shown below. (In the formula, R' is an aromatic or aliphatic hydrocarbon residue, and n is 0, 1 or 2.) Representative compounds include octadecyl isocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, Examples include reaction products of aromatic and aliphatic isocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, and triphenylmethane triisocyanate with ethyleneimine, and are usually used in the form of an aqueous dispersion. An adhesive solution containing an ethylene urea compound and resorcinol/formaldehyde latex is prepared by first mixing the ethylene urea compound dispersed in water with a dispersant and rubber latex, and then mixing with a resorcinol/formaldehyde solution that has been precondensed in advance, or, It can be prepared by first mixing the ethylene urea compound and the resorcinol/formaldehyde liquid, and then mixing the rubber latex, or by preparing the resorcinol/formaldehyde latex and then adding and mixing the ethylene urea compound aqueous dispersion. There are no particular restrictions on the mixing method of rubber latex, and polybutadiene latex or styrene latex can be mixed.
The butadiene latex and the styrene-butadiene-vinylpyridine latex may be mixed in advance, or each latex may be added sequentially. The prepared resorcinol formaldehyde latex liquid is usually aged at 16 to 25°C for 16 hours or more before use, but in the case of the present invention, it can also be used immediately after preparation in an unaged state. . Furthermore, after preparing and aging the resorcinol formaldehyde latex liquid, it is also possible to add and mix an ethylene urea compound before use. The concentration of the adhesive liquid is adjusted to 15 to 25% by weight, but when used, it is diluted to an appropriate concentration depending on the amount of adhesive to the polyester synthetic fiber material. After being treated with an epoxy compound, the heat-treated polyester fiber material is treated with a resorcinol-formaldehyde-latex adhesive solution containing an ethylene urea compound prepared as described above at 100-150°C for 0.5~ After drying for 10 minutes,
Heat treatment is performed at 150 to 260°C for 0.5 to 5 minutes to cause a curing reaction. In this case, if the temperature is less than 150°C, sufficient adhesive strength will not be developed, and if the temperature exceeds 260°C, the strength of the fiber material will decrease or the hardness will increase. The amount of adhesive liquid solids attached to polyester synthetic fiber material varies depending on the application, but is 1 to 10% by weight.
It may be within the range of 1.5 to 8.0% by weight, preferably 1.5 to 8.0% by weight. A polyester fiber material treated with a resorcinol-formaldehyde-latex adhesive containing an ethylene urea compound is vulcanized and bonded to an ethylene-propylene copolymer rubber composition under heat and pressure. The above-mentioned ethylene/propylene copolymer rubber composition is mainly an ethylene/propylene/diene terpolymer rubber composition, and the diene components include dicyclopentadiene, methyltetrahydroindene, methylenenorbornene, ethylidenenorbornene, 1 , 4-hexadiene and the like are used. The amount of diene component used is about 3 to 25 in terms of iodine value. The copolymerization ratio of ethylene and propylene in the terpolymer of ethylene, propylene, and diene is that the propylene content is 10 to 70 mol%,
The ratio of each component of ethylene, propylene, and diene is determined depending on the intended use, and those produced by known methods are used. <Action of the Invention> Although the reason why the polyester synthetic fiber exhibits good adhesion to the ethylene-propylene copolymer rubber composition according to the present invention is not clear, it is due to the following reason. It is presumed that this is the case. That is, first, by treatment with an epoxy compound, it reacts with the terminal carboxyl group or hydroxyl group of the polyester synthetic fiber, or it is internally diffused to open the ring.
It polymerizes and hardens, creating a strong epoxy film with many hydroxyl groups due to the anchoring effect, which wets well with the adhesive resorcinol, formaldehyde, and latex, and also reacts with the hydroxyl groups of the epoxy film, and the added ethylene urea further improves the adhesion. Liquid resorcinol
It is presumed that it reacts or interacts with the formaldehyde component, and furthermore, it self-polymerizes, thereby significantly increasing the cohesive force of the adhesive layer. In addition, polybutadiene latex, which is a latex component in resorcinol formaldehyde latex, or styrene-butadiene copolymer latex, which is made by copolymerizing butadiene as a main component and up to 30% by weight of styrene component, is a polybutadiene latex that is a latex component in resorcinol formaldehyde latex. It has a solubility index (solubility parameter) relatively similar to that of the copolymer rubber composition, and during vulcanization, the adhesive strength between the adhesive layer and the rubber is improved by mutual diffusion and co-vulcanization. It is thought that this is the case. Furthermore, styrene-butadiene-vinylpyridine latex also exhibits almost the same effect as polybutadiene latex or styrene-butadiene copolymer latex, but rather the interaction with the polyester fiber material is involved in improving the cohesive force of the adhesive layer. It is thought that this is the case. <Effects of the present invention> As described above, the polyester fiber material treated by the treatment method of the present invention has a high rubber adhesion rate and adhesive strength to the ethylene-propylene copolymer rubber composition, and is extremely strong. It exhibits excellent adhesive strength, and extremely remarkable effects can be obtained particularly in applications where ethylene/propylene copolymer rubber compositions are suitable, such as cords for hoses. <Examples> The present invention will be explained in more detail with reference to Examples below. In the examples, T-adhesion strength indicates the adhesive strength between the fiber material and rubber, and the treated cord is embedded in a rubber block and vulcanized at 150°C for 30 minutes under pressure. from the rubber block
It is pulled out at a speed of 200 mm/min, and the load detected at that time is expressed in kg/cm. In addition, the inter-ply peel force indicates the adhesive force between the fiber material and the rubber, and two-ply treated cords are embedded as parallel plies (cord density 36 ends/2.54 cm) in compound rubber, and then under pressure, The force required to peel both plies at a tensile rate of 200 mm/min after vulcanization at 150° C. for 30 minutes is expressed in Kg/2.54 cm. Example 1, Comparative Examples 1 to 4 Ethylene glycol diglycidyl ether and 10 mole adduct of laurylamine ethylene oxide at 10% by weight based on the ethylene glycol diglycidyl ether in the spinning oil The mixture was mixed and dispersed, and ethylene glycol diglycidyl ether was attached to the melt-spun polyethylene terephthalate fiber so that the amount of ethylene glycol diglycidyl ether attached was 0.5% by weight. After drawing, it was heat-treated at 200℃ to form a 1000 de / 250 fil yarn. Obtained. Next, three of these polyethylene terephthalate fibers were twisted together to form a twisted yarn cord with a twist count of 10T/10cm. On the other hand, 10 g of 10% caustic soda aqueous solution and 30 g of 28% ammonia aqueous solution were added to 260 g of water, and after stirring thoroughly, 60 g of resorcinol formaldehyde initial condensate (40% acetone solution), which had been condensed with an acidic catalyst in advance, was added to this aqueous solution. Add and stir thoroughly to disperse. Next, Nipole 2518 FS (product of Nippon Zeon Co., Ltd.).
Add 170 g of 40% aqueous dispersion (styrene vinyl pyridine latex) and 130 g of Nipol LX-111 (product of Nippon Zeon Co., Ltd., 52% aqueous dispersion, polybutadiene latex) to 240 g of water, stir thoroughly, and then add the above-mentioned resorcinol. formaldehyde solution (RF),
Add slowly while stirring, then add 20g of formaldehyde solution (37%), and add 80g of diphenylmethane/diethylene urea aqueous dispersion (25% dispersion).
was added and then aged at 20°C for 48 hours to obtain an aqueous adhesive solution. Next, the twisted yarn cord was immersed in the adhesive solution using a computer treater (tire cord processor made by CA Ritzler), and then dried at 100°C for 120 seconds.
It was further heat-treated at ℃ for 120 seconds. The obtained treated cord was embedded in a compounded unvulcanized rubber mainly composed of the following ethylene-propylene copolymer rubber composition, and after vulcanization at 150°C for 30 minutes under pressure, the T adhesion strength and inter-ply strength were determined. Peel force was measured. Unvulcanized rubber composition Espren 512 100 parts (Sumitomo Chemical Co., Ltd. product. Ethylene propylene copolymer rubber) Sonic R1000 50 parts (Ciel Sekiyu Co., Ltd. product. Naphthenic oil) Mercaptobenzothiazole 1.0 part (Accelerator) G- Zinc n-butyldiocarbamate (promoter) 2.0 parts Tetramethylthulum 0.6 part Disulfide (promoter) Tellurium diethyldithiocarbamate 0.4 part (promoter) Sulfur 1.5 parts For comparison, an epoxy compound was added to the spinning oil. Comparative Example 1 is a case where the process is carried out under the same conditions as in Example 1 except that diphenylmethane/diethylene urea is not added to the adhesive solution. 2. Example 1 except that a phenol block of diphenylmethane diisocyanate was added to the adhesive solution instead of diphenylmethane diethylene urea.
Comparative Example 3 is a case in which the adhesive is treated under the same conditions as in Example 1, and Comparative Example 4 is a case in which the latex component in the adhesive is replaced with cross-sulfonated polyethylene latex, and the other conditions are the same as in Example 1. ,
The adhesive performance measurement results are shown in Table 1 in comparison with the results of Example 1. It is clear from Table 1 that the cords treated by the method of the present invention have better adhesion performance than any of Comparative Examples 1-4.

[Table] Examples 2 to 8, Comparative Examples 5 and 6 Same as Example 1 except that the mixing ratio of polybutadiene latex and butadiene-styrene-vinylpyridine latex, which are latex components in the adhesive liquid, was variously changed. treated under the conditions. In the same manner as in Example 1, each of the obtained treated cords was embedded in a compounded unvulcanized rubber containing an ethylene/propylene copolymer rubber composition as the main component, and then heated under pressure.
After vulcanization at 150° C. for 30 minutes, T-adhesion strength and inter-ply peel strength were measured. The results are shown in Table 2. When polybutadiene latex (BR) or styrene-butadiene-vinylpyridine latex (SBVp) was used alone, the adhesive strength was low (Comparative Example 5, 6) It is clear that the adhesion strength is significantly improved by using a mixture of both.

[Table] Example 9 In Example 1, the latex component of the adhesive was changed to Nipole 2518FS170g and Nipole LX-111130.
Instead of g, Nipole 2518FS69g and Nipole
Using 276 g of LX-112 (Nippon Zeon Co., Ltd. product, 40% aqueous dispersion, styrene-butadiene copolymer latex, copolymerization ratio of styrene component 15% by weight), the other conditions were the same as in Example 1. The adhesion was evaluated. The results are shown in Table 3.

[Table] As is clear from Table 3, similar to Example 1, extremely excellent adhesive strength was obtained. Comparative Example 7 In Example 1, the treatment with ethylene glycol diglycidyl ether was not performed, and further, instead of diphenylmethane diethylene urea,
2.6-bis(2',4'dihydroxy-phenyl)-4
- Using an adhesive to which 100 g of chlorophenol (20% 5N ammonia solution) was added, the other conditions were the same as in Example 1, and the adhesiveness was evaluated. 6.5Kg/cm
However, the adhesion was poor.

Claims (1)

[Claims] 1. A polyester synthetic fiber material containing at least 2
After attaching an epoxy compound having 1 or more epoxy groups, heat treatment is performed at 150 to 260℃, and in the subsequent process the general formula (In the formula, R' is an aromatic or aliphatic hydrocarbon residue, and n is 0, 1 or 2) The main components are an ethylene urea compound and polybutadiene latex or butadiene, with a styrene component of 30% by weight. A resorcinol formaldehyde latex using a rubber latex blended with a styrene-butadiene copolymer latex made by copolymerizing up to A method for improving the adhesion of a polyester-based synthetic fiber material for reinforcing an ethylene-propylene-based copolymer rubber composition, the method comprising treating it with an adhesive solution containing the ethylene-propylene copolymer rubber composition and then heat-treating it at 150 to 260°C.