JPH0813346A - Method for improving adhesion of polyester monofilament - Google Patents

Abstract

PURPOSE:To obtain a polyester monofilament improved in adhesion to a matrix rubber. CONSTITUTION:The characteristic of this method for improving the adhesion of a polyester monofilament comprises irradiating the polyester monofilament with an ultraviolet pulsed laser beam having <=380nm wavelength before or after treatment thereof with an aqueous solution of an epoxy resin having <=2 epoxy groups, subsequently treating the resultant monofilament with the second treating agent containing the resorcin-formalin-rubber latex(RFL) and a blocked polyisocyanate compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the adhesiveness of polyester monofilament as a fiber for reinforcing rubber such as tires, hoses and belts.

[0002]

2. Description of the Related Art Polyester fiber has high strength and high Young's modulus, and it is extremely useful as a fiber for reinforcing rubber of tires, hoses, belts, etc. Generally, it is used in the state of a cord obtained by twisting a multifilament consisting of a filament bundle in which tens or hundreds of filaments each having a single yarn fineness of about 3 to 6 denier are gathered.

In recent years, there has been a movement to use polyester monofilaments for polyester twisted yarn cords made of polyester multifilaments. This is because there is no need for a twisting process, and therefore there is no twist shrinkage, so there is little heat shrinkage, and therefore when it is applied as a reinforcing fiber for the matrix, there is an advantage that the dimensional stability of the composite is improved. is there.

However, when a polyester monofilament is applied, its surface is relatively inactive because it is polyester, and since it is in the shape of a monofilament, its surface is extremely smooth and the adhesion of adhesive is limited. Yes, the adhesiveness with a matrix such as rubber or resin is insufficient.

Therefore, a chemical treatment method using various chemicals, for example, a method of treating the fiber surface with a highly reactive chemical chemical such as an epoxy compound or an isocyanate compound has been proposed and put into practical use, but it is not always sufficient. .

On the other hand, the physical treatment methods using sputtering, low-temperature plasma, electron beam, ultraviolet rays, etc. have advantages and disadvantages, and none of them can be practically used alone.

[0007]

OBJECTS OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyester monofilament having improved adhesion to a matrix.

[0008]

That is, according to the present invention, "(Claim 1) a polyester monofilament is treated with 380 before or after treatment with an aqueous epoxy solution having two or more epoxy groups.
Adhesiveness of polyester monofilament characterized by irradiating an ultraviolet pulsed laser beam having a wavelength of nm or less and subsequently treating resorcin formalin rubber latex (RFL) with a second treatment agent containing a blocked polyisocyanate compound Improved method. (Claim 2) Polyester monofilament, 38
After irradiation with an ultraviolet pulsed laser beam having a wavelength of 0 nm or less, it is treated with an aqueous epoxy solution having two or more epoxy groups, and then resorcinol formalin rubber latex (RFL) containing a blocked polyisocyanate compound The method for improving adhesion of a polyester monofilament according to claim 1, which is treated with a treating agent. (Claim 3) A polyester monofilament is treated with an aqueous epoxy solution having two or more epoxy groups, and then immediately irradiated with an ultraviolet pulsed laser beam having a wavelength of 380 nm or less, and then resorcinol formalin rubber latex (RFL). The second treating agent containing a blocked polyisocyanate compound is treated with
For improving the adhesion of polyester monofilaments. ".

As the polyester monofilament,
Polyesters containing ethylene glycol and tetramethylene glycol as the main glycol components, such as polyethylene terephthalate or polybutylene terephthalate, are preferably used.

The polyepoxide compound imparted to the polyester fiber in the present invention is a compound containing 0.2 g equivalent or more of at least two epoxy groups per molecule per 100 g of the compound, and ethylene glycol, glycerol, sorbitol, penta Reaction products of polyhydric alcohols such as erythritol and polyethylene glycol with halogen-containing epoxides such as epichlorohydrin, polyhydric phenols such as resorcin / bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resin, resorcin / formaldehyde resin And a polyepoxide compound obtained by oxidizing an unsaturated compound with peracetic acid, hydrogen peroxide or the like. As a specific example,
3,4-epoxy cyclohexene epoxide, 3,4-
Epoxy cyclohexene methyl-3,4-epoxy cyclohexene carboxylate, bis (3,4 epoxy-
6-methylcyclohexylmethyl) adipate and the like can be mentioned.

Of these, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is preferable because it exhibits excellent performance. Such a polyepoxide compound is usually used as an emulsion. In order to prepare an emulsion or solution, for example, such a polyepoxide compound as it is or a solution obtained by dissolving it in a small amount of a solvent as necessary is a known emulsifier, for example, sodium alkylbenzenesulfonate, dioctylsulfosuccinate sodium salt, nonylphenolethylene. Emulsify or dissolve using an oxide adduct or the like. From the viewpoint of the manufacturing process, it is preferable to apply the polyepoxide compound together with the application of the oil agent in the step of stretching the polyester fiber, and subsequently heat set.

The blocked polyisocyanate compound used in the RFL adhesion treatment agent of the present invention is an adduct of a polyisocyanate compound and a blocking agent, and the block component is liberated by heating to produce an active polyisocyanate compound. Is. As the isocyanate compound, for example, tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, or the like, or a compound having two or more of these isocyanates and active hydrogen atoms, for example, triamine Methylol propane, pentaerythritol, etc. have a ratio of isocyanate groups (-NCO) and hydroxyl groups (-OH) of 1
Examples thereof include a polyalkylene glycol adduct polyisocyanate containing a terminal isocyanate group obtained by reacting at a molar ratio of over 10. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl isocyanate are preferable because they exhibit excellent performance.

Examples of the blocking agent include phenols such as phenol, thiophenol, cresol and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, phthalamides, lactams such as caprolactam and valerolactam, and the like. There are oximes such as acetoxime, methyl ethyl ketone oxime, and cyclohexane oxime, and acidic sodium sulfite.

The RFL adhesion treatment agent applied in the present invention is a mixture of an initial condensate obtained by reacting resorcin-formalin under an alkaline or acidic catalyst and a rubber latex, which is a resorcin-formalin rubber latex. The effect can be seen even if any of the known techniques is applied to the mixing ratio of.

The ultraviolet laser light referred to in the present invention is 15
XeF, X having a wavelength of 0 to 380 nm
In addition to lasers such as eCl, KrF, and ArF, higher harmonic laser light such as copper vapor laser and YAG laser can be used. There is no particular limitation on the laser light irradiation method. Irradiation may be performed in air, in an inert gas, under pressure, or in vacuum. The temperature during irradiation is
The range from room temperature to 100 ° C is desirable. Irradiation fluence and the number of irradiation shots are important as irradiation conditions. Irradiation fluence is usually 1 to 500 mJ / cm ² /
The range of the pulse is desirable, but various settings are made depending on the purpose of reforming. In the case of polyester monofilament, 10 mJ / cm ² / pulse or more is desirable. Irradiation with high fluence is of course possible, but in the case of polyester monofilament, the melting point of the polymer itself is 240 to
If it is at 260 ° C. and is irradiated with an excessively high fluence, the surface will be melted and the physical properties will be deteriorated. To prevent this, 350 mJ / cm ² / pulse or less is desirable. Irradiation at a threshold value or more and as low a fluence as possible is desirable from the balance of physical properties and surface modification.

The timing of irradiating the laser is before treatment with an aqueous epoxy solution having two or more epoxy groups.
Alternatively, it is preferable that the treatment is followed by continuous irradiation. After irradiation, it may be wound up once, or may be continuously subjected to the next treatment. Subsequently, it is treated with an adhesive containing resorcin / formalin / rubber latex (RFL). The RFL applied in the present invention is a mixture of an initial condensate obtained by reacting resorcin / formalin under an alkali or acidic catalyst and a rubber latex, and the effect can be seen by applying any known technique. As the cross-linking agent, the one containing the blocked polyisocyanate described above is used.

[0017]

INDUSTRIAL APPLICABILITY According to the present invention, a polyester monofilament having a smooth surface is irradiated with an ultraviolet pulse laser beam before or after an epoxy compound having two or more epoxy groups is applied to the polyester monofilament. With the increase of the amorphous part in the monofilament surface layer part, the compatibility with the epoxy compound is improved, and the polyester monofilament has fine irregularities formed on the smooth surface, and the surface area is increased, so that the treatment is continued. By increasing the contact area with a so-called RFL adhesive, it is possible to obtain a polyester monofilament having improved adhesiveness with a matrix such as rubber or resin.

The present invention will be specifically described below with reference to examples. The evaluations in the examples were according to the following methods. <Peel separation adhesive strength between plies and rubber adhesion rate> Twenty-five monofilaments that have been previously subjected to an adhesive treatment are arranged in one direction, and adhesive rubber is covered from both sides of the monofilaments to form a sandwich. After being vulcanized under predetermined conditions in the mold as it is, the cord and either one of the rubber surfaces are slowly peeled off (50 mm / min). At this time, the force (peeling adhesion force) required and the rubber adhesion state (rubber adhesion rate) on the cord surface after peeling are visually determined.

[0019]

Examples 1 to 6 and Comparative Examples 1 to 5 Polyethylene terephthalate monofilament fiber (manufactured by Teijin Limited, [η]
0.85) 3000 denier using an excimer laser generator (LP120cci) manufactured by Lambda Physics, using KrF (oscillation wavelength 248 nm), repetition frequency 1 Hz, fluence 10-350 mJ / cm ²
And the pulse width was 20 ns in full width at half maximum, and the surface was uniformly irradiated from three directions around the polyester monofilament. Then, as a polyepoxide compound containing two or more epoxy groups as the first treatment liquid,
Denacol Ex-611 (Nagase Sangyo Co., Ltd., sorbitol polyglycidyl ether) 6 g, as a surfactant Neocol SW-30 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.,
4 g of dioctyl sulfosuccinate sodium salt aqueous solution) is added and uniformly dispersed. Then, a dispersion liquid in which water was dispersed in a phenol block body of 4,4'diphenylmethane diisocyanate (manufactured by Meisei Chemical Co., Ltd., S-
3, 30% solution) 60g, and Nipol 2518G
L (manufactured by Nippon Zeon Co., Ltd., 40% water emulsion of vinylpyridine / styrene / butadiene polymer in water) (125 g) was added, and the mixture was uniformly mixed and immersed. Continue 1
Heat treatment was performed at 30 ° C. for 90 seconds and then at 235 ° C. for 60 seconds.

Then, as a second treating agent, 10 g of a 10% aqueous solution of caustic soda and 30 g of a 28% aqueous ammonia solution were added.
60 g of resorcinol-formalin initial condensate (40% acetone solution) condensed in advance with an acidic catalyst was added to 260 g of water and well stirred, and thoroughly stirred and dispersed. Next, Nipol 2518G
L, 340 g was added to 200 g of water and sufficiently stirred, and then the resorcinol-formalin initial condensate solution was slowly added with stirring, and then formalin solution (37%) 2
0 g was added to obtain an aqueous adhesive. The adhesive solution was aged at 20 ° C. for 48 hours. Then 4,4 'diphenylmethane
After dipping in a solution obtained by adding 80 g of a dispersion (S-3, 30% aqueous solution, manufactured by Meisei Chemical Co., Ltd.) in which water is dispersed in a phenol block of diisocyanate, at 140 ° C. using a heat treatment machine. After drying for 90 seconds, heat treatment was performed at 230 ° C. for 120 seconds.

The obtained adhesive-treated polyester monofilament was embedded in unvulcanized rubber containing natural rubber as a main component and vulcanized at 150 ° C. for 30 minutes to measure the peel adhesion between plies and the rubber adhesion ratio after peeling. went. The results are shown in Table 1.

[0022]

Examples 7 to 12 and Comparative Examples 6 to 9 Polyethylene terephthalate monofilament fiber (manufactured by Teijin Ltd.,
[Η] 0.85) Denacol Ex-611 (manufactured by Nagase & Co., Ltd., sorbitol polyglycidyl ether) as a polyepoxide compound containing two or more epoxy groups as the first treatment liquid in 3000 denier. 4 g of Neocol SW-30 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., 30% aqueous solution of dioctyl sulfosuccinate sodium salt) is added to 6 g of the above mixture and uniformly dispersed. Then 4,4 'diphenylmethane diisocyanate pheno-
60 g of a dispersion liquid (manufactured by Meisei Chemical Co., Ltd., S-3, 30% solution) in which water is dispersed in a rubber block body, and Nipol 2
518GL (Zeon Corporation, vinyl pyridine
40% water emulsion of styrene-butadiene polymer) 1
25 g was added and uniformly mixed, and then processed.

Subsequently, an excimer laser generator (LP120cci) manufactured by Lambda Physic was used and Kr was used.
F (oscillation wavelength 248 nm) is used and the repetition frequency is 1
Hz and fluence were 10 to 350 mJ / cm ² , and pulse width was 20 ns at full width at half maximum, and both sides were uniformly irradiated directly from both sides of the polyester monofilament.

Next, as the second treating agent, 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, 60 g of a resorcinol-formalin initial condensation product (40% acetone solution) that had been condensed with an acidic catalyst in advance was added to this aqueous solution, and the mixture was thoroughly stirred and dispersed. Next, Nippon Pole 2518GL,
After adding 340 g to 200 g of water and thoroughly stirring, the resorcinol-formalin initial condensate solution was slowly added with stirring, and then the formalin solution (37%) 20
g was added to obtain an aqueous adhesive. 4 this adhesive liquid at 20 ℃
Aged for 8 hours. Then, a dispersion liquid in which water is dispersed in a phenol block body of 4,4'-diphenylmethane diisocyanate (S-3, 30% aqueous solution, manufactured by Meisei Chemical Co., Ltd.)
After dipping in a solution containing 80 g, 1 with a heat treatment machine
After drying at 40 ° C. for 90 seconds, heat treatment was performed at 230 ° C. for 120 seconds. Table 2 shows the results.

[0025]

[Table 1]

[0026]

[Table 2]

The comparative example is data in the case where the excimer laser is not irradiated and the irradiation energy is extremely small or too large. Examples 1 to 1
As shown in Fig. 2, excimer laser irradiation has a remarkable effect on improving the adhesive performance between the linear aromatic polyester cord and the rubber. As you can see from the table, fluence is 10
In the range of up to 350 mj / cm ² , both the adhesive peel strength and the rubber adhesion rate are well balanced, and excimer laser irradiation in this range is desirable.

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Claims (3)

[Claims] 1. A polyester monofilament is irradiated with an ultraviolet pulsed laser beam having a wavelength of 380 nm or less before or after being treated with an aqueous epoxy solution having two or more epoxy groups, and then resorcinol formalin rubber latex (RFL). ) Is treated with a second treatment agent containing a blocked polyisocyanate compound. 2. A polyester monofilament comprising 38
After irradiation with an ultraviolet pulsed laser beam having a wavelength of 0 nm or less, it is treated with an aqueous epoxy solution having two or more epoxy groups, and then resorcinol formalin rubber latex (RFL) containing a blocked polyisocyanate compound A method for improving the adhesiveness of a polyester monofilament, which comprises treating with a treating agent. 3. A polyester monofilament is treated with an aqueous epoxy solution having two or more epoxy groups, and then immediately irradiated with an ultraviolet pulsed laser beam having a wavelength of 380 nm or less, followed by resorcinol formalin rubber latex (RFL). A method for improving the adhesiveness of a polyester monofilament, which comprises treating with a second treating agent containing a blocked polyisocyanate compound.