JPS6259637A - Improvement of adhesiveness - Google Patents

Abstract

PURPOSE:To obtain a drawn product which is excellent in adhesion to a polar material and can give a composite material excellent in mechanical strength, by graft-polymerizing an unsaturated carboxylic acid (derivative) onto the surface of a drawn super-MW polyolefin subjected to plasma discharge or the like treatment. CONSTITUTION:A drawn super-MW polyolefin such as a high-modulus high- tensile strength super-MW PE obtained by drawing super-MW PE of an intrinsic viscosity of, for example, 5dl/g or above at a draw ratio of as high as 10 or above, is subjected to plasma discharge treatment or electron beam irradiation treatment, and is brought into contact with an unsaturated carboxylic acid (derivative), e.g., (meth)acrylic acid, dissolved in a solvent such as water or an alcohol in an inert gas atmosphere such as N2 and the monomer is graft- polymerized thereonto at 0-80 deg.C for 1-120min. This is infiltrated into or added to an inorganic or organic polar material such as cement, ceramics or a thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for improving the adhesion of drawn ultra-high molecular weight polyolefin products. More specifically, the present invention relates to a method of improving adhesion by subjecting a stretched product of ultra-high molecular weight polyolefin to plasma discharge treatment or the like and then graft polymerizing a predetermined monomer onto the surface of the stretched product.

[Conventional technology]

Fiber-reinforced plastics have excellent strength and rigidity, so they are used in a wide range of applications, such as automobile parts, appliance parts housings, industrial materials, small ships, sporting goods, medical materials, civil engineering materials, and building materials. However, since most of the fiber reinforcement materials used in it are glass fibers, the resulting composite material has the disadvantage of being heavier than unreinforced plastic, and has the disadvantage of being lightweight and having good mechanical properties. Composite materials with strength are desired.

On the other hand, polyolefins such as high-density polyethylene, especially filaments made by drawing ultra-high molecular weight polyethylene at extremely high magnification, have high elasticity, high strength, and are lightweight, so they are expected to be suitable fiber reinforcing materials for reducing the weight of composite materials. There is. However, as is well known (polyolefin has poor adhesion with other polar materials, it is essential to improve its adhesion in order to use it as a reinforcing material. One way to do this is to treat polyolefin molded products with plasma discharge treatment. Method for improving adhesion with matrix material
Publication No. 3-794, JP 57-1770327703
Publication No. 2 is published. Similarly, U
S P , 344041B is known. In particular, JP-A-57-177032 proposes treating a molded article with a potassium chromate solution before plasma discharge treatment. By adopting such a method, the adhesion between the polyolefin reinforcement and the matrix resin has been considerably improved. Materials, acoustic materials, etc. are still insufficient depending on the intended use (further improvement is desired. However, it is possible to perform plasma treatment on polyaramid fibers containing m-polymer monomers, or to apply polymerizable monomers to polyaramid fibers after plasma treatment. The exposure method is described in Chemical Abstracts Vol. 95 (1981), 63359, and US Pat. The former differs from the present invention in that relatively expensive and heavy polyaramid fibers are used.Furthermore, the former is concerned with improving the adhesion of a material that originally has relatively good adhesion to polar materials, etc. On the other hand, the present invention is significantly different in that the material polymer is polyolefin, which has extremely poor adhesion.Also, the latter uses a stretched ultra-high molecular weight polyolefin, and the material itself has poor strength and elastic modulus, even if it is fibrous. However, the performance of the treated material as a fiber reinforcing material is significantly inferior.Furthermore, since it is not a stretched material, the processing cost with plasma etc. is low, and therefore, the treated material is used as a reinforcing material for polar materials. Even when used as a material, the adhesion is not sufficiently improved, and mechanical strengths such as flexural strength and flexural modulus are not sufficiently improved.

Also, as a technology similar to the latter, Japanese Patent Application Laid-Open No. 59-43010
The publication discloses an embodiment in which a polyolefin film is used. However, this also applies to the above USP 3600.
There is a problem similar to 122.

[Means for solving problems]

The present invention is an ultrahigh molecular weight polyolefin drawn product, which is characterized by subjecting the ultrahigh molecular weight polyolefin drawn product to plasma discharge treatment or electron beam treatment, and then graft polymerizing an unsaturated carboxylic acid or a derivative thereof onto the surface of the ultrahigh molecular weight polyolefin drawn product. The present invention provides a method for improving the adhesion of a stretched product of high molecular weight polyolefin.

[For production]

The polyolefin drawn product using the method of the present invention can be polyethylene, polypropylene, poly1-butene, poly4-methyl-1-pentene, or different α-olefins such as ethylene, propylene, 1-butene, 1-hexane, 1 It is a material obtained by stretch-molding a highly crystalline thermoplastic resin such as a copolymer of -octene, 4-methyl-1-pentene, etc. using various known methods. Among these drawn polyolefin products, oriented products such as monofilaments and tapes with high elastic modulus obtained by extrusion drawing are preferable as lightweight reinforcing materials, and among them, the intrinsic viscosity [η] measured at 135 degrees in decalin solvent is 5a/ g
Furthermore, by using a stretched ultra-high molecular weight polyethylene with high elasticity and high tensile strength obtained by stretching ultra-high molecular weight polyethylene in the range of F to 30 dl/g at a high magnification of 10 times or more, it is extremely lightweight. This is preferable because a composite material can be obtained. 6. Methods for obtaining drawn ultra-high molecular weight polyolefin products having high elasticity and high tensile strength are disclosed in JP-A-56-15408, JP-A-58-5228, JP-A-59-130313, and JP-A-59-130313. 1977-
As detailed in Japanese Patent No. 187614, etc., ultra-high molecular weight polyethylene is made into a dilute solution or a low molecular weight compound is added to ultra-high molecular weight polyethylene to improve the drawability of ultra-high molecular weight polyethylene and stretch it to a high ratio. An example of how to do this can be given.

The ultra-high molecular weight polyolefin stretched product has a tensile modulus of 20 GPa or more, preferably 50 GPa, and a tensile strength of 1.2 GPa or more, preferably 1.5 GPa or more, since it is lightweight, has high rigidity, and high tensile strength, so it can be reinforced. As a material, it is most suitable as a stretched ultra-high molecular weight polyolefin product of the present invention. In addition, when such a stretched product is used as a composite material, if the stretched product is in the form of a filament, it can be processed into a rope, net, cloth sheet, non-woven fabric, or paper and impregnated with or laminated with a polar material as described below. If it is in the form of a tape, it can be used by processing it into a rope or the like and impregnating or laminating it with a polar material as described below, or by cutting the filament or tape as appropriate and impregnating it with a polar material as a fibrous reinforcing material. can be taken.

Examples of the plasma discharge treatment in the present invention include high frequency discharge, microwave discharge, and glow discharge, and examples of the gas to be treated include air, nitrogen, oxygen, argon, helium, and the like. These gases may be used alone or in a mixture at any ratio. Preferred processing conditions include an output of 20 to 100
Watts, more preferably 50 to 100 Watts, degree of vacuum 10-'' to 10 Torr, more preferably 10
Nitrogen, air, oxygen, argon, etc. are used as the processing gas at 5 Torrs, and the processing time is 1800 seconds, preferably 10 to 300 seconds.

After the treatment, the unsaturated carboxylic acid or its derivative is grafted under an inert gas atmosphere such as nitrogen gas, usually without exposure to air.

The electron beam irradiation treatment in the present invention is carried out using, for example, an area beam type electron beam irradiation device Curetro P manufactured by Kuushin High Voltage Co., Ltd. The processing conditions are an accelerating voltage of 100 to 100 KV, preferably 200 to 400 KV, an electron current of 1 to 10 a+A, preferably 2 to 8 mA, particularly preferably 3 to 7 mA, and an irradiation dose of 0.1 to 10 megarads, preferably 0.
．． 5 to 5 megarads.

After the treatment, the sample may be left as it is until post-treatment, but it is preferable to hold the sample at a low temperature of about 150 degrees Celsius. When grafting the treated product by impregnating it with a solution or dispersion of an unsaturated carboxylic acid or its derivative, it is usually possible to expose it to air, but all operations should especially be performed under an atmosphere of an inert gas such as nitrogen. is preferred.

Specific examples of unsaturated carboxylic acids or derivatives thereof used in the method of the present invention include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nagic-(endosys-bicyclo(2,2,
1) unsaturated mono- and dicarboxylic acids such as hept-1-ene-2,3-dicarboxylic acid, or derivatives thereof, such as acid halides, amides, imides, anhydrides, esters, etc. Specifically, chlorinated malenyl, maleimide,
Examples include maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maley 1.

Among these, unsaturated mono- and dicarboxylic acids such as acrylic acid, methacrylic acid, maleic acid, etc. are preferred.

In addition, these may be used in combination of two or more types.

As a method for grafting a, the above-mentioned plasma-treated or electron-beam irradiated stretched ultra-high molecular weight polyolefin is brought into contact with an unsaturated carboxylic acid or its derivative under an inert gas atmosphere such as nitrogen as described above. good.

As for the method of contacting, it is preferable to make the unsaturated carboxylic acid, etc. into a solution in a suitable solvent such as water or alcohol, or make it into a dispersion in a hydrocarbon solvent, and then contact it with the solution or dispersion. However, it is not limited to this. It is preferable to use water as the solvent. The reaction conditions depend on the previous treatment and the degree of monomer used, but are usually 0°C to 80°C, preferably room temperature to 60°C.
The reaction is allowed to take place at a temperature of 1 to 120 minutes, preferably 5 to 60 minutes.

After the reaction, the treated stretched product is usually washed with water to remove unreacted monomers and produced homopolymers.

Examples of the polar materials to be bonded to the stretched ultra-high molecular weight polyolefin obtained by the above method or impregnated with the molding material include cements such as Portland cement I and alumina cement, AJLz O3, S i OL%B, and Cs.
Inorganic loss materials such as ceramics such as TtB and ZrBz, thermosetting resins such as phenolic resin, epoxy resin, unsaturated polyester resin, diallyl phthalate resin, urethane resin, melamine resin, and urea resin, nylon, polyester, and polycarbonate. Organic polar materials such as polyacecool, polyvinyl chloride, cellulose resins, polystyrene, thermoplastic resins such as acrylonitrile-styrene copolymers, etc. are used. If the polyolefin stretched product has a temperature below the softening point, the two can be bonded by heating below the softening point. On the other hand, for polar materials exceeding the softening point of the ultra-high molecular weight polyolefin stretched product, a method may be adopted in which the stretched product is impregnated with a solution in which the polar material is dissolved in an organic solvent or the like, and then the organic solvent is removed and dried.

〔Effect of the invention〕

By the method of the present invention, the adhesiveness of the ultra-high molecular weight polyolefin stretched product obtained by the treatment with the polar material is significantly improved. Used as reinforcing fiber,
When manufacturing composite materials such as sporting goods such as rackets, skis, fishing rods, golf clubs, and bamboo swords, leisure goods such as yachts, boats, and surfing boards, and medical materials such as artificial joints and denture stands, the , mechanical strength such as flexural strength and flexural modulus is significantly improved.

〔Example〕

Example 1 ■Using a high-frequency plasma processing device manufactured by Samco International Laboratories, ultra-high molecular weight polyethylene monofilament with a tensile strength of 1.6 GPa, a tensile modulus of elasticity of 75 GPa, and an Iji degree of 150 denier was produced at an output of 50 W and a vacuum degree of 2.
The treatment is performed at X 10-' Torr, using nitrogen as the treatment gas, and for a treatment time of 90 seconds. This was thoroughly degassed by nitrogen bubbling without being exposed to air.
(by weight)% acrylic acid aqueous solution, and then heated at 50°C.
Heat to and leave for 30 minutes. After the post-treatment (polymerization), the product is washed with water for about 3 hours to wash away the produced homopolymer and unreacted monomers, and then dried under reduced pressure for about 24 hours. This was used as a sample and epoxy resin (Mitsui Petrochemicals epoxy product Ebomic R-1,40/Q-640 = 100/60
) and cured at 80° C. for 2 hours, then a pull-out test was conducted. The test method was in accordance with JIS, L, 1017r "Adhesion Strength A Method (T Test) of Test Methods for Chemical Fiber Curtain Cord". The results are shown in Table 1.

Example 2 The same ultra-high molecular weight polyethylene monofilament as in Example 1 was plasma treated under the same conditions as in Example 1, and then immersed in a 50% (by weight) aqueous methacrylic acid solution that had been sufficiently degassed by nitrogen bubbling. Heat to 3℃
Leave for 0 minutes. The sample was washed and dried and subjected to the same pull-out test as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same ultra-high molecular weight polyethylene monofilament as in Example 1 was used as a sample, and a drawing test was conducted in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 The same ultra-high molecular weight polyethylene monofilament as in Example 1 was plasma-treated under the same conditions as in Example 1, and a drawing test was conducted using this as a sample.

The results are shown in Table 1.

Example 3 Using an electron beam irradiation device manufactured by Nisshin High Voltage Co., Ltd., the same ultra-high molecular weight polyethylene monofilament as in Example 1 was irradiated with an electron beam under the conditions of an acceleration voltage of 200 KV, an electron current of 6 mA, and an irradiation dose of 5 megarads. Process. This was post-treated in the same manner as in Example 1 and used as a sample to perform a pull test. The results are shown in Table 1.

Comparative Example 3 The same ultra-high molecular weight polyethylene monofilament as in Example 1 was subjected to electron beam irradiation treatment under the same conditions as in Example 2. A pullout test was conducted using this as a sample.

The results are shown in Table 1.

Table 1 Example 4 Tensile modulus 2.46GPa, tensile strength 70GPa,
Example 1 was applied to an ultra-high molecular weight polyethylene multifilament having 120 filaments and a fineness of 1000 denier.
The same treatment was applied. This is combined with two main epoxy resins (
EPO old #p-3on+go and R-140, manufactured by Mitsui Petrochemical Industries, Ltd.), dicyanodiamide, 3-(P
-chlorophenyl) -1,1-dimethylurea and dimethylformamide at 87.5/30/5, respectively.
/ 5 / 25 weight ratio, impregnated with resin mixed with 10
Prepregs were prepared by drying at 0° C. for 30 minutes, and after being laminated, press molding was performed at 100° C. for 1 hour to produce a unidirectional laminate. Next, the bending strength, bending elastic modulus (JIS K 691), and interlaminar shear strength (A
STM D 2 & 44) was measured. The results are shown in Table 2.

Comparative Example 4 A sample was prepared in the same manner as in Example 4 without performing any treatment on the same ultra-high molecular weight polyethylene multifilament as in Example 4, and the same evaluation was performed.

The results are shown in Table 2.

Comparative Example 5 The same ultra-high molecular weight polyethylene multifilament as in Example 4 was subjected to the plasma treatment in Example 1,
A sample was prepared in the same manner as in Example 4, and the same evaluation was performed. The results are shown in Table 2.

Claims (1)

[Claims] (1) Ultra-high molecular weight polyolefin drawn product is subjected to plasma discharge treatment or electron beam irradiation treatment, and then an unsaturated carboxylic acid or a derivative thereof is graft-polymerized on the surface of the ultra-high molecular weight polyolefin drawn product. A method for improving the adhesion of a drawn product of high molecular weight polyolefin.