JPH0314680A - Modified polyethylene fiber having high strength and elastic modulus and fiber-reinforced composite material made thereof - Google Patents

Abstract

PURPOSE:To improve the adhesivity of polyethylene fiber to a matrix polymer by coating a part or total of the surface of a specific polyethylene fiber having high strength and modulus with a specific modified copolymer. CONSTITUTION:At least a part of a polyethylene fiber having a tensile strength of >=20g/d, a tensile modulus of >=700g/d and a single filament denier of 0.5-4d and composed of a polyethylene having a viscosity-average molecular weight of >=500.000 is coated with a polymer produced by grafting an unsaturated copolymer composed of 80-99.45mol% of ethylene, 0.05-20mol% of a non- conjugated diene of formula (R1 is <=8C alkyl; R2 and R3 are H or <=8C alkylene; (n) is 1-10) and 0.5-10mol% of a 3-12C alpha-olefin with an unsaturated organic acid or its derivative (e.g. acrylic acid or maleic acid) and containing >=5mol% of residual unsaturated group originated from said non-conjugated diene. The polyethylene fiber modified by this process has improved adhesivity to a matrix polymer and gives a fiber-reinforced composite material having high strength.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to polyethylene fibers modified to improve the adhesiveness of polyethylene TA fibers having high strength and high modulus, and fiber reinforced composites using the same. It's about the body.

[Prior art] It is already known that ultra-high molecular weight polyethylene fibers exhibit high strength and high modulus. Such polyethylene fibers and fiber-reinforced composites of polyethylene fibers and matrix polymers, etc.
It is already being used in various industrial fields, including the aircraft and automobile industries. However, such high-strength, high-modulus polyethylene fibers do not have any reactive functional groups in their chemical structure, or because they have high crystallinity, their tensile strength as a polymer is low. As a result, the compatibility with other polymers deteriorates, and for example, when used as an adherend, there is a problem that the other material is difficult to adhere to (hereinafter referred to as polyethylene fiber or simply polyethylene) (means one with high strength and high elastic modulus). As a means of improving the adhesive properties of polyethylene, (a) a method of graft-modifying polyethylene using an unsaturated carboxylic acid or its derivative (Japanese Unexamined Patent Publication No. 61-576
No. 04) ([13 Method of subjecting polyethylene to corona discharge treatment (JP-A No. 60-1 46078) (c) Method of coating polyethylene with a specific adhesive resin (JP-A No. 58-169521), etc. is proposed.

[Problem to be solved by the invention] However, each of the above methods has the following problems.

First, with method (a), it is necessary to control the amount of grafting, but not only is this control not always easy, but the residual heptamer may reduce adhesive strength or cause a bad odor. There is a possibility that this may occur. Next, in the method (mentioned), the fibers are constantly exposed to electric discharge, so there is a risk of yarn breakage, and corona discharge treatment is not quick enough, which reduces operability and productivity. However, it is not always possible to obtain sufficient adhesion.

In method (c), it is necessary to raise the temperature of the solvent to a certain degree when coating with the adhesive resin, which not only risks reducing the strength and elastic modulus of the polyethylene fibers, but also increases the temperature of the solvent. It is less economical because it requires heating equipment, equipment to prevent the diffusion of solvent vapor generated by heating, equipment to remove or recover it, and the adhesion of the resulting product is not necessarily satisfactory. It's not possible. The present invention was developed in view of the above circumstances, and its purpose is to improve the strength and elasticity of the fibers by solubilizing or uniformly dispersing them in a solvent at room temperature when coating polyethylene fibers with an adhesive resin. The purpose of the present invention is to provide polyethylene fibers with excellent adhesion properties without reducing adhesiveness, and a fiber reinforced composite using the same.

[Means for Solving the Problems] The present invention provides that part or all of the surface of the fiber shown in (a) below is made of 0.1 to 10 parts by weight of (b) below with respect to 100 parts by weight of this fiber. The gist is that it is coated with the modified copolymer shown.

(a) Made of polyethylene with a viscosity average molecular weight of 500,000 or more, with a tensile strength of 20 g/d or more and 70
A polyethylene TA fiber having a tensile modulus of 0 g/d or more and having a l-1M fiber of 0.5 to 4 deniers.

(b) Ethylene = 80 to 99.45 mol%, the following formula (1
) Non-conjugated dienes represented by: 0.05 to 20 mol% α-refin having 3 to 12 carbon atoms = 0.5 to 10 mol% An unsaturated copolymer consisting of an unsaturated organic acid or its derivative A modified copolymer which has been graft-modified with and has a residual rate of unsaturated groups derived from the non-conjugated diene of 5 mol% or more.

(Rl is an alkyl group having 8 or less carbon atoms, R2 and R are a hydrogen atom or an alkyl group having 8 or less carbon atoms, and n is 1 to 1
It is an integer of 0. ) Further, a fiber-reinforced composite obtained by combining such modified polyethylene fibers with an arbitrary matrix polymer is also an important component of the present invention.

[Function] In the present invention, as described above, a part or all of the surface of polyethylene fiber is coated with a polyethylene coating material. The most important feature of its composition is that the modified copolymer used as the coating material is
The point is that conditions b) and (0) are met.

(a) An unsaturated polymer consisting of ethylene, a nonconjugated diene represented by the above formula (1), and the above α-olefin is graft-modified with an unsaturated organic acid or a derivative thereof.

(Example) The residual rate of unsaturated groups derived from non-conjugated genes in the modified copolymer is 5 mol% or more.

First, in the configuration (a), by using ethylene (80 to 99.45 mol %) monomer as the main component of the coating material, excellent adhesion to polyethylene, which is the material to be coated, is achieved.

Also, due to the structure (a), vinyl groups derived from non-conjugated genes and acid anhydride groups derived from unsaturated organic acids are present in the molecules of the modified unsaturated copolymer of the coating material. For this reason, for example, when manufacturing fiber-reinforced composites, covalent bonds are formed between the epoxy resin, vinyl ester resin, unsaturated polyester resin, etc. used as the matrix, resulting in extremely excellent adhesion between the two. It becomes something. Furthermore, non-conjugated dienes and α
-Since it contains olefins, copolymerization of these creates a coating material that can be dissolved or uniformly dispersed in a solvent at room temperature. Next, regarding the structure of (mouth), since unsaturated groups derived from non-conjugated dienes are present in the modified copolymer, matrix polymers with radical polymerization performance such as vinyl ester resins and unsaturated polyester resins are Excellent adhesion for coalescence. The amount of the coating material used in the present invention will be explained.

Ethylene: 80-99.45 mol% Experiments have shown that if the blending amount is too small than the above range, the adhesion to polyethylene fibers decreases, making it impossible to achieve the object of the present invention. On the other hand, if the amount is too large, other essential components cannot be blended in the necessary predetermined amounts, and the expected effects of each component will not be exhibited, resulting in problems such as decreased solubility in solvents, for example.

By the way, methods for coating polyethylene fibers with the coating material include applying it in a molten state, a solution state, or a dispersed state. However, since the fiber to be coated is polyethylene, treatment at high temperatures may lead to a decrease in strength, elastic modulus, etc. Furthermore, in the case of a coating material with low solubility that immediately forms a precipitate when cooled to room temperature after being heated and dissolved, there is a risk that coating spots may occur. Therefore, as described above, it is not preferable that the amount of ethylene becomes excessive and the solubility decreases.

For the above reasons, it is preferable to carry out the coating in a solution state or a dispersion state, and in order to uniformly perform the coating, it is desirable to perform the treatment in a solution state at room temperature. In order to achieve this, in the present invention, the appropriate upper limit of the ethylene component is determined, and as already mentioned, the idea is to copolymerize a non-conjugated diene and an α-olefin as a coating material component.

Non-conjugated genes represented by the following formula (1): O. OS
~20 mol% (R+, R2. Rs and n have the same meanings as before) Although the theoretical basis has not been confirmed, experiments have shown that even if the blending amount is lower or higher than the above range, it will not interact with polyethylene. Adhesion is reduced. Preferably, in the non-conjugated genes represented by the formula (1), n is 1 to 5 and R1 is carbon number 1 to 4.
In the alkyl group, R2 and R3 do not simultaneously become hydrogen atoms. More preferably, n is 1 to 3, R1 is an alkyl group having 1 to 3 carbon atoms, R and R3 are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R and R are simultaneously hydrogen atoms. This is not true. Specific examples of these non-conjugated dienes include 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 4.
5-dimethyl-1,4-hexadiene, 4-methyl-1
．． 4-heptadiene, 4-ethyl-1,4-heptadiene, 5-methyl-1,4-heptadiene, 5-methyl-
1.4-dienes such as 1.4-octadiene; 1.5-dienes such as 5-methyl-1.5-hebutadiene and 6-methyl-1.5-heptadiene; 6-methyl-1,
1,6-dienes such as 6-octadiene and 7-methyl-1% 6-octadiene are suitable.

Among these, a particularly preferable example is 4-methyl-1.4
-hexadiene or 5-methyl-1,4-hexadiene or 7-methyl-1,6-octadiene. These non-conjugated dienes may be used alone or in combination of two or more, and a preferred example of a combination of them is a combination of 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene. (f [quantity ratio 95:5 to 5:95). If a conjugated diene such as butadiene or isobutene is used instead of a non-conjugated diene, the copolymerization activity with ethylene and α-olefin will be significantly lower, which will not only be uneconomical but also cause the main chain of the produced copolymer to deteriorate. Ozone resistance, weather resistance, The heat deterioration resistance deteriorates significantly, making it practically undesirable. α-Olefin: 0.5 to 10 mol% Those having 3 to 12 carbon atoms can be used. Experiments have shown that the adhesion to polyethylene decreases when the amount is less than or greater than the above range. Moreover, if the blending amount exceeds the above-mentioned upper limit and becomes excessive, the solubility in the solvent decreases, which is disadvantageous.

Specific examples of the above α-olefin include propylene, 1
-butene, 1-bentene, 1-hexene, 1-octene, 3-methyl-1-butene, 3-methyl-1-bentene, 4-methyl-1-pentene, 3,3-dimethyl-1-
Butene, 4.4-dimethyl-1-bentene, 3-methyl-1-hexene, 4-methyl-1-hexene, 4.4-
dimethyl-1-hexene, 5-methyl-1-hexene,
Allylcyclobentane, allylcyclohexane, styrene, allylbenzene, 3-cyclohexyl-1-butene, vinylcyclopropane, vinylcyclopentane, vinylcyclohexane, 2-vinylbicyclo[2,2.1
] Examples include mono-heptane. Among these, preferred examples are propylene, 1-butene, 1-hexene,
These include 1-octene and 4-methyl-1-bentene.
Two or more types of these α-olefins may be included.
The elastic modulus of the above unsaturated copolymer consisting of ethylene, nonconjugated dienes, and α-olefin is determined according to JIS K 7.
Flexural modulus measured in accordance with 203 is 500 to 1
Preferably, it is a resin-like material with a weight of 0 0 0 0 kg/cm'. Those with an elastic modulus of less than 500 kg/c1 are undesirable because they are woody and rubbery and have poor adhesion to polyethylene fibers. Elastic modulus is 1 0 0
If it exceeds 0 0 kg/cm', the solubility in the solvent may decrease. Such an unsaturated copolymer can be produced by copolymerization using a Ziegler-Natta catalyst for alpha-olefin polymerization using the same method and apparatus as those used for producing alpha-olefin polymers.

The manufacturing method is not specified, and it can be performed using a known manufacturing method (Japanese Patent Application Laid-open No. 55-165907, No. 5
6-30413, 56-55409, etc.). The α-olefin is preferably polymerized so that it is randomly contained in the unsaturated copolymer.

Examples of unsaturated organic acids or derivatives thereof used for graft modification of this unsaturated copolymer include acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, fumaric acid, hymic acid, crotonic acid, and methaconic acid. Examples include acids, sorbic acid, esters thereof, acid anhydrides, metal salts, amides, imides, etc., and those having a maleic anhydride group are particularly preferred. The production of the graft-modified copolymer is also not specified and can be carried out by a known method (Japanese Patent Laid-Open No. 57-98508).

In the graft-modified copolymer, the unsaturated groups derived from the non-conjugated dienes in the unsaturated copolymer remain in an amount of 5 mol % or more, preferably 10 to 90 mol %, of the amount before modification. If it is less than 5 mol %, the adhesion to matrix resins, particularly to matrix polymers having radical polymerization performance such as vinyl ester resins and unsaturated polyester resins described below, decreases, which is not preferable.

Next, the polyethylene used in the present invention is an ultra-high molecular weight ethylene homopolymer with a viscosity average molecular weight of 500,000 or more, preferably 1,000,000 or more, or a copolymer of ethylene and a small amount of α-olefin of 1 ffi or more. It is highly crystalline. If the viscosity average molecular weight is less than 500,000, the strength of the polyethylene fiber obtained through the drawing process is insufficient. Specific examples of the α-olefin include brobylene, 1-butene, 4-methyl-1-bentene, 1-hexene, and 1-decene. As this ultra-high molecular weight polyethylene, known commercially available products can be used.

For example, Hizex 240M [manufactured by Mitsui Petrochemical Co., Ltd., weight average molecular weight (M): 2X10'] Hizex 340M [manufactured by Mitsui Petrochemical Co., Ltd., Mw: 3 xl]
G']}11xex 145M [Manufactured by the company Mw:
1 x 10'] Hifax 900 [Hercu
Manufactured by LES Mw: 5 x 10'] HB 312
CM [manufactured by Himont Mw: 2 x
10' ].

The tensile strength of the polyethylene fibers is at least 20
g/d or more, preferably 30 g/d or more,
Further, the tensile modulus is at least 700 g/d or more, preferably 1000 g/d or more. Strength is 20g/d
If the elastic modulus is less than 700 g/d, the impact strength of the fiber itself and the composite material will decrease, which is undesirable. In addition, the single fiber denier of this polyethylene fiber is 0.5
The above is 4 or less. If the single ia fiber denier exceeds 4 denier, the adhesion of the composite shape to the resin will decrease, which is not preferable. Furthermore, it is technically impossible to manufacture anything with a denier of less than 0.5 denier. Next, a method for coating part or all of the surface of such polyethylene fibers with a modified copolymer as a coating material will be explained.

This modified copolymer is preferably used after being dissolved in a solvent from the viewpoint of workability.

The type of solvent is not limited, but volatile solvents are preferred. Specifically, aromatic solvents such as benzene, toluene, and xylene; halogen solvents such as chloroform, carbon tetrachloride, dichloroethane, trichloroethane, trichloroethylene, tetrachloroethane, and tetrachloroethylene; and decalin, petroleum ether, and ligroin. In addition to hydrocarbon solvents, tetrahydrofuran (THF)
, ether and ester solvents such as ethyl acetate can be used alone or in combination. Among these, toluene, xylene, trichloroethane, and tetrachloroethane are particularly preferred.

Additionally, coating solutions using these solvents include:
Known pigments, dyes, and oil components such as antistatic agents, water repellents, and sizing agents can be included. The modified copolymer is applied on at least a portion of the polyethylene fibers in an amount of 0.1 to 1% by weight per 100 weight of the polyethylene fibers.
An amount of 0 parts by weight, preferably 0.15 to 5 parts by weight, more preferably 0.2 to 3 parts by weight is coated. 0.
If the amount is less than 1 part by weight, the adhesion becomes uneven and the adhesion to polyethylene fibers decreases, which is not preferable. On the other hand 10
If it exceeds the weight part, cohesive failure will occur in the coating layer, resulting in a decrease in adhesion to the polyethylene fibers, which is undesirable. Next, the m-fiber reinforced composite using polyethylene fibers of the present invention will be explained.

The polyethylene fibers of the present invention can impart extremely excellent functions to various thermosetting resins or thermoplastic resins, and are suitable as reinforcing fibers for FRP and FRTP, for example. Examples of the thermosetting resin include epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin, and urethane resin.

Epoxy resin has at least two epoxy groups in one molecule.
It is a compound having a molecular weight of 280 to 7,000, and commercially available products are available. Specifically, the following are examples. Bisphenol A type products include Ebikoat 828, 1001, 1004, and 1007 (manufactured by Shell Chemical Co.), and novolac type products include Epicoat 152 and Epicoat 154 (made by Shell Chemical Co., Ltd.).
, Ebon 812 (manufactured by Shell Chemical Co., Ltd.) as a glycidyl ether type of aliphatic alcohol, Chissonok 221 (manufactured by Chisso Co., Ltd.) as an alicyclic epoxy resin,
Eboxidized oils include epoxidized soybean oil and epoxidized products of dimer acid. In addition, glycidyl methacrylate or a copolymer containing glycidyl acrylate, etc.
Oligomers and polymers with a molecular weight of 200 or more that have two or more epoxy groups in the molecule, or synthetic resins such as polyester, acrylic resin, polyurethane, and polybutadiene, modified with epoxy compounds to introduce epoxy groups into the resin skeleton. Examples can also be given. Among these, bisphenol A type is particularly preferred. Furthermore, these various epoxy resins can be used alone or as a mixture of 2 fffi or more. The unsaturated polyester resin is a composition consisting of an unsaturated linear polyester obtained by a polycondensation reaction of a saturated dibasic acid, an unsaturated dibasic acid, and a glycol, and a reactive vinyl monomer. Saturated dibasic acids used include phthalic anhydride, isophthalic acid, adivic acid, sebacic acid, and tetrahydrophthalic anhydride. Examples include endomethylenetetrahydrophthalic anhydride, hetacetic anhydride, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride. Examples of unsaturated dibasic acids include maleic anhydride, fumaric acid, and itaconic acid. Glycols include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1.4-butanediol, 1.3-butanediol, neobentyl glycol, 2,2.4-
}-limethyl-1,3-pentanediol, 2,2-bis[bala(2-hydroxy-n-proboxy)phenylbrobanco, bisphenol A1 hydrogenated bisphenol A
, 4,4°-bis(2-hydroxyamino)octachlorobiphenyl and the like. Vinyl monomers include styrene, vinyltoluene, chlorostyrene, t
-Butylstyrene, methyl methacrylate, diallyl phthalate, triallyl cyanurate, etc. are exemplified. At least one of the above ingredients is selected and used from each precept. Vinyl ester resins are obtained by an addition reaction between an epoxy compound and a vinyl unsaturated carboxylic acid. Examples of epoxy compounds include bisphenol types such as bisphenol A and bisphenol F, cycloaliphatic types, epoxidized polybutadiene types, and novolac types. Examples of vinyl unsaturated carboxylic acids include acrylic acid and methacrylic acid. Phenolic resins include both resol type and novolak type, and also include those mixed with polyvinyl butyral resin. Urethane resin is a resin obtained by polyaddition of polyisocyanate and polyol. Examples of polyisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate. As the polyol, in addition to polyether polyols such as ethylene glycol, propylene glycol, diethylene glycol, and dibrobylene glycol, polyester polyols, polymer polyols, and the like can be used.

Next, examples of thermoplastic resins include alpha-olefin resin,
For example, mono- or copolymer resins of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, and modified products (chlorinated, sulfonated, etc.) of these olefin polymers. , styrenation,
oxidation, etc.), copolymer resins of α-olefins and monomers other than α-olefins (unsaturated organic acids or derivatives thereof, vinyl esters, unsaturated organic silane compounds), or
Modified products thereof (including saponified products of ethylene vinyl acetate), polystyrene, acrylonitrile-butadiene-styrene resin (ABS resin, polyamide, polyester, polycarbonate, polyvinyl chloride, etc.) or elastomers, such as styrene-butadiene -Styrene block copolymer, ethylene-propylene rubber (including EPDM), ethylene-1-butene rubber (
The evening after copolymerizing Borien. - including polymer rubber),
natural rubber, polybutadiene rubber, polyisoprene rubber,
Rubber components such as styrene-butadiene rubber (SBR) and butyl rubber can be mentioned, but resins containing α-olefin as a main component are particularly preferred. Applications of the fiber-reinforced composite of the present invention are not particularly limited, but include, for example, aircraft, automobiles, bicycles, ships, yachts, speaker cones, helmets, tensile strength materials, fishing rods, tennis rackets, and tennis rackets. , golf shafts, and other sports equipment. The above-mentioned composite material of the present invention has no risk of lightning strikes compared to conventional carbon fiber reinforced composite materials, so it can be used in items used in places where there is a risk of lightning strikes, especially fishing rods, golf shafts, etc.
Suitable for tennis rackets, etc.

Examples of the present invention will be described below, but the present invention is not limited to the following examples, and it is within the technical scope of the present invention to make appropriate design changes in accordance with the spirit described above and below.

[Example] The method of measuring physical properties used for evaluation of the present invention was as follows.

(Average molecular weight) After measuring the viscosity of a decalin solution at 135°C according to ASTM 0 2 8 5 7 and determining the intrinsic viscosity [η]
η] was substituted into the following formula to calculate the average molecular weight (M,).

Mw=3. 64 x 10' x [η11.
The tensile strength, tensile modulus and impact strength of the 3+5 fibers were measured in accordance with the method specified in JIS-L1013 (1981).

Charby Impact Strength Measuring Method> A test piece with a thickness of 3 mm, a width of 15 mm, and a length of 42 mm is applied to a Charpy impact tester, and the Charby impact strength is calculated using the following formula.

Charpy impact strength = - (Kg-cm/cm”)
A ε: Charby impact energy (Kg-cm) A: Cross-sectional area of test piece (cm2) Measuring method of shear stress (ILSS)〉Thickness 3■, Width 6
The maximum shear stress was P (Kg) and test piece cross-sectional area A (m
m') to ILSS value = 3-P/4・A (Kg/m
m') was calculated.

Four types of resins shown in Table 1 were used for ILSS measurements. V
Adjusted to f=50. Evaluation of coating material (unsaturated copolymer) Modulus of elasticity by the method specified in JIS-K7203. Coating rate depends on the weight change of unit length of yarn before and after coating treatment.

Enter X: Weight before coating X: Weight after coating Melt flow rate (MFR) According to the method specified in JIS-K7210.

(230°C) - Heat and dissolve 1 g of soluble coating material in 100 mg of tetrachloroethane. After that, it is cooled and returned to room temperature, and then visually judged immediately. × if there is sediment, otherwise O
Indicated by

・Composition analysis Vartan XL-300 75M
Hz” C-NMR analysis.

Solvent: O-dichlorobenzene/tetrachloroethane-d
= 2/1 Crystallinity; 1 1 0°C Production of polyethylene fiber by industrial engineering Ultra high molecular weight polyethylene having a flexible polymer button with a viscosity average molecular weight of 1.8 XIO' was dissolved in decalin. After preparing a spinning dope, the spinning dope was extruded into the air at room temperature from a spinneret in a spinning device at a temperature at which the polyethylene solution would not solidify, and cooled to form a gel-like fiber. This gel-like fiber containing decalin was stretched at a high draw ratio at various stretching ratios at a temperature at which the gel-like fiber would not melt to obtain a 200d/200f multifilament having the properties shown in Table 2.

Production of coating material> Copolymer of ethylene, 1-butene and methylhexadiene (mixture of 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene in a molar ratio of 8:2) Resin (1-butene: 2.5 mol%, methylhexadiene=
3.4 mol%, elastic modulus: 2800 kg/cm')
100 parts by weight and 5 parts by weight of maleic anhydride were kneaded for 1 minute at 250°C using a kneader under a nitrogen stream.
Take out raw materials from the kneader and heat at 250℃ under nitrogen stream for 3 minutes.
Heat treated for 0 minutes. The obtained product was dissolved in hot xylene and reprecipitated with a large excess of acetone to obtain a maleic anhydride graft-modified copolymer powder. The maleic anhydride grafting rate was determined from 13C-NMR after extracting the modified copolymer powder with boiling acetone for 16 hours.

Coating Treatment> In order to quickly dissolve the coating material, it was dissolved in hot tetrachloroethane at a ratio of Ig/100ml. After cooling it to room temperature, the above coating solution was put into the coating bath and the polyethylene fibers were coated at 20 m/oIi.
The material was fed out at a speed of 100 m, crushed in the coating solution, squeezed, and then passed through a dryer at 80° C. and wound up.

Adhesion to various resins was evaluated. For comparison, the adhesion of polyethylene fibers before coating was also measured. All results are shown in Table 2.

The same polyethylene fiber as in Example 1 was used. Production of coating material> Copolymer resin with ethylene, 1-butene and methylhexadiene (1-butene content 7.9 mol%, methylhexadiene content 3.8 mol%, elastic modulus 1200 kg/
cm"), 10 parts by weight of maleic anhydride, and 0.5 parts by weight of BPO were brought into contact with each other for 6 hours under stirring in 2600 parts by weight of xylene. After the reaction was completed, the mixture was precipitated with a large excess of acetone. , a modified copolymer was obtained.

Evaluation was performed in the same manner as in Example 1 using this modified copolymer. The results are shown in Table 2.

The same polyethylene fiber as in Example 1 was used. Manufacturing of coating materials〉 Ethylene. Copolymer resin with 1-butene and 4-methyl-1,4-hexadiene (1-butene content: ffi 0.8 mol%, methylhexadiene content: 8.3 mol%, elastic modulus: 1
800 kg/c+n2) 100 parts by weight, 20 parts by weight of acrylic acid, and 1 part by weight of benzoyl peroxide were brought into contact with each other for 6 hours under stirring in 2600 parts by weight of xylene.

After the reaction was completed, a large excess of acetone was added to precipitate the mixture to obtain a modified copolymer.

This modified copolymer was used and evaluated in the same manner as in Example 1. The results are shown in Table 2. Comparative Example 1 Manufacture of polyethylene fiber> High molecular weight polyethylene having a flexible polymer chain with a viscosity average molecular weight of IXIO' was dissolved in decalin to prepare a spinning stock solution, and then the above spinning stock solution was prepared at a temperature at which the polyethylene solution would not solidify. The fibers were extruded from a spinneret into the air at room temperature in a spinning device and cooled to form gel-like fibers. This gel-like fiber containing decalin was stretched at a lower draw ratio than in Example 1 at a temperature at which the gel-like fiber would not melt, to obtain a 400d/200f multifilament having the properties shown in Table 2.

A coating treatment was carried out using the coating material described in Example 1 and the method described in Example 1. The results are shown in Table 2. Tensile strength: 42 g/d, tensile modulus: 1350
The coating material described in Example 1 was used on polyethylene IA fibers of g/d.

Coating treatment> Add 5 g of the above coating material to hot tetrachloroethane.
It was dissolved at a ratio of /l00ml.

After the coating solution was cooled, it was put into a coating bath, and the polyethylene fibers were fed out at a speed of 20 m/min, immersed in the coating solution, and squeezed.
It was passed through a dryer at 0°C and wound up. Adhesion to various resins was evaluated.

The results are shown in Table 2.

Tensile strength: 42 g/d Tensile modulus: 1350 g/d
The coating material described in Example 1 was used on polyethylene fibers.

<Coating treatment> Add the above coating material to hot tetrachloroethane. 0
2g was dissolved in 7100ml. Coating treatment was carried out in the same manner as in Example 1. The results are shown in Table 2.

Comparative example 4 The same polyethylene fibers as in Example 1 were used.

Production of coating material> Copolymer resin with ethylene and methyl hexadiene (methyl hexadiene content 25.5 mol%, elastic modulus 4 5
0 kg/cm') 100 parts by weight, 10 parts by weight of maleic anhydride, and 0.5 parts by weight of benzoyl peroxide were brought into contact with each other for 6 hours under stirring in 2600 parts by weight of xylene. After the reaction was completed, a large excess of acetone was added to cause precipitation, yielding a modified copolymer. This modified copolymer was used and evaluated in the same manner as in Example 1. The results are shown in Table 2. Comparative Example 5 Polyethylene fibers with a tensile strength of 42 g/d and a tensile modulus of 1350 g/d were used. Production of coating material> 100 parts by weight of a copolymer resin of ethylene and methyl hexadiene (methyl hexadiene content: 3.5 mol%), 5 parts by weight of maleic anhydride, and 1 part by weight of BP0 were added as described in Example 1. A maleic anhydride-modified copolymer was prepared by the method.

Coating treatment> The above coating material was heated with 1 g of tetrachloroethane (71 g).
It was dissolved at a ratio of 0.00 ml. When cooled to room temperature, a precipitate was formed, so the polyethylene fibers were coated in the same manner as in Example 1 while maintaining the coating solution in the coating bath at 90 t in a homogeneous solution state.

The results are shown in Table 2.

Wataru Shiokoe Tensile strength: 42g/d, tensile modulus: 1350g/
d (7) Polyethylene fiber was used.

Production of coating material> A copolymer resin consisting of ethylene, 1-butene and methylhexadiene (methylhexadiene content: 4.3 mol%, 1-butene content: 2.8 mol%) was prepared in Example 2. A maleic anhydride-modified eutectic composite was produced by the method described. Coating treatment was carried out in the same manner as in Example 1. The results are shown in Table 2. The maleic anhydride unmodified unsaturated copolymer produced in Example 1 was used as a coating material on polyethylene fibers having a tensile strength of 42 g/d and a tensile modulus of 1350 g/d. Coating was carried out in the same manner. The results are shown in Table 2.

Manufacture of polyethylene fibers> The temperature at which the polyethylene solution does not solidify after dissolving ultra-high molecular weight polyethylene having a flexible polymer chain with a viscosity average molecular weight of 1.8 Then, the above-mentioned spinning dope is extruded from the spinneret into the air at room temperature in the spinning device, cooled, and turned into a gel! a-fibers were formed. This gel-like fiber containing decalin was stretched at a high draw ratio at various stretching ratios at a temperature at which the gel-like fiber would not melt to obtain a 1000 d/200 f multifilament having the properties shown in Table 2.

Next, using the coating material used in Example 1, the multifilament obtained above was coated in the same manner as in Example 1. The results are shown in Table 2. Comparative Example 9 Polyethylene 1a fibers having a tensile strength of +2 g/d and a tensile modulus of 1350 g/d were used.

Production of coating material> 100 parts by weight of a copolymer resin consisting of ethylene, 1-butene and methylhexadiene (methylhexadiene content: 3.4 mol%, 1-butene content: -i 2.5 mol%),
10'O parts by weight of maleic anhydride and 5 parts by weight of BPO were brought into contact with each other for 6 hours with stirring in 2600 parts by weight of xylene.

After the reaction was completed, a large excess of acetone was added to precipitate the mixture to obtain a modified copolymer.

This modified copolymer was used and evaluated in the same manner as in Example 1. The results are shown in Table 2. Comparative Example 10 A comparative example was prepared using the same polyethylene fiber as in Example 1 and a copolymer resin of ethylene and acrylic acid (acrylic acid content: 3.4 mol%, elastic modulus: 2600 kg/am2). Coating treatment was carried out in the same manner as in Example 9. The results are shown in Table 2.

Comparative Example 11 Using the same polyethylene fiber as in Example 1 and using acrylic acid grafted polyethylene (acrylic acid content 5 mol%, elastic modulus 3000 kg/cm2), Comparative Example 9
Coating was carried out in the same manner. The results are shown in Table 2.

As is clear from the results in Table 2, the polyethylene fibers according to the present invention include epoxy/acid anhydride, epoxy/aromatic amine, vinyl ester/BPO, and unsaturated polyester/BPO.
A composite material with excellent adhesion to PO etc. and excellent strength properties was obtained, but the strength properties of the composite material using polyethylene fibers in the comparative example were poor and lacked adhesion to each of the composite materials used. I can see that it is something.

[Effects of the Invention] Since the present invention is structured as described above, it is possible to provide a high-strength, high-modulus polyethylene fiber with excellent adhesive properties, and also to provide a high-strength, high-modulus polyethylene fiber according to the present invention. By combining fibers and a matrix polymer, a reinforced fiber composite with excellent strength properties can be provided.

Claims (2)

[Claims] (1) Part or all of the surface of the fiber shown in (a) below is coated with 0.1 to 10 parts by weight of the modified copolymer shown in (b) below based on 100 parts by weight of this fiber. A modified high-strength, high-modulus polyethylene fiber that is characterized by (a) Made of polyethylene with a viscosity average molecular weight of 500,000 or more, with a tensile strength of 20g/d or more and 700g/d
or more, and has a single fiber denier of 0.5
~4 denier polyethylene fiber. (b) Ethylene: 80 to 99.45 mol%, the following formula (1
): 0.05 to 20 mol% of non-conjugated dienes represented by C3 to 12 α-olefins: 0.5 to 10 mol% of unsaturated copolymers with unsaturated organic acids or derivatives thereof. A modified copolymer which has been graft-modified and has a residual rate of unsaturated groups derived from the non-conjugated diene of 5 mol% or more. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (R_1 is alkyl with 8 or less carbon atoms, R_2 and R_3
represents a hydrogen atom or an alkyl group having 8 or less carbon atoms, and n is an integer of 1 to 10. ) (2) A fiber-reinforced composite, characterized in that the modified high-strength/high-modulus polyethylene fiber according to claim (1) is composited with a matrix polymer.