JPH01225647A - Resin composition - Google Patents

Abstract

PURPOSE:To make it possible to form a molding resin composition having excellent impact resistance, flexibility and abrasion resistance and wide applicability, by mixing a mixed resin comprising a polyolefin and an alpha-olefin/glycidyl (meth)acrylate copolymer with a polyester fiber. CONSTITUTION:This resin composition comprises a mixed resin comprising 99.5-50wt.% polyolefin (a) and 0.5-50wt.% copolymer (b) composed of 80-99wt.% alpha-olefin and 20-1wt.% glycidyl (meth)acrylate and a fiber (c) of a polyester comprising an acid component containing at least 40mol.% terephthalic acid and a diol component in a ratio of 10-150pts.wt. (c) to 100pts. wt. sum of (a)+(b). As component (a), one based on polyethylene or polypropylene is desirable. As the alpha-olefin in component (b), ethylene or propylene is particularly desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polyolefin resin composition with improved mechanical properties such as impact resistance, flexibility, and abrasion resistance.

[Conventional technology]

Composite materials basically consist of three elements: a resin matrix, reinforcing fibers, and an interface between the resin matrix and the reinforcing fibers. Matrix resins include thermoplastic resins such as polyolefins and thermosetting resins such as epoxy resins and unsaturated polyesters, and reinforcing fibers include fibers such as glass, polyester, polyamide, and polyolefin. Since the main function of the matrix/fiber interface is to transfer stress from the matrix to the reinforcing fibers, the chemical and physical properties of the interface greatly influence the mechanical properties of the composite material. The compatibility of the matrix and reinforcing fibers is a determining factor in load distribution in composite materials, and fiber coatings have been used to increase the compatibility between the matrix and reinforcing fibers. For example, US Pat. No. 5,657,417 discloses the use of silane coupling agents to bond dissimilar materials such as organic polymers and glass fibers in the field of reinforced plastics.

Further, JP-A-56-24423 discloses the use of a silane-based casobling agent to improve the adhesion between rubber and fibers. However, even with these measures, the adhesion at the interface between the matrix and reinforcing fibers was not sufficient, and the mechanical properties of the resulting reinforced composite material were also insufficient.

[Problem that the invention seeks to solve]

As a result of conducting research to improve these problems, the present inventors discovered a resin composition for molding that has excellent impact resistance, flexibility, and abrasion resistance, and has a wide range of practical applications. Completed the invention.

[Means for solving problems]

The present invention comprises 99.5 to 50% by weight of polyolefin (a) and 80 to 99% by weight of α-olefin tocricidyl (
Copolymer (b) with 20-1% by weight of meth)acrylate
A polyester fiber (c) consisting of a resin consisting of 0.5 to 50% by weight, an acid component and a diol component containing 40 mol% or more of terephthalic acid,
This is a resin composition containing (c) in a ratio of 10 to 150 parts by weight.

The polyolefin (a) used in the present invention includes low density polyethylene, high density polyethylene, polypropylene mainly having an isotactic structure, ethylene copolymers, propylene copolymers, and mixtures thereof. Those mainly composed of polyethylene or polypropylene are preferred.

Examples of the α-olefin of α=olefin-glycidyl (meth)acrylate copolymer (1)) include ethylene, propylene, butene-1, isobutylene, pentene-1, hexene-1, heptene-1, octene-1, Dodecene-1,4-methyl-pentene-1 and the like, as well as mixtures thereof, are used. Particular preference is given to ethylene and propylene. This copolymer (1)) may be a random copolymer, a block copolymer, or a graft copolymer.

The copolymer (b) may contain a vinyl compound other than α-olefin, glycidyl methacrylate, or glycidyl acrylate as a copolymerization component. Such vinyl compounds and compounds such as styrene, vinyl acetate, methyl (meth)acrylate, ethyl acrylate, vinyl chloride, α-methylstyrene, divinylbenzene, acrylic acid, tetrafluoroethylene, difluoroethylene,
Vinylidene chloride, acrylonitrile, acrylamide, etc. are used.

The α-olefin content in the copolymer (b) is 80 to 99
Weight%, glycidyl (meth)acrylate content is 20
~1% by weight. When the glycidyl (meth)acrylate content is less than 1% by weight, no improvement in impact resistance is observed. Further, even if the amount exceeds 20% by weight, no particular improvement in impact resistance is observed, and gel components may occur.

The ratio of polyolefin (a) to copolymer (b) is 995 to 0.5 to 50, preferably 995 to 60 by weight.
:0.5-40. If the amount of copolymer (b) is less than this, no improvement in the physical properties of the molded article will be observed. Moreover, if the amount is more than this, the impact resistance of the molded product will decrease.

Other acid components for the polyester fiber (c) consisting of an acid component containing 40 mol% or more of terephthalic acid and a diol component include inphthalic acid, p-β-oxyethoxybenzoic acid, 2,6-naphthalene dicarboxylic acid, 4.4
Examples include dicarboxylic acids such as '-dicarboxydiphenyl, 4,4'-dicarboxybenzophenone, bis(4-carboxyphenyl)ethane, acihinic acid, cepacic acid, and 5-sodium sulfoisophthalic acid. In addition, the diol components include propylene glycol, butanediol, neopentyl glycol, diethylene glycol,
Examples include ethylene oxide adducts of bisphenol A.

Conopolyester is produced by a method in which an aromatic dicarboxylic acid is directly reacted with a glycol, and a transesterification method in which a dimethyl ester of an aromatic dicarboxylic acid is transesterified with a glycol.

The polyester fiber (c) has a single fiber fineness of 1 to 1.
Examples include milled fibers of 0 denier, preferably 1 to 5 denier, cut fibers, filament yarns, and the like. If the single fiber fineness is less than 1 denier, it is difficult to provide sufficient physical and chemical performance to the resin composite molded product.

Moreover, if it is larger than 10 denier, the adhesion area of the fiber to the resin matrix per unit weight decreases, making it difficult to maintain good adhesion.

The polyester fiber (c) preferably has a strength of 6 to 10 g/denier, an elongation of 10 to 50%, and a flood shrinkage rate of 0.5 to 10%. If the strength of the single fiber is less than 31/denier or the elongation is higher than 50%, it becomes difficult to impart sufficient performance, particularly impact resistance, to the resin composite molded product. Flood shrinkage rate is a factor that greatly affects the appearance of resin composite molded products. For example, when polypropylene resin is molded at 190°C using polyester fibers with a water shrinkage rate of 10% as a reinforcing material, the shrinkage rate relative to the mold dimensions of a resin composite molded product is 0.6%, but the flood shrinkage rate is 0.6%. 11.8% and 13.
When 2% polyester fiber is used, the shrinkage rate of the molded product increases sharply to 0.46% and 0.61%, respectively, which causes cracks to occur in the molded product. Furthermore, if polyester fibers having a flood shrinkage rate of less than 0.5% are used, the bending strength of the molded product may decrease. The cross-sectional shape of polyester fiber is trilobal, which is called a circular shape.
It may have any shape such as a four-lobed shape, or may be a hollow fiber.

The resin composition of the present invention is obtained by melt-mixing polyolefin (a), copolymer (bl), and polyester fiber (c).

The blending amount of polyester fiber (c) is as follows: polyolefin (
The amount is 10 to 150 parts by weight, preferably 1° to 100 parts by weight, per 100 parts by weight of the mixed resin of a) and copolymer (b). If the amount of polyester fiber (c) is less than 10 parts by weight, the effects of improving the rigidity, dimensional stability, heat resistance, paintability, etc. of the molded article will be insufficient. Moreover, if it exceeds 150 parts by weight, the fluidity and moldability of the resin composition and the strength of the molded product will decrease.

The resin composition of the present invention may contain other reinforcing fibers, inorganic fillers, plasticizers for resins, and the like.

Examples of other reinforcing fibers include glass fibers, carbon fibers, polyamide fibers, and cellulose fibers, and inorganic fillers include silica, alumina, calcium carbonate, magnesium silicate, aluminum silicate, barium sulfate, and calcium sulfate. By adding an inorganic filler, it is possible to improve the dispersibility of fibers, the impact resistance, flame retardance, rigidity, heat resistance, etc. of molded products.

The polyolefin (a), the copolymer (b) and the polyester fiber (c) are mixed in any order using a Bamba I7 mixer, a roll mixer, a Niegoo, an extruder, a high-speed rotating mixer, or the like.

〔Effect of the invention〕

The resin composition of the present invention can be molded by a molding method such as extrusion molding or injection molding, and the resulting molded product has significantly improved mechanical properties such as impact resistance, flexibility, and abrasion resistance. Therefore, it is suitable for automobile interior and exterior parts, electroacoustic parts, etc.

Examples 1 to 3 and Comparative Example 1.2 Melt flow rate 30, 38 parts by weight of polypropylene block copolymer containing 8.0% by weight of ethylene, melt flow rate 0.4, number of ethyl branches per 1000 carbon atoms 2 A mixture of 10 parts by weight of high-density polyethylene with a melt flow rate of 6°0 and an ethylene content of 88% by weight and linear saturated polyester fibers were added to this as shown in Table 1. After mixing in a Henschel mixer, approximately 190
The pellets were produced by melt mixing at a temperature of °C. The obtained pellet was injection molded to prepare an Izod impact test piece, and the impact value was measured.

For comparison, test pieces were also prepared for a composition containing no polyester fiber (Comparative Example 1) and a composition containing no ethylene-glycidyl methacrylate copolymer (Comparative Example 2), and the impact values were measured. The results are shown in Table 1. As the test piece, a test piece without R and with a V notch was used. The blending ratios in the table mean parts by weight.

Table 1 *1 Mixture of 38 parts of propylene block copolymer and 10 parts of high-density polyethylene 2 Ethylene-glycidyl methacrylate copolymer *3
Fineness 2.0 denier, strength 7.59/7'' neel, elongation 10.4%, water production shrinkage rate 3.0%, acid component: terephthalic acid 100 mol% Example 4.5 and Comparative Example 6 Contains ethylene Test pieces were prepared in the same manner as in Example 2 except that different amounts of ethylene-glycidyl methacrylate copolymers were used, and the impact values were measured.For comparison, polyethylene was used instead of the above copolymer. A similar test was conducted using

The results are shown in Table 2. E/G in the table means ethylene/glycidyl methacrylate.

Table 2

Claims (1)

[Claims] Polyolefin (a) 99.5 to 50% by weight and α-
Copolymer (b) of 80-99% by weight of olefin and 20-1% by weight of glycidyl (meth)acrylate (b) 0.5-5
Polyester fiber (c) consisting of a resin consisting of 0% by weight, an acid component containing 40% by mole or more of terephthalic acid, and a diol component, and 10 to 10% of (c) for 100 parts by weight of (a) + (b). A resin composition containing 150 parts by weight.