JPH03197538A - Polyolefinic resin composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. having an excellent moldability, high- temp. rigidity, dimensional accuracy, etc., and giving a molded product with a relatively low density by dispersing a polyphenylene ether resin in a polyolefinic resin under a specific condition. CONSTITUTION:50-1 pts.wt. polyphenylene ether resin [e.g. poly(2,6-dimethyl-1,4- phenylene)ether] is dispersed in 50-99 pts.wt. polyolefinic resin (e.g. an ethylene- propylene block copolymer), the sum of the two resins being 100 pts.wt., under such a condition that the former in a nonmelted state is dispersed as fine particles in the latter.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a novel polyolefin resin composition, more specifically, moldability, high temperature rigidity, dimensional accuracy, scratch resistance and whitening property,
It has excellent balance of physical properties such as good surface appearance, and
A polyolefin resin composition made of unmolten polyphenylene ether resin dispersed in fine particles, which can give molded products with relatively low specific gravity and is suitable as a material for parts of automobiles, home appliances, office automation equipment, etc. It is related to.

[Conventional technology] Conventionally, polyolefin resins have been used in automobiles, home appliances, and OA.
Although it is widely used as a material for various parts and films in fields such as equipment, it has the disadvantage of being inferior in rigidity, especially at high temperatures, and dimensional accuracy, which limits its use as it is. ing.

Therefore, in order to improve the rigidity and dimensional accuracy of this polyolefin resin, various methods have been used, such as calcium carbonate, talc, mica, asbestos, diatomaceous earth,
Attempts have been made to incorporate inorganic fillers such as glass fibers into polyolefin resins, or to melt blend polyphenylene ether resins, polycarbonate resins, etc. with polyolefin resins.

However, although the method of blending inorganic fillers improves rigidity and dimensional accuracy, the resulting molded products have a high specific gravity, poor scratch and whitening resistance, or 70-marks and silver streaks. This results in unfavorable situations such as poor appearance due to the oxidation process, and it is difficult to use it in applications that require light specific gravity and good appearance.

On the other hand, in the method of melt blending polyphenylene ether resin, polycarbonate resin, etc. into polyolefin resin, although the resulting resin composition has some improvement in mechanical properties such as rigidity at high temperatures, these resins and polyolefin resin Due to their inherent poor compatibility with resins, delamination is likely to occur particularly in injection molded products, which impairs the appearance of the molded product and may also reduce scratch and whitening resistance. .

[Problems to be Solved by the Invention] Under these circumstances, the present invention has an excellent balance of physical properties such as moldability, high temperature rigidity, dimensional accuracy, scratch resistance and whitening resistance, and good surface appearance. The purpose of this invention is to provide a polyolefin resin composition that provides a molded article with a relatively low specific gravity.

[Means for Solving the Problems] As a result of extensive research by the present inventors to develop a polyolefin resin composition having the above-mentioned preferable properties,
It was discovered that the objective could be achieved by dispersing polyphenylene ether resin in a predetermined ratio in the form of fine particles in a polyolefin resin without melting it, and based on this knowledge, the present invention was completed. .

That is, the present invention provides (A) a polyolefin resin and (
B) Polyphenylene ether resin weight ratio: 50:
The present invention provides a polyolefin resin composition containing polyphenylene ether resin in a ratio of 50 to 99:1, and characterized in that the polyphenylene ether resin is dispersed in the polyolefin resin in the form of fine particles without being melted.

The present invention will be explained in detail below.

In the composition of the present invention, examples of the 3--leakable polyolefin resin used as component (A) include ethylene, fluoropylene, butene-1,3-methylbutene-1,3
Examples include homopolymers of a-olefins such as -methylpentene-1,4-methylpentene-1, copolymers thereof, and copolymers of these and other copolymerizable unsaturated monomers. Among these, polyethylenes and polypropylenes are preferred.

Examples of the polyethylenes include high-density, medium-density, and low-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, ethylene α-olefin copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid. Examples include ester copolymers.

On the other hand, examples of polypropylenes include propylene homopolymers, copolymers of propylene and other α-olefins, and modified polypropylene. Other a-olefins used in this copolymer include:
Those having 2 to 8 carbon atoms, such as ethylene, butene-11pentene-11hexene-1, heptene-11octene-1
Among them, ethylene and butene-1 are preferred. Further, as the copolymer, a block copolymer or a random copolymer containing the above-mentioned other α-olefin units in an amount of usually 40% by weight or less, preferably 30% by weight or less is used.

In the present invention, as the polyolefin resin of component (A), one type of the above-mentioned polyolefin resins may be used, or two or more types may be used in combination, but among these, in particular, 20% by weight or less Powdered block polypropylene containing ethylene units is preferred. There are no particular restrictions on the melt index (MI) of this polypropylene, but the blow grade is usually 0.0.
5 to 4, and as the injection grade, those having Ml of 3 to 60 are used.

In the composition of the present invention, the polyphenylene ether resin used as component (B) has the general formula... (1) (R1 and R2 in the formula are hydrogen atoms, halogen atoms, linear or primary or a secondary branched alkyl, hydroxyalkyl or haloalkyl group, preferably having 1 to 4 carbon atoms, or an aryl group, in which R1
and R2 may be the same or different from each other, but cannot be hydrogen atoms at the same time), a repeating unit represented by the above general formula (1) Units and general formula... (I
I) (In the formula, R3, R', R5 and R6 are each a hydrogen atom, a halogen atom, a straight chain or a primary or secondary branched alkyl preferably having 1 to 4 carbon atoms, hydroxy A repeating unit represented by an alkyl or haloalkyl group, or an aryl group, which may be the same or different, or R3 and R1 cannot be hydrogen atoms at the same time. A copolymer consisting of these homopolymers or copolymers graft-polymerized with an aromatic monovinyl monomer such as styrene; Those modified with resin can be used.

Typical examples of polyphenylene ether homopolymers include:
Poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-danityl-1,4 phenylene) ether, poly(2,6-di-n-propyl-1,4-7 enylene) ether, Poly(2,6-dichloro-1,4-phenylene)ether, poly(2,6-dipromo 1.4
-phenylene) ether, poly(2-methyl-6-ethyl 1,4-phenylene) ether, poly(2-methyl-6-isopropyl-1,4-phenylene) ether, poly(2-methyl-6-n- butyl-1,4-phenylene)
Ether, poly(2-methyl-6-hytroquine ethyl ether, poly(2-methyl-6-phenyl 1,4-phenylene) ether, poly(2-methyl-1,4-phenylene) ether, poly(2-methyl-6-phenyl 1,4-phenylene) ether, poly(2-methyl-6-phenyl 1,4-phenylene) ether, Ethyl-6-inpropyl-1,4-phenylene)ether, poly(2-ethyl-
6-n-propyl-1,4-phenylene) ether, poly(2,3,6-drimethyl-1,4-phenylene) ether, poly(2,3-dimethyl-6-ethyl 1,4)
-) 2-2-2-2-2-2-2-phenylene) ether, poly[2-(4'methylphenyl)-1,4-phenylene] ether, poly(2-phenyl-1,4-phenylene) ether, poly(2-chloro-1.4 -phenylene) ether, poly(2-chloro-6-methyl-1,4-phenylene) ether, poly(2-chloro-6-ethyl-1,4-phenylene) ether, poly(2-bromo-6-7enyl) 1.4-phenylene)ether, poly(2-chloro-6-bromo-1)
．． 4-phenylene)ether, poly(2-methyl-6-
Examples include homopolymers such as chloroethyl-1,4-7 enylene) ether.

On the other hand, as a polyphenylene ether copolymer, 2,
6-dimethylphenol and 0-cresol or 2,3.6-trimethyl represented by the general formula % ([[) (R3, R4, RS and R6 in the formula have the same meanings as above) Examples include polyphenylene ether copolymers obtained by copolymerizing with alkyl-substituted phenols such as phenols.

Among these polyphenylene ether resins, poly(2,6-dimethyl-1,4-phenylene) ether is particularly suitable. Moreover, the polyphenylene ether resin has 1
A species may be used, or two or more species may be used in combination.

It is preferable that the intrinsic viscosity of these polyphenylene ether resins is large, and the intrinsic viscosity in chloroform at 30° C. is usually 0-25 dQ/9 or more, preferably 0.3t.
ta/y or more, particularly preferably 0.4dQ79 or more, is suitable.

In the composition of the present invention, the polyolefin resin as the component (A) and the polyphenylene ether resin as the component (B) are mixed in a weight ratio of 50:50 to 99:1, preferably 60:40 to 95:5. It is necessary to contain If the content of the polyphenylene ether resin is less than the above range, the rigidity and dimensional accuracy at high temperatures will decrease, and sink marks will tend to increase, while if it is more than the above range, moldability will decrease and the specific gravity will increase. Furthermore, the manufacturing cost is high, which is economically disadvantageous.

The polyolefin resin composition of the present invention is characterized in that the polyphenylene ether resin as the component (B) is uniformly dispersed in the form of fine particles in the polyolefin resin as the component (A) without being melted. Therefore, when the polyphenylene ether resin is melt-blended with a polyolefin resin, the molded product suffers from delamination, significantly impairing its appearance, and having poor scratch and whitening resistance, making it impossible to fully achieve the object of the present invention. .

In the composition of the present invention, the average particle size of the polyphenylene ether resin fine particles is 0.1 to 1000 μm, preferably 0.1 to 300 μm, more preferably 0.1 to 100 μm.
It is desirable to be in the μm range. If this average particle diameter deviates from the above range, the effects of the present invention will not be fully exhibited.

The composition of the present invention may include various known additive components as necessary within the range that does not impair the purpose of the present invention, such as carbonic acid,
Talc, mica, silica, asbestos, glass peas,
Inorganic fillers such as glass flakes, titanium oxide, alumina, quartz powder, metal powder, reinforcing agents such as glass am, carbon fiber, metal whiskers, antioxidants, ultraviolet absorbers, heat stabilizers, 1 12 mold release agents, It may contain additives such as lubricants, flame retardants, antistatic agents, and colorants, and may also contain other thermoplastic resins and rubbers, such as polyvinyl chloride resins, polyamide resins, polyimide resins, and polyester resins. , polycarbonate resin, polyacetal resin, polyaromatic ether ketone resin, polyphenylene sulfide resin, polyaromatic ester resin, polysulfone resin, styrene resin, acrylate resin, natural rubber, polybutadiene, polyisoprene, Polyisobutylene, neoprene, ethylene-propylene copolymer rubber, polysulfide rubber, silicone rubber, acrylic rubber, urethane rubber,
A styrene-butadiene copolymer rubber, a rubber obtained by partially or completely hydrogenating the butadiene portion of a styrene-butadiene block copolymer, or the like may be blended.

The polyolefin resin composition of the present invention can be produced by, for example, mixing a polyolefin resin, polyphenylene ether resin particles of a predetermined particle size, and various additive components used as necessary in a Henschel mixer, a single or twin screw extruder, or a pan. It can be prepared by kneading using a burr mixer, rolls, etc. At this time, the kneading is carried out at a temperature at which the polyolefin resin melts and the polyphenylene ether resin does not melt.

Furthermore, when molding the composition, it is necessary to mold at a temperature at which the polyphenylene ether resin dispersed in the form of fine particles in the composition does not melt and the polyolefin resin melts.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

The physical properties and appearance performance of the molded product were determined as follows.

(1) A flat test piece with a shrinkage rate of 420mm
The shrinkage rate in the MD direction (420 mm length direction) after standing for a period of time was determined.

(2) Appearance performance (a) Scratch and whitening resistance When the flat surface of a colored test piece was scratched with the edge of a 500 yen coin, the state of scratches and whitening was observed and evaluated according to the following criteria.

0: Whitening due to scratches or not observed at all O: Whitening due to scratches is hardly observed △: Whitening due to scratches is slightly observed ×: Whitening due to scratches is considerably observed (mouth) Planar appearance Caused by filler components and layer peeling Visually observe the appearance defects and evaluate them according to the following criteria.

○: No appearance defects observed ×: Appearance defects are observed. (c) Color development Evaluation was made according to the following criteria.

O: Excellent color development △ Slightly poor color development ×: Considerably poor color development (2) Sink Using a test piece for bending evaluation of 5 inches x 1/2 inch x 1/8 inch, 5 inches x 1/2 Observe the sink marks that occur in the MD force direction on the inch surface and evaluate them according to the following criteria.

■: No sink marks observed at all. O: Almost no sink marks are observed. △: Some sink marks are observed. ×: Significant sink marks are observed In addition, the following resins were used.

・Block polypropylene propylene-ethylene block copolymer, ethylene unit content 6.5% by weight, MIIO [manufactured by Idemitsu Petrochemical Co., Ltd.] ・Polyphenylene ether poly(2,6-dimethyl-1,4-phenylene) ether [Aldrich Co., Ltd.] Example 1 90 parts by weight of block polypropylene and 10 parts by weight of polyphenylene ether having an average particle diameter of 5 6 20 μm,
After kneading and pelletizing with an extruder at 220 ° C (temperature at which Pro 7 Kuripropylene melts and polyphenylene ether does not melt), the pellets were injection molded at 220 ° C to create a test piece. Physical properties and appearance performance were evaluated. The results are shown in Table 1.

Examples 2 to 4 Tests were carried out in the same manner as in Example 1, except that block polypropylene and polyphenylene ether were used in the amounts shown in Table 1, and the polyphenylene ether had an average particle size shown in Table 1. A piece was prepared and its physical properties and appearance performance were evaluated. The results are shown in Table 1.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 except that polyphenylene ether was not used, and the physical properties and appearance performance were evaluated. The result is the first
Shown in the table.

Comparative Example 2 In Example 2, polyphenylene ether pellets were used instead of polyphenylene ether particles with an average particle size of 20 μm, and the kneading temperature and molding temperature were changed to 29 μm, respectively.
A test piece was prepared in the same manner as in Example 2, except that the temperature was 0°C (the temperature at which both block polypropylene and polyphenylene ether melt), and the physical properties and appearance performance were evaluated. The results are shown in Table 1.

Comparative Example 3 A test piece was prepared in the same manner as in Example 2, except that talc was used instead of polyphenylene ether, and the physical properties and appearance performance were evaluated. The results are shown in Table 1.

(The following is a blank space) [Effects of the Invention] The polyolefin resin composition of the present invention is composed of a polyphenylene ether resin homogeneously dispersed in the form of fine particles without being melted in a polyolefin resin, which prevents delamination. It has a good appearance without any formation, and has excellent moldability, high-temperature rigidity, dimensional accuracy, scratch resistance and whitening resistance, and has an excellent balance of physical properties, as well as a relatively small specific gravity. For example, it is suitably used as a material for parts in various fields such as automobiles, home appliances, and OA equipment.

Claims (1)

[Claims] 1. Contains (A) a polyolefin resin and (B) a polyphenylene ether resin in a weight ratio of 50:50 to 99:1, and the polyphenylene ether resin is not melted in the polyolefin resin. A polyolefin resin composition characterized in that it is directly dispersed in the form of fine particles. 2 The average particle size of the polyphenylene ether resin fine particles is 0
．． The polyolefin resin composition according to claim 1, which has a diameter of 1 to 1000 μm.