JPS645066B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a molding resin composition. More specifically, the present invention relates to a molding resin composition that significantly improves impact resistance and bending resistance without substantially reducing the rigidity of the ionomer resin. Metal ions of ethylene-α,β-unsaturated carboxylic acid copolymer or ethylene-α,β-unsaturated carboxylic acid-α,β-unsaturated carboxylic acid ester ternary copolymer, which is generally called ionomer resin. Because the crosslinked product has hydrogen bonds and metal ion crosslinked structures in its molecules, it has excellent processability and
It shows transparency, strength, impact resistance, abrasion resistance, etc.
For this reason, it is used in many plastic molded products, such as office machine parts, automobile parts, sporting goods, construction goods, household goods, and medical goods.
Among these applications, when used in ski boots, sports shoe counters, freezer partitions, etc., high impact resistance and bending resistance are required, and ionomer resins have relatively good impact resistance and Although it exhibits bending resistance, further improvement was desired. To improve these properties, a method of blending elastomers is generally used.
When an elastomer such as styrene-butadiene copolymer rubber, polyisoprene rubber, polychloroprene rubber, acrylonitrile-butadiene copolymer rubber, or butyl rubber is blended with the ionomer resin by such a method, the effect of improving impact resistance remains at room temperature. However, it is not possible to improve the problem at low temperatures, and phenomena such as delamination are also observed during injection molding. The applicant previously developed an ionomer resin with a density of 0.85.
~0.90g/ ^cm3 of low crystalline to amorphous ethylene-
It has been discovered that the low-temperature impact resistance and non-clouding properties of ionomer resins can be improved by mixing a butene-1 copolymer (see Japanese Patent Application No. 15182/1982); however, as a result of further investigation, α, β to low-density crystalline to non-crystalline ethylene-α-olefin copolymer
- When a modified product obtained by graft copolymerization of unsaturated carboxylic acids is mixed with an ionomer resin, the molded product obtained therefrom further improves impact resistance and flex resistance without substantially reducing stiffness. Here we have discovered that it is possible to improve the Moreover, the serious drawback of delamination, which is often seen in the case of blend molding, is also effectively eliminated in the present invention. Therefore, the present invention relates to a molding resin composition used for injection molding, extrusion molding (including extrusion coating), etc., and this resin composition comprises (A) ethylene-
50 to 90 parts by weight of a metal ion crosslinked product of α,β-unsaturated carboxylic acid copolymer or ethylene-α,β-unsaturated carboxylic acid-α,β-unsaturated carboxylic acid ester terpolymer and (B )Density 0.85~0.90g/ ^cm3
(ASTM D-1505) 50 to 10 parts by weight of a graft modified product obtained by graft copolymerizing an α,β-unsaturated carboxylic acid or its derivative to a low-crystalline to amorphous ethylene-α-olefin copolymer are mixed. It will be done. The ionomer resin to be modified, component (A), is produced, for example, by the method described in Japanese Patent Publication No. 39-6810. That is, a copolymer of ethylene and an unsaturated carboxylic acid having 3 to 8 carbon atoms such as acrylic acid, methacrylic acid, itaconic acid, or fumaric acid, or in addition to this, methyl acrylate, ethyl acrylate, isobutyl acrylate, or methacrylate. Carvone in a ternary copolymer containing an α,β-unsaturated carboxylic acid ester having 4 to 8 carbon atoms such as methyl acid, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, and dimethyl fumarate as the third component. Some or all of the acid groups are crosslinked with metal ions. The content of unsaturated carboxylic acid in the copolymer is generally about 0.5 to 15 mol%
and preferably about 1 to 8 mol%. In addition, the content of the unsaturated carboxylic acid ester copolymerized as the third component is generally about 0.2 to 10 mol%,
Preferably it is about 1-6 mol%. Metal ions used for metal ion crosslinking include monovalent metal ions such as lithium, sodium, potassium, and cesium; divalent metal ions such as magnesium, calcium, strontium, barium, copper, and zinc; and trivalent metal ions such as aluminum and iron.
Examples include valent metal ions. The amount of metal ions used in the form of metal compounds varies depending on the acid content in the copolymer, melt index, type of ion, and its use, but generally it is about 10% or more. Preferably, it is used in an amount that neutralizes about 15-80% of the carboxylic acid groups. The ethylene-α-olefin copolymer, which is the base polymer of the graft modified component (B) blended with the ionomer resin, has a density of 0.85 to
It is 0.90 g/cm ³ and has low crystallinity to non-crystallinity (crystallinity by the specific volume method is about 20 to 0%). This copolymer contains ethylene and 3 to 3 carbon atoms.
It is obtained by copolymerizing α-olefin of No. 9, preferably butene-1 or propylene, using a composite catalyst of a vanadium compound represented by vanadium trichloride or vanadium tetrachloride and an organoaluminum compound, etc. , preferably about 5 to 30 mol % of α-olefin is copolymerized in the copolymer, thereby controlling the crystallinity, and the melt index is about 0.5 to 30 g/
Preferably within 10 minutes. Examples of α,β-unsaturated carboxylic acids or derivatives thereof to be graft copolymerized to these ethylene-α-olefin copolymers include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride, etc. Maleic anhydride is particularly preferred. These α,β-unsaturated carboxylic acids are graft copolymerized in an amount such that the resulting graft modified product accounts for 0.1 to 5.0% by weight. The ionomer resin of component (A) and the graft modified product of component (B) are 50 to 90 parts by weight and 50 to 10 parts by weight, respectively.
They are used by mixing them in parts by weight. If the mixing ratio of component (B) is higher than this, the rigidity of the molded product formed from it will be significantly reduced, and conversely, if component (B) is used in a ratio lower than this, the object of the present invention will not be achieved. I can't. The resin composition for molding is prepared by dry-blending or melt-blending the above-mentioned components simultaneously or sequentially. In the case of dry blending, the graft modified product is also easily and uniformly melt-mixed with the ionomer resin at the stage where the ionomer resin is melted and plasticized in the molding machine. In the case of melt blending, melt mixing may be performed using a single screw extruder, a twin screw extruder, various mixers such as a Banbury mixer, rolls, various kneaders, and the like. The molding resin composition according to the present invention significantly improves the impact resistance and bending resistance of molded products obtained from it without substantially reducing the rigidity of the ionomer resin, and also improves delamination resistance. However, this is because low-crystalline to non-crystalline ethylene-α-olefin copolymers exhibit relatively better compatibility with ionomer resins than other elastomers; , by graft copolymerizing β-unsaturated carboxylic acids, hydrogen bonds with the carboxylic acid group of the ionomer resin and metal ion bonds with the carboxylic acid metal base are formed, resulting in a significant increase in compatibility. This is thought to be an effect brought about by As a result, low crystallinity to non-crystalline ethylene-α
- When the olefin copolymer is used as it is without graft copolymerization, the effect of improving low-temperature impact resistance is seen only in the ethylene-butene-1 copolymer, and in the case of other copolymers. Although not effective, in the resin composition of the present invention, any of a wide variety of graft-modified ethylene-α-olefin copolymers including ethylene-butene-1 copolymer can be used. Next, the present invention will be explained with reference to examples. Example 1 Ionomer resin (Mitsui Polychemical product Himilan 1601, Na type, melt index
1.2) 70 parts (weight, same below) and ethylene-
Butene-1 copolymer (density 0.88 g/cm ³ , butene-1 copolymer
1 content 15 mol%, melt index 4) 30 parts of a maleic anhydride graft modified product (maleic anhydride grafting amount 0.4% by weight) was heated at 180°C using a 40 mm diameter extruder (L/D = 20). The mixture was kneaded at a temperature of 100 mL, and then pelletized. The physical properties of the resulting resin composition were measured for the following items, and the results are shown in the table below. Bending rigidity: thickness 3 according to ASTM D-747
Measurements were made on a press sheet of mm. Tensile impact strength: 260 according to ASTM D-1822
Flow direction (longitudinal direction) of 80 x 140 x 2 mm square plate injection molded at °C
And the values in the direction perpendicular to this (lateral direction) were measured at 23°C and -30°C, respectively. Bending resistance: Using a daytimer tester, the above square plate was bent under the condition of -5℃ and without notches, and the number of times the square plate was bent until defects such as cracking, netting, peeling, and cutting occurred was measured. Layer peelability: Judgment visually on the square plate Example 2 In Example 1, instead of the ethylene-butene-1 copolymer graft modified product, ethylene-propylene copolymer (density 0.88 cm ³ /g, propylene-containing The same amount of maleic anhydride graft modified product (maleic anhydride grafting amount 0.4% by weight) was used. Example 3 In Example 1, other ionomer resins (Mitsui Polychemical product Himilan 1557, Zn type,
The same amount of melt index 5.0) was used. Example 4 In Example 3, the same amount of the graft modified ethylene-propylene copolymer used in Example 2 was used in place of the graft modified ethylene-butene-1 copolymer. Example 5 In Example 3, ionomer resin and ethylene-butene-1 copolymer were used in proportions of 85 parts and 15 parts, respectively. Example 6 In Example 3, ionomer resin and ethylene-butene-1 copolymer were used in amounts of 50 parts each. Comparative Example 1 In Example 1, 30 parts of the ethylene-butene-1 copolymer that was not graft modified was used as it was. Comparative Example 2 In Example 2, 30 parts of the ethylene-propylene copolymer that was not graft modified was used as it was. Comparative Example 3 In Example 3, 30 parts of the ethylene-butene-1 copolymer that was not graft modified was used as it was. Comparative Example 4 In Comparative Example 2, another ethylene-propylene copolymer (density 0.88 g/cm ³ , propylene content 20
The same amount of mol %, melt index 1.2) was used. Comparative Example 5 In Comparative Example 2, the same amount of yet another ethylene-propylene copolymer (density 0.88 g/cm ³ , propylene content 20 mol %, melt index 5.0) was used. Comparative Example 6 The ionomer resin used in Example 3 was used alone. Comparative Example 7 The ionomer resin used in Example 1 was used alone. Comparative Example 8 Another ionomer resin (Mitsui Polychemical product Himilan) showing approximately the same bending rigidity as each resin composition of Examples 1 to 4 and Comparative Examples 1 to 5 was used.
1652, Zn type, melt index 5.0) was used alone. The measurement results of Examples 2-6 and Comparative Examples 1-8 are also shown in the following table.

[Table] From the above results, compared to the ionomer resin alone, the mixture of low-crystalline or non-crystalline ethylene-α-olefin copolymer has a
Ethylene-butene-1 copolymer has improved impact resistance and bending resistance, and does not exhibit delamination properties, but ethylene-propylene copolymer does not show any particular improvement in any of these respects, and On the other hand, in the case of a mixture of a graft modified product of a low-crystalline or non-crystalline ethylene-α-olefin copolymer, the stiffness can be substantially reduced regardless of the type of ethylene-α-olefin copolymer used as the base polymer. A further significant improvement in impact resistance and flex resistance is achieved without any deterioration, and no delamination properties are shown.

Claims (1)

[Scope of Claims] 1 (A) Ethylene-α,β-unsaturated carboxylic acid copolymer or ethylene-α,β-unsaturated carboxylic acid-α,β-unsaturated carboxylic acid ester ternary copolymer 50 to 90 parts by weight of metal ion crosslinked material and (B) density
Graft modified product obtained by graft copolymerizing α, β-unsaturated carboxylic acid or its derivative onto a low-crystalline to non-crystalline ethylene-α-olefin copolymer of 0.85 to 0.90 g/cm ³ (ASTM D-1505). A molding resin composition prepared by mixing 50 to 10 parts by weight. 2. The molding resin composition according to claim 1, wherein component (B) is a graft modified product of an ethylene-butene-1 copolymer. 3. The molding resin composition according to claim 1, wherein component (B) is a graft modified product of an ethylene-propylene copolymer. 4. The molding resin composition according to claim 1, 2 or 3, wherein component (B) is a maleic anhydride graft modified product of an ethylene-α-olefin copolymer. 5. The molding resin composition according to claim 1 or 4, wherein component (B) is a graft-modified product obtained by graft copolymerizing 0.1 to 5.0% by weight of an α,β-unsaturated carboxylic acid or a derivative thereof. thing.