JPS60202151A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:The titled compsn. excellent in resistance to heat, chemicals, wear and impact, and in bending elasticity, comprising a polyamide resin and a specified graft modification material. CONSTITUTION:A copolymer of M.I. of 0.5-300dg/min comprising 78-99mol% ethylene and 22-1mol% alkyl (meth)acrylate, and 0.1-8wt% maleic anhydride are subjected to graft polymn. in the presence of a free radical-generating compd. at 120-250 deg.C in an extruder to obtain a graft product. The 40-5pts.wt. graft product is blended with 60-95pts.wt. polyamide resin such as nylon 6 and, if necessary, 5-60pts.wt., based on 100pts.wt. blended components, glass fiber, 2-10mm. in length and 5-15mum in diameter, which is surface treated with a silane-coupling agent such as aminosilane is mixed.

Description

[Detailed description of the invention] The present invention relates to a polyamide resin composition.

More specifically, the present invention relates to a polyamide resin composition that has significantly improved impact resistance without substantially impairing the desirable properties inherent in polyamide resins.

Polyamide resins generally have excellent heat resistance, chemical resistance, abrasion resistance, and bending elasticity, so they are widely used as engineering resins for various mechanical parts and automobile parts. It has the disadvantage of not being satisfactory in terms of impact resistance.

In order to compensate for these drawbacks, various proposals have been made to modify polyamide resins by blending them with other types of resins. For example, ethylene-α, β-unsaturated carboxylic acid-α, β-unsaturated carboxylic acid metal salts (-α,
β-unsaturated carboxylic acid ester) copolymer resin [ionomer resin] blend (Japanese Patent Publication No. 54-4743,
No. 55-44108, etc.) can improve impact resistance without substantially impairing desirable properties such as heat resistance and bending elasticity, but the improvement effect is not fully satisfactory.

On the other hand, blends of polyamide resins with maleic anhydride graft modified versions of ethylene-alkyl (meth)acrylate copolymers do not substantially impair the desirable properties originally possessed by these polyamide resins. The inventors have found that impact resistance can be significantly improved.

Therefore, the present invention relates to a polyamide-based resin composition, and this polyamide-based resin composition comprises a polyamide-based resin of about 60 to
95 melon dish part and maleic anhydride graft modified product of ethylene-alkyl (meth)acrylate copolymer about 40-5
Consists of parts by weight.

In addition, polyamide resins are often used by filling them with glass fibers to increase their mechanical strength, but in this case there is a significant drop in impact resistance. The improvement of this is also a major issue, but the present invention also solves this issue. Therefore, the present invention also provides
The present invention relates to a polyamide resin composition in which the blend is further filled with glass fibers.

Examples of the polyamide resin that forms the main component of the composition include nylon-6, nylon-66, and nylon-610.
, nylon-11, nylon-12, nylon-14, etc. are used.

Ethylene-(
The alkyl methacrylate copolymer is produced by radical copolymerization of ethylene and alkyl acrylate or alkyl methacrylate, preferably their methyl esters, and more preferably their ethyl esters, using a high-pressure polyethylene manufacturing equipment. can be obtained. The copolymerization ratio of alkyl (meth)acrylate in this copolymer is 1 to 22 mol%, preferably 3 to 20 mol%. If the copolymerization ratio of alkyl (meth)acrylate is higher than this, it will not only be difficult to produce the copolymer, but also the flexural rigidity and heat resistance of the graft modified product will be extremely reduced, and the composition will not be able to be used. On the other hand, if the copolymerization ratio is smaller than this, the intended effect of improving the impact resistance of the composition will be reduced.

The melt index of this base polymer [:
ASTM D-1238 (190°C, 2160 ml)] is generally about 0.5 to 300 dg/min, preferably about 4 to 200.1 g/min, although it varies depending on the melt viscosity of the polyamide resin used. It is generally difficult to produce copolymers outside this range.

In addition, even if a copolymer can be produced, if a copolymer with a melt index lower than this is used, the melt index will decrease when graft-modified with maleic anhydride, leading to poor dispersion when blended with polyamide resin. On the other hand, if a material with a melt index higher than this is used, the effect of improving the impact resistance of the composition will be reduced.

The amount of hydrothermal maleic acid grafted onto the ethylene-alkyl (meth)acrylate copolymer is 0.1 to 8%, preferably 0.3 to 5% based on the base polymer. It is within the % range. If the amount of grafting is less than this, the desired effect of improving the impact resistance cannot be obtained, and on the other hand, even if the amount of grafting is more than this, the effect of improving the impact resistance of the composition will not be obtained any more, and on the contrary, the grafting will The fluidity of the modified product decreases, leading to poor dispersion when it is made into a composition.

The method of grafting is not particularly limited, but is generally carried out by reacting an ethylene-alkyl (meth)acrylate copolymer with maleic anhydride in the presence of a free radical-generating compound, such as tert-butyl peroctoate. In terms of construction, it is economical to carry out the reaction at a temperature of about 120 to 250°C using an extruder width.

The composition contains about 4 parts by weight of the graft modified product for about 60 to 95 parts by weight of polyamide resin, preferably about 70 to 90 parts by weight.
1 by blending in a proportion of 0 to 5 parts by weight, preferably about 30 to 10 parts by weight.

If the proportion of the polyamide thread resin is lower than this, the desirable properties inherent to the polyamide resin will not be exhibited, and conversely, if the proportion is higher than this, the composition will not have high impact resistance.

The effect of improving the impact resistance of such a blend is fully exhibited even in the case of glass fiber filling, which is one of the main uses of polyamide resins. Generally, glass fibers having a fiber length of about 2 to 10 wI + 1 fiber diameter of about 5 to 15 μm, surface-treated with a silane coupling agent such as aminosilane or vinyl silane, are used in an amount of about 5 to 60 parts per 10 gills of the blend. used at a rate of If it is used in a proportion of about 5 parts by weight or more, an effect of reinforcing mechanical properties can be expected, whereas if it is used in a proportion of about 25 parts by weight or more, the impact resistance will be greatly reduced.

Preparation of the composition is 1. Further, various additives such as inorganic fillers such as calcium carbonate, anti-oxidation agents, heat stabilizers, ultraviolet absorbers, lubricants, and pigments are added as necessary, and then each component of the composition is triblended. or by melt blending. In the case of tri-blend, each component is melt-mixed uniformly at the stage of plasticization in a molding machine, and in the case of melt-blend, various mixers such as a single-screw or twin-screw extruder or a Banbury mixer are used. , a roll, a kneader, etc. may be used to melt and mix.

The polyamide resin composition according to the present invention significantly improves impact resistance without substantially impairing all of the desirable properties inherent in polyamide resins, such as heat resistance and bending elasticity. It can be effectively used in the fields of various molding techniques such as film molding, injection molding, press molding, blow molding, and profile extrusion molding. For example, when this polyamide yarn resin composition is molded into a roller skate wheel, it has excellent impact resistance at low temperatures, so even if the wheel is subjected to impact in the winter, it will not crack. There aren't many.

Next, the present invention will be explained with reference to examples.

Example 1 Nylon-6 (Amiran CM-1017o manufactured by Toshi Products) 8
0 parts (heavy state, same hereinafter) and maleic anhydride graft modified product (g, rat amount 2 20 parts of
A 1ζ test piece was prepared by injection molding using the kneaded phybolyamide thread resin composition as specified by the following test method.

Regarding this test piece, Izot impact strength (specimen thickness 5 ? i un i compliant with ASTM D 256, notched, -20℃ and -30℃), bending strength modulus (specimen thickness 2ntllll + compliant with ASTM D 790) )
and heat distortion temperature (sample 1ilj piece q; 3 can
; Based on ASTM D-648, 0.45 MPa
) were measured respectively.

Example 2 In Example 1, another ethylene-ethyl acrylate copolymer (ethyl acrylate-containing f) was used as the base polymer.
f115.7 mol%, melt index 7 dg/min)
was used.

Example 3 In Example 1, another ethylene-ethyl acrylate copolymer (ethyl acrylate content 13.1 mol%, melt index 25 dg/min) was used as the base polymer.
was used.

Example 4 In Example 1, the grafting amount of maleic anhydride was 0.
It was changed to 5 Jyusha%.

Example 5 In Example 1, the amount of maleic anhydride grafted was changed to 4% by weight.

Example 6 In Example 1, other ethylene-acrylic dispersion ethyl copolymer (ethyl acrylate-containing f) was used as the base polymer.
9.4 mol %, melt index 200 dvH) was used, and the amount of maleic anhydride grafted was changed to 3 mol %.

Example 7 A composition was prepared in Example 1 except that 90 parts of nylon-6 and 10 parts of the maleic anhydride graft modified product were used.

Example 8 A composition was prepared in Example 1 except that 70 parts of C1 nylon-6 and 30 parts of maleic anhydride graft modified material were used.

Example 9 In Example 1, the blend was further filled with 10 parts of glass fiber (Nitto Boseki product, diameter 13 μtn, length 61 mm) to prepare a °C composition.

Comparative Example 1 In Example 1, anhydrous maleic 1* graft modified product was not used.

Comparative Example 2 In Example 1, instead of the maleic anhydride graft modified product, its base polymer, ethylene-ethyl acrylate co-combination, was used as h-1t.

Comparative Example 3 In Example 1, instead of the maleic anhydride graft modified product, an ionomer resin insole was also used, which is an ester copolymer resin that is said to have a large impact improvement effect on nylon, namely ethylene-methacrylic acid-isobutyl acrylate (93, 6:
3.8: 2.6 mol%) copolymer resin (melt index 35 aF!A+) An ionomer resin ionized with rough 0% Zn ions was used.

Comparative Example 4 In Comparative Example 3, a composition was prepared by changing the amount of nylon-6 to 70 parts and the amount of the ionomer resin to 30 parts.

Comparative Example 5 In Comparative Example 3, the ionomer resin was replaced with a copolymer resin thereof in which Zn was not ionized.

Comparative Example 6 In Comparative Example 5, copolymer resins (10 dg/9) having the same copolymer composition but different melt indexes were used.

Comparative Example 7 In Comparative Example 5, a copolymer resin in which maleic anhydride was grafted at 20% was used.

Comparative Example 8 In Comparative Example 6, tJ of maleic anhydride was added to the copolymer resin.
hU% grafted was used.

Comparative Example 9 A composition was prepared in Comparative Example 8 except that nylon-6 was changed to 70 parts and maleic anhydride graft-modified copolymer resin was changed to 30 parts.

Comparative Example 10 In Comparative Example 3, 10 parts of the glass fiber used in Example 9 was further filled to prepare a composition.

The measurement results of physical property values in each of the above Examples and Comparative Examples are shown in the following table.

Example 1 134 96 1670 172// 2
152 104 1500 165 3 137 8
7 1600 167//4 106 80 1750
182/15 150 100 1650 162/
/6 96 63 1450 160//7 80 5
0 1950 180u 8 NB 150 1200
140//9 - 38 21 (10187 Comparative example 1 - 8 2050 185 //2 - 10 1800 179

Claims (1)

[Scope of Claims] 1. A polyamide resin comprising about 60 to 95 parts by weight of a polyamide resin and about 40 to 5 parts by weight of a maleic anhydride graft modification of an ethylene-alkyl (meth)acrylate copolymer. 2. Claim 1 in which a maleic anhydride graft modified product of a copolymer containing 78 to 99 mol% of ethylene and 22 to 1 mol% of alkyl acetate (meth)acrylate is used. The polyamide resin composition described in 3.Claims in which a graft modified product obtained by graft copolymerizing 0.1 to sit% of maleic anhydride to a polyethylene-alkyl (meth)acrylate copolymer is used. The polyamide resin composition according to item 2. 4. A blend of about 60 to 95 parts by weight of a polyamide resin and about 40 to 5 parts by weight of a maleic anhydride graft modified version of an ethylene-alkyl (meth)acrylate copolymer. to the body,
A polyamide resin composition according to claim 4, which is further filled with glass fiber in an amount of about 5 to 60 parts by weight per 100 parts by weight of the blend. .