JPH0782477A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition consisting of a polyamide- resin, a specific ethylenic random copolymer and a propylene-based random copolymer, excellent in flexibility, lowtemperature impact resistance and resistance to water absorption and salt water resistance and useful as a automobile part. CONSTITUTION:This composition contains (A) a polyamide resin, (B) an ethylenic random copolymer, composed of (i) ethylene and (ii) a 3-20C alpha-olefine, in which the content of recurring unit derived from the component (i) is in the range of 60-95mol% and the melt flow rate is in the range of 0.1-50g/10min and (C) a propylene-based random copolymer, composed of (iii) propylene and the component (i) or a 4-20C alpha-olefine, in which the content of recurring unit derived from the component (iii) is in the range of 50-95% and the melt flow rate is in the range of 0.1-50g/10min, and either one of these components B and C is grafted and modified with an unsaturated carboxylic acid (derivative).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a polyamide resin composition, and more specifically, it can provide a molded article excellent in flexibility, low temperature impact resistance, water absorption resistance and salt water resistance. And a polyamide resin composition.

[0002]

BACKGROUND OF THE INVENTION Polyamide resins are expected to be in great demand as engineering plastics due to their excellent physical properties. However, the polyamide resin cannot be said to have sufficient performances such as flexibility, low temperature impact resistance, water absorption resistance, salt water resistance, etc., and various improvements in these performances have been studied. Polyamide resin has a wide range of applications from mechanical parts, electric appliance parts, automobile parts to sports equipment such as ski shoes and sports shoes if it can improve its flexibility and low temperature impact resistance. Is big.

As a method for improving the water resistance or salt water resistance of a polyamide resin such as flexibility and water absorption, a neutralized ethylene / α, β-unsaturated monocarboxylic acid copolymer (ionomer resin) is blended with the polyamide resin. How to do
JP-A-53-80014 and JP-A-56-1677
No. 51, JP-A-56-109247, and JP-A-56-157451.

However, although the polyamide resin compositions proposed in these publications can improve water resistance such as water absorption resistance and salt water resistance, they have impact resistance such as Izod impact strength, especially at low temperature. There is a problem that the effect of improving the impact resistance is poor.

Further, as a method for improving impact resistance such as Izod impact strength of a polyamide resin, for example, Japanese Patent Publication No. 42-12546, Japanese Patent Publication No. 55-44108, and Japanese Patent Publication No. 55-9662 disclose. A method has been proposed in which an ethylene / α-olefin copolymer grafted with an α, β-unsaturated carboxylic acid is blended with a polyamide resin.

However, the polyamide resin compositions proposed in these publications have insufficient flexibility,
Further, there is a problem that impact resistance at low temperature is insufficient. Further, these polyamide resin compositions have a problem that the moldability is lowered depending on the molding method.

Further, as a method for particularly improving the flexibility of the polyamide resin, for example, Japanese Patent Publication No. 62-13379 discloses an ethylene / propylene copolymer obtained by grafting an α, β-unsaturated carboxylic acid onto a polyamide resin. Alternatively, a method has been proposed in which the ethylene / 1-butene copolymer is blended in a proportion of more than 2/3 of the amount of the polyamide resin used and not more than 6 times by weight.

However, although the polyamide resin composition proposed in this publication has sufficient flexibility, it still has insufficient impact resistance at low temperatures, and has a serious problem of deterioration in moldability. is there.

Therefore, it has long been desired to develop a polyamide resin composition having excellent moldability, which can provide a molded article having excellent flexibility, low temperature impact resistance, water absorption resistance and salt water resistance.

[0010]

It is an object of the present invention to solve the problems associated with the prior art as described above, and to provide a molded article excellent in flexibility, low temperature impact resistance, water absorption resistance and salt water resistance. Another object of the present invention is to provide a polyamide resin composition which is excellent in moldability.

[0011]

SUMMARY OF THE INVENTION The polyamide resin composition according to the present invention comprises
Polyamide resin (A), ethylene and 3 to 20 carbon atoms
Of α-olefin, the content of repeating units derived from ethylene is in the range of 60 to 95 mol%, and the melt flow rate is 0.1 to 50 g / 1.
The ethylene-based random copolymer (B) in the range of 0 minutes, and propylene and ethylene or an α-olefin having 4 to 20 carbon atoms, and the content of the repeating unit derived from propylene is 50-95
It is in the range of mol% and has a melt flow rate of 0.1 to
An ethylene random copolymer (B) and a propylene random copolymer (C) containing a propylene random copolymer (C) in the range of 50 g / 10 minutes.
At least one of which is graft-modified with an unsaturated carboxylic acid or a derivative thereof, and the total graft amount of the ethylene random copolymer (B) and the propylene random copolymer (C) is an unmodified ethylene random copolymer. The total amount of the polymer (B) and the unmodified propylene random copolymer (C) is within the range of 0.01 to 10% by weight based on 100% by weight, and the ethylene random copolymer (B).
And the total amount of the propylene random copolymer (C) is
5-6 with respect to 100 parts by weight of the polyamide resin (A)
It is characterized by being 6.6 parts by weight.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The polyamide resin composition according to the present invention will be specifically described below. The polyamide resin composition according to the present invention comprises a polyamide resin (A), a specific ethylene-based random copolymer (B) and a specific propylene-based random copolymer (C) in a specific ratio. At least one of the random copolymer (B) and the random copolymer (C) of propylene is graft-modified with an unsaturated carboxylic acid or a derivative thereof, and the total graft amount of both copolymers is within a specific range. It is in.

Polyamide Resin (A) The polyamide resin (A) used in the present invention is not particularly limited and means all amino acid lactams, or melt-polymerizable and melt-moldable polymers composed of diamine and carboxylic acid. .

Polyamide resin (A) used in the present invention
Specifically, the following resins may be mentioned. (1) Polyhexamethylene adipamide which is a polycondensation product of an organic dicarboxylic acid having 4 to 12 carbon atoms and an organic diamine having 2 to 13 carbon atoms, for example, a polycondensation product of hexamethylenediamine and adipic acid. [6,6 nylon], polyhexamethylene azamide, which is a polycondensation product of hexamethylenediamine and azelaic acid [6,9 nylon], polyhexamethylene sebaca, which is a polycondensation product of hexamethylenediamine and sebacic acid Mido [6,10 nylon], polyhexamethylene dodecanoamide [6,12 nylon], which is a polycondensation product of hexamethylenediamine and dodecanedioic acid, and polycondensation of bis-p-aminocyclohexylmethane and dodecanedioic acid. Polybis (4-aminocyclohexyl) methanddecane, which is a product, (2) ω
A polycondensate of an amino acid, for example polyundecaneamide [11 nylon] which is a polycondensate of ω-aminoundecanoic acid, (3) a ring-opening polymer of lactam, for example a polycapramide which is a ring-opening polymer of ε-aminocaprolactam. [6 nylon], polylauric lactam [12 nylon], a ring-opening polymer of ε-aminolaurolactam, and the like. Among them, polyhexamethylene adipamide (6,
6 nylon), polyhexamethylene azamide (6,9)
Nylon) and polycaprolamide (6 nylon) are preferably used.

In the present invention, for example, a polyamide resin produced from adipic acid, isophthalic acid and hexamethylenediamine can also be used, and a mixture of 6 nylon and 6,6 nylon can be used. Two
It is also possible to use a blended product containing at least one polyamide resin.

The polyamide resin (1) is, for example, an organic dicarboxylic acid having 4 to 12 carbon atoms and 2 carbon atoms.
It can be prepared by polycondensation with the organic diamine contained in -13. Further, if necessary, the organic dicarboxylic acid can be used in a larger amount than the organic diamine so that the carboxy group in the polyamide resin is in excess of the amino group, and conversely, the amino group in the polyamide resin is carboxy. It is also possible to use the organic dicarboxylic acid in a smaller amount than the organic diamine so that it is in excess of the groups.

Specific examples of the above organic dicarboxylic acid include adipic acid, pimelic acid, suberic acid, sebacic acid and dodecanedioic acid. Specific examples of the organic diamine include hexamethylenediamine and octamethylenediamine.

The polyamide resin (1) is prepared from a derivative capable of forming a carboxylic acid such as an ester or an acid chloride and a derivative capable of forming an amine such as an amine salt in the same manner as in the above method. You can also do it.

The polyamide resin (2) can be prepared, for example, by heating an ω-amino acid in the presence of a small amount of water to cause polycondensation. Often, small amounts of viscosity stabilizers such as acetic acid are added.

The polyamide resin (3) can be prepared, for example, by heating a lactam in the presence of a small amount of water to cause ring-opening polymerization. Often, small amounts of viscosity stabilizers such as acetic acid are added.

Ethylene random copolymer (B) and pro
Pyrene-based random copolymer (C) Ethylene-based random copolymer (B) used in the present invention
The ethylene-based random copolymer (B) is an elastic body containing a repeating unit derived from ethylene as a main repeating unit, and specifically, ethylene and C 3 -C 3
It is composed of 20 α-olefins.

When an α-olefin having a carbon atom number of 3 to 20 is used, an ethylene random copolymer (B) rich in rubber elasticity can be obtained. In the present invention, when such an ethylene-based random copolymer (B) is used, a polyamide resin composition having excellent fluidity, that is, moldability capable of providing a molded article having excellent impact resistance can be obtained.

Specific examples of such α-olefins include propylene, 1-butene, 1-pentene and 4-methyl.
-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-
Examples include octene and 1-decene. Of these, propylene, 1-butene and 4-methyl-1-pentene are preferable.

As described above, the ethylene-based random copolymer (B) used in the present invention is soft and has rubber elasticity, and the crystallinity measured by the X-ray diffraction method is usually 4 or less.
It is 0% or less, preferably 20% or less.

The ethylene-based random copolymer (B)
The content of the repeating unit derived from ethylene constituting the is 60 to 95 mol%, preferably 70 to 90 mol%
Is within the range of. When the ethylene-based random copolymer (B) in which the content of the repeating unit derived from ethylene is within the above range, blocking is less likely to occur, the handling property of the resin is improved, and the low temperature impact resistance is improved. It is possible to obtain a polyamide resin composition that can provide a molded article having excellent properties.

Further, the ethylene random copolymer (B) has a melt flow rate (MFR; ASTM D-1).
238, 230 ° C.) is in the range of 0.1 to 50 g / 10 minutes, preferably 0.1 to 20 g / 10 minutes. MFR
The ethylene-based random copolymer (B) having the above range is excellent in dispersibility in the polyamide resin (A).

Such an ethylene random copolymer (B) can be used alone or in combination. The above ethylene-based random copolymer (B) is obtained by adding ethylene and α-C 3-20 in the presence of a known vanadium catalyst or metallocene catalyst.
It can be prepared by copolymerizing with an olefin.

The vanadium-based catalyst used in this method includes vanadium compounds such as vanadyl trichloride, vanadyl monoethoxydichloride, triethoxyvanadyl, vanadium oxydiacetylacetate, vanadium triacetylacetonate, and organoaluminum compounds. And the like.

Next, a specific example of the method for preparing the ethylene random copolymer (B) using such a vanadium catalyst is shown below. For example, by using vanadium oxytrichloride and ethylene aluminum sesquichloride as a catalyst, a mixed gas of ethylene and an α-olefin having 3 to 20 carbon atoms is continuously supplied to a reaction vessel in the presence of hydrogen in a hexane solvent. While carrying out continuous polymerization. Then, the reaction liquid containing the copolymer produced as described above is continuously withdrawn from the reaction vessel, and the solvent is separated from the reaction liquid containing the copolymer to obtain the above ethylene-based random copolymer ( B) can be obtained.

For example, with respect to the ethylene random copolymer (B) prepared as described above, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are measured by GPC.
When this is measured and the ratio (Mw / Mn) of the two is taken, this value is usually 7 or less, preferably 3 or less.

The propylene random copolymer (C) used in the present invention is an elastic body containing a repeating unit derived from propylene as a main repeating unit, and specifically, propylene and a specific α- It is composed of olefins.

The α-olefin used in the present invention is ethylene and an α-olefin having 4 to 20 carbon atoms,
Ethylene and α-olefins having 4 to 10 carbon atoms are preferable, and ethylene and α-olefins having 4 to 5 carbon atoms are more preferable. When an α-olefin having a carbon atom number within the above range is used, a propylene random copolymer (C) rich in rubber elasticity can be obtained. In the present invention, when such a propylene random copolymer (C) is used, a polyamide resin composition having excellent fluidity, that is, moldability, which can provide a molded article having excellent impact resistance, can be obtained.

Specific examples of the α-olefin other than ethylene include 1-butene, 1-pentene and 4-methyl-1-
Examples include pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene. Such α-olefin and ethylene may be used alone or in combination.

As described above, the propylene random copolymer (C) used in the present invention is soft and has rubber elasticity. The crystallinity of this copolymer (C) measured by the X-ray diffraction method is not particularly limited, but is preferably 40%.
Or less, more preferably 20% or less.

The content of repeating units derived from propylene constituting the propylene random copolymer (C) is 50 to 95 mol%, preferably 60 to 8%.
It is within the range of 5 mol%. When the propylene random copolymer (C) having a content of the repeating unit derived from propylene within the above range is used, blocking is less likely to occur, the handling property of the resin is improved, and the low temperature resistance is improved. It is possible to obtain a polyamide resin composition that can provide a molded article having excellent impact properties.

This propylene random copolymer (C)
The content of repeating units derived from ethylene and the above α-olefin in the copolymer (C) is 2
When it is a component system, it is inevitably in the range of 5 to 50 mol%, preferably 15 to 40 mol%.

Further, the propylene random copolymer (C) has a melt flow rate (MFR; ASTM D-
1238, 230 ° C.) is in the range of 0.1 to 50 g / 10 minutes, preferably 0.1 to 20 g / 10 minutes. MF
The propylene random copolymer (b) having R in the above range has excellent dispersibility in the polyamide resin (A).

The propylene-based random copolymer (C) is
In the polyamide resin composition, it mainly serves as a compatibilizing material for the ethylene random copolymer (B) and the polyamide resin (A).

Such a propylene-based random copolymer (C) contains, for example, a catalyst formed from a solid titanium catalyst component and a metal organic compound component, or a catalyst formed from both components and an electron donor. Can be manufactured using.

Examples of the solid titanium catalyst component used here include titanium trichloride compositions produced by various methods, or magnesium, halogen, electron donor (preferably aromatic carboxylic acid ester or alkyl group-containing). Ether) and titanium are essential components, and a supported titanium catalyst component having a specific surface area of preferably 100 m ² / g or more can be mentioned. In the present invention, the propylene random copolymer (b) produced using the latter supported titanium catalyst component is particularly preferable.

The organometallic compound component is preferably an organoaluminum compound, and specific examples thereof include trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide and alkylaluminum dihalide. Such an organometallic compound component is selected in consideration of a titanium catalyst component that is usually used.

The above-mentioned electron donor is an organic compound containing nitrogen, phosphorus, sulfur, oxygen, silicon, boron, etc., such as ester and ether are preferable. Next, specific examples of the method for preparing the propylene-based random copolymer (b) using the above supported titanium catalyst component will be shown below.

The propylene random copolymer (C)
Is, for example, using a supported titanium catalyst component obtained by a known method, triisobutylaluminum and diphenylmethoxysilane, in a hexane solvent in the presence of hydrogen, propylene and the above α-olefin having 2 to 20 carbon atoms ( Continuous polymerization is carried out while continuously supplying a mixed gas (excluding propylene) to the reactor. Then, the reaction solution containing the copolymer produced as described above is continuously withdrawn from the reaction apparatus, and the solvent is separated from the reaction solution to obtain the propylene random copolymer (C).
Can be obtained.

For example, with respect to the propylene random copolymer (C) prepared as described above, the weight average molecular weight (Mw) and the number average molecular weight (M
When n) is measured and the ratio (Mw / Mn) of both is taken, this value is usually 10 or less, preferably 6 or less.

As described above, in the present invention, at least one of the ethylene random copolymer (B) and the propylene random copolymer (C) is graft-modified with an unsaturated carboxylic acid or its derivative. However, both copolymers are unmodified ethylene-based random copolymers (B)
And the polymerization ratio [(B) / (C)] of the unmodified propylene random copolymer (C) is 95/5 to 5/95, preferably 9
5/5 to 20/80, more preferably 80/20 to 2
It is used in such a ratio that it falls within the range of 0/80.

The polyamide resin composition according to the present invention contains a polyamide resin (A), a specific ethylene random copolymer (B) and a specific propylene random copolymer (C) in a specific ratio. At least one of the ethylene-based random copolymer (B) and the propylene-based random copolymer (C) is graft-modified with an unsaturated carboxylic acid or its derivative, and the total graft amount of both copolymers is specified. Is within the range of.

In the present invention, the total graft amount of the ethylene-based random copolymer (B) and the propylene-based random copolymer (C) is such that the unmodified ethylene-based random copolymer (B) and the unmodified propylene-based copolymer Random copolymer (C)
The total amount is 0.01 to 10% by weight, preferably 0.1 to 5% by weight. When the total graft amount of the unsaturated carboxylic acid or the like is within the above range, these copolymers have excellent dispersibility in the polyamide resin (A) and also have excellent thermal stability, and the resin is colored when melted. Nothing. Moreover, by using these copolymers, it is possible to obtain a polyamide resin composition capable of providing a molded article having excellent mechanical strength.

In the present invention, the method of graft-modifying the ethylene random copolymer (B) and / or the propylene random copolymer (C) by blending an unsaturated carboxylic acid or the like is as follows. There are various methods. (1) The unmodified ethylene random copolymer (B) and the unmodified propylene random copolymer (C) have a weight ratio [(B) / (C)] of both copolymers within the above range. And then the resulting blend is graft-modified with an unsaturated carboxylic acid or the like. (2) After the unmodified ethylene random copolymer (B) and the unmodified propylene random copolymer (C) are separately graft-modified with an unsaturated carboxylic acid or the like, both the copolymers before graft modification A method of blending so that the weight ratio [(B) / (C)] of both copolymers is within the above range. (3) After the ethylene-based random copolymer (B) is graft-modified with an unsaturated carboxylic acid or the like, the modified ethylene-based random copolymer (B) and the unmodified propylene-based random copolymer (C) obtained Is blended such that the weight ratio [(B) / (C)] of the ethylene random copolymer (B) before graft modification and the unmodified propylene random copolymer (C) is within the above range. how to. (4) The modified propylene random copolymer (C) and the unmodified ethylene random copolymer (B) obtained by graft-modifying the propylene random copolymer (C) with an unsaturated carboxylic acid or the like. Is blended so that the weight ratio [(B) / (C)] of the unmodified ethylene-based random copolymer (B) and the propylene-based random copolymer (C) before graft modification is within the above range. how to.

However, no matter which method is adopted, the total graft amount of unsaturated carboxylic acid or the like is within the above range in the whole ethylene random copolymer (B) and propylene random copolymer (C). Need to be in.

In the present invention, the polyamide resin (A)
From the viewpoint of dispersibility of both copolymers therein, the modified blend obtained by the method (1) is preferable. Next, the graft modification method (1) will be described in detail.

The above-mentioned unmodified blend can be obtained by mixing the unmodified ethylene random copolymer (B) and the unmodified propylene random copolymer (C) by a usual method.

Specific examples of the unsaturated carboxylic acid used in the above graft modification include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid,
Examples thereof include citraconic acid, crotonic acid, isocrotonic acid and nadic acid ^™ (endocis-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid).

Examples of unsaturated carboxylic acid derivatives include acid halide compounds, amide compounds, imide compounds, acid anhydrides and ester compounds of the above unsaturated carboxylic acids. Specific examples include maleenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate and glycidyl maleate. Of these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and maleic acid, nadic acid ^TM or acid anhydrides thereof are particularly preferable.

There are no particular restrictions on the grafting position of the unsaturated carboxylic acid or derivative thereof (hereinafter sometimes referred to as unsaturated carboxylic acid, etc.) that is grafted to the above blend, and the ethylene that constitutes this blend is not particularly limited. It suffices that an unsaturated carboxylic acid or the like is bonded to any carbon atom of the random copolymer (B) and the random copolymer (C) of propylene.

The modified blend as described above can be produced by various conventionally known methods, for example, the following methods. (1) The above unmodified ethylene random copolymer (B)
A method in which a blended product of the unmodified propylene random copolymer (C) is melted, an unsaturated carboxylic acid or the like is added, and graft copolymerization is performed. (2) The above unmodified ethylene-based random copolymer (B)
A method in which a blend of the unmodified propylene-based random copolymer (C) is dissolved in a solvent and an unsaturated carboxylic acid or the like is added to perform graft polymerization.

In any case, it is preferable to carry out the graft reaction in the presence of a radical initiator in order to efficiently graft-polymerize the above-mentioned unsaturated carboxylic acid or the like and the monomer.

As the radical initiator, organic peroxides, azo compounds and the like are used. Specific examples of such a radical initiator include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) hexyne 3, 1, 1.
4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butylperacetate, 2,5-dimethyl-2,5-di (tert-butylperoxide) hexyne-3,2,5-dimethyl-2,5-di (tert- Butyl peroxide) hexane, tert-butyl perbenzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl peru sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl per Organic peroxides such as diethyl acetate; azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (tert-butylperoxy) hexane , 1,4-bis (tert
Dialkyl peroxide such as -butylperoxyisopropyl) benzene is preferably used.

These radical initiators are usually used in an amount of 0.0 with respect to 100 parts by weight of the above blend before graft modification.
It is used in an amount of 01 to 1 part by weight, preferably 0.005 to 0.5 part by weight, more preferably 0.01 to 0.3 part by weight.

The reaction temperature in the graft reaction using the radical initiator as described above or in the graft reaction performed without using the radical initiator is usually 60 to 350.
C., preferably in the range of 150 to 300.degree.

In the present invention, the total amount of the ethylene random copolymer (B) and the propylene random copolymer (C) is 5 to 66.6 with respect to 100 parts by weight of the polyamide resin (A). It is used in a proportion of parts by weight, preferably 5 to 50 parts by weight, more preferably 10 to 40 parts by weight. However, at least one of these copolymers is
Has been graft modified. When the ethylene random copolymer (B) and the propylene random copolymer (C) are used in the above proportions, a molded article excellent in impact resistance and water absorption resistance as well as rigidity and heat resistance is obtained. It is possible to obtain a polyamide resin composition that can provide

Other Additives In addition to the above polyamide resin (A), ethylene-based random copolymer (B) and propylene-based random copolymer (C), other additives are required in the polyamide resin composition of the present invention. Depending on, antioxidant, ultraviolet absorber, light protector, phosphite heat stabilizer, peroxide decomposer, basic co-stabilizer,
Nucleating agents, plasticizers, lubricants, antistatic agents, flame retardants, pigments,
Additives such as dyes and fillers can be added within a range that does not impair the object of the present invention. Further, the polyamide resin composition according to the present invention may be blended with another polymer within a range that does not impair the object of the present invention.

Examples of the above-mentioned filler include carbon black, asbestos, talc, silica and silica-alumina. Preparation of Polyamide Resin Composition The polyamide resin composition according to the present invention comprises the above polyamide resin (A), an ethylene random copolymer (B),
It is prepared by melt-mixing the propylene-based random copolymer (C) and the additives to be blended as necessary by various conventionally known methods.

For example, (1) a modified blend of an ethylene-based random copolymer (B) and a propylene-based random copolymer (C) prepared in advance is used as a polyamide resin (A).
, (2) the polyamide resin (A) is first blended with the ethylene random copolymer (B), and then the propylene random copolymer (C) is blended, (3) the polyamide resin ( A method in which the propylene random copolymer (C) is first blended with A) and then the ethylene random copolymer (B) is blended;
(4) A method in which the polyamide resin (A), the ethylene random copolymer (B), and the propylene random copolymer (C) are blended at the same time may be used. However, in the above methods (2), (3) and (4), at least one of the ethylene random copolymer (a) and the propylene random copolymer (b) is the above graft modified product. .

As described above, in the present invention, from the viewpoint of dispersibility of both copolymers in the polyamide resin (A),
A method in which a modified blend of the ethylene random copolymer (B) and the propylene random copolymer (C) prepared in advance is blended with the polyamide resin (A) is preferable.

If necessary, the above-mentioned additives, such as antioxidants, may be added at any of these stages. As described above, the polyamide resin composition according to the present invention has the above-mentioned components simultaneously or sequentially charged into, for example, a Henschel mixer, a V-type blender, a tumbler mixer, a ribbon blender and the like, and then mixed with a single screw. It can be obtained by melt-kneading with an extruder, a multi-screw extruder, a kneader, a Banbury mixer, or the like.

Among these, a multi-screw extruder, a kneader,
When a device excellent in kneading performance such as a Banbury mixer is used, a high quality polyamide resin composition in which each component is more uniformly dispersed can be obtained.

The polyamide resin composition of the present invention obtained as described above is prepared by various conventionally known melt molding methods,
For example, various shapes can be formed by a method such as injection molding, extrusion molding, compression molding, and foam molding.

[0068]

The polyamide resin composition according to the present invention is
A polyamide resin (A), a specific ethylene random copolymer (B) and a specific propylene random copolymer (C) are contained in a specific ratio, and the ethylene random copolymer (B) and propylene are contained. At least one of the random copolymers (C) is graft-modified with an unsaturated carboxylic acid or a derivative thereof, and the total graft amount of both copolymers is within a specific range. It is possible to provide a molded article having excellent properties, water absorption resistance and salt water resistance.

Further, the polyamide resin composition according to the present invention is excellent in fluidity, that is, moldability. The polyamide resin composition according to the present invention having the above effects,
It can be widely used for applications such as automobile parts, electric equipment, electric parts, sports goods, industrial parts such as oil tubes, flexible tubes and air hoses.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0071]

Example 1 The repeating content derived from ethylene was 81 mol%, and the melt float (ASTM D-1
238, 230 ° C.) is 0.7 g / 10 minutes, and 8 kg of an ethylene / propylene random copolymer (hereinafter sometimes referred to as EPR) having a crystallinity of 5% as measured by an X-ray diffraction method, and propylene The content of the repeating unit derived from is 59 mol% and the melt flow rate (ASTM D-1238, 230 ° C.) is 0.4 g / 10.
And the crystallinity measured by X-ray diffraction is 4%.
Propylene / ethylene random copolymer (hereinafter PE
2kg and maleic anhydride 50
g (0.5% by weight based on 100% by weight of total EPR and PER) and 3 g of di-tert-butyl peroxide
Was blended in a Henschel mixer with a solution of 50 g in acetone.

Next, the blend obtained as described above was charged from the hopper of a single-screw extruder having a screw diameter of 40 mm and L / D = 26, a resin temperature of 260 ° C. and an extrusion rate of 6
The mixture was extruded into a strand at kg / hour, cooled with water, and pelletized to obtain a maleic anhydride graft-modified blend.

Unreacted maleic anhydride was extracted from the obtained graft-modified blend with acetone, and the amount of maleic anhydride grafted in this graft-modified blend was measured. As a result, the grafted amount was 0.43% by weight. there were.

Next, 6 nylon [manufactured by Toray Industries, Inc., Amilan CM1017, MFR (235 ° C., 2.16 k
g): 33 g / 10 min] 100 parts by weight and 25 parts by weight of the above maleic anhydride graft-modified blend were mixed using a Henschel mixer to prepare a dry blend.

Then, this dry blend was prepared at 245 ° C.
The mixture was fed to the twin-screw extruder (L / D = 40, 30 mmφ) set to 1. to prepare pellets of the polyamide resin composition. The pellets of the obtained polyamide resin composition were dried at 80 ° C. for one day and then injection-molded under the following conditions to prepare a test piece for physical property test. The spiral flow is 3.
Using a mold having a spiral groove of 8 mmφ and a semicircle, injection was performed under the following conditions, and the flow distance was measured.

(Injection molding conditions) Cylinder temperature: 245 ° C. Injection pressure: 1000 kg / cm ² Mold temperature: 80 ° C. Subsequently, a polyamide was prepared by the following method. The physical properties of the resin composition were evaluated. (1) Bending test: ASTM test specimens with a thickness of 1/8 "were used.
The flexural modulus (FM; kg / cm ² ) was measured according to D 790. In addition, the condition of the test piece is adjusted to 23 ° C.
2 days. (2) Izod impact test: Notched Izod impact strength was measured at −40 ° C. according to ASTM D 256 using a test piece having a thickness of 1/8 ″. The test piece was prepared in a dry state at 23 ° C. (3) Water absorption test: According to ASTM D 570, a test piece having a diameter of 2 inches and a thickness of 1/8 "is dried at 100 ° C for 24 hours and then absorbed in warm water of 50 ° C for 48 hours. Test,
The water absorption was determined from the weight change of the test piece before and after the test.

The results are shown in Table 1.

[0078]

Example 2 A maleic anhydride graft-modified blend and a polyamide resin composition were prepared in the same manner as in Example 1, except that the amounts of EPR and PER were 4 kg and 6 kg, respectively. Then, the spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 1.

[0080]

Example 3 A maleic anhydride graft-modified blend was prepared in the same manner as in Example 1 except that the amounts of EPR and PER were 4 kg and 6 kg, respectively, and that 100 g of maleic anhydride was used. Further, a polyamide resin composition was prepared, and its spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 1.

[0082]

Example 4 A maleic anhydride graft-modified blend and further a polyamide resin composition were prepared in the same manner as in Example 1 except that the amounts of EPR and PER were 2 kg and 8 kg, respectively. Then, the spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 1.

[0084]

Example 5 A maleic anhydride graft-modified blend and further a polyamide resin composition were prepared in the same manner as in Example 1, except that the amounts of EPR and PER were 5 kg and 5 kg, respectively. Then, the spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 1.

[0086]

Example 6 A maleic anhydride graft-modified blend was prepared in the same manner as in Example 1, except that the amounts of EPR and PER were 5 kg and 5 kg, respectively. Then, 60 parts by weight of the maleic anhydride graft-modified blend obtained as described above and 100 parts by weight of 6-nylon were prepared in the same manner as in Example 1 to prepare a polyamide resin composition, which was then subjected to spiral flow and bending. The elastic modulus, impact strength with notch at -40 ° C, and water absorption were measured.

The results are shown in Table 1.

[0088]

Example 7 In Example 2, the content of repeats derived from ethylene was 89 mol% instead of 4 kg of EPR, and the melt float (ASTM D-1238,
190 ° C.) is 3.6 g / 10 minutes and the crystallinity of the ethylene / 1-butene random copolymer measured by X-ray diffraction is 15% (hereinafter sometimes referred to as EBR) 4
A maleic anhydride graft-modified blend and further a polyamide resin composition were prepared in the same manner as in Example 2 except that kg was used, and its spiral flow, flexural modulus, and notched impact strength at -40 ° C, And the water absorption was measured.

The results are shown in Table 1.

[0090]

Comparative Example 1 An unmodified blend was prepared in the same manner as in Example 2 except that maleic anhydride was not used. Hereinafter, a polyamide resin composition was prepared in the same manner as in Example 2 except that the unmodified blend obtained as described above was used in place of the maleic anhydride graft-modified blend of Example 2. The spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 2.

[0092]

Comparative Example 2 A polyamide resin composition was prepared in the same manner as in Example 2 except that the maleic anhydride graft-modified blend of Example 2 was added in an amount of 70 parts by weight. Flow, flexural modulus, -40
The notched impact strength at ℃ and water absorption were measured.

The results are shown in Table 2.

[0094]

Comparative Example 3 A maleic anhydride graft-modified EP was prepared in the same manner as in Example 2 except that the amounts of EPR and PER were 10 kg and 0 kg, respectively.
R, and further a polyamide resin composition was prepared, and its spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 2.

[0096]

Comparative Example 4 A maleic anhydride graft-modified PE was prepared in the same manner as in Example 2, except that the amounts of EPR and PER were 0 kg and 10 kg, respectively.
R, and further a polyamide resin composition was prepared, and its spiral flow, flexural modulus, notched impact strength at -40 ° C, and water absorption were measured.

The results are shown in Table 2.

[0098]

[Comparative Example 5] The spiral flow, flexural modulus, impact strength with notch at -40 ° C, and water absorption of 6 nylon of Example 1 were measured in the same manner as in Example 1.

The results are shown in Table 2.

[0100]

[Table 1]

[0101]

[Table 2]

Claims (1)

[Claims] 1. A polyamide resin (A), which comprises ethylene and an α-olefin having 3 to 20 carbon atoms, and has a repeating unit content of 60 to 60 derived from ethylene.
The ethylene random copolymer (B) having a melt flow rate in the range of 95 mol% and a melt flow rate in the range of 0.1 to 50 g / 10 minutes, and propylene and ethylene or α- having 4 to 20 carbon atoms. It is composed of olefin and has a repeating unit content of 50 derived from propylene.
To 95 mol%, and contains a propylene-based random copolymer (C) having a melt flow rate of 0.1 to 50 g / 10 minutes, and an ethylene-based random copolymer (B). ) And at least one of the propylene-based random copolymer (C) is graft-modified with an unsaturated carboxylic acid or a derivative thereof, and the ethylene-based random copolymer (B) and the propylene-based random copolymer (C) are The total graft amount was 0. 0 based on 100% by weight of the total amount of the unmodified ethylene-based random copolymer (B) and the unmodified propylene-based random copolymer (C).
The total amount of the ethylene random copolymer (B) and the propylene random copolymer (C) is within the range of 01 to 10% by weight, relative to 100 parts by weight of the polyamide resin (A). A polyamide resin composition, characterized in that it is 5 to 66.6 parts by weight.