JPH0445150A - Impact-resistant polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent drop impact strength, tensile elongation at break, heat-resistance, dimensional stability, etc., and suitable for automobile parts such as bumper by compounding a polyamide with a specific rubber-reinforced resin and a modified poly-epsilon-caprolactone. CONSTITUTION:The objective composition is produced by compounding (A) 90-10wt.% of a polyamide (e.g. nylon 6) with (B) 10-90wt.% of a rubber- reinforced resin (e.g. ABS resin) produced by reacting a rubbery substrate (e.g. polybutadiene) with a polymerizable component composed mainly of a vinyl cyanide compound (e.g. acrylonitrile) and an aromatic vinyl compound (e.g. styrene), (C) 0.5-30wt.% of a modified poly-epsilon-caprolactone containing carboxyl group and/or its functional derivative group introduced into the molecule and, as necessary, (D) 1-25wt.% of a modified polyolefin elastomer containing carboxyl group and/or its functional derivative group introduced into the molecule.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has excellent physical properties, especially excellent strength against impact, and high tensile elongation at break, as well as heat resistance and dimensional stability. This invention relates to a polyamide resin composition that provides molded products with good properties and an excellent appearance.This resin composition takes advantage of the above properties to be used in various molded products such as automobile parts such as bumpers and housing members for office equipment. It is useful as a material for

[Prior art] For example, polyamide resin has excellent weather resistance and high temperature stability, but it lacks moisture resistance, impact resistance, flexibility, etc., so various methods have been used to improve these properties. Blending with polymers (including resin-like materials, the same applies hereinafter) and polymer alloying are being considered.

For example, JP-A-62-11760 discloses a grafted rubber composition in which acrylonitrile or a styrene monomer is graft-polymerized onto a rubber substrate, and a terpolymer of styrene, acrylonitrile, and maleic anhydride in a polyamide. A technique for improving the impact resistance by blending it with a resin is disclosed, and Japanese Patent Application Laid-Open No. 64-66255 discloses a method of blending a styrene resin with a carboxyl group into a polyamide resin and a styrene resin with a carboxyl group introduced into the polyamide resin. By blending polyolefin elastomer with #
Techniques have been disclosed to improve impact resistance and flexibility.

[Problems to be Solved by the Invention] The method disclosed in the above-mentioned publication can achieve a considerable modification effect on the notched isot impact strength.
When it comes to surface impact such as falling weight impact, the modification effect is small and brittle fracture occurs easily, and these blend molded products also have insufficient tensile elongation at break, causing cracks during processing. has been pointed out.

The present invention was made in view of these circumstances, and its purpose is to provide polyamide-based resin without adversely affecting its inherent tensile strength, bending strength, heat resistance, high-temperature stability, etc. The object of the present invention is to provide a polyamide resin composition having excellent physical properties, particularly excellent strength against surface impact such as falling weight impact, and high tensile elongation at break.

[Means for Solving the Problems] The composition of the polyamide-based resin composition according to the present invention that can solve the above problems is as follows: (1) polyamide, (2) a rubber-like substrate containing mainly a vinyl cyanide compound and an aromatic vinyl compound. A rubber-reinforced resin obtained by reacting a polymerizable component as an ingredient, and a modified poly ε-caprolactone in which a carboxyl group and/or its functional 8 derivative group is introduced into the molecule. It is.

In addition to the above components (1), (2), and (2), the polyamide resin composition obtained by containing (1) a modified polyolefin elastomer in which a carboxyl group and/or its functional derivative group is introduced into the molecule has low-temperature impact properties. This results in even better properties such as bending properties and bending properties.

[Function] The present inventors conducted studies to find out the reason why the physical properties of polyamide resin compositions obtained by the polymer blending method as disclosed in the above-mentioned publication are not necessarily as expected. I did this. As a result, it was thought that a major cause was poor compatibility (miscibility) between the polymer blended as a modifying component with the polyamide and the polyamide. In other words, the modified polyamide resin composition disclosed in the above-mentioned publication appears to be well-blended uniformly, but judging from the physical properties of the molded product, it is not necessarily uniformly blended. I don't think so. However, the reason why molded products made from the above-mentioned modified polyamide resin compositions are weak against falling weight impact and lack tensile elongation at break is that when subjected to impact force or tensile force, the modified polyamide resin composition mixed into the polyamide This is thought to be because interfacial peeling occurs between the polymer and polyamide, leading to brittle fracture.

Therefore, by increasing the compatibility (miscibility) of the modifying polymer and polyamide to make their kneading more uniform, and at the same time suppressing the above-mentioned interfacial peeling, it is possible to increase the resistance of the molded product to brittle fracture. We thought that it would be possible to do so, and proceeded with improvement research along that line.

As a result, as mentioned above, as a modifying component of polyamide,
If the rubber-reinforced resin specified in (■) above and the modified polyε-caprolactone specified in (■) are used, or if the modified polyolefin elastomer specified in (1) is used in addition to these, the modification component and polyamide It has been found that a polyamide resin composition with significantly improved miscibility and excellent falling weight impact properties and tensile elongation at break can be obtained.

In the present invention, the type of polyamide defined as component (1) is not particularly limited; Nylon 66), polyhexamethylene sebacamide (Nylon 6)
10), or their copolymer nylon 6/
610, nylon 6/66, nylon 6/12, or aromatic diamines, aliphatic diamines, and aromatic dicarboxylic acids such as polyxylylene adipamide, polyhexamethylene terephthalamide, polyphenylene phthalamide, etc. Examples include polyamides derived from aliphatic dicarboxylic acids and aliphatic dicarboxylic acids, which can be used alone or in a suitable combination of two or more.

However, considering the heat resistance and physical properties of the resulting resin composition, the melting point should be 200°C or higher, more preferably 220°C or higher, and the relative viscosity [JIS K6810 (1970)]
The value measured in 98% sulfuric acid according to 1.8 or more,
It is more preferable to select and use a polyamide with a polyamide of 2.0 or more.

Next, the rubber-reinforced resin defined as component (1) is obtained by reacting (graft polymerization) with a rubber-like substrate a copolymerization component whose main components are a vinyl cyanide compound and an aromatic vinyl compound. Rubber substrates include diene polymers such as polybutadiene and polyisoprene; rubbers obtained by copolymerizing diene polymers such as butadiene and isoprene with styrene, α-methylstyrene, vinyltoluene, etc. styrene-diene polymer; nitrile rubber; butyl rubber: chlorinated polyethylene; acrylate elastomer made of ethyl acrylate or butyl acrylate alone or as a copolymer;
Ethylene-propylene rubber (ethylene:propylene-
90:10 to 20:80) or rubber-like polymers obtained by copolymerizing these with a small amount of non-conjugated diene. Although they can be used in combination, it is preferable to select and use those having a glass transition point (Tg) of 0° C. or lower in order to effectively exhibit the impact property modification effect.

Examples of vinyl cyanide compounds reacted with the rubbery substrate include acrylonitrile and methacrylonitrile, and examples of aromatic vinyl compounds include styrene, α-methylstyrene, dimethylstyrene, and vinyltoluene, which are also necessary. Accordingly, two or more types of each can be used in combination. In the present invention, in addition to the vinyl cyanide compound and the aromatic vinyl compound, one type of other copolymerization component such as methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, hydroxypropyl methacrylate, etc. Or two or more types can be used together.

The amount of cyanide vinylide metal, aromatic vinyl compound, etc. to be reacted with the rubbery substrate is not particularly limited, but if it shows a more preferable usage ratio in order to enhance the modifying effect on polyamide, then The content of the rubbery matrix is 5 to 50% by weight, more preferably 10 to 50% by weight.
The amount of the rubbery substrate to be used is determined to be 30% by weight, and the ratio of the vinyl cyanide compound to the aromatic vinyl compound to be used is preferably set in the range of 10:90 to 35 to 65 by weight. When outside the above range, use polyamide ■ or modified polyε-caprolactone ■ of the rubber reinforced resin ■ obtained.
Alternatively, the compatibility or miscibility with the modified polyolefin elastomer (1) may deteriorate, and the above-mentioned modification effect intended by the present invention may not be sufficiently exhibited.

Specific examples of rubber-reinforced resins having the above-mentioned preferable requirements include acrylonitrile (10-20% by weight)/butadiene (10-30% by weight)/styrene (50-80% by weight) copolymer [ABS resin], acrylonitrile ( 1
0-20% by weight) styrene (50-80% by weight)/butyl acrylate (10-30% by weight) copolymer [ASA
Typical examples include acrylonitrile (10-20% by weight) styrene (50-80% by weight)/ethylene-propylene-diene (10-30% by weight) copolymer [AES resin].

Modified poly ε-caprolactone, which is defined as component It can be obtained by copolymerizing a carboxylic acid derivative, or by graft polymerizing a similar polymerizable carboxylic acid or carboxylic acid derivative to poly ε-caprolactone, and furthermore, it can be obtained by copolymerizing a carboxylic acid derivative or by graft polymerizing a similar polymerizable carboxylic acid or carboxylic acid derivative to poly ε-caprolactone. It can also be obtained by changing the group to another functional group.

Examples of carboxyl groups or functional derivative groups thereof to be introduced into polyε-caprolactone include free carboxyl groups or salts thereof, carboxylic acid anhydride groups, amide groups, imide groups, various ester groups, carboxylic acid halide groups, etc. The compounds used for their introduction include monobasic acids such as acrylic acid, methacrylic acid, and α-ethyl acrylic acid; Basic acid:
Preferable examples include mono- or diesters of these acids; acid anhydrides such as maleic anhydride and citraconic anhydride; acid amides such as acrylamide and methacrylamide. These can be used alone, or two or more can be used together if necessary.

This modified polyε-caprolactone (■) is the most important component for contributing to improved impact resistance by increasing the mutual compatibility with the above-mentioned polyamide (■) and rubber-reinforced resin (■) or the modified polyolefin elastomer (■) described later. ,
In order to exhibit these effects more effectively, the amount of the above-mentioned functional group introduced into polyε-caprolactone is 0.
1 to 1000eq/10'g, more preferably 1
-200 eq/lO'H and a number average molecular weight of 5,000 or more, more preferably 10,000 or more.

Furthermore, the modified polyolefin elastomer defined in (1) above is an effective component in improving the low-temperature impact properties of the polyamide resin composition, and the polyolefin elastomer has a carboxyl group and/or its functional derivative group in the molecule. It has been introduced.

This modified polyolefin elastomer (■) is obtained by copolymerizing an olefin with the same polymerizable carboxylic acid or its derivative as used in the production of the above-mentioned modified polyε-caprolactone (2), or by copolymerizing the same polymerizable carboxylic acid or its derivative as used in the production of the modified polyε-caprolactone (■), or by copolymerizing the same polymerizable carboxylic acid or its derivative as used in the production of the modified polyε-caprolactone (■), or It can be obtained by graft polymerization of a polymerizable carboxylic acid or a derivative thereof.

Examples of polyolefin elastomers to be modified include ethylene or α-olefins having 3 or more carbon atoms, such as propylene, butene-1, hexene-1, decene-1,4-methylpentene-1, etc. alone or copolymerized. Examples include various elastomers obtained by combination or copolymerization of these olefins with α,β-unsaturated carboxylic acid esters (eg, ethyl acrylate, butyl acrylate, etc.). The amount of the functional group introduced is preferably 1 to 300 eq/10'g, more preferably 10
The number average molecular weight of the elastomer is preferably 10,000 or more, more preferably 40,000 or more.

Specific examples of modified polyolefin elastomers that meet the above preferable requirements include maleic anhydride grafted and
Typical examples include ethylene-propylene copolymer, ethylene-allylic acid ester-maleic anhydride copolymer, and the like.

The preferred blending amounts of the above components (■ to ■) can be selected from a wide range depending on the intended use and required properties of the resin composition to be obtained. In terms of amount, polyamide (2) is 90 to 10% by weight, more preferably 80 to 50% by weight, and rubber reinforced resin (2) is 10 to 9% by weight in the entire resin composition.
0% by weight, more preferably from 20 to 50% by weight, and modified poly ε-caprolactone (2) from 0.5 to 30% by weight, more preferably from 1 to 10% by weight. In addition, when the modified polyolefin elastomer (2) is used in combination, the preferred blending amount is 1 to 25% by weight, more preferably 2 to 15% by weight.When this component (2) is used in combination, the resin composition has impact properties, especially at low temperatures. is significantly improved.

There are no restrictions on the method of blending components 1 to 2. For example, a conventional kneading device such as a roller kneader, 1 double-arm kneader, 1 single or multiple screw kneading extruder, etc. may be used to blend components 1 to 0. A method of simultaneously blending and melt-mixing 3 or 4 components with component 2 added thereto, or first melting and mixing components 2 and 2, and then adding components 2 and 2 sequentially, preferably at the same time. It can be diagnosed by adopting a method such as melting and mixing.

The temperature at the time of melting and mixing should be such that each component (■) to (■) does not undergo thermal decomposition, and as a preferred standard, it should be lower than the melting point of polyamide (■). A high temperature of about 10°C and a range of 300°C or less, more generally a range of 230 to 280°C, is preferable.
In this melt-mixing process, a part of the functional groups introduced into the modified polyε-caprolactone (■) and the modified polyolefin elastomer (■) react with the terminal amino groups of the polyamide (■),
Coupled with this reaction, it is possible to obtain a resin composition in which components (1) to (2) or these and component (2) are extremely uniformly blended.

The resin composition of the present invention obtained in this way can be used alone as a molding material, but depending on the use and purpose, it may be added with commonly used additives such as lubricants, mold release agents, stabilizers, antistatic agents, flame retardants. agents, colorants (pigments and dyes), fillers, reinforcing materials (glass beads, mica, silica, quartz, talc,
Titanium dioxide, silica lime, etc.) can be blended in appropriate amounts, and in particular, when a reinforcing material is used in combination, a resin composition can be obtained that provides a molded body with excellent strength as a structural material. however,
If the amount of these additives is too large, the characteristics of the resin composition according to the present invention may not be fully utilized.
It should be more preferably suppressed to about 10 to 40% by weight.

Regarding polyhalogen diphenyl, polyhalogen diphenyl ether, polyhalogen phthalic acid and its derivatives, polyhalogenated polycarbonate, polyhalogenated polyethylene, etc. that can be blended as a flame retardant, 30% by weight based on the resin composition. In this case, it is preferable to use an appropriate amount of a synergist such as antimony trioxide together with the flame retardant, since the flame retardant effect can be further enhanced.

[Examples] The composition of the present invention will be explained based on Examples, but the present invention is not limited thereto.

In addition, the Izod impact values in Examples and Comparative Examples are ASTM
-D256 k: According to ASTM-D838 tensile strength
&: According to ASTM-079 for bending strength and elastic modulus
Measured in accordance with 0. Also, regarding the falling weight impact strength, D
It was measured based on the upont type falling weight impact test, and the maximum absorbed energy value in the region where the material does not break is shown. The thickness of the sample was 178 inches, and the kneading extruder for melt kneading had a cylinder tip diameter of 3.2 ml11.
, a pedestal with a diameter of 8 mm was used.

Synthesis of component C
MAn) and dicumyl peroxide (DPO),
The mixture was fed to a 301 m twin screw kneading extruder under a nitrogen stream.
A graft reaction was carried out while melt-kneading at a cylinder temperature of 180° C. to obtain maleic anhydride grafted polyε-caprolactone (component @).

Unreacted maleic anhydride was removed under reduced pressure by heating, and the amount of maleic anhydride added was determined by the signal of the acid anhydride group at 1785 cm-' by the IR (infrared) difference Sventl method.

The results are summarized in the lt table.

The amount of maleic anhydride added was adjusted by changing the amounts of maleic anhydride and dicumyl peroxide added.

Surface side 1-8 and 1-5 Nylon 6 with a relative viscosity of 2.5 dl/g and ABS resin "Diabet^O5-3001J" manufactured by Mitsubishi Rayon Co., Ltd. and "SA resin "Dialac^, S" manufactured by Mitsubishi Rayon Co., Ltd. −
300'' was used, and the modified polyε obtained in Reference Example 1 was added to this.
- Add a predetermined amount of caprolactone (C-0) to (C-3) and mix with a Brabender, and then add a cylinder diameter of 30+++
Using a twin-screw kneading extruder, the cylinder temperature was 25.
The mixture was kneaded and extruded at 0°C to form a pellet.

After vacuum drying the obtained pellets at 100°C for 5 hours,
Mold temperature 7 using an injection molding machine (barrel temperature 250℃)
Injection molding was performed at 0° C., and the physical properties of each molded product obtained were examined. The blending composition and physical property measurement results of the resin composition are 's2
As is clear from Table 2, which is summarized in Table 2, (a)
No matter how the blending ratio of the component and the component (b) is changed, the impact properties will hardly be improved unless the component (c) is blended. Furthermore, even when component (C) is blended, if a carboxyl group is not introduced into the component (C), the *ii property improvement effect cannot be obtained. It can be seen that in the blended products (Examples 1 to 8), the high Izot impact value was significantly improved, and the falling weight impact absorption energy was dramatically improved.

Flow Sides 9 to 11 and Examples 6 to 7 Maleic anhydride grafted ethylene/propylene copolymer (
Ethylene maleic anhydride/propylene rubber VA-18
01 (manufactured by Exxon) was added, and the experiment was conducted in the same manner as in the above Examples and Comparative Examples. In addition, as physical property tests, tests of tensile strength, bending strength, and bending elastic modulus were added.

The formulation composition and physical property test results are summarized in Table 3.

As is clear from Table 3, the resin composition of the present invention (Example It can be seen that samples 9 to 11) have very excellent impact properties, especially at low temperatures.

As described above, the polyamide resin composition of the present invention has excellent elongation and impact resistance, especially at temperatures between -40°C and
In addition to significantly improved drop weight impact strength, it has good dimensional stability against heat, high dimensional stability, and high chemical resistance, such as materials subject to thermal stress, automobile parts, bumpers, and office equipment. It can be widely used as a molding material for injection molding, extrusion molding, injection blow molding, etc. of housings, etc.

[Effects of the Invention] The present invention is constructed as described above, and by specifying the type of component added as a modifier to polyamide, excellent physical properties, especially against impact such as drop impact, can be achieved. It has now become possible to provide a polyamide resin composition that has excellent strength and high tensile elongation at break, as well as good heat resistance and dimensional stability, and provides a molded article with an excellent appearance.

Outer person east Western spinning achievements KK formula

Claims (2)

[Claims] (1) [a] polyamide, [b] a rubber-reinforced resin obtained by reacting a rubber-like substrate with a polymerizable component whose main components are a vinyl cyanide compound and an aromatic vinyl compound, and [c] a carboxyl group and An impact-resistant polyamide resin composition comprising modified polyε-caprolactone in which/or a functional derivative group thereof is introduced into the molecule. (2) [a] polyamide, [b] a rubber-reinforced resin obtained by reacting a rubbery substrate with a polymerizable component whose main components are a vinyl cyanide compound and an aromatic vinyl compound, [c] a carboxyl group and/or or a modified poly ε-caprolactone in which a functional derivative group thereof is introduced into the molecule, and a modified polyolefin elastomer in which a [d] carboxyl group and/or a functional derivative group thereof is introduced into the molecule. An impact-resistant polyamide resin composition.