JPS6060158A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To provide a polyamide resin having improved dimensional stability, molding stability, hygroscopicity, etc., by blending a copolymer of a styrene compd. and an alpha,beta-unsaturated carboxylic acid with a polyamide resin in a specified weight ratio. CONSTITUTION:A copolymer (A) composed of 85-95wt% styrene compd. such as styrene or alpha-methylstyrene and 15-5wt% alpha,beta-unsaturated carboxylic acid such as methacrylic acid and a polyamide resin (B) such as polycaprolactam or polyhexamethyleneadipamide are prepd. with the ratio of weight-average MW of component A to that of component B in the range of 1.1-12.5. 30-55wt% component A is mixed with 70-45wt% component B to obtain the desired polyamide resin compsn. The resulting resin compsn. has well-balanced flow characteristics while retaining mechanical toughness and durability inherent to polyamide.

Description

[Detailed description of the invention] 1-< maintains the excellent mechanical toughness and durability of polyamide, while improving hygroscopicity, process stability, molding stability, and fluidity. This invention relates to a polyamide resin composition with improved moldability and good moldability.

It has been proposed to melt-mix polystyrene and styrene-acrylonitrile copolymers for the purpose of improving the hygroscopicity of polyamide ('% Kosho/IO-7180), but these are not compatible with polyamide. It is known that the molded product exhibits a delaminar state and the mechanical strength is significantly reduced, making it difficult to obtain a good molding material.3 When mixing an olefin polymer and polyamide, Acid 2 ester as a polymer.

A method for producing a polymer composition with good quality by using a modified olefin polymer into which at least one of amide, acid anhydride, and epoxide groups has been introduced has been proposed (Japanese Patent Publication No. 30954/1973). However, this modified polyolefin is said to be a polyolefin made by reacting maleic anhydride with polypropylene, or a kraft copolymerization of polypropylene, methacrylic acid, and styrene in a ratio of 7:3, and polypropylene. Maleic anhydride is 0 () 5 to 01% by weight or methacrylic acid-styrene graft ratio is 3% by weight and low (・R
There is a fence. The purpose of this modification is during spinning of blended products of polypropylene and polyamide or polyethylene terephthalate]; [J] The main purpose is to improve yarn deflection, and to improve bulge generation and yarn breakage during stretching. The invention relates to a method for producing a polymer composition with polyamide or polyethylene terephthalate.

On the other hand, as a proposal to reduce the hygroscopicity of the polyamide resin and improve the accuracy of the Xj method, a polyamide resin composition was proposed in which the polyamide resin contains glass fiber and 10 to 40 M% of a thermoplastic resin. (Tokuko 1977)
-1394/I) In this case, the thermoplastic resin is added for the purpose of contributing to a decrease in hygroscopicity, and Garasuhama Anti is a combination of this heat 〒iJ plastic resin and polyamide,
It is added to prevent the peeling phenomenon at the interface with 1f11 fat). Although this resin composition achieves the purpose of reducing moisture absorption ability and improving dimensional accuracy, the glass fibers and t(Ii) cause wear of various parts of the molding equipment such as the screw of the extruder and the mold, and 2. After becoming a molded product, ion blating, sputtering,
Secondary processing such as painting becomes difficult, and fluidity is not good enough.
There are some problems.

In addition, JP-A-56-62844 discloses a copolymer of a styrene compound and an α, β, β sum carboxylic acid, or a copolymer of a styrene compound and an α, β, β sum carboxylic acid and an α, β, β sum carboxylic acid.
Copolymer 2 consisting of Japanese carboxylic acid ester ()~80% by weight (based on resin components) and polyamide) Resin 80~20
5 to 60% by weight of glass fiber to the resin composition (based on resin components) (based on the total composition)
A resin composition consisting of additives 1-1 has been disclosed (・ru. However, this resin composition has problems such as wear of the molding equipment due to the elegance of the molding and ℃・5, and also has poor fluidity in the mold. It's not very good, and the molding conditions have to be somewhat limited.

Even without adding glass fiber, it has the mechanical strength and durability that polyamide itself has, and also has improved dimensional stability with moisture absorption and molding stability, and has a well-balanced λ.
It has been desired to develop a polyamide resin composition that has good fluidity and excellent moldability.

In order to solve the ten-point problem, the inventor of the present invention ((As a result of intensive study), a specific copolymer consisting of a styrene compound and α, β, and β-carboxylic acids and a polyamide resin were blended in a specific composition range. As a result, polyamide has a structure in which a copolymer of styrene compound and α,β unsaturated carboxylic acid is stably microdispersed in the sea state, while maintaining the mechanical toughness of polyamide. It was discovered that a polyamide resin composition with reduced hygroscopicity and good legal properties can be obtained, and that this composition has excellent molding stability. A copolymer whose improving effect is based on a styrene compound and α, β, and β-sum carboxylic acids;
It has been found that the ratio of each sub-HH1,:LF-equal molecular weight of the polyamide and the ratio of the two is significantly different depending on certain specific conditions.

Therefore, the present invention is a copolymer consisting of a styrene compound and α, β, β carboxylic acid, i () ~ 55% by weight, and a polyamide resin 70 ~ 4571i: F, '%, and a styrene compound and α , β, and the weight average molecular weight ratio of the copolymer consisting of β-carboxylic acid and the polyamide is 11 to 32.
This is a polyamide resin composition characterized in that the polyamide resin composition is 5.

A copolymer consisting of a styrene compound and an α, β, β-sum carboxylic acid can be obtained by combining a styrene monomer with a (χ, β unsaturated carboxylic acid).

Styre/system 0'1. Styrene as jj+ body, α-
Methylstyrene/, )-methylstyrene, etc. can be used alone or in combination, and as the α, β, β-sum carboxylic acid, ivy acrylic acid, acrylic acid, etc. are used.

Polyamides suitable for use in the present invention include polyglolactate (nylon-6) and polyhexamethylene adipamide (nylon-6,6).

When polyamide is in dlj state, styrene compound and α,
By creating a structure in which the copolymer consisting of β-unsaturated carboxylic acid is micro-dispersed in the form of islands, it is possible to maintain the excellent durability that is characteristic of nylon, such as oil resistance and slipperiness, and also to have excellent mechanical properties. Toughness can be maintained.

In the resin composition, in order to make the polyamide in a sea state, 45 to 701% polyamide powder and SfV-/based compound-α are added.
, β vesicles and carboxylic acid coelectrolyte must be blended in a range of 55 to 30%. By using this blending ratio, it is possible to improve the dimensional stability and molding stability as well as the decrease in hygroscopicity C'. Polyamide is 45-6
0 p5 ; i, In the area of "Engine", the above improvement effect is significant. It is suitable for various uses, such as the production of large molded products.

In the sea of polyamide, this uncombined styrene tip α.

Copolymer 6 consisting of β-unsaturated carboxylic acid: For microdispersion, styrene-based 1 [; Somono 8: 11' in 3-05
L%, α, β, β-sum carboxylic acid 15-1) Flt:
It is possible with a composition ratio of '> i, +, but it is preferable -I
L < (r, j styrenic compound 88-93%,
α,β unsaturated vesicle monocarboxylic acid 12 to 7% by weight is preferable. α in a copolymer of styrenic compounds and α,β unsaturated carboxylic acids.

The proportion of β-unsaturated carboxylic acids is 5 h;-“/(l;4
If ζ6,1 or more, the compatibility with the polyamide becomes poor and phenomena such as peeling of the molded product are observed depending on the molding month.
:j Copolymer particles of about 3 μ or less are polyamide iY! j
It is in a stable and uniform state with 61 particles dispersed in it. Also,
α.

If the proportion of β-unsaturated carboxylic acid exceeds 15% by weight, a gel-like substance is formed during the production of the copolymer, which has the disadvantage that it is difficult to modify the polymer i1.

Styrenic compounds - molecules determined by gel permeation chromatography of α, β, β carboxylic acid copolymers –
; enemy: styrenic compound polymer catalyzed molecule by measurement.
, ril city h; average molecular weight 1 (10,000-50
”O,OO01ljf :l: t,, < is 150
．． Preferably in the range 000-7I00.0001. stomach. The types of polyamides are polycaproctam and polyhexamethylene adivamide, which have a weight average molecular weight of 4.
o, 000~90,000 Yoshisho I or 45,00
3. Desirably ranges from 0 to 80,000. That is, if the weight average molecular weight ratio of the styrenic compound - α, β unsaturated vesicular carboxylic acid copolymer and polyamide is 11 to 125, preferably 19 to 89.:11, the injection molded product is Physical properties improve. Styrenic compound - The weight average molecular weight ratio of α, β, β carboxylic acid copolymer and polyamide is 1
If the ratio is less than 0, the tensile strength will decrease, and if the ratio is more than 126, the fluidity will be extremely low, which is undesirable for molding.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

In addition, in the following examples and ratios) + 12 examples, test pieces were prepared by molding the mixture with q = 2, and the tensile strength was determined. Izot impact strength As'J'M-1) 256), heating deformation temperature (As'J'M-,1) 648),
Melt flow index (230" C13, 8 kg load - claw, I 5O-11, 1133), water absorption rate (4-1 to AST) 57 (, 1,), molding shrinkage rate (see Figure 3, but 7, A -150m7n, 13=15 (li+
n, If 3 mm, M Bingate's row (cow).

) was measured.

In addition, the peeling condition of the molded product (adhering adhesive tape to the fractured surface of the test piece, and then peeling it off using the method -J'-J-)
η "The condition after the test was observed with the naked eye.

Example 1. Comparative Example 1 Polyglolactam (2:UOO3Asahifl-Seitamagyo(a)
)) 50 parts by weight and weight average molecular weight 2 ] 0. (, +
(+ +1 styrene-methacrylic acid copolymer (methacrylic acid-containing i-F, -: 8% by weight) 5 () parts by weight (
Example 1) Styrene-acrylonitrile copolymer (containing acrylonitrile)
f, 1% by weight) 50 parts by weight (Comparative Example 1) They were mixed in the form of pellets, and melted and mixed in a 40 mmφ single-limb extruder at 250°C. Each of these mixtures was observed using an electron microscope.

FIG. 1 shows an electron micrograph of a mixture of the styrene-methacrylic acid copolymer and polycaprolactam of the present invention, and the second
Section 1 shows an electron micrograph of a mixture of styrene-acrylonitrile copolymer and polycarbohydrate-1 lactam.
, and the sea-island relationship is Q;
The appearance of the molded product is very good with no peeling of +1, and the mechanical properties are well balanced, which is preferable based on the month of molding. The water absorption rate also decreased to 86%, and the molding shrinkage rate also decreased to 110.78 and 072% on the B side. If a flow mark appears on the exterior of the molded product,
Also, peeling is expected (q'l'), and as a result of molding, it cannot be used.

Example 2 Weight average molecular weight of the styrene-methacrylic acid copolymer in Example 1 2 1 0. 0 0 (3 instead of l
Similarly to Example 1, a styrene-methacrylic acid copolymer of 50,000 ml was kneaded using melt F alone. The results of the physical property tests are shown in Table-1.

Example 3 In place of polycaprolactam in Example 1, polyhexamethylene adipamide (Leona e'+ 20 OS
, Asahi Kasei Kogyo Co., Ltd., at a melt-kneading temperature of 280℃.
The same procedure as in Example 1 was carried out except that the temperature was changed to °C.

The results of the physical property tests are shown in Table-1.

Example 4 The SMΔA/N-6 blend ratio (wt%) in Example 2 was replaced with 30/10, and the rest was as in Example 2.
Melt and knead in the same manner as above. Table the results of the physical property test.
It was shown to.

Comparative Example 2 In place of the styrene-methacrylic acid copolymer link acrylic acid content of 8% by weight in Example 1, a methacrylic acid-containing tower of 2% by weight was used, and the same melt-kneading was performed at °C. An electron micrograph of the A4Suda mixture revealed that it was a dispersed state of coarse particles of about 16μ. Furthermore, injection molded products have severe flow marks and severe peeling. Unused: ``One gun is enough.

Comparative Example 3 The ivy acrylic acid content of the 7-tyrene-methacrylic acid copolymer of Example 1 was 8% by weight, and the weight average molecular weight was 210.
0 0 0, the methacrylic acid content is 19% by weight, and the weight average molecular weight is 3 0 0. Melt kneading was performed in the same manner using 0 0 0. From an electron micrograph of the obtained mixture, coarse particles of about 8 μm in size were observed. Furthermore, the melt flow index was extremely low, flow marks on the exterior of the molded product were noticeable, and some peeling of the molded product was observed.

Comparative Example 4 The weight average molecular weight of the styrene-methacrylic acid copolymer of Example 1 was 2 1 0, O 0 instead of I 0,
0 0 0 was used. That is, both of these ratios of 05 were melt-kneaded. The obtained mixture is 09 from an electron micrograph.
Particles of ~2.1μ were observed to be dispersed.

There are no flow marks or peeling of the molded product, but the mechanical properties, especially the tensile strength, are extremely low (r), making it unsuitable for use depending on the month of molding.

Comparative Example 5 Mixing weight ratio of styrene-methacrylic acid copolymer and polycaprolactam in Example 1: 90 instead of 50:50
: Melt kneading was carried out at +==10. An electron micrograph of the obtained mixture showed that the tin-methacrylic acid copolymer was in the state of a sea. In addition, the mechanical properties, especially the tensile strength, are extremely low (unsuitable for use due to molding).

Comparative Example 6 The mixing weight ratio of styrene-methacrylic acid copolymer and polycaprolactam in Example 1 was 10.9 instead of 50°50.
0 and melt-kneaded. Physical property tests of the obtained mixture showed that the striped heating deformation temperature was low and the water absorption rate could not be reduced to 10%, meaning that the goal of polyamide modification could not be achieved.

Comparative Example 7 Weight of the styrene-methacrylic acid copolymer of Example 1; Tsuji average weight J'Jj210. 500 instead of OOO. (
) 00, the average molecular weight of polyamide was 33,000 instead of 50,000. That is, both of these materials having a ratio of 151 were melt-kneaded. Physical property tests of the resulting mixture showed that the melt flow index was extremely low and flow marks appeared on the appearance of molded products, making it unsuitable for use as a molding additive.

<Remarks> (1) SMAA; styrene-methacrylic acid copolymer (21N-6i borinol glolactam [3) N-6, (i, polyhexanothylene adipamide

[Brief explanation of the drawing]

FIG. 1 is an electron micrograph showing the dispersion state of the resin of a resin composition consisting of styrene-acrylic acid combination and polycaprolactam as an example of the present invention.
] is an electron micrograph showing the dispersion state of the resin of a resin composition made of styrene-acrylonitrile copolymer and polycaprolactam as a comparative example, and Figure 3 is an X12 plane showing the shape of the sample for measuring mold shrinkage rate. It is a diagram. Applicant Asahi Kasei Kogyo Co., Ltd. Agent Yutaka 1) Yoshio Figure 1 procedural amendment (method) February 1981 811 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Case indication patent application No. 167525 1982, Name of the invention: Polyamide resin composition 3, side dish 1t jE Relationship with the case Patent applicant: 15<1-rl-12-6 Dojima, Kita-ku, Osaka-shi, Osaka (
003) Asahi Kasei Industries Co., Ltd. President and Representative Director Ichizaki Miya 4, Agent Sanshin Building 2, 1-1-14-1 Yurakucho, Chiyoguchi 1-ku, Tokyo
Room 04 Telephone: 501-2138□+1N＼ ＼ 5. Amendment order attached to FJ in 1982 l JJ 310 (shipping date) 6. Column 7 of "Brief explanation of drawings" of the specification subject to amendment, Contents of amendment 7-1 The "Brief Description of Drawings" column of the specification shall be amended as follows. (1) In the specification section, page 17, line 8, J indicating the dispersion state of the resin in U is corrected to ``indicates a structure in which styrene-methacrylic acid copolymer particles are microdispersed in polycaprolactam.'' (2) In the same book, page 17, line 11, "indicates the dispersion state of the resin" is corrected to "indicates the structure in which styrene-acrylonitrile copolymer particles are dispersed in polycaprolactam."

Claims (5)

[Claims] (1) 30 to 55% by weight copolymer of styrene compound and α, β, and β carboxylic acids and 70% polyamide resin
45% by weight, and the ratio of the weight average molecular weight of the copolymer consisting of a styrene compound and a β-unsaturated carboxylic acid to the polyamide is 11 to 125. (2) Styrene compound and α,β unsaturated carboxylic acid copolymer containing 85 to 95% by weight of a styrene compound and 15 to 5% by weight of α,β,β-carboxylic acid copolymer The polyamide resin composition according to claim 1. (3) A patent claim in which the copolymer consisting of a styrene compound and α, β, β-sum carboxylic acid is a styrene-methacrylic acid copolymer consisting of 85 to 95 M% of methylene fluoride and 15 to 5% by weight of methacrylic acid. The range of the polyamide tree 11i'UX described in item 1 is paraboloid. (4) Polyamide is polyamide, and r[')
Ru! (1J”) The polyamide resin composition according to claim 1. (5) The polyamide resin composition according to claim 1, wherein the polyamide is polyhexamethyleneazibamide.