JPS6047062A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. which gives moldings having high impact resistance and excellent appearance and color tone, by blending a specified modified polyolefin with a polyamide resin. CONSTITUTION:5-100pts.wt mixture consisting of a linear low-density polyethylene copolymer (A) having a crystallization temp. of 90-110 deg.C and contg. ethylene and a 4-8 C alpha-olefin as its constituent components and an ethylene/C 3-6 alpha-olefin copolymer (B) having a crystallinity index of 25% or below, in a weight ratio of A to B of 90:10-10:90, is blended with 100pts.wt polyamide resin. Either or both of said copolymers A and B contains 0.05-3wt% alpha,beta-unsaturated carboxylic acid or derivative thereof added thereto.

Description

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

Specifically, the present invention relates to a polyamide resin composition comprising polyamide and modified polyolefin that provides a molded article having extremely high #1 impact resistance and excellent appearance and color tone.

Due to its excellent physical properties, polyamide is expected to be in great demand as an engineering plastic.However, due to its low impact resistance, its growth is currently sluggish. Various methods have been proposed to improve the impact resistance of polyamide, but a typical method is to add a polymer having rubber elasticity and active groups that can react with polyamide to polyamide. Although it is possible to obtain a molded article with relatively improved impact resistance by such a method, it is not necessarily possible to obtain a molded article with extremely high impact resistance.

Moreover, according to this method, molded products that are colored and have a poor appearance are often obtained, which naturally limits its use.

In other words, 'In this method, it is important to select a polymer to be added to the polyamide that does not cause the above-mentioned problems, and it is important to select such a polymer from among a large number of polymers. is extremely difficult.

In view of this, the present inventors conducted extensive research and found that a specific modified ethylene copolymer is effective as a polymer to be added to polyamide.
273t%%% Application Br3.3-37-1f2737, proposed in Japanese Patent Application No. 33-10630. Unfortunately, polyamides produced by these methods have drawbacks such as poor extrudability when producing modified ethylene copolymers, and discoloration of extrudates during long-term operation. The present inventors have made intensive studies to improve these points and develop a lower-cost engineering plastic, and as a result, they have arrived at the present invention.

That is, the gist of the present invention is that a linear low-density poly(3+) ethylene co-electronic product (Al and crystallinity, 2t% or less) having as constituent components ethylene with a crystallization temperature of O to 1 to C and an α-olefin with a carbon number of ≠ to r )
, ethyleneto α-olefin copolymer having 3 to 6 carbon atoms (
O,OS ~ 3% by weight of α,β-unsaturated carboxylic acid or its acid derivative is not added to at least one of B), and the mixing ratio of the N component and the component (B) is The polyamide resin composition is comprised of a mixture having a weight ratio of 5 to 100 parts by weight per 100 parts by weight of a boria amide resin.

Hereinafter, the present invention will be described in detail. As the polyamide used as a raw material in the present invention, various well-known polyamides can be mentioned.

For example, oxalic acid, adipic acid, speric acid, sebacic acid,
dicarboxylic acids such as terephthalic acid, isophthalic a, t, ≠-cyclohexyldicarboxylic acid, toethylenediamine, pentamethylenediamine, hexamethylenediamine,
Decamethylenediamine % Polyamide obtained by polycondensing diamines such as lt”-cyclohegicyldiamine and m-xylylene diamine; Polyamide obtained by polymerizing cyclic lactams such as caprolactam and lauryl lactam; or Examples include polyamides obtained by copolymerizing a cyclic lactam, a salt of a dicarboxylic acid, and a diamine.

Preferred examples of these polyamides are nylons such as 6 nylon, 6 otsu nylon, tto nylon, tt7tio nylon, 6/66 nylon, and J/66 nylon.
IT nylon (a copolymer of a salt of caprolactam, terephthalic acid and hexamethylene diamine) is mentioned, and particularly preferred are nylon 6 and nylon 66.

In the present invention, in order to obtain impact-resistant polyamide,
At least a linear low density polyethylene copolymer (A) with a crystallization temperature of 0-//QC and a copolymer of ethylene and α-olefin having 3 to 6 carbon atoms (B) with a crystallinity of 2J or less On the one hand, a modified polyolefin is used, in which an α,β-unsaturated carboxylic acid or an acid derivative thereof is added to the above mixture in a weight ratio of 00 Oj' to 3.

The linear low-density polyethylene copolymer is a copolymer containing ethylene and another α-olefin with a carbon number of ≠ to r, and has a crystallization temperature of θ to l/θC. If the crystallization temperature is less than 00, the rigidity will be undesirably low. Moreover, if it exceeds /10C, the impact strength will be insufficient.

More preferably, a powdery low density polyethylene copolymer having a crystallization temperature of 1 osC and a melt index of θ, θ/-, 2'Of 10 minutes is used.

As the copolymer of ethylene and α-olefin having 3 to 3 carbon atoms, those having a crystallinity of 2j% or less, preferably 1-λo%, or a mixture of these copolymers are used. 2
If it exceeds 3%, the impact resistance will deteriorate, which is undesirable.As the α-olefin having 3 to 6 carbon atoms, which is a copolymerization component, propylene 1-butene-11hexene-11pentene-11
Examples include goomethylpentene-1 and the like, with propylene and butene-7 being particularly preferred.

It is preferable that the content of this α-olefin is determined by /g Omolti. Also, the melt index is o, o
t,, 5o17to, density is o, g s~O0riOf
/cd is preferred. However, such a copolymer (B) of ethylene and α-olefin having 3 to 6 carbon atoms
For example, using a Ziegler-Natsuta catalyst, particularly a vanadium compound such as sodium trichloride or vanadium tetrachloride, and an organoaluminum compound, ethylene and aO
less than molti preferably 20-, tt% ruti carbon number 3~
Examples include those obtained by copolymerizing with α-olefin (B). A particularly suitable unmodified ethylene copolymer is Mitsui Petrochemical Co., Ltd.
A series of polymers commercially available under the Tafmer trademark, such as Toughmer A4' (Toughmer A4')
o, Tafmer A series (ethylene-butene-7 copolymer) such as Tafmer A20; -P021
0. Tafmer P series (ethylene-
propylene copolymer).

The mixing ratio of the linear low-density polyethylene copolymer (A) and the ethylene-α-olefin copolymer (B) may be such that the weight ratio of the former and the latter is 0', io or IO = 0. preferable. If the weight ratio is less than 0, the molded product during injection molding should be 30 to 30 0, more preferably tυ: 30 to 30, the impact resistance of the polyamide resin composition will be 11 It is preferable in terms of conical shape and extrudability of the molded product without causing deterioration.

On the other hand, the α,β-unsaturated carboxylic acids or acid derivatives thereof (hereinafter collectively referred to simply as α,β-unsaturated carboxylic acids) to be added include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, Examples include acids, esters, and acid anhydrides of the acids. Among these, maleic anhydride is particularly preferred.

Too much or too little amount of α,β-unsaturated carboxylic acid is not effective in improving the impact resistance of the polyamide. Further, if the amount is too large, there is a problem that the polyamide is colored yellow to red when added to the polyamide.

Therefore, the amount of added bone must be within the above range, preferably 0. It is in the range below /-/weight.

Although it is necessary to add the unsaturated carboxylic acid to at least one of the (A) component and (B) component, it is preferable to add it to both the (A) component and the (seasonal component). In that case, the amount to be added is ( Based on the sum of A) component and (B) component.

Therefore, the modified polyolefin in the present invention is preferably prepared by tri-blending the above-mentioned linear low-density polyethylene copolymer) and the ethylene-α-olefin copolymer CB+ in required amounts, or by using an extruder or heating roll in advance. to which α, β-unsaturated carboxylic acid was added, and 1
．． It is produced by melting and kneading at tO to 300C and adding α,β-unsaturated carboxylic acid to the mixture under reaction conditions commonly referred to as graft polymerization or graft reaction. A screw type extruder is often used for melt mixing.

Of course, in order to efficiently cause the addition, an organic peroxide such as α1Cf-bis-t-butylperoxy-p-diisopropylbenzene is added to the linear low density polyethylene copolymer (A) and ethylene-α. - from 0.007 to 0.00 for the mixture of olefin copolymers (B). Oj You may use a large amount of weight.

The melt index of the modified polyolefin thus obtained is 0.00! -/ Of 710 minutes especially o, oor~! Li-710 minutes is preferred. The modified polyolefin obtained (2) may be a linear low-density polyethylene copolymer (B) obtained by adding an α,β-unsaturated carboxylic acid to an ethylene-α-olefin copolymer (B), or a further modified polyolefin. Depending on the conditions, it is estimated that the linear low-density polyethylene copolymer (Al and ethylene-α-olefin joint type body CB) chemically bonds to form a modified polyolefin that is integrated.

Of course, only one of the (A) component or (Bl component)
・I When transmuting, or transmuting both individually,
This method can be applied even when mixing is performed later.

In addition, the melt index is ASTM D-'/J, 3g
The value measured at loC according to J7T (in g-7t
.

minutes) and melt flow index 7 is ASTMT).
-/, 23g -70, the value was measured at 230°C (unit: tyio minutes), and the outflow ratio was 790°C.
/0” dyne/cd and 10’dyne
The ratio of the outflow amount measured at /* (/0"/ /0 is υ, the density is the value measured according to JIS-7//2, and the crystallization temperature is the differential scanning calorimeter. (Perki
The heating rate crystallinity was determined using X-rays using DSC-2i) manufactured by n-Elmer Co., Ltd. in accordance with the description in Journal of Polymer Science, Vol. This is the value measured using the method.

In the present invention, a polyamide resin composition is produced by melt-mixing such a modified polyolefin with a polyamide. Melt mixing can be carried out according to conventional methods, using an extruder or similar equipment.

The amount of modified polyolefin used is polyamide 10
Based on 0 parts by weight, the amount ranges from 5 parts by weight to 100 parts by weight, preferably from io parts by weight to 70 parts by weight.゛If the amount of modified polyolefin used is more than the above range, the matrix of the resulting molded product will convert to polyolefin, and the product will lose the properties of nylon, such as chemical resistance and abrasion resistance, and cannot be used for normal purposes. , it is difficult to achieve the purpose of the present invention if the number of digits is small.

Of course, the polyamide resin composition obtained by the present invention is
In addition to the above-mentioned components, it may contain inorganic fillers, glass fibers, and various well-known additives, and these can be added at any stage according to conventional methods.

Crystallization temperature as above! A linear low density polyethylene copolymer of Po-/i0c is used as a raw material for modified polyolefin.
In the production of modified polyolefin used as a component, moldability is better than in production without the linear low-density polyethylene copolymer, that is, the extruded strands are stable, the extrusion amount is increased, and the occurrence of discoloration is reduced or It has the advantage of being allowed to disappear. The resulting polyamide resin composition has extremely high impact resistance and flexural modulus sufficient to withstand use as engineering plastics, and has an excellent external color tone.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In addition, in the following examples, "parts" indicate "parts by weight."

Examples 1 to 3 and Comparative Example 1-G (11) Production of modified polyolefin Linear low-density polyethylene copolymer (ethylene-butene-
7 copolymer, melt index! . 01 Crystallization temperature t
o3r:) Part O, 60 parts of propylene-containing i/ff molten ethylene-propylene copolymer (melt index O, Guhiro, crystallinity jφ), α, d-bis-t- dissolved in a small amount of acetone. Butylperoxy V-rp-diinobrobylbenzene 0.023 parts and maleic anhydride O
, S parts were blended in a Henschel mixer. This blend has an inner diameter of 30 rtim% L/D = 2
The resulting product was extruded into pellets using a λ extruder at 1.21OC to obtain a modified polyolefin (hereinafter referred to as APO-/).

After pulverizing a portion of the pellets, unreacted maleic anhydride was extracted with acetone using a Soxhlet extractor for 12 hours. This product was dried and then pressed, and the amount of maleic anhydride was determined by infrared absorption spectrum, and it was found that maleic anhydride in an amount of 0.7M was added.

In the above method, the modified polyolefin (APO
-λ~g) was obtained. Only APO-2, which uses ethylene-propylene copolymer alone as the base polymer, has black color in the strand.The extrusion molding amount (W
).

Ethe, ethylene-Hiromethylpentene-/copolymer (Tart index, !, 2, crystallization temperature/ozC
) (-APO-j), high pressure process polyethylene homopolymer, (melt inch mix 0 ψ, crystallization temperature 01: ) (APO-4), high density polyethylene homopolymer (melt index O,,□, crystallization temperature,
tt3C) A modified polyolefin was produced. The measurement results are shown in Table-/.

(2) Adjustable relative viscous box (polyamide) with a fat composition of 71
(Value measured at 26C for a 7V polymer solution in concentrated sulfuric acid with f'%) 3.2! A polyamide resin composition was produced by melt-mixing 20 parts of t-nylon go and modified polyolefin in a 21,0 (:) single-screw extruder, cooling with water and pelletizing. A test piece was injection molded.

The mechanical properties measurement results are shown in Table-λ.

In addition, the Izotsu impact strength (3 legs, with notch) is AST
According to MD-λj6, bending elastic modulus and bending strength are ASTM
Measured according to D-7. In addition, the mold releasability of injection molded pieces (
IOxgOx3. ) was determined by the degree of adhesion to the fixed plate during molding.

Table-7

Claims (4)

[Claims] (1) A linear low-density polyethylene copolymer (A) containing ethylene with a crystallization temperature of 0 and 1 ioC and an α-olefin with a carbon number of up to t as constituent components, and a crystallinity of 25%.
The following copolymerization of ethylene and an α-olefin having 3 to 6 carbon atoms is carried out by adding α, β-unsaturated carboxylic acid or an acid derivative thereof to at least one side of the copolymer with 0.03 to 3 times A polyamide prepared by blending a mixture in which the mixing ratio of the component (A) and the component (B) is O:1 ON to: O at a ratio of j to ioo parts by weight to 700 parts by weight of the polyamide resin. Resin composition. (2) Component (A) has a melt index of o, ot-s. P/10 minutes, crystallization temperature! ~/ 0! The composition according to claim 1, which is a linear low-density polyethylene copolymer having as a constituent component an α-olefin having an ethylene carbon number of ≠ to 1. (3) The composition according to any one of claims 1 to 2, wherein the (Bl) component is an ethylene-propylene copolymer or/and an ethylene-butene-l copolymer. (4) The composition according to any one of claims 1 to 3, wherein maleic anhydride is used as the α,β-unsaturated carboxylic acid or its acid derivative.