JPS62179546A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thremoplastic resin compsn. having well-balanced physical properties including resistance to impact and heat and moldability, by blending a polyamide resin with an ethylene/alpha-olefin copolymer and a maleimide copolymer resin... CONSTITUTION:A resin compsn. consists of 10-90wt% polyamide resin (a), 1-50wt% ethylele/alpha-olefin copolymer (h) having a modification rate of 0.03-5wt% and 5-80wt% malleimide copolymer (c). The modified ethylene/alpha- olefin copolymer (b) is one obtd. by modifying an ethylene/alpha-olefin copoplymer with at least one compd. selected from among pref. unsaturated acids and unsaturated carboxylic acid anhydrides. The maleimide copolymer is a copolymer obtd. by polymerizing a monomer mixture mainly composed of a maleimide compd. and an arom. vinyl compd. in the presence or absence of a rubbery polymer.

Description

Detailed Description of the Invention a. Industrial Field of Application The present invention relates to a thermoplastic resin composition having excellent heat resistance, moldability, and impact resistance, and more specifically to a thermoplastic resin composition having excellent heat resistance, moldability, and impact resistance. The present invention relates to a thermoplastic resin composition comprising a copolymer and a maleimide copolymer resin.

b. Prior Art Due to its excellent physical properties, polyamide is widely used as an engineering plastic in automobile parts, office equipment, electrical appliance parts, etc.

However, due to poor impact resistance, molded products may crack or crack. Therefore, the current situation is that the expansion of the field of use is slowing down.

C8 Problems to be Solved by the Present Invention Various methods have been proposed to improve the impact resistance of polyamide, but a typical method is to use a polymer having active groups that can react with polyamide and rubber elasticity. , is a method of adding it to polyamide. By such a method, it is possible to obtain a molded article with relatively improved impact resistance, but the addition of a rubbery polymer usually causes a significant decrease in moldability and heat resistance.

As a result of intensive studies on polyamide resin compositions with an excellent balance of physical properties such as impact resistance, heat resistance, and moldability, the present inventors surprisingly found that modified ethylene-α olefin copolymers and maleimide copolymer resins A polyamide resin composition containing a specific amount of
It was discovered that a composition having a well-balanced physical property of moldability can be obtained, and the present invention was achieved based on this knowledge.

Means for solving the d0 problem, that is, the thermoplastic resin composition of the present invention is: a) Polyamide resin composition 10-90% b) Modification rate 0
．． The present invention provides a thermoplastic resin composition characterized by comprising: 0.3 to 5% by weight of an ethylene-α-olefin copolymer and 1 to 50% of a maleimide copolymer resin.

The polyamide resin of component (1) (a) used in the present invention is usually a linear diamine represented by the formula % (wherein, X is an integer between 4 and 12), such as ethylene diamine, Pentamethylene diamine, hexamethylene diamine, decamethylene diamine and a linear carboxylic acid of the formula 1, where y is an integer between 2 and 12, such as oxalic acid, adipic acid, superric acid, Those manufactured by condensation with sebacic acid and those manufactured by cyclic polymerization of lactams such as caprolactam and laurinlactam can be used.

Preferred examples of these polyamides include nylon 6
・6, Nylon 6/9, Nylon 6/10, Nanlon 6
・12, nylon 6, nylon 12, nylon 1). There are nylon 4, 6, etc.

Also, nylon 6/6/6, nylon 6/6/10, nylon 6/12, nylon 6/6/12, nylon 6/
Copolyamides such as nylon 6/6/6/10 and nylon 6/6/6/12 are also used.゛More nylon 6/
6.T, (T: terephthalic acid component), obtained from an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid and an alicyclic diamine such as m-xylylene diamine or 1,4-cyclohexyldiamine Mention may be made of semi-aromatic polyamides, polyamides obtained from m-xylylene diamine and the above-mentioned linear carboxylic acids, polyesteramides, polyetheramides and polyesteretheramides.

Note that the polyamide may be used alone, or two or more types of polyamides may be used in combination.

The above polyamides which are component (b) of the present invention may be used in combination.

The blending amount of the polyamide in the thermoplastic resin composition of the present invention is 10 to 90%, preferably 20 to 80%.
It is. If the amount of polyamide is less than 10% by weight, there will be no significant effect on improving moldability or chemical resistance, and if it exceeds 90% by weight, impact resistance will decrease, which is not preferable.

The modified ethylene-α-olefin copolymer (b) used in the present invention preferably has at least one compound selected from unsaturated acids, unsaturated dicarboxylic anhydrides, etc., added to the ethylene-α-olefin copolymer. It may be modified with a certain type of unsaturated compound, added to an ethylene-α-olefin copolymer, and/or grafted with a polymer. The α-olefin is an α-olefin having 3 to 12 carbon atoms, and specific examples thereof include propylene, butene-1,4-methylpentene-1) hexene-1, octene-1, and the like. Preferred is propylene. These α-olefins can be used alone or in combination of two or more. Moreover, those obtained by copolymerizing non-conjugated diene compounds can also be used.

The ratio of ethylene, α-olefin, and optionally used non-conjugated diene compound in the ethylene-α-olefin copolymer used is preferably ethylene/α-olefin/ Non-conjugated diene compound - 0.2-0.81 0.2-0.810-0.1, more preferably 0.2-0.71 0.25-0.751
It is 0 to 0.05. Mooney viscosity (ML+ -a,
Io. C) is preferably 5 to 150, more preferably lO to 70.

Examples of the unsaturated compound that modifies the ethylene-α-olefin copolymer include α, β-unsaturated carboxylic acids or acid-attracting pollutants thereof (hereinafter, these are collectively referred to simply as α).

(referred to as β-unsaturated carboxylic acid), acrylic acid,
Examples include methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, and esters or acid anhydrides of the aforementioned acids. Among these, maleic anhydride is preferred. α to modify ethylene-α-olefin copolymer
If the amount of β-unsaturated carboxylic acid is too large or too small, it will not be effective in improving the impact resistance of the polyamide. The modification rate is 0.603% to 5% by weight, preferably 0.1% to 3% by weight, based on the ethylene-α-olefin copolymer, and if it deviates from this range, the desired impact strength cannot be obtained.

The ethylene-α-olefin copolymer may be modified by bonding a modifying polymer, and preferred modifying polymers include α,β-unsaturated carboxylic acid anhydride copolymers. Specific examples include ethylene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, and acrylonitrile-maleic anhydride copolymer. , allyl acetate-maleic anhydride copolymer, methyl acrylate-maleic anhydride copolymer, methyl methacrylate-maleic anhydride copolymer, vinyl acetate-maleic anhydride copolymer, and vinyl chloride-maleic anhydride copolymer and one or more derivatives of these copolymers (for example, hydrolysates of these copolymers or esterified products obtained by esterifying the hydrolysates with alkyl having 1 to 6 carbon atoms). , preferably styrene-
It is a maleic anhydride copolymer. Modification rate is ethylene-α
- 0.03 to 5% by weight based on the olefin copolymer,
The content is preferably 0.1 to 3% by weight, and if it is outside this range, the desired impact strength cannot be obtained.

Here, the modification rate is based on the ethylene-α-olefin copolymer and is expressed as the addition or graft bonding ratio (polymerization %) of a polar monomer or polymer to the copolymer.

As a method for modifying the ethylene-α-olefin copolymer of component (b), for example, the unsaturated compound or the unsaturated compound mixture and a peroxide are mixed,
0.5 to 300°C, preferably 150 to 250°C
It is obtained by heat treatment for 30 minutes, preferably 1 to 20 minutes.

These modification reactions can be carried out using an extruder, kneader, Banbury mixer, etc.

Alternatively, it can also be obtained by dissolving the ethylene-α-olefin copolymer, the unsaturated compound, and the organic peroxide in an organic solvent and heating the solution. As the solvent used at this time, a hydrocarbon having 6 to 12 carbon atoms, a halogenated hydrocarbon having 1 to 12 carbon atoms, tetrahydrofuran, or the like is used. 40-300℃, preferably 50℃
Heat treatment is performed at ~200°C for 1 minute to 10 hours, preferably 5 minutes to 5 hours. After the reaction is complete, the mixture is poured into a polymer-insoluble solvent such as alcohol, solidified by coagulation or steam stripping, and then dried. Obtainable. As the peroxide used here, all known organic peroxides are used.

The amount of the ethylene-α-olefin copolymer used in the present invention is 1 to 50% by weight, preferably 3 to 4% by weight.
0% weight. If the amount of the ethylene-α-olefin copolymer is less than 1% by weight, no impact resistance improvement effect will be observed, and if it exceeds 50% by weight, moldability and heat resistance, which is the objective of the present invention, will decrease. Therefore, it is not desirable.

The maleimide copolymer used in the present invention is a copolymer obtained by polymerizing a monomer mixture containing a maleimide compound and an aromatic vinyl compound as main components in the presence or absence of a rubbery polymer. It is.

Examples of rubbery polymers include polybutadiene (BR
), diene rubbers such as styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), olefin rubbers such as ethylene-propylene rubber (EPR), ethylene-propylene-nonconjugated diene rubber (EPDM), and acrylic rubber. It will be done.

There is no particular restriction on the content of the rubbery polymer.

Examples of maleimide compounds used in the present invention include maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, N-o-chlorophenylmaleimide, N-cyclohexylmaleimide, etc., and particularly preferred. is N-phenylmaleimide,
These include N-o-chlorophenylmaleimide and N-cyclohexylmaleimide, and these may be used alone or in combination of two or more.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, methylstyrene, motsupromustyrene, dibromostyrene, etc., and one or more of them may be used. Preferred aromatic vinyl compounds are styrene and α-methylstyrene.

Other copolymerizable monomers include, for example, vinyl cyanide jtl such as acriconyl 1-lyl and methacrylonitrile, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, maleic anhydride, itaconic anhydride, etc. Examples include unsaturated acid anhydrides. These may be used alone or in combination of two or more.

Specific combinations of these are illustrated below.

■Styrene ■Styrene-acrylonitrile ■Styrene-methyl methacrylate ■Styrene-acrylonitrile-methyl methacrylate By replacing some or all of these styrenes with α-methylstyrene, a maleimide copolymer with high heat resistance can be made. .

Furthermore, flame retardancy can be imparted by replacing part or all of styrene with halogenated styrene.

Here, the weight ratio of the monomer mixture mainly consisting of the maleimide compound and the aromatic vinyl compound is preferably 70/3.
0-1O/90, more preferably 60/40-20/
The range is 80.

In the present invention, a preferred polymerization method for preparing a maleimide copolymer resin is to continuously add a rubbery polymer and monomers mainly consisting of a maleimide compound and an aromatic vinyl compound to the polymerization system as a homogeneous solution. Supply and polymerize. Appropriate polymerization methods include block polymerization, solution polymerization, and the like, and the polymerization catalyst and polymerization temperature can be selected from common vinyl monomer radical polymerization methods.

The content of the maleimide copolymer resin (C) in the composition of the present invention is preferably 5 to 80% by weight. More preferably, the repellency is 10 to 70%. If it is less than 5% by weight, heat resistance is low. If it exceeds 80% by weight, moldability and impact resistance will be low.

Methods for blending each component of the thermoplastic resin composition of the present invention include: (1) A method in which each component is dissolved in a Ja-containing solvent, swollen, and mixed.

■ A method in which each component is mixed using a mixer, etc., then melted and mixed using an extruder, and then pelletized.

(2) A method in which the powder mixture recovered using a non-solvent in the method (2) is melt-mixed using an extruder and then pelletized.

There are methods such as using the pellets or powders obtained by methods (1) and (2) to (3) alone or by mixing them, or adding and mixing each component and then using an injection molding machine to obtain a molded product. Further, it is also possible to use known mixing equipment such as a Banbury or a kneader in each of the above methods.

Furthermore, thermoplastic resins such as styrene resins, polyesters, acrylic resins, and other polymers may be added to the composition of the present invention.

The thermoplastic resin composition of the present invention can be processed into various molded products by injection molding, sheet extrusion, vacuum molding, irregular molding, foam molding, and the like.

When using the thermoplastic resin composition of the present invention, commonly used antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents, blowing agents, glass fibers, etc. can be added.

e. Examples The present invention will now be explained in more detail with reference to Examples.
All of these are illustrative and do not limit the content of the present invention. In addition, parts and % in each side below indicate parts by weight and % by weight, respectively.

Production example (1) Production method of ethylene-α-olefin copolymer Japan synthetic rubber 0 views JSREPO2P (Mooney viscosity ML+
*a++o. Ethylene rubber with a value of 24) 100
1 part of maleic anhydride and 0.3 parts of organic peroxide (Kayahexa AD) were premixed in advance using a 55 Dragon φ extruder (single screw, full flight type screw). The heat treatment was carried out at 200° C. and a screw rotation speed of 30 rpm (residence time: 4 minutes).

The obtained reaction product was extracted with acetone (boiling point x 2 hours), the polymer was formed into a film, and the stars of bound maleic anhydride were determined by infrared spectroscopy. The modification rate of maleic anhydride was 0.5 parts by weight based on 100 parts by weight of ethylene propylene rubber.

Polymers B-2 to B-6 Polymers B-2 to B-6 are obtained by changing the amount of maleic anhydride under the manufacturing conditions of Polymer B-1, and B-6 is the same as B-6.
This is a product in which the maleic anhydride in No. 1 is replaced with a styrene-maleic anhydride copolymer.

Table 1 (2) Maleimide-based copolymer resin Two polymerization reactors equipped with ribbon blades having an internal content of 301 were connected together, and the polymerization was carried out under the following conditions.

Table 2 20 parts by weight of BR was mixed with 45 parts by weight of styrene and 40 parts by weight of toluene to make a homogeneous solution at 50°C, and 20 parts by weight of N-phenylmaleimide was mixed with 15 parts by weight of acrylonitrile and 40 parts by weight of toluene at 50°C to form a homogeneous solution. As a solution, L-dodecyl mercaptan is 0.1 part by weight and toluene 10ff
1 part to make a 1% solution, and benzoyl peroxide is 0.
．． A 4% solution was prepared with 4 parts by weight and 10 parts by weight of toluene, and each was supplied to the first group polymerization vessel.

The polymerization reaction was carried out continuously for 24 hours, and the last portion was subjected to evaluation.

The polymerization mixture was desolvented by steam distillation, and after pulverization and drying,
40w with the addition of 0.5 parts by weight of Irganox 1076
The polymer was collected as pellets through an extruder (240°C). Table 2 shows the composition and polymerization conversion rate of the obtained resin.
Shown below.

Polymers C-2 to C-5 For C-2 to C-4, the type of base rubber was changed to EIIDH in the same manner as in C-1 above.

C-5 was run in a similar manner and is a rubber-free system. The composition and polymerization conversion rate of the obtained resin are shown in Table-
Shown in 2.

Examples and Comparative Examples Various polymers were mixed according to the composition ratios in Table 3, extruded into pellets using a twin-screw kneading extruder at a temperature of 260 to 300°C, thoroughly dried, and then made using an injection molding machine. A test piece was prepared and its impact resistance and heat resistance were measured. Furthermore, the moldability of the pelletized thermoplastic resin composition was evaluated.

Evaluation of each characteristic was performed according to the following method.

■Heat resistance (Vikaft softening point) Measured according to STM D 1525 using a test piece (thickness 5 m).

■Impact resistance Measured according to ASTM port 256 with thickness + A# notch.

■Moldability JIS K 72 using Takara Kogyo melt indexer
10, melt flow index (MFR)) (g/10a+) at cylinder temperature 280℃ and load 10kg
in) was measured.

(2) A chemical resistance test piece (thickness 178'') is strained to 1%, kerosene is applied to it, and the presence or absence of cracks is measured after 24 hours.

○ Unbreakable △ Cracks occur × Breaks Hereinafter, a comparative example will be explained in comparison with an example.

Comparative Example 1.2 Comparative Example 1 is a composition in which the amount of polyamide is less than the range of the present invention, Comparative Example 2 is a composition in which the amount of polyamide exceeds the range of the present invention, and the former has poor processability and chemical resistance. On the other hand, the latter is not preferred because of its poor impact resistance.

Comparative Example 3.4 Comparative Example 3 has a composition in which the amount of the modified ethylene-propylene copolymer is below the range of the present invention, while Comparative Example 4 is a composition beyond the range of the present invention; The latter is not preferable because it has poor processability and heat resistance.

Comparative Example 5.6 Comparative Example 5 is a composition in which the modification rate of the ethylene-propylene copolymer is below the range of the present invention, while Comparative Example 6 is a composition exceeding the range of the present invention, and both the former and the latter have poor impact resistance. inferior in sex.
Comparative Example 7.8 Comparative Example 7 has a composition in which the amount of maleimide copolymer resin is less than the range of the present invention, while Comparative Example 8 is a composition that exceeds the range of the present invention, the former having heat resistance and the latter having poor processability. Poor impact resistance.

f. Effects of the Invention Currently, in the molding industry that uses thermoplastic resins, molded products tend to become more complex and larger due to the diversification of molded product applications. In order to obtain such a molded product, it is required to have better heat resistance, moldability, and impact resistance than conventional molded products. However, conventional polyamide resins have not been sufficient to meet these requirements.

The composition of the present invention is highly balanced in heat resistance, moldability, and impact strength.

Therefore, the composition of the present invention is a molding material that improves the drawbacks of conventional polyamide resins and satisfies the demands of the molding industry, and has great industrial value.

Claims (4)

[Claims] (1) (a) Polyamide resin 10 to 90% by weight (b) Ethylene-α-olefin copolymer with a modification rate of 0.03 to 5% by weight 1 to 50% by weight (c) Maleimide copolymer resin 5 to 50% by weight 80% by weight of a thermoplastic resin composition. (2) Component (b) is an ethylene-α-olefin copolymer modified with at least one compound selected from unsaturated acids and unsaturated dicarboxylic anhydrides. Thermoplastic resin composition according to item 1). (3) The thermoplastic according to claim (1), wherein the ethylene-α-olefin copolymer of component (b) is modified with an α,β-unsaturated carboxylic acid anhydride copolymer. Resin composition. (4) The maleimide copolymer resin is obtained by polymerizing a monomer mainly composed of a maleimide compound and an aromatic vinyl compound in the presence or absence of a rubbery polymer. The thermoplastic resin composition described in (1).