JPS62223259A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent resistance to heat and impact, by blending a polycarbonate resin with an arom. vinyl/conjugated diene block copolymer and a specified maleimide copolymer. CONSTITUTION:An arom. vinyl compd. (i) is copolymerized with a conjugated diene compd. (ii) to obtain an arom. vinyl/conjugated diene block copolymer (a) having a component (i) content of 25-90% (by weight; the same applies hereinbelow), represented by formulas I and/or II and/or III [wherein A is a polymer block of the component (i) and contains at least 50% of the whole of the component (i) and the sum of the component (i) in the block A is 50-100% of the whole of the component (i); B is a polymer block of the component (b) or composed of not more than 50% copolymerized component (i); m is a number of not smaller than 1; X is a residue of a coupling agent; n is a number of 2-6]. Separately, a maleimide compd. is copolymerized with the component (i) and optionally, other copolymerizable monomer in the presence of optionally, a rubbery copolymer to obtain a maleimide copolymer (b). 3-40% component (a) is blended with 5-85% component (b) and 5-90% polycarbonate resin (c).

Description

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

b. Prior Art Polycarbonate resin is widely known as an engineering plastic having excellent impact resistance and heat resistance.

However, in terms of impact resistance, the notch sensitivity is sensitive,
If there is a cut or scratch on the molded product, the stress will cause the joint to simply break.

As a method to improve this, a resin with high impact resistance and improved notch sharpness has been developed and commercially available by blending a polycarbonate resin with a rubber-reinforced styrene resin, such as ABS resin. However, this resin has low heat resistance and may not be sufficient as a material for parts of automobiles and 2004 equipment.

Problems to be Solved by the C0 Invention As mentioned above, it has been difficult to produce engineering plastics with excellent heat resistance and impact resistance using conventional methods.

Therefore, as a result of intensive studies, the present inventors found that a resin composition with excellent heat resistance and impact resistance was created by mixing a maleimide copolymer with a polycarbonate resin and an aromatic vinyl-conjugated diene block copolymer. The present invention has been achieved based on the discovery that the present invention can be obtained.

A means for solving the d0 problem, that is, the present invention, consists of: Ta) polycarbonate resin 5 to 90% by weight (bl aromatic vinyl-conjugated diene block copolymer 3 to 40% by weight) and (c) rubbery polymer. Provided is a thermoplastic resin composition comprising 5 to 85% by weight of a maleimide 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 the compound. It is something to do.

As the polycarbonate resin (a) used in the present invention,
Examples include aromatic polycarbonate, aliphatic polycarbonate, and aliphatic-aromatic polycarbonate. For example, a polymer consisting of bisphenols such as 2,2-bis(4-oxyphenyl)alkane, bis(4-oxyphenyl)ether, bis(4-oxyphenyl)sulfone sulfide or sulfoxide,
Alternatively, it may be a copolymer, and may be a polymer using bisphenols substituted with halogen depending on the purpose. Regarding the type and manufacturing method of the polycarbonate resin (a), all those described in detail in "Polycarbonate Resin" published by Nikkan Kogyo Shimbun (September 30, 1964) can be used.

The content of polycarbonate resin (a) in the resin composition of the present invention is 5 to 90% by weight, preferably 10 to 80% by weight.
Weight%. If it is less than 5% by weight, the heat resistance of the resulting resin composition will be low, and if it is more than 90% by weight, the impact resistance (notched impact) will be low.

Aromatic vinyl compound-conjugated diene block copolymer (b) used in the present invention (hereinafter referred to as block copolymer (b)
) is a block copolymer of an aromatic vinyl compound and a conjugated diene, and the amount used is 3 to 40% of the total composition.
% by weight, preferably 5 to 30% by weight. 40
If it exceeds the weight limit, the heat resistance that is the objective of the present invention will decrease,
Further, if it is less than 3% by weight, the impact resistance decreases, which is not preferable.

Aromatic vinyl compounds constituting block copolymer (bl) include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, dibromustyrene, α-methylstyrene, α-ethylstyrene, methyl-α- Examples include methylstyrene, dimethylstyrene, vinylnaphthalene, etc. Among these, styrene, p-methylstyrene, and α-methylstyrene are preferred, and styrene, α-methylstyrene, or a mixture thereof is more preferred.

On the other hand, examples of conjugated diene compounds include butadiene,
Examples include isoprene and piperylene.

Among these, preferred are butadiene and isoprene.

The preferable block copolymer (b) used in the present invention includes a wholly aromatic vinyl compound content represented by the following general formula % A-B-A and/or (A-B)I, X. is 25 to 90% by weight,
Preferably it is a block copolymer of 28 to 90% by weight.

A particularly preferred block copolymer (b) has the following structure, and when this block copolymer is used, even more excellent impact resistance can be expected.

That is, it is a block copolymer having an aromatic vinyl compound content of 25 to 95% by weight, the copolymer is represented by the general formula (%), and the aromatic vinyl compound is 1% by weight per monomer unit. The content of aromatic vinyl compounds constituting a chain of 1 or 4 or less is 1 to 4 of the total aromatic vinyl compounds.
The amount is 25% by weight, preferably 2 to 20% by weight, and more preferably 5 to 20% by weight.

Further, the preferable number of the tapered blocks is 2 to 7.

The block copolymer (b) used in the present invention can be produced, for example, by the following method.

An aromatic vinyl compound is first polymerized by adding ether or a tertiary amine to a hydrocarbon solvent and using an organic lithium compound as a polymerization initiator, and after the polymerization reaction has substantially completed, a conjugated diene compound or an aromatic vinyl compound is added. A mixture of a vinyl compound and a conjugated diene compound is preferably added in 2 to 10 portions for polymerization, and if necessary, then an amount of conjugated diene equivalent to the amount added in one portion is added for polymerization.

Furthermore, the block copolymer of general formula ABA is obtained by adding an aromatic vinyl compound and polymerizing it.

Further, a block copolymer having a structure represented by the general formula (A-B) or X can be obtained by performing a coupling reaction using a conventionally known coupling agent such as tetrachlorosilane.

The mixture of conjugated dienes of the above aromatic vinyl compound is
In the step of polymerizing by dividing the addition into 10 times, it is preferable that the amount of monomer added each time is about the same, and the method of adding the monomer is a method of adding a monomer mixture, or a method of adding a conjugated diene. The aromatic vinyl compounds may be added separately and simultaneously.

The preferred chain distribution amount of the aromatic vinyl compound in the block copolymer (bl) is 0.005 parts by weight of ether or tertiary amine in a hydrocarbon solvent per 100 parts by weight of monomer.
It is obtained by adding ~5 parts by weight, preferably 0.005 to 0.5 parts by weight.

The weight average molecular weight of the block copolymer (b) used in the present invention is from 10,000 to soo,ooo, preferably from so,ooo to 500,000, and if it is smaller than this range, improvement in impact resistance is expected. If it is larger than this range, the compatibility with components (a) and (c) will deteriorate, which is not preferable.

As the hydrocarbon solvent used for producing the block copolymer (b), cyclopentadiene, cyclohexane, benzene, xylene, and mixtures of these with pentahexane, heptane, butane, etc. are used.

Further, as the organic lithium compound, n-butyllithium, 5ec-butyllithium, tert-butyllithium, n-hexyllithium, 1So-hexyllithium, phenyllithium, naphthyllithium, etc. are used.

The maleimide copolymer (c) 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 a polymer.

As the rubbery polymer, for example, polybutadiene (BR)
, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and other diene rubbers,
Examples include olefin rubbers such as ethylene-propylene rubber (EPR) and ethylene-propylene-nonconjugated diene rubber (HDPM), and acrylic rubbers such as polybutyl acrylate.

There is no particular restriction on the content of the rubbery polymer in the copolymer (c).

Examples of the maleimide compound used in the present invention include maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, N-〇-chlorophenylmaleimide, N-cyclohexylmaleimide, etc., but preferably N- Phenylmaleimide, N
These include 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, monobromustyrene, dibromostyrene, and the like, which may be used alone or in combination of two or more. A preferred aromatic vinyl compound is styrene.

The maleimide copolymer (c) of the present invention has the above maleimide and aromatic vinyl compounds as main components, but may contain other copolymerizable components.

Other copolymerizable monomers include vinyl cyanide monomers such as acrylonitrile and methacrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, and unsaturated monomers such as maleic anhydride and itaconic anhydride. Examples include acid anhydrides.

These may be used alone or in combination of two or more.

Specific combinations of monomers that can be copolymerized with these maleimide monomers are illustrated below.

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

Moreover, flame retardancy can also be imparted by substituting part or all of styrene with halogenated styrene.

In the present invention, a preferred polymerization method for obtaining the maleimide copolymer (c) is to polymerize a rubbery polymer, a monomer mixture mainly consisting of a maleimide compound and an aromatic vinyl compound as a homogeneous solution. Polymerize by continuously supplying to Appropriate polymerization methods include bulk polymerization, solution polymerization, and the like, and the polymerization solvent and polymerization temperature can be the same as those used in general radical polymerization of vinyl monomers.

Maleimide copolymer (c) in the resin composition of the present invention
The content of is 5 to 85% by weight, preferably 10 to 7% by weight.
Weight with 0 heavy view%. If it is less than 5% by weight, the heat resistance is low, and 85
If it exceeds % by weight, the impact resistance will be low, which is not preferable.

Methods for preparing the thermoplastic resin composition of the present invention include: (1) A method in which each component is dissolved in an organic 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, in the method (2), the powder mixture recovered using a non-solvent is melt-mixed using an extruder and then pelletized.

(2) The pellets or powder obtained by the methods (2) to (2) may be used alone or in combination, or each component may be added and mixed, followed by a method of obtaining a molded product using an injection molding machine.

Further, in each of the above methods, it is also possible to use known mixing equipment such as a Banbury or a kneader.

Furthermore, other thermoplastic resins, styrene resins, polyphenylene ethers, polyamides, polyesters, acrylic resins, or other polymers are added and mixed to the resin composition of the present invention obtained by the above method, and this is mixed in an extruder. The composition may be obtained by melt mixing.

The thermoplastic resin composition of the present invention can be used as 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.

The thermoplastic resin composition of the present invention can be suitably used for automobile parts, electrical appliances, household goods, various industrial goods, and the like.

e. Examples Next, the present invention will be explained in more detail with reference to Production Examples and Examples, but these are merely illustrative and do not limit the content of the present invention. Note that parts and % on each side below indicate parts by weight and % by weight, respectively.

Production Example +11 Aromatic vinyl compound-conjugated diniblock copolymer washed and dried In an autoclave equipped with a stirrer and a jacket, 4500 g of cyclohexane and tetrahydrofuran Ig were charged under a nitrogen atmosphere, and the internal temperature was then raised to 70°C.

Next, a hexane solution containing 0.5 g of n-butyllithium was added, and then 130 g of styrene was added and polymerized for 60 minutes.

The polymerization conversion rate of styrene was 100%. Next, a mixture consisting of 15 g of styrene and 115 g of butadiene was added and polymerized for 60 minutes. The polymerization conversion rate of styrene and butadiene was 100%. This operation was further repeated twice. Next, 115g of butadiene was added to increase the polymerization conversion rate to 10.
It was polymerized to 0%. After that, 13 more styrene
0 g was added and polymerized for 60 minutes to obtain block copolymer B-1 shown in Table 1.

B-2, B-3 Next, using samples in which the amount of styrene of block copolymer B-1 was changed, Table 1 was obtained by the same method as B-1 above.
B-2 and B-3 shown in were obtained.

Table 1 Note: The method for measuring styrene chains was as follows: Professor Naka Naka of Tokyo University of Agriculture and Technology (2) Maleimide Copolymer A maleimide copolymer having the following composition was prepared.

(Table 2) Examples 1 to 16, Comparative Examples 1 to 6 Various polymers were mixed according to the composition ratios shown in Table 3, and the mixture was extruded into pellets at a temperature of 260 to 300°C using a twin-screw kneader. After that, it was sufficiently dried and a test piece was molded at 240 to 280°C using an injection molding machine.

Table 3 shows the results of evaluating the characteristics using these materials using the methods described below.

(1) Heat Resistance Measured at 264 psi using a 2" thick test piece according to ASTM D648.

(2) Impact resistance Measured using a notched test piece having a thickness of A# according to ASTM D256.

Hereinafter, the resin compositions obtained in Examples and Comparative Examples will be explained while comparing the properties shown in Table 3.

The resin compositions of Examples 1 to 6 and Comparative Example 1.2 have varying amounts of polycarbonate, and Comparative Example 1.2
indicates a case where the amount of polycarbonate resin is outside the range of the present invention, and in Comparative Example 1, the amount of polycarbonate resin is greater than the range of the present invention, so the impact resistance is low. Furthermore, Comparative Example 2 has low heat resistance because the amount of polycarbonate resin is small.

The resin compositions of Example 7.8 and Comparative Example 3.4 were obtained by varying the amount of block copolymer, respectively. In Comparative Example 3, the content is higher than the range of the present invention, and the heat resistance is low. Moreover, Comparative Example 4 is a case where the amount is less than the range of the present invention, and the impact resistance is low.

The resin compositions of Examples 9 and 10 show cases in which the types of block copolymers are different.

The resin compositions of Examples 11 to 16 have different types of maleimide copolymers.

In the resin compositions of Comparative Example 5.6, the amount of maleimide copolymer was outside the range of the present invention. Comparative Example 5 is a case where the maleimide copolymer is not included, and the heat resistance is low. Comparative Example 6 is a case where the amount of maleimide copolymer is larger than the range of the present invention, and the impact resistance is low.

Effects of the f0 invention Currently, automobile and light electrical appliance manufacturers that use thermoplastic resins tend to make molded products more complex and larger due to diversification of applications.

Molded products for such uses are required to have even better heat resistance and impact resistance than conventional products.

However, conventional polycarbonate/ABS compositions have not been sufficient to meet these demands.

Since the resin composition of the present invention has a highly balanced heat resistance and impact resistance, it
It is a material that improves the drawbacks of the composition of S and satisfies the requirements of the above manufacturers, and has great industrial value.

Claims (2)

[Claims] (1) (a) Polycarbonate resin 5-90% by weight (b
) Aromatic vinyl-conjugated diene block copolymer 3 to 4
0% by weight and (c) maleimide-based copolymer 5 obtained by polymerizing a monomer mixture containing a maleimide-based compound and an aromatic vinyl compound as main components in the presence or absence of a rubbery polymer.
A thermoplastic resin composition consisting of 85% by weight. (2) The aromatic vinyl-conjugated diene block copolymer has the following general formula (A-B)_n and/or A-B-A and/or (A-B)_nX, where A is an aromatic vinyl A polymer block of a compound containing 50% by weight or more of a wholly aromatic vinyl compound, B is a conjugated diene or a polymer block in which 50% by weight or less of an aromatic vinyl compound is copolymerized in B, and A The total content of is 50 to 100% by weight of the wholly aromatic vinyl compound, m is 1
the above integer, X is a residue of a coupling agent, and n is an integer of 2 to 6. The content of fully aromatic vinyl compounds is 25 to 90
% by weight of a block copolymer. Thermoplastic resin composition according to claim (1).