JPS59152946A - Production of thermoplastic resin composition - Google Patents

Abstract

PURPOSE:The cyclization of a maleimide copolymer by dehydration and the phase transition of a rubber-modified graft copolymer are simultaneously effected to produce a composition with high impact resistance and heat resistance through a simplified process. CONSTITUTION:A modified vinyl copolymer that is obtained by allowing a vinyl copolymer containing 5-50mol% of maleic anhydride to react with ammonia or a primary amine in an organic solvent, and a graft copolymer that is obtained by suspension polymerization 40-95wt% of a monomer mixture consisting of an aromatic vinyl monomer and other vinyl monomers copolymerizable therewith in the presence of 5-60wt% of a rubber polymer substantially free from gel are mixed so that the content of the rubber polymer becomes 5-40wt% based on both components, then they are melt mixed under shear stress at 150-350 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently producing a thermoplastic resin having excellent heat resistance and impact resistance.

Maleimide copolymers made by copolymerizing maleimide monomers such as N-phenylmaleimide and vinyl monomers such as styrene have a high heat distortion temperature and excellent thermal stability. However, there are disadvantages in that the method for synthesizing the maleimide monomer used as a starting material is not simple and it is difficult to obtain it at a low cost. Therefore, as a method for obtaining a maleimide copolymer without using a maleimide monomer as a starting material, a copolymer of maleino acid anhydride and another vinyl monomer is reacted with ammonia or a primary amine. , and a method of converting the maleic anhydride units into maleimide units by further dehydration and imidization reaction (U.S. Patent No. 3.
998.907 specification and JP-A-57-55901
Furthermore, a composition with excellent heat resistance and impact resistance made by mixing the thus obtained maleimide polymer and a rubber-modified graft copolymer (Japanese Patent Application Laid-open No. 1983-1997) is known. -125242) is also being proposed. However, the impact resistance of this composition is still insufficient, and the manufacturing process for the maleimide copolymer is complicated, and the rubber-modified graft copolymer must be prepared in another independent process. This includes undesirable problems in terms of productivity. In addition, various methods are generally known for producing rubber-modified graft copolymers, such as emulsion polymerization, bulk polymerization, and suspension polymerization.
Suspension polymerization is considered to be the most ideal method in terms of easy recovery of the polymer and low impurity content, and suspension polymerization is also considered the most ideal method in terms of ease of polymer recovery and low impurity content. It is desirable to use a rubber-modified graft copolymer obtained by polymerization method 1 from the viewpoint of process and productivity. However, in rubber-modified graft copolymers obtained by suspension polymerization, the rubber-like polymer forms a continuous network film, in which the resin phase consisting of vinyl monomers is dispersed in islands. Therefore, it has the disadvantage that impact resistance is inferior to rubber-modified graft copolymers in which the rubbery polymer phase is dispersed in island shapes obtained by other polymerization methods. Therefore, the rubber-modified graft copolymer obtained by suspension polymerization is further melt-mixed to cause a phase transition, and the rubber-like polymer is transformed into an island shape (
This requires an extra step of dispersion.

Therefore, in view of the above-mentioned actual situation, the present inventors have developed a composition with an excellent balance of heat resistance and impact resistance, which is made of a blend of a so-called maleimide copolymer and a rubber-modified graft copolymer, and is highly productive and efficient. As a result of intensive studies aimed at manufacturing the copolymer using a simple process, we found that a simple process was achieved by simultaneously carrying out the dehydration imidization ring-closing reaction of the maleimide copolymer and the phase transition of the rubber-modified graft copolymer obtained by the suspension polymerization method. The inventors have discovered that a thermoplastic resin composition with extremely excellent impact resistance and good heat resistance can be obtained by a process using a method of oxidation, and the present invention has been achieved.

That is, the present invention is +A) a modified vinyl copolymer obtained by reacting a vinyl copolymer containing 5 to 503 mole % of maleic anhydride with ammonia or a primary amine in an organic solvent; An aromatic vinyl monomer and a graft copolymer obtained by polymerizing under suspension polymerization conditions in the presence of 5 to 60% by weight of a gel-free rubbery polymer are added to the ratio of the rubbery polymer described above. A thermoplastic resin composition characterized in that it is blended in an amount of 5 to 40% by weight with respect to the total amount of the compound, and then melt-mixed under shear stress at a temperature of 150. to 350°C. The present invention provides a method for manufacturing.

The above method of the present invention is characterized in that (5) the dehydration imidization closed step of the maleimide copolymer and (B) the phase transition step of the graft copolymer are carried out simultaneously, which makes it more effective than conventional methods. A composition with significantly improved impact resistance can be obtained, and this effect is much greater than that of a composition prepared by melt-mixing a dehydrated imide-ring-closed maleimide-based co-electronic 4-copolymer and a graft copolymer. , perhaps some kind of reaction occurs between the rubbery polymer particles that are uniformly dispersed in the composition by melt mixing and the maleimide copolymer that is undergoing ring closure.
This is expected to be due to increased binding or affinity between them.

The maleic anhydride-containing vinyl copolymer used as the starting material for the (A+ modified vinyl copolymer) of the present invention is obtained by copolymerizing maleic anhydride and another vinyl monomer copolymerizable with maleic anhydride. It is a copolymer with the following formula [l
) containing maleic anhydride units.

~CH-CH~ 1 Here, other vinyl monomers copolymerizable with maleic anhydride include styrene, α-methylstyrene,
Aromatic hinyl monomers such as p-methylstyrene and p-1-butylstyrene, (meth)acrylic acid ester Ilimers such as methyl methacrylate and methyl acrylate, and acrylonitrile and I-lyl methacrylate. Examples include noanated hinyl monomers, and two or more of these can be used in combination. The maleic anhydride-containing vinyl copolymer is produced by a known polymerization method such as ordinary solution polymerization or bulk polymerization, and the copolymerized amount of maleic anhydride is 5 to 50 mol%, particularly 10 to 45 mol%. The range of mole % is not limited. If the copolymerized amount of maleino acid anhydride is less than 5 mol%, the heat distortion temperature of the resulting maleimide copolymer will be insufficient, and if it exceeds 50 mol%, the heat distortion temperature of the maleimide copolymer will be high. This is not preferable because it becomes difficult to melt and mold it.

The Al-modified vinyl copolymer of the present invention can be obtained by reacting the maleic anhydride-containing vinyl copolymer with ammonia or a primary amine in an organic solvent. The solvent is not particularly limited as long as it can uniformly disperse the maleino acid anhydride-containing vinyl copolymer and does not interfere with the reaction with ammonia or primary amines, such as acetone, methyl ethyl ketone, Diethyl ketono.

Ketons such as methylinobutyl chloride, amides such as dimethylformamide, etc. can be selected. Further, the reaction temperature and reaction apparatus are not particularly limited, and any device that can maintain uniform temperature and stir can be used.

The ammonia or primary amine used to obtain the modified vinyl copolymer (A) of the present invention is a compound represented by the following formula C11), where A is hydrogen and has 1 carbon atom.
~20 substituted or unsubstituted hydrocarbons.

These compounds include ammonia, methylamine, isopropylamine, t-butylamine, aniline, p-
Chloraniline, p-toluylene, p-methoxyaniline, 3,5-dime7-monylanilino, p-aminoethylbenzene. Examples include 4-amylphenyl, 2-aminodiphenylmethane, 1-aminonaphthalene, and 2-aminoathracene, which contain more than 10 equivalents of maleic anhydride contained in the above-mentioned copolymer as a starting material. , preferably 1.
0.02 equivalent or more. Here, the reaction between the copolymer and ammonia or primary amine is thought to proceed as shown in the following formula (1). Also, the reaction of formula 1 is (B)
During melt mixing with the graft copolymer (this is a dehydration imidization ring-closing reaction that occurs simultaneously with the phase transition of the rubbery polymer).

(1) I For modified vinyl copolymer ~CH-CH~ ~CH-CH~+1
11 1 A + AI A After the reaction of the maleimide copolymer 8 set (1), it is necessary to remove the organic solvent. Examples include a method of removing the organic solvent and a method of removing the organic solvent by heating.

Here, removing the organic solvent means increasing the concentration of the resulting copolymer to 90% or more. In addition, in the latter method, the copolymer (formula ['l
150℃ or less, especially 120℃ because the reaction of V) proceeds.
It is preferable to remove the solvent in as short a time as possible at the following temperatures:

What is the essentially gel-free rubbery polymer that is a component of the graft copolymer of the present invention?

A rubber-like polymer having a glass transition temperature of 110° C. or lower, such as polybutadiene rubber.

Acrylonitrile-butadiene copolymer rubber (NBR,
), diene rubbers such as styrene-butadiene copolymer rubber (SBR), acrylic rubbers such as polyphthyl acrylate and polypropyl acrylate, and ethylene-propylene-diene rubber (EPDM). However, B) a monomer mixture consisting of a rubber-like polymer in () in the graft copolymer, an aromatic vinyl monomer, and at least one other vinyl monomer copolymerizable with it. The proportion is important, 5-60% by weight of rubbery polymer
In particular, in the presence of 10 to 55% by weight of the monomer mixture 4
It is necessary to polymerize 0 to 95% by weight, especially 45 to 90% by weight. If the proportion of the rubbery polymer is less than 5% by weight, the resulting resin will not have sufficient impact resistance;
Exceeding this percentage by weight is undesirable because mechanical strength decreases.

Aromatic hydrogen which is a constituent component of +B1 graft copolymer
Styrene, α-methylstyrene, p-based monomers include
- Styrene intermediates such as methylstyrene, pt-butylstyrene, and chlorostyrene 7, and substituted monomers thereof; among these, styrene and α-methylstyrene are particularly preferred. Other vinyl monomers that can be copolymerized with this include noaninated vinyl monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, methyl acrylate, and methyl methacrylate. Examples include (meth)acrylic acid ester monomers represented by, among others, acrylonitrile and methyl methacrylate are particularly preferably used.

In addition, (B) the method of polymerizing the graft copolymer is a suspension polymerization method in which the rubber-like polymer is polymerized in a continuous phase while suspended in a solvent in the case of an aqueous polymer.

In addition, when suspension polymerization is carried out in a solvent, it is produced (Bl
Graph 1.15 Any solvent may be used as long as the polymer is wood-insoluble, and two or more solvents may be used in combination. Any suspension stabilizer may be used as long as it can stably undergo suspension polymerization.

There are no particular restrictions.

Next, in the present invention, m) the modified vinyl copolymer obtained in this way and (B) the graft copolymer are blended,
By melt-kneading under shear stress at a temperature of 150 to 350°C, (2) dehydrated imide ring closure of the modified vinyl copolymer and (B) a rubber forming a continuous phase of the GRA-11-ft copolymer. Dispersion of the polymer, i.e., phase transition, is carried out at the same time.

Here, the mixing ratio of (A) and (Bl) is based on the total amount of both.
A proportion of the rubbery polymer of 5 to 40% by weight is appropriate; if it is less than 5% by weight, the impact resistance of the resulting composition will be poor;
If it is more than 40% by weight, mechanical properties such as tensile strength will be poor, which is not preferable. Furthermore, if the melt crosstalk temperature is less than 150° C., the imide ring closure of the modified vinyl copolymer (A) will not proceed sufficiently, resulting in a resin lacking in thermal stability.

If the temperature exceeds 350°C, thermal decomposition of the resin will occur, which is not preferable.

During melt-kneading, it is necessary to uniformly disperse the rubbery polymer of the graft copolymer (B).
As long as the conditions are such that the shear rate is C or higher, there is no restriction on the equipment to be used, and a conventional extruder with Ben 1, Brabender, etc. can be used.

The thermoplastic resin composition obtained in the present invention, that is, the rubber-modified maleimide resin composition, has low miscibility with rubber-modified resins known as ABS12-resin, AES resin, MBS resin, etc., and is highly compatible with these resins. It can also be used as a modifier that imparts heat resistance.

If desired, vinyl copolymers such as styrene-acrylonide 11' copolymer, α-methylstyrene-acrylonide 1-lyl copolymer, polyamide polymers such as nylon, and polyethylene terephthalate copolymers are also available. It is also possible to mix it with other polymers such as polyester polymers such as Tare-1 and polybutylene terephthalate. It is also possible to add stabilizers, lubricants, fibrous reinforcing agents, colorants, flame retardants, conductive materials, etc. during mixing.

The effects of the present invention will be further explained below with reference to Examples and Comparative Examples. In the Examples and Comparative Examples, the heat distortion temperature was measured in accordance with ASTM D-648-56° Izoll, and the impact value was measured in accordance with ASTM D-256-56 Method A. In addition, the number of parts is 1% by weight, which means % by weight.

Reference Example 1 [Production of copolymer] 60 parts of styrene, 742 parts of methyl ethyl keto, and 06 parts of benzoyl peroxide (initiator) were charged into a polymerization tank equipped with a reflux conotensor, a stirrer, and a dropping roller 1, and thoroughly dissolved. Separately, 742 parts of methyl ethyl keto containing 40% maleic anhydride was prepared and charged into dropping funnel 1.

Next, while maintaining the temperature inside the polymerization tank at 75°C, and stirring, from dropping row 1 to maleic anhydride-methylethyl 1-
The solution was added at a rate of 333 parts/hr for 3 hours, and held for 1 hour after the addition was completed. After that, the temperature inside the polymerization tank was cooled to 30°C, and a colorless and transparent polymer solution was obtained.The polymerization rate was 94%, and only styrene remained.Next, 162 parts of reaction system hair 11 was added and kept at 30℃ for 3
Stirring was continued for 0 minutes. Next, the reaction solution was added to a large amount of toluene, and after removing methyl ethyl ketone and unreacted styrene, it was dried to obtain a light brown modified vinyl copolymer.

The copolymer formula obtained in Reference Example 1 was converted into 2 using a vented extruder.
The mixture was kneaded at 50°C and subjected to a dehydrated imide ring-closing reaction to obtain a maleimide copolymer (A').

Reference Example 3 [Production of Copolymer ■-1) to Graph 1] 30 parts of cotton-like polybutadiene rubber (Diene NF-35A' manufactured by Asahi Kasei Corporation) was dissolved in 50 parts of styrene and 25 parts of acrylonitrile in an autoclave. , to this monomer mixed solution
0.3 part of rt-dodecylmercaptan and 0.4 part of azohisisobutyronitrile were dissolved and mixed uniformly.

Next, 0.1 part of methyl methacrylate/acrylamide-20/80 (weight ratio) copolymer and 0.1 part of monosodium phosphate were dissolved in 200 parts of pure water, and after adding t-aqueous solution, the gas phase Replace with nitrogen gas and stir vigorously for 7 minutes.
The temperature was raised to 0°C.

The graft polymerization was completed by polymerizing at 70° C. for 4 hours and then at 110° C. for 1 hour. The polymerization rate was 99%. The obtained polymerization slurry was filtered, washed with water, and dried to obtain a graft copolymer (B-1).

15- Reference Example 4 [Graph 1 - Manufacture of copolymer (B-2)] Ethylene-propylene-geno rubber (iodine value 24, Mooney viscosity 65°, ethylene/furopylene = 77.6 / 22.4 mol) in an autoclave After dissolving 40 parts of It) in a mixed solvent of 150 parts of n-hebutane and 250 parts of inoprobilbenzene.

Add 35 parts of styrene, 25 parts of acrylonitrile and 1 part of penzoylberoquinde (initiator) and mix uniformly.

Next (polyacrylic acid (polymerization degree 200) is added to 700 parts of pure water.
0) After adding an aqueous solution containing 3 parts of a 25% aqueous solution, the gas phase was replaced with nitrogen gas, the temperature was raised to 80° C. with vigorous stirring, and graft polymerization was carried out for 7 hours. Polymerization rate is 98%
Met.

The obtained polymerization slurry was filtered, washed with a large amount of methanol, and then dried to obtain copolymer (B-2).
child.

Reference Example 5 [Production of graft copolymer ω')] Polybutadiene rubber latex (manufactured by Toshiku Co., Ltd.), gel content 90%
), a styrene-butadieno-acrylonitrile graft copolymer ω') having a rubber content of 40% and a styrene/acrylonitrile weight ratio of 70/30 was obtained by conventional emulsion polymerization.

Example 1 T copolymer 4 obtained in Reference Example 1 and T copolymer 4 obtained in Reference Example 3
This graft copolymer (B-1) was blended at a blending ratio of 1 to 1 as shown in Table 1, and extruded at a temperature of 250°C and a shear rate of 350 seconds.
A rubber-modified maleimide resin composition was obtained by melt-kneading using a vented extruder under the following conditions.This composition was injection molded. The impact strength was measured and the results are shown in Table 1.

Examples 2 and 3 Same as Example 1 except that graft copolymer No. 1) of Example 1 was replaced with graft copolymer No. 1- and copolymer (B-2) obtained in Reference Example 4. A rubber-modified maleimide resin composition was obtained as follows: 1. The heat distortion temperature and Izotsu impact strength were measured. The results are also shown in Table-1.

Comparative Example 1 A rubber-modified maleimide resin composition was prepared in the same manner as in Example 1, except that the T copolymer (A') obtained in Reference Example 5 was used instead of the copolymer in Example 1. The heat deformation temperature and Izod impact strength were measured. Table 1 shows the results.
It is also shown in .

Comparative Example 2 In place of the graft copolymer (B-1,) in Example 1, the graft copolymer (B') obtained in Reference Example 5 was used, and the same procedure as in Example 1 was carried out except for T. A rubber-modified maleimide resin composition was obtained, and its heat distortion temperature and Izod impact strength were measured.The results are also shown in Table 1.

As is clear from Table 1, the resin compositions obtained by the production method of the present invention (Examples 1 to 3) have high heat distortion temperatures and high Izod impact values, whereas maleimide copolymer When imide ring closure of the coalescence was performed and then melt kneaded with the copolymer from Graph 1 (Comparative Example 1), the gono-like polymer obtained by ordinary emulsion polymerization formed a continuous film. The composition prepared in this case (Comparative Example 2) using a graft copolymer without the oxidizing agent had a low Izot impact value and insufficient impact resistance.

Claims (1)

[Claims] (A vinyl copolymer containing 5 to 50 mol% of maleic anhydride was mixed with ammonia or
Modified vinyl copolymers obtained by reacting with grade amines and essentially gel-free rubbery polymers 5 to 60
A graft copolymer obtained by polymerizing 40 to 95% by weight of an aromatic vinyl monomer and a monomer Δ40 to 95% by weight that can be polymerized with the aromatic vinyl monomer under suspension polymerization conditions in the presence of The ratio of coalescence is 5 to 4 for the total amount of (Ai + (B) 81)
0% by weight, and then add 150 to 3% by weight.
A method for producing a thermoplastic resin composition, which comprises melt-mixing under shear stress at a temperature of 50°C.