JPS60155216A - Production of thermoplastic resin - Google Patents

Abstract

PURPOSE:To produce a thermoplastic resin excellent in heat stability, impact resistance and moldability, by graft-polymerizing an aromatic vinyl monomer, an unsaturated dicarboxylic acid anhydride, etc. with a rubber-like polymer in the presence of a specified radical initiator and imidating the graft polymer. CONSTITUTION:A polymerization initiator prepared by mixing a peroxide radical generating initiator (e.g., benzoyl peroxide) with an azoic radical generating initiator (e.g., azobisisobutyronitrile) at a weight ratio of 9/1-1/9 is used in the graft-polymerization of 60-95pts.wt. monomer mixture comprising 50-90wt% aromatic vinyl monomer, 5-50wt% unsaturated dicarboxylic acid anhydride and 0-30wt% vinyl monomer with 5-40pts.wt. rubber-like polymer. The obtained graft polymer is reacted with NH3 or a prim. amine at 80-350 deg.C to produce an imido group-containing thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermoplastic resin having an imide group, and more specifically, to a rubber-like polymer, an aromatic vinyl monomer, an unsaturated dicarboxylic acid anhydride, and a method capable of copolymerizing with these. A copolymer obtained by graft polymerizing a monomer mixture consisting of vinyl monomers using a specific radical-generating initiator is reacted with ammonia or a primary amine to improve heat stability, impact resistance, and moldability. This invention relates to a method for producing an excellent thermoplastic resin.

BACKGROUND ART Conventionally, a method for producing a copolymer has been proposed in which a rubber-like polymer is graft-polymerized with an aromatic vinyl monomer, maleic anhydride, and a vinyl monomer copolymerizable with these. (
JP-A-48-42091, JP-A-49-28693, JP-A-53-78252, JP-A-53-80490
However, although these polymers copolymerized with maleic anhydride have high heat distortion temperatures, in both cases, acid anhydride groups caused by maleic anhydride are present in the copolymer chain. Therefore, it is easy to cause chemical changes and decompose not only when exposed to water at high temperatures, but also when exposed to heat, and there are significant restrictions when molding and processing, and when the processed product is not brought into contact with water or steam. However, when exposed to high temperatures, mechanical properties, especially impact strength, deteriorate.

Also known is a method for producing a copolymer in which the acid anhydride group of these maleic anhydride copolymers is imidized with ammonia or a primary amine.

(Unexamined Japanese Patent Publication No. 57-100.104) Although this improved heat resistance stability, hot water resistance, etc., it was still insufficient to simultaneously satisfy impact resistance and fluidity during molding.

As a result of intensive studies, the present inventors simultaneously improved impact resistance and fluidity during molding by using a peroxide-based radical-generating initiator and an azo-based radical-generating initiator in a specific ratio. This is the first time I have succeeded in doing so. That is, 5 to 40 parts by weight of a rubbery polymer, 50 to 90 weight % of an aromatic vinyl monomer, 5 to 50 weight % of an unsaturated dicarboxylic acid anhydride, and 0 to 30 weight % of a vinyl monomer copolymerizable with these. %, and a peroxide-based radical-generating initiator and an azo-based radical-generating initiator in a weight ratio of 9/1 to 110. The resulting copolymer is reacted with ammonia or a primary amine at a temperature of 80 to 350°C to obtain imide group-containing heat-resistant stability, hot water resistance, and impact resistance.
The present invention aims to provide a method for producing a thermoplastic resin that has excellent fluidity during molding.

In the present invention, the rubber-like polymer content ratio 4- can be selected in the range of 5 to 40% by weight based on the copolymer before imidization, depending on the impact strength required of the plastic resin. As the content of the rubbery polymer increases, the impact strength improves, but when the content of the rubbery polymer exceeds 40% by weight, the heat resistance and moldability of the final thermoplastic resin decrease. The impact improvement effect is insufficient at less than 5% by weight (M). Rubbery polymers include butadiene homopolymer, copolymer of butadiene and vinyl monomer copolymerizable, ethylene-propylene copolymer. ethylene-propylene-diene copolymers, block copolymers of phtadiene and aromatic vinyl, acrylic ester polymers, and copolymers of acrylic esters and vinyl monomers copolymerizable with them. used.

In the present invention, the monomers to be grafted onto the rubbery polymer include 50 to 90% by weight of aromatic vinyl monomer, 5 to 50% by weight of unsaturated dicarboxylic acid anhydride, and 0 to 90% by weight of vinyl monomer copolymerizable with these monomers. If the amount of the aromatic vinyl monomer is less than 50% by weight, the characteristics of the aromatic vinyl compound, especially in the case of styrene, the moldability and dimensional stability are lost. If the amount of unsaturated dicarboxylic acid anhydride is less than 5% by weight, the heat resistance will not be sufficient, and if it exceeds 50% by weight, the copolymer will become brittle and the moldability will deteriorate significantly.

The aromatic vinyl monomer in the present invention includes styrene,
These include styrene monomers such as α-methylstyrene, vinyltoluene, t-butylstyrene, and chlorostyrene, and substituted monomers thereof, and among these, styrene and α-methylstyrene are particularly preferred. Examples of the unsaturated dicarboxylic anhydride include anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid, with maleic anhydride being particularly preferred.

Vinyl monomers that can be copolymerized with these include vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and acrylic acids such as methyl acrylate, ethyl acrylate, and butyl acrylate. Ester monomers, methacrylic ester monomers such as methyl methacrylic ester and ethyl methacrylic ester, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acryl amide, methacrylic amide, acenaphthylene and N-vinyl Of these, monomers such as acrylonitrile, methacrylic acid ester, acrylic acid, and methacrylic acid are preferred, including carbazole and the like.

In the graft polymerization of the present invention, a peroxide radical generating initiator and an azo radical generating initiator are used in a weight ratio of 971 to 1/9, preferably 4/1 to 1/9.
It is important to use it at a ratio of 1/4. Here, the peroxide-based radical generation initiator is a compound having 10-0-group in the molecule, specifically benzoyl peroxide, acetyl peroxide, lauryl peroxide, bis-3,5,5 -ToIJ Me/'-ruhexanol peroxide, 〇-methylbenzoyl peroxide, dicumyl peroxide, 1.1-di-1-butylperoxy-335-)limethylcyclohexane, 1.
1-di-t-butylperoxycyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxybenzoate, t-butylperoxyisopropyl carbonate, etc. be. Azo radical generation initiators are compounds that have -N=N- groups in their molecules, and specifically include azobisinobutyronitrile, azobiscyclohexanenitrile, azobismethylpropionitrile, and azobismethylbutyronitrile. Examples include lonitrile. In addition, the total amount of these radical generating initiators used may be the amount used in normal polymerization,
0.0% per 100 parts by weight of the monomer mixture to be grafted.
0.005 to 0.5 parts by weight is preferred. The weight ratio of peroxide radical generation initiator/azo radical generation initiator is 9/
If it exceeds 1, the resulting resin will not have sufficient fluidity during molding, and if it is less than 1/9, it will have poor impact resistance.

Ammonia and primary amines used in the imidization reaction of the present invention may be in either an anhydrous or aqueous state, and examples of primary amines include methylamine, ethylamine, n-propylamine, isopropylamine, and butylamine. , pentylamine, cyclohexylamine, etc., and chloro- or bromo-substituted alkylamines, aromatic amines such as aniline, tolylamine, naphthylamine, and no-rogen-substituted aromatic amines such as chloro- or bromo-substituted aniline, Among these, aniline is one of the most preferred.

In the present invention, a catalyst may be present when the rubbery polymer-aromatic vinyl-unsaturated dicarboxylic acid anhydride copolymer is imidized with ammonia and/or a primary amine, and usually a tertiary amine. is used.

When the imidization reaction is carried out in a solution or suspension state, it is preferable to use an ordinary reaction vessel, such as an autoclave, and when carried out in a bulk molten state, an extrusion type equipped with a devolatilization device may be used.

The temperature of the imidization reaction is about 80 to 350°C, preferably 100 to 300°C. If the temperature is lower than 80°C, the reaction rate is slow and the reaction takes a long time, which is not practical. On the other hand, if the temperature exceeds 350°C, the physical properties will deteriorate due to thermal decomposition of the polymer.

The imidized copolymer of maleic anhydride copolymer produced by the method described below maintains a high heat distortion temperature, has a high degree of stability against water and heat, and has high resistance to water and heat. It also has excellent impact resistance and moldability.

These imidized copolymers include styrene-acrylonitrile copolymer (SAN resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, and acrylonitrile-acrylic rubber. - Styrene copolymer, acrylonitrile-ethylene fist propylene rubber-styrene copolymer, styrene-methyl methacrylate copolymer, methyl methacrylate-butadiene-styrene copolymer, aromatic polycarbonate, aromatic polyester, polyphenylene oxide, and styrene-modified polycarbonate It can also be mixed with phenylene oxide and the like. In particular, mixtures with ABS resin are favorable in terms of impact resistance (11ii) and moldability.
It is also possible to add lubricants, fillers, colorants, etc.

All parts and parts in the following examples are expressed on a weight basis unless otherwise specified.

Example 1 Styrene (hereinafter 8 tons) was placed in an autoclave equipped with a stirrer.
) 60 parts, methyl isobutyl ketone (hereinafter referred to as MiBK)
) and 15 parts of polybutadiene cut into small pieces (Diene NF35R, manufactured by Asahi Kasei Kogyo Co., Ltd.) were charged, and after purging the system with nitrogen gas, the mixture was stirred at room temperature all day and night to dissolve the rubber. After setting the temperature to 80°C, 40 parts of maleic anhydride (hereinafter abbreviated as MAR) and 0.0 parts of topenzoyl peroxide were added.
09 parts, azobisisobutyronitrile 0.09 parts
A solution dissolved in 250 parts of iBK was added continuously over 8 hours. The temperature was maintained at 80° C. for an additional 4 hours after the addition. A portion of the reaction solution was sampled and the amount of unreacted monomer was determined by gas chromatography, and the polymerization rate was determined to be 5t, 96cm, and MAH, 99cm. Add 37 parts of aniline and 1 part of triethylamine to this polymerization solution for 14 hours.
The reaction was carried out at 0°C for 7 hours. The reaction solution was cooled to 90°C, poured into 1000 parts of vigorously stirred methanol, and precipitated.
F was separated and dried to obtain an imidized copolymer. C-C-13
Partial analysis showed that the conversion rate of acid anhydride groups to imide groups was 96%. Imidized copolymer 60 thus obtained
and 40 parts of acrylonitrile-styrene resin (manufactured by Denki Kagaku Kogyo ■, H8-30 (1)), and this blend was extruded using a screw extruder equipped with a devolatilization equipment to pelletize. 7 osphite and o, a parts of octadecyl 3-(3,5-ditertiarybutyl-4-hydroxyphenyl)-propionate.

The physical properties of the composition thus obtained are shown in Table 1.

Example 2 In the same manner as in Example 1, 55 parts of 5t, 10 parts of acrylonitrile, 50 parts of MiBK, and 19 parts of polybutadiene were charged into an autoclave, and after replacing the inside of the system with nitrogen gas, the mixture was stirred at room temperature all day and night to dissolve the rubber. After setting the temperature to 80°C, 35 parts of MAH, 0.06 parts of benzoyl peroxide, and 0.12 parts of azobisisobutyronitrile were mixed with M i B
A solution dissolved in 250 parts of K was added continuously over a period of 8 hours. The temperature was maintained at 80° C. for an additional 4 hours after the addition. From the quantitative determination of unreacted monomers, the polymerization rate was St99, MAH98.
It was 90% acrylonitrile. Add 32.4 parts of aniline and 1 part of triethylamine to this polymerization solution and make 140
The reaction was carried out at ℃ for 7 hours.

The conversion rate of acid anhydride groups to imide groups was 97%. Thereafter, the same procedure as in Example 1 was carried out to obtain a powder of an imidized copolymer.

Further, in order to obtain an acrylonitrile-butadiene-styrene copolymer, the following operation was performed. Namely, 143 parts of polybutadiene latex (solid content 35%, weight average particle size 0.35μ, gel content 90%), 1 part potassium stearate, 0.1 part sodium formaldehyde sulfoxylate, tetrasodium ethylenediamine tetra Heat 0.03 parts of acetic acid, 0.003 parts of ferrous sulfate, and 150 parts of water to 50°C, and add 5t70% to this.
Monomer mixture 5 consisting of and 30 acrylonitrile
0 parts, 0-2 parts of t-dodecylmercaptan, and 0.15 parts of cumene hydroperoxide were continuously added over 6 hours, and after the addition, the temperature was raised to 65°C and polymerized for 2 hours. The polymerization rate was determined by gas chromatography analysis to be 98% for St and 97% for acrylonitrile. After adding an antioxidant to this latex, it was coagulated with calcium chloride, washed with water, and dried to obtain a graft copolymer as a white powder.

60 parts of the imidized copolymer thus obtained, 30 parts of acrylonitrile-butadiene-styrene copolymer, and As resin (Denki Kagaku Kogyo@m4, As-8) 10
After adding additives in the same manner as in Example 1, the mixture was extruded into pellets, and the physical properties thereof were measured and shown in Table 1.

Comparative Example 1 Completely the same as Example 2 except that 0.06 parts of benzoyl peroxide and 0.12 parts of azobisisobutyronitrile as polymerization initiators in Example 2 were replaced with 0.18 parts of benzoyl peroxide. An imidized copolymer was obtained by the operation. The polymerization rate was 5t95%, MAH 98%, and acrylonitrile 90%. Further, the conversion rate of acid anhydride groups to imide groups was 97%. 60 parts of the imidized copolymer thus obtained were mixed with 30 parts of the same acrylonitrile-butadiene-styrene copolymer as in Example 2 and As.
After blending with 10 parts of resin and adding additives in the same manner as in Example 2, the mixture was extruded into pellets, and the physical properties thereof were measured and shown in Table 1.

Comparative Example 2 Same as Example 2 except that 0.06 parts of benzoyl peroxide and 0.12 parts of azobisisobutyronitrile as polymerization initiators in Example 2 were replaced with 0.18 parts of azobisisobutyronitrile. An imidized copolymer was obtained in a similar manner. The polymerization rate was 5t99%, MAH 98%, and acrylonitrile 89%. The conversion rate of acid anhydride groups to imide groups was 98%.

60 parts of the imidized copolymer thus obtained was blended with 30 parts of acrylonitrile-butadiene-styrene copolymer, 10 parts of As resin, and additives in the same manner as in Example 2, and then extruded into pellets. Measure the first
Shown in the table.

Table 1 From Table 1, the thermoplastic resin obtained by the production method of the present invention has significant improvements in impact strength and fluidity during molding without deteriorating the conventional thermal stability, heat resistance, and hot water resistance. Is recognized.

The physical properties were measured by the following method.

(1) Impact strength: notched izot impact strength.

According to ASTM D-256.

(2) MFI (melt flow index): Temperature: 270° C., load: 5 Kf, according to ASTM D-1238.

(3) Thermal stability: The temperature is shown when the weight loss of the polymer in thermobalance analysis is 1 weight under the conditions of nitrogen flow of 50cc15+ and temperature increase rate of 10Q minutes.

(4) VSP (Vicat Softening Point)...Load 5 odor, AS
According to TM D-1525.

(5) Hot water resistance: A notched Izot test piece according to ASTM D-256 was immersed in hot water at 100°C for 24 hours, and the retention rate of the measured impact value (1) was shown.

Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 5 to 40 parts by weight of rubbery polymer and 50 parts by weight of aromatic vinyl monomer
~90% by weight, 5 to 50% by weight of unsaturated dicarboxylic anhydride, and 0 to 30% of vinyl monomer copolymerizable with these
Graft polymerization using 60 to 95 parts by weight of a monomer mixture consisting of 60 to 95 parts by weight as a polymerization initiator and a peroxide radical generation initiator and an azo radical generation initiator at a weight ratio of 9/1 to 1/9. A method for producing a thermoplastic resin having an imide group, which comprises reacting the resulting copolymer with ammonia or a primary amine at a temperature of 80 to 350°C.