JPS5915404A - Production of maleimide copolymer - Google Patents

Abstract

PURPOSE:To obtain, in good efficiency, a maleimide compound having a high heat distortion temperature and a high thermal heat decomposition temperature, by reacting a maleic anhydride-containing copolymer with an isocyanate ester compound in a nonaqueous organic solvent. CONSTITUTION:A (rubber-modified) vinyl copolymer containing 5-50mol% maleic anhydride unit of formula I , is prepared either by copolymerizing maleic anhydride with other vinyl monomers copolmerizable therewith (e.g., styrene) or by carrying out this copolymerization in the presence of a rubber-like polymer (e.g., polybutadiene). Then, this copolymer is reacted in a nonaqueous solvent (e.g., acetone) with an isocyanate ester compound (e.g., methyl isocyanate) in an amount of at least 1 equivalent per equivalent of the maleic anhydride contained in the copolymer, whereby its imidation is effected according to the reaction of formula II to obtain the purpose maleimide copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an efficient and novel method for producing maleimide copolymers having high heat distortion temperatures and high thermal decomposition temperatures.

Maleimide copolymers have high heat distortion temperatures.

Although it is attracting attention for its excellent heat resistance, the synthesis method for maleimide monomers such as N-phenylmaleimide used as starting materials is complicated, and in addition, it requires dehydrating agents, catalysts, and co-catalysts. The disadvantage is that it is difficult to obtain the desired maleimide copolymer at a low cost.

In response to this, studies have been conducted on methods for producing maleimide copolymers without using maleimide monomers as starting materials, and Japanese Patent Publication No. 56-39651 and Japanese Patent Application Laid-Open No. 57-55901 The specification of the publication states that a copolymer containing maleic anhydride and ammonia or
A method for producing a maleimide copolymer by reacting a primary amine has been proposed. However, since this method consists of a ring-opening reaction of maleic anhydride units and an imide ring-opening reaction, it not only takes a long time for the reaction but also makes it difficult to completely close the imide ring. The disadvantage is that the specific thermal stability of molding cannot be fully satisfied.

Therefore, the present inventors conducted extensive studies with the aim of efficiently producing a maleimide copolymer having a high heat distortion temperature and thermal decomposition temperature, and as a result, developed a vinyl copolymer containing kerosene maleic acid. The inventors have discovered that the above object can be effectively achieved by reacting isonic acid ester compounds, and have arrived at the present invention.

That is, the present invention uses maleic anhydride in an amount of 5 to 5 mm/I/
% of the vinyl copolymer or rubber-modified vinyl copolymer in a non-aqueous organic solvent at a 417 V
The present invention provides a method for producing a maleimide copolymer, which is characterized by reacting with an acid ester compound and imidizing it.

A vinyl copolymer containing maleic anhydride or a rubber-modified vinyl copolymer (
Copolymer (hereinafter abbreviated as copolymer) refers to copolymerization of maleic anhydride and other vinyl monomers that can be copolymerized with maleic anhydride, or the copolymerization is carried out in the presence of a rubbery polymer. It is a copolymer obtained by the following process and contains maleic anhydride units of the following formula [E].

-Here, other hinyl-based monomers copolymerizable with maleic anhydride are defined as styrene, aromatic vinyl-based monomers such as α-methylstyrene, methacrylate, methyl ester, methyl acrylate, etc. Examples include (mek)acrylic acid ester monomers such as (meth)acrylic acid ester monomers, and cyanide vinyl tv monomers such as acrylonitrile and methacrylonitrile, and two or more of these may be used in combination. In addition, examples of rubber-like polymers for modification include polybutadiene rubber, diene rubber such as acrylonitrile-butadiene copolymer rubber (NBR), styrene-butylene copolymer rubber (EIBR), polyglutyl acrylate, Examples include acrylic rubber such as polybutyl acrylate and ethylene-propylene-diene rubber (EPDM).

These copolymers (gradients) are produced by ordinary solution polymerization or bulk polymerization, but the copolymerized amount of maleic anhydride is 5 to 5.
It should be selected within the range of 0 molar ratio.

If the copolymerized amount of maleic 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 become too high. , which is not preferred because it makes melt molding difficult. The composition ratio of the vinyl copolymer other than maleic anhydride and the rubbery polymer in the copolymer (/1) is not particularly limited and can be arbitrarily selected.

The incyanate ester compound used for imidizing the copolymer (6) in the present invention is a compound represented by the following formula (II), where R is a hydrocarbon having 1 to 20 carbon atoms. It was selected from.

R N=C=O CTD These compounds include butyl insinate, ethyl insinate,
Butyl incyanate, butyl incyanate, butyl incyanate, etc. are mentioned, and these are more than equivalent to the maleic anhydride contained in the copolymer, preferably 1.02 equivalent. Used at a higher rate.

The shaping reaction of the maleimide copolymer according to the present invention proceeds through the following reaction.

That is, a maleimide unit and carbon dioxide are produced from a maleic anhydride unit and an incyanate ester compound. Through this reaction, the maleimide copolymer (g), which is the object of the present invention, is formed.

It is important that the reaction of the present invention is carried out in a non-aqueous state.

This is because, in the presence of water, the incyanate ester compound reacts with water to produce primary amines and carbon dioxide. Therefore, it is necessary to pay attention to the moisture content of the incyanate ester compound and the organic bath medium. The reaction of the present invention is generally carried out in a non-aqueous organic solvent, and the organic solvent used here is a copolymer (a copolymer that can uniformly disperse the gradient and does not interfere with the reaction with the isonic acid compound). There are no particular restrictions as long as it is acetone, methyl chloride ketone, methyl chloride ketone,
Ketones such as methyl isobutyl ketone and amides such as dimethylformamide can be selected.

The reaction temperature of the present invention is 0 to 650°C, especially room temperature to 250°C.
℃ is preferable; below 0℃, the reaction rate is slow;
If the temperature exceeds 0°C, thermal decomposition of the copolymer (6) and (copolymer) will occur, which is undesirable.The reaction time can be set appropriately in consideration of the reaction temperature, but from the viewpoint of productivity
~5000 seconds and (60 to 5000 seconds) are preferred. The reaction pressure is preferably in the range of normal pressure to 5 atm.

The apparatus for carrying out the reaction of the present invention is not particularly limited, and any apparatus may be used as long as it has the functions of mixing the reaction system, regulating the temperature, and removing the generated carbon dioxide, such as a normal polymerization tank or a vent. It is also possible to use an extruder with an attached extruder.

Thus, according to the present invention, a maleimide-based copolymer having high heat distortion temperature and thermal decomposition temperature and excellent heat resistance can be efficiently obtained using a copolymer containing maleic anhydride as a starting material.

Furthermore, the maleimide copolymer obtained in the present invention has excellent miscibility with rubber-modified resins known as ABS resin, ABS resin, MBS resin, etc., and is a modifier that imparts excellent heat resistance to these resins. It can be used as

That is, polybutadiene rubber, acrylonide-butadiene copolymer rubber (tqBR), styrene-
diene rubber such as butadiene copolymer rubber (SBR),
Acrylic rubbers such as polybutyl acrylate-1-, polypropyl acrylate, and ethylene-propylene-
Aromatic vinyl monomer, diene rubber (KPDM), etc.
The maleimide copolymer obtained in the present invention is mixed into a rubber-modified resin obtained by graft copolymerizing at least one of a (meth)ac IJ/L/acid esthetic μ-based extender and a vinyl cyanide monomer. By doing so, it is possible to produce an impact-resistant resin composition that has a high heat distortion temperature, a high thermal decomposition temperature, and a high impact strength.

In this case, there is no particular restriction on the mixing ratio of the maleimide copolymer and the above-mentioned rubber-modified resin, and the ratio of the rubber-like polymer and the vinyl monomer to be graft-polymerized in the above-mentioned rubber-modified resin is subject to particular technical restrictions. There are no restrictions.

If desired, vinyl copolymers such as styrene-acrylonitrile t' copolymer, a-methylnutylene-acrylonitrile μ copolymer, l-lyamide copolymers such as nylon, etc. It is also possible to simultaneously mix other polymers such as polyester polymers such as , polybutylene lentilicrate, polybutylene lentilicrate, and the like. The mixing method is not limited to any conventional means, and 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 addition, the heat distortion temperature in Examples and Comparative Examples is ASTM D-648-56, and the Izod impact value is AE.
Measured according to JTMD-2'56756 Method A. The thermal decomposition temperature is determined by increasing the temperature at a rate of 10°C/min under a nitrogen stream using a thermogravimetric analyzer and measuring the change in weight of the sample.The temperature at which the sample weight decreases by 6% is defined as the thermal M temperature. did. Further, the number of parts represents parts by weight.

Example 1 [Production of copolymer (a)] 5 kg of styrene, 2.5 kg of methyl ethyl ketone, and 65 g of benzoyl peroxide (initiator) were charged into a 2010 volume polymerization tank equipped with a reflux condenser, a stirrer, and a dropping funnel, and sufficiently dissolved. Ta.

Separately, a solution of 40 parts by weight of maleic anhydride in methyl ethyl ketone was prepared and charged into the dropping funnel. Next, the temperature inside the polymerization tank was kept at 75'C and stirring was carried out, and 835% of the maleic anhydride-methyl ethyl ketone solution was added from the Nacala dropping funnel.
The mixture was added at a rate of g/hr for 3 hours and held for 1 hour after the addition was completed. At this time, the polymerization rate had reached 94. Next, 1,240 g of Phenyl Isocyanate A was added to the reaction system, and
Stirring was continued for 2 hours while maintaining the temperature at 5°C. Next, a large amount of toluene was added to the reaction system to remove methyl ethyl ketone and unreacted monomers, and the mixture was dried to obtain 8 kg of a pale and colored copolymer (a)/). This copolymer (a
) /L/ was measured and found to be the same as the infrared absorption spectrum of the styrene-N-phenylmaleimide copolymer.

Example 2 [Production of Copolymer ■] In the same polymerization tank as in Example 1, 5.8 kL of styrene, 1.2 kg of acrylonitrile, 3.7 kg of methane, ethyl ketone, and gel were added. 1 kg of polybutadiene rubber with a content of 90% was charged and sufficiently dissolved.

Separately, a solution prepared by dissolving 9 g of azobisisobutyronitrile/l and 2 kg of maleic anhydride in 5 kg of methyl ethyl ketone was charged into the dropping funnel. Next, add the polymerization tank to 8
The mixture was heated to 0° C., and the above maleic anhydride-methyl ethyl ketone solution was added dropwise at a rate of 87.5 VAr, and held for 2 hours after the completion of the addition. Thereafter, 30 g of diphenylisodecyl phosphite and 40 g of 3.5-di-t-glyhydroxytoluene were added as antioxidants to the reaction solution, and while the temperature inside the polymerization tank was maintained at 80ti, butyl isocyanate/
1/2500 g was added and stirring continued for 6 hours. Next, the reaction solution was placed in a tray and dried in a vacuum oven at 110°C for 8 hours to remove the solvent and residual monomer, and the copolymer (
5.8 kfl of b) was obtained. When the infrared absorption spectrum of this copolymer was measured, it was found to be the same as the infrared absorption spectrum of styrene-acrylic[1-nitrile-N-butylmaleimide-getadiene copolymer.

Comparative Example 1 [Manufacture of copolymer (C)] In the same polymerization tank as in Example 1, 5 kg of styrene, 2.5 kg of methyl ethyl ketone, and 559 ml of Bency peroxide IV (initiator) were charged and sufficiently dissolved. Separately, a 40% by weight solution of maleic anhydride in methyl ethyl ketone was prepared and charged into the dropping funnel. Next, while maintaining the temperature inside the polymerization tank at 75° C. and stirring, a maleic anhydride-methyl ethyl ketone solution was added from the dropping funnel at a rate of 833 QAr for 6 hours, and after the addition was completed, the solution was maintained for 1 hour. Thereafter, when the humidity in the polymerization tank was cooled to 60 U, a colorless and transparent viscous liquid was obtained, and the polymerization rate was 94%. Next, the reaction solution was added to a large amount of petroleum benzine, methyl ethyl kerene and unreacted monomers were removed, and the white styrene-maleic anhydride copolymer (C) was obtained by drying.
゜6 got 9.

Example 6 Copolymer (a) obtained in Example 1.2 and Comparative Example 1
When the heat distortion temperature and thermal decomposition temperature of ~(e) were measured,
The results were as shown in Table-1.

Table 1 As is clear from Table 1, the copolymer (C) containing maleic anhydride has a low thermal decomposition temperature and insufficient thermal stability.

On the other hand, copolymers (a), (
G) has extremely high heat distortion temperature and thermal decomposition temperature, and has extremely high heat resistance.

Example 4 70 parts of the copolymer (a), (+)) obtained in Example 1.2 and the copolymer (C) obtained in Comparative Example 1, and styrene with a rubber content of 6Oi and 1%. Acryloni t・IJ t
Legtadiene copolymer (ABS) or styrene-acrylonitrile copolymer (SA 1,1)
30 parts were blended, melt-extruded using an extruder, and injection molded, and the physical properties of the obtained test piece were measured. The measurement results of heat distortion temperature, thermal decomposition temperature and Izod impact strength are shown in Table 2 along with the blending ratio.

Table 2 As is clear from the results in Table 2, the composition containing the copolymers @) and (+)l obtained by the method of the present invention has a high thermal distortion temperature, thermal decomposition temperature, and Izod impact strength. On the other hand, the composition containing the maleic anhydride-containing copolymer (C) has a low thermal decomposition temperature and insufficient thermal stability.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Claims] A vinyl copolymer or a rubber-modified vinyl copolymer containing 5 to 50 moJv% of maleic anhydride is added in an amount equivalent to or more of the maleic anhydride contained in the copolymer in a non-aqueous organic solvent. 1. A method for producing a maleimide copolymer, which comprises reacting with an isocyanic acid ester compound and imidizing the maleimide copolymer.