JPH06256442A - Production of graft copolymer - Google Patents

Abstract

PURPOSE:To obtain a graft copolymer which can markedly improve the compatibility of a polyester with a styrenic resin. CONSTITUTION:This production process comprises reacting an amino or hydroxy styrene derivative or an amino or hydroxy acrylic acid derivative with a thermoplastic polyester having a carboxyl group at one molecular terminal and grafting a styrenic monomer onto the obtained terminal-polymerizable polyester.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing a graft copolymer useful as a compatibilizing agent for obtaining a composite resin in which a polyester and a styrene resin are finely and uniformly compatible with each other.

[0002]

2. Description of the Related Art Polyester has excellent electrical properties, transparency, adhesive properties and the like and is used in a wide range of fields such as paints, inks, adhesives, coating agents and FRP improvers.

On the other hand, styrenic resin has rigidity, heat resistance,
It has different properties from polyester such as molding processability and is used in various fields. If a resin having good characteristics different from each other can be obtained, its utility value will be high and its range of use will be expanded. Therefore, its appearance is desired. Because it ’s difficult
The current situation is that we have not been able to obtain satisfactory results.

The reason for this is that the compatibility of both resins is poor, and various methods for improving this point have been investigated. For example, a method of using a graft copolymer of unsaturated polyester and styrene as a compatibilizing agent, a method of using a copolymer obtained by grafting a vinyl monomer onto polyester in the presence of a free radical initiator as a compatibilizing agent, etc. However, in the former case, gelation is likely to occur during the reaction, so that an insoluble and infusible substance is formed, and the complex itself is agglomerated, so that a good complex cannot be obtained. Also in the latter case, a sufficient amount of vinyl homopolymer is produced and the grafting efficiency is extremely low, so that a sufficient complex cannot be obtained.

Therefore, if a graft copolymer or a block copolymer which can serve as a compatibilizing agent for obtaining a composite resin in which both resins are uniformly and finely compatible with each other is obtained, the technical value thereof is very large.

[0006]

SUMMARY OF THE INVENTION In consideration of the above-mentioned problems of the prior art, the present invention provides a compatibilizer for obtaining a composite resin in which a polyester and a styrene resin are uniformly and finely compatible with each other. It is an object to provide a method for producing a useful graft copolymer.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted various studies in order to solve the above problems, and as a result, have introduced a styrene derivative or an acryl derivative into a thermoplastic polyester by a specific method to obtain a terminal polymerizable compound. The present invention has been completed by finding that a copolymer obtained by graft-polymerizing a styrenic monomer on polyester has an extremely large compatibilizing ability.

That is, the present invention provides a terminally polymerizable polyester obtained by reacting a thermoplastic polyester having a carboxyl group at one end of a molecular chain with a styrene derivative having an amino group or a hydroxyl group or an acrylic derivative having an amino group or a hydroxyl group. Is a method for producing a graft copolymer, which comprises graft-copolymerizing a styrene-based monomer.

The thermoplastic polyester having a carboxyl group at one end of the molecular chain used in the present invention is produced by binding an acid anhydride to one of the hydroxyl groups at both ends of the thermoplastic polyester.

Specific examples of the acid anhydride include succinic anhydride, glutaric anhydride, phthalic anhydride and the like.
Examples of the thermoplastic polyester include one or more dicarboxylic acids selected from terephthalic acid, isophthalic acid, p-oxybenzoic acid, diphenylmethanedicarboxylic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, and ethylene glycol, propylene. Glycol, 1,
One or two selected from 4-butanediol, 1,6-hexanediol, neopentylene glycol, cyclohexanedimethanol, diethylene glycol, etc.
Examples of the polyester include polyesters obtained by polycondensation of one or more kinds of diols under an excess of diols. At that time, since a polyester having a high crystallinity is difficult to dissolve in a solvent, an amorphous or low crystalline thermoplastic polyester is preferable, and a crystallinity by X-ray analysis of less than 10% is preferable. The number average molecular weight is preferably 500 to 50,000, and 1
Those of 000 to 30,000 are more preferable.

The reaction of the above-mentioned thermoplastic polyester and acid anhydride can be carried out by using a basic catalyst such as sodium acetate or pyridine in accordance with ordinary reaction conditions of alcohol and acid anhydride. The molar ratio of the acid anhydride is 0.45 to 0.
The amount is preferably 55 mol, and it is preferable that the acid anhydride is gradually added dropwise.

Examples of the styrene derivative having an amino group or a hydroxyl group or the acryl derivative having an amino group or a hydroxyl group in the present invention include aminostyrene: aminomethylstyrene: amino, methylstyrene: amino, dimethylstyrene: amino, amino such as chlorostyrene. Styrene derivatives; acrylamide, methacrylamide, 2
-Aminoacryl derivatives such as aminoethyl methacrylate; hydroxystyrene derivatives such as hydroxystyrene and hydroxymethylstyrene; hydroxyacryl derivatives such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. Amide, 2-hydroxyethyl methacrylate is preferred.

The terminal-polymerizable polyester in the present invention is a dehydration condensation reaction of the above-mentioned thermoplastic polyester having a carboxyl group at one end of the molecular chain with the above-mentioned styrene derivative having an amino group or hydroxyl group or an acrylic derivative having an amino group or hydroxyl group. Manufactured by.
As the dehydration catalyst, dicyclohexylcarbodiimide,
Examples thereof include phosphorus oxychloride, phosphorus trichloride, thionyl chloride and the like, and dicyclohexylcarbodiimide is preferable in terms of product yield, purity, ease of reaction and the like.

The reaction solvent is not particularly limited as long as it is a solvent which dissolves a thermoplastic polyester, a styrene derivative having an amino group or a hydroxyl group, an acrylic derivative having an amino group or a hydroxyl group, a catalyst or the like and is inert to the reaction. Examples thereof include halogenated hydrocarbon solvents such as dichloromethane and chloroform; cyclic ether solvents such as tetrahydrofuran and dioxane; aromatic solvents such as benzene, toluene and xylene.

The reaction temperature varies depending on the catalyst used, but when a dicyclohexylcarbodiimide catalyst is used, it is preferably -10 to 50 ° C, and 0 to 30 ° C.
Is more preferable. The reaction time is, for example, preferably 1 to 10 hours, more preferably 2 to 5 hours in the above system.
Furthermore, in order to completely remove dicyclohexylurea formed as a by-product, it is preferable to leave the mixture at room temperature overnight after the completion of the reaction.

In the case of the above-mentioned system, the terminal polymerizable polyester is isolated by filtering off the by-product dicyclohexylurea and then pouring the reaction mixture into a polyester poor solvent such as alcohol such as methanol or ethanol. The polymerizable polyester is precipitated and isolated by filtration or centrifugation. At this time, the amount of the poor solvent is preferably 5 to 20 times the amount of the reaction mixture. The obtained terminal polymerizable polyester is further washed with alcohol, filtered and dried.

The graft copolymer in the present invention is produced by graft-copolymerizing a styrene-based monomer with the terminal polymerizable polyester obtained by the above method. Examples of the styrene-based monomer include styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chloromethylstin, α-methylstyrene, and chlorostyrene. Further, a mixture of a polymerizable monomer such as an acrylic ester, a methacrylic ester, acrylonitrile, maleic anhydride and a styrene-based monomer may be used as long as the content is 50% by weight or less.

The weight ratio of the styrenic monomer to the terminal polymerizable polyester is 1 terminal polymerizable polyester.
The styrene-based monomer is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, based on parts by weight.

Graft copolymerization is usually by radical polymerization, but may be ionic polymerization. The radical polymerization may be solution polymerization or suspension polymerization. In the case of solution polymerization, as a solvent for dissolving the terminal polymerizable polyester and the styrenic monomer,
For example, toluene, xylene, tetrahydrofuran, dioxane, N, N-dimethylformamide or the like is used, and a radical initiator is added. In the case of suspension polymerization, a radical initiator is added to a solution prepared by dissolving the terminal-polymerizable polyester in the styrene-based monomer in advance, and the radical initiator is poured into a large amount of water and suspended.

As the radical initiator, those used in general radical polymerization may be used, and organic peroxides such as benzoyl peroxide and lauroyl peroxide; azo compounds such as azobisisobutyronitrile; hydrogen peroxide and peroxides. Examples thereof include inorganic peroxides such as potassium sulfate. The graft copolymerization temperature is preferably 20 to 150 ° C., 5
0-120 degreeC is more preferable. The graft copolymerization time is
1 to 30 hours are preferable, and 3 to 20 hours are more preferable.

The graft copolymer can be isolated by a method of pouring the polymerization solution into a poor solvent such as methanol or ethanol for precipitation in solution polymerization, or by filtration or centrifugation in suspension polymerization. The number average molecular weight of the polystyrene-based polymer in the graft copolymer is 3000 to 1500.
00 is preferable, and 5000-100,000 is more preferable.

Further, the graft copolymer produced in the present invention is a styrene-based copolymer in the graft copolymer as long as it is in accordance with the weight ratio of the terminal polymerizable polyester and the styrene-based monomer and the above-mentioned copolymerization method. A homopolymer of the monomer and an unreacted end-polymerizable polyester may be present.

[0023]

In the graft copolymer produced by the present invention, both the polyester unit resin and the polystyrene unit resin are efficiently graft-copolymerized, so that general polyester and styrene resin are finely dispersed and mixed. At the same time, the interfaces of these different resins are firmly bonded.

Therefore, according to the present invention, the styrene resin has excellent dimensional stability, electrical properties, water resistance, low cost and the like, and polyester has excellent weather resistance, oil resistance and chemical resistance. It is possible to obtain a resin having both heat resistance, heat resistance and mechanical strength.

[0025]

EXAMPLES The present invention will be described more specifically by showing Examples, Comparative Examples and Reference Examples below.

Example 1 <Synthesis of Polymerizable Polyester (a) at Terminal> Thermoplastic polyester having a carboxyl group at one end of a molecular chain (amorphous, molecular weight: 8000, glass transition temperature (Tg): 72)
℃, acid value: 7mgKOH / g) 800g and aminostyrene 1
6.7 g was dissolved in 4.5 liters of dichloromethane,
A solution of 31 g of dicyclohexylcarbodiimide / 0.5 liter of dichloromethane was added dropwise thereto. 20 ° C, 5
After stirring for an hour, the reaction mixture was left overnight at room temperature. Then, the reaction mixture was filtered to remove the by-product dicyclohexylurea. The reaction solution was poured into 75 liters of methanol to precipitate the terminal polymerizable polyester, and the mixture was centrifuged.
Furthermore, it was washed with 75 liters of methanol and dried with hot air at 50 ° C. for 10 hours to give 810 g of a terminal polymerizable polyester (a).
Got In IR measurement, NH: 3307 cm ^-1 , CON
H: 1635 and 1558 cm ^-1 , respectively, characteristic absorptions were observed, and a vinyl group peak of styrene was observed in the vicinity of 5.6 to 6.2 ppm by NMR measurement. Further, the acid value was measured, and it was found to be 0.07 mgKOH / g, which was a large decrease, and thus the target terminal polymerizable polyester (a) was confirmed.

<Synthesis of Graft Copolymer 1> 560 g of the terminally polymerizable polyester (a) obtained above is dissolved in 1470 g of styrene, and a radical initiator 67.7 is contained therein.
g (benzoyl peroxide, trade name: Niper BW,
Nippon Oil & Fats Co., Ltd.) was added. 60g of surfactant (trade name:
An aqueous solution in which 6 liters of water (UF-170, manufactured by Unitika Ltd.) was dissolved was heated to 80 ° C., and the styrene solution was added dropwise with vigorous stirring. After polymerizing at 80 ° C for 6 hours,
Cool and isolate the graft copolymer by centrifugation,
It was thoroughly washed with water and dried at 50 ° C. for 10 hours with hot air. Graft copolymer 1 was obtained with a yield of 1970 g. The molecular weight of the polystyrene unit in the graft copolymer 1 was about 20,000.

Example 2 <Synthesis of Terminal Polymerizable Polyester (b)> 2-Hydroxyethyl methacrylate 1 instead of aminostyrene
The same procedure as in Example 1 was carried out except that 8.2 g was used to obtain 806 g of a terminal polymerizable polyester (b). In the NMR measurement, the peak of the vinylene group of methacryl is 5.7 to
It is found around 6.8ppm and the acid value is 0.08mgKOH / g.
It was confirmed that the target terminal polymerizable polyester (b) was synthesized.

<Synthesis of Graft Copolymer 2> 560 g of the terminal polymerizable polyester (b) obtained above, 1900 g of styrene, 200 g of n-butyl acrylate, and 27 g of lauroyl peroxide were dissolved in 3 liters of xylene and stirred. Polymerization was performed at 90 ° C. for 10 hours. afterwards,
The mixture was cooled to room temperature, poured into 20 liters of methanol to precipitate a graft copolymer, centrifuged, washed with 10 liters of methanol, and dried with hot air at 50 ° C. for 10 hours to obtain 2340 g of a graft copolymer 2. The molecular weight of the polystyrene unit in the graft copolymer 2 was about 35,000.

Example 3 <Synthesis of Terminal Polymerizable Polyester (c)> 779 g of terminal polymerizable polyester (c) was prepared in the same manner as in Example 1 except that 9.95 g of acrylamide was used instead of aminostyrene. Obtained. In the NMR measurement, the peak of the vinylene group of methacryl was found around 5.7 to 6.8 ppm, and the acid value was reduced to 1.03 mgKOH / g, so the target end-polymerizable polyester (c) It was confirmed that was synthesized.

<Synthesis of Graft Copolymer 3> 560 g of the terminal polymerizable polyester (c) obtained above, 1900 g of styrene, 200 g of n-butyl acrylate and 27 g of lauroyl peroxide were dissolved in 3 liters of xylene and stirred. Polymerization was carried out at 90 ° C. for 10 hours. Then, the mixture was cooled to room temperature, poured into 20 liters of methanol to precipitate the graft copolymer, centrifuged, and further added with methanol 1
It was washed with 0 liter and dried with hot air at 50 ° C. for 10 hours to obtain 2250 g of graft copolymer 3. The molecular weight of the polystyrene unit in the graft copolymer 3 was about 35,000.

Example 4 <Synthesis of Terminal Polymerizable Polyester (d)> 781 g of terminal polymerizable polyester (d) was prepared in the same manner as in Example 1 except that 11.9 g of methacrylamide was used instead of aminostyrene. Got In the NMR measurement, the peak of the vinylene group of methacryl was found around 5.7 to 6.8 ppm, and the acid value was reduced to 0.97 mgKOH / g, so the target end-polymerizable polyester (d) was It was confirmed that it was synthesized.

<Synthesis of Graft Copolymer 4> 560 g of the terminal polymerizable polyester (d) obtained above, 1900 g of styrene, 200 g of n-butyl acrylate and 27 g of lauroyl peroxide were dissolved in 3 liters of xylene and stirred, Polymerization was carried out at 90 ° C. for 10 hours. Then, the mixture was cooled to room temperature, poured into 20 liters of methanol to precipitate the graft copolymer, centrifuged, and further added with methanol 1
It was washed with 0 liter and dried with hot air at 50 ° C. for 10 hours to obtain 2280 g of graft copolymer 4. The molecular weight of the polystyrene unit in the graft copolymer 4 was about 35,000.

Application Example 1 Commercially available styrene resin (trade name: Dianal BR-5
2. 650 g of Mitsubishi Rayon Co., Ltd., 350 g of polyester (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) and 40 g of the graft copolymer 1 synthesized in Example 1 were melted at a resin temperature of 130 ° C. using a twin-screw extruder. After the strands obtained by blending were cooled, they were cut into pellet-shaped resin compositions. The pellets thus obtained are dried in a vacuum dryer at 80 ° C. for 5 hours, and then molded into a molded product by an injection molding machine, and then subjected to ASTM D256.
The Izod impact strength was measured according to. The results are shown in Table 1.

[0035]

[Table 1]

Application Example 2 The procedure of Application Example 1 was repeated, except that the amount of the graft copolymer 1 was changed to 80 g. The results are shown in Table 1.

Application Example 3 The procedure of Application Example 1 was repeated except that 40 g of the graft copolymer 2 synthesized in Example 2 was used instead of the graft copolymer 1. The results are shown in Table 1.

Comparative Application Example Application Example 1 except that Graft Copolymer 1 was not used.
It carried out similarly to. The results are shown in Table 1.

[0039]

As described above, according to the production method of the present invention, a graft copolymer which remarkably improves the compatibility between polyester and styrene resin can be obtained.

Claims (1)

[Claims] 1. A terminal-polymerizable polyester obtained by reacting a thermoplastic polyester having a carboxyl group at one end of a molecular chain with a styrene derivative having an amino group or a hydroxyl group or an acrylic derivative having an amino group or a hydroxyl group, to obtain a styrene-based polyester A method for producing a graft copolymer, which comprises graft-copolymerizing a monomer.