JP2004315796A - Manufacturing method of thermoplastic copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a thermoplastic copolymer excellent in heat resistance, colorless transparency and stagnation stability. <P>SOLUTION: A metal salt-containing copolymer comprising (i) an alkyl unsaturated carboxylate unit, (ii) an unsaturated carboxylic acid metal salt unit and (iii) an unsaturated carboxylic acid unit is manufactured. Subsequently, the metal salt-containing copolymer (A) is subjected to a heat treatment thereby causing an intramolecular cyclization reaction by a dealcoholation reaction, a dehydration reaction or a demetallation reaction to give the thermoplastic copolymer containing a glutaric anhydride unit and unit (i). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a thermoplastic copolymer containing glutaric anhydride units, which is excellent in heat resistance, colorless transparency, and retention stability.

  Amorphous resins such as polymethyl methacrylate (hereinafter, referred to as PMMA) and polycarbonate (hereinafter, referred to as PC) utilize their transparency and dimensional stability to make use of optical materials, home electric appliances, OA appliances, automobiles, and the like. It is used in a wide range of fields, including various parts.

  In recent years, these amorphous resins have been widely used for higher performance optical materials such as optical lenses, prisms, mirrors, optical disks, optical fibers, sheets and films for liquid crystal displays and light guide plates, in particular. As a result, the optical properties and heat resistance required of the resin have become higher.

  However, although PMMA has excellent transparency and weather resistance, there is a problem that heat resistance is not sufficient. On the other hand, although PC is excellent in heat resistance and impact resistance, it has a problem such as a large birefringence, which is an optical distortion, and optical anisotropy in a molded product.

  Therefore, for the purpose of improving the heat resistance of PMMA, a resin in which a maleimide-based monomer or a maleic anhydride monomer is introduced as a heat-resistance-imparting component has been developed. However, maleimide-based monomers are expensive and have low reactivity, and maleic anhydride has a problem of poor thermal stability.

  As a method for improving the heat resistance of PMMA, a copolymer containing glutaric anhydride units obtained by heating a copolymer containing unsaturated carboxylic acid units (for example, see Patent Document 1) is known. . The method for obtaining this copolymer is a method of subjecting only a copolymer containing an unsaturated carboxylic acid unit to an extruder to produce a copolymer containing a glutaric anhydride unit. The reaction from the carboxylic acid unit to the glutaric anhydride unit does not proceed sufficiently, and the unsaturated carboxylic acid unit remaining in the copolymer containing the glutaric anhydride unit increases. In this case, at the time of molding such as injection molding, since the reaction to glutaric anhydride units proceeds, there is a problem that a reaction by-product having a low boiling point is generated, which causes a silver streak of the molded product. . Also, if the residual amount of the unsaturated carboxylic acid unit is large, the retention stability is deteriorated, so that there is a problem that the color is largely colored at the time of molding.

  As a method for solving such a problem, a method of adding a basic compound for the purpose of accelerating the reaction to glutaric anhydride during the production of a copolymer containing glutaric anhydride units (For example, see Patent Document 2), a method of adding an organic carboxylate and / or a carbonate (for example, see Patent Document 3), and further adding hypophosphite for the purpose of suppressing coloring. A method (for example, see Patent Document 4) has been proposed.

However, according to the technique of adding a catalyst, although the reaction to glutaric anhydride units is certainly promoted and the coloring is suppressed to some extent, the problem that the coloring is still large as compared with a general acrylic resin. there were. Further, in these patent documents, it is disclosed that the amount of catalyst added is reduced to a very small amount in order to further suppress coloration. The reaction to the anhydride unit was not promoted, and as a result, the residual amount of the unsaturated carboxylic acid unit was increased, and the retention stability was deteriorated. Further, when the above-described additive is added in an amount sufficient to sufficiently react with the glutaric anhydride unit, the aggregate of the additive or the metal-containing substance generated during the reaction with the glutaric anhydride unit is added. However, there is a problem in that it remains up to the final product and becomes a foreign substance, which greatly impairs the colorless transparency of the final product and the retention stability during recycling of the final product.
JP-A-49-85184 (Page 1-2, Example) JP-A-61-254608 (page 1-2, Example) JP-A-61-261303 (Page 1-2, Example) JP-A-9-48818 (page 1-2, Example)

  An object of the present invention is to solve the above-mentioned problems in the prior art, that is, to promote a reaction to glutaric anhydride units and to create a method for producing a glutaric anhydride unit-containing thermoplastic copolymer in which coloring is suppressed. As a result of the examination, it has been achieved.

  Therefore, an object of the present invention is to provide a glutaric anhydride having a high degree of heat resistance, colorless transparency and stagnant stability recently required by a technique different from the conventional technique of adding an additive such as a metal salt. An object of the present invention is to provide a method for producing a thermoplastic copolymer containing a substance unit.

  The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that glutaric anhydride units produced by a method using a metal salt-containing copolymer (A) containing unsaturated carboxylic acid metal salt units can be used. The present inventors have found that the contained thermoplastic copolymer (B) is excellent in heat resistance, colorless transparency and retention stability, and have reached the present invention.

That is, the present invention
(I) producing a metal salt-containing copolymer (A) having an unsaturated carboxylic acid alkyl ester unit, (ii) an unsaturated carboxylic acid metal salt unit and (iii) an unsaturated carboxylic acid unit (first step); Thereafter, the metal salt-containing copolymer (A) is subjected to a heat treatment to perform (a) a dealcoholation reaction, (b) a dehydration reaction, or (c) an intramolecular cyclization reaction with a demetalization compound (second step), (Iv) a thermoplastic copolymer comprising a glutaric anhydride unit represented by the following general formula (1) and (i) a thermoplastic copolymer (B) containing an unsaturated carboxylic acid alkyl ester unit: It is intended to provide a method for producing a united product.

(However, R ¹ and R ² represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.)

In the method for producing a thermoplastic copolymer of the present invention,
(Iii) that the unsaturated carboxylic acid unit has a structure represented by the following general formula (2);

(However, R ³ represents hydrogen or an alkyl group having 1 to 5 carbon atoms)
(I) the unsaturated carboxylic acid alkyl ester unit has a structure represented by the following general formula (3);

(However, R ⁴ represents hydrogen or an alkyl group having 1 to ⁵ carbon atoms, and R ⁵ represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms, or a hydroxyl group or halogen having at least one but no more than carbon atoms.) Represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms substituted with
(Ii) the metal of the unsaturated carboxylic acid metal salt unit is at least one metal selected from alkali metals and alkaline earth metals;
The first step comprises polymerizing a monomer mixture containing an unsaturated carboxylic acid alkyl ester monomer, an unsaturated carboxylic acid metal salt monomer and an unsaturated carboxylic acid monomer, thereby forming a metal salt-containing copolymer. Being a step of obtaining a coalescence (A),
The polymerization temperature of the metal salt-containing copolymer (A) is 95 ° C. or less;
In the first step, the raw copolymer (C) containing the (i) unsaturated carboxylic acid alkyl ester unit and (iii) unsaturated carboxylic acid unit is treated with a basic aqueous solution containing a metal ion. And the step of obtaining the metal salt-containing copolymer (A), and the polymerization temperature of the raw copolymer (C) being 95 ° C. or lower, all being preferred conditions.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the thermoplastic copolymer excellent in heat resistance, colorless transparency, and residence stability can be provided.

  Hereinafter, the method for producing the thermoplastic copolymer containing glutaric anhydride unit of the present invention will be specifically described.

  The thermoplastic copolymer (B) of the present invention includes (iv) a thermoplastic copolymer containing a glutaric anhydride unit represented by the following general formula (1) and (i) an unsaturated carboxylic acid alkyl ester unit. These can be used alone or in combination of two or more.

(In the above formula, R ¹ and R ² represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.)

  The method for producing a thermoplastic copolymer of the present invention is a method described below. That is, the metal salt-containing copolymer (A) containing (i) an unsaturated carboxylic acid alkyl ester unit, (ii) an unsaturated carboxylic acid metal salt unit, and (iii) an unsaturated carboxylic acid unit is heated to (a) This is a production method in which a dealcoholization reaction, (b) a dehydration reaction, or (c) an intramolecular cyclization reaction with a demetallation compound is performed (second step) to obtain a thermoplastic copolymer (B).

  In this case, typically, in the second step, water is eliminated from the carboxyl group of two units (iii) unsaturated carboxylic acid units by heating the metal salt-containing copolymer (A), or An alcohol is eliminated from one adjacent unit of (iii) unsaturated carboxylic acid unit and one unit of (i) unsaturated alkyl ester unit of carboxylic acid, or one adjacent unit of (ii) metal unsaturated carboxylic acid The metal content is eliminated from the salt unit and one unit of (i) an unsaturated carboxylic acid alkyl ester unit or one unit of (iii) an unsaturated carboxylic acid unit to form one unit of (iv) glutaric anhydride unit. Generated.

  The method (first step) for producing the metal salt-containing copolymer (A) according to the present invention is not particularly limited, but is preferably (a) an unsaturated carboxylic acid alkyl ester monomer or an unsaturated carboxylic acid metal. A method of obtaining a metal salt-containing copolymer (A) by polymerizing a monomer mixture containing a salt monomer and an unsaturated carboxylic acid monomer, and (b) the above (i) an unsaturated alkyl carboxylate A method of obtaining a metal salt-containing copolymer (A) by treating a raw copolymer (C) containing an ester unit and (iii) an unsaturated carboxylic acid unit with a basic aqueous solution containing a metal ion. Can be used.

  (A) A method of polymerizing a monomer mixture containing an unsaturated carboxylic acid alkyl ester monomer, an unsaturated carboxylic acid metal salt monomer, and an unsaturated carboxylic acid monomer, provides a metal salt-containing copolymer (A The unsaturated carboxylic acid monomer used for obtaining the above (1) is not particularly limited, and any unsaturated carboxylic acid monomer that can be copolymerized with another vinyl compound can be used. As a preferred unsaturated carboxylic acid monomer, the following general formula (4)

(However, R ³ represents hydrogen or an alkyl group having 1 to 5 carbon atoms)
And maleic acid, and furthermore, a hydrolyzate of maleic anhydride, and the like. Among them, acrylic acid and methacrylic acid are preferable, and methacrylic acid is more preferable in terms of particularly excellent thermal stability. These can be used alone or in combination of two or more. The unsaturated carboxylic acid monomer represented by the general formula (4) gives, when copolymerized, (iii) an unsaturated carboxylic acid unit having a structure represented by the general formula (2).

  The unsaturated carboxylic acid alkyl ester-based monomer is not particularly limited, but preferred examples include those represented by the following general formula (5).

(However, R ⁴ represents hydrogen or an alkyl group having 1 to ⁵ carbon atoms, and R ⁵ represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms, or a hydroxyl group or halogen having at least one but no more than carbon atoms.) Represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms substituted with

  Of these, acrylates and / or methacrylates having an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms or a hydrocarbon group having a substituent are particularly preferred. The unsaturated carboxylic acid alkyl ester monomer represented by the general formula (5) gives (i) an unsaturated carboxylic acid alkyl ester unit having a structure represented by the general formula (3) when copolymerized. .

  Preferred specific examples of the unsaturated carboxylic acid alkyl ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylate. ) T-butyl acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate, 2,3,4,5-tetrahydroxypentyl (meth) acrylate and the like. Of these, methyl methacrylate is most preferably used. One or more of these can be used.

  The unsaturated carboxylic acid metal salt monomer is not particularly limited, but preferred examples include a metal salt of an unsaturated carboxylic acid monomer represented by the above general formula (4). More preferred are metal acrylates or metal methacrylates, and even more preferred are metal methacrylates. The unsaturated carboxylic acid metal salt monomer gives (ii) an unsaturated carboxylic acid metal salt unit when copolymerized.

  The metal used in the unsaturated carboxylic acid metal salt monomer is not particularly limited, but is preferably an alkali metal or an alkaline earth metal. More preferably, lithium, sodium, and potassium are alkali metals. Examples of the earth metal include beryllium, magnesium, and calcium, and sodium is particularly preferable. Specific examples of the unsaturated carboxylic acid metal salt monomer include sodium acrylate and sodium methacrylate, and particularly preferably sodium methacrylate.

  (B) treating a raw copolymer (C) containing the above (i) an unsaturated carboxylic acid alkyl ester unit and (iii) an unsaturated carboxylic acid unit with a basic aqueous solution containing a metal ion to obtain a metal salt As a method for producing the raw copolymer (C) used for obtaining the containing copolymer (A), a monomer mixture containing an unsaturated carboxylic acid alkyl ester monomer and an unsaturated carboxylic acid monomer is used. Is polymerized. Preferred embodiments of the unsaturated carboxylic acid alkyl ester monomer and unsaturated carboxylic acid monomer used in this case include the above-mentioned (a) the unsaturated carboxylic acid alkyl ester monomer and the unsaturated carboxylic acid metal salt. By polymerizing a monomer mixture containing a monomer and an unsaturated carboxylic acid monomer, an unsaturated carboxylic acid alkyl ester monomer and an unsaturated carboxylic acid monomer used for obtaining a metal salt-containing copolymer (A) are obtained. Same as the carboxylic acid monomer.

  In the production of the metal salt-containing copolymer (A) or the raw copolymer (C) of the present invention, other vinyl monomers may be used as long as the effects of the present invention are not impaired. . Preferred specific examples of other vinyl monomers include aromatic monomers such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene and pt-butylstyrene. Group vinyl monomers, acrylonitrile, methacrylonitrile, vinyl cyanide monomers such as ethacrylonitrile, allyl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, maleic anhydride, itaconic anhydride, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, aminoethyl acrylate, acrylic acid Propylaminoethyl, glycidyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, glycidyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, Examples include methallylamine, N-methylallylamine, p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, and 2-styryl-oxazoline. From the viewpoint of certain colorless and transparent properties, a monomer containing no aromatic ring can be more preferably used. These can be used alone or in combination of two or more.

  The polymerization method of the metal salt-containing copolymer (A) or the raw copolymer (C) is basically a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization by radical polymerization. Although it can be used, solution polymerization, bulk polymerization, and suspension polymerization are particularly preferred in that they have less impurities.

  In addition, the production of the metal salt-containing copolymer (A) or the raw copolymer (C) at a polymerization temperature of 95 ° C. or lower is advantageous in terms of the colorless and transparent aspect of the thermoplastic copolymer (B) of the present invention. A preferred and more preferred polymerization temperature is 85 ° C or lower, particularly preferably 75 ° C or lower. The lower limit of the polymerization temperature is not particularly limited as long as the polymerization proceeds, but is usually 50 ° C. or higher, preferably 60 ° C. or higher from the viewpoint of productivity in consideration of the polymerization rate. For the purpose of improving the polymerization yield or the polymerization rate, it is possible to raise the polymerization temperature in accordance with the progress of the polymerization, but also in this case, the upper limit temperature is preferably controlled to 95 ° C. or lower, It is also preferable to carry out at a relatively low temperature of 75 ° C. or less. The polymerization time is not particularly limited as long as it is a time sufficient to obtain a required polymerization rate, but is preferably in the range of 60 to 360 minutes, particularly preferably in the range of 90 to 180 minutes from the viewpoint of production efficiency.

  In the present invention, (a) a monomer mixture containing an unsaturated carboxylic acid alkyl ester monomer, an unsaturated carboxylic acid metal salt monomer and an unsaturated carboxylic acid monomer is polymerized to form a metal salt-containing monomer. The preferable ratio of the monomer in the monomer mixture used for obtaining the polymer (A) is 0.1% by weight of the unsaturated carboxylic acid metal salt monomer, based on 100% by weight of the monomer mixture. It is from 0.1 to 10% by weight, more preferably from 0.05 to 5% by weight, and still more preferably from 0.1 to 3% by weight. A desirable ratio of the unsaturated carboxylic acid monomer is 15 to 50% by weight, more preferably 20 to 45% by weight. When other copolymerizable vinyl monomers are used, the preferable ratio is 0 to 35% by weight. The remainder is an unsaturated carboxylic acid alkyl ester monomer.

  When the amount of the unsaturated carboxylic acid metal salt monomer is less than 0.01% by weight, the glutaric anhydride unit represented by the above general formula (1) by heating the metal salt-containing copolymer (A) is used. The amount of generation tends to decrease. On the other hand, when the amount of the unsaturated carboxylic acid metal salt monomer exceeds 10% by weight, a large amount of the metal compound produced as a by-product remains after the cyclization reaction of the metal salt-containing copolymer (A) by heating. The colorless transparency tends to decrease due to the aggregates. When the amount of the unsaturated carboxylic acid monomer is less than 15% by weight, the amount of the glutaric anhydride unit represented by the above general formula (1) due to the heating of the raw copolymer tends to decrease. is there. On the other hand, when the amount of the unsaturated carboxylic acid monomer exceeds 50% by weight, a large amount of the unsaturated carboxylic acid unit tends to remain after the cyclization reaction of the raw copolymer by heating, and the colorless and transparent resin has Retention stability tends to decrease.

  In the present invention, (b) the raw copolymer (C) containing the (i) unsaturated carboxylic acid alkyl ester unit and (iii) the unsaturated carboxylic acid unit is treated with a basic aqueous solution containing a metal ion. By doing so, in producing the raw copolymer (C) used in obtaining the metal salt-containing copolymer (A), the monomer mixture used in the production of the raw copolymer (C) is preferably used. As for the ratio, the unsaturated carboxylic acid monomer is preferably 15 to 50% by weight, more preferably 20 to 45% by weight, and the unsaturated carboxylic acid alkyl ester-based monomer is preferably 50% by weight, with the monomer mixture being 100% by weight. -85% by weight, more preferably 55-80% by weight. When other copolymerizable vinyl monomers are used, the preferable ratio is 0 to 35% by weight.

  When the amount of the unsaturated carboxylic acid monomer is less than 15% by weight, the amount of the glutaric anhydride unit represented by the above general formula (1) due to the heating of the raw copolymer (C) tends to decrease. There is. On the other hand, when the amount of the unsaturated carboxylic acid monomer exceeds 50% by weight, a large amount of the unsaturated carboxylic acid unit tends to remain after the cyclization reaction of the raw copolymer (C) by heating, and Transparency and retention stability tend to decrease.

  (B) treating the raw copolymer (C) containing the above (i) an unsaturated carboxylic acid alkyl ester unit and (iii) an unsaturated carboxylic acid unit with a basic aqueous solution containing a metal ion to obtain a metal salt The method for obtaining the containing copolymer (A) is to treat the (iii) unsaturated carboxylic acid unit in the raw copolymer (C) in a basic aqueous solution containing a metal ion, thereby obtaining (iii) In this method, unsaturated carboxylic acid units are converted into (ii) unsaturated carboxylic acid metal salt units.

  (B) treating the raw copolymer (C) containing the above (i) an unsaturated carboxylic acid alkyl ester unit and (iii) an unsaturated carboxylic acid unit with a basic aqueous solution containing a metal ion to obtain a metal salt The metal ion in the basic aqueous solution containing the metal ion used for obtaining the containing copolymer (A) is not particularly limited, but is preferably an alkali metal or an alkaline earth metal, and more preferably an alkali metal. Include lithium, sodium and potassium, and examples of alkaline earth metals include beryllium, magnesium and calcium.

  The method for preparing the basic aqueous solution is not particularly limited, but a method of dissolving a basic metal compound which ionizes and generates metal ions in water by preparing the aqueous solution can be used. There is no particular limitation on the basic metal compound that ionizes to form a metal ion when converted to an aqueous solution, and examples thereof include metal hydroxides, metal carbonates, and metal hydrogen carbonates, and preferably metal hydroxides. It is.

  The pH of the basic aqueous solution adjusted by the above method is in the range of 7.1 to 14 as measured with a Castani ACT pH meter D-20 manufactured by HORIBA. This basic aqueous solution is subjected to the treatment of the metal salt-containing copolymer. Generally, the higher the pH of this aqueous solution, the more the content of the metal salt introduced into the copolymer tends to increase. The pH can be adjusted by controlling the concentration of the basic aqueous solution so that the desired unit amount of (ii) the unsaturated carboxylic acid metal salt is obtained.

  The treatment of the raw copolymer (C) with the basic aqueous solution is performed by charging the raw copolymer (C) into the basic aqueous solution and performing a stirring treatment. For example, when the raw copolymer (C) is obtained by suspension polymerization, the raw copolymer (C) is obtained in the form of beads, and the raw copolymer (C) in the form of beads is added to a basic aqueous solution. And stirring is performed. When the raw copolymer (C) is obtained by bulk polymerization, the raw copolymer (C) can be obtained as a bulk or a pellet, but the bulk or pellet of the raw copolymer (C) is pulverized. After pulverization, it is charged into a basic aqueous solution and stirred.

  There is no particular limitation on the temperature at which the stirring treatment is performed when the raw copolymer (C) is treated with the basic aqueous solution, but it is preferably 10 to 100 ° C, more preferably 15 to 90 ° C, and further preferably 20 to 80 ° C. It is about. The stirring time is not particularly limited as long as the desired (ii) unsaturated carboxylic acid metal salt unit amount can be contained in the metal salt-containing copolymer (A), but is preferably from 15 minutes to 15 minutes. The time is 15 hours, more preferably 30 minutes to 13 hours, even more preferably about 30 minutes to 10 hours.

  The content of (ii) the unsaturated carboxylic acid metal salt unit in 100% by weight of the metal salt-containing copolymer (A) obtained by treating the raw copolymer (C) with a basic aqueous solution is 0.01 to 10%. % By weight, more preferably 0.05 to 5% by weight, even more preferably 0.1 to 3% by weight, and the amount of metal ions in the basic aqueous solution is as follows: (ii) unsaturated carboxylic acid metal salt units Is an amount falling within this range.

In addition, an infrared spectrophotometer can be used for quantifying (ii) the unsaturated carboxylic acid metal salt unit in the metal salt-containing copolymer (A) of the present invention. (Ii) The unsaturated carboxylic acid metal salt unit is characterized by absorption at 1610 to 1550 cm ^-1 and 1400 to 1300 cm ^-1 , and (iii) an unsaturated carboxylic acid unit and (i) an unsaturated carboxylic acid alkyl ester unit. Can be distinguished from

  By heating the metal salt-containing copolymer (A) in the present invention, (a) a dealcoholization reaction and / or (b) a dehydration reaction and / or (c) an intramolecular cyclization reaction with a demetallation compound, The method for producing the thermoplastic polymer (B) containing a glutaric anhydride unit is not particularly limited, but may be a method in which the thermoplastic polymer (B) is produced by passing it through a heated extruder having a vent, or a method in which heat is removed in a nitrogen stream or under vacuum. Preferred is a method of manufacturing in a recognizable device. The temperature for degassing by heating by the above method is not particularly limited as long as (a) a dealcoholization reaction and / or (b) a dehydration reaction and / or (c) an intramolecular cyclization reaction by a demetallation compound occurs. However, the lower limit temperature is preferably 180 ° C, more preferably 200 ° C, and the upper limit temperature is preferably 320 ° C, 310 ° C, 300 ° C, 280 ° C. In addition, the time for heating and degassing at this time is not particularly limited and can be appropriately set depending on the desired copolymer composition, but is usually 3 minutes to 60 minutes, preferably 5 minutes to 30 minutes, and more preferably The range is from 8 minutes to 20 minutes.

  Further, the thermoplastic copolymer (B) produced by the present invention preferably has a weight average molecular weight of 50,000 to 150,000. The thermoplastic copolymer (B) having such a molecular weight has a desired molecular weight, that is, a weight average molecular weight of 50,000 to 15 at the time of polymerization of the metal salt-containing copolymer (A) or the raw copolymer (C). This can be achieved by controlling in advance. When the weight-average molecular weight exceeds 150,000, there is a tendency for coloring during heating and degassing in a subsequent step. On the other hand, when the weight average molecular weight is less than 50,000, the mechanical strength of the molded article tends to decrease.

  The method for controlling the molecular weight of the metal salt-containing copolymer (A) or the raw copolymer (C) is not particularly limited, and for example, generally known techniques can be applied. For example, azo compounds, controlled by the addition amount of a radical polymerization initiator such as a peroxide, or the addition amount of a chain transfer agent such as an alkyl mercaptan, carbon tetrachloride, carbon tetrabromide, dimethylacetamide, dimethylformamide, and triethylamine. can do. In particular, from the viewpoint of polymerization stability, ease of handling, and the like, a method of controlling the amount of alkyl mercaptan as a chain transfer agent can be preferably used.

  Examples of the alkyl mercaptan used in the present invention include, for example, n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, and among others, t-dodecyl mercaptan, n-Dodecyl mercaptan is preferably used.

  The amount of these alkyl mercaptans to be added is not particularly limited, but is usually 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, based on 100 parts by weight of the total amount of the monomer mixture. 0.8 parts by weight, 0.9 parts by weight, and 1.0 parts by weight are preferred, and the upper limit of the addition amount is 5.0 parts by weight, 4.0 parts by weight, and 3.0 parts by weight.

  Further, in the present invention, when the metal salt-containing copolymer (A) is heated by the above-mentioned method or the like, the ring to glutaric anhydride may be added as long as the effects of the present invention are not impaired in colorless transparency and retention stability. One or more acids, bases and salt compounds can be added as a catalyst for accelerating the chemical reaction. The addition amount is preferably less than 0.1 part by weight based on 100 parts by weight of the metal salt-containing copolymer (A). There are no particular restrictions on the types of these acids, bases, and salt compounds, and examples of the acid catalyst include hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, phosphoric acid, phosphorous acid, phenylphosphonic acid, and methyl phosphate. . Examples of the basic catalyst include metal hydroxides, amines, imines, alkali metal derivatives, alkoxides, and ammonium hydroxide salts. Further, examples of the salt-based catalyst include metal acetate, metal stearate, and metal carbonate. Among the salt-based catalysts, those exhibiting acidity or basicity when prepared as an aqueous solution are included. These are salt-based catalysts and are distinguished from acid catalysts or basic catalysts. One or more of these catalysts can be added as long as the object of the present invention is not impaired. Among them, a basic catalyst can be preferably used because it shows an excellent reaction promoting effect with a relatively small amount of addition. Specifically, hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkoxide compounds such as sodium methoxide, sodium ethoxide, sodium phenoxide, potassium methoxide, potassium ethoxide and potassium phenoxide, lithium acetate And organic carboxylate salts such as sodium acetate, potassium acetate and sodium stearate. Among them, sodium hydroxide, sodium methoxide, lithium acetate and sodium acetate can be preferably used.

The content of the (iv) glutaric anhydride unit represented by the general formula (1) in the thermoplastic copolymer (B) of the present invention is preferably in 100% by weight of the thermoplastic copolymer (B). 5 to 50% by weight, more preferably 10 to 45% by weight. In addition, an infrared spectrophotometer can be used to determine (iv) glutaric anhydride units and (ii) unsaturated carboxylic acid metal salt units. (Iv) glutaric anhydride units are characterized by absorption at 1800 cm ^-1 and 1760 cm ^-1 , (iii) unsaturated carboxylic acid units, (ii) unsaturated carboxylic acid metal salt units and (i) unsaturated units It can be distinguished from carboxylic acid alkyl ester units. (Ii) the unsaturated carboxylic acid metal salt unit is characterized by absorption at 1610 to 1550 cm ^-1 and 1400 to 1300 cm ^-1 , (iv) glutaric anhydride unit, (iii) unsaturated carboxylic acid unit and (iii) i) Can be distinguished from unsaturated carboxylic acid alkyl ester units. Therefore, the composition ratio of (iv) glutaric anhydride unit and (ii) unsaturated carboxylic acid metal salt unit can be determined by a method using an infrared spectrophotometer.

In addition, for the quantitative determination of each component contained in the thermoplastic copolymer (B) of the present invention, a method based on ¹ H-NMR can be used together with the method based on the infrared spectrophotometer described above. For example, glutaric anhydride units, methacrylic acid, in the case of a copolymer consisting of methyl methacrylate, the assignment of the spectrum, peaks of 0.5 to 1.5 ppm methacrylic acid, methyl methacrylate and glutaric anhydride ring compound , A peak at 1.6 to 2.1 ppm is a hydrogen of a methylene group in the polymer main chain, a peak at 3.5 ppm is a hydrogen of a carboxylic acid ester of methyl methacrylate (—COOCH ₃ ), The peak at 4 ppm can determine the copolymer composition in combination with the hydrogen of carboxylic acid of methacrylic acid, the integration ratio of the spectrum and the result of measurement by the infrared spectrophotometer.

  When (iii) an unsaturated carboxylic acid unit is contained in the thermoplastic copolymer (B) of the present invention, the amount of the (iii) unsaturated carboxylic acid unit is preferably from 0 to 5% by weight, most preferably. 0 to 1% by weight. (Iii) When the amount of the unsaturated carboxylic acid unit exceeds 5% by weight, the colorless transparency and the retention stability tend to decrease. When (ii) an unsaturated carboxylic acid metal salt unit is contained, the amount of the (ii) unsaturated carboxylic acid metal salt unit is preferably 0 to 5% by weight, more preferably 0 to 3% by weight.

  Further, (i) the amount of the unsaturated carboxylic acid alkyl ester unit is preferably 50 to 95% by weight, more preferably 55 to 90% by weight, and the other copolymerizable vinyl monomer is preferably 0 to 35% by weight. %.

  Although the intrinsic viscosity of the thermoplastic copolymer (B) of the present invention is not particularly limited, the intrinsic viscosity measured at 30 ° C. in a dimethylformamide solution using an Ubbelohde type viscosity system is 0.05 to 0.8 dl / g. Is preferably, more preferably 0.1 to 0.7 dl / g, and still more preferably 0.3 to 0.6 dl / g.

  Further, the thermoplastic copolymer (B) of the present invention has excellent heat resistance such as a glass transition temperature of 120 ° C. or more, and is preferable in terms of practical heat resistance. Further, in a preferred embodiment, it has extremely excellent heat resistance with a glass transition temperature of 130 ° C. or higher. In addition, the glass transition temperature mentioned here is a glass transition temperature measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSK-7 manufactured by Perkin Elmer).

  Further, at the time of producing the thermoplastic copolymer (B) of the present invention, a hindered phenol-based, benzotriazole-based, benzophenone-based, benzoate-based, cyanoacrylate-based ultraviolet absorber and Antioxidants, lubricants and plasticizers such as higher fatty acids, acid esters and acid amides, and higher alcohols; release agents such as montanic acid and its salts, esters, half esters thereof, stearyl alcohol, stearamide, and ethylene wax , Phosphites, hypophosphites, etc., coloring inhibitors, halogen-based flame retardants, phosphorus-based and silicone-based non-halogen-based flame retardants, nucleating agents, amine-based, sulfonic-based, polyether-based, etc. Additives such as colorants such as inhibitors and pigments may optionally be included. However, it is necessary to add the additive within a range in which the color of the additive does not adversely affect the thermoplastic copolymer (B) of the present invention and the transparency does not decrease.

  The method for mixing these additives is not particularly limited as long as these additives are sufficiently dispersed in the thermoplastic copolymer (B) of the present invention, and the metal salt-containing copolymer (A) or It can be mixed at the time of production of the raw copolymer (C) and at the time of production of the thermoplastic copolymer (B), but is preferably at the time of production of the thermoplastic copolymer (B).

  The thermoplastic copolymer (B) produced according to the present invention makes use of its excellent heat resistance, colorless transparency, and retention stability to make use of electric / electronic parts, automobile parts, mechanical mechanism parts, OA equipment, and home electric appliances. It can be used for various applications such as housings and parts thereof, general goods and the like.

  Specific uses of the molded article made of the thermoplastic copolymer (B) produced according to the present invention include, for example, housings for electric equipment, housings for OA equipment, various covers, various gears, various cases, sensors, LED lamps. , Connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable condenser cases, optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small motors, Electric / electronic parts such as magnetic head base, power module, housing, semiconductor, liquid crystal, FDD carriage, FDD chassis, motor brush holder, parabolic antenna, computer related parts; VTR parts, TV parts, irons, hair dryers Appliances, rice cooker parts, microwave oven parts, audio parts, audio equipment parts such as audio / laser discs / compact discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, etc. Product parts, office computer related parts, telephone related parts, facsimile related parts, copier related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings, etc., various bearings, motor parts, lighters, typewriters, etc. Representative mechanical-related parts, optical equipment such as microscopes, binoculars, cameras, watches, etc., precision machinery-related parts; alternator terminals, alternator connectors, IC regulators, various valves such as exhaust gas valves, fuel-related, exhaust systems, intake Various pipes, air Intake nozzle snorkel, intake manifold, fuel pump, engine cooling water joint, carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow Meter, Thermostat base for air conditioner, Heating hot air flow control valve, Brush holder for radiator motor, Water pump impeller, Turbine vane, Wiper motor related parts, Dust distributor, Starter switch, Starter relay, Transmission wire harness, Window washer Nozzle, air conditioner panel switch board, fuel related solenoid valve coil, Examples include a fuse connector, a horn terminal, an electrical component insulating plate, a step motor rotor, a lamp socket, a lamp reflector, a lamp housing, a brake piston, a solenoid bobbin, an engine oil filter, and an ignition device case. In addition, because of their excellent transparency and heat resistance, they are used as video equipment-related parts, such as cameras, VTRs, projection TVs and other shooting lenses, viewfinders, filters, prisms, Fresnel lenses, and other optical recording and optical communication-related parts. Liquid crystal display, flat panel display, plasma, etc. as information equipment related parts such as various optical disk (VD, CD, DVD, MD, LD, etc.) substrates, various disk substrate protection films, optical disk player pickup lenses, optical fibers, optical switches, optical connectors, etc. Display light guide plate, Fresnel lens, polarizing plate, polarizing plate protective film, retardation film, light diffusion film, viewing angle widening film, reflection film, antireflection film, antiglare film, brightness enhancement film, prism sheet, pickup lens Parts for transportation equipment such as automobiles, such as lenses, light guide films for touch panels, covers, etc., include tail lamp lenses, head lamp lenses, inner lenses, amber caps, reflectors, extensions, side mirrors, room mirrors, side visors, instrument needles, and instrument covers. , Glazing represented by window glass, medical equipment related parts, spectacle lenses, spectacle frames, contact lenses, endoscopes, analytical optical cells, etc., building materials related parts, lighting windows, road translucent plates, lighting covers It can also be applied to signboards, translucent sound insulating walls, bathtub materials and the like, and is extremely useful for these various uses.

  Hereinafter, the configuration and effects of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples.

Production of thermoplastic copolymer (B) [Example 1]
(B-1):
(First step)
In a stainless steel autoclave having a capacity of 5 liters and equipped with a baffle and a Faudra type stirring blade, a methyl methacrylate / acrylamide copolymer suspension (prepared by the following method: 20 parts by weight of methyl methacrylate, 80 parts by weight of acrylamide) Then, 0.3 parts by weight of potassium persulfate and 1500 parts by weight of ion-exchanged water were charged into a reactor, and the temperature of the reactor was maintained at 70 ° C. while replacing the reactor with nitrogen gas. The reaction was continued until the conversion, and an aqueous solution of methyl methacrylate and acrylamide copolymer was obtained. The obtained aqueous solution was used as a suspending agent. A solution of 0.05 part in 165 parts of ion-exchanged water was supplied, and 400 rpm was supplied. And the system was purged with nitrogen gas.

Next, the following mixture was added while stirring the reaction system, and the temperature was raised to 70 ° C. The time when the internal temperature reached 70 ° C. was defined as the start of polymerization, and was maintained for 180 minutes to complete the polymerization. Thereafter, the reaction system was cooled, the polymer was separated, washed, and dried according to a conventional method to obtain a bead-shaped metal salt-containing copolymer. The polymerization rate of this metal salt-containing copolymer was 98%.
Sodium methacrylate 0.5 parts by weight Methacrylic acid (MAA) 29.5 parts by weight Methyl methacrylate (MMA) 70 parts by weight t-dodecylmercaptan 1.2 parts by weight 2,2'-azobisisobutyronitrile 0.32 Parts by weight

(2nd process)
The bead-shaped metal salt-containing copolymer is supplied at a rate of 5 kg / h from a hopper port of a vented co-rotating twin screw extruder (TEX30XSSST manufactured by Nippon Steel Works) having a screw diameter of 30 mm and an L / D of 45.5. Then, the resin was melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm to obtain a thermoplastic copolymer (B-1) containing pelletized glutaric anhydride units. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The results obtained thermoplastic copolymer (B-1) was analyzed with an infrared spectrophotometer, absorption peaks were observed at 1800 cm ^-1 and 1760 cm ^-1, the thermoplastic copolymer (B-1 It was confirmed that a glutaric anhydride unit was formed in ()). In addition, since there was no absorption at 1610 to 1550 cm ^-1 and 1400 to 1300 cm ^-1 , it was confirmed that no sodium methacrylate unit was present. In addition, this copolymer was dissolved in heavy dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature (23 ° C.) to determine the copolymer composition. As a result, 73% by weight of methyl methacrylate unit, glutaric acid The content was 25% by weight of an anhydride unit, 2% by weight of a methacrylic acid unit, and 0% by weight of a sodium methacrylate unit. The intrinsic viscosity of the thermoplastic copolymer (B-1) was 0.42 dl / g. Table 1 shows the results of evaluating the obtained thermoplastic copolymer (B-1) by the following methods (1) to (4).
(1) Heat resistance (Tg)
The obtained thermoplastic copolymer (B) was subjected to a differential scanning calorimeter (DSK-7, manufactured by Perkin Elmer), and Tg was measured at a temperature rising rate of 20 ° C./min under a nitrogen atmosphere.
(2) Transparency (total light transmittance, haze)
The obtained thermoplastic copolymer (B) is subjected to a hot press T2-4 manufactured by Toho Press Co., Ltd., and the press temperature is set to 250 ° C. to obtain a sheet of 70 mm × 70 mm × 3 mm, and a direct reading haze manufactured by Toyo Seiki Co., Ltd. Using a meter, total light transmittance (%) and haze (cloudiness) (%) at 23 ° C. were measured, and the transparency of the obtained sheet was evaluated.
(3) Degree of coloring (ΔYI value)
The obtained thermoplastic copolymer (B) was subjected to a hot press T2-4 manufactured by Toho Press Co., Ltd., and the press temperature was set to 250 ° C. to obtain a 70 mm × 70 mm × 3 mm sheet. The ΔYI value was measured using a color computer (manufactured by Suga Test Instruments Co., Ltd.).
(4) Retention stability YI difference of 70 mm × 70 mm × 3 mm molded product before and after the obtained thermoplastic copolymer (B) was retained in an injection molding machine at a glass transition temperature of + 140 ° C. for 20 minutes. Was calculated.

[Example 2]
(B-2):
(First step)
Polymerization was carried out in the same manner as in Example 1 except that the charged monomer composition was changed to the following composition, to obtain a bead-shaped raw copolymer. The conversion of this raw copolymer was 98%.
Methacrylic acid (MAA) 30 parts by weight Methyl methacrylate (MMA) 70 parts by weight t-Dodecyl mercaptan 1.2 parts by weight 2,2'-azobisisobutyronitrile 0.32 parts by weight

  This beaded raw copolymer was stirred at 23 ° C. for 5 hours in an aqueous solution of sodium hydroxide having a pH of 14 (an amount of 0.5% by weight of sodium hydroxide based on 100% by weight of the raw copolymer). Processed. After confirming that the pH of the aqueous solution reached 7, the beads were filtered and dried to obtain a bead-shaped metal salt-containing copolymer.

(2nd process)
The above bead-shaped metal salt-containing copolymer was fed from a hopper port of a vented co-rotating twin-screw extruder (TEX30XSSST manufactured by Nippon Steel Works) having a screw diameter of 30 mm and an L / D of 45.5 at 5 kg / h. The mixture was fed and melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm to obtain a thermoplastic copolymer (B-2) containing pelletized glutaric anhydride units. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-2) was determined in the same manner as in Example 1. The copolymer composition was determined to be 72% by weight of methyl methacrylate units, 27% by weight of glutaric anhydride units, and methacrylic acid. The acid unit was 1% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of the thermoplastic copolymer (B-2) was 0.43 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-2) in the same manner as in Example 1 are also shown in Table 1.

[Example 3]
(B-3):
(First step)
Polymerization was carried out by the same composition and method as in Example 2, and a bead-shaped metal salt-containing copolymer was obtained in the same steps.

(2nd process)
The above-mentioned bead-shaped metal salt-containing copolymer and sodium methoxide (an amount of 0.01% by weight with respect to 100% by weight of the raw copolymer) were added to a vent having a screw diameter of 30 mm and an L / D of 45.5. It is supplied at 5 kg / h from the hopper port of a co-rotating twin-screw extruder (TEX30XSSST manufactured by Nippon Steel Works Co., Ltd.), melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm, and contains pelletized glutaric anhydride units. The obtained thermoplastic copolymer (B-3) was obtained. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-3) was determined in the same manner as in Example 1. As a result, methyl methacrylate unit was 68% by weight, glutaric anhydride unit was 32% by weight, and methacrylic acid was obtained. The acid unit was 0% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of the thermoplastic copolymer (B-3) was 0.44 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-3) in the same manner as in Example 1 are also shown in Table 1.

[Comparative Example 1]
(B-4):
Polymerization was carried out under the same composition ratios and conditions as in Example 2 to obtain a beaded original copolymer. The conversion of this raw copolymer was 98%.

  This beaded raw copolymer and sodium methoxide (an amount of 0.5% by weight with respect to 100% by weight of the raw copolymer) were placed in a same direction with a vent having a screw diameter of 30 mm and an L / D of 45.5. The extruder is fed at 5 kg / h from a hopper port of a rotary twin-screw extruder (Tex30XSSST manufactured by Nippon Steel Works), melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm, and heated in a pellet form containing glutaric anhydride units. A plastic copolymer (B-4) was obtained. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-4) was determined in the same manner as in Example 1. The copolymer composition was determined to be 67% by weight of methyl methacrylate unit, 33% by weight of glutaric anhydride unit, and 33% by weight of methacrylic acid. The acid unit was 0% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of the thermoplastic copolymer (B-4) was 0.45 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-4) in the same manner as in Example 1 are also shown in Table 1.

[Comparative Example 2]
(B-5):
Polymerization was carried out in the same manner as in Example 2 except that the polymerization temperature and time were changed to 80 ° C. for 100 minutes, and then to 98 ° C. for 60 minutes, to obtain a beaded raw copolymer. The conversion of this raw copolymer was 98%.

  This beaded raw copolymer and sodium methoxide (an amount of 0.5% by weight with respect to 100% by weight of the raw copolymer) were placed in a same direction with a vent having a screw diameter of 30 mm and an L / D of 45.5. The extruder is fed at 5 kg / h from a hopper port of a rotary twin-screw extruder (Tex30XSSST manufactured by Nippon Steel Works), melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm, and heated in a pellet form containing glutaric anhydride units. A plastic copolymer (B-5) was obtained. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-5) was determined in the same manner as in Example 1. As a result, methyl methacrylate unit was 67% by weight, glutaric anhydride unit was 33% by weight, and methacrylic acid was obtained. The acid unit was 0% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of this thermoplastic copolymer (B-5) was 0.45 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-5) in the same manner as in Example 1 are also shown in Table 1.

[Comparative Example 3]
(B-6):
Polymerization was carried out in the same manner as in Example 2 except that the polymerization temperature and time were changed to 80 ° C. for 100 minutes, and then to 98 ° C. for 60 minutes, to obtain a beaded raw copolymer. The conversion of this raw copolymer was 98%.

  The beaded raw copolymer and sodium hypophosphite (an amount of 0.5% by weight with respect to 100% by weight of the raw copolymer) were provided with a vent having a screw diameter of 30 mm and an L / D of 45.5. It is supplied at 5 kg / h from the hopper port of a co-rotating twin-screw extruder (TEX30XSSST manufactured by Nippon Steel Works), melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm, and contains pelletized glutaric anhydride units. The obtained thermoplastic copolymer (B-6) was obtained. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-6) was determined in the same manner as in Example 1. As a result, 69% by weight of methyl methacrylate units, 31% by weight of glutaric anhydride units, and methacrylic acid were added. The acid unit was 0% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of the thermoplastic copolymer (B-6) was 0.45 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-6) in the same manner as in Example 1 are also shown in Table 1.

[Comparative Example 4]
(B-7):
Polymerization was carried out under the same composition ratios and conditions as in Example 2 to obtain a beaded original copolymer. The conversion of this raw copolymer was 98%.

  The beaded raw copolymer and sodium methoxide (an amount of 0.01% by weight with respect to 100% by weight of the raw copolymer) were placed in the same direction with a vent having a screw diameter of 30 mm and an L / D of 45.5. The extruder is fed at 5 kg / h from a hopper port of a rotary twin-screw extruder (Tex30XSSST manufactured by Nippon Steel Works), melt-extruded at a resin temperature of 280 ° C. and a screw rotation speed of 100 rpm, and heated in a pellet form containing glutaric anhydride units. A plastic copolymer (B-7) was obtained. The residence time (time from supply of the raw material to discharge from the discharge port) at this time was about 7 minutes. The copolymer composition of the obtained thermoplastic copolymer (B-7) was determined in the same manner as in Example 1. As a result, 74% by weight of methyl methacrylate units, 22% by weight of glutaric anhydride units, and The acid unit was 4% by weight and the sodium methacrylate unit was 0% by weight. The intrinsic viscosity of this thermoplastic copolymer (B-7) was 0.41 dl / g.

  The results of evaluating the obtained thermoplastic copolymer (B-7) in the same manner as in Example 1 are also shown in Table 1.

  From the results of Examples 1 to 3 and Comparative Examples 1 to 4, the thermoplastic copolymer produced by the production method of the present invention is superior in heat resistance, colorless transparency and retention stability as compared with Comparative Examples. It turns out to be something.

  The thermoplastic copolymer produced according to the present invention can be used for various applications such as housings for electric / electronic parts, automobile parts, mechanical mechanism parts, OA equipment, home electric appliances and the like, and their parts, and general goods. .

Claims (8)

(I) producing a metal salt-containing copolymer (A) having an unsaturated carboxylic acid alkyl ester unit, (ii) an unsaturated carboxylic acid metal salt unit and (iii) an unsaturated carboxylic acid unit (first step); Thereafter, the metal salt-containing copolymer (A) is subjected to a heat treatment to perform (a) a dealcoholation reaction, (b) a dehydration reaction, or (c) an intramolecular cyclization reaction with a demetalization compound (second step), (Iv) a thermoplastic copolymer comprising a glutaric anhydride unit represented by the following general formula (1) and (i) a thermoplastic copolymer (B) containing an unsaturated carboxylic acid alkyl ester unit: Manufacturing method of coalescence.

(However, R ¹ and R ² represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.) The method for producing a thermoplastic copolymer according to claim 1, wherein the (iii) unsaturated carboxylic acid unit has a structure represented by the following general formula (2).

(However, R ³ represents hydrogen or an alkyl group having 1 to 5 carbon atoms) 3. The method for producing a thermoplastic copolymer according to claim 1, wherein the (i) unsaturated carboxylic acid alkyl ester unit has a structure represented by the following general formula (3). 4.

(However, R ⁴ represents hydrogen or an alkyl group having 1 to ⁵ carbon atoms, and R ⁵ represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms, or a hydroxyl group or halogen having at least one but no more than carbon atoms.) Represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms substituted with The heat according to any one of claims 1 to 3, wherein the metal of the (ii) unsaturated carboxylic acid metal salt unit is at least one metal selected from alkali metals and alkaline earth metals. A method for producing a plastic copolymer. The first step comprises polymerizing a monomer mixture containing an unsaturated carboxylic acid alkyl ester monomer, an unsaturated carboxylic acid metal salt monomer and an unsaturated carboxylic acid monomer, thereby forming a metal salt-containing copolymer. The method for producing a thermoplastic copolymer according to any one of claims 1 to 4, wherein the method is a step of obtaining a united product (A). The method for producing a thermoplastic copolymer according to claim 5, wherein the polymerization temperature of the metal salt-containing copolymer (A) is 95C or lower. In the first step, the raw copolymer (C) containing the (i) unsaturated carboxylic acid alkyl ester unit and (iii) unsaturated carboxylic acid unit is treated with a basic aqueous solution containing a metal ion. The method for producing a thermoplastic copolymer according to any one of claims 1 to 4, wherein the step is a step of obtaining a metal salt-containing copolymer (A). The method for producing a thermoplastic copolymer according to claim 7, wherein the polymerization temperature of the raw copolymer (C) is 95 ° C or lower.