JP2007191706A - Thermoplastic copolymer, method for producing the same and thermoplastic resin composition composed thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic copolymer having high heat-resistance and colorless transparency, excellent low water-absorption and fluidity and generating remarkably reduced amount of gas in retention under heating, a method for producing the copolymer, a thermoplastic resin composition containing the thermoplastic copolymer and a molded article or a film produced by forming the composition, etc. <P>SOLUTION: The thermoplastic copolymer contains (i) 5-30 wt.% unsaturated carboxylic acid ester unit containing an alicyclic alkyl group; (ii) 5-85 wt.% unsaturated carboxylic acid alkyl ester unit; (iii) 0-10 wt.% unsaturated carboxylic acid unit; (iv) 10-50 wt.% glutaric anhydride unit; and 0-5 wt.% other vinyl monomer unit and/or aromatic vinyl monomer unit in total. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermoplastic copolymer excellent in heat resistance, colorless transparency, mechanical properties, particularly excellent in low water absorption, fluidity and retention stability, and a method for producing the same, and further, the thermoplastic copolymer The present invention relates to a thermoplastic resin composition comprising a coalescence.

  Amorphous resins such as polymethyl methacrylate (hereinafter referred to as PMMA) and polycarbonate (hereinafter referred to as PC) make use of their transparency and dimensional stability to make various parts such as optical materials, household electrical appliances, office automation equipment and automobiles. Used in a wide range of fields.

  In recent years, these resins have been widely used in higher performance optical materials such as optical lenses, prisms, mirrors, optical disks, optical fibers, liquid crystal display sheets and films, light guide plates, etc. The optical properties, moldability, and heat resistance required for these products are also higher.

  At present, these transparent resins are also used as lamp members for automobiles such as tail lamps and head lamps, but in recent years, tail lamp lenses, inner lenses, There is a tendency to reduce the distance between various light sources such as headlamps and shield beams and the light source, and to reduce the thickness of the parts, and excellent moldability is required. Further, since the vehicle is used under severe conditions, it is required to have a small shape change under high temperature and high humidity, and excellent scratch resistance, weather resistance, and oil resistance.

  However, although the PMMA resin has excellent transparency and weather resistance, there is a problem that the shape change under high temperature and high humidity conditions is large due to insufficient heat resistance and high water absorption. On the other hand, PC resin is excellent in heat resistance and impact resistance, but has a large birefringence, which is an optical distortion, and has optical anisotropy in the molded product, remarkably in moldability, scratch resistance, and oil resistance. There was a problem of being inferior.

  Therefore, for the purpose of improving the heat resistance and water absorption of PMMA, a copolymer in which a methacrylic acid ester monomer having an alicyclic alkyl group such as cyclohexyl methacrylate or isobornyl methacrylate is introduced as a third component has been developed. (See Patent Documents 1 and 2). However, in order to improve the water absorption, there is a problem that the content of the methacrylic ester unit having these alicyclic alkyl groups is increased, and the thermal stability and mechanical strength of the copolymer are lowered. In addition, there was a problem that the effect of improving heat resistance could not be sufficiently obtained.

  On the other hand, as a method for solving the heat resistance of PMMA, a method of introducing a glutaric anhydride unit using an intramolecular cyclization reaction is disclosed (see Patent Documents 3 and 4). However, although these methods improve heat resistance, there is a problem that melt viscosity is lowered and molding processability is inferior, and furthermore, the water absorption problem of PMMA cannot be solved.

As a method for solving these problems, glutar obtained by subjecting a copolymer containing the above alicyclic alkyl group-containing methacrylic acid ester and an unsaturated carboxylic acid monomer unit to a cyclization reaction by heat treatment is used. A copolymer having an acid anhydride unit and an alicyclic alkyl group-containing methacrylic ester unit as main components is disclosed (see Patent Document 5). However, in the polymerization method disclosed in this patent document, when the copolymerization amount of the aromatic vinyl unit is large, the birefringence becomes large and the optical isotropy is inferior, and when the aromatic vinyl unit is not copolymerized. In this case, the alicyclic alkyl group-containing methacrylic acid ester unit is not sufficiently copolymerized, and the intended polymer cannot be obtained. Further, in the method disclosed in this patent document, since the content of glutaric anhydride units is low, heat resistance and thermal stability are not sufficient, and furthermore, using the method of this patent document, glutaric acid is used. In order to increase the content of the anhydride unit, when trying to copolymerize a large amount of methacrylic acid in the original copolymer (a), the precise polymerization control intended in the present invention cannot be achieved, The present invention cannot be achieved.
JP 59-1518 A (page 1-2, Examples) JP 60-115605 A (page 1-2, Examples) JP-A-49-85184 (page 1-2, Examples) JP-A-2004-29281 (page 1-2, Examples) JP-A-2-151602 (Page 1-2, Examples)

  Therefore, the present invention has high heat resistance and colorless transparency, and at the same time, excellent fluidity, suppresses the amount of gas generated during heat retention, has excellent thermal stability, and further has dimensional stability under high temperature and high humidity. It is an object of the present invention to provide an extremely excellent thermoplastic copolymer, a production method thereof, and a thermoplastic resin composition containing the same.

  As a result of intensive studies to solve the above problems, the present inventors have produced a copolymer having an unsaturated carboxylic acid unit and an alicyclic alkyl group-containing unsaturated carboxylic acid ester in a specific polymerization method, Is obtained by heat-treating the copolymer to obtain a copolymer containing glutaric anhydride units, so that the highly colorless transparency and heat resistance, fluidity, and It has been found that a thermoplastic copolymer excellent in dimensional stability under high temperature and high humidity can be produced, and the present invention has been achieved.

That is, the present invention
[1] (i) 5-30% by weight of an alicyclic alkyl group-containing unsaturated carboxylic acid ester unit represented by the following general formula (1), (ii) an unsaturated carboxylic acid represented by the following general formula (2) 5 to 85% by weight of an acid alkyl ester unit, (iii) 0 to 10% by weight of an unsaturated carboxylic acid unit, (iv) 10 to 50% by weight of a glutaric anhydride unit represented by the following general formula (3), and A thermoplastic copolymer containing 0 to 5% by weight in total of other vinyl monomer units and / or aromatic vinyl monomer units.

(In the above formula, R1 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and R2 represents any one selected from an alicyclic alkyl group having 5 to 22 carbon atoms.)

(In the above formula, R3 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R4 is an unsubstituted or C1-C6 fatty acid in which at least one carbon is substituted with a hydroxyl group or a halogen. Represents a hydrocarbon group)

(In the above formula, R5 and R6 are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.)
[2] The thermoplastic copolymer according to [1], wherein the weight average molecular weight is 3 to 150,000.
[3] (i) The thermoplasticity according to [1] or [2], wherein the alicyclic alkyl group-containing unsaturated carboxylic acid ester unit is an unsaturated carboxylic acid cyclohexyl unit represented by the following general formula (4): Copolymer.

(In the above formula, R7 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.)
[4] 100% by weight of monomer mixture, 5 to 50% by weight of unsaturated carboxylic acid monomer, 5 to 30% by weight of alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer, unsaturated carboxylic acid A monomer mixture consisting of 15 to 90% by weight of an alkyl ester monomer and 0 to 5% by weight of an aromatic vinyl monomer is dissolved in the monomer mixture which is a raw material, and the monomer mixture is copolymerized. A first step of obtaining an original copolymer (a) by copolymerizing in an organic solvent (B) not containing an aromatic group having a solubility of the copolymer (a) of 1 g / 100 g or less,
Subsequently, the original copolymer (a) obtained in the first step is subjected to heat treatment, and (b) an intramolecular cyclization reaction by dehydration and / or (b) dealcoholization reaction,
A method for producing a thermoplastic copolymer, wherein the thermoplastic copolymer according to any one of [1] to [3] is produced.
[5] The organic solvent (B) in which the absolute value (ΔSP) of the difference between the solubility parameter of the original copolymer (a) and the solubility parameter of the organic solvent (B) is 1.0 or more is used in the above [4]. The manufacturing method of the thermoplastic copolymer of description.
[6] The organic solvent (B) in which the absolute value (ΔSP) of the difference between the solubility parameter of the original copolymer (a) and the solubility parameter of the organic solvent (B) is 1.5 to 1.7 is used. [4] The method for producing a thermoplastic copolymer according to [4].
[7] The heat according to any one of [4] to [6], wherein the organic solvent (B) is at least one selected from aliphatic hydrocarbons, carboxylic acid esters, and ketones. A method for producing a plastic copolymer.
[8] The method for producing a thermoplastic copolymer according to any one of [4] to [7], wherein the heat treatment in the second step is performed using a continuous kneading extrusion apparatus.
[9] In the continuous kneading and extruding device, the first shaft extending from the biaxial screw portion and the biaxial screw portion in which the first shaft and the second shaft forming the screw portion are arranged in parallel are arranged in the casing. The biaxial screw portion and the monoaxial screw portion are provided with a flow rate adjusting mechanism, the casing is provided with a raw material supply port communicating with the biaxial screw portion, and the extension The method for producing a thermoplastic copolymer as described in [8] above, which is a biaxial / single-shaft composite continuous kneading and extruding apparatus having a discharge port communicating with the end portion of the first shaft.
[10] In the second step, 0.001 to 1 part by weight of an alkali metal compound is added to 100 parts by weight of the copolymer (a) and heated at 180 to 380 ° C. And / or (b) a dealcoholization reaction, wherein the method for producing a thermoplastic copolymer according to any one of [4] to [9].
[11] (A) 50 to 99 parts by weight of the thermoplastic copolymer according to any one of [1] to [3], and (C) 1 to 50 parts by weight of a rubber-containing polymer. A thermoplastic resin composition.
[12] A molded article or film obtained by melt-processing the thermoplastic copolymer according to any one of [1] to [3] or the thermoplastic resin composition according to [11].

  According to the present invention, it has high heat resistance, and at the same time, coloring when generating glutaric anhydride units in the copolymer by heating is suppressed, and it has high colorless transparency that has been required in recent years. Not only is excellent in fluidity and low water absorption, but a thermoplastic copolymer in which the amount of gas generated at the time of heat retention is suppressed can be obtained. Therefore, the thermoplastic copolymer of the present invention has high dimensional stability even under high temperature and high humidity, excellent molding processability, few defects (silver, voids) in the molded article, A molded article having excellent colorless transparency, heat resistance, and mechanical properties can be provided.

  The thermoplastic copolymer of the present invention will be specifically described.

  The thermoplastic copolymer (A) of the present invention comprises (i) 5 to 30% by weight of an alicyclic alkyl group-containing unsaturated carboxylic acid ester unit represented by the following general formula (1), (ii) 5 to 85% by weight of unsaturated carboxylic acid alkyl ester unit represented by (2), (iii) 0 to 10% by weight of unsaturated carboxylic acid unit, (iv) glutaric anhydride represented by the following general formula (3) It is a thermoplastic copolymer containing 10 to 50% by weight of physical units and 0 to 5% by weight in total of other vinyl monomer units and / or aromatic vinyl monomer units.

(In the above formula, R1 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and R2 represents any one selected from an alicyclic alkyl group having 5 to 22 carbon atoms.)

(In the above formula, R3 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R4 is an unsubstituted or C1-C6 fatty acid in which at least one carbon is substituted with a hydroxyl group or a halogen. Represents a hydrocarbon group)

(In the above formula, R5 and R6 are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.)

  The alicyclic alkyl group-containing unsaturated carboxylic acid ester unit (i) represented by the general formula (1) in the thermoplastic copolymer of the present invention imparts low water absorption to the thermoplastic copolymer (A). In addition, it is an essential component for improving fluidity, and the content thereof is required to be 5 to 30% by weight in 100% by weight of the thermoplastic copolymer (A), and more preferably 5 to 5%. 25% by weight, more preferably 5 to 20% by weight. When the alicyclic alkyl group-containing unsaturated carboxylic acid ester unit is 5% by weight or less, low water absorption is not sufficient, and when it is 30% by weight or more, the mechanical strength and thermal stability are deteriorated, The present invention cannot be achieved.

  In a preferred embodiment of the present invention, an unsaturated carboxylic acid cyclohexyl unit represented by the following general formula (4) can be preferably used as the alicyclic alkyl group-containing unsaturated carboxylic acid ester unit (i). Furthermore, in the most preferred embodiment, cyclohexyl acrylate units and / or cyclohexyl methacrylate units can be used.

(In the above formula, R7 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.)

  Further, the glutaric anhydride-containing unit (iv) represented by the general formula (3) in the thermoplastic copolymer of the present invention imparts the heat resistance and thermal stability of the thermoplastic copolymer (A). Therefore, the content of the thermoplastic copolymer (A) must be 10 to 50% by weight in 100% by weight of the thermoplastic copolymer (A), and more preferably 15 to 50% by weight. Preferably it is 25 to 50% by weight. When the glutaric anhydride content unit is less than 10% by weight, the heat resistance and thermal stability are lowered, and when it is 50% by weight or more, the fluidity is lowered and the molding processability is deteriorated. The present invention cannot be achieved.

  The content of the unsaturated carboxylic acid alkyl ester unit (ii) represented by the general formula (2) is 5 to 85% by weight, preferably 10 to 10% by weight in 100% by weight of the thermoplastic copolymer (A). More preferably, it is 30 to 65% by weight.

  Further, the content of the unsaturated carboxylic acid unit (iii) contained in 100% by weight of the thermoplastic copolymer (A) of the present invention is 10% by weight or less, that is, 0 to 10% by weight, more preferably. 0 to 5% by weight, most preferably 0 to 3% by weight. When the unsaturated carboxylic acid unit (iii) exceeds 10% by weight, colorless transparency and residence stability tend to be lowered.

  The unsaturated carboxylic acid unit (iii) preferably has a structure represented by the following general formula (5).

(However, R8 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms)

  Further, the thermoplastic copolymer (A) of the present invention can contain other vinyl monomer units and / or aromatic vinyl monomer units as required. In that case, the total content of other vinyl monomer units and / or aromatic vinyl monomer units is 5 wt% or less in 100 wt% of the thermoplastic copolymer (A), that is, 0 to 5 It is necessary to make it into the range of weight%, More preferably, it is 0 to 3 weight%. In particular, when the content of the aromatic vinyl monomer unit is 5% by weight or more, colorless transparency, optical isotropy, and solvent resistance are lowered, and the object of the present invention cannot be achieved.

In general, an infrared spectrophotometer or a proton nuclear magnetic resonance (1H-NMR) measuring instrument is used for quantification of each component unit in the thermoplastic copolymer (A) of the present invention. In infrared spectroscopy, glutaric anhydride containing units are characterized by absorption at 1800 cm ⁻¹ and 1760 cm ⁻¹ , unsaturated carboxylic acid units, unsaturated carboxylic acid alkyl ester units and aromatic vinyl monomer units. Can be distinguished from In the 1H-NMR method, the copolymer composition can be determined from the integral ratio of the spectrum. For example, in the case of a copolymer comprising a cyclohexyl methacrylate unit, a methyl methacrylate unit, a methacrylic acid unit, a glutaric anhydride-containing unit, and a styrene unit, the attribution of the spectrum measured in a dimethyl sulfoxide heavy solvent is 0. The peak at 5 to 1.5 ppm is the hydrogen of the α-methyl group of methacrylic acid, methyl methacrylate, cyclohexyl methacrylate and glutaric anhydride ring compounds, and the peak at 1.6 to 2.1 ppm is the methylene group of the polymer main chain. Hydrogen, 3.5 ppm peak is methyl methacrylate carboxylate (-COOCH ₃ ) hydrogen, 4.5 ppm peak is cyclohexyl methacrylate cyclohexyl group methylene group bonded to carboxylic acid ester group (-COO-CH ₂ -) of hydrogen, 12.4 Peak of pm is hydrogen of the carboxylic acid of methacrylic acid. In addition to the above, in the case of a copolymer containing styrene as another copolymer component, hydrogen of an aromatic ring of styrene is seen at 6.5 to 7.5 ppm, and the copolymer is similarly obtained from the spectral ratio. The composition can be determined.

  The weight average molecular weight (Mw) of the thermoplastic copolymer (A) of the present invention is 30,000 to 150,000 in a preferred embodiment, and the weight average molecular weight is 50,000 to 150,000 in a more preferred embodiment. In addition, the weight average molecular weight as used in the field of this invention shows the weight average molecular weight in the absolute molecular weight measured by multi-angle light scattering gel permeation chromatography (GPC-MALLS).

  Such a thermoplastic copolymer (A) of the present invention can basically be produced by the following two steps. That is, first, in the first step, the alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer, the unsaturated carboxylic acid alkyl ester monomer, and the subsequent heating step are represented by the general formula (1). When containing an unsaturated carboxylic acid monomer giving a glutaric anhydride containing unit (iv) and other vinyl monomer units including an aromatic vinyl monomer unit, the vinyl type giving the unit A step of copolymerizing the monomers to produce the raw copolymer (a) (first step), and then the raw copolymer (a) in the presence or absence of a suitable catalyst. It is a production method comprising a step (second step) of producing by heating (i) dehydration and / or (b) intramolecular cyclization reaction by dealcoholization.

  In this case, typically, by heating the original copolymer (a), by a dehydration reaction between the carboxyl groups of two adjacent unsaturated carboxylic acid units (iii), or adjacent unsaturated The dealcoholization reaction between the carboxylic acid unit (iii) and the unsaturated carboxylic acid alkyl ester unit (ii) produces one unit of the above (iv) glutaric anhydride-containing unit.

  Preferable examples of the alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer used in this case include the following general formula (6)

(In the above formula, R9 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and R10 represents any one selected from an alicyclic alkyl group having 5 to 22 carbon atoms.)
The compound represented by these can be mentioned. When the alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer represented by the general formula (6) is copolymerized, the alicyclic alkyl group-containing unsaturated carboxylic acid monomer having the structure represented by the general formula (1) is obtained. Saturated carboxylic ester units (i) are given.

Specific examples of the alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer include cyclopentyl acrylate, cyclohexyl acrylate, methyl cyclohexyl acrylate, trimethyl cyclohexyl acrylate, norbornyl acrylate, norbornyl methyl acrylate, Cyanonorbornyl acrylate, isobornyl acrylate, bornyl acrylate, menthyl acrylate, fentyl acrylate, adamantyl acrylate, dimethyladamantyl acrylate, tricyclo [5.2.1.0 ^2,6 ] deca-8 - yl, acrylic acid tricyclo [5.2.1.0 ^{2, 6]} deca-4-methyl, cyclodecyl acrylate, methacrylic acid cyclopentyl, cyclohexyl methacrylate, methyl cyclohexyl methacrylate, methacryl Trimethylcyclohexyl acid, norbornyl methacrylate, norbornyl methyl methacrylate, cyano norbornyl methacrylate, phenyl norbornyl methacrylate, isobornyl methacrylate, bornyl methacrylate, menthyl methacrylate, fentyl methacrylate, adamantyl methacrylate, methacrylic acid Dimethyl adamantyl acid, tricyclo [5.2.1.0 ^2,6 ] dec-8-yl methacrylate, tricyclo [5.2.1.0 ^2,6 ] dec-4-methyl methacrylate, cyclodecyl methacrylate, etc. These may be used alone or in combination of two or more. Among these, in terms of low hygroscopicity, cyclopentyl methacrylate, cyclohexyl methacrylate, methyl cyclohexyl methacrylate, trimethyl cyclohexyl methacrylate, norbornyl methacrylate, norbornyl methacrylate, isobornyl methacrylate, bornyl methacrylate, menthyl methacrylate Fentyl methacrylate, adamantyl methacrylate, dimethyl adamantyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] deca-8-yl methacrylate, tricyclo [5.2.1.0 ^2,6 ] methacrylate Deca-4-methyl, cyclodecyl methacrylate and the like are preferable. Further, from the viewpoint of heat resistance and low hygroscopicity, cyclohexyl methacrylate, isobornyl methacrylate, norbornyl methacrylate, norbornyl methyl methacrylate, tricyclomethacrylate [5.2.1.0 ^2,6 ] Deca-8-yl, tricyclo [5.2.1.0 ^2,6 ] deca-4-methyl methacrylate, and most preferably unsaturated carboxylic acid represented by the following general formula (7) A cyclohexyl monomer can be used.

(However, R11 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms)

  In addition, the unsaturated carboxylic acid cyclohexyl monomer represented by the general formula (7) gives an unsaturated carboxylic acid cyclohexyl unit (i) represented by the general formula (4) when copolymerized.

  Among these unsaturated carboxylic acid cyclohexyl monomers, the most preferred embodiment is cyclohexyl acrylate and / or cyclohexyl methacrylate.

  Moreover, the compound represented by following General formula (8) can be mentioned as a preferable example of an unsaturated carboxylic acid alkylester monomer.

(However, R12 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R13 is substituted with an aliphatic group having 1 to 6 carbon atoms or a hydroxyl group or halogen having a number of 1 to 5 carbon atoms. Represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms)

  The unsaturated carboxylic acid alkyl ester monomer represented by the general formula (8) gives an unsaturated carboxylic acid alkyl ester unit (ii) having a structure represented by the general formula (2) when copolymerized. .

  Specific preferred examples of the unsaturated carboxylic acid alkyl ester monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, n-butyl acrylate, N-butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, chloromethyl acrylate, chloromethyl methacrylate, 2-chloroethyl acrylate, methacrylic acid 2-chloroethyl, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2,3,4,5,6-pentahydroxyhexyl acrylate, methacrylic acid 2,3,4,5,6-pe Data hydroxyhexyl, and the like of acrylic acid 2,3,4,5-hydroxypentyl and methacrylic acid 2,3,4,5-hydroxypentyl. Among these, acrylic acid esters and / or methacrylic acid esters are particularly suitable, and methyl methacrylate is most preferably used. These can be used alone or in combination of two or more thereof.

  As the unsaturated carboxylic acid monomer, any unsaturated carboxylic acid monomer that can be copolymerized with other vinyl compounds can be used. As a preferable unsaturated carboxylic acid monomer, the following general formula (9)

(However, R14 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms)
And a hydrolyzate of maleic anhydride and maleic anhydride. In particular, acrylic acid or methacrylic acid is preferable from the viewpoint of excellent thermal stability, and methacrylic acid is more preferable. These can be used alone or in combination of two or more thereof. The unsaturated carboxylic acid monomer represented by the general formula (9) gives an unsaturated carboxylic acid unit (iii) having a structure represented by the general formula (5) when copolymerized.

  Other vinyl-based monomers and / or aromatic vinyl-based monomers can be used as necessary within the range not impairing the effects of the present invention.

  Preferred specific examples of other vinyl monomers include copolymerizable vinyl unsaturated monomers such as vinyl acetate, vinyl benzoate, styrene, α-methylstyrene, and acrylonitrile. These unsaturated monomers may be used alone or as a mixture of two or more.

  Preferred examples of the aromatic vinyl monomer include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene and pt. -Butylstyrene etc. can be mentioned, However, The usage-amount needs to be the range which does not impair the optical characteristic of the thermoplastic copolymer (A) obtained.

  Regarding the polymerization method for producing the original copolymer (a) in the first step, basically, radical polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, precipitation polymerization and other polymerization methods, and bulk suspension are used. A combination of known polymerization methods such as turbid polymerization is preferably used. In particular, it is possible to reduce foreign matters in the copolymer of the present invention, particularly unmelted polymer, etc., and achieve low foreign matters required for optical material applications. From the viewpoint of solution polymerization, precipitation polymerization, and a combination of these polymerization methods, precipitation polymerization is most preferable in view of handling properties and cost reduction in separation and recovery of the produced original copolymer (a).

  Here, the precipitation polymerization is, for example, in a solvent in which the monomer mixture that is the raw material of the original copolymer (a) is dissolved and the solubility of the original copolymer (a) is 1 g / 100 g or less. It can be defined as a polymerization method for carrying out a polymerization reaction. In this case, as the polymerization reaction proceeds from the organic solvent phase containing a uniform monomer mixture, the original copolymer (a) is precipitated, The raw copolymer (a) can be isolated by filtering and drying the slurry solution.

  Here, the “solubility of the original copolymer (a)” means the amount of the original copolymer (a) dissolved in 100 g of the organic solvent (B) after stirring at 23 ° C. for 24 hours. .

  Furthermore, in the precipitation polymerization of the original copolymer (a) in the first step, the monomer mixture is 100% by weight, the unsaturated carboxylic acid monomer is 20 to 50% by weight, the alicyclic alkyl group-containing unsaturated. A monomer mixture comprising 5 to 30% by weight of a carboxylic acid ester monomer, 15 to 70% by weight of an unsaturated carboxylic acid alkyl ester monomer and 0 to 5% by weight of an aromatic vinyl monomer is used as a raw material. The monomer mixture is dissolved, and the original copolymer (a) in which the monomer mixture is copolymerized is copolymerized in an organic solvent (B) containing no aromatic group and having a solubility of 1 g / 100 g or less. A method for obtaining the polymer (a) is preferred.

  In the present invention, it is necessary to consider the balance of solubility in the original copolymer (a) and the organic solvent (B) in order to easily precipitate and precipitate the original copolymer (a). From this point of view, it is preferable to design polymerization conditions such as copolymer species, copolymer composition, and reaction solvent in consideration of solubility parameters of each component.

  Among them, in the present invention, (i) an alicyclic alkyl group-containing unsaturated carboxylic acid ester unit, (ii) an unsaturated carboxylic acid alkyl ester unit, and (iii) an unsaturated copolymer containing an unsaturated carboxylic acid unit (a) It is preferable to select a copolymer composition and a solvent type such that the absolute value (ΔSP) of the difference between the solubility parameter δp of the organic solvent and the solubility parameter δs of the organic solvent (B) is 1.0 or more. The polymerization is preferably performed under the condition of 1 or more, particularly 1.2 or more, because there is no adhesion to the wall surface of the polymerization tank during the polymerization, and the produced copolymer is easily taken out as a powder. In addition, by designing the polymerization conditions in the above-described ΔSP in the range of 1.0 to 1.9, more preferably in the range of 1.2 to 1.8, and still more preferably in the range of 1.5 to 1.7, Precise control that does not cause a large shift between the composition of the charged monomer mixture before the start of polymerization and the copolymer composition of the copolymer to be produced, and narrow molecular weight distribution and high molecular weight control It was found that the effect of greatly improving the thermal stability and colorless transparency of the thermoplastic copolymer (A) obtained through the second step was developed.

  The solubility parameter δp of the original copolymer (a) containing (i) an alicyclic alkyl group-containing unsaturated carboxylic acid ester unit and (ii) an unsaturated carboxylic acid alkyl ester unit (iii) an unsaturated carboxylic acid unit is preferably Is 7.0 to 12.0, and more preferably 7.5 to 10.5. When δp is less than 7.0, the thermoplastic copolymer (A) obtained through the second step is inferior in heat resistance and chemical resistance, and may be subject to many restrictions in practice. When δp exceeds 12.0, the cohesive strength of the polymer becomes too strong, and when it is supplied to the second step, the viscosity becomes too high and the handleability tends to deteriorate.

  In addition, the solubility parameter said here is the method of Small by referring to “Introduction to Synthetic Resins for Paints”, Kyozo Kitaoka, p23-p31, Kobunshi Shuppankai (1986), Tables 2-8 and 2-9. It was calculated by.

  That is, the cohesive energy constant F (cal1 / 2cc1 / 2 / mol) of a specific atom and atomic group given by the method of small, the density is s (g / cc), the basic molecular weight is M, and δ = (sΣF) The value calculated by / M is taken as the solubility parameter δ. In the present invention, the value of small is used as the cohesive energy F.

(1) Monomer solubility parameter
As an example, Table 1 shows a calculation example of methyl methacrylate (density 0.944 g / cc).

  F of each component constituting methyl methacrylate is

It becomes. Therefore, the solubility parameter δm of methyl methacrylate is
δm = 0.944 × 947 ÷ 100 = 8.94
It becomes.

  Table 2 shows the solubility parameters of typical monomers obtained by this calculation method.

(2) Solubility parameter δp of the original copolymer (a)
In the present invention, the solubility parameter δp of the original copolymer (a) was calculated according to the following formula. That is, it is calculated by the following formula from the molar fraction Xi (%) of each monomer in the original copolymer (a) and the solubility parameter δi of each monomer.
δp = Σ (δi × Xi / 100)

  Therefore, in order to bring the solubility parameter δp of the original copolymer (a) into the above range, the composition may be adjusted in consideration of the solubility parameter of the monomer used.

(3) Solubility parameter δs of organic solvent (B)
The solubility parameter δs of the organic solvent (B) is obtained in the same manner as the calculation method of the solubility parameter δp of the original copolymer (a). Examples of n-heptane are shown in Table 3.

δs = 0.676 × 1093 ÷ 100 = 7.39

In addition, the solubility parameter δs when the organic solvent (B) is a mixture of two or more types is calculated from the following formula based on the molar fraction Xi (%) of each solvent component in the mixed organic solvent and the solubility parameter δi of each solvent component. Is calculated by
δp = Σ (δi × Xi / 100)

  The organic solvent (B) used in the present invention is not particularly limited as long as it is an organic solvent that enables the above-described precipitation polymerization method, and the relationship with the original copolymer (a) is within the above range. Specific examples include one or more selected from aliphatic hydrocarbons, aromatic hydrocarbons, carboxylic acid esters, ketones, ethers, and alcohols. Among them, one or more selected from aliphatic hydrocarbons, carboxylic acid esters, and ketones are preferable. In particular, aliphatic hydrocarbons are used in that the copolymer composition and molecular weight distribution of the copolymer to be produced are more precisely controlled. One or more selected from carboxylic acid esters can be preferably used, and it is more preferable to select the relationship with the original copolymer (a) as described above within a preferable range.

  Examples of the aliphatic hydrocarbon used in the present invention include a straight chain having 5 to 10 carbon atoms, a chain having a side chain, and an alicyclic group. Specific examples include n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, n-nonane, n-decane and various isomers thereof.

  The carboxylic acid ester used in the present invention is an ester composed of a saturated aliphatic carboxylic acid and a saturated alcohol. Specific examples of the saturated carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, etc., and a saturated alcohol. Can be linear and branched having 1 to 10 carbon atoms. Preferred carboxylic acid esters include formic acid-n-propyl, isopropyl formate, formic acid-n-butyl, formic acid isobutyl, formic acid-n-pentyl, formic acid-n-hexyl, acetic acid-n-propyl, isopropyl acetate, acetic acid-n- Butyl, isobutyl acetate, acetic acid-n-pentyl, acetic acid-n-hexyl, acetic acid-n-heptyl, acetic acid-n-octyl, acetic acid-n-nonyl, methyl propionate, ethyl propionate, propionate-n-propyl, Isopropyl propionate, n-butyl propionate, isobutyl propionate, n-pentyl propionate, n-hexyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, Various different types such as isobutyl butyrate, n-pentyl butyrate, n-hexyl butyrate Mention may be made of the body.

  The ketone used in the present invention is a ketone having 1 to 10 carbon atoms and comprising a linear and branched saturated aliphatic group. Specific examples thereof include methyl-n-butyl ketone, methyl isobutyl ketone, and ethyl isobutyl. Examples thereof include ketones and diisobutyl ketone.

  Among these, in the present invention, a mixture of an aliphatic hydrocarbon and a carboxylic acid ester can be preferably used. In this case, the preferred mixing ratio of the aliphatic hydrocarbon and the carboxylic acid ester is not particularly limited, but the weight ratio is preferably in the range of 5/95 to 70/30, preferably 10/90 to 50/50, especially 20 / 80-40 / 60 is preferable. When the mixing ratio is less than 5/95, the copolymer formed during the polymerization tends to stick to the reaction vessel. On the other hand, when the mixing ratio is larger than 70/30, the copolymer has a very fine particle diameter and tends to be inferior in handleability.

  In addition, when performing precipitation polymerization in the production method of the present invention, if water is used in the polymerization reaction system, it may be difficult to precisely control the copolymer composition, and water should be kept within the controllable range of the copolymer composition. Most preferably, water is not positively added unless the component used in the polymerization reaction system such as an organic solvent contains a very small amount of water as an impurity.

  The polymerization temperature in the first step can be arbitrarily set, but is preferably a temperature not higher than the boiling point of the organic solvent to be used. Among these, polymerization is preferably performed at a polymerization temperature of 100 ° C. or less, and polymerization is more preferably performed at a polymerization temperature of 90 ° C. or less. 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 considering the polymerization rate. The polymerization time is not particularly limited as long as it is a time sufficient to obtain a necessary polymerization rate, but is preferably in the range of 60 to 360 minutes, and particularly preferably in the range of 90 to 240 minutes from the viewpoint of production efficiency.

  In addition, controlling the dissolved oxygen concentration in the polymerization solution to 5 ppm or less in the first step improves the excellent colorless transparency, residence stability and thermal stability of the thermoplastic copolymer (A) after the heat treatment. Since it can be achieved, it is preferable. Furthermore, in order to further suppress coloring after the heat treatment, a preferable range of dissolved oxygen concentration is 0.01 to 3 ppm, and more preferably 0.01 to 1 ppm. When the dissolved oxygen concentration exceeds 5 ppm, the thermoplastic copolymer (A) after the heat treatment tends to be colored, and the thermal stability of the thermoplastic copolymer (A) is lowered. I can't reach my goal. Here, the dissolved oxygen concentration in the present invention is a value obtained by measuring dissolved oxygen in the polymerization solution using a dissolved oxygen meter (for example, DO meter B-505 manufactured by Iijima Electronics Co., Ltd., which is a galvanic oxygen sensor). is there. For the method of reducing the dissolved oxygen concentration to 5 ppm or less, a method of passing an inert gas such as nitrogen, argon or helium into the polymerization vessel, a method of bubbling an inert gas directly into the polymerization solution, or an inert gas before starting the polymerization A method of performing pressure relief once or twice after filling the polymerization vessel, a method of degassing the closed polymerization vessel before charging the monomer mixture, and then filling with an inert gas, A method of passing an inert gas through the polymerization vessel can be exemplified.

  In the present invention, the preferred proportion of these monomer mixtures used in the production of the original copolymer (a) is that the total monomer mixture is 100% by weight, and the alicyclic alkyl group-containing unsaturated carboxylic acid ester. Monomer is 5 to 30% by weight, more preferably 5 to 25% by weight, unsaturated carboxylic acid alkyl ester monomer is 15 to 70% by weight, more preferably 20 to 70% by weight, unsaturated carboxylic acid monomer The body is 15-50% by weight, more preferably 20-45% by weight.

  When the content of the unsaturated carboxylic acid monomer is less than 15% by weight, when the thermoplastic copolymer (A) is produced by heating the original copolymer (a), the above general formula (1) ), The amount of the glutaric anhydride-containing unit (i) produced is reduced, and the effect of improving the heat resistance of the thermoplastic copolymer (A) tends to be reduced. On the other hand, when the content of the unsaturated carboxylic acid monomer (iii) exceeds 50% by weight, when the thermoplastic copolymer (A) is produced by heating the original copolymer (a), The unsaturated carboxylic acid unit (iii) tends to remain in a large amount, and the colorless transparency and residence stability of the thermoplastic copolymer (A) tend to be lowered.

  When other vinyl monomers and / or aromatic vinyl monomers copolymerizable with these are used, the preferred ratio is 0 to 5% by weight. In particular, when an aromatic vinyl monomer is used, the content of the aromatic vinyl monomer needs to be 0 to 5% by weight from the viewpoint of the optical properties of the resulting thermoplastic copolymer (A). Yes, and a more preferable ratio is 0 to 3% by weight.

  Moreover, as above-mentioned, it is preferable that the weight average molecular weights of the thermoplastic copolymer (A) of this invention are 30,000-150,000. The thermoplastic copolymer (A) having such a molecular weight is previously controlled to have a weight average molecular weight of 30,000 to 150,000 when the raw copolymer (a) is produced. Can be achieved.

  As for the molecular weight control method of the original copolymer (a), for example, the addition amount of radical polymerization initiators such as azo compounds and peroxides, or alkyl mercaptan, carbon tetrachloride, carbon tetrabromide, dimethylacetamide, dimethylformamide. It can be controlled by the addition amount of a chain transfer agent such as triethylamine. In particular, a method of controlling the amount of alkyl mercaptan added as a chain transfer agent can be preferably used from the viewpoint of stability of polymerization, ease of handling, and the like.

  Examples of the alkyl mercaptan used in the present invention include n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, etc., among which t-dodecyl mercaptan or n-dodecyl mercaptan is preferably used.

  The amount of the alkyl mercaptan added is preferably 0.2 to 5.0 parts by weight, more preferably 0.3 to 4 parts by weight based on 100 parts by weight of the total amount of the monomer mixture in order to control the molecular weight to a preferable level. 0.0 part by weight, more preferably 0.4 to 3.0 parts by weight.

  The present invention relates to an organic solvent slurry containing an original copolymer (a) obtained by copolymerization in an organic solvent (B) that is a specific polymerization solvent in the present invention. The proportion of the original copolymer (a) in the total weight of is not particularly limited, but is preferably 5% by weight or more from the viewpoint of productivity, more preferably 7% by weight or more, and still more preferably 10%. % By weight or more.

  The organic solvent slurry can be separated and separated from the original copolymer (a) and the organic solvent (B) by, for example, solid-liquid separation using a centrifuge (hereinafter, the solid-liquid separation step is the first). Sometimes called filtration). The method for solid-liquid separation of the original copolymer (a) slurry in the first filtration is not particularly limited, and a normal centrifugal separator, a pressure filter, a suction filter, a vibration filter, a belt filter and the like are preferable. By using it, the cake of the original copolymer (a) can be obtained.

  Further, if necessary, the organic solvent (B) is dried by drying the copolymer (a) containing about several percent of the organic solvent (B) with a shelf dryer, a conical dryer, a centrifugal dryer or the like. It is also possible to produce a raw copolymer (a) that does not contain

  More simply, if possible, the original copolymer (a) can be recovered by a spray dryer, and at the same time, the dried polymer can be recovered and the organic solvent (B) can be recovered.

  Thus, the original copolymer (a) particles obtained from the cake of the original copolymer (a) obtained by copolymerization in the specific organic solvent (B) of the present invention are organic other than the organic solvent (B). Compared to the particles obtained by washing the original copolymer cake obtained by copolymerization in a solvent, there is no stickiness, no rise of particles when moving the particles, and during filtration or drying Since there is no coalescence of particles, the handling property is extremely excellent in operations such as washing and / or drying prior to the second step and the second step. Furthermore, the colorless transparency of the copolymer of the present invention obtained through the second step can be improved.

  Furthermore, in this invention, the organic-solvent slurry (henceforth original copolymer (A) containing the original copolymer (a) copolymerized in the specific organic solvent (B) of this invention obtained in the 1st process. ) (Referred to as slurry) can be subjected to the following washing step prior to the treatment in the second step.

  That is, after solid-liquid separation of the original copolymer (a) slurry by first filtration, water is added to the obtained cake of the original copolymer (a), washed at a temperature of 5 to 120 ° C., Solid-liquid separation (hereinafter sometimes referred to as “second filtration”) at 5 to 120 ° C. from the washing liquid to obtain the washed original copolymer (a), and then the original copolymer (a) By using the second step, the raw copolymer (a) particles having few volatile components and extremely excellent handling properties can be obtained. Here, the volatile content in the cake of the original copolymer (a) after the second filtration is not particularly limited, and is usually 50 to 90% by weight. When the above-described washing is performed on the cake of the original copolymer (a) obtained by copolymerization in the specific organic solvent (B), the number average particle diameter of the original copolymer (a) is not particularly limited. Is controlled in the range of 1 to 20000 μm, preferably in the range of 1 to 2000 μm, more preferably in the range of 2 to 1000 μm, and particularly preferably in the range of 2 to 500 μm. In addition, the number average particle diameter mentioned here represents the number average particle diameter calculated by observing with a scanning electron microscope (SEM) at 150 times or 10,000 times and analyzing the primary particle diameter.

  As a method for controlling the number average particle system, water is added to the cake of the original copolymer (a) obtained by solid-liquid separation by the first filtration, and heated with stirring, The coalescence (a) is washed and the polymer particles are agglomerated to control the particles within the specific range. The amount of water added at the time of washing is not particularly limited, but is preferably 200 to 2000 parts by weight, more preferably 200 to 1000 parts by weight with respect to 100 parts by weight of the cake obtained by the first filtration. Most preferably, it is 200 to 600 parts by weight. When the amount of water added is 200 parts by weight or less, the cleaning effect tends to decrease. When the amount of water added exceeds 2000 parts by weight, the wastewater treatment load increases, which is not preferable.

Moreover, the concentration of the copolymer (a) in the cleaning liquid is preferably 0.1 to 50% by weight, more preferably by setting the ratio of the copolymer cake and water obtained by the first filtration to the above range. It can be 1-30% by weight, most preferably 1-20% by weight. Here, the concentration of the original copolymer (a) in the cleaning liquid is calculated as follows.
Concentration (% by weight) of the original copolymer (a) in the cleaning liquid
= 100 × (1−α / 100) × (raw copolymer cake amount (parts by weight)) / (raw copolymer cake amount (parts by weight) + water addition amount (parts by weight)).
α: volatile content of copolymer cake (% by weight)

The volatile content (% by weight) in the copolymer cake is a value calculated from the weight change when the cake is heated in a vacuum dryer at 140 ° C. for 30 minutes.
Volatile content in copolymer cake (% by weight) = weight reduction rate (%)
= [(Weight before heat treatment-weight after heat treatment) / weight before heat treatment] × 100.

  The apparatus for performing the above washing operation is not particularly limited as long as the washing temperature can be controlled within the above range, and an autoclave or the like equipped with a normal stirrer can be used. In washing, the slurry of the original copolymer (a) and / or water added thereto can be preheated.

  In the present invention, the washing temperature and the second filtration temperature are not particularly limited, but it is preferably performed in the range of 5 to 120 ° C. More preferably, it is the range of 50-120 degreeC. When the washing temperature and the second filtration temperature are less than 5 ° C., the washing effect tends to decrease.

  The method of solid-liquid separation (second filtration) of the water slurry obtained by the above washing operation is not particularly limited as long as it can be filtered at the above temperature, and is a normal centrifuge, pressure filtration. However, from the viewpoint of reducing the volatile matter after solid-liquid separation and reducing the load of the subsequent drying process, the centrifugal separation will be explained. preferable. By carrying out the cleaning method of the present invention, the volatile content of the copolymer after the second filtration is 10 to 80% by weight, preferably 20 to 70% by weight, more preferably 20 to 50 parts by weight. It is possible to reduce the load of the subsequent drying process.

  Furthermore, if necessary, the raw copolymer (a) cake containing the water and the organic solvent (B) obtained by the washing operation is dried with a shelf dryer, a conical dryer, a centrifugal dryer, or the like. Thus, it is also possible to produce the original copolymer (a) that does not contain the organic solvent (B).

  In addition, the original copolymer (a) obtained in the present invention can be obtained in the production method of the preferred embodiment, wherein the weight average molecular weight (hereinafter sometimes referred to as Mw) is in the range of 2000 to 1000000. In a more preferred embodiment, those in the range of 2000 to 500000 can be obtained, more preferably in the range of 2000 to 200000, and particularly preferably in the range of 5000 to 100,000. When Mw is less than 2000, the original copolymer (a) may not be precipitated or precipitated as a dispersoid in the organic solvent (B) and may not meet the purpose of the present invention. In addition, the polymer is brittle and the mechanical properties tend to be poor. When Mw exceeds 1,000,000, high-molecular weight substances that are not sufficiently melted or dissolved in melt-molded or solution-coated products tend to remain as foreign matters, and tend to suffer from fisheye and repellency defects. .

  The molecular weight distribution of the original copolymer (a) of the present invention is not particularly limited, but is preferably in the range of 2.0 to 3.0, and the lower limit of the molecular weight distribution is preferably 2.05 or more, more preferably. Is 2.25 or more, more preferably 2.3 or more. On the other hand, the upper limit of the molecular weight distribution in the copolymer of the present invention is preferably 2.95 or less, more preferably 2.9 or less. When the molecular weight distribution of the original copolymer (a) of the present invention is less than 2.0, the melt viscosity at the time of melting tends to be high. When the molecular weight distribution of the original copolymer (a) of the present invention exceeds 3.0, the molecular weight distribution obtained through the intramolecular cyclization reaction tends to increase.

  In addition, the sequence of the original copolymer (a) is not particularly limited, but (iii) it is preferable that the number of sequences in which the unsaturated carboxylic acid units are continuous for 10 or more (10-sequence) is small, more preferably. (Iii) It does not have a 10-sequence of unsaturated carboxylic acid units at all, and more preferably does not contain a sequence (5-sequence) continuous in 5 or more continuations. As a method of obtaining the original copolymer (a) having such a sequence, it is preferable to perform precipitation polymerization in the organic solvent (B). (Iii) When a 10-sequence of unsaturated carboxylic acid units is present, the amount of (iii) unsaturated carboxylic acid units remaining after the intramolecular cyclization reaction tends to increase.

  In the present invention, the method for producing the thermoplastic copolymer (A) by heating the original copolymer (a) and performing an intramolecular cyclization reaction by dehydration and / or dealcohol is not particularly limited. A method using a continuous melt kneader having a vent or a method using a batch type melt kneader for heating and devolatilizing the original copolymer (a) in an inert gas atmosphere or vacuum is preferable. When an intramolecular cyclization reaction is carried out by heating in the presence of oxygen, the yellowness tends to deteriorate, so it is preferable to sufficiently replace the system with an inert gas such as nitrogen. Examples of the melt kneader include a single screw extruder, a twin screw extruder, a twin / single screw combined continuous kneading extruder, a triaxial extruder, a continuous or batch kneader equipped with a “unimelt” type screw. Type of kneader, etc. can be used. Among them, a biaxial extruder having a vent, a continuous biaxial reactor equipped with a plurality of convex lens-type and / or elliptical plate-shaped paddles, and biaxial / uniaxial A composite type continuous kneading extrusion apparatus can be preferably used.

  A continuous biaxial reaction device having a plurality of convex lens-type and / or elliptical plate-shaped paddles is a so-called highly self-cleaning device having no scale adhesion, and is located at a position away from the inner cavity (cylinder). The material supply port and the discharge port are provided with a temperature control jacket on the outer periphery of the cylinder, and the inside of the middle cavity is provided with two stirring shafts positioned parallel to the longitudinal direction of the cylinder, The agitation shaft has a plurality of plate-shaped paddles fixed so as to be close to each other. As such an extruder, specifically, “KRC kneader” manufactured by Kurimoto Iron Works can be preferably used.

  Among these melt kneaders, particularly preferably, from the viewpoint of completing the cyclization reaction as described later and suppressing coloration while suppressing the amount of gas generated in the resulting glutaric anhydride-containing copolymer. It is most preferable to use a biaxial / uniaxial composite continuous kneading extrusion apparatus. As the biaxial / uniaxial composite continuous kneading and extruding apparatus, it is preferable to use, for example, an apparatus described in JP-A No. 2004-307834 (page 1-2, Examples).

  Further, it is more preferable that these apparatuses have a structure capable of introducing an inert gas such as nitrogen. For example, as a method of introducing an inert gas such as nitrogen into a twin-screw extruder or a twin-screw / single-screw composite continuous kneading extrusion apparatus, the upper and / or lower portions of the hopper are about 10 to 100 liters / minute. The method of connecting the piping of an active gas stream is mentioned.

  The temperature for heat devolatilization is not particularly limited as long as the cyclization reaction proceeds, but is preferably 180 to 380 ° C, more preferably 250 to 360 ° C. By performing heat degassing within this temperature range, the cyclization reaction can be completed and the amount of gas generated in the resulting thermoplastic copolymer (A) can be reduced.

  In addition, the heating and devolatilization time in this case can be appropriately set depending on the desired copolymer composition, but is usually preferably 10 minutes to 60 minutes, more preferably 10 minutes to 30 minutes, and particularly preferably 10 minutes. The range is ~ 20 minutes. In order to secure a heating time for a sufficient intramolecular cyclization reaction to proceed using an extruder, L / D is 40 or more and 110 or less, where L is the length of the extruder screw and D is the diameter. It is preferable. When an extruder with a short L / D is used, a large amount of unreacted unsaturated carboxylic acid units remain, so that the reaction proceeds again during the heat molding process, and there is a tendency for silver and bubbles to be seen in the molded product and molding retention. Sometimes color tends to deteriorate. When the L / D of the extruder is larger than 110, it is not preferable because practical advantages are reduced due to mechanical strength and structural problems of the extruder.

  Furthermore, in the present invention, as the catalyst for promoting the cyclization reaction to glutaric anhydride when the original copolymer (a) is heated by the above method or the like, one or more selected from acids, alkalis and salt compounds are used. Can be added. The addition amount is preferably about 0.01 to 1 part by weight with respect to 100 parts by weight of the original copolymer (a). 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, ammonium hydroxide and the like. Furthermore, examples of the salt-based catalyst include acetic acid metal salts, stearic acid metal salts, metal carbonate salts, and ammonium salts including various alkyl ammonium salts. Etc. However, it is preferable to add the catalyst in such a range that the color of the catalyst does not adversely affect the coloring of the thermoplastic copolymer and the transparency is not lowered. Among them, the compound containing an alkali metal can be preferably used because it exhibits an excellent reaction promoting effect with a relatively small addition amount. 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 carboxylates such as sodium acetate, potassium acetate and sodium stearate. In particular, sodium hydroxide, sodium methoxide, lithium acetate, and sodium acetate can be preferably used.

  The thermoplastic copolymer (A) thus obtained has an excellent heat resistance with a glass transition temperature (Tg) of 120 ° C. or higher, and is 130 ° C. or higher in a preferred embodiment, and 150 ° C. in a more preferred embodiment. That's it. Moreover, as an upper limit, it is about 170 degreeC normally. In addition, the glass transition temperature here is a glass transition temperature (Tg) measured at a heating rate of 20 ° C./min using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer).

  Further, the thermoplastic copolymer (A) of the present invention has a yellowness index value of 5 or less and coloring is extremely suppressed, and in a more preferable aspect, 4 or less, and in a most preferable aspect, 3 or less. Extremely colorless. Thereby, the yellowness degree of the thermoplastic resin composition of the present invention containing the thermoplastic copolymer (A) described later can also be 5 or less, more preferably 4 or less, and most preferably 3 or less. When the yellowness value of the thermoplastic copolymer (A) is large, a part of the thermoplastic copolymer (A) is thermally decomposed and the transparency tends to be lowered. Also in this point, it is preferable that the yellowness of the thermoplastic copolymer (A) is in the above range. In addition, the yellowness (Yellowness Index) here refers to injection molding of the thermoplastic copolymer (A) or the thermoplastic resin composition of the present invention, and the obtained 2 mm-thick molded product according to JIS-K7103. YI value measured using an SM color computer (manufactured by Suga Test Instruments Co., Ltd.).

Further, the thermoplastic copolymer (A) of the present invention has a water absorption of 0.8% by weight or less, more preferably 0.6% by weight or less, most preferably 0.5% by weight or less. It has an extremely high low water absorption property that could not be achieved by a thermoplastic copolymer containing an acid anhydride unit, and has a feature of extremely excellent dimensional stability under high temperature and high humidity. The water absorption referred to here is a molded product of 70 mm × 70 mm × 2 mm obtained by injection molding at a glass transition temperature of + 150 ° C. of thermoplastic copolymer (A) in pure water at 23 ° C. for 24 hours. It is a value (% by weight) calculated from the following formula from the change in weight of the molded product before and after immersion.
Water absorption rate (% by weight) = (weight after immersion−weight before immersion) / weight of molded product before immersion × 100

In a preferred embodiment, the thermoplastic copolymer (A) of the present invention preferably has a photoelastic coefficient of 8 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 6 × 10 ⁻¹² Pa. ⁻¹ or less, and most preferably has excellent optical isotropy of 4 × 10 ⁻¹² Pa ⁻¹ or less. Further, the lower limit of the photoelastic coefficient is usually about 2 × 10 ⁻¹² Pa ⁻¹ . The photoelastic coefficient referred to here is the stress (σ) when a non-oriented film having a thickness of about 100 μm (100 ± 5 μm) obtained by the casting method is uniaxially stretched 1.5 times, and this The stretched film was irradiated at 23 ° C. using an ellipsometer (LCD cell gap inspection apparatus RETS-1100, manufactured by Otsuka Electronics Co., Ltd.) at an angle of 90 ° with respect to the film sample surface, and the transmitted light was 633 nm. It is a value calculated by the following formula based on the measured retardation (Re) and the thickness (d) of the stretched film at 23 ° C.
Photoelastic coefficient = Re (nm) / d (nm) / σ (Pa)

  The thermoplastic copolymer (A) of the present invention preferably has a melt viscosity of 50,000 poise or less measured at a glass transition temperature of + 150 ° C. and a shear rate of 12 / sec, more preferably from the viewpoint of fluidity. 30000 poise or less, more preferably 20000 poise or less. The melt viscosity referred to here is a melt viscosity (poise) measured at the above temperature and shear rate using a Capillograph type 1C (die diameter φ1.0 mm, die length 5.0 mm) manufactured by Toyo Seiki Co., Ltd.

  The thermoplastic copolymer (A) of the present invention is required to have a heating loss of 1.0% by weight or less, preferably 0.5% by weight when heated at a glass transition temperature + 150 ° C. for 30 minutes. Below, more preferably 0.3% by weight or less.

  Further, at the time of producing the thermoplastic copolymer of the present invention, hindered phenol-based, benzotriazole-based, benzophenone-based, benzoate-based, and cyanoacrylate-based ultraviolet absorbers and antioxidants are within the range not impairing the object of the present invention. , Higher fatty acids, acid esters and acid amides, lubricants and plasticizers such as higher alcohols, montanic acid and salts thereof, esters thereof, half esters thereof, stearyl alcohol, stearamide and ethylene wax, release agents such as phosphorus Anti-coloring agents such as acid salts and hypophosphites, halogen-based flame retardants, phosphorus-based and silicone-based non-halogen flame retardants, nucleating agents, amine-based, sulfonic acid-based, polyether-based anti-static agents, Additives such as colorants such as pigments may optionally be included. However, it is necessary to add in a range where the color of the additive does not adversely affect the thermoplastic copolymer of the present invention and the transparency is not lowered.

  Moreover, in this invention, it is excellent without impairing the outstanding characteristic of a thermoplastic copolymer (A) by containing a rubber-containing polymer (C) in said thermoplastic copolymer (A). High impact resistance can be imparted.

  The rubber-containing polymer (C) used in the present invention is composed of a layer containing one or more rubber-like polymers and one or more layers composed of different polymers, and one layer inside. In the presence of the rubber-like polymer, a multilayer structure polymer called a so-called core-shell type structure having a layer containing the rubber-like polymer, or a monomer mixture composed of a vinyl monomer or the like was copolymerized. Although a graft copolymer etc. can be used preferably, a multilayered structure polymer is particularly preferable because of its excellent transparency and little coloring.

  The number of layers constituting the multilayer structure polymer may be two or more, and may be three or more or four or more. A multilayer having one or more rubber layers (core layers) inside. A structural polymer is preferred. In the multilayer polymer, the type of the rubber layer is not particularly limited as long as it is composed of a polymer component having rubber elasticity. For example, acrylic monomers, silicone monomers, styrene monomers, nitrile monomers, conjugated diene monomers, monomers that form urethane bonds, ethylene monomers, propylene monomers Examples thereof include rubbers formed by polymerizing monomers and isobutene monomers. Preferred rubbers include, for example, acrylic units such as ethyl acrylate units and butyl acrylate units, silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, styrene units such as styrene units and α-methylstyrene units, It is a rubber composed of nitrile units such as acrylonitrile units and methacrylonitrile units, and conjugated diene units such as butadiene units and isoprene units. A rubber composed of a combination of two or more of these components is also preferred. For example, rubber composed of acrylic units such as ethyl acrylate units and butyl acrylate units, and silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, acrylic units such as ethyl acrylate units and butyl acrylate units And rubber composed of styrene units such as styrene units and α-methylstyrene units, acrylic units such as ethyl acrylate units and butyl acrylate units, and conjugated diene units such as butanediene units and isoprene units. Rubber, acrylic units such as ethyl acrylate units and butyl acrylate units, silicone units such as dimethylsiloxane units and phenylmethylsiloxane units, and styrene units such as styrene units and α-methylstyrene units. Examples include rubbers that are made. Among these, a rubber which is an acrylate containing an acrylic acid alkyl ester unit and a substituted or unsubstituted styrene unit is most preferable from the viewpoint of transparency and mechanical properties. In addition to these components, a rubber obtained by crosslinking a copolymer composed of a crosslinking component such as a divinylbenzene unit, an allyl acrylate unit, and a butylene glycol diacrylate unit is also preferable.

  In the multilayered polymer, the type of layer other than the rubber layer is not particularly limited as long as it is composed of a polymer component having thermoplasticity. However, the layer having a glass transition temperature higher than that of the rubber layer. A coalescence component is preferred. Polymers having thermoplastic properties include unsaturated carboxylic acid alkyl ester units, unsaturated carboxylic acid units, unsaturated glycidyl group-containing units, unsaturated dicarboxylic anhydride units, aliphatic vinyl units, aromatic vinyl units, cyanide. Examples thereof include polymers containing one or more units selected from vinyl units, maleimide units, unsaturated dicarboxylic acid units, and other vinyl units. Among them, a polymer containing an unsaturated carboxylic acid alkyl ester unit is preferable, and in addition, one or more units selected from an unsaturated glycidyl group-containing unit, an unsaturated carboxylic acid unit and an unsaturated dicarboxylic anhydride unit are contained. More preferred is a polymer.

  Although it does not specifically limit as a monomer used as the raw material of the said unsaturated carboxylic acid alkylester unit, Acrylic acid alkylester or methacrylic acid alkylester is used preferably. Specifically, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, t-butyl acrylate , T-butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, stearyl acrylate, stearyl methacrylate, octadecyl acrylate , Octadecyl methacrylate, phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, chloromethyl acrylate, chloromethyl methacrylate, 2-chloroethyl acrylate, methacrylic acid -Chloroethyl, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2,3,4,5,6-pentahydroxyhexyl acrylate, methacrylic acid 2 , 3,4,5,6-pentahydroxyhexyl, 2,3,4,5-tetrahydroxypentyl acrylate, 2,3,4,5-tetrahydroxypentyl methacrylate, aminoethyl acrylate, propylamino acrylate Examples include ethyl, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, and cyclohexylaminoethyl methacrylate. From the viewpoint that the effect of improving impact resistance is great, methyl acrylate or methyl methacrylate is preferably used. These units can be used alone or in combination of two or more.

  The unsaturated carboxylic acid monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, and further a hydrolyzate of maleic anhydride. In particular, acrylic acid and methacrylic acid are preferable from the viewpoint of excellent thermal stability, and methacrylic acid is more preferable. These can be used alone or in combination.

  The monomer used as a raw material for the unsaturated glycidyl group-containing unit is not particularly limited, but is glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, diglycidyl itaconate, allyl glycidyl ether, styrene-4-glycidyl. Examples include ether and 4-glycidylstyrene, and glycidyl acrylate or glycidyl methacrylate is preferably used from the viewpoint that the effect of improving impact resistance is great. These units can be used alone or in combination of two or more.

  Examples of the monomer used as the raw material for the unsaturated dicarboxylic acid anhydride unit include maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, and aconitic anhydride, which have the effect of improving impact resistance. From the viewpoint of being large, maleic anhydride is preferably used. These units can be used alone or in combination of two or more.

  Moreover, ethylene, propylene, butadiene, etc. can be used as a monomer used as the raw material of the said aliphatic vinyl unit. Examples of the monomer used as a raw material for the aromatic vinyl unit include styrene, α-methylstyrene, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, and 2-ethyl. -4-Benzylstyrene, 4- (phenylbutyl) styrene, halogenated styrene and the like can be used. Acrylonitrile, methacrylonitrile, ethacrylonitrile, etc. can be used as a monomer as a raw material for the vinyl cyanide unit. Examples of the monomer used as a raw material for the maleimide unit include maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (p- Bromophenyl) maleimide and N- (chlorophenyl) maleimide can be used. As a monomer used as the raw material of the unsaturated dicarboxylic acid unit, maleic acid, maleic acid monoethyl ester, itaconic acid, phthalic acid, and the like can be used. Examples of other monomers used as raw materials for vinyl units include acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, N-vinyldiethylamine, N-acetylvinylamine, allylamine, and methallylamine. N-methylallylamine, p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, 2-styryl-oxazoline, and the like can be used. These monomers can be used alone or in combination of two or more.

The rubbery polymer (C) of the present invention has a multilayer structure in which the outermost layer (shell layer) is, as described above, an unsaturated carboxylic acid alkyl ester unit, an unsaturated carboxylic acid unit, an unsaturated glycidyl group-containing unit. , Polymers containing one or more units such as aliphatic vinyl units, aromatic vinyl units, vinyl cyanide units, maleimide units, unsaturated dicarboxylic acid units, unsaturated dicarboxylic anhydride units, and other vinyl units And at least one selected from. Among these, at least one selected from polymers containing unsaturated carboxylic acid alkyl ester units, unsaturated carboxylic acid units, unsaturated glycidyl group-containing units, unsaturated dicarboxylic acid anhydride units, and the like is preferable.
As a rubbery polymer to be subjected to melt kneading with the thermoplastic copolymer of the present invention, a multilayer structure polymer having a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit as an outermost layer is used. Is most preferred.

  When the outermost layer is a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit, by heating, the intramolecular cyclization reaction is performed as in the production of the copolymer of the present invention described above. As a result, the glutaric anhydride-containing unit represented by the general formula (1) is generated. Therefore, by mixing the multilayer structure polymer having a polymer containing an unsaturated carboxylic acid alkyl ester unit and an unsaturated carboxylic acid unit in the outermost layer with the thermoplastic copolymer (A), by heating during melt kneading, A multilayer structure polymer containing the glutaric anhydride-containing unit represented by the general formula (1) in the outermost layer is obtained. Thereby, the multilayer structure polymer containing the glutaric anhydride-containing unit represented by the general formula (1) is well dispersed in the copolymer of the present invention which becomes a continuous phase (matrix phase). It becomes possible, and it is considered that extremely high transparency can be exhibited with improvement in mechanical properties such as impact resistance of the thermoplastic resin composition of the present invention.

  As a monomer used as the raw material of the unsaturated carboxylic acid alkyl ester unit here, an acrylic acid alkyl ester or a methacrylic acid alkyl ester is preferable, and methyl acrylate or methyl methacrylate is more preferably used.

  Moreover, as a monomer used as the raw material of an unsaturated carboxylic acid unit, acrylic acid or methacrylic acid is preferable, and methacrylic acid is more preferably used.

  As a preferable example of the rubbery polymer (C) to be included in the thermoplastic resin composition of the present invention, the core layer is a butyl acrylate / styrene copolymer, and the outermost layer is methyl methacrylate / the above general formula (1 ), A core layer is a butyl acrylate / styrene copolymer, and an outermost layer is represented by methyl methacrylate / the above general formula (1). Glutaric anhydride containing unit / methacrylic acid copolymer, core layer is dimethylsiloxane / butyl acrylate copolymer and outermost layer is methyl methacrylate polymer, core layer is butanediene / styrene copolymer And the outermost layer is a methyl methacrylate polymer, and the core layer is a butyl acrylate polymer and the outermost layer is a methyl methacrylate polymer. That. Here, “/” indicates copolymerization. Furthermore, a preferable example is one in which either one or both of the rubber layer and the outermost layer is a polymer containing a glycidyl methacrylate unit. Among them, the core layer is a butyl acrylate / styrene polymer, the outermost layer is a copolymer composed of methyl methacrylate / glutaric anhydride-containing units represented by the general formula (1), and the core layer is an acrylic. A butyl acid / styrene copolymer whose outermost layer is methyl methacrylate / glutaric anhydride-containing unit represented by the general formula (1) / methacrylic acid polymer is a continuous phase (matrix phase). It is possible to approximate the refractive index with the copolymer of the present invention, and to obtain a good dispersion state in the resin composition, and express transparency that can satisfy the demands that have become more sophisticated in recent years. It can be preferably used.

  About the average particle diameter of a multilayer structure polymer, it is preferable that they are 0.01 micrometer or more and 1000 micrometers or less. The average particle diameter is more preferably 0.02 μm or more and 100 μm or less, further preferably 0.05 μm or more and 10 μm or less, and most preferably 0.05 μm or more and 1 μm or less. If it is less than the above range, the impact strength of the resulting thermoplastic composition tends to decrease, and if it exceeds the above range, transparency may decrease. The average particle size of the multilayer structure polymer can be calculated from a Guinier plot or a transmission electron micrograph by small angle light scattering measurement.

  In the multilayer structure polymer of the present invention, the weight ratio of the core to the shell is preferably 30% by weight or more and 90% by weight or less for the core layer and 50% by weight for the core layer with respect to the entire multilayer structure polymer. As mentioned above, it is more preferable that it is 90 weight% or less, and it is especially preferable that it is 60 weight% or more and 80 weight% or less.

  As the multilayer structure polymer of the present invention, a commercially available product that satisfies the above-described conditions may be used, or it may be prepared by a known method.

  As a commercial product of a multilayer structure polymer, for example, “Metablene (registered trademark)” manufactured by Mitsubishi Rayon Co., Ltd., “Kaneace (registered trademark)” manufactured by Kaneka Chemical Industry Co., Ltd., “Paralloid (registered trademark)” manufactured by Kureha Chemical Industry Co., Ltd. , “Acryloid (registered trademark)” manufactured by Rohm and Haas, “Staffyroid (registered trademark)” manufactured by Gantz Kasei Kogyo Co., Ltd., and “Parapet (registered trademark) SA” manufactured by Kuraray Co., Ltd. More than seeds can be used.

  Further, specific examples of the rubber-containing graft copolymer used as the rubber-containing polymer include unsaturated carboxylic acid ester monomers (the specific examples thereof are the same as described above) in the presence of the rubber-like polymer. ), Unsaturated carboxylic acid monomer (specific examples are the same as those described above), aromatic vinyl monomer (specific examples are the same as those described above), and, if necessary, copolymerizable with these Examples thereof include graft copolymers obtained by (co) polymerizing monomers (mixtures) selected from one or more of other vinyl monomers (specific examples are the same as those described above).

  Diene rubber, acrylic rubber, ethylene rubber and the like can be used as the rubbery polymer used for the graft copolymer. Specific examples include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer. , Butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer, and ethylene-methyl acrylate A copolymer etc. are mentioned. These rubbery polymers can be used alone or in a mixture of two or more.

  The weight average particle diameter of the rubbery polymer constituting the graft copolymer in the present invention is preferably in the range of 0.1 to 0.5 μm, particularly 0.15 to 0.4 μm. If it is less than the above range, the impact strength of the resulting thermoplastic composition tends to decrease, and if it exceeds the above range, transparency may decrease. The weight average particle diameter of the rubber polymer is the sodium alginate method described in “Rubber Age, Vol. 88, p. 484-490 (1960), by E. Schmidt, P. H. Biddison”, that is, sodium alginate. By using the fact that the diameter of the polybutadiene particles to be creamed differs depending on the concentration of the cream, it can be measured by a method of determining the particle size of 50% cumulative weight fraction from the weight proportion of cream and the cumulative weight fraction of sodium alginate concentration. .

  The graft copolymer in the present invention is a rubbery polymer in the presence of 10 to 80% by weight, preferably 20 to 70% by weight, more preferably 30 to 60% by weight. It is obtained by copolymerizing 90% by weight, preferably 30 to 80% by weight, more preferably 40 to 70% by weight. When the ratio of the rubbery polymer is less than the above range or exceeds the above range, the impact strength and the surface appearance may be lowered.

  The graft copolymer may contain an ungrafted copolymer that is produced when the monomer mixture is graft copolymerized with the rubbery polymer. From the viewpoint of impact strength, the graft ratio is preferably 10 to 100%. Here, the graft ratio is a weight ratio of the grafted monomer mixture to the rubbery polymer. Further, the intrinsic viscosity of the ungrafted copolymer measured at 30 ° C. is preferably 0.1 to 0.6 dl / g from the viewpoint of the balance between impact strength and moldability. .

  The intrinsic viscosity of the graft copolymer according to the present invention measured at 30 ° C. is not particularly limited, but 0.2 to 1.0 dl / g has a balance between impact strength and moldability. It is preferably used from the viewpoint, and more preferably 0.3 to 0.7 dl / g.

The method for producing the graft copolymer in the present invention is not particularly limited, and may be a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, or a combination of these polymerization methods such as bulk suspension polymerization. Obtainable.
Moreover, when the refractive indexes of the thermoplastic copolymer and the rubber-containing polymer of the present invention are close to each other, it is preferable because a thermoplastic resin composition having excellent transparency can be obtained. Specifically, the difference in refractive index between the two is preferably 0.05 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less. In order to satisfy such a refractive index condition, a method of adjusting the monomer unit composition of the thermoplastic copolymer of the present invention and / or a rubbery polymer or a single polymer used for a rubbery-containing polymer. Examples thereof include a method for preparing a composition of a monomer.

  In addition, the refractive index difference said here is the value measured by the method shown below. In the solvent in which the copolymer of the present invention is soluble, the thermoplastic resin composition of the present invention is sufficiently dissolved under appropriate conditions to obtain a cloudy solution, which is subjected to an operation such as centrifugation, whereby a solvent soluble part and an insoluble part are obtained. To separate. After refining this soluble part (part containing the copolymer of the present invention) and insoluble part (part containing the rubber-containing polymer), the difference in the measured refractive index (23 ° C., measurement wavelength: 550 nm) was determined. It is defined as the difference in refractive index.

  The copolymer composition and molecular weight distribution of the thermoplastic copolymer of the present invention and the rubber-containing polymer (C) in the resin composition are determined after the separation operation of the soluble component and the insoluble component with the solvent. Analyze each component individually.

  In this invention, it is preferable that the weight ratio at the time of mix | blending the thermoplastic copolymer of this invention and a rubber-containing polymer is the range of 99 / 1-50 / 50, Furthermore, 99 / 1-60 / A range of 40 is more preferable, and a range of 99/1 to 70/30 is particularly preferable.

  When producing the thermoplastic resin composition of the present invention, a method is used in which the thermoplastic copolymer of the present invention and the rubber-containing polymer (C) are heated and melted and mixed under an appropriate shear field. In order to suppress agglomeration of the rubber-containing polymer particles in the thermoplastic resin composition to be produced, it is preferable to melt and knead so that the shearing force is not excessively applied at a relatively low temperature and a low rotational speed. Specifically, when the resin temperature in the kneading zone is T, it is preferable to control within the range of (Tg + 100 ° C. of copolymer of the present invention) ≦ T ≦ (1% decomposition temperature of rubber-containing polymer), Furthermore, it is more preferable to control within the range of (Tg + 120 ° C. of copolymer of the present invention) ≦ T ≦ (0.5% decomposition temperature of rubber-containing polymer). Here, 1% decomposition temperature of the rubber-containing polymer is a temperature range of 100 to 450 ° C. using a differential thermogravimetric simultaneous measurement apparatus (TG / DTA-200, manufactured by Seiko Denshi Kogyo) in nitrogen. Is a temperature at which the weight reduction rate reaches 1% when the weight before heating is 100% by a heating test conducted at a heating rate of 20 ° C./min. When the resin temperature is lower than the range of the present invention, the melt viscosity becomes extremely high, and melt kneading becomes practically impossible, which is not preferable. On the other hand, when the resin temperature is higher than the range of the present invention, re-aggregation and coloring of the rubber-containing polymer (C) become remarkable, which is not preferable.

  The thermoplastic resin composition of the present invention thus obtained has a haze value (turbidity), which is one of the indices representing transparency, preferably 3% or less, more preferably 1% or less. Thereby, it has high transparency. Further, the lower limit of the haze value is usually about 0.5%.

  The total light transmittance and haze of the thermoplastic resin composition are values obtained by measuring a 2 mm-thick molded product obtained by injection molding in accordance with JIS-K7361 and JIS-K7136.

In a preferred embodiment, the thermoplastic resin composition of the present invention preferably has a photoelastic coefficient of 8 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 6 × 10 ⁻¹² Pa ⁻¹ or less. Most preferably, it has excellent optical isotropy of 4 × 10 ⁻¹² Pa ⁻¹ or less. Further, the lower limit of the photoelastic coefficient is usually about 2 × 10 ⁻¹² Pa ⁻¹ . The photoelastic coefficient referred to here is the stress (σ) when a non-oriented film having a thickness of about 100 μm (100 ± 5 μm) obtained by the casting method is uniaxially stretched 1.5 times, and this The stretched film was irradiated at 23 ° C. using an ellipsometer (LCD cell gap inspection apparatus RETS-1100, manufactured by Otsuka Electronics Co., Ltd.) at an angle of 90 ° with respect to the film sample surface, and the transmitted light was 633 nm. It is a value calculated by the following formula based on the measured retardation (Re) and the thickness (d) of the stretched film at 23 ° C.
Photoelastic coefficient = Re (nm) / d (nm) / σ (Pa)

  In addition, the thermoplastic resin composition of the present invention has excellent fluidity with a melt viscosity of 50,000 poise or less measured at a glass transition temperature of + 150 ° C. and a shear rate of 5 / sec. Has fluidity. The melt viscosity is more preferably 30000 poise or less, more preferably 20000 poise or less. The melt viscosity referred to here is a melt viscosity (poise) measured at the above temperature and shear rate using a Capillograph type 1C (die diameter φ1.0 mm, die length 5.0 mm) manufactured by Toyo Seiki Co., Ltd.

Further, the thermoplastic resin composition of the present invention has a water absorption of 0.8% by weight or less, more preferably 0.6% by weight or less, most preferably 0.5% by weight or less, and has a high low water absorption. It has a feature that is extremely excellent in dimensional stability under high temperature and high humidity. The water absorption referred to here is a 70 mm × 70 mm × 2 mm molded product of a thermoplastic composition obtained by injection molding at a glass transition temperature of the thermoplastic copolymer (A) + 150 ° C. It is a value (% by weight) calculated from the following formula from the weight change of the molded product before and after being immersed in water for 24 hours.
Water absorption rate (% by weight) = (weight after immersion−weight before immersion) / weight of molded product before immersion × 100

  In addition, the thermoplastic resin composition of the present invention contains the thermoplastic copolymer (A) glass transition temperature + 150% by weight or less, preferably 0.5% by weight when heated at 150 ° C. for 30 minutes. In the following, more preferably 0.3% by weight or less, the amount of gas generated at the time of heat retention is suppressed, and a molded product having excellent molding processability and less defects (silver, voids) can be provided.

  The thermoplastic resin composition of the present invention preferably has a heat distortion temperature of 100 ° C. or higher, more preferably 110 ° C. or higher, and particularly preferably 115 ° C. or higher. Thereby, it has extremely excellent heat resistance. The upper limit of the heat distortion temperature is usually about 140 ° C. In addition, the heat distortion temperature said here shows the value which measured the thickness 6.4mm molded article obtained by injection molding according to ASTM D648.

  In the present invention, in addition to the rubber-containing polymer (C), a monophosphite compound can be further contained. Thereby, since decomposition | disassembly of a rubber-containing polymer (C) is suppressed and a significant coloring suppression and a fluid improvement effect are acquired, it can use preferably.

  The monophosphite compound used in the present invention is an organic phosphite ester having one phosphorus atom and three organic groups bonded in the molecule, and preferably has a molecular weight of 300 to 2000 from the viewpoint of heat resistance. Furthermore, it is more preferable that it is the range of molecular weight 350-1500, and it is most preferable that it is the range of molecular weight 400-1000 especially. When the molecular weight is 300 or less, it tends to volatilize during melt-kneading, and it is difficult to obtain the effect of suppressing coloration and improving fluidity. When the molecular weight is 2000 or more, there is a problem that high transparency is easily obtained. Furthermore, although there are forms such as liquid or solid as properties, there is no restriction in use, and in the case of liquid, the viscosity is preferably in the range of 1 to 10000 mPa · s, and further the viscosity is in the range of 2 to 7000 mPa · s. More preferably, the viscosity is most preferably in the range of 5 to 5000 mPa · s. Alternatively, in the case of solid properties, the melting point is preferably 60 to 220 ° C, more preferably 80 to 210 ° C, and most preferably 100 to 200 ° C. Further, a cyclic monophosphite compound in which two or more of the three oxygen atoms of the organic phosphite are bonded to an aromatic residue, or the three oxygen atoms of the organic phosphite Of these, a monophosphite compound in which at least one of them is bonded to an aromatic residue is preferable. Specific phosphite compounds include triphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2-t-butylphenyl) phos Phyto, tris (2,5-t-butylphenyl) phosphite, tris (mixed mono and di-nonylphenyl) phosphite, tris (2-t-butyl-4-methylphenyl) phosphite, tris (2- t-butyl-5-methylphenyl) phosphite, tris (2-t-butyl-4,6-dimethylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylenephos Phonite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 4,4′-butyl Isopropylidene - bis (3-methyl -6-t-butylphenyl - di - tridecyl) phosphite, and the like.

  Among these, tris (2-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2,5-t-butylphenyl) phosphite, 2,2- Methylene bis (4,6-di-t-butylphenyl) octyl phosphite can be used particularly preferably. These specific phosphite compounds can be used alone or in combination of two or more.

  The monophosphite compound used in the present invention can be used in combination with a hindered phenol compound or a thioether compound. By using at least one kind of hindered phenolic compound and thioether compound in combination, the decomposition of the rubber-containing polymer is further suppressed, and a significant color tone improving effect is obtained.

  Specific hindered phenolic compounds having a molecular weight of 400 or more are preferred, and specifically, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propione. -To], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5- t-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 2-t-butyl-6- ( 3′-t-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methyl) ) Propionyloxy} -1,1-dimethylethyl] -2,4,8,10-pyro [5.5] undecane.

  Specific thioether compounds include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate). ), Pentaerythritol-tetrakis (3-dodecylthiopropionate), pentaerythritol-tetrakis (3-octadecylthiopropionate), pentaerythritol-tetrakis (3-myristylthiopropionate), pentaerythritol-tetrakis (3 -Stearyl thiopropionate).

  As a method for producing a resin composition containing a rubbery polymer (C) and, if necessary, a phosphite-based compound in the thermoplastic copolymer (A) of the present invention, the raw copolymer (a ) In a heat treatment apparatus to produce the copolymer of the present invention, 0.001 relative to 100 parts by weight of the total amount of the rubber-containing polymer (C) and the original copolymer (a). ~ 5 parts by weight of a phosphite compound added simultaneously with the original copolymer (a) and melt-kneaded, in the course of producing the thermoplastic copolymer of the present invention, in the middle of the heat treatment, A method of adding 0.001 to 5 parts by weight of a phosphite compound to 100 parts by weight of the total amount of the union (C) and the original copolymer (a), and melt-kneading the thermoplastic copolymer of the present invention After the production of the thermoplastic copolymer of the present invention and the rubber-containing polymer (C), A method in which melt-kneading the phosphite compound of 0.001 to 5 parts by weight relative to the amount 100 parts by weight and the like. There are no restrictions on the heat treatment apparatus that can be used, for example, a single screw extruder, a twin screw extruder, a twin / single screw combined continuous kneading extruder, a triaxial extruder, a continuous or batch kneader kneader, etc. It can be preferably used.

  In addition, the thermoplastic resin composition containing the thermoplastic copolymer (A) of the present invention, and further the rubbery polymer (C), may contain other thermoplastic resins, for example, within a range not impairing the object of the present invention. Thermosetting resins such as polyethylene, polypropylene, acrylic resin, polyamide, polyphenylene sulfide resin, polyether ether ketone resin, polyester, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyether imide, phenol resin, melamine resin, polyester resin, One or more selected from silicone resins, epoxy resins, and the like can be further contained. In addition, lubricants and plasticizers such as higher fatty acids, acid esters and acid amides, higher alcohols, montanic acid and salts thereof, esters thereof, half esters thereof, stearyl alcohol, stearamide and ethylene wax, phosphorous acid Anti-coloring agents such as salts and hypophosphites, halogen-based flame retardants, phosphorus-based and silicone-based non-halogen-based flame retardants, nucleating agents, amine-based, sulfonic acid-based, polyether-based anti-static agents, pigments Additives such as colorants such as dyes and fluorescent brightening agents may be optionally added. However, in light of the characteristics required for the application to be applied, it is preferable to add the additive within a range where the color of the additive does not adversely affect the thermoplastic copolymer and the transparency is not lowered. The thermoplastic copolymer and the thermoplastic resin composition of the present invention are excellent in mechanical properties and molding processability, and can be melt-molded, so that extrusion molding, injection molding, press molding, etc. are possible. Films, sheets, tubes, rods, and other molded articles having any desired shape and size can be used.

  Moreover, a well-known method can be used for the manufacturing method of the sheet | seat or film which consists of a thermoplastic resin composition of this invention. That is, production methods such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used. Preferably, an inflation method, a T-die method, a cast method or a hot press method can be used. In the case of a production method using an inflation method or a T-die method, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. The melt extrusion temperature for producing the film of the present invention is preferably 150 to 350 ° C, more preferably 200 to 300 ° C. Moreover, when melt-kneading using a melt-extrusion apparatus, it is preferable to perform the melt-kneading under reduced pressure or the melt-kneading under nitrogen stream from a viewpoint of coloring suppression.

  When the film of the present invention is produced by the casting method, solvents such as tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone can be used. Preferred solvents are acetone, methyl ethyl ketone, N-methylpyrrolidone and the like. The film is prepared by dissolving the thermoplastic resin composition of the present invention in one or more of the above solvents, and using the solution with a bar coater, a T die, a T die with a bar, a die coat, etc. It can be produced by casting on a flat plate or curved plate (roll) such as a film, steel belt, or metal foil and using a dry method in which the solvent is removed by evaporation, or a wet method in which the solution is solidified with a coagulating liquid.

  The thermoplastic copolymer and the thermoplastic resin composition produced according to the present invention make use of its excellent heat resistance, colorless transparency, and retention stability, and are used for electrical / electronic parts, automotive parts, mechanical mechanism parts, OA equipment. It can be used for various applications such as housings for home appliances, parts thereof, general sundries and the like.

  Specific examples of the molded article comprising the thermoplastic copolymer and the thermoplastic resin composition of the present invention include, for example, electrical equipment housings, OA equipment housings, various covers, various gears, various cases, sensors, LED lamps. , Connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor 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 Home appliances such as liers, rice cooker parts, microwave oven parts, acoustic parts, audio equipment parts such as audio / laser discs / compact discs, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, office electricity Product parts, office computer related parts, telephone related parts, facsimile related parts, copying machine related parts, cleaning jigs, oilless bearings, stern bearings, underwater bearings, various bearings, motor parts, lighters, typewriters, etc. Representative machine-related parts, optical instruments such as microscopes, binoculars, cameras, watches, precision machine-related parts; alternator terminals, alternator connectors, IC regulators, various valves such as exhaust gas valves, fuel-related / exhaust systems / intake Various pipes, Er intake nozzle snorkel, intake manifold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant 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 Oscher nozzle, air conditioner panel switch board, coil for fuel related solenoid valve , Fuse connectors, horn terminals, electrical component insulation plates, step motor rotors, lamp sockets, lamp reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters and ignition device cases. In addition, because of its excellent transparency and heat resistance, it is used as a component for optical recording / communications, such as imaging equipment, such as cameras, VTRs, projection TVs, viewfinders, filters, prisms, and Fresnel lenses. Various optical equipment (VD, CD, DVD, MD, LD, etc.) substrates, various disc substrate protective films, optical disc player pickup lenses, optical fibers, optical switches, optical connectors, and other information equipment related parts such as liquid crystal displays, flat panel displays, plasmas Display light guide plate, Fresnel lens, polarizing plate, polarizing plate protective film, retardation film, light diffusion film, viewing angle widening film, reflective film, antireflection film, antiglare film, brightness enhancement film, prism sheet, pickup lens , Light guide films for touch panels, covers, etc., as parts related to transportation equipment such as automobiles, tail lamp lenses, head lamp lenses, inner lenses, amber caps, reflectors, extensions, side mirrors, room mirrors, side visors, instrument needles, instrument covers , Glazing typified by window glass, etc. as medical equipment related parts, spectacle lenses, spectacle frames, contact lenses, endoscopes, optical cells for analysis, etc., as building material related parts, lighting windows, road translucent plates, lighting covers It can also be applied to signboards, translucent sound insulation walls, bathtub materials, etc., and is extremely useful for these various applications.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Each measurement and evaluation was performed by the following method.

(1) Weight average molecular weight / molecular weight distribution The obtained copolymer was dissolved in tetrahydrofuran to prepare a measurement sample. Gel permeation chromatograph (pump: model 515, manufactured by Waters, column: TSK-gel-GMHXL, manufactured by Tosoh Corporation) equipped with a DAWN-DSP type multi-angle light scattering photometer (manufactured by Wyatt Technology) using tetrahydrofuran as a solvent. ) Was used to measure the weight average molecular weight (absolute molecular weight) and the number average molecular weight (absolute molecular weight). The molecular weight distribution was calculated by weight average molecular weight (absolute molecular weight) / number average molecular weight (absolute molecular weight).

(2) Each component composition In heavy dimethyl sulfoxide, 1H-NMR was measured at 30 degreeC and the composition of each copolymer unit was determined.

(3) Solubility parameter difference (ΔSP value)
“Introduction to Synthetic Resins for Paints”, Kyozo Kitaoka, p23-p31, Kobunshi Kyokukai (1986), Tables 2-8 and 2-9. ), The solubility parameter δp of the original copolymer (a) and the solubility parameter δs of the organic solvent (B) were calculated, and the absolute value of the difference was determined as the solubility parameter difference.

(A) Solubility parameter δp of the original copolymer (a)
It calculated by the following formula from the molar fraction Xi of each monomer unit in the copolymer (A) and the solubility parameter δi of each monomer.
δp = Σ (δi × Xi / 100)

(B) Solubility parameter δs of organic solvent (B)
The calculation was performed in the same manner as the method for calculating the solubility parameter δp of the original copolymer (a). In addition, the solubility parameter δs when the organic solvent (B) is a mixture of two or more types is calculated from the following formula based on the molar fraction Xi (%) of each solvent component in the mixed organic solvent and the solubility parameter δi of each solvent component. Calculated by
δp = Σ (δi × Xi / 100)

(4) Solubility The obtained original copolymer (a) was added to 100 g of the organic solvent (B) used for the copolymerization, and the solution state after stirring for 24 hours at 23 ° C. was visually observed. Then, the weight of the original copolymer (a) to be dissolved was evaluated.

(5) Glass transition temperature (Tg)
Using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), the measurement was performed at a temperature increase rate of 20 ° C./min in a nitrogen atmosphere.

(6) Transparency (total light transmittance, haze)
The obtained thermoplastic copolymer was injection-molded at a glass transition temperature of + 140 ° C., and the total light transmittance (%) and haze (haze) (%) at 23 ° C. of the obtained 1 mm-thick molded product Transparency was evaluated by measuring using a direct reading haze meter manufactured by Seiki Co., Ltd.

(7) Yellowness Index
The obtained thermoplastic copolymer was injection molded at a glass transition temperature of + 140 ° C., and the YI value of the obtained 1 mm-thick molded product was measured using an SM color computer (manufactured by Suga Test Instruments Co., Ltd.) according to JIS-K7103. did.

(8) Izod impact strength (Izod impact value)
For each of the obtained thermoplastic copolymer (A) and thermoplastic resin composition, the glass transition temperature of the thermoplastic copolymer + 150 ° C. (in the case of the thermoplastic resin composition, the thermoplastic copolymer that is the matrix) Notched Izod impact strength was measured at 23 ° C. according to ASTM D256 using a notched test piece having a thickness of 1/2 inch obtained by injection molding at a temperature of glass transition temperature + 150 ° C. .

(9) Elongation at break The thermoplastic resin composition of the present invention was subjected to a 40 mm diameter vented single screw extruder equipped with a T-die for film production having a width of 200 mm and extruded at a rate of 10 kg / h at 280 ° C. A film having a thickness of 0.1 mm was obtained. ASTM-1 dumbbells were punched from the obtained film to prepare test pieces, and the tensile elongation at break was measured according to JIS K-7113.

(10) Photoelastic coefficient The thermoplastic resin composition of the present invention was dissolved in methyl ethyl ketone to obtain a 25 wt% concentration solution. Using the obtained solution, a non-oriented film having a thickness of about 100 μm (100 ± 5 μm) was obtained by a casting method. The unoriented film was uniaxially stretched 1.5 times at a glass transition temperature of the thermoplastic resin (A) of + 5 ° C. at a rate of 0.5 mm / sec, and the stress (σ) was measured. According to ASTM D542, this stretched film is irradiated at 23 ° C. using an ellipsometer (manufactured by Otsuka Electronics Co., Ltd., LCD cell gap inspection apparatus RETS-1100) at an angle of 90 ° with respect to the film sample surface. Then, the retardation (Re) of the transmitted light at 633 nm was measured. Moreover, the thickness (d) at 23 degreeC of the said stretched film was measured using the Mitsutoyo digimatic indicator, and the photoelastic coefficient was computed by the following formula based on these.
Photoelastic coefficient = Re (nm) / d (nm) / σ (Pa)

(11) Refractive Index, Refractive Index Difference Acetone is added to the thermoplastic resin composition of the present invention, refluxed for 4 hours, and then centrifuged at 9,000 rpm for 30 minutes, so that it is insoluble in acetone soluble component (component A). Separated into minutes (component B). These were each dried under reduced pressure at 60 ° C. for 5 hours. Each of the obtained solids was press-molded at 250 ° C. to form a film having a thickness of 0.1 mm, and then the refractive index at 23 ° C. and 550 nm wavelength was measured with an Abbe refractometer (manufactured by Atago Co., Ltd., DR-M2). It was measured. The absolute value of the difference between the refractive index of the A component and the refractive index of the B component was taken as the refractive index difference.

(12) Water absorption 70 mm × 70 mm × 2 mm molding obtained by injection molding of the thermoplastic copolymer (A) and the thermoplastic resin composition at a glass transition temperature of the thermoplastic copolymer (A) + 150 ° C. The water absorption was calculated from the following equation from the weight change of the molded product before and after the product was immersed in pure water at 23 ° C. for 24 hours.
Water absorption rate (% by weight) = (weight after immersion−weight before immersion) / weight of molded product before immersion × 100.

(13) Melt Viscosity The pellets of the thermoplastic copolymer or thermoplastic resin composition of the present invention are used at a temperature of 280 ° C. and a shear rate of 5 / using a Capillograph type 1C (die diameter φ1 mm, die length 5 mm) manufactured by Toyo Seiki Co., Ltd. Measured in seconds.

(14) Gas generation amount during residence The obtained thermoplastic copolymer pellets were pre-dried at 80 ° C. for 12 hours, and the weight before and after being heat-treated in a heating furnace adjusted to 280 ° C. for 30 minutes was measured. The weight reduction rate calculated by the following equation was evaluated as the amount of gas generated during residence.
Weight reduction rate (%) = [(weight before heat treatment−weight after heat treatment) / weight before heat treatment] × 100.

<Reference Examples 1 to 8: Production of raw copolymer (a)>
(A-1)
(I) Polymerization step: Synthesis of raw copolymer slurry (a-1) A mixed substance of the following (A) is supplied to a stainless steel autoclave having a capacity of 20 liters and equipped with a baffle and a foudra-type stirring blade, The mixture was dissolved with stirring at 250 rpm, and the system was bubbled with nitrogen gas at 10 L / min for 120 minutes. Next, nitrogen gas was flowed at a flow rate of 5 L / min, and the reaction system was heated to 95 ° C. while stirring. The following mixed substances (b) were sequentially added over 40 minutes, and after maintaining for another 60 minutes, the polymerization was terminated to obtain a raw copolymer slurry (a-1). A small amount of the obtained slurry was sampled, and qualitative filter paper No. As a result of performing suction filtration using 1 and drying at 80 ° C. for 12 hours and analyzing the obtained powdery copolymer, the polymerization rate was 55%, and the weight average molecular weight by GPC measurement was 14,000, The molecular weight distribution (Mw / Mn) was 3.11. The copolymer composition by 1H-NMR was cyclohexyl methacrylate unit (CHMA) / methyl methacrylate unit (MMA) / methacrylic acid unit (MAA) (weight ratio) = 7/65/28.
Mixed substance (I):
10 parts by weight of cyclohexyl methacrylate,
65 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate,
n-dodecyl mercaptan 1.0 part by weight.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(Ii) Washing Step The raw copolymer slurry (a-2) obtained in the above (a) polymerization step is subjected to solid-liquid separation at 25 ° C. with a pressure filter (manufactured by Mitsubishi Chemical Corporation). A coalescence cake was obtained. Subsequently, the obtained cake was supplied to a stainless steel washing tank equipped with a baffle and a foudra-type stirring blade, 400 parts of ion exchange water was added to 100 parts of the cake, and 25 ° C. and a rotation speed of 250 rpm. Agitation was started. While continuously stirring this mixture at 250 rpm, the temperature was raised to 80 ° C. over 60 minutes, and a washing operation was performed for 90 minutes from the time when the internal temperature reached 80 ° C. Subsequently, while the obtained slurry was kept at 80 ° C., it was transferred to a pressure filter, subjected to solid-liquid separation at 80 ° C., and further dried at 80 ° C. for 12 hours to obtain a particulate raw copolymer ( a-1) was obtained. The weight average molecular weight by GPC measurement was 14,000 and the molecular weight distribution (Mw / Mn) was 3.05. The copolymer composition of the original copolymer (a-1) is cyclohexyl methacrylate unit (CHMA) / methyl methacrylate unit (MMA) / methacrylic acid unit (MAA) (weight ratio) = 7/65/28, and washed. Same as before.

(A-2)
The raw copolymer slurry (a-2) is polymerized by the same production method as (a-1) except that the mixed substances (A) and (B) in (a-1) are changed to the following compositions. Obtained at a rate of 77%. Table 4 shows the properties of the original copolymer (a-3) obtained in the washing step.
Mixed substance (I):
20 parts by weight of cyclohexyl methacrylate,
55 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate,
n-dodecyl mercaptan 1.0 part by weight.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(A-3)
Except for changing the addition amount of n-dodecyl mercaptan as a chain transfer agent to 1.2 parts by weight, the polymerization rate of the original copolymer slurry (a-3) is 75% by the same production method as (a-1). I got it. Table 4 shows the properties of the original copolymer (a-3) obtained after the washing step.

(A-4)
The raw copolymer slurry (a-4) is polymerized by the same production method as (a-1) except that the mixed substances (A) and (B) in (a-1) are changed to the following compositions. Obtained at a rate of 77%. Table 4 shows the properties of the original copolymer (a-4) obtained after the washing step.
Mixed substance (I):
10 parts by weight of cyclohexyl methacrylate,
65 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
3 parts by weight of styrene,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate,
n-dodecyl mercaptan 1.0 part by weight.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(A-5)
The raw copolymer slurry (a-5) is polymerized by the same production method as (a-1) except that the mixed substances (A) and (B) in (a-1) are changed to the following compositions. Obtained at a rate of 76%. Table 4 shows the properties of the original copolymer (a-5) obtained after the washing step.
Mixed substance (I):
10 parts by weight of cyclohexyl methacrylate,
73 parts by weight of methyl methacrylate,
17 parts by weight of methacrylic acid,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate,
n-dodecyl mercaptan 1.0 part by weight.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(A-6)
The raw copolymer slurry (a-6) is polymerized by the same production method as (a-1) except that the mixed substances (A) and (B) in (a-1) are changed to the following compositions. Obtained at a rate of 77%. Table 4 shows the properties of the original copolymer (a-6) obtained after the washing step.
Mixed substance (I):
10 parts by weight of cyclohexyl methacrylate,
82 parts by weight of methyl methacrylate,
8 parts by weight of methacrylic acid,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate,
n-dodecyl mercaptan 1.0 part by weight.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(A-7)
The raw copolymer slurry (a-7) is polymerized by the same production method as (a-1) except that the mixed substances (A) and (B) in (a-1) are changed to the following compositions. Obtained at a rate of 76%. Table 4 shows the properties of the original copolymer (a-7) obtained after the washing step.
Mixed substance (I):
75 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
175 parts by weight of n-heptane,
525 parts by weight of butyl acetate.
Mixed substances (b):
25 parts by weight of n-heptane,
75 parts by weight of butyl acetate,
Lauryl peroxide 0.8 parts by weight.

(A-8)
In accordance with the method disclosed in Patent Document 5, the following monomer mixture is prepared, continuously fed at a rate of 1 L / h to a 2 L jacketed fully mixed reactor, and polymerized at a temperature of 125 ° C., An original copolymer (a-8) polymerization solution was obtained. As a result of measuring solid content from the loss of heating when this polymerization liquid was heated in a vacuum dryer at 140 ° C. for 30 minutes, it was 40.0% by weight. The polymerization rate was 50%, the weight average molecular weight was 105,000, Mw / Mn was 2.88, and the copolymer composition of the original copolymer (a-8) was cyclohexyl methacrylate units (CHMA) / It was methyl methacrylate unit (MMA) / methacrylic acid unit (MAA) (weight ratio) = 15/65/10.
21 parts by weight of cyclohexyl methacrylate,
64 parts by weight of methyl methacrylate,
9 parts by weight of methacrylic acid,
6 parts by weight of styrene,
11 parts by weight of ethylbenzene,
0.05 parts by weight of n-octyl mercaptan,
1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane
0.005 part by weight.

(A-9)
Polymerization was carried out by the same production method as in (a-8) except that the monomer mixture in (a-8) was changed to the following composition. As a result, it became difficult to carry out the polymerization in a uniform system, and furthermore, stirring became impossible, so the polymerization rate could not be increased and the polymerization rate was 22%. Table 4 shows the properties of the obtained original copolymer (a-9).
10 parts by weight of cyclohexyl methacrylate,
65 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
11 parts by weight of ethylbenzene,
0.05 parts by weight of n-octyl mercaptan,
1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane
0.005 part by weight.

(A-10)
The following mixed substances were supplied to a stainless steel autoclave having a capacity of 20 liters and equipped with a baffle and a foudra-type stirring blade, and the system was bubbled with nitrogen gas at 10 L / min for 15 minutes while stirring at 250 rpm. Next, nitrogen gas was flowed at a flow rate of 5 L / min, and the reaction system was heated to 80 ° C. while stirring. When the internal temperature reached 80 ° C., the polymerization was started. The internal temperature was maintained at 80 ° C. for 90 minutes, and after the temperature was raised to 90 ° C., the polymerization was further continued for 90 minutes to complete the polymerization. The reaction system was cooled to room temperature to obtain a polymer solution (a-10) having no insoluble precipitate. The powder obtained by dropping the polymer solution (a-10) into a large amount of ion-exchanged water was dried at 80 ° C., but 72 hours were required to completely remove ethylene glycol monoethyl ether as a polymerization solvent. . The weight average molecular weight of the obtained copolymer (a-10) was 100,000.
10 parts by weight of cyclohexyl methacrylate,
65 parts by weight of methyl methacrylate,
25 parts by weight of methacrylic acid,
Ethylene glycol monoethyl ether 200 parts by weight 2,2′-azobis-2,4-dimethylvaleronitrile 0.3 part by weight.

  Table 4 shows each component composition and copolymerization result of the original copolymer (a) obtained in Reference Examples 1 to 8.

Reference Example 9: Preparation of rubber-containing polymer (C) 120 parts by weight of deionized water, 0.5 parts by weight of potassium carbonate, 0.5 parts by weight of dioctyl sulfosuccinate in a glass container (capacity 5 liters) with a cooler Then, 0.005 part by weight of potassium persulfate was charged, and after stirring in a nitrogen atmosphere, 53 parts by weight of butyl acrylate, 17 parts by weight of styrene, and 1 part by weight of allyl methacrylate (crosslinking agent) were charged. These mixtures were reacted at 70 ° C. for 30 minutes to obtain a core layer polymer. Next, a mixture of 21 parts by weight of methyl methacrylate, 9 parts by weight of methacrylic acid, and 0.005 parts by weight of potassium persulfate was continuously added over 90 minutes, and the mixture was further maintained for 90 minutes to polymerize the shell layer. The polymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a rubber-containing polymer (C) having a two-layer structure. The number average particle diameter of the polymer particles measured with an electron microscope was 155 nm.

Examples 1 to 6, Comparative Examples 1 to 5: Production of thermoplastic copolymers (A-1) to (A-10) Original copolymers (a-1) to (a) obtained in Reference Examples 1 to 10 ( a-10) Into 100 parts by weight, 0.2 parts by weight of lithium acetate as a catalyst was blended, and a 38 mmφ biaxial / uniaxial composite continuous kneading extruder (HTM38 (manufactured by CTE, L / D = 47.5, Vent part: 2 places) While purging nitrogen at a rate of 10 L / min from the hopper part, at a screw rotation speed of 75 rpm and a raw material supply rate of 10 kg / h, each was intramolecular under the cylinder temperature conditions shown in Table 1. A cyclization reaction was performed to obtain a pellet-like glutaric anhydride-containing thermoplastic copolymer (A).

Tables 5 and 6 summarize the results of Examples 1 to 6 and Comparative Examples 1 to 4.
From Examples 1-6 and Comparative Examples 1-4, in the first step, the monomer mixture as a raw material is dissolved, and the raw copolymer (a) is polymerized in a specific organic solvent that does not dissolve. It can be seen that the thermoplastic copolymer of the present invention has high transparency and heat resistance, is particularly excellent in fluidity, and generates very little gas during heating.

  On the other hand, from Comparative Example 1, when there is no alicyclic alkyl group-containing unsaturated carboxylic acid ester unit in the thermoplastic copolymer (A), low water absorption is not sufficient, and the melt viscosity is high, It can be seen that sufficient fluidity cannot be obtained.

  In Comparative Example 2, the polymerization and the cyclization reaction were performed by the methods disclosed in Patent Document 5 and Example 1 described above, but the content of glutaric anhydride units was low and the heat resistance was not sufficient. Further, since the cyclization reaction is not completed, the amount of gas generation is not sufficient.

  Furthermore, in Comparative Example 3, the polymerization solution obtained in Reference Example 9 was attempted to undergo a cyclization reaction under high temperature vacuum as shown in Patent Document 5, but in the first step of Reference Example 9, Since the polymerization control of the compound (a) was insufficient, the alicyclic alkyl group-containing unsaturated carboxylic acid ester unit amount was not sufficiently copolymerized, which is not sufficient in terms of low water absorption.

  Furthermore, the thermoplastic copolymer of the present invention has a high degree of colorless transparency, heat resistance and low water absorption even when compared with PMMA (Comparative Example 5), and the amount of gas generated during heat retention is suppressed. You can see that

[Examples 7 to 12, Comparative Examples 6 to 10]
The thermoplastic copolymers (A) obtained in Examples 1 to 6 and Comparative Examples 1 to 4 and the rubbery polymer (C) obtained in Reference Example 9 were blended in the compositions shown in Table 6. Using a twin screw extruder (TEX30 (manufactured by Nippon Steel Co., Ltd., L / D = 44.5)), kneading was performed at a cylinder temperature of 280 ° C. and a screw rotation speed of 100 rpm to obtain a pellet-shaped thermoplastic resin composition. The obtained pellet-shaped thermoplastic resin composition was subjected to an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.) to mold each test piece under the molding temperature: (thermoplastic copolymer). (A) Glass transition temperature +150) ° C., mold temperature: 80 ° C., injection time: 5 seconds, cooling time: 10 seconds, molding pressure: pressure at which the resin is completely filled in the mold (molding lower limit pressure) +1 MPa went.

  In Comparative Example 10, PMMA ("Delpet (registered trademark) 80N (manufactured by Asahi Kasei Co., Ltd.)" was used instead of the thermoplastic copolymer (A), and Mitsubishi instead of the rubbery polymer (C). Table 7 shows the results of evaluation using “Metablene (registered trademark) W377” (core: acrylic polymer, shell: methyl methacrylate polymer) manufactured by Rayon.

  From the comparison of Examples 7 to 12 and Comparative Examples 6 to 10, the thermoplastic resin composition of the present invention contains the thermoplastic copolymer (A) obtained in Examples 1 to 6 and has an excellent low It has water absorption and fluidity, and can suppress gas generation during heating. That is, it can be seen that the thermoplastic resin composition of the present invention is excellent in high transparency, heat resistance and toughness, particularly excellent in fluidity, and generates very little gas during heating. On the other hand, it can be seen that the thermoplastic resin composition outside the scope of the present invention is inferior in terms of the color tone, fluidity, low water absorption, and amount of generated gas of the thermoplastic copolymer.

  Furthermore, the thermoplastic resin composition of the present invention has a high degree of colorless transparency even when compared with the composition of PMMA and an acrylic rubber polymer (Comparative Example 10), and generates gas when heated. It can be seen that is suppressed.

Claims (12)

(I) 5-30 wt% of an alicyclic alkyl group-containing unsaturated carboxylic acid ester unit represented by the following general formula (1), (ii) an unsaturated carboxylic acid alkyl ester represented by the following general formula (2) 5 to 85% by weight unit, (iii) 0 to 10% by weight of unsaturated carboxylic acid unit, (iv) 10 to 50% by weight of glutaric anhydride unit represented by the following general formula (3), and other vinyl A thermoplastic copolymer containing 0 to 5% by weight of monomer units and / or aromatic vinyl monomer units in total.

(In the above formula, R1 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms, and R2 represents any one selected from an alicyclic alkyl group having 5 to 22 carbon atoms.)

(In the above formula, R3 represents any one selected from hydrogen and an alkyl group having 1 to 5 carbon atoms, and R4 is an unsubstituted or C1-C6 fatty acid in which at least one carbon is substituted with a hydroxyl group or a halogen. Represents a hydrocarbon group)

(In the above formula, R5 and R6 are the same or different and represent any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.) The thermoplastic copolymer according to claim 1, having a weight average molecular weight of 3 to 150,000. (I) The thermoplastic copolymer according to claim 1 or 2, wherein the alicyclic alkyl group-containing unsaturated carboxylic acid ester unit is an unsaturated carboxylic acid cyclohexyl unit represented by the following general formula (4).

(In the above formula, R7 represents any one selected from a hydrogen atom and an alkyl group having 1 to 5 carbon atoms.) The monomer mixture is 100% by weight, the unsaturated carboxylic acid monomer is 5 to 50% by weight, the alicyclic alkyl group-containing unsaturated carboxylic acid ester monomer is 5 to 30% by weight, the unsaturated carboxylic acid alkyl ester monomer A monomer mixture comprising 15 to 90% by weight of a monomer and 0 to 5% by weight of an aromatic vinyl monomer. A first step of obtaining a raw copolymer (a) by copolymerizing in an organic solvent (B) not containing an aromatic group having a solubility of (a) of 1 g / 100 g or less,
Subsequently, the original copolymer (a) obtained in the first step is subjected to heat treatment, and (b) an intramolecular cyclization reaction by dehydration and / or (b) dealcoholization reaction,
The manufacturing method of the thermoplastic copolymer which manufactures the thermoplastic copolymer of any one of Claims 1-3 by this. The thermoplasticity according to claim 4, wherein an organic solvent (B) having an absolute value (ΔSP) of a difference between the solubility parameter of the original copolymer (a) and the solubility parameter of the organic solvent (B) is 1.0 or more. A method for producing a copolymer. The organic solvent (B) having an absolute value (ΔSP) of a difference between the solubility parameter of the original copolymer (a) and the solubility parameter of the organic solvent (B) of 1.5 to 1.7 is used. A method for producing a thermoplastic copolymer. The organic solvent (B) is at least one selected from an aliphatic hydrocarbon, a carboxylic acid ester, and a ketone, The production of the thermoplastic copolymer according to any one of claims 4 to 6, Method. The method for producing a thermoplastic copolymer according to any one of claims 4 to 7, wherein the heat treatment in the second step is performed using a continuous kneading extruder. In the continuous kneading and extruding apparatus, a single shaft in which a first shaft extending from a biaxial screw portion and a biaxial screw portion in which a first shaft and a second shaft forming a screw portion are arranged in parallel are arranged in a casing. A shaft screw portion, and a communication portion between the biaxial screw portion and the monoaxial screw portion is provided with a flow rate adjusting mechanism, the casing is provided with a raw material supply port communicating with the biaxial screw portion, and the extended first 9. The method for producing a thermoplastic copolymer according to claim 8, wherein the thermoplastic copolymer is a biaxial / single-shaft composite continuous kneading and extruding apparatus having a discharge port communicating with an end portion of one axis. In the second step, 0.001 to 1 part by weight of an alkali metal compound is added to 100 parts by weight of the copolymer (a) and heated at 180 to 380 ° C., so that (i) dehydration and / or (B) A method for producing a thermoplastic copolymer according to any one of claims 4 to 9, wherein a dealcoholization reaction is carried out. A thermoplastic resin composition comprising (A) 50 to 99 parts by weight of the thermoplastic copolymer according to any one of claims 1 to 3, and (C) 1 to 50 parts by weight of a rubber-containing polymer. object. The molded article or film formed by melt-processing the thermoplastic copolymer of any one of Claims 1-3, or the thermoplastic resin composition of Claim 11.