JP5464621B2 - Method for producing thermoplastic resin composition - Google Patents

Description

  The present invention relates to a thermoplastic resin composition and a method for producing the same. More specifically, the present invention relates to a thermoplastic resin composition having a very small amount of foreign matter and containing no aromatic ring in the main chain, and a method for producing the same.

  Thermoplastic resins having no aromatic ring in the main chain, such as methacrylic resins and cyclic polyolefin resins, are known to exhibit excellent optical characteristics such as high transparency and low birefringence. In particular, methacrylic resins are excellent in surface gloss and light resistance, and have a good balance of mechanical strength, molding processability, and surface hardness, and thus are widely used in optical related applications such as automobiles and home appliances.

  Since the thermoplastic resin contains various foreign substances such as gel generated during the polymerization reaction and contaminants mixed in during the production process, it is necessary to remove these foreign substances. As a method for removing foreign matter, for example, a method of performing filtration with a screen mesh of 200 to 600 mesh is known (for example, see Patent Document 1).

JP 9-263614 A (published on October 7, 1997)

  However, the above-described conventional configuration causes a problem that the removal of foreign matters is insufficient.

Specifically, in the method described in Patent Document 1, foreign matter having a particle size of 80 μm or more can be reduced to 1 piece / m ² or less, but for use in optical applications, the foreign matter having a particle size of less than 80 μm. Must be reduced to a very small amount.

  The present invention has been made in view of the above problems, and an object thereof is to realize a thermoplastic resin composition having a low birefringence and a small amount of foreign matter, and a method for producing the same.

  In order to solve the above problems, a method for producing a thermoplastic resin composition according to the present invention includes an extruder provided with a polymer filter having a filtration accuracy of 10 μm or less, and a thermoplastic resin having a main chain made of an aliphatic compound. And including a step of filtration and purification under conditions where the resin melt viscosity at a shear rate of 100 / sec is 800 Pa · sec or less.

  According to the above method, a thermoplastic resin having a main chain of an aliphatic compound and a low birefringence is filtered under the condition that the resin melt viscosity at a shear rate of 100 / sec is 800 Pa · sec or less. Even if it is a polymer filter of 5 micrometers or less, it can filter without causing the pressure rise in a filter. For this reason, there exists an effect that a thermoplastic resin composition with low birefringence and few foreign materials can be manufactured.

  In the method for producing a thermoplastic resin composition according to the present invention, in the filtration and purification step, the temperature inside the polymer filter is preferably in the range of 260 ° C. or more and 310 ° C. or less.

  According to the above method, since the filtration is performed at a temperature within the above range, the resin melt viscosity at a shear rate of 100 / sec can be 800 Pa · sec or less.

  In the method for producing a thermoplastic resin composition according to the present invention, the polymer filter is preferably a leaf disk type polymer filter.

  According to the above method, the leaf disk type polymer filter has a large filtration area, and even when a highly viscous resin is filtered, the pressure loss is small, so that the filtration processing speed can be increased and the production is lower. There is a further effect that it can be manufactured at a low cost.

  In the method for producing a thermoplastic resin composition according to the present invention, the thermoplastic resin is preferably a heat-resistant acrylic resin.

  According to the above method, since the thermoplastic resin is a heat-resistant acrylic resin, it is possible to produce a thermoplastic resin composition having not only a low birefringence and a small amount of foreign matter, but also excellent transparency. There is a further effect.

  In the method for producing a thermoplastic resin composition according to the present invention, the heat-resistant acrylic resin preferably has a lactone ring structure.

  According to the said method, there exists the further effect that heat resistance can be improved, without significantly deteriorating the optical characteristic of a thermoplastic resin composition.

  In the method for producing a thermoplastic resin composition according to the present invention, the heat-resistant acrylic resin is represented by the following general formula (1).

(In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms, and the organic residue may contain an oxygen atom.)
It preferably has a structure represented by

  In order to solve the above problems, the heat-resistant acrylic resin composition according to the present invention is characterized in that 100 or less foreign substances having a particle diameter of 20 μm or more are contained per gram.

  According to the said structure, there exists an effect that transparency is high, a birefringence index is low, and a heat resistant acrylic resin composition with few foreign materials can be provided.

  The heat-resistant acrylic resin composition according to the present invention is preferably used for optical applications.

  The method for producing a thermoplastic resin composition according to the present invention, as described above, is performed by using an extruder equipped with a polymer filter having a filtration accuracy of 10 μm or less, and shearing a thermoplastic resin having a main chain made of an aliphatic compound. It includes a step of filtering and purifying under the condition that the resin melt viscosity at a speed of 100 / sec is 800 Pa · sec or less.

  For this reason, there exists an effect that a thermoplastic resin composition with low birefringence and few foreign materials can be manufactured.

  As described above, the heat-resistant acrylic resin composition according to the present invention is characterized in that 100 or less foreign substances having a particle diameter of 20 μm or more are contained per gram.

  For this reason, there is an effect that it is possible to provide a heat-resistant acrylic resin composition having high transparency, low birefringence, and few foreign matters.

It is a top view which shows schematic structure of the apparatus used with the manufacturing method of the thermoplastic resin composition which concerns on this embodiment.

  Hereinafter, the present invention will be described in detail. However, the scope of the present invention is not limited to these descriptions, and modifications other than the following examples can be made as appropriate without departing from the spirit of the present invention.

  Materials used in optical applications are strongly required to reduce foreign matters having a diameter of 20 μm or less. In order to satisfy this requirement, it is necessary to perform filtration with a polymer filter having a filtration accuracy of 10 μm or less.

  Conventionally, in thermoplastic resins such as polyester and polycarbonate having an aromatic ring in the main chain, various devices such as using a polymer filter and preparing a production environment have been made in order to reduce foreign matter. For example, JP-A-5-239334 discloses a method of filtering molten polycarbonate with a polymer filter. JP 2000-351114 discloses a transparent heat with a small amount of foreign matter by setting the air space from the die to the cutting machine to a cleanliness class 7 or less and filtering the strand water-cooled water with a filter having a filtration accuracy of 5 μm. A method for producing plastic resin pellets is disclosed, and it is described that it is preferable to filter a transparent thermoplastic resin in a molten state. Japanese Patent Application Laid-Open No. 9-254251 discloses a method of cooling a melt-extruded polycarbonate using cooling water having a low electrical conductivity and a small amount of foreign matter.

  However, since the thermoplastic resin has an aromatic ring in the main chain, it has drawbacks in optical properties such as a high birefringence, and its use as an optical material is limited. Therefore, there has been a demand for a thermoplastic resin (thermoplastic resin composition) having a small number of foreign substances, excellent optical characteristics, containing no aromatic ring in the main chain, and the main chain comprising an aliphatic compound.

  However, a thermoplastic resin such as a methacrylic resin whose main chain is made of an aliphatic compound has no aromatic ring in the main chain, and therefore has a low ceiling temperature and a limited heating and melting temperature. Even if the main chain is a thermoplastic resin whose heat resistance is improved and the main chain is made of an aliphatic compound, the main chain is decomposed at a certain temperature or higher, so the heating conditions are limited.

  As described above, the thermoplastic resin whose main chain is made of an aliphatic compound has a limitation on the heat-melting temperature, so far, the thermoplastic resin whose main chain is made of an aliphatic compound has a filtration accuracy of 10 μm or less. Filtration with a polymer filter was not performed.

  In the method for producing a thermoplastic resin composition according to the present embodiment, the main chain is a fat with a polymer filter having a filtration accuracy of 10 μm or less by performing filtration under specific filtration conditions using a specific thermoplastic resin. It was possible to filter a thermoplastic resin composed of a group compound.

  In the method for producing a thermoplastic resin composition according to the present embodiment, a thermoplastic resin whose main chain is a chain hydrocarbon is used with an extruder provided with a polymer filter having a filtration accuracy of 10 μm or less, and the shear rate is It includes a step of filtration and purification under the condition that the resin melt viscosity at 100 / sec is 800 Pa · sec or less.

  FIG. 1 is a plan view showing an example of a schematic configuration of an apparatus used in the method for producing a thermoplastic resin composition according to the present embodiment.

  As shown in FIG. 1, in the apparatus used in the method for producing a thermoplastic resin composition according to the present embodiment, an extruder 2 provided with a polymer filter 4, a cooling water 5, a pelletizer 6, a tank 7, Each device is connected in this order. In the method for producing a thermoplastic resin composition according to the present embodiment, a raw material 1 such as a thermoplastic resin is put into an extruder 2, the raw material 1 is melted, and foreign matters are removed through a polymer filter 4. And a thermoplastic resin composition is manufactured by cooling a melt with cooling water and pelletizing with the pelletizer 6. FIG. Thereafter, the obtained thermoplastic resin composition is filled into the filling container 8 through the tank 7. Hereafter, the manufacturing method of the thermoplastic resin composition which concerns on this Embodiment is demonstrated in detail.

  In addition, the term “foreign matter” in the specification refers to contaminants mixed in all processes from the raw material through polymerization to obtaining a molded product such as pellets, by-products such as gel generated during the polymerization reaction, It means all substances that have properties that are not compatible with thermoplastic resins, including by-products caused by deterioration of resins such as carbides generated in extrusion and devolatilization processes.

  Further, “weight” is treated as a synonym for “mass”, and “weight%” is treated as a synonym for “mass%”. Further, “A to B” indicating a range indicates that the range is A or more and B or less.

  Further, “main component” is treated as meaning that 50% by weight or more is contained, and “ppm” means a value in terms of mass unless otherwise specified.

(I) Thermoplastic resin composition The thermoplastic resin composition according to the present embodiment is composed mainly of a thermoplastic resin whose main chain is composed of an aliphatic compound, softens by heating, exhibits plasticity, and solidifies when cooled. The resin composition is not particularly limited. Examples of the thermoplastic resin include resins made of a polymer whose main chain is a chain hydrocarbon such as an acrylic resin, a cycloolefin polymer (olefin resin), and polyvinyl alcohol. Of these, acrylic resins are preferred. These thermoplastic resins may be used alone or in combination of two or more.

  In the present specification, the “aliphatic compound” includes not only a compound having a molecular structure in a chain structure, but also a cyclic hydrocarbon such as cyclohexane, an anhydride of a dicarboxylic acid, a lactone ring, a cyclic ether, and the like. Including. That is, “aliphatic compound” means a compound other than an aromatic compound. Accordingly, polyesters and polycarbonates having an aromatic ring such as a benzene ring in the main chain are not included in the “aliphatic compound”.

  The acrylic resin is more preferably a heat resistant acrylic resin. The “heat-resistant acrylic resin” is an acrylic resin having a glass transition temperature exceeding 110 ° C., for example, maleimide polymer, polyglutarimide polymer, polyglutaric acid polymer, maleic anhydride Examples thereof include a polymer and a lactone ring-containing polymer. Among these, the maleimide polymer and the polyglutarimide polymer are likely to be colored during hot melting, and the polyglutaric acid polymer and the maleic anhydride polymer are foamed due to a decarboxylation reaction during hot melting. Lactone ring-containing polymer is more preferable.

  The acrylic resin composition according to the present embodiment is a resin composition mainly composed of an acrylic resin, and the heat resistant acrylic resin composition is composed mainly of a heat resistant acrylic resin. It is a resin composition.

  The acrylic resin is not particularly limited as long as it is a resin obtained by polymerizing a monomer composition containing (meth) acrylic acid ester as a main component. Examples of the (meth) acrylic acid ester include the general formula (2)

(In the formula, R ⁴ and R ⁵ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)
A compound (monomer) having a structure represented by the formula: Acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, etc. Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate and benzyl methacrylate; You may use only a seed | species and may use 2 or more types together. Among these, in particular, a compound having a structure represented by the general formula (2), methyl methacrylate, is more preferable from the viewpoint of excellent heat resistance and transparency.

  Examples of the compound represented by the general formula (2) include methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, isopropyl 2- (hydroxymethyl) acrylate, and 2- (hydroxymethyl). ) Normal butyl acrylate, tertiary butyl 2- (hydroxymethyl) acrylate, and the like. Among these, methyl 2- (hydroxymethyl) acrylate and 2- (hydroxymethyl) ethyl acrylate are preferable, and methyl 2- (hydroxymethyl) acrylate is particularly preferable in that the effect of improving heat resistance is high. As for the compound represented by General formula (2), only 1 type may be used and 2 or more types may be used together.

  The acrylic resin may have a structure other than the structure obtained by polymerizing the (meth) acrylic acid ester described above. The structure other than the structure obtained by polymerizing (meth) acrylic acid ester is not particularly limited, but a hydroxyl group-containing monomer, an unsaturated carboxylic acid, the following general formula (3)

(Wherein R ⁶ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an —OAc group, a —CN group, a —CO—R ⁷ group, or —C -O-R ⁸ group is represented, Ac group represents an acetyl group, R ⁷ and R ⁸ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)
The polymer structural unit (repeating structural unit) constructed by polymerizing at least one selected from the monomers represented by

  The hydroxyl group-containing monomer is not particularly limited as long as it is a hydroxyl group-containing monomer other than the monomer represented by the general formula (2). For example, α-hydroxymethylstyrene, α-hydroxyethylstyrene; 2 2- (hydroxyalkyl) acrylic acid such as-(hydroxyethyl) acrylic acid; and the like. These may be used alone or in combination of two or more.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, α-substituted acrylic acid, α-substituted methacrylic acid and the like. These may be used alone or in combination of two or more. May be. Among these, acrylic acid and methacrylic acid are preferable in that the effects of the present invention are sufficiently exhibited.

  Examples of the compound represented by the general formula (3) include styrene, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, and vinyl acetate, and these may be used alone. Two or more kinds may be used in combination. Among these, styrene and α-methylstyrene are particularly preferable in that the effects of the present invention are sufficiently exhibited.

  When the acrylic resin is a resin obtained by polymerizing a monomer containing a compound having the structure represented by the general formula (2), the acrylic resin may have a lactone ring structure. Preferred (hereinafter, an acrylic resin having a lactone ring structure is referred to as a “lactone ring-containing polymer”). Hereinafter, the lactone ring-containing polymer will be described.

  Examples of the lactone ring structure include the following general formula (1)

(Wherein R ¹ , R ² and R ³ each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.)
The structure represented by is mentioned.

  The organic residue in the general formulas (1), (2), and (3) is not particularly limited as long as it has a carbon number in the range of 1 to 20, but for example, a linear or branched alkyl group , A linear or branched alkylene group, an aryl group, an —OAc group, a —CN group and the like.

  The content of the lactone ring structure in the acrylic resin is preferably in the range of 5 to 90% by weight, more preferably in the range of 10 to 70% by weight, and still more preferably in the range of 10 to 60% by weight. Especially preferably, it exists in the range of 10-50 weight%. When the content of the lactone ring structure is less than 5% by weight, the heat resistance, solvent resistance, and surface hardness may be insufficient, which is not preferable. When the content of the lactone ring structure is more than 90% by weight, the moldability tends to be poor, which is not preferable.

  In the lactone ring-containing polymer, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is that of a polymer structural unit (repeating structural unit) constructed by polymerizing (meth) acrylic acid ester. In this case, it is preferably in the range of 10 to 95% by weight, more preferably in the range of 10 to 90% by weight, further preferably in the range of 40 to 90% by weight, particularly preferably in the range of 50 to 90% by weight. .

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing a hydroxyl group-containing monomer, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is preferably 0 to It is in the range of 30% by weight, more preferably in the range of 0 to 20% by weight, further preferably in the range of 0 to 15% by weight, particularly preferably in the range of 0 to 10% by weight.

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing an unsaturated carboxylic acid, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is preferably 0 to 30. It is in the range of% by weight, more preferably in the range of 0 to 20% by weight, further preferably in the range of 0 to 15% by weight, particularly preferably in the range of 0 to 10% by weight.

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing the monomer represented by the general formula (3), it contains a structure other than the lactone ring structure represented by the general formula (1). The proportion is preferably in the range of 0 to 30% by weight, more preferably in the range of 0 to 20% by weight, still more preferably in the range of 0 to 15% by weight, particularly preferably in the range of 0 to 10% by weight. is there.

  The method for producing the lactone ring-containing polymer is not particularly limited, but preferably, after the polymer having a hydroxyl group and an ester group in the molecular chain is obtained by the polymerization step, the obtained polymer is heat-treated. Thus, a lactone ring-containing polymer can be obtained by carrying out a lactone cyclization condensation step for introducing a lactone ring structure into the polymer.

  A polymer having a hydroxyl group and an ester group in the molecular chain is obtained by performing a polymerization reaction of the monomer composition containing the compound represented by the general formula (2).

  The content ratio of the compound represented by the general formula (2) in the monomer composition provided in the polymerization reaction (polymerization step) is preferably within the range of 5 to 90% by weight, more preferably 10 to 70% by weight. More preferably, it is in the range of 10 to 60% by weight, particularly preferably in the range of 10 to 50% by weight. When the content of the monomer represented by the general formula (2) in the monomer component provided in the polymerization step is less than 5% by weight, heat resistance, solvent resistance, and surface hardness may be insufficient. Yes, not preferred. If the content of the monomer represented by the general formula (2) in the monomer composition provided in the polymerization process is more than 90% by weight, gelation may occur during polymerization or lactone cyclization, The molding processability of the obtained polymer may be poor, which is not preferable.

  The monomer composition used in the polymerization step may contain a monomer other than the monomer represented by the general formula (2). As such a monomer, for example, the (meth) acrylic acid ester, the hydroxyl group-containing monomer, the unsaturated carboxylic acid, and the monomer represented by the general formula (3) are preferably exemplified. Only one type of monomer other than the monomer represented by formula (2) may be used, or two or more types may be used in combination.

  When (meth) acrylic acid esters other than the monomer represented by the general formula (2) are used, the content ratio in the monomer component to be subjected to the polymerization step is sufficient to exert the effect of the present invention. In the range of 10 to 95% by weight, more preferably in the range of 10 to 90% by weight, still more preferably in the range of 40 to 90% by weight, and particularly preferably in the range of 50 to 90% by weight.

  In the case of using a hydroxyl group-containing monomer other than the monomer represented by the general formula (2), the content ratio in the monomer component to be subjected to the polymerization step is sufficient to exert the effect of the present invention. Preferably it is in the range of 0 to 30% by weight, more preferably in the range of 0 to 20% by weight, still more preferably in the range of 0 to 15% by weight, and particularly preferably in the range of 0 to 10% by weight.

  In the case of using an unsaturated carboxylic acid, the content ratio in the monomer component to be subjected to the polymerization step is preferably in the range of 0 to 30% by weight, more preferably 0, in order to sufficiently exert the effects of the present invention. It is in the range of -20% by weight, more preferably in the range of 0-15% by weight, particularly preferably in the range of 0-10% by weight.

  When the monomer represented by the general formula (3) is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by weight in order to sufficiently exhibit the effects of the present invention. More preferably, it is in the range of 0 to 20% by weight, more preferably in the range of 0 to 15% by weight, and particularly preferably in the range of 0 to 10% by weight.

  The form of the polymerization reaction for polymerizing the monomer composition to obtain a polymer having a hydroxyl group and an ester group in the molecular chain is preferably a polymerization form using a solvent, and solution polymerization is particularly preferred. .

  The polymerization temperature and the polymerization time vary depending on the type of monomer (monomer composition) used, the ratio of use, etc., but preferably the polymerization temperature is in the range of 0 to 150 ° C., and the polymerization time is 0.5 to The polymerization time is in the range of 20 hours, more preferably, the polymerization temperature is in the range of 80 to 140 ° C., and the polymerization time is in the range of 1 to 10 hours.

  In the case of a polymerization form using a solvent, the polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran Etc., and only one of these may be used, or two or more may be used in combination. Moreover, since the residual volatile matter of the lactone ring containing polymer finally obtained will increase when the boiling point of the solvent to be used is too high, the thing whose boiling point is in the range of 50-200 degreeC is preferable.

  During the polymerization reaction, a polymerization initiator may be added as necessary. Although it does not specifically limit as a polymerization initiator, For example, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amyl Organic peroxides such as peroxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2, Azo compounds such as 4-dimethylvaleronitrile), and the like. These may be used alone or in combination of two or more. The amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of the monomers used and the reaction conditions.

  When performing the polymerization, it is preferable to control the concentration of the produced polymer in the polymerization reaction mixture to be 50% by weight or less in order to suppress gelation of the reaction solution. Specifically, when the concentration of the produced polymer in the polymerization reaction mixture exceeds 50% by weight, it is preferable that the polymerization solvent is appropriately added to the polymerization reaction mixture and controlled to be 50% by weight or less. . The concentration of the produced polymer in the polymerization reaction mixture is more preferably 45% by weight or less, still more preferably 40% by weight or less. Note that if the concentration of the polymer in the polymerization reaction mixture is too low, the productivity is lowered. Therefore, the concentration of the polymer in the polymerization reaction mixture is preferably 10% by weight or more, and more preferably 20% by weight or more. It is more preferable.

  The form in which the polymerization solvent is appropriately added to the polymerization reaction mixture is not particularly limited, and the polymerization solvent may be added continuously or intermittently. By controlling the concentration of the produced polymer in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more sufficiently suppressed, and in particular, to increase the lactone ring content and improve the heat resistance. Even when the ratio of hydroxyl groups and ester groups in the molecular chain is increased, gelation can be sufficiently suppressed. The polymerization solvent to be added may be the same type of solvent used during the initial charging of the polymerization reaction or may be a different type of solvent, but is the same as the solvent used during the initial charging of the polymerization reaction. It is preferable to use different types of solvents. Further, the polymerization solvent to be added may be only one type of solvent or a mixed solvent of two or more types.

  The polymer obtained in the above polymerization step is an ester group in the molecular chain (in the case where the polymer is a monomer containing a compound having a structure represented by the general formula (2), Hydroxyl group and ester group), and the weight average molecular weight of the polymer is preferably in the range of 1,000 to 2,000,000, more preferably in the range of 5,000 to 1,000,000. Of these, more preferably in the range of 10,000 to 500,000, particularly preferably in the range of 50,000 to 500,000.

  In the polymer obtained by polymerizing the monomer containing the compound having the structure represented by the general formula (2), the lactone ring structure is introduced into the polymer by heat treatment in the subsequent lactone cyclization condensation step. It can be made into a lactone ring-containing polymer.

  In the polymerization reaction mixture obtained when the above polymerization step is completed, a solvent is usually contained in addition to the obtained polymer. When the above polymer is a lactone ring-containing polymer, it is not necessary to completely remove the solvent and take out the polymer in a solid state, and the subsequent lactone cyclization condensation step is performed in a state containing the solvent. Is preferred. If necessary, after taking out in a solid state, a solvent suitable for the subsequent lactone cyclization condensation step may be added again.

  The reaction for introducing a lactone ring structure into the polymer is a reaction in which a hydroxyl group and an ester group present in the molecular chain of the polymer are cyclized and condensed to form a lactone ring structure by heating. Alcohol is a by-product of condensation. By forming the lactone ring structure in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the polymer. If the reaction rate of the cyclization condensation reaction leading to the lactone ring structure is insufficient, the heat resistance will not be improved sufficiently, or the condensation reaction will occur during the molding process due to the heat treatment during molding, and the resulting alcohol will be contained in the molded product. It is not preferable because it may exist as bubbles or silver streaks.

  The lactone ring-containing polymer obtained in the lactone cyclization condensation step preferably has a lactone ring structure represented by the general formula (1).

  The method for heat-treating the polymer is not particularly limited, and a known method can be used. For example, you may heat-process the polymerization reaction mixture containing the solvent obtained by the superposition | polymerization process as it is. Moreover, you may heat-process using a ring-closing catalyst as needed in presence of a solvent. Further, the heat treatment can be performed using a heating furnace or reaction apparatus having a vacuum apparatus or a devolatilizing apparatus for removing volatile components, an extruder having a devolatilizing apparatus, or the like.

  In carrying out the cyclization condensation reaction, other thermoplastic resins may coexist in addition to the polymer. Further, when performing the cyclization condensation reaction, if necessary, an esterification catalyst or a transesterification catalyst such as p-toluenesulfonic acid generally used as a catalyst for the cyclization condensation reaction may be used. Organic carboxylic acids such as propionic acid, benzoic acid, acrylic acid, and methacrylic acid may be used as a catalyst. As disclosed in JP-A-61-254608 and JP-A-61-261303, basic compounds, organic carboxylates, carbonates and the like may be used.

  In carrying out the cyclization condensation reaction, it is preferable to use an organic phosphorus compound as a catalyst. By using an organophosphorus compound as a catalyst, the cyclization condensation reaction rate can be improved, and coloring of the resulting lactone ring-containing polymer can be greatly reduced. Furthermore, by using an organophosphorus compound as a catalyst, it is possible to suppress a decrease in molecular weight that can occur when a devolatilization step described later is used in combination, and to impart excellent mechanical strength.

  Examples of the organic phosphorus compound that can be used as a catalyst in the cyclocondensation reaction include alkyl (aryl) phosphonous acids such as methylphosphonous acid, ethylphosphonous acid, and phenylphosphonous acid (however, Tautomers (which may be alkyl (aryl) phosphinic acid) and diesters or monoesters thereof; dimethylphosphinic acid, diethylphosphinic acid, diphenylphosphinic acid, phenylmethylphosphinic acid, phenylethylphosphinic acid, etc. Dialkyl (aryl) phosphinic acids and esters thereof; alkyl (aryl) phosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, trifluoromethyl phosphonic acid, phenyl phosphonic acid, and their diesters or monoesters; Alkyl (aryl) phosphinic acids such as phosphoric acid, ethylphosphinic acid, phenylphosphinic acid and their esters; methyl phosphite, ethyl phosphite, phenyl phosphite, dimethyl phosphite, phosphorous acid Phosphorous acid diester or monoester or triester such as diethyl, diphenyl phosphite, trimethyl phosphite, triethyl phosphite, triphenyl phosphite; methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, phosphorus Isodecyl phosphate, lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, phosphorus Diisostearyl acid, diphenyl phosphate, trimethyl phosphate , Phosphoric diesters or monoesters or triesters such as triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisostearyl phosphate, triphenyl phosphate; methylphosphine, ethylphosphine, phenylphosphine, dimethyl Phosphine, diethylphosphine, diphenylphosphine, trimethylphosphine, triethylphosphine, triphenylphosphine, etc. mono-, di- or trialkyl (aryl) phosphine; methyldichlorophosphine, ethyldichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine, Alkyl (aryl) halogen phosphines such as diphenylchlorophosphine; Sphine, phenylphosphine oxide, dimethylphosphine oxide, diethylphosphine oxide, diphenylphosphine oxide, trimethylphosphine oxide, triethylphosphine oxide, triphenylphosphine oxide, mono-, di- or trialkyl (aryl) phosphines; tetramethylphosphonium chloride, chloride And halogenated tetraalkyl (aryl) phosphonium such as tetraethylphosphonium and tetraphenylphosphonium chloride. Among these, alkyl (aryl) phosphonous acid, phosphorous acid diester or monoester, phosphoric acid diester or monoester, and alkyl (aryl) phosphonic acid are preferable because of high catalytic activity and low colorability. ) Phosphorous acid, phosphorous acid diester or monoester, phosphoric acid diester or monoester are more preferred, and alkyl (aryl) phosphonous acid, phosphoric acid diester or monoester is particularly preferred. These organic phosphorus compounds may use only 1 type and may use 2 or more types together.

  The amount of the catalyst used in the cyclization condensation reaction is not particularly limited, but is preferably in the range of 0.001 to 5% by weight, more preferably 0.01 to 2.5% by weight with respect to the polymer. %, More preferably 0.01 to 1% by weight, particularly preferably 0.05 to 0.5% by weight. If the amount of the catalyst used is less than 0.001% by weight, the reaction rate of the cyclization condensation reaction may not be sufficiently improved. On the other hand, if the amount exceeds 5% by weight, coloring may occur, This is not preferable because it may be difficult to melt and form by crosslinking of the coalesced.

  The addition timing of the catalyst is not particularly limited, and it may be added at the beginning of the reaction, during the reaction, or both.

  It is preferable to carry out the cyclization condensation reaction in the presence of a solvent and to use a devolatilization step in combination with the cyclization condensation reaction. In this case, a mode in which the devolatilization step is used throughout the cyclization condensation reaction and a mode in which the devolatilization step is not used over the entire cyclization condensation reaction but only in a part of the process. In the method using the devolatilization step in combination, the alcohol produced as a by-product in the condensation cyclization reaction is forcibly devolatilized and removed, so that the equilibrium of the reaction is advantageous for the production side.

  The devolatilization step refers to a step of removing volatile components such as a solvent and residual monomers and alcohol produced as a by-product by a cyclocondensation reaction leading to a lactone ring structure, if necessary under reduced pressure heating conditions. If this removal treatment is insufficient, the residual volatile matter in the produced resin increases, resulting in problems such as coloration due to alteration during molding and the like, and molding defects such as bubbles and silver streaks.

  In the case of a form in which a devolatilization step is used throughout the cyclization condensation reaction, the apparatus to be used is not particularly limited. It is preferable to use an extruder equipped with a vent, or a device in which the devolatilizer and the extruder are arranged in series, and it is more preferable to use a devolatilizer comprising a heat exchanger and a devolatilization tank or an extruder equipped with a vent. preferable.

  In the case of using a devolatilizer comprising the heat exchanger and the devolatilization tank, the reaction treatment temperature is preferably in the range of 150 to 350 ° C, more preferably in the range of 200 to 300 ° C. If the reaction treatment temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient and the residual volatile matter may increase, and if it is higher than 350 ° C., coloring or decomposition may occur.

  In the case of using a devolatilizer comprising the heat exchanger and the devolatilization tank, the pressure during the reaction treatment is preferably within a range of 931 to 1.33 hPa (700 to 1 mmHg), and 798 to 66.5 hPa (600 to 50 mmHg). ) Is more preferable. When the pressure is higher than 931 hPa, there is a problem that volatile components including alcohol easily remain, and when the pressure is lower than 1.33 hPa, there is a problem that industrial implementation becomes difficult.

  When using the extruder with a vent, one or a plurality of vents may be used, but it is preferable to have a plurality of vents.

  In the case of using the vented extruder, the reaction treatment temperature is preferably in the range of 150 to 350 ° C, more preferably in the range of 200 to 300 ° C. If the temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient and the residual volatile content may increase. If the temperature is higher than 350 ° C., coloring or decomposition may occur.

  In the case of using the extruder with a vent, the pressure during the reaction treatment is preferably within a range of 931 to 1.33 hPa (700 to 1 mmHg), and more preferably within a range of 798 to 13.3 hPa (600 to 10 mmHg). When the pressure is higher than 931 hPa, there is a problem that volatile components including alcohol easily remain, and when the pressure is lower than 1.33 hPa, there is a problem that industrial implementation becomes difficult.

  In the case of using the devolatilization step throughout the cyclization condensation reaction, as described later, the physical properties of the lactone ring-containing polymer obtained may be deteriorated under severe heat treatment conditions. It is preferable to use a catalyst for a dealcoholization reaction and under a mild condition as much as possible using an extruder with a vent.

  In the case of using a devolatilization step throughout the cyclization condensation reaction, preferably, the polymer obtained in the polymerization step is introduced into the cyclization condensation reactor system together with a solvent. Then, it may be passed once again through the reactor system such as an extruder with a vent.

  You may perform the form used together only in a part of process, without using a devolatilization process over the whole process of cyclization condensation reaction. For example, the apparatus for producing the polymer is further heated, and if necessary, a part of the devolatilization step is used together to advance the cyclization condensation reaction to some extent in advance, and then the devolatilization step is used at the same time. In this mode, the cyclization condensation reaction is performed to complete the reaction.

  In the embodiment in which the devolatilization step is used throughout the cyclization condensation reaction described above, for example, when the polymer is heat-treated at a high temperature of about 250 ° C. or higher using a twin screw extruder, Depending on the difference, partial decomposition or the like may occur before the cyclization condensation reaction occurs, and the physical properties of the resulting lactone ring-containing polymer may be deteriorated. Therefore, if the cyclization condensation reaction is allowed to proceed to some extent before the cyclization condensation reaction using the devolatilization step at the same time, the latter reaction conditions can be relaxed and the physical properties of the resulting lactone ring-containing polymer deteriorated. Is preferable. A particularly preferred form is a form in which the devolatilization step is started after a while from the start of the cyclization condensation reaction, that is, the hydroxyl group and ester group present in the molecular chain of the polymer obtained in the polymerization step are cyclized in advance. A form in which a condensation reaction is performed to increase the cyclization condensation reaction rate to some extent, and then a cyclization condensation reaction using a devolatilization step in combination is performed. Specifically, for example, a cyclization condensation reaction is allowed to proceed to a certain reaction rate in the presence of a solvent in advance using a kettle-type reactor, and then a reactor equipped with a devolatilizer, for example, a heat Preferred is a mode in which the cyclization condensation reaction is completed with a devolatilizer comprising an exchanger and a devolatilization tank, an extruder with a vent, or the like. Particularly in this form, it is more preferable that a catalyst for the cyclization condensation reaction is present.

  As described above, the hydroxyl group and ester group present in the molecular chain of the polymer obtained in the polymerization step are subjected to a cyclization condensation reaction in advance to increase the cyclization condensation reaction rate to some extent. The method of carrying out the cyclization condensation reaction simultaneously used is a preferred form for obtaining a lactone ring-containing polymer. With this configuration, a lactone ring-containing polymer having a higher cyclization condensation reaction rate, a higher glass transition temperature, and excellent heat resistance can be obtained. In this case, as a measure of the cyclization condensation reaction rate, the weight loss rate between 150 and 300 ° C. in the dynamic TG measurement shown in the examples is preferably 2% or less, more preferably 1.5% or less. More preferably, it is 1% or less.

  The reactor that can be employed in the cyclization condensation reaction that is performed in advance before the cyclization condensation reaction using the devolatilization process at the same time is not particularly limited, but preferably an autoclave, a kettle reactor, a heat exchanger, and a devolatilization tank A vented extruder suitable for a cyclocondensation reaction in which a devolatilization step is simultaneously used can also be used. More preferred are autoclaves and kettle reactors. However, even when using a reactor such as an extruder with a vent, by adjusting the temperature condition, barrel condition, screw shape, screw operating condition, etc. It is possible to carry out the cyclization condensation reaction in the same state as the reaction state in the kettle reactor.

  In the case of the cyclization condensation reaction performed in advance before the cyclization condensation reaction using the devolatilization step at the same time, preferably, a mixture containing the polymer and the solvent obtained in the polymerization step is added (i) a catalyst. And (ii) a method of performing a heat reaction without a catalyst, and a method of performing the above (i) or (ii) under pressure.

  The “mixture containing a polymer and a solvent” to be introduced into the cyclization condensation reaction in the lactone cyclization condensation step may be the polymerization reaction mixture obtained in the polymerization step as it is, or once the solvent is removed. After that, it means that a solvent suitable for the cyclization condensation reaction may be added again.

  The solvent that can be re-added in the cyclization condensation reaction that is carried out in advance before the cyclization condensation reaction simultaneously used in the devolatilization step is not particularly limited, for example, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; chloroform, DMSO, tetrahydrofuran and the like may be used, but the same type of solvent that can be used in the polymerization step is preferable.

  Examples of the catalyst added in the above method (i) include esterification catalysts such as p-toluenesulfonic acid or transesterification catalysts, basic compounds, organic carboxylates, carbonates and the like that are generally used. Is preferably the above-described organophosphorus compound.

  The addition timing of the catalyst is not particularly limited, and it may be added at the beginning of the reaction, during the reaction, or both. The amount of the catalyst to be added is not particularly limited, but is preferably in the range of 0.001 to 5% by weight, more preferably in the range of 0.01 to 2.5% by weight, still more preferably based on the weight of the polymer. It is in the range of 0.01 to 0.1% by weight, particularly preferably in the range of 0.05 to 0.5% by weight. The heating temperature and heating time in method (i) are not particularly limited, but the heating temperature is preferably room temperature or higher, more preferably 50 ° C. or higher, and the heating time is preferably in the range of 1 to 20 hours. More preferably, it is in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. Further, if the heating time is too long, the resin may be colored or decomposed, which is not preferable.

  Examples of the method (ii) include a method of heating the polymerization reaction mixture obtained in the polymerization step as it is using a pressure-resistant kettle or the like. The heating temperature is preferably 100 ° C. or higher, more preferably 150 ° C. or higher. The heating time is preferably in the range of 1 to 20 hours, more preferably in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. Further, if the heating time is too long, the resin may be colored or decomposed, which is not preferable.

  Both the above methods (i) and (ii) have no problem even under pressure depending on conditions. Moreover, in the case of the cyclization condensation reaction performed beforehand before the cyclization condensation reaction which used the devolatilization process simultaneously, even if a part of the solvent volatilizes naturally during the reaction, there is no problem.

  The weight loss rate between 150 and 300 ° C. in dynamic TG measurement at the end of the cyclization condensation reaction performed in advance before the cyclization condensation reaction simultaneously using the devolatilization step, that is, immediately before the start of the devolatilization step is 2% or less is preferable, More preferably, it is 1.5% or less, More preferably, it is 1% or less. When the weight reduction rate is higher than 2%, the cyclization condensation reaction rate does not rise to a sufficiently high level even if the cyclization condensation reaction is performed simultaneously with the devolatilization step, and the physical properties of the resulting lactone ring-containing polymer. May decrease. In addition, when performing said cyclization condensation reaction, in addition to a polymer, you may coexist other thermoplastic resins.

  Cyclization using a hydroxyl group and an ester group present in the molecular chain of the polymer obtained in the polymerization step in advance by a cyclization condensation reaction to increase the cyclization condensation reaction rate to a certain extent, followed by a devolatilization step at the same time. In the case of a form in which a condensation reaction is performed, a polymer obtained by a previously performed cyclization condensation reaction (a polymer in which at least a part of hydroxyl groups and ester groups in the molecular chain are subjected to a cyclization condensation reaction) and a solvent are isolated. Without carrying out, you may perform the cyclization condensation reaction which used the devolatilization process simultaneously. Further, if necessary, other treatments such as re-adding a solvent after isolating the polymer (a polymer in which at least a part of hydroxyl groups and ester groups present in the molecular chain are subjected to cyclization condensation reaction) are performed. After that, you may perform the cyclization condensation reaction which used the devolatilization process simultaneously.

  The devolatilization step is not limited to being completed at the same time as the cyclization condensation reaction, and may be completed after a lapse of time from the completion of the cyclization condensation reaction.

  In addition, even after a sufficient amount of cyclization condensation reaction is carried out by adding a catalyst, a small amount of unreacted reactive groups remain in the polymer. Therefore, foaming or cross-linking between polymer molecules may occur during molding. Problems such as thickening may occur. For this reason, it is preferable to add a deactivation agent for the cyclization condensation catalyst (hereinafter sometimes referred to as “foaming inhibitor”) after adding the catalyst and sufficiently performing the cyclization condensation reaction.

  In the cyclization condensation reaction, an acidic catalyst or a basic catalyst is often used. In that case, the deactivator deactivates the catalyst by a neutralization reaction. For this reason, when the catalyst is an acidic substance, the deactivating agent may be a basic substance. Conversely, when the catalyst is a basic substance, the deactivating agent may be an acidic substance.

  The deactivator is not particularly limited as long as it does not generate a substance or the like that inhibits the physical properties of the resin composition during heat processing. When a basic substance is used as the deactivator, for example, a metal carboxylate, a metal complex, A metal oxide etc. are mentioned. Among these, metal carboxylates and metal oxides are preferable, and metal carboxylates are particularly preferable.

  The metal in the basic substance is not particularly limited as long as it does not inhibit the physical properties of the resin composition and causes environmental pollution at the time of disposal. For example, alkali metals such as lithium, sodium and potassium; magnesium and calcium Alkaline earth metals such as strontium and barium; zinc; zirconium and the like.

  The carboxylic acid constituting the metal carboxylate is not particularly limited. For example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, Examples include myristic acid, palmitic acid, stearic acid, behenic acid, tridecanoic acid, pentadecanoic acid, heptadecanoic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, and adipic acid. .

  Although it does not specifically limit as an organic component in the said metal complex, Acetyl acetone etc. are mentioned. Examples of the metal oxide include zinc oxide, calcium oxide, magnesium oxide and the like, and zinc oxide is preferable.

  Moreover, when using an acidic substance for a quencher, an organic phosphoric acid compound, carboxylic acid, etc. are mentioned, for example. The quenching agent that can be used in the present embodiment may be used alone or in combination of two or more. The quenching agent may be used in any form such as a solid state such as a powder or a state dispersed in a solvent such as a suspension or an aqueous solution.

  The addition amount of the deactivator may be appropriately adjusted according to the amount of the catalyst used in the cyclization condensation reaction, and is not particularly limited, but is preferably 10 to 10 to the thermoplastic resin (polymer). It is within the range of 000 ppm (weight conversion), more preferably within the range of 50 to 5,000 ppm (weight conversion), and even more preferably within the range of 100 to 3,000 ppm (weight conversion).

  When the addition amount of the deactivator is less than 10 ppm, the function of the deactivator becomes insufficient, and thickening due to foaming or cross-linking between polymer molecules may occur during molding. On the other hand, when the addition amount of the deactivator exceeds 10,000 ppm, the deactivator is used more than necessary, and the physical properties of the resin composition may be inhibited, for example, the molecular weight is lowered.

  The timing of adding the deactivator is after the catalyst is added and the cyclization condensation reaction is sufficiently performed in the production of the thermoplastic resin (polymer), and before the obtained resin composition is thermally processed. As long as it is, it is not particularly limited. For example, a deactivator is added at a predetermined stage during the production of a thermoplastic resin, or after producing a thermoplastic resin, the thermoplastic resin, the deactivator, and other components are simultaneously heated and melted and kneaded. Method of adding a deactivator after heating and melting the thermoplastic resin and other components; kneading; adding a deactivator and other components after heating and melting the thermoplastic resin And kneading.

  Moreover, when adding a quencher, it is preferable to perform a devolatilization process after kneading a thermoplastic resin and a quencher from a viewpoint that the obtained thermoplastic resin hardly causes foaming at the time of heat processing. As the devolatilization step, the same step as the devolatilization step performed in the production of the lactone ring-containing polymer described above can be performed.

  The obtained lactone ring-containing polymer has a weight average molecular weight of preferably in the range of 1,000 to 2,000,000, more preferably in the range of 5,000 to 1,000,000, and even more preferably 10. In the range of 50,000 to 500,000, particularly preferably in the range of 50,000 to 500,000.

  The lactone ring-containing polymer preferably has a weight reduction rate of 150% to 300 ° C in dynamic TG measurement of 1% or less, more preferably 0.5% or less, and even more preferably 0.3% or less. is there.

  Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, it is possible to avoid the disadvantage that bubbles and silver streaks enter the molded product after molding. Furthermore, since the lactone ring structure is sufficiently introduced into the polymer due to a high cyclization condensation reaction rate, the obtained lactone ring-containing polymer has sufficiently high heat resistance.

  The lactone ring-containing polymer preferably has a coloring degree (YI) in a 15% by weight chloroform solution of 6 or less, more preferably 3 or less, still more preferably 2 or less, and most preferably 1 or less. If the coloring degree (YI) exceeds 6, transparency may be impaired due to coloring, and it may not be used for the intended purpose.

  The lactone ring-containing polymer preferably has a 5% weight loss temperature in thermogravimetric analysis (TG) of 330 ° C. or higher, more preferably 350 ° C. or higher, and still more preferably 360 ° C. or higher. The 5% weight loss temperature in thermogravimetric analysis (TG) is an indicator of thermal stability, and if it is less than 330 ° C., sufficient thermal stability may not be exhibited.

  The lactone ring-containing polymer has a glass transition temperature (Tg) of preferably 115 ° C. or higher, more preferably 125 ° C. or higher, further preferably 130 ° C. or higher, more preferably 135 ° C. or higher, and most preferably 140 ° C. or higher. .

  The total amount of residual volatile components contained in the lactone ring-containing polymer is preferably 1500 ppm or less, more preferably 1000 ppm or less. If the total amount of residual volatile components is more than 1500 ppm, it may cause molding defects such as coloration, foaming, or silver streak due to alteration during molding.

  The lactone ring-containing polymer preferably has a total light transmittance of 85% or more, more preferably 88% or more, and still more preferably a molded product obtained by injection molding, as measured by a method according to ASTM-D-1003. Is 90% or more. The total light transmittance is a measure of transparency, and if it is less than 85%, the transparency is lowered and there is a possibility that it cannot be used for the intended purpose.

  The thermoplastic resin composition according to the present embodiment may contain various additives. Examples of additives include antioxidants such as hindered phenols, phosphorus, and sulfur; stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fibers and carbon fibers; phenyls UV absorbers such as salicylate, (2,2′-hydroxy-5-methylphenyl) benzotriazole, 2-hydroxybenzophenone; near infrared absorbers; tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide, etc. Flame retardants; Antistatic agents such as anionic, cationic and nonionic surfactants; Colorants such as inorganic pigments, organic pigments and dyes; Organic fillers and inorganic fillers; Resin modifiers; Organic fillers and inorganic fillers Agents, plasticizers, lubricants, antistatic agents, flame retardants, and the like.

  The content of the additive in the thermoplastic resin composition is preferably in the range of 0 to 5% by weight, more preferably in the range of 0 to 2% by weight, and still more preferably in the range of 0 to 0.5% by weight. Is within. The additive may be added before the thermoplastic resin is added to the extruder described later, or may be added simultaneously when the thermoplastic resin is added to the extruder. It may be added after the thermoplastic resin is added to.

  The thermoplastic resin composition according to the present embodiment preferably has a glass transition temperature within the range of 110 to 170 ° C, more preferably within the range of 120 to 160 ° C, and more preferably 130 to 150 ° C. More preferably, it is in the range.

  In the thermoplastic resin composition according to the present embodiment, the total amount of residual volatiles contained is preferably 2000 ppm or less, more preferably 1500 ppm or less, and even more preferably 1000 ppm or less. The total amount of residual volatiles is more than 2000 ppm. If it is too large, it may cause coloring or foaming due to deterioration during molding, or cause molding defects such as silver streak.

  Here, the residual volatile matter is a low molecular weight organic component contained in the thermoplastic fat composition. Specifically, the manufacturing process of the thermoplastic resin used in the thermoplastic resin composition and the thermoplastic resin composition. The organic solvent used during the manufacturing process, the produced by-product, the monomer produced by depolymerization of the thermoplastic resin, and the residual monomer contained in the thermoplastic resin used in the thermoplastic resin composition.

  The thermoplastic resin composition according to the present embodiment can be reduced to 100 or less foreign matters having a particle diameter of 20 μm or more per gram by performing filtration using a polymer filter described later.

(II) Extruder The extruder 2 includes a polymer filter 4 having a filtration accuracy of 10 μm or less. As the extruder 2, a conventionally known extruder can be used, and for example, a single screw extruder or a twin screw extruder can be used. The extruder 2 is more preferably provided with a vent 3 as shown in FIG.

  The thermoplastic resin in the extruder 2 is subjected to heat shear in the filter portion having high filtration accuracy in addition to heat shear in the extruder, and therefore, volatile substances remaining in the thermoplastic resin composition, Due to the influence of volatile substances generated by the decomposition, problems such as foaming and coloring of the molding material in the process are likely to occur, and a large amount of residual volatiles are easily contained in the molded product. For this reason, providing the vent 3 in the extruder 2 enables more stable production and suppresses the amount of volatile substances contained in the obtained molding material. When an acrylic resin is used as the thermoplastic resin, it is more preferable that the extruder 2 is provided with a vent 3 because the acrylic resin easily causes depolymerization. A plurality of vents may be provided (not shown).

  The pressure in the vent 3 is preferably 150 torr or less, and more preferably 50 torr or less. Moreover, when using a twin screw extruder, it is more preferable to install a gear pump (not shown) between the polymer filter 4 and the extruder 2.

  The cylinder temperature of the extruder 2 is appropriately set depending on the processing amount, the number of rotations, and the like, and can be set to a temperature within a range of 220 to 300 ° C, for example. The temperature of the thermoplastic resin composition in the extruder 2 is preferably 260 ° C or higher, and more preferably 270 ° C or higher. Moreover, it is preferable that it is 310 degrees C or less, It is more preferable that it is 300 degrees C or less, It is especially preferable that it is 290 degrees C or less.

  When extruding a thermoplastic resin having a main chain made of an aliphatic compound such as a methacrylic resin, it is generally performed at a temperature in the range of 310 to 440 ° F. (154 to 227 ° C.) Even if it is a grade, it is carried out at a temperature within a range of 325 to 450 ° F. (163 to 232 ° C.), and when drying is sufficient, if the melting temperature is too high, problems such as foaming occur (“plastic Extrusion molding and its application "(see Keiji Sawada, Seikodo Shinkosha Co., Ltd., issued July 1, 1971), pages 224-226).

  In addition, “Transparent Plastic Molding Material Grade Handbook” (Synthetic Resin Industry Newspaper, 1988 edition), pages 234 to 237, describe the acrylic resin grade of each company, but the standard molding temperature in injection molding is 180 to 270. It is within the range of ℃, and the highest temperature is 270 ℃. Even in the case of injection molding where the time for one cycle is short and the time for receiving a heat history is short, the temperature is usually raised only to 270 ° C. That is, in the method for producing a thermoplastic resin composition according to the present embodiment, extrusion molding is performed at a very high temperature compared to conventional conditions. Thereby, it becomes possible to filter with the polymer filter mentioned later, and a foreign material can be reduced. In other words, conventionally, since the temperature at the time of extrusion molding and filtration was set low, the viscosity of the resin to be filtered increased, and filtration could not be performed with a polymer filter having a filtration accuracy of 10 μm or less.

  The viscosity of the thermoplastic resin composition in the extruder 2 is preferably such that the resin melt viscosity at a shear rate of 100 / sec is 800 Pa · sec or less, more preferably 700 Pa · sec or less, and 600 Pa · sec. It is particularly preferred that

(III) Polymer filter The polymer filter 4 has a filtration accuracy of preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and more preferably 1 μm or more and 3 μm or less. More preferably within the range. If the filtration accuracy is less than 1 μm, the filtration residence time becomes long and the production efficiency is lowered, which is not preferable. In addition, when the filtration residence time is long, the thermoplastic resin and the like are likely to be thermally deteriorated, which may increase foreign matter. Further, if the filtration accuracy exceeds 10 μm, it is not preferable because foreign matters are easily mixed.

  The polymer filter 4 is not particularly limited as long as it has a filtration accuracy within the above range, and a conventionally known polymer filter can be used. Examples of the polymer filter 4 include a leaf disk type polymer filter, a pack disk filter, a cylindrical filter, and a candle filter. Among these, a leaf disk type polymer filter is more preferable because a filtration area is wide and pressure loss is small even when a highly viscous resin is filtered.

  When the polymer filter 4 is a leaf disk type polymer filter, the filter is made of a material obtained by sintering a metal fiber nonwoven fabric, a material made of a material obtained by sintering metal powder, or a laminate of several metal meshes. Is mentioned. In these, what consists of the material which sintered the metal fiber nonwoven fabric is more preferable.

The filtration area with respect to the resin treatment amount per hour in the polymer filter 4 is appropriately selected depending on the treatment amount, and is not particularly limited. For example, 0.001 to 0.15 m ² / (kg / h) can do.

  In the filtration with the polymer filter 4, the temperature inside the polymer filter 4 (temperature of the thermoplastic resin composition) is preferably 260 ° C. or higher, and more preferably 270 ° C. or higher. Moreover, it is preferable that it is 310 degrees C or less, It is more preferable that it is 300 degrees C or less, It is still more preferable that it is 290 degrees C or less.

  The viscosity of the thermoplastic resin composition (when measured at a shear rate of 100 / s) during filtration through the polymer filter 4 is in the same range as the viscosity of the thermoplastic resin composition in the extruder 2 described above. It is preferable.

  The residence time of the thermoplastic resin composition during filtration with the polymer filter 4 is preferably 20 minutes or less, more preferably 10 minutes or less, and even more preferably 5 minutes or less. Moreover, the filter inlet pressure at the time of filtration with the polymer filter 4 can be in the range of 3 to 15 MPa, for example, and the outlet pressure of the filter can be in the range of 0.3 to 10 MPa, for example. Moreover, it is preferable that the pressure loss in a filter exists in the range of 1-15 Mpa. If the pressure loss is less than 1 MPa, the melted thermoplastic resin composition tends to be biased in the flow path through the polymer filter 4, and the quality of the thermoplastic resin composition after filtration tends to deteriorate. Conversely, when the pressure loss exceeds 15 MPa, the filter is easily damaged.

  In addition, before filtering with the polymer filter 4, it is more preferable to process the raw materials 1 such as thermoplastic resin with another filter in advance. Thereby, since the quantity of the foreign material which should be removed by filtration of 4 with a polymer filter reduces, it can filter by the polymer filter 4 in a shorter time. Moreover, since not only the filtration time by the polymer filter 4 can be shortened but also foreign matters can be removed more efficiently, the amount of foreign matters in the obtained thermoplastic resin composition is further reduced.

(IV) Cooling Water The cooling water 5 is provided for cooling the thermoplastic resin composition after passing through the polymer filter 4. The water temperature of the cooling water 5 is preferably in the range of 30 to 80 ° C, more preferably in the range of 40 to 70 ° C, and particularly preferably in the range of 50 to 60 ° C. When the water temperature is less than 30 ° C., bubbles are likely to be contained when pelletized, and fine powder is likely to be generated during cutting by the pelletizer 6 described later. On the other hand, when the water temperature exceeds 80 ° C., the molded pellets are not sufficiently cooled, so that problems such as blocking tend to occur.

(V) Pelletizer As the above pelletizer 6, a conventionally known pelletizer can be used. For example, a general strand pelletizer that cuts strands, a hot-cut type pelletizer that cuts in a semi-molten state at the outlet of a die, etc. Can be used.

  The pelletized thermoplastic resin composition is then filled into the filling container 8 via the tank 7.

  In addition, after pelletizing, it is desirable to remove pellets from the metal foreign matter with a iron remover, fine powder with a sieve, missed pellets, and the like.

  The pellet particle diameter is not particularly limited, but both the length and the cross-sectional diameter are preferably 4 mm or less.

  In addition, a high level of cleanliness is required for everything that comes in contact with the thermoplastic resin composition, including filling tanks (tanks 7), piping, transport containers, etc., and transportation such as air and pressure feeding in the working environment, etc. The air used for the air is air (air) cleaned with a hepa filter or the like.

  The filling container 8 is not particularly limited, and examples thereof include an aluminum bag, a container, and a tank lorry.

  The thermoplastic resin composition according to the present embodiment, particularly the heat-resistant acrylic resin composition, is not only excellent in transparency and heat resistance, but also has desired properties such as low colorability, mechanical strength, and moldability. Therefore, it is useful for optical applications such as an optical lens, an optical prism, an optical film, an optical fiber, and an optical disk. Among these, an optical lens, an optical prism, and an optical film are particularly preferable.

  The thermoplastic resin composition according to the present embodiment can be formed into various shapes depending on the application. Examples of shapes that can be formed include films, sheets, plates, disks, blocks, balls, lenses, rods, strands, cords, fibers, and the like. The molding method is not particularly limited as long as it is appropriately selected from conventionally known forming methods according to the shape.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

<Glass transition temperature>
Thermal analysis of the thermoplastic resin and the thermoplastic resin composition (acrylic resin composition) was performed under the conditions of a sample of about 10 mg, a temperature increase rate of 10 ° C./min, and a nitrogen flow of 50 cc / min, manufactured by DSC (Rigaku Corporation). , Apparatus name: DSC-8230). The glass transition temperature (Tg) was determined by the midpoint method according to ASTM-D-3418.

<Measurement of melt viscosity>
The melt viscosity of the thermoplastic resin and the thermoplastic resin composition (acrylic resin composition) was measured with a die having a diameter of 1 mm and a length of 16 mm using a capillary rheometer RH10 manufactured by Borin Instruments.

<Measurement of the number of foreign objects>
5 g of the obtained pellets were dissolved in 100 mL of chloroform and measured using a particle counter (manufactured by Pamas, model: SVSS-C, sensor specification: HCB-LD-50 / 50). In addition, the thing whose major axis is 20 micrometers or more was counted as a foreign material.

<Dynamic TG>
A thermoplastic resin and a thermoplastic resin composition (acrylic resin composition) (or polymer solution or pellet) are once dissolved or diluted in tetrahydrofuran, poured into excess hexane or methanol, re-precipitated, and taken out. Volatile components and the like were removed by vacuum drying (1 mmHg (1.33 hPa), 80 ° C., 3 hours or more), and the obtained white solid resin was analyzed by the following method (dynamic TG method).
Measuring apparatus: Thermo Plus2 TG-8120 Dynamic TG (manufactured by Rigaku Corporation)
Measurement conditions: Sample amount 5 to 10 mg
Temperature increase rate: 10 ° C / min
Atmosphere: Nitrogen flow 200ml / min
Method: Step-like isothermal control method (controlled at a weight reduction rate value of 0.005% / sec or less between 60 ° C and 500 ° C)
<Content of lactone ring structural unit>
The content ratio of the lactone ring structural unit was determined as follows.

  First, based on the weight loss that occurs when all hydroxyl groups are dealcoholated as methanol from the polymer composition obtained by polymerization, the decomposition of the polymer begins at 150 ° C. before the weight loss starts in dynamic TG measurement. The dealcoholization reaction rate was determined from the weight loss due to the dealcoholization reaction up to the previous 300 ° C.

  Here, in the dynamic TG measurement of the polymer having a lactone ring structure, the weight reduction rate between 150 ° C. and 300 ° C. is measured, and the obtained actual weight reduction rate is defined as (X). On the other hand, the theoretical weight reduction amount when assuming that all hydroxyl groups are dealcoholated from the composition of the weight body (that is, the weight reduction calculated assuming that a possible dealcoholization reaction has occurred in the polymer composition 100%. Amount) is defined as (Y).

  The theoretical weight reduction amount (Y) is more specifically the molar ratio of raw material monomers having a structure (hydroxyl group) involved in the dealcoholization reaction in the polymer, that is, the raw material unit in the polymer composition. It can be calculated from the content of the monomer.

And the following formula: Dealcoholization reaction rate = (1- (actually measured weight decrease rate (X) / theoretical weight decrease amount (Y)))
From this, the dealcoholization reaction rate can be determined.

  As an example, the proportion of the lactone ring structure in the thermoplastic resin composition (A-2) obtained in Example 1 described later is calculated. The theoretical weight loss (Y) of the thermoplastic resin composition (A-2) is that the molecular weight of methanol is 32, the molecular weight of methyl 2- (hydroxymethyl) acrylate is 116, and 2- (hydroxymethyl) Since the content (weight ratio) of methyl acrylate in the polymer is 20% by weight in terms of composition, (32/116) × 20≈5.52% by weight.

On the other hand, the measured weight loss rate (X) of the thermoplastic resin composition (A-2) by dynamic TG measurement was 0.16% by weight. When these values are applied to the above-mentioned formula for the dealcoholization reaction rate,
(1- (0.16 / 5.52)) ≈0.971
And the dealcoholization rate is 97.1%.

Then, assuming that the lactone cyclization reaction was performed by the amount corresponding to the above dealcoholization reaction rate, the content ratio (wt%) of the following formula lactone ring = B × A × M _R / M _m
(Wherein, B is the weight proportion in the monomer composition used in the copolymerization raw monomer having a structure (hydroxyl group) responsible for the lactonization, M _R lactone ring structure to generate The unit formula weight, M _m is the molecular weight of the raw material monomer having a structure (hydroxyl group) involved in lactone cyclization, and A is the dealcoholization reaction rate)
Thus, the lactone ring content ratio can be calculated.

  For example, in the case of Example 1, the content of 2- (hydroxymethyl) methyl acrylate in the thermoplastic resin composition (A-2) is 20.0% by weight, the calculated dealcoholization reaction rate is 97.1%, Since the formula weight of the lactone ring structural unit produced when methyl 2- (hydroxymethyl) acrylate having a molecular weight of 116 is condensed with methyl methacrylate is 170, the lactone in the thermoplastic resin composition (A-2) The ring content is 28.5 (= 20.0 × 0.971 × 170/116) wt%.

<Measurement of volatile content in polymer>
The amount of residual volatile components contained in the resin was measured using gas chromatography (manufactured by Shimadzu Corporation, apparatus name: GC-14A).

[Example 1]
In a 30 L capacity reactor equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introduction pipe, 8,000 g of methyl methacrylate (MMA) and 2,000 g of methyl 2- (hydroxymethyl) methyl acrylate (MHMA) were added. ) 10,000 g of toluene was charged, and the temperature was raised to 105 ° C. while refluxing nitrogen. When refluxed, 10.0 g of t-amylperoxyisononanoate (Lupazole 570, Atofina Yoshitomi ( At the same time, a solution consisting of 20.0 g of t-amylperoxyisononanoate and 100 g of toluene was added dropwise over 2 hours while solution polymerization was carried out at about 105 to 110 ° C. under reflux. Aged for another 4 hours.

  To the obtained polymer solution, 10 g of stearyl phosphate / distearyl phosphate mixture (Phoslex A-18, manufactured by Sakai Chemical Industry Co., Ltd.) was added and cyclized at about 90-110 ° C. for 5 hours under reflux. A condensation reaction was carried out to produce a polymer solution (A-1).

  Next, the amount of resin is added to a vent type screw twin screw extruder equipped with a leaf disk type polymer filter (5 inches, 5 sheets, manufactured by Nagase Sangyo) with a filtration accuracy of 5 μm and 1 rear vent and 4 fore vents. The polymer (thermoplastic resin) solution (A-1) was introduced at a treatment rate of 2.0 kg / h in terms of conversion, and devolatilization treatment was performed simultaneously with polymer filter treatment. In the above treatment, zinc octylate (18% Nikka octix zinc, manufactured by Nippon Chemical Industry Co., Ltd.) is used as a foam inhibitor (deactivator) between the third and fourth forvents. The toluene solution was injected so that zinc octylate was 700 ppm by weight with respect to the obtained thermoplastic resin composition.

  The temperature in the polymer filter at this time was 280 ° C., and the resin melt viscosity at a shear rate of 100 / sec was 400 Pa · sec.

  After passing through a die provided at the tip of the twin screw extruder, filtered with a filter (manufactured by Organo, product name: Micropore filter 1EU) with a pore size of 1 μm, and maintained at a temperature within a range of 60 ± 5 ° C. The strand was cooled with a filled water tank and introduced into a cutting machine (pelletizer) to obtain a pellet of the thermoplastic resin composition (A-2). During the production of pellets, a clean space was provided so that the environmental cleanliness from the die to the cutting machine was 5000 or less (US federal standard FED-STD-209E).

  The thermoplastic resin composition (A-2) obtained had a glass transition temperature of 130 ° C. and the number of foreign matters was 25 / g.

  Further, the amount of methyl methacrylate (residual volatile matter) contained in the thermoplastic resin composition (A-2) was 950 ppm (weight conversion), and the mass reduction by dynamic TG measurement was 0.16% by mass. It was.

[Example 2]
The polymer solution (A-1) obtained in Example 1 is treated at a processing rate of 2.0 kg / h in terms of resin in a vent type screw twin screw extruder having one rear vent and four forevents. The pellets (B-2) were obtained by performing devolatilization treatment and pelletizing the extruded strands.

  The obtained pellet (B-2) had a glass transition temperature of 131 ° C. and a weight loss by dynamic TG measurement of 0.18% by mass.

  The obtained pellet (B-2) and acrylonitrile-styrene (AS) resin (Stylac AS783, manufactured by Asahi Kasei Chemicals Co., Ltd.) at a weight ratio of 90 ppm together with 400 ppm of zinc acetate as a foaming inhibitor (deactivator): Introduced into a vent type screw single-screw extruder equipped with a leaf disk type polymer filter (5 inches, 5 sheets, manufactured by Nagase Sangyo) with a filtration accuracy of 5 μm at a rate of 10 and kneaded and devolatilized simultaneously went.

  The temperature in the polymer filter at this time was 270 ° C., and the resin melt viscosity at a shear rate of 100 / sec was 460 Pa · sec.

  After passing through a die provided at the tip of the twin screw extruder, filtered with a filter (manufactured by Organo, product name: Micropore filter 1EU) with a pore size of 1 μm, and maintained at a temperature within a range of 60 ± 5 ° C. The strand was cooled with a filled water tank and introduced into a cutting machine (pelletizer) to obtain pellets of the thermoplastic resin composition (B-3). During the production of pellets, a clean space was provided so that the environmental cleanliness from the die to the cutting machine was 5000 or less.

  The thermoplastic resin composition (B-3) obtained had a glass transition temperature of 126 ° C. and the number of foreign substances was 16 / g. Moreover, the amount of methyl methacrylate (residual volatile matter) contained in the thermoplastic resin composition (B-3) was 1100 ppm (weight conversion).

Example 3
A pellet of the thermoplastic resin composition (D-3) was obtained in the same manner as in Example 2 except that a single screw extruder without a vent was used instead of the vent type screw single screw extruder. .

  The thermoplastic resin composition (D-3) obtained had a glass transition temperature of 125 ° C. and the number of foreign substances was 26 / g.

  Moreover, the amount of methyl methacrylate (residual volatile matter) contained in the thermoplastic resin composition (D-3) was 2150 ppm (weight conversion).

[Comparative Example 1]
A thermoplastic resin composition (C-2) was produced in the same manner as in Example 1, except that a leaf disk type polymer filter having a filtration accuracy of 20 μm was used as the leaf disk type polymer filter.

  The obtained thermoplastic resin composition (C-2) had a glass transition temperature of 130 ° C., and the number of foreign substances was 2000 / g. Moreover, the amount of methyl methacrylate (residual volatile matter) contained in the thermoplastic resin composition (C-2) was 350 ppm (weight conversion).

[Comparative Example 2]
The polymer solution (A-1) of Example 1 was provided with a leaf disk type polymer filter (5 inches, 5 sheets, manufactured by Nagase Sangyo Co., Ltd.) having a filtration accuracy of 5 μm, and had 1 rear vent and 4 forevents. Using the vent type screw twin screw extruder, the polymer solution (A-1) was introduced at a treatment rate of 2.0 kg / h in terms of resin amount. The temperature in the polymer filter at this time was 240 ° C., and the resin melt viscosity at a shear rate of 100 / sec was 1000 Pa · sec. As a result, immediately after the polymer solution (A-1) was introduced, pressure was increased in the filter part, and resin pellets could not be obtained.

  The thermoplastic resin composition according to the present invention, in particular, the heat-resistant acrylic resin composition is not only excellent in transparency and heat resistance, but also has desired properties such as low colorability, mechanical strength, and moldability. And the number of foreign objects is small. For this reason, it can be used widely for optical applications and the like, and can be suitably used particularly in the field related to optical materials.

1 Raw material 2 Extruder 4 Polymer filter

Claims (5)

  Glass transition temperature selected from maleimide polymer, polyglutarimide polymer, polyglutaric acid polymer, maleic anhydride polymer, or lactone ring-containing polymer exceeds 110 ° C., and the main chain is made of an aliphatic compound. A thermoplastic resin composition containing an acrylic resin and having a glass transition temperature in the range of 110 to 170 ° C., using an extruder equipped with a leaf disk type polymer filter having a filtration accuracy of 10 μm or less. The process includes a step of filtering and purifying under conditions where the temperature inside the filter is in a range of 260 ° C. or higher and 310 ° C. or lower, and the resin melt viscosity at a shear rate of 100 / sec is 800 Pa · sec or less. A method for producing a plastic resin composition.   The method for producing a thermoplastic resin composition according to claim 1, wherein the extruder is an extruder provided with a vent.   The method for producing a thermoplastic resin composition according to claim 1 or 2, wherein the extruder is a twin screw extruder.   The method for producing a thermoplastic resin composition according to claim 2, wherein a plurality of the vents are provided.   The method for producing a thermoplastic resin composition according to claim 2, wherein the pressure in the vent is 150 torr or less.

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