JP6231839B2 - Method for producing thermoplastic resin composition containing ultraviolet absorber - Google Patents

Description

  The present invention relates to a method for producing a thermoplastic resin composition containing an ultraviolet absorber. More specifically, the present invention includes a step of melt-kneading a thermoplastic resin and an ultraviolet absorber with an extruder, and a step of introducing a heat-melted composition formed by melt-kneading into a polymer filter and filtering it. The manufacturing method of the thermoplastic resin composition containing these.

  Amorphous thermoplastic resins such as polymethyl methacrylate (PMMA) and polycarbonate (PC) have excellent optical properties, such as high light transmittance, and are excellent in mechanical strength, moldability and surface hardness. Because of its excellent balance, it is widely used for transparent members or optical members in various products including automobile parts and home appliances.

  When these products are exposed to light containing ultraviolet rays, the portion composed of the thermoplastic resin may turn yellow (yellowing) and the transparency may be lowered. This yellowing can be suppressed by adding an ultraviolet absorber. In Patent Document 1, as a method for obtaining a thermoplastic resin composition containing a thermoplastic resin and an ultraviolet absorber, and the resin composition, the ultraviolet absorber is added in a liquid state into an extruder and is in a hot-melt state. A method of kneading with a thermoplastic resin is disclosed, and it is described that yellowing, foaming, and bleeding out of an ultraviolet absorber during molding of the thermoplastic resin composition can be suppressed by this method. Further, in this document, by filtering the resin composition after kneading with a polymer filter, the number of foreign matters contained in the obtained molded body is suppressed, and in addition to the suppression of yellowing, foaming and bleed out by the above method. Thus, it is described that defects in appearance or optical defects of the obtained molded body can be reduced.

JP 2010-111729 A

  In the production of a thermoplastic resin composition containing a thermoplastic resin and an ultraviolet absorber by melt kneading using an extruder, at the start (when the extruder is started), the obtained resin composition is mixed with the yellow resin. A brown discoloration different from discoloration may occur. This brown discoloration occurs particularly noticeably when a resin composition in a hot melt state formed by melt kneading is introduced into a polymer filter and filtered. When such a discoloration occurs in the resin composition, the above-exemplified features are impaired and cannot be used as a product.

  One of the objects of the present invention is to melt and knead a thermoplastic resin and an ultraviolet absorber in an extruder, and to introduce a thermoplastic resin composition in a hot melt state formed by melt kneading into a polymer filter. A method for producing a thermoplastic resin composition comprising an ultraviolet absorber, wherein the brown discoloration of the resin composition at the start-up of an extruder and a polymer filter is suppressed, and a rapid resin composition It is in the provision of a method that can achieve the production start-up.

  The production method of the present invention is a production method of a thermoplastic resin composition (C) containing an ultraviolet absorber (B) at a content of X mass%; the thermoplastic resin (A) and the ultraviolet absorber (B) And melt-kneading with an extruder, and introducing and filtering the composition in the hot-melt state formed by the melt-kneading into a polymer filter; and After starting the introduction, the introduction amount of the composition into the polymer filter is made lower than the steady state until the route of the composition inside the polymer filter is filled with the composition, and in the composition The content of the ultraviolet absorber is set to Y% by mass (where 0 ≦ Y ≦ 1.5 × X); then, the introduction amount is set to a steady state, and the content is set to X% by mass. Object (C) That.

  According to the present invention, brown discoloration of the resin composition (C) at the start-up of the extruder and the polymer filter is suppressed, and quick start-up of the resin composition (C) can be achieved.

  In the production method of the present invention, the thermoplastic resin (A) and the ultraviolet absorber (UVA); (B) are melt-kneaded with an extruder (step (i)), and the hot-melt state formed by this melt-kneading The composition is introduced into a polymer filter and filtered (step (ii)) to obtain a thermoplastic resin composition (C) containing UVA (B) at a content of X mass%. In the resin composition (C) and the thermoplastic resin molded product (molded product) obtained by further molding the composition (C), yellowing due to light including ultraviolet rays is suppressed by containing UVA (B). . Moreover, since it passes through the filtration (melt filtration) by the polymer filter in the hot melt state, the number of foreign substances contained in the gel or the like is small, and for example, occurrence of defects in appearance as a molded body is suppressed. When the molded body is an optical member, for example, an optical member in which the occurrence of optical defects is suppressed can be obtained.

  In the production method of the present invention, at the time of starting up the extruder and the polymer filter (at the start of step (i) and step (ii)), the thermoplasticity in the hot melt state introduced into the polymer filter as follows: The resin composition is controlled. That is, after starting the introduction of the composition into the polymer filter, the amount of the composition introduced into the polymer filter is set to be higher than the steady state until the route of the composition inside the polymer filter is filled with the composition. While making it low, let the content rate of UVA (B) in the said composition be Y mass% (however, 0 <= Y <= 1.5 * X). Then, after the polymer filter is filled with the composition, the amount of the composition introduced into the polymer filter is set to a steady state, the content of UVA (B) in the composition is set to X mass%, and UVA (B ) Is obtained at a content of X mass%. In this specification, the thermoplastic resin (A) and UVA (B) introduced into the polymer filter at the start-up of such an extruder and the polymer filter, the UVA (B) content is Y mass. % Of the thermoplastic resin composition is distinguished from the thermoplastic resin composition (C) to be a thermoplastic resin composition (D).

  When the polymer filter is started up, the resin composition path (including the filter medium) in the filter is filled with the resin composition so as to replace the air in the path. The resin composition introduced into the polymer filter has a relatively high viscosity even though it is in a heat-melted state. For this reason, compared with the steady state after the inside of a path | route is filled with the resin composition, the load added to the member inside a polymer filter at the time of starting, especially a filter medium is large. In the production method of the present invention, after the introduction of the resin composition into the polymer filter is started, the amount of the composition introduced into the polymer filter until the resin composition path inside the polymer filter is filled with the composition. Is lower than the steady state. Thereby, the breakage of the polymer filter, particularly the breakage of the filter medium, from the start of the introduction of the resin composition to the filling of the above-mentioned path inside the polymer filter with the composition is suppressed.

  In the production method of the present invention, after the introduction of the resin composition into the polymer filter is started, the UVA (B) in the resin composition is filled until the path of the resin composition inside the polymer filter is filled with the composition. Is controlled to Y mass% (the resin composition (D) having a UVA (B) content of Y mass% is introduced). In order to make the amount of the resin composition introduced into the polymer filter lower than the steady state at the time of starting up the extruder and the polymer filter, it is a main component of the resin composition and its high viscosity factor (UVA is Simply reducing the amount of the thermoplastic resin (A) (which usually does not affect the viscosity of the resin composition) simply increases the UVA (B) content in the resin composition, resulting in a high content. The UVA (B) comes into contact with the air in the above path of the polymer filter at a high temperature, and a brown discoloration presumably due to the oxidation of the UVA (B) occurs in the resin composition. In particular, such a brown discoloration is likely to occur in a filter medium having a large contact area between air and the resin composition due to its structure. On the other hand, by controlling the content of UVA (B) to Y mass%, the brown discoloration of the resin composition presumed to be due to the oxidation of UVA (B) at the start-up and filling of such a polymer filter is caused. It is suppressed. After the polymer filter is filled with the composition (D) in which the content of UVA (B) is controlled to Y mass%, the polymer filter is no longer easily damaged, and UVA ( Since contact between B) and oxygen, particularly contact in the filter medium, is suppressed, the content of UVA (B) in the resin composition to be introduced into the polymer filter is controlled to a desired X mass%. Thus, the rapid production start-up in which the brown discoloration of the resin composition (C) containing the resin (A) and the UVA (B) having a content of X mass% is suppressed is achieved, and the resin composition ( C) Productivity and yield are improved.

  The polymer filter has a resin composition path in a heat-melted state therein. The path includes a filter medium disposed within the polymer filter. It can be confirmed that the resin composition is filled in the polymer filter by, for example, the resin composition introduced into the polymer filter being continuously and stably discharged from the outlet (discharge port) of the filter. In that case, it is not always necessary that the above-mentioned route inside the polymer filter is filled with the resin composition. Air may partially remain in the path.

  The “steady state” means a state in which, after the polymer filter is filled with the resin composition, melt kneading by an extruder and filtration of the resin composition (C) by the polymer filter are continuously performed. However, in the steady state, the amount of the resin composition (C) obtained by melt kneading and the amount of filtration of the composition (C) by the polymer filter do not necessarily have to be constant. These amounts usually involve some fluctuations in the production of the resin composition (C), and can be freely controlled as necessary.

  The content Y of UVA (B) in the resin composition (D) is not necessarily constant, and the content of UVA (B) in the resin composition (C) is 0% by mass, where X (% by mass). It may be changed (changed) in the range of 1.5 × X mass% or less. In order to start the production of the resin composition (C) stably and quickly, it is preferable that the content Y is constant from the start of the polymer filter to the completion of filling. The content Y of UVA (B) in the resin composition (D) is preferably 0% by mass or more and less than 1.0 × X% by mass. At this time, the occurrence of brown discoloration is further suppressed, and it becomes possible to start production of the resin composition (C) more promptly.

  The content of UVA (B) in the resin compositions (C) and (D) depends on, for example, the amount of thermoplastic resin including resin (A) supplied to the extruder and / or the amount of UVA (B). Can be controlled.

  In the step (i), the melt kneading of the resin (A) and the UVA (B) is performed by a known extruder both when the resin composition (D) is obtained and when the resin composition (C) is obtained. It can be carried out by a known melt kneading technique.

  In the step (i), the resin (A) and the UVA (B) are individually supplied to the extruder and melt-kneaded, whereby the content of the UVA (B) in the resin compositions (C) and (D) It is preferable because it is easy to control. Moreover, it is preferable to supply UVA (B) to an extruder in the state of a solution, In this case, yellowing at the time of shaping | molding of a resin composition (C), foaming, and bleed-out of UVA are suppressed. In this case, occurrence of defects in appearance or optical defects in the resin composition (C) and a molded product obtained by further molding the composition (C) is further suppressed. The supply in the state of a solution is, for example, supply of UVA that is liquid at room temperature or supply temperature to an extruder, or supply of a solution in which UVA is dissolved in a solvent. It is preferable to supply UVA (B), which is liquid at room temperature (25 ° C.), to the extruder. When supplying UVA (B) in the state of a solution, it is preferable to supply the filtered said solution from a viewpoint of reducing the number of the foreign materials contained in the obtained resin composition. For example, a high-pressure metering pump can be used to supply the UVA (B) in a solution state. The pump preferably includes a check valve.

  The UVA (B) content X in the resin composition (C) is set so that, for example, the transmittance T380 of light having a wavelength of 380 nm, which will be described later, is less than 10%.

  The type of the extruder is not particularly limited, and any of single-screw, twin-screw, and multi-screw extruders can be used. The L / D value (L is the cylinder length of the extruder and D is the cylinder inner diameter) of the extruder is preferably 10 or more and 100 or less, more preferably 15 or more and 80 or less, and further preferably 20 or more and 60 or less. Within these ranges, it is easy to achieve sufficient plasticization and a good kneading state of the resin composition. When the L / D value becomes excessively large, the shear heat generation becomes excessively large, and the resin (A) may be thermally decomposed during melt kneading.

  The set temperature of the cylinder of the extruder is preferably 200 ° C. or higher and 350 ° C. or lower, more preferably 250 ° C. or higher and 320 ° C. or lower. Within these ranges, the melt viscosity of the resin composition is in a state suitable for improving the productivity of the composition, and thermal decomposition of the resin (A) is also suppressed.

  The extruder preferably has at least one vent portion. By using an extruder having a vent part, gas generated by decomposition of the resin composition and volatile components such as a polymerization solvent can be sucked (devolatized) from the vent part, and the obtained resin composition (C ) Can be reduced. Thereby, for example, foaming at the time of molding of the resin composition (C) is suppressed, and defects in appearance or optical properties in the molded product obtained by further molding the resin composition (C) and the composition (C). The occurrence of defects is further suppressed. In order to devolatilize volatile components from the vent part, for example, the vent part may be in a reduced pressure state, and the degree of pressure reduction is preferably 1.3 hPa or more and 906 hPa or less in the pressure atmosphere of the vent part. 3 hPa or more and 798 hPa or less are preferable. When the pressure atmosphere in the vent portion is higher than 906 hPa, volatile components tend to remain in the resin composition. On the other hand, it is industrially difficult to keep the pressure in the vent portion lower than 1.3 hPa.

  In other words, the production method of the present invention further includes a step of removing a volatile component contained in the resin composition (C) from a vent portion in a pressure atmosphere of 1.3 hPa or more and 906 hPa or less provided in the extruder. You may go out. In addition, by having a vent portion in the extruder and making the inside of the above path inside the polymer filter a pressure atmosphere of 1.3 hPa or more and 906 hPa or less, unnecessary contact with oxygen of UVA (B) can be avoided, The brown discoloration of the resin composition estimated to be due to the above-described oxidation of UVA (B) can be reduced.

  The extruder may be provided with a side feeder. In this case, a further thermoplastic resin is supplied from the side feeder to the extruder, and melted and kneaded together with the resin (A) and UVA (B) to contain the further resin. A resin composition (C) can be formed. Specific examples of the resin will be described later in the description of the resin composition (C).

  When the extruder and polymer filter are started up, the resin composition (D) is filled into the filter by introducing the composition (D) obtained by melt-kneading in the extruder into the polymer filter. it can. The introduction of the resin composition (C) obtained by melt kneading in the step (ii) into the polymer filter and the filtration through the polymer filter can be performed by a known melt filtration technique using a known polymer filter.

  The polymer filter is at least one selected from, for example, a leaf disk filter, a candle filter, a pack disk filter, and a cylindrical filter. Among these, a leaf disc filter or a candle filter having a high effective filtration area is preferable. Among these, the leaf disk filter is suitable for filtering a high-viscosity material, but is easily damaged by a load because of its structure. For this reason, when a leaf disk filter is used for the polymer filter, the effect of the manufacturing method of the present invention becomes more remarkable.

  The filter medium is not particularly limited, and may be any of a type in which a metal fiber nonwoven fabric is sintered, a type in which metal powder is sintered, a type in which a wire mesh is laminated, or a hybrid type in which these are combined. Among these, a type in which a metal fiber nonwoven fabric is sintered is most preferable.

  The filtration accuracy of the polymer filter is not particularly limited, but is usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less. The lower limit of the filtration accuracy is not limited, but is 1 μm, for example. If the filtration accuracy is too small, the demerit (for example, thermal deterioration of the resin composition) due to the resin composition staying in the polymer filter for a long time becomes larger than the effect of removing foreign substances. On the other hand, if the filtration accuracy is excessively large, it is difficult to remove foreign substances contained in the resin composition.

  The shape of the polymer filter is not particularly limited, for example, an internal flow type having a plurality of resin flow ports and a resin flow path in the center pole; the cross section is on the inner peripheral surface of the filter medium at a plurality of vertices or faces And an external flow type having a resin flow path on the outer surface of the center pole. In order to suppress the residence of the resin composition in the polymer filter, it is preferable to employ an external flow type in which the resin composition has few residence portions. The residence time of the resin composition (C) in the polymer filter is not particularly limited, but is preferably 20 minutes or less, more preferably 10 minutes or less, and even more preferably 5 minutes or less.

  In filtering the resin composition (C) with the polymer filter, it is preferable to install a gear pump between the extruder and the polymer filter and introduce the resin composition (C) into the polymer filter while applying pressure by the pump. . By this method, the pressure of the resin composition (C) in the polymer filter is stabilized. This gear pump can also be used for introducing the resin composition (D) into the polymer filter, whereby the composition (D) can be stably introduced into the polymer filter.

  The temperature inside the polymer filter for filtering the resin composition (C) is preferably 260 ° C. or higher and 330 ° C. or lower. In this case, the composition (C) can be stably filtered while suppressing the thermal deterioration of the resin composition (C). Even when the resin composition (D) is introduced into the polymer filter, the temperature inside the polymer filter is preferably 260 ° C. or higher and 330 ° C. or lower.

The filtration amount per hour of the resin composition (C) in the polymer filter can be set as appropriate. In a steady state, for example, the effective filtration area of the polymer filter (filtering area of the filter medium) is 15 kg / hour or more and 65 kg / hour or less per 1 m ^2. It is. In addition, since the effective filtration area of a polymer filter is generally about 5 to 15 m ² , a resin composition (C) of several hundred kg to several tons per hour is filtered and manufactured at an actual production site. become. For this reason, the effects of improving the productivity and yield of the composition (C) by the rapid production start-up realized by the production method of the present invention are very advantageous industrially.

  Filtration is preferably controlled so that the filter inlet pressure and the filter outlet pressure are 3 to 15 MPa and 0.3 to 10 MPa, respectively. Moreover, it is preferable to control filtration so that the pressure loss (pressure difference between the filter inlet pressure and the filter outlet pressure) of the polymer filter in a steady state is 1 to 15 MPa. Within these ranges, the melt filtration of the resin composition (C) can be carried out more uniformly and stably, and the obtained resin composition (C) and the molded product obtained by further molding the composition (C) can be obtained. The quality can be further improved. If the pressure loss is excessively reduced, the flow path of the resin composition (C) in the polymer filter tends to be biased. If the pressure loss is excessively large, the polymer filter tends to be damaged during filtration.

  In the production method of the present invention, steps (i) and (ii) are usually carried out continuously. The continuous steps (i) and (ii) can be performed by, for example, an extruder having a polymer filter connected to the tip (discharge port side).

  The production method of the present invention may include any step other than the steps described above as long as the effect of the present invention is obtained.

  The resin composition (C) after filtration with a polymer filter can be subjected to any step. The process is, for example, a molding process for molding the resin composition (C) after filtration. For example, the resin composition (C) is pelletized to produce pellets of the resin composition (C) or melt-molded as it is, and the resin composition is formed. The molded object which has the arbitrary shapes comprised from (C) can be manufactured. A molded object is a film and a sheet | seat, for example, and can be used for arbitrary uses, for example, the use as an optical member. A specific example is an optical film such as a retardation film or a polarizer protective film. In the case of use as an optical member, there are particularly merits in that there are few defects in appearance or optical defects.

  In the production method of the present invention, following the steps (i) and (ii), the above arbitrary steps can be carried out continuously. That is, the molded object comprised from a resin composition (C) can be manufactured continuously, and the manufacture start-up is quicker than before.

[Thermoplastic resin (A)]
The thermoplastic resin (A) is not particularly limited. Examples of the resin (A) include olefin resins such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1-pentene), and norbornene polymer; halogen-containing resins such as vinyl chloride and chlorinated vinyl resins; Styrene resins having styrene units as structural units such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; acrylics such as polymethyl methacrylate (PMMA) Resin; Polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; Polyamide such as nylon 6, nylon 66, nylon 610; Cellulose such as triacetyl cellulose; Poly Acetal; polycarbonate (PC); a polyamide-imide; polyphenylene oxide; polyphenylene sulfide; polyether ether ketone; polyether nitrile; polysulfone; polyether sulfone; polyoxyethylene Penji Ren.

  When the resin composition (C) or a molded body obtained by further molding the composition (C) is used for an optical member, the resin (A) is preferably an amorphous thermoplastic resin.

  The resin (A) may be an acrylic resin, and in this case, a resin composition (C) excellent in optical transparency is obtained. The acrylic resin is an amorphous thermoplastic resin.

  The acrylic resin is a resin having a (meth) acrylic acid ester unit and / or a (meth) acrylic acid unit as a constituent unit. The acrylic resin may have a structural unit derived from a (meth) acrylic acid ester and / or a derivative of (meth) acrylic acid. The total of the proportion of structural units derived from (meth) acrylic acid ester units, (meth) acrylic acid units and the above derivatives in all structural units of the acrylic resin is usually 50 mol% or more, preferably 60 mol% or more, More preferably, it is 70 mol% or more. The acrylic resin may have two or more of these units as structural units.

  (Meth) acrylic acid ester units are, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t- (meth) acrylic acid t- Butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, (meth) acryl Dicyclopentanyl acid, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid 2, 3,4,5,6-pentahydroxyhexyl, 2,3,4,5-tetrahydro (meth) acrylic acid Shipenchiru is a structural unit derived from 2- (hydroxymethyl) acrylate, 2- (hydroxymethyl) acrylate, in each monomer of 2- (hydroxyethyl) acrylate.

  The (meth) acrylic acid unit is, for example, a structural unit derived from each monomer of acrylic acid, methacrylic acid, crotonic acid, 2- (hydroxymethyl) acrylic acid, and 2- (hydroxyethyl) acrylic acid.

  The acrylic resin preferably has a methyl methacrylate (MMA) unit. In this case, the resin composition (C) containing the acrylic resin as the resin (A) and the composition (C) were further molded. The thermal stability of the molded body is improved.

  Hereinafter, the thermoplastic resin (A) which is an acrylic resin will be described.

  The resin (A) which is an acrylic resin may have a ring structure in the main chain. That is, the resin (A) may be an acrylic resin having a ring structure in the main chain. In this case, the glass transition temperature (Tg) of the resin (A) and the resin composition (C) containing the resin (A) is increased, and the composition (C) and the composition (C) are further molded. The heat resistance of the molded body is improved. A molded body with improved heat resistance, such as an optical member and one type of optical film, is disposed near a heat generating part such as a light source, a power source, and a circuit board in an image display device such as a liquid crystal display (LCD). It becomes easy. Such ease of arrangement increases, for example, the degree of design freedom and design of the image display apparatus.

  When the resin (A) is an acrylic resin having a ring structure in the main chain, it is necessary to increase the melt kneading temperature and the molding temperature of the resin composition (C) by increasing the Tg of the resin (A). Even in such a case, the production method of the present invention can reduce the number of gels generated in a high temperature environment by melt filtration using a polymer filter, and further mold the resin composition (C) and the composition (C). Thus, it is possible to reduce the number of foreign substances contained in the obtained molded body. Moreover, yellowing at the time of shaping | molding of a resin composition (C), foaming, and bleed-out of UVA can be suppressed by using together supply of UVA (B) in the liquid state to an extruder.

  The type of the ring structure that the resin (A) that is an acrylic resin may have in the main chain is not particularly limited, and examples thereof include a lactone ring structure, a glutaric anhydride structure, a glutarimide structure, an N-substituted maleimide structure, and an anhydride. It is at least one selected from maleic acid structures. The ring structure is preferably at least one selected from a lactone ring structure, a glutarimide structure, and an N-substituted maleimide structure.

  Formula (1) shows a maleic anhydride structure and an N-substituted maleimide structure.

In the formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group, and X ¹ is an oxygen atom or a nitrogen atom. When X ¹ is an oxygen atom, R ³ does not exist, and when X ¹ is a nitrogen atom, R ³ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group.

When X ¹ is an oxygen atom, the ring structure represented by the formula (1) is a maleic anhydride structure. The acrylic resin having a maleic anhydride structure in the main chain can be formed, for example, by copolymerization of maleic anhydride and (meth) acrylic acid ester.

When X ¹ is a nitrogen atom, the ring structure represented by Formula (1) is an N-substituted maleimide structure. The acrylic resin having an N-substituted maleimide structure in the main chain can be formed, for example, by copolymerization of an N-substituted maleimide and a (meth) acrylic acid ester.

N- substituted maleimide structure, at least one N- phenylmaleimide structure (R ³ is a phenyl group) and N- cyclohexyl maleimide structure (R ³ is a cyclohexyl group) selected from the preferred.

  Formula (2) shows a glutaric anhydride structure and a glutarimide structure.

R ⁴ and R ⁵ in the formula (2) are each independently a hydrogen atom or a methyl group, and X ² is an oxygen atom or a nitrogen atom. When X ² is an oxygen atom, R ⁶ is not present, and when X ² is a nitrogen atom, R ⁶ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group, or a phenyl group.

When X ² is an oxygen atom, the ring structure represented by the formula (2) is a glutaric anhydride structure. The acrylic resin having a glutaric anhydride structure in the main chain can be formed, for example, by subjecting a copolymer of (meth) acrylic ester and (meth) acrylic acid to dealcoholization cyclocondensation in the molecule.

When X ² is a nitrogen atom, the ring structure represented by the formula (2) is a glutarimide structure. The acrylic resin having a glutarimide structure in the main chain can be formed, for example, by imidizing a (meth) acrylic acid ester polymer with an imidizing agent such as methylamine.

  The lactone ring structure that the resin (A) that is an acrylic resin may have in the main chain is not particularly limited. For example, the lactone ring structure may be a 4- to 8-membered lactone ring structure. A 5-membered or 6-membered lactone ring structure is preferable, and a 6-membered lactone ring structure is more preferable. The 6-membered lactone ring structure is, for example, the structure disclosed in Japanese Patent Application Laid-Open No. 2004-168882, but the high polymerization yield of the precursor and the high lactone ring due to the cyclization condensation reaction of the precursor. The structure represented by the formula (3) is preferable because an acrylic resin having a content rate can be obtained and a polymer having a MMA unit as a constituent unit can be used as a precursor.

R ⁷ , R ⁸ and R ⁹ in the formula (3) are each independently a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.

  The organic residue of the formula (3) is, for example, an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, or a propyl group; an unsaturated aliphatic group having 1 to 20 carbon atoms such as an ethenyl group or a propenyl group Hydrocarbon group; an aromatic hydrocarbon group having 1 to 20 carbon atoms such as a phenyl group and a naphthyl group. In these alkyl groups, unsaturated aliphatic hydrocarbon groups, and aromatic hydrocarbon groups, one or more hydrogen atoms of the group are represented by at least one group selected from a hydroxyl group, a carboxyl group, an ether group, and an ester group. May be substituted.

  In the acrylic resin having the ring structure other than the lactone ring structure in the main chain, the content of the ring structure in the resin is not particularly limited, and is, for example, 5 to 90% by mass, preferably 10 to 70% by mass, 10-60 mass% is more preferable, and 10-50 mass% is further more preferable.

  In the acrylic resin having a lactone ring structure in the main chain, the content of the lactone ring structure in the resin is not particularly limited, and is, for example, 5 to 90% by mass, preferably 10 to 80% by mass, and 10 to 70% by mass. Is more preferable, and 12-50 mass% is further more preferable.

  When the resin (A) is an acrylic resin having a cyclic structure in the main chain, the content of the cyclic structure in the resin is determined by further molding the resin composition (C) or the composition (C). Can be controlled in accordance with desired characteristics such as heat resistance, solvent resistance, surface hardness, and formability handling. If the content of the ring structure is too small, desired heat resistance, solvent resistance and surface hardness may not be obtained. If the content of the ring structure is excessively large, moldability and handling properties may be deteriorated.

  The acrylic resin having a ring structure in the main chain can be formed by a known method. An acrylic resin having a glutaric anhydride structure or a glutarimide structure in the main chain can be formed, for example, by the method described in WO2007 / 26659 and WO2005 / 108438. An acrylic resin having a maleic anhydride structure or an N-substituted maleimide structure in the main chain can be formed, for example, by the methods described in JP-A-57-153008 and JP-A-2007-31537. An acrylic resin having a lactone ring structure in the main chain can be formed, for example, by the method described in JP-A-2006-96960, JP-A-2006-171464, or JP-A-2007-63541.

  Resin (A) which is an acrylic resin may have structural units other than the (meth) acrylic acid ester unit, the (meth) acrylic acid unit, and the unit derived from the said derivative | guide_body. Such structural units include, for example, styrene, vinyl toluene, α-methyl styrene, α-hydroxymethyl styrene, α-hydroxyethyl styrene, acrylonitrile, methacrylonitrile, methallyl alcohol, allyl alcohol, ethylene, propylene, 4- It is a structural unit derived from each monomer of methyl-1-pentene, vinyl acetate, 2-hydroxymethyl-1-butene, methyl vinyl ketone, N-vinyl pyrrolidone, and N-vinyl carbazole. Resin (A) may have 2 or more types of these units as a structural unit.

  Resin (A) may have a structural unit having an effect of giving negative intrinsic birefringence to the resin. In this case, the degree of freedom of control of birefringence in the resin composition (C) and a molded body obtained by further molding the composition (C) can be improved. And the use as an optical member of a resin composition (C) and the said molded object expands by this improvement in a freedom degree, for example. The structural unit having an effect of giving negative intrinsic birefringence to the resin is a structural unit having a negative value of the intrinsic birefringence of the homopolymer when a homopolymer comprising only this structural unit is formed. Say. The intrinsic birefringence value refers to the alignment from the refractive index n1 of light in the direction parallel to the direction (orientation axis) in which molecular chains are oriented in a layer (for example, film) in which the molecular chains of the resin (polymer) are uniaxially oriented A value obtained by subtracting the refractive index n2 of light in the direction perpendicular to the axis (that is, "n1-n2"). The sign of the intrinsic birefringence of the resin (A) itself is determined by the balance between the action of the structural unit with respect to the intrinsic birefringence and the action of the other structural unit of the resin (A).

  The structural unit having an effect of giving negative intrinsic birefringence to the resin (A) is, for example, a styrene unit.

  The resin (A) may have a structural unit (UVA unit) having ultraviolet absorbing ability as a structural unit. In this case, the ultraviolet absorbing ability of the molded product obtained by further molding the resin composition (C) and the composition (C) is further improved. Depending on the structure of the UVA unit, the compatibility between the resin (A) and the UVA (B) is improved.

  When the resin (A) has a UVA unit as a constituent unit, the content of the UVA unit in the resin (A) is preferably 20% by mass or less, more preferably 15% by mass or less. When the content rate of a UVA unit becomes large too much, the heat resistance of resin (A) and the resin composition (C) containing the said resin may fall.

  The Tg of the resin (A) is, for example, 80 ° C. or higher, preferably 110 ° C. or higher, more preferably 120 ° C. or higher.

  The weight average molecular weight of resin (A) is 1000-300000, for example, Preferably it is 5000-250,000, More preferably, it is 10000-200000, More preferably, it is 50000-200000.

[Ultraviolet absorber (B)]
UVA (B) is not limited as long as it has a UV-absorbing ability and is compatible with the resin (A). It is preferable that UVA (B) does not contain a repeating unit derived from a monomer (that is, it is not a polymer). In general, it is difficult to ensure compatibility with the resin (A) for the ultraviolet absorber that is a polymer, and depending on additives such as a polymerization initiator and a chain transfer agent remaining in the polymer, the resin composition (C And a molded product obtained by further molding the composition (C) may be colored.

As UVA (B), for example, benzophenone compounds, Sarishi les over preparative compounds, benzoate type compounds, at least one member selected from triazole compounds and triazine compounds may be used. Of these, UVA (B), which is a triazole compound and a triazine compound, is preferable because of its high ultraviolet absorbing ability.

  Triazole compounds include, for example, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (3 5-Di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl)- 4,6-bis (1-methyl-1-phenylethyl) phenol, 2-benzotriazol-2-yl-4,6-di-t-butylphenol, 2- [5-chloro (2H) -benzotriazole-2 -Yl] -4-methyl-6- (t-butyl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-di-t-butylphenol, 2- (2H-ben Triazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5, 6-tetrahydrophthalimidylmethyl) phenol, methyl-3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate / polyethylene glycol 300 reaction product, 2 -(2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy- 3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 3- (2H-benzotriazol-2-yl) -5 (1,1-dimethylethyl) -4-hydroxy -C7-9-side and straight chain alkyl esters,. A triazole compound having a halogen atom, such as a chlorine atom, is preferred because of its high ultraviolet absorption ability.

  Examples of triazine compounds include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-ethoxy). Phenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-butoxy) Phenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy) -4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, , 4-Diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-benzyloxyphenyl) -1,3 , 5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxy) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-butoxyphenyl) -6 (2,4-dibutoxyphenyl) -1,3-5-triazine, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine, 2 , 4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4- (3-alkyloxy-2-hydroxypropyloxy) -5-α-cumylphenyl] -s-triazine skeleton (a Rukyloxy; UVA having a long-chain alkyloxy group such as octyloxy, nonyloxy, decyloxy). Among them, 2,4-bis (2,4-dimethylphenyl) -6- [2-hydroxy-4 is highly compatible with the resin (A) which is an acrylic resin and has excellent ultraviolet absorption performance. UVA having — (3-alkyloxy-2-hydroxypropyloxy) -5-α-cumylphenyl] -s-triazine skeleton (alkyloxy; long-chain alkyloxy groups such as octyloxy, nonyloxy, decyloxy, etc.) is preferable.

  The molecular weight of UVA (B) is not particularly limited, but is preferably 600 or more, more preferably 700 or more and 800 or more. The upper limit of the molecular weight of UVA (B) is, for example, 10,000. When the molecular weight of UVA (B) becomes excessively large, the compatibility with the resin (A) decreases, and the optical transparency of the resin composition (C) and a molded product obtained by further molding the composition (C) are obtained. Sex is reduced. The upper limit of the molecular weight of UVA (B) is preferably 8000, and more preferably 5000.

  UVA (B) may be a commercially available substance, for example, Tinuvin 477 (manufactured by BASF) and Adeka Stub LA-F70 (manufactured by ADEKA).

The UVA (B) has an ultraviolet absorption capacity of 10,000 (L · mol ⁻ ) in terms of a molar extinction coefficient (chloroform solution) with respect to light having a wavelength within the wavelength range of 300 to 380 nm and maximum absorption by UVA (B). ¹ · cm ⁻¹ ) or more is preferable.

  UVA (B) is preferably a substance that is liquid at room temperature (25 ° C.). As UVA (B) that is liquid at room temperature, commercially available substances such as tinuvin 213, tinuvin 571, and tinuvin 477 (all manufactured by BASF) can be used.

  UVA (B) may be a mixture of two or more compounds.

[Thermoplastic resin composition (C)]
The resin composition (C) obtained by the production method of the present invention contains a resin (A) and UVA (B). Although the content rate X of UVA (B) in the resin composition (C) varies depending on the type of UVA (B), it is, for example, 0.01 to 5 mass%, preferably 0.05 to 3 mass. When the content X of UVA (B) in the resin composition (C) is too small, the resin composition (C) and the resin composition (C) can be obtained by being exposed to light containing ultraviolet rays without obtaining the desired ultraviolet absorbing ability. Yellowing easily occurs in a molded product obtained by further molding the composition (C). On the other hand, if the content ratio X of UVA (B) is excessively large, the disadvantage that foaming occurs during the molding of the resin composition (C) or UVA bleeds out, rather than the advantage of suppressing yellowing by UVA (B). Is bigger.

  The content X of UVA (B) in the resin composition (C) can be set so that, for example, the transmittance T380 of light having a wavelength of 380 nm measured by the following method is less than 10%. In this case, the content rate X can be set smaller as the ultraviolet absorbing ability of UVA (B) is larger. T380 prepared a chloroform solution (concentration 0.4% by mass) of the resin composition, accommodated in a quartz cell having an optical path length of 1 cm, and measured the transmittance of light at a wavelength of 380 nm in the solution with an absorptiometer. This is the value obtained. T380 corresponds to the ultraviolet absorbing ability of the resin composition (C) and a molded product obtained by further molding the composition (C).

  The Tg of the resin composition (C) is, for example, 80 ° C. or higher, preferably 110 ° C. or higher, more preferably 120 ° C. or higher. The higher the Tg, the better the heat resistance of the resin composition (C) and the molded product obtained by further molding the composition (C). As an optical member used for an image display device, Tg of the resin composition (C) is preferably 110 ° C. or higher.

  The ultraviolet ray absorbing ability of the resin composition (C) is preferably less than 10% at T380, more preferably 9% or less. Further, the visible light transmittance of the resin composition (C) is preferably 90% or more, and more preferably 95% or more in terms of the transmittance T590 of light having a wavelength of 590 nm, measured in the same manner as T380. T380 and T590 of the resin composition (C) are preferably less than 10% and 90% or more, respectively. In other words, taking into account the measurement method of T380 and T590, the chloroform solution (concentration 0.4% by mass) of the resin composition (C) was stored in a quartz cell having an optical path length of 1 cm and measured with an absorptiometer. It is preferable that the transmittance of light with wavelengths of 380 nm and 590 nm exhibited by the solution is less than 10% and 90% or more, respectively.

  The resin composition (C) may contain two or more kinds of resins (A). Moreover, the resin composition (C) may contain the further thermoplastic resin other than resin (A). However, when using the resin composition (C) and a molded body obtained by further molding the composition (C) for an optical member, in order to ensure sufficient optical properties, the resin (A) and the further above The resin must be compatible with each other.

  Examples of the additional resin include olefin resins such as polyethylene, polypropylene, ethylene-propylene polymer, and poly (4-methyl-1-pentene); halogen-containing resins such as vinyl chloride and chlorinated vinyl resins; polyethylene terephthalate, poly Polyesters such as butylene terephthalate and polyethylene naphthalate; polyamides such as nylon 6, nylon 66 and nylon 610; polyacetals; polycarbonates; polyphenylene oxides; polyphenylene sulfides; polyether ether ketones; Imide; a rubbery polymer. The resin composition (C) may contain two or more of these resins. The content of the additional resin in the resin composition (C) is, for example, less than 50% by mass, and preferably 40% by mass or less.

  When the resin (A) is an acrylic resin, in particular, when the resin is an acrylic resin having a ring structure in the main chain, since the compatibility with the resin (A) is excellent, the additional resin is a vinyl cyanide monomer. A copolymer having a structural unit derived from the above and a structural unit derived from an aromatic vinyl monomer is preferable. The copolymer is, for example, a styrene-acrylonitrile copolymer. That is, the resin composition (C) may contain an acrylic resin and a styrene-acrylonitrile copolymer, and at this time, the acrylic resin may have a ring structure in the main chain.

  When the resin (A) exhibits positive intrinsic birefringence, the resin composition (C) may further include a thermoplastic resin exhibiting negative intrinsic birefringence. At this time, the degree of freedom in controlling birefringence (for example, phase difference) in the resin composition (C) and a molded product obtained by further molding the composition (C) is improved. The styrene-acrylonitrile copolymer exhibits negative intrinsic birefringence.

  The styrene-acrylonitrile copolymer can be formed by various polymerization methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. When the resin composition (C) and a molded product obtained by further molding the composition (C) are used for an optical member, the transparency and optical properties are improved, so that the resin composition (C) is formed by solution polymerization or bulk polymerization. Styrene-acrylonitrile copolymers are preferred.

  The resin composition (C) can contain materials other than the thermoplastic resin and UVA (B), for example, additives. Additives include, for example, antioxidants, light stabilizers, weather stabilizers, heat stabilizers and other stabilizers; phase difference adjusting agents such as phase difference increasing agents, phase difference reducing agents, phase difference stabilizers; glass fibers, Reinforcing materials such as carbon fibers; near-infrared absorbers; flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents containing anionic, cationic, and nonionic surfactants; inorganic pigments Colorants such as organic pigments and dyes; organic fillers, inorganic fillers, resin modifiers, plasticizers and lubricants. The content of the additive in the resin composition (C) is preferably less than 5% by mass, more preferably 2% by mass or less, and further preferably 1% by mass or less.

  These additives can be added to the resin composition (C) by an arbitrary time and method. For example, what is necessary is just to melt-knead with resin (A) and UVA (B) in process (i).

  The resin composition (C) after the melt filtration in the step (ii) can be molded into an arbitrary shape by a known molding method such as extrusion molding, blow molding or injection molding. The shape of the resin composition (C) after molding is, for example, a pellet, a film, or a sheet. Once formed into a pellet, it may be further formed into a molded body such as a film or sheet.

  The use of the resin composition (C) and a molded product obtained by further molding the composition (C) is not limited, and is, for example, an optical member. More specific examples are retardation film and polarizer protection. An optical film such as a film.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the examples shown below.

  Initially, the evaluation method of the thermoplastic resin composition produced in a present Example is shown.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) of the thermoplastic resin composition was determined according to the provisions of JIS K7121. Specifically, a differential scanning calorimeter (manufactured by Rigaku, DSC-8230) is used, and a sample of about 10 mg is heated from normal temperature to 200 ° C. (temperature increase rate: 20 ° C./min) in a nitrogen gas atmosphere. The DSC curve was evaluated by the starting point method. Α-alumina was used as a reference.

[Weight average molecular weight]
The weight average molecular weight Mw of the thermoplastic resin composition was determined in terms of polystyrene using gel permeation chromatography (GPC). The apparatus and measurement conditions used for the measurement are as follows.
System: Tosoh GPC system HLC-8220
Measurement side column configuration:
Guard column (manufactured by Tosoh, TSK guard column Super HZ-L)
・ Two separation columns (manufactured by Tosoh, TSKgel SuperHZM-M) in series connection Reference side column configuration:
・ Reference column (manufactured by Tosoh Corporation, TSKgel SuperH-RC)
Developing solvent: Chloroform (Wako Pure Chemical Industries, special grade)
Flow rate of developing solvent: 0.6 mL / min Standard sample: TSK standard polystyrene (manufactured by Tosoh, PS-oligomer kit)
Column temperature: 40 ° C

[Transmissivity]
The light transmittance of the thermoplastic resin composition with respect to light having wavelengths of 380 nm and 590 nm is obtained by preparing a chloroform solution (concentration 0.4% by mass) of the obtained resin composition, and then using the chloroform solution for a quartz cell having an optical path length of 1 cm. And obtained using a spectrophotometer (Shimadzu Corporation, UV-3100) which is a kind of absorptiometer. The transmittance of light with a wavelength of 380 nm is T380 (%), and the transmittance of light with a wavelength of 590 nm is T590 (%).

[Brown discoloration]
In each of the examples and comparative examples, how long the brown discoloration of the thermoplastic resin composition discharged from the polymer filter attached to the tip of the extruder is suppressed after the extruder and the polymer filter are started up. Was evaluated. Specifically, after the introduction and filling of the resin composition into the polymer filter is completed and the resin composition starts to be discharged from the outlet of the filter, the transparent resin composition not having a brownish taste is within 2 hours. The case obtained was “得”, the case obtained within 2 hours or more within 3 hours was “◯”, and the case obtained after 3 hours or more passed was designated as “X”. More specifically, the presence or absence of the brown taste of the thermoplastic resin composition (resin pellet) that was discharged from the polymer filter and then pelletized by a pelletizer was determined.

[Content of glutarimide unit]
The content of glutarimide units in the acrylic resins used in Example 6 and Comparative Example 3 was determined by measuring the infrared absorption spectrum (IR spectrum) of the acrylic resin pellets, and having a wave number of 1670 cm corresponding to the imide carbonyl group. ^It was determined from the ratio between the absorption intensity in the vicinity of ⁻¹ and the absorption intensity in the vicinity of wave number 1720 cm ⁻¹ corresponding to the ester carbonyl group and the absorption intensity in the vicinity of wave number 1760 cm ⁻¹ corresponding to the carbonyl group of the acid anhydride.

(Production Example 1)
In a reaction kettle equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introduction pipe, 230 parts by mass of methyl methacrylate (MMA), 33 parts by mass of methyl 2- (hydroxymethyl) acrylate (MHMA), and toluene 250 as a polymerization solvent. A mass part, 0.15 mass part of an antioxidant (manufactured by ADEKA, Adeka Stub 2112) and 0.2 mass part of n-dodecyl mercaptan were charged, and the temperature was raised to 105 ° C. while passing nitrogen through the mass.

  When the reflux accompanying the temperature rise began, 0.28 parts by mass of t-amyl peroxyisononanoate (Arkema Yoshitomi, trade name: Luperox 570) was added as a polymerization initiator, and the above t-amyl peroxy isono While 0.56 parts by mass of nanoate and 12 parts by mass of styrene were added dropwise over 2 hours, solution polymerization was allowed to proceed under reflux at about 105 to 110 ° C., followed by further heating and aging for 4 hours.

  Next, 0.2 parts by mass of stearyl phosphate (manufactured by Sakai Chemical Industry Co., Ltd., Phoslex A-18) is added to the resulting polymerization solution as a catalyst for the cyclization condensation reaction (cyclization catalyst). The cyclization condensation reaction in which a lactone ring structure located in the main chain was formed was allowed to proceed for 2 hours under reflux to obtain a polymerization solution (a-1).

(Production Example 2)
MMA 42.5 parts by mass, N-phenylmaleimide 5 parts by mass, styrene 0.5 parts by mass, toluene 50 parts by mass as a polymerization solvent, organic acid in a reaction kettle equipped with a stirrer, temperature sensor, cooling pipe and nitrogen introduction pipe As acetic anhydride, 0.2 parts by mass of acetic anhydride and 0.06 parts by mass of n-dodecyl mercaptan were charged as a chain transfer agent. Then, when the temperature in the tank reached 100 ° C., 0.075 parts by mass of t-butyl peroxyisopropyl carbonate was added, and simultaneously, bubbling of nitrogen was started in the dropping tank. Next, a mixture of 2 parts by mass of styrene and 0.075 parts by mass of t-butylperoxyisopropyl carbonate was dropped into the polymerization tank at a constant rate over 5 hours while refluxing at a polymerization temperature of 105 to 110 ° C. The polymerization reaction was allowed to proceed for 15 hours.

  Next, 9,10-dihydro-9-oxa-10-phosphanenanthrene-10-oxide (manufactured by Sanko Co., Ltd., HCA) as a phosphoric acid-based antioxidant and phenol-based polymer solution were obtained. As an antioxidant, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by ADEKA, AO-60) was added in an amount of 0.1 parts by mass and 0. 02 parts by mass was added to obtain a polymerization solution (a-2).

(Production Example 3)
MMA 40 parts by mass, MHMA 10 parts by mass and toluene 50 parts by mass as a polymerization solvent were charged in a reaction kettle equipped with a stirrer, temperature sensor, cooling pipe and nitrogen introduction pipe, and the temperature was raised to 105 ° C. while passing nitrogen through the reactor. It was.

  When the reflux accompanying the temperature increase started, 0.03 parts by mass of t-amylperoxyisononanoate (manufactured by Arkema Yoshitomi, trade name: Luperox 570) was added as a polymerization initiator, and the t-amylperoxyisononoate was added. While 0.06 parts by mass of nanoate was added dropwise over 2 hours, solution polymerization was allowed to proceed under reflux at about 105 to 110 ° C., followed by further heating and aging for 4 hours.

  Next, 0.05 part by mass of stearyl phosphate (manufactured by Sakai Chemical Industry, Phoslex A-18) as a cyclization catalyst was added to the obtained polymerization solution, and the main chain was refluxed at about 90 to 110 ° C. for 2 hours. The cyclization condensation reaction in which the lactone ring structure located at is formed was advanced to obtain a polymerization solution (a-3).

Example 1
The polymerization solution (a-1) produced in Production Example 1 was passed through a multitubular heat exchanger heated to 240 ° C. to complete the cyclization condensation reaction in which a lactone ring structure was formed. The polymerization solution (a-1) contains an acrylic resin (A-1) having a lactone ring structure in the main chain.

  Next, the polymerization solution (a-1) was treated with a barrel temperature of 250 ° C., a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1 and a forevent number of 4 (first, second, A vent type screw twin screw extruder (L / D = 52) having a leaf disk type polymer filter (filtration accuracy 5 μm, temperature 270 ° C.) connected to the tip via a gear pump. ) At a processing rate of 12.5 parts by mass / hour (resin amount conversion). Volatilization was carried out at this treatment speed, and the filling of the resin composition (D) in the hot melt state including the acrylic resin (A-1) into the path inside the polymer filter was completed. The composition (D) of Example 1 does not contain an ultraviolet absorber (the content Y of the ultraviolet absorber was 0% by mass). Completion of filling was confirmed by starting the discharge of the composition (D) from the outlet of the polymer filter.

  After confirming the completion of filling, the introduction rate of the polymerization solution (a-1) into the extruder is increased to 31.2 parts by mass (resin amount conversion), and the second and fourth vents of ion-exchanged water are further increased. Charge from the front (each charge rate 0.47 parts by mass / hour), and supply of a 35% by weight toluene solution of UV absorber (B-1); (Adeka, Adeka Stub LA-F70) (feed rate 0.63) Mass parts / hour) was started. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump.

Thereby, the devolatilized resin composition in the heat-melted state became a steady state in which the filter was continuously discharged from the filter at a rate of 58.2 kg / hour per 1 m ² of the effective filtration area of the polymer filter. The discharged resin composition was continuously pelletized with a pelletizer, and a resin composition (C-1) containing an acrylic resin (A-1) having a lactone ring structure in the main chain and an ultraviolet absorber (B-1). ) Was obtained.

  The resin composition (C-1) had a Tg of 121 ° C. and a weight average molecular weight of 130,000. The content X of the ultraviolet absorber (B-1) in the resin composition (C-1) is 0.7% by mass (= (0.63 × 0.35) / (0.63 × 0.35 + 31.2). ) × 100). T380 of the resin composition (C-1) was 6%, and T590 was 100%.

  In Example 1, the content Y was 0% by mass, and the ratio Y / X of the content Y to the content X was 0. And the grade of the time when generation | occurrence | production of brown discoloration continues in the resin composition (C-1) was "(double-circle)".

(Example 2)
Even when the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-1) to the extruder is 12.5 parts by mass (resin amount conversion)), Acrylic resin (A-1) and UV absorption in the same manner as in Example 1 except that 35 wt% toluene solution of UV absorber (B-1) was supplied (supply rate 0.125 parts by mass / hour). The pellet of the resin composition (C-1) containing an agent (B-1) was obtained. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump. The ultraviolet absorber content Y in the composition (D) of Example 2 is 0.35% by mass (= (0.125 × 0.35) / (0.125 × 0.35 + 12.5) × 100). there were.

  In Example 2, the content Y was 0.35% by mass, the content X was 0.7% by mass as in Example 1, and the ratio Y / X was 0.5. And the grade of the time when generation | occurrence | production of brown discoloration continues in the resin composition (C-1) was "(double-circle)".

(Example 3)
Even when the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-1) to the extruder is 12.5 parts by mass (resin amount conversion)), Acrylic resin (A-1) and UV absorption in the same manner as in Example 1 except that 35 wt% toluene solution of UV absorber (B-1) was supplied (supply rate 0.176 parts by mass / hour). The pellet of the resin composition (C-1) containing an agent (B-1) was obtained. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump. The ultraviolet absorber content Y in the composition (D) of Example 3 is 0.49% by mass (= (0.176 × 0.35) / (0.176 × 0.35 + 12.5) × 100). there were.

  In Example 3, the content Y was 0.49% by mass, the content X was 0.7% by mass as in Example 1, and the ratio Y / X was 0.7. And the grade of the time when generation | occurrence | production of brown discoloration continues in the resin composition (C-1) was "(double-circle)".

Example 4
Even when the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-1) to the extruder is 12.5 parts by mass (resin amount conversion)), Acrylic resin (A-1) and UV absorption in the same manner as in Example 1 except that 35 wt% toluene solution of UV absorber (B-1) was supplied (supply rate 0.252 parts by mass / hour). The pellet of the resin composition (C-1) containing an agent (B-1) was obtained. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump. The ultraviolet absorber content Y in the composition (D) of Example 4 is 0.7% by mass (= (0.252 × 0.35) / (0.252 × 0.35 + 12.5) × 100). there were.

  In Example 4, the content Y was 0.7% by mass, the content X was 0.7% by mass as in Example 1, and the ratio Y / X was 1.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-1) was "(circle)".

(Example 5)
Even when the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-1) to the extruder is 12.5 parts by mass (resin amount conversion)), Acrylic resin (A-1) and UV absorption in the same manner as in Example 1 except that 35 wt% toluene solution of UV absorber (B-1) was supplied (supply rate: 0.379 parts by mass / hour). The pellet of the resin composition (C-1) containing an agent (B-1) was obtained. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump. The ultraviolet absorber content Y in the composition (D) of Example 5 is 1.05% by mass (= (0.379 × 0.35) / (0.379 × 0.35 + 12.5) × 100). there were.

  In Example 5, the content Y was 1.05% by mass, the content X was 0.7% by mass as in Example 1, and the ratio Y / X was 1.5. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-1) was "(circle)".

(Comparative Example 1)
Even when the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-1) to the extruder is 12.5 parts by mass (resin amount conversion)), Acrylic resin (A-1) and UV absorption in the same manner as in Example 1 except that 35 wt% toluene solution of UV absorber (B-1) was supplied (supply rate 0.507 parts by mass / hour). The pellet of the resin composition (C-1) containing an agent (B-1) was obtained. The UV absorbent solution was supplied from before the third vent after passing through a filter having a filtration accuracy of 1 μm using a high-pressure pump. The ultraviolet absorber content Y in the composition (D) of Comparative Example 1 is 1.4% by mass (= (0.507 × 0.35) / (0.507 × 0.35 + 12.5) × 100). there were.

  In Comparative Example 1, the content Y was 1.4% by mass, the content X was 0.7% by mass as in Example 1, and the ratio Y / X was 2. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-1) was "x".

  The results of Examples 1-5 and Comparative Example 1 are summarized in Table 1 below.

(Example 6)
The polymerization solution (a-2) produced in Production Example 2 was passed through a multitubular heat exchanger heated to 240 ° C. The polymerization solution (a-2) contains an acrylic resin (A-2) having an N-phenylmaleimide structure in the main chain.

  Next, the polymerization solution (a-2), barrel temperature 250 ° C., degree of vacuum 13.3 to 400 hPa (10 to 300 mmHg), rear vent number 1 and fore vent number 4 (first, second, A vent type screw twin screw extruder (L / D = 52) having a leaf disk type polymer filter (filtration accuracy 5 μm, temperature 280 ° C.) connected to the tip via a gear pump. ) At a processing speed of 10.8 parts by mass / hour (resin amount conversion). At this time, before the third vent of the extruder, a high-pressure pump was used to pass a 35 mass% toluene solution of the ultraviolet absorber (B-1) through a filter having a filtration accuracy of 1 μm, and then 0.218 mass parts / hour. Was fed at a feed rate of. Volatilization is carried out at this treatment speed, and the resin composition (D) in a hot melt state containing acrylic resin (A-2) and ultraviolet absorber (B-1) to the path inside the polymer filter. ) Filling was completed. The ultraviolet absorber content Y in the composition (D) of Example 6 is 0.7% by mass (= (0.218 × 0.35) / (0.218 × 0.35 + 10.8) × 100). there were. Completion of filling was confirmed by starting the discharge of the composition (D) from the outlet of the polymer filter.

  After confirming the completion of filling, the introduction rate of the polymerization solution (a-2) into the extruder is increased to 27.1 parts by mass (resin amount conversion), and the second and fourth vents of the ion exchange water are further increased. While starting the charging from the front (each charging speed of 0.41 parts by mass / hour), the supply rate of the toluene solution of the ultraviolet absorber (B-1) was changed to 0.546 parts by mass / hour.

As a result, the devolatilized resin composition in a heat-melted state was in a steady state in which it was continuously discharged from the filter at a rate of 50.5 kg / hour per 1 m ² of the effective area of the polymer filter. The discharged resin composition is continuously pelletized with a pelletizer, and a resin composition (C-2) containing an acrylic resin (A-2) having an N-phenylmaleimide structure in the main chain and an ultraviolet absorber (B-1). -2) pellets were obtained.

  The resin composition (C-2) had a Tg of 133 ° C. and a weight average molecular weight of 160,000. The content X of the ultraviolet absorber (B-1) in the resin composition (C-2) is 0.7% by mass (= (0.546 × 0.35) / (0.546 × 0.35 + 27.1). ) × 100). T380 of the resin composition (C-2) was 6%, and T590 was 100%.

  In Example 6, both the contents X and Y were 0.7% by mass, and the ratio Y / X was 1.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-2) was "(circle)".

(Comparative Example 2)
Ultraviolet rays supplied to the extruder when the composition (D) is filled into the polymer filter (at this time, the introduction rate of the polymerization solution (a-2) into the extruder is 10.8 parts by mass / resin amount)) The acrylic resin (A-2) and the ultraviolet absorber (B-1) are the same as in Example 6 except that the rate of the toluene solution of the absorbent (B-1) is 0.438 parts by mass / hour. The pellet of the resin composition (C-2) containing this was obtained. The content Y of the ultraviolet absorber in the composition (D) of Comparative Example 2 is 1.4% by mass (= (0.438 × 0.35) / (0.438 × 0.35 + 10.8) × 100). there were.

  In Comparative Example 2, the content Y was 1.4% by mass, the content X was 0.7% by mass as in Example 6, and the ratio Y / X was 2.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-2) was "x".

(Example 7)
Acrylic resin (A-3) having a glutarimide structure in the main chain (manufactured by Daicel-Evonik, Pleximimide 8813, glutarimide unit content 42% by mass), barrel temperature 250 ° C., vacuum degree 13.3 to 400 hPa 10 to 300 mmHg), rear vent number 1 and fore vent number 4 (referred to as first, second, third and fourth vents from the upstream side), a leaf disk type polymer filter (filtered through a gear pump at the tip) It was introduced into a vent type screw twin screw extruder (L / D = 52) to which a precision of 5 μm and a temperature of 280 ° C. was connected, using a feeder at a processing speed of 10.8 parts by mass / hour. At this time, before the second vent of the extruder, a high-pressure pump was used to pass a 35 mass% toluene solution of the ultraviolet absorber (B-1) through a filter with a filtration accuracy of 1 μm, and then 0.218 parts by mass / hour. Was fed at a feed rate of. Volatilization is carried out at this treatment speed, and further, a resin composition (D) in a hot-melt state containing acrylic resin (A-3) and ultraviolet absorber (B-1) to the path inside the polymer filter. ) Filling was completed. The ultraviolet absorber content Y in the resin composition (D) of Example 7 is 0.7% by mass (= (0.218 × 0.35) / (0.218 × 0.35 + 10.8) × 100). Met. Completion of filling was confirmed by starting the discharge of the composition (D) from the outlet of the polymer filter.

  After confirming the completion of filling, the introduction speed of the acrylic resin (A-3) into the extruder is increased to 27.1 parts by mass (resin amount conversion), and further from before the third vent of the ion exchange water. While starting charging (charging speed 0.41 parts by mass / hour), the supply speed of the toluene solution of the ultraviolet absorber (B-1) was changed to 0.546 parts by mass / hour.

As a result, the devolatilized resin composition in a heat-melted state was in a steady state in which it was continuously discharged from the filter at a rate of 50.5 kg / hour per 1 m ² of the effective area of the polymer filter. The discharged resin composition was continuously pelletized with a pelletizer, and a resin composition (C-3) containing an acrylic resin (A-3) having a glutarimide structure in the main chain and an ultraviolet absorber (B-1). ) Was obtained.

  The resin composition (C-3) had a Tg of 128 ° C. and a weight average molecular weight of 142,000. The content X of the ultraviolet absorber (B-1) in the resin composition (C-3) is 0.7% by mass (= (0.546 × 0.35) / (0.546 × 0.35 + 27.1). ) × 100). T380 of the resin composition (C-3) was 6%, and T590 was 100%.

  In Example 7, both the contents X and Y were 0.7% by mass, and the ratio Y / X was 1.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-3) was "(circle)".

(Comparative Example 3)
Ultraviolet rays supplied to the extruder when the composition (D) is filled in the polymer filter (at this time, the introduction speed of the acrylic resin (A-3) to the extruder is 10.8 parts by mass / hour (resin amount conversion)). The acrylic resin (A-3) and the ultraviolet absorber (B-1) were the same as in Example 7 except that the speed of the toluene solution of the absorbent (B-1) was 0.438 parts by mass / hour. The pellet of the resin composition (C-3) containing this was obtained. The ultraviolet absorber content Y in the composition (D) of Comparative Example 3 is 1.4% by mass (= (0.438 × 0.35) / (0.438 × 0.35 + 10.8) × 100). there were.

  In Comparative Example 3, the content Y was 1.4% by mass, the content X was 0.7% by mass as in Example 7, and the ratio Y / X was 2.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-3) was "x".

(Example 8)
The polymerization solution (a-3) produced in Production Example 3 was passed through a multitubular heat exchanger heated to 240 ° C. to complete the cyclization condensation reaction. The polymerization solution (a-3) contains an acrylic resin (A-4) having a lactone ring structure in the main chain.

  Next, the polymerization solution (a-3), barrel temperature 250 ° C., degree of vacuum 13.3 to 400 hPa (10 to 300 mmHg), rear vent number 1 and fore vent number 4 (first, second, A leaf disk type polymer filter (filtration accuracy 5 μm, temperature 295 ° C.) is connected to the tip portion via a gear pump, and a side feeder is provided between the third vent and the fourth vent. It was introduced into a vent type screw twin screw extruder (L / D = 52) provided at a processing rate of 9.6 parts by mass / hour (resin amount conversion). At this time, pellets of styrene-acrylonitrile copolymer (the ratio of styrene unit / acrylonitrile unit is 73% by mass / 27% by mass, weight average molecular weight 220,000) are charged from the side feeder at a rate of 1.2 parts by mass / hour. Before the fourth vent of the extruder, using a high-pressure pump, the mixed solution of the ultraviolet absorber (B-2) and the antioxidant was passed through a filter with a filtration accuracy of 1 μm, and then 0.15 parts by mass / hour. Supplied at feed rate. In the mixed solution, 0.9 parts by mass of a phenol-based antioxidant (manufactured by BASF Japan, Irganox 1010), 0.9 part by mass of a sulfur-based antioxidant (manufactured by ADEKA, ADK STAB AO-412S) and an ultraviolet absorber ( B-2); (BASF Japan make, Tinuvin 477 (active ingredient 80%)) The solution which dissolved 68.4 mass parts in toluene 29.8 mass parts was used. The active ingredient amount of the ultraviolet absorber (B-2) in the mixed solution is 54.7% by mass. Volatilization is carried out at this treatment speed, and further, a resin composition (D) in a molten state containing acrylic resin (A-4) and ultraviolet absorber (B-2) to the path inside the polymer filter. ) Filling was completed. The ultraviolet absorber content Y in the resin composition (D) of Example 8 was 0.75% by mass (= (0.15 × 0.547) / (0.15 × 0.547 + 9.6 + 1.2) × 100). Completion of filling was confirmed by starting the discharge of the composition (D) from the outlet of the polymer filter.

  After confirming the completion of the filling, the introduction rate of the polymerization solution (a-3) into the extruder was set to 24.0 parts by mass (resin amount conversion), and the charging rate of the styrene-acrylonitrile copolymer pellets was set to 3.0. In addition, the ion exchange water was added before the second vent (injection speed 0.36 parts by mass / hour) and the quencher solution was added before the third vent (injection). The rate of supplying the mixed solution containing the ultraviolet absorber (B-2) was changed to 0.757 parts by mass / hour. As a deactivator (deactivator for cyclization catalyst) solution, a solution in which 36 parts by mass of calcium octylate (manufactured by Nippon Kagaku Sangyo Co., Ltd., 5% of Nikka octix calcium) was dissolved in 64 parts by mass of toluene was used.

This resulted in a steady state in which the devolatilized resin composition in the hot melt state was continuously discharged from the filter at a rate of 50.9 kg / hour per 1 m ² of the effective area of the polymer filter. The discharged resin composition is continuously pelletized by a pelletizer and contains an acrylic resin (A-4) having a lactone ring structure in the main chain, a styrene-acrylonitrile copolymer, and an ultraviolet absorber (B-2). A pellet of the resin composition (C-4) was obtained.

  The resin composition (C-4) had a Tg of 124 ° C. and a weight average molecular weight of 149,000. The content X of the ultraviolet absorber (B-2) in the resin composition (C-4) is 1.5% by mass (= (0.757 × 0.547) / (0.757 × 0.547 + 24 + 3) × 100). T380 of the resin composition (C-4) was 7%, and T590 was 100%.

  In Example 8, the content X was 1.5% by mass, the content Y was 0.75% by mass, and the ratio Y / X was 0.5. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-4) was "(double-circle)".

Example 9
When the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-3) into the extruder is 9.6 parts by mass / hour (resin amount), and the styrene-acrylonitrile copolymer Except that the speed of the above mixed solution containing the ultraviolet absorber (B-2) supplied to the extruder at an input speed of 1.2 parts by mass / hour was 0.30 parts by mass / hour, the same as in Example 8. Thus, a pellet of a resin composition (C-4) containing an acrylic resin (A-4), a styrene-acrylonitrile copolymer, and an ultraviolet absorber (B-2) was obtained. The ultraviolet absorber content Y in the composition (D) of Example 9 was 1.5% by mass (= (0.30 × 0.547) / (0.30 × 0.547 + 9.6 + 1.2) × 100. )Met.

  In Example 9, the content Y was 1.5% by mass, the content X was 1.5% by mass as in Example 8, and the ratio Y / X was 1.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-4) was "(circle)".

(Comparative Example 4)
When the composition (D) is filled in the polymer filter (at this time, the introduction rate of the polymerization solution (a-3) into the extruder is 9.6 parts by mass / hour (resin amount), and the styrene-acrylonitrile copolymer Example 8 except that the rate of the mixed solution containing the ultraviolet absorbent (B-2) supplied to the extruder at 1.2 parts by mass / hour is 0.61 parts by mass / hour. Thus, a pellet of a resin composition (C-4) containing an acrylic resin (A-4), a styrene-acrylonitrile copolymer, and an ultraviolet absorber (B-2) was obtained. The content Y of the ultraviolet absorber in the composition (D) of Comparative Example 4 is 3.0% by mass (= (0.61 × 0.547) / (0.61 × 0.547 + 9.6 + 1.2) × 100. )Met.

  In Comparative Example 4, the content Y was 3.0% by mass, the content X was 1.5% by mass as in Example 8, and the ratio Y / X was 2.0. And the grade of the time when generation | occurrence | production of brown discoloration continues in a resin composition (C-4) was "x".

  The results of Examples 6-9 and Comparative Examples 2-4 are summarized in Table 2 below.

  As shown in Tables 1 and 2, when the ratio Y / X is 1.5 or less, brown discoloration of the resin composition at the start-up of the extruder and the polymer filter is suppressed, and the production start-up of the resin composition is quick Was achieved.

  The thermoplastic composition resin composition obtained by the production method of the present invention can be used for various uses similar to conventional thermoplastic resin compositions. One of the uses is an optical member such as an optical film.

Claims (13)

A method for producing a thermoplastic resin composition (C) comprising an ultraviolet absorber (B) at a content of X mass%,
A step of melt-kneading the thermoplastic resin (A) and the ultraviolet absorber (B) with an extruder, a step of introducing a hot-melt composition formed by the melt-kneading into a polymer filter, and filtering. Including,
After the introduction of the composition into the polymer filter is started, the introduction amount of the composition into the polymer filter from a steady state until the route of the composition inside the polymer filter is filled with the composition. And the content of the ultraviolet absorber in the composition is Y mass% (however, 0 ≦ Y ≦ 1.5 × X),
Thereafter, the introduction amount is set to a steady state, the content is set to X mass%, and the thermoplastic resin composition (C) is obtained.
The thermoplastic resin (A) is an acrylic resin having a ring structure in the main chain,
The manufacturing method of the thermoplastic resin composition containing the ultraviolet absorber whose molecular weight of the said ultraviolet absorber (B) is 10,000 or less . The thermoplastic resin containing an ultraviolet absorber according to claim 1, wherein the ultraviolet absorber (B) is at least one selected from a benzophenone compound, a salicylate compound, a benzoate compound, a triazole compound, and a triazine compound. A method for producing a resin composition. The manufacturing method of the thermoplastic resin composition containing the ultraviolet absorber of Claim 1 whose said ultraviolet absorber (B) is at least 1 sort (s) chosen from a triazole type compound and a triazine type compound. The manufacturing method of the thermoplastic resin composition containing the ultraviolet absorber of Claim 1 whose said ultraviolet absorber (B) is a triazine type compound. The ring structure that the thermoplastic resin (A) has in the main chain is at least one selected from a lactone ring structure, a glutaric anhydride structure, a glutarimide structure, an N-substituted maleimide structure, and a maleic anhydride structure. The manufacturing method of the thermoplastic resin composition containing the ultraviolet absorber in any one of 1-4. The ring structure that the thermoplastic resin (A) has in the main chain is at least one selected from a lactone ring structure, a glutarimide structure, and an N-substituted maleimide structure, according to any one of claims 1 to 4. A method for producing a thermoplastic resin composition comprising an ultraviolet absorber. The method for producing a thermoplastic resin composition containing an ultraviolet absorber according to claim 5 or 6, wherein the N-substituted maleimide structure is an N-phenylmaleimide structure. The heat | fever containing the ultraviolet absorber in any one of Claims 1-7 whose content rate X of the said ultraviolet absorber (B) in the said thermoplastic resin composition (C) is 0.01-5 mass%. A method for producing a plastic resin composition. The ultraviolet ray according to any one of claims 1 to 8 , further comprising a step of removing a volatile component contained in the composition from a vent portion in a pressure atmosphere of 1.3 hPa or more and 906 hPa or less provided in the extruder. A method for producing a thermoplastic resin composition comprising an absorbent. The manufacturing method of the thermoplastic resin composition containing the ultraviolet absorber in any one of Claims 1-9 whose temperature inside the said polymer filter which filters the said composition is 260 degreeC or more and 330 degrees C or less. The thermoplastic resin containing an ultraviolet absorber according to any one of claims 1 to 10 , wherein in the steady state, the composition is filtered at a rate of 15 kg / hour to 65 kg / hour per 1 m ^{2 of} an effective filtration area of the polymer filter. A method for producing the composition. Production method of the polymer filter is a leaf disc filter, a thermoplastic resin composition containing the ultraviolet absorbent according to any one of claims 1 to 11. A chloroform solution (concentration: 0.4% by mass) of the thermoplastic resin composition (C) was housed in a quartz cell having an optical path length of 1 cm and measured with an absorptiometer. There is respectively 10% and less than 90%, method for producing a thermoplastic resin composition containing the ultraviolet absorbent according to any one of claims 1 to 12.