Method for producing acrylic resin film and apparatus for producing acrylic resin film

Abstract

[Problem] The present invention provides a method for manufacturing an acrylic resin film and an apparatus for manufacturing an acrylic resin film that can maintain uniformity of quality, such as thickness, of the acrylic resin film. [Solution] The method for manufacturing the above acrylic resin film is, A supply process for supplying raw materials for acrylic resin film from a raw material feeder to an extruder, and An extrusion process for melting and mixing raw materials supplied from a raw material feeder within an extruder and extruding the molten material obtained by melting and mixing to the downstream side of the extruder, and A pressurization process is provided to increase the pressure of the molten material extruded from the extruder by means of a gear pump connected to the downstream side of the extruder, and The extruder has a screw and a motor that drives the screw to rotate, In the extrusion process, When the rotational speed of the screw is N and the amount of raw material supplied to the extruder is Q, N is controlled so that the pressure of the molten material between the extruder and the gear pump becomes constant, and also the following (i), (ii), (iii): (i) Not controlling Q, (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value. (iii) Controlling Q by dulling the effect of Q control so that the pressure of the molten material between the extruder and the gear pump becomes constant Execute one of the following.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing an acrylic resin film and an apparatus for manufacturing an acrylic resin film. Background Technology

[0002] Conventionally, an apparatus for manufacturing acrylic resin films is described in Japanese Patent Publication No. Heisei 2-6118. This apparatus comprises a raw material feeder, an extruder that receives raw materials from the raw material feeder, a gear pump connected to the downstream side of the extruder, a die connected to the downstream side of the gear pump, and a control device for controlling the raw material feeder and the extruder. The extruder is equipped with a screw and a motor that rotates and drives the screw, and mixes and melts the raw materials to extrude them as a molten material. The control device measures the pressure of the molten material between the discharge side of the extruder and the suction side of the gear pump, and controls the amount of raw material supplied to the extruder (Q) and the rotational speed (N) of the screw so that this pressure becomes constant, thereby controlling the amount of molten material extruded from the extruder. Prior art literature

[0003] Patent Document 1: Japanese Patent Publication No. Heisei 2-6118 The problem to be solved

[0004] However, even if Q and N are controlled, the extrusion volume of the molten material from the extruder is not stable, so when manufacturing an acrylic resin film from the molten material using a die, the quality, such as the thickness of the acrylic resin film, may become non-uniform.

[0005] Therefore, the present disclosure is to provide a method for manufacturing an acrylic resin film and an apparatus for manufacturing an acrylic resin film that can maintain uniformity in quality of the acrylic resin film. means of solving the problem

[0006] To solve the above problem, a method for manufacturing an acrylic resin film, which is one embodiment of the present disclosure, is,

[0007] A supply process for supplying raw materials for acrylic resin film from a raw material feeder to an extruder, and

[0008] An extrusion process for melting and mixing raw materials supplied from the raw material feeder within the extruder and extruding the molten material obtained by the melting and mixing to the downstream side of the extruder, and

[0009] A pressurization process is provided to increase the pressure of the molten material extruded from the extruder by means of a gear pump connected to the downstream side of the extruder, and

[0010] The above extruder has a screw and a motor that rotates and drives the screw,

[0011] In the above extrusion process,

[0012] When the rotational speed of the screw is N and the amount of raw material supplied to the extruder is Q, N is controlled so that the pressure of the molten material between the extruder and the gear pump becomes constant, and also the following (i), (ii), (iii):

[0013] (i) Not controlling Q,

[0014] (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value.

[0015] (iii) Controlling Q by dulling the effect of controlling Q so that the pressure of the molten material between the extruder and the gear pump becomes constant.

[0016] Execute one of the following.

[0017] The inventors have discovered, through careful examination, that when controlling Q and N, controlling N accelerates the pressure response on the discharge side of the extruder, whereas controlling Q slows down the pressure response on the discharge side of the extruder. As such, since the response of Q control is slow, it becomes difficult to stably and constantly control the pressure on the discharge side of the extruder. Consequently, when manufacturing an acrylic resin film from a molten material using a die, there is a risk that the quality, such as the thickness of the acrylic resin film, may become non-uniform.

[0018] According to the above embodiment, N is controlled so that the pressure of the molten material between the extruder and the gear pump becomes constant, and Q is not controlled or is controlled more loosely than the control of N, thereby reducing the influence of Q control on the pressure on the discharge side of the extruder. As a result, it becomes easier to stably and constantly control the pressure on the discharge side of the extruder, and when manufacturing an acrylic resin film from the molten material downstream of the gear pump, uniformity of quality, such as the thickness of the acrylic resin film, can be maintained.

[0019] Preferably, in one embodiment of the method for manufacturing an acrylic resin film, in (ii) above, the effect of controlling Q is also dulled to control Q.

[0020] According to the above embodiment, since the control of Q can be loosened, the pressure on the discharge side of the extruder can be controlled more stably.

[0021] Preferably, in one embodiment of the method for manufacturing an acrylic resin film, in (iii) above, Q is controlled such that when the range of variation from the reference value of Q / N exceeds a set value, the range of variation of Q / N becomes less than or equal to the set value.

[0022] According to the above embodiment, since the control of Q can be loosened, the pressure on the discharge side of the extruder can be controlled more stably.

[0023] Preferably, in one embodiment of the method for manufacturing an acrylic resin film, the extruder is a twin-screw extruder.

[0024] According to the above embodiment, although pressure fluctuations are more likely to occur in a twin-screw extruder compared to a single-screw extruder, pressure fluctuations on the discharge side of the twin-screw extruder can be effectively reduced.

[0025] Preferably, in one embodiment of the method for manufacturing an acrylic resin film, the raw material comprises a plurality of materials having different shapes.

[0026] According to the above embodiment, even when multiple types of materials with different shapes are fed into the extruder, pressure fluctuations at the discharge side of the extruder can be effectively reduced.

[0027] In addition, an apparatus for manufacturing an acrylic resin film, which is one embodiment of the present disclosure, is

[0028] A raw material feeder containing raw materials for acrylic resin film, and

[0029] An extruder having a screw and a motor that rotates and drives the screw, and which melts and mixes raw materials supplied from the raw material feeder and extrudes them as a molten material, and

[0030] A gear pump connected to the downstream side of the extruder and pressurizing and discharging the molten material extruded from the extruder, and

[0031] When the rotational speed of the screw is N and the amount of raw material supplied to the extruder is Q, N is controlled so that the pressure of the molten material between the extruder and the gear pump becomes constant, and also the following (i), (ii), (iii):

[0032] (i) Not controlling Q,

[0033] (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value.

[0034] (iii) Controlling Q by dulling the effect of controlling Q so that the pressure of the molten material between the extruder and the gear pump becomes constant.

[0035] It is equipped with a control device that executes any one of the following.

[0036] According to the above embodiment, N is controlled so that the pressure of the molten material between the extruder and the gear pump (hereinafter also referred to as the pressure on the discharge side of the extruder) becomes constant, and Q is not controlled or is controlled more loosely than N, thereby reducing the influence of Q control on the pressure on the discharge side of the extruder. As a result, it becomes easier to stably and constantly control the pressure on the discharge side of the extruder, and when manufacturing an acrylic resin film from the molten material downstream of the gear pump, uniformity of quality, such as the thickness of the acrylic resin film, can be maintained.

[0037] Preferably, in one embodiment of the apparatus for manufacturing an acrylic resin film, in (ii) above, the effect of controlling Q is dulled and Q is controlled.

[0038] According to the above embodiment, since the control of Q can be loosened while maintaining the fluctuation range of Q / N below a set value, the pressure on the discharge side of the extruder can be controlled more stably.

[0039] Preferably, in one embodiment of the manufacturing apparatus for an acrylic resin film, in (iii) above, Q is controlled such that when the range of variation from the reference value of Q / N exceeds a set value, the range of variation of Q / N becomes less than or equal to the set value.

[0040] According to the above embodiment, since the control of Q can be loosened while maintaining the fluctuation range of Q / N below a set value, the pressure on the discharge side of the extruder can be controlled more stably.

[0041] Preferably, in one embodiment of the apparatus for manufacturing an acrylic resin film, the extruder is a twin-screw extruder.

[0042] According to the above embodiment, although pressure fluctuations are more likely to occur in a twin-screw extruder compared to a single-screw extruder, pressure fluctuations on the discharge side of the twin-screw extruder can be effectively reduced. Effects of the invention

[0043] According to the method for manufacturing an acrylic resin film and the apparatus for manufacturing an acrylic resin film, which are embodiments of the present disclosure, the uniformity of the quality of the acrylic resin film can be maintained. Brief explanation of the drawing

[0044] FIG. 1 is a schematic diagram showing one embodiment of an apparatus for manufacturing an acrylic resin film. Figure 2 is a schematic diagram showing a raw material feeder of an acrylic resin film manufacturing apparatus. Figure 3 is a schematic diagram showing each component of an acrylic resin film manufacturing apparatus, excluding the raw material feeder. Specific details for implementing the invention

[0045] Hereinafter, a method for manufacturing an acrylic resin film and an apparatus for manufacturing an acrylic resin film, which are embodiments of the present disclosure, will be described in detail according to the illustrated embodiments. Additionally, some drawings are schematic and may not reflect actual dimensions or proportions.

[0046] (Embodiment)

[0047] <Overview Structure>

[0048] FIG. 1 is a schematic diagram showing an embodiment of an acrylic resin film manufacturing apparatus. As shown in FIG. 1, the acrylic resin film manufacturing apparatus (1) comprises a raw material feeder (2), an extruder (3), a first gear pump (4), a coarse filter (5), a second gear pump (6), a high-fine filter (7), a die (8), and a control device (9).

[0049] The acrylic resin film manufacturing apparatus (1) melts and mixes the raw materials for the acrylic resin film and forms the acrylic resin film from the melt. In FIG. 1, the direction in which the melt flows is indicated by an arrow. The raw material feeder (2), extruder (3), first gear pump (4), coarse filter (5), second gear pump (6), high-pressure filter (7), and die (8) are arranged in order from upstream to downstream of the flow of the melt.

[0050] The raw material feeder (2) contains raw materials for an acrylic resin film. The extruder (3) mixes and melts the raw materials supplied from the raw material feeder (2), and extrudes the molten material obtained by this melting and mixing to the downstream side of the extruder (3). The extruder (3) has a screw and a motor that rotates and drives the screw.

[0051] The first gear pump (4) is connected to the downstream side of the extruder (3) and pressurizes and discharges the molten material extruded from the extruder (3). The second gear pump (6) is connected to the downstream side of the first gear pump (4) and pressurizes and discharges the molten material discharged from the first gear pump (4).

[0052] The jaw filter (5) is connected between the first gear pump (4) and the second gear pump (6) and filters the molten material discharged from the first gear pump (4). The fixed filter (7) is connected to the downstream side of the second gear pump (6) and filters the molten material discharged from the second gear pump (6).

[0053] The die (8) is connected to the downstream side of the fixed-pressure filter (7) and molds the molten material discharged from the fixed-pressure filter (7) into a film shape, and then conveys it to a subsequent molding roll not shown. By doing so, an acrylic resin film can be manufactured.

[0054] The control device (9) controls N so that the pressure of the molten material between the extruder (3) and the first gear pump (4) becomes constant when the rotational speed of the screw is N and the amount of raw material supplied to the extruder (3) is Q, and also the following (i), (ii), (iii):

[0055] (i) Not controlling Q,

[0056] (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value.

[0057] (iii) Controlling Q by dulling the effect of Q control so that the pressure of the molten material between the extruder (3) and the first gear pump (4) becomes constant.

[0058] Execute one of the following.

[0059] According to the above configuration, N is controlled so that the pressure of the molten material between the extruder (3) and the first gear pump (4) (hereinafter also referred to as the pressure on the discharge side of the extruder (3)) becomes constant, and Q is not controlled or is controlled more loosely than N, thereby reducing the influence of Q control on the pressure on the discharge side of the extruder (3). In short, the inventors discovered that the response of Q is delayed compared to the response of N, and found that due to this delay in the response of Q, it becomes difficult to stably and constantly control the pressure on the discharge side of the extruder (3). Based on this finding, the inventors devised to not control Q or to control Q more loosely than N.

[0060] As a result, it is easy to stably and consistently control the pressure on the discharge side of the extruder (3), so that when manufacturing an acrylic resin film with molten material on the downstream side of the first gear pump (4), the uniformity of quality, such as the thickness of the acrylic resin film, can be maintained.

[0061] In addition, it is not necessary to control N and Q so that Q / N becomes constant, and it is acceptable to control N and Q so that Q / N becomes non-constant. By doing so, it is not necessary to strictly control Q, and the pressure on the discharge side of the extruder (3) can be controlled more stably.

[0062] Here, the supply amount Q of the raw material corresponds to the measured value of the raw material measured by a meter. Therefore, if Q is strictly controlled, a time lag occurs in the response of the measured value by the meter, and the response of the pressure on the discharge side of the extruder (3) becomes increasingly delayed, making it impossible to perform stable control. To explain in detail, based on the value of Q, the indicated supply amount is distributed to each of the multiple meters in a ratio corresponding to the raw material recipe. Furthermore, if the value of Q fluctuates up and down, the indicated value to each meter also fluctuates, and due to the difference in responsiveness of each meter, the raw material is supplied to the extruder (3) at a ratio that deviates from the raw material recipe for a moment. As a result, problems arise in which the volume density of the raw material changes, causing the extruder (3) to become prone to fluctuation (i.e., pressure fluctuation occurs), and the performance of the product differs due to the raw material ratio being different from the one originally designed. In this regard, in this embodiment, as described above, since the control of Q is not strictly performed, the pressure on the discharge side of the extruder (3) can be controlled more stably.

[0063] <Desirable configuration of each component>

[0064] (Acrylic resin film)

[0065] As for acrylic resins used in acrylic resin films, examples include methacrylic resin (a homopolymer of methacrylic acid esters or a copolymer with methacrylic acid esters as the main component). From the perspective of imparting impact resistance to the film, it is preferable that the acrylic resin be one in which rubber particles are incorporated, particularly that rubber particles be incorporated into methacrylic resin. Methacrylic resin is a homopolymer of methacrylic acid esters or a copolymer with methacrylic acid esters as the main component. As for the methacrylic acid ester, an alkyl ester of methacrylic acid is typically used, and the number of carbon atoms in the alkyl group is about 1 to 4. When forming a copolymer, an acrylic acid ester known to be advantageous as a copolymerization component of methacrylic resin, or other polymerizable monomers capable of copolymerizing with alkyl methacrylic acid esters and / or acrylic acid esters, are used.

[0066] The methacrylate resin is preferably obtained by polymerizing a monomer comprising 50 to 100 weight% of an alkyl methacrylate ester having an alkyl group having 1 to 4 carbon atoms, 0 to 50 weight% of an acrylic acid ester, and 0 to 49 weight% of at least one of other polymerizable monomers copolymerizable with these. Preferably, it is a thermoplastic polymer having a glass transition temperature of 40°C or higher. Here, the acrylic acid ester is more preferably used in the range of 0.1 to 50 weight%, and the copolymerization ratio of the alkyl methacrylate ester is more preferably in the range of 50 to 99.9 weight%. Furthermore, the glass transition temperature of this methacrylate resin is more preferably 60°C or higher. Additionally, when the term "monomer" is used simply in this specification, it includes not only cases where a single type of monomer is included, but also cases where a plurality of monomers are mixed.

[0067] In this thermoplastic polymer, alkyl methacrylate esters having 1 to 8 carbon atoms in the alkyl group may be used as the alkyl ester. The number of carbon atoms in the alkyl group is preferably 1 to 4. Among these, methyl methacrylate is particularly preferably used from the perspective of durability. The alkyl methacrylate ester may be used as a single type or two or more types may be used in combination.

[0068] As an acrylic acid ester, an alkyl acrylate ester is typically used. Examples of alkyl acrylate esters include alkyl acrylate esters in which the alkyl group has 1 to 8 carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 4. As for the acrylic acid ester, only one type may be used, or two or more types may be used in combination.

[0069] Other polymerizable monomers copolymerizable with alkyl methacrylate esters and / or acrylic acid esters include various monomers conventionally known in the art. Examples of such monomers include monofunctional monomers having one polymerizable carbon-carbon double bond in the molecule, polyfunctional monomers having at least two polymerizable carbon-carbon double bonds in the molecule, and monofunctional monomers are preferably used. Specifically, monofunctional monomers include styrene-based monomers such as styrene, α-methylstyrene, vinyltoluene, styrene halides, and hydroxystyrene; vinyl cyanide such as acrylonitrile and methacrylonitrile; unsaturated acids such as acrylic acid, methacrylic acid, maleic anhydride, and itaconic anhydride; and maleimides such as N-methylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide. Examples include unsaturated alcohols such as metallyl alcohol and allyl alcohol; other monomers such as vinyl acetate, vinyl chloride, ethylene, propylene, 4-methyl-1-pentene, 2-hydroxymethyl-1-butene, methylvinylketone, N-vinylpyrrolidone, N-vinylcarbazole, etc.

[0070] Examples of polyfunctional monomers include, specifically, polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, and allyl cinnamate; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, trialyl cyanurate, and trialyl isocyanurate; and aromatic polyalkenyl compounds such as divinylbenzene.

[0071] Other polymerizable monomers copolymerizable to such alkyl methacrylate esters and / or acrylic acid esters may be used as a single type or in combination of two or more types.

[0072] As for the methacrylate resin, as described above, a thermoplastic polymer obtained by polymerizing a monomer comprising 50 to 100 weight%, more preferably 50 to 99.9 weight%, of an alkyl methacrylate ester having 1 to 4 carbon atoms, 0 to 50 weight%, more preferably 0.1 to 50 weight%, of an acrylic acid ester, and 0 to 49 weight% of at least one of other polymerizable monomers copolymerizable with these is suitable, and the polymer falling within this range can be used alone or as a mixture of two or more polymers.

[0073] Methacryl resin may have a ring structure in the polymer main chain to increase the durability of the film. The ring structure is preferably a complex ring structure, such as a cyclic acid anhydride structure, a cyclic imide structure, or a lactone ring structure. Specifically, examples include cyclic acid anhydride structures such as glutaric anhydride and succinic anhydride structures; cyclic imide structures such as glutarimide and succinimide structures; and lactone ring structures such as butyrolactone and valerolactone. The higher the content of the ring structure in the main chain, the higher the glass transition temperature of the methacrylic resin can be. Cyclic acid anhydride structures or cyclic imide structures can be introduced into the main chain by methods such as copolymerizing monomers having cyclic structures, such as maleic anhydride or maleimide; introducing cyclic acid anhydride structures by dehydration and demethanol condensation reactions after polymerization; or introducing cyclic imide structures by reacting with amino compounds.

[0074] The polymerization method of the above thermoplastic polymer is not particularly limited, but can be carried out by conventional suspension polymerization, emulsion polymerization, bulk polymerization, etc. In addition, it is preferable to use a chain transfer agent during polymerization to obtain a suitable glass transition temperature or to obtain a viscosity that exhibits suitable moldability into a film. The amount of the chain transfer agent may be appropriately determined according to the type and composition of the monomer.

[0075] Rubber particles may be incorporated into the above methacrylate resin for the purpose of imparting impact resistance to the film. It is preferable that the rubber particles have an average particle size in the range of 0.05 to 0.4 μm, further 0.06 to 0.3 μm, and particularly 0.1 to 0.25 μm.

[0076] Rubber particles are included in a ratio of preferably 3 to 60 parts by weight, more preferably 5 to 50 parts by weight, and even more preferably 10 to 40 parts by weight, out of a total of 100 parts by weight of acrylic resin (e.g., methacrylate resin) and rubber particles.

[0077] The rubber particles are preferably rubber-containing polymers formed by polymerizing 10 to 400 parts by weight of a monomer comprising 50 to 100 parts by weight of a methacrylic acid ester, 0 to 50 parts by weight of an acrylic acid ester, and 0 to 49 parts by weight of at least one other vinyl monomer copolymerizable thereto, in the presence of 100 parts by weight of an elastic copolymer having a layer comprising 50 to 99.9 parts by weight of an alkyl acrylate ester, 0 to 49.9 parts by weight of at least one other vinyl monomer copolymerizable thereto, and 0.1 to 10 parts by weight of a crosslinkable monomer copolymer, thereby bonding at least one polymerization layer from the latter monomer to the surface of the elastic copolymer. The rubber particles may be manufactured with different average particle sizes by changing the polymerization conditions.

[0078] This rubber-containing polymer is obtained, for example, by the following method. The above-mentioned component for an elastic copolymer is polymerized in at least one reaction step according to an emulsion polymerization method or the like to obtain an elastic copolymer. In the presence of this obtained elastic copolymer, a monomer containing the above-mentioned methacrylic acid ester is polymerized in at least one reaction step according to an emulsion polymerization method or the like. Through such multiple-step polymerization, the monomer containing the methacrylic acid ester used in the subsequent step is graft copolymerized into the elastic copolymer, thereby producing a cross-linked elastic copolymer having a graft chain. That is, this rubber-containing polymer becomes a graft copolymer having a multilayer structure containing an alkyl acrylate ester as the main component of the rubber. In addition, when polymerizing an elastic copolymer in two or more stages, or when subsequently polymerizing a monomer with methacrylic acid ester as the main component in two or more stages, in either case, it is sufficient if the monomer composition as a whole, rather than the monomer composition of each stage, falls within the above range.

[0079] As for the alkyl acrylate ester in the above rubber-containing polymer, for example, those having 1 to 8 carbon atoms in the alkyl group may be used. Among these, it is preferable that the alkyl group has 4 to 8 carbon atoms, such as butyl acrylate or 2-ethylhexyl acrylate.

[0080] Other vinyl monomers copolymerizable to alkyl acrylate esters in rubber-containing polymers include, for example, alkyl methacrylate esters such as methyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate, styrene, acrylonitrile, etc.

[0081] In rubber-containing polymers, the copolymerizable crosslinkable monomer used to form the elastic copolymer preferably has at least two polymerizable carbon-carbon double bonds within one molecule. Examples of such crosslinkable monomers include, for instance, unsaturated carboxylic acid diesters of glycols such as ethylene glycol dimethacrylate and butanediol dimethacrylate; alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, and allyl cinnamate; polyalkenyl esters of polycarboxylic acids such as diallyl phthalate, diallyl maleate, trialyl cyanurate, and trialyl isocyanurate; unsaturated carboxylic acid esters of polyhydric alcohols such as trimethylolpropane triacrylate; and divinylbenzene. Among these, alkenyl esters of unsaturated carboxylic acids or polyalkenyl esters of polycarboxylic acids are preferred. These crosslinkable monomers can be used individually or in combination of two or more as needed.

[0082] An elastic copolymer obtained by polymerizing a monomer mainly composed of an alkyl acrylate ester as described above is grafted with a monomer comprising 50 to 100 weight% of a methacrylate ester, 0 to 50 weight% of an acrylic acid ester, and 0 to 49 weight% of at least one of other vinyl monomers copolymerizable with these. The methacrylate ester grafted onto the elastic copolymer is preferably an alkyl methacrylate ester, and examples include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, etc. As for the acrylic acid ester copolymerized with these methacrylate esters according to the preference, examples include alkyl acrylate esters such as methyl acrylate, butyl acrylate, and cyclohexyl acrylate. In addition, other vinyl monomers copolymerizable to methacrylic acid esters and / or acrylic acid esters include, for example, styrene, acrylonitrile, etc.

[0083] The grafted monomer can be used in an amount of preferably 10 to 400 parts by weight, more preferably 20 to 200 parts by weight, per 100 parts by weight of the elastomeric copolymer, and polymerized in at least one reaction step. Here, if the amount of the grafted monomer used is 10 parts by weight or more, aggregation of the elastomeric copolymer is less likely to occur, and transparency is improved.

[0084] In addition, a hard layer mainly composed of methacrylic acid ester may be provided on the inner side of the elastic copolymer layer. In this case, it is preferable to first polymerize the monomer of the hard layer constituting the innermost layer. Subsequently, the monomer constituting the elastic copolymer is polymerized in the presence of the obtained hard polymer. In addition, it is preferable to polymerize the graft monomer mainly composed of methacrylic acid ester in the presence of the obtained elastic copolymer. Here, the hard layer that becomes the innermost layer is preferably formed by polymerizing a monomer comprising 70 to 100 weight% of methacrylic acid ester and 0 to 30 weight% of another vinyl monomer copolymerizable thereto. At this time, it is also effective to use a copolymerizable crosslinkable monomer as one of the other vinyl monomers. As for the methacrylic acid ester, alkyl methacrylate esters, particularly methyl methacrylate, are effective. A rubber-containing polymer with such a three-layer structure is disclosed, for example, in Japanese Patent Publication No. Showa 55-27576.

[0085] In addition, the average particle size of the rubber particles can be determined by observing with an electron microscope. For example, individual rubber particles are mixed with methacrylate resin to form a film, and the rubber component is dyed using ruthenium oxide in the cross-section thereof. After dyeing, the diameter can be determined from the diameter of the outer layer of the dyed particles by observing with an electron microscope. Therefore, the particle size referred to here is the number-average particle size.

[0086] The above acrylic resin may contain conventional additives, such as ultraviolet absorbers, organic dyes, inorganic dyes, pigments, antioxidants, antistatic agents, surfactants, etc. Among these, ultraviolet absorbers are preferably used to provide a film with excellent weather resistance for a longer period of time.

[0087] These ultraviolet absorbers can be used individually or in a mixture of two or more types. The content of the ultraviolet absorber is appropriately set according to the desired thickness of the acrylic resin extruded film, typically 0.1 parts by weight or more, preferably 0.3 parts by weight or more, and typically 5 parts by weight or less, per 100 parts by weight of the acrylic resin. The transmittance at a wavelength of 380 nm of the acrylic resin extruded film having the desired thickness can be selected within a range such that it is preferably 25% or less, more preferably 15% or less, and even more preferably 5% or less. For example, in the case of a film having a thickness of 80 μm, in order to exhibit the same ultraviolet absorption capacity as a triacetylcellulose film used as an acrylic resin film, it is suitable to set the amount of the ultraviolet absorber to about 2.0 parts by weight based on 100 parts by weight of the total of methacrylate resin and rubber particles. It is desirable that these additives, including ultraviolet absorbers, have a melting point of 180°C or higher to prevent them from evaporating as volatile matter when extruding acrylic resin from the die and contaminating rolls, etc.

[0088] (Raw material feeder (2))

[0089] FIG. 2 is a schematic diagram showing a raw material feeder (2). As shown in FIG. 2, the raw material feeder (2) has a first meter (21) and a second meter (22). All meters (21, 22) are connected to an extruder (3) through a transport pipe (25). Raw material for an acrylic resin film is fed into each meter (21, 22) from a raw material chamber not shown. The raw material includes multiple types of materials with different shapes.

[0090] Specifically, acrylic resin (PMMA) pellets are fed into the first meter (21) as raw material, and an additive is fed into the second meter (22) as raw material. The raw material fed into the first meter (21) and the raw material fed into the second meter (22) have different shapes.

[0091] Each meter (21, 22) measures the weight of each raw material and sends the amount of raw material determined by the control device (9) to the extruder (3) through the transport pipe (25). That is, the control device (9) controls the supply amount of raw material by controlling each meter (21, 22) as a control element to control the amount of molten material extruded from the extruder (3).

[0092] In this way, when multiple types of materials with different shapes are fed from the raw material feeder (2) into the extruder (3), pressure fluctuations are usually likely to occur on the discharge side of the extruder (3). However, as described above, since the first gear pump (4) and the second gear pump (6) are provided, pressure fluctuations on the discharge side of the extruder (3) can be effectively reduced. Additionally, the raw material may include multiple types of materials with the same shape. Furthermore, the number of meters may be increased or decreased.

[0093] (Extruder (3))

[0094] FIG. 3 is a schematic diagram showing each component of an acrylic resin film manufacturing apparatus (1), excluding the raw material feeder (2). As shown in FIG. 3, the extruder (3) is a twin-screw extruder. The extruder (3) has a casing (30), a first screw (31) and a second screw (32) disposed within the casing (30), and a motor (35) that rotates the first screw (31) and the second screw (32).

[0095] The casing (30) has an inlet (30a) into which raw materials are fed from the raw material feeder (2). That is, the inlet (30a) is connected to the transport pipe (25) of the raw material feeder (2). Additionally, there may be multiple inlets (30a).

[0096] The first screw (31) and the second screw (32) are arranged parallel to each other and rotate in the same direction as indicated by the arrows. Additionally, the first screw (31) and the second screw (32) may rotate in opposite directions.

[0097] The raw material introduced from the inlet (30a) is mixed by the rotation of the first screw (31) and the second screw (32) and sent downstream. At the same time, the raw material being transported by the first screw (31) and the second screw (32) is melted by a heater not shown provided in the casing (30), and as a result, a molten material is produced.

[0098] The motor (35) is controlled by the control device (9). That is, the control device (9) controls the motor (35) as a control element to control the rotational speed of the first screw (31) and the second screw (32) in order to control the amount of molten material extruded from the extruder (3).

[0099] As such, since the extruder (3) is a twin-screw extruder, pressure fluctuations at the leading edge are more likely to occur compared to a single-screw extruder. However, as described above, since it has a first gear pump (4) and a second gear pump (6), pressure fluctuations at the leading edge of the extruder (3) can be effectively reduced.

[0100] (First gear pump (4))

[0101] As shown in FIG. 3, the first gear pump (4) has a first gear (41), a second gear (42), and a motor (45) that rotates the first gear (41) and the second gear (42). The first gear (41) and the second gear (42) mesh with each other and rotate in opposite directions as indicated by the arrows. Then, the molten material extruded from the extruder (3) is sent downstream by the rotation of the first gear (41) and the second gear (42). At this time, the molten material is pressurized by the first gear pump (4). That is, the value of the second pressure sensor (12) provided between the first gear pump (4) and the choke filter (5) becomes greater than the value of the first pressure sensor (11) provided between the extruder (3) and the first gear pump (4). The pressure increase range of the molten material by the first gear pump (4) is, for example, 5 MPa, and is preferably 3 MPa to 15 MPa.

[0102] Thus, according to the manufacturing apparatus of the present embodiment, since it has a first gear pump (4), even if the pressure of the molten material fluctuates due to fluctuations in the amount of molten material extruded from the extruder (3), the pressure fluctuation of the molten material downstream of the first gear pump (4) can be mitigated by the first gear pump (4), so that the molding of the molten material downstream of the fixed filter (7) can be performed stably.

[0103] (Jo Filter (5))

[0104] As shown in FIG. 3, the filter (5) is a filter with a mesh size of, for example, 20 μm to 80 μm, preferably 20 μm to 40 μm.

[0105] The mesh of the coarse filter (5) is coarser than the mesh of the high-precision filter (7). According to this, the molten material, which is pressurized only by the first gear pump (4), can be passed through the coarse coarse filter (5). In other words, since the first gear pump (4) only needs to pressurize the molten material to the pressure required to pass it through the coarse filter (5), the pressure increase range of the molten material by the first gear pump (4) can be reduced.

[0106] The molten material is depressurized by passing through the trough filter (5). That is, the value of the third pressure sensor (13) provided between the second gear pump (6) and the trough filter (5) becomes smaller than the value of the second pressure sensor (12). The depressurization range of the molten material by the trough filter (5) is, for example, 5 MPa.

[0107] In this way, since a coarse filter (5) is provided between the first gear pump (4) and the second gear pump (6), even if the extrusion amount of the molten material extruded from the extruder (3) fluctuates and the pressure of the molten material fluctuates, the pressure fluctuation of the molten material at each downstream side can be mitigated by the coarse filter (5) in addition to the first gear pump (4) and the second gear pump (6), so that the molding of the molten material at the downstream side of the fixed filter (7) can be performed more stably. As a result, the uniformity of the quality of the acrylic resin film can be maintained more effectively.

[0108] In addition, since a jaw filter (5) is provided between the first gear pump (4) and the second gear pump (6), even if pressure fluctuations generated between the extruder (3) and the first gear pump (4) are propagated to the downstream side, these pressure fluctuations can be mitigated by the jaw filter (5).

[0109] In addition, since a filter (5) is provided upstream of the fixed filter (7), the durability of the fixed filter (7) can be improved.

[0110] (Second gear pump (6))

[0111] As shown in FIG. 3, the second gear pump (6) has a first gear (61), a second gear (62), and a motor (65) that rotates the first gear (61) and the second gear (62). The first gear (61) and the second gear (62) mesh with each other and rotate in opposite directions as indicated by the arrows. Then, the molten material filtered by the sieve filter (5) is discharged to the downstream side by the rotation of the first gear (61) and the second gear (62). At this time, the molten material is pressurized by the second gear pump (6). That is, the value of the fourth pressure sensor (14) provided between the second gear pump (6) and the fixed filter (7) becomes greater than the value of the third pressure sensor (13). The pressure increase range of the molten material by the second gear pump (6) is, for example, 9 MPa, and is preferably 1 MPa to 15 MPa.

[0112] In this way, since the second gear pump (6) is provided, even if the amount of molten material extruded from the extruder (3) fluctuates and the pressure of the molten material fluctuates, the pressure fluctuation of the molten material downstream of the second gear pump (6) can be mitigated by the second gear pump (6), so that the molding of the molten material downstream of the fixed filter (7) can be performed stably.

[0113] In addition, since the molten material is pressurized by the first gear pump (4) and the second gear pump (6), the pressure difference between each gear pump can be reduced. By doing so, backflow of the molten material in each gear pump can be reduced.

[0114] (Fixed filter (7))

[0115] As shown in FIG. 3, the high-precision filter (7) is a polymer filter with a mesh size of, for example, 0.5 μm to 30 μm, preferably 1 μm to 10 μm.

[0116] The mesh of the high-pressure filter (7) is finer than the mesh of the coarse filter (5). Accordingly, the molten material boosted by the first gear pump (4) and the second gear pump (6) can be passed through the high-pressure filter (7) with fine mesh. In other words, it is necessary to boost the molten material to a high pressure to pass it through the high-pressure filter (7), and since the molten material can be boosted by both the first gear pump (4) and the second gear pump (6), the boosting of the molten material can be easily increased.

[0117] The molten material is depressurized by passing through the fixed-pressure filter (7). That is, the discharge pressure value from the fixed-pressure filter (7) becomes smaller than the value of the fourth pressure sensor (14). The discharge pressure value from the fixed-pressure filter (7) is the same as the discharge pressure value from the die (8). The depressurization range of the molten material by the fixed-pressure filter (7) can be selected according to the mesh of the fixed-pressure filter (7), the temperature or flow rate of the molten material, etc., for example, 7 MPa to 12 MPa.

[0118] (Die(8))

[0119] As shown in FIG. 3, the die (8) is, for example, a T die. The molten material filtered by the fixed filter (7) is formed into a sheet shape by the die (8). Then, the sheet-shaped molten material extruded from the discharge port of the die (8) is returned to a molding roll (not shown) located below the discharge port of the die (8), and is cooled and solidified on the molding roll to produce an acrylic resin film.

[0120] (Control device (9))

[0121] As shown in FIGS. 2 and 3, the control device (9) controls the operation of each component. The control device (9) has a first control unit (91), a second control unit (92), and a raw material supply unit (93).

[0122] The first control unit (91) receives a signal from the third pressure sensor (13) and transmits a signal to the motor (45) of the first gear pump (4). Specifically, the first control unit (91) controls the motor (45) of the first gear pump (4) so ​​that the resin pressure detected by the third pressure sensor (13) becomes constant, thereby controlling the rotational speed of the first gear pump (4).

[0123] The second control unit (92) receives a signal from the first pressure sensor (11), transmits a signal to the motor (35) of the extruder (3), and also transmits a signal of supply amount Q to the raw material feeder control unit (93). The raw material feeder control unit (93) transmits a signal of a set value of supply amount Q based on the received signal of supply amount Q to each meter (21, 22) of the raw material feeder (2). That is, the raw material feeder control unit (93) transmits a signal to each meter (21, 22) at an arbitrary ratio that was previously set for the received signal of supply amount Q.

[0124] In this way, the second control unit (92) performs feedback control on the rotational speed N of the first screw (31) and the second screw (32) of the extruder (3) and the amount of raw material supplied to the extruder (3). The control of the rotational speed N is performed by controlling the motor (35) of the extruder (3). The control of the amount of supply Q is performed by controlling each meter (21, 22) of the raw material feeder (2).

[0125] Specifically, the second control unit (92) controls N so that the pressure of the first pressure sensor (11) becomes constant, and also the following (i), (ii), (iii):

[0126] (i) Not controlling Q,

[0127] (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value.

[0128] (iii) Control Q by making the control effect of Q dull so that the pressure of the first pressure sensor (11) becomes constant.

[0129] Execute one of the following.

[0130] Here, the second control unit (92) may be pre-set to any one of (i), (ii), and (iii). Alternatively, the second control unit (92) may be set to select any one of (i), (ii), and (iii).

[0131] In the above (i), the second control unit (92) always turns off the control of Q. That is, the second control unit (92) only controls N.

[0132] In the above (ii), the second control unit (92) controls Q when the range of variation from the reference value of Q / N exceeds the set value, but turns off the control of Q when the range of variation of Q / N is less than or equal to the set value. That is, Q / N does not have to be constant to the reference value. The reference value is a value predetermined for each manufacturing device. The range of variation refers to the absolute value of the difference from the reference value. For example, Q / N is in the range of 4.5 to 7.5, preferably in the range of 5.5 to 7.0, and more preferably in the range of 6.0 to 6.8. In addition, the appropriate range of Q / N varies depending on the size or specifications of the extruder.

[0133] In the above (iii), the second control unit (92) controls Q so that the pressure of the first pressure sensor (11) becomes constant, and at the same time, controls Q so that the effect of controlling Q becomes dull.

[0134] Here, dulling the effect of the control of Q means dulling the effect of the feedback control applied to Q. Specifically, if the feedback control is PID control, "dull control" or "loose control" means that the gain value set for each control item of proportional control (P), derivative control (D), and integral control (I) results in a small influence of the control (response to the control, etc.) such that the variation range of Q / N is within a predetermined range. In (iii) above, a gain value is set for Q such that the influence of the feedback control can be reduced (the control can be dulled). As a result, the response to the control of Q, etc. becomes dull.

[0135] According to this, the second control unit (92) controls N so that the pressure of the first pressure sensor (11) becomes constant, and also does not control Q or controls Q more loosely than the control of N, thereby reducing the influence of the control of Q on the pressure on the discharge side of the extruder (3). Therefore, it becomes easier to stably and constantly control the pressure on the discharge side of the extruder (3), and thus the uniformity of the quality of the acrylic resin film can be maintained.

[0136] Preferably, in (ii) above, the effect of controlling Q is dulled to control Q. According to this, since the control of Q can be loosened, the pressure on the discharge side of the extruder can be controlled more stably.

[0137] Preferably, in (iii) above, when the range of variation from the reference value of Q / N exceeds the set value, Q is controlled such that the range of variation of Q / N becomes less than or equal to the set value. According to this, since the control of Q can be loosened, the pressure on the discharge side of the extruder can be controlled more stably.

[0138] Furthermore, the manufacturing apparatus of the present disclosure is not limited to the aforementioned embodiments and can be modified in design without departing from the gist of the present disclosure. For example, the increase or decrease in the number of gear pumps or the increase or decrease in the number of filters can be modified in design.

[0139] Manufacturing Method

[0140] Next, an embodiment of a method for manufacturing an acrylic resin film will be described using FIGS. 1 to 3.

[0141] First, the raw material for the acrylic resin film is supplied from the raw material feeder (2) to the extruder (3) (hereinafter referred to as the supply process). Then, the raw material supplied from the raw material feeder (2) is melt-mixed inside the extruder (3), and the molten material obtained by the melt-mixing is extruded to the downstream side of the extruder (3) (hereinafter referred to as the extrusion process). Then, the molten material extruded from the extruder (3) is pressurized by the first gear pump (4) connected to the downstream side of the extruder (3) (hereinafter referred to as the pressurization process).

[0142] In the extrusion process, when the rotational speed of the screws (31, 32) is set to N and the amount of raw material supplied to the extruder (3) is set to Q, N is controlled so that the pressure of the molten material between the extruder (3) and the first gear pump (4) becomes constant, and also the following (i), (ii), (iii):

[0143] (i) Not controlling Q,

[0144] (ii) When the range of variation of Q / N from the reference value exceeds the set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value.

[0145] (iii) Controlling Q by dulling the effect of Q control so that the pressure of the molten material between the extruder (3) and the first gear pump (4) becomes constant.

[0146] Execute one of the following.

[0147] According to this, N is controlled so that the pressure of the molten material between the extruder (3) and the first gear pump (4) becomes constant, and Q is not controlled or is controlled more loosely than N, so the influence of Q control on the pressure on the discharge side of the extruder (3) can be reduced. Therefore, it is easy to stably and constantly control the pressure on the discharge side of the extruder (3), thereby maintaining the uniformity of the quality of the acrylic resin film.

[0148] Preferably, in (ii) above, the effect of controlling Q is dulled to control Q. According to this, since the control of Q can be loosened while maintaining the fluctuation range of Q / N below a set value, the pressure on the discharge side of the extruder (3) can be controlled more stably. The fluctuation range of Q / N can be set within the range of, for example, 4.5 to 7.5, preferably 5.5 to 7.0, and more preferably 6.0 to 6.8.

[0149] Preferably, in (iii) above, when the range of variation from the reference value of Q / N exceeds the set value, Q is controlled such that the range of variation of Q / N becomes less than or equal to the set value. According to this, since the control of Q can be loosened while maintaining the range of variation of Q / N less than or equal to the set value, the pressure on the discharge side of the extruder (3) can be controlled more stably.

[0150] In addition, the manufacturing method of the present disclosure is not limited to the embodiments described above, and design changes are possible within the scope of not deviating from the gist of the present disclosure. For example, the manufacturing method of the present disclosure is not limited to being realized by the manufacturing device (1) of FIG. 1, but may be realized by other devices.

[0151] (Example)

[0152] Next, examples will be described.

[0153] [Example 1]

[0154] (1) Production of raw resin

[0155] As the methacrylate resin, pellets of a thermoplastic polymer (glass transition temperature 104°C) copolymerizing 97 wt% methyl methacrylate and 3 wt% methyl acrylate were used. As the acrylic rubber particles, a spherical three-layer structure was used, prepared in the same manner as Example 3 of Japanese Patent Publication No. Showa 55-27576, comprising: an innermost layer of a hard polymer copolymerizing a small amount of allyl methacrylate with methyl methacrylate; an intermediate layer of an elastomer copolymerizing butyl acrylate with styrene and a small amount of allyl methacrylate; and an outermost layer of a hard polymer copolymerizing a small amount of methyl methacrylate with methyl methacrylate, with an average particle size of 0.22 μm.

[0156] 70 parts of methacrylate resin pellets and 30 parts of acrylic rubber particles were mixed using a super mixer. Subsequently, the mixture was melt-kneaded using a twin-screw extruder to form pellets of the resin composition, which were then used as an acrylic resin.

[0157] (2) Production of acrylic resin film

[0158] The obtained pellet was melted by a separate twin-screw extruder (extrusion temperature 230°C to 270°C), passed through a first gear pump, a jaw filter, a second gear pump, and a high-precision filter in that order, extruded from a die, passed through a molding roll (surface temperature 60°C to 100°C), and the discharge volume and line speed were appropriately adjusted so that the thickness became 80 μm to obtain an acrylic resin film (width 1300 mm to 2000 mm). In addition, the pellet was pressurized in the first gear pump and the second gear pump under the following conditions.

[0159] In the preparation of the acrylic resin film in Example 1, control of Q and N (QN control) in the extruder was not performed, that is, control of the raw material supply amount Q shown in (i) above was not performed.

[0160] [Comparative Example 1]

[0161] An acrylic resin film was prepared in the same manner as in Example 1, except that feedback control was performed on the raw material supply amount Q so that Q / N=6.5 was constant according to the screw rotation speed N.

[0162] Next, Table 1 shows the measured values ​​of the first pressure sensor in Example 1 and Comparative Example 1.

[0163] condition Measurement of 1st pressure sensor [MPa] (30-minute total) average standard deviation maximum minimum value Comparative Example 1 6.0 0.8 8.2 3.1 Example 1 5.9 0.4 6.9 4.3

[0164] As shown in Table 1, compared to Comparative Example 1, Example 1 has a smaller range between the maximum and minimum values ​​and a smaller standard deviation. Thus, it was found that the measurement value of the first pressure sensor in Example 1 is stably constant compared to Comparative Example 1. Therefore, in Example 1, since the pressure on the discharge side of the extruder can be stably and constantly controlled, the uniformity of the quality of the acrylic resin film can be maintained. Explanation of the symbols

[0165] 1: Manufacturing apparatus for acrylic resin film 2: Raw Material Feeder 21, 22: 1st and 2nd meters 3: Extruder 31, 32: 1st and 2nd screws 35: Motor 4: First gear pump 41, 42: 1st and 2nd gears 45: Motor 5: Jo Filter 6: Second gear pump 61, 62: 1st and 2nd gears 65: Motor 7: High-precision filter 8: Die 9: Control unit 91, 92: 1st and 2nd control units 93: Raw Material Feeder Control Unit 11∼14: 1st∼4th pressure sensors

Claims

Claim 1 The apparatus comprises a supply process for supplying raw materials for an acrylic resin film from a raw material feeder to an extruder, an extrusion process for melting and kneading the raw materials supplied from the raw material feeder within the extruder and extruding the molten material obtained by the melting and kneading to the downstream side of the extruder, and a pressure boosting process for boosting the molten material extruded from the extruder by means of a gear pump connected to the downstream side of the extruder, wherein the extruder has a screw and a motor that rotates and drives the screw, and in the extrusion process, when the rotational speed of the screw is N and the amount of raw material supplied to the extruder is Q, N is controlled so that the pressure of the molten material between the extruder and the gear pump becomes constant, and furthermore, the following (i), (ii), (iii): (i) not controlling Q, (ii) when the range of variation from the reference value of Q / N exceeds a set value, Q is controlled so that the range of variation of Q / N becomes less than or equal to the set value, while Q is not controlled when the range of variation of Q / N is less than or equal to the set value, (iii) the pressure of the molten material between the extruder and the gear pump A method for manufacturing an acrylic resin film, wherein one of the methods for controlling Q is performed by dulling the effect of controlling Q so as to make it constant, and the raw material comprises multiple types of materials having different shapes. Claim 2 A method for manufacturing an acrylic resin film according to claim 1, wherein in (ii) above, the effect of controlling Q is also dulled to control Q. Claim 3 A method for manufacturing an acrylic resin film according to claim 1 or 2, wherein in (iii) above, Q is controlled such that when the range of variation from the reference value of Q / N exceeds the set value, the range of variation of Q / N becomes less than or equal to the set value. Claim 4 A method for manufacturing an acrylic resin film, wherein, in claim 1 or 2, the extruder is a twin-screw extruder. Claim 5 A method for manufacturing an acrylic resin film according to claim 1 or 2, wherein the gear pump comprises a first gear pump and a second gear pump, a jaw filter is connected between the first gear pump and the second gear pump, and the jaw filter filters a molten material discharged from the first gear pump. Claim 6 A raw material feeder comprising a raw material for an acrylic resin film; an extruder having a screw and a motor that rotates and drives the screw, which melts and kneads the raw material supplied from the raw material feeder and extrudes it as a molten material; a gear pump connected to the downstream side of the extruder and which increases the pressure of the molten material extruded from the extruder and discharges it; and a control device that controls N such that the pressure of the molten material between the extruder and the gear pump becomes constant when the rotational speed of the screw is N and the amount of raw material supplied to the extruder is Q, and also performs any one of the following (i), (ii), and (iii): (i) not controlling Q; (ii) when the range of variation from the reference value of Q / N exceeds a set value, the range of variation of Q / N becomes less than or equal to a set value, while not controlling Q when the range of variation of Q / N is less than or equal to a set value; (iii) when the pressure of the molten material between the extruder and the gear pump becomes constant, the control device that controls Q by dulling the effect of controlling Q, and the raw material having a plurality of different shapes An apparatus for manufacturing acrylic resin film containing a type of material. Claim 7 In claim 6, an apparatus for manufacturing an acrylic resin film that controls Q by dulling the effect of controlling Q in (ii) above. Claim 8 An apparatus for manufacturing an acrylic resin film according to claim 6 or 7, wherein in (iii) above, when the range of variation from the reference value of Q / N exceeds the set value, the range of variation of Q / N becomes less than or equal to the set value. Claim 9 An apparatus for manufacturing an acrylic resin film, wherein, in claim 6 or 7, the extruder is a twin-screw extruder. Claim 10 An apparatus for manufacturing an acrylic resin film according to claim 6 or 7, wherein the gear pump comprises a first gear pump and a second gear pump, and a jaw filter is connected between the first gear pump and the second gear pump, and the jaw filter filters a molten material discharged from the first gear pump.

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