JP2007112900A - Resin composition for microlens and molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which is used for microlenses and is excellent in optical characteristics such as transparency and light resistance and molding properties such as transferability and peelability, to provide a molded article which is obtained by molding the composition and is used for microlenses, and to provide an optical equipment using the molded article. <P>SOLUTION: This resin composition for microlenses comprises 2 to 44.9 pts.mass of a rubber-containing polymer, 98 to 55.1 pts.mass of a thermoplastic polymer (herein the total amount of the rubber-containing polymer and the thermoplastic polymer is 100 pts.mass), and 0.2 to 2 pts.mass of a glyceryl fatty acid ester. The resin composition for the microlenses is used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin composition for microlenses, a resin molded body for microlenses obtained by molding the resin composition, and an optical apparatus using the molded body. In particular, the present invention relates to a resin composition for microlenses having excellent transparency, light resistance, moldability such as transferability and peelability, and a resin molded article for microlens obtained by molding the resin composition and the molded article thereof. The present invention relates to an optical apparatus using the.

  Research and development of optical devices that combine light sources and optical components, for example, image projection devices that combine light sources and microlens arrays, are progressing rapidly. Among them, portable information terminals (mobile computers, mobile phones, portable games) In the case of a machine or an electronic book), it is desired to reduce the weight and thickness. However, it is difficult to reduce the weight of the microlens array incorporated in these image projection devices because a material such as glass is used. In addition, for example, clamshell mobile phones that use two backlights and two liquid crystal displays in the display section are required to be thinner, lighter, and lower in cost. There is a strong demand from the industry to reduce the thickness.

  On the other hand, acrylic resins are widely used taking advantage of their excellent transparency, light resistance, and processability. Especially, those made into films are laminated on the surface of various resin molded products, woodwork products, and metal molded products. Has been used. Specific examples of the application include skin materials for vehicle interiors, furniture, door materials, window frames, baseboards, bathroom interiors, and other building materials, marking films, high-intensity reflector coating films, and the like. An acrylic resin film for protecting such a substrate has been used as an outer skin of a molded product or the like.

  Various acrylic resins have been proposed so far, and acrylic resin compositions excellent in transparency, releasability, weather resistance and impact resistance have been proposed (Patent Documents 1 and 2). reference). In addition, an acrylic resin composition for an edge-light type light guide plate that has no appearance defects such as cracks even when injection-molded at a relatively low temperature has been proposed (see Patent Document 3).

  However, when these acrylic resin compositions are used as materials for microlenses, they are excellent in transparency and weather resistance, but sufficient cooling time is taken in order to improve releasability when molding into microlenses. There was a problem that it was inferior in productivity.

  A resin film for forming a microlens array has been proposed in a patent publication relating to a microlens array and a method for manufacturing the same (see Patent Document 4). However, this patent publication does not specifically refer to the resin film, and when molding them to obtain microlenses, in the same manner as described above, in order to improve the releasability when molding into microlenses. However, there is a problem that the cooling time has to be taken sufficiently and the productivity is inferior.

JP-A-6-57081 JP-A-6-57082 Japanese Patent No. 3499322 JP 2002-122706 A

  The present invention provides a resin composition for a microlens that solves the above-mentioned problems of the prior art, and has excellent optical characteristics such as transparency and light resistance, and excellent moldability such as transferability and peelability. An object of the present invention is to provide a microlens molded body obtained by molding this composition and an optical apparatus using the molded body.

  In order to solve the above-mentioned problems, the present inventors have intensively studied a resin composition used for a lens portion of a microlens array, and have excellent transparency, light resistance, transferability and releasability. The object was found and the present invention was reached.

  That is, the present invention provides a microlens resin composition, a microlens molded body obtained by molding the composition, and an optical apparatus using the molded body. Have.

  (1) 2-44.9 parts by mass of a rubber-containing polymer, 98-55.1 parts by mass of a thermoplastic polymer (the total of the rubber-containing polymer and the thermoplastic polymer is 100 parts by mass), and glycerin The resin composition for microlenses containing 0.2-2 mass parts of fatty acid ester.

(2) The resin for microlenses according to (1) above, wherein the rubber-containing polymer is the following rubber-containing polymer (A) and / or rubber-containing multistage polymer (I) and / or rubber-containing multistage polymer (II). Composition.
<Rubber-containing polymer (A)>
An alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms in the presence of an elastic polymer obtained by polymerizing a monomer (i) having an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms as a main component. A polymer composed of an elastic polymer and a hard polymer obtained by graft polymerization of a monomer (ii) having a main component as a main component <Rubber-containing multistage polymer (I)>
A first elastic polymer (IA) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as constituents of the polymer. A second elastic polymer (IB) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and a graft crossing agent as a constituent of the polymer, an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and And / or an intermediate polymer (ID) comprising at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as a constituent component of the polymer, and at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms Rigid polymer (IC) as a polymer component is polymerized in this order The polymer <rubber-containing multistage polymer (II)>
(1) An elastic polymer (II-A) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and a graft crossing agent as a constituent component of the polymer, (2) a glass transition temperature of 25 to 100 ° C. An elastic polymer (II-A) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as constituents of the polymer Intermediate polymer (II-B) having a composition different from that of (1) and (3) a hard polymer (II-C) comprising at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms as a constituent component of the polymer in this order. Polymerized polymer

  (3) A resin molded product for microlens obtained by molding the resin composition for microlens of (1) or (2) above.

  (4) The resin molded product for microlenses according to (3), which is in the form of a film.

  (5) The resin molded product for microlenses according to (4), wherein the haze value is 3% or less when measured according to JIS K 7136.

  (6) The resin molded product for microlenses according to (4) or (5), wherein the thickness is 20 to 200 μm or less.

  (7) A microlens array in which the microlens resin molded body according to any one of (3) to (6) is laminated on a substrate portion made of glass or a translucent resin.

  (8) An image projection apparatus using the microlens array of (7) above.

  According to the present invention, it is possible to provide a resin composition for a microlens excellent in optical properties such as transparency and light resistance, and moldability such as transferability and peelability, and obtained by molding this composition. It is possible to provide a molded article for microlenses excellent in transparency and light resistance, and an optical device excellent in optical properties obtained by using this molded article.

  The configuration of the present invention will be specifically described below, but this is mainly for explaining preferred embodiments of the present invention, and the present invention is not limited only to these embodiments. It should be understood that various modifications are possible within the spirit and spirit of the present invention.

<Resin composition>
The ratio of the rubber-containing polymer and the thermoplastic polymer in the resin composition for a microlens of the present invention is such that the rubber-containing polymer is 2-44.9 parts by mass and the thermoplastic polymer is 98-55.1 parts by mass ( Here, the sum of the rubber-containing polymer and the thermoplastic polymer must be 100 parts by mass). When the rubber-containing polymer is less than 2 parts by mass in 100 parts by mass of the resin composition, the impact resistance is inferior, and when it exceeds 44.9 parts by mass, the resin composition for microlenses is formed into a microlens by press molding or the like. The cooling time at the time of molding becomes long and the productivity is inferior. A desirable ratio of these components is 5 to 30 parts by mass for the rubber-containing polymer and 95 to 70 parts by mass for the thermoplastic polymer.

  Moreover, in the composition of this invention, the addition amount of glycerol fatty acid ester must be 0.2-2 mass parts with respect to 100 mass parts in total of a rubber containing polymer and a thermoplastic polymer. When the addition amount of glycerin fatty acid ester is less than 0.2 parts by mass, the effect of improving the releasability when molding the composition is insufficient, and the microlens resin composition is formed into a microlens shape by press molding or the like. As a result, the cooling time for molding into a long time results in poor productivity. On the other hand, when the addition amount of glycerin fatty acid ester exceeds 2 parts by mass, the heat resistance of the composition is lowered, and the moldability becomes poor because the effect of improving the releasability when molding the composition becomes insufficient. In addition, a part of the metal deposits on the metal surface or the like during processing to cause a surface defect when the microlens is molded.

<Rubber-containing polymer>
The rubber-containing polymer contained in the resin composition for microlenses of the present invention is mainly composed of acrylic (meth) acrylate. For example, the rubber-containing polymer (A) described below or a rubber-containing multistage Examples thereof include polymer (I) and rubber-containing multistage polymer (II). Since the resin composition for microlenses containing these rubber-containing polymers has good light resistance and transparency, it can be suitably used for microlenses.

<Rubber-containing polymer (A)>
The rubber-containing polymer (A) preferably used in the resin composition for a microlens of the present invention is obtained by polymerizing a monomer (i) whose main component is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms. In the presence of the obtained elastic polymer, an elastic polymer and a hard polymer formed by graft polymerization of a monomer (ii) mainly composed of an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms to form a hard polymer A polymer composed of a polymer. Here, when polymerizing each monomer (i) and (ii), the elastic polymer and the hard polymer can be polymerized at once or can be polymerized in two or more stages. .

  Examples of the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, which is the main component of the monomer (i), include conventionally known alkyl acrylates having various alkyl groups having 1 to 8 carbon atoms. In particular, butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable.

  35-99.9 mass% is preferable in the total monomer (i) (100 mass%), and, as for the usage-amount of the alkyl acrylate which has a C1-C8 alkyl group, 50-99.9 mass% is more preferable. . When the amount of the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms is 35% by mass or more, the moldability tends to be good.

  Even when the monomer (i) is polymerized in two or more stages when the elastic polymer is obtained, the amount of the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms is used in the monomer (i). What is necessary is just 35 mass% or more. For example, in the case of an elastic polymer polymerized in two or more stages, if the total amount of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms in each polymerization stage is 35% by mass or more, the first stage The usage-amount of the alkyl acrylate which has a C1-C8 alkyl group can also be set arbitrarily.

  As the monomer (i), in addition to the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, other vinyl monomers copolymerizable therewith can also be used. When other vinyl monomers are used, the amount used is preferably 64.9% by mass or less in the total monomer (i) (100% by mass). As other vinyl monomers, for example, alkyl methacrylates such as methyl methacrylate, butyl methacrylate and cyclohexyl methacrylate, styrene, acrylonitrile and the like are preferable. These can be used alone or in combination of two or more.

  It is preferable to use a crosslinkable monomer as a part of the monomer (i). Examples of the crosslinkable monomer include ethylene glycol dimethacrylate, butanediol dimethacrylate, allyl acrylate, allyl methacrylate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, diallyl maleate, Examples include trimethylolpropane triacrylate and allyl cinnamate. These can be used alone or in combination of two or more. As for the usage-amount of a crosslinkable monomer, 0.1-10 mass% is preferable in all the monomers (i) (100 mass%).

  Examples of the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, which is the main component of the monomer (ii) used in the graft polymerization, include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and the like. Is mentioned. As for the usage-amount of the alkylmethacrylate which has a C1-C4 alkyl group, 50 mass% or more is preferable in all the monomers (ii) (100 mass%).

  As the monomer (ii), in addition to the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, other vinyl monomers copolymerizable therewith can also be used. When other vinyl monomers are used, the amount used is preferably 50% by mass or less in the total monomer (ii) (100% by mass). As other vinyl monomers, for example, alkyl acrylates such as methyl acrylate, butyl acrylate and cyclohexyl acrylate, styrene, acrylonitrile and the like are preferable. These can be used alone or in combination of two or more.

  When the rubber-containing polymer (A) is polymerized, the amount of the monomer (ii) mainly composed of an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms is an alkyl having an alkyl group having 1 to 8 carbon atoms. Preferably it is 10-400 mass parts with respect to 100 mass parts of monomers (i) which have an acrylate as a main component, More preferably, it is 20-200 mass parts.

  The average particle size of the rubber-containing polymer (A) is preferably from 0.01 to 0.5 μm, more preferably from 0.08 to 0.3 μm. In particular, from the viewpoint of moldability and transparency, the average particle size of the rubber-containing polymer (A) is preferably 0.08 μm or more.

  As a production method of the rubber-containing polymer (A), that is, a polymerization method for forming an elastic polymer and a polymerization method for forming a hard polymer, for example, a conventionally known emulsion polymerization method is used. be able to. The optimum value of the polymerization temperature varies depending on the type and amount of the polymerization initiator used, and is usually preferably 40 ° C or higher, more preferably 60 ° C or higher, preferably 95 ° C or lower, more preferably 120 ° C or lower.

  Various conventionally known initiators can be used as the polymerization initiator. The polymerization initiator may be added to one or both of the aqueous phase and the monomer phase.

  Examples of the emulsifier used for emulsion polymerization include anionic, cationic and nonionic surfactants, and anionic surfactants are particularly preferable. Anionic surfactants include, for example, carboxylate surfactants such as potassium oleate, sodium stearate, sodium myristate, sodium N-lauroyl sarcosinate, dipotassium alkenyl succinate; sulfuric acid such as sodium lauryl sulfate Ester salt surfactants; sulfonate surfactants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate; phosphate ester-based interfaces such as sodium polyoxyethylene alkylphenyl ether phosphate Examples include activators.

  The polymer latex obtained by emulsion polymerization is, for example, filtered through a filter having an opening of 100 μm or less, and then recovered by a known method such as an acid precipitation coagulation method, a salting out coagulation method, a freeze drying method, or a spray drying method. The In the acid precipitation solidification method, an inorganic acid such as sulfuric acid, hydrochloric acid or phosphoric acid, or an organic acid such as acetic acid can be used. In the salting out coagulation method, inorganic salts such as sodium sulfate, magnesium sulfate, aluminum sulfate and calcium chloride, and organic salts such as calcium acetate and magnesium acetate can be used. The rubber-containing polymer (A) is obtained by further washing, dehydrating and drying the coagulated polymer.

<Rubber-containing multistage polymer (I)>
The rubber-containing multi-stage polymer (I) preferably used in the resin composition for microlenses of the present invention is a rubber-containing multi-stage polymer having a known constituent of alkyl acrylate, alkyl methacrylate and a graft crossing agent as constituents of the polymer. It is a polymer.

  More specific examples of the more preferable rubber-containing multistage polymer (I) include an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent. A first elastic polymer (IA) as a constituent component of the coal, a second elastic polymer (I-A) having at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and a graft crossing agent as constituent components of the polymer B), an intermediate polymer (ID) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as a constituent component of the polymer. ), At least polymerized alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms Rigid polymer comprising as a constituent of (I-C) can be mentioned those which are polymerized in this order.

  The first elastic polymer (IA) constituting the preferred rubber-containing multistage polymer (I) is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms ( I-A1), another monomer having a copolymerizable double bond (I-A2) used as necessary, and a polyfunctional monomer (I-A3) used as needed, A polymer comprising a graft crossing agent (I-A4) as a constituent component, which is first polymerized when the rubber-containing multistage polymer (I) is polymerized.

  Among the components (I-A1) constituting the first elastic polymer (IA), the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms may be either linear or branched. . Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Among them, those having a low glass transition temperature (hereinafter referred to as Tg) are more preferable. In addition, among the components (I-A1), the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms may be either linear or branched. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like. These can be used alone or in admixture of two or more.

  The alkyl (meth) acrylate (I-A1) is preferably used within a range of 80 to 100 parts by mass with respect to 100 parts by mass of the total amount of the components (I-A1) to (I-A3). In addition, the alkyl (meth) acrylate of the type used in the first elastic polymer (IA) is unified when the polymers (IA) to (ID) are subsequently polymerized. Most preferably, it is used. However, in each polymer of (IA)-(ID), 2 or more types of alkyl (meth) acrylates may be mixed, or another type of acrylate may be used. “(Meth) acrylate” means acrylate and / or methacrylate.

  The other monomer (IA2) having a copolymerizable double bond constituting the first elastic polymer (IA) may be used as necessary. Specific examples thereof include acrylate monomers such as higher alkyl acrylate, lower alkoxy acrylate and cyanoethyl acrylate having an alkyl group having 9 or more carbon atoms, acrylamide, acrylic acid, methacrylic acid, styrene, alkyl-substituted styrene, acrylonitrile, methacrylo A nitrile etc. are mentioned. The monomer (I-A2) is preferably used in the range of 0 to 20 parts by mass with respect to 100 parts by mass in total of the components (I-A1) to (I-A3).

  What is necessary is just to use the polyfunctional monomer (I-A3) which comprises a 1st elastic polymer (IA) as needed. As specific examples thereof, alkylene glycol dimethacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate are preferably used. Further, polyvinyl benzene such as divinyl benzene and trivinyl benzene can also be used. Further, even when the polyfunctional monomer (I-A3) does not act at all, a rubber-containing multistage polymer is obtained which is considerably stable as long as the graft crossing agent is present. For example, when the hot strength or the like is strictly required, it may be arbitrarily used depending on the purpose of addition. The polyfunctional monomer (I-A3) is preferably used within a range of 0 to 10 parts by mass with respect to 100 parts by mass in total of the components (I-A1) to (I-A3).

  Examples of the graft crossing agent (I-A4) constituting the first elastic polymer (IA) include allyl, methallyl or crotyl ester of copolymerizable α, β-unsaturated carboxylic acid or dicarboxylic acid. Can be mentioned. Particularly preferred are acrylic esters of acrylic acid, methacrylic acid, maleic acid or fumaric acid. Among them, allyl methacrylate has an excellent effect. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. Graft-crossing agent (I-A4) reacts much faster than the allyl group, methallyl group or crotyl group, and chemically bonds mainly with the conjugated unsaturated bond of the ester.

  The amount of the graft crossing agent (I-A4) used is extremely important, and is preferably 0.1 to 5 parts by mass with respect to a total of 100 parts by mass of the components (I-A1) to (I-A3). 5-2 mass parts is more preferable. The lower limit of these ranges is significant in terms of the effective amount of graft bonds. The upper limit value moderately suppresses the amount of reaction with the second elastic polymer (B) that is polymerized in the second stage, and prevents the elastic degradation of the two-stage crosslinked rubber elastic body having a two-stage elastic structure. There is significance in doing.

  The content of the first elastic polymer (IA) in the preferred rubber-containing multistage polymer (I) is preferably 5 to 35% by mass, and more preferably 5 to 15% by mass. Further, it is preferably less than the content of the second elastic polymer (IB).

  The second elastic polymer (IB) constituting the preferred rubber-containing multistage polymer (I) is a main component that imparts rubber elasticity to the rubber-containing multistage polymer (I), and is an alkyl having 1 to 8 carbon atoms. An alkyl acrylate having a group (I-B1), another monomer having a copolymerizable double bond (I-B2) used if necessary, and a polyfunctional monomer used if necessary ( It is a second elastic polymer (IB) comprising I-B3) and a graft crossing agent (I-B4) as constituent components.

  Preferred specific examples of the components (I-B1) to (I-B4) are the same as those described for the components (I-A1) to (I-A4) of the first elastic polymer (IA). . The amount of component (I-B1) used is preferably 80 to 100 parts by mass. The amount of component (I-B2) used is preferably 0 to 20 parts by mass. The amount of component (I-B3) used is preferably 0 to 10 parts by mass. As for the usage-amount of a component (I-B4), 0.1-5 mass parts is preferable. The range of these amounts used is based on a total of 100 parts by mass of components (I-B1) to (I-B3).

  The Tg of the second elastic polymer (IB) alone is preferably 0 ° C. or lower, and more preferably −30 ° C. or lower. When this Tg is 0 ° C. or lower, there is a tendency to exhibit excellent elasticity. The content of the second elastic polymer (IB) in the rubber-containing multistage polymer (I) is preferably 10 to 45% by mass and more than the content of the first elastic polymer (IA). Is preferred.

  The hard polymer (I-C) constituting the preferred rubber-containing multistage polymer (I) is a moldability and machine when the rubber-containing multistage polymer (I) is used as the rubber-containing polymer of the resin composition for microlenses. And other monomers (I-C1) having an alkyl group having 1 to 4 carbon atoms and other monomer having a copolymerizable double bond used as necessary (I) -C2) as a constituent component, which is polymerized at the end of the rubber-containing multistage polymer (I).

  Preferred specific examples of the components (I-C1) and (I-C2) are the same as those described for the components (I-A1) and (I-A2) of the first elastic polymer (IA). . As for the usage-amount of a component (I-C1), 51-100 mass parts is preferable. The amount of component (I-C2) used is preferably 0 to 49 parts by mass. The range of these amounts used is based on a total of 100 parts by mass of components (I-C1) and (I-C2).

  The Tg of the hard polymer (IC) alone is preferably 60 ° C. or higher, and more preferably 80 ° C. or higher. 10-80 mass% is preferable and, as for content of the hard polymer (IC) in a preferable rubber-containing multistage polymer, 40-60 mass% is more preferable.

  A preferred rubber-containing multistage polymer (I) is a basic structure composed of the first elastic layer polymer (IA), the second elastic polymer (IB) and the hard polymer (IC) described above. Have as. Further, before the second elastic polymer (IB) is polymerized and the hard polymer (IC) is polymerized, the intermediate polymer (ID) is polymerized.

  The intermediate polymer (ID) includes an alkyl acrylate (ID 1) having an alkyl group having 1 to 8 carbon atoms, an alkyl methacrylate (ID 2) having an alkyl group having 1 to 4 carbon atoms, and necessary. Other monomers (I-D3) having a copolymerizable double bond used depending on the case, polyfunctional monomers (I-D4) used if necessary, and graft-crossing agent (I-D5) ) As a constituent component of the polymer, and the amount of the alkyl acrylate component monotonously decreases from the second elastic polymer (IB) toward the hard polymer (IC).

  Here, monotonically decreasing means that the intermediate polymer (ID) has a composition at one point between the second elastic polymer (IB) and the hard polymer (IC), and the second elasticity. It means that the composition gradually (continuously) approaches the polymer (IB) to the hard polymer (IC), and that the composition approaches step by step, and in particular has one intermediate composition. It is preferable because when the resin composition is used as a rubber-containing polymer of the resin composition for microlenses and is molded, the transparency becomes good.

  Preferred specific examples of the components (I-D1) to (I-D5) are the same as those described for the components (I-A1) to (I-A4) of the first elastic polymer (IA). . In particular, the graft crossing agent (I-D5) used for the intermediate polymer (ID) is a component necessary for tightly bonding the respective polymers and obtaining excellent properties.

  The amount of component (I-D1) used is preferably 10 to 90 parts by mass. As for the usage-amount of a component (I-D2), 10-90 mass parts is preferable. The amount of component (I-D3) used is preferably 0 to 20 parts by mass. The amount of component (I-D4) used is preferably 0 to 10 parts by mass. The amount of component (I-D5) used is preferably 0.1 to 5 parts by mass. The range of these amounts used is based on a total of 100 parts by mass of the components (I-D1) to (I-D4).

  The content of the intermediate polymer (ID) in the preferred rubber-containing multistage polymer (I) is preferably 5 to 35% by mass. If the content is 5% by mass or more, it functions well as an intermediate polymer, and if it is 35% by mass or less, the balance of the final polymer is good.

  The average particle size of the rubber-containing multistage polymer (I) produced by the emulsion polymerization method of the present invention is 0.08 to 0.2 μm in consideration of the mechanical properties and transparency of a molded product containing this as a main component. A range is preferred.

  Further, when the rubber-containing multistage polymer (I) is dispersed in acetone, the number of particles having a diameter of 55 μm or more present in the dispersion is 0 to 50 per 100 g of the rubber-containing multistage polymer. When the multistage polymer (I) is molded into a molded body such as a film, the appearance tends to be good. When the rubber-containing multistage polymer is dispersed in acetone, the number of particles having a diameter of 55 μm or more present in the dispersion is 0-50 per 100 g of the rubber-containing multistage polymer (I) The method for obtaining the polymer by emulsion polymerization is not particularly limited. For example, when the above-mentioned preferable rubber-containing multistage polymer (I) is produced by emulsion polymerization, the first elastic polymer (IA) is particularly preferred. ) Mixing a monomer mixture containing at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent with water and a surfactant The emulsion prepared in this manner was fed to the reactor and polymerized, and then the second elastic polymer (IB), intermediate polymer (ID) and hard polymer (IC) were given. That monomeric or monomer mixture was fed to each reactor in the order, a method of polymerization is preferred.

  When an emulsion prepared by mixing the monomer mixture giving the first elastic polymer (IA) with water and a surfactant is supplied to the reactor and polymerized, particularly when dispersed in acetone. In addition, the rubber-containing multistage polymer (I) in which the number of particles having a diameter of 55 μm or more present in the dispersion is 0 to 50 per 100 g of the rubber-containing multistage polymer can be easily obtained.

  The mass ratio of the monomer mixture and water used in this case is preferably 10 to 500 parts of water with respect to 100 parts of the monomer mixture, more preferably 100 to 300 parts of water with respect to 100 parts of the monomer mixture. Part range.

  As the surfactant used in preparing the emulsion, an anionic, cationic, and nonionic surfactant can be used, and an anionic surfactant is particularly preferable. Examples of anionic surfactants include rosin acid soap, potassium oleate, sodium stearate, sodium myristate, sodium N-lauroylsarcosate, alkenyl succinate dipotassium salt, sulfate ester such as sodium lauryl sulfate, etc. Examples thereof include salts, sulfonic acid salts such as sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate, and phosphoric acid ester salts such as sodium polyoxyethylene alkylphenyl ether phosphate.

  In addition, as a method for preparing an emulsion, a method of charging a surfactant after charging a monomer mixture in water, a method of charging a monomer mixture after charging a surfactant into water, a monomer Examples thereof include a method in which water is added after charging a surfactant into the mixture. Among them, the method of charging the surfactant after charging the monomer mixture into water and the method of charging the monomer mixture after charging the surfactant into water include the rubber-containing multistage polymer (I). It is preferable as a method of obtaining.

  Moreover, as a mixing device for preparing an emulsion obtained by mixing a monomer mixture that gives the first elastic polymer (IA) with water and a surfactant, a stirrer, a homogenizer, and a homomixer equipped with a stirring blade And various forced emulsifiers, membrane emulsifiers and the like.

  In addition, the emulsion to be prepared may have either a W / O type or an O / W type dispersion structure, but particularly an O / W type in which oil droplets of a monomer mixture are dispersed in water. The diameter of the oil droplets in the dispersed phase is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 15 μm or less. When the diameter of the oil droplets in the dispersed phase exceeds 100 μm, the number of particles having a diameter of 55 μm or more present in the dispersion increases when the resulting rubber-containing multistage polymer (I) is dispersed in acetone. There is a tendency.

  On the other hand, the first elastic polymer (IA), the second elastic polymer (IB), the intermediate polymer (ID) and the hard polymer (I) constituting the preferred rubber-containing multistage polymer (I). As the polymerization initiator used when forming -C), known ones can be used, and as the addition method, a method of adding to one or both of the aqueous phase and the monomer phase can be used. Examples of particularly preferred initiators include peroxides, azo initiators, or redox initiators in which an oxidizing agent and a reducing agent are combined. Among them, a redox initiator is more preferable, and a sulfoxylate-based initiator in which ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, Rongalite and hydroperoxide are combined is particularly preferable.

  In particular, an emulsion prepared by mixing the monomer mixture giving the first elastic polymer (IA) with water and a surfactant is supplied to the reactor for polymerization, and then the second elastic polymer. In the method in which a monomer or a monomer mixture that gives (IB), an intermediate polymer (ID), and a hard polymer (IC) are sequentially fed to a reactor and polymerized, After heating the aqueous solution containing monoiron, ethylenediaminetetraacetic acid disodium salt and Rongalite to the polymerization temperature, the prepared emulsion is supplied to the reactor for polymerization, and then a second containing a polymerization initiator such as peroxide. A method in which a monomer mixture that gives an elastic polymer (IB), an intermediate polymer (ID), and a hard polymer (IC) is sequentially fed to a reactor and polymerized is preferable. Most preferred as a method for obtaining the union (I).

  In addition, although superposition | polymerization temperature changes with kinds and quantity of the polymerization initiator to be used, Preferably it is 40-120 degreeC, More preferably, it is 60-95 degreeC.

  The polymer latex containing the preferable rubber-containing multistage polymer (I) obtained by the above-described method can be treated using a filtration apparatus provided with a filter medium as necessary. This filtration treatment is for removing scales generated during the polymerization from the latex or for removing impurities mixed in from the polymerization raw material or from the outside during the polymerization. In order to obtain a rubber-containing multistage polymer (I) This is a preferable method.

  In addition, as a filtering device in which the filter medium used at that time is arranged, a GAF filter system of ISP Filters PTE Ltd. using a bag-shaped mesh filter or a cylindrical filter medium on the inner surface of a cylindrical filter chamber is used. A preferred example is a centrifugal separation apparatus having a stirring blade disposed in the filter medium.

  A preferable rubber-containing multistage polymer (I) can be produced by recovering the rubber-containing multistage polymer (I) from the polymer latex produced by the above-described method. The method for recovering the rubber-containing multistage polymer (I) from the polymer latex is not particularly limited, and examples thereof include salting out or acid precipitation coagulation, spray drying, freeze drying, and the like, which are recovered in powder form. .

  In the powdery rubber-containing multistage polymer (I) obtained by the above method, particles having a diameter of 55 μm or more present in the dispersion when dispersed in acetone are present per 100 g of the rubber-containing multistage polymer. A range of 0 to 50 is preferable.

<Rubber-containing multistage polymer (II)>
The rubber-containing multistage polymer (II) used as a preferred rubber-containing polymer of the resin composition for microlenses of the present invention is obtained by polymerizing the monomer components shown in Table 1 below: (1) Elastic polymer ( II-A), (2) an intermediate polymer (II-B) having a glass transition temperature of 25 to 100 ° C. and a composition different from that of the elastic polymer (II-A), and (3) a rigid polymer (II -C) is polymerized in this order. Here, “different composition” means that the kind and / or amount of at least one component of the monomer component which is a raw material of each polymer is different.

  The alkyl acrylate (II-A1) having an alkyl group having 1 to 8 carbon atoms may be either a linear or branched alkyl group. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Of these, n-butyl acrylate is preferred.

  The alkyl methacrylate (II-A2) having an alkyl group having 1 to 4 carbon atoms may have either a linear or branched alkyl group. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl methacrylate is preferred.

  Other monomers (II-A3) having a double bond capable of copolymerization include acrylic monomers such as lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, methacrylic acid, styrene, alkyl-substituted styrene, Examples include acrylonitrile and methacrylonitrile. These can be used alone or in admixture of two or more.

  The polyfunctional monomer (II-A4) is defined as a monomer having two or more copolymerizable double bonds in one molecule. As the polyfunctional monomer (II-A4), alkylene glycol dimethacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate are preferable. In addition, polyvinylbenzene such as divinylbenzene and trivinylbenzene can be used. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. These can be used alone or in admixture of two or more. Of these, 1,3-butylene glycol dimethacrylate is preferred. Even when the polyfunctional monomer (II-A4) does not act at all, as long as the graft crossing agent (II-A5) is present, a fairly stable rubber-containing multistage polymer (II) is obtained. The polyfunctional monomer (II-A4) can be arbitrarily added depending on the purpose, for example, when the hot strength or the like is strictly required.

  The graft crossing agent (II-A5) is defined as a monomer having two or more different copolymerizable double bonds in one molecule. Specific examples thereof include allyl, methallyl and crotyl esters of copolymerizable α, β-unsaturated carboxylic acid or dicarboxylic acid. Particularly preferred are allyl esters of acrylic acid, methacrylic acid, maleic acid or fumaric acid. Of these, allyl methacrylate is preferable because of its excellent effect. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. These can be used alone or in admixture of two or more. Graft-crossing agent (II-A5) is chemically bonded, mainly because the conjugated unsaturated bond of its ester reacts much faster than allyl group, methallyl group or crotyl group.

  The monomer component that is a raw material of the elastic polymer (II-A) may be polymerized in the presence of a chain transfer agent.

  The content of the alkyl acrylate (II-A1) having an alkyl group having 1 to 8 carbon atoms is 50 to 99.9 mass in the monomer component (100 mass%) which is a raw material of the elastic polymer (II-A). % Is preferred. Furthermore, from the viewpoint of moldability of the resin composition for microlenses, 55% by mass or more is more preferable, and 60% by mass or more is particularly preferable. Moreover, 79.9 mass% or less is more preferable, and 69.9 mass% or less is especially preferable.

  The content of the alkyl methacrylate (II-A2) having an alkyl group having 1 to 4 carbon atoms is 0 to 49.9 mass in the monomer component (100 mass%) which is a raw material of the elastic polymer (II-A). % Is preferred. More preferably, it is 20 mass% or more, Most preferably, it is 30 mass% or more. Further, it is more preferably 44.9% by mass or less, particularly preferably 39.9% by mass or less.

  The other monomer (II-A3) having a copolymerizable double bond is preferably 0 to 20% by mass in the monomer component (100% by mass) which is a raw material of the elastic polymer (II-A). . More preferably, it is 15 mass% or less.

  The content of the polyfunctional monomer (II-A4) is preferably 0 to 10% by mass in the monomer component (100% by mass) which is a raw material of the elastic polymer (II-A). From the viewpoint of moldability of the resin composition for microlenses, the content is more preferably 0.1% by mass or more, and particularly preferably 3% by mass or more. From the viewpoint of imparting sufficient toughness to the obtained resin molding, it is preferably 6% by mass or less, and particularly preferably 5% by mass or less.

  The content of the graft crossing agent (II-A5) is preferably 0.1 to 10% by mass in the monomer component (100% by mass) which is a raw material of the elastic polymer (II-A). By setting the content of the graft crossing agent (II-A5) to 0.1% by mass or more, the moldability when obtaining a resin molded article is improved, and molding is performed without degrading optical properties such as transparency. be able to. More preferably, it is 0.5 mass% or more. Moreover, sufficient toughness can be provided to a resin molding by making content of a graft crossing agent (II-A5) into 10 mass% or less. More preferably, it is 5 mass% or less, Most preferably, it is 2 mass% or less.

  The Tg of the elastic polymer (II-A) alone is preferably 10 ° C. or less, and more preferably 0 ° C. or less. If Tg is 10 ° C. or less, the resulting rubber-containing multistage polymer (II) exhibits favorable impact resistance. The Tg (glass transition temperature) in the present invention is determined according to the polymer handbook [Polymer HandBook, J. et al. Brandgup, Interscience, 1989], and Tg calculated from the FOX equation.

  When the elastic polymer (II-A) is polymerized, the amount of the monomer component that is the raw material of the elastic polymer (II-A) is the same as the monomer component that is the raw material of the elastic polymer (II-A). 15-50 mass% is preferable in the total amount (100 mass%) of the monomer component which is a raw material of intermediate polymer (II-B), and the monomer component which is a raw material of hard polymer (II-C). By setting the amount of the monomer component that is a raw material of the elastic polymer (II-A) to 15% by mass or more, the moldability of the resin composition for microlenses can be imparted. In addition, by setting the content of the monomer component, which is a raw material of the elastic polymer (II-A), to 50% by mass or less, a resin molded body having heat resistance necessary as a microlens tends to be obtained. . More preferably, it is 35 mass% or less.

  When obtaining the elastic polymer (II-A), the monomer component that is the raw material of the elastic polymer (II-A) can be polymerized in a lump or in two or more stages. . It is preferable to polymerize in two or more stages. When the polymerization is performed in two or more stages, it is preferable that the constitutional ratio of the monomer units in each polymerization stage is different.

  When the elastic polymer (II-A) is polymerized in two or more stages, from the viewpoint of moldability of the resulting resin composition, the Tg of the elastic polymer (II-A-1) polymerized in the first stage is obtained. Is preferably lower than the Tg of the elastic polymer (II-A-2) polymerized in the second stage. Specifically, the Tg of the elastic polymer (II-A-1) polymerized in the first stage is preferably less than −30 ° C., and the elastic polymer (II-A-2) polymerized in the second stage. The Tg is preferably -15 ° C to 10 ° C.

  From the viewpoint of moldability, the amount of monomer component polymerized to obtain the elastic polymer (II-A-1) polymerized in the first stage is the raw material of the elastic polymer (II-A). The amount of the monomer component polymerized in order to obtain the elastic polymer (II-A-2) polymerized in the second stage is preferably 1 to 20% by mass in the monomer component (100% by mass). 80-99 mass% is preferable in the monomer component (100 mass%) which is a raw material of coalescence (II-A).

  The alkyl acrylate (II-B1) having an alkyl group having 1 to 8 carbon atoms may have either a linear or branched alkyl group. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl acrylate and n-butyl acrylate are preferred.

  The alkyl methacrylate (II-B2) having an alkyl group having 1 to 4 carbon atoms may have either a linear or branched alkyl group. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl methacrylate is preferred.

  Other monomers (II-B3) having a double bond capable of copolymerization include acrylic monomers such as lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, methacrylic acid, styrene, alkyl-substituted styrene, Examples include acrylonitrile and methacrylonitrile. These can be used alone or in admixture of two or more.

  As the polyfunctional monomer (II-B4), alkylene glycol dimethacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate are preferable. In addition, polyvinylbenzene such as divinylbenzene and trivinylbenzene can be used. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. Of these, 1,3-butylene glycol dimethacrylate is preferred. These can be used alone or in admixture of two or more. Even when the polyfunctional monomer (II-B4) does not act at all, as long as the graft crossing agent (II-B5) is present, a fairly stable rubber-containing multilayer polymer (II) is obtained. The polyfunctional monomer (II-B4) can be arbitrarily added according to the purpose, for example, when the hot strength or the like is strictly required.

  Examples of the graft crossing agent (II-B5) include allyl, methallyl, and crotyl esters of copolymerizable α, β-unsaturated carboxylic acid or dicarboxylic acid. Particularly preferred are allyl esters of acrylic acid, methacrylic acid, maleic acid or fumaric acid. Of these, allyl methacrylate is preferable because of its excellent effect. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. These can be used alone or in admixture of two or more. Graft-crossing agent (II-B5) reacts much faster than the allyl group, methallyl group or crotyl group and chemically bonds mainly with the conjugated unsaturated bond of its ester.

  The monomer component that is a raw material of the intermediate polymer (II-B) may be polymerized in the presence of a chain transfer agent.

  The content of the alkyl acrylate (II-B1) having an alkyl group having 1 to 8 carbon atoms is 9.9 to 90 mass in the monomer component (100 mass%) which is a raw material of the intermediate polymer (II-B). % Is preferred. Furthermore, 19.9 mass% or more is more preferable from a viewpoint of a moldability, and 29.9 mass% or more is especially preferable. Further, it is more preferably 60% by mass or less, particularly preferably 50% by mass or less.

  The content of the alkyl methacrylate (II-B2) having an alkyl group having 1 to 4 carbon atoms is 9.9 to 90 mass in the monomer component (100 mass%) which is a raw material of the intermediate polymer (II-B). % Is preferred. Furthermore, 39.9 mass% or more is more preferable from a viewpoint of a moldability, and 49.9 mass% or more is especially preferable. Further, it is more preferably 80% by mass or less, particularly preferably 70% by mass or less.

  The content of the other monomer (II-B3) having a double bond capable of copolymerization is 0 to 20 mass in the monomer component (100 mass%) which is a raw material of the intermediate polymer (II-B). % Is preferred. More preferably, it is 15 mass% or less.

  The content of the polyfunctional monomer (II-B4) is preferably 0 to 10% by mass in the monomer component (100% by mass) which is a raw material for the intermediate polymer (II-B). From the viewpoint of imparting sufficient toughness to the obtained resin molding, it is preferably 6% by mass or less, and particularly preferably 3% by mass or less.

  The content of the graft crossing agent (II-B5) is preferably 0.1 to 10% by mass in the monomer component (100% by mass) which is a raw material for the intermediate polymer (II-B). By setting the content of the graft crossing agent (II-B5) to 0.1% by mass or more, molding can be performed without deteriorating the optical characteristics of the obtained resin molded body. More preferably, it is 0.5 mass% or more. Moreover, sufficient toughness can be provided to the resin molding obtained by making content of a graft crossing agent (II-B5) into 10 mass% or less. More preferably, it is 5 mass% or less, Most preferably, it is 2 mass% or less.

  The Tg of the intermediate polymer (II-B) alone is preferably 25 to 100 ° C. If Tg is 25 ° C. or higher, the heat resistance of the obtained resin molded product tends to be a level required for the microlens. More preferably, it is 40 degreeC or more, Most preferably, it is 50 degreeC or more. Moreover, if Tg is 100 degrees C or less, the resin composition for microlenses with favorable moldability will be obtained. More preferably, it is 80 degrees C or less, Most preferably, it is 70 degrees C or less.

  Thus, by providing the intermediate polymer (II-B) having a specific composition and Tg, a resin composition for microlenses having good transparency and moldability can be obtained. When the intermediate polymer (II-B) is polymerized, the amount of the monomer component that is the raw material of the intermediate polymer (II-B) is the same as that of the monomer component that is the raw material of the elastic polymer (II-A). 5-35 mass% is preferable in the total amount (100 mass%) of the monomer component which is a raw material of intermediate polymer (II-B), and the monomer component which is a raw material of hard polymer (II-C). Within this range, the functions of the intermediate polymer (II-B) important for satisfying moldability can be expressed, and other physical properties of the resulting resin molded body, for example, transparency, etc. Can be granted. More preferably, it is 20 mass% or less.

  When the intermediate polymer (II-B) is obtained, the monomer component that is the raw material of the intermediate polymer (II-B) can be polymerized in a lump or in two or more stages. You can also.

  The alkyl methacrylate (II-C1) having an alkyl group having 1 to 4 carbon atoms may be either a linear or branched alkyl group. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl methacrylate is preferred.

  The alkyl acrylate (II-C2) having an alkyl group having 1 to 8 carbon atoms may have either a linear or branched alkyl group. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl acrylate and n-butyl acrylate are preferred.

  Other monomers (II-C3) having a double bond capable of copolymerization include acrylic monomers such as lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, methacrylic acid, styrene, alkyl-substituted styrene, Examples thereof include unsaturated dicarboxylic anhydrides such as acrylonitrile, methacrylonitrile, maleic anhydride and itaconic anhydride, N-phenylmaleimide, N-cyclohexylmaleimide and the like. These can be used alone or in admixture of two or more.

  The content of the alkyl methacrylate (II-C1) having an alkyl group having 1 to 4 carbon atoms is 80 to 100% by mass in the monomer component (100% by mass) which is a raw material of the hard polymer (II-C). preferable. 90 mass% or more is more preferable from a viewpoint of the moldability of the resin molding obtained, and 93 mass% or more is especially preferable. Moreover, it is 99 mass% or less more preferably.

  The content of the alkyl acrylate (II-C2) having an alkyl group having 1 to 8 carbon atoms is 0 to 20% by mass in the monomer component (100% by mass) which is a raw material of the hard polymer (II-C). preferable. More preferably, it is 1 mass% or more. Further, it is more preferably 10% by mass or less, particularly preferably 7% by mass or less.

  The content of the other monomer (II-C3) having a copolymerizable double bond is 0 to 20 mass in the monomer component (100 mass%) which is a raw material of the hard polymer (II-C). % Is preferred. More preferably, it is 15 mass% or less.

  A chain transfer agent can be used at the time of polymerization of the monomer component which is a raw material of the hard polymer (II-C), and the molecular weight of the hard polymer (II-C) can be adjusted. The chain transfer agent can be selected from those used for normal radical polymerization. Specific examples include alkyl mercaptans having 2 to 20 carbon atoms, mercapto acids, thiophenol, carbon tetrachloride and the like. These can be used alone or in admixture of two or more. As for content of a chain transfer agent, 0.01-5 mass parts is preferable with respect to 100 mass parts of monomer components which are the raw materials of a hard polymer (II-C). More preferably, it is 0.2 mass part or more, Most preferably, it is 0.4 mass part or more.

  The Tg of the hard polymer (II-C) alone is preferably 60 ° C. or higher. If Tg is 60 ° C. or higher, a resin molded body having heat resistance suitable for an optical member tends to be obtained. More preferably, it is 80 degreeC or more, Most preferably, it is 90 degreeC or more.

  When polymerizing the hard polymer (II-C), the amount of the monomer component that is the raw material of the hard polymer (II-C) is the same as the monomer component that is the raw material of the elastic polymer (II-A). 15-80 mass% is preferable in the total amount (100 mass%) of the monomer component which is a raw material of intermediate polymer (II-B), and the monomer component which is a raw material of hard polymer (II-C). If the amount of the monomer component that is the raw material of the hard polymer (II-C) is 15% by mass or more, the heat resistance of the obtained resin molded product tends to be good. More preferably, it is 45 mass% or more. If the amount of the monomer component that is a raw material of the hard polymer (II-C) is 80% by mass or less, toughness can be imparted to the obtained resin molded body.

  When obtaining the hard polymer (II-C), the monomer component that is the raw material of the hard polymer (II-C) can be polymerized in a lump or in two or more stages. .

The gel content of the rubber-containing multistage polymer (II) is preferably 50% or more and more preferably 60% or more from the viewpoint of moldability. Furthermore, in order to improve the moldability, the presence of a predetermined amount or more of free polymer is necessary, and therefore the gel content is preferably 80% or less. The gel content means that a predetermined amount (mass before extraction) of a rubber-containing multistage polymer (II) is extracted under reflux in an acetone solvent, the treated solution is separated by centrifugation, dried and then insoluble in acetone. Is the value calculated by the following formula.
Gel content (%) = mass after extraction (g) / mass before extraction (g) × 100

  The mass average particle diameter of the rubber-containing multistage polymer (II) is preferably 0.03 to 0.3 μm. From the viewpoint of the mechanical properties of the obtained resin molding, it is more preferably 0.07 μm or more, particularly preferably 0.09 μm or more. Further, from the viewpoint of transparency of the obtained resin molded body, it is more preferably 0.15 μm or less, and particularly preferably 0.13 μm or less. The mass average particle diameter is measured by a dynamic light scattering method using a light scattering photometer DLS-700 (trade name) manufactured by Otsuka Electronics Co., Ltd.

  As a method for producing the rubber-containing multistage polymer (II), the sequential multistage polymerization method by the emulsion polymerization method is the most suitable polymerization method, but is not particularly limited thereto. It can also be carried out by an emulsion suspension polymerization method in which the polymerization of the monomer component which is the raw material of the combined (II-C) is converted into a suspension polymerization system.

  When the rubber-containing multistage polymer (II) is produced by emulsion polymerization, the monomer component that is the raw material of the elastic polymer (II-A) in the rubber-containing multistage polymer (II) is previously added with water and a surfactant. After the emulsion prepared by mixing with the polymer is supplied to the reactor and polymerized, the monomer component that is the raw material of the intermediate polymer (II-B) and the single component that is the raw material of the hard polymer (II-C) A method is preferred in which the monomer components are sequentially fed to the reactor and polymerized.

  The monomer component which is a raw material of the elastic polymer (II-A) was dispersed in acetone by supplying an emulsion prepared beforehand by mixing with water and a surfactant to the reactor and polymerizing it. In this case, the rubber-containing multistage polymer (II) in which the number of particles having a diameter of 55 μm or more present in the dispersion is 0 to 50 per 100 g of the rubber-containing multistage polymer (II) can be easily obtained. A resin molded body using the rubber-containing multistage polymer (II) thus obtained as a raw material has a characteristic that the number of foreign matters in the molded body is small, and is particularly excellent in optical characteristics.

  As the surfactant used in preparing the emulsion, anionic, cationic and nonionic surfactants can be used, and anionic surfactants are particularly preferable. Examples of anionic surfactants include rosin soap, potassium oleate, sodium stearate, sodium myristate, sodium N-lauroyl sarcosinate, dipotassium alkenyl succinate, and sulfate esters such as sodium lauryl sulfate. Sulfonic acid salts such as sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate, sodium alkyldiphenyl ether disulfonate; phosphate esters such as polyoxyethylene alkylphenyl ether sodium phosphate; polyoxyethylene alkyl ether sodium phosphate And phosphoric acid ester salts. Among them, phosphate ester salts such as sodium polyoxyethylene alkyl ether phosphates are preferable. Preferable specific examples of the surfactant include NC-718 manufactured by Sanyo Kasei Kogyo Co., Ltd., Phosphanol LS-529, Phosphanol RS-610NA, Phosphanol RS- manufactured by Toho Chemical Industry Co., Ltd. 620NA, Phosphanol RS-630NA, Phosphanol RS-640NA, Phosphanol RS-650NA, Phosphanol RS-660NA, Latemul P-0404, Latemul P-0405, Latemul P-0406 manufactured by Kao Corporation Latemul P-0407 (above, trade name) and the like.

  As a method for preparing an emulsified liquid, a method in which a monomer component is charged in water and then a surfactant is added; a method in which a surfactant is charged in water and then a monomer component is charged; a monomer Examples thereof include a method in which water is added after a surfactant is charged into the components. Among them, a method in which a monomer component is charged in water and then a surfactant is charged, and a method in which a monomer component is charged after a surfactant is charged in water are preferable.

  Examples of the mixing device for preparing the emulsion include various forced emulsification devices such as a stirrer equipped with a stirring blade, a homogenizer, and a homomixer, a membrane emulsification device, and the like.

  The emulsified liquid may have either a W / O type in which water droplets are dispersed in the monomer component oil or an O / W type dispersion structure in which oil droplets of the monomer component are dispersed in water. It is preferable that the droplets are O / W type in which the oil droplets of the monomer component are dispersed and the diameter of the oil droplets in the dispersed phase is 100 μm or less.

  As the polymerization initiator used when forming the elastic polymer (II-A), the intermediate polymer (II-B) and the hard polymer (II-C), known ones can be used. Examples of the polymerization initiator include peroxides, azo initiators, or redox initiators in which an oxidizing agent and a reducing agent are combined. Among them, redox initiators are preferable, and particularly ferrous sulfate, ethylenediamine tetrachloride. A sulfoxylate-based initiator in which acetic acid disodium salt, Rongalite and hydroperoxide are combined is preferable. What is necessary is just to determine the addition amount of a polymerization initiator suitably according to superposition | polymerization conditions.

  Examples of the method for adding a polymerization initiator include a method of adding to one or both of an aqueous phase and a monomer phase (oil phase).

  As a method for synthesizing the rubber-containing multistage polymer (II), the temperature of an aqueous solution containing ferrous sulfate, ethylenediaminetetraacetic acid disodium salt and Rongalite charged in the reactor was raised to the polymerization temperature, and then an elastic polymer ( An emulsion prepared by mixing a monomer component, which is a raw material of II-A), and a polymerization initiator such as peroxide with water and a surfactant is supplied to the reactor for polymerization, and then an intermediate polymer ( The monomer component that is a raw material of II-B) is supplied to a reactor together with a polymerization initiator such as a peroxide for polymerization, and then the monomer component that is a raw material of the hard polymer (II-C) is passed through. A method in which polymerization is carried out by supplying it to a reactor together with a polymerization initiator such as oxide is preferred.

  The polymerization temperature varies depending on the type and amount of the polymerization initiator used, and is usually preferably 40 ° C or higher, more preferably 60 ° C or higher, preferably 120 ° C or lower, and more preferably 95 ° C or lower.

  It is preferable to treat the polymer latex containing the rubber-containing multistage polymer (II) obtained by the above-described method using a filtration device provided with a filter medium as necessary. This filtration treatment is a treatment for removing scales generated during the polymerization from the latex, and removing impurities mixed in from the polymerization raw material or from the outside during the polymerization.

  As a filtration device with filter media, a GAF filter system of ISP Filters PTA Ltd. using a bag-like mesh filter; a cylindrical filter media is arranged on the inner surface of a cylindrical filter chamber, and the filter media is stirred. A centrifugal type filtration device having blades; or a vibration type filtration device in which the filter medium performs horizontal circular motion and vertical amplitude motion with respect to the filter medium surface is preferable.

  The rubber-containing multistage polymer (II) can be produced by recovering the rubber-containing multistage polymer (II) from the polymer latex produced by the above method. Examples of the method for recovering the rubber-containing multistage polymer (II) from the polymer latex include salting out or acid precipitation coagulation, spray drying, freeze drying and the like. According to these methods, the rubber-containing multistage polymer (II) is recovered in powder form.

  When the rubber-containing multistage polymer (II) is recovered by salting out coagulation using a metal salt, the residual metal content in the finally obtained rubber-containing multistage polymer (II) should be 800 ppm or less. Is preferred. In particular, when using a metal salt having a strong affinity for water, such as magnesium salt or sodium salt, as the salting-out agent, if the residual metal content is not reduced as much as possible, for example, the finally obtained rubber-containing multistage weight When a resin molded body made of the coalescence (II) as a raw material is immersed in boiling water, a whitening phenomenon occurs, which is a serious problem in practice. In addition, although salting out coagulation using calcium salt or aciding out coagulation using sulfuric acid shows a relatively good tendency, in order to give excellent water whitening resistance in any case, the amount of residual metal is It is necessary to make it 800 ppm or less, and it is so good that it is a trace amount.

<Thermoplastic polymer>
The thermoplastic polymer contained in the resin composition for microlenses is a polymerization of alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and other monomers having a copolymerizable double bond used as necessary. A thermoplastic polymer having a reduced viscosity (0.1 g of a polymer dissolved in 100 ml of chloroform and measured at 25 ° C.) of 0.1 l / g or less is obtained. It is preferable that this reduced viscosity is 0.1 l / g or less from the viewpoint of maintaining good fluidity.

  It is preferable that the usage-amount of the alkylmethacrylate which has a C1-C4 alkyl group used for a thermoplastic polymer is 50 mass parts or more. The amount used is based on a total of 100 parts by mass of the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and another monomer having a double bond copolymerizable therewith. If this is 50 mass parts or more, the moldability at the time of molding into a microlens is good and the transparency is also good. As the alkyl methacrylate, methyl methacrylate is most preferable.

  When the alkyl methacrylate is polymerized in order to obtain a thermoplastic polymer, another monomer having a double bond can be copolymerized. When using another monomer, it is preferable that the usage-amount is less than 50 mass parts in a monomer. The amount used is based on a total of 100 parts by mass of the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and another monomer having a double bond copolymerizable therewith. Specific examples of the copolymerizable vinyl monomer include linear or branched alkyl acrylates having an alkyl group having 1 to 8 carbon atoms, aromatic vinyl compounds, and vinyl cyan compounds. Specific examples of the alkyl acrylate having a linear or branched alkyl group having 1 to 8 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, and the like. It is done. These can be used alone or in admixture of two or more. Examples of the aromatic vinyl compound include styrene, α-substituted styrene, nucleus-substituted styrene, and derivatives thereof (for example, α-methylstyrene, chlorostyrene, vinyltoluene, and the like). Examples of the vinylcyan compound include acrylonitrile and methacrylonitrile.

  The polymerization method of the thermoplastic polymer is not particularly limited. For example, conventionally known various methods such as suspension polymerization and emulsion polymerization can be applied.

  The thermoplastic polymer useful in the present invention is industrially available as the Acrypet series manufactured by Mitsubishi Rayon Co., Ltd.

<Glycerin fatty acid ester>
The glycerol fatty acid ester added to the resin composition for microlenses of the present invention is not particularly limited, but glycerol mono fatty acid esters such as glycerol monomyristate, glycerol monopalmitate, glycerol monostearate, glycerol monobehenate, Glycerin dimyristate, glycerin dipalmitate, glyceryl distearate, glycerin difatty acid ester such as glycerin dibehenate and the like, and these may be used alone or in admixture of two or more.

  The added amount of glycerin fatty acid ester must be 0.2 to 2 parts by mass with respect to 100 parts by mass of the resin composition for microlens comprising the rubber-containing polymer and the thermoplastic polymer in the present invention. When the addition amount of glycerin fatty acid ester is less than 0.2 parts by mass, the effect of improving the releasability when molding the composition is insufficient, and the resin composition for microlens is formed into a microlens shape by press molding or the like. The cooling time at the time of molding becomes long and the productivity is inferior. Moreover, when the addition amount of glycerin fatty acid ester exceeds 2 parts by mass, the heat resistance of the composition is lowered, and the mold releasability improving effect when molding the composition becomes insufficient, resulting in poor moldability. A part of it is deposited on a metal surface or the like during processing to cause a surface defect when a microlens is molded.

<Additives to resin composition for microlenses>
The resin composition for a microlens of the present invention may contain general additives such as stabilizers, lubricants, processing aids, plasticizers, impact aids, antibacterial agents, antifungal agents, and antistatic agents as necessary. An agent and an ultraviolet absorber can be added. For example, in the case of an ultraviolet absorber, the molecular weight is preferably 300 or more, particularly preferably 400 or more. The ultraviolet absorber is not particularly limited, but a benzotriazole type having a molecular weight of 400 or more or a triazine type having a molecular weight of 400 or more can be particularly preferably used. As a specific example of the former, Tinuvin 234 of Ciba Specialty Chemicals Co., Ltd. can be used. Specific examples of the latter such as Adeka Stub LA-31 from Asahi Denka Kogyo Co., Ltd. include Tinuvin 1577 from Ciba Specialty Chemicals.

  Moreover, it is preferable to add the following thermoplastic polymer (III) from the point of film-forming stabilization as a processing aid added when shape | molding the resin composition for microlenses of this invention in a film form.

  The thermoplastic polymer (III) is obtained by polymerizing 50 to 100% by mass of methyl methacrylate and 0 to 50% by mass of another vinyl monomer copolymerizable therewith, and the reduced viscosity ( A polymer obtained by dissolving 0.1 g of a polymer in 100 ml of chloroform and measuring so as to be 0.2 to 2 l / g (measured at 25 ° C.), and forming a microlens resin composition into a film shape It is a component that plays an important role in processability and chemical resistance. The reduced viscosity of the thermoplastic polymer (III) is important, the preferred reduced viscosity is 0.2 to 1.2 l / g, and the particularly preferred reduced viscosity is 0.2 to 0.8 l / g.

  In the thermoplastic polymer (III), other vinyl monomers copolymerizable with methyl methacrylate include alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and alkyl having an alkyl group having 2 to 4 carbon atoms. Methacrylate, aromatic vinyl compound, vinyl cyanide compound and the like can be mentioned. The alkyl acrylate having an alkyl group having 1 to 8 carbon atoms may be linear or branched, and specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and n-octyl. An acrylate etc. are mentioned. Moreover, the alkyl methacrylate having an alkyl group having 2 to 4 carbon atoms may be either linear or branched, and specific examples thereof include ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like. Examples of the aromatic vinyl compound include styrene, α-substituted styrene, nucleus-substituted styrene and derivatives thereof, for example, α-methylstyrene, chlorostyrene, vinyltoluene and the like. Examples of the vinylcyan compound include acrylonitrile and methacrylonitrile.

  Examples of the polymerization initiator used for obtaining the thermoplastic polymer (III) from the above monomers include ordinary inorganic initiators such as persulfates, organic peroxides, and azo compounds. In addition, the above compounds and sulfites, hydrogen sulfites, thiosulfates, first metal salts, sodium formaldehyde sulfoxylate, and the like can be used in combination as redox initiators. Preferred persulfates as the polymerization initiator include sodium persulfate, potassium persulfate, ammonium persulfate and the like. Examples of the organic peroxide include t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, and lauroyl peroxide.

  Since the molecular weight and molecular weight distribution of the thermoplastic polymer (III) are important factors for the processability-imparting effect, an appropriate chain transfer may be performed according to the purpose in the production of the thermoplastic polymer (III). Agents can be used.

  The polymerization can be carried out at a temperature equal to or higher than the decomposition temperature of the polymerization initiator under the usual emulsion polymerization conditions, and can be polymerized in one or more stages depending on the purpose. In general, the polymer can be recovered in the form of powder by salting out or solidifying by acid precipitation, followed by filtration, washing with water, and recovering in powder form, or spray drying or freeze drying.

  The thermoplastic polymer (III) is industrially available as Metablene P manufactured by Mitsubishi Rayon Co., Ltd.

  The blending amount of the thermoplastic polymer (III) is 2 to 45 parts by mass of the rubber-containing polymer, 98 to 55 parts by mass of the thermoplastic polymer (here, the total of the rubber-containing polymer and the thermoplastic polymer is 100 parts by mass). 0.1 to 10 parts by mass is preferable. When the blending amount of the thermoplastic polymer (III) is less than 0.1 part by mass, for example, film formation stabilization when the resin composition for microlenses is formed into a film tends to be insufficient. On the other hand, when the compounding quantity of thermoplastic polymer (III) exceeds 10 mass parts, the melt viscosity at the time of shape | molding the resin composition for microlenses in a film form will become high, and it exists in the tendency for film moldability to fall. Furthermore, the compounding quantity of a preferable thermoplastic polymer (III) is 0.5-5 mass parts.

  There are various methods for adding the additive, including a method of supplying the resin composition for microlenses of the present invention together with an acrylic resin to a film forming machine for forming a film, and a mixture in which an additive is previously added to the acrylic resin. There is a method of kneading and mixing with a kneader. Examples of the kneader used in the latter method include ordinary single screw extruders, twin screw extruders, Banbury mixers, roll kneaders, and the like.

<Method for Molding Resin Composition (Film)>
The resin composition for microlenses of the present invention may be formed into a film or the like. The method for forming the resin composition for microlenses into a film is not particularly limited, and examples thereof include known melt casting methods such as a melt casting method, a T-die method, and an inflation method. From the viewpoint of properties, the T-die method is most preferable.

<Transparency of molded resin>
It is preferable that the haze value is 3% or less when a resin molded body such as a film formed of the resin composition for microlenses of the present invention is measured according to JIS K 7136. When the haze value exceeds 3%, the light transmittance is lowered and the performance as an optical component tends not to be satisfied. A preferred haze value is 3% or less, more preferably 2% or less, and most preferably 1.5% or less. The total light transmittance is preferably 80% or more when measured according to JIS K7361-1. When the total light transmittance of the resin molded body is 80% or more, the light from the light source is transmitted efficiently. For example, the light emission quality of an image projection apparatus using the light molded article is preferable. More preferably, it is 85% or more, more preferably 90% or more.

<Thickness of resin molding>
It is preferable that the thickness of the film-shaped resin molded body made of the resin composition for microlenses of the present invention is 20 to 200 μm. When the thickness of the film-shaped resin molded body is less than 20 μm, for example, when forming a microlens by press molding with a mold, the shape of the microlens becomes difficult to be transferred, and further, the handleability tends to be difficult. is there. Further, when it exceeds 200 μm, for example, when it is used as a mobile optical component, it tends to be difficult to reduce the weight and thickness, or to increase the cost. The thickness of a preferable film-shaped resin molded body is 20 to 200 μm, more preferably 30 to 180 μm, and most preferably 50 to 150 μm.

<Microlens molding method>
When manufacturing the resin composition for microlenses of this invention in a microlens shape, the method is not specifically limited, It manufactures by a well-known method. For example, a method of forming an acrylic resin into a lens shape by injection molding, a method of previously forming an acrylic resin into a sheet shape, and forming this sheet into a lens shape by press molding with a mold, an acrylic resin on the substrate portion of the microlens array A method of laminating and press-molding the acrylic resin surface with a metal mold is exemplified. When the resin molding is a film, it is preferable because it can be easily molded into a microlens by press molding or the like and can be easily laminated on the substrate portion of the microlens array.

<Description of micro lens array>
The resin molded body for microlenses of the present invention is laminated on a substrate portion made of glass such as soda lime glass or non-alkali glass, or a translucent resin such as polycarbonate, acrylic, polyolefin, polyester, and used as a microlens array. It is done. The resin molded body for a microlens of the present invention is useful because it has a good light transmittance and thus has a good performance as an optical component such as a microlens array for an image projection device or the like.

  EXAMPLES The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

  In the examples and comparative examples, “part” represents “part by mass”, and “%” represents “% by mass”. Abbreviations in the reference examples are as follows.

Methyl methacrylate MMA
Methyl acrylate MA
Butyl acrylate BA
Styrene St
Allyl methacrylate AMA
1,3-butylene glycol dimethacrylate 1,3BD
t-Butyl hydroperoxide tBH
Cumene hydroperoxide CHP
n-octyl mercaptan nOM
Emulsifier (1): Sodium mono-n-dodecyloxytetraoxyethylene phosphate [trade name Phosphanol RS-610NA, manufactured by Toho Chemical Co., Ltd.]

  In the examples and comparative examples, the prepared rubber-containing multistage polymer, evaluation of the rubber-containing polymer, and measurement of various physical properties of the transparent protective layer were carried out by the following test methods.

1) Weight average particle diameter of rubber-containing multistage polymer and rubber-containing polymer The polymer latex of the rubber-containing multistage polymer obtained by emulsion polymerization was used with a light scattering photometer DLS-700 manufactured by Otsuka Electronics Co., Ltd. It was determined by measuring with a dynamic light scattering method.

2) Rubber-containing multistage polymer, gel content of rubber-containing polymer Weighed rubber-containing multistage polymer or rubber-containing polymer was subjected to extraction treatment under reflux in an acetone solvent, and this extraction treatment liquid was fractionated by centrifugation. . Subsequently, after drying the obtained solid content, mass measurement (mass after extraction) was carried out and it calculated | required with the following formula | equation.
Gel content rate (%) = (mass before extraction (g) −mass after extraction (g)) / mass before extraction (g)

3) Total light transmittance of resin molded body It evaluated based on JISK7361-1.

4) Haze of resin molded body It evaluated based on JISK7136.

5) Transferability of resin molded body When a resin molded body is pressed at a heating temperature of 110 ° C. and a pressure of 7 MPa for 2 minutes using a press plate in which the shape of a microlens is engraved, the microlens-shaped transfer state is evaluated. When the transfer state is good, it is marked with ◯, when it is not partially transferred, Δ, and when the transfer state is poor, it is marked with X.

6) Peelability of resin molded body from mold Using a press plate in which the shape of the microlens is engraved, the resin molded body is pressed at a heating temperature of 110 ° C. and a pressure of 7 MPa for 2 minutes, and then a cooling press is used. The peelability from the press plate after use and cooling at a pressure of 7 MPa for 10 seconds was evaluated. The case where the peelability was good was marked with ◯, and the case where sticking was seen on the mold was marked with x.

Example 1
<Production of rubber-containing polymer (A)>
In a nitrogen atmosphere, put 320 parts of deionized water in a reaction vessel equipped with a reflux condenser, raise the temperature to 80 ° C., add (a) shown below, and stir the following raw material (b) (polymer) 1/10 of the mixture of (A-1) raw material) and charged for 15 minutes. Thereafter, the remaining raw material (b) was continuously added at an increase rate of 8% / hour of the monomer mixture with respect to water. Thereafter, it was kept for 1 hour to obtain a latex of the polymer (A-1).

  Subsequently, 0.2 parts of sodium formaldehyde sulfoxylate was added to this latex, kept for 15 minutes, and stirred at 80 ° C. in a nitrogen atmosphere, with the following raw materials (c) (rubber polymer (A- The raw material (2) was continuously added at an increase rate of the monomer mixture with respect to water at 4% / hour. The latex of the elastic polymer ((A-1) + (A-2)) was obtained by holding the polymer for 2 hours and then polymerizing the rubber polymer (A-2).

  Subsequently, 0.2 parts of sodium formaldehyde sulfoxylate was added to this latex, and the mixture was held for 15 minutes and stirred at 80 ° C. in a nitrogen atmosphere, while the following raw materials (d) (hard polymer (A- The raw material (3) was continuously added at an increase rate of 10% / hour of the monomer mixture with respect to water. The latex of the rubber-containing polymer (A) was obtained by holding for 1 hour and then performing the hard polymer (A-3). The rubber-containing polymer (A) had an average particle size of 0.28 μm.

  The rubber-containing polymer (A) latex was subjected to coagulation, aggregation and solidification using calcium acetate, filtered, washed with water and dried to obtain a rubber-containing polymer (A).

(I)
Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.00004 parts Disodium ethylenediaminetetraacetate 0.00012 parts (b)
MMA 22.0 parts BA 15.0 parts St 3.0 parts AMA 0.4 parts 1,3BD 0.14 parts tBH 0.18 parts Emulsifier (1) 1.0 part (c)
BA 49.5 parts St 10.5 parts AMA 1.05 parts 1,3BD 0.15 parts CHP 0.17 parts Emulsifier (1) 0.96 parts (d)
MMA 57.0 parts MA 3.0 parts nOM 0.18 parts tBH 0.1 part

  The polymer latex of the obtained rubber-containing polymer (A) is filtered using a vibration type filtration device equipped with a SUS mesh (average opening 150 μm) as a filter medium, and then an aqueous solution containing 3 parts of calcium acetate. The mixture was salted out, washed with water, separated and recovered, and then dried to obtain a powdery rubber-containing polymer (A). The gel content of the rubber-containing polymer (A) was 89%.

  Next, 16 parts of a rubber-containing polymer (A) was used as the rubber-containing polymer, and 84 parts of Acrypet VH (trade name, manufactured by Mitsubishi Rayon Co., Ltd.) as the thermoplastic polymer and RIKEN vitamin as the glycerin fatty acid ester. 1 part of “Rikemar S100” manufactured by Co., Ltd., 1 part of “Adeka Stub LA-31RG” manufactured by Asahi Denka Kogyo Co., Ltd., 0.1 part of “Adeka Stub AO-60” manufactured by Asahi Denka Kogyo Co., Ltd., Asahi Denka Kogyo Co., Ltd. “Adeka Stub LA-67” 0.15 part, Asahi Denka Kogyo Co., Ltd. “Adeka Stub P” 0.4 part, Mitsubishi Rayon Co., Ltd. “Metablene P551A” 1 part and Mitsubishi Rayon Co., Ltd. ) "Metablene L1000" 0.8 parts was added, then mixed using a Henschel mixer, and the resulting mixture was heated to 230 ° C degassing extruder (P, manufactured by Ikekai Tekko Co., Ltd.) CM-30) and kneaded to obtain pellets.

  The pellets produced by the above method were dried overnight at 80 ° C., and the dried pellets were supplied to a 40 mmφ non-vent screw type extruder (L / D = 26) equipped with a 300 mm wide T-die to obtain a 125 μm-thickness. A film-like resin molded body was produced. The conditions at that time were a cylinder temperature of 200 to 240 ° C., a T die temperature of 250 ° C., and a cooling roll temperature of 70 ° C.

  Further, the obtained film-like resin molded body was used by using a press plate in which the shape of the microlens was engraved, heating temperature 110 ° C., heating time 2 minutes, heating pressure 7 MPa, cooling time 10 seconds, cooling Pressing at a pressure of 7 MPa at the time, a microlens-like resin molded body was obtained.

  Table 2 below shows the evaluation results of the total light transmittance and haze of the resin molded body before press molding, and the transferability and peelability during press molding.

Example 2
<Production of rubber-containing multistage polymer (I)>
After charging 8.5 parts of ion-exchanged water into a container equipped with a stirrer, a monomer mixture consisting of (e) shown below was charged and stirred and mixed. Next, 1.1 parts of the same emulsifier (1) was added to the vessel while stirring, and stirring was continued again for 20 minutes to prepare an emulsion (N-1). The average particle size of the dispersed phase in the obtained emulsion was 10 μm.

  Next, 186.5 parts of ion-exchanged water is put into a polymerization vessel equipped with a cooler, the temperature is raised to 70 ° C., and a mixture prepared by adding the following (f) to 5 parts of ion-exchanged water is added all at once. did. Next, while stirring under nitrogen, the emulsion (N-1) was dropped into the polymerization vessel over 8 minutes, and then the reaction was continued for 15 minutes to complete the polymerization of the first elastic polymer (I-1). It was. Subsequently, the monomer mixture consisting of (g) shown below was added in 90 minutes, and then the reaction was continued for 60 minutes to complete the polymerization of the second elastic polymer (I-2) at the second stage. .

  Subsequently, a mixture of (h) shown below was dropped into the polymerization vessel over 45 minutes, and then the reaction was continued for 60 minutes to complete the polymerization of the intermediate polymer (I-3).

  Subsequently, after dropping the monomer mixture consisting of (i) into the polymerization vessel over 140 minutes, the reaction is continued for 60 minutes to complete the polymerization of the hard polymer (I-4), and the rubber-containing multistage polymer ( A polymer latex of I) was obtained.

  The weight average particle diameter measured after polymerization was 0.12 μm.

(E)
MMA 0.3 part BA 4.5 part 1,3BD 0.2 part AMA 0.05 part CHP 0.025 part (f)
Sodium formaldehyde sulfoxylate 0.2 part Ferrous sulfate 0.0001 part EDTA 0.0003 part (G)
MMA 1.5 parts BA 22.5 parts BD 1.0 part AMA 0.25 parts CHP 0.016 parts (H)
MMA 6.0 parts BA 4.0 parts AMA 0.075 parts CHP 0.0125 parts (Li)
MMA 55.2 parts BA 4.8 parts nOM 0.204 parts tBH 0.08 parts

  The polymer latex of the obtained rubber-containing multistage polymer (I) is filtered using a vibration type filtration apparatus equipped with a SUS mesh (average opening 62 μm) as a filter medium, and then contains 3 parts of calcium acetate. The solution was poured into an aqueous solution, salted out, washed with water, separated and recovered, and dried to obtain a powdery rubber-containing multistage polymer (I). The gel content of the rubber-containing multistage polymer (I) was 60%.

  Next, Examples were used except that 40 parts of the rubber-containing multistage polymer (I) was used as the rubber-containing polymer, and 60 parts of Acrypet VH (trade name, manufactured by Mitsubishi Rayon Co., Ltd.) was used as the thermoplastic polymer. 1 to obtain a resin molded body.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

Example 3
<Production of rubber-containing multistage polymer (II)>
After charging 10.8 parts of deionized water in a container equipped with a stirrer, it consists of MMA 0.3 part, n-BA 4.5 part, 1,3-BD 0.2 part, AMA 0.05 part and CHP 0.025 part. Monomer components were added and stirred and mixed at room temperature. Next, 1.3 parts of an emulsifier (manufactured by Toho Chemical Industry Co., Ltd., trade name “Phosphanol RS610NA”) was charged into the container while stirring, and stirring was continued for 20 minutes to prepare an emulsion.

  Next, 139.2 parts of deionized water was put into a polymerization vessel equipped with a cooler, and the temperature was raised to 75 ° C. Further, a mixture prepared by adding 0.20 part of sodium formaldehyde sulfoxylate, 0.0001 part of ferrous sulfate and 0.0003 part of EDTA to 5 parts of ion-exchanged water was put into the polymerization vessel at once. Next, the prepared emulsion was dropped into the polymerization vessel over 8 minutes while stirring under nitrogen, and then the reaction was continued for 15 minutes to complete the first stage polymerization of the elastic polymer (II-A-). 1). Subsequently, a monomer component consisting of 9.6 parts of MMA, 14.4 parts of n-BA, 1.0 part of 1,3-BD and 0.25 part of AMA was dropped into the polymerization vessel over 90 minutes together with 0.016 part of CHP. Thereafter, the reaction was continued for 60 minutes to complete the polymerization of the second stage polymer of the elastic polymer (II-A-2) to obtain an elastic polymer (II-A). The Tg of the polymer (II-A-1) alone was -48 ° C, and the Tg of the polymer (II-A-2) alone was -10 ° C.

  Subsequently, a monomer component consisting of 6 parts of MMA, 4 parts of MA and 0.075 part of AMA was dropped into the polymerization vessel over 45 minutes together with 0.0125 part of CHP, and then the reaction was continued for 60 minutes to obtain an intermediate polymer (II- B) was formed. The Tg of the intermediate polymer (II-B) alone was 60 ° C.

  Subsequently, a monomer component consisting of 57 parts of MMA, 3 parts of MA, 0.264 part of n-OM and 0.075 part of t-BH was dropped into the polymerization vessel over 140 minutes, and then the reaction was continued for 60 minutes to obtain a hard polymer ( II-C) was formed to obtain a polymer latex of a rubber-containing multistage polymer (II). The Tg of the hard polymer (II-C) alone was 99 ° C. The mass average particle diameter of the rubber-containing multistage polymer (II) measured after polymerization was 0.11 μm.

  The polymer latex of the rubber-containing multistage polymer (II) thus obtained was filtered using a vibration type filtration device equipped with a SUS mesh (average opening: 62 μm) as a filter medium, and then 3.5 parts of calcium acetate. It was salted out in an aqueous solution containing water, washed and collected, and then dried to obtain a powdery rubber-containing multistage polymer (II). The gel content of the rubber-containing multistage polymer (II) was 70%.

  Next, Examples were used except that 40 parts of the rubber-containing multistage polymer (II) was used as the rubber-containing polymer, and 60 parts of Acrypet VH (trade name, manufactured by Mitsubishi Rayon Co., Ltd.) was used as the thermoplastic polymer. 1 to obtain a resin molded body.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the results of evaluation of transferability and peelability during press molding.

Example 4
A resin molded product was obtained in the same manner as in Example 1 except that 1.5 parts of glycerin fatty acid ester “Riquemar S100” was used.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

Example 5
A resin molded body was obtained in the same manner as in Example 1 except that the rubber-containing polymer (A) was 10 parts and the acripet VH was 90 parts.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

Comparative Example 1
An attempt was made to obtain a resin molded body by the same method as in Example 1 except that the rubber-containing polymer (A) was 1 part and the acripet VH was 99 parts. However, since this composition is brittle, a molded body is obtained. I couldn't.

Comparative Example 2
A resin molded body was obtained in the same manner as in Example 1 except that the rubber-containing polymer (A) was 55 parts and the acripet VH was 45 parts.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

Comparative Example 3
A resin molded body was obtained in the same manner as in Example 1 except that glycerin fatty acid ester was not added.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

Comparative Example 4
A resin molded body was obtained in the same manner as in Example 1 except that Riquemar S100 was changed to 3 parts.

  Table 2 shows the total light transmittance and haze of the resin molded body before press molding, and the evaluation results of transferability and peelability during press molding.

  From the examples and comparative examples described above, the following became clear.

  When the resin composition for microlenses in Examples 1 to 5 is molded into a microlens shape, transferability and releasability are improved, and productivity is improved. Moreover, since the resin molding has good transparency and exhibits very good performance as a microlens, the resin composition for a microlens and the resin molding of the present invention have high industrial utility value.

  On the other hand, it is difficult to make a microlens-like molded product having a small amount of rubber-containing polymer as in Comparative Example 1, while the glycerin fatty acid ester of Comparative Example 3 having a large amount of rubber-containing polymer in Comparative Example 2 Those having no glycerin and those having a large amount of the glycerin fatty acid ester of Comparative Example 4 are inferior in productivity because the peelability at the time of molding deteriorates. Therefore, those resin compositions are industrially used for microlenses. The value is very low.

  The present invention provides a microlens resin composition excellent in optical characteristics such as transparency and light resistance and moldability such as transferability and releasability. Therefore, the molded article for microlenses and the optical apparatus are excellent in optical characteristics. It is industrially useful because it can be produced efficiently.

Claims (8)

  2-44.9 parts by mass of a rubber-containing polymer, 98-55.1 parts by mass of a thermoplastic polymer (here, the total of the rubber-containing polymer and the thermoplastic polymer is 100 parts by mass), and glycerin fatty acid ester 0 . A resin composition for microlens containing 2 to 2 parts by mass. The resin composition for microlenses according to claim 1, wherein the rubber-containing polymer is the following rubber-containing polymer (A) and / or rubber-containing multistage polymer (I) and / or rubber-containing multistage polymer (II). .
<Rubber-containing polymer (A)>
An alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms in the presence of an elastic polymer obtained by polymerizing a monomer (i) having an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms as a main component. A polymer composed of an elastic polymer and a hard polymer obtained by graft polymerization of a monomer (ii) having a main component as a main component <Rubber-containing multistage polymer (I)>
A first elastic polymer (IA) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as constituents of the polymer. A second elastic polymer (IB) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and a graft crossing agent as a constituent of the polymer, an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and And / or an intermediate polymer (ID) comprising at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as a constituent component of the polymer, and at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms Rigid polymer (IC) as a polymer component is polymerized in this order The polymer <rubber-containing multistage polymer (II)>
(1) An elastic polymer (II-A) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and a graft crossing agent as a constituent component of the polymer, (2) a glass transition temperature of 25 to 100 ° C. An elastic polymer (II-A) comprising at least an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as constituents of the polymer Intermediate polymer (II-B) having a composition different from that of (1) and (3) a hard polymer (II-C) comprising at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms as a constituent component of the polymer in this order. Polymerized polymer   The resin molding for microlenses obtained by shape | molding the resin composition for microlenses of Claim 1 or 2.   The resin molded body for a microlens according to claim 3, which is in the form of a film.   The resin molded product for a microlens according to claim 4, wherein a haze value measured according to JIS K 7136 is 3% or less.   The resin molded body for microlenses according to claim 4 or 5, wherein the thickness is 20 to 200 µm or less.   A microlens array in which the resin molded body for a microlens according to any one of claims 3 to 6 is laminated on a substrate portion made of glass or a translucent resin.   An image projection apparatus in which the microlens array according to claim 7 is used.