JP2018035347A - (meth)acrylate-styrene based copolymer, composition thereof and molding product thereof - Google Patents

Abstract

PURPOSE: To provide a (meth)acrylate-styrene based copolymer that has low yellowness and low hygroscopicity at the same time, a composition thereof and a molding product thereof.SOLUTION: The (meth)acrylate-styrene based copolymer contains 10 wt.%-75 wt.% of a (meth)acrylate based monomer unit, and 25 wt.%-90 wt.% of a styrene based monomer unit. In the (meth)acrylate-styrene based copolymer, the contents of pentamers to hendecamers range between 500 ppm and 2000 ppm.SELECTED DRAWING: None

Description

  The present invention relates to a copolymer, and more particularly to a (meth) acrylate-styrene copolymer, a composition thereof, and a molded product thereof.

  Polymethylmethacrylate is excellent in all of processability, physical properties, and mechanical properties. The molded product produced has a good appearance, has a light transmittance of 92%, is superior to glass, and has birefringence. Due to its low (Birefringence), it is currently one of the best polymer transparent materials. Polymethylmethacrylate is also referred to as “organic glass” and is often used as various optical elements such as camera lenses, lenses, car tail lamps, signboards, or consumer products. However, polymethyl methacrylate has excellent optical properties and processability, but has high hygroscopicity.

  Polystyrene has excellent low hygroscopicity and process moldability, but has poor weather resistance, and therefore, when irradiated with light for a long time, coloration and deterioration of mechanical properties occur.

  The methyl methacrylate-styrene copolymer obtained by polymerizing styrene and methyl methacrylate as the main raw material combines the advantages of polystyrene and polymethyl methacrylate, and the disadvantages of both polymers are partially improved. In the application requirements of each optical product (for example, LCD light guide plate), with increasing size, the requirements for optical properties (for example, chromaticity) and moisture absorption properties of resin molded products have become more severe. As a result, the above-mentioned methyl methacrylate-styrene copolymer still cannot satisfy this requirement.

  The present invention combines the advantages of polystyrene and polymethyl methacrylate, and at the same time has a low yellowness and low hygroscopicity, and can be applied to a copolymer composition that forms a molded article (meth) acrylate-styrene A copolymer is provided.

  The (meth) acrylate-styrene copolymer of the present invention comprises 10% to 75% by weight of a (meth) acrylate monomer unit and 25% to 90% by weight of a styrene monomer unit. The content range of pentamer to elevenmer in the (meth) acrylate-styrene copolymer is 500 ppm to 2000 ppm.

  In one embodiment of the present invention, the content range of the (meth) acrylate monomer unit described above is 10 wt% to 60 wt%, and the content range of the styrene monomer unit is 40 wt%. % To 90% by weight.

  In one embodiment of the present invention, the content range of the (meth) acrylate monomer unit described above is 10 wt% to 50 wt%, and the content range of the styrene monomer unit is 50 wt%. % To 90% by weight.

  In one embodiment of the present invention, the content range of the pentamer to elevenmer described above is 500 ppm to 1800 ppm.

  In one embodiment of the present invention, the content range of the pentamer to elevenmer described above is 500 ppm to 1500 ppm.

  In one embodiment of the present invention, the content range of the dimer to trimer in the (meth) acrylate-styrene copolymer described above is 100 ppm to 3000 ppm.

  The (meth) acrylate-styrene copolymer composition of the present invention includes the above-described (meth) acrylate-styrene copolymer.

  In one embodiment of the present invention, the above-described (meth) acrylate-styrene copolymer composition further includes an antioxidant, and the total weight of the (meth) acrylate-styrene copolymer is 100. The content range of the antioxidant is 0.005 to 2 parts by weight with respect to parts by weight.

  In one embodiment of the present invention, the (meth) acrylate-styrene copolymer composition described above further includes a lubricant, and the total weight of the (meth) acrylate-styrene copolymer is 100 parts by weight. On the other hand, the content range of the lubricant is 0.03 to 5 parts by weight.

  The molded article of the present invention is formed from the above-described (meth) acrylate-styrene copolymer composition.

  As described above, the (meth) acrylate-styrene copolymer of the present invention has a (meth) acrylate monomer unit of 10 wt% to 75 wt% and a styrene monomer of 25 wt% to 90 wt%. Including pentamer to elevenmer having a monomer unit and a content range of 500 ppm to 2000 ppm, it not only combines the advantages of polystyrene and polymethylmethacrylate, but also has a low long optical path yellowness (yellow index, YI) value and low hygroscopicity.

  In order to make the above and other objects, features and advantages of the present invention more comprehensible, several embodiments accompanied with figures are described below.

  In the present text, the range displayed as “from one numerical value to another numerical value” is a general display method for avoiding listing all the numerical values within the range in the specification. Accordingly, a depiction of a particular numerical range is meant to include any numerical value within that numerical range and any relatively small numerical range that is limited by any numerical value within that numerical range. The numerical value and the relatively small numerical range are the same as specified.

  Further, in the text, (meth) acrylate ((meth) acrylate) indicates acrylate and / or methacrylate. In the present text, the monomer unit refers to a structural unit formed by polymerizing a monomer.

  The (meth) acrylate-styrene copolymer provided in one embodiment of the present invention comprises 10% to 75% (meth) acrylate monomer units and 25% to 90% by weight. Contains styrenic monomer units. More specifically, in this embodiment, the content range of the (meth) acrylate monomer unit is 10 wt% to 75 wt%, and the content range of the styrene monomer unit is 25 wt% to 90 wt%. %, Since the (meth) acrylate-styrene copolymer has low hygroscopicity, a molded product produced later has excellent size stability; content range of styrene monomer units Is 25 wt% to 90 wt%, and when the content range of the (meth) acrylate monomer unit is 10 wt% to 75 wt%, the (meth) acrylate-styrene copolymer is long. Since the yellow index (YI) value of the optical path is low, a molded product manufactured later is unlikely to cause yellowing even when irradiated with light for a long time.

  In one embodiment, the (meth) acrylate-styrene copolymer is more preferably 10 wt% to 60 wt% of (meth) acrylate monomer units and 40 wt% to 90 wt%. Of styrene monomer units, and more preferably 10% to 50% by weight of (meth) acrylate monomer units and 50% to 90% by weight of styrene monomer units.

  The (meth) acrylate monomer used for the polymerization of the poly (meth) acrylate-styrene copolymer is, for example, (1) methacrylate compounds: methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, octadecyl methacrylate, Phenyl methacrylate, benzyl methacrylate, or 2-ethylhexyl methacrylate; (2) acrylate compounds: methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, or 2-ethylhexyl acrylate ( 2-ethylhexyl acrylate), etc. (but not limited to). The (meth) acrylate monomer of the present invention is more preferably a methacrylate compound.

  Examples of the styrene monomer used for the polymerization of the poly (meth) acrylate-styrene copolymer include, but are not limited to, styrene or substituted styrene compounds. Examples of substituted styrene compounds include (1) styrene compounds substituted with halogen such as chlorostyrene or bromostyrene; (2) vinyl toluene or α-methyl styrene. Styrene compounds substituted with an alkyl group of (but not limited to). The styrenic monomer of the present invention is more preferably selected from styrene and α-methylstyrene.

  The monomers used for the polymerization of the poly (meth) acrylate-styrene copolymer of the present invention include (meth) acrylate-based monomers other than the (meth) acrylate monomers and styrene monomers described above. If necessary, other comonomer may be used within a range that does not significantly impair the effect of the styrene copolymer. More specifically, if the total of the (meth) acrylate monomer and the styrene monomer is 100% by weight, the amount of other copolymer monomers used may be 0% by weight to 30% by weight. Good. Other copolymer monomers include, for example, (1) unsaturated carboxylic acid and its anhydrides: acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc .; (2) maleimide compounds: N -Methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide and the like; (3) (meth) acrylate compounds containing a hydroxy group: glycerol monoacrylate or 2-hydroxyethyl (meth) acrylate (2-hydroxyethyl ( (4) Other compounds containing unsaturated double bonds: acrylamide, acrylonitrile, allyl glycidyl ether, or glycidyl (meth) acrylate) acrylate), etc. (but not limited to).

  In this embodiment, the content range of pentamer to elevenmer in the (meth) acrylate-styrene copolymer is 500 ppm to 2000 ppm. More specifically, in this embodiment, when the content range of the pentamer to the 11-mer is 500 ppm to 2000 ppm, the (meth) acrylate-styrene copolymer has a low YI value, and is produced later. The molded product is less likely to cause yellowing even when irradiated with light for a long time.

  Moreover, in one embodiment, the content range of the pentamer to the 11-mer in the (meth) acrylate-styrene copolymer is more preferably 500 ppm to 1800 ppm, and further preferably 500 ppm. ˜1500 ppm.

  In one embodiment, the pentamer comprises, for example, M5, M4S1, M3S2, M2S3, M1S4, S5, or combinations thereof, where M represents a (meth) acrylate monomer unit and S is styrene A system monomer unit is shown. That is, the pentamer may include a homopentamer, a heteropentamer, or a combination thereof. From another viewpoint, the pentamer is, for example, a (meth) acrylate-styrene pentamer. Based on the above description, hexamer, heptamer, octamer, nonamer, decamer, and elevenmer can be inferred, and thus the description thereof is omitted here. The same applies to dimers and trimers described later.

  It should be mentioned that in this embodiment, the polymer comprises 10% to 75% by weight of (meth) acrylate monomer units and 25% to 90% by weight of styrene monomer units, and is a pentamer. -The content range of the 11-mer is 500 ppm to 2000 ppm, which combines the advantages of polystyrene and polymethylmethacrylate, not only has excellent processability and thermal stability, but also has a lower long optical path YI value and It can also have low hygroscopicity.

  In the present embodiment, the content range of the dimer to trimer in the (meth) acrylate-styrene copolymer described above is more preferably 3000 ppm or less. More specifically, in this embodiment, when the content of the dimer to trimer is 3000 ppm or less, the (meth) acrylate-styrene copolymer has low hygroscopicity. In one embodiment, the content of dimer to trimer is more preferably 100 ppm to 3000 ppm.

  In one embodiment, a method for preparing a (meth) acrylate-styrene copolymer includes preparing a (meth) acrylate-styrene copolymer precursor and then performing a post-treatment on the precursor. Including methods. More specifically, the method of preparing the (meth) acrylate-styrene copolymer precursor is not particularly limited, and a monomer mixture composed of a styrene monomer and a (meth) acrylate monomer The radical initiator can be completed by a solution copolymerization reaction or a bulk copolymerization reaction, and is preferably completed by a copolymerization reaction in the presence of a solvent. In the monomer mixture described above, the content of the styrenic monomer is 25% to 90% by weight, more preferably 40% to 90% by weight, and still more preferably 50% to 90% by weight. 90% by weight. The content of the (meth) acrylate monomer is 10% to 75% by weight, more preferably 10% to 60% by weight, and still more preferably 10% to 50% by weight. .

  Moreover, the radical initiator mentioned above is not specifically limited here, You may use individually or may be used in mixture. Examples of radical initiators are: (1) Azo compounds: 2,2′-azobis (isobutyronitrile) (2,2′-azobis- (isobutyronitrile), AIBN), 2,2′-azobis (2- Methylbutyronitrile) (2,2'-azobis- (2-methyl butyronitrile, AMBN) or 2,2'-azobis (2,4-dimethylvaleronitrile) (2,2'-azobis- (2,4 (2) diacyl peroxide compounds: dilauroyl peroxide, decanoyl peroxide, or dibenzoyl peroxide (BPO), etc .; 3) Dialkyl peroxide compounds: 2,5-dimethyl-2,5-di (t-butylperoxy) hexane) (2,5-dimethyl-2,5-di- (t-butylperoxy) hexane) ), Dicumyl peroxide, Or 1,3-bis (t-butylperoxyisopropyl) benzene) (1,3-bis- (t-butylperoxyisopropyl) benzene), etc .; (4) peroxyester compounds: t-butyl T-butyl peroxypivalate or 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane) (2,5-dimethyl-2,5-di (2-ethyl hexanoyl peroxy) hexane) etc .; (5) peroxycarbonate compounds: t-amyl peroxy 2-ethylhexyl carbonate or t-butyl peroxy 2-ethylhexyl carbonate 2-ethylhexyl carbonate) and the like; (6) peroxydicarbonate compounds: dimyristyl peroxydicarbonate or di (4- -Butyl cyclohexyl) peroxydicarbonate (di (4-tert-butyl cyclohexyl) peroxydicarbonate) and the like; (7) peroxyketal compounds: 1,1, -di (t-butylperoxy) -3, 3,5-trimethylcyclohexane) (1,1-di (tert-butylperoxy) -3,3,5-trimethylcyclohexane) or 2,2-di (4,4-di (t-butylperoxy) cyclohexyl) Propane (2,2-di (4,4-di (tert-butyl peroxy) cyclohexyl) propane), etc .; (8) Hydroperoxide compounds: t-butyl hydroperoxide or isopropyl (9) Others: 2,3-dimethyl-2,3-diphenyl butane and the like (however, this includes, but is not limited to, isopropyl cumyl hydroperoxide) Not limited). The amount of radical initiator used is 0.01 parts by weight to 1 part by weight, more preferably 0.01 parts by weight to 0.5 parts by weight, based on 100 parts by weight of the total monomer mixture. Preferably, it is 0.01 weight part-0.1 weight part.

  In addition, the reactor used for the above-described reaction can be a continuous stirred tank reactor (CSTR), a laminar flow reactor, a plug flow reactor (PFR), or a static mixing reactor. It may be one type of static mixing reactor or a combination of different types. In addition, the above-described reaction can proceed at room temperature, and the reaction system can be heated to increase the polymerization reaction rate. Specifically, the reaction temperature range may be from 25 ° C to 200 ° C, more preferably from 50 ° C to 180 ° C; the reaction operation time range is from 6 hours to 10 hours, The reaction pressure range may be 400 to 800 torr.

  The boiling point of the above-mentioned solvent is most preferably close to the boiling point of the main monomer used in the polymerization reaction. For example, a solvent having a boiling point close to that of the (meth) acrylate monomer or styrene monomer is used. Optionally, the mixture formed by the solvent and the above-described monomers has a relatively narrow boiling range, thereby reducing the probability that contaminants will be introduced when the mixture circulates back. On the other hand, it is not necessary to carry out an intermediate fractionation process. Specifically, the solvent may have a boiling range of 40 ° C. to 225 ° C., more preferably a hydrocarbon solvent or an aromatic hydrocarbon solvent of 60 ° C. to 180 ° C., and an example thereof is hexane. , Heptane, octane, benzene, toluene, p-xylene, o-xylene, m-xylene, ethylbenzene, cyclohexane, cyclodecane, or isooctane, including but not limited to, May be used.

  The post-treatment method of the (meth) acrylate-styrene copolymer precursor is not particularly limited, and for example, a solvent treatment method can be used. The solvent treatment method uses different solvents to generate different solubilities for the (meth) acrylate-styrene copolymer precursor, and the (meth) acrylate-styrene copolymer precursor oligomers. This is a method for preparing the (meth) acrylate-styrene copolymer of the present invention by controlling the content. Specifically, the solvent treatment method includes the following steps: First, a solvent mixture is formulated based on the required solubility. The solvent mixture described above comprises a solvent having good solubility in the (meth) acrylate-styrene copolymer precursor and a solvent having poor solubility in the (meth) acrylate-styrene copolymer precursor. Including. Solvents with good solubility for the (meth) acrylate-styrene copolymer precursor are hexane, heptane, octane, benzene, toluene, chloroform, p-xylene, o-xylene, m-xylene, ethylbenzene, cyclohexane, Solvents that are poorly soluble in (meth) acrylate-styrene copolymer precursors include, but are not limited to, tetrahydrofuran, cyclodecane, or isooctane; acetone, dimethylformamide, methanol, ethanol, cyclohexanone, Including, but not limited to, dimethylacetamide, dimethylsulfoxide, or 1,4-dioxane. More specifically, the type and content of the solvent contained in the solvent mixture are not particularly limited as long as the required solubility can be achieved.

  Subsequently, the solvent mixture and the (meth) acrylate-styrene copolymer precursor are mixed. More specifically, in this step, the solvent mixture generates a specific solubility for the (meth) acrylate-styrene copolymer precursor, so that the undissolved portion is precipitated.

  Then, the part which precipitated in the above-mentioned step is taken out, and a devolatilization process is performed with respect to the part mentioned above with the devolatilizer. If it demonstrates in detail, the devolatilization apparatus mentioned above is a devolatilization tank provided with the vacuum pump installation, for example. One devolatilization tank may be used, or a plurality of devolatilization tanks may be connected in series. The temperature of the devolatilization tank is controlled to 210 ° C. to 280 ° C., more preferably 220 ° C. to 270 ° C. The degree of vacuum of the devolatilization tank is controlled to 100 torr or less, and more preferably 30 torr or less. Further, the above-described devolatilization apparatus may be other suitable devolatilization equipment such as a single-screw or twin-screw extruder provided with a devolatilization port and a thin film evaporator.

  It should be mentioned that in the solvent treatment method, the number of the above three steps is not particularly limited, and is 10% to 75% by weight of (meth) acrylate monomer unit and 25% to 90% by weight. It is only necessary to obtain a (meth) acrylate-styrene copolymer having a content range of pentamer to elevenmer in the range of 500 ppm to 2000 ppm.

  In addition, the above-described embodiment discloses that a (meth) acrylate-styrene copolymer is prepared by performing a solvent treatment method on a (meth) acrylate-styrene copolymer precursor. However, the present invention is not limited to this. In another embodiment, a (meth) acrylate-styrene copolymer is prepared using or combining methods such as use of a polymerization process, equipment control, enhanced devolatilization, devolatilized recovery liquid purification, and the like. The objective may be achieved.

  The (meth) acrylate-styrene copolymer composition provided by another embodiment of the present invention includes any one (meth) acrylate-styrene copolymer in the above-described embodiment. Since the related description of the (meth) acrylate-styrene copolymer has already been described in detail in the above-described embodiment, it will not be repeated here.

  In the present embodiment, the (meth) acrylate-styrene copolymer composition is selectively added with an additive as long as the effect of the (meth) acrylate-styrene copolymer is not significantly impaired. The additives mentioned above may be, for example, antioxidants, lubricants, processing aids, UV absorbers, UV stabilizers, antistatic agents, fillers, reinforcing agents, colorants, thermal stabilizers, thermal discoloration. Examples thereof include, but are not limited to, an inhibitor, a light diffusing agent, a plasticizer, a flame retardant, a flame retardant aid, a coupling agent, and other additives. Moreover, the addition time of the additive is not particularly limited, and the additive may be added before the polymerization reaction, during the polymerization reaction, or after the polymerization reaction if actually required for the process.

  Antioxidants may be used alone or in combination, and include, but are not limited to, phenolic antioxidants, thioether antioxidants, phosphorus antioxidants, and the like. ). The content range of the above-mentioned antioxidant is 0.005 parts by weight to 2 parts by weight with respect to 100 parts by weight of the total weight of the (meth) acrylate-styrene copolymer.

  Examples of phenolic antioxidants are n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-t-butyl-5-methyl -4-hydroxyphenyl) propionate], tetra [methylene-3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate] methane, 2-t-butyl-6- (3-t-butyl- 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-t) -Butylphenol), 2,2'-thio-diethylene-bis [3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate], and Includes, but is not limited to, 2,2'-ethylenediamide-bis [ethyl-3- (3,5-bis-t-butyl-4-hydroxyphenyl) propionate] and the like.

  Examples of thioether antioxidants include distearoyl thiodipropionate, dipalmitoyl thiodipropionate, erythritol-tetra- (β-dodecyl-thiopropionate), or bisoctadecyl thioether. Not limited to).

  Illustrative examples of phosphorus antioxidants include phosphorous acids, phosphoric acids, phosphonous acids, phosphonic acids, phosphites, phosphate esters, phosphonites, phosphonates, tertiary phosphines, Including, but not limited to, triorganophosphates or compounds of acidic phosphates. Of the phosphorous antioxidants described above, compounds of phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, triorganophosphoric acid ester, or acidic phosphoric acid ester are particularly preferable. Moreover, among acidic phosphoric acid ester compounds, the organic group can include mono-, di-, or poly-substitution. The compounds exemplified below may be used alone or in combination.

  Examples of triorganophosphate compounds are trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, tridodecyl phosphate, trilauryl phosphate, tristearin. Including phosphate ester, tricresyl phosphate ester, triphenyl phosphate ester, trichlorophenyl phosphate ester, diphenyl cresyl phosphate ester, diphenyl mono-O-biphenyl phosphate ester, or tris (butoxyethyl) phosphate ester But not limited to this). More preferably, the triorganophosphate compound is a trialkylphosphate compound; more preferably, the alkyl group in the trialkylphosphate compound described above has 1 to 22 carbon atoms; More preferably, the carbon number of the alkyl group in the trialkyl phosphate compounds described above is 1 to 4. In one embodiment, the trialkyl phosphate ester compound is a trimethyl phosphate ester.

  Examples of acidic phosphate compounds include methyl acidic phosphate, ethyl acidic phosphate, butyl acidic phosphate, butoxyethyl acidic phosphate, octyl acidic phosphate, decyl acidic phosphate, lauryl acidic phosphate. Acid ester, stearic acid phosphate ester, oil acid phosphate ester, docosyl acid phosphate ester, phenyl acid phosphate ester, nonylphenyl acid phosphate ester, cyclohexyl acid phosphate ester, phenoxyethyl acid phosphate ester, alkoxy polyethylene glycol An acidic phosphate ester, a bisphenol A acidic phosphate ester, or the like is included (but not limited thereto). Among the above-mentioned acidic phosphate compounds, the long-chain dialkyl acidic phosphate ester having 10 or more carbon atoms has a high thermal stability, and also has a (meth) acrylate-styrene copolymer composition. It is also possible to effectively increase the thermal stability of the object.

  Examples of phosphite compounds are triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, tri (octadecyl) phosphite, didecyl Phenyl phosphite, Dioctylphenyl phosphite, Diisopropylphenyl phosphite, Butyl diphenyl phosphite, Decyl diphenyl phosphite, Octyl diphenyl phosphite, Tris (diethylphenyl) phosphite , Tri (diisopropylphenyl) phosphite, tris (di-n-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2,6-di -T-butylphenyl) phosphite Ter, distearyl pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) Pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis {2,4-bis (1-methyl-1-phenylethyl) Phenyl} pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dicyclohexylpentaerythritol diphosphite, etc. Not limited to).

  The lubricant may be used alone or in combination, and (1) metal soap: calcium stearate, magnesium stearate, lithium stearate, etc .; (2) compound: ethylene bis (stearamide) ( ethylene bis (stearamide), methylene bis (stearamide), palmitic acid amide, butyl stearate, stearic acid palmitic acid, polypropionic acid alcohol tristearic acid ester, pentaerythritol stearate ester, behenic acid (docosanoic acid), stearin Acids, sterols, etc .; (3) Waxes: including polyethylene wax, octacosanoic acid wax, Carnauba wax, or petroleum waxes; (4) Higher alcohols: including stearyl alcohol (however, This But it is not limited to). The content range of the lubricant is 0.03 parts by weight to 5 parts by weight with respect to 100 parts by weight of the total weight of the (meth) acrylate-styrene copolymer.

  The processing aid can improve the extrudability and thermoformability. For example, an acrylate-based processing aid or a core-shell type processing aid having a weight average molecular weight of 500,000 or more can be used. You can choose. The processing aids described above may be used alone or in combination.

  The ultraviolet absorber may be used alone or in combination, and includes a benzotriazole compound, a benzophenone compound, a cyanoacrylic acid compound, and the like ( However, it is not limited to this).

  The ultraviolet stabilizer may be used alone or in combination, and includes (but is not limited to) a hindered amine compound.

  The content ranges of the processing aid, the ultraviolet absorber, and the ultraviolet stabilizer described above with respect to the total weight of 100 parts by weight of the (meth) acrylate-styrene copolymer are 0.02 to 2.0 parts by weight, respectively. Parts by weight.

  The antistatic agent may be used alone or in combination, and it is a permanent antistatic property such as a tertiary amine compound, a low molecular weight compound such as a quaternary ammonium salt compound, or a polyamide polyether. Including, but not limited to, polymers having

  Fillers may be used alone or mixed and include (but are not limited to) calcium carbonate, siliceous earth, mica and the like.

  The reinforcing agent may be used alone or in combination, and includes (but is not limited to) glass fiber, carbon fiber, various whiskers and the like.

  The colorant may be used alone or in combination, and includes (but is not limited to) titanium oxide, iron oxide, graphite, phthalocyanine dye, and the like.

  The light diffusing agent may be used alone or in combination, and (1) inorganic diffusing agent: aluminum oxide, silicon dioxide, magnesium oxide, iron oxide, titanium dioxide, zinc oxide, tin oxide, Inorganic particles such as silicon nitride, aluminum nitride, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, calcium silicate, aluminum silicate, zirconium silicate, or potassium titanate; (2) organic diffusing agent: epoxy resin, Including resin particles such as melamine resin, urea resin, (meth) acrylate resin, polyorganosiloxane resin, phenol resin, polyimide resin, polyamide resin, polyester resin, or Teflon resin (however, Not limited to this).

  As mentioned above, as mentioned above, the (meth) acrylate-styrene copolymer not only has excellent processability and thermal stability, but also has a low YI value and low hygroscopicity at the same time. The (meth) acrylate-styrene copolymer composition also has excellent processability and thermal stability, low YI value, and low hygroscopicity. Therefore, the (meth) acrylate-styrene copolymer composition of the present embodiment can be applied to the production of a molded article, and the properties required for the production of a subsequent molded article by blending the additive. Can be matched.

  The molding provided by another embodiment of the present invention is formed from any of the (meth) acrylate-styrene copolymer compositions in the above-described embodiments. Since the related description of the (meth) acrylate-styrene copolymer composition has been described in detail in the above-described embodiment, it will not be repeated here.

  The molded article may be various molded articles manufactured by injection molding, compression molding, or various molded articles manufactured by extrusion molding, blow molding, thermoforming, vacuum molding, or hollow molding. More specifically, examples of molded products include (but are not limited to) optical grade plates (for example, light guide plates, diffusion plates, etc.) and thin film molded products.

  As mentioned above, as described above, since the (meth) acrylate-styrene copolymer has a low YI value and low hygroscopicity, it is produced from the (meth) acrylate-styrene copolymer composition. The molded article is less susceptible to yellowing even when irradiated with light for a long time, and is less susceptible to structural deformation due to the influence of moisture and steam. Therefore, the molded product of this embodiment is excellent in service life, storage stability, and size stability, and is particularly suitable as an optical grade plate.

Hereinafter, the features of the present invention will be described more specifically with reference to Examples 1 to 9 and Comparative Examples 1 to 9. Examples 1 to 9 below will be described. However, materials used, amounts and ratios, processing details, processing procedures, and the like may be appropriately changed as long as they do not exceed the scope of the present invention. Accordingly, the present invention should not be construed as limited to the examples set forth below.

Synthesis Examples 1-11
Preparation of a composition containing a (meth) acrylate-styrene copolymer precursor

  The polymerization apparatus for preparing the composition containing the (meth) acrylate-styrene copolymer precursors of Synthesis Examples 1 to 11 includes a fully mixed reactor, a laminar flow reactor, and a devolatilizer. To clearly illustrate the preparation process, Synthesis Example 1 below is described, and all other synthesis examples are prepared in a similar manner.

  Based on the type and amount of each component shown in Table 1, each component is continuously placed in the above-described complete mixing reactor to perform a continuous solution polymerization reaction. The reaction temperature is maintained at 100 ° C. and the pressure is 600 torr. Each component is sufficiently stirred and mixed in the mixing reactor to form a reaction, and after holding for about 3.5 hours, the above-described reactants are continuously put into the above-described laminar flow reactor. In the laminar flow reactor described above, after holding for about 5 hours, a polymer solution is formed. Then, after putting the polymer solution mentioned above in the devolatilizer mentioned above and heating to 235 degreeC, a devolatilization process is performed in a pressure-reduced environment, The (meth) acrylate type-styrene-type copolymer of the synthesis example 1 A composition containing the precursor is prepared.

  In Table 1, a (parts by weight) is calculated based on the total weight of the monomer mixture being 100 parts by weight; b (parts by weight) is the total of the (meth) acrylate-styrene copolymer. The weight is calculated as 100 parts by weight.

[Example 1]
Preparation of (meth) acrylate-styrene copolymer composition

A composition containing 100 parts by weight of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 1 was added to a solvent mixture composed of 100 parts by weight of ethylbenzene and 600 parts by weight of acetone, and homogeneously added. Stir and mix. Subsequently, the portion that did not dissolve in the solvent mixture and precipitated was removed by filtration. Then, after putting the taken-out part into a devolatilizer and heating to 235 ° C., the (meth) acrylate-styrene-copolymer of Example 1 was performed by performing a devolatilization step under a reduced pressure environment (30 torr). A polymer composition is prepared.
[Example 2]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 2 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 2 was 100 wt. Part of the composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 2 is added to a solvent mixture composed of 100 parts by weight of cyclohexane and 500 parts by weight of methanol.
[Example 3]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 3 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 3 was 100 wt. A composition containing 3 parts of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 3 is added to a solvent mixture composed of 100 parts by weight of toluene and 500 parts by weight of dimethylformamide.
[Example 4]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 4 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 4 was 100 wt. A composition containing 4 parts of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 4 is added to a solvent mixture composed of 100 parts by weight of octane and 400 parts by weight of dimethyl sulfoxide.
[Example 5]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 5 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 5 was 100 wt. The solvent treatment method was performed twice using the composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 5 and the first solvent treatment method was performed using 100 parts by weight of ethylbenzene and 300 parts by weight. A solvent mixture composed of parts by weight of acetone is used, and the second solvent treatment method uses a solvent mixture composed of 100 parts by weight of cyclohexane and 400 parts by weight of methanol.
[Example 6]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 6 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 6 was 100 wt. A composition containing part of Synthesis Example 6 (meth) acrylate-styrene copolymer precursor is added to a solvent mixture composed of 100 parts by weight of ethylbenzene and 450 parts by weight of acetone.
[Example 7]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 7 was prepared by the same preparation process as in Example 1, and the main differences were as follows: Example 7 was 100 wt. A composition containing part of Synthesis Example 7 (meth) acrylate-styrene copolymer precursor is added to a solvent mixture composed of 100 parts by weight of ethylbenzene and 450 parts by weight of acetone.
[Example 8]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 8 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 8 was 100 wt. A composition comprising part (8) of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 8 is added into a solvent mixture composed of 100 parts by weight ethylbenzene and 500 parts by weight acetone.
[Example 9]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Example 9 was prepared by the same preparation process as Example 1, and the main differences were as follows: Example 9 was 100 wt. A composition comprising part (9) of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 9 is added to a solvent mixture composed of 100 parts by weight ethylbenzene and 550 parts by weight acetone.
[Comparative Example 1]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Comparative Example 1 was prepared by the same preparation process as in Example 1, and the differences were mainly as follows: Comparative Example 1 was 100 wt. The solvent treatment method was performed 4 times using the composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 1 and the first solvent treatment method was performed using 100 parts by weight of ethylbenzene and 350 parts by weight. A solvent mixture composed of parts by weight of acetone was used, the second solvent treatment method used was a solvent mixture composed of 100 parts by weight cyclohexane and 300 parts by weight methanol, and the third solvent treatment method was A solvent mixture composed of 100 parts by weight toluene and 400 parts by weight dimethylformamide, and the fourth solvent treatment method consists of 100 parts by weight octane and 4 parts by weight. 0 using the configured solvent mixture with dimethyl sulfoxide parts.
[Comparative Example 2]
Preparation of (meth) acrylate-styrene copolymer composition

The (meth) acrylate-styrene copolymer composition of Comparative Example 2 was prepared by the same preparation process as in Example 1, and the main differences were as follows: Comparative Example 2 was 100 wt. A composition containing 10 parts of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 10 is added to a solvent mixture composed of 100 parts by weight of ethylbenzene and 550 parts by weight of acetone.
[Comparative Example 3]

A composition containing 100 parts by weight of the (meth) acrylate-styrene copolymer precursor of Synthesis Example 5 is placed directly in a vacuum oven and treated for 1 hour at a vacuum of 1000 Pa and a temperature of 250 ° C. To prepare the (meth) acrylate-styrene copolymer composition of Comparative Example 3.
[Comparative Example 4]

As the (meth) acrylate-styrene copolymer composition of Comparative Example 4, a composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 1 without any treatment is directly used. .
[Comparative Example 5]

As the (meth) acrylate-styrene copolymer composition of Comparative Example 5, a composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 9 without any treatment is directly used. .
[Comparative Example 6]

The (meth) acrylate-styrene copolymer composition of Comparative Example 6 directly uses a composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 10 without any treatment. .
[Comparative Example 7]

For the (meth) acrylate-styrene copolymer composition of Comparative Example 7, a composition containing the (meth) acrylate-styrene copolymer precursor of Synthesis Example 11 without any treatment is directly used. .
[Comparative Example 8]

Unlike Examples 1-9 and Comparative Examples 1-7, Comparative Example 8 does not prepare a (meth) acrylate-styrene copolymer composition by itself, but is commercially available from TX-800LF (Electrochemical Co., Ltd.). ) Directly.
[Comparative Example 9]

  Unlike Examples 1-9 and Comparative Examples 1-7, Comparative Example 9 does not prepare a (meth) acrylate-styrene copolymer composition by itself and is a commercial product MS-500 (purchased from Nippon Steel Corporation). Use directly.

Then, with respect to the (meth) acrylate-styrene copolymer compositions of Examples 1 to 9 and Comparative Examples 1 to 9, respectively, the content of the monomer unit of the (meth) acrylate-styrene copolymer Is measured, the oligomer content in the (meth) acrylate-styrene copolymer is measured, the long optical path yellowness (YI) is measured, and the hygroscopicity is measured. The description and evaluation criteria for each measurement described above are as follows, and the measurement results and evaluation results are as shown in Table 2.
<Measurement of monomer unit content>

First, each of the (meth) acrylate-styrene copolymer compositions of Examples 1 to 9 and Comparative Examples 1 to 9 was measured using a nuclear magnetic resonance (NMR) analysis method. Acquire a magnetic resonance hydrogen spectrum. Subsequently, the contents of the (meth) acrylate monomer unit and the styrene monomer unit are calculated from the area ratio of specific wave peaks in the nuclear magnetic resonance hydrogen spectrum. (Wt%) in Table 2 is calculated based on the total weight of the (meth) acrylate-styrene copolymer.
<Measurement of oligomer content>

Using a gas chromatograph (Agilent; number: 7890) and a liquid chromatograph mass spectrometer (Agilent; number: G2246A) having a flame ionization detector (FID) The (meth) acrylate-styrene copolymer compositions of Examples 1-9 and Comparative Examples 1-9 are each analyzed and quantified. (Ppm) in Table 2 is calculated based on the total weight of the (meth) acrylate-styrene copolymer.
<Measurement of long optical path yellowness (YI)>

Test pieces of 220 mm × 20 mm × 3 mm were prepared using the (meth) acrylate-styrene copolymer compositions of Examples 1-9 and Comparative Examples 1-9, respectively, and a long optical path spectral transmission colorimeter (NEC) The YI value of the test piece is measured by Color Industry Co., Ltd .; model number: NIPPON DENSHOKU ASA-1).
○: YI <5.50;
Δ: 5.50 ≦ YI <7.50;
X: YI ≧ 7.50.
<Measurement of hygroscopicity>

Each test piece obtained by YI measurement is weighed to obtain a weight value W1. Then, after immersing these test pieces in 60 degreeC water for 24 hours, it takes out and wipes off the surface with a dust-free cloth. Thereafter, these test pieces are again weighed to obtain a weight value W2. The hygroscopicity is calculated by the following formula and evaluated according to the following criteria.
Hygroscopicity (%) = [(W2-W1) / (W1)] × 100%
○: Hygroscopicity <1.5%;
Δ: 1.5% ≦ hygroscopicity <5%;
X: Hygroscopicity ≧ 5%.

  As can be seen from Table 2 above, the (meth) acrylate-styrene copolymer compositions of Examples 1 to 9 are excellent in both long-path yellowness and hygroscopicity. This result comprises 10% to 75% by weight of (meth) acrylate monomer units and 25% to 90% by weight of styrene monomer units, and (meth) acrylate-styrene copolymer The content range of pentamer to elevenmer in the coalescence is 500 ppm to 2000 ppm, so that the (meth) acrylate-styrene copolymer composition has a low YI value and a low hygroscopicity at the same time. Demonstrate.

  Moreover, as can be seen from Table 2 above, the contents of dimer to trimer in the (meth) acrylate-styrene copolymer compositions of Examples 1 to 9 are all 3000 ppm or less. .

  Moreover, as can be seen from Table 2 above, the content of pentamer to eleven monomer in the (meth) acrylate-styrene copolymer composition of Comparative Example 1 is much lower than 500 ppm, YI value is high.

  Moreover, as can be seen from Table 2 above, the content of pentamer to eleven monomer in the (meth) acrylate-styrene copolymer composition of Comparative Example 2 is between 500 ppm and 2000 ppm. However, since the content of the (meth) acrylate monomer unit is higher than 75% by weight, the (meth) acrylate-styrene copolymer composition has poor hygroscopicity.

  Further, as can be seen from Table 2 above, the (meth) acrylate-styrene copolymer composition of Comparative Example 3 in which the content of the oligomer was adjusted by performing vacuum heat treatment in the preparation process was a dimer- Although the content of trimer is low, the YI value is high because the content of pentamer to elevenmer is still higher than 2000 ppm.

  As described above, the present invention has been disclosed by the embodiments. However, the present invention is not intended to limit the present invention, and is within the scope of the technical idea of the present invention so that those skilled in the art can easily understand. Therefore, the scope of patent protection should be defined based on the scope of claims and the equivalent area.

Claims (10)

10% by weight to 75% by weight of a (meth) acrylate monomer unit;
25% to 90% by weight of styrenic monomer units;
(Meth) acrylate-styrene copolymer in which the content range of pentamer to elevenmer in the (meth) acrylate-styrene copolymer is 500 ppm to 2000 ppm.   The content range of the (meth) acrylate monomer unit is 10% by weight to 60% by weight, and the content range of the styrene monomer unit is 40% by weight to 90% by weight. The (meth) acrylate-styrene copolymer described.   The content range of the (meth) acrylate monomer unit is 10 wt% to 50 wt%, and the content range of the styrene monomer unit is 50 wt% to 90 wt%. The (meth) acrylate-styrene copolymer described.   2. The (meth) acrylate-styrene copolymer according to claim 1, wherein a content range of the pentamer to the 11-mer is 500 ppm to 1800 ppm.   2. The (meth) acrylate-styrene copolymer according to claim 1, wherein a content range of the pentamer to the 11-mer is 500 ppm to 1500 ppm.   The (meth) acrylate-styrene copolymer according to claim 1, wherein the content range of dimer to trimer in the (meth) acrylate-styrene copolymer is 100 ppm to 3000 ppm.   A (meth) acrylate-styrene copolymer composition comprising the (meth) acrylate-styrene copolymer according to any one of claims 1 to 6.   An antioxidant is further included, and the content range of the antioxidant is 0.005 to 2 parts by weight with respect to 100 parts by weight of the total weight of the (meth) acrylate-styrene copolymer. Item 8. The (meth) acrylate-styrene copolymer composition according to Item 7.   The lubricant content is further included, and the content range of the lubricant is 0.03 to 5 parts by weight with respect to 100 parts by weight of the total weight of the (meth) acrylate-styrene copolymer. (Meth) acrylate-styrene copolymer composition.   The molded product formed from the said (meth) acrylate type-styrene-type copolymer composition of any one of Claims 7-9.