JP2014077044A - Method of producing nuclear hydrogenated polymer using material containing no sulfur - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a nuclear hydrogenated polymer with a high nuclear hydrogenation rate quickly and with good reproducibility.SOLUTION: This invention provides a method of producing a nuclear hydrogenated polymer by nuclear hydrogenating the aromatic ring portion of an aromatic polymer using a supported catalyst. The method is characterized in that the sulfur content is less than 50 mass ppm in an analysis based on JIS-K2541-6 in the aromatic polymer.

Description

In the present invention, the aromatic ring part of an aromatic polymer not containing sulfur as a polymer component or a trace impurity is hydrogenated in the presence of a catalyst (hereinafter sometimes referred to as nuclear hydrogenation), thereby promptly. In addition, the present invention relates to a method for producing an aromatic hydrogenated polymer with good reproducibility.

In recent years, amorphous plastics such as acrylic resin, methacrylic resin, styrene resin, polycarbonate resin, and cyclic polyolefin resin have been used in various applications. There is much demand as optical materials such as. This type of optical material is required to have not only high transparency but also high performance with excellent balance of high heat resistance, low water absorption, mechanical properties and the like.

Conventionally used materials do not have all of these requirements but have problems to be solved. For example, polystyrene has the disadvantages that it is mechanically brittle, has a large birefringence, and has poor transparency. Polycarbonate is excellent in heat resistance, but it also has a large birefringence and transparency is almost the same as that of polystyrene. Polymethyl methacrylate has high transparency but high water absorption, so that it has poor dimensional stability and low heat resistance. Polyvinylcyclohexane obtained by nuclear hydrogenation of polystyrene is excellent in transparency, but has a problem that mechanical strength is weak, heat resistance is poor, and adhesion to other materials is also poor (see, for example, Patent Documents 1 to 3). As a method for improving the adhesion, there is an example (Patent Document 4) in which a polystyrene hydride, a conjugated diene-polystyrene double bond and an aromatic ring hydride, and a saturated hydrocarbon resin are mixed, but the operation is complicated. is there. In addition, after copolymerizing a vinyl aromatic compound such as styrene and an unsaturated dibasic acid such as maleic anhydride, when 30% or more of the aromatic ring is hydrogenated, transparency and birefringence are higher than those of polystyrene. Although an improved example is disclosed (Patent Document 5), the optical properties are still inferior to those of acrylic resins.

Among these resins, a copolymer of methyl methacrylate (hereinafter referred to as MMA) and styrene (hereinafter referred to as MS resin) has high transparency, and has dimensional stability, rigidity, specific gravity and the like. Although the resin is excellent in balance, there is a problem that the birefringence is large. However, when the MS resin is nuclear hydrogenated, the birefringence is improved as compared with the raw material MS resin, and a resin (hereinafter referred to as MSH) having an excellent balance of transparency, heat resistance and mechanical properties is obtained. In particular, when the MS resin having 50% or more of MMA-derived sites in the molecule is nucleated, the improvement in birefringence becomes significant (Patent Document 6).

A method of hydrogenating an aromatic ring polymer in the presence of a hydrogenation catalyst is already known (for example, Patent Document 7). Many examples relating to hydrogenation of polymers such as conjugated diene polymers as well as aromatic ring polymers (Patent Document 8, etc.) are known, and hydrogenation catalysts include metals such as Pd, Pt, Rh, Ru, Re, and Ni. Is mainly used which is supported on a carrier such as activated carbon, alumina, silica or diatomaceous earth.

However, the hydrogenation of the polymer is difficult to react due to its high molecular weight, and it is difficult to obtain a high nuclear hydrogenation rate and a sufficient reaction rate. It is also known that the activity is likely to decrease due to repeated reactions. In order to improve them, the catalyst carrier type, pore structure and particle size have been devised (Patent Documents 2, 9, 10, 11, 12). Various studies have also been made on solvents, and examples have been reported in which esters are selected while avoiding ethers having a low ignition point and hydrocarbons having low resin solubility (Patent Document 6, etc.). .

  While studies have been made on catalysts and solvents, aromatic polymers that are nuclear hydrogenated often start with descriptions of the blending ratio and molecular weight distribution of the component monomers. There are few examples that give detailed descriptions. In industrial polymer production, reactants such as polymerization initiators, chain transfer agents, and polymerization terminators are used, and after the reaction, chemicals such as antioxidants and UV absorbers are kneaded as stabilizers. Generally, it is commercially available. Some of these reactants and stabilizers remaining in the polymer significantly inhibit the nuclear hydrogenation reaction of the aromatic ring, and depending on the aromatic polymer used, the reactivity of the nuclear hydrogenation reaction, Reproducibility and physical properties of hydrogenated polymer may be greatly affected.

As described above, in producing aromatic ring hydrogenated polymers having high optical properties, clarifying the relationship to impurities in the raw material resin leads to the establishment of a stable and rapid production method of the polymer, and industrially. Is also useful.

JP 2003-138078 A Japanese Patent No. 3094555 JP 2004-149549 A Japanese Patent No. 2725402 Japanese Patent Publication No. 7-94496 JP 2006-89713 A German Patent Application No. 1131885 JP-A-1-213306 Japanese National Patent Publication No. 11-504959 Japanese Patent No. 3200057 JP 2002-521509 A Special table 2002-521508 gazette

The present invention provides a method for producing an aromatic ring hydrogenated polymer (nuclear hydrogenated polymer) having a high nuclear hydrogenation rate quickly and with good reproducibility.

As a result of intensive studies, the inventors of the present invention, when using an aromatic polymer containing a sulfur content as a trace impurity such as a polymer component or additive, the hydrogenation catalyst is greatly inhibited, and the nuclear hydrogenated polymer It has been found that the acquisition of the above is hindered, and the present invention has been achieved.

That is, the present invention relates to a method for producing a nuclear hydrogenated polymer by nuclear hydrogenation of an aromatic ring portion of an aromatic polymer using a supported catalyst, wherein the analysis is based on JIS-K2541-6 in the aromatic polymer. In which a sulfur content is less than 50 ppm by mass.
The present invention also relates to a nuclear hydrogenated polymer obtained by the production method.
Furthermore, the present invention relates to an optical material containing the nuclear hydrogenated polymer.

According to the present invention, by using an aromatic ring polymer that does not contain a sulfur component as a polymer component or a trace impurity, the aromatic ring in the polymer can be hydrogenated quickly and with good reproducibility. The obtained nuclear hydrogenated polymer exhibits various physical properties such as high transparency, low birefringence, high heat resistance, high surface hardness, low water absorption, and low specific gravity. In particular, the present invention has excellent characteristics as an optical material, and can be used for a wide range of applications such as an optical lens, a light guide plate, a light diffusion plate, an optical disk substrate material, a front panel, and the like, and thus has great industrial significance.

Hereinafter, the present invention will be described in detail. In the present invention, the aromatic polymer used for nuclear hydrogenation preferably has a sulfur content reduced as much as possible as a polymer constituent or a trace impurity. Specifically, in the analysis based on JIS-K2541-6 in the aromatic polymer, the sulfur content is less than 50 ppm by mass, desirably less than 10 ppm by mass, and more desirably less than 3 ppm by mass. In the radical polymerization of a polymer, a polymerization initiator or a chain transfer agent is often used, and usually those containing sulfur atoms such as mercaptan and thiol are selected from the viewpoint of price and handling. It is desirable to use no sulfur-free substitutes. In the presence of sulfur, the nuclear hydrogenation reaction becomes extremely slow, and in order to obtain the desired hydrogenation rate, it is necessary to use a large amount of hydrogenation catalyst, higher temperature and pressure reaction conditions, and longer reaction time. . If the hydrogenation does not proceed, the resin remaining without being hydrogenated is not preferable because optical properties and mechanical properties are significantly lowered.

Specific examples of the aromatic polymer used in the present invention include polymers having an aromatic vinyl compound as a monomer such as styrene, α-methylstyrene, p-hydroxystyrene, alkoxystyrene, and chlorostyrene. A polymer as a monomer is preferred. It is also possible to copolymerize two or more types of aromatic vinyl compounds.

  In the present invention, it is possible to hydrogenate a polymer composed only of an aromatic vinyl compound. However, for the purpose of improving surface adhesion and optical properties, other units that can be copolymerized with an aromatic vinyl compound are used. It is also possible to hydrogenate a copolymer obtained by copolymerizing a monomer. Examples of the copolymerizable monomer include unsaturated fatty acid esters, cyanovinyl compounds, unsaturated dibasic acids or derivatives thereof, and unsaturated fatty acids or derivatives thereof. In order to improve optical properties, a combination with an unsaturated fatty acid ester is particularly preferable, and a combination with (meth) acrylate is particularly preferable. Specifically, (meth) acrylate is methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic. (Meth) acrylic acid alkyl such as cyclohexyl acid, isobornyl (meth) acrylate; (meth) acrylic acid (2-hydroxyester), (meth) acrylic acid (2-hydroxypropyl), (meth) acrylic acid (2- Hydroxyalkyl (meth) acrylates such as hydroxy-2-methylpropyl; alkoxyalkyl (meth) acrylates such as (meth) acrylic acid (2-methoxyethyl), (meth) acrylic acid (2-ethoxyethyl), It has an aromatic ring such as benzyl (meth) acrylate and phenyl (meth) acrylate. ) Acrylic acid ester and (meth) acrylic acid ester having a phospholipid-like functional group such as 2- (meth) acryloyloxyethyl phosphorylcholine, etc., but from the balance of physical properties, alkyl methacrylate alone Or alkyl methacrylate and alkyl acrylate are preferably used in combination. In that case, it is particularly preferable to use 80 to 100 mol% of methyl methacrylate and 0 to 20 mol% of alkyl acrylate. Of the alkyl acrylates used, particularly preferred are methyl acrylate or ethyl acrylate. In this specification, “acrylic acid” and “methacrylic acid” are collectively referred to as (meth) acrylic acid, and “acrylate” and “methacrylate” are collectively referred to as (meth) acrylate.

As a method for polymerizing the monomer containing the aromatic vinyl compound and (meth) acrylate, a known method can be used, but industrially, a method by radical polymerization may be simple. For the radical polymerization, a known method such as a bulk polymerization method, a solution polymerization method, an emulsion polymerization method or a suspension polymerization method can be appropriately selected. For example, as an example of a bulk polymerization method or a solution polymerization method, a continuous polymerization method in which a monomer composition containing a monomer, a chain transfer agent, and a polymerization initiator is continuously fed to a complete mixing tank and polymerized at 100 to 180 ° C. and so on. In solution polymerization methods, hydrocarbon solvents such as toluene, xylene, cyclohexane and methylcyclohexane, ester solvents such as ethyl acetate, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran and dioxane, methanol and isopropanol, etc. An alcohol solvent or the like is fed together with the monomer composition. The reaction liquid after polymerization is extracted from the polymerization tank and introduced into a devolatilization extruder or vacuum devolatilization tank to devolatilize the volatile matter and obtain an aromatic polymer.

  The polymerization initiator used in the above radical polymerization may be a well-known polymerization initiator for vinyl monomers as long as it does not have a sulfur functional group. For example, azo compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile), azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate; t-butyl peroxypivalate, t Peroxyesters such as butylperoxy 2-ethylhexanoate and cumylperoxy-2-ethylhexanoate; organic peroxidation such as di-8,5,5-trimethylhexanoyl peroxide and diuraroyl peroxide Or 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), (1-phenylethyl) -azodiphenylmethane, 2 , 2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 2,2′-azobis (2 Methylbutyronitrile), azo compounds such as 1,1'-azobis (1-cyclohexane carbonitrile) and the like.

  When the aromatic vinyl compound used in the present invention is copolymerized by radical polymerization, a chain transfer agent is not necessarily required. When used, for example, carbon tetrachloride, carbon tetrabromide, carbon tetrahalide such as carbon tetraiodide, or dimers of styrenes such as 2,4-diphenyl-4-methyl-1-pentene. Is preferably used. Mercaptan compound-based chain transfer agents generally used for radical polymerization of acrylic copolymers are not preferred because sulfur functional groups are introduced at the ends of the polymer and inhibit the nuclear hydrogenation reaction. In general, when no mercaptan compound chain transfer agent is used, the thermal decomposability of the raw material polymer is lowered, but in the hydrogenated polymer after the nuclear hydrogenation reaction in the present invention, the physical properties such as the decomposition temperature are hydrogenated. Depending on the rate only, if the hydrogenation rate is the same, the use of a sulfur chain transfer agent does not affect the decomposition temperature.

  In the case of a vinyl copolymer such as an aromatic polymer in the present invention, the composition of the constituent unit of the copolymer does not necessarily match the composition of the charged monomer, and the monomer actually incorporated into the copolymer by the polymerization reaction Determined by the amount. The ratio of the constituent units of the copolymer is the same as the charged monomer composition ratio when the polymerization rate is 100%, but in practice, it is often produced at a polymerization rate of 50 to 80%. Since it is easily taken into the copolymer, a deviation occurs between the charged composition of the monomer and the composition of the constituent unit of the copolymer, so that the composition ratio of the charged monomer needs to be appropriately adjusted.

In the structural unit of the aromatic polymer used for the nuclear hydrogenation reaction in the present invention, the molar ratio (A / B) of the structural unit (A mole) derived from the (meth) acrylate monomer to the structural unit (B mole) of the aromatic vinyl compound monomer. ) Is not less than 0.25 and not more than 4.0. If it is less than 0.25, the mechanical strength is inferior and the practicality may not endure. If it exceeds 4.0, since there are few aromatic rings to be nuclear hydrogenated, performance improvement effects such as improvement of the glass transition temperature by the nuclear hydrogenation reaction may be insufficient.

In the present invention, the weight average molecular weight of the aromatic polymer used for nuclear hydrogenation is preferably 10,000 to 1,000,000, more preferably 50,000 to 700,000, and particularly preferably 100,000. More than 500,000. Aromatic polymers less than 10,000 or more than 1,000,000 can also be nuclear hydrogenated by the method of the present invention, but less than 10,000 may not be practical in terms of mechanical strength, If it exceeds 1,000,000, it may be difficult to handle in terms of viscosity. The weight average molecular weight can be obtained in terms of polystyrene by gel permeation chromatography (GPC) using THF as a solvent.

The catalyst used in the nuclear hydrogenation reaction in the present invention is not particularly limited as long as it has hydrogenation activity. Specific examples include nickel, ruthenium, rhodium, palladium, platinum and the like. Among them, the one in which palladium is supported on a carrier is preferable as the reaction rate is high and the solvent is maintained before and after the reaction without causing side reactions. In general, activated carbon, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), silica-alumina (SiO ₂ -Al ₂ O ₃ ), diatomaceous earth, zirconium oxide, or the like is used as the catalyst carrier. Although there is no restriction | limiting as a support | carrier of the catalyst in this invention, It is preferable to use activated carbon or a zirconium oxide.

The amount of palladium metal supported on the carrier is usually in the range of 0.01 to 50% by weight, preferably 0.05 to 20% by weight, and more preferably 0.1 to 10% by weight. In terms of economy, it is preferable that the amount of expensive noble metal palladium used is as small as possible. However, when activated carbon or zirconium oxide is used as a support, it is possible to support palladium in a highly dispersed state, and moreover, per unit palladium. Since the reaction rate is very high, a sufficient reaction rate can be maintained even when the supported amount of palladium is 0.1 to 1.0% by weight. When measuring the degree of dispersion of palladium, a known method such as a pulse adsorption method of carbon monoxide is used.

  As the precursor of palladium, a known salt such as palladium chloride, palladium nitrate, palladium acetate, or a complex can be used. When impregnating and supporting on a support, the precursor is made into a solution. Examples of the precursor solution combination (precursor / solvent) include palladium chloride / hydrochloric acid, palladium chloride / sodium chloride water, palladium nitrate / water, Examples thereof include palladium nitrate / hydrochloric acid water, palladium acetate / hydrochloric acid water, and palladium acetate / organic solvent.

  The aromatic polymer used in the present invention is dissolved in a suitable solvent to carry out a nuclear hydrogenation reaction. As a point to consider when selecting a solvent, copolymers before and after the nuclear hydrogenation reaction (aromatic polymer, nuclear hydrogenation) It is necessary to take into consideration that the solubility of the polymer) and the solubility of hydrogen are good, the polymer does not have hydrogenated sites, and the reaction is carried out quickly. Moreover, when devolatilization of the solvent component after reaction is assumed, it is important that the ignition point of the solvent is high. A carboxylic acid ester compound is suitable as a solvent that satisfies all of these requirements.

As the carboxylic acid ester compound, an aliphatic ester compound is used, and a compound represented by the following general formula (1) is preferred. In the formula, R ₁ is an alkyl group having 1 to 6 carbon atoms, and R ₂ is an alkyl group having 1 to 6 carbon atoms. Examples of R ₁ and R ₂ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, and a cyclohexyl group. Ester compounds include methyl acetate, ethyl acetate, n-butyl acetate, pentyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, n-butyl propionate, methyl n-butyrate, methyl isobutyrate , N-butyric acid-n-butyl, n-methyl valerate, n-hexanoic acid methyl, etc. are used, but methyl acetate, ethyl acetate, methyl propionate, methyl isobutyrate, methyl n-butyrate are particularly preferred It is done.
R ₁ COOR ₂ (1)

The concentration of the copolymer (aromatic polymer + nuclear hydrogenated polymer) in the solution during the nuclear hydrogenation reaction is usually 1 to 50% by weight, preferably 3 to 30% by weight, more preferably 5 to 25% by weight. It is. If the concentration of the copolymer is too high, it is not preferable from the viewpoint of inconvenience of handling due to a decrease in reaction rate or an increase in solution viscosity, and a low concentration is not preferable from the viewpoint of productivity and economy.

  The nuclear hydrogenation reaction in the present invention is performed using a raw material solution in which a raw aromatic polymer is dissolved in a solvent, and may be any of a reaction in a suspension bed or a fixed bed, such as a batch reaction or a continuous flow reaction. A known method can be used. When the reaction is carried out in a suspended bed, the carrier particle size is usually in the range of 0.1 to 1,000 μm, preferably 1 to 500 μm, more preferably 5 to 200 μm. If the particle size is too small, it is difficult to separate the catalyst after the nuclear hydrogenation reaction.

Preferred reaction conditions are a temperature of 60 to 250 ° C., a hydrogen pressure of 3 to 30 MPa, and a reaction time of 3 to 20 hours. If the reaction temperature is too low, the reaction rate is slow, and if the reaction temperature is too high, side reactions such as polymer decomposition and solvent hydrogenation occur. Further, when the hydrogen pressure is low, the reaction rate is slow, and it is not economically preferable because a high pressure reactor is required to increase the hydrogen pressure.

  After the nuclear hydrogenation reaction, the catalyst can be separated by a known method such as filtration or centrifugation. In consideration of coloring, influence on mechanical properties, etc., the residual catalyst metal concentration in the polymer needs to be as low as possible, preferably 10 ppm or less, more preferably 1 ppm or less.

  After separating the catalyst, the solvent is separated from the obtained nuclear hydrogenated polymer solution to purify the polymer. 1) By continuously removing the solvent from the polymer solution to obtain a concentrated solution and extruding it in a molten state. Method of pelletizing 2) Method of pelletizing after evaporating the solvent from the polymer solution, 3) Adding the polymer solution to the poor solvent, or pelleting after adding the poor solvent to the polymer solution and precipitating 4) A known method such as 4) a method of making pellets after contact with hot water to obtain a lump can be used.

  The nuclear hydrogenated polymer obtained by the present invention is useful as an optical material. Since the nuclear hydrogenated polymer has thermoplasticity, it can be precisely and economically light-diffused by various methods such as extrusion molding, injection molding, and secondary processing molding of sheet molding. Optical articles can be manufactured. Specific applications of the light diffusing optical article include various light guide plates and light guides, display front panels, plastic lens substrates, optical filters, optical films, lighting covers, lighting signs, and the like.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not particularly limited to the following examples. In addition, the evaluation method of resin is as follows.
(1) The nuclear hydrogenation rate was determined by UV spectrum measurement before and after the hydrogenation reaction. That is, a 260 nm absorption spectrum characteristic of an aromatic ring was measured using THF as a solvent, and the ratio of unhydrogenated aromatic rings was calculated by calibration using a raw material MS resin.
(2) The weight average molecular weight (Mw) was determined by gel permeation chromatography (GPC) using an RI detector. Using THF as a solvent, calibration was performed using standard polystyrene.
(3) The sulfur content in the polymer was measured by oxidative decomposition / ultraviolet fluorescence method defined in JIS (JIS-K2541-6). The lower limit of quantification is 3 mass ppm.
(4) The thermal decomposition temperature of the polymer was determined by differential operation calorimetry (DSC).

Example 1
・ Copolymer production (resin 1)
Monomer in which MMA 49.9 mol% and styrene 49.9 mol% are blended as monomer components, and t-amylperoxy 2-ethylhexanoate is blended to a concentration of 4.2 × 10 ⁻³ mol% as a polymerization initiator. The composition was continuously fed at a rate of 1 kg / hour into a 10 liter complete mixing vessel equipped with a helical ribbon blade, and continuous polymerization was carried out at an average residence time of 2.5 hours and a polymerization temperature of 150 ° C. The reaction liquid is withdrawn from the bottom with a gear pump so that the polymerization tank liquid level is constant, and while maintaining the polymerization liquid at 150 ° C., it is introduced into a devolatilizing extruder equipped with a vent port to devolatilize the volatile matter, The strand was cut into pellets (Resin 1). At this time, the molar ratio (A / B) of the structural units in the copolymer was 1.0, and the decomposition temperature was 277 ° C.
-Nuclear hydrogenation reaction 0.5 g of the resin 1 obtained above (weight average molecular weight 150,000, sulfur content less than 3 ppm by mass) is dissolved in 4.5 g of methyl isobutyrate (hereinafter referred to as IBM), 0.5% A 20 ml autoclave was prepared together with 0.025 g of Pd / ZrO ₂ (manufactured by NV Chemcat, NN type), and a nuclear hydrogenation reaction was carried out for 15 hours under conditions of a hydrogen pressure of 9 MPa and a temperature of 200 ° C. After the reaction, the catalyst was removed by filtration, and the reaction solution was dropped into excess methanol to recover the polymer. The obtained polymer had a nuclear hydrogenation rate of 98% and a decomposition temperature of 350 ° C.

Comparative Example 1
Resin 2 (manufactured by Nippon Steel Chemical Co., Ltd., MS500 (MMA / styrene molar ratio = 5/5), molar ratio (A / B) is 1.0, weight average molecular weight 160,000, sulfur content 76 mass ppm, decomposition temperature 288 ° C. ) 0.5 g was dissolved in 4.5 g of IBM and charged into a 20 ml autoclave with 0.025 g of 0.5% Pd / ZrO ₂ (manufactured by NN Chemcat, NN type), 15 under the conditions of hydrogen pressure 9 MPa, temperature 200 ° C. A time nuclear hydrogenation reaction was carried out. After the reaction, the catalyst was removed by filtration, and the reaction solution was dropped into excess methanol to recover the polymer. The polymer had a nuclear hydrogenation rate of 29.5% and a decomposition temperature of 295 ° C.

Comparative Example 2
A nuclear hydrogenation reaction was carried out under the same conditions as in Comparative Example 1 except that the catalyst amount was changed to 0.125 g. The obtained polymer had a nuclear hydrogenation rate of 97.6% and a decomposition temperature of 345 ° C.

Example 2
・ Copolymer production (Resin 3)
A resin was synthesized in the same manner as in the production of the copolymer of Example 1 except that MMA was 29.9 mol% and styrene was 69.9 mol% (Resin 3). The molar ratio (A / B) of the structural units of the obtained resin 3 was 0.43.
-Nuclear hydrogenation reaction Resin 3 obtained above (weight average molecular weight 190,000, sulfur content less than 3 ppm by mass, decomposition temperature 279 ° C) was subjected to a nuclear hydrogenation reaction in the same manner as in Example 1. The polymer had a nuclear hydrogenation rate of 97.8% and a decomposition temperature of 358 ° C.

Comparative Example 3
The copolymer is resin 4 (manufactured by Nippon Steel Chemical Co., Ltd., MS300 (MMA / styrene molar ratio = 3/7).
), And the molar ratio (A / B) was 0.43, the weight average molecular weight was 170,000, the sulfur content was 160 mass ppm, the decomposition temperature was 294 ° C., and the nuclear hydrogenation reaction was performed in the same manner as in Comparative Example 1. . The resulting polymer had a nuclear hydrogenation rate of 16% and a decomposition temperature of 294 ° C.

Example 3
・ Copolymer production (Resin 5)
A resin was synthesized in the same manner as in the production of the copolymer of Example 2 except that MMA was changed to 80.0 mol% and styrene was changed to 19.8 mol% (Resin 5). The molar ratio (A / B) of the structural units of the obtained resin 5 was 4.0.
-Nuclear hydrogenation reaction In the same manner as in Example 1, a nuclear hydrogenation reaction was performed on the resin 5 obtained above (weight average molecular weight 100,000, sulfur content less than 3 mass ppm, decomposition temperature 279 ° C). The obtained polymer had a nuclear hydrogenation rate of 97.9% and a decomposition temperature of 362 ° C.

Comparative Example 4
The copolymer is resin 6 (manufactured by Nippon Steel Chemical Co., Ltd., MS800 (MMA / styrene molar ratio = 8/2), molar ratio (A / B) is 4.0, weight average molecular weight 90,000, sulfur content 160 mass ppm, A nuclear hydrogenation reaction was performed in the same manner as in Comparative Example 1 except that the decomposition temperature was changed to 295 ° C. The obtained polymer had a nuclear hydrogenation rate of 21% and a decomposition temperature of 299 ° C.

Claims (11)

A method for producing a nuclear hydrogenated polymer by nuclear hydrogenation of an aromatic ring portion of an aromatic polymer using a supported catalyst, wherein the sulfur content in the analysis according to JIS-K2541-6 in the aromatic polymer is 50 A method for producing a nuclear hydrogenated polymer, characterized by being less than ppm by mass. The process according to claim 1, wherein the aromatic polymer has a weight average molecular weight of 10,000 to 1,000,000. The production method according to claim 1, wherein the aromatic polymer is a copolymer of an aromatic vinyl compound and (meth) acrylate. The molar ratio (A / B) of the structural unit (A mole) derived from the (meth) acrylate monomer to the structural unit (B mole) of the aromatic vinyl compound monomer in the structural unit of the aromatic polymer is 0.25 to 4.0. The method according to claim 1, wherein The process according to claim 1, wherein the (meth) acrylate monomer comprises 80 to 100% methyl methacrylate and 0 to 20% alkyl acrylate, and the aromatic vinyl compound monomer is styrene. The method according to any one of claims 1 to 5, wherein the aromatic hydrogenation rate of the aromatic ring is 85% or more. The production method according to claim 1, wherein the reaction solvent is a carboxylic acid ester compound.   The process according to claim 1, wherein the catalyst is a catalyst supporting palladium, platinum, ruthenium, rhodium or nickel.   The process according to claim 1, wherein the carrier in the catalyst is activated carbon, zirconium oxide, alumina, silica, silica-alumina or diatomaceous earth. The polymer obtained by the manufacturing method in any one of Claims 1-9. An optical material comprising the polymer according to claim 10.