JP2010229198A - Manufacturing method for polymer, polymer, thermoplastic composition and molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer that is readily radically polymerized, exhibits heat resistance, is inhibited from thermal decomposition when molded, is formed into a molded body excellent in external appearances and mechanical properties, and is suitable for applications for optical materials. <P>SOLUTION: The manufacturing method comprises radically polymerizing a monomer component comprising a monomer (a) represented by formula (1) in the presence of a chain transfer agent in an organic solvent. The polymer is obtained by the method. In the formula, R<SB>1</SB>is hydrogen or a methyl group; and R<SB>2</SB>is a cyano group bonded to any one of an ortho-position, a meta-position and a para-position of the benzene ring. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a polymer, a polymer obtained by the production method, a thermoplastic resin composition containing the polymer, and a molded body obtained by molding the thermoplastic resin composition.

  In recent years, the demand for optical materials has been increasing, and there is a demand for a resin that is inexpensive and excellent in many performances such as transparency, mechanical properties, and heat resistance. However, conventional resins for optical materials do not have these required performances in a well-balanced manner, and have various drawbacks as resins for optical materials.

  For example, acrylic resins and polycarbonate resins have been conventionally used as highly transparent resins for optical materials. Acrylic resin has excellent optical properties such as high transparency and low birefringence. However, when the resin is exposed to high temperatures during molding, the resin is decomposed and colored due to residual double bonds in the resin. And has the disadvantage of causing foaming. Polycarbonate resin has a high glass transition temperature and excellent heat resistance, but has a drawback that it easily undergoes hydrolysis because it has an ester bond in the polymer chain.

  As resins for optical materials that can improve the above problems, Patent Documents 1 and 2 propose hydrogenated ring-opening polymers of norbornene monomers and addition copolymers of norbornene monomers and ethylene. Has been. Although the polymer is excellent in transparency and heat resistance, the norbornene monomer is difficult to radically polymerize. Moreover, since it is necessary to use a metal catalyst in radical polymerization, the resulting polymer has a problem of causing coloration.

  Patent Document 3 proposes a polymer of a (meth) acrylate monomer component having a cyano group. Although the polymer is excellent in heat resistance, when the polymerization system is bulk polymerization, it is difficult to complete the polymerization because of its high glass transition temperature, and many monomers remain in the polymer, and foaming occurs during molding. Adversely affect. In addition, a polymer obtained by bulk polymerization is difficult to dissolve in an organic solvent and is difficult to purify.

JP-A 64-24826 Japanese Patent Laid-Open No. 61-115912 JP-A-2-211401

  An object of the present invention is to provide a polymer having heat resistance, suppressing thermal decomposition during molding, and having excellent appearance and mechanical properties of the molded body, using solution polymerization that can be purified.

  The present invention is a method for producing a polymer by radical polymerization of a monomer component containing the monomer (a) represented by the following general formula (1) in an organic solvent in the presence of a chain transfer agent. .

(Wherein R ₁ represents hydrogen or a methyl group, and R ₂ represents a cyano group bonded to any of the ortho, meta, and para positions of the benzene ring.)
Moreover, this invention is a polymer obtained by the said method.

  Moreover, this invention is the said polymer whose number average molecular weight is 30,000-1 million.

  Moreover, this invention is a thermoplastic resin composition containing the said polymer.

  Moreover, this invention is a molded object obtained by shape | molding the said thermoplastic resin composition.

  The polymer of the present invention is particularly suitable for optical materials because it has heat resistance, suppresses thermal decomposition during molding, and is excellent in appearance and mechanical properties of the molded body.

  The monomer component of this invention contains the monomer (a) represented by following General formula (1).

(Wherein R ₁ represents hydrogen or a methyl group, and R ₂ represents a cyano group bonded to any of the ortho, meta, and para positions of the benzene ring.)
Among these monomers, cyanophenyl methacrylate in which R ₁ is a methyl group is preferable from the viewpoint of heat resistance, and R ₂ is a cyano group bonded to the para position from the viewpoint of monomer synthesis ( Meth) acrylic acid-4-cyanophenyl is preferred. Further, among these monomers, 4-cyanophenyl methacrylate, in which R ₁ is a methyl group and R ₂ is a cyano group bonded to the para position, is more preferable. These monomers (a) may be used individually by 1 type, and may use 2 or more types together.

  In the present invention, (meth) acryl represents acrylic or methacrylic.

  The monomer (a) of the present invention can be synthesized by a known synthesis method, for example, transesterification reaction between 4-cyanophenol and methyl methacrylate, reaction between 4-cyanophenol and methacrylic anhydride, Synthesis is possible by the reaction of 4-cyanophenol and methacryloyl chloride.

  The monomer component of the present invention may contain a monomer (b) other than the monomer (a) as necessary.

  The monomer (b) can be appropriately set according to the intended use of the polymer to be obtained. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n- (meth) acrylate Butyl, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, ( (Meth) acrylic acid esters such as phenyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, and 2-aminoethyl (meth) acrylate; Aromatic vinyl monomers such as styrene, vinyl toluene, α-methyl styrene, styrene sulfonic acid and salts thereof; vinyl chloride Chlorine-containing monomers such as vinylidene chloride; fluorine-containing monomers such as perfluoroethylene and vinylidene fluoride; silicon-containing monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, Maleic acid monomers such as maleic acid monoalkyl ester or dialkyl ester; fumaric acid monomers such as fumaric acid, fumaric acid monoalkyl ester or dialkyl ester; maleimide, N-methylmaleimide, N-phenylmaleimide, N -Maleimide monomers such as cyclohexylmaleimide; Cyano group-containing monomers such as (meth) acrylonitrile; Amide group-containing monomers such as (meth) acrylamide; Vinyl acetate, vinyl propionate, vinyl pivalate, benzoic acid Vinyl esters such as vinyl; ethylene, propylene, etc. Kens; conjugated dienes such as butadiene and isoprene are exemplified. Among these, from the viewpoint of the reactivity with the monomer (a) and the properties of the resulting polymer, (meth) acrylic acid esters such as methyl (meth) acrylate and n-butyl (meth) acrylate, styrene Aromatic vinyl monomers such as cyano group-containing monomers such as (meth) acrylonitrile are preferred, and (meth) acrylic acid esters and cyano group-containing monomers are more preferred. These monomers (b) may be used individually by 1 type, and may use 2 or more types together.

  When the monomer component of the present invention includes the monomer (b), the content of the monomer (a) in 100 mol% of the monomer component is preferably 20 to 99 mol%, more preferably 25 to 90 mol%. Preferably, 30 to 80 mol% is more preferable. If the content of the monomer (a) in the monomer component is 20 mol% or more, the resulting polymer has good heat resistance, and if it is 99 mol% or less, the monomer in the resulting polymer (B) It has unit characteristics.

  When the monomer component of the present invention contains the monomer (b), the content of the monomer (b) in the monomer mixture 100 mol% is preferably 1 to 80 mol%, more preferably 10 to 75 mol%. Preferably, 20 to 70 mol% is more preferable. If the content of the monomer (b) in the monomer component is 1 mol or more, the resulting polymer has the characteristics of the monomer (b) unit and can be obtained if it is 80 mol% or less. The heat resistance of the polymer is improved.

  The polymer of the present invention is produced by radical polymerization. The radical polymerization method is not particularly limited, and a known radical polymerization method can be used. Further, known controlled radical polymerization such as atom transfer radical polymerization and reversible addition-fragmentation chain transfer polymerization can also be used.

  Examples of the polymerization initiator in the radical polymerization of the present invention include peroxide initiators such as benzoyl peroxide and di-t-butyl peroxide; 2,2′-azobisisobutyronitrile, 2,2′- Azo initiators such as azobis-2,4-dimethylvaleronitrile, 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis-2-methylbutyronitrile Is mentioned. Among these polymerization initiators, benzoyl peroxide, 2,2'-azobisisobutyronitrile, and 2,2'-azobis-2,4-dimethylvaleronitrile are preferable from the viewpoint of polymerization performance. The amount of the polymerization initiator used is preferably 0.001 to 1 mol and more preferably 0.01 to 0.1 mol with respect to 100 mol of the monomer component.

  The polymerization atmosphere in the radical polymerization of the present invention is not particularly limited, but an oxygen-free atmosphere is preferable because oxygen easily reacts with radicals and inhibits radical polymerization.

  The polymerization temperature in the radical polymerization of the present invention is not particularly limited, but is preferably −50 to 200 ° C., more preferably 0 to 150 ° C.

  The polymer of the present invention is obtained by a solution polymerization method in which a monomer component is polymerized in an organic solvent. The organic solvent in the solution polymerization method is not particularly limited, and examples thereof include ether solvents such as diethyl ether and tetrahydrofuran; halogenated hydrocarbon solvents such as methylene chloride and chloroform; acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like. Ketone solvents; nitrile solvents such as acetonitrile, propionitrile, benzonitrile; ester solvents such as ethyl acetate and n-butyl acetate; carbonate solvents such as ethylene carbonate and propylene carbonate; N, N-dimethylformamide; dimethyl Examples include sulfoxide. Among these solvents, a solvent in which the monomer component and the resulting polymer are dissolved is preferable, a ketone solvent such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, N, N-dimethylformamide is preferable, and a ketone solvent is more preferable. . These solvents may be used alone or in combination of two or more.

  Although the usage-amount of the organic solvent of this invention is not restrict | limited in particular, 50-10000 mass parts is preferable with respect to 100 mass parts of monomer components, and 100-1000 mass parts is more preferable. If the amount of the organic solvent used is 50 parts by mass or more, the polymer does not precipitate when the monomer component is polymerized, and if it is 10000 parts by mass or less, the polymerization proceeds easily.

  The polymer of the present invention is obtained by radical polymerization of a monomer component in the presence of a chain transfer agent. The chain transfer agent is not particularly limited, and examples thereof include n-dodecyl mercaptan, t-dodecyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan, n-butyl mercaptan. Such as mercaptan compounds; halogen compounds such as carbon tetrachloride and ethylene bromide; and α-methylstyrene dimer. The amount of the chain transfer agent used is preferably 0.001 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, with respect to 100 parts by mass of the monomer component. More preferably, it is 1 part by mass.

  The number average molecular weight of the polymer of the present invention is preferably 30,000 to 1,000,000, more preferably 40,000 to 500,000. If the number average molecular weight of the polymer is 30,000 or more, the resulting polymer has good mechanical strength, and if it is 1,000,000 or less, molding such as melt molding becomes easy. In the present invention, the number average molecular weight and molecular weight distribution are measured using gel permeation chromatography (GPC).

  The polymer of the present invention preferably has a 1% mass reduction temperature of 235 ° C. or higher, more preferably 250 ° C. or higher. If it is 235 degreeC or more, when carrying out melt molding at 220-235 degreeC, zipper decomposition | disassembly from the terminal double bond of a polymer will be suppressed, and a molded article external appearance will become favorable. The 1% mass reduction temperature is a temperature at which the mass of the polymer is reduced by 1% when the temperature is increased from 30 ° C. at a temperature increase rate of 10 ° C. per minute in a nitrogen atmosphere.

  The thermoplastic resin composition of the present invention contains the polymer of the present invention. The thermoplastic resin composition of the present invention may be only the polymer of the present invention, and may contain a resin other than the polymer of the present invention, additives and the like as necessary.

  Examples of the resin include chlorine-containing resins such as vinyl chloride resin, chlorinated vinyl chloride resin and vinylidene chloride resin; olefin resins such as polypropylene and polyethylene; styrene resins such as polystyrene and acrylonitrile-butadiene-styrene resin; polymethyl methacrylate Acrylic resins such as: polycarbonate resins; polyamide resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polylactic acid; polyphenylene ether resins, polyoxymethylene resins, polysulfone resins, polyarylate resins, Engineering plastics such as polyphenylene resins and thermoplastic polyurethane resins; styrene elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers Polyester elastomers include thermoplastic elastomers such as polyamide elastomer.

  Examples of additives include fillers such as calcium carbonate, aluminum hydroxide, and talc; pigments such as titanium oxide and carbon black; dyes; lubricants; antioxidants; ultraviolet absorbers; antistatic agents; Agents; processing aids; flame retardants.

  When obtaining a thermoplastic resin composition containing a resin or additive other than the polymer of the present invention, it can be kneaded by a known method, for example, a mill roll, a Banbury mixer, a super mixer, a single screw or a twin screw extruder. Is mentioned.

  The molded product of the present invention is obtained by molding the thermoplastic composition of the present invention. As the molding method, a known method can be used, and examples thereof include a calendar molding method, an injection molding method, a T-die extrusion molding method, a profile extrusion molding method, a blow molding method, a vacuum molding method, and an inflation molding method.

  Since the polymer of the present invention has heat resistance, suppresses thermal decomposition during molding, and is excellent in transparency and mechanical properties of the molded body, it is particularly suitable for optical material applications.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

In the examples, “parts” and “%” represent “parts by mass” and “% by mass”.
(1) Identification of monomer (a) For the measurement, ¹ H-NMR (model name “JNM-EX270”, manufactured by JEOL Ltd.) was used.

The synthesized monomer (a) was dissolved in deuterated chloroform, and tetramethylsilane was used as a reference substance, and measurement was performed at a measurement temperature of 25 ° C. and 16 integrations. The monomer (a) was identified from the integration ratio of the peak intensity and the peak position.
(2) Uniformity of polymerization solution The uniformity of the polymerization solution was visually confirmed with the following indicators.

○: Transparent Δ: Polymer is precipitated and cloudy ×: Polymer precipitate can be confirmed (3) Composition ratio of polymer For measurement, ¹ H-NMR (model name “JNM-EX270”, JEOL Ltd.) was used.

The obtained polymer was dissolved in deuterated acetone, and tetramethylsilane was used as a reference substance, and measurement was performed at a measurement temperature of 25 ° C. and 16 integrations. The composition ratio of the copolymer was calculated from the integral ratio between the peak derived from the monomer (a) and the peak intensity derived from the other monomer (b).
(4) Number average molecular weight and molecular weight distribution The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the obtained polymer are expressed as follows using polystyrene as a standard and gel permeation chromatography (GPC). Measured under conditions.

Model name: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSK GUARD COLUMN SUPER H-H (manufactured by Tosoh Corporation, 4.6 × 35 mm), TSK-GEL SUPER HZM-H (manufactured by Tosoh Corporation, 6.0 × 150 mm), 2 series connection Eluent: Dimethylformamide Measurement temperature: 40 ° C
Flow rate: 0.6 ml / min Sample concentration: 0.1%
Sample injection volume: 10 μl
(5) Glass transition temperature For the measurement, a differential scanning calorimeter (model name “DSC220C”, manufactured by Seiko Instruments Inc.) was used.

After heating up to 150 degreeC and cooling, it measured by the temperature increase rate of 10 degree-C / min in nitrogen atmosphere in the temperature range of -30-200 degreeC.
(6) 1% mass reduction temperature A thermogravimetric / differential thermal analyzer (model name “TG / DTA6300”, manufactured by Seiko Instruments Inc.) was used for the measurement.

The measurement was performed at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere in a temperature range of 30 to 500 ° C.
(7) Mechanical strength of the molded body After the polymer was melt-molded, the molded body was peeled from the mold, and then whether or not the molded body was cracked was confirmed by the following index.

○: No cracking occurs in the molded body △: Cracking may occur in the molded body ×: Cracking occurs in the molded body (8) Appearance of the molded body confirmed.

○: Transparent Δ: Slightly colored / white turbidity can be confirmed ×: Colored / white turbidity can be confirmed [Formation Example 1] Synthesis of methacrylic acid-4-cyanophenyl (a1) Three-necked flask under nitrogen atmosphere To this, 21.2 g (178 mmol) of 4-cyanophenol was added and dissolved in 100 mL of dichloromethane and 21.9 g (216 mmol) of triethylamine to prepare a solution. Thereafter, 22.6 g (216 mmol) of methacryloyl chloride was added dropwise to the prepared solution and reacted at 25 ° C. for 24 hours. The obtained reaction solution was washed with water three times, and dichloromethane was distilled off, followed by recrystallization with methanol to obtain a white powder.

About the obtained white powder, the measurement result of ¹ H-NMR is shown below. From the measurement results, it was confirmed that the obtained white powder was methacrylic acid-4-cyanophenyl (a1). The yield was 82%.

¹ H-NMR (δ (ppm))
1.26 (s, 6H), 1.31 (s, 6H), 1.65 (m, 2H), 1.89 (d, 2H), 1.93 (s, 3H), 4.83 (s) 2H), 5.11 (m, 1H), 5.54 (s, 1H), 6.08 (s, 1H), 7.34 (m, 5H)
[Example 1]
In a three-necked flask, 50 parts (35 mol%) of the monomer (a1) obtained in Production Example 1, 50 parts (65 mol%) of methyl methacrylate (b1), 1.2 parts of n-octyl mercaptan, and 310 parts of methyl ethyl ketone. In addition, a monomer mixture solution was prepared and nitrogen bubbling was performed for 30 minutes. Next, 0.2 part of 2,2′-azobisisobutyronitrile was added, and the flask was immersed in an oil bath at 75 ° C. to initiate polymerization. After 7 hours, the contents were poured into methanol to obtain a precipitate. The operation of dissolving the obtained precipitate in acetone, pouring it into methanol and obtaining the precipitate was repeated three times, and the precipitate was dried to obtain a white powder.

^From the measurement result of ¹ H-NMR, it was confirmed that the obtained white powder was a polymer of (a1) units / (b1) units = 42/58 (mol ratio). Moreover, from the measurement result of GPC, Mn was 25900 and Mw / Mn was 1.75.

The obtained polymer was made into a thermoplastic resin composition and molded at 220 ° C. to 235 ° C. with a small injection molding machine (model name “CS-183-MMX”, manufactured by Custom Scientific Instruments), A molded body was obtained.
[Examples 2 to 4, Comparative Examples 1 to 4]
The same procedure as in Example 1 was performed except that the monomer mixture solution was changed to Table 1.
[Comparative Example 5]
To the three-necked flask, 50 parts (35 mol%) of the monomer (a1) obtained in Production Example 1, 50 parts (65 mol%) of methyl methacrylate (b1) and 1.2 parts of n-octyl mercaptan were added, and And a monomer mixture was prepared, followed by nitrogen bubbling for 30 minutes. Next, 0.2 part of 2,2′-azobisisobutyronitrile was added and the flask was immersed in an oil bath at 75 ° C. to initiate polymerization. After 7 hours, a white solid was obtained.

^From the measurement result of ¹ H-NMR, it was confirmed that the obtained white solid was a polymer of (a1) unit / (b1) unit = 43/57 (mol ratio). Moreover, from the measurement result of GPC, Mn was 163300 and Mw / Mn was 1.66.

  The obtained polymer was used as a thermoplastic resin composition, and injection molding was attempted in the same manner as in Example 1. However, the polymer was decomposed, and the molded product became cloudy and foamed.

  Table 1 shows various physical properties of the obtained polymer and molded article.

  In addition, the symbol in Table 1 shows the following compounds.

4CPMA: 4-cyanophenyl methacrylate MMA: methyl methacrylate n-OM: n-octyl mercaptan MEK: methyl ethyl ketone DMF: N, N-dimethylformamide In Examples 1 to 4, the glass transition temperature and 1% mass of the polymer The reduction temperature, the appearance of the molded body and the mechanical strength were all excellent. In particular, Examples 1 and 2 using methyl ethyl ketone as the organic solvent had a significantly high 1% mass loss temperature of the polymer. In Comparative Example 1, since methacrylic acid-4-cyanophenyl (a1) was not used, the glass transition temperature of the polymer was low. In Comparative Examples 2 to 4, since no chain transfer agent was used, the 1% mass reduction temperature of the polymer was low, and the appearance of the molded article was inferior. In Comparative Example 5, since no organic solvent was used, polymerization of the monomer component was not completed, and purification of the obtained polymer was difficult, and the 1% mass loss temperature of the polymer was significantly low. The appearance of the molded body was inferior.

  The polymer of the present invention is particularly suitable for optical materials because it has heat resistance, suppresses thermal decomposition during molding, and is excellent in appearance and mechanical properties of the molded body.

Claims (5)

A method for producing a polymer by radical polymerization of a monomer component containing a monomer (a) represented by the following general formula (1) in an organic solvent in the presence of a chain transfer agent.

(Wherein R ₁ represents hydrogen or a methyl group, and R ₂ represents a cyano group bonded to any of the ortho, meta, and para positions of the benzene ring.)   A polymer obtained by the method according to claim 1.   The polymer according to claim 2, having a number average molecular weight of 30,000 to 1,000,000.   A thermoplastic resin composition comprising the polymer according to claim 2.   The molded object obtained by shape | molding the thermoplastic resin composition of Claim 4.