JP2009280713A - Surface hardness improver for polycarbonate based resin, polycarbonate based resin composition, and molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface hardness improver for a polycarbonate based resin can improve surface hardness of the surface of a molded product without spoiling fluidity and mechanical characteristics upon molding of the polycarbonate based resin, to provide a polycarbonate based resin composition including the surface hardness improver for the polycarbonate based resin, and to provide a molded product obtained by molding the polycarbonate based resin composition. <P>SOLUTION: The surface hardness improver for the polycarbonate based resin is a polymer having mass average molecular weight of 1,000 to 100,000 and containing a glycidyl (meth)acrylate unit as a monomer unit. The polycarbonate based resin composition includes 100 pts.mass polycarbonate based resin and 0.3 to 30 pts.mass surface hardness improver for the polycarbonate based resin. The molded product is obtained by molding the polycarbonate based resin composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface hardness improver for polycarbonate resins, a polycarbonate resin composition, and a molded article.

  Aromatic polycarbonate resins are materials that occupy a large share in various fields such as automobiles, OA equipment, electronic equipment, and mobile phones. However, aromatic polycarbonate resins have a problem that they are easily scratched because of their low surface hardness.

As a method for improving the scratch resistance of the surface of the thermoplastic resin, a method of laminating a high hardness film on the surface of the thermoplastic resin can be mentioned. For example, Patent Document 1 proposes a synthetic resin laminate in which a primer layer made of a thermosetting acrylic resin and a cured film layer made of a polyfunctional alkoxysilane are formed on the surface of a transparent synthetic resin layer. However, this technique has a problem that the manufacturing cost increases because the number of processes increases.
Patent Document 2 discloses a methyl methacrylate polymer having a functional group such as an aromatic polycarbonate or an epoxy group for the purpose of combining the excellent characteristics of both an aromatic polycarbonate resin and polymethyl methacrylate. And the polymer composition which consists of an elastic polymer which has a group which can react with the said functional group is proposed. Furthermore, Patent Document 3 contains a liquid crystalline resin, a thermoplastic resin, and an epoxy-modified vinyl copolymer for the purpose of imparting excellent mechanical properties of the liquid crystalline resin to a thermoplastic resin such as a polycarbonate resin. A thermoplastic resin composition has been proposed. However, these techniques are intended to improve the physical properties of the entire resin composition and do not modify the surface of the resin product.
Patent Document 4 discloses a resin containing a compatibilizing agent having a functional group such as a thermoplastic polyester resin, an acrylic resin, and a glycidyl group for the purpose of improving the surface hardness of the recyclable thermoplastic polyester resin. Compositions have been proposed. However, Patent Document 4 does not disclose improvement of the surface hardness of the polycarbonate resin product.
JP 2006-51655 A JP-A-6-345934 JP-A-8-183910 JP 2007-92038 A

  An object of the present invention is to provide a surface hardness improver for a polycarbonate resin that can improve the surface hardness of the molded product without impairing the fluidity and mechanical properties during the molding of the polycarbonate resin, and a polycarbonate resin. It is providing the molded product obtained by shape | molding the polycarbonate-type resin composition containing the surface hardness improver for use, and the polycarbonate-type resin composition.

The gist of the present invention is that a surface hardness improver for a polycarbonate resin (hereinafter referred to as a polymer) having a mass average molecular weight of 1,000 to 100,000 and containing a glycidyl (meth) acrylate unit as a monomer unit. , "This surface hardness improver") is the first invention.
The gist of the present invention is that the polycarbonate resin composition containing 100 parts by mass of the polycarbonate resin and 0.3 to 30 parts by mass of the surface hardness improver (hereinafter referred to as “the present resin composition”). Is a second invention.
Furthermore, the gist of the present invention is a molded product obtained by molding the resin composition as a third invention.

  Molded products obtained by molding the present resin composition containing the present surface hardness improver have excellent surface hardness and excellent mechanical properties, and therefore can be used in a wide range of fields such as mobile phones and OA equipment. Can do.

The surface hardness improver is a polymer having a mass average molecular weight of 1,000 to 100,000 and containing a glycidyl (meth) acrylate unit as a monomer unit.
In the present invention, (meth) acrylate represents at least one of acrylate and methacrylate.
The surface hardness improver can be stably produced when the surface hardness improver has a mass average molecular weight of 1,000 or more. Moreover, the surface hardness of the molded product obtained when the mass average molecular weight of the surface hardness improver is 100,000 or less is good.

  The content of the glycidyl (meth) acrylate unit in the surface hardness improver is preferably 2% by mass or more, and more preferably 20% by mass or more in terms of the effect of improving the surface hardness of the obtained molded product.

The surface hardness improver can contain a copolymerizable vinyl monomer unit in addition to the glycidyl (meth) acrylate unit.
Examples of the copolymerizable vinyl monomer that is a raw material for constituting a copolymerizable vinyl monomer unit include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl (meth) acrylate. , I-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, i-butyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, n-octyl (meth) ) Acrylate, i-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, etc. Alkyl (meth) Acrylate; styrene, t-butylstyrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene Aromatic vinyl compounds such as N, N-diethyl-p-aminoethylstyrene, vinylpyridine, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, fluorostyrene, ethylstyrene, vinylnaphthalene; acrylonitrile, methacrylonitrile Cyanide vinyl compounds such as maleimide, N-methylmaleimide, N-butylmaleimide, N- (p-methylphenyl) maleimide, N-phenylmaleimide, N-cyclohexylmaleimide and other maleimide compounds; Examples thereof include unsaturated carboxylic acids such as crylic acid and unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride and citraconic anhydride.
Said copolymerizable vinyl monomer can be used alone or in combination of two or more. Of these, methyl methacrylate is preferred.

The surface hardness improver preferably has a glass transition temperature (hereinafter referred to as “Tg”) of 0 to 150 ° C., more preferably 30 to 120 ° C.
When the surface hardness improver has a Tg of 0 to 150 ° C., the surface hardness of the resulting molded product tends to be good.
In the present invention, Tg is a value calculated by the Fox equation shown by the following equation (1).
1 / Tg = Σ (W _i / Tg _i ) (1)
(W _i represents the mass ratio of monomer i to all monomers, and Tg _i represents the Tg of the homopolymer of monomer i.)
In addition, as a numerical value of Tg of a homopolymer, the numerical value described in POLYMER HANDBOOK THIRD EDITION (WILEY INTERSCIENCE) was used.

  The epoxy equivalent of the surface hardness improver is preferably 200 g / eq or less, and more preferably 170 g / eq or less.

  The shape of the surface hardness improver is preferably a spherical particle in terms of handleability and blendability with a polycarbonate resin.

  Examples of the polymerization method of the surface hardness improver include known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Among these, suspension polymerization is preferred because a polymer of spherical particles can be easily obtained.

  Examples of the polymerization initiator used for polymerization of the surface hardness improver include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), and 2,2′-azobis. Azo compounds such as (2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, t-hexylperoxy 2-ethylhexanoate, 1,1, Examples include organic peroxides such as 3,3-tetramethylbutylperoxy 2-ethylhexanoate and t-hexyl hydroperoxide, and inorganic peroxides such as hydrogen peroxide, sodium persulfate, and ammonium persulfate. Of these, 2,2'-azobis (2,4-dimethylvaleronitrile) is preferred.

Examples of the dispersant used for the suspension polymerization of the surface hardness improver include, for example, poorly water-soluble inorganic compounds such as calcium phosphate, calcium carbonate, aluminum hydroxide, and starch silica; polyvinyl alcohol, polyethylene oxide, and cellulose derivatives. Nonionic polymer compounds such as poly (meth) acrylic acid alkali metal salts, alkali metal salts of (meth) acrylic acid and methyl (meth) acrylate copolymers, (meth) acrylic acid alkali metal salts and methyl (meth) And anionic polymer compounds such as copolymers of acrylate and (meth) acrylic acid sulfonic acid ester alkali metal salts.
Among these, a copolymer of (meth) acrylic acid alkali metal salt, methyl (meth) acrylate, and (meth) acrylic acid sulfonic acid ester alkali metal salt is preferable.

In the polymerization of the surface hardness improver, a chain transfer agent can be used as necessary.
Examples of the chain transfer agent include mercaptans such as n-dodecyl mercaptan; thioglycolic acid esters such as octyl thioglycolate and α-methylstyrene dimer. Of these, n-dodecyl mercaptan is preferred.

  In the present invention, the surface hardness improver can be blended with a polycarbonate-based resin to form the resin composition described later.

The polycarbonate resin is not particularly limited, but an aromatic polycarbonate resin is preferable.
Examples of the molecular weight of the aromatic polycarbonate resin include those having a viscosity average molecular weight of 10,000 to 60,000, and more preferably 15,000 to 30,000.

Examples of the aromatic polycarbonate resin used in the present invention include aromatic polycarbonate resins derived from dihydric phenols.
The aromatic polycarbonate resin is usually obtained by reacting a dihydric phenol and a carbonate precursor by a solution method or a melting method.

Examples of the dihydric phenol used here include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), and a part or all of the dihydric phenol can be replaced with another dihydric phenol.
Examples of the other dihydric phenol include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and 2,2-bis (4-hydroxy-). 3,5-dimethylphenyl) propane and bis (4-hydroxyphenyl) sulfone.

Examples of the carbonate precursor include carbonyl hydride, carbonyl ester, and haloformate.
Specific examples of the carbonate precursor include dihaloformates such as phosgene, diphenyl carbonate and dihydric phenol, and mixtures thereof.

For example, when phosgene is used as the carbonate precursor, it is usually reacted with a dihydric phenol in the presence of an acid binder and a solvent.
Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and amine compounds such as pyridine.
Examples of the solvent include halogenated hydrocarbons such as methylene chlorobenzene chloride.
In order to accelerate the reaction between the dihydric phenol and phosgene, for example, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used. In this case, the reaction temperature is usually 0 to 40 ° C., and the reaction time is several minutes to 5 hours.

When an aromatic polycarbonate resin is produced by a transesterification reaction using a carbonic acid diester such as diphenyl carbonate as the carbonate precursor, a predetermined proportion of the aromatic dihydroxy component and the carbonic acid diester are heated in an inert gas atmosphere. Stir to distill the resulting alcohol or phenols. The reaction temperature in this case is usually 120 to 300 ° C., although it varies depending on the boiling point of the alcohol or phenol produced. Further, the reaction can be completed while distilling off the produced alcohol by reducing the pressure of the reaction system from the initial stage of the reaction. Furthermore, in order to accelerate | stimulate reaction of a bihydric phenol and a carbonic acid diester, the catalyst normally used for transesterification can be used.
Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Among these, diphenyl carbonate is preferable.

  When producing an aromatic polycarbonate resin, a molecular weight modifier or the like can be used as necessary. The aromatic polycarbonate resin thus obtained can be used alone or in combination of two or more.

In this invention, it is preferable to contain 0.3-30 mass parts of this surface hardness improver with respect to 100 mass parts of polycarbonate-type resin in this resin composition, and it is more preferable to contain 5-20 mass parts. preferable.
When the content of the surface hardness improver is 0.3 parts by mass or more, the effect of improving the surface hardness of the obtained molded product tends to be good. In addition, when the content of the surface hardness improver is 30 parts by mass or less, the surface of the obtained molded product tends to be less likely to generate flaws.

The resin composition includes a flame retardant; other resins such as polyester, polyamide, ABS, and polyphenylene ether; talc, mica, glass fiber, carbon fiber, fibrous titanium oxide, and titanium as long as the object of the present invention is not impaired. Strengthening agents such as whisker typified by potassium acid whisker and aluminum borate whisker; stabilizers such as phosphite esters and phosphate esters; antioxidants such as hindered phenol compounds; fluidity such as polycaprolactone An additive such as a modifier; a release agent; an ultraviolet absorber; an antistatic agent;
Examples of the flame retardant include sulfonic acid metal salt and sulfonate flame retardants. These flame retardants are preferable because the effects can be exhibited with a small addition amount, and there is little fear of deterioration of physical properties of the obtained product.
Further, in order to further improve the flame retardancy, polytetrafluoroethylene having further fibril forming ability can be blended with the present resin composition.

  As a method for producing the present resin composition, for example, the surface hardness improver, polycarbonate resin and additives as necessary are mixed with a Henschel mixer, tumbler, etc., and then melt mixed with an extruder, kneader, mixer, etc. Examples thereof include a method, a method in which other components are sequentially mixed with a previously melted component, and a method in which the resin composition is directly charged into an injection molding machine to obtain a molded product.

  In the present invention, as described above, the molded product is a method in which the resin composition is melt-mixed into a pellet and then molded into an injection molding machine or the like, or the resin composition is directly injected into an injection molding machine or the like. To obtain a molded product.

Hereinafter, the present invention will be described with reference to examples. In the following, the mass average molecular weight of the surface strength improver, the content of glycidyl methacrylate (GMA) units and the epoxy equivalent, and the Izod impact strength, flexural modulus, flexural strength, Rockwell hardness and MI value of the molded product are as follows: Measured by the method.
In the following, “part” and “%” indicate “part by mass” and “% by mass”, respectively.

(1) Mass average molecular weight The mass average molecular weight was calculated | required from the analytical curve by polymethylmethacrylate with known molecular weight on the following conditions using Tosoh Co., Ltd. product GPC and HPLC-8220GPC (brand name).
Column: Tosoh Corporation TSK-Gel SUPER HZM-M (trade name)
Measurement temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Eluent speed: 0.6 ml / min Detector: RI

(2) Epoxy equivalent The epoxy equivalent was measured by the following method.
1. Put 2 g of hydrochloric acid into a 100 ml volumetric flask and make up with ethanol / dioxane = 20/80 solution to prepare solution A.
2. Precisely weigh 0.15 to 0.20 g of surface hardness improver in a 100 ml conical flask with a stopper. Add 20 ml of dioxane and irradiate ultrasonic waves for about 1 hour using an ultrasonic cleaner to dissolve the surface hardness improver. The solution temperature during dissolution is about 40 ° C.
3. After the surface hardness improver is dissolved, 10 ml of solution A is added to the Erlenmeyer flask.
4). The solution of the surface hardness improver after the addition of solution A is titrated with 0.1 mol / l-KOH (ethanol) using phenolphthalein as an indicator.
5. Titration is similarly performed for the blank liquid in the case where the surface hardness improver is not added in 2 above.
6). The epoxy equivalent of the surface hardness improver was calculated from the amount of the surface hardness improver, the appropriate amount of the surface hardness improver solution and the blank liquid.

(3) Content rate of GMA unit It calculated according to the following formula using the value of epoxy equivalent.
GMA unit content (%) = (1 / epoxy equivalent) × 100 × 142

(4) Izod impact strength Pellets of polycarbonate resin composition were injection molded at 230 ° C. using an injection molding machine (SE-100DU (trade name) manufactured by Sumitomo Heavy Industries, Ltd.), width 100 mm × thickness A molded product having a length of 4 mm and a length of 100 mm was obtained. A milled notch test piece having a width of 12.7 mm, a thickness of 4 mm, and a length of 64.5 mm was prepared from the obtained molded product, and the Izod impact strength was measured at 23 ° C. according to JIS K-7110.

(5) Flexural modulus and flexural strength A molded product was obtained in the same manner as in the measurement of the Izod impact strength. A test piece having a width of 10 mm, a thickness of 4 mm, and a length of 12.7 mm was prepared from the obtained molded product, and the bending elastic modulus and bending strength were measured at 23 ° C. according to JIS K-7171.

(6) Rockwell hardness A molded product having a width of 100 mm, a length of 100 mm and a thickness of 3 mm was obtained in the same manner as in the measurement of the Izod impact strength. After the obtained molded products were stacked on two sheets, the Rockwell hardness was measured on the M scale according to JIS K-7202.

(7) MI value (melt flowability)
Using a descending flow tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the MI value of the polycarbonate resin composition pellets under a load of 3.8 kgf was measured by the following method. The measurement temperature was 280 ° C.
The resin flowing out for 30 seconds was collected, the mass was measured, and the amount of flowing out per 10 minutes was calculated. The outflow amount per 10 minutes was measured three times, and the average value was defined as the MI value.

(Production Example 1) Production of surface hardness improver (1) In a polymerization vessel equipped with a thermometer, a nitrogen introduction tube, a reflux condenser and a stirrer and capable of heating and cooling, 200 parts of deionized water, (meta ) 0.01 part of an alkali metal salt of a copolymer of acrylic acid and methyl (meth) acrylate was added and stirred to obtain an aqueous solution of a dispersant.
After stopping the stirring, 100 parts of glycidyl methacrylate was charged into the polymerization vessel, and then the stirring was started again. After the inside of the polymerization vessel was purged with nitrogen, 1.0 part of 2,2′-azobis (2,4-dimethylvaleronitrile) and 1.5 parts of n-dodecyl mercaptan were added to the polymerization vessel, and the temperature was raised to 75 ° C. The reaction was carried out for 2 hours while maintaining the reaction temperature at 75-80 ° C. Next, the temperature inside the polymerization vessel was raised to 95 ° C. and reacted for 1 hour to obtain a slurry of the surface hardness improver (1).
The slurry of the surface hardness improver (1) was filtered, dehydrated and dried with a mesh having an opening of 30 μm to obtain a granular material of the surface hardness improver (1). Table 1 shows the evaluation results of the surface hardness improver (1).

(Production Examples 2 to 4) Production of surface hardness improvers (2) to (4) Surface hardness improvement in the same manner as in Production Example 1 except that the monomer composition for surface hardness improver shown in Table 1 was used. Granules of agents (2) to (4) were obtained. Table 1 shows the evaluation results of the surface hardness improvers (2) to (4).

(Production Example 5) Production of surface hardness improver (5) 1.5 parts of n-dodecyl mercaptan was changed to 2.0 parts. Other than that was carried out similarly to manufacture example 1, and obtained the granular material of the surface hardness improver (5). Table 1 shows the evaluation results of the surface hardness improver (5).

(Production Example 6) Production of surface hardness improver (1 ') Surface hardness improver (1') in the same manner as Production Example 1 except that the monomer composition for surface hardness improver shown in Table 1 was used. Of granular material was obtained. Table 1 shows the evaluation results of the surface hardness improver (1 ′).

(Production Example 7) Production of surface hardness improver (2 ') In a 5-liter separable flask equipped with a stirring blade, a condenser, a thermocouple and a nitrogen inlet, 290 parts of deionized water, sodium alkylbenzenesulfonate (Kao Corporation ), Product name; Neoperex G-15) 1 part, 80 parts of methyl methacrylate, 20 parts of n-butyl acrylate and 0.03 part of n-octyl mercaptan were charged, and the temperature was raised to 65 ° C. in a nitrogen stream. Next, 0.2 parts of potassium persulfate dissolved in 10 parts of deionized water was added to the above separable flask to initiate radical polymerization reaction. After the heat generation was completed, the temperature in the separable flask was kept at 65 ° C. for 1 hour to obtain a latex of the surface hardness improver (2 ′). The solid content concentration of the latex of the surface hardness improver (2 ′) was 25%.
The latex of the surface hardness improver (2 ′) was spray-dried with a spray dryer to obtain a powder of the surface hardness improver (2 ′). Table 1 shows the evaluation results of the surface hardness improver (2 ′).

表中の略号は以下のものを示す。
ＭＭＡ：メチルメタクリレート
ＭＡＡ：メタクリル酸
ＢＡ：ブチルアクリレート

The abbreviations in the table indicate the following.
MMA: Methyl methacrylate MAA: Methacrylic acid BA: Butyl acrylate

Example 1
100 parts of Mitsubishi Engineering Plastics polycarbonate resin (PC) (Iupilon S2000F (trade name), viscosity average molecular weight 21,000) and 5 parts of the surface hardness improver (1) obtained in Production Example 1 Is supplied to a twin screw extruder (PCM-30 (trade name), manufactured by Ikegai Iron Works Co., Ltd.) having an inner diameter of 30 mm and a cylinder effective length / cylinder diameter (L / D) = 28.5 at 280 ° C. By melt-kneading, a pellet (A) of a polycarbonate resin composition was obtained.
The molded product was evaluated using the pellets (A) of the obtained polycarbonate resin composition. The evaluation results are shown in Table 2.

(Examples 2-6 and Comparative Examples 1-4)
The surface hardness improvers (2) to (5), (1 ′) and (2 ′) obtained in Production Examples 2 to 7 were used, and the formulations having the ratios shown in Table 2 were used. Other than that was carried out similarly to Example 1, and obtained the pellet (B)-(J) of the polycarbonate-type resin composition.
The molded articles were evaluated using the obtained polycarbonate resin composition pellets (B) to (J). The evaluation results are shown in Table 2.

Claims (4)

  A surface hardness improver for a polycarbonate resin, which is a polymer having a mass average molecular weight of 1,000 to 100,000 and containing a glycidyl (meth) acrylate unit as a monomer unit.   The surface hardness improver for a polycarbonate resin according to claim 1, wherein the monomer units of the polymer are 2 to 100% by mass of glycidyl (meth) acrylate units and 0 to 98% by mass of copolymerizable vinyl monomer units. .   A polycarbonate resin composition comprising 100 parts by mass of a polycarbonate resin and 0.3 to 30 parts by mass of a surface hardness improver for a polycarbonate resin according to claim 1 or 2.   A molded product obtained by molding a polycarbonate resin composition.