JP6810565B2 - Polycarbonate resin composition - Google Patents

Description

The present invention relates to a polycarbonate resin composition, and more specifically, it has excellent scratch resistance on nails, excellent scratch resistance that eliminates even slight scratches at low hardness in a pencil hardness test, and excellent fluidity and appearance. Further, the present invention relates to a polycarbonate resin composition having excellent transparency.

Polycarbonate resin has excellent mechanical strength, electrical properties, transparency, etc., and is widely used as an engineering plastic in various fields such as electrical and electronic equipment fields and automobile fields. In recent years, in these fields of application, the thickness, size, and weight of molded products have been reduced, and further improvement in the performance of molded materials has been required. Among them, the development of polycarbonate resin having high hardness has been desired. , Some suggestions have been made.

For example, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, that is, polycarbonate having excellent surface hardness using an aromatic dihydroxy compound having a specific structure different from that of conventional bisphenol A such as bisphenol C. Known methods include copolycarbonate (Patent Document 1 and Patent Document 2), and a method of blending dimethylbisphenol cyclohexane type polycarbonate and bisphenol A type polycarbonate (Patent Document 3).

Japanese Unexamined Patent Publication No. 64-069625 Japanese Unexamined Patent Publication No. 08-183852 International Publication No. 2009/089333

It is true that bisphenol C-based polycarbonate resin shows a high pencil hardness of 2H, but when this molded product is actually used as a product, there are some problems with scratch resistance such as being easily scratched by rubbing with nails. It turned out that there was. Although the pencil hardness itself must be an important index for scratch resistance, it has been found that this alone is not always sufficient for scratch resistance. Pencil hardness is expressed by pressing the pencil lead against the surface of the sample at 45 ° with a load of 750 g, pressing it to move it, and expressing the scratch hardness of the sample by the hardness of the pencil lead (6B to HB to 9H) depending on the presence or absence of scratches. As for the test method, when the bisphenol C-based polycarbonate resin shows a high pencil hardness such as 2H, when the above measurement operation is performed with a pencil having a hardness lower than 2H, a slight scratch is formed on the surface of the test piece. It turned out that there is. Pencil hardness has been established as a method for evaluating the surface hardness of plastics, and it is strongly required that such low pencil hardness does not cause slight scratches.
An object (problem) of the present invention is to provide a polycarbonate resin using an aromatic dihydroxy compound having a specific structure different from that of conventional bisphenol A such as bisphenol C, which is excellent in scratch resistance on nails and low in pencil hardness test. It is an object of the present invention to provide a polycarbonate resin composition which is excellent in scratch resistance, excellent in fluidity and appearance, and also excellent in transparency, which eliminates even a slight scratch on hardness.

As a result of diligent studies to achieve the above problems, the present inventor has added a polycarbonate-polyorgano to a polycarbonate resin using an aromatic dihydroxy compound having a specific structure different from that of conventional bisphenol A such as bisphenol C. We have found that a polycarbonate resin composition containing a specific amount of a graft copolymer having a vinyl-based polymer segment as a side chain in the main chain of a siloxane copolymer and a polyethylene-based polymer can solve the above problems. The invention was completed.
The present invention relates to the following polycarbonate resin compositions and molded articles.

[1] 5 to 200 parts by mass of the polycarbonate-polyorganosiloxane copolymer (B) and a polyethylene-based weight with respect to 100 parts by mass of the polycarbonate resin (A) containing the structural unit represented by the following general formula (1). A polycarbonate resin composition containing 0.1 to 25 parts by mass of a graft copolymer (C) having a coalescence as a main chain and a vinyl polymer segment as a side chain.
(In the general formula (1), R ¹ represents a methyl group, R ² and R ³ independently represent a hydrogen atom or a methyl group, and X represents an alkylene group or an alkylidene group.)

[2] The polycarbonate resin composition according to the above [1], wherein the graft copolymer (C) is a graft copolymer having a polyethylene polymer main chain and a styrene polymer segment as a side chain.
[3] The polycarbonate according to the above [1], wherein the graft copolymer (C) is a graft copolymer composed of at least 50 to 95% by mass of polyethylene-based polymer segments and 5 to 50% by mass of vinyl-based polymer segments. Resin composition.
[4] The polycarbonate resin according to any one of the above [1] to [3], wherein the graft copolymer (C) is a graft copolymer further containing 0.5 to 30% by mass of a polyorganosiloxane segment. Composition.
[5] The above-mentioned [1] to [4], wherein the graft copolymer (C) has an endothermic peak of 100 ° C. or lower as measured by a differential scanning calorimeter (DSC) in accordance with JIS K7121. Polycarbonate resin composition.
[6] The polycarbonate according to any one of the above [1] to [5], further containing 0.01 to 5 parts by mass of the blackening agent (C) with respect to 100 parts by mass of the polycarbonate resin (A). Resin composition.
[7] A molded product of the polycarbonate resin composition according to any one of the above [1] to [6].

The polycarbonate resin composition of the present invention is highly transparent by combining a polycarbonate-polyorganosiloxane copolymer (B) and the above-mentioned graft copolymer (C) with a polycarbonate resin (A) that is not a conventional bisphenol A type. It has properties, high pencil hardness, and excellent scratch resistance on nails, eliminates slight scratches at low hardness in the pencil hardness test, and has excellent scratch resistance. On the other hand, even if the graft copolymer (C) is blended with a general-purpose bisphenol A type polycarbonate resin, or the graft copolymer (C) is blended with a polycarbonate-polyorganosiloxane copolymer (B), Although it exhibits a certain degree of scratch resistance, it cannot achieve the effects of the present invention, such as scratch resistance on nails and elimination of slight scratches at low hardness in a pencil hardness test. Further, even if only the graft copolymer (C) is blended with the conventional polycarbonate resin (A) which is not the bisphenol A type, the transparency is low and it cannot be used for transparent applications. The reason for this has not yet been fully elucidated, but the presence of a methyl group in R ¹ of the general formula (1) improves the affinity of the graft copolymer (C) with polyethylene, which is the main skeleton. This is because the compatibility between the polycarbonate resin (A) and the graft copolymer (C) was improved, and the refractive index of the polycarbonate resin phase was reduced by adding the polycarbonate-polyorganosiloxane copolymer (B). I'm guessing it might be.
The polycarbonate resin composition of the present invention having such an effect is particularly used for vehicle interior parts, particularly liquid crystal display panel members for car navigation and audio, touch panel display cover members, electronic and electrical equipment, OA equipment, and the like. It can be suitably used for housing members of information terminal devices, various tablet-type mobile terminals such as smartphones, tablet-type personal computers, smartphone cases, and the like.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples shown below, and is not deviating from the gist of the present invention. It can be changed arbitrarily and implemented.

The polycarbonate resin composition of the present invention has a polyethylene-based polymer main chain and a vinyl-based polymer segment side chain with respect to 100 parts by mass of the polycarbonate resin (A) having the structural unit represented by the general formula (1). It is characterized by containing 0.1 to 25 parts by mass of the graft copolymer (C).

[Polycarbonate resin (A)]
The polycarbonate resin (A) is a polycarbonate resin containing a structural unit represented by the following general formula (1).
(In the general formula (1), R ¹ represents a methyl group, R ² and R ³ independently represent a hydrogen atom or a methyl group, and X represents an alkylene group or an alkylidene group.)

In the above general formula (1), R ¹ is a methyl group and R ² and R ³ are independent hydrogen atoms or methyl groups, respectively, but R ² and R ³ are particularly preferably hydrogen atoms.
Further, X is an alkylene group or an alkylidene group, and the alkylene group is preferably an alkylene group having 1 to 6 carbon atoms, and may be linear or branched. Examples thereof include methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,6-hexylene and the like.
The alkylidene group is preferably an alkylidene group having 2 to 10 carbon atoms, and examples thereof include ethylidene, 2,2-propylidene, 2,2-butylidene, and 3,3-hexylidene.
X is preferably an alkylidene group, particularly preferably a 2,2-propyridene group (ie, an isopropylidene group).

Preferred specific examples of the polycarbonate resin (A) include the following polycarbonate resins a) to b).
B) Those having 2,2-bis (3-methyl-4-hydroxyphenyl) propane structural units, that is, structural units in which R ¹ is a methyl group, R ² and R ³ are hydrogen atoms, and X is an isopropylidene group. Have
B) It has a 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane structural unit, that is, a structural unit in which R ¹ is a methyl group, R ² and R ³ are methyl groups, and X is an isopropylidene group. thing,
Of the above, the polycarbonate resin of the above a) is particularly preferable.

These polycarbonate resins are produced by using 2,2-bis (3-methyl-4-hydroxyphenyl) propane and 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane as dihydroxy compounds. be able to.

As the polycarbonate resin (A), one type may be used, or two or more types may be used in any combination and in any ratio.

The polycarbonate resin (A) may be a polycarbonate resin having a carbonate structural unit other than the structural unit represented by the general formula (1), and may be, for example, a structural unit represented by the following general formula (2) or a structural unit. It may have structural units derived from other dihydroxy compounds as described below. At this time, the copolymerization amount of the structural unit other than the structural unit represented by the general formula (1) is usually less than 50 mol%, preferably 40 mol% or less, more preferably 30 mol% or less, and further. Is preferably 20 mol% or less, particularly preferably 10 mol% or less.
(In the formula, X is synonymous with X in the general formula (1).)

A preferable specific example of the polycarbonate structural unit represented by the general formula (2) is 2,2-bis (4-hydroxyphenyl) propane, that is, a carbonate structural unit derived from bisphenol A.
When the polycarbonate resin (A) contains a carbonate structural unit derived from bisphenol A as a copolymerization component, the component derived from bisphenol A is preferably less than 50 mol%, more preferably 30% by mass or less, still more preferably. It is preferably 20% by mass or less, particularly 10% by mass or less, and particularly preferably 5% by mass or less.

Examples of dihydroxy compounds other than the structural unit represented by the general formula (2) include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) butane, and 2,2-bis ( 4-Hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) phenylmethane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxy) Preferred are phenyl) cyclooctane, 9,9-bis (4-hydroxyphenyl) fluorene, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxyphenyl ether and the like.

The viscosity average molecular weight (Mv) of the polycarbonate resin (A) is preferably 19,000 to 32,000. When the viscosity average molecular weight is in this range, it is easy to obtain a molded product having good moldability, high mechanical strength, and good scratch resistance. If it is less than 19,000, the pencil hardness of the resin composition becomes low. It is easy, and the wear resistance is likely to decrease, and if it exceeds 32,000, the melt viscosity tends to increase and injection molding tends to be difficult. The lower limit of the molecular weight of the polycarbonate resin (A) is more preferably 20,000, still more preferably 22,000, particularly 24,000, and the upper limit is preferably 30,000, more preferably 28,000. ..

In the present invention, the viscosity average molecular weight [Mv] of the polycarbonate resin is determined by using methylene chloride as a solvent and using an Ubbelohde viscometer to determine the ultimate viscosity [η] (unit: dl / g) at a temperature of 20 ° C. It is a value calculated from the following Schnell viscosity formula.
[Η] = 1.23 × 10 ^-4 Mv ^0.83

The polycarbonate resin (A) has a carbonate structural unit other than the structural unit represented by the general formula (1), as in the polycarbonate resin (A) containing the structural unit represented by the general formula (1). It may be a mixture with a polycarbonate resin. When such other polycarbonate resins are mixed, it is less than 50% by mass, preferably 40% by mass or less, more preferably 30% by mass or less, and further 20% by mass or less based on a total of 100% by mass of both. Is preferable.

When the polycarbonate resin (A) is a mixture with a polycarbonate resin other than the structural unit represented by the general formula (1), the other polycarbonate resin is a polycarbonate structure represented by the general formula (2). A polycarbonate resin composed of units is preferable, and a preferable specific example thereof is 2,2-bis (4-hydroxyphenyl) propane, that is, a carbonate resin derived from bisphenol A.
This may be a copolymer having a structural unit derived from a dihydroxy compound other than the structural unit represented by the general formula (2), and examples thereof include bis (4-hydroxyphenyl) methane, 2, 2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxy) Phenyl) decane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) phenylmethane, 1,1-bis ( 4-Hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclooctane, 9,9-bis (4-hydroxyphenyl) fluorene, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxyphenyl A unit derived from ether or the like is preferably mentioned.

The polycarbonate resin (A) is defined as being different from the polycarbonate-polyorganosiloxane copolymer (B), and the polycarbonate resin (A) does not contain the polycarbonate-polyorganosiloxane copolymer (B). Absent.

The viscosity average molecular weight (Mv) of the other polycarbonate resin that may be mixed with the polycarbonate resin (A) is preferably 15,000 to 30,000. When the viscosity average molecular weight is in this range, it is easy to obtain a molded product having good moldability, high mechanical strength, and good scratch resistance. If it is less than 15,000, the pencil hardness of the resin composition becomes low. It is easy to decrease the abrasion resistance, and if it exceeds 30,000, the melt viscosity tends to increase and injection molding tends to be difficult. The lower limit of the molecular weight of the polycarbonate resin (A) is more preferably 20,000, still more preferably 22,000, particularly 24,000, and the upper limit is preferably 28,000, more preferably 26,000. ..

Method for Producing Polycarbonate Resin The method for producing the polycarbonate resin used in the present invention is not particularly limited, and any method can be adopted. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, and a solid phase transesterification method of a prepolymer.
Hereinafter, particularly suitable of these methods will be specifically described.

Interfacial polymerization method First, a case where the polycarbonate resin is produced by the interfacial polymerization method will be described.
In the interfacial polymerization method, the pH is usually maintained at 9 or higher in the presence of an organic solvent inert to the reaction and an aqueous alkaline solution, and the dihydroxy compound is reacted with a carbonate precursor (preferably phosgene), and then the polymerization catalyst is used. A polycarbonate resin is obtained by performing interfacial polymerization in the presence. If necessary, a molecular weight modifier (terminal terminator) may be present in the reaction system, or an antioxidant may be present to prevent oxidation of the dihydroxy compound.

The dihydroxy compound and carbonate precursor are as described above. It is preferable to use phosgene among the carbonate precursors, and the method using phosgene is particularly called a phosgene method.

Examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene; and aromatic hydrocarbons such as benzene, toluene and xylene. Be done. As the organic solvent, one type may be used, or two or more types may be used in any combination and ratio.

Examples of the alkaline compound contained in the alkaline aqueous solution include alkali metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium hydrogen carbonate, and alkaline earth metal compounds. Among them, sodium hydroxide and water. Potassium oxide is preferred. As the alkaline compound, one type may be used, or two or more types may be used in any combination and ratio.

The concentration of the alkaline compound in the alkaline aqueous solution is not limited, but is usually used at 5 to 10% by mass in order to control the pH in the alkaline aqueous solution of the reaction to 10 to 12. Further, for example, when phosgene is blown, the molar ratio of the bisphenol compound to the alkaline compound is usually 1: 1.9 or more in order to control the pH of the aqueous phase to be 10 to 12, preferably 10 to 11. Above all, it is preferably 1: 2.0 or more, and usually 1: 3.2 or less, and above all, 1: 2.5 or less.

Examples of the polymerization catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine and trihexylamine; and alicyclic such as N, N'-dimethylcyclohexylamine and N, N'-diethylcyclohexylamine. Formula tertiary amines; aromatic tertiary amines such as N, N'-dimethylaniline, N, N'-diethylaniline; quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride, triethylbenzylammonium chloride, etc. ; Pyridine salt; etc. As the polymerization catalyst, one type may be used, or two or more types may be used in any combination and ratio.

Examples of the molecular weight modifier include aromatic phenols having a monovalent phenolic hydroxyl group; fatty alcohols such as methanol and butanol; mercaptans; imide phthalates, and the like, and aromatic phenols are preferable. Specific examples of such aromatic phenols include alkyl groups such as m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-long chain alkyl-substituted phenol. Substituted phenols; vinyl group-containing phenols such as isopropenylphenol; epoxy group-containing phenols; carboxyl group-containing phenols such as o-hydroxybenzoic acid and 2-methyl-6-hydroxyphenylacetic acid; and the like. As the molecular weight adjusting agent, one type may be used, or two or more types may be used in any combination and ratio.

The amount of the molecular weight modifier used is usually 0.5 mol or more, preferably 1 mol or more, and usually 50 mol or less, preferably 30 mol or less, based on 100 mol of the dihydroxy compound. By setting the amount of the molecular weight adjusting agent used in this range, the thermal stability and hydrolysis resistance of the resin composition can be improved.

At the time of the reaction, the order in which the reaction substrate, reaction medium, catalyst, additives and the like are mixed is arbitrary as long as a desired polycarbonate resin can be obtained, and an appropriate order may be set arbitrarily. For example, when phosgene is used as the carbonate precursor, the molecular weight modifier can be mixed at any time between the time of the reaction (phosgenation) between the dihydroxy compound and phosgene and the start of the polymerization reaction.
The reaction temperature is usually 0 to 40 ° C., and the reaction time is usually several minutes (for example, 10 minutes) to several hours (for example, 6 hours).

Molten transesterification method Next, a case where the polycarbonate resin is produced by the molten transesterification method will be described.
In the melt transesterification method, for example, a transesterification reaction between a carbonic acid diester and a dihydroxy compound is performed.

The dihydroxy compound is as described above.
On the other hand, examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate; diphenyl carbonate; and substituted diphenyl carbonate such as ditril carbonate. Of these, diphenyl carbonate and substituted diphenyl carbonate are preferable, and diphenyl carbonate is particularly preferable. In addition, 1 type of carbonic acid diester may be used, and 2 or more types may be used in arbitrary combination and ratio.

The ratio of the dihydroxy compound to the carbonic acid diester is arbitrary as long as a desired polycarbonate resin can be obtained, but it is preferable to use an equimolar amount or more of the carbonic acid diester with respect to 1 mol of the dihydroxy compound, and 1.01 mol or more is particularly used. Is more preferable. The upper limit is usually 1.30 mol or less. By setting the range to such a range, the amount of terminal hydroxyl groups can be adjusted to a suitable range.

In polycarbonate resin, the amount of terminal hydroxyl groups tends to have a great influence on thermal stability, hydrolysis stability, color tone and the like. Therefore, the amount of terminal hydroxyl groups may be adjusted as necessary by any known method. In the transesterification reaction, usually, a polycarbonate resin having an adjusted amount of terminal hydroxyl groups can be obtained by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound; the degree of reduced pressure during the transesterification reaction. By this operation, the molecular weight of the normally obtained polycarbonate resin can also be adjusted.

When the mixing ratio of the carbonic acid diester and the dihydroxy compound is adjusted to adjust the amount of terminal hydroxyl groups, the mixing ratio is as described above.
Further, as a more aggressive adjustment method, a method of separately mixing a terminal terminator at the time of reaction can be mentioned. Examples of the terminal terminator at this time include monohydric phenols, monovalent carboxylic acids, and carbonic acid diesters. In addition, as the terminal terminator, 1 type may be used, and 2 or more types may be used in arbitrary combination and ratio.

When producing a polycarbonate resin by the transesterification method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among them, for example, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. Alternatively, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination. As the transesterification catalyst, one type may be used, or two or more types may be used in any combination and ratio.

In the melt transesterification method, the reaction temperature is usually 100 to 320 ° C. Further, it is preferable that the pressure at the time of reaction is usually carried out under a reduced pressure of less than normal pressure, the state of reduced pressure is adjusted according to the progress of the reaction, and finally the condition is 2 mmHg or less. As a specific operation, the melt polycondensation reaction may be carried out under the above conditions while removing by-products such as aromatic hydroxy compounds.

The melt polycondensation reaction can be carried out by either a batch method or a continuous method. In the case of batch method, the order of mixing the reaction substrate, reaction medium, catalyst, additives and the like is arbitrary as long as a desired aromatic polycarbonate resin can be obtained, and an appropriate order may be arbitrarily set. However, considering the stability of the polycarbonate resin and the like, it is preferable to carry out the melt polycondensation reaction in a continuous manner.

In the molten transesterification method, a catalytic deactivator may be used if necessary. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. As the catalyst deactivator, one type may be used, or two or more types may be used in combination in any combination and ratio.

The amount of the catalyst deactivator used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, relative to the alkali metal or alkaline earth metal contained in the transesterification catalyst. It is preferably 5 equivalents or less. Further, it is usually 1 ppm or more, and usually 100 ppm or less, preferably 20 ppm or less, with respect to the polycarbonate resin.

[Polycarbonate-polyorganosiloxane copolymer (B)]
The polycarbonate resin composition of the present invention contains a polycarbonate-polyorganosiloxane copolymer (B).
The polycarbonate-polyorganosiloxane copolymer (B) is composed of a polycarbonate portion and a polyorganosiloxane portion. As the polyorganosiloxane portion in the polycarbonate-polyorganosiloxane copolymer (B), a segment composed of polydimethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane or the like is preferable, and a polydimethylsiloxane segment is particularly preferable.

The polycarbonate-polyorganosiloxane copolymer (B) contains, for example, a previously produced polycarbonate oligomer constituting a polycarbonate portion, and o-allylphenol residues and p-hydroxystyrene residues at the terminals constituting the polyorganosiloxane portion. , Polyorganosiloxane having a reactive group such as Eugenol residue is dissolved in a solvent such as methylene chloride, chlorobenzene, chloroform, etc., a caustic alkaline aqueous solution of dihydric phenol is added, and a tertiary amine (triethylamine, etc.) is used as a catalyst. ) Or a quaternary ammonium salt (such as trimethylbenzylammonium chloride) can be produced by performing an interfacial polycondensation reaction in the presence of a terminal terminator.

The polycarbonate oligomer used in the production of this polycarbonate-polyorganosiloxane copolymer (B) can be obtained by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride, or by reacting the carbonate precursor. It can be easily produced by reacting a valent phenol with a carbonic acid ester compound, for example, a carbonate precursor such as dichloromethane.

Examples of the divalent phenol include the same ones described above for the polycarbonate resin of the general formula (2) or the general formula (1), but in particular, 2,2-bis (4-hydroxyphenyl) propane. (That is, bisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 4, 4'-Dihydroxydiphenyl, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) oxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) Sulfoxide, bis (4-hydroxyphenyl) ketone and the like can be preferably mentioned. Among these, bis (hydroxyphenyl) alkane-based ones are more preferable, and 2,2-bis (4-hydroxyphenyl) propane is particularly preferable.
The divalent phenol may be used alone or in combination of two or more.

Examples of the carbonate precursor include carbonyl halide, carbonyl ester, haloformate and the like, and specifically, phosgene, dihalohomet of divalent phenol, diphenyl carbonate, dimethyl carbonate, diethyl carbonate and the like. Examples of the carbonic acid ester compound include diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.
The polycarbonate oligomer used for producing the polycarbonate-polyorganosiloxane copolymer (B) may be a homooligomer using one of the above-mentioned divalent phenols, or a co-oligomer using two or more of them. May be good.
Further, it may be a thermoplastic random branched oligomer obtained by using a polyfunctional aromatic compound in combination with the above-mentioned divalent phenol.
In that case, as a branching agent, 1,1,1-tris (4-hydroxyphenyl) ethane, α, α', α''-tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, 1 -[Α-Methyl-α- (4'-hydroxyphenyl) ethyl] -4- [α', α'-bis (4''-hydroxyphenyl) ethyl] benzene, fluoroglucin, trimellitic acid, isatinbis (o-) Cresol) etc. can be used.

Such a polycarbonate-polyorganosiloxane copolymer (B) is disclosed in, for example, JP-A-50-29695, JP-A-3-292359, JP-A-4-202466, and the like.

As the polycarbonate-polyorganosiloxane copolymer (B), those having a degree of polymerization of the polycarbonate part of about 3 to 100 and a degree of polymerization of the polyorganosiloxane part of about 2 to 500 are preferably used.
The content of the polyorganosiloxane portion in the polycarbonate-polyorganosiloxane copolymer (B) is preferably 2 to 10% by mass, more preferably 2.2 to 7% by mass, and particularly preferably 2.5 to 5%. It is mass%.

The viscosity average molecular weight (Mv) of the polycarbonate-polyorganosiloxane copolymer (B) is usually 5,000 to 100,000, preferably 10,000 to 30,000, particularly preferably 12,000 to 20, It is 000.
The viscosity average molecular weight (Mv) is a value obtained in the same manner as the method described in the above-mentioned section of the polycarbonate resin (A).

The melt flow rate (MFR) of the polycarbonate-polyorganosiloxane copolymer (B) measured at 300 ° C./1.2 kg is preferably 1 to 35 g / 10 min, more preferably 5 to 30 g. It is / 10 min, more preferably 10 to 20 g / 10 min.

The content of the polycarbonate-polyorganosiloxane copolymer (B) is 5 to 200 parts by mass, preferably 10 to 150 parts by mass, and more preferably 40 to 120 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). It is a part by weight. If it is less than 5 parts by mass, the haze increases and the transparency becomes low, and if it exceeds 200 parts by mass, the pencil hardness decreases, and the scratch resistance on the nail and the slight scratch resistance at low hardness in the pencil hardness test. Causes a decrease in.

[Graft copolymer (C)]
The polycarbonate resin composition of the present invention contains a graft copolymer (C) having a polyethylene-based polymer as a main chain and a vinyl-based polymer segment as a side chain. In this graft copolymer (C), the polyethylene-based polymer serves as the main chain of the graft copolymer, and the segment obtained by polymerizing the vinyl-based monomer serves as the side chain of the graft copolymer.

The polyethylene-based polymer constituting the main chain may be either a homopolymer of ethylene or a copolymer containing ethylene as a main component and copolymerizing with other α-olefins other than ethylene.
Other α-olefins other than ethylene are α-olefins having a carbon atom number of usually 3 to 20, preferably 3 to 12, such as propylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1. -Pentene, 1-octene, 1-decene, 1-dodecene and the like are preferably mentioned.
When the polyethylene-based polymer is a copolymer, the amount of the α-olefin unit is usually 0 to 50% by mass, preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and further 0 to 10% by mass. Is preferable.

The molecular weight of the polyethylene-based polymer is usually about 10,000 to 600,000 in terms of number average molecular weight (Mn). Here, the number average molecular weight means what is obtained in terms of polystyrene by gel permeation chromatography (GPC).

Examples of the polyethylene-based polymer include commercially available high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (VLDPE), or a high-pressure method obtained by a high-pressure radical method. It may be any of low density polyethylene (HPLD) and the like, but low density polyethylene, linear low density polyethylene, ultra low density polyethylene, high pressure method low density polyethylene are preferable, and ultra low density polyethylene (VLDPE) is more preferable. preferable.

The density of the low density polyethylene is usually 0.91 to 0.94 g / cm ³ , preferably 0.912 to 0.935 g / cm ³ . The linear low-density polyethylene preferably has a density of 0.91 to 0.94 g / cm ³ . Ultra-low density polyethylene is a copolymer of ethylene and α-olefin, and usually has a density in the range of 0.86 to 0.91 g / cm ³ . The high-pressure method low-density polyethylene by the high-pressure method preferably has a density of 0.91 to 0.94 g / cm ³ .

Examples of the vinyl-based monomer for forming the vinyl-based polymer segment include a styrene-based monomer, α, β-unsaturated carboxylic acid, α, β-unsaturated carboxylic acid ester, and an unsaturated nitrile-based single amount. The body and the like are preferably mentioned.

Examples of the styrene-based monomer include styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorostyrene and the like, and styrene is particularly preferable.
Examples of α, β-unsaturated carboxylic acids include (meth) acrylic acid esters such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxypropyl (meth) acrylate, acrylic acid, and methacrylic acid. , Fumaric acid, maleic anhydride, itaconic acid and the like are preferable.
Examples of α, β-unsaturated carboxylic acid esters include methyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, and n methacrylate. -Butyl, isobutyl methacrylate and the like are preferable.
Acrylonitrile is preferably used as the unsaturated nitrile-based monomer.

Among these vinyl-based monomers, styrene-based monomers, particularly styrene, are preferable because they have high compatibility with the polycarbonate resin (A) and are excellent in scratch resistance, and styrene alone or with styrene. It is preferable to copolymerize with OH group-containing (meth) acrylate such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, or acrylonitrile.

The molecular weight of the vinyl-based polymer segment is more preferably 5,000 to 500,000 in terms of mass average molecular weight. Here, the mass average molecular weight means what is obtained in terms of polystyrene by gel permeation chromatography (GPC).

It is also preferable that the graft copolymer (C) further contains a polyorganosiloxane. When it contains polyorganosiloxane, it may be present as the main chain or side chain of the graft copolymer (C), and is one of the graft copolymers that forms a multi-layer structure such as a core / shell type. It may be contained as a part.

The polyorganosiloxane is not particularly limited, and examples thereof include polydimethylsiloxane and polymethylphenylsiloxane, and examples thereof include polydimethyldiphenylsiloxane copolymer, polydimethylphenylmethylsiloxane copolymer, and polymethylphenyldiphenylsiloxane copolymer. Of these, a polymer containing a dialkylsiloxane unit, particularly a dimethylsiloxane unit as a constituent unit is preferable.
Further, as the polyorganosiloxane, those containing a siloxane containing a vinyl group as a constituent component are preferable. A siloxane containing a vinyl group is well known, and is a siloxane containing a vinyl group to which an organosiloxane is bonded via a siloxane bond.

The proportion of the polyethylene-based polymer segment in the graft copolymer (C) is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and further preferably 65 to 80% by mass. is there. The proportion of the vinyl-based polymer segment is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, further preferably 20 to 35% by mass, and most preferably 20 to 30% by mass. It is mass%.
Further, when the polyorganosiloxane segment is further contained, the content is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and further preferably 2 to 10% by mass. .. However, when the polyorganosiloxane segment is contained, the total amount of the polyethylene-based polymer segment, the vinyl-based polymer segment, and the polyorganosiloxane segment is 100% by mass.

The graft copolymer (C) preferably has an endothermic peak of 100 ° C. or lower as measured by a differential scanning calorimetry (DSC) in accordance with JIS K7121. When the endothermic peak temperature is 100 ° C. or lower, the scratch resistance on the nail when blended with the polycarbonate resin and the slight scratch resistance at low hardness in the pencil hardness test are good, which is preferable. The reason for this is that when the heat absorption peak temperature is 100 ° C. or lower, the polyethylene polymer main chain having a low affinity with the polycarbonate resin easily enters between the polycarbonate resin molecules, and the affinity with the polycarbonate resin is improved. It is presumed that this is because the dispersion of the graft copolymer (C) phase in the polycarbonate resin phase is improved.
The graft copolymer (C) may have a plurality of endothermic peaks, and even if there are a plurality of endothermic peaks, it is preferable to have an endothermic peak at 100 ° C. or lower. The endothermic peak temperature is preferably 90 ° C. or lower, more preferably 80 ° C. or lower, and the lower limit thereof is usually 60 ° C. or higher.

In the present invention, the endothermic peak of the graft copolymer (C) is measured according to JIS K7121 using a differential scanning calorimeter DSC7020 manufactured by Seiko Instruments Inc. of the graft copolymer (C). This is done by observing 10 mg of the sample by heating from 30 ° C. to 300 ° C. at 10 ° C./min. The graft copolymer (C) has a plurality of endothermic peaks, and the temperature of the endothermic peak on the lowest temperature side is measured.

Any of various known graft copolymerization methods may be used to produce the graft copolymer (C), and examples thereof include the methods shown below.

That is, the polyethylene-based polymer is suspended in water, and the vinyl-based monomer, a radically polymerizable organic peroxide (for example, t-butylpeoxymethacryloyloxyethyl carbonate, etc.) and a polymerization initiator (for example, t-butylpeoxymethacryloxyethyl carbonate) are suspended therein. For example, it is a method of producing a graft copolymer by adding a mixed solution in which (3,5,5-trimethylhexanoyl polyethylene, etc.) is dissolved and then heating and copolymerizing.

Further, the graft copolymer (C) is commercially available and can also be used. For example, it is sold as "NOFALOY (registered trademark) KA series" by NOF CORPORATION, for example, "NOFALOY KA147". Etc. can be used.

The content of the graft copolymer (C) is 0.1 to 25 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the above-mentioned polycarbonate resin (A). It is a part by weight. If it is less than 0.1 parts by mass, the scratch resistance on the nail and the effect of improving slight scratches at low hardness in the pencil hardness test will be small, and if it exceeds 25 parts by mass, the hue will deteriorate and the mechanical strength will deteriorate. And the heat resistance is lowered.

[Stabilizer (D)]
The polycarbonate resin composition of the present invention preferably contains a stabilizer (D). Examples of the stabilizer (D) in the present invention include antioxidants and heat stabilizers. In the present invention, the antioxidant or the heat stabilizer may be used alone, but it is preferable to use both the antioxidant and the heat stabilizer in combination.

[Antioxidant]
Examples of the antioxidant applicable to the polycarbonate resin composition of the present invention include a hindered phenolic antioxidant. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexane-1,6-diylbis [3- (3,5-di-) tert-butyl-4-hydroxyphenyl) propionamide], 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) ] Methyl] Phosphoate, 3,3', 3 ", 5,5', 5" -Hexa-tert-butyl-a, a', a "-(mesitylen-2,4,6-triyl) tri-p- Cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5- Triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine-2-ylamino ) Phenol and the like. These may be contained in only one kind, or two or more kinds may be contained in any combination and ratio.

Among the above, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate is preferred. These two phenolic antioxidants are commercially available from BASF Japan Ltd. under the names "Irganox (registered trademark, the same applies hereinafter) 1010" and "Irganox 1076".

The content of the antioxidant is usually 0.001 to 1 part by mass, preferably 0.% by mass, based on 100 parts by mass of the total of the polycarbonate resin (A), the copolymer (B) and the graft copolymer (C). It is 01 to 0.5 parts by mass. If the content of the antioxidant is less than 0.001 part by mass, the effect as an antioxidant is insufficient, and if it exceeds 1 part by mass, the effect reaches a plateau and is not economical.

[Heat stabilizer]
Examples of the heat stabilizer applicable to the polycarbonate resin composition of the present invention include phosphorus compounds. Any known phosphorus compound can be used as the phosphorus compound. Specific examples include phosphoric acid, phosphonic acid, phosphite, phosphinic acid, polyphosphoric acid and other phosphorus oxo acids; acidic sodium pyrophosphate, potassium pyrophosphate, acidic calcium pyrophosphate and other acidic pyrophosphate metal salts; phosphoric acid. Phosphates of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, zinc phosphate; organic phosphate compounds, organic phosphite compounds, organic phosphonite compounds, etc., but organic phosphite compounds Especially preferable.

Examples of the organic phosphite compound include triphenylphosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl-phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, and monooctyl. Diphenylphosphite, dioctylmonophenylphosphite, monodecyldiphenylphosphite, didecylmonophenylphosphite, tridecylphosphite, trilaurylphosphite, tristearylphosphite, 2,2-methylenebis (4,6-di-) tert-Butylphenyl) octylphosphite and the like can be mentioned.
Specific examples of such an organic phosphite compound include "ADEKA STAB (registered trademark, the same applies hereinafter) 1178", "ADEKA STAB 2112", "ADEKA STAB HP-10" manufactured by ADEKA CORPORATION, and Johoku Chemical Industry Co., Ltd. Examples thereof include "JP-351", "JP-360", "JP-3CP" manufactured by the company, and "Irgafos (registered trademark) 168" manufactured by BASF Japan Ltd.
The heat stabilizer may be contained in only one type, or two or more types may be contained in any combination and ratio.

The content of the heat stabilizer is usually 0.001 part by mass or more, preferably 0.005 with respect to 100 parts by mass of the total of the polycarbonate resin (A), the copolymer (B) and the graft copolymer (C). It is more than parts by mass, more preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less. If the content of the heat stabilizer is less than the lower limit of the above range, the heat stabilization effect may be insufficient, and if the content of the heat stabilizer exceeds the upper limit of the above range, the effect peaks out. It may become uneconomical.

[Release agent]
The polycarbonate resin composition of the present invention also preferably contains a mold release agent. Examples of the release agent include an aliphatic carboxylic acid, an ester of an aliphatic carboxylic acid and an alcohol, an aliphatic hydrocarbon compound having a number average molecular weight of 200 to 15,000, and a polysiloxane-based silicone oil.

Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Among these, the preferred aliphatic carboxylic acid is a monovalent or divalent carboxylic acid having 6 to 36 carbon atoms, and an aliphatic saturated monovalent carboxylic acid having 6 to 36 carbon atoms is more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, caproic acid, lauric acid, araquinic acid, bechenic acid, lignoceric acid, cerotic acid, melissic acid, tetraliacontanic acid, montanic acid, and adipine. Examples include acid and azelaic acid.

As the aliphatic carboxylic acid in the ester of the aliphatic carboxylic acid and the alcohol, for example, the same one as the above-mentioned aliphatic carboxylic acid can be used. On the other hand, examples of alcohols include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monohydric or polyhydric saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic saturated monohydric alcohol or an aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferable. Here, the aliphatic term also contains an alicyclic compound.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. Can be mentioned.

The above ester may contain an aliphatic carboxylic acid and / or an alcohol as an impurity. Further, the above ester may be a pure substance or a mixture of a plurality of compounds. Further, as the aliphatic carboxylic acid and the alcohol which are combined to form one ester, one kind may be used, or two or more kinds may be used in any combination and ratio.

Specific examples of esters of aliphatic carboxylic acid and alcohol include beeswax (a mixture containing myricyl palmitate as a main component), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, and glycerin monosteer. Examples thereof include rate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, fisher-tropus wax, α-olefin oligomer having 3 to 12 carbon atoms, and the like. Here, the aliphatic hydrocarbon also includes an alicyclic hydrocarbon. Moreover, these hydrocarbons may be partially oxidized. The number average molecular weight is preferably 5,000 or less. The aliphatic hydrocarbon may be a single substance, or a mixture of various constituents and molecular weights can be used as long as the main component is within the above range.

Among these, paraffin wax, polyethylene wax or a partial oxide of polyethylene wax is preferable, paraffin wax and polyethylene wax are more preferable, and polyethylene wax is particularly preferable.

In addition, 1 type may be contained in the mold release agent, and 2 or more types may be contained in arbitrary combinations and ratios.
The content of the release agent is usually 0.001 part by mass or more, preferably 0.01 with respect to 100 parts by mass of the total of the polycarbonate resin (A), the copolymer (B) and the graft copolymer (C). It is at least 2 parts by mass, and usually 2 parts by mass or less, preferably 1 part by mass or less. If the content of the release agent is less than the lower limit of the above range, the effect of the release property may not be sufficient, and if the content of the release agent exceeds the upper limit of the above range, the hydrolysis resistance There is a possibility that the mold will be reduced and the mold will be contaminated during injection molding.

[Other ingredients]
The polycarbonate resin composition of the present invention may contain other components other than the above, if necessary, as long as the desired physical properties are not significantly impaired. Examples of other components include resins and elastomers other than the above-mentioned resins, and various resin additives other than the above. In addition, 1 type may be contained in the other component, and 2 or more types may be contained in arbitrary combinations and ratios.

Examples of other resin additives include ultraviolet absorbers, flame retardants, anti-dripping agents, antistatic agents, anti-fog agents, lubricants, anti-blocking agents, plasticizers, dispersants, antibacterial agents and the like. In addition, 1 type may be contained in the resin additive, and 2 or more types may be contained in arbitrary combinations and ratios.

[Manufacturing method of polycarbonate resin composition]
The method for producing the polycarbonate resin composition of the present invention is not limited, and a known method for producing the polycarbonate resin composition can be widely adopted, and the polycarbonate resin (A), copolymer (B) and graft copolymer (C), In addition, other components to be blended as necessary are premixed using various mixers such as a tumbler and a Henschel mixer, and then a Banbury mixer, a roll, a brabender, a single-screw kneading extruder, and a twin-screw kneading extruder. , A method of melt-kneading with a mixer such as a kneader.
The temperature of melt-kneading is not particularly limited, but is preferably in the range of 240 to 320 ° C, particularly preferably 240 to 300 ° C.

[Molding]
The above-mentioned polycarbonate resin composition (pellet) is molded by various molding methods to obtain a molded product.
The shape of the molded product is not particularly limited and may be appropriately selected depending on the intended use and purpose of the molded product. For example, plate-shaped, plate-shaped, rod-shaped, sheet-shaped, film-shaped, cylindrical, annular, etc. Examples thereof include a circular shape, an elliptical shape, a polygonal shape, a deformed product, a hollow product, a frame shape, a box shape, and a panel shape.

The method for molding the molded product is not particularly limited, and a conventionally known molding method can be adopted. For example, an injection molding method, an injection compression molding method, an extrusion molding method, a deformed extrusion method, a transfer molding method, a hollow molding method, etc. Gas assist hollow molding method, blow molding method, extrusion blow molding, IMC (in-mold coating molding) molding method, rotary molding method, multi-layer molding method, two-color molding method, insert molding method, sandwich molding method, foam molding method , Pressurization molding method and the like.
Above all, molding is preferably performed by an injection molding method, and for example, injection molding is performed using a known injection molding machine such as an injection molding machine, an ultra-high speed injection molding machine, or an injection compression molding machine. The cylinder temperature of the injection molding machine at the time of injection molding is preferably 240 to 320 ° C., more preferably 250 to 300 ° C., and further preferably 260 to 280 ° C. The injection speed during injection molding is preferably 10 to 1,000 mm / sec, more preferably 10 to 500 mm / sec.

The molded product of the polycarbonate resin composition of the present invention can be used in a wide range of fields, such as electronic and electrical equipment and its parts, OA equipment, information terminal equipment, mechanical parts, home appliances, vehicle parts, building materials, and various types. It is useful for various purposes such as containers, leisure goods / miscellaneous goods, and lighting equipment, and is expected to be particularly applied to electronic and electrical equipment, OA equipment, information terminal equipment parts, and vehicle interior parts.

Electronic electrical equipment, OA equipment, and information terminal equipment include display devices such as personal computers, game machines, and televisions, printers, copiers, scanners, fax machines, electronic notebooks and PDAs, cameras, video cameras, mobile phones, and tablet terminals. , Members such as touch panel type portable devices.
Vehicle interior parts include displays such as inner door handles, center panels, instrumental panels, console boxes, luggage floorboards, door pockets, and car navigation systems.
Among them, the molded product of the polycarbonate resin composition of the present invention is excellent in scratch resistance, appearance, and transparency, so that it is excellent in various tablet-type mobile terminals such as smartphones, tablet-type personal computers, car navigation systems, and car audio systems. It is particularly suitable as a member for a liquid crystal display panel, particularly a cover member for a touch panel.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
The raw material components used in the following examples and comparative examples are as shown in Table 1 below.

In Table 1 above, (A1) and (A2) used as the polycarbonate resin (A) were produced according to the following Production Examples 1 and 2, respectively.

<Manufacturing Example 1: Production of Polycarbonate Resin (A1)>
26.14 mol (6.75 kg) of 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter referred to as "BPC") and 26.79 mol (5.74 kg) of diphenyl carbonate were added. It was placed in a SUS reactor (internal volume 10 liters) equipped with a stirrer and a distillate condensing device, the inside of the reactor was replaced with nitrogen gas, and the temperature was raised to 220 ° C. over 30 minutes in a nitrogen gas atmosphere.
Next, the reaction solution in the reactor was stirred, and cesium carbonate (Cs ₂ CO ₃ ) as a transesterification reaction catalyst was added to the reaction solution in the molten state so as to be 1.5 × ^10-6 mol with respect to 1 mol of BPC. In addition, the reaction solution was stirred and cultivated at 220 ° C. for 30 minutes in a nitrogen gas atmosphere. Next, at the same temperature, the pressure in the reactor was reduced to 100 Torr over 40 minutes, and the reaction was further carried out for 100 minutes to distill out phenol.
Next, the temperature inside the reactor was raised to 284 ° C. over 60 minutes and the pressure was reduced to 3 Torr to distill off phenol corresponding to almost the entire theoretical amount of distillation. Next, the pressure in the reactor was kept below 1 Torr at the same temperature, and the reaction was continued for another 60 minutes to complete the polycondensation reaction. At this time, the stirring rotation speed of the stirrer was 38 rotations / minute, the reaction liquid temperature immediately before the end of the reaction was 289 ° C., and the stirring power was 0.75 kW.
Next, the reaction solution in the molten state is fed into the twin-screw extruder, and a 4-fold molar amount of butyl p-toluenesulfonate with respect to cesium carbonate is supplied from the first supply port of the twin-screw extruder. After kneading with the reaction solution, the reaction solution was extruded into a strand shape through a die of a twin-screw extruder and cut with a cutter to obtain pellets of carbonate resin.

The physical characteristics of the obtained polycarbonate resin (A1) were as follows.
Pencil hardness: 2H
Viscosity average molecular weight (Mv): 22,000

(Examples 1 to 5, Comparative Examples 1 to 6)
Each component listed in Table 1 above is blended in the proportion shown in Table 2 below (all indicated by parts by mass), mixed uniformly with a tumbler mixer, and then a twin-screw extruder (Japan Steel Works, Ltd.). TEX30α) was fed to the extruder from the barrel at the upstream part of the extruder at a cylinder temperature of 260 ° C., a screw rotation speed of 200 rpm, and a discharge rate of 25 kg / hr, and melt-kneaded to obtain pellets of a polycarbonate resin composition. ..

[Total light transmittance (unit:%) and haze (unit:%)]
The pellets obtained by the above method are injection molded by an injection molding machine (J55-60H manufactured by Japan Steel Works, Ltd.) under the conditions of a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., and a molding cycle of 50 seconds. A multipurpose test piece (2 mm thick) was manufactured.
Using the obtained ISO multipurpose test piece (2 mm thick), according to JIS K7105, using an NDH-2000 type haze meter manufactured by Nippon Denshoku Kogyo Co., Ltd., using a D65 light source and a 10 ° field of view, total light transmittance ( Unit:%) was measured. The haze (unit:%) at a thickness of 2 mm was also measured.

[Measurement of pencil hardness]
In the same manner as above, a flat plate-shaped test piece (90 mm × 50 mm × 2 mm thickness) was produced. With respect to this flat plate-shaped test piece, the pencil hardness measured under a load of 750 g was determined using a pencil hardness tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with ISO 15184.

[Judgment of slight scratches with low pencil hardness]
When the pencil hardness of each hardness of 3B to 3H was measured using the above flat plate-shaped test piece with a pencil, the presence or absence of slight scratches was visually confirmed and microscopically (magnified 50 times). Judgment was made according to the criteria of.
⊚: No slight scratches are confirmed.
◯: A slight scratch cannot be visually confirmed, but a slight scratch is slightly confirmed with a microscope (50x magnification).
X: The occurrence of scratches can be clearly confirmed.

[Evaluation of nail damage]
The toes of solid nails without nail polish were rubbed against the surface of the flat plate-shaped test piece (90 mm × 50 mm × 2 mm thick), and the scratch resistance due to the nails was evaluated by the following visual judgment.
◯: No scratches are confirmed even if rubbed strongly.
Δ: It is confirmed that scratches occur when rubbed strongly.
X: It can be clearly confirmed that scratches have occurred.
The above evaluation results are shown in Table 2 below.

Since the polycarbonate resin composition of the present invention is a polycarbonate resin material having excellent scratch resistance, appearance, and transparency, it is particularly a vehicle interior part, particularly a member for a liquid crystal display panel such as a car navigation system or an audio system, and a touch panel. It can be suitably used for display cover members, electronic and electrical devices, OA devices, housing members for information terminal devices, various tablet-type mobile terminals such as smartphones, tablet-type personal computers, smartphone cases, etc., and has industrial utility. Some are very expensive.

Claims (5)

Mainly 5 to 200 parts by mass of the polycarbonate-polyorganosiloxane copolymer (B) and a polyethylene-based polymer with respect to 100 parts by mass of the polycarbonate resin (A) containing the structural unit represented by the following general formula (1). A polycarbonate resin composition containing 0.1 to 25 parts by mass of a graft copolymer (C) having a styrene-based polymer segment as a chain as a side chain.
(In the general formula (1), R ¹ represents a methyl group, R ² and R ³ independently represent a hydrogen atom or a methyl group, and X represents an alkylene group or an alkylidene group.) The polycarbonate resin composition according to claim 1, wherein the graft copolymer (C) is a graft copolymer composed of at least 50 to 95% by mass of a polyethylene-based polymer segment and 5 to 50% by mass of a styrene-based polymer segment. The polycarbonate resin composition according to claim 1 or 2 , wherein the graft copolymer (C) is a graft copolymer further containing 0.5 to 30% by mass of a polyorganosiloxane segment. The polycarbonate resin composition according to any one of claims 1 to 3 , wherein the graft copolymer (C) has an endothermic peak temperature of 100 ° C. or lower as measured by a differential scanning calorimetry (DSC) in accordance with JIS K7121. The molded product of the polycarbonate resin composition according to any one of claims 1 to 4 .