KR101194557B1 - Polycarbonate resin composition and molding thereof - Google Patents

Abstract

It provides a polycarbonate resin composition excellent in weld strength.

(a) 60 to 95 parts by weight of an aromatic polycarbonate resin, (b) a styrene / (meth) acrylonitrile copolymer 4 to 39 formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of a rubber. To 100 parts by weight of a total of 1 to 36 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene-based monomer and a (meth) acrylonitrile-based monomer in the absence of a rubber part (b ') ( c) The said component (a) + (b) in the polycarbonate resin composition which mix | blends 0-40 weight part of phosphorus flame retardants, (d) 0-5 weight part of fluorinated polyolefin, and (e) 0-50 weight part of inorganic fillers. When the total weight ratio of the component (b) component + (b ') component to the total weight of the component + (b') component is Bwt%, an electron micrograph of the composition can be measured by image processing. Average occupied area of the styrene / (meth) acrylonitrile-based copolymer domain (hereinafter referred to as "AS domain") dispersed in the carbonate resin matrix, average occupied area of rubber particles dispersed in the Sd (μm ² ) and As domain A polycarbonate resin composition characterized by that Sg (μm ² ) satisfies the following relation (1):

Polycarbonate, resin composition, molded article, weld strength, styrene, (meth) acrylonitrile

Description

Polycarbonate resin composition and molded article thereof

The present invention relates to a polycarbonate resin composition, and more particularly, to a polycarbonate resin composition and its molded article having improved weld strength.

Conventionally, carbonate resins have excellent mechanical properties and have been widely used industrially as raw materials in the automotive, OA, and electrical and electronic fields, but have high melt viscosity, poor fluidity, and large thickness dependence of impact strength. There were defects such as dots. In order to secure the fluidity, there is a method of using a polycarbonate having a low molecular weight or a method of blending various fluidity modifiers, but all of these have been confirmed to improve fluidity, but at the cost of sacrificing the original impact strength of the polycarbonate, There existed a fault, such as a fall. Therefore, styrene resins, such as ABS resin (acrylonitrile butadiene styrene copolymer), are mix | blended and these defects are improved.

BACKGROUND ART In recent years, thermoplastic resin compositions made of polycarbonate and styrene resins have been used in large molded articles such as automobile fields, OA devices, and small molded articles such as portable terminals. These products are becoming thinner every year for the purpose of weight reduction, high functionality, and the like, and those having good flow in resin are used, and multipoint gates are preferably used in design. Particularly when a molded article is to be obtained by a multi-point gate, the molded article is formed with a portion where the molten resin joins at the time of molding, namely, a weld, but a thermoplastic resin composition composed of polycarbonate and styrene-based resin has a strength ("weld strength") at the weld portion. In particular, there is a problem in that the weld strength is particularly inferior in staying.

Patent Document 1 discloses a method of using a polycarbonate having a specific end group for the purpose of improving the weld strength in a molded article of a resin composition containing a polycarbonate and an ABS resin. There is no description of the relationship between morphology and weld strength. In addition, even in the resin composition containing the polycarbonate and ABS resin having the specific terminal group, the weld strength may not be improved at all.

Patent Document 2 discloses a method of using a polycarbonate having specific viscoelasticity as a thermoplastic resin composition composed of a polycarbonate and a styrene resin having excellent weld strength, rib strength, and transferability, but similarly to Patent Document 1 There is no description regarding the specific relationship between the monomer composition and form of an ABS resin, and weld strength.

Patent Document 3 discloses a rubber-reinforced vinyl-based resin used in a composition in which a rubber-reinforced vinyl-based resin / PC / slice filler is blended. The combination of the following large particle rubbers is described as useful, but there is no description regarding the relationship between the monomer composition, the form, and the weld strength. In addition, although the patent document 3 does not describe the measuring method of an average particle diameter at all, and defines a particle diameter as a weight average, it does not mention the definition at all. Therefore, it is not clear even what invention of rubber | gum of the particle size is proposed in invention of patent document 3.

Patent Document 1: Japanese Patent Application Laid-Open No. 7-98892

Patent Document 2: Japanese Patent Application Laid-Open No. 2003-20395

Patent Document 3: Japanese Patent No. 3384902

DISCLOSURE OF INVENTION

Problems to be solved by the invention

An object of the present invention is to provide a polycarbonate resin composition excellent in weld strength and a molded article thereof. In particular, using AS resin (acrylonitrile styrene copolymer, etc.) together with ABS resin as the styrene resin blended with polycarbonate provides a composition that can solve the problem of improving the weld strength but lowering the weld strength. have.

Means for solving the problem

The present invention has been made to solve the above problems, the gist of which is (a) 60 to 95 parts by weight of an aromatic polycarbonate resin, (b) at least styrene monomer and (meth) acrylonitrile monomer in the presence of rubber 4 to 39 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerization, and (b ') a styrene / (meth) acryl formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a rubber. (C) 0 to 40 parts by weight of phosphorus flame retardant, (d) 0 to 5 parts by weight of fluorinated polyolefin, and (e) 0 to 50 parts by weight of inorganic filler based on 100 parts by weight in total of 1 to 36 parts by weight of ronitrile copolymer. When the total weight ratio of the (b) component + (b ') component to the total weight of the (a) component + (b) component + (b') component is Bwt% , Average occupied area Sd (μm) of styrene / (meth) acrylonitrile-based copolymer domains (hereinafter referred to as "AS domains") dispersed in a polycarbonate resin matrix which can be measured by image processing of an electron micrograph of the composition ² ) and the average occupied area Sg (μm ² ) of the rubber particles dispersed in the As domain satisfy the following relation (1):

Effects of the Invention

The polycarbonate resin composition of the present invention is excellent in fluidity and weld strength and is useful as large molded articles and thin thickness molded articles in the fields of electric and electronic devices and precision machinery.

Carrying out the invention  Best form for

Hereinafter, the present invention will be described in detail.

(a) aromatic polycarbonate resin:

In the present invention, as the (a) aromatic carbonate resin, there may be mentioned a branched thermoplastic polymer or copolymer which can be obtained by reacting an aromatic dihydroxy compound or a small amount of polyhydroxy compound with a phosgene or a carbonic acid diester. Can be. The manufacturing method of a polycarbonate resin is not specifically limited, It can be based on conventional methods, such as a phosgene method (interface polymerization method) or a melting method (ester exchange method). Moreover, the polycarbonate resin manufactured by the melting method and manufactured by adjusting the amount of OH groups of terminal groups may be sufficient.

The blending amount of the aromatic polycarbonate resin is (a) an aromatic polycarbonate resin, (b) a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of a rubber, (b ') 60 to 95 parts by weight with respect to a total of 100 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a rubber. Is 65 to 90 parts by weight. If the compounding quantity of aromatic polycarbonate resin exceeds an upper limit, fluidity will fall easily, and below a minimum, heat resistance will fall easily.

As an aromatic dihydroxy compound, 2, 2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethyl bisphenol A, bis (4-hydroxyphenyl) -p- diisopropyl benzene, hydroquinone, a rezo Lecinol, 4,4-dihydroxydiphenyl, etc. are mentioned, Preferably bisphenol A is mentioned. Moreover, as said aromatic dihydroxy compound, the compound in which one or more sulfonic acid tetraalkyl phosphonium was couple | bonded can be used.

In order to obtain a branched aromatic polycarbonate resin, phloroglucine, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) hepten-2,4,6-dimethyl-2,4,6- Tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) hepten-3,1,3,5-tri (4-hydroxyphenyl) benzene, Polyhydroxy compounds such as 1,1,1-tri (4-hydroxyphenyl) ethane, or 3,3-bis (4-hydroxyaryl) oxyindole (= isatin bisphenol), 5-chlorisatin, 5 A part of the aromatic dihydroxy compound may be substituted with, 7-dichloroisatin, 5-bromisatin, etc., and the amount of use is 0.01 to 10 mol%, preferably 0.1 to 2 mol% with respect to the dihydroxy compound. to be.

In order to adjust molecular weight, a monovalent aromatic hydroxy compound may be used. Examples of monovalent aromatic hydroxy compounds include aromatic monohydroxy compounds such as m- and p-methylphenols, m- and p-propylphenols, p-tert-butylphenols, and p-long-chain alkyl substituted phenols.

As aromatic polycarbonate resin, Preferably it is a polycarbonate resin derived from 2, 2-bis (4-hydroxyphenyl) propane, or from 2, 2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxy compounds. Polycarbonate copolymers derived. It is also possible to copolymerize polymers or oligomers having a siloxane structure. You may use these aromatic polycarbonate resins in mixture of 2 or more types.

The molecular weight of the aromatic polycarbonate resin is 16,000 to 30,000, preferably 18,000 to 28,000 in terms of viscosity average molecular weight in terms of a solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. When the viscosity average molecular weight exceeds the upper limit, fluidity becomes insufficient, and below the lower limit, the impact resistance becomes insufficient.

(b) Styrene / (meth) acrylonitrile-based copolymers:

In the present invention, (b) the styrene / (meth) acrylonitrile-based copolymer polymerizes at least a styrene-based monomer and a (meth) acrylonitrile-based monomer in the presence of rubber, and if necessary, a styrene-based monomer and a (meth) acrylonitrile-based copolymer. It is a styrene / (meth) acrylonitrile-type copolymer formed by superposing | polymerizing together the other monomer which can copolymerize a monomer. In this styrene / (meth) acrylonitrile-based copolymer, the two or more kinds of monomers are not limited to all graft polymerized with rubber to form a graft copolymer. Rather, it is customary that only the two or more monomers together with the graft copolymer are mixtures containing a large amount of a copolymer copolymerized with each other.

In the present invention, examples of the (b) styrene / (meth) acrylonitrile-based copolymer include ABS resins, AES resins, AAS resins, and the like, depending on the type of rubber and monomers constituting. Moreover, as a manufacturing method of these copolymers, well-known methods, such as emulsion polymerization method, solution polymerization method, suspension polymerization method, or block polymerization method, are mentioned.

(b) The amount of styrene / (meth) acrylonitrile-based copolymer blended in the presence of (a) an aromatic carbonate resin and (b) rubber is at least styrene / (meth) acrylonitrile-based monomer. 100 parts by weight of a total of styrene / (meth) acrylonitrile copolymers formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a meta) acrylonitrile copolymer and (b ') rubber. 4 to 39 parts by weight, preferably 10 to 35 parts by weight. When the compounding quantity of this (b) styrene / (meth) acrylonitrile-type copolymer exceeds an upper limit, impact resistance will fall easily, and below a minimum, fluidity will fall easily.

(b ') Styrene / (meth) acrylonitrile-based copolymer:

In the present invention, (b) a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of a rubber cannot be used alone, and is necessarily a (b ') rubber. Styrene / (meth) acryl which is polymerized at least in the absence of styrene-based monomer and (meth) acrylonitrile-based monomer and polymerized together with other monomers copolymerizable with styrene-based monomer and (meth) acrylonitrile-based monomer as necessary. It is mix | blended with (a) polycarbonate resin in combination with a nitrile copolymer, such as AS resin. However, in both (b) and (b ') components used together, the monomer unit which comprises these may be the same type, or may be different types.

(b) The styrene / (meth) acrylonitrile-based copolymer may be blended with styrene / (meth) acrylonitrile-based monomer by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of (a) an aromatic polycarbonate resin and (b) rubber. 100 parts by weight of a total of styrene / (meth) acrylonitrile copolymers formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of the (meth) acrylonitrile copolymer and the (b ') rubber. It is 1 to 36 parts by weight, preferably 3 to 25 parts by weight relative to. When the compounding quantity of this (b ') styrene / (meth) acrylonitrile-type copolymer exceeds an upper limit, impact resistance will fall easily, and below a minimum, fluidity will fall easily.

Examples of the styrene monomers include styrene, α-methylstyrene, p-methylstyrene, and the like, and styrene is preferable. As a (meth) acrylonitrile-type monomer, an acrylonitrile, methacrylonitrile, etc. are mentioned, for example.

Examples of the monomer copolymerizable with the styrene monomer and the (meth) acrylonitrile monomer include (meth) acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, and ethyl methacrylate, maleimide, and N. -Phenyl maleimide etc. are mentioned, Preferably (meth) acrylic-acid alkylester etc. are mentioned.

As rubber, Preferably, it is rubber whose glass transition temperature is 10 degrees C or less. Specific examples of the rubber include diene rubber, acrylic rubber, ethylene / propylene rubber, silicone rubber and the like. Among them, a diene rubber, an acrylic rubber, or the like is preferably selected from the viewpoint of balance between performance and cost.

Examples of the diene rubber include polybutadiene, butadiene / styrene copolymer, polyisoprene, butadiene / (meth) acrylic acid lower alkyl ester copolymer, butadiene / styrene / (meth) acrylic acid lower alkyl ester copolymer, and the like. As methacrylic acid lower alkyl ester, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, etc. are mentioned, for example. In the butadiene / (meth) acrylic acid lower alkyl ester copolymer or the butadiene / styrene / (meth) acrylic acid lower alkyl ester copolymer, the ratio of the (meth) acrylic acid lower alkyl ester is preferably 30% by weight or less of the rubber weight.

Examples of the acrylic rubber include alkyl acrylate rubbers, and the alkyl group preferably has 1 to 8 carbon atoms. Specific examples of the alkyl acrylate rubber include ethyl acrylate, butyl acrylate, and ethyl hexyl acrylate. An optionally crosslinkable ethylenically unsaturated monomer may be used for the alkyl acrylate rubber, and examples of the crosslinking agent include alkylenediol di (meth) acrylate, polyester di (meth) acrylate, divinylbenzene, trivinylbenzene, and cyanuric acid triacrylate. Aryl, (meth) acrylic acid aryl, butadiene, isoprene, etc. are mentioned. As an acrylic rubber, the core-shell polymer which has crosslinked diene rubber as a core is mentioned.

(c) Phosphorus flame retardant:

In the present invention (c) as a phosphorus flame retardant is a compound containing phosphorus in the molecule, preferably a phosphorus compound represented by the following formula (1) or (2):

Wherein R ¹ , R ² and R ³ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group, and h, i and j each represent 0 or 1;

The phosphorus compound represented by the formula (1) can be prepared from phosphorus oxy chloride or the like by a known method. Specific examples of the phosphorus compound represented by the general formula (1) include triphenyl phosphate, triccredil phosphate, diphenyl 2-ethylcredil phosphate, tri (isopropylphenyl), methylphosphonic acid diphenyl ester, and phenylphosphonic acid diethyl. Ester, diphenylcredyl phosphate, tributyl phosphate, and the like.

Wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group which may be substituted with an alkyl group, and p, q, r and s each represent 0 or 1 T is an integer from 1 to 5 and X represents an arylene group.

The phosphorus compound represented by the above formula (2) is a condensed phosphate ester having t of 1 to 5, and t is an average value of these mixtures with respect to a mixture of condensed phosphate esters having different t. X represents an arylene group and is, for example, a divalent group derived from dihydroxy compounds such as resorcinol, hydroquinone, bisphenol A and the like. As a specific example of the phosphorus compound represented by General formula (2), when resorcinol is used for a dihydroxy compound, phenylresorcin. Polyphosphate, credil. Resorcin. Polyphosphate, phenyl. Resorcin. Polyphosphate, xylyl. Resorcin. Polyphosphate, phenyl-p-t-butylphenyl. Resorcin. Polyphosphate, phenyl. Isopropylphenyl. Resorcinin polyphosphate, credil. Xylyl. Resorcin. Polyphosphate, phenyl. Isopropylphenyl. Diisopropylphenyl. Resorcin polyphosphate, etc. are mentioned.

In the present invention, the (c) phosphorus flame retardant may be a phosphazene compound. As such a compound, it is at least 1 sort (s) chosen from a cyclic phenoxy phosphazene compound, a chain | strand-shaped phenoxy phosphazene compound, and a bridge | crosslinked phenoxy phosphazene compound.

The compounding quantity of the phosphorus flame retardant is (a) an aromatic polycarbonate resin, (b) a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of rubber, (b) ') 0 to 40 parts by weight, preferably 3, based on 100 parts by weight of the total of the styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a rubber. To 30 parts by weight, more preferably 5 to 25 parts by weight. When the compounding quantity of a phosphorus flame retardant exceeds an upper limit, mechanical property will fall easily.

(d) fluorinated polyolefins:

In the present invention, the (d) fluorinated polyolefin may include, for example, fluorinated polyethylene, and preferably polytetrafluoroethylene having fibril-forming ability, and is easily dispersed in the polymer, and the polymers are bonded to each other to form a fibrous form. It shows the tendency to make materials. Polytetrafluoroethylene with fibril forming ability is classified as Type 3 by ASTM standards. Examples of polytetrafluoroethylene having fibril-forming ability are commercially available from Mitsui DuPont Floro Chemicals Co., Ltd. as Teflon® 6J or Teflon® 30J or from Daikin Kogyo Co., Ltd. as polyflon. have.

The compounding quantity of a fluorinated polyolefin is (a) aromatic polycarbonate resin, (b) styrene / (meth) acrylonitrile copolymer formed by superposing | polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in presence of rubber, ( b ') 0 to 5 parts by weight with respect to a total of 100 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a rubber. 0.02 to 4 parts by weight, preferably 0.03 to 3 parts by weight. When the compounding quantity of a fluorinated polyolefin exceeds an upper limit, the fall of the appearance of a molded article will arise and it is unpreferable.

(e) inorganic filler:

Although it does not specifically limit as (e) inorganic filler in this invention, All the inorganic fillers normally used are mentioned. Specific examples include glass fibers, glass powder, glass beads, crushed glass, hollow glass, talc, clay, mica, carbon fiber, wollastonite, potassium titanate whisker, titanium oxide whisker, zinc oxide whisker, and the like. Pulverized glass, talc, clay, wollastonite and the like are preferably used from the viewpoint of appearance, and the number average particle diameter measured by laser diffraction method is 9.0 µm or less, and the content of Fe and Al in talc is respectively Untreated talc which is not more than 0.5% by weight as Fe ₂ O ₃ and Al ₂ O ₃ is preferably used.

The amount of the inorganic filler is (a) an aromatic polycarbonate resin, (b) a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of a rubber, ( b ') 0 to 50 parts by weight with respect to a total of 100 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the absence of a rubber, preferably 1 to 40 parts by weight, more preferably 3 to 30 parts by weight. When the compounding quantity of an inorganic filler exceeds the upper limit, the fall of the molded article external appearance and impact strength will arise, and it is unpreferable.

Average occupied areas Sd and Sg of rubber particles and AS domains, which can be measured by imaging electron micrographs of the composition:

The resin composition of the present invention or a molded article thereof is usually contained in at least a styrene-based monomer and (meth) in the presence of (b) component-rubber in a continuous phase composed of component (a) -aromatic polycarbonate resin (referred to herein as "matrix"). Styrene / (meth) acrylonitrile copolymer formed by polymerizing acrylonitrile monomer and (b ') component-Styrene formed by polymerizing at least styrene monomer and (meth) acrylonitrile monomer in the absence of rubber. A large number of discontinuous phases consisting of a mixture of meta) acrylonitrile-based copolymers (referred to herein as "b domains" regardless of those derived from component (b) and "b '). It may include and do not include) is dispersed, form. This state can be easily confirmed by an electron microscope by applying an appropriate dyeing technique such as two-stage dyeing with osmium tetraoxide and ruthenium tetraoxide.

That is, as shown in FIG. 1 or FIG. 4 attached in the transmission electron microscope observation after two-stage staining, (A) a gray matrix, (B) a light AS domain and (C) a dark inside AS light domain It is recognized by dividing the color into three discontinuous images. Among these, (C) the dark discontinuous phase is a dye by osmium tetraoxide of rubber in which both monomers are graft polymerized or not polymerized.

However, the inventors have examined the correlation between the welded strength and the mean occupied area of this form of the composition, in particular (B) the light colored AS domain and (C) the dark colored discontinuous phase (rubber particles). It is reached. That is, when the total weight ratio of (b) component + (b ') component is Bwt% to the total weight of component (a) component + (b) component + (b') component, The relationship between the average occupied area Sd (μm ² ) of the AS domain dispersed in the polycarbonate resin matrix and the average occupied area Sg (μm ² ) of the rubber particles dispersed in the AS domain, which can be measured by image processing of an electron micrograph. , Sg / (Sd / B ^2/3 ) has a value of 0.5 or more, that is, Sd and Sg need to satisfy the following relation (1):

The value of said relation (1) becomes like this. Preferably it is 0.55 or more, More preferably, it is 0.6 or more. In the above relation (1), the value of Sd has various values, for example, by the composition ratio and manufacturing conditions of the resin composition, the type of the (b) component and the (b ') component, the production method, and the like, and Sg / (Sd / B ^{2 /} The larger the value of ³ ), the larger the ratio of the rubber particle diameter Sg to the AS domain diameter Sd. The present inventors found that an improvement in the weld strength, which is the object of the present invention, is achieved under conditions satisfying the relation (1). Among them, monomer units constituting two styrene / (meth) acrylonitrile-based copolymers of component (b) and component (b ') among these factors that determine the Sg / (Sd / B ^2/3 ) value. Focusing on the composition ratio of, and examining the relationship with the Sg / (Sd / B ^2/3 ) value, the composition ratios of the monomer units constituting the component (b) and the component (b ') are sufficiently different, that is, When satisfying the following relational formula (3), it discovered that the resin composition and desired molded article which have desired weld strength were obtained.

The value of said relation (3) becomes like this. Preferably it is four or more, More preferably, it is five or more. Abwt% is the weight ratio of the (meth) acrylonitrile-based monomer unit with respect to the total weight of the styrene-based monomer unit + (meth) acrylonitrile-based monomer unit which comprises (b) component, and Ab'wt% is ( b ') The weight ratio of the (meth) acrylonitrile-type monomer unit with respect to the total amount of the styrene-based monomer unit + (meth) acrylonitrile-type monomer unit which comprises a component is shown.

By using in combination (b) component and (b ') component which satisfy | fill such conditions, the AS domain derived from (b) component and the AS domain derived from (b') component are hard to be compatible, and large AS It becomes difficult to form a domain, and it becomes easy to satisfy said relationship (1).

For example, when the weight ratio Abwt% of the (meth) acrylonitrile monomer in the component (b) is 26% by weight, the weight ratio of the (meth) acrylonitrile monomer in the component (b ') is also about the same in terms of compatibility. It is common to use the 'wt% is about 26wt%. However, in the present invention, dispersibility of the AS domain is improved by using a combination of sufficiently different composition ratios of monomer units of component (b) and component (b '), which is not usually used too much, and as a result, It is now possible to express high weld strength. In addition, it is possible to maintain high weld strength even in the case of a resin composition containing an inorganic filler which is usually considered to have a reduced strength.

In the present invention, the procedure for measuring the average occupied area Sd of the AS domain dispersed in the polycarbonate resin matrix and the average occupied area Sg of the rubber particles dispersed in the AS domain by image processing the electron micrograph of the composition dyed as described above is as follows. Outline is as follows.

(1) The electron micrograph (analog information) is digitized to be monoclonal image information.

(2) From this monoclonal image information, only specific information is taken as measurement image information. Specific information to be taken is information regarding the shape and dimensions of the contours of (B) the light colored AS domain or (C) the dark colored rubber particles, which can measure the occupied area of individual AS domains or rubber particles.

(3) The occupied area of individual AS domains or rubber particles is measured from the image information for measurement, and the average occupied area Sd or Sg as the number average is calculated.

In the measurement procedure of said (1)-(3), the following theorem (4) and (5) which are necessary considering the correlation with weld intensity are implemented.

(4) Domains or particles having a measured occupation area of 0.01 μm ² or less are excluded from the calculation of the number average value.

(5) In the measurement procedure of Sg, the area of (B) the bright AS domain existing inside the outline of the (C) dark rubber particles is also included in the occupied area of the rubber particles.

Process for preparing polycarbonate resin composition:

As a method for producing the polycarbonate resin composition of the present invention, the average occupied area Sd and Sg of the AS domain dispersed in the composition and the rubber particles dispersed in the AS domain, which can be measured by measuring an electron micrograph of the composition, can be measured. Is not particularly limited, such as, for example, an aromatic polycarbonate resin, (b) and (b ') two styrene / (meth) acrylonitrile copolymers, phosphorus flame retardants, and polytetrafluoroethylene in one batch melt kneading. The method of kneading, aromatic polycarbonate resin, two styrene / (meth) acrylonitrile-type copolymers, and polytetrafluoroethylene are knead | mixed previously, the flame retardant is supplied from the middle of an extruder, and the method etc. are mentioned.

(a) The average occupation area Sg can be adjusted also by the kind and manufacturing method of two types of (b) and (b ') styrene / (meth) acrylonitrile-type copolymers mix | blended with aromatic polycarbonate resin, (b) Constituting the weight ratio (Abwt%) of the (meth) acrylonitrile monomer unit to the total weight of the styrene monomer unit + (meth) acrylonitrile monomer unit constituting the component and the component (b '). It is preferable that the weight ratio (Ab'wt%) of the (meth) acrylonitrile-based monomer unit with respect to the total weight of the styrene-based monomer unit + (meth) acrylonitrile-based monomer unit satisfy | fills following formula (3). .

The value of the said relational formula (3) becomes like this. Preferably it is four or more, More preferably, it is five or more.

To the carbonate resin composition of the present invention, additives such as stabilizers such as ultraviolet absorbers and antioxidants, pigments, dyes, lubricants, mold release agents, plasticizers, antistatic agents, sliding modifiers, elastomers, compatibilizers, and other flame retardants may be added and blended as necessary. can do. These addition methods can be suitably added by a conventionally well-known method taking advantage of these characteristics.

In the polycarbonate resin composition of the present invention, in addition to the aromatic polycarbonate resin as the component (a) and the two styrene / (meth) acrylonitrile copolymers as the component (b) and (b '), polybutylene terephthalate and polyethylene Thermoplastic resins, such as polyester resins, such as terephthalate, a polyamide resin, a polyphenylene ether resin, and a polyolefin resin, can be mix | blended. The blending amount of the thermoplastic resin other than the aromatic polycarbonate resin and the two styrene / (meth) acrylonitrile-based copolymers is preferably 40% by weight or less, more preferably 30% by weight or less of the thermoplastic resin composition.

The polycarbonate resin composition of the present invention is preferably a non-halogenated polycarbonate resin composition, and the components to be blended in the composition of the present invention are each non-halogen, or those having a low halogen content, such as corrosion or environmental problems of a molding machine or a mold. It is preferable at the point.

The molding processing method of the polycarbonate resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, namely injection molding, blow molding, extrusion molding, press molding, sheet molding, thermoforming, rotational molding, Molding methods such as laminate molding can be applied, and among these, injection molding is preferably used.

1 is an electron micrograph of the ultrathin section of the pellet obtained in Example 1.

FIG. 2 is an image for Sd measurement created from FIG. 1. FIG.

3 is an image for Sg measurement created from FIG. 1.

Figure 4 is an electron micrograph of the ultrathin section of the pellet obtained in Comparative Example 1.

FIG. 5 is an image for Sd measurement created from FIG. 4. FIG.

FIG. 6 is an image for Sg measurement created from FIG. 4. FIG.

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the summary is exceeded. In Examples and Comparative Examples, the raw materials described below were used.

(1) Polycarbonate resin -1: Poly-4,4-isopropylidene diphenyl carbonate, Mitsubishi Engineering Plastics (KK) "Epiron S-2000", viscosity average molecular weight 25000. ("PC-1" hereafter) Is called)

(2) Polycarbonate resin -2: Poly-4,4-isopropylidene diphenyl carbonate, Mitsubishi Engineering Plastics (KK) "Epiron S-3000", viscosity average molecular weight 22000. ("PC-2" hereafter) Is called)

(3) ABS resin: Emulsion polymerization ABS resin, rubber-type polybutadiene, "DP-611" by Technopolymer Co., Ltd., AN ratio 26%.

(4) AS resin-1: AS resin, "SAN-T" manufactured by Technopolymer Co., Ltd., AN ratio 34%

(5) AS resin-2: AS resin, "SAN-R" manufactured by Technopolymer Co., Ltd., AN ratio 20%

(6) AS resin-3: AS resin, "SAN-C" manufactured by Technopolymer Co., Ltd., AN ratio 26%

(7) Flame retardant: Condensed phosphate ester represented by the following general formula (3) (wherein t ₂ = 1.08), manufactured by Asahi Denka Kogyo Co., Ltd. (FP-700)

(8) Polytetrafluoroethylene (PTFE): "Polyflon F-201L" manufactured by Daikin Corporation

(9) inorganic filler:

Talc, number average particle size 4.9 탆, no surface treatment, manufactured by Hayashi Kasei Co., Ltd. "Micron White 5000S"

Evaluation of the physical properties of the test piece was performed as described below.

(10) Tensile strength: In accordance with ISO 527-1 and 2, a 1A test piece having a thickness of 4 mm was used, and a tensile test was performed at a test speed of 50 mm / min. In forming a test piece having welds, a tensile test under the same conditions as in the case where a weld was formed in the center without a weld using a mold having two points on the surface center line in the longitudinal direction and the surface (170 mm between gates) Was carried out. The measurement results are expressed as the tensile strength, the weld tensile strength, and the weld tensile strength retention, depending on the type of test piece. For the purpose of weld strength evaluation, percentages were calculated for the tensile strength in terms of weld tensile strength and weld tensile strength retention and expressed as respective retention rates.

(11) Fluidity: using a Baffle mold (thickness 2 mm, width 20 mm, φ 1.5 mm pingate), cylinder set temperature 240 ℃, mold set temperature 60 ℃, injection pressure 100 MPa, injection time 5 seconds, molding cycle The flow length was measured under the condition of 45 seconds (unit is mm).

(12) Transmission electron microscope observation:

(Ultra thin slice)

Sections were cut out from the sample pellets so that a surface orthogonal to each direction appeared as a cross section at the center portion in the strand direction thereof. From the cross section of this section, a ultrathin section was cut out using a diamond knife with a Weltoramicrotom (LETRA, UNTRACUT UCT) equipped with a sample cooling device (cooler unit). The cutting conditions set are -100 ° C of sample room temperature and 100 nm of ultra thin slice thickness.

(Two steps of dyeing)

The ultrathin sections were loaded on a copper grit and dyed in two steps with osmium tetraoxide and ruthenium tetraoxide. As shown in Fig. 1 or 4 attached by this dyeing, the polycarbonate is a gray matrix (A) and the styrene / (meth) acrylonitrile-based copolymer is a light colored domain (B) and butadiene rubber. Is observed as a dark discontinuous phase (C) in light colored dominees.

(Electron micrograph)

The dyed ultrathin sections were observed with a transmission electron microscope ("1200EXII" manufactured by Denshisha, Japan) at an acceleration pressure of 100 KV and a magnification setting of 5000 times. Photograph was taken at the time of observation, and the image was recorded on the film FG (dimensions: 5.9 x 8.2 cm) for the electron microscope by Fuji Photographic Film. The range of recorded images is about 11 × 15 μm.

(Image processing)

Images recorded on the negative film by photography were digitized with a film scanner (Unika Minolta Photo Imaging Co., Ltd .: Dimage Sacan Multi F-3000 type). Digitization was performed at 564 dpi to obtain a monochrome image film of about 1240 x 1800 pixels.

AS domain:

The obtained monochrome image file was processed using "PhotoShop" (Ver. 7) manufactured by Adobe Corporation, and an AS domain was extracted and binarized to create a measurement image (see FIG. 2 or FIG. 5 attached). . The criteria for the extraction and binarization of this AS domain are (1) the result of the two-stage staining (B) which is observed as the light-colored domain as "AS domain". At this time, (B) dark rubber particles (C) present inside the light domain are also included in the occupied area of the "AS domain". (2) The threshold of binarization was set to a value of appropriate brightness such that only light colors of the "AS domain" were selected, and darker (A) gray matrices and (C) darker rubber particles were not selected.

The occupied area of the AS domain was measured from the measurement image using "ImagePro Plus" (ver 4.0) manufactured by Media Cybernetics. In the measurement, the length on the screen was calibrated based on the scale recorded at the time of shooting in each image, and the measurement was performed in the broken line range in the middle. Thus, the occupied area and number of the measured AS domains were totaled, and the number average value of the occupied areas was calculated to be the average occupied area Sd. The domain whose occupied area measured at that time was 0.01 µm ² or less was excluded from the calculation of the number average value.

Rubber particles:

The obtained monochrome image file was processed using "PhotoShop" (Ver. 7) manufactured by Adobe, and rubber measurement was performed to create a measurement image (see FIG. 3 or FIG. 6) attached to a binary image. The criteria for the extraction and binarization of this rubber particle are (1) the result of the two-stage dyeing (C) that is observed as a dark discontinuous phase is extracted as "rubber particles". At this time, the light-colored domain (B) existing inside (C) is also included in the occupied area of "rubber particles". (2) The threshold of binarization was set to an appropriate brightness value such that only the dark color of the "rubber particles" was selected, from which the bright (A) gray matrix and (B) light colored domain were not selected.

The occupied area of the rubber particles was measured from the measurement image using "ImagePro Plus" (ver 4.0) manufactured by Media Cybernetics. In the measurement, the length on the screen was calibrated on the basis of the scale recorded at the time of shooting in each image, and the measurement was performed in the broken line range in the middle. Thus, the occupied area and the number of the measured rubber particles were added together, and the number average value of the occupied area was calculated to be the average occupied area Sg. The particle | grains whose occupied area measured at that time were 0.01 micrometer <^2> or less were excluded from calculation of a number average value.

EXAMPLES 1-4, COMPARATIVE EXAMPLES 1-3

Each component except the flame retardant was blended in the ratio (weight ratio) shown in Table 1 and mixed for 20 minutes by a turntable, followed by a twin screw extruder with a screw diameter of 32 mm and L / D = 42 ("TEX-30 HSST" manufactured by Nippon Steel Mill). The mixture was kneaded at a barrel set temperature of 250 ° C., a screw set speed of 250 rpm, and a set extrusion amount of 20 Kg / hr. When the flame retardant was added, the liquid was injected in the middle of the twin screw extruder at the ratio (weight ratio) shown in Table 1.

The pellet obtained by cutting the extruded strand was dried at 80 ° C. for 5 hours, and then welded at a cylinder temperature of 250 ° C., a mold temperature of 70 ° C., and a molding cycle 60 seconds by an injection molding machine (“SG-75” manufactured by Sumitomo Heavy Machinery Co., Ltd.). And 1A test pieces having welds were formed and evaluated for tensile strength and weld tensile strength, respectively. Similarly, after the obtained pellets were dried at 80 ° C. for 5 hours, an injection molding machine (“SG-75” manufactured by Sumitomo Heavy Industries, Ltd.)

The 1A type molded piece which has a weld was shape | molded by the cylinder temperature of 300 degreeC, the mold temperature of 70 degreeC, and 180 second of molding cycles, and the evaluation at the weld tensile strength stay was performed. Table 1 shows the evaluation results of the examples and the comparative examples.

From the above result,

(a) Aromatic polycarbonate resin component + (b) Styrene / (meth) acrylonitrile copolymer component + (b ') rubber formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of rubber Total weight ratio of the component (b) + component (b ') to the total weight of the styrene / (meth) acrylonitrile copolymer component formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence. When Bwt% is, the average occupation area Sd of the AS domain dispersed in the polycarbonate resin matrix which can be measured by image processing of the electron micrograph of the composition, and the average occupation area Sg of the rubber particles dispersed in the AS domain are represented by the chemical formula Satisfying (1) showed a high weld strength retention.

On the other hand, even if the compounding ratio of each component (a)-(e) is a composition which all satisfy | fills the predetermined | prescribed requirement of this invention, the thing which does not satisfy | fill Formula (1) shows the value of low weld strength retention. In addition, in order to satisfy the said Formula (1), the weight ratio (Abwt%) of a (meth) acrylonitrile-type monomer unit with respect to the total weight of the styrene-type monomer unit + (meth) acrylonitrile-type monomer unit which comprises (b) component. ) And the weight ratio (Ab'wt%) of the (meth) acrylonitrile monomer unit to the total weight of the styrene monomer unit + (meth) acrylonitrile monomer unit constituting the component (b ') It can be achieved by satisfying (3).

[Injection molded product]

The pellets obtained in Example 3 and Comparative Example 2 were used to form a box having an outer dimension of 150 mm x 150 mm x 20 m and a thickness of 2 mm with a four-point pingate having a diameter of 1.5 mm (coordinate of gate position is 150 mm). injection molding by 25 mm, 75 mm; 75 mm, 25 mm; 75 mm, 125 mm; 125 mm, 75 mm) on the x 150 mm plane. From Example 3, all the molded articles had an appearance including welds, but there was no problem in rigidity. However, the molded article from Comparative Example 2 was poor in appearance of the weld and was destroyed in the weld portion when a force was applied.

Claims (9)

(a) 60 to 95 parts by weight of an aromatic polycarbonate resin, (b) a styrene / (meth) acrylonitrile copolymer 4 to 39 formed by polymerizing at least a styrene monomer and a (meth) acrylonitrile monomer in the presence of a rubber. To 100 parts by weight of a total of 1 to 36 parts by weight of a styrene / (meth) acrylonitrile copolymer formed by polymerizing at least a styrene-based monomer and a (meth) acrylonitrile-based monomer in the absence of a rubber part (b ') ( c) The said component (a) + (b) in the polycarbonate resin composition which mix | blends 0-40 weight part of phosphorus flame retardants, (d) 0-5 weight part of fluorinated polyolefin, and (e) 0-50 weight part of inorganic fillers. When the total weight ratio of the component (b) component + (b ') component to the total weight of the component + (b') component is Bwt%, an electron micrograph of the composition can be measured by image processing. Average occupied area of the styrene / (meth) acrylonitrile-based copolymer domain (hereinafter referred to as "AS domain") dispersed in the carbonate resin matrix, average occupied area of rubber particles dispersed in the Sd (μm ² ) and As domain The (meth) acrylonitrile monomer with respect to the total weight of the styrene-based monomer unit + (meth) acrylonitrile-based monomer unit which Sg (μm ² ) satisfies the following relation (1) and constitutes the component (b). Weight ratio of the (meth) acrylonitrile-based monomer unit to the total weight of the weight ratio (Abwt%) of the unit and the styrene-based monomer unit constituting the component (b ') + (meth) acrylonitrile-based monomer unit (Ab' wt%) satisfies the following relation (3):

The polycarbonate resin composition according to claim 1, wherein B, Sd, and Sg satisfy the following relation (2):

delete The polycarbonate resin composition according to claim 1, wherein in the component (b) and the component (b '), Ab and Ab' satisfy the following relationship (4):

The polycarbonate resin composition according to claim 1, wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 16,000 to 30,000. The polycarbonate resin composition according to claim 1, wherein the phosphorus flame retardant is a phosphorus compound represented by the following general formula (1) or (2):

(One) Wherein R ¹ , R ² and R ³ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group, and h, i and j each represent 0 or 1;

(2) Wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group which may be substituted with an alkyl group, and p, q, r and s each represent 0 or 1 T is an integer from 1 to 5 and X represents an arylene group. The polycarbonate resin composition according to claim 1, wherein the inorganic filler is talc. A molded article obtained by injection molding the polycarbonate resin composition according to claim 1. The molded article according to claim 8, which is injection molded by a multi-point gate.

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