KR100542139B1 - Thermoplastic Resin Composition - Google Patents

Abstract

The thermoplastic resin composition of the present invention comprises (A) 45 to 95 parts by weight of a polycarbonate resin; (B) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene, or mixtures thereof, acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 5 to 95 parts by weight of methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide, or a mixture thereof with 5 to 50 parts by weight of butadiene rubber, acrylic rubber, ethylene / propylene rubber, Styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene terpolymer (EPDM) and polyorganosiloxane / polyalkyl (meth) acrylate rubber composites or ones thereof 1 to 50 parts by weight of rubber-modified styrenic graft copolymer resin grafted to 5 to 95 parts by weight of the mixture; (C) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene or mixtures thereof, acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 meta 0.5 to 50 parts by weight of a styrenic copolymer obtained by copolymerizing 5 to 50 parts by weight of acrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide or a mixture thereof; And (D) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C _1-8 methacrylic acid, alkyl esters, C _1-8 methacrylic acid esters or mixtures thereof 5 to 50 parts by weight of acrylonitrile, methacrylonitrile or a mixture thereof and 0.5 to 30 parts by weight of a compatibilizer prepared by copolymerizing 0.01 to 10 parts by weight of an amine group-containing vinyl monomer.

Polycarbonate Resin, Compatibilizer, Bisphenol A, SAN Resin, ABS Rubber

Description

Thermoplastic Resin Composition             

1 is a transmission electron micrograph of a high-temperature injection molded specimen without adding a compatibilizer.

Figure 2 is an electron micrograph of a high-temperature injection molded specimen added with a compatibilizer.

Field of invention

The present invention relates to a thermoplastic resin composition. More specifically, the present invention relates to a thermoplastic resin composition comprising a polycarbonate resin, a rubber modified styrene graft copolymer, a styrene copolymer and a compatibilizer.

Background of the Invention

Polycarbonate resins are excellent in transparency, mechanical strength as well as heat resistance, and are widely used in applications such as electric, electronic products, and automobile parts. However, polycarbonate resins are used in combination with other types of resins due to their low notch impact strength and poor processability. For example, blends of polycarbonate / styrene-containing copolymers have improved notch impact strength while maintaining high notch impact strength. It can be referred to as a resin mixture. However, when the blend of the polycarbonate / styrene-containing copolymer stays at a high temperature during the extrusion or injection process, the domain size of the components constituting the dispersed phase is increased, which is a continuous phase ( When the viscosity of the resin forming the matrix is lowered, it is more easily generated. As the phase size of the components constituting the dispersed phase increases, the mechanical properties of the molding rapidly decrease, and in particular, the low temperature impact resistance rapidly decreases.

U. S. Patent No. 5,292, 786 discloses a resin composition having improved weld-line strength composed of polycarbonate resin, ABS resin, phosphorus flame retardant and polyalkyl methacrylate resin. However, in the above technique, when the polyalkyl methacrylate resin is used in an appropriate amount or more, the thermal stability and appearance characteristics of the resin composition may be degraded due to decomposition (or depolymerization) of the polyalkyl methacrylate resin.

U.S. Patent Nos. 5,373,065 and 5,552,480 disclose techniques for introducing amine groups into styrene or olefinic resins and examples of using such resins to improve the compatibility of resin compositions. However, this technique is limited in practical commercial use due to the complicated procedure of introducing amine groups into the resin and the difficult manufacturing conditions.

US Pat. No. 5,910,538 also discloses a technique of using a compatibilizer in which a secondary amine group is introduced into a styrene resin copolymerized with maleic anhydride or the like in order to improve compatibility of a polycarbonate resin and a vinyl polymer. However, the above technique also uses a method of introducing an amine group to a pre-prepared resin through a method such as extrusion, which is difficult to use commercially because the procedure is complicated and the manufacturing conditions are difficult.

On the other hand, the inventors of the present invention, in order to overcome the above problems, styrene / methacrylic acid ester, acrylonitrile, amine as a compatibilizer in a composition composed of polycarbonate resin, rubber modified styrene graft copolymer, styrene copolymer By using a copolymer resin prepared from a mixture of group-containing vinyl monomers, such as low temperature impact resistance, thermal stability, heat resistance, workability and appearance, without deterioration in mechanical properties such as impact strength of the molded product at high temperature injection. It is an attempt to develop a thermoplastic resin composition having an excellent balance of physical properties.

An object of the present invention is to provide a thermoplastic resin composition that does not exhibit a decrease in mechanical properties such as impact strength of the molded product at high temperature injection.

Another object of the present invention is to provide a thermoplastic resin composition having excellent low temperature impact resistance.                         

Still another object of the present invention is to provide a thermoplastic resin composition having excellent balance of physical properties such as thermal stability, heat resistance, workability and appearance.

The above and other objects of the present invention can be achieved by the present invention described below.

The thermoplastic resin composition of the present invention comprises (A) polycarbonate resin, (B) rubber modified styrene graft copolymer resin, (C) styrene copolymer resin, and (D) compatibilizer, Detailed description is as follows.

(A) polycarbonate resin

The polycarbonate resin of the present invention is prepared by reacting diphenols represented by the following general formula (1) with phosgene, halogen formate or diester carbonate as an aromatic polycarbonate containing no halogen:

Wherein A is a single bond, alkylene of C _1-5 , alkylidene of C _2-5 , cycloalkylidene of C _5-6 , S or SO ₂ .

Examples of the diphenols represented by the formula (1) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxyphenyl) -propane, and 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2-bis- (3-chloro-4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane etc. are mentioned. Among them, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 1,1-bis- (4- Bisphenols, such as hydroxyphenyl) -cyclohexane, are preferable, and 2,2-bis- (4-hydroxyphenyl) -propane also called bisphenol-A is the most preferable.

The polycarbonate resin (A) of the present invention has a weight average molecular weight (M _w ) of 10,000 to 200,000, preferably 15,000 to 80,000. The branched polycarbonate resin may be used, and preferably, may be prepared by adding a compound having 0.05 to 2 mol% of a trivalent or more phenol group based on the total amount of diphenols used in the polymerization. The polycarbonate (PC) used in the preparation of the resin composition of the present invention may be used in the form of a homopolymer, a copolymer, or a mixture thereof. In addition, the polycarbonate resin (A) may be used in part or in whole by an aromatic polyester-carbonate resin obtained by polymerizing in the presence of an ester precursor, such as a bifunctional carboxylic acid.

Polycarbonate resin (A) is used in the range of 45-95 weight part.

(B) rubber modified styrene graft copolymer resin

Rubber-modified graft copolymer resin used in the present invention is 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene, or a mixture thereof and acrylonitrile, methacrylonitrile, C _1-8 meta 5 to 95 parts by weight of a mixture of 5 to 50 parts by weight of alkyl acrylates, C _1-8 methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide, or mixtures thereof Rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene terpolymer (EPDM), and polyorganosiloxane / polyalkyl (meth) acrylate rubber It is a copolymer grafted to 5 to 95 weight part of one or a mixture of these selected from the group which consists of composites. The C _1-8 methacrylic acid alkyl esters or C _1-8 acrylic acid alkyl esters are monohydryl alcohols each containing 1 to 8 carbon atoms as esters of acrylic acid or methacrylic acid. Preferred examples include methacrylic acid methyl ester, methacrylic acid ethyl ester or methacrylic acid propyl ester, most preferably methacrylic acid methyl ester.

The styrene-based graft copolymer resin can be prepared by a conventional polymerization method, but is most preferably synthesized by emulsion polymerization and bulk polymerization.

Preferred examples of the styrene-based graft copolymers include those obtained by graft copolymerization of butadiene rubber, acryl rubber, or styrene / butadiene rubber in the form of a mixture of styrene, acrylonitrile and optionally (meth) acrylic acid alkyl ester monomers. Most preferred is an acrylonitrile / butadiene / styrene (ABS) resin in which acrylonitrile and styrene are grafted to butadiene rubber.

The rubber-modified styrene graft copolymer is used in the range of 1 to 50 parts by weight of the total base resin. The average size of the rubber particles used in preparing the graft copolymer is suitably in the range of 0.05 to 4 μm in consideration of impact strength and appearance.

(C) Styrene Copolymer Resin

Styrene-based copolymers used in the present invention are 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene or a mixture thereof and acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl ester Styrene copolymers obtained by copolymerizing 5 to 50 parts by weight of C _1-8 methacrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide, or mixtures thereof. . This styrene copolymer resin is used in 0.5-50 weight part.

The C _1-8 methacrylic acid alkyl esters or C _1-8 acrylic acid alkyl esters are monohydryl alcohols having 1 to 8 carbon atoms as esters of acrylic acid or methacrylic acid, respectively. Preferred examples include methacrylic acid methyl ester, methacrylic acid ethyl ester or methacrylic acid propyl ester, and most preferably methacrylic acid methyl ester.

Styrene-based copolymers may be produced as by-products in the preparation of rubber-modified styrene-based graft copolymers (B), especially when the excess monomer is grafted to a small amount of rubbery polymer. The content of the styrene copolymer (C) used in the preparation of the resin composition of the present invention is not shown including the by-products generated during the production of the rubber-modified styrene-based graft copolymer (B). That is, the styrene-based copolymer (C) used in the production of the resin composition of the present invention is a thermoplastic resin and does not contain a rubbery polymer.

Preferred embodiments of the styrene copolymer (C) include monomer mixtures of styrene and acrylonitrile and optionally methacrylic acid methyl ester, monomer mixtures or styrene of α-methylstyrene and acrylonitrile and optionally methacrylic acid methyl ester , prepared from monomer mixtures of α-methylstyrene and acrylonitrile and optionally methacrylic acid methyl ester. The styrene / acrylonitrile copolymer may be prepared by emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization, and it is preferable to use a weight average molecular weight (M _w ) of 15,000 to 200,000.

As the styrene monomer used in the preparation of the styrenic copolymer (C) of the present invention, other substituted styrene monomers such as p-methylstyrene, vinyltoluene, 2,4-dimethylstyrene and α-methylstyrene may be used.

The styrenic copolymers (C) described above can also be used alone or in mixture of two or more thereof.

(D) compatibilizer

Compatibilizers used in the present invention include styrene, α-methylstyrene, halogen or methyl ring-substituted styrenes, C _1-8 methacrylic acid, alkyl esters, C _1-8 methacrylic acid esters or mixtures thereof. 95 parts by weight of 5 to 50 parts by weight of acrylonitrile, methacrylonitrile or a mixture thereof and 0.01 to 10 parts by weight of an amine group-containing vinyl monomer are copolymerized, and a compatibilizer is used in the range of 0.5 to 30 parts by weight. .

The compatibilizer is excellent in compatibility with the rubber-modified styrene graft copolymer which is itself a component (B) and the styrene copolymer which is a component (C), and reacts with a polycarbonate resin through an amine group. It will improve the compatibility of the resin composition.

As the amine group-containing monomer, vinyl aniline, aminoethyl methacrylate ester, aminoethyl acrylate ester, or the like can be used, and the amount of the amine group-containing monomer is used in the monomer used to prepare the styrene copolymer (D). 0.01 to 10 parts by weight can be used, and preferably 0.1 to 5 parts by weight is used. When the amount of the amine group-containing monomer is 0.01 parts by weight or less, the effect of improving the compatibility through the reaction with the polycarbonate resin is small, and when the amount is 10 parts by weight or more, the rubber-modified styrene-based graft copolymer and the component (B) C) may degrade compatibility with the styrenic copolymer.

As the method for preparing the compatibilizer, any of emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization may be used, and a weight average molecular weight of 20,000 to 300,000 is preferably used.

In addition, the thermoplastic resin composition of the present invention may include general additives such as flame retardants, lubricants, mold release agents, nucleating agents, antistatic agents, stabilizers, reinforcing agents, inorganic additives, pigments, or dyes according to the respective uses, and the inorganic additives added may be based on It can be used in the range of 0 to 60 parts by weight, preferably 10 to 40 parts by weight based on 100 parts by weight of the resin component (A) + (B) + (C). In the case of preparation including the additive, the additive is added and then mixed in a conventional mixer. This mixture is prepared into a resin composition in pellet form through an extruder.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

The specifications of (A) polycarbonate resin, (B) rubber modified styrene graft copolymer resin, (C) styrene copolymer resin, and (D) compatibilizer used in the following Examples and Comparative Examples are as follows. same.

(A) polycarbonate resin

 A polycarbonate of bisphenol-A type having a weight average molecular weight (Mw) of 22,000 was used.

(B) rubber modified styrene graft copolymer resin

Butadiene rubber latex was added so that the butadiene content was 45 parts by weight based on the total amount of the monomers, 1.0 parts by weight of potassium oleate, cumene hydroperoxide, an additive necessary for a mixture of 36 parts by weight of styrene, 14 parts by weight of acrylonitrile, and 150 parts by weight of deionized water. 0.4 parts by weight, 0.3 parts by weight of mercaptan-based chain transfer agent was added to the reaction while maintaining at 75 ℃ for 5 hours to prepare an ABS graft latex. A 1% sulfuric acid solution was added to the resulting polymer latex, solidified and dried to prepare a graft copolymer resin in a powder state.

(C) Styrene Copolymer Resin

A SAN copolymer resin was prepared by suspension polymerization by adding 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of tricalcium phosphate, which are necessary additives to a mixture of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile, and 120 parts by weight of deionized water. . The copolymer was washed with water, dehydrated and dried to obtain a SAN copolymer resin in powder form.

(D) compatibilizer

0.05 parts by weight of azobisisobutyronitrile was added to 71 parts by weight of styrene, 29 parts by weight of acrylonitrile, 1 part by weight of vinyl aniline, and 150 parts by weight of benzene, and the copolymer was precipitated in n-hexane and dried. A powdery SAN-VA terpolymer resin was prepared.

Table 1 shows the composition and measured physical properties of each component used in Examples 1 to 5 and Comparative Examples 1 and 2. Examples 1 to 5 used compatibilizers, and Comparative Examples 1 and 2 did not use compatibilizers.

As shown in Table 1, each component was mixed, antioxidant and heat stabilizer were added, mixed in a conventional mixer, extruded using a twin screw extruder having L / D = 35 and Φ = 45 mm, and then the extrudate was Prepared in pellet form.

Specimens for measuring the general physical properties were prepared using a 10 oz injection machine under the usual molding conditions at an injection temperature of 250 ℃. These specimens were measured for 40 hours at 23 ° C and 50% relative humidity, and then measured for physical properties according to ASTM standards.

Specimens for measuring physical properties during high temperature injection were prepared using a 10 oz injection machine with a cooling time of 5 minutes at an injection temperature of 300 ° C. It was.

division Example 1 Example 2 Example 3 Example 4 Example 5  Comparative Example 1  Comparative Example 2 ingredient  (A) polycarbonate resin 60 60 60 60 60 60 60  (B) Styrene-based graft copolymer 15 15 15 15 15 15 20  (C) Styrene Copolymer 24 22 20 15 10 25 20  (D) Compatibilizer One 3 5 10 15 - - Properties  Izod Notch Impact Strength (23 ℃) (1/8 ″, kgcm / cm) 61 60 60 58 57 61 62  Hot Injection Notch Impact Strength (23 ℃) (1/8 ″, kgcm / cm) 60 60 59 59 60 30 35  Izod Notch Impact Strength (-30 ℃) (1/8 ″, kgcm / cm) 40 40 41 39 39 40 42  Hot Injection Notch Impact Strength (-30 ℃) (1/8 ″, kgcm / cm) 39 38 39 37 37 15 16

The Izod impact strength is measured by ASTM D256.

As shown in the Examples and Comparative Examples of Table 1, when the compatibilizer is used, the notch impact strength (23 ° C) of the specimen injected at high temperature (300 ° C) is determined by the impact strength of the specimen injected under the general injection conditions. Compared with almost no decrease, but not using a compatibilizer can be seen that the notch impact strength of the specimen injected at a high temperature is rapidly reduced. In addition, when the compatibilizer is used, the low temperature (-30 ° C.) impact strength of the high-temperature injected specimens is also maintained without deterioration. In addition, it can be seen that using such a compatibilizer is much more effective in increasing the high temperature injection impact strength than increasing the amount of the graft copolymer improving the impact strength (Comparative Example 2).

These results can also be seen through the electron micrograph shown in Figure 1. 1 is a transmission electron micrograph of a high-temperature injected specimen of Comparative Example 2, Figure 2 is an electron micrograph of a high-temperature injected specimen of Example 4. As can be seen, without the use of a compatibilizer, the phases of the graft copolymer, component (B), and the styrene-based copolymer, component (C), tend to aggregate (phase agglomeration). It can be seen that a large phase is formed. As the size of the dispersed phase increases, the Izod impact strength, particularly at low temperatures, is known to rapidly decrease. On the other hand, in the specimens using the compatibilizer, no clumping occurs and it can be seen that it is very well dispersed. In this case, excellent impact strength can be exhibited even at low temperatures.

The present invention uses a copolymer prepared by copolymerizing a styrene-based, acrylonitrile-based, amine group-containing vinyl monomer, etc. as a compatibilizer, thereby reducing the mechanical properties such as impact strength of the molded product during high-temperature injection due to increased compatibility It is excellent in the balance of physical properties such as low temperature impact resistance, thermal stability, heat resistance, workability and appearance without the appearance of a thermoplastic resin composition which is useful for manufacturing an injection molding of a computer housing or other office equipment. Has

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.                     

Claims (4)

(A) 45-95 parts by weight of polycarbonate resin; (B) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene or mixtures thereof, acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 meta 5 to 95 parts by weight of a mixture of 5 to 50 parts by weight of krylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide or mixtures thereof, butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / Polymers selected from butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, terpolymer (EPDM) of ethylene-propylene-diene, polyorganosiloxane / polyalkyl (meth) acrylate rubber composites or mixtures thereof 1 to 50 parts by weight of rubber-modified graft copolymer resin grafted in 95 parts by weight; (C) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or alkyl substituted styrene or mixtures thereof, acrylonitrile, methacrylonitrile, C _1-8 methacrylic acid alkyl esters, C _1-8 meta 0.5 to 50 parts by weight of a styrenic copolymer obtained by copolymerizing 5 to 50 parts by weight of acrylic acid esters, maleic anhydride, C _1-4 alkyl or phenyl N-substituted maleimide or a mixture thereof; And (D) 50 to 95 parts by weight of styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C _1-8 methacrylic acid, alkyl esters, C _1-8 methacrylic acid esters or mixtures thereof and acryl 0.5 to 30 parts by weight of a compatibilizer prepared by copolymerizing 5 to 50 parts by weight of ronitrile, methacrylonitrile or a mixture thereof and 0.01 to 10 parts by weight of an amine group-containing vinyl monomer; Thermoplastic resin composition, characterized in that consisting of. The thermoplastic resin composition according to claim 1, wherein the amine group-containing vinyl monomer of the compatibilizer is vinyl aniline or aminoethyl methacrylic acid ester. The thermoplastic resin composition according to claim 1, wherein the content of the compatibilizer is 1 to 20 parts by weight. The thermoplastic resin of claim 1, wherein the resin composition further comprises a flame retardant, an inorganic additive, a heat stabilizer, an antioxidant, a light stabilizer, a plasticizer, a pigment, a dye, a lubricant, a mold release agent, a filler, a nucleating agent, or an antistatic agent. Composition.

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