KR20040021822A - Acrylonitrile-Butadiene-Styrene Resin Composition with Excellent Thermal Stability, Impact Strength, Flowability and Antistatics - Google Patents

Abstract

PURPOSE: Provided is an acrylonitrile-butadiene-styrene copolymer resin composition having excellent heat resistance, impact resistance and flow property as well as antistatic property. CONSTITUTION: The antistatic and heat resistant ABS copolymer resin composition comprises: (A) 100 parts by weight of ABS resin with a rubber content of 15-20 wt% comprising (A1) 65-70 wt% of a SAN resin with a weight average molecular weight of 90,000-130,000 consisting of (A11) 45-50 wt% of an alpha-methyl styrene based SAN resin containing 70-80 wt% of the alpha-methyl styrene and (A12) 50-55 wt% of a SAN resin containing 20-40 wt% of acrylonitrile; and (A2) 30-35 wt% of a graft copolymer obtained by the graft polymerization of 30-45 wt% of a styrene monomer and 10-15 wt% of an acrylonitrile monomer with 40-60 wt% of a rubber selected from the group consisting of a butadiene rubber, an isoprene rubber, a copolymer of butadiene with styrene and an alkyl acrylate rubber; and (B) 0.1-1 parts by weight of an amine-based antistatic compound.

Description

Acrylonitrile-Butadiene-Styrene Resin Composition with Excellent Thermal Stability, Impact Strength, Flowability and Antistatics}

Field of invention

The present invention relates to an acrylonitrile-butadiene-styrene copolymer resin composition. More specifically, the present invention provides an acrylonitrile having excellent heat resistance, impact resistance, fluidity, and antistatic properties by adding an amine compound as an antistatic additive to an ABS resin including an α-methyl styrene-based styrene-acrylonitrile copolymer. It relates to a butadiene-styrene copolymer resin composition.

Background of the Invention

In general, acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as 'ABS resin') is widely used for manufacturing interior and exterior parts such as electrical / electronic products and office automation equipment because of its excellent processability and mechanical strength and excellent appearance. . However, ABS resin is itself a non-conductor for electricity, so it does not flow well on its surface, causing static electricity. Static electricity can reduce productivity or cause fire, electric shock and dust absorption. For this reason, antistatic properties are required as exterior materials of electrical appliances such as home appliances and electrical junction boxes in Europe.

As a method of imparting antistatic property to ABS resins, a method of reducing the surface resistance of the resin by adding an additive of a component that allows electricity to flow well to these ABS resins has been used. However, when the antistatic additive is used, desired antistatic properties can be obtained, but there is a problem in that deterioration of physical properties such as heat resistance, impact resistance, fluidity, and the like occurs.

In particular, as electrical and electronic products become more functional and lightweight, demand for thermoplastic resins having high heat resistance and excellent processability to withstand heat generation of electronic products increases, and thus, the chargeable ABS resin is manufactured. In order to maintain excellent chargeability, a technique for minimizing the degradation of physical properties such as heat resistance, impact resistance, fluidity, workability, and weather resistance is required.

On the other hand, the present inventors have solved the problem of the ABS resin and the amine antistatic compound containing a styrene-acrylonitrile copolymer (hereinafter referred to as 'SAN resin') containing 70 to 80% by weight of α-methyl styrene With the proper combination, it has been developed a resin composition which is very useful for the manufacture of interior and exterior parts, such as various electrical and electronic products and office automation equipment by having excellent heat resistance, impact resistance, fluidity and antistatic properties.

An object of the present invention is to provide an acrylonitrile-butadiene-styrene copolymer resin composition excellent in antistatic properties.

Another object of the present invention is to provide an acrylonitrile-butadiene-styrene copolymer resin composition having excellent antistatic properties and excellent heat resistance, impact resistance and flowability.

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

The resin composition of the present invention (A) (A1) 100 parts by weight of the ABS resin consisting of 65 to 70% by weight of the SAN resin containing (A1) α-methyl styrenic SAN resin and (A2) 30 to 35% by weight of the graft copolymer and (B) 0.1 to 1 part by weight of the amine antistatic compound, and detailed description of each of these components is as follows.

(A) ABS resin

(A1) styrene-acrylonitrile copolymer (SAN resin)

SAN resin (A1) used in the present invention is a 45 to 50% by weight α-methyl styrene-based SAN resin (A ₁₁ ) having an α-methyl styrene content of 70 to 80% by weight and 20 to 40% by weight of acrylonitrile 50% to 55% by weight of the SAN resin (A ₁₂ ).

The α-methyl styrene SAN resin (A ₁₁ ) is prepared by suspension polymerization of 70 to 80 wt% of α-methyl styrene and 20 to 30 wt% of acrylonitrile, and the α-methyl styrene SAN resin is generally used. Compared to the matrix resin, Viscat Softening Temperature (VST) is much higher (about 115 ° C), which is easy to increase the heat resistance of ABS resin.

The weight average molecular weight of SAN resin (A1) used for this invention is 90,000-130,000. In general, when the weight average molecular weight of the SAN resin is less than 100,000, it exhibits high fluidity, but it is difficult to secure appropriate impact resistance, and in the case of 100,000 or more, high impact resistance is secured, while fluidity of the resin composition is deteriorated. In order to solve the above problem, in the present invention, α-methyl styrene-based SAN resin (A ₁₁ ) having a molecular weight of 100,000 or more and a SAN resin (A ₁₂ ) having a molecular weight of less than 100,000 were used.

(A2) graft copolymer

The graft copolymer (A2) used in the present invention comprises 30 to 45% by weight of styrene monomer and 10 to 15% by weight of acrylonitrile monomer, butadiene rubbers, isoprene rubbers, copolymers of butadiene and styrene or alkylacrylate rubbers. It is prepared by graft polymerization with 40 to 60% by weight of rubber selected from the back.

ABS resin (A) of the present invention comprises 65 to 70% by weight of the SAN resin (A1) and 30 to 35% by weight of the graft copolymer (A2). The rubber content of the ABS resin (A) is 15 to 20% by weight, the styrene-acrylonitrile copolymer content is 80 to 85% by weight.

(B) Amine Antistatic Compound

An antistatic agent refers to an additive that acts to reduce or remove static electricity formed on the surface of a product by treating the surface of the finished product or added to the thermoplastic resin.

In order to improve the chargeability by static electricity, there are methods of introducing hydrophilicity by chemically treating the surface, grafting of hydrophilic monomers, and adding a good substance such as metal powder. The most commonly used method due to problems is the use of antistatic agents.

Antistatic agents are classified into permanent antistatic agents and fast-acting antistatic agents. Permanent antistatic agents blend antistatic block copolymers with resins, and at least 10 parts by weight should be added to 100 parts by weight of ABS resin (A). There is a disadvantage. On the other hand, the fast-acting antistatic agent forms a conductive film on the surface of the resin with only a small amount of addition and combines with moisture in the air to exhibit chargeability. In the present invention, the latter fast-acting antistatic agent is used.

In the present invention, as the antistatic agent, all of the amine compounds generally used as antistatic agents may be used, which may be easily selected by those skilled in the art to which the present invention pertains. Representative examples include N-Hydroxyethyl-N (2-Hydroxy Alkyl) Amine, represented by the following formula:

The amine compound is a kind of surface active agent, and the antistatic action is as follows:

First, the hygroscopic action of the antistatic agent. Water is already known to be extremely good in electrical conductivity, and generally surfactants, ie antistatic agents, are hydrophobic and hydrophilic. The hydrophobic part is arranged inside the resin and the hydrophilic part is arranged on the outermost side of the resin, so that 7-10 pieces of water molecules in the air are received by the migration of the hydrophilic group to form a hydrophilic continuous film layer on the surface of the resin, thereby improving electrical conductivity. Will be. Therefore, the chargeability is greatly influenced by the humidity in the air, but the antistatic property is more excellent in the summer when the humidity is high.

Second, it is due to the electrical conductivity of the antistatic agent. The surface active agent used as an antistatic agent is a material having good electrical conductivity per se, and particularly in the case of an ionic active agent, neutralizes the opposite charge to prevent charging.

Third, due to the action of lowering the friction coefficient due to the antistatic agent. The antistatic agent adhering to the resin surface lowers the friction coefficient of the resin surface, so that the generation of static electricity is suppressed.

The antistatic properties include the half-life method and the surface resistance measurement method. The half-life method measures the time when the charge amount is reduced by half after giving a constant charge to the resin, and there is no specific range, but it is possible to grasp the characteristics of the chargeability.

The surface resistance measurement method measures the surface resistance of the resin itself. The surface resistance of general antistatic resin is about 10 ^{15 15,} the surface resistance of fast-acting antistatic resin is 10 ¹² ~ 10 ¹³ Ω, the surface resistance of permanent antistatic resin 10 ^8-10 is a ¹⁰ Ω. This surface resistance represents the time when electricity flows away. If the resistance is 10 times, the required time is also 10 times.

In the present invention, the amine antistatic compound (B) is used in an amount of 0.1 to 1 parts by weight based on 100 parts by weight of the ABS resin (A). When the amine-based antistatic compound is used in an amount of 0.1 parts by weight or less, sufficient antistatic effect cannot be obtained, and when used in an amount of 1 part by weight or more, physical properties such as heat resistance, tensile strength, and flexural strength decrease.

In addition to the above components, the antistatic heat resistant ABS resin composition of the present invention may be added with inorganic additives, waxes, antioxidants, hindered amine-based and benzotriazole-based light stabilizers, pigments, dyes, etc. according to their respective uses. Can be.

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

Specifications of the ABS resin (A), the amine compound (B) and other additives used in the following Examples and Comparative Examples are as follows.

(A) ABS resin

(A1) SAN resin

Cheil Industries 'AP-TJ (trade name) was used as the α-methyl styrene SAN resin (A ₁₁ ), and Cheil Industries' AP-65 (trade name) was used as the SAN resin (A ₁₂ ).

(A2) graft copolymer

The rubber contents were used by mixing CHT (trade name) and CHA (trade name) of Cheil Industries with 58 wt% and 45 wt%, respectively.

(B) Amine Antistatic Compound

N-hydroxyethyl-N (2-hydroxyalkyl) amine (trade name: DUSPAR 125B) manufactured by Miyoshi Oil Industries, Japan was used.

As other antioxidants, hindered phenol antioxidants and phosphite antioxidants were used together.Stearate-based metal lubricants, silicone oil impact modifiers, and hindered amine-based optical compounds Tablets and the like were purchased commercially and used as they are without further purification.

Example 1 and Comparative Example 1-4

Mix by using the ingredients in Table 1, 0.2 parts by weight of antioxidant, 0.3 parts by weight of metal stearate external lubricant, 0.02 parts by weight of impact modifier and 0.2 parts by weight of hindered amine light stabilizer, and then uniform with a mixer After mixing, the mixture was extruded by an extruder to prepare pellets. Test specimens for physical properties, etc. were prepared by injection molding from the prepared pellets. The measurement method for each property item was experimentally evaluated based on the following test analysis criteria, and the results are shown in Table 1.

Impact Resistance: Evaluated for 1/4 inch thickness by ASTM D-256 test method.

Fluidity: It was evaluated under the condition of 220 ° C and 5 kg load by the ASTM D-1238 test method.

Heat resistance: evaluated at 5 kg load by ASTM D-1525 test method.

Tensile strength: evaluated at 5 mm / min by ASTM D-638 test method.

Flexural strength: evaluated under the condition of 2.8 mm / min by the ASTM D-790 test method.

Hardness: evaluated by ASTM D-785 test method.

Half-life: After 8 kV of charge was applied to the test specimens, the time for which the charge amount was reduced to 1/2 was measured.

Surface resistance: The surface electrical resistance of the resin itself was measured by the surface resistance meter.

Example Comparative Example One 2 One 2 3 4 Composition (parts by weight) (A) ABS resin (A1) (A ₁₁ ) 32 32 30 30 30 28 (A ₁₂ ) 36 38 41 41 41 40 (A2) CHT / CHA 18/14 17/15 14/15 14/15 14/15 17/15 (B) amine compound 0.4 0.4 - 0.4 1.2 0.4 Properties Impact resistance (kgcm / cm) 17 16 12 13 14 17 Fluidity (g / 10min) 12 12 14 14 14 13 Heat resistance (℃) 103 103 103 102 100 101 Tensile Strength (kgf / ㎠) 450 450 475 470 460 445 Flexural Strength (kgf / ㎠) 700 700 730 715 705 690 Hardness (R-Scale) 104 105 107 106 106 105 Surface resistance (x10 ⁿ Ω) 13 13 ∞ 13 13 13 Half-life (seconds) 15 15 ∞ 15 One 15

As shown through the comparison of physical properties of Comparative Examples 1-3 in Table 1, when the amine compound is used as an antistatic agent, the half-life tends to decrease in proportion to the amount used, but when used in an amount of 1.0 parts by weight or more, Also, it can be seen that physical properties such as tensile strength and flexural strength are reduced.

Compared to Example 1 using ABS resin having a rubber content of 14.87% by weight, the tensile strength and flexural strength of the comparative example 2 were slightly increased, but the impact strength was greatly reduced. Able to know.

In addition, in Comparative Example 4 in which the content of α-methyl styrene-based SAN resin was 41 wt% SAN resin, the heat resistance and tensile strength were compared with those in Example 2, in which the content of α-methyl styrene-based SAN resin was 45.7 wt%. It can be seen that the bending strength and the like decrease.

From the above results, it is possible to prepare an antistatic heat resistant ABS resin composition having excellent impact resistance and fluidity by adding an amine compound as an antistatic agent and using an ABS resin containing a predetermined amount of α-methyl styrene SAN resin. It can be seen.

The present invention provides an acrylonitrile-butadiene- having excellent anti-static property and excellent heat resistance, impact resistance and fluidity by adding an amine antistatic compound to an ABS resin containing α-methyl styrene-based styrene-acrylonitrile copolymer. It has the effect of providing the styrene copolymer resin composition.

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 (2)

(A) (A1) (A ₁₁ ) 45-50 wt% of α-methyl styrene-based SAN resin having 70-80 wt% of α-methyl styrene and 20-40 wt% of (A ₁₂ ) acrylonitrile 65 to 70% by weight of a SAN resin having 50 to 55% by weight of phosphorus SAN resin and having a weight average molecular weight of 90,000 to 130,000; And (A2) 30 to 45% by weight of styrene monomer and 10 to 15% by weight of acrylonitrile monomer are 40 to 60% by weight of rubber selected from butadiene rubbers, isoprene rubbers, copolymers of butadiene and styrene or alkyl acrylate rubbers 30 to 35 wt% of a graft copolymer prepared by vitr polymerization; 100 parts by weight of an ABS resin having a rubber content of 15 to 20 wt%; And (B) 0.1 to 1 parts by weight of the amine antistatic compound; Antistatic heat resistant ABS resin composition, characterized in that consisting of. The antistatic heat resistant ABS resin composition according to claim 1, further comprising an inorganic additive, a wax, an antioxidant, a hindered amine-based and a benzotriazole-based light stabilizer, a pigment, a dye, and the like.