KR20150033843A - Thermoplastic ABS resin composition with improved mold shrinkage for blow molding - Google Patents

Abstract

The present invention relates to a thermoplastic ABS resin composition for blow molding with improved mold shrinkage, which has drastically reduced occurrence of a post-modification, a size defect, and the like. More specifically, the thermoplastic ABS resin composition for blow molding comprises 0.01 to 2 parts by weight of metallic stearate based on 100 parts by weight of a matrix resin, wherein the matrix resin includes (a) 30 to 50 weight % of graft copolymer in which a conjugated diene-based rubber polymer of a monomodal having 2500 to 5000 Å of an average particle diameter is graft polymerized with a vinyl aromatic compound and a vinyl cyanide compound, and in which the graft polymerized compound is coagulated with a coagulant selected from the group consisting of magnesium sulfate, calcium chloride, aluminium sulfate, or a mixture of at least two thereof; (b) 30 to 60 weight % of AMS copolymer; and (c) 5 to 40 weight % of SAN resin of which weight average molecular weight is 150,000 to 200,000 and a flow index is 8 to 12.

Description

TECHNICAL FIELD [0001] The present invention relates to a thermoplastic ABS resin composition for blow molding having improved mold shrinkage,

The present invention relates to a thermoplastic ABS resin composition for blow molding having improved mold shrinkage, and more particularly, to a thermoplastic ABS resin composition for blow molding which has a reduced mold shrinkage ratio and significantly reduces occurrence of post- .

ABS resin composed of acrylonitrile-butadiene-styrene is a representative resin having both functionality and versatility, and has excellent properties such as impact strength, tensile strength, elastic modulus, and flame retardancy, and is suitable for automobile parts and various electric / It is widely used for the purpose. As the resin processing method, injection is performed most extensively, and extrusion and blow molding are also performed. Particularly, in the case of blow molding, it is used for molding various kinds of containers such as water bottles, and it is known that the injection molding process is somewhat complicated and difficult.

One of the auto parts made by blow molding is spoiler. Since the spoiler is relatively large and is attached to the exterior of the car, it must be of good appearance and free of post-distortion or size problems. For blow molding, the fluidity of the product should be kept relatively low, and the melt strength must be kept higher than the injection molding material. As a method of imparting the melt strength of the resin, there are a method of using two types of butadiene-based grafts having different molecular weights (Korean Patent Laid-Open No. 2001-0046875), the acrylonitrile composition of the ABS resin and the SAN resin Nitrile resin) (Japanese Patent Publication No. 3-243646), and a method using an organosilane compound (Japanese Patent Publication No. 3-263451).

However, the above-mentioned prior arts have not improved the blow moldability by a patent on blow moldability or by this method. In particular, in the case of the method using an organosilane compound, there is a problem that mass production is difficult and the manufacturing cost is increased. In addition, after the blow molding, there is a problem of size deficiency due to shrinkage, and it is necessary to improve this.

Therefore, there is a demand for development of a thermoplastic ABS resin composition for blow molding which is excellent in impact strength and glossiness, and in particular, has an improved mold shrinkage ratio in blow molding.

An object of the present invention is to provide a thermoplastic ABS resin composition for blow molding which is excellent in impact strength and gloss, and in particular, has a reduced mold shrinkage in blow molding.

In order to achieve the above object, the thermoplastic ABS resin composition according to the present invention comprises 0.01 to 2 parts by weight of a metal-based stearate relative to 100 parts by weight of a matrix resin, wherein the matrix resin comprises (a) monomodal 30 to 50 weight parts of a graft copolymer which is graft-polymerized with a vinyl aromatic compound and a vinyl cyan compound and coagulated with a flocculant selected from the group consisting of magnesium sulfate, calcium chloride, aluminum sulfate or a mixture of two or more thereof, %; (b) from 30 to 60% by weight of AMS copolymer; And (c) 5 to 40% by weight of a SAN resin having a weight average molecular weight of 150,000 to 200,000 and a flow index of 8 to 12.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a thermoplastic ABS resin composition for blow molding which is excellent in impact strength and gloss, and in particular, has improved mold shrinkage in blow molding.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a thermoplastic ABS resin composition having excellent impact strength and gloss and having improved shrinkage characteristics after blow molding.

The thermoplastic ABS resin composition according to the present invention comprises 0.01 to 2 parts by weight of a metal-based stearate relative to 100 parts by weight of a matrix resin, wherein the matrix resin comprises (a) a monodomally conjugated diene rubber polymer having an average particle diameter of 2500 to 5000 Å From 30 to 50% by weight of a graft copolymer which is graft-polymerized with a vinyl aromatic compound and a vinyl cyan compound and aggregated with a flocculant selected from the group consisting of magnesium sulfate, calcium chloride, aluminum sulfate or a mixture of two or more thereof; (b) from 30 to 60% by weight of AMS copolymer; And (c) 5 to 40% by weight of SAN resin having a weight average molecular weight of 150,000 to 200,000 and a flow index of 8 to 12.

Hereinafter, the matrix resin constituting the thermoplastic ABS resin composition according to the present invention will be described in detail by dividing the components (a) to (c) and the metal-based stearate separately.

(a) a conjugated diene-based graft copolymer

The conjugated diene-based graft copolymer in the matrix resin constituting the thermoplastic ABS resin composition according to the present invention is prepared by graft copolymerizing a conjugated diene-based rubbery polymer with a vinyl aromatic compound and a vinyl cyan compound. The conjugated diene-based rubbery polymer is first prepared by preparing a small-diameter rubbery polymer having a relatively small average particle size and fusing it with an acid to prepare a large-diameter rubbery polymer having a relatively larger average particle size.

The particle size and the gel content of the conjugated diene-based rubbery polymer used in the production of the conjugated diene-based graft copolymer greatly influence the impact strength and workability of the resin. That is, generally, the smaller the particle size of the rubbery polymer is, the lower the impact strength and processability, the larger the particle size, the larger the impact strength. The smaller the gel content, the larger the swelling of the monomer in the rubbery polymer, And the impact strength is improved. However, there is a problem that the content of the rubbery polymer is large, and the larger the particle size, the lower the graft rate. The graft ratio greatly affects the physical properties of the conjugated diene-based graft copolymer. If the graft ratio is lowered, there are many untrafted rubber-like polymers, resulting in poor thermal stability.

Therefore, it is important to prepare a conjugated diene-based rubbery polymer having a proper particle diameter and gel content, and it is important that the conjugated diene-based rubbery polymer has an appropriate graft ratio when graft copolymerizing the vinyl aromatic compound and the vinyl cyanide compound.

Hereinafter, a method for producing a conjugated diene-based graft copolymer for use in the present invention will be described. (I) Production of a small diameter conjugated diene rubber polymer, (ii) Production of a large diameter conjugated diene rubber polymer, and (iii) And the production of a conjugated diene-based graft copolymer by the above-mentioned method.

(i) Preparation of conjugated diene rubber polymer of small diameter

The small diameter conjugated diene rubber polymer used in the production of the conjugated diene-based graft copolymer according to the present invention can be prepared by mixing and emulsion polymerization of a conjugated diene monomer, an emulsifier, a polymerization initiator, an electrolyte, a molecular weight regulator and water .

The conjugated diene-based monomer is preferably at least one selected from the group consisting of butadiene, isoprene, and chloroisoprene, and more preferably, butadiene.

The emulsifier is preferably at least one selected from the group consisting of alkyl aryl sulfonates, alkali metal alkyl sulfates, sulfonated alkyl esters, fatty acid soaps and rosin acid alkali salts, Is preferably 1 to 4 parts by weight based on 100 parts by weight of the resin.

The polymerization initiator may be a water-soluble persulfate or a peroxy compound, and an oxidation-reduction system may be used. The most preferred water soluble persulfates are sodium and potassium persulfates and the fat soluble polymerization initiators are cumene hydroperoxide, diisopropylbenzene hydroperoxide, azobisisobutylnitrile, t-butyl hydroperoxide, para-methane hydroperoxide and Benzoyl peroxide, and the like. The amount of the monomer to be used is preferably 0.1 to 0.6 parts by weight based on 100 parts by weight of the conjugated diene monomer.

Also, the electrolyte may be selected from the group consisting of KCl, NaCl, KHCO ₃ , NaHCO ₃ , K ₂ CO ₃ , Na ₂ CO ₃ , KHSO ₃ , NaHSO ₃ , K ₄ P ₂ O ₇ , K ₃ PO ₄ , Na ₃ PO ₄ , K ₂ HPO ₄ , and Na ₂ HPO ₄ , and the amount thereof is preferably 0.1 to 1 part by weight based on 100 parts by weight of the conjugated diene monomer.

The molecular weight regulator is preferably t-dodecyl mercaptan or n-octyl mercaptan, and the amount thereof is preferably 0.1 to 0.5 parts by weight based on 100 parts by weight of the conjugated diene monomer.

The water is preferably ion-exchanged water, and the amount of the water is preferably 90 to 130 parts by weight based on 100 parts by weight of the conjugated diene-based monomer.

The conjugated diene monomer and the polymerization additives are firstly charged into a reactor and subjected to primary polymerization at 50 to 65 ° C for 7 to 12 hours and further added with 0.05 to 1.2 parts by weight of a molecular weight modifier, To thereby produce a small diameter conjugated diene rubber polymer.

The small diameter conjugated diene-based rubbery polymer prepared as described above preferably has an average particle diameter of 600 to 1,500 angstroms. When the average particle diameter is less than 600 angstroms, the mechanical properties such as impact strength and tensile strength may be deteriorated and thermal stability may be deteriorated. When the average particle diameter is more than 1500 angstroms, I do not.

(ii) Production of large diameter conjugated diene rubbery polymer

The large-diameter conjugated diene-based rubbery polymer can be prepared by fusing the small-diameter conjugated diene-based rubbery polymer with an acid, and the production method thereof is as follows.

First, 2.5 parts by weight to 4.5 parts by weight of an acetic acid aqueous solution is gradually added to 100 parts by weight of the small diameter conjugated diene-based rubbery polymer for 1 hour so that fusion of the conjugated diene-based rubbery polymer particles with small diameter is caused. After the above-mentioned process is performed for about 1 hour, stirring is stopped, and when the rubber polymer is left for a predetermined period, the rubbery polymer is enlarged to produce a large diameter conjugated diene rubber polymer having an average particle diameter of 2500 to 5000 angstroms.

The particle diameter of the large diameter conjugated diene rubber polymer is very important for imparting impact strength to the thermoplastic ABS resin, and it is preferable that the average particle diameter is in the range of 2500 to 5000 ANGSTROM to satisfy the physical properties required in the present invention. If the average particle diameter of the large diameter conjugated diene rubber polymer is less than 2500 angstroms, mechanical properties such as impact strength and tensile strength may be deteriorated, and if it exceeds 5000 angstroms, gloss and fluidity may be lowered and the graft rate may be lowered.

(iii) Production of conjugated diene-based graft copolymer by graft polymerization

A conjugated diene-based graft copolymer is prepared by adding an emulsifier, a molecular weight modifier, a polymerization initiator, and water to a reaction mixture containing the above-prepared large diameter conjugated diene rubber polymer, a vinyl aromatic compound and a vinyl cyan compound, followed by emulsion polymerization .

The vinyl aromatic compound is preferably at least one member selected from the group consisting of styrene, alpha-methylstyrene, para-methylstyrene, ortho-ethylstyrene, para-ethylstyrene and vinyltoluene, more preferably styrene. The amount of the vinyl aromatic compound to be used is preferably 30 to 60 parts by weight, more preferably 38 to 57 parts by weight, based on 100 parts by weight of the large-diameter rubbery polymer. If the amount of the vinyl aromatic compound is less than 30 parts by weight, the color may be yellowed. If the amount is more than 60 parts by weight, the compatibility with the SAN resin constituting the matrix resin may be deteriorated.

The vinyl cyan compound is preferably at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile, and more preferably acrylonitrile. The amount of the vinyl cyan compound to be used is preferably 10 to 30 parts by weight, more preferably 13 to 29 parts by weight, based on 100 parts by weight of the large diameter rubbery polymer. If the amount of the vinyl cyan compound used is less than 10 parts by weight, there may be a problem such as lower compatibility with the SAN resin constituting the matrix resin, and if it exceeds 30 parts by weight, I do not.

The emulsifier is preferably at least one selected from the group consisting of alkylaryl sulfonates, alkali metal alkyl sulfates, sulfonated alkyl esters, fatty acid soap, and rosin acid alkali salts, Is preferably 0.2 to 1 part by weight based on 100 parts by weight.

The molecular weight regulator is preferably t-dodecyl mercaptan or n-octyl mercaptan, and the amount thereof is preferably 0.2 to 0.6 parts by weight based on 100 parts by weight of the large diameter conjugated diene rubber polymer.

Also, the polymerization initiator may be at least one selected from the group consisting of peroxides including cumene hydroperoxide, diisopropylbenzene hydroperoxide or persulfate, and peroxides such as sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, And a reducing agent including sodium or sodium sulfite, and the amount thereof is preferably 0.1 to 0.5 parts by weight based on 100 parts by weight of the large diameter conjugated diene rubber polymer.

The water is preferably ion-exchanged water, and the amount of the water is preferably 80 to 150 parts by weight based on 100 parts by weight of the large diameter conjugated diene rubber polymer.

When the reaction mixture and the polymerization additives are added to the reactor, it is preferable that the reaction mixture and the polymerization additives are administered in multiple stages or continuously in order to improve the graft rate and minimize the formation of the coagulated product.

The temperature condition for the emulsion polymerization for producing the conjugated diene-based graft copolymer is preferably 45 to 80 캜, and the polymerization time is preferably 3 to 5 hours.

After completion of the emulsion polymerization, the polymerization conversion ratio of the resultant conjugated diene-based graft copolymer latex is preferably 95% or more, and an antioxidant and a UV stabilizer are added to the conjugated diene-based graft copolymer latex, After coagulation with an aqueous sulfuric acid solution at a temperature, dehydration and drying are carried out to obtain a conjugated diene-based graft copolymer powder.

The polymerization stability of the prepared conjugated diene-based graft copolymer latex can be determined by measuring the solidification percentage (%) by the following formula (1).

[Equation 1]

Solid solid content (%) = (weight (g) of formed solidified product in the reaction tank / total weight of rubbery polymer and monomer) x 100

When the solid solid content is 0.7% or more, the latex stability is extremely low, and it is difficult to obtain a conjugated diene-based graft copolymer suitable for the present invention due to a large amount of solidification product. Therefore, the solidified solid content is preferably less than 0.7%.

The graft ratio of the conjugated diene-based graft copolymer is measured as follows.

That is, the conjugated diene-based graft copolymer latex is solidified, washed and dried to obtain a powder form, and 2 g of the powder is added to 300 ml of acetone and stirred for 24 hours. After separating the solution using an ultracentrifuge, the separated acetone solution is dropped in methanol to obtain a non-grafted portion, which is then dried and weighed. From these weights, the graft rate is calculated by the following equation (2).

&Quot; (2) "

Graft rate (%) = (weight of grafted monomer / total weight of rubbery material) x 100

In the present invention, the graft ratio of the conjugated diene-based graft copolymer is preferably 26 to 60%. If the graft ratio is less than 26%, the thermal stability may be deteriorated. If the graft ratio is more than 60%, the mechanical properties may be deteriorated.

The conjugated diene-based graft copolymer is preferably 30 to 50% by weight based on the total weight of the matrix resin constituting the thermoplastic ABS resin composition of the present invention. When the conjugated diene-based graft copolymer is used in an amount of less than 30% by weight, there may be a problem that the impact strength is significantly lowered, and when it exceeds 50% by weight, the workability and gloss may be lowered not.

(b) AMS copolymer

The AMS copolymer in the matrix resin constituting the thermoplastic ABS resin composition according to the present invention is prepared by copolymerizing 45 to 75 parts by weight of an alpha-methylstyrene monomer, 5 to 10 parts by weight of a vinyl aromatic compound and 20 to 45 parts by weight of a vinyl cyan compound . As the polymerization method thereof, bulk polymerization is preferable. As the solvent, it is preferable to use 26 to 30 parts by weight of toluene and 0.1 to 1.0 part by weight of di-t-dodecylmercaptan as a molecular weight modifier. It is also preferable to keep the amount of the mixed solution of the reactants so that the average reaction time is 2 to 4 hours and maintain the reaction temperature at 140 to 170 ° C.

The manufacturing process is characterized by being a continuous process comprising a raw material feed pump, a continuous stirring tank, a preheating tank and a volatilization tank, a polymer feed pump, and an extrusion processing machine.

The AMS copolymer is preferably contained in an amount of 30 to 60% by weight based on the total weight of the matrix resin constituting the thermoplastic ABS resin composition of the present invention. If the content is less than 30% by weight, the heat resistance of the resin may be lowered. If the content is more than 60% by weight, the impact strength and the melt strength may be lowered.

(c) SAN resin

The SAN resin (acrylonitrile-styrene copolymer resin) in the matrix resin constituting the thermoplastic ABS resin composition according to the present invention is preferably a vinyl aromatic compound, preferably 70 to 95 parts by weight of styrene, a vinyl cyan compound, 5 to 30 parts by weight of ronitril and 100 parts by weight of distilled water. As the initiator, 0.3 to 0.7 parts by weight of benzoyl peroxide, 0.03 to 0.07 part by weight of t-butyl perbenzoate, and 0.1 to 0.5 parts by weight of dicumyl peroxide can be used. As the dispersing agent, 0.2 part by weight of tricalcium phosphate and 0.5 part by weight of TDDM (Tert-Dodecyl Mercaptan) can be used as a molecular weight regulator.

After the reactor was sealed, the reaction temperature was raised to 90 캜. After 2 hours, 0.1 to 0.3 parts by weight of a 10% aqueous solution of potassium persulfate and 0.1 to 0.3 parts by weight of tricalcium phosphate as a dispersing agent And 0.1 to 0.3 parts by weight of a 10% aqueous solution of sodium dodecylbenzenesulfonate are fed into the flask and the reaction temperature is maintained for 3 hours. After the reaction temperature reached 110 캜, it was held for 5 to 9 hours, then cooled to 45 캜, and after the acid treatment, a bead was obtained. After the obtained beads are dehydrated and dried, the final pellets can be obtained.

The content of the SAN resin is preferably 5 to 40% by weight based on the total weight of the matrix resin constituting the thermoplastic ABS resin composition of the present invention. If the content is less than 5% by weight, the melt strength may be lowered and the blow moldability may be deteriorated. If the content is more than 40% by weight, impact strength and workability may be deteriorated.

The weight average molecular weight of the SAN resin is preferably adjusted to be in the range of 150,000 to 200,000. If it is less than 150,000, there may be a problem in molding deflection. If it exceeds 200,000, there may be a problem in workability.

Metal-based stearate

The metal-based stearate may be used in combination of one or both of calcium stearate, magnesium stearate, aluminum stearate, potassium stearate and barium stearate, and used without further purification.

The thermoplastic ABS resin composition of the present invention may be prepared by further adding a conventional lubricant, an antioxidant, an antistatic agent, a release agent, or a UV stabilizer.

The lubricant may be ethylene bis stearamide, polyethylene oxide wax, or a combination thereof. The amount of the lubricant used is preferably 0.1 to 3 parts by weight, more preferably 0.1 to 1 part by weight based on 100 parts by weight of the thermoplastic ABS resin composition Wealth.

The antioxidant may be a phenolic antioxidant such as IR1076. The amount of the antioxidant used is preferably 0.5 to 3 parts by weight based on 100 parts by weight of the thermoplastic ABS resin composition.

The ultraviolet light stabilizer may be TINUVIN 326, which is an ultraviolet absorber, and the amount thereof is preferably 0.05 to 3 parts by weight, more preferably 0.2 to 3 parts by weight based on 100 parts by weight of the thermoplastic ABS resin composition. 1 part by weight.

The thermoplastic ABS resin composition of the present invention as described above is excellent in impact strength and gloss, and has a shrinkage ratio after molding, which is suitable for blow molding.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example

Example 1

(a-1) Production of conjugated diene-based graft copolymer

(i) Production of small-sized rubbery polymer

100 parts by weight of 1,3-butadiene, 1.2 parts by weight of potassium rosinate, 1.5 parts by weight of potassium oleate, 0.1 part by weight of sodium carbonate (Na ₂ CO ₃ ) and 0.1 part by weight of potassium hydrogencarbonate (KHCO ₃ ), 0.3 part by weight of t-dodecyl mercaptan, and 100 parts by weight of ion-exchanged water. The reaction temperature was raised to 55 DEG C, and 0.3 part by weight of potassium persulfate was added thereto to start the reaction. After reacting for 10 hours, 0.05 parts by weight of t-dodecylmercaptan was further added, reacted at 65 DEG C for 8 hours, and the reaction was terminated to prepare a small-sized rubbery polymer. The prepared small-diameter rubbery polymer had a gel content of 90%, a swelling index of 18, and an average particle diameter of about 1000 Å. The average particle size was measured by dynamic laser light scattering using an intensity Gaussian distribution (Nicomp 380).

(ii) Production of large-diameter rubbery polymer

100 parts by weight of the prepared small-diameter rubbery polymer was added to the reaction vessel, the stirring speed was adjusted to 10 rpm and the temperature was adjusted to 30 DEG C, 3.0 parts by weight of 7% acetic acid aqueous solution was gradually added thereto for 1 hour, And allowed to stand for 30 minutes to fuse a small diameter rubbery polymer to prepare a large diameter butadiene rubbery polymer. The large diameter rubbery polymer produced by the above fusion process (acid ratio conversation) was analyzed in the same manner as the small diameter rubbery polymer. At this time, the average particle size of the obtained rubbery polymer was 3100 Å, and the gel content was 90%.

(iii) Production of conjugated diene-based graft copolymer

To 100 parts by weight of the above-prepared large-diameter rubbery polymer were added 65 parts by weight of ion-exchanged water, 0.35 part by weight of potassium rosinate, 0.1 part by weight of sodium ethylenediamine tetraacetate, 0.005 part by weight of ferrous sulfate, And 0.23 parts by weight of sulfoxoxylate were collectively administered to the reaction tank, and the temperature was raised to 70 占 폚. A mixed solution of 40 parts by weight of ion-exchanged water, 0.5 part by weight of potassium rosinate, 32.0 parts by weight of styrene, 13.7 parts by weight of acrylonitrile, 0.3 parts by weight of t-dodecyl mercaptan and 0.3 parts by weight of diisopropylene hydroperoxide was dissolved in 2 10 parts by weight of ion-exchanged water, 0.1 part by weight of potassium rosinate, 16.0 parts by weight of styrene, 5.0 parts by weight of acrylonitrile, 0.1 part by weight of t-dodecyl mercaptan, and 0.1 part by weight of diisopropylene hydrosulfide And 0.1 part by weight of peroxide were continuously added for 1 hour, then the temperature was raised to 80 ° C, and the reaction was terminated by aging for another 1 hour.

At this time, the polymerization conversion was 97.5%, the solid solid content was 0.2%, and the grafting rate was 37%.

The prepared ABS graft copolymer latex was solidified with an aqueous solution of magnesium sulfate, washed, and then dried to obtain a powder.

(a-2) graft copolymer

The conjugated diene-based graft copolymer latex prepared in the above (a-1) was agglomerated with sulfuric acid, washed, and then dried to obtain a powder.

(a-3) graft copolymer

I) 25 parts by weight of a polybutadiene rubber latex having an average particle diameter of 1000 Å and a gel content of 90%, 30 parts by weight of a polybutadiene rubber latex having an average particle diameter of 3000 Å and a gel content of 90%, 10 parts by weight of styrene, 10 parts by weight of potassium lactate, 1.0 part by weight of potassium rosinate, and 75 parts by weight of ion-exchanged water were charged in a polymerization reactor. The temperature of the polymerization reactor was raised to 50 캜, and 0.1 part by weight of t- butylhydroperoxide and 0.001 part by weight of dextrose And 0.3 part by weight of tertiary dodecylmercaptan were added to initiate the polymerization reaction.

Ii) 30 minutes after the initiation of polymerization, 15 parts by weight of styrene, 10 parts by weight of acrylonitrile, 1.0 part by weight of potassium rosinate and 20 parts by weight of ion-exchanged water were mixed with the monomer emulsion And the temperature of the polymerization reactor was gradually raised to 60 DEG C while continuously feeding the reaction product of i) for 2 hours.

Iii) The monomer emulsion of the above ii) was continuously introduced, and 0.1 part by weight of t-butyl hydroperoxide was continuously added for 2 hours with the reaction product of i).

Iv) After completion of the injection of the monomer emulsion of ii) and the peroxide initiator of iii), 0.05 parts by weight of cumyl hydroperoxide, 0.001 part by weight of dextrose and 0.002 parts by weight of ferrous sulfate were collectively administered, Was heated at 75 占 폚 for 2 hours to prepare a graft ABS polymer.

The grafted ABS polymer prepared above was agglomerated with sulfuric acid to obtain the final product.

(a-4) graft copolymer

To 35 parts by weight of ethylbenzene as a reaction medium, 41 parts by weight of styrene, which is a monomer, and 13.5 parts by weight of acrylonitrile were dissolved, and 7.5 parts by weight of butadiene rubber was dissolved. Then, 5 parts by weight of polybutene having a number average molecular weight of 900, 0.02 part by weight of 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and 0.03 part by weight of t-dodecylmercaptan as a molecular weight regulator were added to prepare a polymerization solution. The solution was polymerized at 110 ° C in one step while being introduced into the reactor at a rate of 10 l / hr. Polymerization was carried out at 130 ° C in two steps, and 0.8 parts of t-dodecyl mercaptan And 99.2 parts by weight of ethylbenzene was charged at a rate of 10 l / hr. The mixture was polymerized at a temperature of 145 ° C. The unreacted monomers and the reaction medium were removed through a volatilization vessel, and the pelletized acrylonitrile -Butadiene-styrene (ABS) graft copolymer. At this time, the produced rubber particle size was 10,300 Å.

(b) AMS copolymer

The AMS copolymer was prepared by mixing 70 parts by weight of alpha-methylstyrene monomer, 6 parts by weight of styrene and 24 parts by weight of acrylonitrile monomer, 30 parts by weight of toluene as a solvent and 0.15 part by weight of di-t-dodecylmercaptan as a molecular weight regulator Then, the reactor was continuously charged in the reactor so that the average reaction time was 3 hours, and the reaction temperature was maintained at 148 占 폚. The polymerized liquid discharged from the reaction tank was heated in a preheating tank, the unreacted monomers were volatilized in a volatilization tank, and the polymer temperature was maintained at 210 ° C., and the AMS copolymer was processed into a pellet using a polymer transfer pump extrusion processing machine Respectively.

(c) SAN resin

80 parts by weight of styrene, 20 parts by weight of acrylonitrile, 100 parts by weight of distilled water, 0.5 parts by weight of benzoyl peroxide as an initiator, 0.05 parts by weight of t-butyl perbenzoate, 0.3 parts by weight of dicumylperoxide, 0.2 part by weight of phosphate and 0.5 part by weight of TDDM (Tert-Dodecyl Mercaptan) as a molecular weight regulator were charged in a reactor and the reactor was sealed. The reaction temperature was raised to 90 DEG C with stirring and after 5 hours, 10% aqueous solution of potassium persulfate, 0.2 part by weight of aqueous solution of tricalcium phosphate and 10% aqueous solution of sodium dodecylbenzenesulfonate, and the reaction temperature was maintained for 3 hours. After the reaction temperature reached 110 캜, it was maintained for 7 hours, and then cooled to 45 캜. After the acid treatment, beads were obtained, and the beads were dehydrated and dried, and then the content of acrylonitrile was 30% An acrylonitrile-styrene copolymer having a weight average molecular weight of 170,000 was obtained.

Metal-based stearic acid

The metal-based stearic acid used calcium stearate as it was without purification.

Manufacture of thermoplastic ABS resin

To 100 parts by weight of a matrix resin comprising 35% by weight of the (a-1) conjugated diene-based graft copolymer, (b) 45% by weight of an AMS copolymer, and (c) 20% by weight of a SAN resin, calcium stearate 0.3 , 0.2 parts by weight of EBA as a lubricant and 0.5 parts by weight of IR1076 as an antioxidant were added, and pellets were prepared at 230 DEG C using a twin-screw extruder.

Example 2

45% by weight of the above-prepared (a-1) conjugated diene graft copolymer prepared as in Example 1, (b) 40% by weight of the AMS copolymer, and (c) 15% Pellets were prepared in the same manner as in Example 1, except that 0.2 part by weight of calcium stearate was added to 100 parts by weight of the resin.

Comparative Example 1

A pellet was prepared in the same manner as in Example 1 except that 35% by weight of the conjugated diene-based graft copolymer (a-2) prepared above was added.

Comparative Example 2

A pellet was prepared in the same manner as in Example 1, except that 35% by weight of the conjugated diene-based graft copolymer (a-3) prepared above was added.

Comparative Example 3

10% by weight of the conjugated diene graft copolymer (a-4), 30% by weight of the conjugated diene graft copolymer (b), 45% by weight of the AMS copolymer, and (c) 15 wt%, and 0.2 part by weight of calcium stearate was added to 100 parts by weight of the matrix resin. The pellets were prepared in the same manner as in Example 1,

Comparative Example 4

10% by weight of the conjugated diene graft copolymer (a-3), 25% by weight of the conjugated diene graft copolymer (a-3), 15% by weight of the conjugated diene graft copolymer (a- , (b) 45% by weight of AMS copolymer, and (c) 5% by weight of SAN resin, and that no calcium stearate was added. .

(Performance test)

The pellets prepared in the above Examples and Comparative Examples were injected and the impact strength, flowability, pencil hardness and gloss were measured in the following manner. The results are shown in Table 1 below.

Impact strength (IMP)

It was measured according to ASTM D256.

Flowability (MI)

Measured at 220 캜 under a load of 10 kg and a speed of g / 10 min in accordance with ASTM D1238.

Mold shrinkage

A pre-designed scale was placed on both ends of the dog-bone type specimen, and the molding shrinkage ratio was measured by measuring the distance between the actual scale after injection.

Gloss

The gloss meter was measured at an angle of 45 °.

Example Comparative Example One 2 One 2 3 4 (a-1) graft copolymer 35 45 10 10 (a-2) graft copolymer 35 (a-3) graft copolymer 35 25 (a-4) graft copolymer 30 15 (b) AMS copolymer 45 40 45 45 45 45 (c) SAN resin 20 15 20 20 15 5 Calcium stearate 0.3 0.2 0.3 0.3 0.2 0 Properties Impact Strength (1/4 ") 32.5 41.7 35.3 23.1 21.5 25.7 Flowability (220 ° C / 10 kg) 4.6 4.9 4.9 3.9 3.7 3.9 Mold Shrinkage (%) 0.64 0.65 0.68 0.66 0.66 0.69 Glossiness (45 °) 97 96 96 94 63 75

As can be seen from the above Table 1, Example 1 (agglomerated with magnesium sulfate) according to the present invention has a molded shrinkage ratio of 4/1000 as compared with Comparative Example 1 using a graft copolymer agglomerated with sulfuric acid Can be confirmed.

In addition, the monomodal type according to the present invention is superior in impact strength and fluidity as compared with Comparative Example 2 using a bimodal type graft copolymer.

Further, when Example 2 according to the present invention was compared with Comparative Example 3 and Comparative Example 4, when the graft copolymer prepared by the bulk polymerization was used, the gloss decreased and when the calcium stearate was not used, It can be confirmed that the final quality of the product is affected. In addition, in Comparative Example 3 and Comparative Example 4, compared with Example 2, it was confirmed that the flowability was lowered and the workability was relatively lowered.

The thermoplastic ABS resin composition according to the present invention is excellent in impact strength and gloss, and has a post-deformation and shrinkage ratio after blow molding, which is advantageous in that the defective ratio can be remarkably reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. .

Claims (9)

Wherein the matrix resin comprises (a) a monomodal conjugated diene-based rubber polymer having an average particle diameter of 2500 to 5000 Å, and a vinyl aromatic compound and a vinyl cyanide compound are grafted together with 100 parts by weight of the matrix resin and 0.01 to 2 parts by weight of a metallic stearate, From 30 to 50% by weight of a graft copolymer which is polymerized and aggregated with a flocculant selected from the group consisting of magnesium sulfate, calcium chloride, aluminum sulfate or a mixture of two or more thereof; (b) from 30 to 60% by weight of AMS copolymer; And (c) 5 to 40% by weight of a SAN resin having a weight average molecular weight of 150,000 to 200,000 and a flow index (220 DEG C / 10 kg) of 8 to 12. The method according to claim 1,
Wherein the graft copolymer (a) is contained in an amount of 30 to 60 parts by weight of a vinyl aromatic compound and 10 to 30 parts by weight of a vinyl cyan compound, based on 100 parts by weight of the conjugated diene rubber polymer. The method according to claim 1,
Wherein the conjugated diene-based rubbery polymer of (a) is a polymer of a conjugated diene monomer selected from the group consisting of butadiene, isoprene, chloroisoprene, and a mixture of two or more thereof. The method according to claim 1,
Wherein the vinyl aromatic compound constituting the SAN resin of (a) and the SAN resin of (c) is at least one selected from the group consisting of styrene, alpha-methylstyrene and para-methylstyrene. Composition. The method according to claim 1,
Wherein the graft copolymer of (a) and the vinyl cyan compound constituting the SAN resin of (c) are at least one selected from the group consisting of acrylonitrile, methacrylonitrile and ethacrylonitrile. Resin composition. The method according to claim 1,
Wherein the AMS copolymer (b) is a copolymer of 45 to 75 parts by weight of alpha-methylstyrene, 5 to 10 parts by weight of a vinyl aromatic compound, and 20 to 45 parts by weight of a vinyl cyan compound. The method according to claim 1,
Wherein the SAN resin (c) is a copolymer of 70 to 95 parts by weight of a vinyl aromatic compound and 5 to 30 parts by weight of a vinyl cyan compound. The method according to claim 1,
Wherein the metal-based stearate is selected from the group consisting of calcium stearate, magnesium stearate, aluminum stearate, potassium stearate, barium stearate, and a mixture of two or more thereof. The method according to claim 1,
Wherein the thermoplastic ABS resin composition further comprises at least one additive selected from the group consisting of a lubricant, an antioxidant, an antistatic agent, a release agent, and a UV stabilizer.