KR101520341B1 - Method for preparing graft-copolymer latex having excellent glossiness and dispersibility - Google Patents

Abstract

One embodiment of the present invention relates to an emulsion polymerization process for graft-polymerizing a monomer mixture to a rubber latex, comprising the steps of: (a) charging 45 to 55 parts by weight of a conjugated diene rubber latex having an average particle diameter of 0.06 to 0.15 탆 into a reactor ; (b) 1 to 15% by weight of an aromatic vinyl compound and a vinyl cyan compound in a proportion of 40 to 60 parts by weight of a monomer mixture mixed at a weight ratio of 70 to 80: 20 to 30 to the reactor, 20 to 40% By weight, 10 to 30% by weight in 0.1 to 2.0 parts by weight of an emulsifier, and 0.051 to 0.51 part by weight of an activator in a batch or continuously; And (c) continuously adding the remaining amount of the monomer mixture, the polymerization initiator, and the emulsifier to the reactor and reacting the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graft copolymer latex having excellent gloss and dispersibility,

The present invention relates to a process for producing a graft copolymer latex, and more particularly, to a process for producing a graft copolymer latex which can improve gloss characteristics, dispersibility, and mechanical properties of a thermoplastic resin produced using the latex .

ABS (acrylonitrile-butadiene-styrene) resin is excellent in mechanical properties, colorability, and moldability, and is widely used for housings, toys, office equipment, automobiles, and the like of various electronic products including home appliances such as refrigerators and washing machines. In addition, as the importance of interior and design has increased in household appliances and automobile products, ABS resins with various properties have been developed, one of which is given the glossiness of ABS resin.

Examples of the method for producing such an ABS resin include a method in which a rubber component is dissolved in acrylonitrile, styrene and a solvent to effect solution polymerization in order to disperse a rubber component in an acrylonitrile-styrene resin, and a method in which a rubber latex A method has been proposed in which a graft copolymer is prepared by graft-polymerizing acrylonitrile and styrene, and mixed with an ABS resin produced by separate solution polymerization.

The ABS resin is usually prepared by blending a graft copolymer obtained by copolymerizing one or two or more monomers with a rubber latex produced by an emulsion polymerization method and a styrenic copolymer prepared by bulk polymerization or solution polymerization.

On the other hand, as a method for imparting the ABS resin with a gloss characteristic, there has been proposed a method of using an ABS resin having a particle diameter smaller than the rubber particle size of an ordinary ABS resin.

Korean Patent Laid-Open Publication No. 10-1997-0027131 discloses a method for producing a thermoplastic resin having a graft body in which a mixture of small-particle-size rubber latex and large-volume inorganic rubber latex is mixed at a certain ratio. However, the graft ratio The aggregation phenomenon may occur, and as the rubber particles become larger, the surface gloss of the final product may be lowered and the thermal stability may be lowered.

In addition, when grafted ABS resin is produced by mixing small amount of rubber latex and large amount of rubber latex at a certain ratio, it is necessary to obtain a product having a single mixing ratio. Therefore, And there is a problem that the graft ratio is decreased due to the use of an excess amount of the rubber latex and the molecular weight regulator during the production of the latex, and the gloss characteristics of the ABS resin as the final product may be deteriorated.

KR 10-1997-0027131 A

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a rubber latex having a high graft rate, To provide high-gloss characteristics, and to provide a method for producing a graft copolymer latex which does not deteriorate gloss characteristics and discoloration even in a high-temperature molding process.

In order to accomplish the above object, in one embodiment of the present invention, there is provided an emulsion polymerization process for graft polymerizing a monomer mixture to a rubber latex, comprising the steps of: (a) mixing a conjugated diene rubber latex 45 having an average particle diameter of 0.06 to 0.15 ≪ / RTI > to 55 parts by weight; (b) 1 to 15% by weight of an aromatic vinyl compound and a vinyl cyan compound in a proportion of 40 to 60 parts by weight of a monomer mixture mixed at a weight ratio of 70 to 80: 20 to 30 to the reactor, 20 to 40% By weight, 10 to 30% by weight in 0.1 to 2.0 parts by weight of an emulsifier, and 0.051 to 0.51 part by weight of an activator in a batch or continuously; And (c) continuously adding the remaining amount of the monomer mixture, the polymerization initiator, and the emulsifier to the reactor and reacting the same.

In one embodiment, the conjugated diene rubber latex may be a butadiene rubber latex having a gel content of 85 to 95% by weight.

In one embodiment, the temperatures of the reactor in steps (a) to (c) are Ta, Tb, and Tc, Ta is 50 to 70 ° C, Tb is 60 to 75 ° C, 80 deg. C, and a relation of Ta < Tb < Tc can be satisfied.

In one embodiment, the aromatic vinyl compound may be at least one selected from the group consisting of styrene, alphamethylstyrene, alphaethylstyrene, paramethylstyrene, and vinyltoluene.

In one embodiment, the vinyl cyan compound may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile.

In one embodiment, the monomer mixture is selected from the group consisting of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-phenylmaleimide, methylmethacrylate, methyl acrylate, butyl acrylate, Acrylic acid, and maleic anhydride. The vinyl monomer may further contain one or more vinyl monomers selected from the group consisting of acrylic acid, maleic acid, acrylic acid, and maleic anhydride.

In one embodiment, the polymerization initiator may be a hydroperoxide-based initiator.

In one embodiment, the hydroperoxide-based initiator is selected from the group consisting of tertiary butyl hydroperoxide, cumene hydroperoxide, isopropylbenzene hydroperoxide, potassium persulfate, sodium persulfate, and ammonium persulfate. Lt; / RTI &gt;

In one embodiment, the emulsifier may be one or more selected from the group consisting of fatty acid soaps, rosin acids, or alkali salts of oleic acid, alkylaryl sulfonates, alkaline methyl alkyl sulfates, and sulfonated alkyl esters.

In one embodiment, the activator may be one or more selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium pyrophosphate, and sodium sulfate .

In one embodiment, the grafting rate of the graft copolymer latex can be 65-90%.

In one embodiment, the step (c) may further include (d) reacting the product of step (c) at a temperature of 65 to 80 ° C for 30 to 120 minutes.

According to one embodiment of the present invention, graft copolymer latex having a high graft rate and inhibited aggregation between rubber latex particles can be produced by controlling the content of the conjugated diene rubber latex without the administration of the molecular weight modifier.

In addition, when the thermoplastic resin is prepared using the graft copolymer latex thus prepared, the graft copolymer latex has excellent dispersibility in the SAN matrix, so that the retention gloss does not deteriorate even under high temperature molding conditions, A thermoplastic resin imparted with thermal stability can be produced.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a schematic view of a method for producing a graft copolymer latex according to an embodiment of the present invention.
FIG. 2 is a schematic view illustrating a method for producing a graft copolymer latex according to another embodiment of the present invention.
FIG. 3 is a graphical representation of the results of physical property tests on the graft copolymer latex prepared according to the process for producing a graft copolymer latex according to an embodiment of the present invention and the thermoplastic resin prepared using the latex.
FIG. 4 is a microscopic image of a graft copolymer latex prepared according to a method of producing a graft copolymer latex according to an embodiment of the present invention and a comparative example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "indirectly connected" . Also, when an element is referred to as "comprising &quot;, it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Graft  Method for producing copolymer latex

1 is a schematic view of a method for producing a graft copolymer latex according to an embodiment of the present invention.

(A) 45 to 55 parts by weight of a conjugated diene rubber latex having an average particle diameter of 0.06 to 0.15 占 퐉 are charged into a reactor in accordance with an embodiment of the present invention in an emulsion polymerization process in which a monomer mixture is graft-polymerized in a rubber latex ; (b) 1 to 15% by weight of an aromatic vinyl compound and a vinyl cyan compound in a proportion of 40 to 60 parts by weight of a monomer mixture mixed at a weight ratio of 70 to 80: 20 to 30 to the reactor, 20 to 40% By weight, 10 to 30% by weight in 0.1 to 2.0 parts by weight of an emulsifier, and 0.051 to 0.51 part by weight of an activator in a batch or continuously; And (c) continuously adding the remaining amount of the monomer mixture, the polymerization initiator, and the emulsifier to the reactor and reacting the monomer mixture, the polymerization initiator, and the emulsifier.

In the step (a), the conjugated diene rubber latex may have an average particle diameter of 0.06 to 0.15 탆, and preferably 0.08 to 0.11 탆. If the average particle diameter is less than 0.06 mu m, the rubber particles become too small and the graft rate may be lowered. If the average particle diameter is more than 0.15 mu m, the gloss may be lowered due to excessively large rubber particles.

The content of the conjugated diene rubber latex may be 45 to 55 parts by weight. If the content of the conjugated diene rubber latex is less than 45 parts by weight, the rubber latex content may be lowered and the impact strength may be lowered. If the content is more than 55 parts by weight, the graft ratio may be lowered due to a high rubber latex content.

The administration time of the conjugated diene rubber latex is preferably within 20 minutes, preferably within 10 minutes, so as to improve the productivity by shortening the reaction time in the following step and the time required for preparing the graft copolymer latex .

In one embodiment, the conjugated diene rubber latex may be a butadiene rubber latex having a gel content of 85 to 95% by weight. If the gel content of the conjugated diene rubber latex is less than 85% by weight, mechanical properties may deteriorate as the graft rate decreases. If the gel content exceeds 95% by weight, the glass transition temperature (Tg) may increase and the impact strength may decrease.

The conjugated diene rubber may be a butadiene rubber, and preferably a 1,3-butadiene rubber.

In the step (b), the monomer mixture may be a mixture of the aromatic vinyl compound and the vinyl cyan compound in a weight ratio of 70 to 80: 20 to 30. When the mixing ratio of the monomer mixture is out of the above range, mixing with SAN resin produced by bulk polymerization or solution polymerization is difficult, and the impact strength may be significantly lowered. The gloss of the resin may be lowered.

In one embodiment, the aromatic vinyl compound may be at least one member selected from the group consisting of styrene, alphamethylstyrene, alphaethylstyrene, paramethylstyrene, and vinyltoluene, and preferably styrene. It is not.

In one embodiment, the vinyl cyan compound may be one or more selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile, and preferably acrylonitrile, no.

In one embodiment, the monomer mixture is selected from the group consisting of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-phenylmaleimide, methylmethacrylate, methyl acrylate, butyl acrylate, Acrylic acid, and maleic anhydride, but the present invention is not limited thereto.

In the above steps (b) to (c), 40 to 60 parts by weight of the monomer mixture may be used, and 1 to 15% by weight of the monomer mixture may be added to the reactor. If the amount of the monomer mixture is less than 1 wt%, the mechanical properties may be deteriorated. If the amount of the monomer mixture is more than 15 wt%, it may be difficult to control the reaction heat.

In the step (b) to (c), 0.1 to 0.2 parts by weight of the polymerization initiator may be used, and 20 to 40% by weight of the polymerization initiator may be added to the reactor in the step (b). If the amount of the polymerization initiator is less than 20% by weight, the graft ratio may be lowered. If the amount of the polymerization initiator is more than 40% by weight, a low molecular weight graft copolymer may be produced and mechanical properties may be deteriorated.

In one embodiment, the polymerization initiator may be a hydroperoxide-based initiator.

In one embodiment, the hydroperoxide-based initiator is selected from the group consisting of tertiary butyl hydroperoxide, cumene hydroperoxide, isopropylbenzene hydroperoxide, potassium persulfate, sodium persulfate, and ammonium persulfate. And preferably is tertiary butyl hydroperoxide, but is not limited thereto.

The emulsifier may be used in an amount of 0.1 to 2.0 parts by weight, and 10 to 30% by weight of the emulsifier may be added to the reactor in the step (b). If the amount of the emulsifier is less than 10% by weight in the step (b), coagulation may occur between the rubber particles and the gloss may be lowered. If the amount is more than 30% by weight, mechanical properties may be deteriorated.

In one embodiment, the emulsifier may be at least one selected from the group consisting of fatty acid soap, rosin acid or alkali salts of oleic acid, alkylaryl sulfonates, alkaline methyl alkyl sulfates, and sulfonated alkyl esters, May be an alkali salt of oleic acid, more preferably potassium oleate, but is not limited thereto.

In the step (b), the activator may be used in an amount of 0.051 to 0.51 parts by weight, and preferably the activator is 0.03 to 0.3 parts by weight of lactose, 0.02 to 0.2 parts by weight of sodium pyrophosphate, 0.001 to 0.01 part by weight.

If the dose of the activator is out of the above range, it may be difficult to balance the mechanical properties of the final product. The activating agent may be used together with the hydroperoxide-based initiator to cause a graft polymerization reaction even at a temperature of 50 ° C or lower, and may accelerate the graft polymerization reaction or improve the grafting rate depending on the amount used.

In one embodiment, the activator may be one or more selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium pyrophosphate, and sodium sulfate, , But is not limited thereto.

On the other hand, in the step (b), the reactant containing the monomer mixture, the polymerization initiator, the emulsifier, and the activator may be administered in a batch or continuously to the reactor, And some of them can generate an intermediate product and can be administered in a batch so as to smoothly induce continuous graft polymerization reaction thereafter.

In the step (b), the graft polymerization reaction may be continued for 10 to 60 minutes. If it is less than 10 minutes, it is difficult to obtain an intermediate product in an amount required for subsequent continuous reaction. If it exceeds 60 minutes, Side reaction may occur and unnecessary by-products may be generated.

In the step (c), the step (b) is terminated and the remaining amount of the monomer mixture, the polymerization initiator, and the emulsifier is continuously added to the product of step (b) for 5 to 6 hours to react.

The respective components usable in the step (c) may be the same as those used in the step (b).

Meanwhile, the process for preparing the graft copolymer latex according to an embodiment of the present invention is characterized in that no additional molecular weight regulator is used.

Generally, when preparing a large-diameter graft copolymer latex having an average particle diameter of 0.25 to 0.4 μm, a molecular weight modifier, in particular, a mercaptan molecular weight modifier, is used.

However, when the graft copolymer latex having an average particle diameter of 0.20 占 퐉 or less, preferably 0.15 占 퐉 or less, is used, when the mercaptan molecular weight modifier is used, a chain transfer reaction of the polymer chain is caused to lower the graft rate The method of preparing the graft copolymer latex according to an embodiment of the present invention does not use any molecular weight regulator.

In one embodiment, the temperatures of the reactor in steps (a) to (c) are Ta, Tb, and Tc, Ta is 50 to 70 ° C, Tb is 60 to 75 ° C, 80 deg. C, and a relation of Ta < Tb < Tc can be satisfied.

In the step (a), the temperature (Ta) of the reactor may be maintained at 50 to 70 ° C through a heat exchanger. If the temperature Ta is less than 50 캜, the reaction time may become long due to a low charging temperature. If the temperature Ta is higher than 70 캜, the latex may solidify due to high temperature at the time of charging.

In the step (b), the temperature (Tb) of the reactor may be maintained at 60 to 75 ° C through a heat exchanger. When the temperature Tb is less than 60 ° C, the graft polymerization reaction between the monomer mixture and the monomer mixture which is administered in a batch or continuously with the graft copolymer latex is difficult to start within a relatively short time (10 to 60 minutes) due to a low reaction temperature, Lt; 0 &gt; C, it may be difficult to control the process due to excessive reaction heat in the subsequent step.

In the step (c), the temperature (Tc) of the reactor may be maintained at 65 to 80 ° C through a heat exchanger. If the temperature Tc is lower than 65 ° C, the graft polymerization of the monomer mixture continuously administered due to the low reaction temperature may not be smoothly performed, and the graft rate may be lowered. If the temperature Tc is higher than 80 ° C, have.

Meanwhile, in the above steps (a) to (c), the temperature of the reactor may be gradually increased in each step, so that the relationship Ta <Tb <Tc can be satisfied.

In the step (a), the conjugated diene rubber latex is injected into the reactor alone, and the temperature of the reactor can be kept relatively low in the range of 50 to 70 ° C because no other reactant is administered.

Wherein the step (b) comprises the step of subjecting the conjugated diene rubber latex to a batch administration or a continuous administration of a reactant including the monomer mixture, wherein the conjugated diene rubber latex has a heat level sufficient to initiate a reaction between the conjugated diene rubber latex and the other reactant The temperature of the reactor may be raised to a range of 60 to 75 ° C.

Wherein the step (c) is a step of continuously supplying the remaining amount of the reactant in a state in which the reaction between the conjugated diene rubber latex and the reactant including the monomer mixture is started, wherein a sufficient level of heat The temperature of the reactor may be further raised to a range of 65 to 80 ° C.

In one embodiment, the grafting rate of the graft copolymer latex can be 65-90%. If the graft ratio of the graft copolymer latex is less than 65%, the gloss may be deteriorated due to the agglomeration phenomenon between the rubber particles. If the graft ratio is more than 90%, the kneading property with the large graft copolymer in the preparation of the thermoplastic resin The mechanical properties of the final product may be deteriorated.

FIG. 2 is a schematic view illustrating a method for producing a graft copolymer latex according to another embodiment of the present invention.

In one embodiment, the step (c) may further include (d) reacting the product of step (c) at a temperature of 65 to 80 ° C for 30 to 120 minutes.

In step (d), the product of step (c) may be further polymerized at a temperature of 65 to 80 ° C for 30 to 120 minutes to remove the unreacted monomer mixture in step (c) The reaction can be terminated when the polymerization conversion rate is 99% or more.

Thereafter, the graft copolymer latex is mixed with an antioxidant and coagulated with a conventional coagulant such as sulfuric acid, magnesium sulfate, calcium chloride or aluminum sulfate, and then washed, dehydrated and dried to obtain a graft copolymer .

The final graft ratio of the graft copolymer latex prepared according to the above production method may be 65% or more, and preferably 75 to 85%.

The weight average molecular weight (Mw) of the grafted SAN of the graft copolymer latex prepared according to the above-described method may be 60,000 to 80,000, and preferably 65,000 to 70,000. If the weight average molecular weight (Mw) of the grafted SAN is less than 60,000, a low molecular weight graft copolymer may be produced and mechanical properties may be deteriorated. If the weight average molecular weight is over 80,000, a long chain graft copolymer may be produced, And the gloss characteristics of the ABS resin, which is the final product, may be deteriorated.

Thermoplastic resin composition

According to one embodiment of the present invention, there is provided a process for producing a graft copolymer, which comprises: (a) a graft copolymer in powder form prepared by the above production process, (b) a graft copolymer in an emulsion state in powder form, and There is provided a thermoplastic resin composition comprising a SAN resin.

The above a) and b) may be mixed at a weight ratio of 5: 5, but the present invention is not limited thereto and the proportion thereof can be controlled according to the use of the final product, so that the physical properties of the product can be diversified according to the application.

As the ratio of (a) increases, the gloss and coloring property of the product may be improved, but mechanical properties such as impact strength may be deteriorated. When the ratio of (b) increases, the mechanical properties are improved, Can be degraded.

Hereinafter, embodiments of the present invention will be described in detail.

Example

50 parts by weight of a butadiene rubber latex having an average particle diameter of 0.09 mu m and a gel content of 88 wt% was introduced into a nitrogen-pumped polymerization reactor through a heat exchanger at 55 DEG C, and the mixture was heated to 68 DEG C and held therein. Then, 1.9 parts by weight of styrene, 0.6 parts by weight of nitrile, 0.05 part by weight of tertiary butyl hydroperoxide, 0.22 parts by weight of oleic acid emulsifier, 0.12 part by weight of activated lactose, 0.025 part by weight of sodium pyrophosphate and 0.001 part by weight of ferrous sulfate were mixed and mixed The reaction was continued for a minute.

Thereafter, 35.6 parts by weight of styrene, 11.9 parts by weight of acrylonitrile, 1.14 parts by weight of oleic acid emulsifier, and 0.138 parts by weight of tertiary butyl hydroperoxide were continuously injected for 360 minutes. At this time, the reaction temperature was raised from 68 占 폚 to 75 占 폚. After the continuous administration, the reaction was further continued at 75 DEG C for 120 minutes.

0.9 parts by weight of an antioxidant was mixed with the prepared graft copolymer latex, and the resultant was coagulated with MgSO ₄ and dried to obtain a graft copolymer resin having a small particle size.

The graft ratio of the graft latex having a small particle size was obtained by dissolving 2 g of the graft copolymer resin in powder form in 100 mL of acetone for 24 hours to dissolve the grafted styrene copolymer in the rubber component and then separating the gel and the sol by a centrifugal separator Was calculated according to the following equation (1).

[Equation 1]

Graft rate (%) = {(weight of grafted SAN) / (weight of butadiene rubber)} 100

Comparative Example  One

Butadiene rubber latex was added in an amount of 60 parts by weight to prepare a graft copolymer.

Comparative Example  2

The graft copolymer was prepared in the same manner as in the Example except that the molecular weight modifier of t-dodecyl mercaptan (TDM) was added during the continuous administration of the monomer mixture.

Comparative Example  3

The graft copolymer was prepared in the same manner as in Example except that the polymerization was carried out at a reaction temperature of 64 캜 in the continuous administration step of the monomer mixture.

Comparative Example  4

A graft copolymer was prepared in the same manner as in Example except that 0.38 part by weight of a potassium persulfate initiator was added all at once in the reaction initiation step without using a hydroperoxide redox initiator as a polymerization initiator.

Comparative Example  5

A graft copolymer was prepared in the same manner as in Example except that the proportion of the monomer mixture used in the reaction initiation step was 16 wt% based on the total weight of the monomer mixture.

On the other hand, ABS resin prepared for measuring gloss and thermal stability characteristics was prepared by mixing 14 parts by weight of small particle size graft latex Powder according to the above Examples and Comparative Examples 1 to 5, 100 parts by weight of large graft latex Powder 14 And 72 parts by weight of Bulk SAN resin were mixed and reacted, and then extruded to prepare a thermoplastic resin specimen.

The above-mentioned large-volume rubber latex is prepared by administering a butadiene rubber latex having an average diameter of less than 0.25 to 0.40 탆 through a heat exchanger at 50 to 70 캜, adding a monomer mixture composed of an aromatic vinyl compound and a vinyl cyan compound, Initiating the reaction by collectively administering a toxic initiator, an activator, an emulsifier, and a molecular weight regulator; Adding all the additives of the above step and simultaneously reacting the reactant with a monomer consisting of an aromatic vinyl compound and a vinyl cyan compound, a hydroperoxide-based redox initiator, and an emulsifier; And maintaining the reaction product in the above step at 75 DEG C or higher, and further allowing the reaction time to be reached.

The graft copolymer of the present invention may have a graft rate of 30 to 40%, and HR181 of Kumho Petrochemical may be used as a large graft powder to be used.

The monomer mixture used in the production of the thermoplastic resin may generally comprise 20 to 40 parts by weight of a vinyl cyanide compound and 60 to 80 parts by weight of an aromatic vinyl compound, (Mw) of 120,000 to 160,000 can be used. The available Bulk SAN resin is SAN326 from Kumho Petrochemical.

The graft ratio, impact strength, tensile strength, surface gloss, and thermal stability of the small particle size graft copolymer powder prepared according to the above Examples and Comparative Examples 1 to 5 and the thermoplastic resin specimen prepared using the small particle size graft copolymer powder were measured , And the results are shown in Table 1 below.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 BD rubber
Latex content
(Parts by weight) 50 60 50 50 50 50 Polymerization temperature
(° C) 68 68 68 64 68 68 Polymerization initiator Hydro
Peroxide Hydro
Peroxide Hydro
Peroxide Hydro
Peroxide Potassium
Persulfate Hydro
Peroxide Molecular weight regulator
(TDM, parts by weight) 0 0 0.2 0 0 0 Initiation step monomer content
(weight%) 5 5 5 5 5 16 Graft rate
(%) 80.9 54.5 70 65 70 73 Grafted
SAN molecular weight
(Mw) 68,000 70,000 67,000 98,000 80,000 73,000 Izod
Impact strength
(1/4 ", kg · cm / cm) 17 16 17 18 18 17 The tensile strength
(kg / cm ² ) 485 490 477 470 480 482 Surface gloss
(gloss) 103 93 99 97 100 100 Injection stay gloss
(Δgloss) 2.5 10.2 4.3 8.5 5 3.8 Injection stay
Thermal stability
(ΔE) 2.19 3.2 2.55 3.2 2.45 2.45

Izod Impact Strength: Measured according to the method of ASTM D256. At this time, the thickness of the specimen was 1/4 inch.

Tensile Strength: Measured according to the method of ASTM D638.

- Surface gloss: The ABS resin is made of 7 cm × 5 cm color chip specimen and the gloss is measured at an angle of 60 °. The higher the value, the better the gloss.

- Injection stay gloss: The difference in glossiness before and after retention of the molded specimen after the resin stay in the screw of the injection molding machine set at 240 캜 for 10 minutes. The smaller the difference, the better the glossiness. And exhibits a uniform glossiness as a whole.

- Injection stability thermal stability: The resin was retained for 10 minutes in an extruder screw set at 240 DEG C, and then the molded specimen was subjected to a color change degree as shown in the following equation (2) based on CIE 1976 L * a * b * color difference (? E), where? E is the difference between the color values before and after the stay, and the closer the value is to 0, the better the thermal stability.

&Quot; (2) &quot;

ΔE = [(L-L ' ) 2 + (a-a') 2 + (b-b ') 2] 1/2, (L: brightness index, a, b: perception chromaticity index)

FIG. 3 is a graphical representation of the results of physical properties of a graft copolymer and a thermoplastic resin prepared according to the process for producing a graft copolymer latex according to an embodiment of the present invention.

The graft copolymer latex prepared according to the above example and the thermoplastic resin prepared using the latex had a significantly higher graft rate (80.9%) than the comparative examples 1 to 5, an injection resisting gloss (2.5) and an injection resisting thermal stability (2.19) was measured to be low, it was found to have excellent gloss characteristics and thermal stability even under high temperature molding conditions.

FIG. 4 is a microscopic image of a graft copolymer latex prepared according to a method of producing a graft copolymer latex according to an embodiment of the present invention and a comparative example. 4, it was confirmed that the graft copolymer latex prepared according to the above example was greatly improved in the agglomeration phenomenon between the rubber particles as compared with the rubber latex prepared according to Comparative Example 2 using TDM as a molecular weight modifier.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (12)

In an emulsion polymerization process for graft-polymerizing a monomer mixture to a rubber latex,
(a) charging 45 to 55 parts by weight of a conjugated diene rubber latex having an average particle diameter of 0.06 to 0.15 占 퐉 into a reactor;
(b) 1 to 15% by weight of an aromatic vinyl compound and a vinyl cyan compound in 40 to 60 parts by weight of a monomer mixture mixed at a weight ratio of 70 to 80: 20 to 30, (b) 40 to 40% by weight of the emulsifier, 10 to 30% by weight of the emulsifier and 0.1 to 2.0% by weight of the emulsifier, and 0.051 to 0.51 part by weight of the activator; And
(c) continuously adding the remaining amount of the monomer mixture, the polymerization initiator, and the emulsifier to the reactor and reacting,
Wherein the temperature of the reactor in the steps (a) to (c) is Ta, Tb, and Tc, respectively, and Ta <Tb <Tc.
The process for producing a graft copolymer latex according to claim 1, wherein the conjugated diene rubber latex is a butadiene rubber latex having a gel content of 85 to 95% by weight.
The method of claim 1, wherein the Ta, Tb, and Tc are 50 to 70 ° C, 60 to 75 ° C, and 65 to 80 ° C, respectively.
The process for producing a graft copolymer latex according to claim 1, wherein the aromatic vinyl compound is at least one selected from the group consisting of styrene, alpha methyl styrene, alpha ethyl styrene, para methyl styrene, and vinyl toluene.
The process for producing a graft copolymer latex according to claim 1, wherein the vinyl cyan compound is at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile.
2. The composition of claim 1, wherein the monomer mixture is selected from the group consisting of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-phenylmaleimide, methylmethacrylate, methyl acrylate, Wherein the graft copolymer latex further comprises at least one vinyl monomer selected from the group consisting of acrylic acid, maleic anhydride, acrylic acid, and maleic anhydride.
The process for producing a graft copolymer latex according to claim 1, wherein the polymerization initiator is a hydroperoxide-based initiator.
The method of claim 7, wherein the hydroperoxide-based initiator is selected from the group consisting of tertiary butyl hydroperoxide, cumene hydroperoxide, isopropylbenzene hydroperoxide, potassium persulfate, sodium persulfate, and ammonium persulfate. By weight based on the weight of the graft copolymer latex.
The composition according to claim 1, wherein the emulsifier is at least one selected from the group consisting of fatty acid soap, rosin acid, or alkali salts of oleic acid, alkylaryl sulfonates, alkaline methyl alkyl sulfates, and sulfonated alkyl esters , A method for producing a graft copolymer latex.
The method of claim 1, wherein the activator is at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, lactose, dextrose, sodium pyrophosphate, and sodium sulfate By weight of the graft copolymer latex.
The process for producing a graft copolymer latex according to claim 1, wherein the graft copolymer latex has a graft ratio of 65 to 90%.
The method according to any one of claims 1 to 11, further comprising the step (d) of reacting the product of step (c) at a temperature of 65 to 80 ° C for 30 to 120 minutes after step (c) &Lt; / RTI &gt; wherein the graft copolymer latex is a graft copolymer latex.

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