KR102465134B1 - Method for preparing graft copolymer - Google Patents

Abstract

The present invention is a primary thickening step of preparing an enlarged diene-based rubbery polymer by adding a coagulant to the diene-based rubbery polymer; a first copolymerization step of preparing a first copolymer by adding and copolymerizing the enlarged diene-based rubbery polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer; a second thickening step of preparing an enlarged second copolymer by adding a coagulant to the first copolymer; and a secondary copolymerization step of copolymerizing the second copolymer, wherein the coagulant is a (meth) acrylate-based monomer and a carboxylic acid-based monomer. it's about

Description

Method for producing a graft copolymer {METHOD FOR PREPARING GRAFT COPOLYMER}

The present invention relates to a method for producing a graft copolymer, and more particularly, to a method for producing a graft copolymer having excellent impact resistance.

The acrylonitrile-butadiene-styrene copolymer (ABS copolymer) is a thermoplastic copolymer, prepared by graft copolymerization of styrene and acrylonitrile to butadiene rubbery polymer.

ABS copolymer has excellent physical properties such as high impact resistance, chemical resistance, thermal stability, colorability, fatigue resistance, rigidity, and workability compared to conventional high-impact polystyrene (HIPS), and of these, processability is particularly excellent. do. Due to these characteristics, the ABS copolymer can be used in interior and exterior materials for automobiles, office equipment, parts of various electric and electronic products, or toys.

On the other hand, in order to prepare an ABS copolymer having excellent impact resistance, the particle size of the diene-based rubber polymer must be appropriately adjusted. In general, when the average particle diameter is 0.25 to 0.5 μm, the surface gloss property is not deteriorated and excellent impact resistance is obtained. can be implemented However, when the diene-based rubbery polymer having the above-described average particle diameter is prepared by emulsion polymerization, the polymerization time is too long, resulting in poor productivity. Accordingly, after preparing a diene-based rubbery polymer having an average particle diameter of about 0.1 μm, a method of enlarging the diene-based rubbery polymer using a coagulant has been proposed. However, when acetic acid is used as a coagulant during hypertrophy, excess agglomerates are generated, and in order to reduce the generation of agglomerates, lowering the concentration of the diene-based rubbery polymer latex causes a problem in that productivity is lowered. In order to solve this problem, a method of using a copolymer containing an acid group and having a core-shell structure as a coagulant has been proposed. There was a problem of degradation.

KR2004-0147655A

The present invention is to solve the above problems, and to provide a method for producing a graft copolymer having excellent productivity, excellent impact resistance, and excellent latex stability.

In order to solve the above-mentioned problem, the present invention is a first enlarged step of preparing a diene-based rubbery polymer by adding a coagulant to the diene-based rubbery polymer; a first copolymerization step of preparing a first copolymer by adding and copolymerizing the enlarged diene-based rubbery polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer; a second thickening step of preparing an enlarged second copolymer by adding a coagulant to the first copolymer; and a secondary copolymerization step of copolymerizing the second copolymer, wherein the coagulant is a (meth) acrylate-based monomer and a method for producing a graft copolymer comprising a copolymer of a monomer mixture including a carboxylic acid-based monomer. to provide.

According to the manufacturing method of the graft copolymer of the present invention, it is possible to prepare a graft copolymer having excellent stability as well as excellent impact resistance of the diene-based rubbery polymer latex and the graft copolymer latex.

Hereinafter, the present invention will be described in more detail to help the understanding of the present invention.

The terms or words used in the present specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present invention, the average particle diameter of the diene-based rubber polymer, the graft copolymer, and the copolymer included in the coagulant can be measured using a dynamic light scattering method, and specifically, Nicomp 380 equipment (product name, manufacturer: Nicomp) ) can be used to measure

In the present specification, the average particle diameter may mean an arithmetic average particle diameter in a particle size distribution measured by a dynamic light scattering method, that is, an average particle diameter of scattering intensity.

In the present invention, the weight average molecular weight can be measured as a relative value with respect to a standard PS (standard polystyrene) sample through GPC (Gel Permeation Chromatography, waters breeze) using THF (tetrahydrofuran) as an eluent.

In the present invention, the polymerization conversion rate refers to the polymerization rate of the monomers input in the method for preparing the graft copolymer, that is, the degree to which the monomers are polymerized to form the copolymer, that is, the shell, and can be calculated by the following formula.

Polymerization conversion (%) = {(Total weight of rubber polymer and monomers added during preparation of graft copolymer) - (Total weight of unreacted monomers)}/(Total of rubber polymer and monomers added during preparation of graft copolymer weight) x 100

In the present invention, the aromatic vinyl-based monomer may be at least one selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene, among which styrene is preferable. In the present invention, the aromatic vinyl-based unit may mean a unit derived from an aromatic vinyl-based monomer.

In the present invention, the vinyl cyan-based monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile and α-chloroacrylonitrile, of which acrylonitrile This is preferable. In the present invention, the vinyl cyan-based unit may mean a unit derived from a vinyl cyan-based monomer.

In the present invention, the (meth)acrylate-based monomer may be a C ₁ to C ₄ alkyl (meth)acrylate-based monomer. The C ₁ to C ₄ alkyl (meth) acrylate-based monomer is selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and n-butyl (meth) acrylate and at least one selected from the group consisting of ethyl (meth)acrylate and n-butyl (meth)acrylate, among them, is preferable. In the present invention, the (meth)acrylate-based unit may mean a unit derived from a (meth)acrylate-based monomer.

In the present invention, the carboxylic acid-based monomer may be at least one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumiric acid, and maleic acid, of which methacrylic acid is preferable. In the present invention, the carboxylic acid-based unit may be a unit derived from a carboxylic acid-based monomer.

In the present invention, the input amount of the diene-based rubbery polymer and the coagulant may be based on the solid content.

One. graft Method for preparing copolymer

The method for producing a graft copolymer according to an embodiment of the present invention includes: 1) a primary thickening step of preparing an enlarged diene-based rubbery polymer by adding a coagulant to the diene-based rubbery polymer; 2) a first copolymerization step of preparing a first copolymer by adding and copolymerizing the enlarged diene-based rubbery polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer; 3) a second thickening step of preparing an enlarged second copolymer by adding a coagulant to the first copolymer; and 4) a secondary copolymerization step of copolymerizing the second copolymer, wherein the coagulant includes a copolymer of a monomer mixture including a (meth)acrylate-based monomer and a carboxylic acid-based monomer.

The copolymer of the monomer mixture may be a linear or branched copolymer, preferably a linear or branched copolymer including a (meth)acrylate-based unit and a carboxylic acid-based unit. The copolymer of the monomer mixture may have a single glass transition temperature, unlike a copolymer having a core-shell structure in which a (meth)acrylate-based polymer is polymerized with a (meth)acrylate-based monomer and a carboxylic acid-based monomer.

The copolymer of the monomer mixture may have an average particle diameter of 50 to 150 nm, 80 to 120 nm, or 90 to 110 nm, of which 90 to 110 nm is preferable. When the above-mentioned range is satisfied, the diene-based rubbery polymer can be easily enlarged, has an appropriate average particle diameter, and an enlarged diene-based rubbery polymer having excellent latex stability can be prepared.

The copolymer of the monomer mixture may be at least one selected from the group consisting of an ethyl acrylate/methacrylic acid copolymer and an n-butyl acrylate/methacrylic acid copolymer, and the ethyl acrylate/methacrylic acid copolymer is preferable

The copolymer of the monomer mixture is preferably in the form of latex in order to more easily perform mixing and agglomeration with the diene-based rubbery polymer in the form of latex. The latex type copolymer may be prepared by emulsion polymerization.

Meanwhile, the copolymer of the monomer mixture may be prepared by emulsion polymerization of the monomer mixture in a reactor.

The monomer mixture may include a (meth)acrylate-based monomer and a carboxylic acid-based monomer in a weight ratio of 97:3 to 80:20 or 94:6 to 82:18, of which 94:6 to 82:18 It is preferable to include it in a weight ratio of When the above-mentioned range is satisfied, the carboxylic acid-based unit in the copolymer of the monomer mixture can sufficiently enlarge the diene-based rubbery polymer, and the occurrence of agglomerates during the preparation of the copolymer of the monomer mixture can be suppressed.

The emulsion polymerization may be performed by adding at least one selected from the group consisting of an initiator, an emulsifier, a molecular weight regulator, and water together with the monomer mixture.

The initiator is sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide, t-butyl peroxide, cumene hydroperoxide, p-mentane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide Oxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5,5-trimethylhexanol peroxide, t-butyl peroxy isobutylate, azobis isobutyronitrile, azo It may be at least one selected from the group consisting of bis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and methyl azobisisobutyric acid (butyric acid), of which potassium persulfate is preferable.

The initiator may be added in an amount of 0.02 to 2 parts by weight or 0.07 to 0.8 parts by weight based on 100 parts by weight of the monomer mixture, of which 0.07 to 0.8 parts by weight is preferred. When the above-mentioned range is satisfied, the copolymer of the monomer mixture has an appropriate molecular weight, so that the diene-based rubbery polymer can be easily enlarged.

The emulsifier is sodium dicyclohexyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodium di-2-ethylhexyl sulfosuccinate, potassium di-2-ethylhexyl sulfosuccinate, sodium dioctyl sulfosuccinate nate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium octadecyl sulfate, sodium oleic sulfate sodium salt, sodium dodecyl sulfate, potassium octadecyl sulfate, potassium rosinate and sodium rosinate or more, of which sodium dodecyl benzene sulfonate is preferable.

The emulsifier may be added in an amount of 0.1 to 2 parts by weight or 0.3 to 0.7 parts by weight based on 100 parts by weight of the monomer mixture, of which 0.3 to 0.7 parts by weight is preferred. When the above-described range is satisfied, the average particle diameter of the copolymer of the monomer mixture is appropriate, so that the diene-based rubbery polymer can be easily enlarged while minimizing the occurrence of agglomerates during hypertrophy.

The water may be ion-exchanged water or distilled water.

On the other hand, the emulsion polymerization may be carried out at 50 to 90 ℃ or 60 to 80 ℃, of which it is preferably carried out at 60 to 80 ℃.

Hereinafter, each step of the method for producing a graft copolymer according to an embodiment of the present invention will be described in detail.

1) 1st hypertrophy stage

A coagulant is added to the diene-based rubbery polymer to prepare an enlarged diene-based rubbery polymer.

The diene-based rubbery polymer is prepared by emulsion polymerization, specifically, a crosslinking reaction of a conjugated diene-based monomer, and may be in the form of a latex, and the conjugated diene-based monomer is 1,3-butadiene, isoprene, chloroprene, and piperylene. It may be one or more selected from, among which 1,3-butadiene may be preferable.

The diene-based rubbery polymer may have an average particle diameter of 50 to 150 nm, or 80 to 120 nm, of which 80 to 120 nm is preferable. If the above-mentioned range is satisfied, since enlargement is easy, it is possible to prepare an enlarged diene-based rubbery polymer having an appropriate average particle diameter and excellent latex stability.

The coagulant may be added in an amount of 0.3 to 2 parts by weight or 0.5 to 1.5 parts by weight, preferably 0.5 to 1.5 parts by weight, based on 100 parts by weight of the diene-based rubbery polymer. If the above-mentioned range is satisfied, the diene-based rubbery polymer can be easily enlarged and the generation of agglomerates can be minimized.

The enlarged diene-based rubbery polymer may have an average particle diameter of 200 to 500 nm, or 250 to 350 nm, of which 250 to 350 nm is preferable. When the above-described range is satisfied, the graft copolymer can implement not only excellent impact resistance, but also excellent surface gloss.

2) First copolymerization step

Then, the enlarged diene-based rubbery polymer, aromatic vinyl-based monomer and vinyl cyan-based monomer are added and copolymerized to prepare a first copolymer.

The copolymerization may be emulsion polymerization.

The enlarged diene-based rubbery polymer may be added in an amount of 50 to 70 parts by weight or 55 to 65 parts by weight, based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, aromatic vinyl-based monomer and vinyl cyan-based monomer, It is preferable to add 55 to 65 parts by weight of it. When the above-mentioned range is satisfied, a graft copolymer having excellent impact resistance and surface gloss properties can be prepared.

The aromatic vinyl-based monomer may be added in an amount of 20 to 40 parts by weight or 25 to 35 parts by weight based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, the aromatic vinyl-based monomer and the vinyl cyanide monomer, of which 25 It is preferable to add to 35 parts by weight. When the above-described range is satisfied, processability is improved, and compatibility with a copolymer including an aromatic vinyl-based unit and a vinyl cyan-based unit that are mixed together during the preparation of the thermoplastic resin composition may be remarkably improved.

The vinyl cyan-based monomer may be added in an amount of 1 to 35 parts by weight or 5 to 15 parts by weight based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, the aromatic vinyl-based monomer and the vinyl cyan-based monomer, of which 5 It is preferable to add to 15 parts by weight. When the above-described range is satisfied, chemical resistance may be improved, and compatibility with a copolymer including an aromatic vinyl-based unit and a vinyl cyan-based unit that are mixed together during the preparation of the thermoplastic resin composition may be remarkably improved.

The copolymerization may be performed by adding at least one selected from the group consisting of an initiator, an activator, a molecular weight modifier, and water together with the enlarged diene-based rubbery polymer, aromatic vinyl-based monomer and vinyl cyan-based monomer.

The type of the initiator is the same as described above, of which cumene hydroperoxide is preferable. The initiator may be added in an amount of 0.001 to 0.5 parts by weight or 0.005 to 0.1 parts by weight, of which 0.005 to 0.1 parts by weight, based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, the aromatic vinyl-based monomer, and the vinyl cyan-based monomer. It is preferable to put it in wealth. When the above-mentioned range is satisfied, a graft copolymer having excellent impact resistance and fluidity can be prepared.

The activator may be at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrophosphate, sodium pyrophosphate anhydiros and sodium sulfate, Among them, at least one selected from the group consisting of sodium ethylenediamine tetraacetate, ferrous sulfate and sodium aldehyde sulfoxylate is preferable.

The activator may be added in an amount of 0.01 to 0.5 parts by weight or 0.05 to 0.2 parts by weight, of which, 0.05 to 0.2 parts by weight, based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, the aromatic vinyl monomer and the vinyl cyanide monomer. It is preferably added in parts by weight. When the above-mentioned range is satisfied, a graft copolymer having excellent impact resistance and fluidity can be prepared.

The type of the molecular weight modifier is the same as described above, and t-dodecyl mercaptan is preferable. The molecular weight modifier may be added in an amount of 0.1 to 0.6 parts by weight or 0.25 to 0.4 parts by weight, of which, 0.25 to 0.4 parts by weight, based on 100 parts by weight of the total of the enlarged diene-based rubbery polymer, the aromatic vinyl-based monomer and the vinyl cyan-based monomer. It is preferably added in parts by weight. When the above-described range is satisfied, a graft copolymer having more improved impact resistance can be prepared.

On the other hand, when the diene-based rubber polymer and the coagulant are added in the form of latex, the emulsifier may not be separately added in the first copolymerization step due to the emulsifier contained in their latex.

The primary copolymerization may be performed for 10 to 50% of the time or 15 to 50% of the total polymerization time, and is preferably performed for 15 to 50% of the time. If the primary copolymerization is carried out too short, there are too many of the enlarged diene-based rubbery polymers during the secondary copolymerization to be described later, so that a lot of aggregation occurs between the enlarged diene-based rubbery polymers, and it helps to improve impact resistance The aggregation of the enlarged diene-based rubbery polymer and the grafting copolymer is less likely to occur. Accordingly, the impact resistance of the graft copolymer, which is the final product, may not be improved. If the primary copolymerization is carried out for too long, the enlarged diene-based rubbery polymer exists in too little compared to the grafting copolymer during the secondary copolymerization to be described later, so that a lot of aggregation occurs between the grafting copolymers, resulting in excessive agglomeration Therefore, polymerization stability may be significantly reduced.

Here, the grafting polymer may mean an intermediate in which the graft polymerization of the aromatic vinyl-based monomer and the vinyl cyan-based monomer to the diene-based rubbery polymer is not sufficiently performed.

When the total polymerization time of the graft copolymer is 180 minutes, the primary copolymerization may be performed for 18 minutes to 90 minutes or 27 to 90 minutes, of which it is preferably performed for 27 to 90 minutes. If the primary copolymerization is carried out too short, there are too many of the enlarged diene-based rubbery polymers during the secondary copolymerization to be described later, so that a lot of aggregation occurs between the enlarged diene-based rubbery polymers, and it helps to improve impact resistance The aggregation of the enlarged diene-based rubbery polymer and the grafting copolymer is less likely to occur. Accordingly, the impact resistance of the graft copolymer, which is the final product, may not be improved. If the primary copolymerization is carried out for too long, the enlarged diene-based rubbery polymer exists in too little compared to the grafting copolymer during the secondary copolymerization to be described later, so that a lot of aggregation occurs between the grafting copolymers, resulting in excessive agglomeration Therefore, polymerization stability may be significantly reduced.

3) 2nd hypertrophy stage

The coagulant is added to the first copolymer and enlarged to prepare a second copolymer.

The coagulant may be added to the first copolymer at a time when the polymerization conversion is 55 to 80% or when the polymerization conversion is 60 to 75%, and the first copolymer at a time when the polymerization conversion is 60 to 75% It is preferable to introduce the coagulant. If the coagulant is added too quickly, there are too many of the enlarged diene-based rubbery polymers during secondary copolymerization to be described later, so that a lot of agglomeration occurs between the enlarged diene-based rubbery polymers, and the impact resistance is improved. The agglomeration of the enlarged diene-based rubbery polymer and the grafting copolymer is less likely to occur. Accordingly, the impact resistance of the graft copolymer, which is the final product, may not be improved. If the coagulant is added too late, the enlarged diene-based rubbery polymer is present in too little compared to the grafting copolymer during the secondary copolymerization to be described later, so that a lot of aggregation occurs between the grafting copolymers. Stability may be significantly reduced.

The coagulant is preferably continuously added in order to minimize deterioration of polymerization stability.

The coagulant may be added in an amount of 0.3 to 2 parts by weight or 0.5 to 1.5 parts by weight, preferably 0.5 to 1.5 parts by weight, based on 100 parts by weight of the diene-based rubbery polymer. If the above-mentioned range is satisfied, the diene-based rubbery polymer can be easily enlarged and the generation of agglomerates can be minimized.

4) Secondary copolymerization step

The second copolymer is copolymerized.

The secondary copolymerization may be performed for 50 to 90% of the time or 50 to 85% of the time based on the total polymerization time, and is preferably performed for 50 to 85% of the time. If the secondary copolymerization is carried out for too long, there are too many of the enlarged diene-based rubbery polymers during the secondary copolymerization, so that a lot of aggregation occurs between the enlarged diene-based rubbery polymers, and the impact resistance is improved. The agglomeration of the enlarged diene-based rubbery polymer and the grafting copolymer is less likely to occur. Accordingly, the impact resistance of the graft copolymer, which is the final product, may not be improved. If the secondary copolymerization is performed too short, the enlarged diene-based rubbery polymer during secondary copolymerization is too small compared to the grafting copolymer, so that a lot of aggregation occurs between the grafting copolymers. Stability may be significantly reduced.

When the total polymerization time of the graft copolymer is 180 minutes, the secondary copolymerization may be performed for 90 minutes to 162 minutes or 90 to 153 minutes, of which it is preferably performed for 90 to 153 minutes. If the secondary copolymerization is carried out for too long, there are too many of the enlarged diene-based rubbery polymers during the secondary copolymerization, so that a lot of aggregation occurs between the enlarged diene-based rubbery polymers, and the impact resistance is improved. The agglomeration of the enlarged diene-based rubbery polymer and the grafting copolymer is less likely to occur. Accordingly, the impact resistance of the graft copolymer, which is the final product, may not be improved. If the secondary copolymerization is performed too short, the enlarged diene-based rubbery polymer during secondary copolymerization is too small compared to the grafting copolymer, so that a lot of aggregation occurs between the grafting copolymers. Stability may be significantly reduced.

When the secondary copolymerization step is completed, a graft copolymer latex may be prepared.

On the other hand, in the method for producing a graft copolymer according to an embodiment of the present invention, when the secondary copolymerization step is completed, the step of preparing the graft copolymer powder may be further performed.

In detail, at least one selected from the group consisting of sulfuric acid, calcium chloride and magnesium sulfate as a coagulant is added to the graft copolymer latex obtained in the secondary copolymerization step, and agglomerated, aged, dehydrated, washed, and dried After the graft copolymer powder can be prepared.

2. Thermoplastic resin composition

The thermoplastic resin composition according to another embodiment of the present invention includes the graft copolymer powder prepared according to the embodiment of the present invention, and a matrix copolymer including an aromatic vinyl-based unit and a vinyl cyan-based unit.

The matrix copolymer may be a copolymer of a second monomer mixture including an aromatic vinyl-based monomer and a vinyl cyan-based monomer.

The matrix copolymer may be at least one selected from the group consisting of a styrene/acrylonitrile copolymer and an α-methyl styrene/acrylonitrile copolymer.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

production example One

82 parts by weight of butyl acrylate, 18 parts by weight of methacrylic acid, 0.15 parts by weight of potassium persulfate as an initiator, 0.4 parts by weight of sodium dodecylbenzene sulfonate as an emulsifier, and 38 parts by weight of ion-exchanged water were uniformly mixed to prepare a polymerization solution did.

170 parts by weight of ion-exchanged water, 0.05 parts by weight of potassium persulfate as an initiator, and 0.1 parts by weight of sodium dodecylbenzene sulfonate as an emulsifier were added to a nitrogen-substituted polymerization reactor, and the internal temperature of the polymerization reactor was raised to 80 ° C. Polymerization was performed while continuously introducing the polymerization solution at a constant rate for 4 hours to obtain a copolymer latex (weight average molecular weight: 250,000 g/mol, average particle diameter: 110 nm).

production example 2

A polymerization solution was prepared by uniformly mixing 94 parts by weight of ethyl acrylate, 6 parts by weight of methacrylic acid, 0.15 parts by weight of potassium persulfate as an initiator, 0.5 parts by weight of sodium dodecylbenzene sulfonate as an emulsifier, and 38 parts by weight of ion-exchanged water. .

170 parts by weight of ion-exchanged water, 0.05 parts by weight of potassium persulfate as an initiator, and 0.1 parts by weight of sodium dodecylbenzene sulfonate as an emulsifier were added to a nitrogen-substituted polymerization reactor, and the internal temperature of the polymerization reactor was raised to 80 ° C. Polymerization was performed while continuously introducing the polymerization solution at a constant rate for 4 hours to obtain copolymer latex (weight average molecular weight: 30000 g/mol, average particle diameter: 105 nm).

production example 3

208 parts by weight of ion-exchanged water and 0.75 parts by weight of sodium dioctyl sulfosuccinate as an emulsifier were added to a nitrogen-substituted polymerization reactor, and the internal temperature of the polymerization reactor was raised to 80° C. and stirred, and then potassium persulfate as an initiator 0.034 parts by weight and 50 parts by weight of butyl acrylate were added and polymerized for 90 minutes to prepare a core.

In the presence of the core, 41 parts by weight of butyl acrylate, 9 parts by weight of methacrylic acid, and 0.099 parts by weight of an aqueous potassium persulfate solution (concentration: 3% by weight) as an initiator (concentration: 3% by weight) were continuously introduced at a constant rate for 90 minutes while polymerization was performed, and the polymerization conversion rate was At 98%, polymerization was terminated to prepare a copolymer latex having a core-shell structure (average particle diameter: 110 nm).

production example 4

208 parts by weight of ion-exchanged water and 0.75 parts by weight of sodium dioctyl sulfosuccinate as an emulsifier were added to a nitrogen-substituted polymerization reactor, and the internal temperature of the polymerization reactor was raised to 80° C. and stirred, and then potassium persulfate as an initiator 0.034 parts by weight and 50 parts by weight of ethyl acrylate were added and polymerized for 90 minutes to prepare a core.

In the presence of the core, 47 parts by weight of ethyl acrylate, 3 parts by weight of methacrylic acid, and 0.099 parts by weight of an aqueous solution of potassium persulfate (concentration: 3% by weight) as an initiator (concentration: 3% by weight) were continuously introduced for 90 minutes at a constant rate while graft polymerization was carried out, and polymerization was carried out. When the conversion rate was 98%, polymerization was terminated to prepare a copolymer latex having a core-shell structure (average particle diameter: 105 nm).

Example One

<1st non-dialog phase>

0.45 parts by weight (based on solid content) of the copolymer latex of Preparation Example 1 was added to 60 parts by weight (based on solid content) of butadiene rubbery polymer latex (average particle diameter: 100 nm), and stirred for 30 minutes to enlarge butadiene rubbery polymer A (average particle size: 200 nm).

<First polymerization step>

60 parts by weight of the enlarged butadiene rubbery polymer A, 30 parts by weight of styrene, 10 parts by weight of acrylonitrile, 0.35 parts by weight of t-dodecyl mercaptan as a molecular weight regulator, and 0.35 parts by weight of t-dodecyl mercaptan as an initiator 0.02 parts by weight of cumene hydroperoxide, 0.06 parts by weight of dextrose as an activator, 0.04 parts by weight of sodium pyrophosphate, 0.001 parts by weight of ferrous sulfate, and 2.1 parts by weight of ion-exchanged water were added at once, and the polymerization conversion rate was 55 % was carried out. At this time, the first polymerization time was 30 minutes.

<Second stage of non-conversation>

Then, 0.45 parts by weight (based on solid content) of the copolymer latex of Preparation Example 1 was continuously added to the polymerization reactor at a constant rate for 5 minutes while being enlarged.

<Secondary polymerization step>

Then, secondary polymerization was performed while raising the internal temperature of the polymerization reactor to 70° C. at a constant rate over 150 minutes, and then the polymerization was terminated to prepare a graft copolymer latex A (average particle diameter: 310 nm).

<Preparation of graft copolymer powder>

2 parts by weight of MgSO ₄ was added to the total amount of the graft copolymer latex A, and agglomerated, aged, dehydrated, washed, and dried to obtain a graft copolymer powder A.

<Production of thermoplastic resin composition>

A thermoplastic resin composition A was prepared by mixing 23 parts by weight of the graft copolymer powder A and 77 parts by weight of 92HR manufactured by LG Chem.

Example 2

After the primary polymerization was performed until the polymerization conversion rate was 70% (1st polymerization time: 60 minutes), the copolymer latex of Preparation Example 1 was added, and the second polymerization was carried out for 120 minutes. A graft copolymer latex B (average particle diameter: 310 nm) was prepared in the same manner as in Example 1.

In addition, a graft copolymer powder B was prepared in the same manner as in Example 1, except that the graft copolymer latex B was used instead of the graft copolymer latex A.

In addition, a thermoplastic resin composition B was prepared in the same manner as in Example 1, except that the graft copolymer powder B was used instead of the graft copolymer powder A.

Example 3

After the first polymerization was performed until the polymerization conversion rate was 80% (first polymerization time: 90 minutes), the copolymer latex of Preparation Example 1 was added, and the second polymerization was performed for 90 minutes. A graft copolymer latex C (average particle diameter: 320 nm) was prepared in the same manner as in Example 1.

In addition, a graft copolymer powder C was prepared in the same manner as in Example 1, except that the graft copolymer latex C was used instead of the graft copolymer latex A.

In addition, a thermoplastic resin composition C was prepared in the same manner as in Example 1, except that the graft copolymer powder C was used instead of the graft copolymer powder C.

Example 4

<1st non-dialog phase>

0.45 parts by weight of the copolymer latex of Preparation Example 2 was added to 60 parts by weight (based on solid content) of butadiene rubbery polymer latex (average particle diameter: 100 nm), and the butadiene rubbery polymer D (average particle diameter: 230 nm) enlarged by stirring for 30 minutes was prepared.

<First polymerization step>

60 parts by weight of the enlarged butadiene rubbery polymer D, 30 parts by weight of styrene, 10 parts by weight of acrylonitrile, 0.35 parts by weight of t-dodecyl mercaptan as a molecular weight regulator, and 0.35 parts by weight of t-dodecyl mercaptan as an initiator in a polymerization reactor substituted with nitrogen and having an internal temperature of 60 ° C. 0.02 parts by weight of cumene hydroperoxide, 0.06 parts by weight of dextrose as an activator, 0.04 parts by weight of sodium pyrophosphate, 0.001 parts by weight of ferrous sulfate, and 2.1 parts by weight of ion-exchanged water were added at once, and the polymerization conversion rate was 55 % was carried out. At this time, the first polymerization time was 30 minutes.

<Second stage of non-conversation>

Then, 0.45 parts by weight (based on solid content) of the copolymer latex of Preparation Example 1 was continuously added to the polymerization reactor at a constant rate for 5 minutes while being enlarged.

<Secondary polymerization step>

Then, secondary polymerization was performed while raising the internal temperature of the polymerization reactor to 70° C. at a constant rate over 150 minutes, and then the polymerization was terminated to prepare a graft copolymer latex D (average particle diameter: 330 nm).

<Preparation of graft copolymer powder>

2 parts by weight of MgSO ₄ was added to the total amount of the graft copolymer latex D, and agglomerated, aged, dehydrated, washed, and dried to obtain a graft copolymer powder A.

<Production of thermoplastic resin composition>

A thermoplastic resin composition D was prepared by mixing 23 parts by weight of the graft copolymer powder D and 77 parts by weight of 92HR manufactured by LG Chem.

Example 5

After the first polymerization was performed until the polymerization conversion rate was 70% (first polymerization time: 60 minutes), the copolymer latex of Preparation Example 2 was added, and the second polymerization was carried out for 120 minutes. A graft copolymer latex E (average particle diameter: 340 nm) was prepared in the same manner as in Example 4.

In addition, a graft copolymer powder E was prepared in the same manner as in Example 1, except that the graft copolymer latex E was used instead of the graft copolymer latex D.

In addition, a thermoplastic resin composition E was prepared in the same manner as in Example 1, except that the graft copolymer powder E was used instead of the graft copolymer powder D.

comparative example One

<Non-conversation phase>

0.9 parts by weight of the copolymer latex of Preparation Example 1 (based on solid content) was added to 60 parts by weight of the butadiene rubber polymer latex (average particle diameter: 0.1 μm), and the butadiene rubber polymer F (average particle diameter: 310 nm) was stirred for 30 minutes to enlarge ) was prepared.

<Production of graft copolymer latex>

60 parts by weight of the enlarged butadiene rubbery polymer F, 30 parts by weight of styrene, 10 parts by weight of acrylonitrile, 0.35 parts by weight of t-dodecyl mercaptan as a molecular weight regulator, and 0.35 parts by weight of t-dodecyl mercaptan as an initiator 0.02 parts by weight of cumene hydroperoxide, 0.06 parts by weight of dextrose as an activator, 0.04 parts by weight of sodium pyrophosphate and 0.001 parts by weight of ferrous sulfate, and 180 parts by weight of ion-exchanged water were all added, and polymerization was performed for 180 minutes. , to terminate polymerization to prepare a graft copolymer latex F (average particle diameter: 320 nm).

<Preparation of graft copolymer powder>

2 parts by weight of MgSO ₄ was added to the total amount of the graft copolymer latex F, and agglomerated, aged, dehydrated, washed, and dried to obtain a graft copolymer powder F.

<Production of thermoplastic resin composition>

23 parts by weight of the graft copolymer powder F and 77 parts by weight of 92HR manufactured by LG Chem were mixed to prepare a thermoplastic resin composition F.

comparative example 2

Butadiene rubbery polymer G (average particle diameter) in the same manner as in Comparative Example 1, except that 0.9 parts by weight (based on solids) of the copolymer latex of Preparation Example 2 was added instead of 0.9 parts by weight of the copolymer latex of Preparation Example 1 (based on solid content) : 320 nm) was prepared.

In addition, a graft copolymer latex G (average particle diameter: 330 nm) was prepared in the same manner as in Comparative Example 1 except that butadiene rubbery polymer G was used instead of butadiene rubbery polymer F.

A graft copolymer powder G was prepared in the same manner as in Comparative Example 1, except that the graft copolymer latex G was used instead of the graft copolymer latex F.

A thermoplastic resin composition G was prepared in the same manner as in Comparative Example 1, except that the graft copolymer powder G was used instead of the graft copolymer powder F.

comparative example 3

Butadiene rubber polymer H ( average particle diameter: 200 nm).

In addition, butadiene rubbery polymer H was added instead of butadiene rubbery polymer A, and 0.45 parts by weight of copolymer latex of Preparation Example 3 (based on solids) was added instead of 0.45 parts by weight of copolymer latex of Preparation Example 1 (based on solid content) prepared a graft copolymer latex H (average particle diameter: 300 nm) in the same manner as in Example 1.

In addition, a graft copolymer powder H was prepared in the same manner as in Example 1, except that the graft copolymer latex H was used instead of the graft copolymer latex A.

In addition, a thermoplastic resin composition H was prepared in the same manner as in Example 1, except that the graft copolymer powder H was used instead of the graft copolymer powder A.

comparative example 4

Butadiene rubbery polymer I ( average particle diameter: 220 nm) was prepared.

In addition, the butadiene rubbery polymer I was added instead of the butadiene rubbery polymer A, and 0.45 parts by weight of the copolymer latex of Preparation Example 4 (based on solid content) was added instead of 0.45 parts by weight of the copolymer latex of Preparation Example 1 Example 1 A graft copolymer latex I (average particle diameter: 320 nm) was prepared in the same manner as described above.

In addition, a graft copolymer powder I was prepared in the same manner as in Example 1, except that the graft copolymer latex I was used instead of the graft copolymer latex A.

In addition, a thermoplastic resin composition I was prepared in the same manner as in Example 1, except that the graft copolymer powder I was used instead of the graft copolymer powder A.

Experimental example One

The physical properties of the graft copolymer latex of Examples and Comparative Examples were measured as follows, and the results are described in [Table 1] and [Table 2] below.

① Average particle size (nm): After leaving the graft copolymer latex at room temperature for 30 minutes, 1 day, 2 days, 3 days, 4 days and 5 days, respectively, the average particle size was measured using Nicomp 380 HPL equipment from Nicomp. Thus, it was measured by a dynamic light scattering method.

② Coagulation amount (ppm) of graft copolymer latex: After filtering the graft copolymer latex using a 100 mesh net, it was put into a convection oven, and then left at 80 °C for 720 minutes. Then, the weight of the agglomerate caught in a 100 mesh net was measured and the amount of agglomeration of the graft copolymer latex was calculated according to the following formula.

Amount of agglomerate (ppm) of graft copolymer latex = {(weight of agglomerate caught in 100 mesh net)/(theoretical total weight of butadiene rubber polymer, styrene, acrylonitrile, and additives added during manufacture of graft copolymer)} × 1,000,000

Experimental example 2

The thermoplastic resin compositions of Examples and Comparative Examples were extruded to prepare pellets. The physical properties of the pellets were measured as follows, and the results are described in [Table 1] and [Table 2] below.

① Flow index (g/10 min): Measured under the conditions of 220 °C and 10 kg in accordance with ASTM D1238.

Experimental example 3

Specimens were prepared by extrusion and injection of the thermoplastic resin compositions of Examples and Comparative Examples. The physical properties of the specimens were measured as follows, and the results are described in [Table 1] and [Table 2] below.

① Impact strength (kg·m/m, 1/4 In): Measured according to ASTM D256.

② Surface gloss (%): It was measured at 45° with a gloss meter in accordance with ASTM D528. The higher the number, the better the surface gloss.

division Example 1 Example 2 Example 3 Example 4 Example 5 Flocculant Type Preparation Example 1 Preparation Example 1 Preparation Example 1 Preparation 2 Preparation 2 1st copolymerization time (min) 30 60 90 30 60 Secondary copolymerization time (min) 150 120 90 150 120 graft copolymer latex
average particle diameter
(nm) 30 minutes 310 310 320 330 340 1 day 310 310 320 330 340 2 days 320 310 320 330 340 3 days 320 310 320 340 340 4 days 320 310 320 340 340 5 days 320 310 320 340 340 Graft copolymer latex agglomeration (ppm) <100 150 300 200 300 flow index 19.2 19.8 17.8 19.0 19.5 surface gloss 97.6 98.5 94.3 97.0 98.7 impact strength 26.0 27.3 26.5 28.0 29.3

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Flocculant Type Preparation Example 1 Preparation 2 Preparation 3 Preparation 4 1st copolymerization time (min) 180 180 30 30 Secondary copolymerization time (min) - - 150 150 graft copolymer latex
average particle diameter
(nm) 30 minutes 320 330 300 320 1 day 320 330 300 320 2 days 320 330 300 320 3 days 320 330 300 330 4 days 320 330 300 330 5 days 320 330 300 330 Graft copolymer latex agglomeration (ppm) <100 300 <100 400 flow index 18.9 19.0 18.8 18.9 surface gloss 98.7 97.2 97.8 97.0 impact strength 25.6 26.3 24.5 25.2

Referring to Tables 1 and 2, in the case of Examples 1 to 5, it was confirmed that the impact strength was excellent compared to Comparative Examples 1 to 4. In addition, comparing Examples 1 to 5, it was confirmed that Examples 2 and 5, in which the primary copolymerization time was 60 minutes, had excellent flow index, surface gloss and impact strength, and the copolymer of Preparation Example 2 It was confirmed that Example 5, using as a coagulant, had the best flow index, surface gloss and impact strength.

On the other hand, when Examples 1 to 3 and Comparative Examples 1, 4 and 5 and Comparative Example 2 are compared, respectively, it can be confirmed that Comparative Examples 1 and 2 had excellent surface gloss, but reduced impact strength. could

When Example 1, Example 4, Comparative Example 3 and Comparative Example 4 were compared, it was confirmed that Example 1 and Example 4 were all excellent in flow index, surface gloss and impact strength compared to Comparative Examples 3 and 4 . From these results, it was confirmed that the use of a copolymer of a monomer mixture as a coagulant was more effective in improving physical properties than using a copolymer of a core-shell structure as a coagulant.

Claims (10)

A first thickening step of preparing an enlarged diene-based rubbery polymer by adding a coagulant to the diene-based rubbery polymer;
a first copolymerization step of preparing a first copolymer by adding and copolymerizing the enlarged diene-based rubbery polymer, an aromatic vinyl-based monomer and a vinyl cyan-based monomer;
a second thickening step of preparing an enlarged second copolymer by adding a coagulant to the first copolymer; and
A secondary copolymerization step of copolymerizing the second copolymer,
The coagulant includes a copolymer of a monomer mixture including a (meth)acrylate-based monomer and a carboxylic acid-based monomer,
The method for producing a graft copolymer wherein the copolymer of the monomer mixture is a linear or branched copolymer.
The method according to claim 1,
The second enlarged step is a method for producing a graft copolymer that is a step of preparing a second copolymer enlarged by adding the coagulant to the first copolymer at a time when the polymerization conversion rate is 55 to 80%.
The method according to claim 1,
The second enlarged step is a step of preparing a second enlarged copolymer by adding the coagulant to the first copolymer at a time when the polymerization conversion rate is 60 to 75%.
The method according to claim 1,
In the first thickening step, the coagulant is added in an amount of 0.3 to 2 parts by weight based on 100 parts by weight of the diene-based rubbery polymer.
The method according to claim 1,
In the second thickening step, the coagulant is added in an amount of 0.3 to 2 parts by weight based on 100 parts by weight of the diene-based rubbery polymer.
The method according to claim 1,
The copolymer of the monomer mixture has an average particle diameter of 50 to 150 nm.
The method according to claim 1,
The copolymer of the monomer mixture is at least one selected from the group consisting of ethyl acrylate/methacrylic acid copolymer and n-butyl acrylate/methacrylic acid copolymer.
The method according to claim 1,
The copolymer of the monomer mixture is a method for producing a graft copolymer in the form of a latex.
9. The method of claim 8,
The latex type copolymer is a method for producing a graft copolymer prepared by emulsion polymerization.
The method according to claim 1,
The monomer mixture is a method for producing a graft copolymer comprising a (meth) acrylate-based monomer and a carboxylic acid-based monomer in a weight ratio of 97:3 to 80:20.