KR100998429B1 - Acrylic copolymer latex, preparation method thereof, acrylic copolymer powder, and acrylic sol and resin composition comprising the same - Google Patents

Abstract

The present invention is composed of (A) (a1) an acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) methyl methacrylate, wherein the composition of (a1) goes from the center of the core to the outermost part of the core. A core having a gradient structure in which the ratio is continuously reduced and the component ratio of (a2) is continuously increased; And (B) a shell covering the core, (b1) methyl methacrylate, and (b2) a shell made of an aromatic vinyl compound and a vinyl monomer copolymerizable therewith, an acrylic copolymer latex comprising: It relates to a preparation method thereof, an acrylic copolymer powder, an acryl sol and a resin composition comprising the same.

According to the present invention, by including a core having a gradient structure, the acrylic copolymer latex having excellent fluidity, storage stability and mechanical strength and excellent solubility in a plasticizer, a powder thereof, an acryl sol and calender process comprising the same to prepare a sheet There is an effect of providing an environmentally friendly resin composition that can be.

Acrylic copolymer latex, powder, gradient structure, core, shell, acryl sol, sheet, storage stability

Description

ACRYLIC COPOLYMER LATEX, PREPARING METHOD THEREOF, ACRYLIC COPOLYMER POWDER, AND ACRYLZOL AND RESIN COMPOSITIOM THEREFROM}

The present invention relates to an acrylic copolymer latex, a preparation method thereof, an acrylic copolymer powder, an acryl sol and a resin composition comprising the same, and more particularly, excellent fluidity, storage stability and mechanical strength, and excellent solubility in a plasticizer. The present invention relates to an acrylic copolymer latex, powder thereof, an acryl sol containing the same, and an environment-friendly resin composition capable of producing a sheet by calendar processing.

Plastic sol is prepared in a sol state by dispersing the resin powder and filler in a plasticizer, polyvinyl chloride resin is widely known as a resin for preparing the sol.

However, in the case of using polyvinyl chloride resin, the incinerator is markedly damaged by the hydrogen chloride gas generated during the combustion treatment for the disposal of the molded article, causing the ozone layer to be destroyed and acid rain, and harmful substances such as dioxins There is a non-environmental problem such as generating.

Therefore, an acryl sol using an acrylic resin has been proposed as a plastic sol which does not generate hydrogen chloride gas during combustion.

As an acrylic resin for preparing such an acryl, European Patent No. 0533026A (published on March 24, 1993) discloses an acrylic polymer prepared by containing an acid in a skeleton of a core-shell structure. However, the acrylic polymer has a low compatibility with a plasticizer, and in particular, when a low polarizer such as a phthalic ester plasticizer is used, there is a problem that it is difficult to produce a coating film having good physical properties due to lack of solubility.

U.S. Patent No. 5,441,994A (1665.08.15) discloses an acrylic polymer comprising a shell prepared by preparing particles having a uniform structure and then alkali hydrolyzing the particles to convert ester groups on the surface of the particles into carboxyl groups. However, the thickness of the shell is very thin, there is a problem that the shell does not exhibit a function to improve the storage stability.

Japanese Patent Laid-Open Nos. 7-233299 (published 1995.09.05) and 8-295850 (published Nov. 12, 1996) include a core having a good compatibility with a plasticizer and a shell having a poor compatibility with a plasticizer. An acrylic polymer having a shell structure is disclosed. However, the acrylic polymer may not be balanced because the compatibility with the plasticizer is not optimized, and thus there is a problem that the utilization of the product is reduced in terms of storage stability and plasticizer preservation of the coating film.

Japanese Patent Application Laid-open No. Hei 8-295850 (published on November 12, 1996) and Japanese Patent Application Laid-open No. Hei 9-077950 (published on March 25, 1997) are made of a specific monomer having good compatibility with the plasticizer (a) and a plasticizer and Component (b) consisting of a specific monomer having poor compatibility with, but the composition ratio of component (a) decreases in multiple stages or continuously from the center of the acrylic polymer to the outermost layer, and the component ratio of component (b) An acrylic polymer having a multistage or continuously increasing structure is disclosed. However, the compatibility of the outermost layer of the acrylic polymer with the plasticizer is low, the diffusion of the plasticizer from the secondary particles to the primary particles is poor, there is a problem that the projections are generated due to the secondary particles during the coating film formation, deteriorating the quality of the final product. .

In order to solve the problems of the prior art as described above, an object of the present invention is to provide an acrylic copolymer latex having excellent fluidity, storage stability and mechanical strength, and excellent solubility in a plasticizer and a method for preparing the same.

In another aspect, the present invention is to provide an acrylic copolymer powder, an acryl sol comprising the same and an environmentally friendly resin composition.

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

In order to achieve the above object, the present invention

(A) (a1) An acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) Methyl methacrylate, wherein the composition ratio of (a1) is continuous from the center of the core to the outermost part of the core. Decreased in, the core of the gradient structure in which the composition ratio of (a2) continuously increases; And

(B) covering the core, and (b1) methyl methacrylate, and (b2) a shell made of an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; providing an acrylic copolymer latex comprising: do.

In addition,

(I) (iii-1) preparing an emulsion (a1) and a methyl methacrylate emulsion (a2) each composed of an acrylic monomer or a mixture thereof having a glass transition temperature of 65 ° C. or lower; And

     (Iii-2) The emulsion (a1) and the polymerization initiator are continuously introduced into the reactor, while the emulsion (a2) is continuously added to the emulsion (a1), and the emulsion (a1), the polymerization initiator, and the emulsion (a2) Preparing a core having a gradient structure; And

(II) polymerizing methyl methacrylate (b1) and an aromatic vinyl compound with a vinyl monomer (b2) copolymerizable with the prepared core to prepare a shell; acrylic copolymer latex comprising a It provides a method of manufacturing.

In addition,

(A) (a1) An acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) Methyl methacrylate, wherein the composition ratio of (a1) increases from the center of the core to the outermost portion of the core. Continuously decreasing, the core of the gradient structure in which the composition ratio of (a2) continuously increases; And

(B) covering the core, and (b1) methyl methacrylate, and (b2) a shell made of an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; providing an acrylic copolymer powder comprising: do.

The present invention also provides an acryl sol and a resin composition comprising the acrylic copolymer powder.

Hereinafter, the present invention will be described in detail.

Acrylic Copolymer Latex

The acrylic copolymer latex of the present invention comprises a core having a gradient structure and a shell covering the core.

The core of the gradient structure may further include a seed made of an acrylic monomer, an aromatic vinyl compound, or a mixture thereof at the center of the core.

The seed is determined in consideration of compatibility with the plasticizer and sol formation. The composition of the seed preferably does not exceed 65% by weight of methyl methacrylate in the seed forming monomers and core forming monomers. When the content of methyl methacrylate exceeds 65% by weight, phase separation may occur during sol storage, and there is a problem in that the plasticizer is eluted after the sol processing.

The acryl-based monomer is at least one member selected from the group consisting of alkyl methacrylate having 2 to 18 carbon atoms in the alkyl group, and alkyl acrylate having 1 to 18 carbon atoms in the alkyl group, and the aromatic vinyl compound is styrene or α-methyl. It may be at least one selected from the group consisting of styrene, p-methyl styrene and t-butyl styrene.

The seed may be included in 1 to 30% by weight of 100% by weight of the acrylic copolymer latex. When the content is 1 to 30% by weight, there is an effect of controlling the polymer forming reaction and the average particle size.

The seed preferably has an average particle diameter of 1000 to 5000 mm 3. When the average particle diameter of the seed is less than 1000 mm 3, primary particles having a size not corresponding to the scope of the present invention may be generated, and thus, the viscosity and storage stability of the sol may be problematic. This can happen.

The core consists of (A) (a1) an acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) methyl methacrylate, wherein the composition ratio of (a1) goes from the center of the core to the outermost part of the core. This is the core of the gradient structure which continuously decreases and the composition ratio of (a2) continuously increases.

The acrylic monomer having a glass transition temperature of 65 ° C. or less may be at least one selected from the group consisting of alkyl methacrylate having 2 to 18 carbon atoms in the alkyl group, and alkyl acrylate having 1 to 18 carbon atoms in the alkyl group.

The core preferably has a glass transition temperature of 20 to 100 ° C. If the glass transition temperature is less than 20 ℃, the tensile strength is lowered, causing a decrease in the storage stability of the sol, if it exceeds 100 ℃ there is a problem of elution of the plasticizer, film formation and tensile elongation.

The core is comprised of 49 to 98% by weight of 100% by weight of the acrylic copolymer latex. If the content is less than 49% by weight, there is a problem that the plasticizer elutes, and when the content exceeds 98% by weight, there is a problem that the storage stability of the sol is lowered.

The shell covers the core and consists of (b1) methyl methacrylate and (b2) an aromatic vinyl compound and a vinyl monomer copolymerizable therewith.

In addition, the shell is composed of (b1) methyl methacrylate, (b2) an aromatic vinyl compound and a vinyl monomer mixture copolymerizable therewith, and the proportion of the composition (b1) is gradually increasing from the interface of the core to the shell to the outermost part of the shell. This is a shell with a gradient structure which is continuously decreased and the component ratio of (b2) is continuously increased.

The aromatic vinyl compound may be at least one selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, vinyltoluene and t-butylstyrene, and styrene is preferable.

Examples of the vinyl monomer copolymerizable with the methyl methacrylate and the aromatic vinyl compound include alkyl methacrylate having 2 to 18 carbon atoms in the alkyl group, alkyl acrylate having 1 to 18 carbon atoms in the alkyl group, and unsaturated unsaturated having 1 to 9 carbon atoms. It may be at least one selected from the group consisting of organic acids (including aromatics), with unsaturated organic acids being particularly preferred. In the case of unsaturated organic acids, the use of a hydrophilic organic acid in the shell portion not only assists in shell formation but also has excellent storage stability of the sol.

The shell is contained in 1 to 50% by weight of 100% by weight of the acrylic copolymer latex. If the content is less than 1% by weight or more than 50% by weight, there is a problem that the plasticizer is eluted.

The acrylic copolymer latex is a multilayer latex copolymer comprising a core having a gradient structure and a shell covering the core, or further comprising a core having a gradient structure and a shell having a gradient structure covering the core.

The acrylic copolymer latex preferably has a weight average molecular weight of 200,000 to 3,000,000.

Method for producing acrylic copolymer latex

The method for producing an acrylic copolymer latex of the present invention includes (I) preparing a core having a gradient structure and (II) preparing a shell covering the core.

(I) preparing a core having a gradient structure comprises (i-1) preparing an emulsion (a1) consisting of an acrylic monomer having a glass transition temperature of 65 ° C. or less, or a mixture thereof, and a methyl methacrylate emulsion (a2), respectively. step; And (i-2) the emulsion (a1) and the polymerization initiator are continuously added to the reactor, and the polymerization is started after the polymerization is started, and the emulsion (a2) is continuously added to the emulsion (a1) for polymerization. The initiator, and the emulsion (a2) are all the step of the addition is completed for the same time; It includes.

The core manufacturing step (I) of the gradient structure may further include preparing a seed by polymerizing an acrylic monomer, an aromatic vinyl compound, or a mixture thereof before the step (iii-1).

The step of preparing the shell (II) is a step of preparing a shell by polymerizing methyl methacrylate (b1), and an aromatic vinyl compound and a vinyl monomer (b2) copolymerizable with the aromatic core compound.

In addition, the preparing of the (II) shell may include (ii-1) preparing a methyl methacrylate emulsion (b1) and an emulsion (b2) each comprising an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; And (ii-2) continuously adding the emulsion (b1) and the polymerization initiator to the prepared cores, and polymerizing the emulsion (b2) by continuously adding the emulsion (b2) to the emulsion (b1) after initiation of polymerization. The polymerization initiator and the emulsion (b2) are both the step of adding the same for the same time; It further includes.

As said aromatic vinyl compound, 1 or more types chosen from the group which consists of styrene, (alpha) -methylstyrene, p-methylstyrene, vinyltoluene, and t-butylstyrene can be used, Preferably styrene is used.

Examples of the vinyl monomer copolymerizable with the methyl methacrylate and the aromatic vinyl compound include alkyl methacrylate having 2 to 18 carbon atoms in the alkyl group, alkyl acrylate having 1 to 18 carbon atoms in the alkyl group, and unsaturated unsaturated having 1 to 9 carbon atoms. One or more types selected from the group consisting of organic acids (including aromatics) can be used, and preferably unsaturated organic acids are used.

The method of preparing the acrylic copolymer latex as described above is preferably emulsion polymerization, and during emulsion polymerization, emulsifiers, polymerization initiators, molecular weight regulators and the like commonly known in the art may be used.

In the preparation of the acrylic copolymer latex, 100% by weight of the total monomers used may be prepared by polymerizing monomers of 1 to 30% by weight, 49 to 98% by weight of the core, and 1 to 50% by weight of the shell.

Acrylic Copolymer Powder

The acrylic copolymer powder of the present invention has the same structure as the acrylic copolymer latex, and comprises (A) (a1) an acrylic monomer having a glass transition temperature of 65 ° C. or less, or a mixture thereof, and (a2) methyl methacrylate. A core having a gradient structure in which the component ratio of (a1) continuously decreases from the center of the core to the outermost portion of the core, and the component ratio of (a2) continuously increases; And (B) a shell covering the core and comprising (b1) methyl methacrylate and (b2) an aromatic vinyl compound and a vinyl monomer copolymerizable therewith.

(A) The core of the gradient structure may further include a seed composed of an acrylic monomer, an aromatic vinyl compound, or a mixture thereof at the center of the core.

The seed preferably has an average particle diameter of 1000 to 5000 mm 3. When the average particle diameter of the seed is less than 1000 mm 3, primary particles having a size not corresponding to the scope of the present invention may be generated, and thus, the viscosity and storage stability of the sol may be problematic. This can happen.

As the acrylic monomer and the acrylic monomer having a glass transition temperature of 65 ° C. or less, the same monomers as in the acrylic copolymer latex may be used.

The core of the (A) gradient structure is preferably a glass transition temperature of 20 to 100 ℃. If the glass transition temperature is less than 20 ℃, the tensile strength is lowered, causing a decrease in the storage stability of the sol, if it exceeds 100 ℃ there is a problem of elution of the plasticizer, film formation and tensile elongation.

The shell (B) covers the core and comprises (b1) methyl methacrylate and (b2) an aromatic vinyl compound and a vinyl monomer copolymerizable therewith.

In addition, the shell (B) is composed of (b1) methyl methacrylate, (b2) an aromatic vinyl compound and a vinyl monomer mixture copolymerizable therewith, from the interface of the core to the shell toward the outermost side of the shell. It is a shell of a gradient structure in which the composition ratio of (b1) continuously decreases, and the composition ratio of (b2) continuously increases.

As the aromatic vinyl compound and the vinyl monomer copolymerizable therewith, the same ones as in the acrylic copolymer latex may be used.

The acrylic copolymer powder is an acrylic copolymer using a method of preparing an acrylic copolymer latex commonly known in the art, specifically, using a salt, followed by dehydration and drying to produce a powder or spray drying. It can be prepared in powder.

The acrylic copolymer powder prepared as described above preferably has an average particle diameter of 1 μm to 100 μm. If the average particle diameter is less than 1 μm, the viscosity of the sol may be increased. If the average particle diameter is more than 100 μm, it is difficult to prepare a uniform sol.

Acryl sol and resin composition

The acryl sol of the present invention comprises 50 to 200 parts by weight of a plasticizer based on 100 parts by weight of the acrylic copolymer powder.

In addition, the resin composition of the present invention comprises 100 parts by weight of the acrylic copolymer powder, 5 to 100 parts by weight of filler, 5 to 100 parts by weight of plasticizer, and 5 to 100 parts by weight of impact modifier.

The resin composition may be applied to produce a sheet by calendar processing.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

<Acryl Copolymer Preparation>

Example 1

(I) Preparation of Core Latex

In a 3-liter four-necked flask reactor equipped with a stirrer, thermometer, nitrogen inlet and circulation condenser, 130.15 g of ion-exchanged water, 0.015 g of sodium dododecylsulfosuccinate, 0.001 g of n-dodecyl melcaptan, sodium dicarbonate (NaHCO ₃ ) 0.2 g, 7 g of butyl methacrylate, and 4 g of 2-ethylhexyl methacrylate were added to prepare an emulsion. The internal temperature of the reactor was maintained at 75 ° C., replaced with a nitrogen atmosphere, 0.05 g of potassium persulfate was added thereto, and the exothermic temperature was confirmed, followed by reaction for 60 minutes to prepare seed latex.

63 g of butyl methacrylate, 41 g of 2-ethylhexyl methacrylate, 0.063 g of n-dodecyl mercaptan, 0.068 g of sodium dododecylsulfosuccinate and 67.5 g of ion-exchanged water were added to a 0.5 L beaker, followed by stirring And emulsification to prepare an emulsion (a1). In addition, 50 g of methyl methacrylate, 0.027 g of sodium dododecylsulfosuccinate and 32.5 g of ion-exchanged water were added to a 0.5 L beaker, followed by stirring and emulsification to prepare an emulsion (a2).

The internal temperature of the reactor where the reaction of the seed latex was terminated was maintained at 75 ° C., and 20 g of the emulsion (a1) and potassium persulfate (0.5% diluent) were continuously added in the presence of the seed latex to immediately start the polymerization. Emulsion (a2) was continuously added to the emulsion (a1) and polymerized. At this time, the emulsion (a1), potassium persulfate and emulsion (a2) were all continuously added and polymerized within 320 minutes. The polymerization reaction was further proceeded for a minute.

(II) Preparation of Shell

After the reaction of the core latex was completed, the internal temperature of the reactor was maintained at 75 ° C., 20 g of ion-exchanged water, 47 g of methyl methacrylate, 6 g of styrene, 2 g of methacrylic acid, 0.01 g of sodium dododecyl sulfosuccinate, A mixture prepared by adding 0.036 g of n-dodecyl melcaptan and 10 g of potassium persulfate (0.5% diluent) were continuously added to the reactor for 120 minutes continuously, and the reaction was further performed for 60 minutes after the addition was completed. The final acrylic copolymer latex was prepared. At this time, the polymerization conversion rate was 98.8%.

The final acrylic copolymer latex was spray-dried to obtain an acrylic copolymer powder having an average particle diameter of 100 μm or less.

Example 2

27 g of butyl methacrylate, 27 g of 2-ethylhexyl methacrylate, 0.063 g of n-dodecyl mercaptan, 0.068 g of sodium dododecylsulfosuccinate and 35.1 of ion-exchanged water in the preparation of the core (I) in Example 1 g was added to a 0.5 L beaker, followed by stirring and emulsification to prepare an emulsion (a1), 100 g of methyl methacrylate and 0.027 g of sodium dododecylsulfosuccinate and 64.9 g of ion-exchanged water were added to a 0.5 L beaker. Then, the mixture was stirred and emulsified to prepare an emulsion (a2), and the same procedure as in Example 1 was carried out except that itaconic acid was used in the preparation of the (II) shell. At this time, the polymerization conversion rate was 98.8%.

Example 3

The preparation of the (II) shell in Example 1 was carried out in the same manner as in Example 1, except that it was carried out in the following manner.

(II) Preparation of Shell

15.1 g of ion-exchanged water, 0.0085 g of sodium dododecylsulfosuccinate and 47 g of methyl methacrylate were added to a 0.2 L beaker, followed by stirring and emulsification to prepare an emulsion (b1). Further, 4.9 g of ion-exchanged water, 6 g of styrene, 2 g of methacrylic acid, 0.0015 g of sodium dododecylsulfosuccinate and 0.0036 g of n-dodecyl mulchettan were added to a 0.05 L beaker, followed by stirring and emulsification to obtain an emulsion ( b2) was prepared.

The internal temperature of the reactor in which the reaction of the core latex was completed was maintained at 75 ° C., and polymerization was started by continuously adding 20 g of the emulsion (b1) and potassium persulfate (0.5% diluent) in the presence of the core latex. Immediately after the addition of the emulsion (b2) into the emulsion (b1) continuously and polymerized, wherein the emulsion (b1), potassium persulfate and emulsion (b2) were all continuously added within 120 minutes to polymerize, after the completion of the addition The polymerization reaction was further proceeded for 60 minutes. At this time, the polymerization conversion rate was 98.8%.

The final acrylic copolymer latex prepared was spray-dried to obtain an acrylic copolymer powder having an average particle diameter of 100 μm or less.

Example 4

In Example 3, except that the final acrylic copolymer latex was agglomerated with calcium chloride (CaCl ₂ ), dehydrated, and dried in an oven at 65 ° C. to prepare an acrylic copolymer powder having an average particle diameter of 100 μm or less. It was carried out in the same manner as.

Example 5

27 g of butyl methacrylate, 27 g of 2-ethylhexyl methacrylate, 0.063 g of n-dodecyl mercaptan, 0.068 g of sodium dododecylsulfosuccinate and 35.1 of ion-exchanged water in the preparation of the core (I) in Example 3 g was added to a 0.5 L beaker, followed by stirring and emulsification to prepare an emulsion (a1). Further, 100 g of methyl methacrylate, 0.027 g of sodium dododecylsulfosuccinate and 32.5 g of ion-exchanged water were added to a 0.5 L beaker, followed by stirring and emulsification to prepare an emulsion (a2), to prepare a (II) shell. The same procedure as in Example 3 was carried out except that itaconic acid was used. At this time, the polymerization conversion rate was 98.8%.

Examples 6-11

The same method as in Example 3 except that the content of the monomer used in the preparation of the acrylic copolymer latex in Example 3 was adjusted to the composition shown in Table 1, and thus the amount of ion-exchanged water was used. Was carried out.

Comparative Example 1

(I) Preparation of Core

In a 3-liter four-necked flask reactor equipped with a stirrer, thermometer, nitrogen inlet and circulation condenser, 190.15 g of ion-exchanged water, 0.015 g of sodium dododecylsulfosuccinate, 0.001 g of n-dodecyl melcaptan, sodium dicarbonate (NaHCO ₃ ) 0.2 g, 7 g of butyl methacrylate, and 4 g of 2-ethylhexyl methacrylate were added to prepare an emulsion. The internal temperature of the reactor was maintained at 75 ° C., replaced with a nitrogen atmosphere, and then 0.05 g of potassium persulfate was added, and the exothermic temperature was confirmed. The reaction was performed for 120 minutes to prepare seed latex.

A mixture prepared by adding 63 g of butyl methacrylate, 41 g of 2-ethylhexyl methacrylate, 50 g of methyl methacrylate, 0.1 g of sodium dododecylsulfosuccinate, and 0.063 g of n-dodecyl mercaptan and potassium persulfate (potassium persulfate, 0.5% diluent) 20 g of the polymer was continuously added to each other continuously for 320 minutes at the same time, and the reaction was further performed for 60 minutes after the addition was completed to prepare a core latex.

(II) Preparation of Shell

After the reaction of the core latex was completed, the internal temperature of the reactor was maintained at 75 ° C., methyl methacrylate 47 g, styrene 6 g, methacrylic acid 2 g, sodium dododecylsulfosuccinate 0.01 g, n-dodecyl melcaptan A mixture consisting of 0.036 g and 10 g of potassium persulfate (0.5% diluent) were simultaneously added to the reactor continuously for 120 minutes, and after the addition was completed, the reaction was further performed for 60 minutes to prepare a final acrylic copolymer latex. At this time, the polymerization conversion rate was 98.8%.

The final acrylic copolymer latex was spray-dried to obtain an acrylic copolymer powder having an average particle diameter of 100 μm or less.

Comparative Example 2

Comparative Example 1 was prepared in the same manner as in Comparative Example 1, except that 27 g of butyl methacrylate, 27 g of 2-ethylhexyl methacrylate, and 100 g of methyl methacrylate were used to prepare the core (I). It was. At this time, the polymerization conversion rate was 98.8%.

Comparative Example 3

Except for using styrene and methacrylic acid in the preparation of the (II) shell in Example 1, except that methyl methacrylate was used alone, it was carried out in the same manner as in Example 1.

Comparative Example 4

Except for using 2-ethylhexyl methacrylate alone in the preparation of the core (I) in Example 1 was carried out in the same manner as in Example 1. At this time, the glass transition temperature of the prepared core latex was -10 ℃.

Comparative Example 5

Except for using methyl methacrylate alone in the preparation of the core (I) in Example 1 was carried out in the same manner as in Example 1. At this time, the glass transition temperature of the prepared core latex was -105 ℃.

Comparative Example 6

Into a 3-liter four-necked flask reactor equipped with a stirrer, a thermometer, a nitrogen inlet, and a circulation condenser, 200 g of ion-exchanged water and 8 g of 3% by weight of sodium lauryl sulfate (SLS) solution were added and stirred. 54 g of methyl methacrylate, 6 g of ethyl acrylate, and 0.01 g of t-dodecyl mulchettan were introduced into the reactor. After keeping the internal temperature of the reactor at 60 ° C. and replacing with nitrogen atmosphere, 0.1 g of potassium persulfate and 0.015 g of dixodium ethylenediaminetetraacetate, 0.02 g of formaldehyde sodium sulfoxylate, A polymer latex was prepared by adding 10 g of an activator solution consisting of 0.001 g of ferrous sulfate and 1.165 g of ion-exchanged water and performing a reaction for 2 hours.

In addition, 100 g of ion-exchanged water, 10 g of 3% by weight of sodium lauryl sulfate (SLS) solution, 100 g of methyl methacrylate, 26 g of ethyl acrylate, and 14 g of styrene are mixed to stabilize the preemulsion. Was prepared.

The internal temperature of the reactor in which the reaction of the polymer latex was terminated was maintained at 65 ° C., and the prepared preemulsion was temporarily injected, and at the same time, 3% potassium persulfate solution sieve latex was prepared. In this case, the polymerization conversion rate was 99.2%, and the average particle diameter of the final polymer latex was 0.15 μm.

division Monomer composition (g) core
Glass transition temperature (℃) Polymerization conversion rate
(%) Seed core Shell Example One nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / MA
47/6/2 33 98.8 2 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
27/27/100 MMA / ST / IA
47/6/2 62 98.8 3 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / MA
47/6/2 33 98.8 4 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / IA
47/6/2 33 98.9 5 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
27/27/100 MMA / ST / IA
47/6/2 62 98.8 6 MMA
11 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / MA
47/6/2 33 99.0 7 MMA / 2EHMA
6/5 nBMA / MMA
104/50 MMA / ST / IA
47/6/2 43 98.9 8 nBMA
11 nBMA / MMA
50/104 MMA / ST / IA
50/3/2 72 99.1 9 ST / nBMA
6/5 nBMA / MMA
104/50 MMA / ST / IA
50/3/2 43 98.7 10 ST
11 nBMA / nBA / MMA
84/20/50 MMA / ST / IA
47/6/2 29 98.8 11 ST
11 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / IA
47/6/2 33 98.7 Comparative example One nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
63/41/50 MMA / ST / MA
47/6/2 33 98.8 2 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
27/27/100 MMA / ST / IA
47/6/2 62 98.8 3 nBMA / 2EHMA
7/4 nBMA / 2EHMA / MMA
63/41/50 MMA
55 33 98.7 4 nBMA / 2EHMA
7/4 2EHMA
154 MMA / ST / IA
47/6/2 -10 98.8 5 nBMA / 2EHMA
7/4 MMA
154 MMA / ST / IA
47/6/2 105 98.9 6 - MMA / EA
54/6 MMA / EA / ST
100/26/14 87 99.2

<Production of Resin Composition Containing Acrylic Copolymer>

Example 12

100 parts by weight of the acrylic copolymer powder prepared in Example 4, methyl methacrylate-butadiene-styrene resin (MBS) MB870 (manufactured by LG Chem) as an impact modifier 30 parts by weight, neopentyl glycol plasticizer (neopentyl glycol) 30 parts by weight of LGflex EBN (manufactured by LG Chemical), 50 parts by weight of calcium carbonate (CaCO ₃ ), and 100 parts by weight of titanium oxide (TiO ₂ ) were mixed well to prepare a resin composition for sheet processing.

Example 13

Example 12 was carried out in the same manner as in Example 12, except that 30 parts by weight of IM808A (manufactured by LG Chemical), an acrylic impact modifier, was used instead of MB870.

Example 14

Example 12 was carried out in the same manner as in Example 12, except that 30 parts by weight of acrylonitrile-butadiene-styrene resin (ABS) DP270 (manufactured by LG Chemical) was used instead of MB870.

Examples 15-18

Except that the impact modifier in Example 12 was used in the kind and composition shown in Table 2 was carried out in the same manner as in Example 12.

Comparative Examples 7 to 9

In Example 12, using 100 parts by weight of the acrylic copolymer powder prepared in Comparative Example 6, except for using the MBA, acrylic impact modifier or ABS in the composition shown in Table 2 in the same manner as in Example 12 Was carried out.

division Impact modifier MB870 IM808A DP270 Example 12 30 - - 13 - 30 - 14 - - 30 15 15 15 - 16 - 15 15 17 15 - 15 18 10 10 10 Comparative example 7 30 - - 8 - 30 - 9 - - 30

[Test Example]

The glass transition temperature of the acrylic copolymer latex prepared in Examples 1 to 11 and Comparative Examples 1 to 6 was measured by the following method, and the physical properties of the acrylic copolymer powder were measured by the following method and shown in Table 3 below. It was.

* Glass transition temperature (T _g ) was calculated by the formula of Fox in the following formula (1).

Fox Formula = 1 / (T _g + 273) = Σ (W _i / (T _gi + 273))

In Equation 1, W _i is the weight fraction of the monomer i, T _gi is the polymer glass transition temperature of the monomer i.

* Weight average molecular weight-The acrylic copolymer powder sample was dissolved in tetrahydrofurane (THF), and then the weight average molecular weight was measured by gel permeation chromatography (Gel Permeation Chromatography, GPC). At this time, the calibration curve was a polystyrene reference sample.

* Fluidity-100 parts by weight of the acrylic copolymer powder, 140 parts by weight of EBN, and 50 parts by weight of calcium carbonate were mixed with a mixer to prepare an acryl sol. When 24 hours have elapsed after the preparation of the acryl sol prepared above, the Brookfield Viscometer No. The fluidity of acryl sol was evaluated by measuring the viscosity at 25 ° C. and 20 rpm using a Brookfield Viscometer No. 6 Spindle. In this case, a lower viscosity indicates better fluidity.

(Evaluation Criteria)

◎: 3,000 cps or less (very good)

○: more than 3,000 to less than 5,000 cps (good)

△: 5,000 or more but less than 10,000 cps (bad)

×: 10,000 cps or more (very bad)

* Film Formation-The acryl sol prepared at the time of measuring the fluidity was applied to the Teflon plate with a thickness of 1 mm, and then left in an oven at 80 ° C. for 4 hours to examine the state of the coating film. In this case, when the film is transparent, there is no bubble, and the adhesive strength is good, the film is formed well.

(Evaluation Criteria for Film Formation)

◎: very good, ○: good, △: bad, ×: very bad

* Storage stability-After 3 hours after the preparation of the acryl sol prepared for the measurement of the fluidity, the viscosity (V1) at 25 ℃ and the viscosity (V2) at 25 ℃ after standing for 2 days at 25 ℃ Brookfield Viscometer No. Using 6 spindles (Brookfield Viscometer No. 6 Spindle) was measured at 25 ℃, 4 rpm, respectively. At this time, storage stability was evaluated by calculating V2 / V1.

(Evaluation Criteria for Storage Stability)

◎: V2 / V1 = less than 2 (very good)

○: V2 / V1 = 2 or more but less than 3 (good)

Δ: V2 / V1 = 3 or more but less than 4 (bad)

×: V2 / V1 = 4 or more (very bad)

* Mechanical properties-100 parts by weight of acrylic copolymer powder and 100 parts by weight of EBN are mixed well, degassing process is applied, and then applied to 2 mm thickness on easily peelable paper and gelled in 160 ℃ oven for 30 minutes to test specimen of ASTM D638 standard. After the preparation, tensile strength (kg / cm ² ) and tensile elongation (%) were measured using a tensile and compression tester (Zwick) measuring instrument.

division Weight average molecular weight
(just) liquidity Storage stability Film formation Mechanical properties The tensile strength
(Kg / cm ² ) Tensile elongation
(%) Example One 108 ◎ ◎ ○ 42 220 2 100 ◎ ◎ ○ 45 260 3 110 ◎ ◎ ○ 45 270 4 110 ◎ ◎ ○ 46 270 5 105 ◎ ◎ ○ 50 210 6 110 ◎ ◎ ○ 42 230 7 110 ◎ ◎ ◎ 45 250 8 100 ◎ ◎ ○ 52 240 9 110 ◎ ◎ ○ 45 220 10 110 ◎ ◎ ○ 41 250 11 105 ◎ ◎ ○ 48 210 Comparative example One 108 ○ ○ ○ 29 170 2 105 ○ ○ ○ 33 190 3 110 △ ○ × - - 4 115 △ △ ○ 20 250 5 100 ○ ○ × - - 6 100 × × × - -

The sheet processing properties of the resin compositions prepared in Examples 12 to 18 and Comparative Examples 7 to 9 were measured by the method of the group, and the results are shown in Table 4 below.

* Sheet processing-100 g of the resin composition for sheet processing was processed using a 6 inch choline test roll, the roll temperature was 175 ° C, the front roll 22 rpm, the rear roll 20 rpm, and the roll interval was 0.4 mm for 4 minutes to prepare a sheet. , The adhesiveness at the time of processing and the surface state of the sheet | seat after processing were evaluated.

(Evaluation Standard for Sheet Machinability)

◎: Less adhesion and good sheet surface during processing

○: High adhesion or bad sheet surface during processing

×: A lot of adhesion during processing and bad sheet surface

division Example Comparative example 12 13 14 15 16 17 18 7 8 9 Sheet
Machinability ◎ ○ ◎ ◎ ◎ ◎ ◎ × × ×

As shown in Tables 3 and 4, according to the present invention, a shell having a core or aromatic compound having a glass transition temperature of 20 to 100 ° C., an aromatic compound, and a vinyl monomer copolymerizable therewith, particularly having a shell or gradient structure containing an unsaturated organic acid monomer. The acrylic copolymers of Examples 1 to 11 consisting of shells were excellent in fluidity, film formability, storage stability, and mechanical strength, and were found to be excellent in workability at the time of sheet production.

On the other hand, Comparative Examples 1 to 2, which do not include the core of the gradient structure, Comparative Example 3, which comprises a core of the gradient structure, but does not contain an aromatic compound and a vinyl monomer copolymerizable therewith, the glass transition temperature of the core is seen The acrylic copolymers of Comparative Examples 4 to 5 and Comparative Example 6, which are not multi-layered structures of the core-shell, which do not fall within the scope of the invention, do not have excellent fluidity, film formability, storage stability, and have a significant decrease in mechanical strength. In the preparation of the processability was also confirmed that not good.

As described above, according to the present invention provides an acrylic copolymer latex having excellent fluidity, storage stability and mechanical strength, and excellent solubility in a plasticizer, powder thereof, and manufacturing a sheet by acryl sol and calender processing including the same. There is an effect of providing an environmentally friendly resin composition that can be.

Claims (20)

(A) (a1) An acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) Methyl methacrylate, wherein the composition ratio of (a1) is continuous from the center of the core to the outermost part of the core. Decreased in, the core of the gradient structure in which the composition ratio of (a2) continuously increases; And (B) covering the core, (b1) methyl methacrylate, and (b2) a shell made of an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; Acrylic copolymer latex. The method of claim 1, The core of the (A) gradient structure further comprises a seed made of an acrylic monomer, an aromatic vinyl compound or a mixture thereof in the center of the core. Acrylic copolymer latex. The method of claim 1, The core of the (A) gradient structure, the glass transition temperature is characterized in that 20 to 100 ℃ Acrylic copolymer latex. The method of claim 1, The shell (B) is composed of (b1) methyl methacrylate and (b2) an aromatic vinyl compound and a vinyl monomer mixture copolymerizable with these, and from the interface of the core to the shell toward the outermost side of the shell (b1) The composition ratio of is continuously reduced, characterized in that the gradient structure of continuously increasing the composition ratio of (b2) Acrylic copolymer latex. The method according to claim 1 or 4, The aromatic vinyl compound is at least one member selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and t-butylstyrene. Acrylic copolymer latex. The method according to claim 1 or 4, The copolymerizable vinyl monomer is one selected from the group consisting of alkyl methacrylate having 2 to 18 carbon atoms of alkyl group, alkyl acrylate having 1 to 18 carbon atoms of alkyl group, and unsaturated organic acid having 1 to 9 carbon atoms. It is ideal Acrylic copolymer latex. The method of claim 1, The acrylic copolymer latex has a weight average molecular weight of 200,000 to 3,000,000 Acrylic copolymer latex. (I) (iii-1) preparing an emulsion (a1) and a methyl methacrylate emulsion (a2) each composed of an acrylic monomer or a mixture thereof having a glass transition temperature of 65 ° C. or lower;      (Iii-2) The emulsion (a1) and the polymerization initiator are continuously introduced into the reactor, and the polymerization is started by continuously adding the emulsion (a2) to the emulsion (a1) after polymerization is initiated. Emulsion (a2) is all the same time the input is completed; preparing a core comprising; And (II) polymerizing the methyl methacrylate (b1) and the aromatic vinyl compound with a vinyl monomer (b2) copolymerizable with the prepared core to prepare a shell; characterized in that it comprises a Method for producing acrylic copolymer latex. The method of claim 8, The core manufacturing step (I) further comprises the step of preparing a seed by polymerizing an acrylic monomer, an aromatic vinyl compound or a mixture thereof before the step (iii-1). Method for producing acrylic copolymer latex. The method of claim 8, The (II) shell manufacturing step, (Ii-1) preparing a methyl methacrylate emulsion (b1) and an emulsion (b2) each comprising an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; And (Ii-2) The emulsion core (b1) and the polymerization initiator were continuously added to the prepared core, and the polymerization was started by continuously adding the emulsion (b2) to the emulsion (b1) after polymerization was initiated. Initiator and emulsion (b2) are both the step of completion of the input for the same time; characterized in that it comprises a Method for producing acrylic copolymer latex. (A) (a1) An acrylic monomer having a glass transition temperature of 65 ° C. or lower, or a mixture thereof, and (a2) Methyl methacrylate, wherein the composition ratio of (a1) is continuous from the center of the core to the outermost part of the core. Decreased in, the core of the gradient structure in which the composition ratio of (a2) continuously increases; And (B) covering the core, (b1) methyl methacrylate, and (b2) a shell made of an aromatic vinyl compound and a vinyl monomer copolymerizable therewith; Acrylic copolymer powder. The method of claim 11, The core of the (A) gradient structure further comprises a seed made of an acrylic monomer, an aromatic vinyl compound or a mixture thereof in the center of the core. Acrylic copolymer powder. The method of claim 11, The core of the (A) gradient structure, the glass transition temperature is characterized in that 20 to 100 ℃ Acrylic copolymer powder. The method of claim 11, The shell (B) is composed of (b1) methyl methacrylate and (b2) an aromatic vinyl compound and a vinyl monomer mixture copolymerizable with these, and from the interface of the core to the shell toward the outermost side of the shell (b1) The composition ratio of is continuously reduced, characterized in that the gradient structure of continuously increasing the composition ratio of (b2) Acrylic copolymer powder. The method according to claim 11 or 14, The aromatic vinyl compound is at least one member selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and t-butylstyrene. Acrylic copolymer powder. The method according to claim 11 or 14, The copolymerizable vinyl monomer is one selected from the group consisting of alkyl methacrylate having 2 to 18 carbon atoms of alkyl group, alkyl acrylate having 1 to 18 carbon atoms of alkyl group, and unsaturated organic acid having 1 to 9 carbon atoms. It is ideal Acrylic copolymer powder. The method of claim 11, The acrylic copolymer powder is characterized in that the average particle diameter is 1 to 100 ㎛ Acrylic copolymer powder. Claims 11, 12, 13, 14, 17, characterized in that it comprises 100 parts by weight of the acrylic copolymer powder, and 50 to 200 parts by weight of a plasticizer. Acryl sol. Claims 11, 12, 13, 14, 17, 100 parts by weight of the acrylic copolymer powder, 5 to 100 parts by weight of filler, 50 to 100 parts by weight of plasticizer, and 5 to impact modifiers Characterized in that it comprises 100 parts by weight Resin composition. The method of claim 19, The said resin composition is applied to manufacture a sheet | seat by a calendar process, It is characterized by the above-mentioned. Resin composition.