KR20100039509A - Manufacturing method of acrylic polymer with impact resistance using emulsion latex - Google Patents

Abstract

PURPOSE: A method for manufacturing an acrylic polymer is provided to improve the impact strength of an acrylic resin even in the presence of a low impact modifier and to prepare an acrylic resin with excellent shock resistance and transparency without a high temperature melting process of a separate impact modifier. CONSTITUTION: A method for manufacturing an acrylic polymer with excellent impact resistance comprises (A) performing emulsion polymerization of an acrylic latex consisting of 5~30 weight% seed, 50~70 weight% rubbery core grafted with seeds, and 10~30 weight% grafted with a core; (B) adding the acrylic latex to a suspension in which an acrylic monomer and a dispersing agent are mixed in ion exchanged water, injecting a coagulant, and transferring latex to an acrylic monomer layer; and (C) performing suspension polymerization by injecting a chain transfer agent and an initiator into the suspension.

Description

Manufacturing method of acrylic resin with excellent impact resistance {Manufacturing method of acrylic polymer with impact resistance using emulsion latex}

The present invention relates to a method for producing an acrylic resin that is transparent, such as a material for home appliance exterior, and applicable to fields requiring impact resistance and hardness. In particular, the present invention relates to a method for producing an acrylic resin that can be directly applied without undergoing extrusion processing using a separate impact modifier after polymerization.

Polymethyl methacrylate (hereinafter referred to as PMMA) resin is a polymer of methyl methacrylate (hereinafter referred to as 'MMA'), which is polymerized by MMA alone or by bulk polymerization, suspension polymerization or solution polymerization of a small amount of other acrylate monomers. It is resin manufactured by copolymerization. However, acrylic resins prepared in this way have a weaker impact strength than other plastic materials, so they have the drawback of being easily broken by external impacts. Therefore, techniques for impact resistance reinforcement using impact modifiers have been studied.

Conventional impact-resistant acrylic resin is obtained through the process of extruding the melt or powder flake impact modifier obtained in the step of flocculating, dehydrating and drying the elastomer latex at high temperature with the acrylic resin.

However, it is difficult to say that the latex produced by emulsion polymerization in powder form is satisfactory in terms of economics and energy saving. In addition, the high temperature melt mixing method has a problem in that the impact modifier dispersion into the matrix resin has a problem that a large amount of impact modifier must be used to express the impact strength.

In order to overcome this disadvantage, Japanese Patent Laid-Open Nos. 56-50907 and 50-31598 skip the dehydration and drying steps mentioned above, partially coagulate the emulsion-polymerized latex, and add an ethylene monomer to prepare a matrix resin under stirring. An emulsion-suspension polymerization method has been proposed as a method of performing suspension polymerization after switching a polymerization system from an emulsion system to a suspension system.

In addition, Korean Patent Laid-Open Publication No. 2008-0023551 also discloses that when a vinyl chloride-based graft copolymer is prepared, a flocculant is administered before suspension polymerization, and the suspension-polymerization is carried out by changing from an emulsion system to a suspension system. It is evenly distributed and shows that the impact resistance is improved.

However, there has been no case where the emulsification system of the impact modifier is converted to the suspension system by suspension polymerization in the production of acrylic resin.

Accordingly, the inventors of the present invention improve the dispersibility of the impact modifier in the matrix resin by using a flocculant in the same manner as described above, but sufficiently increase the rubber content to improve the impact resistance during the emulsion polymerization, and the acrylic monomer and It is intended to provide a method for producing an acrylic resin having a high impact strength even at a low impact modifier content by minimizing the content of the latex outermost layer surrounding the rubber for compatibility.

That is, the present invention is not a method of manufacturing an acrylic resin having impact resistance by hot melt processing an impact modifier and an acrylic resin in the related art, but maximizes the amount of rubber during emulsion polymerization and surrounds the rubber for compatibility with the acrylic resin. A method of producing an acrylic resin having high impact resistance and high impact resistance without the process of performing high temperature melt processing of a separate impact modifier by performing suspension polymerization with an acrylic monomer using an acrylic rubber latex having a minimum content of the latex outermost layer as a flocculant. To provide.

In addition, the present invention is to provide a method for producing an acrylic resin that can freely control the composition ratio of the core / shell structure of the acrylic latex.

In addition, the present invention is prepared by the above-mentioned suspension method, when using the same amount of impact modifiers, the impact strength is significantly higher than the impact-resistant acrylic resin prepared through high temperature mixing, dehydration, drying process, transparency, yellow index, An object of the present invention is to provide an impact resistant acrylic resin bead that minimizes the degradation of other physical properties such as hardness.

As a result of efforts to solve the above problems, the present inventors maximize the content of the rubber phase when preparing the emulsion polymerization latex using an anionic emulsifier and minimize the content of the acrylic resin of the outermost layer surrounding the rubber phase to a small content The present invention has been completed by discovering that a resin exhibiting excellent impact resistance can be stably prepared by emulsion-suspension polymerization.

The present invention comprises the steps of: (A) obtaining an impact modifier in the form of a latex through emulsion polymerization using an anionic emulsifier; (B) mixing the impact modifier with an acrylic unsaturated monomer and dispersing the acrylic latex which has been separated by using a specific flocculant into the unsaturated monomer layer; (C) suspending the acrylic unsaturated monomer phase in which the transferred latex is dispersed.

At this time, in the step (B) using a flocculant to move the acrylic latex aggregated to a size of 10㎛ or less, preferably 0.1 ~ 7㎛ to the acrylic unsaturated monomer layer.

More specifically, the present invention

(A) Emulsion polymerization of acrylic latex consisting of 5 to 30% by weight of the total latex solid content, 50 to 70% by weight of the rubber core grafted to the seed, and 10 to 30% by weight of the shell grafted to the core Making;

(B) adding an acrylic latex to the suspension in which the acrylic monomer and the dispersant are mixed with ion-exchanged water, stirring the acrylic latex, and then adding a flocculant to disperse the latex by dispersing the acrylic monomer layer;

(C) suspension polymerization by adding a chain transfer agent and an initiator to the suspension;

It includes.

In addition, the emulsion polymerization of the step (A),

A first stage polymerization for preparing a seed having an glass transition temperature of 20 ° C. or more and an average particle diameter of 60 to 200 nm by adding an acrylic monomer, an anionic emulsifier, a graft agent, and an initiator to ion-exchanged water;

An acrylic monomer, a comonomer, a crosslinking agent, an emulsifier, an initiator, and a graft agent were added to the reaction product in one step to graf the rubber phase having a glass transition temperature of 0 ° C. or lower to the seed, thereby preparing a core having an average particle diameter of 100 to 600 nm. Second stage polymerization;

The third step of preparing a shell having an average particle diameter of 150 ~ 800nm by injecting an acrylic monomer, an initiator and a chain transfer agent into the two-step reaction product to graf the uncrosslinked glass phase having a glass transition temperature of 20 ℃ or more to the core. polymerization;

.

In the impact-resistant acrylic resin prepared in the present invention, it is possible to achieve the object of the present invention that the content ratio of acrylic latex: acrylic monomer is 1 to 40:99 to 60 weight ratio in the solid content.

Hereinafter will be described in detail with respect to the configuration of the present invention.

In the present invention, the step (A) of preparing an impact modifier on the latex prepared by emulsion polymerization is prepared to have a seed / core / shell structure by three-step emulsion polymerization to reinforce hard acrylic resin.

The process for producing the latex of the present invention comprises the first step of producing a cross-linked glass seed having a glass transition temperature of 20 ℃ or more; A second step of preparing a core in which a rubber phase having a glass transition temperature of 0 ° C. or less is grafted on the glass phase polymerized in the first step; The glass transition temperature is 20 ° C. or higher on the two phases formed above, and the glass phase acrylic homopolymer or copolymer compatible with the acrylic resin is grafted to prepare a shell for the third step of polymerization.

More specifically, the first stage polymerization to prepare a seed having a glass transition temperature of 20 ℃ or more and an average particle diameter of 60 ~ 200nm by adding an acrylic monomer, an anionic emulsifier, a graft agent and an initiator to ion-exchanged water; An acrylic monomer, a comonomer, a crosslinking agent, an emulsifier, an initiator, and a graft agent were added to the reaction product in one step to graf the rubber phase having a glass transition temperature of 0 ° C. or lower to the seed, thereby preparing a core having an average particle diameter of 100 to 600 nm. Second stage polymerization; And a third step of preparing a shell having an average particle diameter of 150 to 800 nm by injecting an acrylic monomer, an initiator, and a chain transfer agent into the two-stage reaction product to graf the uncrosslinked glass phase having a glass transition temperature of 20 ° C. or higher to the core. Step polymerization; Is done.

First, in the first step, when the temperature of ion-exchanged water reaches 70-90 ° C. under a nitrogen stream, a solution containing an acrylic monomer, an anionic emulsifier, a graft agent, and an initiator is added to the reactor to have an average particle diameter of 60 to 200 nm. A crosslinked glass phase is obtained. In order to control the size of the polymer of the seed, the content of the emulsifier is controlled, and the solid content is lowered. The amount of acrylic monomers in the range of 5 to 30% by weight relative to the total monomer content used in latex production is appropriate, and less than 5% by weight. When it is used as a shock, it cannot be expressed.

In the next two-step polymerization, an acrylic monomer capable of forming a rubbery core in the reaction product of the first step and a styrene derivative having a high refractive index or a styrene derivative substituted with a halogen or an alkyl or aryl group having 1 to 20 carbon atoms in order to control the refractive index Polymerize using as comonomer.

The acrylic monomer may be an alkyl (meth) acrylate having 1 to 15 carbon atoms, preferably n-butyl acrylate, ethyl acrylate, etc. having 2 to 8 carbon atoms. The acrylic monomer and the comonomer are preferably used by mixing in a weight ratio of 4 to 9: 1.

It is preferable to adjust the content of the acrylic monomer and the comonomer so that the weight of the rubber polymer of the second step is 50 to 70% by weight relative to the total weight of the impact modifier. If the content is less than 50% by weight, the impact resistance is lowered. If the content is more than 70% by weight, the impact resistance is improved, but the hardness and the heat resistance may be reduced. The crosslinking agent, the emulsifier, the initiator, and the graft agent are slowly added dropwise to the solution to prepare a crosslinked rubber phase. If the dropping time and polymerization time of the monomers used in the second step is not sufficient or the emulsifier is not used, the monomers may aggregate together. The average size of the crosslinked rubbery polymer is preferably 100 to 600 nm, more preferably about 150 to 300 nm, and the particle size is very uniform.

Next, the third stage polymerization will be described. The three-step polymerization step yields an uncrosslinked glassy polymer by not using a surfactant and a crosslinking agent, and also uses a chain transfer agent for controlling the molecular weight. The content of the acrylic unsaturated monomer is preferably 10 to 30% by weight, and the shell layer, which is the outermost layer, may be used in a very small amount compared to the core layer, thereby exhibiting excellent impact resistance. When the shell layer is used at less than 10% by weight, the stability during suspension polymerization is lowered, and when it exceeds 30% by weight, impact resistance may be lowered.

The size of the emulsion of the impact modifier for the transparent acrylic resin after the shell layer polymerization of the final glass phase is preferably 150 to 800 nm, and the final particle size is also uniform. When it is less than 150 nm, impact resistance falls, and when it exceeds 800 nm, optical properties fall significantly.

If the glassy shell layer is not coated on the rubbery core layer, when the latex particles are polymerized by moving from the emulsion system to the suspension system, the stability decreases and suspension polymerization becomes impossible, and the polymerization of the monomers depends on the thickness of the outer layer thickness. The reaction may proceed by deteriorating the polymerization stability.

The acrylic monomers used in the above steps 1 and 3 are any one or a mixture of two or more selected from an aromatic vinyl monomer, an alkyl (meth) acrylate monomer having 1 to 15 carbon atoms, and a (meth) acrylic acid monomer having 1 to 15 carbon atoms. . Specifically, for example, styrene may be used as the aromatic vinyl monomer, and as the alkyl (meth) acrylate monomer having 1 to 15 carbon atoms, ethyl acrylate, ethyl methacrylate, methyl acrylate, methyl methacrylate, Butyl acrylate, butyl methacrylate, and the like can be used.

In the present invention, the emulsifier may be an alkaline emulsifier such as an alkaline alkyl phosphate having 4 to 30 carbon atoms and an alkyl sulfate salt such as sodium dodecyl sulfate and sodium dodecylbenzene sulfate. The emulsifier is used 0.2 to 4 parts by weight based on 100 parts by weight of the total monomer content used in the latex production.

In the present invention, the crosslinking agent is 1,2-ethanedioldi (meth) acrylate, 1,3-propanedioldi (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,5-pentanedioldi (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, divinylbenzene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate , Triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polybutylene glycol di (meth) acrylate or allyl (meth) acrylate, etc. are used. And, the amount of these used is 0.1 to 10 parts by weight based on 100 parts by weight of the total monomer content used in the latex production. If the amount is less than 0.1 part by weight, the hardness may be lowered. If the amount is less than 10 parts by weight, the rubber may not function properly.

In the present invention, the graft agent uses at least one monomer having a double bond having different reactivity such as allyl (meth) acrylate or diallyl maleate. The amount of these used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the total monomer content used in the latex production. 0.1 to 10 parts by weight is used. If the amount is less than 0.1 part by weight, the hardness may be lowered. If the amount is less than 10 parts by weight, the rubber may not function properly.

In the present invention, as an initiator, cumene hydroperoxide, tertiary butyl peroxide, etc. are used in the presence of ferrous sulfate, ethylenediaminetetraacetate sodium, sodium formaldehyde sulfoxylate, and the amount thereof is used as the total monomer used in the production of latex. It is preferable to use 0.01 to 10 parts by weight based on 100 parts by weight of. If the amount is less than 0.01 part by weight, the effect is insignificant, and if it is used more than 10 parts by weight, it is difficult to control the reaction rate.

In addition, the chain transfer agent for molecular weight control used in step 3 may be used an alkyl mercaptan having 2 to 18 carbon atoms, benzyl mercaptan, mercaptoic acid and the like, preferably an alkyl mercaptan having 4 to 12 carbon atoms. The amount is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the total monomer used in the production of latex. 0.01 to 10 parts by weight is used. If the amount is less than 0.01 part by weight, the effect is insignificant. If it is used more than 10 parts by weight, molecular weight control and physical properties may be reduced.

Ion-exchanged water is used in an amount of 100 to 500 parts by weight based on 100 parts by weight of the total monomer used in the production of latex.

Next, step (B) of the present invention will be described.

Step (B) is a step of transferring the latex to the acrylic monomer layer using a small amount of flocculant because a layer separation phenomenon occurs when the latex obtained through step (A) is added to a suspension containing an acrylic monomer and a dispersant. . The agglomerated latex is preferably moved to the acrylic monomer layer in an agglomerated state in a size of 0.1 ~ 10㎛ to improve the dispersibility in the matrix resin after suspension polymerization.

More specifically, in step (B), the acrylic unsaturated monomer is added to ion-exchanged water, the latex obtained in step (A) is sufficiently stirred, and the coagulant is added dropwise to reduce the stability of the latex, and the dispersant is then added. The monomers containing the latex particles uniformly dispersed in the swollen state are suspended in the water layer.

The flocculant used in the present invention uses an aqueous organic acid salt solution, and in detail, sodium acetate, calcium acetate, sodium formate, calcium formate and the like can be used. When an excessive amount of flocculant is added, the flocculant concentration is increased to produce latex particles having a size of 10 μm or more. Since this lowers the dispersibility of the latex particles in the monomer layer, it is preferable to use a small amount of flocculant so as to be 10 μm or less. The organic acid amount used is 0.01 to 5 parts by weight, more preferably 0.03 to 1 part by weight based on 100 parts by weight of the total suspension polymerization solution. By using the above content range, the acrylic latex can be aggregated to a size of 0.1 ~ 10㎛.

The acrylic monomers used in step (B) may use the acrylic monomers of step (A) described above. Preferably, the polymerization is carried out at a ratio of 80 to 99% by weight of methyl methacrylate and 20 to 1% by weight of a comonomer selected from methyl acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and styrene. More preferably, the use of 85 to 97% by weight of methyl methacrylate and 15 to 3% by weight of comonomer does not lose the hardness and heat resistance of the matrix resin. The ratio of suspension monomers and water is between 0.1 and 1, preferably between 0.3 and 0.5.

In step (B) per 100% by weight of the suspension monomer containing latex particles, 99 to 60% by weight of the suspension monomer and 1 to 40% by weight of latex solid particles can be used, more preferably 93 to 75% by weight of Suspension monomers and latex solid particles of 7-25% by weight are used.

In this invention, the dispersing agent is a copolymer of (meth) acrylic acid and methyl methacrylate, its salt, polyvinyl alcohol, etc. are used. The preferred amount is 0.1 to 2 parts by weight based on 100 parts by weight of the total monomer in the aqueous solution, a small amount of inorganic salt may be used as a dispersing aid.

Step (C) in the present invention is a step of performing suspension polymerization by adding a suspension initiator and a chain transfer agent to the composition of step (B).

Suspension polymerization is polymerized by heating the composition obtained as a result of step (B) for a sufficient time at a temperature of 60 ~ 110 ℃ at a stirring speed of 500 ~ 700rpm, under a nitrogen atmosphere. Upon completion of the reaction, washing and drying is performed to obtain an acrylic resin in a bead state having impact resistance.

Acrylic resin beads according to the present invention may include common thermoplastic additives such as fillers, reinforcing agents, colorants, lubricants, stabilizers, antioxidants, heat resistant and ultraviolet stabilizers and other compound components as desired.

Based on the above description, those skilled in the art will be able to easily understand the essential features of the present invention, and changes and modifications suitable for various uses, conditions, and specific examples can be made without departing from the spirit and scope of the present invention. Can be applied.

The composition according to the present invention can be manufactured into a molded article by a method such as injection and extrusion, and specifically, it can be applied to a product requiring impact resistance without harming the surface hardness, heat resistance and optical properties.

As described above, the present invention has a less rubber when the acrylic resin suspension polymerization using the acrylic rubber latex obtained by minimizing the content of the outermost layer of the latex surrounding the rubber with the rubber properties maximized through emulsion polymerization In addition, the impact strength can be remarkably improved, and since the emulsion-polymerized latex is made into a powder, the processing and the high temperature melt kneading process with the matrix resin are omitted, so that the impact-resistant acrylic resin can be obtained inexpensively, but the hardness and impact strength are It is possible to apply to injection-molded products that need both transparency and impact resistance by achieving desirable balance of physical properties.

In addition, it is possible to freely control the composition ratio of the core / shell structure of the acrylic latex, which was the limitation of the high temperature melt mixing process of the acrylic rubber latex, and has the effect of controlling the content of the rubber as desired through the emulsion polymerization.

Hereinafter, the present invention will be described by way of example for specific description of the present invention, but the present invention is not limited to the following examples.

In the present invention, various physical properties were measured by the following method.

Brittleness: Notched Izod impact strength (kg.cm/cm) was measured at room temperature according to ASTM D256 method.

Transparency (%) and Turbidity (Haze): Measured by Hazemeter according to ASTM D1003 method.

Yellow index (YI): measured by ASTM D1925 method.

Hardness: measured by ASTM D785 method.

In the following Examples and Comparative Examples, the weight% indicates the content of the monomer used in the production of latex and acrylic beads, and the content of the remaining components based on 100 parts by weight of the total monomers used is expressed in parts by weight.

Example 1

This embodiment relates to the production of an acrylic resin comprising 15% by weight of an acrylic emulsified latex polymer.

(A) step: production of acrylic latex by emulsion polymerization

In the first step, 250 parts by weight of ion-exchanged water, 0.002 parts by weight of ferrous sulfate, 0.008 parts by weight of EDTA.2Na salt, 0.2 parts by weight of sodium formaldehyde sulfoxylate, and 0.05 parts by weight of sodium dodecyl sulfate were added to a reactor with a stirrer and replaced with nitrogen. Then, it heated up to 80 degreeC. A mixed solution of 14% by weight of methyl methacrylate, 6% by weight of ethyl acrylate, 0.1 part by weight of allyl methacrylate, and 0.05 part by weight of cumene hydroperoxide was added dropwise for 2 hours, followed by 1 hour at 80 ° C. The emulsion was polymerized with stirring at 400 rpm. The average particle diameter of the glassy polymer obtained at this time was 130 nm.

In step 2, 0.002 parts by weight of ferrous sulfate, 0.004 parts by weight of EDTA.2Na salt, 0.1 part by weight of sodium formaldehyde sulfoxylate, and 1.8 parts by weight of sodium dodecyl sulfate were injected. A mixed solution of 53.6% by weight of butyl acrylate, 11.4% by weight of styrene, 1.2 parts by weight of allyl methacrylate, 0.2 parts by weight of 1,4-butanediol dimethacrylate, and 0.2 parts by weight of cumene hydroperoxide was mixed for 3 hours. After dropping over, it was polymerized at 80 ° C for 2 hours. At this time, the size of the prepared latex particles was 250nm.

Finally, in step 3, after injecting 0.1 part by weight of sodium formaldehyde sulfoxylate while maintaining the temperature at 80 ° C, 14.25% by weight of methyl methacrylate, 0.75% by weight of methyl acrylate, 0.05 part by weight of dodecyl mercaptan and cumene A mixed solution containing 0.02 parts by weight of hydroperoxide was added dropwise over 1 hour, and then polymerized at 80 ° C. for 1 hour. The average particle size of the final polymer was 280 nm.

(B) step: transferring the latex obtained through the emulsion polymerization of step (A) to the acrylic unsaturated monomer layer, 92.4% by weight of methyl methacrylate, 7.6% by weight of methyl acrylate, 4.5% polyvinyl alcohol aqueous solution 0.1 parts by weight (GF-20: manufactured by Nippon Synthetic Chemical Co., Ltd.) and 0.001 parts by weight of boric acid were added to 250 parts by weight of ion-exchanged water and mixed. To the latex solid particles of step (A): the monomer content was added to 85: 15 weight ratio and the obtained mixture was stirred. Then 0.05 part by weight of calcium acetate relative to the total suspension solution was added dropwise.

(C) step: A suspension polymerization process of the dispersion system obtained in step (B), 0.3 parts by weight of dodecyl mercaptan, 0.15 parts by weight of azobisisobutyronitrile to the solution of step (B) to add a mixed solution After raising to 80 ° C., polymerization was performed for 120 minutes while stirring at 600 rpm to complete suspension polymerization. The average particle diameter of the beads obtained after the polymerization was 180 µm.

[Example 2]

This embodiment relates to the preparation of an acrylic resin comprising 15% by weight of an acrylic emulsified latex polymer, (A) -1 in step 3.5% by weight of methyl methacrylate, 1.5% by weight of ethyl acrylate, butyl acrylate in step 2 The impact-resistant acrylic beads were prepared in the same manner as in Example 1, except that acrylic latex was prepared using 53.6% by weight, 11.4% by weight of styrene, 28.5% by weight of methyl methacrylate and 1.5% by weight of methyl acrylate. Prepared.

Comparative Example 1

To prepare the acrylic latex particles of step (A) in the same manner as in Example 1, to obtain a solid in the form of a powder by slowly stirring the latex thus obtained to 700 g of a 1% magnesium sulfate solution preheated to 90 ℃ However, the stability of the latex was sharply lowered and failed to obtain a solid.

Comparative Example 2

This Comparative Example obtained a solid in the form of a powder obtained after the aggregation was carried out in the same manner as in Comparative Example 1 except for using the acrylic latex made in step (A) of Example 2. This powder was filtered and wiped with distilled water at 70 ° C. three times, followed by drying in a vacuum oven at 80 ° C. for 24 hours to obtain an impact modifier powder. Then, 85% by weight of acrylic beads obtained by suspension polymerization of a solution of 92.4% by weight of methyl methacrylate, 7.6% by weight of methyl acrylate, 0.3 part of dodecyl mercaptan and 0.15 part of azobisisobutyronitrile and the solidification and drying 15% by weight of the impact modifier obtained through the process was extruded to prepare impact resistant acrylic beads.

Comparative Example 3

This comparative example is 17.5% by weight of methyl methacrylate in step A) -1, 7.5% by weight of ethyl acrylate in step A) -1, butyl acrylate in 30.94% in weight, 6.56% by weight of styrene in step 2, methyl meta in step 3. Impact-resistant acrylic beads were prepared in the same manner as in Comparative Example 2, except that acrylic latex was prepared using 31.8% by weight of acrylate and 5.7% by weight of methyl acrylate.

Samples for evaluating basic physical properties were prepared by injection molding machine (LG wire, 170 tons). The injection molded product was measured after a 48-hour stay at room temperature for physical properties evaluation, and the results are shown in Table 1 below.

TABLE 1

From the results of Table 1, the resin prepared by the manufacturing method according to the present invention has improved impact strength at the same rubber content by using latex having the rubber properties maximized during the production of emulsion particles, and also has a light transmittance in optical properties. Not only is it high, its turbidity and yellowness index are also low, which satisfies both transparency and impact resistance. This was found to show the physical properties equivalent to or higher than those of Comparative Examples 2 and 3, which are conventional manufacturing methods.

Claims (11)

(A) Emulsion polymerization of acrylic latex consisting of 5 to 30% by weight of the total latex solid content, 50 to 70% by weight of the rubber core grafted to the seed, and 10 to 30% by weight of the shell grafted to the core Making; (B) adding an acrylic latex to the suspension in which the acrylic monomer and the dispersant are mixed with ion-exchanged water, stirring the acrylic latex, and then adding a flocculant to disperse the latex by dispersing the acrylic monomer layer; (C) suspension polymerization by adding a chain transfer agent and an initiator to the suspension; Method for producing a transparent acrylic resin excellent impact resistance comprising a. The method of claim 1, The emulsion polymerization of the step (A), A first stage polymerization for preparing a seed having an glass transition temperature of 20 ° C. or more and an average particle diameter of 60 to 200 nm by adding an acrylic monomer, an anionic emulsifier, a graft agent, and an initiator to ion-exchanged water; An acrylic monomer, a comonomer, a crosslinking agent, an emulsifier, an initiator, and a graft agent were added to the reaction product in one step to graf the rubber phase having a glass transition temperature of 0 ° C. or lower to the seed, thereby preparing a core having an average particle diameter of 100 to 600 nm. Second stage polymerization; A third step of preparing a shell having an average particle diameter of 150 to 800 nm by injecting an acrylic monomer, an initiator, and a chain transfer agent into the two-stage reaction product and grafting an uncrosslinked glass phase having a glass transition temperature of 20 ° C. or higher to the core. Step polymerization; Method for producing a transparent acrylic resin excellent in impact resistance consisting of. 3. The method of claim 2, The acrylic monomers used in the first and third stage polymerization may be any one or two selected from an aromatic vinyl monomer, an alkyl (meth) acrylate monomer having 1 to 15 carbon atoms, and a (meth) acrylic acid monomer having 1 to 15 carbon atoms. The manufacturing method of the transparent acrylic resin excellent in impact resistance which is a mixture of the above. 3. The method of claim 2, The acrylic monomer used in the second stage polymerization is alkyl (meth) acrylate having 1 to 15 carbon atoms, and the comonomer has impact resistance using styrene or halogen or styrene derivative substituted with alkyl or aryl group having 1 to 20 carbon atoms. Method for producing excellent transparent acrylic resin. 3. The method of claim 2, The anionic emulsifier is a method for producing a transparent acrylic resin excellent in impact resistance using an alkyl alkyl phosphate or alkyl sulfate salt of 4 to 30 carbon atoms. 3. The method of claim 2, The graft agent is a method for producing a transparent acrylic resin excellent in impact resistance using allyl (meth) acrylate or diallyl maleate. The method of claim 1, The flocculant of step B) is a method for producing a transparent acrylic resin having excellent impact resistance using an organic acid salt. The method of claim 7, wherein The flocculant is a method for producing a transparent acrylic resin having excellent impact resistance using 0.01 to 5 parts by weight based on the total suspension polymerization solution. The method according to any one of claims 1 to 8, The method of producing a transparent acrylic resin having excellent impact resistance in the content ratio of the acrylic latex: acrylic monomer in the step B) is 1 to 40: 99 to 60 weight ratio of the solid content. Acrylic resin beads prepared by the manufacturing method according to any one of claims 1 to 8. Acrylic resin beads prepared by the manufacturing method according to claim 9.