KR101052725B1 - Impact modifier, its manufacturing method and methacryl resin composition using the same - Google Patents

Abstract

The impact modifier according to the present invention is a rubbery polymer (A) polymerized with 30 to 45% by weight of a diene monomer and 55 to 70% by weight of an alkyl acrylate; A first graft layer formed by graft polymerization of an acrylic monomer (B), a crosslinking agent, and an aromatic vinyl monomer (C) on the surface of the rubbery polymer (A); And a second graft layer formed by graft polymerization of the methacrylic monomer (D) on the first graft layer. The impact modifier improves physical properties such as impact resistance while maintaining transparency of the plastic resin.

Impact modifiers, rubbery polymers, acrylic monomers, impact resistance, transparency, scratch resistance, emulsion polymerization

Description

Impact modifier, method for preparing the same, and methacryl resin composition using the same {Impact Modifier, Method of Preparing the Same, and Methacrylic Resin Composition Using the Same}

Field of invention

The present invention relates to an impact modifier, a method for producing the same, and a methacryl resin composition using the same. More specifically, the present invention relates to an impact modifier capable of improving impact resistance and rubbing characteristics while maintaining transparency and scratch resistance of methacryl resins, a method of manufacturing the same, and a methacryl resin composition using the same.

Background of the Invention

In general, methacryl-based resins have excellent scratch resistance due to sufficient stiffness, high transmittance and excellent stiffness. Because of these properties, methacryl-based resins have been applied in various fields. Injection products of methacrylic resins are used for taillights, instrument panel covers, and eyeglass lenses of automobiles, and extruded products are used for signboards and various sheet products.

However, these methacrylic resins have a problem in that mechanical properties, particularly impact resistance, are lowered. It is difficult to use as a resin for a housing that requires high impact resistance due to the deterioration of the mechanical properties, particularly impact resistance. In addition, the methacrylic resin has excellent scratch resistance due to its excellent stiffness, but due to its excellent stiffness, it has a disadvantage of deteriorating rubbing characteristics of generating a fine gas on the repeated rub of soft cotton and towels.

In order to improve the impact resistance and rubbing characteristics of the methacrylic resin, a partially soft impact modifier may be introduced to improve surface properties and impact resistance. However, when the soft impact modifier is introduced, the transparency tends to decrease rapidly. There is this.

Some impact modifiers have been developed that can improve the impact resistance without reducing the transparency of the methacryl resin, but even if they are used, the degree of impact resistance improvement is low.

Accordingly, the present inventors perform graft polymerization twice using an acrylic monomer and a methacryl monomer during polymerization of an impact modifier, thereby improving surface properties while improving transparency and impact resistance of a plastic resin, particularly a methacryl resin. To improve the impact modifier and its manufacturing method and methacryl-based resin using the same has led to the development.

An object of the present invention is to provide an impact modifier that can improve the impact resistance of plastic resins, in particular methacryl-based resins.

Another object of the present invention is to provide an impact modifier that can improve rubbing characteristics while maintaining scratch resistance of plastic resins, in particular methacryl-based resins.

Another object of the present invention is to provide an impact modifier that can improve impact strength without impairing the transparency of plastic resins, especially methacryl-based resins.

Another object of the present invention is to provide an impact modifier that can improve the balance of physical properties such as fluidity, yellowness, impact strength, scratch resistance, etc. of plastic resins, in particular methacryl-based resins.

Still another object of the present invention is to provide a method of manufacturing the impact modifier.

Still another object of the present invention is to provide a methacryl-based resin composition having excellent impact resistance, scratch resistance, rubbing characteristics, transparency, etc. using the impact modifier.

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

Summary of the Invention

The present invention provides an impact modifier and a method for producing the same, which improve impact resistance and rubbing properties while maintaining excellent transparency and scratch resistance of plastic resins, in particular methacryl-based resins.

Impact modifier according to an embodiment of the present invention is a rubbery polymer (A) consisting of 30 to 45% by weight of the diene monomer and 55 to 70% by weight of the alkyl acrylate; A first graft layer formed by graft polymerization of an acrylic monomer (B), a crosslinking agent, and an aromatic vinyl monomer (C) on the surface of the rubbery polymer (A); And a second graft layer formed by graft polymerization of the methacrylic monomer (D) on the first graft layer.

Method for producing an impact modifier according to an embodiment of the present invention comprises the steps of polymerizing a monomer mixture consisting of a diene monomer and an alkyl acrylate to prepare a rubbery polymer (A); First graft polymerization by adding an acrylic monomer (B), a crosslinking agent, and an aromatic vinyl monomer (C) to the rubbery polymer (A); And a second graft polymerization by adding a methacryl-based monomer (D) to the first graft polymer.

In another aspect, the present invention provides a methacryl-based resin composition comprising the impact modifier. The methacrylic resin composition comprises 55 to 95% by weight of the methacrylic resin and 5 to 45% by weight of the impact modifier.

Hereinafter, specific contents of the present invention will be described in detail below.

Detailed Description of the Invention

The impact modifier according to an embodiment of the present invention comprises a rubbery polymer, a first graft layer formed on the surface of the rubbery polymer, and a second graft layer formed on the first graft layer. The rubbery polymer increases the impact resistance of plastic resins, in particular methacrylic resins, and the second graft layer improves the compatibility of the rubbery polymer with methacrylic resins. The first graft layer helps to easily graft polymerize the rubbery polymer and the second graft layer, and serves to control the refractive index of the impact modifier.

Specifically, the impact modifier according to an embodiment of the present invention is a rubbery polymer (A) polymerized with 30 to 45% by weight of a diene monomer and 55 to 70% by weight of an alkyl acrylate, the acrylic monomer on the surface of the rubbery polymer (A) (B), a first graft layer formed by graft polymerization of a crosslinking agent and an aromatic vinyl monomer (C), and a second graft polymer formed by methacryl monomer (D) on the first graft layer. It comprises a graft layer.

In an embodiment of the present invention, the content of the rubbery polymer (A) is preferably 45 to 70% by weight based on the total weight of (A) + (B) + (C) + (D), 45 to 60 It is more preferable that it is weight%.

The content of the acrylic monomer (B) is preferably 5 to 30% by weight, more preferably 10 to 25% by weight based on the total weight of (A) + (B) + (C) + (D). .

The content of the aromatic vinyl monomer (C) is preferably 1 to 10% by weight, more preferably 2 to 8% by weight based on the total weight of (A) + (B) + (C) + (D). desirable.

The content of the methacrylic monomer (D) is preferably 10 to 40% by weight, more preferably 20 to 38% by weight based on the total weight of (A) + (B) + (C) + (D). desirable.

The content of the crosslinking agent is preferably 0.3 to 2 parts by weight, more preferably 0.5 to 1.5 parts by weight based on 100 parts by weight of the total (A) + (B) + (C) + (D).

Impact modifier according to an embodiment of the present invention is prepared as follows.

First, a monomer mixture composed of a diene monomer and an alkyl acrylate is polymerized to prepare a rubbery polymer (A).

The monomer used in the preparation of the rubbery polymer (A) is preferably selected to have a low glass transition temperature, preferably about −40 ° C. or lower, so as to express rubber properties, and maintain the same refractive index as the methacrylic resin. The composition ratio of the monomer is adjusted so as to be effective. For example, it is preferable to adjust a refractive index in the range of 1.4-1.6, More preferably, 1.45-1.55, More preferably, 1.485-1.4905 based on the refractive index 1.49 of polymethyl methacrylate resin.

In an embodiment of the present invention, the rubbery polymer (A) is preferably prepared using an emulsion polymerization method.

The diene monomers include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-methyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and these Mixtures and the like can be used, but are not necessarily limited thereto. It is preferable to use butadiene (1, 3- butadiene) among these.

Specific examples of the alkyl acrylate used in the preparation of the rubbery polymer (A) include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and the like. It is not limited to this. These can be used individually or in mixture of 2 or more types. Among these, it is preferable to use butyl acrylate.

The content of the diene monomer is 30 to 45% by weight based on the total weight of the monomer mixture, the content of the alkyl acrylate is preferably 55 to 70% by weight, the content of the diene monomer is 35 to 43 It is more preferable that the content is 57% by weight and 57 to 65% by weight based on the weight of the alkyl acrylate.

When the content ratio of the diene monomer and the alkyl acrylate is out of the above range, a difference in refractive index between the methacryl resin and the methacryl-based resin may occur, thereby lowering transparency.

The monomer mixture consisting of the diene monomer and the alkyl acrylate may be polymerized using additives such as an emulsifier, an electrolyte, a crosslinking agent, and a molecular weight regulator.

In one embodiment of the present invention, the rubbery polymer (A) is prepared by adding an emulsifier and a crosslinking agent to the monomer mixture, followed by emulsion polymerization.

In another embodiment of the present invention, the rubbery polymer (A) is prepared by adding an emulsifier, a crosslinking agent, an electrolyte, and a molecular weight modifier to the monomer mixture, followed by emulsion polymerization.

More specifically, an emulsifier, a crosslinking agent, an electrolyte and a molecular weight regulator are added to a monomer mixture composed of the diene monomer and the alkyl acrylate, and the reaction temperature is raised to about 50 to 90 ° C, preferably about 60 to 80 ° C. , Initiator is added, and emulsion polymerization is carried out to produce the rubbery polymer (A).

As the emulsifier, it is preferable to use a fatty acid-based emulsifier such as derivatives substituted with sodium or potassium in lauryl acid, stearyl acid, oleic acid, and the like. Specific examples of the fatty acid-based emulsifier include sodium lauryl acid, sodium oleate, potassium oleate, potassium stearate, and the like, but are not necessarily limited thereto. These can be used individually or in mixture of 2 or more types.

The emulsifier is preferably used in 1 to 3 parts by weight based on 100 parts by weight of the monomer mixture. When the emulsifier is used in less than 1 part by weight, the emulsion stability may be lowered and the particle size of the formed rubbery polymer (A) may be greater than 250 nm, and if it exceeds 3 parts by weight, a heat removal problem may occur, and the remaining emulsifier As a result, transparency may be reduced or a particle size may be very small, and thus impact resistance may be lowered.

In preparing the rubbery polymer (A), an electrolyte may be used to increase the emulsion stability. The electrolyte is preferably potassium carbamate, but is not necessarily limited thereto. The electrolyte is preferably used in 1 to 3 parts by weight based on 100 parts by weight of the monomer mixture. When the electrolyte is used in less than 1 part by weight, the polymerization stability may be lowered. When the electrolyte is used in an amount greater than 3 parts by weight, the particle size becomes large due to limited agglomeration during emulsion polymerization, and the emulsion stability may be lowered due to high viscosity. Can be.

Conventionally, when the rubber polymer is manufactured, a core is formed by using a monomer having a high glass transition temperature, and then the core / shell structure rubber improves impact resistance by forming a core in the rubber by wrapping it with a rubber having a low glass transition temperature. However, in the embodiment of the present invention by using a relatively reactive crosslinking agent and a molecular weight modifier mixed, by increasing the crosslinking degree of the rubber formed in the initial reaction to form a relatively hard rubber, soft rubbery after the mid-polymerization A rubbery polymer (A) is manufactured by the polymerization method to form.

As the crosslinking agent, triallyl isocyanate (TAIC), allyl methacrylate (AMA), a mixture thereof, and the like may be used, but are not limited thereto. The crosslinking agent is preferably used in 0.3 to 1 part by weight based on 100 parts by weight of the monomer mixture. If the crosslinking agent is used in less than 0.3 parts by weight, the transmittance may be lowered, and when used in excess of 1.0 parts by weight, impact resistance may be lowered, which is not preferable.

Molecular weight regulators include alkyl mercaptans, carbons including n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tertiary dodecyl mercaptan, isopropyl mercaptan, n-amyl mercaptan and the like Halogenated compounds including tetrachloride, etc., aromatic molecular weight modifiers including alphamethyl styrene dimer, alphaethyl styrene dimer, and the like, and mixtures thereof may be used, but are not necessarily limited thereto.

The molecular weight modifier is preferably used in 0.2 to 1 part by weight based on 100 parts by weight of the monomer mixture. When the molecular weight modifier is used in less than 0.2 parts by weight, or in excess of 1 part by weight, relatively lower mechanical properties may occur.

As an initiator used for manufacture of the said rubbery polymer (A), it is preferable to use a water-soluble initiator, and it is more preferable to use a persulfate type initiator. Examples of the persulfate-based initiator include sodium persulfate, ammonium persulfate, potassium persulfate and the like.

The initiator is preferably used in 0.3 to 1 part by weight based on 100 parts by weight of the monomer mixture. When the content of the initiator is less than 0.3 parts by weight, the reactivity may be very slow due to the effects of polymerization inhibitors and impurities remaining in the monomer, and when the content of the initiator is more than 1 part by weight, the reactivity is very good, but the physical properties are deteriorated due to heat removal problems and a decrease in molecular weight. May occur, which is undesirable.

In an embodiment of the present invention, when the rubbery polymer (A) is prepared as described above, the acrylic monomer (B), the crosslinking agent and the aromatic vinylic monomer (C) are added to the rubbery polymer (A), and the first graft is made. The polymerization produces a primary graft polymer. Subsequently, the methacryl-based monomer (D) is added to the first graft polymer to carry out the second graft polymerization.

The rubbery polymer (A) without any treatment has poor compatibility with thermoplastic resins, especially methacrylic resins. Therefore, the rubbery polymer (A) and the methacrylic monomer (D) are graft-polymerized so that the rubbery polymer (A) can express compatibility with the methacrylic resin.

At this time, the rubbery polymer (A) and the methacrylic monomer (D) to easily graft polymerization and to control the refractive index, the rubbery polymer (A) and acrylic monomer (B), crosslinking agent and aromatic vinyl-based The first graft polymer having the first graft layer formed on the surface of the rubbery polymer (A) is prepared by graft polymerization of the monomer (C). The graft polymer having a second graft layer formed on the first graft layer is manufactured by graft polymerizing the first graft polymer and the methacrylic monomer (D).

In the first graft polymerization, the rubbery polymer (A) is preferably used in an amount of 45 to 70 wt% based on the total weight of (A) + (B) + (C) + (D), and 45 to More preferably, it is used at 60% by weight. When the rubbery polymer (A) is used in less than 45% by weight, the production efficiency and the efficiency of the graft polymerization may be lowered and the impact resistance may be lowered, and when used in excess of 70% by weight, even graft polymerization is difficult. In the extrusion or injection process, the problem of dispersion of the impact modifier may occur, which is not preferable.

The acrylic monomer (B) used in the first graft polymerization is preferably alkyl acrylate, but is not necessarily limited thereto. Specific examples of the alkyl acrylate are the same as those used for the preparation of the rubbery polymer (A) described above, and among them, butyl acrylate is preferably used.

The acrylic monomer (B) is preferably used in 5 to 30% by weight based on the total weight of (A) + (B) + (C) + (D), more preferably used in 10 to 25% by weight desirable. When the acrylic monomer (B) is used in less than 5% by weight, the graft efficiency of the first graft layer and the methacryl-based monomer (D) is lowered, thereby lowering transparency and the like, and exceeding 30% by weight In the case of using, since transparency fall and dispersibility may fall, it is unpreferable.

In addition, the specific example of the crosslinking agent used for the said 1st graft polymerization is the same as that used for manufacture of the rubbery polymer (A) mentioned above. The crosslinking agent used in the first graft polymerization is preferably added in an amount of 0.3 to 2 parts by weight, and 0.5 to 1.5 parts by weight based on 100 parts by weight of the total amount of (A) + (B) + (C) + (D). It is more preferable to do. When the crosslinking agent is used in less than 0.3 parts by weight, the graft efficiency is lowered and sufficient dispersion is difficult in the matrix resin, which may lower transparency. However, impact resistance may be lowered.

The aromatic vinyl monomer (C) serves to control the refractive index, it is preferable to use styrene, but is not necessarily limited thereto. The aromatic vinyl monomer (C) may be appropriately selected and used according to specific components of the impact modifier.

The aromatic vinyl monomer (C) is preferably added in an amount of 1 to 10% by weight based on the total weight of (A) + (B) + (C) + (D), and is added in an amount of 2 to 8% by weight. It is more preferable. When the aromatic vinyl monomer (C) is added in less than 1% by weight or in excess of 10% by weight, a large difference in refractive index with methacryl-based resin may occur, which may lower transparency.

In addition, the acrylic monomer (B) and the aromatic vinyl monomer (C) are added in a weight ratio of about 2: 1 to 8: 1, preferably about 4: 1 to 6: 1, more preferably about 5: 1. It is preferable.

In one embodiment of the present invention, the same emulsifier and initiator as used in the preparation of the rubbery polymer (A) may be used in the first graft polymerization. It is preferable that the emulsifier added during the first graft polymerization is 0.5 to 2 parts by weight based on 100 parts by weight of the total of (A) + (B) + (C) + (D), and the initiator is (A) + (B It is preferable to add 0.05 to 0.5 parts by weight based on 100 parts by weight of the total of (+) (C) + (D).

Specifically, in the embodiment of the present invention, the acrylic monomer (B), the aromatic vinyl monomer (C), the crosslinking agent, and the emulsifier are added to the manufactured rubbery polymer (A), and the reaction temperature is raised to about 50 to 60 ° C. After that, an initiator is added to initiate polymerization. After the initiator is introduced, the reaction temperature is raised to about 60 to 80 ° C. by spontaneous exotherm, and the first graft polymerization is performed by maintaining the reaction for about 5 to 20 minutes, preferably about 7 to 12 minutes.

In another embodiment of the present invention, in the second graft polymerization, a second graft polymerization is performed by further adding a molecular weight regulator together with the methacrylic monomer (D). The molecular weight modifier is preferably mixed with the methacryl-based monomer (D) and continuously added.

The molecular weight modifier used in the second graft polymerization is n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tertiary dodecyl mercaptan, isopropyl mercaptan, n-amyl mercaptan Halogen-containing compounds including alkyl mercaptan, carbon tetrachloride, and the like, aromatic molecular weight modifiers including alphamethyl styrene dimer, alphaethyl styrene dimer, and the like, and mixtures thereof may be used, but are not limited thereto. no. In an embodiment of the invention n-octyl mercaptan was used.

It is preferable to add the said molecular weight modifier at 0.01-1 weight part with respect to 100 weight part of (A) + (B) + (C) + (D) whole. When the amount of the molecular weight modifier is less than 0.01 part by weight or more than 1 part by weight, a large decrease in mechanical properties occurs.

In addition, in the second graft polymerization, an initiator used in the preparation of the rubbery polymer (A) may be used. The initiator is preferably added in an amount of 0.2 to 0.6 parts by weight based on 100 parts by weight of (A) + (B) + (C) + (D).

In an embodiment of the present invention, the initiator is further added to the prepared primary graft polymer, the methacryl-based monomer (D) and the molecular weight modifier are mixed, and continuously injected for about 50 to 70 minutes to the secondary graft. The polymerization is carried out.

The graft polymer prepared as described above may be post-treated in a conventional manner and used as an impact modifier. For example, the final impact modifier may be prepared in the form of powder, fine particles, particles, granules and the like, but is not necessarily limited thereto.

In one embodiment of the present invention, the graft polymer prepared is subjected to post-treatment and dehydration drying process using a coagulant to prepare an impact modifier in powder form.

When the impact modifier according to the embodiment of the present invention is applied to a thermoplastic resin, not only the impact resistance of the resin may be improved, but also transparency, scratch resistance, rubbing characteristics, yellowness, and the like may be improved.

In particular, when the impact modifier is applied to the methacrylic resin, it is possible to obtain the effect of improving the impact resistance and rubbing characteristics while maintaining the excellent scratch resistance, transparency, yellowness and the like of the methacrylic resin.

The present invention includes a methacrylic resin composition to which the impact modifier is applied. The methacryl-based resin composition comprises 55 to 95% by weight of methacryl-based resin and 5 to 45% by weight of the impact modifier. It is preferable that the said methacryl-type resin is polymethyl methacrylate. The methacryl-based resin composition may be prepared by blending the impact modifier with methacryl-based resin.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1

60.5 parts by weight of butyl acrylate, 132 parts by weight of process water, 0.6 parts by weight of crosslinking agent (AMA), 0.3 parts by weight of molecular weight regulator (n-octylmercaptan), 2.0 parts by weight of electrolyte (K2CO3, potassium carbamate), emulsifier 2.0 parts by weight of potassium stearate was added and the reactor was sealed. Nitrogen pressurization was carried out to evaluate the leakage of the reactor for airtight evaluation of the reactor, and 39.5 parts by weight of butadiene was added to the reactor. After raising the reactor temperature to 70 ° C, 0.8 parts by weight of an initiator (potassium persulfate) was added to carry out the reaction. The temperature of the reactor was maintained at 70 ° C. using fruit and cooling water in the reactor jacket. At 4 hours after the addition of the initiator, the polymerization rate and the particle size were measured, and the reactor temperature was raised to 85 ° C. for 1 hour. A) was prepared.

50 parts by weight of the rubbery polymer (A) prepared for graft polymerization, 16.5 parts by weight of butyl acrylate, 3.5 parts by weight of styrene, 1 part by weight of crosslinking agent (AMA) and 1.0 part by weight of emulsifier (potassium stearate) were added to the reactor. After the temperature was raised to 60 ° C, 0.2 parts by weight of an initiator (potassium persulfate) was added to initiate the first graft polymerization. After the initiator was added, the reactor temperature was raised to 70 ° C. by spontaneous exotherm, and then the first graft polymerization was performed while maintaining for 10 minutes.

0.4 parts by weight of an initiator (potassium persulfate) before the second graft polymerization was added to the reactor, and 30 parts by weight of methyl methacrylate and 0.05 parts by weight of a molecular weight regulator (n-octyl mercaptan) were mixed, and then, 70 minutes was continuously added to the reactor. Secondary polymerization was carried out. After maintaining the temperature for 40 minutes after the second polymerization, the reactor was cooled to terminate the polymerization.

The rubber size and gelation degree of the rubbery polymer (A) and the physical properties of the graft polymer were measured and shown in Table 1 below.

After analyzing the sample prepared in the latex state to 100 parts by weight to 140 parts by weight to 140 parts by weight of sulfuric acid 1% solution maintained at 250 rpm and 67 ℃ was slowly agglomerated, and the temperature was raised to 90 ℃ to form hard aggregated particles. Dehydration was carried out using a centrifuge, and the water content was dried to 0.5% or less using a fluidized bed dryer.

80 parts by weight of polymethyl methacrylate (PMMA) having a weight average molecular weight of 97,000 obtained through bulk polymerization was mixed with 20 parts by weight of the dried sample to prepare a physical specimen using an extrusion and injection machine at 230 ° C extrusion temperature. The physical properties of the prepared specimens were evaluated, and the evaluation results are shown in Table 1 below.

Example 2

When preparing a rubbery copolymer, it was carried out in the same manner as in Example 1 except for changing the particle size of the rubbery polymer (A) by changing the content of the emulsifier to 1.9 parts by weight.

Example 3

When preparing a rubbery copolymer, the content of the emulsifier was changed to 2.1 parts by weight, and the same procedure as in Example 1 was carried out except that the particle diameter of the rubbery polymer (A) was changed.

Example 4

When preparing a rubbery copolymer, the content of the crosslinking agent was changed to 0.5 parts by weight, and the same procedure as in Example 1 was carried out except that the particle size of the rubbery polymer (A) was changed.

Example 5

When preparing a rubbery copolymer, the content of the crosslinking agent was changed to 0.7 parts by weight, and the same procedure as in Example 1 was carried out except that the particle size of the rubbery polymer (A) was changed.

Comparative Example 1

The rubber copolymer was prepared in the same manner as in Example 1 except that 60.5 parts by weight of butadiene and 39.5 parts by weight of butyl acrylate were changed to 100 parts by weight of butadiene.

Comparative Example 2

The first graft polymerization was carried out in the same manner as in Example 1 except that no crosslinking agent (AMA) was added.

Comparative Example 3

In the first graft polymerization, it was carried out in the same manner as in Example 1 except that 16.5 parts by weight of butyl acrylate and 3.5 parts by weight of styrene were changed to 20 parts by weight of styrene.

Comparative Example 4

In the first graft polymerization, it was carried out in the same manner as in Example 1 except that 16.5 parts by weight of butyl acrylate and 3.5 parts by weight of styrene were changed to 20 parts by weight of butyl acrylate.

Comparative Example 5

PMMA having a weight average molecular weight of 97,000 obtained through bulk polymerization was prepared at 230 ° C. extrusion temperature using an extrusion and injection machine.

The physical properties of each of the specimens prepared in Examples and Comparative Examples were evaluated by the following methods, and the evaluation results are shown in Table 1 below.

(1) Rubbery particle diameter: The volume average particle diameter was measured using Nicomp's particle size analyzer A380.

(2) Gelling level of rubbery (wt.%): The rubbery polymer (A) was swelled in toluene for 24 hours to remove ungelled rubber, dried, and then measured by weight ratio.

(3) Graft rate (wt.%): The graft polymer was dissolved in acetone, and the free polymer which did not participate in the graft polymerization was removed using a centrifugal separator at 20000 rpm, and then dried using a weight ratio.

(4) Notched Izod impact strength (kgfcm / cm): Measured at 1/4 "thickness according to ASTM D256.

(5) Flow index: measured according to ASTM D1238.

(6) Yellowness: measured according to ASTM D1925.

(7) Pencil hardness: After preparing a specimen with a thickness of 3 mm, a length of 10 mm, and a width of 10 mm, the specimen surface was scraped five times at 500 ° C. at 23 ° C. based on JIS K5401, and the degree of scratching was visually determined. When the pencil scratch mark appeared more than once, the pencil hardness grade was determined to 4B-4H.

(8) Rubbing characteristics: After rubbing 1000 times of towels, the degree of scratching of the surface was visually observed and evaluated. (◎: Excellent, ○: Good, △: Decrease, ▲: Bad)

(9) Transparency: Measured by a color computer measuring instrument manufactured by SUGAINSTRUMENT, Japan, and the results are expressed as total light transmittance and HAZE.

Total light transmittance (%) = (sample transmitted light) / (sample irradiation light) × 100

HAZE (%) = (dispersed transmitted light) / (total light transmittance) x 100

As shown in Table 1, compared with Comparative Example 5 without using the impact modifiers, Examples 1 to 5 injecting the impact modifier according to the present invention, the transparency and haze characteristics are not significantly reduced, the impact resistance is individual And excellent surface scratchability such as rubbing characteristics.

Comparative Example 1 in which only the diene monomer was polymerized to prepare a rubbery polymer (A) was confirmed that the physical properties such as transparency, impact strength, yellowness, scratch resistance, and the like significantly decreased. In addition, when the crosslinking agent is not used in the first graft polymerization (Comparative Example 2), when the acrylic monomer (B) is not used (Comparative Example 3) and the aromatic vinyl monomer (C) is not used. Case (Comparative Example 4) was confirmed that the impact strength is lower than in Examples 1 to 5 of the present invention. And these were confirmed that the transparency, scratch resistance and yellowness is low, and rubbing characteristics are not improved.

The present invention provides an impact modifier capable of improving impact resistance and rubbing characteristics, without reducing the excellent transparency and scratch resistance of plastic resins, in particular methacryl-based resins, a manufacturing method thereof, and a methacryl-based resin composition using the same It has the effect of the invention.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (13)

A rubbery polymer (A) consisting of 30 to 45 wt% of a diene monomer and 55 to 70 wt% of an alkyl acrylate; A first graft layer formed by graft polymerization of an acrylic monomer (B), a crosslinking agent, and an aromatic vinyl monomer (C) on the surface of the rubbery polymer (A); And A second graft layer formed by graft polymerization of a methacrylic monomer (D) on the first graft layer; It includes, the content of the rubber polymer (A) is 45 to 70% by weight based on the total weight of the (A) + (B) + (C) + (D), the content of the acrylic monomer (B) Is 5 to 30% by weight based on the total weight of the (A) + (B) + (C) + (D), the content of the aromatic vinyl monomer (C) is the (A) + (B) + 1 to 10% by weight based on the total weight of (C) + (D), the content of the methacrylic monomer (D) is the total weight of the (A) + (B) + (C) + (D) Impact modifier, characterized in that 10 to 40% by weight based on. The method of claim 1. Impact modifier, characterized in that the average particle diameter of the rubbery polymer (A) is 150 ~ 250 nm. According to claim 1, The diene monomer is 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-methyl-1,3-butadiene, 1,3-pentadiene, 1,3- Hexadiene and mixtures thereof, The alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate and mixtures thereof, The acrylic monomer (B) is an alkyl acrylate selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and mixtures thereof, The aromatic vinyl monomer (C) is styrene, The methacrylate monomer (D) is selected from the group consisting of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate and mixtures thereof Alkyl methacrylate, The crosslinking agent is triallyl isocyanate, allyl methacrylate, or a mixture thereof. delete The impact modifier of claim 1, wherein the content of the crosslinking agent is 0.3 to 2 parts by weight based on 100 parts by weight of the total of (A) + (B) + (C) + (D). Preparing a rubbery polymer (A) by polymerizing a monomer mixture composed of a diene monomer and an alkyl acrylate; Primary graft polymerization by introducing an acrylic monomer (B), a crosslinking agent and an aromatic vinyl monomer (C) into the rubbery polymer (A); And Secondary grafting polymerization by adding a methacrylic monomer (D) to the first graft polymerization product; It comprises a step, wherein the rubber polymer (A) is used at 45 to 70% by weight based on the total weight of the (A) + (B) + (C) + (D), the acrylic monomer (B) 5 to 30% by weight based on the total weight of the (A) + (B) + (C) + (D), the aromatic vinyl monomer (C) is the (A) + (B) + ( 1 to 10% by weight based on the total weight of C) + (D), the methacryl-based monomer (D) is the total weight of the (A) + (B) + (C) + (D) Method for producing an impact modifier, characterized in that the input in 10 to 40% by weight as a standard. 7. The method of claim 6, wherein the average particle diameter of the rubbery polymer is 150 to 250 nm. 7. The method of claim 6, wherein the monomer mixture is 30 to 45 wt% of the diene monomer and 55 to 70 wt% of the alkyl acrylate. delete The method of claim 6, wherein the crosslinking agent is added at 0.3 to 2 parts by weight based on 100 parts by weight of the total of (A) + (B) + (C) + (D). 7. The method of claim 6, wherein the monomer mixture is polymerized using an emulsifier and a crosslinking agent. The method according to claim 11, wherein the emulsifier is selected from the group consisting of sodium laurate, sodium oleate, potassium oleate, potassium stearate and mixtures thereof, and used in an amount of 1 to 3 parts by weight based on 100 parts by weight of the monomer mixture. and, The crosslinking agent is triallyl isocyanate, allyl methacrylate, or a mixture thereof, and the method for producing an impact modifier is used in an amount of 0.3 to 1 parts by weight based on 100 parts by weight of the monomer mixture. 55 to 95% by weight of methacrylic resins; And 5 to 45% by weight of the impact modifier of any one of claims 1 to 3 and 5; Methacrylic resin composition comprising a.