KR100829850B1 - Continuous bulk polymerization process of rubber-modified transparent styrenic resin having uniform composition, good transparency and high impact strength - Google Patents

Abstract

A method for preparing a rubber modified styrene-based resin by continuous mass polymerization, and a transparent rubber modified styrene-based resin prepared by the method are provided to improve transparency and impact resistance and to enhance the uniformity of composition. A method for preparing a rubber modified styrene-based resin comprises the steps of injecting 100 parts by weight of a monomer mixture comprising 30-55 wt% of a styrene-based monomer and 45-70 wt% of a methyl methacrylate-based monomer, 5-14 parts by weight of a styrene-butadiene copolymer, and 10-30 parts by weight of a reaction medium into a first reactor and reacting it at 90-120 deg.C for 1-2 hours to prepare a first polymer product having a conversion rate of 20-40 %; injecting the first polymer product into a second reactor, and polymerizing it with adding 6 parts by weight or less of a styrene-based monomer or a methyl methacrylate-based monomer based on 100 parts by weight of the monomer mixture used in the first reactor at 110-140 deg.C for 1-3 hours to prepare a second polymer product having a conversion rate of 40-70 %; and injecting the second polymer product into a third reactor, and reacting it with adding 6 parts by weight or less of a styrene-based monomer or a methyl methacrylate-based monomer based on 100 parts by weight of the monomer mixture used in the first reactor and 0.005-0.03 parts by weight of the polydimethylsiloxane having a viscosity of 10-100 cSt at 25 deg.C based on 100 parts by weight of the final resin at 120-160 deg.C for 1-3 hours to prepare a second polymer product having a conversion rate of 70-95 %.

Description

Continuous Bulk Polymerization Process of Rubber-modified Transparent Styrenic Resin Having Uniform Composition, Good Transparency and High Impact Strength

Field of invention

The present invention relates to a method for producing a continuous block polymerization of a transparent rubber modified styrene resin. More specifically, the present invention relates to a method for producing continuous bulk polymerization of methyl methacrylate-butadiene-styrene resin having a uniform composition and excellent transparency and impact resistance.

Background of the Invention

Since general rubber modified styrene resin (HIPS) is excellent in strength and moldability, it is widely used as a household material such as food containers, packaging containers, and molding materials for home appliances. However, HIPS has a problem in that it cannot be used in a field where transparency is required because of its opaque property. Recently, the demand area of products requiring transparency is expanding and the demand volume is rapidly increasing.These products mainly include Styrene-Acrylonitrile (SAN), Polystyrene (PS), Polymethylmethacrylate (PMMA), Polycarbonate (PC), and MABS (Methyl). Transparent resins such as methacrylate-Acrylonitrile-Butadiene-Styrene copolymer) are used.

However, SAN, PS and PMMA have the advantages of excellent transparency and low price, but their use is limited due to their poor impact resistance.In the case of MABS, all of them have excellent transparency and impact resistance but contain AN (Acrylonitrile) Applications such as containers, toys or medical supplies have their disadvantages of limited use. PC also has the advantages of excellent transparency and impact resistance, but the price is too expensive and the chemical resistance is not good due to the disadvantage of its range of application. Therefore, the development of transparent MBS resins have the advantages of excellent transparency and impact resistance while having the advantages of low manufacturing cost, and can be used in various and wide fields have been actively progressed.

In general, transparent resins are prepared by emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. Among them, emulsion polymerization and suspension polymerization use emulsifiers or flocculants in the polymerization process, and these substances are not easily removed. This will lower the properties of the final product. In addition, since water is used as the reaction medium, an additional process for removing water after completion of the polymerization is required. In contrast, solution polymerization and bulk polymerization do not require additives used in emulsion polymerization or suspension polymerization, so that higher purity products can be obtained and production can be made at a lower cost. (Conversion) is usually more than 95%, the difference in the responsiveness of the constituent monomers may cause a difference in the composition of the polymer produced at the beginning of the polymerization and the composition of the polymer produced at the end of the polymerization so that the refractive index of the rubber and matrix The disadvantage is that it is difficult to match.

G. Odian writes in the book "Principles of Polymerization," and M. Hocking et al. In J. of "Polymer Science" (Part A, vol. 34, 1996) show that polymers are polymerized when radically polymerizing two or more monomer mixtures. The formula for predicting the composition of the inside has been proposed. This formula predicts the composition of the polymer by using the relative reaction rate ratio of each component of the monomer mixture, and indicates that the composition of the monomer does not become the composition of the polymer as long as it is not azeotropic. In other words, since the monomer with a fast reaction rate is quickly converted into a polymer, a component having a fast reaction rate is present in the polymer component at the beginning of the polymerization reaction, and a component having a slow reaction rate is present in the polymer component toward the end. do. If the conversion rate is more than 95%, since most of the monomers are converted into polymers, the average composition will be similar to that of the initial monomers. However, it is expected that a polymer having a different composition will be produced depending on the production time. Can be.

Therefore, even if the average refractive index of the matrix resin prepared by the above technique coincides with the rubber in the disperse phase, the difference in refractive index is partially shown, which adversely affects the transparency.

On the other hand, Japanese Patent Laid-Open Publication Nos. 2001-31833 and 2002-114886 are conventional techniques for mixing a matrix component and polymerizing it first, followed by compounding with a rubber component, to match the refractive index. However, this method also has a problem in that the improvement of the strength is insufficient, and because of the need for compound addition process, there is a problem that the economic efficiency is lowered and transparency is lowered.

In order to sufficiently improve the strength, it is necessary to increase the content of the styrene-butadiene copolymer in polystyrene. However, in this case, the impact resistance is increased, but there is a problem that the transparency is lowered and the cost is further increased.

In addition, Japanese Patent Application Laid-open No. Hei 4-277549 discloses a composition in which an organic polysiloxane is added to a rubber-modified styrene resin copolymerized with styrene, methyl methacrylate and acrylic acid ester in the presence of a rubber copolymer. The method also improves sheet formability but is not sufficiently satisfactory for impact resistance.

Recently, the market is actively moving from high quality resins to cheap styrene resins due to the demand for manufacturing cost down. In order to satisfy these market demands, it is preferable that the composition of the transparent rubber-modified styrene resin is uniform and has excellent properties in both impact resistance and transparency. Accordingly, the present inventors put polydimethylsiloxane into the polymerization process while uniformizing the composition of the transparent rubber-modified styrene resin so that the transparency and impact resistance can be improved at the same time. It has begun to develop a process for producing a continuous bulk polymerization of modified styrene resins.

An object of the present invention is to provide a method for producing a continuous block polymerization of rubber modified styrene resin having excellent transparency.

Another object of the present invention is to provide a method for producing a continuous block polymerization of a rubber-modified styrene resin having a uniform composition.

Still another object of the present invention is to provide a method for producing a continuous block polymerization of a rubber-modified styrene resin having excellent impact resistance.

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

Summary of the Invention

The continuous bulk polymerization production method of the transparent rubber-modified styrene resin according to the present invention comprises (A) 100 parts by weight of a monomer mixture consisting of 30 to 55% by weight of a styrene monomer and 45 to 70% by weight of a methyl methacrylate monomer, and styrene- A raw material mixture consisting of 5 to 14 parts by weight of butadiene copolymer and 10 to 30 parts by weight of reaction medium was added to the first reactor and reacted at 90 to 120 ° C. for 1 to 2 hours to produce a first polymer having a conversion rate of 20 to 40%. To put it on;

(B) The first polymer is introduced into the second reactor, and the styrene monomer or the methyl methacrylate monomer is added to 6 parts by weight or less with respect to 100 parts by weight of the monomer mixture, at 1 to 3 hours at 110 to 140 ° C. Polymerization to produce a second polymer having a conversion of 40 to 70%; And

(C) The second polymer is introduced into a third reactor, and the styrene monomer or the methyl methacrylate monomer is 6 parts by weight or less with respect to 100 parts by weight of the monomer mixture, and the viscosity at 25 ° C. is 10 to 100 cSt. Phosphoric polydimethylsiloxane was added at 0.005 to 0.03 parts by weight based on 100 parts by weight of the final resin, and reacted at 120 to 160 ° C. for 1 to 3 hours to produce a third polymer having a conversion ratio of 70 to 95%;

Characterized in that comprises a step.

In the step (A), 0.1 and 0.35 parts by weight or less may be added to 100 parts by weight of the initiator and the molecular weight modifier monomer mixture, respectively.

The styrene-butadiene copolymer is preferably a block or random copolymer having a styrene content of 10 to 40%.

It is preferable that the refractive index difference of the matrix resin which is continuous phase with the refractive index of the said styrene-butadiene copolymer or its graft copolymer which is the dispersed phase is less than 0.002.

The present invention is prepared according to the above production method, and the final methyl methacrylate- consisting of the methyl methacrylate monomer-styrene resin content of the disperse phase is 5-15% by weight of the diene-based rubber and the continuous phase-styrene resin- Transparent rubber-modified styrene resins, characterized by containing 0.005 to 0.03 parts by weight of polydimethylsiloxane having a viscosity of 10 to 100 cSt at 25 ° C. with respect to 100 parts by weight of butadiene-styrene resin.

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

Detailed Description of the Invention

The transparent rubber-modified styrene resin composition having a uniform composition and excellent impact resistance and transparency according to the present invention is a series of a mixed solution containing a styrene monomer, a methyl methacrylate monomer, a reaction medium, and a styrene-butadiene copolymer (Rubber). It can be prepared through a continuous polymerization process to continuously put into three reactors with a stirring device connected to the reactor and to maintain a constant residence time and a constant temperature and then discharge the reactants continuously.

In the present invention, a monomer or a mixture of monomers consumed by the difference in the reaction rate in the immediately preceding reactor is added to the reactor immediately after each successive participation in the polymerization reaction. The composition of the polymer produced through such a manufacturing method can be maintained uniformly for each reactor. Meanwhile, the conversion rate (Conversion_) of each reactor converted from monomer to polymer while passing through each continuous polymerization reactor is preferable to be less than 40%. If the conversion rate of each step exceeds 40%, the composition of the polymer produced initially is Since the composition of the polymer produced at the end and the end is different, even if the average refractive index is the same, a slight difference in the refractive index is generated, resulting in poor transparency of the final MBS resin.

In addition, the present invention is characterized in that the polydimethylsiloxane is added to the reactor in order to have excellent impact resistance, it is characterized by using a method of controlling through changes in reaction temperature, initiator content, residence time, etc. to achieve conversion in each reactor do.

Each step of the present invention is as follows.

Step (A): Preparation of First Polymer

The method for producing a transparent rubber-modified styrene resin according to the present invention first dissolves a styrene-butadiene copolymer as a rubber component in a mixed solution in which a monomer mixture of a styrene monomer and a methyl methacrylate monomer and a reaction medium are mixed in a dissolution tank. Then, it is transferred to a fully mixed full charge reactor, which is a first reactor with a stirring device.

Styrene monomers used in the present invention is generally styrene, but o-methyl styrene (p-methyl styrene), p-methyl styrene (m-methyl styrene), 2,4-dimethyl styrene, p-ethyl styrene, α-methyl styrene, α-ethyl styrene It is possible.

In addition, methyl methacrylate monomers are generally methyl methacrylate (methyl methacrylate), methacrylate (methacrylate), acrylate (acrylate), methyl acrylate (methyl acrylate), ethyl methacrylate (ethyl metacrylate), ethyl acrylate, 2-ethyl hexyl methacrylate, 2-butyl hexyl methacrylate, butyl acrylate, etc. may be used.

In the present invention, the mixing ratio of the styrene monomer and the methyl methacrylate monomer in the monomer mixture needs to be considered to match the refractive index of the polymer produced by reacting with the rubber component, the styrene monomer 30 to 55% by weight And 45 to 70% by weight of methyl methacryl-based monomers, based on 100 parts by weight of the other components are mixed.

In addition, as the reaction medium according to the present invention, aromatic compounds such as ethyl benzene, benzene, toluene, xylene, and methyl ethyl ketone may be used. . The use amount of the reaction medium is suitably 10 to 30 parts by weight, preferably 15 to 25 parts by weight, based on 100 parts by weight of the monomer mixture. When the amount of the reaction medium is higher than 30 parts by weight with respect to 100 parts by weight of the monomer mixture, a problem may occur in that the conversion speed of the monomer is lowered at the same temperature, the mechanical stability of the rubber phase is lowered, and the impact strength is lowered. If the amount is less than 10 parts by weight, the viscosity of the reactants (Viscosity) is too high to increase the conversion rate of the monomer may be a problem that it is difficult to proceed with the polymerization.

As the styrene-butadiene copolymer which is a rubber component used in the present invention, a block or random copolymer having a styrene skeleton content of 10 to 40% by weight and butadiene of 60 to 90% by weight needs to be used. Preferably, a styrene-butadiene copolymer having a styrene skeleton content of 15 to 40% by weight and a butadiene of 60 to 85% by weight is used. If the ratio of styrene skeleton contained in the rubber component is less than 10% by weight, it is difficult to adjust the rubber particle size and the viscosity of the polymer during polymerization, and the ratio of the styrene skeleton contained in the rubber component When it is higher than 40% by weight, the amount of the styrene-butadiene copolymer rubber component is increased so that the manufacturing cost is excessively increased and impact resistance is lowered.

In addition, in the first reactor, an additive such as an initiator or a molecular weight regulator may be used to maintain the conversion at a constant level, and the type and content of the additive may be appropriately adjusted. As the polymerization initiator in the present invention, benzoyl peroxide, t-butyl peroxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane (1,1- Bis (t-butylperoxy) cyclohexane), 2,2-bis (4,4-di-t-butylperoxy cyclohexane) propane (2,2-Bis (4,4-di-t-butylperoxy cyclohexane) propane) t-hexyl peroxy isopropyl monocarbonate, t-Butyl peroxylaurate, t-Butyl peroxy isopropyl monocarbonate ), t-Butyl peroxy 2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-Butyl peroxyacetate , 2,2-bis (t-butyl peroxy) butane (2,2-Bis (t-butyl peroxy) butane), t-butyl peroxybenzoate (t-Butyl peroxybenzoate), Dicumyl peroxide ) , 2,5-dimethyl-2,5-bis (t-butyl peroxy) hexane (2,5-Dimethyl-2,5-bis (t-butyl peroxy) hexane), t-butyl cumyl peroxide (t- Butyl cumyl peroxide), Di-t-butyl peroxide, Di-t-amyl peroxide, and the like can be used. As the molecular weight regulator, one or more selected from n-octyl mercaptane, n-dodecyl mercaptane, and t-dodecyl mercaptan can be used.

The use amount of the initiator is suitably 0 to 0.1 parts by weight based on 100 parts by weight of the monomer mixture, and the use amount of the molecular weight regulator is suitably 0 to 0.35 parts by weight based on 100 parts by weight of the monomer mixture. When the amount of the initiator is used in excess of 0.1 parts by weight, it is difficult to effectively control the reaction temperature, residence time, etc. due to the rapid polymerization reaction, the molecular weight of the resulting polymer is lowered, the impact strength is lowered, the amount of the molecular weight regulator exceeds 0.35 parts by weight In this case, there may be a problem that the molecular weight of the resulting polymer is sharply lowered and the impact strength is lowered.

The first reactor of the present invention is a fully-charged reactor with a stirring device, and the mixture is fed to the bottom of the reactor so that the reactant comes out to the reactor. After the reaction at a polymerization temperature of 90 to 120 ° C. for 1 to 2 hours, the reaction of the monomer is converted to a phase transition point of 20 to 40%, and then the reactant is continuously transferred to the second reactor. The polymer composition of the mixed solution increases the ratio of the polymer grafted to the styrene-butadiene copolymer rubber to form stable rubber particles in the first reactor to improve the impact strength and physical properties.

Step (B): Preparation of Second Polymer

The first polymer prepared in step (A) is continuously added to a second reactor connected in series with the first reactor to prepare a second polymer having a monomer conversion of 40 to 70%.

The second reactor is a fully mixed reactor having a stirring device, and polymerization proceeds at a polymerization temperature of 110 to 140 ° C. for 1 to 3 hours, and the conversion rate is 40 to 70%.

In the second reactor, a styrene-based monomer or a methyl methacrylate-based monomer is used to uniformize the composition of the matrix polymer in a continuous phase and to match the refractive index of the matrix polymer with the refractive index of the rubbery polymer. 1 to 0 to 6 parts by weight is additionally added to 100 parts by weight of the monomer mixture in the raw material solution mixture composed of the reaction medium, the styrene monomer, the methyl methacrylate monomer and the styrene-butadiene copolymer rubber. The type of monomer added is as in step (A).

Step (C): Preparation of Third Polymer

The second polymer prepared in step (B) is continuously introduced into a third reactor connected in series with the second reactor to prepare a third polymer having a monomer conversion of 70 to 90%.

The third reactor is a fully mixed reactor having a stirring device, the final reactor of the polymerization step, the reaction proceeds for 1 to 3 hours at a reaction temperature of 120 to 160 ℃, the conversion rate is 70 to 95%. In this step, a styrene-based monomer or a methyl methacrylate-based monomer is used to uniformize the composition of the matrix polymer in the continuous phase and to match the refractive index of the rubber polymer in the dispersed phase with the refractive index of the rubber phase polymer in the dispersed phase. 0 to 6 parts by weight of the reaction medium, the styrene monomer, the methyl methacrylate monomer and the styrene-butadiene copolymer in the mixed solution added to the first reactor are additionally added.

In addition, polydimethylsiloxane having a viscosity of 10 to 100 cSt at 25 ° C. with respect to 100 parts by weight of the transparent rubber-modified styrene-based resin composition finally produced in consideration of the conversion rate of the third polymer produced and discharged in the third reactor. siloxan) is further added to contain 0.005 to 0.03 parts by weight.

The general structural formula of polydimethylsiloxane (Poly dimethyl siloxan), an impact improver used in the present invention, is represented by the following Chemical Formula 1.

[Formula 1]

In the above formula, n means the number of bonds of Si units (units) which are basic structural units in polydimethylsiloxane. Although the value is not specifically limited, n is 10-80 level in the viscosity in 25 to 10-100 cSt range.

The polydimethylsiloxane used in the present invention is a polymer in which basic structural units such as Chemical Formula 1 are repeatedly bonded, and an epoxy group, a carboxyl group, a phenyl group, and a methylhydrogen in the terminal or molecule thereof. Poly dimethyl siloxan polymers incorporating methyl hydrogen, hydroxy, fluoro, fluoro, vinyl, and methacrylates alone or in combination of two or more Used. It is preferable that the polydimethylsiloxane has a viscosity of about 10 to 100 cSt at 25 ° C. If the viscosity is too low, the evaporation temperature is low, so it is easily evaporated in the volatile remover, so that sufficient amount of polydimethylsiloxane does not remain in the resin, and the molecular weight is low, so that the impact strength is not improved. As a result, the haze of the resin rises sharply and thus there may be a problem in that transparency is lowered. In addition, the amount of polydimethylsiloxane added is required to maintain the level of 0.005 to 0.03 parts by weight relative to 100 parts by weight of the final transparent rubber modified styrene resin. If the amount of polydimethylsiloxane added is less than 0.005 parts by weight, there is no effect of improving the strength, such as impact resistance, and the strength is improved at 0.03 parts or more, but haze due to the difference in refractive index between the transparent rubber modified styrene resin composition and polydimethylsiloxane. This is because the transparency decreases.

The polymerization composition passed through the third reactor has a high impact strength by forming a stable rubber particles and at the same time the polymer has a uniform composition and excellent transparency by matching the refractive index of the rubber phase and the matrix phase.

The third polymer, which is the final polymer having a conversion rate of 70 to 95% through the third reactor, is transferred to a devolatilizer to remove unreacted monomers and reaction medium, thereby preparing a final transparent rubber-modified styrene resin.

The composition of the transparent rubber-modified styrene resin finally prepared through the continuous polymerization process consisting of the above-described steps is 5-15% by weight of the diene-based rubber (Rubber) in the dispersed phase and methyl methacrylate monomer-styrene in the continuous phase. (B) Poly dimethyl siloxan having a viscosity of 10 to 100 cSt at 25 ° C with respect to 100 parts by weight of methylmethacrylate-butadiene-styrene resin (transparent MBS resin) having a resin content of 85 to 95% by weight. ) 0.005 to 0.03 parts by weight, and the difference in refractive index between the styrene-butadiene copolymer (Rubber) or its graft copolymer and the matrix resin is less than 0.002. Preferably the refractive index difference between the graft copolymer and the matrix phase resin is less than 0.001, more preferably zero. If the difference in refractive index is greater than 0.002, the haze of the manufactured MBS resin rises sharply, resulting in poor transparency.

The present invention will be further illustrated by the following examples, which are merely illustrative of the present invention and are not intended to limit or limit the scope of the present invention.

Example

Example 1

A raw material solution was prepared by dissolving 38 parts by weight of styrene monomer, 36 parts by weight of methyl methacrylate monomer, 6 parts by weight of styrene-butadiene copolymer rubber and 20 parts by weight of ethyl benzene in a mixing bath. As the styrene-butadiene copolymer, a copolymer having a styrene skeleton content of 35% by weight was used. The prepared raw material solution was continuously supplied to a full charge plug flow reactor (PFR) with a stirring device as a first reactor. At the same time, 0.065 parts by weight of t-butyl peroxy-2-ethylhexyl monocarbonate as initiator and 0.2% by weight of t-dodecyl mercaptan as molecular weight regulator were added to 100 parts by weight of the monomer mixture in the raw material solution using a metering pump. In the first reactor, the reaction was performed at 115 ° C. and 100 RPM for 1.5 hours to prepare a first polymer.

125 ° C., while continuously feeding the first polymerized product passed through the first reactor into a fully mixed reactor having a stirring device as a second reactor, and simultaneously adding 1.5 parts by weight of styrene monomer to 100 parts by weight of the monomer mixture in the initial raw material solution mixture. The reaction was carried out at 100 RPM for 2 hours to prepare a second polymer.

Next, the second polymer was continuously introduced into a fully mixed reactor having a stirring device, which is a third reactor, and at the same time, 2.5 parts by weight of styrene monomer was added to 100 parts by weight of the monomer of the initial raw material mixed solution, and the viscosity was increased at 25 ° C. Reaction of 2 hours so that the final conversion rate of the reactant is 80% at 140 ° C. and 100 RPM condition while continuously adding 0.025 parts by weight to 100 parts by weight of the rubber-modified styrene-based resin to be finally prepared by considering the final conversion rate of cdimethyl polydimethylsiloxane. After the reaction was continuously discharged. After removing the unreacted monomer and the reaction medium through the volatilizer through the volatilization reactor and pelletized by using a pelletizer, the final polymer was obtained. The test specimens were manufactured by injection molding to evaluate the physical properties. The results of the evaluation are shown in Table 1. The physical property evaluation method is as follows.

(1) Impact strength (kgcm / cm): Izod impact strength was measured by ASTM D-256.

(2) Haze (%): Measured by ASTM D1003. The specimen used had a thickness of 3.2 mm and was measured using a model name HZ-1 of SUGA Test Instruments.

(3) Total light transmittance (%): It measured by ASTM D1003. The specimen used had a thickness of 3.2 mm and was measured using a model name HZ-1 of SUGA Test Instruments.

(4) Flowability (g / 10 min, 10 kg, 220 ° C.): measured by ASTM D1238.

(5) Average rubber particle size (µm) and distribution of final product: Malvern's Mastersizer S Ver. Measured using 2.14.

(6) Refractive index: The specimen used had a thickness of 3.2 mm and was measured using Metricon prism coupler.

(7) Rubber content in the product: Measured by using an oxo titration method.

Example 2

39 parts by weight of styrene monomer, 34.5 parts by weight of methyl methacrylate monomer, 6.5 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of styrene-butadiene copolymer and 37 parts by weight of ethyl benzene in a mixing tank Was carried out in the same manner as in Example 1 except that t-dodecyl mercaptan, which was added together with the first reactor, was changed to 0.25 parts by weight based on 100 parts by weight of the monomer of the initial raw material solution mixture. .

Example 3

23.0 parts by weight of styrene monomer, 52.0 parts by weight of methyl methacrylate monomer, 5 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of styrene-butadiene copolymer and 20 parts by weight of ethyl benzene in a mixing tank Was continuously added to the first reactor, and the additional styrene monomer was added to 3 parts by weight based on 100 parts by weight of the monomer of the initial raw material mixture in the second reactor, and the additional styrene monomer was added to the monomer of the initial raw material mixture in the third reactor. Except for changing to 5.5 parts by weight based on 100 parts by weight was carried out in the same manner as in Example 1.

Example 4

Raw material solution by dissolving 39 parts by weight of styrene monomer, 33 parts by weight of methyl methacrylate monomer, 8 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of styrene-butadiene copolymer and 20 parts by weight of ethyl benzene in a mixing tank. Was continuously added to the first reactor, and the second styrene monomer addition amount was changed to 1 part by weight based on 100 parts by weight of the monomer of the initial raw material solution mixture, and the additional styrene monomer addition amount was changed to the monomer of the initial raw material solution mixture in the third reactor. Except for changing to 3.0 parts by weight based on 100 parts by weight was carried out in the same manner as in Example 1.

Example 5

Except that the polydimethylsiloxane having a viscosity of 20 cSt at 25 ℃ in the third reactor was changed to 0.005 parts by weight based on 100 parts by weight of the final rubber modified styrene resin was carried out in the same manner as in Example 1.

Example 6

The same procedure as in Example 1 was performed except that the polydimethylsiloxane introduced into the third reactor was changed to polydimethylsiloxane having a viscosity of 100 cSt at 25 ° C.

Example 7

12 parts by weight of a styrene-butadiene copolymer rubber having a styrene skeleton content of 35% by weight of the styrene-butadiene copolymer, 36 parts by weight and 32 parts by weight of styrene monomer, methyl methacrylate monomer, and ethylbenzene, respectively, It was carried out in the same manner as in Example 1 except for changing to 20 parts by weight, dissolving in a mixing tank to continuously feed the raw material solution into the first reactor.

Comparative Example 1

In Example 1 was carried out in the same manner as in Example 1 except that polydimethylsiloxane having a viscosity of 20 cSt at 25 ° C. was not added to the third reactor.

Comparative Example 2

The same procedure as in Example 1 was performed except that the polydimethylsiloxane introduced into the third reactor in Example 1 was changed to polydimethylsiloxane having a viscosity of 200 cSt at 25 ° C.

Comparative Example 3

In Example 1, except that the amount of polydimethylsiloxane having a viscosity of 20 cSt at 25 ° C. in the third reactor was changed to 0.05 parts by weight based on 100 parts by weight of the rubber-modified styrene resin, the remainder was performed in the same manner as in Example 1. Was

Comparative Example 4

The composition of the raw material solution mixture in Example 2 was 33 parts by weight of styrene monomer, 30 parts by weight of methyl methacrylate monomer, 17 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of styrene-butadiene copolymer and 37% by weight of ethyl. Changed 20 parts by weight of benzene into the first reactor continuously, the reaction temperature was changed to 110 ° C. in the first reactor, and the amount of t-dodecyl mercaptan added was 0.35% by weight based on 100 parts by weight of the monomer of the initial raw material solution mixture. The reaction temperature was changed to 120 ° C. in the second reactor, and the additional styrene monomer was added to 2 parts by weight based on 100 parts by weight of the monomer of the initial raw material solution mixture, and the reaction temperature was changed to 137 ° C. in the third reactor. And styrene monomer additional charge was changed to 3 parts by weight relative to 100 parts by weight of the monomer of the initial raw material solution mixture. It was performed in the same manner as in Example 2

Comparative Example 5

The composition of the raw material solution mixture was 39 parts by weight of styrene monomer, 35 parts by weight of methyl methacrylate monomer, and styrene-butadiene copolymer such that the refractive index of the final product was 1.546 without correction for the composition that is changed in each reaction step in Example 1. 6 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of 35 parts by weight and 20 parts by weight of ethyl benzene was continuously added to the first reactor, and styrene monomer was not added in the second reactor and the third reactor. Except that was carried out in the same manner as in Example 1.

Comparative Example 6

In Example 1, the composition of the raw material solution mixture was 40 parts by weight of styrene monomer, 34 parts by weight of methyl methacrylate monomer, 6 parts by weight of styrene-butadiene copolymer rubber having a styrene skeleton content of 35% by weight of styrene-butadiene copolymer and ethyl. Changed 20 parts by weight of benzene into the first reactor continuously, and changed the styrene monomers introduced in the second reactor and the third reactor into methyl methacrylate monomer to monomer in the initial raw material solution mixture in the second reactor and the third reactor, respectively It carried out in the same manner as in Example 1 except that 2 parts by weight based on 100 parts by weight.

The results of the physical properties analysis of the polymerization conditions and the final polymer prepared in Examples 1 to 7 are shown in Table 1, and the results of the physical properties analysis of the polymerized conditions and the final polymer prepared in Comparative Examples 1 to 6 are shown in Table 2. Indicated.

As shown in Examples 1 to 7 of Table 1, using a styrene-butadiene copolymer having a styrene skeleton content of 10 to 40% range, the raw material solution mixture was continuously added and the amount of monomer used in each polymerization step was taken into consideration. In the second reactor and the third reactor, additional monomers are added so that the polymer has a uniform composition while matching the refractive index of the rubber phase with that of the matrix, and the resin has a polydimethylsiloxane having a viscosity of 10 to 100 cSt at 25 ° C from 0.005 to 0.025. When it is contained in parts by weight, even if the rubber content in the resin is not high, it was possible to obtain a product excellent in impact strength and transparency.

On the other hand, when the polydimethylsiloxane is not added as shown in Comparative Example 1, the impact resistance was lowered, and when polydimethylsiloxane having a viscosity higher than 100 cSt was added at 25 ° C as shown in Comparative Examples 2 and 3, When the viscosity of polydimethylsiloxane having a viscosity of 20 cSt at 25 ° C. was added more than 0.03 parts by weight, the impact strength was increased, but the haze was sharply lowered to obtain a desired product. In addition, as shown in Comparative Example 4, when the rubber content of the final product was 16 parts by weight, the impact strength was similarly increased, but the haze was sharply decreased. As shown in Comparative Example 5, the refractive index on the matrix of the final product in the state in which the composition of the polymer was not uniform without correcting the change of the monomer composition at each reaction step due to the difference in the reaction rate for each monomer by adding additional monomers. When only the rubber-like refractive index was matched, the impact resistance was maintained high, but also the haze was lowered, and thus a desired product could not be obtained. On the other hand, when the composition of the raw material solution mixture is changed and the monomers introduced into the second reactor and the third reactor are added with methyl methacrylate instead of styrene, the composition is uniform and impact strength and transparency are the same as those of Examples 1 to 4. It was found that a very good product can be obtained.

When preparing the resin through the production method of the present invention through the above examples and comparative examples it was confirmed that a transparent rubber modified styrene resin having a uniform composition, excellent impact resistance and transparency can be prepared.

The present invention has the effect of providing a method for producing a continuous block polymerization of a rubber-modified styrene resin having a uniform composition and excellent transparency and impact resistance.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (6)

(A) 100 parts by weight of a monomer mixture composed of 30 to 55% by weight of styrene monomer and 45 to 70% by weight of methyl methacrylate monomer, 5 to 14 parts by weight of styrene-butadiene copolymer, and 10 to 30 parts by weight of reaction medium. Adding the raw material mixture to a first reactor and reacting at 90 to 120 DEG C for 1 to 2 hours to produce a first polymer having a conversion rate of 20 to 40%; (B) 110 to 140 while adding the first polymer to the second reactor and adding styrene monomer or methyl methacrylate monomer to 6 parts by weight or less based on 100 parts by weight of the monomer mixture used in the first reactor. Polymerization at 1 ° C. for 1 to 3 hours to produce a second polymer having a conversion of 40 to 70%; And (C) The second polymer was introduced into a third reactor, and the styrene monomer or the methyl methacrylate monomer was added to 6 parts by weight or less based on 100 parts by weight of the monomer mixture used in the first reactor, at 25 ° C. A polydimethylsiloxane having a viscosity of 10 to 100 cSt was added at 0.005 to 0.03 parts by weight based on 100 parts by weight of the final resin, and then reacted at 120 to 160 ° C. for 1 to 3 hours to produce a third polymer having a conversion rate of 70 to 95%. Letting; Method for producing a continuous block polymerization of a transparent rubber-modified styrene resin, characterized in that it comprises a step. The method of claim 1, wherein in step (A), benzoyl peroxide, t-butyl peroxyisobutylate, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4- Di-t-butylperoxy cyclohexane) propane, t-hexyl peroxy isopyrophyll monocarbonate, t-butyl peroxylaurate, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy 2-ethylhexyl Monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate, 2,2-bis (t-butyl peroxy) butane, t-butyl peroxybenzoate, dicumyl peroxide , An initiator selected from the group consisting of 2,5-dimethyl-2,5-bis (t-butyl peroxy) hexane, t-butyl cumyl peroxide, di-t-butyl peroxide and di-t-amyl peroxide Continuous ingot of transparent rubber-modified styrene resin, characterized in that added to 0.1 parts by weight or less based on 100 parts by weight of the monomer mixture Polymerization method. The method of claim 1, wherein in step (A), at least one molecular weight modifier selected from the group consisting of n-octyl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan is added to 100 parts by weight of the monomer mixture. It is added to 0.35 weight part or less, The continuous block polymerization manufacturing method of transparent rubber modified styrene resin characterized by the above-mentioned. The method of claim 1, wherein the styrene-butadiene copolymer is a block or random copolymer having a styrene content of 10 to 40% by weight. The method for producing continuous bulk polymerization of a transparent rubber-modified styrene resin according to claim 1, wherein the difference in refractive index between the styrene-butadiene copolymer as the dispersed phase or the graft copolymer thereof is less than 0.002. 25 to 100 parts by weight of the final methylmethacrylate-butadiene-styrene resin prepared according to the method of any one of claims 1 to 5, consisting of 5 to 15% by weight of the dispersed phase and 85 to 95% by weight of the continuous phase. A transparent rubber-modified styrene resin, which contains 0.005 to 0.03 parts by weight of polydimethylsiloxane having a viscosity of 10 to 100 cSt at ℃.