KR20050034919A - Rubber modified styrene resin having high strength and gloss and preparing method thereof - Google Patents

Abstract

The present invention relates to a rubber-modified styrene-based resin having a bimodal particle size distribution and a method for producing the same, wherein the butadiene rubber polymer and a styrene-based monomer are dissolved in an organic solvent. A pre-graft polymerization step of graft polymerization of a predetermined amount of the mixed solution using a polymerization initiator; And a graft polymerization step of graft polymerization by further adding the remaining amount of the mixed solution to the pre-graft polymer. Made of a rubber-modified styrene resin according to the present invention has an excellent impact strength and gloss.

Description

Rubber Modified Styrene Resin Having High Impact and High Gloss and Manufacturing Method Thereof {Rubber Modified Styrene Resin Having High Strength and Gloss and Preparing Method Thereof}

The present invention relates to a rubber modified styrene resin (HIPS resin) having excellent impact resistance and excellent gloss and a method for producing the same. More specifically, a predetermined weight part of the input butadiene-based rubber polymer is pre-grafted by using a low temperature initiator to prepare a resin by varying the graft ratio of the rubber phase so that the rubbery particles have a high modulus of impact resistance and gloss in a bimodal form. A styrene resin composition and its manufacturing method are related.

Rubber modified styrene resin, which is one of the disadvantages of styrene resins, is a thermoplastic resin obtained by graft copolymerization of styrene monomers in the presence of a rubber polymer. Extruded sheets are used in all areas where impact resistance is required.

The mechanical properties and gloss of these rubber-modified styrene-based resins are affected by the size, composition and content of the rubber particles in the resin.For example, when the low rubber content or the rubber particles in the resin are small, the tensile strength and gloss are improved, but the elongation and impact strength There is a disadvantage in that the decrease in the rubber content in the resin may improve the impact strength, but there is a problem in that the gloss is lowered. Therefore, in order to solve this problem, the rubber particles dispersed in the resin are made in the form of bimodal, and the large rubber particles are advantageous for the impact strength and the small rubber particles are favorable for the gloss. The results are usually not satisfactory.

US Patent Publication US 4,153,645; 4,334,039 prepared a bimodal resin using a variety of butadiene-based rubber, but has a disadvantage in that the gloss is excellent in mechanical properties.

European Patent Publication EP-048,389 forms core-shell and salami forms using styrene butadiene block copolymers and butadiene-based rubbers to form bi-modal distributed particles, resulting in impact strength and gloss. Although an excellent resin is prepared, it has a disadvantage of high manufacturing cost.

U.S. Patent Publication No. 4,146,589 proposes a process for preparing bimodal styrene resins by bulk polymerization. It consists of three reaction zones, two of which produce polymers with small rubbery particle sizes (0.5 to 1.0 μm) and large polymers (2 to 3 μm), respectively. Although a bimodal styrene-based resin was prepared by mixing a polymer and performing a polymerization reaction, the present invention had a disadvantage in that the process was complicated and the production cost was high because separate polymerization should be performed in three regions.

US Patent Publication US 5,491,195; In 4,254,236, the rubber solution is divided into the first reactor and the second reactor, so the rubber phases of the rubber solution introduced into the first reactor become small particles, and the rubber phases introduced into the second reactor become large particles, thereby producing a bimodal polymer. Prepared.

US Patent Publication US 6,444,752; In 5,708,081, a bimodal resin was prepared using butadiene-based rubber having high viscosity solution viscosity and butadiene-based rubber having low viscosity solution viscosity.

US Patent Publication US 5,191,023; 4,587,294; 4,639,494, European Patent Publications EP 277,687 and Japanese Patent Publications JP 59-232140 and 59-179611 to prepare resins using star-branched rubbers in the US patent publications US 6,441,090; 6,350,813, Japanese Patent Publication JP 5-194,676; 5-247,149; 6-166,729 and European Patent Publication EP 160,974 prepared bimodal resins using star butadiene rubbers and linear butadiene rubbers.

However, all of the above had a problem that the balance between the gloss and the mechanical properties are satisfactory.

In order to solve the problems as described above, the present invention, by using a initiator by a predetermined weight part of the butadiene-based rubber polymer by a pre-graft reaction with a certain weight part of the styrene monomer, excellent impact strength and gloss by one continuous process An object of the present invention is to provide a method for producing a rubber modified styrene resin.

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

The present invention to achieve the above object,

In the rubber-modified styrene resin, there is provided a rubber-modified styrene resin, characterized in that it comprises two kinds of rubber-like particles having a size of 0.5 to 2㎛ and 5 to 10㎛.

In another aspect, the present invention provides a method for producing a rubber-modified styrene resin, comprising: a pre-graft polymerization step of graft polymerization of a predetermined amount of a mixed solution in which butadiene rubber polymer and a styrene monomer are dissolved in an organic solvent using a polymerization initiator; And a graft polymerization step of graft polymerization by further adding the remaining amount of the mixed solution to the pre-graft polymer. It provides a method for producing a rubber-modified styrene resin, characterized in that comprises a.

The butadiene rubber polymer is 3 to 10 parts by weight based on the total amount, the styrene monomer is 90 to 97 parts by weight based on the total amount, and the organic solvent may be administered 0 to 30 parts by weight based on the total amount, butadiene rubber of the polymer 10 to 90% by weight of the total amount, 5 to 30% by weight of the total amount of the styrene-based monomer and 50 to 100% by weight of the total amount of the organic solvent mixed with a polymerization initiator in a mixed solution dissolved in the reactor temperature 50 to 100 Pre-graft-polymerization step of graft polymerization at 1 to 3 hours; 10 to 90% by weight of the total amount of butadiene rubber polymer, 70 to 95% by weight of the total amount of the styrene monomer and 0 to 50% by weight of the total amount of the organic solvent in the pre-grafted polymer 2 The present graft polymerization step of graft polymerization by the reactor temperature of 100 to 180 ℃ to the reactor of a continuous polymerization apparatus in which two or more stirring reactors are connected in series; It may be made, including.

During the graft polymerization step, 10 to 30 parts by weight of the styrene monomer and 0.01 to 1.0 parts by weight of the organic peroxide polymerization initiator may be further added.

The butadiene-based rubber polymer may be a solution viscosity of 30% to 200cp 5% styrene at 25 ℃.

The styrene monomers include styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, ethyl styrene, I-butyl styrene, t-butyl styrene or alkyl styrene having equivalent properties; And halogenated styrenes having o-bromo styrene, p-bromo styrene, m-bromo styrene, o-chloro styrene, p-chloro styrene, m-chloro styrene or equivalent properties; It may be one or more selected from the group consisting of.

The polymerization initiator may be 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, dibenzoyl peroxide or diacryl peroxides having the same properties; And 1,1-dimethyl-3-hydroxybutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, α-cumyl peroxyneheptanoate, tertiary-amyl peroxyneodecanoate Tertiary-amyl peroxypivalate, tertiary-butyl peroxypivalate, 2,5-dimethyl-2,5-di- (2-ethylhexanoyl peroxy) hexane, tertiary-amyl peroxy 2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate or peroxyesters having the same properties; It may be one or more selected from the group consisting of.

The pre-graft polymerization step and the present graft polymerization step may be selected from the group consisting of continuous or batch bulk polymerization, solution polymerization, and block-suspension polymerization.

The present invention also provides a rubber-modified styrene resin prepared by the above method.

Hereinafter, the present invention will be described in detail.

The present invention is a continuous process for producing a rubber-modified styrene resin prepared by a method comprising graft polymerization of a styrene monomer in the presence of butadiene-based rubber polymer, having a bimodal particle distribution has excellent impact strength and gloss The rubber-modified styrene-based resin can be produced, and the rubber-modified styrene-based resin according to the present invention is excellent in impact resistance and gloss, and is suitable for molding an injection molding having a thin thickness for a housing application.

Butadiene-based rubber filler used in the present invention is 3 to 10 parts by weight based on the total amount, styrene-based monomer is preferably added to 90 to 97 parts by weight, the styrene monomer is further 10 to 30 during the graft polymerization step. The weight part can be added.

The organic solvent used in the present invention may be any organic solvent capable of forming a solution with a styrene monomer, butadiene rubber polymer and styrene polymer, and benzene, ethyl benzene, toluene and xylene are particularly preferable. .

Since only the butadiene-based rubber polymer and the styrene monomer can be liquefied, the organic solvent may not be added. Preferably, 0 to 30 parts by weight is added to adjust the viscosity of the solution.

The organic peroxide polymerization initiator used in the present invention is preferably added to 0.01 to 1.0 parts by weight based on the total amount.

Hereinafter, the manufacturing steps of the present invention will be described.

I) dissolving 10 to 90% by weight of the total amount of butadiene-based rubber polymer in 5 to 30% by weight of the total amount of the styrene monomer and 50 to 100% by weight of the total amount of the organic solvent to prepare a mixed solution;

Ⅱ) mixing the polymerization initiator with the mixed solution of step I) and then performing pre-graft-polymerization at a reactor temperature of 50 to 100 ° C. for 1 to 3 hours;

Ⅲ) 10 to 90% by weight of the total amount of butadiene-based rubber polymer, 70 to 95% by weight of the total amount of the styrene monomer and 0 to 50% of the total amount of the organic solvent in the graft polymer of step Ⅱ) Preparing a raw material mixture solution;

IV) the mixed solution of step III) is introduced into the first reactor of the continuous polymerization apparatus in which two or more stirring reactors are connected in series at a reactor temperature of 100 to 180 ° C. to perform the graft polymerization;

V) a polymerization step of continuously introducing two or more series-connected copolymers of step IV) into a reactor to obtain a final polymer;

Ⅵ) optionally adding 10 to 30 parts by weight of the styrene monomer of step I) and 0.01 to 1.0 parts by weight of the organic peroxide polymerization initiator in the polymer production step of steps III), IV) or V) to increase the production ;

Iii) devolatilizing and pelletizing the final copolymer of step V) or VI);

To prepare a rubber-modified styrene resin by a method comprising a.

The butadiene-based rubber polymer in the above steps I) and III) is preferably a 5% styrene solution viscosity of 30 to 200cp at 25 ℃. If the styrene solution viscosity is out of the above range, the impact strength and gloss balance are not balanced.

The rubber polymer to be added in the present invention is preferably 3 to 10 parts by weight based on the total amount. If the rubber polymer is less than 3 parts by weight, the impact resistance of the produced resin is significantly lowered. If it exceeds 10 parts by weight, the impact resistance is advantageous, but the gloss is lowered, which is not preferable.

Styrene-based monomers to be introduced in the present invention are alkyl styrene and o- such as styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, ethyl styrene, I-butyl styrene, t-butyl styrene, etc. It can be used in combination of one or more selected from the group consisting of halogenated styrenes such as bromo styrene, p-bromo styrene, m-bromo styrene, o-chloro styrene, p-chromo styrene, m-chloro styrene And preferably styrene.

In the step IV), when the monomer mixed solution is continuously introduced into a continuous polymerization apparatus in which two or more stirring reactors are connected in series, the reactor temperature in the first reactor is preferably 100 to 180 ° C., more preferably 100 to 150 ° C. .

The polymerization temperature in the step II) is preferably 50 to 100 ° C, since the one hour half-life temperature of the polymerization initiator to be introduced is 50 to 100 ° C. If the polymerization temperature is lower than 50 ℃ the efficiency of the graft reaction to the rubber polymer of the styrene monomer is lowered, and if it exceeds 100 ℃ it is not preferable because the control of step III) becomes difficult. More preferably, it is between 70-90 degreeC.

Diacryl peroxides such as 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide and dibenzoyl peroxide as the polymerization initiator; And 1,1-dimethyl-3-hydroxybutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, α-cumyl peroxyneheptanoate, tertiary-amyl peroxyneodecanoate Tertiary-amyl peroxypivalate, tertiary-butyl peroxypivalate, 2,5-dimethyl-2,5-di- (2-ethylhexanoyl peroxy) hexane, tertiary-amyl peroxy Peroxy esters, such as 2-ethylhexanoate and tert-butyl peroxy-2-ethylhexanoate, can be selected from the group consisting of at least one.

In the production method of the present invention, a rubber-modified styrene resin can be prepared by adding a lubricant, a solvent, a plasticizer, an antioxidant, or an ultraviolet absorber, which is used for conventional polymer polymerization.

As the manufacturing process used in the present invention, continuous or batch bulk polymerization, solution polymerization or block-suspension polymerization can be carried out, and continuous bulk polymerization or solution polymerization is regarded as having no problem of productivity and quality uniformity and water pollution. desirable.

The particle diameter of the rubber particles in the rubber-modified styrene resin according to the present invention is 0.5 to 2㎛ in the rubber phase after the pre-grafting polymerization step of step II) by the difference in the degree of graft of the styrene monomer and the butadiene rubber polymer In the case of the rubber phase which is not, it is formed to 5 to 10㎛ to prepare a bimodal styrene resin.

If the particle diameter of the small-diameter particles of the rubber particles exceeds 2㎛ there is a problem that the gloss is inferior, preferably 1 to 1.5㎛ range. In addition, when the particle diameter of the large-diameter particles of the rubber particles is less than 5㎛ there is a problem that the impact strength is lowered, if it exceeds 10㎛ the gloss is lowered, it is not preferable because the efficiency of the rubber against the impact strength drops sharply In addition, there is a problem that the manufacturing cost is increased by increasing the content of the rubber.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples.

Example 1

8.0 parts by weight of butadiene-based rubber polymer (25 ° C., 5% styrene solution viscosity of 173 cp), 78.0 parts by weight of styrene, 14.0 parts by weight of ethylbenzene, and 2.0 parts by weight of lubricant are used as the composition of the final raw material mixed solution.

90% by weight of the total amount of butadiene-based rubber polymer was dissolved in 10% by weight of the total amount of styrene and 100% by weight of the total amount of ethylbenzene, to prepare a mixed solution, and then 0.01% by weight of tert-butyl peroxy pivalate. The part was charged to pre-graft-polymerization for 3 hours at the reactor temperature of 75 ° C.

Thereafter, the remaining rubber polymer and styrene were mixed, and four stirred reactors were introduced into a continuous polymerization apparatus connected in series to continuously carry out the graft polymerization.

The temperature at the inlet of the polymerization apparatus was 125 ° C and the temperature at the outlet was 160 ° C. The final polymerization mixed solution was sent to a devolatilization tank to remove the unreacted monomer and solvent at 230 ° C. and 20 torr, and then to beletized to obtain a final rubber-modified styrene resin. After injection molding the resin obtained as described above and measured the physical properties in the following manner is shown in Table 1.

◎ Particle shape: Observation was performed using a transmission electron microscope (TEM, Jeol JEM-1010). The samples were treated with osmium tetroxide and then made into ultra-tear cut specimens using a microtome.

◎ Average particle size of rubber particles: 0.5 g of styrene-based rubber-modified resin was dissolved in 100 mL of methylethylkenone, and the average particle diameter of the rubber particles was measured using a Coulter counter (Beckman Coulter, LS230).

Izod Impact: Measured by ASTM D256 method.

◎ Tensile strength and elongation: It was measured by ASTM D638 method.

◎ Gloss: An injection test piece having a thickness of 3 mm was prepared and measured according to ASTM 1003.

Example 2

It was carried out in the same composition and method as in Example 1, except that butadiene rubber polymer in the composition before pre-grafting polymerization was prepared by adding 70% by weight to the total amount.

Example 3

In the same composition and method as in Example 1, butadiene rubber polymer in the composition before pre-grafting polymerization was prepared by adding 50% by weight relative to the total amount.

Example 4

In the same composition and method as in Example 1, except that the styrene in the composition before pre-grafting polymerization was prepared by adding 30% by weight to the total amount.

Comparative Example 1

It was carried out in the same composition and method as in Example 1, except that the polymerization mixture solution was prepared by feeding into the reactor No. 1 prior to the graft polymerization process.

division Example Comparative example One 2 3 4 One Rubber particle distribution form (bimodal: O, unimodal: X) O O O O X Impact strength (㎏㎝ / ㎝) (1/4 ") 12.6 10.4 10.1 10.5 8.7 (1/8 ") 18.7 16.2 15.8 15.2 12.4 Polish(%) 98 86 71 75 59 Tensile Strength (㎏ / ㎠) 298 274 254 269 245 % Elongation 21 33 48 67 87

As can be seen in Table 1, the resins of Examples 1 to 4 according to the present invention is very excellent in impact strength and tensile strength, compared to the resin of Comparative Example 1 according to the conventional method, it can be confirmed that excellent gloss. there was.

As described above, the rubber-modified styrene-based resin composition according to the present invention is a useful invention in which the rubber particles in the styrene-based resin have a bimodal form, which has an excellent impact strength and gloss. .

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations fall within the scope of the appended claims. It is also natural.

Claims (9)

In rubber modified styrene resin, Rubber modified styrene resin, characterized in that it comprises two kinds of rubber-like particles having a size of 0.5 to 2㎛ and 5 to 10㎛. In the manufacturing method of the rubber modified styrene resin, A pre-graft polymerization step of graft polymerizing a predetermined amount of a mixed solution in which butadiene rubber polymer and styrene monomer are dissolved in an organic solvent using a polymerization initiator; And The main graft polymerization step of further graft polymerization by adding the remaining amount of the mixed solution to the pre-graft polymer; Method of producing a rubber-modified styrene resin, characterized in that comprises a. The method of claim 2, The butadiene rubber polymer is 3 to 10 parts by weight based on the total amount, the styrene monomer is 90 to 97 parts by weight based on the total amount, and the organic solvent is 0 to 30 parts by weight based on the total amount, Reactor after mixing the polymerization initiator in the mixed solution dissolved in 10 to 90% by weight of the total amount of butadiene rubber polymer, 5 to 30% by weight of the total amount of the styrene monomer and 50 to 100% by weight of the total amount of the organic solvent. Pre-graft-polymerization step of graft polymerization at a temperature of 50 to 100 ° C. for 1 to 3 hours; 10 to 90% by weight of the total amount of butadiene rubber polymer, 70 to 95% by weight of the total amount of the styrene monomer and 0 to 50% by weight of the total amount of the organic solvent in the pre-grafted polymer 2 The present graft polymerization step of graft polymerization by the reactor temperature of 100 to 180 ℃ to the reactor of a continuous polymerization apparatus in which two or more stirring reactors are connected in series; Method of producing a rubber-modified styrene resin, characterized in that comprises a. The method of claim 3, wherein 10 to 30 parts by weight of the styrene-based monomer and 0.01 to 1.0 parts by weight of the organic peroxide polymerization initiator are further added during the present graft polymerization step. The method of claim 2, The butadiene-based rubber polymer is a method of producing a rubber-modified styrene resin, characterized in that 5% styrene solution viscosity of 30 to 200cp at 25 ℃. The method of claim 2, The styrene-based monomer is styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, ethyl styrene, I-butyl styrene, t-butyl styrene or alkyl styrene having equivalent properties thereof; And halogenated styrenes having o-bromo styrene, p-bromo styrene, m-bromo styrene, o-chloro styrene, p-chloro styrene, m-chloro styrene or equivalent properties; Method for producing a rubber-modified styrene resin, characterized in that at least one member selected from the group consisting of. The method of claim 2, The polymerization initiator may be 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, dibenzoyl peroxide or diacryl peroxides having the same properties; And 1,1-dimethyl-3-hydroxybutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, α-cumyl peroxyneheptanoate, tertiary-amyl peroxyneodecanoate Tertiary-amyl peroxypivalate, tertiary-butyl peroxypivalate, 2,5-dimethyl-2,5-di- (2-ethylhexanoyl peroxy) hexane, tertiary-amyl peroxy 2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate or peroxyesters having the same properties; Method for producing a rubber-modified styrene resin, characterized in that at least one member selected from the group consisting of.  The method of claim 2, Wherein said pre-graft polymerization step and the present graft polymerization step are selected from the group consisting of continuous or batch bulk polymerization, solution polymerization, and block-suspension polymerization. Rubber modified styrene resin manufactured by the method of any one of Claims 2-8.