KR20130090311A - A method for preparing abs based graft copolymer with heat resistance and high thermal stability - Google Patents

Abstract

PURPOSE: A manufacturing method of an ABS-based graft copolymer is provided to manufacture an ABS-based graft copolymer with improved stability, heat resistance, and thermal stability by increasing the dispersity of nanosilica per a rubber particle. CONSTITUTION: A manufacturing method of an ABS graft copolymer with excellent heat resistance and thermal stability comprises a step of manufacturing a diene-based rubber by emulsifying a diene-based monomer including a nanosilica dispersion with an emulsifier; and a step of manufacturing the ABS graft copolymer by polymerizing the diene-based rubber, an aromatic vinyl compound, and a vinylcyan compound. The diene-based monomer is at least one among 1,3-butadiene, isoprene, chloroprene, and piperylene.

Description

A method for preparing ABS based graft copolymer with heat resistance and high thermal stability}

The present invention relates to a method for producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, and an ABS-based graft having excellent heat resistance and thermal stability by applying a nanosilicone dispersion capable of acting as a kind of emulsifier in a large diameter rubber latex manufacturing step. Not only to prepare a copolymer but also to improve the dispersibility per rubber particles of the nano-silica and to provide a stability of the latex.

In preparing the ABS resin, in order to disperse the rubber component in acrylonitrile-styrene resin (hereinafter referred to as 'SAN resin'), the rubber component is dissolved in monomers acrylonitrile, styrene, and a solvent for solution polymerization. There is a method of preparing a graft copolymer of acrylonitrile and styrene on a rubber latex prepared by emulsion polymerization, and mixing and processing a SAN resin prepared by separate solution polymerization.

ABS-based resin produced by solution polymerization has mass production, relatively good manufacturing cost, and excellent color, but it is difficult to manufacture various quality products and cannot achieve specialized high added value. In addition, its use is limited because physical properties such as surface gloss, impact strength and thermal stability are allowed, or it is used in combination with ABS resin produced by emulsion polymerization.

Typically, ABS-based resins are prepared by mixing a rubber latex prepared by emulsion polymerization with a graft copolymer obtained by copolymerizing one or more monomers, and a styrene copolymer prepared by bulk polymerization or solution polymerization. Since the ABS-based resin produced by emulsion polymerization has a high manufacturing cost, the final product produces ABS-based resin through mixing with the styrene-based copolymer prepared by solution polymerization. Therefore, various kinds of products having different monomer compositions and molecular weights are manufactured and have excellent surface gloss and impact strength.

In this ABS graft copolymer, the particle size and internal structure are very important factors affecting the handling of resin, blending with subsidiary materials, and processing characteristics of products. Has been. However, until now, the technology is hardly known in relation to the growth or dispersibility of the basic particles of the ABS-based graft copolymer.

In order to increase the advantages of high functionalization and diversification, high value of ABS resin is required through emulsion polymerization.To this end, the total solid content of latex is increased in the existing production line to increase the yield or the rubber content in the latex to increase the final ABS. It is possible to reduce the ABS resin content through emulsion polymerization in the resin. However, there is a limit to increase the total solids content or rubber content, and as a result, when the solids content is increased, latex stability is lowered due to the viscosity increase and coagulations are generated during the polymerization, so that an efficient graft reaction cannot be performed. As a result, mechanical properties, thermal stability, and surface gloss are deteriorated, which makes it difficult to secure stable physical properties during mass production. In addition, since the content of styrene-acrylonitrile having a high glass transition temperature (Tg) decreases as the rubber content increases, heat resistance of the final product may decrease.

In order to prepare such a high value ABS resin, it is important to control the morphology and gel content of the rubber, the molecular weight of the copolymer grafted on the rubber latex, the graft ratio, and the monomer composition ratio. Polymerization stability and effective rubber grafting of monomers are particularly important for producing resins of high solids content and high rubber content.

On the other hand, in view of the above, in the method for producing an ABS-based graft copolymer using emulsion polymerization, a technique using colloidal silica as a latex stabilizer and heat resistance increasing additive is disclosed as Korean Patent Registration No. 10-0785609. have.

That is, the prior art uses silica in the step of grafting SAB (styrene-acrylonitrile) to the rubber particles in the manufacturing process of ABS resin to enhance the polymerization stability and storage stability at high total solid content conditions It is characterized by improving the heat resistance of the final ABS resin while giving.

However, when the prior art is applied, it is possible to secure higher latex stability than before, but the heat resistance and thermal stability are still not satisfactory, and thus an improvement on this is required.

Therefore, the present inventors apply the nano-silica dispersion in a large-diameter rubbery polymer latex manufacturing step in an appropriate manner to improve the dispersibility per rubber particles of the nano-silica and ABS-based graphs that improve the stability, heat resistance and thermal stability of the latex more efficiently. It has been found that the present invention can provide a copolymer and has completed the present invention.

That is, one technical problem to be achieved by the present invention is to provide a method for preparing an ABS-based graft copolymer that can more efficiently provide latex stability, heat resistance, and thermal stability by improving dispersibility per rubber particle of nano silica. have.

According to the present invention,

In order to manufacture an ABS-based graft copolymer having excellent heat resistance and thermal stability,

a) emulsion-polymerizing a diene monomer including an emulsifier and a nanosilica dispersion to prepare a diene rubber; And

b) graft polymerizing the diene rubber, an aromatic vinyl compound, and a vinyl cyan compound to prepare an ABS graft copolymer; And a control unit.

Hereinafter, the present invention will be described in more detail.

First, the present invention relates to a polymerization method of a diene rubber used to prepare an ABS-based graft copolymer, but is not limited thereto. Nano-silica used in connection with a method for preparing an ABS-based graft copolymer is disclosed. The manufacturing method related to the position and dispersibility of the particles may also include the prior art ABS-based graft copolymer manufacturing technology. In the present invention, the stability of the latex in the manufacturing process through the emulsion polymerization method of butadiene-based rubber, and the production of butadiene-based rubber of the appropriate size and when applied to the graft copolymer manufacturing process it is more excellent with the stability of the final latex The present invention relates to a method of securing heat resistance and thermal stability.

The diene monomer used in the present invention is not limited thereto, but may be one or more selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and pyrrylene. As a comonomer, Aromatic vinyl compounds, such as styrene, (alpha) -methyl styrene, m-methyl styrene, p-methyl styrene, and p-tert- butyl styrene; Cyanide compounds such as acrylonitrile, methacrylonitrile, ethylacrylonitrile, isopropyl acrylonitrile and the like, and methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n Acrylate compounds, such as -butyl methacrylate and 2-ethylhexyl acrylate, etc. can also be used together.

Based on a total of 100 parts by weight of such diene monomers, the emulsifier is 0.4 to 4 parts by weight in combination with potassium rosin salt and potassium oleate salt, and the nanosilica dispersion is preferably used within the range of 0.3 to 4 parts by weight. .

In particular, the emulsifier and the nano-silica dispersion is in the total amount of 2 to 5 parts by weight, the weight ratio is preferably 15:85 to 80:20.

The double nanosilica dispersion is preferably in colloidal form with a size of 5 to 100 nm or less and silica content of 20 to 50% or less. A negatively charged form is preferred and various types of dispersions can be used, but spheres are most preferred. The nano silica dispersion may be added alone or in the form of a mixture with other emulsifiers and electrolytes before the reaction. There is a method of dividing a small amount in the middle of the reaction at the time of adding the dispersion, but the content is preferably 5 to 30% of the total amount.

In step a), the polymerization conversion rate is preferably 80 to 95%. The diene rubber thus produced has an average particle diameter of 2500 to 3500 Pa.

Specifically, the step a), as also shown in the following examples, based on 100 parts by weight of the diene monomer, 50 to 100 parts by weight of ion-exchanged water, 0.4 to 5 parts by weight of emulsifier, 0.3 to 4 parts by weight of nano silica dispersion Including the 0.03 to 0.6 parts by weight of the polymerization initiator, 0.1 to 1 parts by weight of the molecular weight regulator to emulsion-polymerize to prepare a diene rubber.

At this time, the emulsifier is preferably at least one selected from the group consisting of alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps, alkali salts of rosin acid, and alkali salts of oleic acid.

The initiator may be a water-soluble persulfate such as potassium persulfate, a peroxy compound such as t-butyl hydroperoxide, cumyl hydroperoxide, and used with a group of redox compounds such as dextrose and sodium pyrrolate. It is possible, and in the case of the initiator, one or more may be used together.

In addition, the molecular weight regulator is preferably at least one selected from the group consisting of thiols such as tertiary dodecyl mercaptan (t-dodecyl mercaptan), n-dodecyl mercaptan, n-octyl mercaptan. .

At this time, the solid coagulant content of the diene rubber is 0.03% or less, as determined in the following examples, the solid coagulant content of the ABS-based graft copolymer is 0.05% or less to ensure the stability of the latex Could.

The ABS graft copolymer was further confirmed that it can improve the thermal stability and heat resistance to the ABS-based resin made through the blending / extrusion process with the styrene-acrylonitrile copolymer. For example, the blending ratio may be a weight ratio of 10:90 to 70:30.

According to the method of the present invention described above, by applying a nano-silica dispersion that serves as a kind of emulsifier in the step of preparing a rubbery latex for producing an ABS-based graft copolymer ABS-based graft air with excellent heat resistance and thermal stability In addition to preparing the copolymer, it is possible to improve the dispersibility per rubber particle of the nano-silica, thereby providing the stability of the latex.

Hereinafter, the constitution and effects of the present invention will be described in more detail with reference to examples and comparative examples. However, these examples are merely intended to clearly understand the present invention and are not intended to limit the scope of the present invention.

Example  One

75 parts by weight of ion-exchanged water, 80 parts by weight of 1,3-butadiene monomer, 1.2 parts by weight of potassium rosin salt, nanosilica dispersion (10 nm) in a nitrogen-substituted autoclave 1.0 parts by weight, 0.5 parts by weight of potassium oleate, 0.6 parts by weight of sodium carbonate, 0.7 parts by weight of potassium bicarbonate, 0.3 parts by weight of tertiary dodecyl mercaptan (TDDM), 0.09 parts by weight of t-butyl hydroperoxide, 0.035 parts by weight of dextrose Part, 0.02 parts by weight of sodium pyrolate, 0.0005 parts by weight of ferrous sulfate were added in a batch, and reacted at a reaction temperature of 65 ° C. for 15 hours, 20 parts by weight of the remaining monomers 1,3-butadiene, 0.05 parts by weight of tertiary dodecyl mercaptan, and 0.2 parts by weight of potassium sulfate was collectively reacted at 75 ° C. for 28 hours, and then the reaction was terminated. As a result of analyzing the obtained rubbery polymer latex, the gel content was 79% and the particle size was 3080 mm 3.

Stability of the prepared latex was stirred for 30 minutes at 10,000rpm using an ultrafast mixer (product name TK ROBIMIC) and then measured the content ratio of the coagulant produced by hanging the latex, the results are summarized in Table 1 below.

Example  2

The same process as in Example 1 was repeated except that 1.5 parts by weight of nanosilica dispersion was used instead of potassium rosin salt, and 1.5 parts by weight of potassium oleate was used instead of 0.5 parts by weight. The gel content of the rubbery polymer latex was 80% and the particle size was 3110 mm 3.

The stability of the prepared latex was measured in the content ratio of the coagulant as in Example 1, and the results are summarized together in Table 1 below.

Example  3

Potassium rosin salt in Example 1 is used in 0.7 parts by weight instead of 1.2 parts by weight, nano silica dispersion is used in 3.0 parts by weight instead of 1.0 parts by weight, except that the potassium oleate salt is not used As a result of repeating the same process, the gel content of the obtained rubbery polymer latex was 77%, and the particle size was 3150 mm 3.

The stability of the prepared latex was measured in the content ratio of the coagulant as in Example 1, and the results are summarized together in Table 1 below.

Comparative example  One

The same procedure as in Example 1 was repeated except that the nanosilica dispersion was not used in Example 1, whereupon the gel content of the obtained rubbery polymer latex was 79% and the particle size was 3080 mm 3.

The stability of the prepared latex was measured in the content ratio of the coagulant as in Example 1, and the results are summarized together in Table 1 below.

Comparative example  2

Proceed in the same manner as in Example 1, except that the potassium rosin and potassium oleate salts were not used at all, except that 2.7 parts by weight of the nanosilica dispersion was used, the rubber polymer obtained as a result of repeating the same process as in Example 1 The gel content of the latex was 75% and the particle size was 3250 mm 3.

The stability of the prepared latex was measured in the content ratio of the coagulant as in Example 1, and the results are summarized together in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Coagulation content (%) 0.01 0.03 0.04 0.01 0.10

As shown in Table 1, in the case of Example 1-3 it was confirmed that the latex stability can be presented than Comparative Example 1,2.

ABS  Suzy Manufacturing example  One

65 parts by weight of polybutadiene latex prepared in Example 1, 75 parts by weight of deionized water, and 0.4 parts by weight of potassium rosinate were administered in a polymerization reactor equipped with a heating device, and the temperature in the reactor was maintained at 50 ° C, followed by 5.4 parts by weight of styrene and acryl. The starting reaction was carried out by collectively administering 2.1 parts by weight of ronitrile, 0.3 parts by weight of tertiary dodecylmercuptane, 0.087 parts by weight of sodium pyrophosphate, 0.11 parts by weight of dextrose, 0.002 parts by weight of ferrous sulfide, and 0.2 parts by weight of cumyl peroxide. .

45 minutes after the start reaction, 10 parts by weight of ion-exchanged water, 19.8 parts by weight of styrene, 7.7 parts by weight of acrylonitrile, 0.8 parts by weight of potassium rosinate, 0.019 parts by weight of sodium pyrophosphate, 0.025 parts by weight of dextrose, ferrous sulfide A mixed solution of 0.001 parts by weight and 0.1 parts by weight of cumyl peroxide was continuously administered for 140 minutes. At this time, the reaction temperature was raised to 70 ° C. for 50 minutes and then maintained at 70 ° C. for 90 minutes.

After the continuous administration, 0.019 part by weight of sodium pyrophosphate, 0.025 part by weight of dextrose, 0.001 part by weight of ferrous sulfide, and 0.05 part by weight of cumyl peroxide were further administered, and the temperature was again raised to 80 ° C., followed by aging for 1 hour. Terminated. At this time, the polymerization conversion rate was 98.9%, and the total solid content was 53.0%.

0.7 parts by weight of antioxidant emulsion IR-1086 (hindered phenolic antioxidant: manufactured by Ciba) was added to the polymerized latex thus prepared, coagulated with 2 parts by weight of aqueous sulfuric acid solution, washed and dried to obtain a powdery graft copolymer. It was.

After adding a lubricant and the like to a thermoplastic resin composition comprising 25.4 parts by weight of the manufactured ABS-based graft copolymer and a weight average molecular weight of about 100,000 and a SAN copolymer having an acrylonitrile content of about 28% by adding a lubricant and the like, extrusion and injection molding were carried out. Specimens were prepared and measured in physical properties and summarized in Table 2 below.

At this time, the coagulum is generated during the polymerization process, and the amount of coagulation increases as the stability of the latex decreases.

In addition, the measurement index of thermal stability is expressed as the square root of the sum of the squares of the differences between the color values L, a, and b of the injected specimen after 15 minutes at 250 ° C in the injection molding machine and the injection molding machine. In addition, the smaller the value of the color difference (? E) between the general injection molding and the retention injection molding, the smaller the color difference, which means higher thermal stability. At this time, Suga Instrument's color difference meter was used as a measuring instrument.

In addition, the heat deformation temperature is a numerical value representing heat resistance, and the higher the temperature, the higher the heat resistance.

Manufacturing example  2

The same procedure as in Preparation Example 1 was repeated except that the polybutadiene latex prepared in Example 2 was used, and the measured physical properties of the obtained specimens were summarized together in Table 2 below.

Manufacturing example  3

The same procedure as in Preparation Example 1 was repeated except that the polybutadiene latex prepared in Example 3 was used, and the measured physical properties of the obtained specimens were summarized together in Table 2 below.

Comparative Manufacturing Example  One

The same procedure as in Preparation Example 1 was repeated except that the polybutadiene latex prepared in Comparative Example 1 was used, and the measured physical properties of the obtained specimens were summarized together in Table 2 below.

Comparative Manufacturing Example  2

The same procedure as in Preparation Example 1 was repeated except that the polybutadiene latex prepared in Comparative Example 2 was used, and the measured physical properties of the obtained specimens were summarized together in Table 2 below.

Comparative Manufacturing Example  3

The polybutadiene latex of Comparative Example 1 was used as the polybutadiene latex, except that the nano silica dispersion was included in the graft step, the same method as in Preparation Example 1 was repeated, and the measured physical properties of the obtained specimen were as follows. It is summarized together in Table 2.

division Coagulant content
(%) Izod impact strength
(1/4 ", kg.cm/cm) Thermal stability ( △ E) Heat Deflection Temperature (℃) Production Example 1 0.02 30 3.2 88.7 Production Example 2 0.03 29 3.0 89.0 Production Example 3 0.05 29 3.3 89.3 Comparative Preparation Example 1 0.13 30 4.2 88.0 Comparative Production Example 2 0.30 26 3.9 89.5 Comparative Production Example 3 0.04 29 3.9 88.5

As shown in Table 2, it can be seen that the high latex stability as the coagulation content is less than the Comparative Preparation Examples 1 and 2 in Preparation Examples 1 to 3, and also high thermal stability without deterioration of impact strength under such stability. And it can be seen that the heat resistance.

Claims (12)

a) emulsion-polymerizing a diene monomer including an emulsifier and a nanosilica dispersion to prepare a diene rubber; And
b) graft polymerizing the diene rubber, an aromatic vinyl compound, and a vinyl cyan compound to prepare an ABS graft copolymer; Method for producing an ABS-based graft copolymer excellent in heat resistance and thermal stability, characterized in that comprises a.
The method of claim 1,
The diene monomer is 1,3-butadiene, isoprene, chloroprene and piperylene is one or more selected from the group consisting of a method for producing an ABS-based graft copolymer having excellent heat resistance and thermal stability.
The method of claim 1,
Based on a total of 100 parts by weight of the diene monomer, the emulsifier is 0.4 to 4 parts by weight, and the nano-silica dispersion is 0.3 to 4 parts by weight of the ABS-based graft copolymer having excellent heat resistance and thermal stability Way.
The method of claim 3,
The emulsifier and the nano-silica dispersion is a total amount of 2 to 5 parts by weight, the weight ratio is 15:85 to 80:20, the method of producing an ABS-based graft copolymer having excellent heat resistance and thermal stability.
The method of claim 1,
The nanosilica dispersion is a negatively charged colloidal silica having an average particle diameter of 5 to 100 nm, containing 20 to 50% of silica, characterized in that the excellent heat resistance and thermal stability of the ABS-based graft copolymer.
The method of claim 1,
The emulsifier is at least one member selected from the group consisting of alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps and alkali salts of rosin acid, and alkali salts of oleic acid. Method for producing this excellent ABS graft copolymer.
The method of claim 1,
Step a) is based on 100 parts by weight of the diene monomer, 50 to 100 parts by weight of ion-exchanged water, 0.4 to 5 parts by weight of emulsifier, 0.3 to 4 parts by weight of nanosilica dispersion, 0.03 to 0.6 parts by weight of polymerization initiator, molecular weight regulator A method for producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, comprising 0.1 to 1 parts by weight to prepare an diene rubber by emulsion polymerization.
The method of claim 1,
The emulsion polymerization of a) is a method for producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, characterized in that the polymerization conversion is 80 to 95%.
The method of claim 1,
The diene rubber has an average particle diameter of 2500 to 3500 kPa, the method of producing an ABS-based graft copolymer having excellent heat resistance and thermal stability.
The method of claim 1,
Solid coagulation content of the diene rubber is a method of producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, characterized in that 0.03% or less.
The method of claim 1,
Solid coagulation content of the ABS-based graft copolymer is a method of producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, characterized in that 0.05% or less.
The method of claim 1,
The ABS-based graft copolymer is a method for producing an ABS-based graft copolymer having excellent heat resistance and thermal stability, characterized in that it is blended with a styrene-acrylonitrile copolymer.