KR960001219B1 - Process for producing thermoplastic resins having a good - Google Patents

Abstract

first graft-polymerising (a) 30-65 wt. pts of the crosslinked acrylic rubber latex. by two steps process, with (b) 14.70-7.35 wt. pts of styrene and (c) 6.30-3.15 wt. pts of acrylonitrile; then second graft-polymerising the first grafted polymer with (b') 34.50-17.15 wt. pts of styrene and (c') 14.50-7.35 wt. pts of acrylonitrile, which are fed continuously with pre-emulsion state. The obtd. acrylic rubber-styrene-acrylonitrile resin has good weather resistance, impact resistance and chemical resistance.

Description

Manufacturing method of thermoplastic resin excellent in weatherability

The present invention relates to a thermoplastic resin, and more particularly, to a method for producing an acrylic rubber-styrene-acrylonitrile resin having excellent weather resistance, impact resistance, and chemical resistance.

Polymers composed of butadiene-based rubber polymers, aromatic vinyl compounds and unsaturated nitriles (hereinafter referred to as "ABS") have excellent mechanical properties and molding processability, so they are used in electrical appliances, electronic products, automobiles, interior and exterior parts, office equipment, and others. It is widely used in the field.

On the other hand, ABS contains a large amount of conjugated diene-based double bond in the rubber component used, the rubber component is easily aging under a wide range of environmental conditions and has a drawback in weather resistance, which is inappropriate in the field of outdoor use, and has a great practical limitation.

In order to solve this problem, in order to supplement the weak weather resistance in outdoor use, the ABS resin is painted, but there is a problem that the coating film is swelled and peeled off and the surface of the coating film is changed to reduce the value of the product.

Therefore, in recent years, a resin having excellent weather resistance, impact resistance, and chemical resistance is required, but in addition to the impact resistance and fluidity, which are generally required, a technology that is sufficiently satisfactory for a use that simultaneously requires weather resistance and chemical resistance of the resin has not been developed. In general, only a method for producing a weather resistant resin that complements weather resistance and impact resistance has been proposed.

Examples of methods for increasing weather resistance include a method of basically improving resin tissue components using acrylic rubber instead of conventional butadiene rubber, and a method of improving weatherability and impact resistance by using a mixture of acrylic rubber and butadiene rubber. have.

However, in the former method, the weather resistance is increased by using acrylic rubber, but the impact resistance is not practical, and the latter method is improved in weather resistance and impact resistance by using a mixture of acrylic rubber and butadiene rubber, but is resistant to solvents such as gasoline. The chemicals have not improved and still do not meet commercial needs.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a method for producing a thermoplastic resin having excellent weather resistance and improved impact resistance and chemical resistance.

The present inventors have studied in order to achieve the above object, in the production of cross-linked acrylic rubber, the average particle by the method of dividing and mixing the acrylic ester and unsaturated nitrile compound having an alkyl group having 1 to 13 carbon atoms in the rubber forming monomer Seed polymerization, a one-step reaction that results in a size of 0.15 to 0.25 microns, and a two-step reaction that grows an average particle size of 0.30 to 0.35 microns, results in a wide range of particle size distribution. In order to prepare a special acrylic rubber polymer having an appropriate crosslinked structure, and in the presence of 30 to 65 parts by weight (hereinafter, abbreviated as "parts") of crosslinked acrylic rubber latex prepared through the two-step reaction, 14.7 to 7.35 parts of acryl After adding 6.3 to 3.15 parts of ronitrile and an emulsifier ion exchange part, swelling rubber particle, the said Various additives and polymerization initiators were added to the mixture to prepare the first polymer (A) by polymerization, whereupon styrene 34.5 to 17.15 parts, acrylonitrile 14.5 to 7.75 parts, emulsifier, molecular weight regulator, polymerization initiator and ion exchanged water were added. Compound (B) prepared in a pre-emulsion state by mixing the grafted to secondary grafting and excellent weatherability and chemical resistance, the impact resistance of the butadiene-based rubber, the fluidity of the appropriately branded resin can be obtained It was revealed to me.

Hereinafter, the present invention will be described in detail.

The two-step manufacturing process of the crosslinked acrylic rubber latex is as follows.

1) 1st step manufacturing process

One or more monomers selected from butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, vinyl acetate, methacrylate butyl ester, more preferably 15 to 65 parts of butyl acrylate, acrylonitrile, meta 1 type of monomer selected from chloronitrile, More preferably, 15-2 parts of acrylates and the polyfunctional monomer which has 2 or more functional groups copolymerizable with the said monomer (for example, triaryl isocyanurate, triaryl Cyanulanate, divinylbenze, arylmethacrylate, ethylene glycol dimethylacrylate, and the like) or one or more crosslinking agents, more preferably 0.03-1.2 parts of triarylcyanunate and an emulsifier, potassium rosin salt (Alkali, such as sodium dodecylbenzene sulfonate, alkali metal salt of alcoholic sulfuric acid of 8-18 carbon atoms, such as sodium lauryl sulfate 1.0 to 3.5 parts of alkali metal salts of sulfonic acid, 0.005 to 1.2 parts of sodium parosulphite, and 0.01 to 0.45 parts of potassium persulfate as a polymerization initiator were added and reacted in the presence of ion-exchanged water to give an average particle size of 0.15 to 0.25 microns. Prepare latex.

2) 2nd step manufacturing process

55-30 parts of butyl acrylate, 15-3 parts of acrylonitrile, 0.1-2.5 parts of a polyfunctional monomer copolymerizable with the monomer, 0.4-2.0 parts of potassium rosin salt and ion-exchanged water were added to the rubber latex. After pre-emulsion, the solution is continuously injected from 1 hour to 3 hours to grow the average particle size to 0.25 ~ 0.38 microns so that the average particle size of the final rubber latex is 0.30 ~ 0.35 micron gel content of 80 ~ 96% by weight. .

In the first and second stages, when the monomer is used in a smaller amount than the above range, it is difficult to control the latex particle size. When the monomer is used in a larger amount than the above range, the reaction heat is not easily controlled.

When the unsaturated nitrile monomer is used in a smaller amount than the above range in steps 1 and 2, it is difficult to obtain a special acrylic rubber latex which improves chemical resistance, and when a large amount is used, the polymerization rate decreases and the glass transition temperature (Tg) increases due to the increase of unreacted monomer. It is not desirable.

When the crosslinking agent is used in a smaller amount than the above range in the first and second stages, the gel content is low, and the workability is lowered. When the amount is used in a large amount, the workability is increased, but the impact resistance is remarkably decreased.

In the presence of the acrylic rubber latex obtained through the two-step manufacturing process, one or two or more monomer mixtures selected from aromatic vinyl monomers and unsaturated nitrile monomers and an emulsifier, a polymerization initiator, a molecular weight regulator, and ion-exchanged water are added in a manner of dispensing. Most of the first introduced monomer to swell the rubber latex particles, and then the redox composition is added to initiate the first graft reaction, and the remaining portion of the distribution is made into a pre-emulsion state and then continuously added to the second graft reaction. It is a method of manufacturing the thermoplastic resin composition characterized by the above-mentioned.

That is, the primary graft rubber latex manufacturing method of the present invention is as follows.

Aromatic vinyl monomers such as styrene, alpha methyl styrene and alpha chloro styrene, divinyl benzene, vinyl toluene, pt-butyl styrene, 2.4 dimethyl styrene, and methacrylonitrile, and acrylo copolymerizable with 30 to 65 parts of cross-linked acrylic rubber lactex solid content 21 to 10.5 parts in the first graft reaction in 70 to 35 parts of a mixture of one or two or more monomers selected from unsaturated nitrile monomers such as nitrile (the total amount of the crosslinked acrylic rubber latex and the monomer mixture is 100 parts), more specifically Is mixed with 14.7 ~ 7.35 parts of styrene, 6.3 ~ 3.15 parts of acrylonitrile and ion-exchanged water, and stirred for 30 minutes to 1 hour while maintaining the temperature of the mixture at 20 ~ 90 ℃, more preferably 40 ~ 60 ℃ So that most of the monomers swell the rubber particles.

Here, an anionic emulsifier having 8 to 18 carbon atoms, more preferably 0.1 to 1.5 parts of potassium oleate and t-dode, such as sodium lauryl sulfate, potassium rosin salt, sodium dodecylbenzenesulfonate, potassium oleate, sodium oleate, etc. 0-1.0 parts of silmercaptan and 0.01-2.5 parts of fat-soluble initiators such as cumene hydroperoxide are heated up, and when the temperature inside the reactor reaches 65 ° C., metal salts such as ferrous sulfate, tetrasodium phosphate, sodium formium sulfoxide, and ethylene A redox composition composed of one or two or more selected from redox agents such as diamine tetraacetic acid texturos, potassium hydroxide, sodium pyrophosphate, and more preferably a composition consisting of ferrous sulfate, tetrasodium parophosphate, and textulos. For each redox agent, 0.001 to 0.40 parts were added to polymerize the first graft latex. The.

The method for producing the secondary graft latex of the present invention is as follows.

34.50 to 17.15 parts of styrene, 14.50 to 7.35 parts of acrylonitrile, 0 to 0.5 parts of t-dodecylmercaptan, 0.2 to 0.45 parts of cumene hydroperoxide, in 49 to 24.5 parts of the monomer residue for distribution to the primary graft latex, 0.3-1.5 parts of potassium oleate and ion-exchanged water are put in a stirred container, made into a pre-emulsion state, and continuously injected for 1 to 3 hours to obtain secondary graft latex.

When the amount of the crosslinked acrylic rubber lactate used in the present invention is used in a smaller amount than the above range, the impact resistance of the resin is lowered, and the use of the large amount is difficult to recover to the solidified and dried fine powder of the graft rubber latex, thereby reducing the appearance of the resin. .

When the amount of the first and second graft monomers is used in a smaller amount than the above range, the impact resistance of the resin and the hardness of the resin are reduced.

When the amount of the first and second stage emulsifiers is used in a smaller amount than the above range, coagulants in the latex are excessively generated, and the use of a large amount of the emulsifier is a shock deterioration factor due to the high occurrence of non-grafted polymer.

The latex prepared by the first and second graft polymerization is coagulated, dehydrated, and dried to obtain a powder, and then the powder of the acrylonitrile-butadiene-based rubber-styrene copolymer prepared separately and good compatibility with ASA resin. When the styrene-acrylonitrile copolymer (SAN) is mixed and subjected to an extrusion and injection process, an excellent ASA resin having excellent weatherability, chemical resistance, and impact resistance can be obtained.

Embodiments of the present invention are as follows.

An embodiment of the crosslinked acrylic rubber latex of the present invention is as follows.

Preparation Example 1

38 parts of butyl acrylate, 2 parts of acrylonitrile, 0.7 parts of triaryl cyanurate, 2.8 parts of potassium rosin salt, 0.1 part of sodium parosulphite and 110 parts of ion-exchanged water were placed in a reactor, and the mixture temperature was 65 ° C. After the increase, 0.09 parts of potassium persulfate was added to initiate the reaction, and then the temperature was increased to 70 ° C., and the reaction was initiated in a one-step reaction. When the polymerization rate reached 70% or more, 32 parts of ion-exchanged water, 1.2 parts of potassium rosin salt, and butyl 57 parts of acrylate, 3 parts of acrylonitrile, and 1.8 parts of triallyl cyanurate were placed in a stirred container, made into a pre-emulsion state, and added continuously to complete addition, and the polymerization rate of the crosslinked acrylic rubber latex was increased. When the amount became 90%, 0.1 part of potassium persulfate was added to obtain a crosslinked acrylic rubber latex having a polymerization rate of 98.2%.

At this time, the polymerization time was 6 hours.

Preparation Example 2)

36 parts of butyl acrylate, 4 parts of acrylonitrile in a one-step reaction was carried out in the same manner as in Preparation Example 1 except that 54 parts of butyl acrylate and 6 parts of acrylonitrile were used in a two-step reaction.

Preparation Example 3

34 parts of butyl acrylate, 6 parts of acrylonitrile, 51 parts of butyl acrylate and 9 parts of acrylonitrile were carried out in the same manner as in Preparation Example 1 except that the reaction was carried out in one step.

Preparation Example 4

Except that 32 parts of butyl acrylate, 8 parts of acrylonitrile in the first step reaction, 48 parts of butyl acrylate in the two step reaction, 12 parts of acrylonitrile were used in the same manner as in Preparation Example 1.

Preparation Example 5

The same procedure as in Preparation Example 1 was carried out except that acrylonitrile was not added in the 1,2-step reaction, but 40 parts of butyl acrylate and 60 parts of butyl acrylate were used in the second step.

Example 1

50 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 1, 11.25 parts of styrene, 3.75 parts of acrylonitrile, 120 parts of ion-exchanged water, and 0.27 parts of potassium oleate were mixed and stirred for 40 minutes while maintaining the mixture temperature at 40 ° C. After the rubber particles were swollen, 0.02 parts of t-dodecylmercaptan, 0.09 parts of cumene hydroperoxide and 0.30 parts of texturos were added to the reactor, and the temperature of the mixture was raised to 60 ° C.

When the temperature of the mixture reaches 60 ° C., 0.005 parts of ferrous sulfate and 0.1 parts of tetrasodium parophosphate are added to initiate the reaction. The mixture temperature is raised to 70 ° C., and 30 minutes after the start of the reaction, 26.25 parts of styrene and 8.75 parts of acrylonitrile are added. 1.2 parts of potassium oleate, 0.1 part of t-dodecylmercaptan, 0.25 parts of cumene hydroperoxide, and 22 parts of ion-exchanged water were placed in a stirred container, made into a pre-emulsion state, and added continuously over 2 hours. When the rate of polymerization of the latex reached 95.1%, the temperature was raised to 80 ° C to terminate the reaction at a polymerization rate of 98.2% or more.

The polymerization time was 4 hours at 70 ° C and 1 hour at 80 ° C.

Example 2)

The same procedure as in Example 1 was conducted except that 50 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 2 were used.

Example 3

The same procedure as in Example 1 was conducted except that 50 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 3 were used.

Example 4

The same procedure as in Example 1 was conducted except that 50 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 4 were used.

Example 5

The same procedure as in Example 1 was carried out except that 50 parts of butadiene rubber latex mold having an average particle diameter of 0.28 micron and a gel content of 80% by weight was used.

Comparative example 1)

The same procedure as in Example 1 was conducted except that 50 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 5 were used.

Comparative example 2)

The same procedure as in Example 1 was carried out except that 37.5 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 3, 12.5 parts of butadiene rubber latex solid having an average particle diameter of 0.28 micron and 80% by weight of gel was used.

Comparative Example 3)

The same procedure as in Example 1 was carried out except that 12.5 parts of the crosslinked acrylic rubber latex solid obtained in Preparation Example 5, 37.5 parts of butadiene rubber latex solid having an average particle diameter of 0.28 micron and a gel content of 80% by weight were mixed.

The content ratios of the graft copolymers of the Examples and Comparative Examples are shown in Table 1 below, and were added and extruded and processed in a powder state.

TABLE 1

.

The physical property evaluation method of the resin obtained as above is as follows, and the result is as Table 2 below.

* Assessment Methods

1) Gel content of crosslinked acrylic rubber latex:

After 1 g of cross-linked acrylic rubber solids were left in acetone for 24 hours, they were placed in a centrifuge and rotated at 25,000 rpm. The solids were recovered and dried to obtain a weight.

[Equation 1]

2) Solvent Resistance:

Samples, such as heat deflection temperature measurements, were added to gasoline and cracks formed were evaluated according to the following evaluation grades by visual inspection.

◎ Very good ○ Good □ Slightly bad × Bad

3) Weather resistance: Measured using ZENON TEST 150S of Germany HERAEUS.

TABLE 2

Claims (7)

Primary grafted by graft polymerization of 14.70 to 7.35 parts by weight of styrene (b) and 6.30 to 3.15 parts by weight of acrylonitrile (c) to 30 to 65 parts by weight of the crosslinked acrylic rubber latex prepared through the step 2 A thermoplastic resin comprising 34.50 to 17.15 parts by weight of styrene (b ') and 14.50 to 7.35 parts by weight of acrylonitrile (c') in a pre-emulsion state, followed by continuous dosing and secondary graft polymerization. Manufacturing method. The method for preparing a thermoplastic resin according to claim 1, wherein the redox catalyst added during the preparation of the first graft latex (A) is added with 0.001 to 0.40 parts of the composition consisting of ferrous sulfate and tetrashodium parophosphate. Way. The method for producing a thermoplastic resin according to claim 1, wherein the method for producing a crosslinked acrylic rubber latex (a) has a two step process. Stage 1) 15 to 65 parts of acrylic ester monomer having 1 to 13 carbon atoms and 15 to 2 parts of unsaturated nitrile monomer, and 0.03 to 1.2 parts of polyfunctional monomer having two or more functional groups copolymerizable with the monomer mixture, potassium rosin A rubbery latex having a mean particle size of 0.15 to 0.25 microns was prepared by adding 0.01 to 0.45 parts of potassium persulfate in the presence of 1.0 to 3.5 parts of salt and ion-exchanged water. Step 2) In the rubber latex prepared in the first step, 55-30 parts of an acrylate ester monomer, 15-3 parts of an unsaturated nitrile monomer, 0.1-2.5 parts of a polyfunctional monomer, 0.4-2.0 parts of potassium rosin salt, and ion-exchanged water are placed in a container which can be stirred. The final rubbery latex was prepared by putting in a pre-emulsion state and continuously adding the average particle size to 0.30 to 0.35 microns. The method for producing a thermoplastic resin according to claim 3, wherein the unsaturated nitrile monomer is acrylonitrile. The method of claim 3, wherein the average particle size of the second stage final rubber latex is 0.30 to 0.35 microns. The method for producing a thermoplastic resin according to claim 3, wherein the gel content of the final rubbery latex of the second stage is 80 to 98%. 30-65 parts by weight of butadiene-based rubber latex manufactured through a two-step process (a) 14.70 to 7.35 parts by weight of styrene (b) and 6.30 to 3.15 parts by weight of acrylonitrile (c) is first graft The polymer is made of 34.50 to 17.15 parts by weight (b ') and 14.50 to 7.35 parts by weight of acrylonitrile (c') in a pre-emulsion state, followed by a continuous graft polymerization of the thermoplastic resin, characterized in that Manufacturing method.