KR100822158B1 - Method for preparing of rubber polymer latex - Google Patents

Abstract

The present invention relates to a method for producing a rubbery polymer latex, and more particularly, in the production of a rubbery polymer latex applied to ABS resin, a) 60 to 70 parts by weight of 100 parts by weight of the total conjugated diene compound monomers before the start of polymerization Administering; b) adding an emulsifier at a time point of 30 to 40% of the polymerization conversion rate in step a), and then collectively administering 15 to 20 parts by weight of the conjugated diene compound; And c) a step of collectively or continuously administering the remaining conjugated diene compound after the time point at which the polymerization conversion rate of step b) is 60%, and the preparation of the rubbery polymer latex comprising the addition of the conjugated diene compound monomer. By controlling the particle size of the latex for each reaction section and having a wide particle size distribution, the reaction rate is controlled to have high productivity at high solids content, and it is a rubbery polymer that has an effect of improving impact strength, elongation and gloss when applied to ABS resin. It has the effect of providing latex.

ABS resin, rubbery polymer, polymerization conversion, particle size control, conjugated diene compound

Description

METHODS FOR PREPARING OF RUBBER POLYMER LATEX

The present invention relates to a method for producing a rubbery polymer latex, and more particularly, by controlling the input of the conjugated diene compound monomer to control the particle diameter of the latex for each reaction section has a high productivity at high solids content, impact when applied to ABS resin A method for producing a rubbery polymer latex having an effect of improving strength, elongation and gloss.

The conjugated diene rubbery polymer represented by polybutadiene is an elastomer widely used in ABS and MBS resins due to its low glass transition temperature, and in particular, the fracture behavior varies according to the particle size and dispersibility of the rubbery polymer in the ABS and MBS resins. It is manufactured by emulsion polymerization method. When the rubber latex is prepared by the emulsion polymerization method, the polymerization time is closely related to the particle size of the rubber latex, and a long polymerization time is required to obtain a rubber latex having a large particle size.

As a method of obtaining a rubbery latex having a large particle diameter in a relatively short time, an agglomeration technique has been proposed. This technique is a method of polymerizing latex with a small particle size in a short time and fusion during the polymerization process. The reaction rate is rapidly increased up to the point of polymerization conversion of 40 to 50%, and thereafter, the reaction rate is rapidly increased, and the diameter is larger than 3,000 kPa. In order to prepare the latex, a reaction time of 50 hours or more is required.

In order to prevent a sharp drop in the reaction rate at a point after the polymerization conversion rate of 40 to 50%, a multi-stage polymerization method containing acrylonitrile as an essential component is proposed, and a technique for producing a large diameter rubber latex in a relatively short time is known. However, the rubber latex obtained by this technique has a problem in that it has an irregular morphology and is not suitable as a raw material of ABS resin.

At present, such emulsion polymerization is performed by a batch method, and much effort is made to increase the capacity of the reactor, to increase the total solid content of the rubbery latex, and to shorten the reaction time in order to improve the productivity of the batch polymerization method.

Since the batch polymerization process is performed intermittently after several times of polymerization to wash the inside of the reactor, a large amount of polymer film is generated inside the reactor. For this reason, productivity improvement is impaired, control of polymerization exotherm becomes difficult, runaway reaction occurs, and the reproducibility of rubber latex between each batch falls, and there exists a problem which cannot carry out stable production.

An improved batch production method aiming at controlling the polymerization temperature in such a batch polymerization reaction has been proposed. In this method, the unreacted monomers do not remain in the polymerization system during the reaction, thereby preventing the runaway reaction of the polymerization and obtaining a heat removal effect due to slight sensitization caused by the difference between the temperature of the water continuously administered during the reaction and the reaction temperature. It is possible to control the polymerization temperature more stably than the general batch polymerization. However, this method is possible because of the low total solid content (TSC) in the case of rubber latex polymerization for producing small diameter particles, but in the case of rubber latex polymerization for producing large diameter particles, the total solid content is high. There is a problem that it is difficult to expect the heat removal effect of the administration of water during the reaction.

In order to solve the problems of the prior art as described above, the present invention controls the reaction rate by controlling the input of the conjugated diene compound monomers to have a wide particle size distribution through the particle size control of the latex for each reaction section to control the reaction rate and high productivity at high solids content. It is intended to provide a method for producing a rubbery polymer latex having an effect of improving the impact strength, elongation and gloss when applied to ABS resin.

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

In order to achieve the above object, the present invention in the manufacture of a rubbery polymer latex applied to the ABS resin,

a) 60 to 70 parts by weight of a total of 100 parts by weight of the conjugated diene compound monomers before the start of polymerization;

b) adding an emulsifier at a time point of 30 to 40% of the polymerization conversion rate in step a), and then collectively administering 15 to 20 parts by weight of the conjugated diene compound; And

c) batch or continuous administration of the remaining conjugated diene compound after the point of time at which the polymerization conversion in step b) is 60%;

It provides a method for producing a rubbery polymer latex comprising a.

Hereinafter, the present invention will be described in detail.

Method for producing a rubbery polymer latex of the present invention

a) 60 to 70 parts by weight of the total 100 parts by weight of the conjugated diene compound monomers, 1 to 4 parts by weight of an emulsifier, 0.2 to 0.4 parts by weight of a polymerization initiator, 0.2 to 2.0 parts by weight of an electrolyte, 0.1 to 0.5 parts by weight of a molecular weight regulator, and ion exchanged water 75 to 100 parts by weight of a batch to react at 55 to 65 ℃;

b) 15 to 20 parts by weight of the conjugated diene compound monomer and 1.0 to 1.5 parts by weight of the emulsifier are reacted at 65 to 75 ° C. at a time when the polymerization conversion rate of a) is 30 to 40%; And

c) reacting the remaining conjugated diene compound monomers in a batch or successive manner after the polymerization conversion rate of b) is 60 to 70%;

It is made, including.

In the method of preparing the rubbery polymer latex, polymerization may be terminated by adding a polymerization inhibitor at a time when the polymerization conversion ratio of (c) is 80 to 95%.

As the conjugated diene compound, 1,3-butadiene, isoprene, chloroprene, pyrrylene or a comonomer thereof may be used.

The conjugated diene compound may be used alone, or may be mixed with an aromatic vinyl compound such as styrene and α-methyl styrene copolymerizable therewith and a vinyl cyan compound such as acrylonitrile.

The copolymerizable monomer is preferably used at a maximum of 20 parts by weight based on the total monomer content.

As the emulsifier, alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps, or alkali salts of rosin acids may be used alone or in combination of two or more thereof.

As said polymerization initiator, water-soluble persulfate initiators, such as potassium persulfate, sodium persulfate, or ammonium persulfate, can be used.

As the electrolyte, KCl, NaCl, KHCO ₃ , NaHCO ₃ , K ₂ CO ₃ , Na ₂ CO ₃ , KHSO ₃ , NaHSO ₃ , K ₄ P ₂ O ₇ , Na ₄ P ₂ O ₇ , K ₃ PO ₄ , Na ₃ PO ₄ , K ₂ HPO ₄ or Na ₂ HPO ₄ may be used alone or in combination of two or more thereof.

As the molecular weight regulator, mercaptans can be mainly used.

The conjugated diene compound monomer of step (a) is preferably used at 60 to 70 parts by weight based on 100 parts by weight of the total monomers used. If the content is less than 60 parts by weight, the number of particles initially generated is extremely small, and the latex particles cannot be fused largely due to the decrease in the particle surface coverage of the emulsifier due to the growth of particles. There is a problem. By using the content less than 60 parts by weight, using a small amount of emulsifier or increasing the total solid content and using a large amount of electrolyte may cause fusion of latex particles. However, these methods may be possible in a small reactor without the generation of coagulum, but when a large capacity is produced in a large reactor, a large amount of coagulant is generated, thereby lowering the polymerization productivity. In addition, when the content exceeds 70 parts by weight, there is a problem in that the heat removal capacity is lowered by the increased heat of polymerization to cause a runaway reaction.

The conjugated diene compound monomer of step (b) is preferably used at 15 to 25 parts by weight when the polymerization conversion rate of step (a) is 30 to 40%. Since the fusion of the latex particles is completed when the polymerization conversion rate is 30 to 40%, it is preferable to collectively administer the conjugated diene compound monomer. In addition, at this point, it is preferable to stop the progress of the fusion of the extra particles by adding an emulsifier in sufficient amount to stabilize the coating of the particle surface to the particles undergoing fusion before the monomer administration.

The emulsifier added in the step (b) may be a disproportionated rosin acid emulsifier, it is more preferable to use an emulsifier having a linear chain such as oleic acid, stearic acid. By adding the emulsifier, an atmosphere in which the monomers can generate new particles is formed, and after this time, the reaction rate increases with the growth of newly generated particles. In addition, the particles having a large particle size and particles having a small particle size coexist and grow to reduce latex viscosity, thereby securing latex stability.

It is preferable that the conjugated diene monomer compound of step (c) is administered in a batch or continuous manner after the time when the polymerization conversion rate of step (b) is 50 to 60%. After the polymerization conversion rate of 50 to 60%, monomer droplets in the latex disappear, and the internal pressure of the reactor is also reduced, so that the polymerization productivity can be stably improved by batch or continuous administration of the remaining monomers. Can be controlled.

The polymerization temperature for preparing the rubbery polymer latex can be adjusted according to the gel content and swelling degree of the rubbery latex, and the selection time and the timing of administration of the polymerization initiator should also be considered.

It is preferable that the rubbery polymer latex prepared above has an average particle diameter of 2,600 to 5,000 mm 3.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

Preparation of Rubbery Polymer Latex

75 parts by weight of ion-exchanged water, 60 parts by weight of 1,3-butadiene as monomer, 1.4 parts by weight of potassium rosin salt as emulsifier, 0.6 parts by weight of potassium oleate salt, and potassium carbonate as electrolyte in a nitrogen-substituted polymerization reactor (autoclave) K ₂ CO ₃ ) 0.9 parts by weight, 0.3 parts by weight of tertiary dodecyl mercaptan (TDDM) as a molecular weight regulator, 0.3 parts by weight of potassium persulfate (K ₂ S ₂ O ₈ ) as an initiator and polymerization at a reaction temperature of 70 ℃ After the reaction was carried out to the point of conversion of 30 to 40%, first 0.7 parts by weight of potassium oleate, and then 20 parts by weight of 1,3-butadiene were collectively reacted at a temperature of 60% of polymerization conversion at 70 ° C. 20 parts by weight of butadiene were collectively heated to 80 ° C, and the reaction was terminated when the polymerization conversion was 95%. The polymerization time was 23 hours, the gel content of the obtained rubbery polymer latex was 76%, the average particle diameter was 3,050 mm 3.

Preparation of Graft Copolymer

55 parts by weight of the prepared rubbery polymer latex and 145 parts by weight of ion-exchanged water were added to a nitrogen-substituted polymerization reactor, and 12.6 parts by weight of acrylonitrile, 32.4 parts by weight of styrene, and 25 parts by weight of ion-exchanged water in a separate mixing device, t 0.12 parts by weight of butyl hydroperoxide, 1.1 parts by weight of potassium rosinate, and 0.3 parts by weight of tertiary dodecyl mercaptan are mixed to form an emulsion and continuously added at 70 ° C. for 4 hours. At this time, 0.054 parts by weight of dextrose, 0.024 parts by weight of sodium pyrolate, and 0.006 parts by weight of ferrous sulfate are continuously added together.

After the addition of the monomer emulsion, 0.08 parts by weight of dextrose, 0.05 parts by weight of sodium pyrolate, 0.001 parts by weight of ferrous sulfate, and 0.05 parts by weight of t-butyl hydroperoxide were collectively added to the reactor, and then the temperature was 80 ° C. The temperature was raised over 1 hour and then the reaction was terminated. The polymerization conversion rate of the obtained polymer was 98%, the graft rate was 49.8%, and the product coagulant content was about 0.3%.

The obtained graft copolymer latex was coagulated with an aqueous sulfuric acid solution, washed, and then prepared as a powder. Then, 33 parts by weight of the prepared powder and 67 parts by weight of SAN (LG Chemical, product name: 92HR) were added to a mixer, followed by mixing. After pelletizing by using the injection molding machine, the physical properties of the specimens were obtained, and the physical properties thereof were measured.

Example 2

In the first embodiment, 70 parts by weight of 1,3-butadiene, which is a monomer, is initially administered in a batch, and 15 parts by weight of 1,3-butadiene is collectively administered at a time of 30 to 40% of polymerization conversion, and after the time of 60% of polymerization conversion. 15 parts by weight of 1,3-butadiene was carried out in the same manner as in Example 1 except that the reaction was terminated at a polymerization conversion rate of 93%. The polymerization time was 26 hours, the gel content of the obtained rubbery polymer latex was 70%, and the average particle diameter was 3,100 mm 3.

Example 3

In Example 1, the reaction was carried out in the same manner as in Example 1, except that the reaction was terminated at the polymerization conversion rate of 94% by continuously administering 20 parts by weight of 1,3-butadiene at the polymerization conversion rate of 60%. The polymerization time was 23 hours, the gel content of the obtained rubbery polymer latex was 73%, and the average particle diameter was 3,150 mm 3.

Example 4

The same process as in Example 1 was conducted except that 0.9 parts by weight of potassium rosin salt was administered at a polymerization conversion rate of 30 to 40% in Example 1. The time taken for the polymerization was 28 hours, the gel content of the obtained rubbery polymer latex was 72%, and the average particle diameter was 3,300 mm 3.

Comparative Example 1

In Example 1, 100 parts by weight of 1,3-butadiene, which is a monomer, was initially administered in a batch, and reacted at a reaction temperature of 65 ° C. up to a point of 30 to 40% of polymerization conversion, and then 0.7 parts by weight of potassium oleate was collectively administered at 70 ° C. After the reaction was completed to the point of polymerization conversion of 60%, the temperature was raised to 80 ° C, and the reaction was terminated at the point of polymerization conversion of 89%. The time taken for the polymerization was 38 hours, the gel content of the obtained rubbery polymer latex was 70%, and the average particle diameter was 3,100 mm 3.

The physical properties of the rubbery polymer latex prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

A) Gel content-The prepared rubbery polymer latex is coagulated with dilute acid or metal salt, washed, dried in a vacuum oven at 60 ℃ for 24 hours, and then chopped rubber mass with scissors, and then 1 g of rubber toluene is cut. 100 g was stored in the dark at room temperature for 48 hours, and then separated into sol and gel, and the gel content was measured by the following formula.

Gel content (%) = weight of insolubles (gel) / weight of sample * 100

B) Particle size and particle size distribution-It was measured by using Nicomp 370HPL by dynamic laser light scattering method.

C) Izod impact strength-The thickness of the specimen was measured in accordance with ASTM D256 method with 1/4 thickness.

D) tensile strength and elongation—measured according to ASTM D638 method.

Surface gloss—measured according to ASTM D528 method at a 45 ° angle.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Impact Strength (kgcm / cm) 32 35 34 36 30 Elongation (%) 45 35 35 28 25 Polish (%) 98 92 96 95 94

As described above, according to the present invention, by controlling the input of the conjugated diene compound monomer to control the particle size of the latex for each reaction section and to have a wide particle size distribution to control the reaction rate to have high productivity at high solids content, ABS resin When applied to has the effect of providing a rubbery polymer latex having the effect of improving the impact strength, elongation and gloss.

Although described in detail above with reference to the specific embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such variations and modifications belong to the appended claims. It is also natural.

Claims (9)

In the preparation of rubbery polymer latex applied to ABS resin, a) 60 to 70 parts by weight of a total of 100 parts by weight of the conjugated diene compound monomers before the start of polymerization; b) adding 0.7 to 1.5 parts by weight of an emulsifier at a time point of 30 to 40% of the polymerization conversion rate in step a), and then collectively administering 15 to 20 parts by weight of the conjugated diene compound; And c) batch or continuous administration of the remaining conjugated diene compound after the point of time at which the polymerization conversion in step b) is 60%; Method for producing a rubbery polymer latex comprising a. The method of claim 1, The rubber polymer latex manufacturing method a) 60 to 70 parts by weight of the total 100 parts by weight of the conjugated diene compound monomers, 1 to 4 parts by weight of an emulsifier, 0.2 to 0.4 parts by weight of a polymerization initiator, 0.2 to 2.0 parts by weight of an electrolyte, 0.1 to 0.5 parts by weight of a molecular weight regulator and ion-exchanged water. 75 to 100 parts by weight of a batch to react at 55 to 65 ℃; b) 15 to 20 parts by weight of the conjugated diene compound monomer and 1.0 to 1.5 parts by weight of the emulsifier are reacted at 65 to 75 ° C. at a time when the polymerization conversion rate of a) is 30 to 40%; And c) reacting the remaining conjugated diene compound monomers in a batch or successive manner after the polymerization conversion rate of b) is 60 to 70%; Method for producing a rubbery polymer latex comprising a. The method according to claim 1 or 2, The conjugated diene compound monomer is a method for producing a rubbery polymer latex, characterized in that at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, pyrrylene and comonomers thereof. The method of claim 2, The emulsifier of step a) is at least one 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. Manufacturing method. The method according to claim 1 or 2, The method of producing a rubbery polymer latex, characterized in that the emulsifier of step b) is selected from the group consisting of disproportionated rosin acid emulsifier and linear chain emulsifier. The method of claim 2, Wherein said polymerization initiator is selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate. The method of claim 2, The electrolyte is KCl, NaCl, KHCO ₃ , NaHCO ₃ , K ₂ CO ₃ , Na ₂ CO ₃ , KHSO ₃ , NaHSO ₃ , K ₄ P ₂ O ₇ , Na ₄ P ₂ O ₇ , K ₃ PO ₄ , Na ₃ PO ₄ , K ₂ HPO ₄ And Na ₂ HPO ₄ at least one selected from the group consisting of. The method of claim 2, The molecular weight regulator is a method for producing a rubbery polymer latex, characterized in that at least one selected from mercaptans. The method of claim 1, The rubbery polymer latex is a method for producing a rubbery polymer latex, characterized in that the average particle diameter of 2,600 to 5,000 mm 3.