KR100380014B1 - Method for preparing rubbery polymer latex - Google Patents

Abstract

PURPOSE: A method for preparing a rubbery polymer latex for producing ABS (acrylonitrile-butadiene-styrene) resins is provided to obtain a resin having excellent impact resistance at a low temperature. CONSTITUTION: The method for preparing a rubbery polymer latex comprises the steps of: (a) introducing 50-95 parts by weight of an aliphatic conjugated diene compound to be used as a monomer in one portion before initiating polymerization and reacting it; and (b) introducing 5-50 parts by weight of the aliphatic conjugated diene compound, when the gel content of the latex reaches 1% to 65%, to perform emulsion polymerization of a large-diameter rubbery polymer latex.

Description

Rubber polymer latex manufacturing method

The present invention relates to a method for producing a rubbery polymer latex, and more particularly, it is excellent when applied to ABS (Acrylonitrile-Butadiene-Styrene) resin by varying the gel content of the latex particles and the large diameter of the rubbery polymer A method for producing a rubbery polymer latex having low temperature impact resistance.

In the production of ABS resin, the physical properties of the resin are greatly influenced by the particle size of the dispersed rubbery polymer and the structure of the particles. For example, in order to obtain an ABS resin having excellent surface gloss, a rubbery polymer having a small particle size should be used, and a rubbery polymer having a large particle size should be used to obtain an ABS resin having excellent impact resistance and workability.

As a method for producing a large diameter rubbery polymer latex to obtain an ABS resin having excellent impact resistance and processability,

1) A method for preparing large-diameter rubbery latex by preparing small-diameter latex and adding acidic substances such as acetic acid and phosphoric acid to lower pH to fusion particles (Japanese Patent Laid-Open Nos. 63-132903, 63-117005, Special Publication 2- 9601);

2) freezing small-diameter latex to produce large-diameter particles;

3) a method for producing a large-diameter rubbery latex by adding an acrylate copolymer latex during the polymerization (US Pat. No. 5,294,659, Japanese Patent Laid-Open No. H1-126301, Japanese Patent Laid-Open No. 59-93701);

4) a method for producing a large diameter latex by adding an electrolyte of a polyvalent metal during polymerization;

5) a method for producing a large diameter latex by applying a shear force to the small diameter latex;

6) a method for producing a large diameter latex using a non-polymerizable organic solvent and an emulsifier during polymerization (Japanese Patent Laid-Open No. Hei 8-27227, Japanese Laid-Open Hei 8-27204); And

7) A method of introducing a small amount of acrylonitrile monomer into the comonomer (Japanese Patent Laid-Open No. 5-17506)

Etc. are known.

The method of 1) can produce a large diameter rubber latex within a short time, but has a problem that a large amount of coagulum is generated when an acidic substance is added, the method of 2) has a problem of controlling the particle size, and the method of 3) has a rubber latex. It has a problem in that it has a limitation in large-diameter hardening, and it has a problem in that impact resistance is lowered when ABS resin is applied, and the method of 4) is difficult to control the particle diameter, and the method of 5) lacks reproducibility in large-diameter hardening of the particle diameter, 6) and 7). The method has a problem that it is difficult to process the monomer remaining after polymerization.

Therefore, in order to solve these problems, a method for producing large diameter rubber latex by direct polymerization without reactant treatment is sometimes used when manufacturing large diameter rubber latex (Japanese Patent Laid-Open No. 56-136807). However, this method takes a long reaction time, and because the concentration of the emulsifier should be low, a lot of coagulum is generated, it is difficult to remove the reaction heat when stirring, there is a limit to improve the impact resistance at low temperatures when applying ABS resin.

Therefore, in order to solve these problems, the present inventors changed the method of administration of the reactants when manufacturing large-diameter rubbery latex to adjust the gel content of the polymerized rubbery latex, and to apply the resin to ABS resin by large-diameter hardening of the particle. Invented a method that can be obtained.

In the present invention, as an emulsion polymerization method, 50 to 95 parts by weight of the conjugated diene compound monomers are totally administered before the start of polymerization in a total of 100 parts by weight of the conjugated diene compound monomers, and the reaction is performed for a predetermined time while controlling the gel content. The present invention relates to a rubbery polymer latex manufacturing method capable of obtaining a resin having excellent impact resistance at low temperatures when applied to an ABS resin by large-sized particle diameter while varying the inner and outer gel contents of the rubbery latex by continuous (sequential) administration.

The present invention is described in detail as follows.

The present invention is 50 to 95 parts by weight, 1 to 4 parts by weight of the emulsifier, 0.2 to 1.5 parts by weight of the polymerization initiator, 0.5 parts by weight of the electrolyte, 0.1 to 0.5 parts by weight of the molecular weight regulator, ion exchange water 75 By weight in a batch, the reaction was carried out at 65 ℃ to 75 ℃ for 8 to 25 hours, and then the remaining conjugated diene compound monomer and a molecular weight modifier in a batch or continuous (sequential) administration for 15 to 35 hours at 70 ℃ to 85 ℃ By reacting the average particle diameter of about 2600 kPa to 5000 kPa and by controlling the internal and external gel content of the latex particles differently relates to a rubbery polymer latex manufacturing method that can have excellent low-temperature impact resistance when applying ABS resin.

As the monomer used in the present invention, a conjugated diene compound may be used alone, or may be mixed with an aromatic vinyl compound, such as styrene and α-methylstyrene, copolymerizable therewith and a vinyl cyan compound such as acrylonitrile. When used, it is recommended to use within 20 parts by weight of the total monomer mixture. The conjugated diene compound is 1,3-butadiene, isoprene, chloroprene, piperylene and the like, and co-monomers copolymerizable therewith are also possible.

Emulsifiers include alkyl aryl sulfonates, alkali methyl alkyl sulfates, sulfonated alkyl esters, fatty acid soaps, alkali salts of rosin acids, and the like, which may be used alone or in admixture of two or more thereof.

A water-soluble persulfate or a peroxy compound can be used as a polymerization initiator, and an oxidation-reduction system can also be used. The most suitable water-soluble persulfates are sodium and potassium persulfates, and fat-soluble polymerization initiators include cumenehydro peroxide, diisopropyl benzene hydroperoxide, azobis isobutylnitrile, tertiary butyl hydroperoxide, paramethane hydroperoxide , Benzoyl peroxide and the like can be used alone or as a mixture of two or more thereof.

As 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 It is possible to use PO ₄ , K ₂ HPO ₄ , Na ₂ HPO _4, etc. alone or in mixture of two or more thereof. Mercaptans are mainly used as a molecular weight regulator.

The polymerization temperature is very important for adjusting the gel content and swelling degree of the rubbery latex, and the initiator selection should also be considered.

In order to obtain an ABS resin having excellent low temperature impact resistance, a suitable rubbery polymer latex has a suitable average particle diameter of 2600 mm to 5000 mm and a standard diameter of 25% or less. In addition, the total gel content is suitable for 60 to 95% and the swelling index is suitable for about 18 to 40. In this case, when the average particle diameter of the rubbery polymer is 2600 mm 3 or less, the impact resistance at low temperature is lowered. When the average particle diameter is 5000 mm 3 or more, the latex stability of the polymer decreases when ABS resin is applied, and a large amount of coagulum is produced.

Example

Example 1 (A1)

In a nitrogen-substituted polymerization reactor (autoclave), the first stage component of A1 in Table 1, namely 75 parts by weight of ion-exchanged water, 80 parts by weight of 1,3-butadiene as monomer, 1.2 parts by weight of potassium rosin salt as emulsifier, potassium oleate 1.5 parts by weight of salt, 0.7 parts by weight of sodium carbonate (Na ₂ CO ₃ ) as the electrolyte, 0.8 parts by weight of potassium hydrogencarbonate (KHCO ₃ ), 0.3 parts by weight of tertiary dodecyl mercaptan (TDDM) as the molecular weight regulator, potassium persulfate as the initiator 0.3 parts by weight of the batch and reacted for 15 hours at a reaction temperature of 70 ℃, 20 parts by weight of the remaining monomers 1,3 butadiene, 0.05 parts by weight of tertiary dodecyl mercaptan was reacted at 75 ℃ for 28 hours and then reacted Terminated. And the obtained rubbery polymer latex was analyzed.

The analysis method of the rubbery polymer is as follows.

a) gel content and swelling index

The rubbery polymer latex is coagulated with dilute acid or metal salt and washed, dried in a vacuum oven at 60 ° C. for 24 hours, and the resulting rubber mass is chopped with scissors, and then 1 g of the rubber section is put into 100 g of toluene for 48 hours. After storage in the dark at room temperature, the sol and gel are separated, and the gel content and swelling index are measured according to the following equation.

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

Swelling index = weight of swollen gel / weight of gel

b) particle size and particle size distribution

It was measured using Nicomp 370 HPL by the dynamic laser light scattering method.

c) product coagulant ratio = weight of coagulum produced in the reactor / weight of total monomers administered * 100

d) Graft Rate = Weight of Grafted Monomer / Rubber Weight * 100

Examples 2 to 4 (A2 to A4)

The reaction was carried out in the same manner as in Example 1, but the reactant composition ratio and administration method were carried out by the methods of A2 to A4 instead of A1 in Table 1.

Comparative example

Comparative Examples 1 to 3 (B1 to B3)

The reaction was carried out in the same manner as in Example 1, but the reactant composition ratio and the administration method were compared by performing the methods of B1 to B3 of Table 2 instead of A1 of Table 1.

Example A1 Example A2 Example A3 Example A4 1. Bulk dosing 1-1. Ion Exchange Water 1-2. 1,3-butadiene 1-3. Potassium rosin salts 1-4. Potassium Oleate Salts 1-5. Sodium carbonate 1-6. Potassium hydrogen carbonate 1-7. Grade 3 dodecyl mercaptan 1-8. Potassium peroxide 75801.21.50.70.80.30.3 7090 ← 1.4 ←←←← 75601.1 ←←←←← 7570 ← 1.3 ←←←← Gel Content Before Second Reaction 20% 2 % 46% 30% 2. Timing of Administration or Partial Administration 2-1. 1,3-butadiene 2-2. Grade 3 dodecyl mercaptan 15 hours after the start of the batch dose reaction ← 10 hours after the start of the reaction10 ← ← 20 hours after the start of the reaction40 ← 18 hours after the start of the continuous dose reaction Polymerization Conversion Gel Content Swelling Index Particle Size 91% 86% 213300 Å 90% 78% 243500 Å 91% 73% 263700 Å 90% 70% 284000 Å

Comparative Example B1 Comparative Example B2 Comparative Example B3 1. Bulk dosing 1-1. Ion Exchange Water 1-2. 1,3-butadiene 1-3. Potassium rosin salts 1-4. Potassium Oleate Salts 1-5. Sodium carbonate 1-6. Potassium hydrogen carbonate 1-7. Grade 3 dodecyl mercaptan 1-8. Potassium peroxide 751001.1 ←←←←← 7080 ← 1.6 ←←←← 75901.2 ←←←←← Gel Content Before Second Reaction · 0.50% 70% 2. Timing of Administration or Partial Administration 2-1. 1,3-butadiene 2-2. Grade 3 dodecyl mercaptan ···· 6 hours after the start of the batch dose reaction 33 hours after the start of the batch dose reaction Polymerization Conversion Gel Content Swelling Index Particle Size 90% 75% 232700 Å 91% 75% 232 800 Å 90% 80% 252 800 Å

Example

Example 1 (C1)

50 parts by weight of the rubbery polymer latex prepared by the method A1 in the nitrogen-substituted polymerization reactor, 65 parts by weight of ion-exchanged water, 0.1 part by weight of sodium ethylenediaminetetraacetate, 0.005 part by weight of ferrous sulfate, formaldehyde sodium sulfoxylate 0.23 weight part and 0.35 weight part of potassium rosinate were put into the reaction tank collectively, and the temperature was raised to 70 degreeC. And 50 parts by weight of ion-exchanged water, 0.65 parts by weight of potassium rosinate, 35 parts by weight of styrene, 15 parts by weight of acrylonitrile, 0.4 parts by weight of tertiary dodecyl mercaptan, and 0.4 parts by weight of diisopropylenebenzenehydroperoxide. After continuously adding for 3 hours, the polymerization temperature was again raised to 80 ° C., and then aged for 1 hour to terminate the reaction. The polymerization conversion rate of the polymer obtained at this time was 98%, the graft rate was 30%, the product coagulant ratio was about 0.3%. The latex was solidified with an aqueous solution of sulfuric acid, washed, and then powdered. 36 parts by weight of the obtained powder and 64 parts by weight of a styrene-acrylonitrile copolymer: SAN (LG Chemical, product name: 80 HF) were added to a mixer, followed by mixing. Pellets were used to obtain physical properties and specimens were measured using an injection molding machine.

Use Examples 2 to 5 (C2 to C5)

Example A2 to Comparative Example B2 were used in place of Example A1 of Tables 1 and 2, except that rubber polymer latex was used in the same manner as in Example 1.

Example C1 Example C2 Example C3 Example C4 Example C5 Rubbery polymer latex Example A1 Example A2 Example A3 Comparative Example B1 Comparative Example B2 Notched Izod Impact Strength (ASTM D256, kgcm / cm) (23 degrees Celsius) (-20 degrees Celsius) 4223 4323 4524 3516 3717 Fluidity (ASTM D1238, g / 10 min, 10 kg, 220 ° C) 16 16 16 15 15

ABS resin was produced from the composition of the present invention to obtain a resin having excellent low temperature impact resistance.

Claims (8)

In preparing a rubbery polymer latex which is used to obtain an ABS resin having excellent low temperature impact resistance, a) reacting 50 to 95 parts by weight of the aliphatic conjugated diene compound to be used as a monomer in a batch before the polymerization is initiated; b) emulsion polymerization of a large diameter rubbery polymer latex by administering from 5 to 50 parts by weight of an aliphatic conjugated diene compound at a time when the gel content of the latex is 1% to 65% How to include. The method of claim 1, A process for producing a rubbery polymer latex using an aliphatic conjugated diene compound alone or a mixture of an aliphatic conjugated diene compound and an ethylenically unsaturated monomer as a monomer. The method of claim 1, A method of collectively or continuously administering an aliphatic diene compound in step b). The method of claim 1, A process for producing a rubbery polymer latex wherein the aliphatic conjugated diene compound is at least one monomer selected from 1,3-butadiene, isoprene, chloroprene and pyrrylene. The method of claim 1, A method for producing a rubbery polymer latex wherein the ethylenically unsaturated monomer is at least one compound selected from aromatic vinyl compounds, acrylic esters, methacrylic acid esters and vinyl cyan compounds. The method of claim 1, A rubbery polymer latex production method, wherein the rubbery polymer latex to be produced has an average particle diameter of 2600 mm 3 to 5000 mm 3. The method of claim 1, A process for producing a rubbery polymer latex having a total gel content of rubbery polymer latex of 60% to 95% and an swelling index of 18 to 40. In the ABS resin containing a rubbery polymer, Rubbery polymer a) reacting 50 to 95 parts by weight of the aliphatic conjugated diene compound to be used as a monomer in a batch before the polymerization is initiated; b) emulsion polymerization of a large diameter rubbery polymer latex by administering from 5 to 50 parts by weight of an aliphatic conjugated diene compound at a time when the gel content of the latex is 1% to 65% ABS resin obtained by the.