KR0160333B1 - Processing method of impact reinforcing acrylic agents having high processability and fransparency for injection molding - Google Patents

Abstract

The present invention relates to a method of manufacturing a high impact acrylic impact modifier used for injection molding, which is i) by adding ion-exchanged water, emulsifiers and initiators to the reactor when the reactor internal temperature reaches 10 ~ 70 ℃ A first step seed polymerization in which a crosslinking agent, a hydrophilic monomer and a seed monomer are added, but 4-10 wt% of the seed monomer is added based on the solid content; ii) The seed polymerization product is continuously injected with monomers of rubber components, crosslinking agents, graft agents and hydrophilic monomers, and the contents of the graft agent and the hydrophilic monomers are 0.4-1.2 parts by weight and 0.6-2.4 parts by weight, respectively, based on the solid content of the final product. Two-stage core polymerization so that the content ratio of the graft agent to the hydrophilic monomer is 1: 1.2 to 2.0; iii) a three-step shell polymerization step of continuously injecting 20-40% by weight of a monomer having hybridity with the matrix into the latex based on the solid content of the rubber latex; Iii) a four-step postpolymerization process for completely polymerizing the unreacted monomers in the core polymerization product; Iii) a 5-step flocculation step of adding a flocculant to the polymer latex obtained through the post-polymerization; And iii) a six-stage recovery process for washing and drying the agglomerated polymer powder, maintaining a high graft efficiency to reach a melt flow index suitable for injection molding while maintaining good transparency and impact strength. Excellent injection molding acrylic impact modifier can be prepared.

Description

Manufacturing method of acrylic impact modifier for injection molding with excellent transparency and processability.

The present invention relates to a method of manufacturing a high impact acrylic impact modifier used for injection molding, and more particularly, to a method of manufacturing an acrylic impact modifier excellent in processability and permeability and impact resistance.

Acrylic resins have excellent gloss and weather resistance, and furthermore, because of their excellent mechanical properties and processability, they are widely used for the manufacture of signboards, lighting fixtures, covers, nameplates and various ornaments. However, acrylic resin products are easily broken by external impacts due to their low impact resistance, so their use is limited.

In general, an ointment for improving impact resistance has been performed by injecting an impact modifier, which is an elastomeric material, into an acrylic resin, and currently commercialized impact resistant acrylic resin is manufactured in pellet form by melt-blending the acrylic resin and the impact modifier by extrusion molding. The pellets can be compressed and injection molded to obtain extruded products such as sheets and injection products of small and large parts.

As such, a method for producing a resin composition having improved impact properties by adding a rubber component impact modifier to thermoplastic resins such as polystyrene and polymethyl methacrylate is already well known (Korean Patent Publication No. 92-473).

On the other hand, in order to obtain the impact-resistant acrylic resin injection molded article, the melt flow index and impact strength that greatly influence the injection properties must be satisfied at the same time. However, when the content of the impact modifier of the rubber component in the acrylic resin is increased, the melt flow index is reduced to reduce the processing phase is not suitable for the trial molding, injection productivity is also reduced. On the contrary, when the content of the impact modifier is decreased, the injection processability is improved, but the impact strength is decreased.

In addition, the rubber component giving the impact strength of the impact modifier is grafted to a component having good kneading with the matrix component.As the graft efficiency is increased, the dispersion is good in the matrix, so that the permeability and the impact strength are increased, but the workability is increased. When the graft efficiency is reduced, the transparency and the impact strength are sharply reduced due to the reduction of kneading with the matrix resin. In order to solve this problem, there is a known method of increasing the melt flow index by controlling the molecular weight of the matrix resin and the adjacent shell component with a chain transfer agent (US Patent No. 3678133), but there is a limit to the increase in the melt flow index. .

In the present invention, in order to solve the above drawbacks, the concentration of the graft monomer and the hydrophilic monomer and the content of the graft monomer and the hydrophilic monomer at the same time by adjusting the concentration of the solid content according to the monomer content in the Seed polymerization step when the impact modifier is prepared The present invention has been found that the acrylic impact modifier for injection molding having excellent transparency and impact strength can be obtained by maintaining a high graft efficiency and reaching a melt flow index suitable for injection molding with excellent transparency and impact strength. Was completed.

Acrylic impact modifier removes one-stage c-depolymerization to determine particle size by multi-stage polymerization, two-stage core polymerization to grow particles of rubber component, three-stage graft weight to give kneading with matrix and unreacted monomer It is prepared by a four-step post-polymerization, the production method of the present invention is a graft agent, a crosslinking agent, a hydrophilic monomer and seed when the ion exchange water, emulsifier and initiator is added to the reactor to reach the reactor temperature of 10 ~ 70 ℃ Adding a monomer, but adding 4-10 parts by weight based on solids of the final product to perform polymerization to determine particle size in one step (Seed) polymerization; Ii) Continuously injecting the monomer, crosslinked product, graft agent and hydrophilic monomer of the rubber component into the seed polymerization product of step (iii), 45-75 parts by weight of monomer monomer of the rubber component, graft agent And 0.4-1.2 parts by weight and 0.6-2.4 parts by weight of the hydrophilic monomer, respectively, so that the content of the graft agent versus the hydrophilic monomer is about 1: 1.2 to 2.0 to grow the particles to produce a polymer latex core (core) )polymerization; Iii) a three-step shell polymerization step of graft polymerization by continuously injecting 20-40% by weight of a monomer having kneading and matrix into the latex based on the solid content of the rubbery latex obtained in step 2; Iii) a four stage postpolymerization step of completely polymerizing the unreacted monomer in the core polymerization product; Iii) a five step flocculation step of preparing a polymer powder by adding a flocculant to the polymer latex obtained through the postpolymerization; And iii) a six-stage recovery process of washing and drying the agglomerated polymer powder to produce an acrylic impact modifier for injection molding with excellent transparency and processability. The impact modifier obtained in this manner is a polymethyl methacrylate. When pellets are manufactured by melt-kneading at a suitable ratio with a resin, and injection molding the pellets, an acrylic injection molded article excellent in transparency and impact resistance can be obtained.

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

150 to 200 parts by weight of ion-exchanged water, 0.1 to 1 part by weight of emulsifier, 0.01 to 2 parts by weight of initiator, 4 to 10 parts by weight of seed monomer, 0.05 to 0.5 parts by weight of crosslinking agent, when the internal temperature reached 10 to 70 ° C, Graft agent 0.02 to 0.05 parts by weight, hydrophilic monomer 0.04 to 0.07 parts by weight in a sufficiently emulsified state, injecting 0.001 to 0.2 parts by weight of the active agent to carry out the reaction to determine the particle size, 2) above 45 to 75 parts by weight of rubber monomer, 10 to 15 parts by weight of copolymerizable aromatic vinyl monomer having high refractive index, 0.05 to 4 parts by weight of crosslinking agent, 0.4 to 1.2 parts by weight of graft agent, hydrophilic monomer Two-stage core polymerization in which particles are grown by continuously injecting 0.6 to 2.4 parts by weight and 0.01 to 2 parts by weight of an active agent for a predetermined time, and 3) Monomer having matrix and kneading property in the rubbery latex obtained in step Shell polymerization to inject 40 parts by weight and 0.005 to 1 parts by weight of active agent continuously for a predetermined time and perform graft reaction, 4) Post polymerization to completely polymerize unreacted monomer in the core polymerization product, 5) Polymer obtained through post polymerization It is composed of a coagulation step for producing a polymer powder by adding 0.1 to 10 parts by weight of a coagulant to the latex, and 6) a recovery step for washing and drying the aggregated polymer powder.

Emulsifiers used in the present invention may be at least one of alkyl sulfates having 12 to 18 carbon atoms or aromatic aromatic sodium sulfate, potassium sulfate, sodium sulfonate and potassium sulfonate. For example, sodium dodecyl sulfate, sodium also decylbenzenesulfo. Nate, potassium dodecyl benzenesulfonate, potassium lauryl sulfate, etc., and the seed monomer is one or two selected from alkyl alkyl esters of 1 to 8 carbon atoms and methacrylic acid alkyl esters of 1 to 8 carbon atoms and aromatic vinyl monomers. It is comprised as mentioned above and 1, 3- butanediol di (meth) acrylate as a crosslinking agent. 1,6-hexanediol diacrylate, divinylbenzene, and the like, and the graft agent is selected from at least one selected from allyl methacrylate, diallysuccinate, and diallyl phthalate, and as a hydrophilic monomer, 2- When at least one of hydroxyethyl acrylate, 2-hydroxymethyl acrylate, 2-hydroxy ethyl methacrylate and 2-hydroxymethyl methacrylate is used, as an initiator, ammonium persulfate, sodium persulfate , Consisting of one or two or more selected from potassium persulfate, and as a flocculant, calcium chlorite, calcium sulfate, magnesium chlorad, magnesium sulfate, sodium chloride, aluminum sulfate, etc. are used, and the active agent is sodium metavia sulfate or Sodium ferrosulfate.

In the present invention, a stabilizer, a lubricant, a pigment and an antioxidant, and other additives may be added as needed in the flocculation process and the kneading process of the acrylic impact modifier. Evaluation and analysis of the impact modifier properties were performed using the method or apparatus shown below. Hereinafter, the present invention will be described in detail with reference to examples and fertilizer examples, which do not limit the scope of the present invention, and unless otherwise specified, a part means parts by weight.

[Haze]

A haze meter was measured using a disk-shaped specimen having a diameter of 50 mm and a thickness of 3.2 mm by the method of ASTM D1005.

[Impact strength]

The universal impact tester was measured using the ASTM D256A method.

Melt Flow Index

The melt index was measured under 1 condition (230 ° C., 3.8 kg) of ASTM D1238 method.

Example 1

The polymerization is carried out in a nitrogen atmosphere in a 100 1 type autoclave using the compounds described below.

a) first step (side-side polymerization)

125 parts by weight of ion-exchanged water was added to the reactor, and 0.5 parts of sodium dodecylbenzenesulfonate as an emulsifier and 0.6 parts of ammonium percellate as an initiator were added to start stirring. When the reactor temperature reaches 50 ° C under stirring, 5 parts of butyl acrylate / styrene (weight ratio 83:17) is used as a monomer, 0.04 parts of 1,4-butanediol dimethacrylate as a crosslinking agent and 0.05 parts of allyl methacrylate as a graft agent. , 0.1 part of 2-hydroxyethyl acrylate as a hydrophilic monomer and 0.1 part of metabisulfite as an activator were dissolved in 25 parts of ion-exchanged water, and the polymerization was carried out by stirring the stirring speed of the stirrer at 100 rpm for 1.5 hours to give a particle size of 0.05. A latex of μm is prepared. At this time, the concentration of the solid content is 3.4wt%.

b) second stage

63.75 parts of the butyl acrylate / styrene, 0.46 part of 1,4-butanediol methacrylate, 0.6 part of allyl kethacrylate, 1.0 part of 2-hydroxy ethyl acrylate, and sodium metabisulphite 0.2 in the first stage polymer The parts were continuously injected at a constant speed over 3 hours to grow into latex having a particle diameter of 0.06 to 0.20 µm. At this time, the concentration of solids is 31.8wt%.

c) third stage

After completion of the two-stage polymerization, 27 parts of methyl methacrylate and 3 parts of methyl acrylate were continuously added and grafted over 1 hour, and then the reaction temperature was raised to 60 ° C. to carry out postpolymerization. At this time, the particle diameter of latex is 0.21 to 0.3 micrometer, and pH is 3.0. At this time, the concentration of solids is 40.4wt%.

d) fourth stage

100 parts of ion-exchanged water is diluted with 100 parts of the latex in the third step, and 100 parts by weight of an aqueous solution of a coagulant (magnesium sulfate) having a concentration of 2wt% is heated to reach 60 ° C. while stirring and the diluted latex is added and contacted. This is washed and then dehydrated and dried to room temperature to obtain 40 parts by weight of an acrylic impact modifier.

e) step 5

20 parts of the acrylic impact modifier prepared above was mixed with 80 parts of polymetal methacrylate resin, and the mixture was mixed at 210 ° C. using a 25 mm diameter twin screw extruder (Model: EO.0410, manufactured by Bestroff). Prepare pellets. The pellet is formed into a predetermined test piece by using an inline screw injection molding machine (Model: EC600, manufactured by Engel) operated under the conditions of molding temperature = 230 ° C, injection pressure = 600kg / cm2 and mold temperature of 60 ° C. Measure

Example 2

In Example 1, except that the content of the butyl acrylate / styrene of the first step of the monomer was used in 6.25 parts was carried out in the same manner as in Example 1 to measure the physical properties. At this time, the solid concentration of the seed polymerization is 4.76wt%.

Example 3

Example 1 was carried out in the same manner as in Example 1, except that the content of the butyl acrylate / styrene as a monomer of the first step was 7.0 parts by weight. At this time, the concentration of solids in the seed polymerization was 5.30 wt%.

Example 4

The same procedure as in Example 1 was conducted except that 0.5 part of allyl methacrylate in the second step and 0.8 part of 2-hydroxymethyl acrylate were used. The resulting latex had a particle diameter of 0.21 to 0.25 μm and a solid content of 40.4 wt%.

Comparative Example 1

Example 1 was carried out in the same manner as in Example 1 except that the butyl acrylate / styrene content of the first step of the monomer in 12 parts. At this time, the concentration of solids in the seed polymerization was 8.76 wt%.

Comparative Example 2

In Example 1, except that 15 parts of butyl acrylate / styrene content of the monomer of the first step, 0.3 parts of the methacrylate of the second step was used in the same manner as in Example 1. At this time, the concentration of solids in the seed polymerization was 10.7 wt%.

Comparative Example 3

Except for using the allyl methacrylate of the second step in Example 1 in 1.2 parts was carried out in the same manner as in Example 1.

[Comparative Example 4]

Example 1 was carried out in the same manner as in Example 1, except that 0.5 parts of the 2-hydroxy methylacrylate of the second step was used.

[Comparative Example 5]

Except for using 1.5 parts of the 2-hydroxy methyl acrylate of the second step in Example 1 was carried out in the same manner as in Example 1.

In the above Examples and Comparative Examples, the characteristics evaluation results of the test piece are shown in Table 1. From the results of the comparative example, the butyl acrylate / styrene content of the monomer during the first stage cide polymerization was in the range of 5.0 to 7.0 parts by weight, and the content of allyl methacrylate, which is a graft agent, and 2-hydroxy ethyl acrylate, which is a hydrophilic monomer, respectively. If it is 0.5 to 0.6 parts by weight, 0.8 to 1.0 parts by weight, the transparency is worse, the melt flow index is lowered, the injection processability is poor and the injection productivity is also poor.

Claims (12)

I) 150-200 parts by weight of ion-exchanged water, 0.1-1 part by weight of emulsifier and 0.01-2 parts by weight of initiator are added to the reactor, and when the reactor internal temperature reaches 10-70 ° C., 0.02 to 0.05 parts by weight of graft agent and crosslinking agent A one-step seed polymerization step in which polymerization is carried out by adding 0.005 to 0.05 parts by weight, hydrophilic monomers of 0.04 to 0.07 parts by weight and 4 to 10 parts by weight of the seed monomer based on the solids content of the first step final product; Ii) 45 to 75 parts by weight of the monomer of the rubber component, 1-15 parts by weight of the synthetic synthetic vinyl vinyl monomer having a high refractive index, 0.05 to 4 parts by weight of the crosslinking agent, based on the solid content of the final product in the first step seed polymerization product, 0.4 to 1.2 parts by weight of the graft agent based on the solids of the step product and 0.6 to 2.4 parts by weight of the hydrophilic monomers are continuously injected based on the solids of the first step product, and the content ratio of the graft agent to the hydrophilic monomer is 1: 1.2 to A two-stage core polymerization step of growing the particles to be 2.4 to prepare a polymer latex; Iii) a three-step shell polymerization step of graft polymerization by continuously injecting 20-40 parts by weight of monomer having a kneading property with matrix and 0.005-1 part by weight of active agent to the latex based on the solids content of the rubber latex obtained in step 2; Iii) a four stage postpolymerization step of completely polymerizing the unreacted monomer in the core polymerization product; Iii) a 5-step flocculation process step of preparing a polymer powder by adding 0.1 to 10 parts by weight of a flocculant to the polymer latex obtained through the post-polymerization; And iii) a six-stage recovery process for washing and drying the agglomerated polymer powder. The method for producing an acrylic impact modifier according to claim 1, wherein 3 to 7 parts by weight of the seed monomer is used with respect to 100 parts by weight of ion-exchanged water. The method of manufacturing an acrylic impact modifier according to claim 1, wherein the total amount of emulsifier required for the entire polymerization is added during the first step seed polymerization, and no further emulsifier is added in the step after the seed polymerization. The method of producing an acrylic impact modifier according to claim 1, wherein the monomer is directly and continuously introduced into the reactor during core polymerization and shell polymerization. The method of manufacturing an acrylic impact modifier according to claim 1, wherein at least one selected from allyl methacrylate, diallyl succinate and diallyl phthalate is used as a graft agent added during seed polymerization and core polymerization. . The hydrophilic monomer to be added during core polymerization is at least one of 2-hydroxyethyl acrylate, 2-hydroxymethyl acrylate, 2-hydroxy ethyl methacrylate and 2-hydroxymethyl methacrylate. Method for producing an acrylic impact modifier, characterized in that used by selecting more than one species. The acrylic impact modifier according to claim 1, wherein the monomer used in seed polymerization is at least one mixture selected from acrylic acid alkyl esters having 1 to 8 carbon atoms, alkyl esters having 1 to 8 carbon atoms and alkyl esters having 1 to 8 carbon atoms. Manufacturing method. The method for producing an acrylic impact modifier according to claim 1, wherein the emulsifier used in the polymerization reaction is at least one of sodium sulfate, potassium sulfate, sodium sulfonate and potassium sulfonate of alkyl or aromatic carbon atoms of 12 to 18, respectively. The method of manufacturing an acrylic impact modifier according to claim 1, wherein at least one of 1,3-butanedioldi (meth) acrylate, 1,6-hexanedioldiacrylate, and divinylbenzene is used as a crosslinking agent. . The method of manufacturing an acrylic impact modifier according to claim 1, wherein one or two or more selected from ammonium persulfate, sodium persulfate and potassium persulfate are used as the initiator. The method of manufacturing an acrylic impact modifier according to claim 1, further comprising a step of injecting 0.001 to 0.2 parts by weight of the active agent after the seed monomer is added during the first stage seed polymerization. The method of manufacturing an acrylic impact modifier according to claim 1, wherein 0.01 to 0.2 parts by weight of the active agent is further added during the two-stage core polymerization.