KR100508906B1 - Processing aids composition of thermoplastic resin and method for preparing thereof - Google Patents

Abstract

The present invention relates to a processing aid composition of a thermoplastic resin and a method for producing the same, in particular, a weight average molecular weight containing at least one monomer selected from the group consisting of methyl methacrylate and acrylate, methacrylate, and mixtures thereof. A weight average molecular weight of 2,500,000 to 12,000,000 containing a low molecular weight copolymer of 200,000 to 1,500,000 and a monomer selected from the group consisting of methyl methacrylate and acrylate, methacrylate, and mixtures thereof By blending a copolymer of molecular weight to have a bimodal molecular weight distribution, it is possible to shorten the melting time in thermoplastic resin processing without affecting the intrinsic properties of vinyl chloride resin, and in extrusion and calendering processing. Reduce the occurrence of fish-eye and flow marks Can be as well, at the same time, compression processing aid for a thermoplastic resin that can satisfy the reliability of the expansion ratio and foam cells at the same time in the foaming process the composition and a process for their preparation.

Description

Processing aid composition of thermoplastic resin and its manufacturing method {PROCESSING AIDS COMPOSITION OF THERMOPLASTIC RESIN AND METHOD FOR PREPARING THEREOF}

The present invention relates to a processing aid composition of a thermoplastic resin and a method for manufacturing the same, and more particularly, it is possible to shorten the melting time in the thermoplastic resin processing without affecting the intrinsic physical properties of the vinyl chloride resin, extrusion processing, knife Processing aid composition of thermoplastic resin that not only reduces the occurrence of fish-eye and flow marks in the rendering process but also simultaneously satisfies the expansion ratio and the stability of the foaming cell in the compression foaming process. And a method for producing the same.

Vinyl chloride resins are widely used in various fields because they provide molded articles having excellent physical and chemical properties. However, the vinyl chloride resin has various processing problems, such as the processing temperature is close to the pyrolysis temperature, so that the moldable temperature range is narrow, and the time to reach the molten state is long.

In order to solve the above problems, a method of adding a plasticizer to a vinyl chloride resin, a method of using a vinyl chloride resin copolymerized with other monomers such as vinyl acetate, and a method of mixing other resin components with a vinyl chloride resin Etc. are known.

Most of the method of mixing the other resin component with the vinyl chloride resin lowers the melt viscosity during molding processing, thereby lowering the processing temperature. Since the kneading energy is consumed by the flow during processing, the gelation of the vinyl chloride resin is insufficient. Accordingly, the physical properties are deteriorated compared to the sufficiently gelled vinyl chloride resin, resulting in a problem of microgelation and flow marks.

Accordingly, U. S. Patent No. 4,052, 482 discloses a method for blending a copolymer containing methyl methacrylate as a main component for preventing fish-eye, transparency and shortening of melting time in the processing of vinyl chloride resin. have. However, the above method has a problem in that it does not exhibit a sufficient effect in preventing the gelate. In addition, U.S. Patent No. 5,306,763 discloses a method of reducing the amount of monomers by increasing the amount of monomer having a low glass transition temperature (Tg), such as butyl acrylate, but for this purpose, an excess amount of butyl acrylate is used. As a result, the overall melt viscosity is lowered, so processing is not performed well, and problems such as bubbles are generated.

U. S. Patent No. 5,541, 256 discloses a method for reducing the generation of microglides in the production of polyvinyl chloride resins by using a modifier prepared using a crosslinkable monomer. However, this method has a problem in that secondary workability such as stretching and stretching is lowered due to the introduction of a crosslinkable monomer, and it is not possible to sufficiently reduce the generation of microglides. In addition, U. S. Patent No. 6,140, 417 discloses a monomer mixture of methyl methacrylate and acrylate in a copolymer made of a large amount of butyl acrylate and a small amount of methyl methacrylate in order to reduce the formation of microglides, improve processability, and improve foamability. And a method of preparing a processing aid for polymerizing butyl acrylate and methyl methacrylate again, but the method has a problem that microgelation may occur because the uniformity of the foaming cells is somewhat insufficient. . In addition, US Pat. No. 6,391,976 discloses a process for combining a two-stage polymer with processing aids in large amounts of methyl methacrylate and small amounts of alkyl methacrylate. When the processing aid is added to the polyvinyl chloride resin, it shows excellent characteristics in the stability of the foaming cell and the appearance of the foamed molded article, but there is a problem that the gelling may occur due to the insufficient dispersibility.

Therefore, it is possible to reduce the generation of microglides and flow traces generated during the processing of the vinyl chloride resin, and research into the processing aid of the thermoplastic resin having excellent foaming properties and stability in compression foaming processing and the vinyl chloride resin containing the same It is more necessary.

In order to solve the problems of the prior art as described above, the present invention can shorten the melting time in the thermoplastic resin processing without affecting the intrinsic physical properties of the vinyl chloride resin, and the foaming characteristics that are disadvantages of the low molecular weight polymer It can reduce the occurrence of fish-eye and flow mark in extrusion and calendering process by improving the processability and reducing the disadvantage of high molecular weight polymer. In addition, an object of the present invention is to provide a processing aid composition of a thermoplastic resin capable of simultaneously satisfying the expansion ratio and the stability of the foaming cell in compression foaming.

Another object of the present invention is to improve the foaming properties, which are disadvantages of low molecular weight copolymers, and at the same time, process aids for thermoplastic resins that can reduce the occurrence of microglides and flow marks that are likely to occur in high molecular weight copolymers. It is to provide a manufacturing method.

It is still another object of the present invention to provide a vinyl chloride-based resin with a marked improvement in the reduction in the number of microglides, the promotion of melting, the reduction of flow marks, and the stability of the foaming cell.

In order to achieve the above object, the present invention is a processing aid composition of a thermoplastic resin,

a) iii) 65-90 weight percent methyl methacrylate; And

  Ii) consisting of acrylates, methacrylates, and mixtures thereof

      Is 10 to 35% by weight of at least one monomer selected from the group

  Low molecular weight containing 200,000 to 1,500,000 by weight average molecular weight

  70 to 95 weight percent of a copolymer of; And

b) iii) 70-95 weight percent methyl methacrylate; And

  Ii) consisting of acrylates, methacrylates, and mixtures thereof

      Is 5 to 30% by weight of at least one monomer selected from the group

  A polymer having a weight average molecular weight containing 2,500,000 to 12,000,000

  5 to 30% by weight of copolymer

It provides a processing aid composition of a thermoplastic resin comprising a.

In addition, the present invention is a method for producing a processing aid of a thermoplastic resin,

a) iii) 65-90 weight percent methyl methacrylate; And

  Ii) consisting of acrylates, methacrylates, and mixtures thereof

      Is 10 to 35% by weight of at least one monomer selected from the group

  Low molecular weight with a weight average molecular weight of 200,000 to 1,500,000 by polymerization

  Preparing a copolymer of; And

b) iii) 70-95 weight percent methyl methacrylate; And

  Ii) consisting of acrylates, methacrylates, and mixtures thereof

      Is 5 to 30% by weight of at least one monomer selected from the group

  Polymerized polymer having a weight average molecular weight of 2,500,000 to 12,000,000

  Preparing self-copolymer

c) 70 to 95% by weight of the low molecular weight copolymer of step a) and b)

   Blending 5-30 wt% of high molecular weight copolymer of step

   Steps to

It provides a method for producing a processing aid of a thermoplastic resin comprising a.

In addition, the present invention is a vinyl chloride resin composition,

a) 100 parts by weight of polyvinyl chloride resin; And

b) iii) a) 65 to 90 weight percent of methyl methacrylate; And

     B) consisting of acrylates, methacrylates, and mixtures thereof

         Of the monomers 10 to 35 selected from the group consisting of

         Volume%

     Low molecular weight containing 200,000 to 1,500,000 by weight average molecular weight

     70 to 95% by weight of the copolymer; And

  Ii) a) 70 to 95 weight percent of methyl methacrylate; And

     B) consisting of acrylates, methacrylates, and mixtures thereof

         Of the monomers 5 to 30 selected from the group

         Volume%

     High weight average molecular weight containing 2,500,000 to 12,000,000

     5 to 30 weight percent of molecular weight copolymer

   0.1 to 20 parts by weight of a processing aid comprising

It provides a vinyl chloride-based resin comprising a.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention can improve the gelling and flow traces generated during processing, and while studying the processing aids of thermoplastic resins which can have excellent foaming properties and stability in compression foaming, the weight average molecular weight is 200,000 to 1,500,000. As a result of blending a low molecular weight copolymer and a high molecular weight copolymer having a weight average molecular weight of 2,500,000 to 12,000,000, the melt time can be shortened during processing, and the fish-eye and flow in extrusion processing and calendering processing. In addition to reducing the occurrence of the mark (flow mark), it was confirmed that at the same time can satisfy the foaming ratio and the stability of the foaming cell at the same time in the compression-foaming process, the present invention was completed based on this.

The processing aid composition of the thermoplastic resin of the present invention has a low molecular weight of 200,000 to 1,500,000 in weight average molecular weight containing at least one monomer selected from the group consisting of methyl methacrylate and acrylate, methacrylate, and mixtures thereof. A high molecular weight air having a weight average molecular weight of 2,500,000 to 12,000,000 containing 70 to 95% by weight of a copolymer, and at least one monomer selected from the group consisting of methyl methacrylate and acrylate, methacrylate, and mixtures thereof. Characterized by having a molecular weight distribution of bimodal (bimodal) including 5 to 30% by weight of the coalescence.

The low molecular weight copolymer having a weight average molecular weight of 200,000 to 1,500,000 used in the present invention is selected from the group consisting of 65 to 90% by weight of methyl methacrylate, and acrylate, methacrylate, and mixtures thereof. It is prepared by emulsion polymerization of 10 to 35% by weight of monomer.

The low molecular weight copolymer preferably has a weight average molecular weight of 500,000 to 1,500,000, and a molecular weight distribution range of 5.0 at most. If the weight average molecular weight is less than 500,000, there is a problem that the workability is lowered, the production of the gelate is increased, and if the weight average molecular weight is more than 1,500,000, there is a problem that the generation of flow marks.

The methyl methacrylate is preferably included in the low molecular weight copolymer composition 65 to 90% by weight, more preferably 75 to 85% by weight. If the content is less than 65% by weight, there is a problem that the compatibility with the vinyl chloride composition in the calendering process is lowered and the workability is worsened. If the content is more than 90% by weight, dispersibility in the vinyl chloride composition in the calendering process is exceeded. There is a problem in that this can be reduced to produce a gelate.

The monomer selected from the group consisting of the acrylate, methacrylate, and mixtures thereof is preferably included in the low molecular weight copolymer composition in 10 to 35% by weight, more preferably 15 to 25% by weight. It is included in%.

The said acrylate is C1-C18 linear alkyl, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, lauryl acrylate, or stearyl acrylate, C1-C18, such as 2-ethylhexyl acrylate C1-C18 cyclic alkyl, such as branched alkyl of these, or cyclohexyl acrylate, etc. can be used.

The methacrylate is n-butyl methacrylate, lauryl methacrylate, stearyl methacrylate, tridecyl methacrylate i-butyl methacrylate, t-butyl methacrylate, 2-ethylnuclear methacrylate Or alkyl having 2 to 18 carbon atoms such as cyclohexyl methacrylate can be used.

The low molecular weight copolymer may be prepared by a method such as emulsion polymerization, suspension polymerization, solution polymerization, etc., in particular, emulsion polymerization is best performed. Of course, the polymer conventional emulsifier, polymerization initiator, redox catalyst and the like can be used.

The low molecular weight copolymer having a weight average molecular weight of 500,000 to 1,500,000 of the present invention is used in an amount of 0.3 to 2.0 parts by weight of an emulsifier, 0.08 to 0.8 parts by weight of a polymerization initiator, and 0.05 to 0.5 parts by weight of a redox catalyst based on 100 parts by weight of a monomer. It can manufacture.

The emulsifier is not particularly limited, and anionic emulsifiers such as aliphatic ester, alkyl benzene sulfonate, alkyl phosphate salt, dialkyl sulfosuccinate and the like Or nonionic emulsifiers such as polyoxyethylene alky ether and alkylamine esters. The said emulsifier can be used individually or in mixture of 2 or more types.

The polymerization initiator is a water-soluble initiator such as potassium persulfate, ammonium persulfate, or sodium persulfate, t-butyl hydroperoxide, cumene hydroperoxide fat-soluble initiators such as organic peroxides such as cumene hydroperoxide, benzoyl poeroxide, lauryl peroxide, and the like, or redox initiators.

The redox catalyst is a redox catalyst such as sodium formaldehyde sulfoxylate, disodium ethylenediaminetetraacetate, formaldehyde sodium sulfoxylate, ferrous sulfate, ferrous sulfate, ethylenesodium diaminetetraacetate, or cupric sulfate Can be used.

The high molecular weight copolymer having a weight average molecular weight of 2,500,000 to 12,000,000 used in the present invention is selected from the group consisting of 70 to 95% by weight of methyl methacrylate, and acrylate, methacrylate, and mixtures thereof. It is prepared by emulsion polymerization of 5 to 30% by weight of monomers.

The high molecular weight copolymer preferably has a weight average molecular weight of 2,500,000 to 12,000,000. If the weight average molecular weight is less than 2,500,000, the melt viscosity is lowered, the foaming stability is lowered, and a lot of open foaming cells are generated. If the weight average molecular weight is more than 12,000,000, the workability is significantly lowered, which may cause processing problems. .

The methyl methacrylate is preferably included in the high molecular weight copolymer composition of 70 to 95% by weight, more preferably 75 to 85% by weight. If the content is less than 70% by weight, the compatibility with the vinyl chloride composition is reduced in the calendering process, making it difficult to uniformly process. If the content exceeds 95% by weight, the glass transition temperature (Tg) is increased and the calendering process is performed. There is a problem that the initial workability is lowered.

The monomer selected from the group consisting of the acrylate, methacrylate, and mixtures thereof is preferably included in the high molecular weight copolymer composition in 5 to 30% by weight, more preferably 15 to 25% by weight. It is included in%.

The acrylate and methacrylate may use the same material as that used for the low molecular weight copolymer. In addition, the method of preparing a high molecular weight copolymer, an emulsifier, a polymerization initiator, and a redox catalyst may use the same method and material as those of preparing the low molecular weight copolymer.

70 to 95% by weight of the low molecular weight copolymer having a weight average molecular weight of 500,000 to 1,500,000, and 5 to 30% by weight of the high molecular weight copolymer having a weight average molecular weight of 2,500,000 to 12,000,000, are blended to form a processing aid for thermoplastic resins. Manufacture. At this time, when the low molecular weight copolymer having a weight average molecular weight of 500,000 to 1,500,000 is less than 70% by weight, there is a problem in that the generation of megilide and flow marks increases in calendering processing, and when it exceeds 95% by weight, There is a problem that the molecular weight is lowered and the foaming characteristics are lowered.

The processing aid of the present invention prepared as described above is preferably in the range of 1,500,000 to 2,700,000 by weight average molecular weight.

As described above, the processing aid prepared by blending the low molecular weight copolymer and the high molecular weight copolymer in a latex state may be agglomerated with calcium chloride, dehydrated and dried to obtain a powder processing aid.

The processing aid of the present invention prepared as described above is applied to calendering molding, extrusion molding, brow molding, injection molding, and the like, and the molded article obtained therefrom has elongation and the like due to the appearance and secondary processability such as transparency, gloss and surface smoothness. It is excellent and is advantageous in calendering, etc., when used in foam molding, it is possible to obtain a low specific gravity foam, and to obtain uniformity and stability of the foaming cell.

The present invention also provides a vinyl chloride-based resin prepared by adding 0.1 to 20 parts by weight of the processing aid as a reinforcing agent to 100 parts by weight of polyvinyl chloride resin.

The vinyl chloride resin prepared according to the present invention may be molded by adding additives such as heat stabilizers, lubricants, processing aids, impact modifiers, plasticizers, UV stabilizers, flame retardants, colorants, or fillers as necessary.

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 low molecular weight copolymer)

480 parts by weight of ion-exchanged water and 15.6 parts by weight of sodium lauryl sulfate solution dissolved in water at 3% by weight with an emulsifier in a 3 L four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet, and a circulation condenser, and 96 parts by weight of methyl methacrylate. Parts, 9 parts by weight of ethyl acrylate were added to make an emulsion. Then, the internal temperature of the reactor was maintained at 70 ° C., replaced with a nitrogen atmosphere, and then 7.8 parts by weight of a potassium persulfate solution dissolved in water at 3% by weight with a polymerization initiator and 9.3 parts by weight of a 3% by weight activator were added. The first batch reaction was carried out.

After the reaction was completed, the mixture was stirred at the same temperature for about 1 hour, and the temperature inside the reactor was reduced to 60 ° C. A monomer mixture comprising 267 parts by weight of ion-exchanged water, 55.8 parts by weight of a sodium lauryl sulfate solution dissolved in water at 3% by weight as an emulsifier, 309 parts by weight of methyl methacrylate, and 36 parts by weight of ethyl acrylate, and 3 as a polymerization initiator. 9.96 parts by weight of potassium persulfate solution dissolved in water by weight% and 1.98 parts by weight of 3% by weight activating solution were added to carry out the second batch reaction.

After the reaction was completed, the mixture was further stirred for 1.5 hours, and the temperature inside the reactor was raised to 70 ° C. A monomer mixture and polymerization initiator comprising 210 parts by weight of ion-exchanged water, 16 parts by weight of a sodium lauryl sulfate solution dissolved in water at 3% by weight as an emulsifier, 52.5 parts by weight of methyl methacrylate, and 97.5 parts by weight of ethyl acrylate. 32 parts by weight of potassium persulfate solution dissolved in water by weight%, 20 parts by weight of 3% by weight activating solution was added to the third batch reaction, and further stirred for about 1 hour after the reaction was completed. At this time, the activation solution used is composed of a redox catalyst, the composition of the activation solution used in the present embodiment is shown in Table 1.

Activation solution composition ingredient content Disodium ethylenediaminetetraacetate (EDTA) 0.015 parts by weight Formaldehyde sodium sulfoxylate (SFS) 0.02 parts by weight Ferrous sulfate 0.001 parts by weight Ion exchange water 1.165 parts by weight

After stirring, the latex was agglomerated with calcium chloride (CaCl ₂ ), and the molecular weight of the powdery low molecular weight copolymer obtained by dehydration and drying was measured using gel permetion chromatography (GPC). As a result, the weight average molecular weight was 1,200,000.

(Manufacture of high molecular weight copolymer)

99 parts by weight of sodium lauryl sulfate solution dissolved in water at 468 parts by weight of ion-exchanged water and 3% by weight of an emulsifier in a 3 L four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet, and a circulation condenser, and 126 parts by weight of methyl methacrylate. Parts, 24 parts by weight of butyl acrylate were added to make an emulsion. Subsequently, the internal temperature of the reactor was maintained at 40 ° C. and replaced with a nitrogen atmosphere. Then, 3 parts by weight of a potassium persulfate solution dissolved in water at 3% by weight with a polymerization initiator and 8.8 parts by weight of a 3% by weight activating solution were added thereto. Batch reaction was carried out.

After completion of the reaction, the mixture was stirred at the same temperature for about 1 hour, and the internal temperature of the reactor was maintained at 40 ° C., followed by 162 parts by weight of ion-exchanged water and 3% by weight of an emulsifier in sodium lauryl sulfate solution 30 6 parts by weight of potassium persulfate solution dissolved in water at 3% by weight with a monomer mixture consisting of parts by weight, 186 parts by weight of methyl methacrylate and 36 parts by weight of butyl acrylate and a polymerization initiator, Second batch reaction was carried out.

After the reaction was completed and further stirred for 1.5 hours, 162 parts by weight of ion-exchanged water, 30 parts by weight of sodium lauryl sulfate solution dissolved in water at 3% by weight with an emulsifier, 186 parts by weight of methyl methacrylate, and butyl acrylate 6 parts by weight of a potassium persulfate solution dissolved in water at 3% by weight with a monomer mixture consisting of 36 parts by weight and a polymerization initiator and 10 parts by weight of a 3% by weight activating solution were subjected to the third batch reaction, and further 1 hour after the reaction was completed. It was stirred.

The weight average molecular weight of the powdery low molecular weight copolymer obtained by coagulating the stirred latex with calcium chloride, dehydrating and drying was 4,500,000.

(Processing aid manufacturing)

The prepared low molecular weight copolymer (weight average molecular weight 1,200,000) and high molecular weight copolymer (weight average molecular weight 4,500,000) were mixed in a latex state at a ratio of 75:25 (solid content ratio) and stirred for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,050,000.

(Vinyl Chloride Resin Composition)

5 parts by weight of the processing aid prepared above was added to 100 parts by weight of vinyl chloride resin having a polymerization degree of 800, and mixed in a Henschel mixer to prepare a vinyl chloride resin composition.

(Manufacture of foaming resin composition)

6.4 parts by weight of composite stabilizer KD-105 (a composite heat stabilizer and a foam stabilizer which is a uniform mixture of thermal stabilizer and lubricant) with 100 parts by weight of vinyl chloride resin, and 14 parts by weight of CaCO ₃ as a filler, and the above-described processing 4 parts by weight of the preparation, 0.8 parts by weight of azodicarbonamide was added as an azo pyrolytic blowing agent, and mixed using a Henschel mixer to prepare a foamed resin composition.

Example 2

(Preparation of low molecular weight copolymer)

In Example 1, except that the reaction temperature of the first batch reaction and the third batch reaction was lowered from 70 ℃ to 65 ℃ polymerization was carried out in the same manner as in Example 1 of the low molecular weight of 1,500,000 Copolymers were prepared.

(Manufacture of high molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,500,000) prepared above and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were mixed at a ratio of 75:25 (solid content ratio) in a latex state. Stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,250,000.

Example 3

(Preparation of low molecular weight copolymer)

A low molecular weight copolymer having a weight average molecular weight of 1,000,000 was prepared in the same manner as in Example 1 except that the reaction temperature of the second batch reaction was increased from 60 ° C. to 65 ° C. for polymerization. .

(Manufacture of high molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,000,000) prepared above and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were mixed at a ratio of 75:25 (solid content ratio) in a latex state. Stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 1,880,000.

Example 4

(Preparation of low molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Manufacture of high molecular weight copolymer)

A high molecular weight of 4,200,000 was carried out in the same manner as in Example 1 except that the reaction temperature of the second batch reaction and the third batch reaction was increased from 40 ° C. to 43 ° C. to polymerize. Copolymers were prepared.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared in Example 1 and the high molecular weight copolymer (weight average molecular weight 4,200,000) prepared above were 75:25 (solid content ratio) in a latex state. Mix and stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 1,950,000.

Comparative Example 1

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared in Example 1 was aggregated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 1,200,000.

Comparative Example 2

The high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 was aggregated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 4,500,000.

delete

delete

delete

delete

delete

delete

delete

delete

delete

delete

delete

delete

delete

delete

Comparative Example 5

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared in Example 1 and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were 97: 3 (solid content ratio) in a latex state. Mix in proportion and stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 1,300,000.

Comparative Example 6

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared in Example 1 and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were 50:50 (solid content ratio) in a latex state. Mix in proportion and stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,850,000.

Experimental Example 1

The physical properties were measured by the following method using the processing aids prepared in Examples 1 to 4 and Comparative Examples 1 to 6, and the results are shown in Table 5 below.

A) molecular weight-measured using gel permeation chromatography (GPC). The applied calibration curve was prepared using a polystyrene reference sample.

B) Melt time-60 g of the polyvinyl chloride composition was measured to a maximum load using a brabender at 180 ° C. and 30 rpm.

Gelate-0.1 mm thick film was extracted at a cylinder temperature of 180 ° C. and a screw speed of 40 rpm using a 20 mm single spindle extruder with T-die. At this time, the number of microglides present in a predetermined region of the film surface was visually observed and evaluated according to the criteria of Table 2 below.

○ Almost no hydrated △ Slightly produced Miguelte × Lots of Miguelate

D) Flow marks-After mixing 100 g of the polyvinyl chloride composition at a temperature of 200 ° C. for 3 minutes using a 6 inch roll, a sheet having a thickness of 0.5 mm was taken out. At this time, the amount of flow marks on the sheet was visually observed and evaluated according to the criteria of Table 3 below.

○ Almost no flow traces △ Slight traces created × Many flow marks are created

ㅁ) Foaming stability-A 5 mm (thickness) x 30 mm (wide) rectangular rod was extracted at a cylinder temperature of 180 ° C. and a screw speed of 30 rpm using a 30 mm single spindle extruder with a lexical slit die. The cut section was observed and evaluated according to the criteria of Table 4 below.

○ Foam cell is uniform △ Foam cell is slightly uneven × Most foam cells are not uniform

Iii) Foamability-The specimens from foam stability evaluation were cut to a certain size and then evaluated for specific gravity. At this time, the lower the specific gravity of the molded article, the higher the expansion ratio.

division Example Comparative example One 2 3 4 One 2 5 6 Molecular Weight (× 10 ³ ) Low molecular weight copolymer 1,200 1,500 1,000 1,200 1,200 - 1,200 1,200 High molecular weight copolymer 4,500 4,500 4,500 4,200 - 4,500 4,500 4,500 Low Molecular Weight Copolymer / High Molecular Weight Copolymer 75/25 75/25 75/25 75/25 100/0 0/100 97/3 50/50 Molecular Weight of Processing Aid (× 10 ³ ) 2,050 2,250 1,880 1,950 1,200 4,500 1,300 2,850 Melting time (s) 95 92 96 95 86 101 88 98 Miguel Cargo ○ ○ ○ ○ △ × △ △ Flow ○ ○ ○ ○ ○ × ○ × Foam stability ○ ○ ○ ○ × ○ ○ △ Effervescent (g / cm3) 0.42 0.43 0.45 0.45 0.65 0.35 0.57 0.38

Through the Table 5, the processing aids of Examples 1 to 4 prepared by blending copolymers having different molecular weights according to the present invention are compared with Comparative Examples 1 to 6, such as gelling, flow marks, foaming stability, and foamability. This excellence could be confirmed. In addition, as the copolymer content of the low molecular weight was increased through Comparative Example 1, it was found that the uniformity and stability of the foaming cell were lowered. In Comparative Example 2, the flow trace characteristics were increased as the content of the high molecular weight copolymer was increased. It was found that the degradation.

Example 5

(Preparation of low molecular weight copolymer)

In Example 1, 96 parts by weight of methyl methacrylate in the first batch reaction, 324 parts by weight of methyl methacrylate in the second batch reaction, and 60 parts by weight of methyl methacrylate in the third batch reaction (total methyl methacrylate). Content: 457.5 → 480) was carried out in the same manner as in Example 1 except that the monomer ratio of methyl methacrylate: ethyl acrylate was 80:20, and the low molecular weight air having a weight average molecular weight of 1,250,000 The coalescence was prepared.

(Manufacture of high molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,250,000) prepared above and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were mixed at a ratio of 75:25 (solid content ratio) in a latex state. Stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,060,000.

Example 6

(Preparation of low molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Manufacture of high molecular weight copolymer)

In Example 1, 126 parts by weight of methyl methacrylate in the first batch reaction, 207 parts by weight of methyl methacrylate in the second batch reaction, and 207 parts by weight of methyl methacrylate in the third batch reaction (total methyl methacrylate). A low molecular weight air having a weight average molecular weight of 4,500,000 using the same method as Example 1 except that the monomer ratio of methyl methacrylate: ethyl acrylate was 90:10 using 498 → 540). The coalescence was prepared.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared in Example 1 and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared above were 75:25 (solid content ratio) in a latex state. Mix and stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,050,000.

Example 7

(Preparation of low molecular weight copolymer)

96 parts by weight of methyl methacrylate in the first batch reaction, 359 parts by weight of methyl methacrylate in the second batch reaction, and 85 parts by weight of methyl methacrylate in the third batch reaction (total methyl methacrylate) A low molecular weight air having a weight average molecular weight of 1,250,000 in the same manner as in Example 1 except that the monomer ratio of methyl methacrylate: ethyl acrylate was 90:10 using 457.5 → 540). The coalescence was prepared.

(Manufacture of high molecular weight copolymer)

It carried out in the same manner as in Example 1.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,250,000) prepared above and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared in Example 1 were mixed at a ratio of 75:25 (solid content ratio) in a latex state. Stir for 30 minutes. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,060,000.

delete

delete

delete

delete

delete

delete

delete

Comparative Example 8

(Preparation of low molecular weight copolymer)

In Example 1, 96 parts by weight of methyl methacrylate in the first batch reaction, 229 parts by weight of methyl methacrylate in the second batch reaction, and 35 parts by weight of methyl methacrylate in the third batch reaction (total methyl methacrylate). Content: 457.5 → 360) was carried out in the same manner as in Example 1, except that the monomer ratio of methyl methacrylate: ethyl acrylate was 60:40, and a low molecular weight air having a weight average molecular weight of 1,200,000 The coalescence was prepared.

(Manufacture of high molecular weight copolymer)

In Example 1, 126 parts by weight of methyl methacrylate in the first batch reaction, 153 parts by weight of methyl methacrylate in the second batch reaction, and 153 parts by weight of methyl methacrylate in the third batch reaction (total methyl methacrylate). A low molecular weight air having a weight average molecular weight of 4,500,000 using the same method as Example 1 except that the monomer ratio of methyl methacrylate: ethyl acrylate was 65:35 using 498 → 390). The coalescence was prepared.

(Processing aid manufacturing)

The low molecular weight copolymer (weight average molecular weight 1,200,000) prepared above and the high molecular weight copolymer (weight average molecular weight 4,500,000) prepared above were mixed in a latex state at a ratio of 75:25 (solid content ratio) for 30 minutes. Was stirred. The stirred latex was agglomerated with calcium chloride, dehydrated and dried to obtain a processing aid having a weight average molecular weight of 2,050,000.

Experimental Example 2

Physical properties were measured in the same manner as in Experimental Example 1 using the processing aids prepared in Examples 5 to 7, and Comparative Examples 7 or 8, and the results are shown in Table 6 below.

division Example Comparative example One 5 6 7 8 Low molecular weight copolymer MMA / EA (%) 76.3 / 23.7 80/20 76.3 / 23.7 90/10 60/40 High molecular weight copolymer MMA / EA (%) 83/17 83/17 90/10 83/17 65/35 Molecular Weight of Processing Aid (× 10 ³ ) 2,050 2,060 2,050 2,060 2,050 Melting time (s) 93 92 95 95 90 Miguel Cargo ○ ○ ○ ○ × Flow ○ ○ ○ ○ × Foam stability ○ ○ ○ ○ △ Effervescent (g / cm3) 0.42 0.43 0.45 0.45 0.40

Through the above Table 6, when the content of methyl methacrylate is raised to 540 parts by weight in either the low molecular weight copolymer or the high molecular weight copolymer, the physical properties were maintained as it is, and there was no difference in the gelate and flow traces. I could confirm it. In addition, when the content of methyl methacrylate of the low molecular weight copolymer and the high molecular weight copolymer was increased to 540 parts by weight through Comparative Example 7, it was confirmed that the gelation and the foaming stability were lowered. In addition, when the methyl methacrylate content was lowered through Comparative Example 8, no significant difference was observed in the foaming stability, but it was confirmed that the flow marks and the migelide were significantly reduced.

According to the present invention, by having a bimodal molecular weight distribution, it is possible to shorten the melting time in the processing of thermoplastic resins without affecting the intrinsic properties of the vinyl chloride resin, the fish-eye and flow traces In addition to reducing the occurrence of (flow mark), it is possible to prepare a processing aid capable of simultaneously satisfying the expansion ratio and the stability of the foaming cell in compression foaming. In addition, by including the processing aid as a reinforcing agent, there is an effect that can be produced a vinyl chloride-based resin with a marked improvement in the reduction of the gelling, promoting the melt, reducing the flow marks, and stability of the foam cell.

Claims (12)

In the processing aid composition of the thermoplastic resin, a) iii) 65-90 weight percent methyl methacrylate; And   Ii) consisting of acrylates, methacrylates, and mixtures thereof       Is 10 to 35% by weight of at least one monomer selected from the group   Low molecular weight containing 200,000 to 1,500,000 by weight average molecular weight   70 to 95 weight percent of a copolymer of; And b) iii) 70-95 weight percent methyl methacrylate; And   Ii) consisting of acrylates, methacrylates, and mixtures thereof       Is 5 to 30% by weight of at least one monomer selected from the group   A polymer having a weight average molecular weight containing 2,500,000 to 12,000,000   5 to 30% by weight of copolymer Processing aid composition of the thermoplastic resin comprising a. The method of claim 1, The acrylates of a) ii) and b) ii) include methyl acrylate, ethyl acrylate, n-butyl acrylate, lauryl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, And a processing aid composition of the thermoplastic resin selected from the group consisting of cyclohexyl acrylate. The method of claim 1, The methacrylates of a) ii) and b) ii) are n-butyl methacrylate, lauryl methacrylate, stearyl methacrylate, tridecyl methacrylate i-butyl methacrylate, t-butyl meta A processing aid composition of a thermoplastic resin selected from the group consisting of acrylate, 2-ethylnuclear methacrylate, and cyclohexyl methacrylate. The method of claim 1, A processing aid composition of a thermoplastic resin having a weight average molecular weight of the processing aid composition of 1,500,000 to 2,700,000. In the manufacturing method of the processing aid of the thermoplastic resin, a) iii) 65-90 weight percent methyl methacrylate; And   Ii) consisting of acrylates, methacrylates, and mixtures thereof       Is 10 to 35% by weight of at least one monomer selected from the group   Low molecular weight with a weight average molecular weight of 200,000 to 1,500,000 by polymerization   Preparing a copolymer of; And b) iii) 70-95 weight percent methyl methacrylate; And   Ii) consisting of acrylates, methacrylates, and mixtures thereof       Is 5 to 30% by weight of at least one monomer selected from the group   Polymerized polymer having a weight average molecular weight of 2,500,000 to 12,000,000   Preparing self-copolymer c) 70 to 95% by weight of the low molecular weight copolymer of step a) and b)    Blending 5-30 wt% of high molecular weight copolymer of step    (blending) Process for producing a processing aid of a thermoplastic resin comprising a. The method of claim 5, The low molecular weight copolymer of step a) V) 65 to 90 weight percent methyl methacrylate; Ii) consisting of acrylates, methacrylates, and mixtures thereof     10 to 35% by weight of at least one monomer selected from the group; Iii) 0.3 to 2.0 parts by weight of an emulsifier; Iii) 0.08 to 0.8 parts by weight of polymerization initiator; And Iii) 0.05 to 0.5 parts by weight of redox catalyst Process for producing a processing aid of thermoplastic resin prepared by emulsion polymerization. The method of claim 6, The emulsifier of iii) is an aliphatic ester, alkyl benzene sulfonate, alkyl phosphate salt, dialkyl sulfosuccinate, polyoxyethylene alkyl ether ( polyoxyethylene alky ether), and a method for producing a processing aid for thermoplastic resins selected from the group consisting of alkylamine esters. The method of claim 6, The polymerization initiator of iii) is potassium persulfate, ammonium persulfate, sodium persulfate, t-butyl hydroperoxide, cumene hydroperoxide A method for producing a processing aid for thermoplastic resins selected from the group consisting of hydroperoxide), benzoyl poeroxide, and lauryl peroxide. The method of claim 6, Preparation of the processing aid of the thermoplastic resin selected from the group consisting of sodium formaldehyde sulfoxylate, ferrous sulfate, ethylene sodium diamine tetra acetate, cupric sulfate, and ascorbic acid, Way. The method of claim 5, The high molecular weight copolymer of step b) V) 70 to 95 wt% methyl methacrylate; Ii) consisting of acrylates, methacrylates, and mixtures thereof     5 to 30% by weight of at least one monomer selected from the group; Iii) 0.3 to 2.0 parts by weight of an emulsifier; Iii) 0.08 to 0.8 parts by weight of polymerization initiator; And Iii) 0.05 to 0.5 parts by weight of redox catalyst Process for producing a processing aid of thermoplastic resin prepared by emulsion polymerization. In a vinyl chloride resin composition, a) 100 parts by weight of polyvinyl chloride resin; And b) iii) a) 65 to 90 weight percent of methyl methacrylate; And      B) consisting of acrylates, methacrylates, and mixtures thereof          Of the monomers 10 to 35 selected from the group consisting of          Volume%      Low molecular weight containing 200,000 to 1,500,000 by weight average molecular weight      70 to 95% by weight of the copolymer; And   Ii) a) 70 to 95 weight percent of methyl methacrylate; And      B) consisting of acrylates, methacrylates, and mixtures thereof          Of the monomers 5 to 30 selected from the group          Volume%      High weight average molecular weight containing 2,500,000 to 12,000,000      5 to 30 weight percent of molecular weight copolymer    0.1 to 20 parts by weight of a processing aid comprising Vinyl chloride-based resin comprising a. The method of claim 11, The vinyl chloride-based resin further comprises at least one additive selected from the group consisting of a heat stabilizer, a lubricant, a processing aid, an impact modifier, a plasticizer, a UV stabilizer, a flame retardant, a colorant, and a filler.