KR101638744B1 - Graft copolymer improving processing property and impact resistance, a method for preparing the same and pvc composition comprising the graft copolymer - Google Patents

Abstract

The present invention relates to a graft copolymer excellent in processability and impact resistance, a process for producing the same, and a vinyl chloride resin composition containing the same, and a process for producing the graft copolymer which improves workability and impact resistance, And a vinyl chloride resin composition excellent in impact resistance. More than 85% There is an effect of improving the flocculation temperature in the production of the high-impact core-shell polymer powder containing a high rubber content.

Description

TECHNICAL FIELD [0001] The present invention relates to a graft copolymer having excellent processability and impact resistance, a process for producing the same, and a vinyl chloride resin composition containing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a graft copolymer which is excellent in workability and impact resistance, a process for producing the same, and a vinyl chloride resin composition containing the same, more particularly, to a graft copolymer which improves workability and impact resistance, To a vinyl chloride resin composition excellent in workability and impact resistance.

PVC is a general-purpose resin widely used in various fields because of its excellent physical and chemical properties. However, since the processing temperature of the vinyl chloride resin is close to the pyrolysis temperature, the moldable temperature range is narrow, the melt viscosity is high and the fluidity is low, so that the vinyl chloride resin adheres to the surface of the processing equipment during processing to form a carbide, There is a problem of.

Therefore, attempts have been made to use a processing aid to improve the extrusion processability of the vinyl chloride resin. However, the processing aid accelerates the flame and increases the working load, and in many cases, the dimensional stability and the impact resistance characteristics are deteriorated as the elastic modulus increases.

On the other hand, even if the lubricant is excessively used to reduce the extruder load, plate-out due to deterioration of the gelation property occurs, resulting in poor long-term workability.

As related related arts, Korean Patent Laid-Open No. 10-2008-0060731 discloses an acrylic impact modifier including a processing aid and a vinyl chloride resin containing the acrylic impact modifier, which has an excellent impact strength in a wide working range, but has a problem of high extrusion load There is a problem that the color is discolored, the gloss is lowered, the extrusion amount is low, the productivity is lowered, and the manufacturing cost is increased.

Another method is to add a lubricant to prevent adhesion to a processing machine and improve fluidity. However, there is a problem that compatibility with polymers is low and it is difficult to predict the behavior of the lubricant when applied in factories.

Therefore, it is urgent to develop an impact modifier that can improve the workability and impact resistance of vinyl chloride resin during processing.

In order to solve the problems of the prior art as described above, it is an object of the present invention to provide a graft copolymer which greatly improves workability and impact resistance, a process for producing the same, and a vinyl chloride resin composition excellent in workability and impact resistance .

In order to achieve the above object, the present invention provides a rubber composition comprising i) 70 to 99% by weight of an acrylic rubber core; And ii) 1 to 30% by weight of a graft shell formed by coating the rubber core with at least one selected from the group consisting of monomers represented by the following formulas (1) to (3) and a (meth) acrylate-based monomer ,

The multifunctional monomer represented by the following general formulas (1), (2) and (3) is contained in an amount of 0.05 to 30% by weight based on 100% by weight of the graft shell, and a process for producing the same.

[Chemical Formula 1]

(2)

(3)

In the above formulas 1, 2 and 3, A is a (meth) acryloyl group, B is a (meth) acryloyl group or hydrogen, and n and m each independently are 3 to 20.

The present invention also provides a vinyl chloride resin composition comprising the graft copolymer and excellent in workability and impact resistance.

Hereinafter, the present invention will be described in detail.

The graft copolymer of the present invention comprises i) 70 to 99% by weight of an acrylic rubber core; ii) 1 to 30% by weight of a graft shell formed by coating the rubber core with at least one monomer selected from the group consisting of monomers represented by the following formulas (1) to (3) and (meth) acrylate monomer,

The multifunctional monomer represented by the following general formulas (1), (2) and (3) is contained in an amount of 0.05 to 30% by weight based on 100% by weight of the graft shell.

[Chemical Formula 1]

(2)

(3)

In the above formulas 1, 2 and 3, A is a (meth) acryloyl group, B is a (meth) acryloyl group or hydrogen, and n and m each independently are 3 to 20.

The acrylic rubber is preferably a rubber composed of an alkyl acrylate monomer having 2 to 18 carbon atoms, and may further comprise a vinyl monomer. Examples of the alkyl acrylate monomers include monomers selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, aryl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate and aryl acrylate Or more can be used.

The acrylic rubber may further include a crosslinkable monomer.

The crosslinkable monomer may be selected from the group consisting of divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, aryl methacrylate, 1,3-butylene glycol diacrylate, and the like.

The crosslinkable monomer is preferably contained in an amount of 0.1 to 5% by weight or less, more preferably 0.1 to 2% by weight or less based on the acrylic rubber, and the impact strength is excellent within this range.

The acrylic rubber may be prepared through one or more steps, but the composition of the monomer for each step is not particularly limited.

The grafted shell can easily act as a lubricant and contribute to an improvement in extrusion processability by allowing the hydrophilic monomer to be distributed at the outermost part of the particles through the introduction of the hydrophilic monofunctional monomer. Further, when a multifunctional monomer having a large molecular weight is used, it acts as a coupling agent rather than a cross-linking agent between polymethylmethacrylate molecules, thereby increasing the molecular weight of the shell and consequently improving the gloss and impact strength.

The multifunctional monomer having such a hydrophilic property and having a weight average molecular weight (Mw) of 200 to 5000 g / mol is at least one selected from the group consisting of monomers represented by the following formulas (1) to (3).

[Chemical Formula 1]

(2)

(3)

In the above formulas 1, 2 and 3, A is a (meth) acryloyl group, B is a (meth) acryloyl group or hydrogen, and n and m each independently are 3 to 20.

The polyfunctional monomer represented by the above formula (1) includes, but is not limited to, poly (ethylene glycol) monoacrylate, poly (ethylene glycol) monomethacrylate, poly (ethylene glycol) diacrylate, poly (ethylene glycol) (Ethyleneglycol) monoacrylate, methoxypoly (ethylene glycol) monoacrylate, methoxypoly (ethylene glycol) monoacrylate, methoxypoly .

The polyfunctional monomer represented by the general formula (2) includes, but is not limited to, poly (propylene glycol) monoacrylate, poly (propylene glycol) monomethacrylate, poly (propylene glycol) diacrylate, poly (propylene glycol) (Propylene glycol) monoacrylate, methoxypoly (propylene glycol) monoacrylate, methoxypoly (propylene glycol) monomethacrylate, phenoxypoly Rate.

The polyfunctional monomer represented by the above formula (3) includes, but is not limited to, poly (ethylene glycol-propylene glycol) monoacrylate, poly (ethylene glycol-prefilene glycol) monomethacrylate, poly (ethylene glycol-propylene glycol) ) Diacrylate, poly (ethylene glycol-propylene glycol) dimethacrylate, methoxypoly (ethylene glycol-propylene glycol) monoacrylate, methoxy (ethylene glycol-propylene glycol) monomethacrylate, methoxypoly (Ethylene glycol-propylene glycol) monomethacrylate, phenoxypoly (ethylene glycol-propylene glycol) monoacrylate, or phenoxypoly (ethylene glycol-propylene glycol) monomethacrylate.

Formula (1) and Formula (2) may be used in a weight ratio of 1:99 to 99: 1, if necessary, and most preferably in a weight ratio of 1: 1 as shown in Example 5 below.

The graft shell of the present invention comprises a graft polymerization step comprising at least one selected from the group consisting of monomers represented by the following general formulas (1) to (3) and a (meth) acrylate-based monomer.

For reference, in Examples, the following polyethylene glycol dimethacrylate ((PEG) ₁₂ DMA) represented by Chemical Formula 4, polypropylene glycol dimethacrylate (PPG ₁₂ DMA) represented by Chemical Formula 5, And polyethylene glycol dimethacrylate (PEG ₆ PPG ₆ DMA) were used. The weight average molecular weight (Mw) is about 783 g / mol.

The (meth) acrylate-based monomer may be an alkyl methacrylate or an alkyl acrylate, and preferably is at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate And the like.

Wherein the graft copolymer comprises 70 to 99% by weight of the acrylic rubber core, 1 to 30% by weight of a shell, 100 to 40% by weight of a graft shell, It is preferable that at least one kind selected from the group consisting of the polyfunctional monomers represented by the above formulas (1), (2) and (3) is 0.05 to 30% by weight and that the (meth) acrylate monomer is 70 to 99.95% The graft copolymer prepared in the present invention is not only excellent in improving the workability and impact resistance of the vinyl chloride resin composition when used as an impact modifier, but also has a high content of rubber of 95% or more, It can also be improved.

The graft copolymer is more preferably 80 to 95% by weight of the acrylic rubber core and 5 to 20% by weight of the graft shell.

Particularly, as is clear from the following examples, the acrylic rubber core is 85 to 93% by weight, the polyfunctional monomer is 0.28 to 0.60% by weight, and the (meth) acrylate monomer is And most preferably 6.72 to 14.4% by weight.

The graft copolymer is preferably used as an impact modifier for vinyl chloride resin.

The process for producing a graft copolymer of the present invention comprises the steps of: a) polymerizing an acrylic rubber core; And (b) adding at least one monomer selected from the group consisting of monomers represented by the following formulas (1) to (3) and a (meth) acrylate monomer to the polymerized rubber core and graft-polymerizing the grafted polymer; , ≪ / RTI &

The polymerized rubber core is 70 to 99% by weight, and the grafted shell formed from at least one monomer selected from the group consisting of monomers represented by the following formulas (1) to (3) and a (meth) acrylate- %, And the multifunctional monomer represented by the following general formulas (1), (2) and (3) is contained in an amount of 0.05 to 30% by weight based on 100% by weight of the graft shell.

[Chemical Formula 1]

(2)

(3)

In the above formulas 1, 2 and 3, A is a (meth) acryloyl group, B is a (meth) acryloyl group or hydrogen, and n and m each independently are 3 to 20.

The method for producing the graft copolymer of the present invention includes all of the contents of the graft copolymer of the present invention.

The graft polymerization is not particularly limited but may be emulsion polymerization. Reaction conditions, reaction medium, emulsifier, initiator, etc. may be selected and controlled within a conventional range, and may be composed of two or more polymerization stages.

The vinyl chloride resin composition having excellent processability and impact resistance of the present invention comprises 0.5 to 20% by weight of the graft copolymer and 80 to 99.5% by weight of a vinyl chloride resin. The vinyl chloride resin composition may contain, if necessary, additives such as antioxidants, heat stabilizers, plasticizers, and coloring agents known in the art.

As described above, the present invention provides a graft copolymer which greatly improves workability and impact resistance, a process for producing the same, and a vinyl chloride resin composition having excellent processability and impact resistance including the same. In addition, it has an effect of improving the flocculation temperature in the production of a high-impact core-shell polymer powder containing a rubber content of 85% or more.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to fall within the scope of the appended claims.

[Example]

Example  One

≪ Preparation of acrylic rubber latex >

The parts by weight of the following compounds are based on 100 parts by weight of the total monomers of the acrylic rubber latex.

A reactor of a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet, and a circulating condenser was prepared, and 80 parts by weight of ion exchange water, 0.2 parts by weight of NaHCO ₃ , 0.001 part by weight of ferrous sulfate and 0.18 parts by weight of disodium ethylenediamine tetraacetate And the inside temperature of the reactor was maintained at 50 캜 under a nitrogen atmosphere.

50 parts by weight of ionized water, 0.60 part by weight of sodium laurylsulfonate, 83.8 parts by weight of butyl acrylate (BA) and 1.2 parts by weight of aryl methacrylate (AMA) were added to prepare a monomer pre-emulsion .

When the internal temperature of the reactor reached 50 ° C, a previously prepared monomer pre-emulsion was added for 5 hours, and 0.2 part by weight of initiator t-butyl hydroperoxide (TBHP) and 0.2 part by weight of sodium formaldehyde sulfoxylate (SFS) Respectively. After 30 minutes of the monomer pre-emulsion addition, 0.01 part by weight of TBHP and 0.02 part by weight of SFS were added and aged for 1 hour.

The polymerization conversion was 99%, the average particle size was 170 nm, and the total solid content was 40% by weight.

< Graft  Preparation of Copolymer Latex>

The parts by weight of the following compounds are based on 100 parts by weight of the total amount of the acrylic rubber latex and the newly added monomer. The reactor temperature was maintained at 50 ° C for shell polymerization.

Before the reaction, 15 parts by weight of ion-exchanged water, 0.1 part by weight of sodium laurylsulfonate, 14.4 parts by weight of methyl methacrylate (MMA), and 0.6 part by weight of polyethylene glycol dimethacrylate (PEG ₁₂ DMA; To prepare a monomer pre-emulsion.

0.07 parts by weight of potassium persulfate as an initiator and 0.03 parts by weight of SFS as an activator were added to the monomer pre-emulsion, and the reaction was allowed to proceed.

After 30 minutes of the monomer-free pre-emulsion addition, 0.02 part by weight of potassium persulfate and 0.01 part by weight of SFS were further added and aged for 60 minutes to prepare a graft copolymer latex having a methacrylic shell.

< Graft  Cohesion of copolymer latex>

Ion exchange water was added to 100 parts by weight of the latex graft copolymer thus prepared to lower the solid content to 10% by weight, to raise the temperature to a constant coagulation temperature, and then to add CaCl ₂ aqueous solution (diluted with 20% To thereby aggregate the polymer particles to prepare a flocculation slurry.

Example  2

Except that in Example 1, 91.69 parts by weight of butyl acrylate, 1.31 parts by weight of aryl methacrylate, 6.72 parts by weight of methyl methacrylate and 0.28 parts by weight of polyethylene glycol methacrylate (PEGDMA) The procedure of Example 1 was repeated.

Example  3

In the above example, methacrylate polymerization was carried out in the same manner as in Example 1, except that (PEG) ₁₂ DMA was replaced by (PPG) ₁₂ DMA (see above Chemical Formula 5).

Example  4

The procedure of Example 1 was repeated except that (PEG) ₁₂ DMA was replaced with (PEG) ₆ (PPG) ₆ DMA (refer to Chemical Formula 6) in methacrylate polymerization in Example 1 above.

Example  5

Except in Example 1 was replaced methacrylate shell polymerization (PEG) ₁₂ DMA 0.60 part by weight of (PEG) ₁₂ DMA 0.30 part by weight and (PPG) ₁₂ DMA 0.30 parts by weight, and are prepared in the same manner as in Example 1, Respectively.

Comparative Example  One

The procedure of Example 1 was repeated except that polyethylene glycol dimethacrylate (PEG ₁₂ DMA) was not used in Example 1.

Comparative Example  2

Except that 83.8 parts by weight of butyl acrylate, 1.2 parts by weight of polyethylene glycol dimethacrylate (PEG ₁₂ DMA) and 15 parts by weight of methyl methacrylate (MMA) were used in Example 1, . &Lt; / RTI &gt;

Comparative Example  3

In Example 1, 83.8 parts by weight of butyl acrylate and 0.6 parts by weight of polyethylene glycol dimethacrylate (PEG ₁₂ DMA) were mixed with 15 parts by weight of methyl methacrylate (MMA) Except that 0.6 part by weight of alkyl methacrylate (AMA) was used.

Comparative Example  4

Except that 92.2 parts by weight of butyl acrylate, 0.98 parts by weight of aryl methacrylate and 7 parts by weight of methyl methacrylate (MMA) were used in Example 2.

[Test Example]

The characteristics of the flocculated slurry prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were measured by the following methods, and the results are shown in Table 1 below.

Shell weight average molecular weight : 3 g of the graft copolymer agglomerated slurry prepared in Example 1-2 and Comparative Example 1-4 was mixed with 50 ml of acetone for 40 hours, followed by sol-gel separation using a centrifuge at 15000 rpm, The separated sol part was dissolved in tetrahydrofuran (THF) for 24 hours and the weight average molecular weight was measured by gel permeation chromatography (GPC).

Rubber Content : The sum of the rubbery core monomers is described.

Then, a total of 118 phr (100 phr, part per hundred resin) of the graft copolymer prepared in the present invention, 42 phr of Ca-Zn stabilizer, 4.0 phr of TiO2 (product name: CR834) and 10 phr of CaCO ₃ Were kneaded in a Henschel mixer at 5000 rpm while being heated to 120 to prepare a vinyl chloride resin. The extrusion processability and the impact strength were measured under the following conditions, and the results are summarized in Table 1 below.

Extrusion processability : The extrusion load (Nm) and the extrusion amount (g / min) were measured under a condition of 40 rpm using a Haake extruder and cylinder -1 / -2 / -3 / die 180/185/185/190.

Impact strength : The Izod impact strength (1/8 inch, kgcm / cm) according to the ISO 180 standard and the luster of the window profile prepared by the extrusion process was measured.

division Example Comparative Example One 2 3 4 5 One 2 3 4 Rubber core
BA 83.8 91.69 83.8 83.8 83.8 83.8 83.8 83.8 92.2 AMA 1.2 1.31 1,2 1.2 1.2 1.2 - 0.60 0.98 (PEG) ₁₂ DMA - - - - - - 1.2 0.60 - Methacrylate
MMA 14.40 6.72 14.40 14.40 14.40 15 15 15 7 (PEG) ₁₂ DMA 0.60 0.28 - - 0.30 - - - - (PPG) ₁₂ DMA - - 0.60 - 0.30 - - - - (PEG) ₆ (PPG) ₆ DMA - - - 0.60 - - - - - Rubber content (%) 85 93 85 85 85 85 85 85 93 Coagulation temperature () 45 30 43 46 47 35 34 33 15 Shell weight average molecular weight 78 million 51 million 70 million 80 million 75 million 45 million 42 million 40 million 20 million Processability Load (Nm) 120 125 118 119 121 130 125 127 132 Extrusion amount (g / min) 85 83 87 86 88 77 75 76 73 Properties Gloss (60 degrees) 56 52 53 57 57 45 40 43 30 Izod shock
Strength (1/8 ",
kgcm / cm) 14.1 15.0 14.0 14.5 14.8 12.5 11.0 12.0 13.5

As shown in Table 1, the vinyl chloride resin compositions (Examples 1 to 5) containing the graft copolymer of the present invention as an impact modifier had excellent processability and impact resistance, and had a high rubber content of 85% In the case of the vinyl chloride resin composition (Comparative Example 1) including a graft copolymer in which PEG ₁₂ DMA was not used as an impact modifier, the processing load was increased compared with Example 1, It was confirmed that the extrusion processability was poor and the gloss and the impact strength were lowered as the shell molecular weight was lowered.

Also, in Comparative Examples 2 and 3 using PEG ₁₂ DMA during core production, it was confirmed that both the gloss and the impact strength were reduced.

Further, in Comparative Example 4 having a rubber content of 93% as in Example 2, it was confirmed that the flocculation temperature was lowered, the processing load was increased, and the extrusion amount and gloss were all reduced.

Claims (8)

From 80 to 99.5% by weight of a vinyl chloride resin and from 0.5 to 20% by weight of a graft copolymer which is an impact modifier thereof,
Wherein the graft copolymer comprises i) 80 to 95% by weight of an acrylic rubber core; And ii) 5 to 20% by weight of a graft shell which surrounds the rubber core and comprises a polyfunctional monomer represented by the following general formulas (1) and (2) and a (meth) acrylate-based monomer, And 2 are mixed in a weight ratio of 1:99 to 99: 1 and are contained in an amount of 0.05 to 30% by weight based on 100% by weight of graft shell.

[Chemical Formula 1]

(2)

In the above formulas 1 and 2, A is a (meth) acryloyl group, B is a (meth) acryloyl group, and n and m are independently 3 to 20.
The method according to claim 1,
Wherein the acrylic rubber further comprises a crosslinkable monomer.
The method according to claim 1,
Wherein the (meth) acrylate monomer is at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, aryl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate and aryl acrylate. By weight or more.
The method according to claim 1,
Wherein the polyfunctional monomer represented by Formula 1 is poly (ethylene glycol) diacrylate having an n value of 3 to 20 or poly (ethylene glycol) dimethacrylate.
The method according to claim 1,
Wherein the polyfunctional monomer represented by Formula 2 is poly (propylene glycol) diacrylate having an m value of 3 to 20 or poly (propylene glycol) dimethacrylate.
delete The method according to claim 1,
The graft copolymer is composed of 85 to 93% by weight of the acrylic rubber core, 0.28 to 0.60% by weight of the polyfunctional monomer, and 6.72 to 14.4% by weight of the (meth) acrylate monomer based on the total weight of the entire graft copolymer Wherein the vinyl chloride resin composition is a polyvinyl chloride resin composition. delete