Core-Shell Copolymer, Method for Preparing the Same and Thermoplastic Resin Composition Including the Same

Abstract

A core-shell copolymer, a method of making the same, and a thermoplastic resin composition including the same are disclosed herein. In some embodiments, a core-shell copolymer includes a core and a shell surrounding the core, the core includes a conjugated diene-based monomer-derived repeating unit and a phosphate-based cross-linking agent-derived cross-linking part represented by Formula 1, and the shell includes a first alkyl (meth)acrylate monomer-derived repeating unit, a second alkyl (meth)acrylate monomer-derived repeating unit, and a sulfonate-based ionic monomer-derived repeating unit represented by Formula 2. The core is 68 parts to 92 parts and the shell is 8 parts to 32 parts, based on 100 parts of the core-shell copolymer, the core has a swell index of 2.7 to 10.9, the shell includes 1 wt % to 16 wt % of the sulfonate-based ionic monomer-derived repeating unit, and the shell has a weight average molecular weight of 105,000 g/mol to 645,000 g/mol.

Claims

1. A core-shell copolymer, comprising: a core:, and a shell surrounding the core, wherein the core includes a conjugated diene-based monomer-derived repeating unit and a phosphate-based cross-linking agent-derived cross-linking part, the phosphate-based cross-linking agent represented by the following Formula 1, wherein the shell includes a first alkyl (meth)acrylate monomer-derived repeating unit, a second alkyl (meth)acrylate monomer-derived repeating unit, and a sulfonate-based ionic monomer-derived repeating unit, the sulfonate-based ionic monomer represented by the following Formula 2, wherein the core is 68 parts by weight to 92 parts by weight and the shell is 8 parts by weight to 32 parts by weight, based on a total of 100 parts by weight of the core-shell copolymer, wherein the core has a swell index of 2.7 to 10.9, wherein the shell includes 1 weight percent (wt %1 to 16 wt % of the sulfonate-based ionic monomer-derived repeating unit, based on the total weight of the shell, and wherein the shell has a weight average molecular weight of 105,000 g/mol to 645,000 g/mol: ##STR00007## wherein R.sub.1 and R.sub.2 are each independently an alkylene group having 1 to 30 carbon atoms, and R.sub.3 and R.sub.4 are each independently hydrogen or a methyl group, and ##STR00008## wherein R.sub.5 is a single bond or an alkylene group having 1 to 30 carbon atoms, R.sub.6 is each independently hydrogen or a methyl group, M is potassium (K), sodium (Na), or hydrogen, and n is 0 or 1.

2. The core-shell copolymer of claim 1, wherein the phosphate-based cross-linking agent includes at least one phosphate-based cross-linking agent-represented by the following Formulas 3 and 4: ##STR00009##

3. The core-shell copolymer of claim 1, wherein the core has a swell index of 4 to 10.

4. The core-shell copolymer of claim 1, wherein the core includes 89 wt % to 99.0 wt % of the conjugated diene-based monomer-derived repeating unit and 0.01 wt % to 11 wt % of the phosphate-based cross-linking agent-derived cross-linking part.

5. The core-shell copolymer of claim 1, wherein the sulfonate-based ionic monomer includes at least one sulfonate-based ionic monomer represented by the following Formulas 5 to 8: ##STR00010##

6. The core-shell copolymer of claim 1, wherein the shell has a weight average molecular weight of 120,000 g/mol to 500,000 g/mol.

7. The core-shell copolymer of claim 1, wherein the shell has a glass transition temperature of 101 C. to 135 C.

8. The core-shell copolymer of claim 1, wherein the shell includes 76 wt % to 94.2 wt % of the first alkyl (meth)acrylate monomer-derived repeating unit, 4.8 wt % to 8 wt % of the second alkyl (meth)acrylate monomer-derived repeating unit, and 1 wt % to 16 wt % of the sulfonate-based ionic monomer-derived repeating unit.

9. A method for preparing a core-shell copolymer, the method comprising: polymerizing a core-forming mixture to prepare a core, the core-forming mixture including a conjugated diene-based monomer and a phosphate-based cross-linking agent represented by the following Formula 1; and polymerizing a shell-forming mixture in the presence of the core to prepare a shell of a core-shell copolymer, the shell-forming mixture including a first alkyl (meth)acrylate monomer, a second alkyl (meth)acrylate monomer, and a sulfonate-based ionic monomer represented by the following Formula 2, wherein the core is 68 parts by weight to 92 parts by weight and the shell is 8 parts by weight to 32 parts by weight, based on a total of 100 parts by weight of the core-shell copolymer, wherein the core has a swell index of 2.7 to 10.9, wherein the shell includes 1 wt % to 16 wt % of a sulfonate-based ionic monomer-derived repeating unit, and wherein the shell has a weight average molecular weight of 105,000 g/mol to 645,000 g/mol: ##STR00011## wherein R.sub.1 and R.sub.2 are each independently an alkylene group having 1 to 30 carbon atoms, and R.sub.3 and R.sub.4 are each independently hydrogen or a methyl group, and ##STR00012## wherein Rs is a single bond or an alkylene group having 1 to 30 carbon atoms, R.sub.6 is hydrogen or a methyl group, M is potassium (K), sodium (Na), or hydrogen, and n is 0 or 1.

10. A thermoplastic resin composition, comprising: the core-shell copolymer of claim 1 and a chlorinated polyvinyl chloride, wherein the thermoplastic resin composition includes 5 parts by weight to 10 parts by weight of the core-shell copolymer, based on 100 parts by weight of the chlorinated polyvinyl chloride.

Description

EXAMPLE

Example 1

[0069] <Preparation of Core-Shell Copolymer>

[0070] Hereinafter, parts by weight are measured based on the total of 100 parts by weight of the core-forming mixture and the shell-forming mixture.

[0071] Into nitrogen-substituted polymerization reactor, 65 parts by weight of ion-exchanged water, core-forming mixture containing 79.2 parts by weight of 1,3-butadiene and 0.8 parts by weight of bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3), 0.6 parts by weight of potassium oleate as an emulsifier, and 0.7 parts by weight of sodium hydrogen sulfate were added and stirred. Then, 0.05 parts by weight of diisopropyl hydroperoxide and 0.15 parts by weight of a redox activator prepared with a redox activator composition (0.001 parts by weight of ferrous sulfate, 0.02 parts by weight of ethylenediamine tetraacetic acid, 0.02 parts by weight of sodium formaldehyde sulfoxylate, and 0.02 parts by weight of sodium hydrogen sulfite) was added thereto, and the reaction was performed to a point where polymerization conversion was 30 to 40% at a reaction temperature of 40 C. Thereafter, 5 parts by weight of ion-exchanged water, 1.0 part by weight of potassium oleate, and 0.07 parts by weight of diisopropyl hydroperoxide were further added thereto. The reaction temperature was raised to 65 C. and the reaction proceeded for 20 hours, and was terminated at polymerization conversion of 95% or more to obtain latex containing a core.

[0072] Into nitrogen-substituted polymerization reactor, 80 parts by weight (based on solids) of the latex containing the obtained core was added. Thereafter, 10 parts by weight of ion-exchanged water, 0.3 parts by weight of oleic acid as an emulsifier and shell-forming mixture containing 18.0 parts by weight of methyl methacrylate, 1.4 parts by weight of butyl acrylate, and 0.6 parts by weight of 3-sulfopropyl methacrylate potassium salt (Formula 5) were added thereto, and then 0.05 parts by weight of a polymerization initiator, t-butyl hydroperoxide and 0.05 parts by weight of a redox activator prepared with a redox activator composition (0.001 parts by weight of ferrous sulfate, 0.02 parts by weight of ethylenediamine tetraacetic acid, 0.02 parts by weight of sodium formaldehyde sulfoxylate, and 0.02 parts by weight of sodium hydrogen sulfite) were added at once, followed by polymerization for 3 hours to obtain latex containing a core-shell copolymer.

[0073] <Preparation of Core-Shell Copolymer Powder>

[0074] To 100 parts by weight (based on solids) of the latex containing the obtained core-shell copolymer, 1 part by weight of an aqueous sulfuric acid solution (concentration 5%) as a coagulant was added to coagulate to obtain a slurry. Then, the slurry was washed three times with ion-exchanged water to wash the by-products and filtered to remove the washed water. Subsequently, the resulting slurry was dried at 80 C. for 2 hours using a fluidized-bed dryer to obtain a core-shell copolymer powder.

[0075] <Chlorinated Polyvinyl Chloride Composition>

[0076] To 100 parts by weight of the chlorinated polyvinyl chloride (HA series, Sekisui), 3.0 parts by weight of tin as a heat stabilizer, 0.3 parts by weight of an antioxidant (IR.sub.1010), 1.5 parts by weight of a processing aid (PA912), 5 parts by weight of a filler (CaCO.sub.3), 2 parts by weight of titanium dioxide, and 0.2 parts by weight of a wax-type lubricant (AC316A) were mixed with 7 parts by weight of the core-shell copolymer powder. Then, the mixture was mixed while raising the temperature to 110 C. using a Henschel mixer to prepare a chlorinated polyvinyl chloride composition.

Example 2

[0077] Example 2 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 78.0 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 2 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Example 3

[0078] Example 3 was performed in the same manner as in Example 1, except that 0.8 parts by weight of bis [2-(acryloyloxy)ethyl] phosphate (Formula 4) was added instead of 0.8 parts by weight of bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) in the preparation of the core.

Example 4

[0079] Example 4 was performed in the same manner as in Example 1, except that 0.6 parts by weight of vinyl sulfonic acid sodium salt (Formula 7) was added instead of 0.6 parts by weight of 3-sulfopropyl methacrylate potassium salt (Formula 5) in the preparation of the core-shell copolymer.

Example 5

[0080] Example 5 was performed in the same manner as in Example 1, except that the polymerization temperature was 50 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.01 parts by weight instead of 0.05 parts by weight, and the redox activator was added at 0.01 parts by weight instead of 0.05 parts by weight in the preparation of the core-shell copolymer.

Example 6

[0081] Example 6 was performed in the same manner as in Example 1, except that 0.6 parts by weight of 3-sulfopropyl acrylate potassium salt (Formula 6) was added instead of 0.6 parts by weight of 3-sulfopropyl methacrylate potassium salt (Formula 5) in the preparation of the core-shell copolymer.

Example 7

[0082] Example 7 was performed in the same manner as in Example 1, except that 0.6 parts by weight of 2-methyl-2-propene-1-sulfonic acid sodium salt (Formula 8) was added instead of 0.6 parts by weight of 3-sulfopropyl methacrylate potassium salt (Formula 5) in the preparation of the core-shell copolymer.

Example 8

[0083] Example 8 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 94.05 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.95 parts by weight instead of 0.8 parts by weight in the preparation of the core; and methyl methacrylate was added at 4.5 parts by weight instead of 18 parts by weight, butyl acrylate was added 0.35 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added 0.15 parts by weight instead of 0.6 parts by weight in the preparation of the core-shell copolymer.

Example 9

[0084] Example 9 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 89.1 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.9 parts by weight instead of 0.8 parts by weight in the preparation of the core; and methyl methacrylate was added at 9.0 parts by weight instead of 18 parts by weight, butyl acrylate was added 0.7 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added 0.3 parts by weight instead of 0.6 parts by weight in the preparation of the core-shell copolymer.

Example 10

[0085] Example 10 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 73.6 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 6.4 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Example 11

[0086] Example 11 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 79.99 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.01 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Example 12

[0087] Example 12 was performed in the same manner as in Example 1, except that the polymerization temperature was 45 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.005 parts by weight instead of 0.05 parts by weight, and the redox activator was added at 0.005 parts by weight instead of 0.05 parts by weight in the preparation of the core-shell copolymer.

Example 13

[0088] Example 13 was performed in the same manner as in Example 1, except that the polymerization temperature was 40 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.0005 parts by weight instead of 0.05 parts by weight, and the redox activator was added at 0.001 parts by weight instead of 0.05 parts by weight in the preparation of the core-shell copolymer.

Comparative Example 1

[0089] Comparative Example 1 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 80.0 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was not added.

Comparative Example 2

[0090] Comparative Example 2 was performed in the same manner as in Example 1, except that butyl acrylate was added at 2.0 parts by weight instead of 1.4 parts by weight and 3-sulfopropyl methacrylate potassium salt (Formula 5) was not added in the preparation of the core-shell copolymer.

Comparative Example 3

[0091] Comparative Example 3 was performed in the same manner as in Example 1, except that the polymerization temperature was 80 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.15 parts by weight instead of 0.05 parts by weight, the redox activator was added at 0.15 parts by weight instead of 0.05 parts by weight, and 0.01 parts by weight of a molecular weight regulator, t-dodecyl mercaptan was further added in the preparation of the core-shell copolymer.

Comparative Example 4

[0092] Comparative Example 4 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 59.4 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.6 parts by weight instead of 0.8 parts by weight in the preparation of the core; and methyl methacrylate was added at 36 parts by weight instead of 18 parts by weight, butyl acrylate was added 2.8 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added 1.2 parts by weight instead of 0.6 parts by weight within the shell-forming mixture in the preparation of the core-shell copolymer.

Comparative Example 5

[0093] Comparative Example 5 was performed in the same manner as in Example 1, except that methyl methacrylate was added at 13.5 parts by weight instead of 18 parts by weight, butyl acrylate was added at 0.5 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added at 6.0 parts by weight instead of 0.6 parts by weight in the preparation of the core-shell copolymer.

Comparative Example 6

[0094] Comparative Example 6 was performed in the same manner as in Example 1, except that the polymerization temperature was 40 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.001 parts by weight instead of 0.05 parts by weight, and the redox activator was added at 0.002 parts by weight instead of 0.05 parts by weight in the preparation of the core-shell copolymer.

Comparative Example 7

[0095] Comparative Example 7 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 70.4 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 9.6 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Comparative Example 8

[0096] Comparative Example 8 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 94.05 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.95 parts by weight instead of 0.8 parts by weight in the preparation of the core; and methyl methacrylate was added at 4.5 parts by weight instead of 18 parts by weight, butyl acrylate was added 0.35 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added 0.15 parts by weight instead of 0.6 parts by weight in the preparation of the core-shell copolymer.

Comparative Example 9

[0097] Comparative Example 9 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 64.35 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.65 parts by weight instead of 0.8 parts by weight in the preparation of the core; and methyl methacrylate was added at 31.5 parts by weight instead of 18 parts by weight, butyl acrylate was added 2.45 parts by weight instead of 1.4 parts by weight, and 3-sulfopropyl methacrylate potassium salt (Formula 5) was added 1.05 parts by weight instead of 0.6 parts by weight in the preparation of the core-shell copolymer.

Comparative Example 10

[0098] Comparative Example 10 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 79.996 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 0.004 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Comparative Example 11

[0099] Comparative Example 11 was performed in the same manner as in Example 1, except that 1,3-butadiene was added at 68.0 parts by weight instead of 79.2 parts by weight and bis [2-(methacryloyloxy)ethyl] phosphate (Formula 3) was added at 12.0 parts by weight instead of 0.8 parts by weight in the preparation of the core.

Comparative Example 12

[0100] Comparative Example 12 was performed in the same manner as in Example 1, except that the polymerization temperature was 70 C. instead of 60 C., a polymerization initiator, t-butyl hydroperoxide, was added at 0.10 parts by weight instead of 0.05 parts by weight, and the redox activator was added at 0.10 parts by weight instead of 0.05 parts by weight in the preparation of the core-shell copolymer.

Experimental Example

Experimental Example 1

[0101] The swell index of the core, and the glass transition temperature and the weight average molecular weight of the shell prepared in Examples 1 to 13 and Comparative Examples 1 to 12 were measured by the following methods, and the composition of the core-shell copolymer composition together with the results is shown in Tables 1 and 2 below.

[0102] Swell index: After immersing the core (solid content) into toluene for 24 hours, the swell index was obtained by the following Equation: Here, the swell index means that the lower the swell index, the higher the cross-linking degree of the rubber.

Swell index=weight of core swollen in toluene/the core after drying the swollen core to remove toluene [Equation]

[0103] Weight average molecular weight (Mw, g/mol): The sample in powder form was dissolved in a tetrahydrofuran (THF) solvent at a concentration of 0.25 wt % and then the weight average molecular weight was measured using gel permeation chromatography.

[0104] Glass transition temperature: The sample in powder form was further dried on a hot air dryer for 30 minutes and then the glass transition temperature was measured using a DSC measuring instrument (Q20 DSC from TA instruments). Here, the rate of temperature rise is 10 C./min.

TABLE-US-00001 TABLE 1 Examples Classification 1 2 3 4 5 6 7 Core BD 79.2 78.0 79.2 79.2 79.2 79.2 79.2 (parts by weight) MEP 0.8 2 0.8 0.8 0.8 0.8 (parts by weight) AEP 0.8 (parts by weight) Swell index 7.6 6.1 7.3 7.6 7.6 7.6 7.6 Shell MMA 18.0 18.0 18.0 18.0 18.0 18.0 18.0 (parts by weight) BA 1.4 1.4 1.4 1.4 1.4 1.4 1.4 (parts by weight) SMAP 0.6 0.6 0.6 0.6 (parts by weight) VSA 0.6 (parts by weight) SAP 0.6 (parts by weight) MSA 0.6 (parts by weight) Glass transition 110 111 110 110 110 110 110 temperature ( C.) Weight average 150,000 130,000 150,000 140,000 250,000 160,000 150,000 molecular weight (g/mol) Chlorinated Chlorinated 100 100 100 100 100 100 100 polyvinyl polyvinyl chloride chloride (parts by weight) composition Core-shell 7 7 7 7 7 7 7 copolymer (parts by weight) Examples Classification 8 9 10 11 12 13 Core BD 69.3 89.1 73.6 79.99 79.2 79.2 (parts by weight) MEP 0.7 0.9 6.4 0.01 0.8 0.8 (parts by weight) AEP (parts by weight) Swell index 7.5 7.7 4.0 10.0 7.6 7.6 Shell MMA 27.0 9.0 18.0 18.0 18.0 18.0 (parts by weight) BA 2.1 0.7 1.4 1.4 1.4 1.4 (parts by weight) SMAP 0.9 0.3 0.6 0.6 0.6 0.6 (parts by weight) VSA (parts by weight) SAP (parts by weight) MSA (parts by weight) Glass transition 111 110 110 111 110 111 temperature ( C.) Weight average 230,000 120,000 150,000 140,000 350,000 500,000 molecular weight (g/mol) Chlorinated Chlorinated 100 100 100 100 100 100 polyvinyl polyvinyl chloride chloride (parts by weight) composition Core-shell 7 7 7 7 7 7 copolymer (parts by weight) BD: 1,3-batadiene MEP: bis[(2-methacryloyloxy)ethyl] phosphate AEP: bis[2-(acryloyloxy)ethyl] phosphate MMA: methyl methacrylate BA: butyl acrylate SMAP: 3-sulfoproplyl methacrylate potassium salt SAP: 3-sulfoproplyl acrylate potassium salt MSA: 2-methyl-2-propene-1-sulfonic acid sodium salt VSA: vinyl sulfonic acid sodium salt

TABLE-US-00002 TABLE 2 Comparative Examples Classification 1 2 3 4 5 6 7 Core BD 80 79.2 79.2 59.4 79.2 79.2 70.4 (parts by weight) MEP 0 0.8 0.8 0.6 0.8 0.8 9.6 (parts by weight) AEP (parts by weight) Swell index 12.0 7.6 7.6 7.7 7.6 7.6 1.2 Shell MMA 18.0 18.0 18.0 36 13.5 18.0 18.0 (parts by weight) BA 1.4 2.0 1.4 2.8 0.5 1.4 1.4 (parts by weight) SMAP 0.6 0 0.6 1.2 6.0 0.6 0.6 (parts by weight) VSA (parts by weight) Glass transition 110 90 110 111 160 110 110 temperature ( C.) Weight average 160,000 150,000 25,000 200,000 110,000 800,000 150,000 molecular weight (g/mol) Chlorinated Chlorinated 100 100 100 100 100 100 100 polyvinyl polyvinyl chloride chloride (parts by weight) composition Core-shell 7 7 7 7 7 7 7 copolymer (parts by weight) Comparative Examples Classification 8 9 10 11 12 Core BD 94.05 64.35 79.996 68.0 79.2 (parts by weight) MEP 0.95 0.65 0.004 12.0 0.8 (parts by weight) AEP (parts by weight) Swell index 7.7 7.4 14.0 0.5 7.6 Shell MMA 4.5 31.5 18.0 18.0 18.0 (parts by weight) BA 0.35 2.45 1.4 1.4 1.4 (parts by weight) SMAP 0.15 1.05 0.6 0.6 0.6 (parts by weight) VSA (parts by weight) Glass transition 105 108 110 111 110 temperature ( C.) Weight average 120,000 220,000 150,000 130,000 80,000 molecular weight (g/mol) Chlorinated Chlorinated 100 100 100 100 110 polyvinyl polyvinyl chloride chloride (parts by weight) composition Core-shell 7 7 7 7 7 copolymer (parts by weight) BD: 1,3-batadiene MEP: bis[(2-methacryloyloxy)ethyl] phosphate AEP: bis[2-(acryloyloxy)ethyl] phosphate MMA: methyl methacrylate BA: butyl acrylate SMAP: 3-sulfoproplyl methacrylate potassium salt VSA: vinyl sulfonic acid sodium salt

Experimental Example 2

[0105] In order to evaluate melting point, impact strength, tensile strength, tensile modulus, processability, and thermal stability of the molded article molded from the chlorinated polyvinyl chloride composition including the core-shell copolymers prepared in Examples 1 to 13 and Comparative Examples 1 to 12 as an impact modifier, a specimen of the chlorinated polyvinyl chloride composition was prepared and evaluated by the following methods. The results are shown in Tables 3 and 4.

[0106] Preparation of the specimen: The chlorinated polyvinyl chloride compositions prepared in Examples and Comparative Examples were prepared in pellet form using a single extrusion kneader at 200 C. and 30 rpm, injected into the pellet to prepare a physical property specimen, and then the following physical properties were measured. The results are shown in Tables 3 and 4.

[0107] Melt index: The chlorinated polyvinyl chloride compositions prepared in Examples and Comparative Examples were prepared in pellet form using a single extrusion kneader at 200 C. and 30 rpm, and the pellet was weighed out of the cylinder at 200 C. and under a load of 10 kg for 10 minutes using a Toyoseiki Melt Index (F-B01) instrument. Here, excellent melt index means that the melt index is 1 g/10 min to 5 g/10 min.

[0108] Izod impact strength: The inch notched specimen was evaluated by the ASTM D256 test method. In this case, the measurements were all performed in a chamber maintained at room temperature (25 C.). After aging the inch notched specimen for 6 hours, the specimen was removed and evaluated by the ASTM D256 test method. Here, excellent Izod impact strength means that the Izod impact strength is 6 kgf/cm.sup.2 to 10 kgf/cm.sup.2.

[0109] Tensile strength and tensile modulus (50 mm/min, kg/cm.sup.2): In accordance with ASTM D638 method, a dumbbell-shaped specimen was pinched by a jaw of an Instron tensile strength meter and pulled under a speed of 50 mm/min to measure the load at the time of cutting. Here, excellent tensile strength means that the tensile strength is 45 MPa or more, and excellent tensile modulus means that the tensile modulus is 2,400 MPa or more.

[0110] Processability (fusion time): 56 g of the chlorinated polyvinyl chloride composition prepared in Examples and Comparative Examples was initially added at 200 C. and 30 rpm in a Hake mixer, and the time taken for the torque to reach its highest point was measured. Here, excellent fusion time means that the fusion time is 80 seconds or less.

[0111] Heat deflection temperature: In order to confirm the thermal stability, the heat deflection temperature was measured under a load of 18.6 kg using a specimen of thickness by ASTM D648 test method. Here, excellent heat deflection temperature means that the heat deflection temperature is 100 C. to 120 C.

TABLE-US-00003 TABLE 3 Examples Classification 1 2 3 4 5 6 7 8 9 10 11 12 13 Melt index 3.2 3.3 3.3 3.2 2.6 3.3 3.2 3.7 3.0 3.4 3.0 2.7 2.4 (g/10 min) Impact strength 8 7.6 7.8 7.9 8.5 8.1 7.9 7.0 8.7 6.7 6.5 7.5 8.3 (kgf/cm.sup.2) Tensile strength 50 53 51 54 51 51 52 54 52 56 51 53 55 (MPa) Tensile modulus 2450 2470 2456 2480 2490 2460 2455 2500 2420 2498 2460 2448 2456 (MPa) Processability 65 62 63 68 74 66 64 75 60 69 61 72 75 (sec) Heat defection 110 111 112 113 113 110 111 112 109 111 111 112 112 temperature ( C.)

TABLE-US-00004 TABLE 4 Comparative Examples Classification 1 2 3 4 5 6 7 8 9 10 11 12 Melt index 3.1 3.0 6.0 2.8 3.4 0.5 2.9 0.5 3.1 0.4 3.2 2.5 (g/10 min) Impact strength 4 8.1 5 4 2 8 1.1 5 3.9 3.5 1.5 5.5 (kgf/cm.sup.2) Tensile strength 40 39 38 53 60 46 45 35 56 32 52 45 (MPa) Tensile modulus 2300 2310 2444 2467 2600 2500 2510 2300 2510 2310 2410 2380 (MPa) Processability 70 68 67 98 120 90 78 65 90 68 45 70 (sec) Heat defection 95 94 98 112 125 111 120 95 110 96 110 110 temperature ( C.)

[0112] As shown in Tables 3 and 4, it was confirmed that in the core-shell copolymer according to the present invention, since the core includes a phosphate-based cross-linking agent-derived cross-linking part, excellent impact strength and thermal stability were obtained by controlling the cross-linking degree of the core, and since the shell includes a sulfonate-based ionic monomer, excellent thermal stability and processability were obtained by controlling the glass transition temperature and the weight average molecular weight of the shell.

[0113] Meanwhile, it was confirmed that for Comparative Example 1 in which no core includes the phosphate-based cross-linking agent-derived cross-linking part, various physical properties such as impact strength, tensile strength, and thermal stability, excluding processability, were degraded.

[0114] In addition, it could be confirmed that for Comparative Example 7 in which the content of the phosphate-based cross-linking agent included in the core exceeds 10 wt %, the cross-linking degree of the core was too high, which leads to a low swell index, and the impact strength was degraded due to brittle properties of the rubber forming the core.

[0115] In addition, it could be confirmed that for Comparative Example 2 in which no shell includes the sulfonate-based ionic monomer-derived repeating unit, tensile strength, tensile modulus, and thermal stability were degraded.

[0116] In addition, it could be confirmed that for Comparative Examples 3 and 12 in which the shell has a weight average molecular weight of less than 100,000 g/mol, impact strength, tensile strength, thermal stability, or the like were degraded; and for Comparative Example 6 in which the shell has a weight average molecular weight of more than 500,000 g/mol, processability was degraded.

[0117] Further, it could be confirmed that for

[0118] Comparative Examples 4 and 9 in which the content of the core is less than 70 parts by weight, based on a total of 100 parts by weight of the core-shell copolymer, impact strength and processability were degraded, and for Comparative Example 8 in which the content of the core is more than 90 parts by weight, based on a total of 100 parts by weight of the core-shell copolymer, various physical properties such as impact strength, tensile strength, and thermal stability, excluding processability, were degraded.

[0119] Furthermore, it could be confirmed that for Comparative Examples 10 and 11 in which the swell index of the core deviates from 3.7 to 10, impact strength was degraded.

[0120] In addition, it could be confirmed that for Comparative Example 5 in which the content of the sulfonate-based ionic monomer-derived repeating unit included in the shell exceeds 20 wt %, impact strength, processability, and thermal stability were degraded.