Vinyl chloride-based copolymer and preparation method thereof

Abstract

Provided are a novel structure of a copolymer, a preparation method thereof, a vinyl chloride-based resin composition including the copolymer, and a coating ink including the vinyl chloride-based resin composition. According to the present invention, when the vinyl chloride-based resin composition including the copolymer is used, compatibility with ethylene vinyl acetate is excellent, and ink dispersibility and ink color are also excellent.

Claims

1. A copolymer of a vinyl chloride monomer, a dicarboxylic acid ester monomer, a hydroxyl monomer and a polyethylene glycol monomer including a (meth) acrylate group represented by the following Chemical Formula 3, includes 8 parts by weight to 15 parts by weight of the dicarboxylic acid ester monomer and 1 part by weight to 9 parts by weight of the hydroxyl monomer with respect to 100 parts by weight of the vinyl chloride monomer, wherein a weight ratio of the dicarboxylic acid ester monomer, and the hydroxyl monomer is 1.5:1 to 2:1, wherein the dicarboxy acid ester monomer is one or more compounds selected from the group consisting of dipentyl maleate, dihexyl maleate, dioctyl maleate, and dinonyl maleate, ##STR00009## in Chemical Formula 3, n is an integer of 2 to 100, and R.sub.4 and R.sub.5 are each independently hydrogen, a hydrocarbyl group having 1 to 10 carbon atoms of a (meth) acrylate group, wherein at least one of R.sub.4 and R.sub.5 is a (meth) acrylate group.

2. The copolymer of claim 1, wherein the copolymer includes 10 parts by weight to 15 parts by weight of the dicarboxylic acid ester monomer; and 5 part by weight to 8 parts by weight of the hydroxyl monomer with respect to 100 parts by weight of the vinyl chloride monomer.

3. The copolymer of claim 1, wherein the dicarboxylic acid ester monomer is dioctyl maleate represented by the following Chemical Formula 1: ##STR00010##

4. The copolymer of claim 1, wherein the hydroxyl monomer includes one or more compounds selected from the group consisting of glycerolmonoacrylate, hydroxyethyl acrylate, hydroxypropylacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylamide, hydroxypolyethoxyallylether, hydroxypropylacrylate, hydroxypropylmethacrylate, pentaerythritol triacrylate, polypropylene glycolmethacrylate, acryloethoxyhydroxybenzophenone, allylhydroxyacetophenone, and methacryloxyhydrobenzophenone monomer.

5. The copolymer of claim 1, wherein the polyethylene glycol monomer including a (meth)acrylate group is included in an amount of 0.1 part by weight to 5 parts by weight with respect to 100 parts by weight of the vinyl chloride-based monomer.

6. A method of preparing the copolymer of claim 1, the method including the step of polymerizing the vinyl chloride monomer, the dicarboxylic acid ester monomer, the hydroxyl monomer, and the polyethylene glycol monomer in the presence of an initiator, wherein introduction of the vinyl chloride monomer is divided into first introduction before the polymerization; and second introduction within 100 minutes after reaching the polymerization temperature, or when the pressure in a reactor decreases to 0.5 kgf/cm.sup.2 to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure.

7. The method of claim 6, wherein the vinyl chloride monomer is primarily introduced in an amount of 10% by weight to 90% by weight of the total input amount of vinyl chloride, before the polymerization, and the rest of the vinyl chloride monomer is secondarily introduced when the temperature in the reactor reaches the polymerization temperature.

8. The method of claim 6, wherein the dicarboxylic acid ester monomer is dioctyl maleate represented by the following Chemical Formula 1: ##STR00011##

9. The method of claim 6, wherein the dicarboxylic acid ester monomer is introduced in an amount of 8 parts by weight to 15 parts by weight with respect to 100 parts by weight of the vinyl chloride-based monomer.

10. The method of claim 6, wherein the hydroxyl monomer includes one or more compounds selected from the group consisting of glycerolmonoacrylate, hydroxyethyl acrylate, hydroxypropylacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylamide, hydroxypolyethoxyallylether, hydroxypropylacrylate, hydroxypropylmethacrylate, pentaerythritol triacrylate, polypropylene glycolmethacrylate, acryloethoxyhydroxybenzophenone, allylhydroxyacetophenone, and methacryloxyhydrobenzophenone.

11. The method of claim 6, wherein the hydroxyl monomer is introduced within 100 minutes after the temperature in the reactor reaches the polymerization temperature, or when the pressure in the reactor decreases to 0.5 kgf/cm.sup.2 to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure.

12. The method of claim 6, wherein the hydroxyl monomer is introduced in an amount of 1 part by weight to 9 parts by weight with respect to 100 parts by weight of the vinyl chloride-based monomer.

13. The method of claim 6, wherein the polyethylene glycol monomer has a weight average molecular weight (Mw) of 200 g/mol to 5000 g/mol.

14. The method of claim 6, wherein the polyethylene glycol monomer is introduced in an amount of 0.1 part by weight to 5 parts by weight with respect to 100 parts by weight of the vinyl chloride-based monomer.

15. The method of claim 6, wherein the polyethylene glycol monomer is introduced before polymerization or at the time point when the degree of polymerization of the monomers is 30% to 80%.

16. The method of claim 6, wherein the polymerization is performed under stirring, and the stirring is performed by increasing the stirring speed within 100 minutes after the temperature in the reactor reaches the polymerization temperature; or when the pressure in the reactor decreases to 0.5 kgf/cm.sup.2 to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure.

17. The method of claim 6, wherein the polymerization is suspension polymerization, micro-suspension polymerization, or emulsion polymerization.

18. A Vinyl chloride-based resin composition comprising the copolymer of claim 1.

19. A coating ink comprising the vinyl chloride resin composition of claim 18.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows an NMR graph of a copolymer prepared in Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Hereinafter, preferred examples will be provided for better understanding of the present invention. However, the following examples are provided only for illustrating the present invention, but the present invention is not limited thereby.

Example 1

(3) Oxygen was removed from a 280 L reactor using a vacuum pump. To the reactor, 40 kg of a vinyl chloride-based monomer, 10 kg of dioctyl maleate, 0.5 kg of Methoxy PEG600 Methacrylate as a polyethylene glycol-based additive, 0.19 kg of dioctiyltin mercaptide as an organotin compound, 3.0 kg of 3% aqueous solution of a cellulose-based suspending agent, and 76 g of azobisisobutyronitrile as an initiator were introduced together with in 150 L of deionized water. Polymerization was initiated under stirring at 350 rpm using a Brumagin impeller.

(4) Immediately after raising the reactor temperature to 73° C., 6 kg of hydroxypropylacrylate was continuously introduced over 5 hours, and 40 kg of the vinyl chloride-based monomer was additionally introduced, when the reactor pressure decreased to 0.5 kgf/cm.sup.2, as compared to the initial polymerization pressure, while increasing the stirring speed of the Brumagin impeller to 600 rpm.

(5) The vinyl chloride-based monomer was additionally introduced over 316 minutes, and after introducing the vinyl chloride-based monomer, the polymerization was stopped, when the reactor pressure decreased to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure, and unreacted monomers were recovered and the polymerization was terminated. The polymerized slurry was dehydrated and dried to obtain particles of the vinyl chloride-based resin composition which is a copolymer having an average particle size of 150 μm.

(6) NMR (13C-NMR) of the obtained copolymer is shown in FIG. 1

(7) A weight average molecular weight (Mw) of the copolymer was 48,135 g/mol, and its yield was 71% (based on a final dry product).

(8) ##STR00008##

Example 2

(9) Oxygen was removed from a 280 L reactor using a vacuum pump. To the reactor, 39 kg of a vinyl chloride monomer, 11 kg of dioctyl maleate, 0.5 kg of Methoxy PEG600 Methacrylate as a polyethylene glycol-based additive, 0.19 g of dioctiyltin mercaptide as an organotin compound, 3.0 kg of 3% aqueous solution of a cellulose-based suspending agent, and 76 g of azobisisobutyronitrile as an initiator were introduced together with in 150 L of deionized water. Polymerization was initiated under stirring at 350 rpm using a Brumagin impeller.

(10) Immediately after raising the reactor temperature to 73° C., 6 kg of hydroxypropylacrylate was continuously introduced over 5 hours, and 39 kg of the vinyl chloride-based monomer was additionally introduced, when the reactor pressure decreased to 0.5 kgf/cm.sup.2, as compared to the initial polymerization pressure, while increasing the stirring speed of the Brumagin impeller to 600 rpm.

(11) The vinyl chloride-based monomer was additionally introduced over 306 minutes, and after introducing the vinyl chloride-based monomer, the polymerization was stopped, when the reactor pressure decreased to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure, and unreacted monomers were recovered and the polymerization was terminated. The polymerized slurry was dehydrated and dried to obtain particles of the vinyl chloride-based resin composition.

(12) A weight average molecular weight (Mw) of the copolymer was 49.341 g/mol, and its yield was 73% (based on a final dry product).

Comparative Example 1

(13) Oxygen was removed from a 280 L reactor using a vacuum pump. To the reactor, 43 kg of a vinyl chloride monomer, 5 kg of vinyl acetate monomer, 0.5 kg of Methoxy PEG600 Methacrylate as a polyethylene glycol-based additive, 0.19 g of dioctiyltin mercaptide as an organotin compound, 3.0 kg of 3% aqueous solution of a cellulose-based suspending agent, and 76 g of azobisisobutyronitrile as an initiator were introduced together with in 150 L of deionized water. Polymerization was initiated under stirring at 350 rpm using a Brumagin impeller.

(14) Immediately after raising the reactor temperature to 73° C., 5 kg of hydroxypropylacrylate was continuously introduced over 250 minutes, and 43 kg of the vinyl chloride-based monomer was additionally introduced, when the reactor pressure decreased to 0.5 kgf/cm.sup.2, as compared to the initial polymerization pressure, while increasing the stirring speed of the Brumagin impeller to 600 rpm.

(15) The vinyl chloride-based monomer was additionally introduced over 336 minutes, and after introducing the vinyl chloride-based monomer, the polymerization was stopped, when the reactor pressure decreased to 1.0 kgf/cm.sup.2, as compared to the initial polymerization pressure, and unreacted monomers were recovered and the polymerization was terminated. The polymerized slurry was dehydrated and dried to obtain particles of the vinyl chloride-based resin composition.

(16) A weight average molecular weight (Mw) of the copolymer was 75.557 g/mol, and its yield was 73% (based on a final dry product).

Comparative Example 2

(17) A saponified vinyl chloride-based resin composition particle (product name: Solbin® A, manufacturer: Shin-Etsu MicroSi, Inc.), which is a terpolymer of vinyl chloride, vinyl alcohol, and vinyl acetate, was prepared.

Preparation Examples 1-A to 1-D

(18) 20% by weight of each vinyl chloride-based resin composition particles obtained in Examples and Comparative Examples was mixed with 40% by weight of ethyl acetate, and 40% by weight of toluene, and stirred at 50° C. for 90 minutes to prepare a mixed solution of Preparation Example corresponding to each of Examples and Comparative Examples.

Preparation Examples 2-A to 2-D

(19) 25 g of each of the mixed solutions according to Preparation Examples 1-A to 1-D, 8 g of pigment (Red 57:1), 17.3 g of ethyl acetate, 11.0 g of toluene, 4.0 g of methyl ethyl ketone, 7.0 g of methyl isobutyl ketone, 35 g of beads (product name: Alumina Bead, manufacturer: SamHwa ceramic), and 27.5 g of an ethylene vinyl acetate solution (product name: EVATANE® 42-60, 20% in Toluene, manufacturer: Arkema) were mixed, and stirred for 1 hr using an ink shaker to prepare each red coating ink corresponding to Examples and Comparative Examples.

Preparation Examples 3-A to 3-D

(20) The same components as in Preparation Examples 2-A to 2-D were mixed, except that pigment (Blue 15.3) was used instead of pigment (Red 57:1), and stirred for 1 hr using an ink shaker to prepare each blue coating ink corresponding to Examples and Comparative Examples.

Experimental Example 1

(21) For the mixed solutions according to Preparation Examples 1-A to 1-D, transparency of each solution was measured using an UV spectrometer (475 nm).

Experimental Example 2

(22) After applying each of the red inks according to Preparation Examples 2-A to 2-D and each of the blue inks according to Preparation Examples 3-A to 3-D onto a PET film and drying them, glossiness was repeatedly measured five times using a gloss meter (BYK, micro-gloss) at 60°, and average values thereof were calculated, and color (color development, a* and b*) was repeatedly measured five times using a color analyzer (Konica Minolta, CR-400), and average values thereof were calculated.

Experimental Example 3

(23) The mixed solutions according to Preparation Examples 1-A to 1-D, the red inks according to Preparation Examples 2-A to 2-D, and the blue inks according to Preparation Examples 3-A to 3-D were stored in an oven at 25° C. for 1 hr or longer, and then each of the mixed solutions was measured (sec) using a #4 size Ford Cup viscometer, and each of the red and blue inks was measured for viscosity (cps) at 100 rpm using a Brookfield viscometer equipped with a #4 size spindle. The degree of phase separation of each ink was observed over time. The results were relatively evaluated according to the following five levels: very excellent (⊚), excellent (∘), good (.box-tangle-solidup.), fair (Δ), and poor (X).

(24) When stability of the ink is not good, layer separation of ink and aggregation of pigment occur within 1 hour after mixing the ink. When ink with poor stability is coated, the glossiness of the coating layer becomes relatively low.

(25) TABLE-US-00001 TABLE 1 Resin Transparency Viscosity Mixed solution composition (%) (sec) Preparation Example 1 93 45 Example 1-A Preparation Example 2 88 37 Example 1-B Preparation Comparative 79 113  Example 1-C Example 1 Preparation Comparative 86 79 Example 1-D Example 2

(26) TABLE-US-00002 TABLE 2 Color Ink Viscos- Glossi- develop- stability Resin ity ness ment (non-agglo- Red ink composition (cps) (GU) (a*) meration) Preparation Example 1  88 14.5 59.5 ⊚ Example 2-A Preparation Example 2  82 14.8 54.6 ⊚ Example 2-B Preparation Comparative 227 10.4 51.6 Δ Example 2-C Example 1 Preparation Comparative 101 14.3 55.4 .box-tangle-solidup. Example 2-D Example 2

(27) TABLE-US-00003 TABLE 3 Color Ink Glossi- develop- stability Resin Viscosity ness ment (non-agglo Red ink composition (cps) (GU) (b*) meration) Preparation Example 1 103 21.7 −58.4 ⊚ Example 3-A Preparation Example 2  76 19.2 −58.0 ⊚ Example 3-B Preparation Comparative 171 17.5 −54.3 Δ Example 3-C Example 1 Preparation Comparative  92 24.1 −58.6 ○ Example 3-D Example 2

(28) As in Comparative Example 1, when vinyl acetate was included, instead of dioctyl maleate, the solution transparency, ink stability and glossiness (dispersibility) as well as the color development were inferior to those of Examples 1 and 2 according to the limit to the change of the monomer composition ratio. In addition, the viscosity of the solution and the ink rapidly increased, making it difficult to use for a long time in actual commercial application.

(29) Meanwhile, it was confirmed that the vinyl chloride-based resin compositions of Examples 1 and 2 according to the present invention exhibited excellent transparency and also had equal or higher glossiness (dispersibility), stability, and color development, as compared with that of Comparative Example 5, which is an existing saponified vinyl chloride-based resin composition, and it was also confirmed that the compositions had viscosity suitable for use as a coating ink.

(30) However, when the experimental results according to the addition amount of dioctyl maleate were compared (Example 1 and Example 2), it was confirmed that when the content of dioctyl maleate was increased, ink stability was improved and ink glossiness (dispersibility) was improved. However, when the content exceeds 15 parts by weight, based on 100 parts by weight of the vinyl chloride monomer, there was a problem in that transparency and color development of the solution were deteriorated. Accordingly, it is most preferable that dioctyl maleate is used in an amount of about 12.5 parts by weight, because the transparency and viscosity of the solution, and the ink stability and glossiness and color development exhibited excellent levels on average.

INDUSTRIAL AVAILABILITY

(31) According to the present invention, there are provided a novel structure of a copolymer, a preparation method thereof, and a vinyl chloride-based resin composition including the copolymer. Particularly, there are provided a vinyl chloride-based resin composition exhibiting excellent compatibility with ethylene vinyl acetate while particularly exhibiting excellent ink dispersibility and ink color, and a coating ink including the vinyl chloride-based resin composition.