Resin composition for high barrier paper-coating

Abstract

Provided is a resin composition for paper-coating comprising aliphatic polycarbonate having an average molecular weight of 30,000 to 300,000 obtained by reaction of one or at least two different kinds of epoxide compounds selected from a group consisting of (C2-C10)alkylene oxide substituted or unsubstituted with carbon dioxide, halogen, or alkoxy; (C4-C20)cycloalkylene oxide substituted or unsubstituted with halogen or alkoxy; and (C8-C20)styrene oxide substituted or unsubstituted with halogen, alkoxy, alkyl or aryl, wherein it contains 0 to 40 weight % of polyolefin-based resin such as polyethylene or polypropylene, based on the total amount of the composition. In addition, the present invention relates to a paper coating method of extrusion-coating the resin composition for paper-coating on paper at 130 to 250 C. to manufacture a coated paper.

Claims

1. A resin composition for paper-coating comprising: 30 to 40 weight %, based on the total amount of the composition, of a polyolefin-based resin including a mixture of homo polypropylene and low-density polyethylene and 60 to 70 weight %, based on the total amount of the composition, of an aliphatic polycarbonate resin having an average molecular weight of 30,000 to 300,000 obtained by reacting carbon dioxide with at least one epoxide compound selected from a group consisting of (C2-C10)alkylene oxide substituted or unsubstituted with halogen or alkoxy; (C4-C20)cycloalkylene oxide substituted or unsubstituted with halogen or alkoxy; and (C8-C20)styrene oxide substituted or unsubstituted with halogen, alkoxy, alkyl or aryl.

2. The resin composition for paper-coating of claim 1, wherein the polyolefin-based resin has a melt index (MI) of 0.5 to 100.

3. The resin composition for paper-coating of claim 1, wherein the aliphatic polycarbonate is represented by the following Chemical Formula 1. ##STR00004##

4. The resin composition for paper-coating of claim 1, wherein the aliphatic polycarbonate has a melt index (MI, 150 C./5 kg) of 0.1 to 20.

5. The resin composition for paper-coating of claim 1, further comprising: one additive selected from a pigment, a dye, a filler, an antioxidant, a sunscreen agent, an antistatic agent, an anti-blocking agent, a slip agent, an inorganic filler, a compatibilizer, a stabilizer, a tackifier resin, a modified resin, a leveling agent, a fluorescent whitening agent, a dispersant, a heat stabilizer, a photo-stabilizer, an ultraviolet absorber, and a lubricant.

6. A paper coating method of extrusion-coating the resin composition for paper-coating of claim 1 on paper at 130 to 250 C. to manufacture a coated paper.

7. A paper coating method of extrusion-coating the resin composition for paper-coating of claim 2 on paper at 130 to 250 C. to manufacture a coated paper.

8. A paper coating method of extrusion-coating the resin composition for paper-coating of claim 3 on paper at 130 to 250 C. to manufacture a coated paper.

9. A paper coating method of extrusion-coating the resin composition for paper-coating of claim 4 on paper at 130 to 250 C. to manufacture a coated paper.

10. A paper coating method of extrusion-coating the resin composition for paper-coating of claims 5 on paper at 130 to 250 C. to manufacture a coated paper.

11. The paper coating method of claim 6, wherein at the time of coating, a coating thickness is 1 to 50 m.

12. The paper coating method of claim 7, wherein at the time of coating, a coating thickness is 1 to 50 m.

13. The paper coating method of claim 8, wherein at the time of coating, a coating thickness is 1 to 50 m.

14. The paper coating method of claim 9, wherein at the time of coating, a coating thickness is 1 to 50 m.

15. The paper coating method of claim 10, wherein at the time of coating, a coating thickness is 1 to 50 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a coated paper according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(2) Hereinafter, the present invention will be understood and appreciated more fully from the following examples, and the examples are for illustrating the present invention and not for limiting the present invention. FIG. 1 shows a coated paper according to the present invention, and a polymer means aliphatic polycarbonate according to the present invention.

PREPARING EXAMPLE 1

Synthesis of Complex Compound 1

(3) A complex compound 1 was synthesized according to the following Chemical Formula 3. A compound A was synthesized by the known method (Bull. Korean Chem. Soc. 2009, 30, 745-748).

(4) ##STR00002##

(5) The compound A (0.376 g, 0.230 mmol) and Co(OAc).sub.2 (0.041 g, 0.230 mmol) were quantified and put into a 50 mL of a round flask within a glove box, and ethanol (17 mL) was added thereto, followed by stirring for 3 hours. 20 mL of diethylether was added thereto, thereby generating precipitation. The resulting material was filtered by using a glass filter and then washed with 10 mL of diethylether three times. The solvent was completely removed from the obtained orange solid under reduced pressure. The Co (II) compound (0.200 g, 0.117 mmol) obtained as described above was dissolved by inputting 2,4-Dinitrophenol (0.022 g, 0.117 mmol) thereinto and adding methylene chloride (5 mL) thereto. Then, the resultant was stirred for 3 hours under oxygen atmosphere to thereby be oxidized, and 60 mol % of sodium dinitrophenolate (0.121 g, 0.585 mmol) was added thereto, followed by stirring for 12 hours. The resultant was filtered by using a glass filter to remove a solid therefrom. The solvent was removed from the obtained methylene chloride solution under reduced pressure, thereby obtaining a reddish-brown solid (0.284 g, 0.111 mmol). Yield 95%, .sup.1HNMR(dmso-d.sub.6,40 C.): 8.62(br, 3H,(NO.sub.2).sub.2C.sub.6H.sub.3O),8.03(br,3H,(NO.sub.2).sub.2C.sub.6H.sub.3O),7.87(br,1H,CHN),7.41-7.22(br,2H, m-H), 6.71(br,3H,(NO.sub.2).sub.2C.sub.6H.sub.3O),3.62(br,1H, cyclohexyl-CH), 3.08(br,16H,NCH.sub.2),2.62(s,3H,CH.sub.3),2.09 (1H,cyclohexyl-CH), 1.89(1H,cyclohexyl-CH),1.72-1.09(br,37H),0.87(br,18H,CH.sub.3)ppm.

PREPARING EXAMPLE 2

Synthesis of Complex Compound 2

(6) A complex compound 2 was synthesized according to the following Chemical Formula 4. A compound B was synthesized by the known method (Bull. Korean Chem. Soc. 2009, 30, 745-748).

(7) ##STR00003##

Synthesis of Compound C

(8) The compound B (100 mg, 0.054 mmol) and AgNO.sub.3 (37.3 mg, 0.219 mmol) were dissolved in ethanol (3 mL), followed by stirring overnight. The mixture was filtered by using celite, thereby removing generated AgI. The solvent was removed by vacuum suction, thereby obtaining yellow solid powder type compound C (0.80 g, 94%).

(9) .sup.1H NMR (CDCl.sub.3): 13.51(s,2H,OH), 8.48(s,2H,CHN), 7.15(s,4H,m-H),3.44(br,2H,cyclohexyl-CH), 3.19(br,32H,NCH.sub.2),2.24(s,6H,CH.sub.3),1.57-1.52(br,4H,cyclohexyl-CH.sub.2),1.43-1.26(br,74H),0.90-0.70(br,36H,CH.sub.3)ppm.

Synthesis of Complex Compound 2

(10) The compound C (95 mg, 0.061 mmol) and Co(OAc)2 (10.7 mg, 0.061 mmol) were put into a flask, and dissolved by adding 3 mL of methylene chloride thereto. The resultant material was stirred at room temperature for 3 hours under oxygen gas, and the solvent was removed under reduced pressure, thereby obtaining a brown solid powder type complex compound 2 (85 mg, 83%).

(11) .sup.1H NMR (DMSO-d.sub.6,38 C.): major signal set, 7.83(s,2H,CHN),7.27(br s,2H,m-H), 7.22, 7.19 (br s,2H, m-H), 3.88(br,1H,cyclohexyl-CH),3.55(br,1H,cyclohexyl-CH), 3.30-2.90(br,32H,NCH.sub.2),2.58(s,3H,CH.sub.3),2.55(s,3H,CH.sub.3),2.10-1.80(br,4H,cyclohexyl-CH.sub.2),1.70-1.15(br m,74H),1.0-0.80(br,36H,CH.sub.3)ppm; miner signal set, 7.65(s,2H,CHN),7.45(s,2H,m-H),7.35(s,2H, m-H), 3.60(br,2H,cyclohexyl-CH),3.30-2.90(br,32H,NCH.sub.2),2.66(s,6H,CH.sub.3),2.10-1.80(br,4H,cyclohexyl-CH.sub.2),1.70-1.15(br m,74H),1.0-0.80(br,36H,CH.sub.3)ppm.

(12) .sup.1H NMR (CD.sub.2Cl.sub.2): 7.65(br,2H,CHN),7.34(br,2H,m-H), 7.16(br,2H,m-H),3.40-2.00(br,32H,NCH.sub.2),2.93(br s,6H,CH.sub.3),2.10-1.80(br m,4H,cyclohexyl-CH.sub.2),1.70-1.15(br m,74H),1.1-0.80(br,36H,CH.sub.3)ppm.

PREPARING EXAMPLE 3

Synthesis of Copolymer (PPC) using carbon dioxide/propyleneoxide

(13) Propylene oxide (1162 g, 20.0 mol) in which the complex compound 1 (0.454 g, which is an amount calculated according to a monomer/catalyst ratio) was dissolved and injected to 3 L of an autoclave reactor through a cannula. The complex compound 1 prepared according to the Preparing Example 1 was used as the complex compound. Carbon dioxide was injected to the reactor at a pressure of 17 bars, and the mixture was stirred while increasing a temperature of the reactor in a circulation water bath of which a temperature is previously set to 70 C. After 30 minutes, the time point when a pressure of the carbon dioxide starts to fall was recorded, and reaction is performed for 2 hours from the time point, then the reaction was terminated by degassing of carbon dioxide. 830 g of propylene oxide was further added into the obtained viscous solution to lower viscosity of the solution, and then was passed through silica gel (50 g, Merck Company, 0.040 to 0.063 mm particle size (230 to 400 mesh)) pads, thereby obtaining a colorless solution. A monomer was removed by vacuum to obtain 283 g of white solid. The obtained polymer had a weight average molecular weight (Mw) of 290,000 and a polydispersity index (PDI) of 1.30. The weight average molecular weight and polydispersity index of the obtained polymer were measured by using GPC.

PREPARING EXAMPLE 4

Synthesis of Copolymer (PPC) using carbon dioxide/propyleneoxide

(14) Propylene oxide (1162 g, 20.0 mol) in which the complex compound 2 (0.224 g, which is an amount calculated according to a monomer/catalyst ratio) was dissolved and injected to 3 L of an autoclave reactor through a cannula. The complex compound 2 prepared according to the Preparing Example 2 was used as the complex compound. Carbon dioxide was input to the reactor at a pressure of 17 bars, and the mixture was stirred while increasing a temperature of the reactor in a circulation water bath of which a temperature is previously set to 70 C. After 30 minutes, the time point when a pressure of the carbon dioxide starts to fall was recorded, and reaction is performed for 2 hours from the time point, then the reaction was terminated by degassing of carbon dioxide. 830 g of propylene oxide was further added into the obtained viscous solution to lower viscosity of the solution, and then was passed through silica gel (50 g, Merck Company, 0.040 to 0.063 mm particle size (230 to 400 mesh)) pads, thereby obtaining a colorless solution. A monomer was removed by vacuum to obtain 348 g of white solid. The obtained polymer had a weight average molecular weight (Mw) of 316,000 and a polydispersity index (PDI) of 1.78. The weight average molecular weight and polydispersity index of the obtained polymer were measured by using GPC.

PREPARING EXAMPLE 5

Synthesis of Terpolymer using carbon dioxide/propylene oxide/cyclohexene oxide (CO2/PO/CHO Ter Polymer)

(15) Propylene oxide (622.5 g, 10.72 mol) in which the complex compound 1 (0.406 g, which is an amount calculated according to a monomer/catalyst ratio) was dissolved, cyclohexene oxide (701.2 g, 7.14 mol) were injected to 3 L of an autoclave reactor through a cannula. The complex compound 2 prepared according to the Preparing Example 2 was used as the complex compound. Carbon dioxide was input to the reactor at a pressure of 17 bars, and the mixture was stirred while increasing a temperature of the reactor in a circulation water bath of which a temperature is previously set to 70 C. After 30 minutes, the time point when a pressure of the carbon dioxide starts to fall was recorded, and reaction is performed for 2 hours from the time point, then the reaction was terminated by degassing of carbon dioxide. 830 g of propylene oxide was further added into the obtained viscous solution to lower viscosity of the solution, and then was passed through silica gel (50 g, Merck Company, 0.040 to 0.063 mm particle size (230 to 400 mesh)) pads, thereby obtaining a colorless solution. A monomer was removed by vacuum to obtain 283 g of white solid.

(16) The obtained polymer had a weight average molecular weight (Mw) of 210,000 and a polydispersity index (PDI) of 1.26, and a ratio of cyclohexene carbonate in the polymer was 25 mol %. The weight average molecular weight and polydispersity index of the obtained polymer were measured by using GPC, and the ratio of the cyclohexene carbonate in the polymer was calculated by analyzing .sup.1H NMR spectrum.

EXAMPLE 1

(17) The polypropylene carbonate (PPC) having an average molecular weight of 150,000, which was prepared in the Preparing Example 3, was extruded through a T-die single screw extruder (Brabender Company) and continuously coated on a paper.

(18) An extruding barrel of the extruder was consisted of 4 parts, and temperatures thereof were 150 C., 170 C., 200 C., and 200 C., respectively. A temperature of T-die was 200 C. In this case, the manufactured coated paper had a total thickness of 200 m and a coating thickness of 15 m.

EXAMPLE 2

(19) The coated paper was manufactured by the same method as in Example 1 except that temperatures of the 4 parts of the extruding barrel in the extruder were 180 C., 210 C., 220 C., and 230 C., respectively, and a temperature of T-die was 230 C. In this case, the manufactured coated paper had a total thickness of 200 m and a coating thickness of 11 m.

EXAMPLE 3

(20) The coated paper was manufactured by the same method as in Example 1 except that PPC, polypropylene, and polyethylene mixed at a weight ratio of 7:2:1 were used instead of PPC, temperatures of the 4 parts of the extruding barrel in the extruder were 150 C., 200 C., 210 C., and 210 C., respectively, and a temperature of T-die was 210 C.

(21) Homo polypropylene (H893S, SK Global Chemical Co.) having a melt index (MI: a flow amount of a melted resin under a load of 2.16 kg and at 230 C. for 10 minutes) of 33 was used as the polypropylene, and low density polyethylene (LDPE: XL700, Honam Petrochemical Co.) having a MI of 12 was used as the polyethylene.

(22) The manufactured coated paper had a total thickness of 200 m and a coating thickness of 15 m.

EXAMPLE 4

(23) The coated paper was manufactured by the same method as in Example 13 except that PPC, polypropylene, and polyethylene mixed at a weight ratio of 6:2:1 were used instead of PPC.

(24) Homo polypropylene (H893S, SK Global Chemical Co.) having a melt index (MI: a flow amount of a melted resin under a load of 2.16 kg and at 230 C. for 10 minutes) of 33 was used as the polypropylene, and low density polyethylene (LDPE: XL700, Honam Petrochemical Co.) having a MI of 12 was used as the polyethylene.

(25) The manufactured coated paper had a total thickness of 200 m and a coating thickness of 16 m.

COMPARATIVE EXAMPLE 1

(26) The coated paper was manufactured by the same method as in Example 1 except that polyethylene was used instead of PPC, An extruding barrel of the extruder is consisted of 4 parts, and temperatures of the 4 parts were 270 C., 300 C., 320 C., and 320 C., respectively, and a temperature of T-die was 320 C.

(27) The manufactured coated paper had a total thickness of 200 m and a coating thickness of 15 m

EXPERIMENTAL EXAMPLE 1

(28) Physical properties of the manufactured Examples 1 to 4 were measured and shown in Table 1.

(29) In Table 1, coating characteristics were evaluated as follows.

(30) <Evaluation on Coating Properties>

(31) O: The coated surface had a good appearance and a uniform coating thickness.

(32) : The coated surface had a good appearance but a variation in coating thickness.

(33) X: The coated surface had a bad appearance and bubbles, and the like.

(34) In Table 1, heat-resistant temperatures were evaluated as follows.

(35) <Evaluation on Heat-Resistant Temperatures>

(36) The upper limit temperature at which delamination or deformation of a coated surface does not occur for 30 minutes in a state in which the manufactured coated paper is put into a water bath and a constant temperature was maintained.

(37) TABLE-US-00001 TABLE 1 Comparative Unit Example 1 Example 2 Example 3 Example 4 Example 1 Coating m 15 11 15 16 15 Thickness Oxygen cc/m.sup.2day 121 182 340 510 >5,000 Permeability (23, RH 0%) Water g/m.sup.2day 143 201 90 85 48 Permeability (38, RH 100%) Coating x Properties Heat-resistant 85 85 100 100 100 Temperature Heat Seal 90 90 150 140 130

(38) As set forth above, the coated paper manufactured according to the present invention may prevent food from being easily rotted when it is used for a food container due to excellent oxygen barrier property thereof. In addition, the resin composition for paper coating according to the present invention may facilitate coating due to excellent printability and adhesion thereof. In addition, the coated paper has heat resistance higher than the existing polyethylene coated paper, such that the coated paper may be used in a microwave oven having high power.