Polymer particle, manufacturing method thereof, and separator for battery comprising the same

Abstract

The present application relates to a polymer particle manufacturing method, and according to an example of the manufacturing method and a manufacturing apparatus therefor, a reduction in energy can be achieved by simplifying a manufacturing process thereof.

Claims

1. A polymer particle manufacturing method, comprising: manufacturing a first polymer solution including a polymer dissolved in a first solvent; heating a manufactured first polymer solution to (T.sub.m+5) C. or above, wherein T.sub.m is a melting point ( C.) of the polymer; and mixing a second solvent with a heated first polymer solution, wherein the temperature of the second solvent to be mixed with the first polymer solution is adjusted to at or below a crystallization temperature of the polymer, and wherein the crystallization temperature of the polymer is lower than the T.sub.m, and wherein a mixture solution of the first polymer solution and the second solvent is a non-emulsion.

2. The polymer particle manufacturing method of claim 1, wherein the first solvent is a good solvent with respect to the polymer.

3. The polymer particle manufacturing method of claim 1, wherein the first solvent has a Hansen relative energy difference of 0.6 or more and less than 2, with respect to the polymer at room temperature.

4. The polymer particle manufacturing method of claim 1, wherein the first solvent is a monovalent alcohol having 6 or more carbons.

5. The polymer particle manufacturing method of claim 1, wherein the second solvent has a Hansen relative energy difference of more than 2 and less than 5 with respect to the polymer at room temperature.

6. The polymer particle manufacturing method of claim 1, wherein the second solvent is a monovalent alcohol having 5 or less carbons, or ketone.

7. The polymer particle manufacturing method of claim 1, wherein the first solvent is a monovalent alcohol and the second solvent is a monovalent alcohol or ketone.

8. The polymer particle manufacturing method of claim 1, wherein the polymer is a polyolefin.

9. The polymer particle manufacturing method of claim 1, wherein the temperature of the second solvent to be mixed with the first polymer solution is adjusted to a range of (T.sub.b-70) C. to T.sub.b C., wherein T.sub.b is a boiling point ( C.) of the second solvent.

10. The polymer particle manufacturing method of claim 1, further comprising adjusting a temperature of the mixture solution of the first polymer solution and the second solvent to a range of (T.sub.b-35) C. to T.sub.b C., wherein T.sub.b is a boiling point ( C.) of the second solvent.

11. The polymer particle manufacturing method of claim 1, further comprising cooling the mixture solution of the first polymer solution and the second solvent.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a diagram showing an apparatus conventionally used for manufacturing a polymer particle.

(2) FIG. 2 is a diagram showing another apparatus conventionally used for manufacturing a polymer particle.

(3) FIG. 3 is a diagram showing an example of a polymer particle manufacturing apparatus according to an embodiment of the present application.

(4) FIG. 4 is a SEM photograph of polyethylene particles manufactured in Example 1.

(5) FIG. 5 is a SEM photograph of polyethylene particles manufactured in Example 2.

(6) FIG. 6 is a SEM photograph of polyethylene particles manufactured in Comparative Example 1.

(7) FIG. 7 is a SEM photograph of polyethylene particles manufactured in Comparative Example 2.

(8) FIG. 8 is a SEM photograph of polyethylene particles manufactured in Comparative Example 3.

(9) FIG. 9 is a SEM photograph of polyethylene particles manufactured in Comparative Example 4.

MODES OF THE INVENTION

(10) Hereinafter, the present application will be discussed in further detail with reference to examples according to the present application and comparative examples that are not in accordance with the present application, however, the scope of the present application is not to be limited by the examples set forth herein.

Experiment Example 1. Measurement of the Average Particle Diameter and Coefficient of Variation of the Manufactured Polyethylene Particle

(11) The scanning electron microscopy (SEM) photograph of polyethylene particles was analyzed using a digital image analysis program, Image Pro of Cybernetics Inc. Using this program, the diameters of polyethylene particles were individually measured, and the average diameter and the C.V. values of the polyethylene particles were obtained by calculating the average and the standard deviation from 1000 particles.

Example 1

(12) In the mixer of the polymer manufacturing apparatus as shown in FIG. 3, polyethylene manufactured via metallocene catalysis (the melting point around 115 C.) was added to the first solvent, dodecanol, such that the polyethylene content of the mixture would be 1 weight % with respect to the total weight of the mixture, was mixed to produce a first polymer solution. The Hansen relative energy difference of the dodecanol with respect to polyethylene at room temperature is 1.32.

(13) The mixture solution was prepared by continuously introducing the first polymer solution which was mixed in the mixer, into the crystallization unit in which the second solvent, ethanol (whose Hansen relative energy difference with respect to polyethylene at room temperature is 2.43) was filled while maintained at 72 C., and at the point of the introduction of the first polymer solution, the temperature was about 144 C. The mixture solution was then crystallized to produce polyethylene particles having the average diameter of 231 nm, the standard deviation therein of 90 nm, and the C.V. of about 39%. The manufactured polyethylene particles were examined using the SEM and the results are shown in FIG. 4.

Example 2

(14) The method described in Example 1 was repeated, except that temperature of the mixture solution of the first polymer solution and the second solvent was adjusted to 77 C., to manufacture polyethylene particles having the average particle diameter of 584 nm, the standard deviation therein of 278 nm, and the C.V. of about 48%. The manufactured polyethylene particles were examined using the SEM, and the results are shown in FIG. 5.

Comparative Example 1

(15) The method described in Example 1 was repeated, except that dodecanol (whose Hansen relative energy difference with respect to polyethylene at room temperature is 1.32) was used as the second solvent, to manufacture polyethylene particles having the average particle diameter of 478 nm, the standard deviation therein of 403 nm, and the C.V. of about 84%. In this case, the temperature of the mixture solution was adjusted to 72 C. by a cooling device. The manufactured polyethylene particles were examined using the SEM, and the results are shown in FIG. 6.

Comparative Example 2

(16) The method described in Example 1 was repeated, except that the temperature of the mixture solution of the first polymer solution and second solvent was adjusted to 28 C., to manufacture polyethylene particles. The manufactured polyethylene particles were examined using the SEM, and the results are shown in FIG. 7.

Comparative Example 3

(17) The method described in Comparative Example 1 was repeated, except that the temperature of the mixture solution of the first polymer solution and the second solvent was adjusted to 28 C., to manufacture polyethylene particles. The manufactured polyethylene particles were examined using the SEM, and the results are shown in FIG. 8.

Comparative Example 4

(18) The method described in Example 1 was repeated, except that water (whose Hansen relative energy difference with respect to polyethylene at room temperature is 5.5) was used as the second solvent (the temperature of water was maintained at 72 C. before the mixing, and at about 144 C. at the point of introduction of the first polymer solution, and the temperature of the mixture solution of the first polymer solution and the second solvent was 72 C.) to manufacture polyethylene particles. The manufactured polyethylene particles were examined using the SEM, and the results are shown in FIG. 9.

(19) According to an embodiment of the manufacturing method for polymer particles of the present application, as can be seen in FIG. 4 to FIG. 8, polyethylene particles can be manufactured without forming an emulsion, and especially, as shown in FIG. 4 and FIG. 5, polyethylene particles having the relatively uniform spherical form can be efficiently manufactured, such as the ones in Example 1 and 2. On the other hand, as in Comparative Example 1 where the second solvent was a monovalent alcohol with large carbon numbers, it was unable to manufacture polyethylene particles having the relatively uniform spherical form, and as in Comparative Examples 2 and 3 where the temperature of the mixture solution of the first polymer solution and the second solvent was lowered, aggregates of polyethylene particles were formed, as can be seen in FIG. 7 and FIG. 8.

(20) When water, instead of a polyalcohol, was used as the second solvent, an emulsion was formed due to the difference in polarity between water and dodecanol, and it can be seen from FIG. 9 that the generation of individual spherical particles was hindered.

Comparative Example 5

(21) In a dissolution device of the polymer particle manufacturing apparatus as shown in FIG. 1, polyethylene manufactured via metallocene catalysis was added to the first solvent dodecanol (whose Hansen relative energy difference with respect to polyethylene at room temperature is 1.32) so that the polyethylene content would be 1 weight % with respect to the total weight of the mixture, and the polyethylene was dissolved at about 144 C. until the polyethylene was completely dissolved.

(22) Diethylene glycol (whose Hansen relative energy difference with respect to polyethylene at room temperature is 2.87) which was maintained in a non-solvent heating unit at the same temperature as the above, was transported into a crystallization unit equipped with an agitator, and the dissolved polymer solution was introduced at the volume ratio of 1:4. The mixture of diethylene glycol and the polymer solution was then agitated at 400 RPM and cooled down to 72 C. During the cooling process, water and dodecanol were phase-separated, resulting in the formation of an opaque emulsion. After the cooling, polyethylene was obtained by filtering the crystal solution in a filtration device. The obtained polyethylene was then washed twice using hexane, twice using ethanol and dried. According to the examination by SEM on the polyethylene particles manufactured above, it was unable to measure the average diameter of the particles due to the formation of aggregates in the polymer particles.

DESCRIPTION OF REFERENCE NUMERALS

(23) 100: Polymer Particle Manufacturing Apparatus 10: Mixer 11: Tank 12: First Agitating Unit 20: Crystallization Unit 21: Second Agitating Unit 22: Cooling Unit 30: Pipe 31: Heating Unit 32: Pump