Composition for forming polyvinylidene fluoride film
The present invention provides a composition for forming a polyvinylidene fluoride film, which contains: a polyvinylidene fluoride; at least one surfactant that is selected from among sulfuric acid-based surfactants, sulfonic acid-based surfactants and quaternary ammonium salt type surfactants; and a solvent.
1. A polyvinylidene fluoride film obtained from a composition, comprising:
polyvinylidene fluoride (PVDF);
at least one surfactant selected from the group consisting of sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, lithium dodecyl sulfate, sodium 1-decanesulfonate, sodium dodecylbenzenesulfonate, and hexadecyltrimethylammonium bromide; and
a solvent,
wherein the degree of crystallinity of the PVDF film is 30 wt % or more in the whole PVDF,
wherein the β-crystallization rate of PVDF in the PVDF film is 50 wt % or more in the crystallized PVDF, and
wherein the film has a thickness of 1 to 10 μm.
2. The polyvinylidene fluoride film according to claim 1 , wherein β-type crystallization rate of the polyvinylidene fluoride is 70 wt % or more.
3. The polyvinylidene fluoride film according to claim 1 , wherein the solvent is at least one selected from the group consisting of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2 pyrrolidone, triethyl phosphate, tetrahydrofuran, cyclopentyl methyl ether, γ-butyrolactone, cyclopentanone, cyclohexanone, 3-methylcyclohexanone, isophorone, menthone, propylene carbonate, ethylene carbonate, trichloroethane, chlorodifluoromethane, acetone, methyl ethyl ketone, methyl amyl ketone, acetonitrile, N,N-dimethylacetamide, hexamethylphosphoramide, tetramethyl urea, ethyl acetate, acetic acid, pyridine, butyl acetate, polyethylene glycol methyl ether acrylate, sulfolane and 1,4-dioxane.
4. The polyvinylidene fluoride film according to claim 1 , wherein use amount of the solvent is 400 to 99,900 parts by weight per 100 parts by weight of PVDF.
5. The polyvinylidene fluoride film according to claim 1 , wherein compounding amount of the surfactant is 0.001 to 20 parts by weight per 100 parts by weight of polyvinylidene fluoride.
6. The polyvinylidene fluoride film according to claim 1 , wherein the degree of crystallinity of PVDF film is about 60 wt % in the whole PVDF.
7. The polyvinylidene fluoride film according to claim 1 , wherein the β-crystallization rate of PVDF in the PVDF film is 65 wt % or more in the crystallized PVDF.
8. The polyvinylidene fluoride film according to claim 1 , wherein the β-crystallization rate of PVDF in the PVDF film 75 wt % or more in the crystallized PVDF.
9. The polyvinylidene fluoride film according to claim 1 , wherein the β-crystallization rate of PVDF in the PVDF film is about 90 wt %.
10. The polyvinylidene fluoride film according to claim 1 , wherein the PVDF film is prepared by heating at 55 to 105° C., for 1 to 240 minutes.
11. The polyvinylidene fluoride film according to claim 1 , wherein the PVDF film is prepared by heating at 60 to 100° C. for 5 to 30 minutes.
12. A method for producing said polyvinylidene fluoride film according to claim 1 , comprising:
forming a film from said composition and performing heat treatment on said film at 55 to 105° C. to produce said polyvinylidene fluoride film.