Aqueous dispersion

Abstract

To provide an aqueous dispersion that enables the creation of a molded product having enhanced physical attributes, including heat resistance and electrical properties (low linear expansion coefficient, low dielectric constant, and low dielectric loss tangent), as well as an exceptional surface appearance, wherein this aqueous dispersion maintains stable dispersion stability and ease of handling, containing a tetrafluoroethylene polymer.SOLUTION: An aqueous dispersion includes: tetrafluoroethylene polymer particles with a melting point of 260°C or more; an organopolysiloxane featuring either a hydroxy group or a polyoxyalkylene group, characterized by a mass loss rate equal to or more than 20 mass% / °C between 200-300°C; and a water-soluble polymer, which is at least one selected from the group consisting of vinyl alcohol polymers, acrylic polymers, polyvinyl pyrrolidone, polypyrrole, polythiophene, polyethyleneimine, and cellulose ethers, each incorporating a polar functional group and demonstrating a mass loss rate less than 40 mass% / °C between 200-300°C; and water. The proportion of the water-soluble polymer to the organopolysiloxane ranges from 0.01 to 0.1.SELECTED DRAWING: None

Claims

1. An aqueous dispersion comprising: particles of a tetrafluoroethylene polymer having a melting point of 260°C or higher; an organopolysiloxane having a hydroxyl group or a polyoxyalkylene group and a mass loss rate of 20% by mass / °C or higher at 200-300°C; at least one water-soluble polymer having a polar functional group selected from the group consisting of vinyl alcohol polymers, acrylic polymers, polyvinylpyrrolidone, polypyrrole, polythiophene, polyethyleneimine, and cellulose ether, and having a mass loss rate of less than 40% by mass / °C at 200-300°C; and water, wherein the ratio of the content of the water-soluble polymer to the content of the organopolysiloxane is 0.01 to 0.

10.

2. The aqueous dispersion according to claim 1, wherein the tetrafluoroethylene polymer contains an oxygen-containing polar group.

3. The aqueous dispersion according to claim 1, wherein the average particle size of the tetrafluoroethylene polymer particles is 1 μm or more and less than 10 μm.

4. The aqueous dispersion according to claim 1, wherein the content of the tetrafluoroethylene polymer particles is 25% by mass or more.

5. The aqueous dispersion according to claim 1, wherein the content of the organopolysiloxane is 1 to 15% by mass relative to the particles of the tetrafluoroethylene polymer.

6. The aqueous dispersion according to claim 1, wherein the content of the water-soluble polymer is 5% by mass or less relative to the particles of the tetrafluoroethylene polymer.

7. The aqueous dispersion according to claim 1, wherein the total content of the organopolysiloxane and the water-soluble polymer is 5% by mass or less relative to the entire aqueous dispersion.

8. The aqueous dispersion according to claim 1, wherein the water-soluble polymer is a vinyl alcohol-based polymer.

9. The aqueous dispersion according to claim 1, wherein the water-soluble polymer is cellulose ether.

10. The aqueous dispersion according to claim 9, wherein the cellulose ether is carboxyalkylcellulose, hydroxyalkylcellulose, or hydroxyalkylalkylcellulose.

11. Furthermore, the aqueous dispersion according to claim 1, further containing an alcohol having 1 to 6 carbon atoms.

12. The aqueous dispersion according to claim 1, wherein the viscosity is 500 to 10,000 mPa·s.

13. The aqueous dispersion according to claim 1, wherein the thixotropy ratio is 1.0 to 2.

5.

14. A method for producing a laminate, comprising placing an aqueous dispersion according to any one of claims 1 to 13 on the surface of a substrate and heating it to form a polymer layer containing the tetrafluoroethylene polymer, thereby obtaining a laminate having a substrate layer composed of the substrate and the polymer layer in this order.