Coating layer and method for forming coating layer
The coating layer has excellent water repellency and satisfactory gloss to a base material and provides a method for forming a coating layer in which the agents used have, for example, excellent storage stability and dispersibility. The coating layer has a layer (I) formed by curing a film-forming agent containing predetermined amounts of a polyorganosiloxane having at least one hydrolyzable functional group in its molecule, a curing catalyst, and an organic solvent including a saturated hydrocarbon solvent and an aromatic hydrocarbon solvent each having 8 to 15 carbon atoms at a predetermined ratio and a layer (II) formed by solidifying a finish treatment agent containing predetermined amounts of a polyorganosiloxane having at least one pendant amino group, a polyorganosiloxane having two or more terminal amino groups, a silicone resin emulsion emulsified with a nonionic or anionic surfactant, a hydrophilic group-containing organic solvent, and water.
1. A coating layer comprising:
a layer (I) prepared by curing 100 parts by mass in total of a film-forming agent (A) containing:
3 to 45 parts by mass of a polyorganosiloxane (a-1) having at least one hydrolyzable functional group in its molecule;
0.05 to 5 parts by mass of a curing catalyst (a-2); and
50 to 96.95 parts by mass of an organic solvent (a-3) comprising a saturated hydrocarbon solvent having 8 to 15 carbon atoms and an aromatic hydrocarbon solvent having 8 to 15 carbon atoms at a mass ratio of the saturated hydrocarbon solvent to the aromatic hydrocarbon solvent of 100/0 to 50/50, and
a layer (II) prepared by solidifying 100 parts by mass in total of a finish treatment agent (B) containing:
0.05 to 15 parts by mass of a polyorganosiloxane (b-1) having at least one pendant amino group;
0.01 to 10 parts by mass of a polyorganosiloxane (b-2) having two or more terminal amino groups;
1 to 20 parts by mass, in terms of the solid content, of a silicone resin emulsion (b-3) emulsified with a nonionic or anionic surfactant;
0.1 to 25 parts by mass of a hydrophilic group-containing organic solvent (b-4); and
30 to 98.84 parts by mass of water (b-5), wherein the layer (I) is disposed on a base material side, and the layer (II) is disposed on a surface side.
2. The coating layer according to claim 1 , wherein the layer (I) is disposed on the base material, and the layer (II) is disposed on the layer (I).
3. The coating layer according to claim 1 , wherein the layer (I) has a thickness of 0.1 to 0.5 μm, and the layer (II) has a thickness of 0.1 to 0.5 μm.
4. The coating layer according to claim 1 , wherein the saturated hydrocarbon solvent having 8 to 15 carbon atoms in the component (a-3) is an isoparaffin solvent.
5. The coating layer according to claim 1 , wherein the component (b-4) is an alcohol.
6. The coating layer according to claim 1 , wherein the component (a-1) is a polydimethylsiloxane having hydrolyzable functional groups at both ends of the molecular chain.
7. The coating layer according to claim 1 , wherein the base material is the exterior of a vehicle.
8. A method for forming a coating layer, the method comprising:
(a) forming a layer (I) by applying 100 parts by mass in total of a film-forming agent (A) containing:
3 to 45 parts by mass of a polyorganosiloxane (a-1) having at least one hydrolyzable functional group in its molecule;
0.05 to 5 parts by mass of a curing catalyst (a-2); and
50 to 96.95 parts by mass of an organic solvent (a-3) comprising a saturated hydrocarbon solvent having 8 to 15 carbon atoms and an aromatic hydrocarbon solvent having 8 to 15 carbon atoms at a mass ratio of the saturated hydrocarbon solvent to the aromatic hydrocarbon solvent of 100/0 to 50/50,
onto a base material and drying the film-forming agent (A) at environmental temperature for 5 to 90 minutes; and
(b) forming a layer (II) by applying 100 parts by mass in total of a finish treatment agent (B) containing:
0.05 to 15 parts by mass of a polyorganosiloxane (b-1) having at least one pendant amino group;
0.01 to 10 parts by mass of a polyorganosiloxane (b-2) having two or more terminal amino groups;
1 to 20 parts by mass, in terms of the solid content, of a silicone resin emulsion (b-3) emulsified with a nonionic or anionic surfactant;
0.1 to 25 parts by mass of a hydrophilic group-containing organic solvent (b-4); and
30 to 98.84 parts by mass of water (b-5),
onto the layer (I) and drying the finish treatment agent (B) at environmental temperature for 10 minutes or more.
9. The method for forming a coating layer according to claim 8 , wherein the film-forming agent (A) in step (a) is applied with a dry cloth, and the finish treatment agent (B) in step (b) is applied with a wet cloth.
10. The method for forming a coating layer according to claim 8 , wherein the amount of the film-forming agent (A) in step (a) is 0.1 to 10 mL/m 2 of the base material, and the amount of the finish treatment agent (B) in step (b) is 0.1 to 10 mL/m 2 of the base material.
11. The method for forming a coating layer according to claim 8 , wherein the saturated hydrocarbon solvent having 8 to 15 carbon atoms in the component (a-3) is an isoparaffin solvent.
12. The method for forming a coating layer according to claim 8 , wherein the component (b-4) is an alcohol.
13. The method for forming a coating layer according to claim 8 , wherein the component (a-1) is a polydimethylsiloxane having hydrolyzable functional groups at both ends of the molecular chain.
14. The method for forming a coating layer according to claim 8 , wherein the base material is the exterior of a vehicle.