Method for producing building material

Patent metadata

Field	Value
Publication number	US-10953435-B2
Application number	US-201615257269-A
Country	US
Kind code	B2
Filing date	Sep 6, 2016
Priority date	Sep 30, 2015
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A method for producing a building material includes a first step of applying an undercoat paint onto a surface of an inorganic base material, curing the undercoat paint, and polishing the undercoat paint; and a second step of applying an enamel paint onto the undercoat paint and curing the enamel paint. The undercoat paint contains an undercoat-forming material and a filler. The enamel paint contains an enamel-forming material and a pigment. The enamel-forming material is a solvent-based resin. A content of the filler in the undercoat paint is 40% to 70% by mass in terms of solid content. A content of the pigment in the enamel paint is 1% to 50% by mass in terms of solid content.

First claim

What is claimed is:

1. A method for producing a building material, comprising the steps of:
polishing a flat surface of a fiber reinforced cement board by a first polisher, so that the fiber reinforced cement board has a polished flat surface;
after the step of polishing, applying an undercoat paint onto the polished flat surface of the fiber reinforced cement board, curing the undercoat paint, and polishing the undercoat paint by a second polisher to form an undercoating having a polished flat surface, the second polisher having a less roughness than the first polisher; and then
applying an enamel paint onto the polished flat surface of the undercoating and curing the enamel paint at 50° C. to 120° C. by a dryer to form an enamel coating having a flat surface and a specular gloss at 60° is 80 or greater,
wherein the undercoat paint contains an undercoat-forming material and a filler,
the enamel paint contains an enamel-forming material and a pigment,
the undercoat-forming material is a solvent-based urethane resin having a glass transition temperature which is higher than that of the enamel-forming material, and
the enamel-forming material is at least one of a solvent-based fluororesin, a solvent-based acrylic resin, and a solvent-based urethane resin,
a content of the filler in the undercoat paint is 50% to 70% by mass in terms of solid content,
a content of the pigment in the enamel paint is 40% to 50% by mass in terms of solid content, and
the filler is at least one of talc, calcium carbonate, silica, glass, quartz, aluminum, and mica.

2. The method according to claim 1 ,
the enamel-forming material is at least one of the solvent-based fluororesin and the solvent-based urethane resin.

3. The method according to claim 1 ,
wherein the pigment is at least one of titanium oxide, carbon, iron oxide, and an organic pigment.

4. The method according to claim 1 ,
wherein the first polisher is a first sandpaper; and
the second polisher is a second sandpaper having a finer grit size than the first sandpaper.

5. The method according to claim 1 ,
wherein the enamel paint is applied onto the polished flat surface of the undercoating in an amount of 80 g/m 2 to 130 g/m 2 .

6. The method according to claim 1 , further comprising a step of applying a protective paint onto the enamel coating to form a protective coating on the enamel coating,
where the protective paint comprises at least one resin selected from the group consisting of a solvent-based fluororesin, a solvent-based acrylic resin, a solvent-based urethane resin, and a solvent-based acrylic silicone resin.

7. The method according to claim 6 , further comprising a step of drying the protective paint at 50° C. to 120° C. by a dryer.

8. The method according to claim 6 ,
wherein the protective coating, as an outermost surface of the building material, is not polished.

9. The method according to claim 1 , further comprising a step of applying a sealer onto the polished flat surface of the fiber reinforced cement board before applying the undercoat paint,
where the sealer comprises at least one resin selected from the group consisting of an epoxy resin, an acrylic resin, and a urethane resin.

10. The method according to claim 1 ,
wherein the enamel coating, as an outermost surface of the building material, is not polished.

11. The method according to claim 1 ,
wherein the undercoat-forming material of the undercoat paint is the solvent-based urethane resin, and the undercoat paint is cured at 50° C. to 120° C. by a dryer.

12. The method according to claim 1 ,
wherein the enamel-forming material of the enamel paint is the solvent-based fluororesin.

13. The method according to claim 1 ,
wherein the glass transition temperature of the solvent-based urethane resin is 15° C. higher than that of the enamel-forming material.

Assignees

• Nichiha Kk

Inventors

• Taguchi Hiroyuki
• Murase Miho

Classifications

• E04F13/148

  with an outer layer of asbestos cement or the like · CPC title

• E04C2/06

  reinforced · CPC title

• C04B41/71

  at least one coating being an organic material · CPC title

• C04B41/52

  Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation} · CPC title

• B05D7/548 Primary

  No curing step for the last layer · CPC title