In-press transfer painting of hardboard

Claim 3

The method according to claim 1 in which the carrier sheet and the paint layer are flexible and have a degree of elongation.

Claim 4

The method according to claim 1 in which the paint coat is sufficiently heat-resistant to remain hardened at a temperature in excess of 450° F., and simultaneously applying pressure and heat in excess of 450° F. to the fibrous layer and the painted carrier sheet.

Claim 5

The method according to claim 1 in which the paint coat consists essentially of a thermosetting resinous material applied to the carrier and crosslinked on the carrier prior to being placed over the fibrous layer.

Claim 6

The method according to claim 4 in which the paint layer includes an adherence coat adjacent the paint coat, the adherence coat being thermally-activated to bond the paint coat to the board from the heat applied during formation of the board.

Claim 7

The method according to claim 5 in which the adherence coat is coated onto the carrier in a thermoplastic state and is crosslinked from the heat applied during formation of the board to bond the paint coat to the board.

Claim 8

The method according to claim 1 in which the paint layer includes an adherence coat adjacent the paint coat; and including placing the carrier sheet over the fibrous layer so the adherence coat is adjacent the fibrous layer, the adherence coat being thermally-activated to bond the paint coat to the hardboard from the heat applied during formation of the board.

Claim 9

The method according to claim 7 in which the adherence coat comprises a thermosetting resinous material which is crosslinked from the heat applied during formation of the board.

Claim 10

The method according to claim 1 including applying pressure in excess of about 400 psi to compress the fibrous layer.

Claim 11

The method according to claim 1 in which the fibrous layer is compressed between about 8 to about 16 times its original thickness for forming the hardboard.

Claim 12

The method according to claim 10 in which the paint layer has a thickness of at least about 0.5 mil.

Claim 13

The method according to claim 1 including forming the hardboard in a press having platens heated to a temperature in excess of 400° F., and including applying pressure in excess of about 400 psi to compress the fibrous layer.

Claim 14

The method according to claim 12 in which the dwell time during the pressing and heating step is from about 11/2 to 5 minutes.

Claim 15

The method according to claim 1 in which the fibrous layer consists essentially of exploded and pulverulent cellulosic material.

Claim 18

The method according to claim 15 including applying pressure above about 400 psi to the painted carrier and the loose fibrous layer.

Claim 19

The method according to claim 15 in which the paint coat is formed by coating an abrasion-resistant coat adjacent the carrier, and coating one or more color coats adjacent the abrasion coat.

Claim 20

The method according to claim 17 including coating a release coat between the carrier and the abrasion coat.

Claim 21

The method according to claim 18 in which the paint coat includes an adherence layer coated adjacent the color coat, the adherence coat being heat-activated from the heat applied during formation of the board to bond the paint coat to the board.

Claim 22

The method according to claim 19 in which the adherence coat comprises a thermosetting synthetic resinous material which is coated onto the carrier in a thermoplastic state but crosslinks in the press from the heat applied during formation of the board.

Claim 23

The method according to claim 20 in which the paint coat remains hardened at temperatures above about 450° F.

Claim 24

The method according to claim 20 in which heat is applied to dry the adherence coat on the carrier, and in which the heat for drying the adherence coat is below 400° F.

Claim 25

The method according to claim 15 in which the fibrous layer consists essentially of exploded and pulverulent cellulosic material.

Claim 26

The method according to claim 15 in which the carrier sheet and the paint layer are flexible and have a degree of elongation.

Claim 27

The method according to claim 24 in which the paint coat contains a urethane resin.

Claim 28

The method according to claim 15 in which the paint coat contains an acrylicurethane crosslinking resin.

Claim 29

In a method for manufacturing hardboard comprising the steps of placing in a heated press a substantially uncompressed layer consisting essentially of exploded and pulverulent cellulosic material and applying pressure in excess of 400 p.s.i. and heat in excess of 400° F. to the layer of cellulosic material to form an integral hardboard piece, the improvement comprising the steps of: coating a paint layer onto a temporary carrier sheet, the paint layer including a continuous paint coat consisting essentially of a pigmented thermosetting resinous material cross-linked to a hardened condition on the carrier and having a heat resistance above 400° F.; placing the painted carrier over an exposed surface of the uncompressed layer of cellulosic material so that the paint layer is adjacent the cellulosic layer; and applying pressure in excess of 400 p.s.i. and heat in excess of 400° F. to compress the layer of cellulosic material and simultaneously transfer the paint coat from the carrier to a surface of the formed hardboard, the paint coat being sufficiently heat-resistant to remain in said hardened condition throughout formation of the board and transfer to the surface of the board for providing a separate and continuous paint coat on the surface of the hardboard.

Claim 30

In a method for manufacturing hardboard comprising the steps of placing in a heated press a substantially uncompressed layer consisting essentially of exploded and pulverulent cellulosic material and applying pressure in excess of 400 p.s.i. and heat in excess of 400° F. to the layer of cellulosic material to form an integral hardboard piece, the improvement comprising the steps of: coating a paint layer onto a temporary carrier sheet, the paint layer including a continuous paint coat consisting essentially of a pigmented thermosetting resinous material cross-linked to a hardened condition on the carrier and having a heat resistance above 400° F.; placing the painted carrier over an exposed surface of the uncompressed layer of cellulosic material so that the paint layer is adjacent the cellulosic layer; and applying pressure in excess of 400 p.s.i. and heat in excess of 400° F. to compress the layer of cellulosic material and simultaneously transfer the paint coat from the carrier to a surface of the formed hardboard, the paint coat being sufficiently heat-resistant to remain in said hardened condition throughout formation of the board and transfer to the surface of the board for providing a separate and continuous paint coat on the surface of the hardboard.

Claim 31

The improvement according to claim 27 in which the paint layer includes a color coat and an adherence coat coated adjacent the color coat, the adherence coat being heat-activated from the heat applied during formation of the board to bond the color coat to the board, the adherence coat comprising a thermosetting, synthetic resinous material which is coated onto the carrier in a thermoplastic state but which crosslinks in the press from the heat applied during formation of the board.

Claim 32

The improvement according to claim 27 in which the layer of cellulosic material is compressed between about 8 to about 16 times its original thickness for forming the hardboard.

Claim 33

The improvement according to claim 27 in which the paint coat is sufficiently heat-resistant to remain hardened at a temperature in excess of 450° F., and including the step of simultaneously applying pressure and heat in excess of 450° F. to the layer of cellulosic material and the painted carrier sheet.