Claims
- 1. A method of using a printing assistant for a lithographic printing plate, which comprises using 0.1 to 35% by weight water-soluble hemicellulose derived from soybean as a water-soluble polymer, the water-soluble hemicellulose not later insolubilized, and applying the printing assistant to the lithographic printing plate to protect nonimage areas of the lithographic printing plate.
- 2. The method of using a printing assistant for a lithographic printing plate according to claim 1 as a plate protective agent, which comprises combining the water-soluble hemicellulose, a surfactant from 0.01 to 10% by weight, and a wetting agent from 0.1 to 5% by weight in an acidic region, thereby forming an agent having a pH of 3 to 6.
- 3. The method of using a printing assistant for a lithographic printing plate according to claim 2 as a plate protective agent, which comprises applying the plate protective agent to the plate using an applicator, removing the plate protective agent by washing the plate with water, and contacting the plate with a dampening roller.
- 4. The method of using a printing assistant for a lithographic printing plate according to claim 2 as a plate protective agent, which comprises using a pH adjuster selected from the group consisting of a mineral acid, an organic acid, an inorganic acid, and an inorganic salt, thereby forming an agent having a pH of 3 to 6.
- 5. A method of using a printing assistant for a lithographic printing plate, which comprises using 0.1 to 5% by weight water-soluble hemicellulose derived from soybean as water-soluble polymer in an image eraser, the water-soluble hemicellulose not later insolubilized, and applying the printing assistant to the lithographic printing plate as the image eraser.
- 6. The method of using a printing assistant for a lithographic printing plate according to claim 5 in an image eraser, which comprises combining the water-soluble hemicellulose, an organic solvent in the range of 50 to 90% by weight, and a surfactant from 3 to 20% by weight in an acidic region, thereby forming an image eraser having a pH of 3 to 6.
- 7. The method of using a printing assistant for a lithographic printing plate according to claim 6 in an image eraser, which comprises using a pH adjuster selected from the group consisting of a mineral acid, an organic acid, an inorganic acid, and an inorganic salt.
- 8. The method of using a printing assistant for a lithographic printing plate according to claim 6 in an image eraser, which comprises coating the eraser on an image portion of the lithographic printing plate, washing the image portion, removing residue from the plate, and erasing the image portion.
- 9. A method of using a printing assistant for a lithographic printing plate, which comprises using 0.001 to 10% by weight water-soluble hemicellulose derived from soybean as water-soluble polymer in a dampening water composition, the water-soluble hemicellulose not later insolubilized, and applying the printing assistant to the lithographic printing plate as the dampening water composition.
- 10. The method of using a printing assistant for a lithographic printing plate according to claim 9 in a dampening water composition, which comprises combining the water-soluble hemicellulose, a pH buffering substance in the range from 0.001 to 1% by weight, an organic solvent in the range of 50 to 90% by weight, a surfactant from 3 to 20% by weight, and a wetting agent in the range of 0.03 to 5% by weight.
- 11. The method of using a printing assistant for a lithographic printing plate according to claim 10 in a dampening water composition, which comprises further adding a preservative in the range of 0.001 to 1% and an anti-foaming agent in the range of 0.001 to 3% by weight, thereby protecting against microorganisms and preventing foaming.
Priority Claims (4)
Number |
Date |
Country |
Kind |
4-317828 |
Nov 1992 |
JPX |
|
4-317829 |
Nov 1992 |
JPX |
|
5-114318 |
May 1993 |
JPX |
|
PCT/JP93/01535 |
Oct 1993 |
WOX |
|
Parent Case Info
This application is a divisional of application Ser. No. 08/256,311, filed as PCT/JP93/01535, Oct. 22, 1993, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3559579 |
Perkins |
Feb 1971 |
|
4874423 |
Colegrove et al. |
Oct 1989 |
|
4874854 |
Colegrove et al. |
Oct 1989 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
256311 |
Jun 1994 |
|