CA1116465A - Fiberous substrate letterpress photopolymer printing plate - Google Patents
Fiberous substrate letterpress photopolymer printing plateInfo
- Publication number
- CA1116465A CA1116465A CA000324518A CA324518A CA1116465A CA 1116465 A CA1116465 A CA 1116465A CA 000324518 A CA000324518 A CA 000324518A CA 324518 A CA324518 A CA 324518A CA 1116465 A CA1116465 A CA 1116465A
- Authority
- CA
- Canada
- Prior art keywords
- fiberous
- support
- printing plate
- letterpress printing
- sheet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
- B41N1/00—Printing plates or foils; Materials therefor
- B41N1/12—Printing plates or foils; Materials therefor non-metallic other than stone, e.g. printing plates or foils comprising inorganic materials in an organic matrix
Abstract
ABSTRACT
A letterpress printing plate of the photopolymer type having a fiberous substrate. Disclosed are features such as forming the letterpress printing plates using a liquid radiation curable polymer relief forming layer, a substrate including a fiberous sheet 5 to 20 mils thick of fibers dyed before being formed into a sheet, a sealing coating on at least one face of the fiberous sheet which may be colored or not depending on the nature of the fibers and a method of processing the letterpress printing plate by dry processing.
A letterpress printing plate of the photopolymer type having a fiberous substrate. Disclosed are features such as forming the letterpress printing plates using a liquid radiation curable polymer relief forming layer, a substrate including a fiberous sheet 5 to 20 mils thick of fibers dyed before being formed into a sheet, a sealing coating on at least one face of the fiberous sheet which may be colored or not depending on the nature of the fibers and a method of processing the letterpress printing plate by dry processing.
Description
In the past, letterpress printing plates of the photopolyn-,er type have nad alumin~,lr~lar and steel substrates. T~ese substrates had various coat-ings on them including vinyl com~ositions. Sone of the coatinys were clear and others contained dyes. Some oontaineG black ~yes.
The le-tterpress printing plates of the present invention contain a substrate that resists elongation muc'n better than the mylar substrates of the prior art-~hile having rluch better compression properties than tne alur,~num and steel substrates of the prior art. ~ne letterpress printing plates of tne pre-sent invention are r~ore easily disposed of after they have been used and the sub-strate is substantially lighter in weight and is predomLnately cor,~osed of a re-newable resource, natural pulp. In addition the letterpress printiny plates of the present invention are less costly.
By an aspect of tne present invention a new type of letterpress photo-polymer printing plate substrate is provided that is fiberous in character.
mus, one aspect of the invention provides a letterpress printing plate comprising a fiberous support and a radiation polyr.~erizable relief forming layer thereover, said fiberous support con~prising fibers that ~lere independently - colored before incorporation in said fiberous support.
Another aspect of the invention provides a method of preparing letter-press printing plates cGmprising depositins a liquid relief forl~ing radiationpolyn~rizable cor,~osition onto a substrate comprising a fiberous sheet, solid-ifying an image in the surface of said composition and air etching said surface, the irnprovement cor~rising providing the properties in the fiberous sheet of individually oolored fibers, colored prior to incorporation in said sheet and a sheet thickness of 5 to 20 mils.
In its preferred form the fibers in the substrate are dyed, prefer-ably kefore being formed into a sheet. m e preferred fibers are cellulosic in .' .
:' , : ' ' ~1~64~S
character, preferably frorn a natural plant pulp. In its preferred forrn the substrate is a fil~erous sheet coated with a polyrneric filrn which acts ~ot7n as an adhesive tie coat and as a sealant for the surface of the sheet. The pre-ferreci sheet is dyed blaclc and the preferred substrate coating is clear and preferably a vinyl chloride-vinylidene chloride copolyrner. The preferred plate has a liquid photocurable polymer over the tie coat.
The letterpress printing plate of the present invention has particular utility when it is part of a plate production systern e~ploying an air knife or otller rnechanical and liquid free developing procedure. mus in one aspect the 10 invention is directed to a new procedure for providing print--la-ff ~
. . . _ .
~-li64~5 ing plates that include placing a cellulose fiber con-tairling substrate in position for receipt of a liquid photopolymer printing relief forming layer, exposing the layer through an image containing negative to actinic light to solidify portions of the plate corresponding to the image. An air knife is then used to forcefully strip away the uncured polymer and provide the desired printing configuration.
BES~' MODE
By this invention a letterpress printing plate of the radiation polymerized type is provided that has a superior supporting subs-trate. The unique substrate is in its basic form a fiberous sheet. In one preferred form the substrate has a coating on at least its face that is to receive the - radiation polymerizable relief forming layer. This coating provides both a sealing of the surface of the sheet stock and superior adhesion of the radia-tion polymerizable relief forming layer. The coating is preferably a solvent base vinyl resin tie coat, preferably of the vinyl chloride-vinylidene chlo-ride type.
The fiberous sheet in one preferred form is formed of natural cel-lulosic pulp. Synthetic plastic fiberous materials may also be used. The preferred sheet is tag stock. The preferred thickness is 5 to 20 mils. This is 5 to 20 point stock. The sheet should have a smooth surface and have relatively low porosity. In a 10 mil thick sheet a basis weight of about - 150 lb. is appropriate. (Basis weight is the weight of 500 sheets sized 2 inches by 36 inches).
In a preferred form the fibers in the sheet are dyed to provide more uniform reflectivity. Preferably the fibers are dyed before being in-corporated into the sheet. However, in some situations the substrate may have a coated on coloring medium or may be the natural color of the fibers.
- Dark colored substrates generally give the best reflective characteristics.
: .
~16~l~iS
Black is most preferred.
The substrate of this invention has particular utili-ty in forming letterpress printing plates fro~ liquid relief forrning cornposi-tions. ~iquid c~npositions having chain extended urethane rnonomers witn terminal unsatura-tion, diacrylate m~onorners and photoinitiators are ideal types. Those con-taining thiol ~onomers are particularly preferred. Such oompositions are il-lustrated in United States Patent 3,615,450.
The printing plate of this invention is forrned by positioning the substrate for receipt of the relief layer o~rnposition. r~nis rnay be done in any convenient rnanner. A United States Patent depicting oonventional com~
merical equiprnent is United States Patent 3,635,711. The relief layer is pro-vided on the substrate to forrn the blank printing plate. Thereafter the blank is imaged conventionally through a negative and the plate is air etc~ned in con-ventional rnanner as is for exarnple shown in United States Patent 3,922,751. Inthe preferred practice of the invention the plate is dry developed or etched because this better maintains the integrity of the fiberous sheet of the sub-strate. After the developrnent of the plate it can be installed on a le-tterpress for the printing operation.
E~lPlE 1 A letterpress printing plate substrate was prepared by coating a sheet of black tag cover stock with a vinyl chloriae-vinylidene chloride co-polyrner (SA ~ F310, a product of D~ Chemical Co.). rme black tag cover stock was n~nufactured by the cylinder process and was 10 point 140 pound basis weight material and exhibited a smooth surface and had a plate finish.
Tne coating was 4.5-6.5 millogra~s/sq. inch dry weight and was applied from v,,~
.
~11646S
a methyl ethyl ketone solvent.
The substrate was positioned in a standard LETTERFLE ~ 290, a prod-uct of W. R. Grace & Co., plate forming machine and 20 millograms of liquid LETTERFLE ~ Y polymer, a product of W. R. Grace & Co., photopolymer printing relief forming material was deposited over the coating in the conventional manner. The photopolymer printing relief forming material was then cured in the conventional manner with actinic light projected through a negative on the plate forming machine. The uncured polymer was then stripped from the plate by an air knife which was part of the plate forming machine. The plate was then installed on a letterpress and gave printing results that exceeded 280,000 impressions with no deleterious effects. 70 wraps were applied and the plates printed well after being cleared. The plate showed little or no evidence of wear while stereotype plates with comparable impressions showed signs of wear to visual observation.
EXAMPLE II
A letterpress printing plate substrate was prepared by coating a sheet natural colored Jute tag cover stock with a vinyl chloride-vinylidene ; chloride copolymer (SAR ~ F310, a product of Dow Chemical Co.). The jute tag cover stock was manufactured by the cylinder process and was 10 point 149 pound basis weight material containing a small percent of jute fibers and exhibited a smooth surface and had a plate finish. The coating was 4.5-6.5 millograms/sq. inch dry weight, contained about 2% carbon black on a dry weight basis and was applied from a methyl ethyl ketone solvent.
The substrate was positioned in a standard LETTERFLE ~ 135, a prod-; uct of W. R. Grace & Co., plate forming machine and 20 millograms of liquid LETTERFLE ~ C polymer, a product of W. R. Grace & Co., photopolymer printing relief forming material was deposited over the coating in the conventional manner. The photopolymer printing relief forming material was then cured in 111~i'165 the conventional manner with actinic light projected through a nega-tive on the plate forming machine. The uncured polymer was then stripped from the plate by an air knife which was part of the plate forming machine. The plate was installed on the letterpress and gave printing results that exceeded 20,000 impressions that by visual inspection appeared to be equal to that produced by plates made in the same way using the conventional aluminum sub-strate.
The le-tterpress printing plates of the present invention contain a substrate that resists elongation muc'n better than the mylar substrates of the prior art-~hile having rluch better compression properties than tne alur,~num and steel substrates of the prior art. ~ne letterpress printing plates of tne pre-sent invention are r~ore easily disposed of after they have been used and the sub-strate is substantially lighter in weight and is predomLnately cor,~osed of a re-newable resource, natural pulp. In addition the letterpress printiny plates of the present invention are less costly.
By an aspect of tne present invention a new type of letterpress photo-polymer printing plate substrate is provided that is fiberous in character.
mus, one aspect of the invention provides a letterpress printing plate comprising a fiberous support and a radiation polyr.~erizable relief forming layer thereover, said fiberous support con~prising fibers that ~lere independently - colored before incorporation in said fiberous support.
Another aspect of the invention provides a method of preparing letter-press printing plates cGmprising depositins a liquid relief forl~ing radiationpolyn~rizable cor,~osition onto a substrate comprising a fiberous sheet, solid-ifying an image in the surface of said composition and air etching said surface, the irnprovement cor~rising providing the properties in the fiberous sheet of individually oolored fibers, colored prior to incorporation in said sheet and a sheet thickness of 5 to 20 mils.
In its preferred form the fibers in the substrate are dyed, prefer-ably kefore being formed into a sheet. m e preferred fibers are cellulosic in .' .
:' , : ' ' ~1~64~S
character, preferably frorn a natural plant pulp. In its preferred forrn the substrate is a fil~erous sheet coated with a polyrneric filrn which acts ~ot7n as an adhesive tie coat and as a sealant for the surface of the sheet. The pre-ferreci sheet is dyed blaclc and the preferred substrate coating is clear and preferably a vinyl chloride-vinylidene chloride copolyrner. The preferred plate has a liquid photocurable polymer over the tie coat.
The letterpress printing plate of the present invention has particular utility when it is part of a plate production systern e~ploying an air knife or otller rnechanical and liquid free developing procedure. mus in one aspect the 10 invention is directed to a new procedure for providing print--la-ff ~
. . . _ .
~-li64~5 ing plates that include placing a cellulose fiber con-tairling substrate in position for receipt of a liquid photopolymer printing relief forming layer, exposing the layer through an image containing negative to actinic light to solidify portions of the plate corresponding to the image. An air knife is then used to forcefully strip away the uncured polymer and provide the desired printing configuration.
BES~' MODE
By this invention a letterpress printing plate of the radiation polymerized type is provided that has a superior supporting subs-trate. The unique substrate is in its basic form a fiberous sheet. In one preferred form the substrate has a coating on at least its face that is to receive the - radiation polymerizable relief forming layer. This coating provides both a sealing of the surface of the sheet stock and superior adhesion of the radia-tion polymerizable relief forming layer. The coating is preferably a solvent base vinyl resin tie coat, preferably of the vinyl chloride-vinylidene chlo-ride type.
The fiberous sheet in one preferred form is formed of natural cel-lulosic pulp. Synthetic plastic fiberous materials may also be used. The preferred sheet is tag stock. The preferred thickness is 5 to 20 mils. This is 5 to 20 point stock. The sheet should have a smooth surface and have relatively low porosity. In a 10 mil thick sheet a basis weight of about - 150 lb. is appropriate. (Basis weight is the weight of 500 sheets sized 2 inches by 36 inches).
In a preferred form the fibers in the sheet are dyed to provide more uniform reflectivity. Preferably the fibers are dyed before being in-corporated into the sheet. However, in some situations the substrate may have a coated on coloring medium or may be the natural color of the fibers.
- Dark colored substrates generally give the best reflective characteristics.
: .
~16~l~iS
Black is most preferred.
The substrate of this invention has particular utili-ty in forming letterpress printing plates fro~ liquid relief forrning cornposi-tions. ~iquid c~npositions having chain extended urethane rnonomers witn terminal unsatura-tion, diacrylate m~onorners and photoinitiators are ideal types. Those con-taining thiol ~onomers are particularly preferred. Such oompositions are il-lustrated in United States Patent 3,615,450.
The printing plate of this invention is forrned by positioning the substrate for receipt of the relief layer o~rnposition. r~nis rnay be done in any convenient rnanner. A United States Patent depicting oonventional com~
merical equiprnent is United States Patent 3,635,711. The relief layer is pro-vided on the substrate to forrn the blank printing plate. Thereafter the blank is imaged conventionally through a negative and the plate is air etc~ned in con-ventional rnanner as is for exarnple shown in United States Patent 3,922,751. Inthe preferred practice of the invention the plate is dry developed or etched because this better maintains the integrity of the fiberous sheet of the sub-strate. After the developrnent of the plate it can be installed on a le-tterpress for the printing operation.
E~lPlE 1 A letterpress printing plate substrate was prepared by coating a sheet of black tag cover stock with a vinyl chloriae-vinylidene chloride co-polyrner (SA ~ F310, a product of D~ Chemical Co.). rme black tag cover stock was n~nufactured by the cylinder process and was 10 point 140 pound basis weight material and exhibited a smooth surface and had a plate finish.
Tne coating was 4.5-6.5 millogra~s/sq. inch dry weight and was applied from v,,~
.
~11646S
a methyl ethyl ketone solvent.
The substrate was positioned in a standard LETTERFLE ~ 290, a prod-uct of W. R. Grace & Co., plate forming machine and 20 millograms of liquid LETTERFLE ~ Y polymer, a product of W. R. Grace & Co., photopolymer printing relief forming material was deposited over the coating in the conventional manner. The photopolymer printing relief forming material was then cured in the conventional manner with actinic light projected through a negative on the plate forming machine. The uncured polymer was then stripped from the plate by an air knife which was part of the plate forming machine. The plate was then installed on a letterpress and gave printing results that exceeded 280,000 impressions with no deleterious effects. 70 wraps were applied and the plates printed well after being cleared. The plate showed little or no evidence of wear while stereotype plates with comparable impressions showed signs of wear to visual observation.
EXAMPLE II
A letterpress printing plate substrate was prepared by coating a sheet natural colored Jute tag cover stock with a vinyl chloride-vinylidene ; chloride copolymer (SAR ~ F310, a product of Dow Chemical Co.). The jute tag cover stock was manufactured by the cylinder process and was 10 point 149 pound basis weight material containing a small percent of jute fibers and exhibited a smooth surface and had a plate finish. The coating was 4.5-6.5 millograms/sq. inch dry weight, contained about 2% carbon black on a dry weight basis and was applied from a methyl ethyl ketone solvent.
The substrate was positioned in a standard LETTERFLE ~ 135, a prod-; uct of W. R. Grace & Co., plate forming machine and 20 millograms of liquid LETTERFLE ~ C polymer, a product of W. R. Grace & Co., photopolymer printing relief forming material was deposited over the coating in the conventional manner. The photopolymer printing relief forming material was then cured in 111~i'165 the conventional manner with actinic light projected through a nega-tive on the plate forming machine. The uncured polymer was then stripped from the plate by an air knife which was part of the plate forming machine. The plate was installed on the letterpress and gave printing results that exceeded 20,000 impressions that by visual inspection appeared to be equal to that produced by plates made in the same way using the conventional aluminum sub-strate.
Claims (11)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A letterpress printing plate comprising a fiberous support and a radiation polymerizable relief forming layer thereover, said fiberous support comprising fibers that were independently colored before incorp-oration in said fiberous support.
2. The letterpress printing plate of Claim 1 comprising a polymeric layer separating the fiberous support from the relief forming layer.
3. The letterpress printing plate of Claim 1 comprising a polymeric layer of polyvinylidene chloride copolymer separating the fiberous support from the relief forming layer.
4. The letterpress printing plate of Claim 1 wherein said fiberous support is comprised of cellulose fibers.
5. The letterpress printing plate of Claim 4 wherein said fiberous support is about 5 to about 20 mils thick, a smooth finish tag stock with a tensile strength in both directions of at least 2,000 lbs. and sealed with a vinyl coating before said relief forming layer is provided there-over and said fibers that were independently colored before incorporation in the fiberous support are independently colored black before said incorporation in the fiberous support,
6. The letterpress printing plate of Claim 5 wherein said tensile strength of the fiberous support in the press direction is at least 3,000 lbs. and said smooth finish tag stock is cover stock and said coating is polyvinylidene chloride latex.
7. The letterpress printing plate of Claim 6 wherein said tensile strength of the fiberous support in the press direction is at least 7,000 lbs.
8. A method of preparing letterpress printing plates comprising depositing a liquid relief forming radiation polymerizable composition onto a substrate comprising a fiberous sheet; solidifying an image in the surface of said composition and air etching said surface, the improvement comprising providing the properties in the fiberous sheet of individually colored fibers, colored prior to incorporation in said sheet and a sheet thickness of 5 to 20 mils.
9. The method of Claim 8 wherein said fibers are colored black.
10. The method of Claim 9 wherein said fiberous sheet is a smooth finish tag stock with a tensile strength in the press direction of at least 3,000 lbs. and is sealed with a vinyl material before said relief forming layer is provided thereover.
11. The method of Claim 10 wherein said tensile strength of the fiberous support in the press direction is at least 7,000 lbs. and said smooth finish tag stock is cover stock and said sealing vinyl material is polyvinylidene chloride latex.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US89243878A | 1978-03-31 | 1978-03-31 | |
| US892,438 | 1978-03-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1116465A true CA1116465A (en) | 1982-01-19 |
Family
ID=25399938
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000324518A Expired CA1116465A (en) | 1978-03-31 | 1979-03-30 | Fiberous substrate letterpress photopolymer printing plate |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS54136904A (en) |
| AU (1) | AU526967B2 (en) |
| CA (1) | CA1116465A (en) |
| DE (1) | DE2913387A1 (en) |
| GB (1) | GB2019023B (en) |
| NL (1) | NL7902502A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4582777A (en) * | 1983-05-18 | 1986-04-15 | W. R. Grace & Co. | Compressible printing plate |
| JPS6158792A (en) * | 1984-08-31 | 1986-03-26 | Sanyo Kokusaku Pulp Co Ltd | Formation of relief image |
| JPS6254253A (en) * | 1985-08-01 | 1987-03-09 | Sanyo Kokusaku Pulp Co Ltd | Formation of relief |
| GB9804743D0 (en) * | 1998-03-06 | 1998-04-29 | Horsell Graphic Ind Ltd | Printing |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE634216A (en) * | 1962-06-27 | |||
| DE1572153B2 (en) * | 1966-06-27 | 1971-07-22 | E I Du Pont de Nemours and Co , Wilmington, Del (V St A ) | PHOTOPOLYMERIZABLE RECORDING MATERIAL |
| GB1251232A (en) * | 1967-10-12 | 1971-10-27 | ||
| DE7120411U (en) * | 1971-05-26 | 1971-10-14 | Turaphot Gmbh | BLACK & WHITE PICTURE MATERIAL IN PARTICULAR BLACK & WHITE PHOTO PAPER |
| JPS5146442B2 (en) * | 1972-12-18 | 1976-12-09 | ||
| US4060656A (en) * | 1973-04-02 | 1977-11-29 | Teijin Limited | Support for photosensitive resin |
| JPS5229302A (en) * | 1975-08-28 | 1977-03-05 | Fuji Photo Film Co Ltd | Photoosensitive printing plate |
-
1979
- 1979-03-30 DE DE19792913387 patent/DE2913387A1/en not_active Withdrawn
- 1979-03-30 NL NL7902502A patent/NL7902502A/en not_active Application Discontinuation
- 1979-03-30 GB GB7911218A patent/GB2019023B/en not_active Expired
- 1979-03-30 CA CA000324518A patent/CA1116465A/en not_active Expired
- 1979-03-31 JP JP3775679A patent/JPS54136904A/en active Pending
- 1979-04-05 AU AU45848/79A patent/AU526967B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54136904A (en) | 1979-10-24 |
| DE2913387A1 (en) | 1979-10-11 |
| GB2019023A (en) | 1979-10-24 |
| GB2019023B (en) | 1982-11-17 |
| NL7902502A (en) | 1979-10-02 |
| AU526967B2 (en) | 1983-02-10 |
| AU4584879A (en) | 1980-04-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |