WO1989001871A1 - Pre-sensitized lithographic printing plate production - Google Patents
Pre-sensitized lithographic printing plate production Download PDFInfo
- Publication number
- WO1989001871A1 WO1989001871A1 PCT/GB1988/000645 GB8800645W WO8901871A1 WO 1989001871 A1 WO1989001871 A1 WO 1989001871A1 GB 8800645 W GB8800645 W GB 8800645W WO 8901871 A1 WO8901871 A1 WO 8901871A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- photo
- range
- lithographic printing
- aluminium substrate
- printing plate
- Prior art date
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
- B41N3/00—Preparing for use and conserving printing surfaces
- B41N3/03—Chemical or electrical pretreatment
- B41N3/034—Chemical or electrical pretreatment characterised by the electrochemical treatment of the aluminum support, e.g. anodisation, electro-graining; Sealing of the anodised layer; Treatment of the anodic layer with inorganic compounds; Colouring of the anodic layer
Definitions
- This invention relates to the production of a pre- sensitized lithographic printing plate.
- Pre-sensitized lithographic printing plates are usually formed from a web of an aluminium substrate which is supplied in roll form, and which passes continuously through successive treatment stages (including an anodising stage) which prepare the surface of the web to receive a suitable light sensitive coating, and then the web is cut- up into printing plates.
- the present invention has-been developed primarily, though not exclusively, with a view to providing an improved coating composition, and an improved anodising treatment of the web, so as to achieve production of a pre- sensitized lithographic printing plate having improved performance.
- aluminium substrate is intended to include aluminium and aluminium alloy substrates of the type suitable for use in the production of lithographic printing plates.
- the present invention is based on the surprising discovery that the difficulties of loss of adhesion encountered with resins of the general type disclosed in DE 3633456 can be overcome in a different way and which can realise additional technical advantages as regards to sensitivity.
- the present invention provides a method for producing a lithographic printing plate which comprises a light sensitive coating applied to an aluminium substrate, in which the method includes an anodising step in which the aluminium substrate is anodised using phosphoric acid present in a range from 100% to 30% by and sulphuric acid present in a range from 0% to 70% by volume of the same normality, and a coating step in which the anodised aluminium substrate is coated with a resin which comprises a photo crosslinkable polymer having a maleimidic functional group plus a sensitiser.
- a lithographic printing plate made in accordance with the method of the present invention is developable using an aqueous developing medium.
- a significant loss of light sensitivity is normally encountered when dye stuffs are added to the polymer resins containing dialkylmaleimidyl functional groups. It has been surprisingly found that by using a mixed acid anodising medium it is possible to overcome this problem by significantly reducing this loss of light sensitivity.
- This improvement in the sensitivity of the coating is regarded as a highly desirable property for a lithographic printing plate.
- the coating composition also includes one or more of a sensitiser, a dye-stuff, a photo-oxidiser and a surfactant.
- the mixed acid medium comprises a mixture of sulphuric and phosphoric acids in a total acid concentration from IN to 20N.
- the ratio of sulphuric acid to phosphoric acid is in the range from 30/70 V/V to 50/50 V/V and more preferably is about 40/60 V/V respectively.
- the preferred total acid concentration is in the range from 3N to 9N.
- the photo crosslinkable polymer is an acrylic polymer.
- the crosslinkable groups are dimethylmaleimidyl groups.
- the polymer may be formed by co-polymerising a dimethylmaleimid 1-functional ised acrylic or methacrylic monomer (DMI-monomer) with one or more acrylic or methacrylic comonomers.
- DMI-monomer dimethylmaleimid 1-functional ised acrylic or methacrylic monomer
- the DMI-monomer may be represented by the formula
- R may be, for instance, alkylene or oxyalkylene.
- R examples of R are ( CH2 ) 2> ( CH2 ) 2 ⁇ 0- ( CH2 ) 2 anc * (CH2)g. the latter being particularly preferred-.
- a photo-oxidiser which may be used in connection with the present invention is a triazine derivative, for instance, one containing a chalcogenide substituent.
- Examples of such ' photo-oxidisers are described in pending British patent application No 8627059. They have the general formula wherein R is an alkyl group or an aryl group, X is S, Se or Te, n and m are 0, or each is an integer of from 1 to 3, the total sum of n + m not being greater than 3 and p and q are 0, or each is an integer of from 1 to 3, the total sum of p + q not being greater than 3.
- results were assessed using a stouffer grey scale to determine sensitivity, and in which S apparently represents the highest fully cured step on the wedge, and C apparently represents the lowest totally uncured step on the wedge.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
- Materials For Photolithography (AREA)
- Printing Plates And Materials Therefor (AREA)
Abstract
There is disclosed a method of producing a lithographic printing plate which comprises a light sensitive coating applied to an aluminium substrate, in which the method includes an anodising step in which the aluminium substrate is anodised using phosphoric acid present in a range from 100 % to 30 % by volume and sulphuric acid present in a range from 0 % to 70 % by volume of the same normality, and a coating step in which the anodised aluminium substrate is coated with a resin which comprises a photo crosslinkable polymer having a maleimidic functional group plus a sensitiser. The invention therefore provides good adhesion of the coating and improved sensitivity.
Description
-
This invention relates to the production of a pre- sensitized lithographic printing plate.
Pre-sensitized lithographic printing plates are usually formed from a web of an aluminium substrate which is supplied in roll form, and which passes continuously through successive treatment stages (including an anodising stage) which prepare the surface of the web to receive a suitable light sensitive coating, and then the web is cut- up into printing plates.
The present invention has-been developed primarily, though not exclusively, with a view to providing an improved coating composition, and an improved anodising treatment of the web, so as to achieve production of a pre- sensitized lithographic printing plate having improved performance.
In this specification, the reference to an "aluminium substrate" is intended to include aluminium and aluminium alloy substrates of the type suitable for use in the production of lithographic printing plates.
It is known from Fuji German specification DE 3633456 to provide a resin which forms a light sensitive coating on an aluminium substrate, and which comprises a photo crosslinkable polymer having a maleimidic functional group. Various examples of resins are disclosed but, as stated in the specification, there are problems with resins of this type in achieving reliable adhesion of the light sensitive coating formed from the resin, and the disclosure teaches a solution to this problem by the use of a negatively functioning diazo resin. While this does indeed help in overcoming problems of improper adhesion i.e. peeling- of the coating, there are well known difficulties with diazo resins in that they are not thermally stable and also they have a short shelf life, especially when used in hotter countries.
The diazo resin therefore loses its effective properties fairly rapidly, with consequent adverse effect on the subsequent development process.
It is also generally known to use acid anodising of substrates to improve the properties of the substrate in the following -areas: (a) water balance on the printing press; (b) coating release during development; (c) durability of substrate; and (d) substrate colour.
However, the present invention is based on the surprising discovery that the difficulties of loss of adhesion encountered with resins of the general type disclosed in DE 3633456 can be overcome in a different way and which can realise additional technical advantages as regards to sensitivity.
Accordingly, the present invention provides a method for producing a lithographic printing plate which comprises a light sensitive coating applied to an aluminium substrate, in which the method includes an anodising step in which the aluminium substrate is anodised using phosphoric acid present in a range from 100% to 30% by and sulphuric acid present in a range from 0% to 70% by volume of the same normality, and a coating step in which the anodised aluminium substrate is coated with a resin which comprises a photo crosslinkable polymer having a maleimidic functional group plus a sensitiser.
A lithographic printing plate made in accordance with the method of the present invention is developable using an aqueous developing medium. A significant loss of light sensitivity is normally encountered when dye stuffs are added to the polymer resins containing dialkylmaleimidyl functional groups. It has been surprisingly found that by using a mixed acid anodising medium it is possible to overcome this problem by significantly reducing this loss of light sensitivity. This improvement in the sensitivity of the coating is regarded as a highly desirable property for a lithographic printing plate.
Preferably the coating composition also includes one or more of a sensitiser, a dye-stuff, a photo-oxidiser and a surfactant.
Preferably the mixed acid medium comprises a mixture of sulphuric and phosphoric acids in a total acid concentration from IN to 20N. Preferably the ratio of sulphuric acid to phosphoric acid is in the range from 30/70 V/V to 50/50 V/V and more preferably is about 40/60 V/V respectively. The preferred total acid concentration is in the range from 3N to 9N.
Preferably the photo crosslinkable polymer is an acrylic polymer. Preferably the crosslinkable groups are dimethylmaleimidyl groups.
Typically the polymer may be formed by co-polymerising a dimethylmaleimid 1-functional ised acrylic or methacrylic monomer (DMI-monomer) with one or more acrylic or methacrylic comonomers. The DMI-monomer may be represented by the formula
in which the group R may be, for instance, alkylene or oxyalkylene.. Examples of R are (CH2)2> (CH2)2~0-(CH2)2 anc* (CH2)g. the latter being particularly preferred-.
An example of a photo-oxidiser which may be used in connection with the present invention is a triazine derivative, for instance, one containing a chalcogenide substituent. Examples of such' photo-oxidisers are described in pending British patent application No 8627059. They have the general formula
wherein R is an alkyl group or an aryl group, X is S, Se or Te, n and m are 0, or each is an integer of from 1 to 3, the total sum of n + m not being greater than 3 and p and q are 0, or each is an integer of from 1 to 3, the total sum of p + q not being greater than 3.
In carrying out the method of the present invention, the following steps will normally be involved: degreasing, water rinse, acid treatment, water rinse, graining, water rinse, acid or alkali treatment, water rinse, anodising, water rinse, post-anodic treatment, water rinse, drying oven, coating and drying oven.
The various processing conditions and the formulations of the materials used in each stage are in accordance with standard procedures well known to those skilled in the art.
While the preferred ratio of sulphuric acid to phosphoric acid in the anodising treatment came in the range 30/70 to 50/50, it has been found in tests that advantageous results can be obtained for both adhesion and improved sensitivity when the phosphoric acid is present from 100% down to 30% and the sulphuric acid present from 0% to 70% by volumes of the same normality.
The use of greater proportions of phosphoric acid tend to form a less durable coating, but for many uses this may be quite acceptable e.g. for proofing purposes.
Experiments " 1)
Formulae
DMI (referred to above)
Thioxanthone sensitizers
Photooxidizer
Dye stuffs
100.0% 100% Using formulae A and B, 2 plates were manufactured at
1. Ogm coating weight.
These formulae were evaluated on the following substrates:
1) sulphuric acid anodized
2) sulphuric / phosphoric (40/60 by volume of same normality) acid anodized
3) phosphoric acid anodized.
The plates were all exposed to the same quantity of light. Then developed in a commercial developer available from Horsell Graphic Industries designated C 1346 for one minute at 20°C and the results were then evaluated.
The results were assessed using a stouffer grey scale to determine sensitivity, and in which S apparently represents the highest fully cured step on the wedge, and C apparently represents the lowest totally uncured step on the wedge.
Results formulae Substrate A B
1 S6-C15 S6-C15
2 S9-C17 S9-C17
3 S13-C19 S14-C19 NB good adhesion was seen on all plates.
2) Formulae
A B
DMI monomer 91% DMI monomer 91%
Thioxanthone sensitizer 9% Ketocoumarin 9%
Again processing conditions, coating weights and substrate designations same as Experiment 1.
Results Substrate A B
1 S6-C15 S4-C13
2 S9-C17 S9-C17
3 S14-C19 S15-C19 NB Good adhesion was seen on all plates.
As can be seen from the above two experiments, a considerable improvement in sensitivity can be achieved by the use of mixed and anodising with sulphuric and phosphoric acid while still retaining good adhesion and a durable anodised substrate.
Claims
1. A method for producing a lithographic printing plate which comprises a light sensitive coating applied to an aluminium substrate, in which the method includes an anodising step in which the aluminium substrate is anodised using phosphoric acid present in a range from 100% to 30% by volume and sulphuric acid present in a range from 0% to 70% by volume of the same normality, and a coating step in which the anodised aluminium substrate is coated with a resin which comprises a photo crosslinkable polymer having a maleimidic functional group plus a sensitiser.
2. A method according to Claim 1, in which the coating composition also includes one or more of a dye- stuff, a photo-oxidiser and a surfactant.
3. A method according to Claim 1 or 2, in which the mixed acid medium comprises a mixture of sulphuric and phosphoric acids in a total acid concentration from IN to 20N.
4. A method according to Claim 3, in which the ratio of sulphuric acid to phosphoric acid is in the range 30/70 V/V to 50/50 V/V, and preferably is about 40/60 V/V respectivel .
5. A method according to any one of the preceding claims, in which the total acid concentration is in the range from 3N to 9N.
6. A method according to any one of the preceding claims, in which the photo crosslinkable polymer is an acrylic polymer.
7. A method according to Claim 6, in which the crosslinkable groups are dimethylmaleimid 1 groups.
8. A method according to Claim 6 or 7, in which the polymer is formed by co-polymerising a dimethylmaleimidylfunctional ised acrylic or methacrylic monomer (DMI-monomer) with one or more acrylic or methacrylic comonomers.
9. A method according to Claim 8, in which the DMI- monomer is represented by the formula
10. A method according to Claim 9, in which the group R is alkylene or oxyalkylene, such as (CH2)2» (CH2)2~0- (CH2 ) 2 and (CH2 )g.
11. A method according to any one of the preceding claims, including the use of a photo-oxidiser which is a triazine derivative, such as for example one containing a chalcogenide substituent.
12. A method according to Claim 11, in which the photo-oxidiser of the following general formula
wherein R is an alkyl group or an akyl group, X is S, Se or Te, n and m are 0, or each is an integer of from 1 to 3, the total sum of n + m not being greater than 3 and p and q are 0, or each is an integer of from 1 to 3, the total sum of p and q not being greater than 3.
13. A lithographic printing plate produced by a method according to any one of the preceding claims.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8720424 | 1987-08-28 | ||
GB878720424A GB8720424D0 (en) | 1987-08-28 | 1987-08-28 | Pre-sensitized lithographic printing plate production |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1989001871A1 true WO1989001871A1 (en) | 1989-03-09 |
Family
ID=10623022
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1988/000645 WO1989001871A1 (en) | 1987-08-28 | 1988-08-05 | Pre-sensitized lithographic printing plate production |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0377589A1 (en) |
AU (1) | AU2132488A (en) |
ES (1) | ES2011850A6 (en) |
GB (1) | GB8720424D0 (en) |
NZ (1) | NZ225783A (en) |
WO (1) | WO1989001871A1 (en) |
ZA (1) | ZA885908B (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6087066A (en) * | 1998-10-15 | 2000-07-11 | Kodak Polychrome Graphics Llc | Polyvinyl acetals having imido groups and use thereof in photosensitive compositions |
US6105500A (en) * | 1995-11-24 | 2000-08-22 | Kodak Polychrome Graphics Llc | Hydrophilized support for planographic printing plates and its preparation |
US6138568A (en) * | 1997-02-07 | 2000-10-31 | Kodak Polcyhrome Graphics Llc | Planographic printing member and process for its manufacture |
US6182571B1 (en) | 1996-11-21 | 2001-02-06 | Kodak Polcyhrome Graphics Llc | Planographic printing |
US6270938B1 (en) | 2000-06-09 | 2001-08-07 | Kodak Polychrome Graphics Llc | Acetal copolymers and use thereof in photosensitive compositions |
US6293197B1 (en) | 1999-08-17 | 2001-09-25 | Kodak Polychrome Graphics | Hydrophilized substrate for planographic printing |
US6357351B1 (en) | 1997-05-23 | 2002-03-19 | Kodak Polychrome Graphics Llc | Substrate for planographic printing |
US6427596B1 (en) | 1997-05-23 | 2002-08-06 | Kodak Polychrome Graphics, Llc | Method for making corrections on planographic printing plates |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1551884A (en) * | 1966-07-01 | 1969-01-03 | ||
FR2341443A1 (en) * | 1976-02-23 | 1977-09-16 | Polychrome Corp | PROCESS FOR THE PRODUCTION OF LITHOGRAPHIC PRINTING PLATES AND PRODUCTS THUS OBTAINED |
EP0008440A2 (en) * | 1978-08-23 | 1980-03-05 | Hoechst Aktiengesellschaft | Process for the anodic oxidation of aluminium and its application as printing-plate substrate material |
EP0085799A1 (en) * | 1980-10-23 | 1983-08-17 | Vickers Plc | Method of making lithographic printing plates |
EP0179448A2 (en) * | 1984-10-23 | 1986-04-30 | Mitsubishi Kasei Corporation | Photosensitive planographic printing plate |
DE3633456A1 (en) * | 1985-10-01 | 1987-04-02 | Fuji Photo Film Co Ltd | LIGHT SENSITIVE COMPOSITION |
-
1987
- 1987-08-28 GB GB878720424A patent/GB8720424D0/en active Pending
-
1988
- 1988-08-05 EP EP88906853A patent/EP0377589A1/en not_active Withdrawn
- 1988-08-05 AU AU21324/88A patent/AU2132488A/en not_active Abandoned
- 1988-08-05 WO PCT/GB1988/000645 patent/WO1989001871A1/en not_active Application Discontinuation
- 1988-08-11 ZA ZA885908A patent/ZA885908B/en unknown
- 1988-08-11 NZ NZ225783A patent/NZ225783A/en unknown
- 1988-08-26 ES ES8802650A patent/ES2011850A6/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1551884A (en) * | 1966-07-01 | 1969-01-03 | ||
FR2341443A1 (en) * | 1976-02-23 | 1977-09-16 | Polychrome Corp | PROCESS FOR THE PRODUCTION OF LITHOGRAPHIC PRINTING PLATES AND PRODUCTS THUS OBTAINED |
EP0008440A2 (en) * | 1978-08-23 | 1980-03-05 | Hoechst Aktiengesellschaft | Process for the anodic oxidation of aluminium and its application as printing-plate substrate material |
EP0085799A1 (en) * | 1980-10-23 | 1983-08-17 | Vickers Plc | Method of making lithographic printing plates |
EP0179448A2 (en) * | 1984-10-23 | 1986-04-30 | Mitsubishi Kasei Corporation | Photosensitive planographic printing plate |
DE3633456A1 (en) * | 1985-10-01 | 1987-04-02 | Fuji Photo Film Co Ltd | LIGHT SENSITIVE COMPOSITION |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6105500A (en) * | 1995-11-24 | 2000-08-22 | Kodak Polychrome Graphics Llc | Hydrophilized support for planographic printing plates and its preparation |
US6182571B1 (en) | 1996-11-21 | 2001-02-06 | Kodak Polcyhrome Graphics Llc | Planographic printing |
US6138568A (en) * | 1997-02-07 | 2000-10-31 | Kodak Polcyhrome Graphics Llc | Planographic printing member and process for its manufacture |
US6357351B1 (en) | 1997-05-23 | 2002-03-19 | Kodak Polychrome Graphics Llc | Substrate for planographic printing |
US6427596B1 (en) | 1997-05-23 | 2002-08-06 | Kodak Polychrome Graphics, Llc | Method for making corrections on planographic printing plates |
US6087066A (en) * | 1998-10-15 | 2000-07-11 | Kodak Polychrome Graphics Llc | Polyvinyl acetals having imido groups and use thereof in photosensitive compositions |
US6293197B1 (en) | 1999-08-17 | 2001-09-25 | Kodak Polychrome Graphics | Hydrophilized substrate for planographic printing |
US6418850B2 (en) | 1999-08-17 | 2002-07-16 | Kodak Polychrome Graphics Llc | Hydrophilized substrate for planographic printing |
US6270938B1 (en) | 2000-06-09 | 2001-08-07 | Kodak Polychrome Graphics Llc | Acetal copolymers and use thereof in photosensitive compositions |
Also Published As
Publication number | Publication date |
---|---|
ES2011850A6 (en) | 1990-02-16 |
EP0377589A1 (en) | 1990-07-18 |
ZA885908B (en) | 1989-04-26 |
GB8720424D0 (en) | 1987-10-07 |
NZ225783A (en) | 1990-04-26 |
AU2132488A (en) | 1989-03-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4578342A (en) | Presensitized diazo lithographic plate with anodized and silicated aluminum plate surface and subbing layer of polymer with sulfonic acid group | |
CA1149217A (en) | Process for manufacture of a negative-working; presensitized planographic printing plate containing a condensation product of an aromatic diazonium salt | |
DE3633456A1 (en) | LIGHT SENSITIVE COMPOSITION | |
DE3931525B4 (en) | Photosensitive composition | |
DE3742387C2 (en) | Positive-acting photosensitive mixture | |
US4576893A (en) | Presensitized lithographic printing plate precursor | |
WO1989001871A1 (en) | Pre-sensitized lithographic printing plate production | |
EP0127893B1 (en) | Light-sensitive composition for use with lithographic printing plates | |
EP0244748B1 (en) | Photosensitive composition and photosensitive registration material prepared therefrom | |
DE69131175T2 (en) | Process for making a lithographic printing plate | |
US5340685A (en) | Light-sensitive composition containing diazo resin, polyurethane resin and fluorine atom-containing copolymer surfactant | |
US4912013A (en) | Photosensitive diazo composition and photosensitive diazo lithographic printing plate with metal complex dyes and color changing agent | |
US4980263A (en) | Light-sensitive diazo resin composition with polyurethane and compound having ureido, thioureido, urethane, or thiourethane unit | |
US4542085A (en) | Negative working diazo light-sensitive composition with oxonol dye and lithographic printing plate using the same | |
US4859562A (en) | Photosensitive mixture and photosensitive recording material produced therefrom with polymeric compound which is reaction product of unsaturated (thio)phosphinic acid iso(thio)cyanate and active hydrogen containing compound | |
EP0530815A1 (en) | Presensitized plate for use in making lithographic printing plate | |
JPS63259657A (en) | Photosensitive composition | |
JPS60217356A (en) | Photosensitive composition | |
JPS61284759A (en) | Photosensitive composition for negative type lithographic plate | |
JPH023049A (en) | Three-dimensional diazonium condensate | |
JP3142185B2 (en) | Manufacturing method of photosensitive lithographic printing plate | |
JP2571354B2 (en) | Photosensitive composition | |
JPS63174037A (en) | Photosensitive composition | |
JPS63174038A (en) | Photosensitive composition | |
JPS63174039A (en) | Photosensitive composition |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AU DK FI JP KR NO US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE FR GB IT LU NL SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1988906853 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1988906853 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1988906853 Country of ref document: EP |