JPH0128372B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to photopolymerizable materials and relief printing plates obtained from these materials. Relief printing plates formed from photopolymerizable materials comprising a transparent thermoplastic film support are disclosed in GB 1321108 and GB 1507660. Such printing plates are produced by exposing a photopolymerizable material comprising a photopolymerizable layer carried by a film support to actinic radiation through a master, such as a photographic image. After the exposure step, the unexposed surface of the photopolymerizable layer is cleaned by treatment with a suitable solvent to obtain a polymerizable relief image within the exposed surface. The adhesion of the relief image to the film support must completely resist damage during repeated use, for example in a rotary printing machine. The present invention is capable of promoting robust adhesion between a film support and a photopolymerized relief area formed by exposing a photopolymerizable layer applied over an adhesive layer. The present invention relates to a photopolymerizable material comprising an adhesive layer. According to the invention, the photopolymerizable material is a self-supporting plastic film or sheet having an adhesive layer provided on at least one side of the plastic film or sheet and a photopolymerizable material superimposed in interfacial contact on the adhesive layer. the adhesive layer in the material has the following formula: (wherein R ₁ and R ₂ are the same or different and represent a lower alkyl group having up to 6 carbon atoms, x and y are the same or different and are integers from 1 to 4 inclusive, and n is an integer including 4 to 30). This type of unsaturated resin is covered by U.S. Patent 2634251
Further, some photopolymerizable compositions of these and other unsaturated resins are disclosed in British Patent No.
1441181. The latter patent states that photopolymerizable compositions can be used, for example, as adhesives between two adjacent layers (one of which must be transparent to visible light), and that they can also be used in printing plates and photoetching resists. It is particularly useful in the preparation of However, these documents do not propose the use of this type of unsaturated resin, which is the subject of the present invention, as an adhesive layer between the photopolymerized layer and the self-supporting plastic film or sheet. The invention also relates to a relief printing plate comprising a relief image obtained from the polymerizable material according to the invention and formed in a photopolymerizable layer. Lower alkyl groups R ₁ and R ₂ of unsaturated resin structure
are preferably selected from methyl or ethyl and also preferably when they are both the same.
Particularly preferred are methyl groups for both R ₁ and R ₂ . The integers x and y in the resin structure are preferably 2 or 3 and preferably both 2 or both 3.
It is. Most preferred is when both x and y are both equal to 3. Preferably, the integer n includes 8 to 12. The unsaturated resin can be obtained from maleic acid or fumaric acid, although it is preferably a fumarate condensate. A preferred unsaturated resin is a propoxylated bisphenol A-fumarate condensate. The unsaturated resin preferably has a molecular weight in the range 2000-10000 and most preferably 3000-4000. If desired, a photoinitiator or a mixture of photoinitiators is included in the adhesive layer, preferably in an amount of 0.01 to 10% by weight, based on the weight of the unsaturated resin, as described for example in British Patent No. As disclosed in US Pat. No. 1,321,108, it is possible to increase the adhesion between an adhesive applied to photopolymerizable materials and a photopolymerizable layer in the production of photopolymerizable materials. Photopolymerization initiators suitable for inclusion in the adhesive layer include benzoin, benzoin isopropyl ether, benzoin isobutyl ether, benzoin methyl ether, benzoin ethyl ether, α-methylbenzoin, benzyl, anthraquinone, diacetylanthraquinone, 1-chloroanthraquinone, 9 , 10-phenanthrenequinone, diphenyl disulfide, 2
-naphthalenesulfonyl chloride, ω-bromoacetophenone, eosin, thionine, and benzophenone. Preferred photoinitiated mixtures for inclusion in the adhesive layer include:
(i) and (ii) below: i.e. (i); [wherein R ₃ and R ₄ are the same or different and are selected from hydrogen or lower alkyl groups having up to 6 carbon atoms, and
R ₅ is the same as or different from R ₃ or R ₄ and is hydrogen, lower alkyl with up to 6 carbon atoms, partially or fully halogen-substituted alkyl with up to 6 carbon atoms group, or the following formula: (wherein R ₆ and R ₇ are the same or different and are the same substituents as in R ₃ and R ₄ ). ] (ii) a compound of the formula (said compound is present in an amount of 0.01 to 2% by weight based on the weight of the unsaturated resin); (ii) and 0.1 to 7% based on the weight of the unsaturated resin;
% by weight of other photoinitiators preferably selected from among the photoinitiators listed above. R ₃ and R ₄ in compound (i) are preferably lower alkyl groups having up to 6 carbon atoms and
Most preferred since both R ₃ and R ₄ are methyl groups. R ₅ is preferably hydrogen, CF ₃ or of the following formula: where R ₆ and R ₇ are lower alkyl groups having up to 6 carbon atoms and most preferably both R ₆ and R ₇ are methyl groups. Compound (i) has the following formula:

【formula】

【formula】

The compound represented by the formula may be used, and the most preferred is 4,4'-bis(dimethylamino)-benzophenone, i.e., the compound represented by the following formula: It is a compound represented by The photoinitiator (i) in such additives, especially 4,
The amount of 4'-bis(dimethylamino)-benzophenone ranges from 0.01 to 1.0% by weight, based on the weight of the resin, and preferably from 0.01 to 1.0% by weight, based on the weight of the resin.
It is 0.5% by weight. The amount of photopolymerization initiator (ii) is 0.25 to 0.25 to the weight of the resin.
Preferably it is present in the additive in the range of 5.0% by weight. Preferred photoinitiators for use in the adhesive layer of the present invention include isopropyl benzoin ether and 4,4'-bis(dimethylamino)-benzophenone. Such additives include about 5% by weight of isopropyl benzoin ether and about 0.25% by weight of 4,4'-bis(dimethylamino)-benzophenone (both amounts based on the weight of the resin); Particularly effective. The adhesive layer may be used to improve properties such as adhesion, slip and blocking resistance of the photopolymerizable layer which are important to the general handling and windability of the film substrate to which the adhesive layer is applied. It may contain up to 10% by weight, based on the weight of the resin, of one or more inert particulate materials. Suitable particulate materials include inorganic particles such as silica and alumina hydrates having an average particle size in the range of 0.1 to 30 μm. The adhesive layer is applied to the surface of the film or sheet by suitable known coating techniques as a solution in an organic solvent such as acetone, methyl ethyl ketone, methylene chloride or methanol, a chlorinated hydrocarbon, or an alcohol. Preferably applied. After applying such a solution, the adhesive
It is preferred to dry to a dry coating thickness of 0.1 to 15 μm, and most preferably to a dry coating thickness of 0.2 to 8 μm. A thickness of less than 0.1 μm will result in poor adhesion to the film, while a thickness of more than 15 μm will result in cohesive failure within the adhesive layer. Self-help plastic films or sheets are made of cellulose esters such as cellulose acetate, polystyrene, polyamides, polymers and copolymers of vinyl chloride, polycarbonates, polymers and copolymers of olefins such as polypropylene, polysulfones and e.g. terephthalic acid, isophthalic acid, phthalic acid, 2,5
-, 2,6- and 2,7-naphthalene dicarboxylic acids, succinic acid, sebacic acid, adipic acid, azelaic acid, diphenyldicarboxylic acid and dicarboxylic acids such as hexahydrophthalic acid or bis-p-carboxylphenoxyethane. or lower alkyl diesters thereof, optionally in combination with a monocarboxylic acid such as pivalic acid, for example, ethylene glycol, 1,
It can be obtained by condensation with one or more glycols such as 3-propanediol, 1,4-butanediol, neopentyl glycol and 1,4-cyclohexane-dimethanol. Films of biaxially oriented and heat set polyethylene terephthalate are particularly useful for the production of film supports according to the invention and can be processed by any known process, for example as disclosed in GB 838,708. It can be manufactured even if it is bent. The surface of the polyester film support may be subjected to an adhesion-promoting pretreatment prior to coating with the adhesive layer. Pretreatment can be used to prepare the film surface, e.g.
0.5 to 20% by weight p-chloro-m-cresol, 2,4-dichlorophenol, 2,4,6-
Alternatively, a solution prepared by dissolving 2,4,5-trichlorophenol or 4-chlororesorcinol in a common organic solvent such as acetone or methanol, or a solution prepared by dissolving a mixture of the above substances in a common organic solvent may be used to swell or swell the film. Preferably, the method includes being subjected to the action of a substance having a dissolving action. Optionally, the pretreatment solution also contains:
Adhesion promoting resins such as partially hydrolyzed or non-hydrolyzable copolymers of vinyl chloride-vinyl acetate may be included. After applying such a solution to the film surface, the film is dried at an elevated temperature for a few minutes before applying the adhesive composition. The pretreatment step can alternatively be omitted and a substance having a swelling or dissolving effect on the polyester film is included in the adhesive composition and the amount of said swelling or dissolving component is 1 part by weight of the copolymer component. about 5 parts by weight. Photopolymerizable materials are produced by injection molding a liquid photopolymerizable layer onto an adhesive layer already applied to the film or sheet. The photopolymerizable layer typically has a thickness of 2000 to 8000 Å in the presence of a photoinitiator.
and a suitable photoinitiator. The photopolymerizable organic unsaturated substance includes an ethylenically unsaturated polymerizable monomer and/or an unsaturated polymer. UK patent no.
As disclosed in No. 1321108, suitable ethylenically unsaturated addition polymerizable monomers include styrene, chlorostyrene, vinyltoluene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate, N,N'-methylenebis acylamide, acrylamide, methacrylamide,
N-hydroxyethyl acrylamide, N-hydroxymethacrylamide, α-acetamide
Acrylamide, acrylic acid, methacrylic acid,
α-chloroacrylic acid, p-carboxystyrene, 2,5-dihydroxystyrene, methyl acrylate, methyl methacrylate, n-butyl acrylate, isobutyl acrylate,
Ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene
Glycol dimethacrylate, triethylene glycol diacrylate, triethylene
Glycol dimethacrylate, trimethylene glycol diacrylate, trimethylene glycol dimethacrylate, tetraethylene
Includes glycol diacrylate and tetraethylene glycol dimethacrylate. Suitable unsaturated polymers include unsaturated polyesters and unsaturated polyurethanes. Such unsaturated polyesters include ethylene glycol, diethylene glycol, triethylene glycol,
Tetraethylene glycol, polyoxyethylene glycol, propylene glycol, dipropylene glycol, represented by the following formula: HO-(CH ₂ CH ₂ -O) _o -H (wherein n is an integer from 5 to 50); formula: (wherein m is an integer from 3 to 30), polyoxypropylene glycol represented by the following formula: HO( _CH2 - _CH2 - _CH2 - _CH2 -O) _x -H (wherein x is an integer from 2 to 30) and -
(CH ₂ −CH ₂ −O) _a − group and −(CH ₂ −CH ₂ −
O) A copolyglycol comprising _b -groups (in which a and b may be the same or different and are integers from 2 to 50), such as maleic acid, fumaric acid, itaconic acid, mesaconic acid, It can be obtained by reaction with unsaturated dicarboxylic acids such as glutaconic acid, or their esters or anhydrides, such as dimethyl or diethyl esters or maleic anhydride. Such unsaturated polyurethanes are obtained by reacting unsaturated polyesters having terminal hydroxyl groups with polyisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate. Unsaturated polyesters having terminal hydroxyl groups are produced by polycondensation of the above-mentioned unsaturated dicarboxylic acids and the above-mentioned excess diols. The polymerization initiator is preferably included in the photopolymerizable layer and comprises one or two of the initiators listed above as preferably included in the adhesive layer. The amount of such photoinitiator used in the polymerizable material preferably ranges from 0.001 to 10% by weight, based on the total weight of the polymerizable composition. If desired, a photopolymerization initiator having the structure of initiator (i) in the adhesive layer may be optionally contained in the photopolymerizable layer. Known stabilizers can be used to maintain the storage stability (shelf life) of photopolymerizable substances.
Typical stabilizers include hydroquinone, mono-tert-butylhydroquinone, benzoquinone, 2,5
-diphenyl-p-benzoquinone, pyridine, phenothiazine, p-diaminobenzene, β-naphthol, naphthylamine, pyrogallol, copper chloride and nitrobenzene. These stabilizers are added to completely inhibit the polymerization reaction in the absence of actinic radiation, such as the radiation used in the manufacture of printing plates. The amount of stabilizer is preferably from 0.005 to 3.0% by weight of the total weight of the photopolymerizable composition. Fillers or binders may also be included within the photopolymerizable layer. Examples of suitable binders include cellulose esters such as acetyl cellulose acetate, hydrogen succinate, nitrocellulose, cellulose acetate pyropionate and cellulose butyrate, polyvinyl alcohol derivatives such as polyvinyl butyral, poly-ε-caprolactam, polyhexamethylene glycol, etc. Polyamides such as bacamide,
copoly (ε-caprolactam hexamethylene sebamide and/or adipamide) and suitable fillers include glass, mica, potter's clay, silica, asbestos, magnesium silicate, magnesium carbonate, alumina and powdered polyethylene. Contains terephthalate. Photopolymerizable layers are generally polymerized by actinic radiation having a wavelength of 2000 to 8000 Å. Practical sources of such actinic radiation include carbon arc lamps, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, UV fluorescein lamps, xenon lamps and sunlight. The production of printing plates begins with a photopolymerizable material as described above, ie a material comprising a film or sheet, an adhesive and a photopolymerizable layer. In a preferred embodiment of the invention, relief printing plates are produced from photopolymerizable materials by a process comprising exposing the material to actinic radiation sequentially from each side of the material. The self-supporting plastic film or sheet to be used in the material should be transparent to the wavelength of light used for photopolymerization. The photopolymerized layer is held tightly adhered to the film or sheet via the adhesive and provides excellent removal of uncured areas of the photopolymerized layer. The shape of the photopolymerizable material according to the invention is explained below with reference to the accompanying drawings, as well as the production of relief printing plates from the material. In the accompanying drawings, FIG. 1 is a cross-sectional view of a substrate comprising a thermoplastic film and an adhesive layer, and FIG. 2 is a cross-sectional view of a substrate in combination with a photopolymerizable layer and arranged for exposure through a master. 1 is a cross-sectional view of the substrate shown in FIG. 1; FIG. 3 is a cross-sectional view showing the effect of exposing the assembly shown in FIG. 2; and FIG. 4 is a cross-sectional view of the completed printing plate. . FIG. 1 shows a conventional transparent biaxially oriented and heat-set polyethylene terephthalate film 1, the surface 2 of which is
5.0 g p-chloro-m-cresol dissolved in 100 ml acetone to obtain a coating weight of mg/dm ²
pretreated by coating with a solution consisting of 1.0 g of a partially hydrolyzed copolymer of vinyl chloride and vinyl acetate (commercially available as "Vinylite" VAGH) and drying at 90° C. for 2 minutes; This dried layer is designated by 3 in FIG. The adhesive layer 4 was obtained by coating the adhesive composition onto the pretreated layer 3. the applied adhesive composition,
Heat and dry at 100℃ for 2 minutes to form dry adhesive layer 4.
I got it. The substrate illustrated in FIG. 1 can be used in the production of photopolymerizable materials and photorelief plates such as those illustrated in FIGS. 2 and 3. The manufacturing procedure includes placing the master on a supporting glass plate 7. The master 6 comprises a conventional photographic negative of the pattern to be formed on the film base material and having radiopaque areas 8 and transparent areas 9 of deposited silver. For simplicity of illustration, the master film support and underlayers are not shown in the drawings. A radiation transparent thermoplastic protective membrane 10 was placed over the master 6. A layer 11 of photopolymerizable material is applied to the protective film 10 by injection and application to a uniform thickness.
It was placed above the . A film base as shown in FIG. 1 was then placed over layer 11 with adhesive layer 4 in contact with the polymerizable material. Polymeric materials can be cured by ultraviolet light. A glass plate 12 was then placed on top of the film base material. A short exposure, i.e. about 12 seconds of ultraviolet light exposure above the film base material and in the direction of arrow A, bonds the layer 11 with the adhesive 4 and as a basis for the relief image the base layer 13 of photopolymerizable material. (See Figure 3) was cured. A longer period of UV exposure, ie about 60 seconds, was then carried out past the master 6 in the direction of arrow B to harden the image areas 14 of the photopolymerizable material corresponding to the transparent areas 9 of the master 6. Finally, master the film assembly 6.
The protective layer 10 was separated from the glass plate 7 and the protective layer 10 was peeled off from the photopolymerizable layer 11. The polymeric material was then washed in a solvent, such as a solution of borax, to remove uncured areas 15 of the polymeric material that corresponded to impermeable areas 8 of master 6. The finished printing plate is illustrated in FIG. 4 and has a printing relief area 14. The total thickness of base layer 13 and relief region 14 was approximately 500 μm. The relief image of the printing plate according to the invention has a strong adhesion to the film base material, so that it can withstand repeated use in a rotary printing press without damage. Furthermore, images with excellent halftone detail and sharpness can be formed with strong adhesion. The printing plates are therefore suitable for use in continuous letterpress and flexographic printing presses and can be used, for example, in newspapers, magazines, forms, and other printing applications. Examples 1 to 3 A substrate having a structure as described in connection with FIG. 1 is replaced with an adhesive layer 4 of a partially hydrolyzed copolymer of vinyl chloride and vinyl acetate, and a pretreated layer 3 consisting of a transparent polyethylene terephthalate film having a thickness of 100 μm. Manufactured by applying. In each of Examples 1 to 3, the unsaturated resin used to form the adhesive layer has a molecular weight range of 3000 to 3000.
Propoxylated bisphenol A with 4000-
Fumarate resin (Atlas Chemical
Commercially available as "Atlac" 33-05 from Industries NV) and the resin was applied as a solution in methyl ethyl ketone to obtain a dry adhesive layer having the thickness indicated in the table. No photoinitiators or special additives were included in the coating composition for the adhesive layer. The photopolymerizable layer 11 is made of Herculus.
photopolymer resin FAl40 (commercially available from Herculus). Images with excellent sharpness are produced in the photopolymerizable layer 11 by the imaging operations described with respect to FIGS. 2, 3, and 4.
formed within. The adhesion of the photopolymerized layer 11 to the substrate was found to be excellent and to withstand repeated use on a printing machine. The adhesive strength of the photopolymerizable layer 11 is
The layer was uniformly exposed in the direction of arrow B over the entire area of the layer (i.e. omitting master 6) and then photopolymerized at 20° C. and 60% relative humidity at a peel rate of 10 cm per minute. The assembly was evaluated by subjecting it to a 180° peel test at the interface of the adhesive layer. By providing a non-adhesive film during the application of the photopolymerizable layer 11, the layers are coated in a small area between the photopolymerizable layer and the adhesive layer in order to provide a grip for the peel test and to facilitate their release. , separated across the region. The peel strength is shown in the table.

[Table] Comparative Example A solution of 5.0 g of p-chloro-m-cresol and 1.0 g of a partially hydrolyzed copolymer of vinyl chloride and vinyl acetate ("Vinyrite VAGH") dissolved in 100 ml of acetone was applied at a wet application rate of 100 mg/dm ² An adhesive layer followed by a photopolymerized layer was applied to one side of a 100 μm thick biaxially oriented and heat set polyethylene terephthalate film, which had been previously treated on the coated side by coating and drying at 90° C. for 2 minutes. Four test films were prepared by coating the adhesive layer applied to the pretreated film surface as follows: (a) applied as a 4% by weight solution of methyl ethyl ketone and dried to a coating thickness of 1 μm; molecular weight
3000-4000 unsaturated propoxylated bisphenol A-fumarate resin (“Atlac” 33-05) (b) Adhesive layer with the following composition, coating thickness 5 μm: Polyester urethane (“Estane”) ”
5715) 20g benzoyl isopropyl ether (photoinitiator:
"Glocure" 31) 0.5 g Silica particles (available as Gasil 64) 0.9 g Methyl ethyl ketone 100 g (c) Polyester derived from propanediol and a 1:1 mixture by weight of phthalic acid and maleic acid 10 g Benzoyl 0.5 g of isopropyl ether photoinitiator (“Glocure” 31) 100 g of methyl ethyl ketone (d) 10 g of polyester derived from propanediol and a 2:1 weight mixture of phthalic acid and maleic acid Glocure 31) 0.5 g methyl ethyl ketone 100 g Samples coated with binder layers (a), (b), (c) and (d) were coated with Glocure photopolymer resin.
It was further coated with a photopolymerizable layer comprising FAl40 to a thickness of 500 μm. Each assembly was then exposed to UV light in a Kalvatone UV exposure unit as follows: Exposure 1: 1600uw/ ^cm2 force for 30 seconds through polyethylene terephthalate film; Exposure 2: 3500uw/ ^cm2 force. 150 seconds on the photopolymerizable layer; Exposure 3: further 600x on the photopolymerizable layer at 300xw/ ^cm2 ;
Exposure for seconds. The adhesive strength of the photopolymerized layer applied to the base film was evaluated as peel strength by the peel test described above, and the results are shown below.

[Table] As is clear from the results in the table above, the adhesive strength obtained by the unsaturated propoxybisphenol A-fumarate resin layer (a) is greater than that obtained by the other adhesive layers (b) to (d). The adhesive strength obtained is far superior.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a substrate comprising a thermoplastic film and an adhesive layer; FIG. 2 is a cross-sectional view of the substrate shown in FIG. 1 in combination with a photopolymerizable layer and positioned for exposure through a master; 3 is a cross-sectional view of the assembly shown in FIG. 2 after exposure, and FIG. 4 is a cross-sectional view of the completed printing plate. 1... Biaxially stretched and heat-set polyethylene terephthalate film, 4... Adhesive layer,
6... Master, 11... Photopolymerizable material layer, 14... Relief area.

Claims (1)

[Scope of Claims] 1. A self-help plastic film or sheet having an adhesive layer overlaid on at least one side of the film or sheet, and a photopolymerizable layer overlaid on the adhesive layer in interfacial contact. a photopolymerizable material comprising: the adhesive layer having the formula: (wherein R ₁ and R ₂ are the same or different and represent a lower alkyl group having up to 6 carbon atoms, x and y are the same or different and are integers from 1 to 4 inclusive, and (n is an integer including 4 to 30) A photopolymerizable material comprising an unsaturated resin having a repeating unit represented by: 2 Lower alkyl group R ₁ of the unsaturated resin and
A photopolymerizable material according to claim 1, wherein R ₂ is methyl or ethyl. 3. The photopolymerizable material according to claim 1 or 2, wherein the integers x and y of the unsaturated resin are 2 or 3. 4. The photopolymerizable material according to any one of claims 1 to 3, wherein the integer n includes 8 to 12. 5. The photopolymerizable material according to any one of claims 1 to 4, wherein the unsaturated resin is a propoxylated bisphenol A fumarate condensate. 6. The photopolymerizable material according to any one of claims 1 to 5, wherein a photopolymerization initiator is contained in the adhesive layer. 7. The photopolymerizable material according to any one of claims 1 to 6, wherein the self-helping plastic film is a biaxially stretched and heat-set polyethylene terephthalate film. 8. A relief printing plate superimposed on at least one side of a self-help plastic film or sheet of the following formula: (wherein R ₁ and R ₂ are the same or different and represent a lower alkyl group having up to 6 carbon atoms, x and y are the same or different and are integers from 1 to 4 inclusive, and (n is an integer including 4 to 30) The film or sheet has an adhesive layer containing an unsaturated resin having a repeating unit represented by A relief printing plate as described above, comprising a photopolymerizable material comprising a photopolymerizable layer, the photopolymerizable material having a relief image formed within the photopolymerizable layer of the material.