JP3166985B2 - Support for polyurethane-based photosensitive resin printing plate and polyurethane-based photosensitive resin printing plate using the support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support for use in producing a printing plate using a polyurethane-based liquid photosensitive resin, and more particularly, to a photocurable polyurethane-based photosensitive resin layer which is firmly adhered to the support. A support for a polyurethane-based photosensitive resin printing plate, which has good workability in a plate making process and a printing process, gives good plate thickness accuracy as a printing plate in the plate making process, and can form a good relief, and the support The present invention relates to a polyurethane-based photosensitive resin printing plate using the same.

[0002]

2. Description of the Related Art In recent years, a method of using a photosensitive resin in the production of a printing plate has been developed, and the handling in the plate making process and the printing process is simple, and a printing plate having a precise and complicated image can be easily manufactured. For this reason, it has been widely used instead of the conventional electrolytic corrosion plate method, paper mold lead plate method, rubber plate method and plastic plate method.

[0003] There are two types of photosensitive resins, liquid and solid, which are appropriately used depending on the purpose of use. It has the advantage that it can be set arbitrarily, and has the advantage that the uncured resin generated during the plate making process can be collected and reused. It is particularly advantageous.

Recently, in a photosensitive resin printing plate having excellent printing performance, for example, in corrugated cardboard printing, there is no need to stop the operation of the printing press during printing and perform wiping of the printing plate. A photosensitive resin plate has been developed. In such a photosensitive resin plate, for example, a polyurethane adhesive or an adhesive composed of a vinyl chloride copolymer is applied to a liquid photosensitive resin composed of an unsaturated polyurethane prepolymer having an ethylenic double bond. A supported support is used. However, the conventional support used when making a plate using such a liquid photosensitive resin does not always sufficiently satisfy the performance required for the photosensitive resin plate, and therefore, a further improved one is desired. Have been.

By the way, in a plate making process for manufacturing a photosensitive resin printing plate using a liquid photosensitive resin, a back deposition layer is usually formed for the purpose of shortening the plate making time and improving the handleability of the plate. Since the back deposition layer is formed by irradiating active light from the support side, after the exposure step,
The photo-cured back deposition layer comes into contact with the uncured layer, and there is a portion where the photocrosslinking reaction is not sufficiently performed at the interface between the cured layer and the uncured layer. Therefore, unless the resin at the interface where the photocrosslinking reaction is not sufficiently performed is sufficiently washed off in the developing step, an extremely strong adhesive portion is formed on the surface of the back deposition layer of the plate after the plate making is completed. In order to obtain a plate with excellent handleability as a photosensitive resin printing plate, in this development process, simply remove the uncured resin that has not reached the actinic ray by using a washing machine using a brush or spray. In addition, it is necessary to forcibly remove the resin having an insufficient photocrosslinking reaction at the interface between the back deposition layer and the uncured resin, and to remove the adhesive portion on the back deposition layer surface. For this reason, if the adhesive strength between the support and the back deposition layer is not strong, a part or the whole of the back deposition layer is peeled off from the support by the brush pressure or spray water pressure used in the developing step, and the plate making and printing work is performed. A printing plate that significantly reduces efficiency. In particular, when the post-treatment such as drying and post-exposure is performed while a part of the cured resin peeled off in the development process is re-adhered to the relief or the image area, the adhered resin reacts again in the post-exposure process and is removed. This makes it difficult to use it as a normal printing plate.

[0006] Normally, once a printing plate has been used,
Normally, it is reused about 2 to 5 times, so it is attached to the plate cylinder of the printing press with double-sided adhesive tape. After printing, the plate is detached from this plate cylinder, and the printing plate dirty with ink etc. is washed with a cleaning agent. It is cleaned and stored until reuse, and this storage period can be as long as one to five years.

Since the photosensitive resin printing plate is subjected to such handling, reuse and storage, if the photocured resin and the support are not firmly adhered to each other, the plate mounted on the printing machine cannot be used. The support and the cured resin layer may peel off during the work of detaching from the plate cylinder, and if the adhesive layer of the support deteriorates under the influence of temperature and humidity during storage of the plate, the cured resin and The adhesive strength with the support is remarkably reduced, resulting in unfavorable situations such as the resin plate peeling off from the support during printing preparation work or printing, and cannot be used as a printing plate.

Furthermore, even if the adhesive performance of the support is sufficient, if the surface of the adhesive applied to the substrate is tacky, the handling of the support in plate making preparation and plate making work and the work of plate making can be performed. Efficiency is significantly reduced and practicality is lost. For this reason, conventionally, for the purpose of improving the plate making operation and maintaining the flatness of the support, a thin protective film is stuck on the surface of the adhesive layer to adhere the adhesive to the support that has conventionally been tacky and has low slippage. Prevention has been done. However,
The support with the protective film attached thereto is used by peeling off the protective film immediately before plate making, so that the plate making workability is reduced, and a process of attaching the protective film at the time of manufacturing the support is added, so that the manufacturing cost is increased. I can not escape.

[0009]

DISCLOSURE OF THE INVENTION The present invention strongly adheres to a photocurable polyurethane-based photosensitive resin layer, has good handleability in a plate making process and a printing process, and has excellent adhesive strength even in long-term storage. In addition to maintaining and providing a good plate thickness accuracy as a printing plate, a polyurethane-based photosensitive resin printing plate support capable of forming a good relief and a polyurethane-based photosensitive resin printing plate using the support are provided. It was made for the purpose of providing.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on a support for a printing plate of a photosensitive resin of a polyurethane-based resin, and as a result, a printing plate is manufactured by using a polyurethane-based liquid photosensitive resin. It has been found that the object can be achieved by laminating three layers made of a specific material on a substrate in a support to be used at that time, and based on this finding, the present invention has been completed.

That is, the present invention relates to a first layer composed of a polyester resin, a second layer composed of an acrylic resin or a modified cellulose resin or a mixture thereof, and an adhesive containing a vinyl chloride polymer, a photopolymerization initiator and ethyl cellulose as components. A support for a polyurethane-based photosensitive resin printing plate having a structure in which a third layer composed of a composition for use is laminated on a substrate in that order, and a polyurethane-based photosensitive resin printing plate using the support. is there.

The substrate of the support of the present invention is not particularly limited, and those conventionally used for liquid photosensitive resin printing plates, for example, transparent and flexible polyethylene terephthalate having a thickness of about 50 to 5000 μm, Films such as polypropylene, triacetate resin, and polystyrene can be used.

The support of the present invention is provided with a composite layer having a three-layer structure on these substrates, and the first layer of the lowermost layer where the composite layer contacts the substrate is a polyester resin such as It is made of polyethylene terephthalate resin. This polyester resin is, for example, Byron 20
0, 300 and 530 (all trade names, manufactured by Toyobo Co., Ltd.), polyester resin No. 49000 and 49001 (all trade names, manufactured by DuPont), Ester 1510 (trade name, manufactured by Hitachi Chemical Co., Ltd.), and Stuffix PCL (trade name, manufactured by Fuji Photo Film Co., Ltd.). Further, the polyethylene terephthalate resin softens at a temperature of about 100 to 200 ° C. and has self-fusing properties.

The first layer made of these polyester resins, for example, polyethylene terephthalate resin, is formed by applying these organic solvent solutions on a substrate and removing the solvent by drying or by co-extrusion with the substrate. In particular, the latter coextrusion method is advantageous. As the film used in the coextrusion method, a film having a heat sealing property is preferable. Such a film is, for example, Lumirror E-35 (trade name, manufactured by Toray Industries, Inc.), Melinex 343, XR-1.
433 (both are trade names, manufactured by ICI). The thickness of the first layer is usually selected in the range of 1 to 30 μm.

In the support of the present invention, an acrylic resin, a modified cellulose resin, or a mixture thereof is used for the second layer provided on the first layer.

As the acrylic resin, for example, a methyl methacrylate polymer or methyl methacrylate and n-
Copolymers with butyl methacrylate are exemplified, and these are commercially available as Dianal (manufactured by Mitsubishi Rayon Co., Ltd.). As the modified cellulose resin, for example, cellulose acetate propionate and cellulose acetate butyrate are preferable, and these are commercially available as CAP and CAB (both manufactured by Eastman Chemical Company).

The second layer composed of these resins is dissolved in a suitable organic solvent such as toluene, methyl ethyl ketone, ethyl acetate, 1,4-dioxane, tetrahydrofuran, N-methylpyrrolidone, methylene chloride and the like. As a solution with a concentration of about 30% by weight,
It can be formed by applying to the surface of the first layer and removing the solvent by drying. In this case, by using a solvent that dissolves or swells the first layer, the first layer and the second layer can be sufficiently integrated. The thickness of the second layer is usually selected in the range of 0.5 to 5 μm.

In the support of the present invention, a third layer provided on the second layer may be a photocurable polyurethane-based photosensitive resin layer (hereinafter also referred to as a photocurable photosensitive resin layer) with a low dose of active light. )), A bonding composition containing a vinyl chloride copolymer, a photopolymerization initiator, and ethylcellulose as components, which adheres strongly. As the vinyl chloride copolymer, for example, a copolymer of vinyl chloride and vinyl acetate,
Copolymers of vinyl chloride, vinyl acetate, and vinyl alcohol, copolymers of vinyl chloride, vinyl acetate, and maleic anhydride, and the like are used.

The photopolymerization initiator used in combination with these vinyl chloride copolymers is for promoting the adhesive strength between the polyurethane-based photosensitive resin layer photocured at a low irradiation dose and the adhesive composition. Thus, as such a photopolymerization initiator,
For example, 2,2-dimethoxy-2-phenylacetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, α-methyl benzoin, benzyl,
Diacetyl, ω-bromoacetophenone, anthraquinone, diphenyl disulfide, 2-naphthalenesulfonyl chloride, eosin, thionin and the like are used.

The adhesive composition contains ethyl cellulose in order to increase the affinity between the adhesive composition and the polyurethane photosensitive resin. As the ethyl cellulose, for example, one containing 43 to 50% by weight of an ethoxy group is preferable.

The adhesive composition may further contain, if desired, powdered silica or the like as an antiblocking agent and a dye or the like as an antihalation agent.

The third layer is formed by dissolving the bonding composition in a suitable solvent, applying the solution as a solution having a solid concentration of about 10 to 30% by weight on the second layer, and removing the solvent by drying. can do. The thickness of this third layer is usually 1
It is selected in the range of 10 to 10 μm. The total thickness of the adhesive layer including the first layer, the second layer, and the third layer is preferably in the range of 5 to 50 μm.

In the thus obtained support of the present invention, the adhesion between the respective layers, that is, the adhesion between the substrate and the first layer composed of the polyester resin, and the adhesion between the first layer and the acrylic resin or the modified cellulose. The adhesion between the second layer and the second layer and between the second layer and the third layer made of the adhesive composition is extremely good, and the third layer and the photocurable photosensitive resin layer are firmly adhered to each other.

FIG. 1 is a sectional view showing an example of the structure of a support for a photosensitive resin printing plate of the present invention. A first layer 2, a second layer 3 and a third layer 4 are formed on a substrate 1. The structure provided sequentially is shown.

The printing plate of the present invention can be obtained by providing a layer comprising a polyurethane-based liquid photosensitive resin composition as a photosensitive layer on the support of the present invention and making a plate by a conventional method. The liquid photosensitive resin composition contains an unsaturated polyurethane prepolymer having an ethylenic double bond, which has fluidity at room temperature and can be crosslinked with a photopolymerization initiator which is easily activated by actinic rays. Are preferred.

[0026]

The support for a photosensitive resin printing plate of the present invention comprises:
An adhesive layer consisting of a three-layer structure is provided on a substrate, which is firmly adhered to the photocurable photosensitive resin layer, has good handleability in the plate making process and printing process, and is excellent in long-term storage. In addition to maintaining the adhesive force, the printing plate can provide good plate thickness accuracy and can form a good relief. In addition, the adhesive layer surface has extremely low tackiness, and there is no need to provide a protective film for preventing sticking.
It is suitably used as a support when producing a printing plate using a liquid photosensitive resin. Further, in the photosensitive resin printing plate of the present invention, the photocurable photosensitive resin layer and the support are firmly adhered,
Good handleability in printing process and good plate thickness accuracy.

[0027]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

Example 1 A first layer of a 100 μm-thick composite polyethylene terephthalate film (Lumirror E-35, manufactured by Toray Industries, Inc.) in which a first layer of a polyester resin layer was previously provided with a thickness of 5 μm. A methyl methacrylate polymer [Diana B-80, manufactured by Mitsubishi Rayon Co., Ltd.]
Was applied by a roll coating method at a solid content of 3 g / m ² , and the solvent was removed by drying to form a second layer made of an acrylic resin.

Next, 25 parts by weight of a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol (Vinylite VAGH, manufactured by UCC) and 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651, manufactured by Ciba Geigy) 3 parts by weight, ethylcellulose (Ethocel STDN)
4, an adhesive coating consisting of 5 parts by weight of Dow Chemical Co., 2 parts by weight of microsilica [Esilyl R-972, manufactured by Nippon Aerosil Co., Ltd.] and 140 parts by weight of a solvent (methyl ethyl ketone / toluene / ethyl acetate / isopropyl alcohol) The liquid was applied on the second layer at a solid content of 3 g / m ² , and the solvent was removed by drying to form a third layer, whereby a support for a photosensitive resin printing plate of the present invention was produced.

Example 2 In Example 1, a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol (described above) was used as an adhesive coating liquid.
5 parts by weight, 2,2-dimethoxy-2-phenylacetophenone (supra) 3 parts by weight, ethylcellulose (supra) 5
Parts by weight, 2 parts by weight of micro silica (described above), polypropylene glycol monomethacrylate [ppm-100
0, manufactured by Mitsubishi Rayon Co., Ltd.] 3 parts by weight, 2,6-di-t
The procedure of Example 1 was repeated, except that the third layer was formed using 0.2 parts by weight of n-butyl-p-cresol and 140 parts by weight of a solvent (methyl ethyl ketone / toluene / ethyl acetate / isopropyl alcohol). A support for a photosensitive resin printing plate of the invention was prepared.

Example 3 In Example 1, a layer having a thickness of 3 μm was formed using a 20% by weight solution of cellulose acetate butyrate (CAB-381-05, manufactured by Eastman Chemical Company) in ethyl acetate / tetrahydrofuran as the second layer. A support for a photosensitive resin printing plate of the present invention was prepared in the same manner as in Example 1 except that was formed.

Example 4 In Example 1, as the second layer, a layer having a thickness of 3 μm was prepared using a 20% by weight solution of cellulose acetate butyrate (CAB-500-01, manufactured by Eastman Chemical Company) in ethyl acetate / tetrahydrofuran. A support for a photosensitive resin printing plate of the present invention was prepared in the same manner as in Example 1 except that was formed.

Example 5 In Example 1, as the second layer, a copolymer of methyl methacrylate and n-butyl methacrylate [Dianal BR-107, manufactured by Mitsubishi Rayon Co., Ltd.] was used at 20% by weight of toluene / 1, 3μ thickness using 4-dioxane solution
A support for a photosensitive resin printing plate of the invention was prepared in the same manner as in Example 1 except that m was formed.

Comparative Example 1 In Example 1, the thickness was 100 μm without the first layer.
The second layer and the third layer of Example 1 were formed on the surface of a polyethylene terephthalate film (Melinex 505, manufactured by ICI Co., Ltd.) to produce a support for a photosensitive resin printing plate of a comparative example.

Comparative Example 2 In Example 1, a polyethylene terephthalate film (Melinex 5) having no first and second layers was formed.
05, manufactured by ICI Co., Ltd., 100 μm), the third layer of Example 1 was formed to prepare a support for a photosensitive resin printing plate of a comparative example.

Comparative Example 3 In Example 1, the third layer was composed of 25 parts by weight of a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol (described above) and a solvent (toluene / methyl ethyl ketone / ethyl acetate) 1
A support for a photosensitive resin printing plate of a comparative example was obtained in the same manner as in Example 1, except that the support was formed using an adhesive coating solution consisting of 30 parts by weight.

Application Example 1 Polypropylene glycol diol (number average molecular weight 20
00) 1 mol of a mixture of 1 mol of polytetramethylene glycol diol (number-average molecular weight 2000) with 2.4 mol of tolylene diisocyanate and 20 ppm of dibutyltin dilaurate were reacted at 80 ° C. for 2 hours to give isocyanate groups at both ends. Was obtained. Next, 2 mol of polypropylene glycol monomethacrylate (molecular weight: 380) was added thereto, and the special absorption of isocyanate groups in the IR spectrum (2260) was added.
(near cm ^-1 ) was hardly observed to obtain an unsaturated polyurethane prepolymer.

To 70 parts by weight of the prepolymer, 18 parts by weight of lauryl methacrylate, 12 parts by weight of tetraethylene glycol monomethyl ether monomethacrylate, 1.5 parts by weight of tetraethylene glycol dimethacrylate, 1 part by weight of trimethylolpropane trimethacrylate, A liquid photosensitive resin composition was prepared by adding 0.7 part by weight of 2-dimethoxy-2-phenylacetophenone and 0.5 part by weight of 2,6-di-t-butyl-p-cresol and mixing and dissolving.

Next, the liquid photosensitive resin composition was applied to the surface of the adhesive layer of each of the supports obtained in Examples and Comparative Examples so as to have a thickness of 1 mm.
0 nm) to cure the photosensitive resin composition to prepare test pieces, respectively, and a peeling test was performed on these test pieces. Table 1 shows the results.

[0040]

[Table 1]

(Note) In the peeling test, a constant-speed tensile peeling test was performed under the conditions of 180 ° peeling and a tensile speed of 50 mm / min, and the peeling was evaluated according to the following symbols. ○ The adhesion-imparting layers (first, second and third layers) are not affected and the photosensitive resin layer is destroyed. Δ: The photosensitive resin layer is partially broken or peeled off at the interface between the adhesion-imparting layers or the interface with the photosensitive resin. × Easy peeling at the interface between the adhesion-imparting layers or the interface with the photosensitive resin layer.

Examples 6 to 10, Comparative Examples 4 to 6 The thickness of the liquid photosensitive resin composition of Application Example 1 on the surface of the adhesive layer of each of the supports of Examples 1 to 5 and Comparative Examples 1 to 3. A 3 mm photosensitive layer is coated with a cover film, a negative film, and an APR flex exposure apparatus AJ manufactured by Asahi Kasei Corporation.
After forming using F-III type, relief exposure and back exposure were performed, and then uncured resin was recovered.

Next, using an aqueous developing solution containing 4% by weight of a surfactant and 0.4% by weight of a silicone-based antifoaming agent, a brush developing device APR-flex ALF-III400W type is used to form the surface of the back deposit layer. The uncured resin and the semi-cured resin were washed off, and after post-exposure and drying, the back deposit layer of the obtained plate was observed. Table 2 shows the results. In the table, the supports are those of Examples and Comparative Examples, and are indicated by respective numbers in that order.

[0044]

[Table 2]

Examples 11 to 15 and Comparative Examples 7 to 9 The thickness of the liquid photosensitive resin composition of Application Example 1 was formed on the surface of the adhesive layer of each of the supports of Examples 1 to 5 and Comparative Examples 1 to 3. After forming a photosensitive layer of 7 mm, cover film,
Negative film, masking film with matte one side, and APR flex exposure apparatus A manufactured by Asahi Kasei Corporation
Using JF-III, masking exposure, relief exposure, and back exposure were performed, and then uncured resin was recovered. Next, 4% by weight of a mixture of the surfactant AOS and nonylphenylethoxylate and the silicone-based antifoaming agent 0.1% were used.
Using an aqueous developing solution containing 4% by weight, the uncured resin and the semi-cured resin on the surface of the back deposit layer are washed away with a spray developing apparatus APRflex AJF-III400W type, and post-exposed in water and dried to obtain a thick film. Table 3 including 7 mm in thickness, 3.5 mm in the thickness of the shelf part, and 0.1 mm in the support.
A printing plate having a back thickness of the peeling limit shown in Table 1 was produced.

FIG. 2 is a cross-sectional view of the printing plate thus obtained, and shows a structure composed of the support 5, the back deposition layer 6, the shelf portion 7 and the relief portion 8. Table 3 shows the peeling limit thickness and the peeling shape of this printing plate. In the table, the supports are those of Examples and Comparative Examples, and are indicated by respective numbers in that order.

[0047]

[Table 3]

Application Example 2 Polypropylene glycol diol (number average molecular weight 20
00) 1 part by weight, 1 part by weight of polypropylene glycol adipate diol (number average molecular weight 2000) and 0.2 part by weight of tolylene diisocyanate were reacted to obtain a both-terminal isocyanate type urethane polymer. Next, this was reacted with polypropylene glycol monomethacrylate (molecular weight: 380) to obtain a polyurethane prepolymer modified at both ends with methacrylate (number average molecular weight: 1650).
0).

To 100 parts by weight of this prepolymer, 25 parts by weight of polypropylene glycol monomethacrylate (number average molecular weight 380), 15 parts by weight of lauryl methacrylate, 10 parts by weight of tetraethylene glycol dimethacrylate, 2,2-dimethoxy-2-phenylacetophenone 1.5 parts by weight and 0.2 parts by weight of 2,6-di-tert-butyl-p-cresol are added, to which erucamide 1.
5 parts by weight were added and mixed and dissolved to prepare a liquid photosensitive resin composition.

Next, the liquid photosensitive resin composition was applied to the surface of the adhesive layer of each of the supports obtained in Examples and Comparative Examples so as to have a thickness of 1 mm.
0 nm) to cure the photosensitive resin composition to prepare test pieces, respectively, and a peeling test was performed on these test pieces. Table 4 shows the results.

[0051]

[Table 4]

(Note) The peel test method and symbols are the same as those in Table 1 footnotes.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one example of a support for a photosensitive resin printing plate of the present invention.

FIG. 2 is a cross-sectional view of one example of a printing plate using the photosensitive resin printing plate support of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 1st layer 3 2nd layer 4 3rd layer 5 Support 6 Back deposit layer 7 Shelf part 8 Relief part

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masahiro Shimoyamada 1-1-1 Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (56) References JP-A-1-283557 (JP, A) JP-A-3-280051 (JP, A) JP-A-58-174946 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/09 G03F 7/00 502

Claims (2)

(57) [Claims] 1. A first layer comprising a polyester resin, a second layer comprising an acrylic resin or a modified cellulose resin or a mixture thereof, and an adhesive composition comprising a vinyl chloride polymer, a photopolymerization initiator and ethyl cellulose as components. A support for a polyurethane-based photosensitive resin printing plate having a structure in which a third layer is laminated on a substrate in that order. 2. A printing plate of a polyurethane-based photosensitive resin using the support of claim 1.