WO2013062082A1

WO2013062082A1 - Layered photosensitive-resin product for letterpress printing plate

Info

Publication number: WO2013062082A1
Application number: PCT/JP2012/077708
Authority: WO
Inventors: 本井　慶一; 雪美八和田
Original assignee: 東洋紡株式会社
Priority date: 2011-10-28
Filing date: 2012-10-26
Publication date: 2013-05-02
Also published as: JP6241034B2; JPWO2013062082A1

Abstract

A layered photosensitive-resin product (1) for letterpress printing plates which includes a support (2), an adhesive layer (3), a photosensitive resin layer (5), and a heat-sensitive mask layer (6), the layered photosensitive-resin product (1) further including an interlayer (4) between the adhesive layer (3) and the photosensitive resin layer (5), the interlayer (4) being constituted of a resin that has the same skeleton as the photosensitive resin which constitutes the photosensitive resin layer (5), having adhesiveness to the photosensitive resin layer (5), and having a Shore D hardness lower by at least 5º than the Shore D hardness of the photosensitive resin layer (5) that was photocured. The photosensitive resin layer (5) has a thickness in the range of 350-700 µm. Thus, it is possible to provide a layered photosensitive-resin product for letterpress printing plates which is excellent in terms of the reproducibility of fine independent dots and images during platemaking and printing.

Description

Photosensitive resin laminate for letterpress printing plates

The present invention relates to a photosensitive resin laminate used for producing a relief printing plate by computer plate making technology. More specifically, the present invention relates to fine independent points and image reproducibility excellent during plate making and printing. The present invention relates to an excellent photosensitive resin laminate for relief printing plates.

Conventionally, as a method for obtaining a relief printing plate, a photosensitive resin laminate (printing original plate) in which a photosensitive resin layer is provided on a support provided with an adhesive layer is used, and photolithography using a negative or positive film is performed. The method of forming the relief layer which formed the unevenness | corrugation in the photosensitive resin layer with the technique was common.

In recent years, in the field of letterpress printing, computer plate making technology (Computer to Plate: CTP technology) known as digital image forming technology has become extremely common. In the CTP technique, information processed on a computer is directly output on a printing plate to obtain a relief pattern that is a relief. Such a CTP technique eliminates the need for a negative film manufacturing process, thereby reducing the cost and the time required to create the negative.

For example, JP-A-7-506201 (Patent Document 1) includes (a) a support, (b) an elastomeric binder, one or more types of monomers, and an initiator sensitive to non-infrared actinic radiation. A photopolymerizable layer comprising a layer that is soluble, swellable or dispersible in a developer solution prior to exposure to actinic radiation, (c) a developer solution for the photopolymerizable layer prior to exposure to actinic radiation One or more barrier layers that are soluble, swellable, dispersible or liftable, and (d) one or more layers of an infrared sensitive material that is substantially opaque to actinic radiation, comprising infrared laser light A photosensitive printing material used to prepare a flexographic printing plate comprising a material that can be ablated from the surface of a barrier layer when exposed to light. In the invention disclosed in Patent Document 1, an infrared ray-sensitive layer (heat-sensitive mask layer) opaque to actinic radiation is provided on a photosensitive resin layer, and the infrared-sensitive layer is evaporated by an infrared laser to form an image mask. It is formed and widely used.

In recent years, the user's request for the photosensitive resin composition used in relief printing plates for letterpress printing has progressed in the direction of reproducing a fine pattern with a short exposure time, and the retention of the minimum independent point has changed from 200 μm in diameter to 100 μm. It is changing. Further, when used for printing for panel use, a finer 15 μm width is required from a 30 μm wide line. As a conventional technique that meets these requirements, a photosensitive resin laminate in which a photosensitive resin layer having a thickness of 200 μm or more is formed on a photosensitive resin layer that has been photocured over 100 μm or more on a support (for example, Japanese Patent Laid-Open No. 58-86) No. 85435 (see Patent Document 2) and a photosensitive resin laminate in which a soft resin cushion layer is provided on a support to improve image reproducibility (for example, JP-A-54-85803 (Patent Document 3). And a photosensitive letterpress printing original plate (see, for example, Japanese Patent Application Laid-Open No. 2010-26036 (Patent Document 4)) whose image reproducibility has been improved by the CTP technique.

However, any of the techniques disclosed in Patent Documents 2 to 4 described above provides a photosensitive resin laminate that can reproduce fine dots in a short exposure time in plate making and obtain a sharp printed matter with less weight during printing. Couldn't get.

On the other hand, Japanese Patent Application Laid-Open No. 2002-244302 (Patent Document 5) discloses a photosensitive resin laminate having at least a support, an adhesive layer, and a photosensitive resin layer, and an intermediate layer between the adhesive layer and the photosensitive resin layer. A photosensitive resin, wherein the intermediate layer has a rebound resilience after photocuring of 15% or more, and the Shore D hardness of the intermediate layer is 5 ° or more lower than that of the photosensitive resin layer A laminate is disclosed. According to the photosensitive resin laminate described in Patent Document 5, it is possible to improve the reproducibility of fine images during plate making and printing, but the adhesive strength at the interface between the intermediate layer and the photosensitive resin layer is improved. There was a problem that it was weak and caused delamination during printing.

JP 7-506201 A JP 58-85435 A JP-A-54-85803 JP 2010-26036 A JP 2002-244302 A

The present invention has been made in order to solve the above-mentioned problems, and its object is to provide a photosensitive resin for letterpress printing plates which is excellent in fine independent points and image reproducibility during plate making and printing. It is to provide a laminate.

As a result of diligent research, the present inventors finally completed the present invention in order to reproduce fine independent points and images with a short exposure time in plate making and to obtain a sharp printed material with less weight at the time of printing. It was. That is, the present invention is as follows.

The photosensitive resin laminate for a relief printing plate of the present invention is a photosensitive resin laminate for a relief printing plate comprising a support, an adhesive layer, a photosensitive resin layer, and a heat-sensitive mask layer. , Formed between the adhesive layer and the photosensitive resin layer with a resin having the same skeleton as the photosensitive resin constituting the photosensitive resin layer, having adhesiveness to the photosensitive resin layer, and after photocuring An intermediate layer having a Shore D hardness that is 5 ° or more lower than the Shore D hardness of the photosensitive resin layer is provided, and the thickness of the photosensitive resin layer is in the range of 350 to 700 μm.

The photosensitive resin laminate for relief printing plates of the present invention preferably has a total thickness in the range of 500 to 1000 μm.

In the photosensitive resin laminate for relief printing plates of the present invention, the Shore D hardness of the photosensitive resin layer after photocuring is preferably in the range of 45 to 75 °.

According to the present invention, it is possible to provide a photosensitive resin laminate for a relief printing plate having excellent reproducibility of fine independent points during plate making and printing, which greatly contributes to the industry.

It is a figure which shows typically the photosensitive resin laminated body 1 for relief printing plates of a preferable example of this invention.

FIG. 1 is a view schematically showing a photosensitive resin laminate 1 for a relief printing plate as a preferred example of the present invention. As schematically shown in FIG. 1, the photosensitive resin laminate 1 of the present invention comprises a support 2, an adhesive layer 3, an intermediate layer 4, a photosensitive resin layer 5, and a mask layer 6 in this order. It has a stacked basic structure.

[A] Support The support 2 used in the photosensitive resin laminate 1 of the present invention is flexible, but a material excellent in dimensional stability is preferable. Examples of such support 2 include metal supports such as steel, aluminum, copper, and nickel, and thermoplastic resin supports such as polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, and polycarbonate film. A suitable example is given. Among these, it is particularly preferable to use a polyethylene terephthalate film having excellent dimensional stability and sufficiently high viscoelasticity as the support 2.

The thickness of the support 2 is not particularly limited, but is preferably in the range of 50 to 350 μm, preferably 100 to 250 μm from the viewpoints of mechanical properties, shape stability, and handleability during plate making. It is more preferable to be within the range. When the thickness of the support 2 is less than 50 μm, there is a tendency that the dimensional stability of the printing plate is impaired or the support is damaged at the time of release, and the thickness of the support 2 exceeds 350 μm. This is because the printing plate tends to be difficult to follow along the cylinder when being applied to the cylindrical cylinder.

[B] Adhesive Layer The adhesive layer 3 used in the photosensitive resin laminate 1 of the present invention is formed using a known appropriate adhesive. The type of the adhesive used for forming the adhesive layer 3 is not particularly limited. For example, a polyester urethane adhesive obtained by curing a soluble polyester with a polyvalent isocyanate, an epoxy adhesive, and the like are preferable examples. Can be mentioned. Among these, a polyester urethane-based adhesive is preferable because of its excellent adhesiveness to a photosensitive resin, and among polyester urethane-based adhesives, an adhesive composed of polyester and isocyanurate type polyisocyanate is more desirable.

The adhesive used for forming the adhesive layer 3 may contain an additive as long as the object of the present invention is not impaired. Examples of the additives include plasticizers, dyes, ultraviolet absorbers, antihalation agents, surfactants, and photopolymerizable vinyl monomers.

The thickness of the adhesive layer 3 in the present invention is not particularly limited, but is preferably in the range of 1 to 50 μm, and more preferably in the range of 5 to 30 μm. This is because when the thickness of the adhesive layer 3 is less than 1 μm, the antihalation function tends to be insufficient, and when the thickness of the adhesive layer 3 exceeds 50 μm, the production processability decreases. It is because it is in a tendency.

[C] Intermediate layer The intermediate layer 4 used in the photosensitive resin laminate 1 of the present invention is formed of a resin having the same skeleton as the photosensitive resin layer 5 described later, and has adhesiveness to the photosensitive resin layer 5. It is. Since the intermediate layer 4 is formed of a resin having the same skeleton as the photosensitive resin layer 5, the adhesive strength at the interface between the intermediate layer 4 and the photosensitive resin layer 5 can be improved, and a fine image can be retained. In addition to the improvement, it is possible to prevent peeling of the interface between the intermediate layer 4 and the photosensitive resin layer 5 that occurs when mounted on a small-diameter cylinder during printing.

Examples of the resin having the same skeleton as the photosensitive resin layer 5 forming the intermediate layer 4 include polyether amide (Japanese Patent Laid-Open No. 55-79437), polyether ester amide (Japanese Patent Laid-Open No. 58-117537, etc.). ), Tertiary nitrogen-containing polyamide (JP-A-50-7605, etc.), ammonium salt type tertiary nitrogen atom-containing polyamide (JP-A-53-35555, etc.), an amide compound having at least one amide bond, Addition polymers with organic diisocyanate compounds (JP-A-58-140737, etc.), addition polymers of diamines having no amide bond and organic diisocyanate compounds (JP-A-4-97154, etc.) Those having the same skeleton are selected according to the resin forming the photosensitive resin layer 5. Among these, by forming the photosensitive resin layer 5 and the intermediate layer 4 with an addition polymer of a diamine having no amide bond and an organic diisocyanate compound, the resilience of the printing plate is increased, and the printability of fine images is increased. This is particularly preferable since the effect of further improving is achieved.

Here, “resin having the same skeleton” means that one or more constituent chemical bonds are the same, and preferable chemical bonds include amide bonds, urethane bonds, Examples include urea bonds and ether bonds. As the resin having the same skeleton, for example, when the resin forming the intermediate layer 4 and the resin forming the photosensitive resin layer 5 are both polyureaurethane skeletons represented by the following structural formula (1) (Example 1 described later) 4 to 8), when both the resin forming the intermediate layer 4 and the resin forming the photosensitive resin layer 5 have a polyamide skeleton as shown in the following structural formula (2) (Examples 2 and 3 described later) In the case of the above), the resin that forms the intermediate layer 4 and the resin that forms the photosensitive resin layer 5 both have a polyetheramide skeleton (in the case of Example 9 described later).

In the structural formula (1), R ¹ is a hydrocarbon group having 2 to 10 carbon atoms, an aliphatic ring or an aromatic ring, and R ² is a hydrocarbon group having 2 to 10 carbon atoms, an aliphatic ring or It is an aromatic ring and R ³ represents ethylene, propylene or tetramethylene.

In the above structural formula (2), R ⁴ is a hydrocarbon group having 4 to 10 carbon atoms, R ⁵ is a hydrocarbon group having 2 to 10 carbon atoms, an aliphatic ring or an aromatic ring, and R ⁶ Represents a hydrocarbon group having 4 to 10 carbon atoms.

In addition, the resin having the same skeleton is preferably the same skeleton as described above, but one or more of the chemical bonds configured as described above may be the same, and not necessarily the same skeleton. As in Example 10 described later, the case where the resin forming the intermediate layer 4 is a polyurethane skeleton and the resin forming the photosensitive resin layer 5 is a polyureaurethane skeleton is also included.

The intermediate layer 4 in the present invention has a Shore D hardness that is 5 ° or more lower than the Shore D hardness of the photosensitive resin layer 5 after photocuring. Since the intermediate layer 4 has such Shore D hardness, the cushioning effect due to the low hardness and high resilience of the intermediate layer 4 reduces the deformation of the photosensitive resin layer 5 due to the printing pressure, and the fineness at the time of printing. There is an effect that the reproducibility of the points can be improved. From the viewpoint of making such an effect more remarkable, the Shore D hardness of the intermediate layer 4 is preferably 10 ° or more lower than the Shore D hardness of the photosensitive resin layer 5 after photocuring, and is 20 °. More preferably, it is lower. If the difference between the Shore D hardness of the intermediate layer and the Shore D hardness of the photosensitive resin layer 5 after photocuring is less than 5 °, it is not preferable because the printability of the solid portion will be blurred. The Shore D hardness of the intermediate layer 4 and the photosensitive resin layer 5 was measured at 25 ° C. using, for example, a Shore type durometer (Shore D type) (manufactured by West German Zubik) in accordance with JIS K6253. Points to the value. In the present invention, the intermediate layer 4 may have a Shore D hardness that is 5 ° or less lower than the Shore D hardness of the photosensitive resin layer 5 after photocuring, but widens the printability of the solid portion. Therefore, in order to widen the material adaptability of the substrate, the adaptability of the printing pressure and the printing speed, the Shore D hardness of the intermediate layer 4 is preferably 10 ° or more, and preferably 20 ° or more. It is more preferable. When forming the intermediate layer 4, for example, by controlling the resin having the same skeleton as the selected photosensitive resin layer by the degree of crosslinking of the photopolymerizable monomer, the intermediate layer 4 having a desired Shore D hardness is formed. Obtainable. The degree of crosslinking of the photopolymerizable monomer can be changed by the number of crosslinking groups introduced into the photopolymerizable monomer. For example, the number of crosslinking groups may be controlled by introducing acrylic acid or methacrylic acid into the hydroxyl group in the polyhydric alcohol through an ester bond.

The intermediate layer 4 in the present invention preferably has a rebound resilience of 15% or more, more preferably 20% or more, and particularly preferably 30% or more. In this way, the rebound resilience of the intermediate layer 4 is 15% or more, and the Shore D hardness is lower by 5 ° or more than the Shore D hardness of the photosensitive resin layer 5 as described above. Can be made to act like a cushion, so that the deformation of the photosensitive resin layer 5 due to the printing pressure can be reduced, and the reproducibility of fine dots during printing can be improved. If the rebound resilience of the intermediate layer 4 is less than 15%, the cushion effect of the intermediate layer 4 is insufficient, which is not preferable. The rebound resilience of the intermediate layer 4 is a height at which a steel ball ball having a diameter of 10 mm (weight: 4.16) is dropped from a height of 20 cm and bounces under conditions of 25 ° C. and 70% RH (a). , And refers to the value measured as (a / 20) × 100% display. In the present invention, the higher the rebound resilience of the intermediate layer 4 is, the better.

In addition, when the intermediate layer 4 in the present invention requires washing oil resistance after printing, the solvent absorption weight increase rate of the intermediate layer 4 with respect to normal hexane is preferably 15% or less as washing oil resistance. It is more preferably 10% or less, and particularly preferably 5% or less. In addition, the solvent absorption amount increase rate of the intermediate layer 4 was determined by removing the normal hexane adhering to the surface after making a 2 cm × 5 cm sample with a sample thickness of 500 μm after exposure and immersing in normal hexane for 5 hours. After measuring
Solvent absorption weight increase rate (%) = (weight after immersion / weight before immersion) × 100
The value calculated by the following formula. In the present invention, the lower the solvent absorption increase rate of the intermediate layer 4 is, the better.

The intermediate layer 4 in the present invention preferably has a thickness of 50 μm or more, and more preferably 80 μm or more, from the viewpoint of cushion effect and strength. This is because when the thickness of the intermediate layer 4 is less than 50 μm, the cushioning effect tends to be poor. In the case of a printing plate with a thin total thickness, the thickness of the intermediate layer 4 is preferably 200 μm or less, and more preferably 150 μm or less so that ink does not adhere to the intermediate layer on the support.

In forming the intermediate layer 4, a photosensitive resin in which a known soluble polymer, a photopolymerizable unsaturated group-containing polymer, a photoinitiator polymerizer, or the like is appropriately blended with the resin having the same skeleton as the photosensitive resin layer 5 as described above. The composition can be suitably used. As a method of providing the intermediate layer 4 on the adhesive layer 3, a known method can be employed. For example, after the solution of the photosensitive resin composition described above is provided on the adhesive layer by a casting method, polyester or the like is used. A method in which the intermediate layer 4 is formed by irradiating with ultraviolet rays and photocuring in a state where oxygen is blocked may be employed.

[D] Photosensitive resin layer In the photosensitive resin laminate 1 of the present invention, the photosensitive resin layer 5 laminated on the intermediate layer 4 is formed by photocuring a photosensitive resin, and its thickness. Is in the range of 350 to 700 μm. When the thickness of the photosensitive resin layer 5 is less than 350 μm, ink adheres to the intermediate layer 4 and stains (background stains) occur in the non-image portions of the printed matter. On the other hand, when the thickness of the photosensitive resin layer 5 exceeds 700 μm, the reproducibility of fine points at the time of plate making is lowered. In particular, since the total thickness of the printing plate used for rotary seal label printing is often 800 μm or 950 μm, the thickness of the photosensitive resin layer 5 is preferably in the range of 450 to 700 μm, and preferably in the range of 490 to 650 μm. More preferably.

The hardness of the photosensitive resin layer 5 after photocuring is preferably 45 to 75 ° in Shore D hardness, more preferably 50 to 70 °, and more preferably 50 to 65 °. It is particularly preferable that the value falls within the range. When the Shore D hardness of the photosensitive resin layer 5 is less than 45 °, it is not preferable because the thickness increases due to deformation during printing, and when it exceeds 75 °, poor ink riding occurs. In addition, the printability of the solid part is unfavorable, which is not preferable. In addition, the photosensitive resin layer 5 which has desired Shore D hardness after photocuring can be obtained by irradiating with the photocuring time of the optimal range which forms an image pattern at the time of formation of the photosensitive resin layer 5. .

For the formation of the photosensitive resin layer 5, an essential component of a synthetic polymer compound, a photopolymerizable unsaturated compound and a photopolymerization initiator, which are materials for the photosensitive resin, a plasticizer, a thermal polymerization inhibitor, a dye, a pigment, A composition containing an optional additive such as an ultraviolet absorber, a fragrance, or an antioxidant is preferably used.

As the synthetic polymer compound, a conventionally known soluble synthetic polymer compound can be used. For example, polyether amide (for example, JP-A-55-79437), polyether ester amide (for example, JP-A-58-117537). Etc.), tertiary nitrogen-containing polyamide (for example, JP-A-50-7605), ammonium salt type tertiary nitrogen atom-containing polyamide (for example, JP-A-53-36555), and one or more amide bonds Addition polymer of amide compound and organic diisocyanate compound (for example, JP-A-58-140737), addition polymer of diamine having no amide bond and organic diisocyanate compound (for example, JP-A-4-97154) Etc. Among these, an addition polymer of a diamine having no amide bond and an organic diisocyanate compound is preferable. Examples of the photopolymerizable or photocrosslinkable monomer include acrylates of polyhydric alcohols, epoxy acrylates of polyhydric alcohols, N-methylol acrylamide, and the like. Examples of photopolymerization initiators include benzyl dimethyl ketal and benzoin dimethyl ether.

[E] Mask Layer In the photosensitive resin laminate 1 of the present invention, the heat-sensitive mask layer 6 formed on the photosensitive resin layer 5 has, for example, a function of absorbing infrared laser and converting it into heat and ultraviolet rays. It is preferably composed of carbon black, which is a material having a blocking function, and a dispersion binder thereof. Moreover, the mask layer 6 can contain a pigment dispersant, a filler, a surfactant, a coating aid, and the like as optional components other than these as long as the effects of the present invention are not impaired. The material for forming the mask layer 6 is a combination of known materials as appropriate, and specific examples thereof will be described later in Examples.

The mask layer 6 preferably has an optical density of 2.0 or more with respect to ultraviolet rays, more preferably an optical density of 2.0 to 3.0, and particularly preferably an optical density of 2.2 to 2.5. It is. This is because when the optical density of the mask layer with respect to ultraviolet rays is less than 2.0, the function of blocking ultraviolet rays is insufficient and the non-image area may be exposed. Note that the optical density of the mask layer 6 with respect to ultraviolet rays indicates a value measured by, for example, a black and white transmission densitometer DM-520 (manufactured by Dainippon Screen Mfg. Co., Ltd.).

The thickness of the mask layer 6 is not particularly limited, but is preferably in the range of 0.5 to 2.5 μm, and more preferably in the range of 1.0 to 2.0 μm. When the thickness of the mask layer 6 is 0.5 μm or more, an optical density of a certain level or more can be obtained without requiring a high coating technique. Moreover, since the thickness of the mask layer 6 is 2.5 μm or less, high energy is not required for evaporation of the mask layer 6, which is advantageous in terms of cost.

In the photosensitive resin laminate 1 of the present invention, it is preferable to provide a peelable flexible cover film 7 on the mask layer 6 to protect the printing original plate. Suitable examples of the peelable flexible cover film 7 include a polyethylene terephthalate film, a polyethylene naphthalate film, and a polybutylene terephthalate film. However, such a flexible cover film (protective film) 7 is not absolutely necessary.

The total thickness of the photosensitive resin laminate 1 of the present invention is not particularly limited, but is preferably in the range of 500 to 1000 μm, and more preferably in the range of 700 to 950 μm. This is because if the total thickness of the photosensitive resin laminate 1 is less than 500 μm, ink may adhere to the floor portion of the plate during printing, and if it exceeds 1000 μm, it is costly. This is because it may be disadvantageous.

The photosensitive resin laminate 1 of the present invention can be formed into a sheet-like material having a desired thickness by using, for example, any known method such as hot pressing, casting, melt extrusion, and solution casting. it can.

Using the photosensitive resin laminate 1 of the present invention as a relief printing original plate, a printing plate can be suitably produced as follows. First, when the flexible cover film 7 exists, the flexible cover film 7 is first removed from the photosensitive resin laminate 1. Thereafter, the mask layer 6 is irradiated imagewise with an IR laser to form a mask on the photosensitive resin layer 5. Examples of suitable IR lasers can include ND / YAG lasers (eg, wavelength 1064 nm) or diode lasers (eg, wavelength 830 nm). Laser systems suitable for computer plate making technology are commercially available, and for example, CDI Spark (Esco Graphics) can be used. This laser system includes a rotating cylindrical drum that holds a printing original, an IR laser irradiation device, and a layout computer, and image information is directly transferred from the layout computer to the laser device.

After writing image information on the heat-sensitive mask layer 6, the entire surface of the photosensitive resin laminate is irradiated with ultraviolet rays through the mask layer 6. This can be done with the plate attached to the laser cylinder, but removing the plate from the laser device and irradiating with a conventional flat irradiation unit is advantageous in that it can cope with non-standard plate sizes. It is general. As the ultraviolet ray, an ultraviolet ray having a wavelength of 150 to 500 nm, particularly 300 to 400 nm can be preferably used. As the light source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, a zirconium lamp, a carbon arc lamp, an ultraviolet fluorescent lamp, or the like can be used.

After exposure, a non-exposed portion is dissolved and removed using an appropriate solvent, preferably water, particularly neutral water, so that development can be carried out quickly and a printing plate (relief plate) can be obtained. As the developing method, it is preferable to use a spray developing device, a brush developing device, or the like.

Next, the present invention will be specifically described using examples, but the present invention is not limited to these examples.

The Shore D hardness, the solvent absorption weight increase rate with respect to normal hexane, the rebound resilience, the exposure time, and the development time of the photosensitive resin laminate (original for letterpress printing) after molding and photocuring were measured by the following methods. . The measurement sample is a photosensitive resin laminate using a photosensitive resin laminate in which a 3 mm photosensitive resin layer is provided on a 250 μm polyester support and a 125 μm polyester film is laminated on the surface of the photosensitive resin layer. Using a chemical lamp of 25 W / m ² from the surface of the photosensitive resin, exposure was performed for 10 minutes from a distance of 5 cm higher than the surface of the photosensitive resin, and photocured. This sample was stored for 24 hours at 20 ° C. and a relative humidity of 65% to prepare a sample.

(1) Shore D hardness Measured at 25 ° C. using a Shore durometer (Shore D type) (manufactured by Zubic, West Germany).

(2) Increasing rate of solvent absorption weight A sample having a thickness of 500 μm after exposure and a 2 cm × 5 cm sample was prepared and immersed in normal hexane for 5 hours, and then the normal hexane adhering to the surface was removed and the weight was measured. The solvent absorption weight increase rate is
Solvent absorption weight increase rate (%) = (weight after immersion / weight before immersion) × 100
It was calculated by the following formula.

(3) Rebound resilience modulus A ball made of steel balls having a diameter of 10 mm (weight: 4.16) was dropped from a height of 20 cm, and the bounce height (a) was read and displayed as (a / 20) × 100%. The measurement was performed under the conditions of 25 ° C. and 70% RH.

<Example 1>
First, an adhesive layer 3 having a thickness of 20 μm was provided on a polyethylene terephthalate film having a thickness of 188 μm as the support 2 with a polyurethane adhesive. The polyurethane adhesive was obtained by dissolving 80 parts by weight of a polyester resin (Byron RV-300, manufactured by Toyobo Co., Ltd.) in 1940 parts by weight of a mixed solvent of toluene / methyl ethyl ketone = 80/20 (weight ratio) at 80 ° C., After cooling, 20 parts by weight of isocyanurate-type polyisocyanate (Desmodur HL, manufactured by Sumitomo Bayer Urethane Co., Ltd.) using hexamethylene diisocyanate and toluene diisocyanate as isocyanurate-type polyisocyanates, and triethylenediamine as a curing catalyst in an amount of 0.1%. A solution prepared by adding 06 parts by weight and stirring for 10 minutes was used. The polyurethane-based adhesive thus obtained was applied onto a polyethylene terephthalate film so as to have a film thickness of 20 μm, and dried and cured at 100 ° C. for 3 minutes to provide an adhesive layer 3.

Next, an intermediate layer 4 made of a photocured photosensitive resin composition having a Shore D hardness of 30 ° and a rebound resilience of 30% was provided on the adhesive layer 3. First, 2.9 parts by weight of 2-methylpentamethylenediamine (MPDA), 6.0 parts by weight of 1,4-bisaminopropylpiperazine (BAPP), 45.5 parts by weight of polyethylene glycol hexamethylene diisocyanate reactant (HE-600) And 1.7 parts by weight of adipic acid were placed in 100 parts by weight of methanol and a heating and melting kettle equipped with a stirring blade, sufficiently purged with nitrogen, sealed, and gradually heated to 65 ° C. with stirring. After stirring for about 2 hours, 0.015 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added and dissolved by stirring for another 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 18 parts by weight of water, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid, 0.8 part by weight of adipic acid, benzyldimethyl ketal 1 as a photoinitiator 1.0 part by weight, 11.4 parts by weight of diglycidyl ether diacrylate (crosslinking agent epoxy ester 400EA, manufactured by Kyoeisha Chemical Co., Ltd.) and 11.4 parts by weight of crosslinking agent light acrylate (HOA-MPE, manufactured by Kyoeisha Chemical Co., Ltd.) Part was further added and dissolved by stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition (photosensitive resin composition for forming an intermediate layer) was obtained.

Next, the photo-cured photosensitive resin composition thus obtained was applied on the adhesive layer 3 formed on the support 2 so that the film thickness was 100 μm, dried at 70 ° C., and further 125 μm. An adhesive layer 3 and an intermediate layer 4 were provided on the support 2 having a total thickness of 310 μm by superimposing the polyester film and exposing it to light curing using a chemical lamp having an illuminance of 10 mw / m ² for 60 seconds. A laminate was obtained.

The rebound elastic modulus of the formed intermediate layer 4 was measured and found to be 30%. Further, the solvent absorption weight increase rate of the intermediate layer 4 with respect to normal hexane was 7.3%, and it was confirmed that the ink was sufficiently resistant to the washing oil.

Next, a photosensitive resin composition (photosensitive resin composition for forming a photosensitive resin layer) prepared as follows was cast on the intermediate layer 4 to form a photosensitive resin layer 5. First, 2.9 parts by weight of 2-methylpentamethylenediamine (MPDA), 6.8 parts by weight of 1,4-bisaminopropylpiperazine (BAPP), 45.4 parts by weight of a polyethylene glycol hexamethylene diisocyanate reactant (HE-600) And 1.7 parts by weight of adipic acid were placed in 100 parts by weight of methanol and a heating and melting kettle equipped with a stirring blade, sufficiently purged with nitrogen, sealed, and gradually heated to 65 ° C. with stirring. After stirring for about 2 hours, 0.03 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added and dissolved by stirring for another 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 12 parts by weight of water, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid, 0.7 part by weight of adipic acid, benzyldimethyl ketal 1 as a photoinitiator 0.0 part by weight, 20.0 parts by weight of glycerin dimethacrylate (crosslinker light ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and 13.5 parts by weight of epoxy ester (40EM, manufactured by Kyoeisha Chemical Co., Ltd.) The mixture was dissolved with stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition (photosensitive resin composition for forming a photosensitive resin layer) was obtained. The photosensitive resin composition had a Shore D hardness of 55 ° after exposure to ultraviolet light and a rebound resilience of 30%. A photosensitive resin layer 5 having a thickness of 640 μm was formed on the intermediate layer 4 using such a photosensitive resin composition.

Next, a mask layer 6 having heat sensitivity was formed on the photosensitive resin layer 5. First, as a dispersion binder, a butyral resin, a tertiary amino group-containing polyamide, an ether group-containing polyamide, a polar group-free polyamide, and polyvinyl alcohol were prepared. BM-5 (manufactured by Sekisui Chemical Co., Ltd.) was used as a butyral resin. Further, as the tertiary amino group-containing polyamide and ether group-containing polyamide, those synthesized as follows were used. As the polyamide containing no polar group, Macromelt 6900 (Henkel) was used. As the polyvinyl alcohol, GH23 (manufactured by Nippon Synthetic Chemical Co., Ltd.) was used.

(Synthesis of tertiary amino group-containing polyamide)
50 parts by weight of ε-caprolactam, 40 parts by weight of N, N′-di (γ-aminopropyl) piperazine adipate, 10 parts by weight of 3-bisaminomethylcyclohexane adipate and 100 parts by weight of water were charged into an autoclave. Sealed and heated gradually. From the time when the internal pressure reached 10 kg / m ³ , water was distilled off until the pressure could not be maintained, returned to normal pressure in about 2 hours, and then reacted at normal pressure for 1 hour. The maximum polymerization reaction temperature was 255 ° C. As a result, a tertiary amino group-containing polyamide having a melting point of 137 ° C. and a specific viscosity of 1.96 was obtained.

(Synthesis of ether group-containing polyamide)
Acrylonitrile is added to both ends of polyethylene glycol having a number average molecular weight of 600, and this is hydrogen-reduced to obtain an equimolar salt of α, ω-diaminopolyoxyethylene and diadipic acid: 60 parts by weight, ε-caprolactam: 20 1 part by weight and an equimolar salt of hexamethylenediamine and adipic acid: 20 parts by weight of melt polymerized ether having a relative viscosity (1 g of polymer dissolved in 100 ml of water chloral and measured at 25 ° C.) of 2.50 A group-containing polyamide was obtained.

(Preparation of mask layer coating solution)
As a dispersion binder, 27 parts by weight of a butyral resin and 39 parts by weight of a tertiary amino group-containing polyamide were dissolved in a solvent, and 34 parts by weight of carbon black was dispersed therein to prepare a dispersion liquid, which was used as a mask layer coating liquid. .

(Create mask layer)
A bar coater that has been appropriately selected so that the layer thickness is 1.5 μm on a PET film support (E5000, manufactured by Toyobo Co., Ltd., thickness: 100 μm) subjected to mold release treatment on both sides. Was applied and dried at 120 ° C. for 5 minutes to form a mask layer 6.

A structure in which a mask layer is formed on the PET film support is laminated on the photosensitive resin layer 5 using a laminator so that the mask layer side is in contact with the photosensitive resin layer, and the total thickness is 950 μm. A photosensitive resin laminate 1 for letterpress printing having a resin layer 5 thickness of 640 μm was obtained. The obtained photosensitive resin laminate 1 was solidified into a plate shape while being stored at 30 ° C. After 24 hours, the photosensitive resin laminate was heated at 103 ° C. for 3 minutes and stored for 7 days or more, and then a relief printing original plate (raw plate) was obtained.

As a result of evaluating the reproducibility of fine independent points of the obtained original for letterpress printing, the exposure time for reproducing 100 μm independent points is 4 minutes, and the relief printing has high sensitivity and excellent reproducibility of independent points. Relief for. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Moreover, when thin print reproducibility evaluated the presence or absence of printing fat visually, there was no printing fat. Further, the printing pressure was adjusted to 200 μm, and the printability of the solid part was evaluated under the condition of a line speed of 20 m / min. As a result, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, the following procedures evaluated the presence or absence of peeling of the photosensitive resin layer at the time of cylindrical molding. First, the plate was rolled into a cylindrical shape with a diameter of 4 cm in the direction of the out curl and fixed in a manner in which the plate was attached to the cylinder during printing. This was heated in a hot air dryer at 60 ° C. for 30 minutes, and tempered. After that, it was taken out from the dryer and left at room temperature for about 30 minutes. Then, when the rounded one is unwound, it is wound into a cylindrical shape. Since distortion occurred between the intermediate layer and the photosensitive resin layer at this time and peeling occurred at the interface, such evaluation was also performed. As a result, peeling of the photosensitive resin layer was not observed during the cylindrical molding.

<Example 2>
52.5 parts by weight of ε-caprolactam, 40.0 parts by weight of N, N′-bis (γ-aminopropyl) piperazine adipate, 7.5 parts by weight of 1,3-bisaminomethylcyclohexane adipate and 100 parts by weight of water, The reactor was placed in a reactor, sufficiently purged with nitrogen, then sealed and gradually heated. When the internal pressure reached 10 kg / cm ² , the water in the reactor was gradually distilled out to return to normal pressure in 1 hour, and then reacted at normal pressure for 1.0 hour. The maximum polymerization temperature was 220 ° C. The obtained polymer obtained a transparent light yellow polyamide having a melting point of 140 ° C. and a specific viscosity of 2.00.

50.0 parts by weight of the obtained polyamide, 5.0 parts by weight of N-ethyltoluenesulfonic acid amide, 0.03 parts by weight of 1,4-naphthoquinone, 50.0 parts by weight of methanol, and 10 parts by weight of water were stirred. After mixing for 2 hours at 60 ° C. in a heated kettle to completely dissolve the polymer, 38.1 parts by weight of an acrylic acid adduct of trimethylolpropane triglycidyl ester, 2.5 parts by weight of glycidyl methacrylate, methacrylic acid 2 .9 parts by weight, hydroquinone monomethyl ether 0.1 part by weight, ammonium sulfite 0.3 part by weight, oxalic acid 0.1 part by weight and benzyldimethyl ketal 1.0 part by weight were added and dissolved for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition (photosensitive resin composition for forming a photosensitive resin layer described later) was obtained. The photosensitive resin composition had a Shore D hardness of 55 ° after exposure to ultraviolet rays and a rebound resilience of 18%.

Next, a photocured intermediate layer 4 having a Shore D hardness of 27 ° and a rebound resilience of 21% is provided on the support 2 which is a polyester film of 188 μm through the adhesive layer 3 formed in the same manner as in Example 1. It was. The intermediate layer 4 is composed of 55.0 parts by weight of the polyamide used in the photosensitive resin composition, 5.0 parts by weight of N-ethyltoluenesulfonic acid amide, 0.03 parts by weight of 1,4-naphthoquinone, 50.0 parts by weight of methanol. The polymer was completely dissolved by mixing 2 parts by weight and 10 parts by weight of water in a heat-dissolved kettle with stirring for 2 hours, and then 32.9 parts by weight of an acrylic acid adduct of diglycidyl ether of polypropylene glycol, 3.1 parts by weight of acid, 2.5 parts by weight of glycidyl methacrylate, 0.1 part by weight of hydroquinone monomethyl ether, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid and 1.0 part by weight of benzyl dimethyl ketal are added Thus, a photosensitive resin composition (photosensitive resin composition for forming an intermediate layer) was obtained. Next, after coating on the adhesive layer 3 formed on the support 2 and drying at 70 ° C. so that the film thickness of the photosensitive resin composition after photocuring thus obtained is 100 μm, Further, a 100 μm intermediate layer 4 was formed by superimposing a 125 μm polyester film and exposing it to light curing for 60 seconds using a chemical lamp having an illuminance of 10 mw / m ² . Further, the solvent absorption weight increase rate of the intermediate layer 4 with respect to normal hexane was 7.3%, and it was confirmed that the ink was sufficiently resistant to the washing oil.

On the intermediate layer 4 thus formed, the above-described photosensitive resin composition for forming a photosensitive resin layer was cast to form a photosensitive resin layer 5 having a thickness of 640 μm in the same manner as in Example 1. . Further, in the same manner as in Example 1, a mask layer 6 was formed on the photosensitive resin layer 5 to obtain a photosensitive resin laminate 1 having a total thickness of 950 μm.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate as an original for letterpress printing, the exposure time to reproduce 100 μm independent points is 6 minutes. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a thin line having a width of 15 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. Also, no peeling at the time of printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 3>
A photosensitive resin laminate 1 was obtained in the same manner as in Example 2 except that the photosensitive resin layer 5 was changed as follows. 50.0 parts by weight of the polyamide used in the photosensitive resin composition for forming the photosensitive resin layer in Example 2, 5.0 parts by weight of N-ethyltoluenesulfonic acid amide, 0.03 parts by weight of 1,4-naphthoquinone Then, 50.0 parts by weight of methanol and 10 parts by weight of water were mixed in a heating and stirring kettle with stirring at 60 ° C. for 2 hours to completely dissolve the polymer, and then the acrylic acid adduct of trimethylolpropane triglycidyl ester and Methacrylic acid adduct (containing 50 mol% acrylic acid) 35.4 parts by weight, glycidyl methacrylate 2.0 parts by weight, methacrylic acid 3.1 parts by weight, hydroquinone monomethyl ether 0.1 parts by weight, ammonium sulfite 0.3 parts by weight Then, 0.1 part by weight of oxalic acid and 1.0 part by weight of benzyldimethyl ketal were added and dissolved for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin layer-forming photosensitive resin composition was obtained. The photosensitive resin composition had a Shore D hardness of 67 ° and an impact resilience of 15% after ultraviolet exposure. Using such a photosensitive resin composition, a 640 μm photosensitive resin layer 5 having the same thickness as in Examples 1 and 2 was formed.

As a result of evaluating the reproducibility of fine independent points using a photosensitive resin laminate having a total thickness of 950 μm obtained by the same method as in Example 1 for an exposure time for reproducing an independent point having a diameter of 100 μm, The exposure time for reproducing an independent point of 100 μm was 6 minutes, and it was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a thin line having a width of 15 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 4>
A photosensitive resin laminate 1 having a total thickness of 800 μm was obtained in the same manner as in Example 1 except that the thickness of the photosensitive resin layer 5 was changed to 490 μm. As a result of evaluating the reproducibility of fine independent points in the same manner as in Example 1 using the photosensitive resin laminate 1 thus obtained as an original plate for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm is This was a letterpress printing original plate having a high sensitivity and excellent independent point reproducibility for 4 minutes. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated, and a 10 μm wide thin line was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 5>
The photosensitive resin laminated body 1 was obtained like Example 1 except having changed the photosensitive resin layer 5 as follows. 2.9 parts by weight of 2-methylpentamethylenediamine (MPDA), 6.8 parts by weight of 1,4-bisaminopropylpiperazine (BAPP), 45.4 parts by weight of a polyethylene glycol hexamethylene diisocyanate reactant (HE-600) and 1.7 parts by weight of adipic acid was placed in 100 parts by weight of methanol and a heating and melting kettle equipped with a stirring blade, and after sufficient nitrogen substitution, the mixture was sealed and gradually heated to 65 ° C and stirred. After stirring for about 2 hours, 0.03 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added and dissolved by stirring for another 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 12 parts by weight of water, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid, 0.7 part by weight of adipic acid, benzyldimethyl ketal 1 as a photoinitiator 0.02 parts by weight, 20.0 parts by weight of glycerin dimethacrylate (crosslinking agent Light Ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and 13.5 parts by weight of epoxy ester 200EA were further added and dissolved by stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition was obtained. The photosensitive resin composition had a Shore D hardness of 47 ° and an impact resilience of 30% after ultraviolet exposure. Using such a photosensitive resin composition, a 640 μm photosensitive resin layer 5 having the same thickness as in Examples 1 and 2 was formed.

As a result of evaluating the reproducibility of fine independent points using a photosensitive resin laminate having a total thickness of 950 μm obtained by the same method as in Example 1 for an exposure time for reproducing an independent point having a diameter of 100 μm, The exposure time for reproducing an independent point of 100 μm was 4 minutes, and it was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 6>
For only diglycidyl ether diacrylate, the Shore D hardness was the same as in Example 1 except that the crosslinker epoxy ester 400EA (manufactured by Kyoeisha Chemical Co., Ltd.) was changed to the crosslinker epoxy ester 200EA (manufactured by Kyoeisha Chemical Co., Ltd.). Was formed in the same manner as in Example 1 except that the intermediate layer 4 having a thickness of 950 μm was obtained.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate 1 as a relief printing original plate, the exposure time to reproduce 100 μm independent points is 4 times. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 7>
The photosensitive resin laminated body 1 was obtained like Example 1 except having changed the intermediate | middle layer 4 as follows. 2.9 parts by weight of 2-methylpentamethylenediamine (MPDA), 6.8 parts by weight of 1,4-bisaminopropylpiperazine (BAPP), 45.4 parts by weight of a polyethylene glycol hexamethylene diisocyanate reactant (HE-600) and 1.7 parts by weight of adipic acid was placed in 100 parts by weight of methanol and a heating and melting kettle equipped with a stirring blade, and after sufficient nitrogen substitution, the mixture was sealed and gradually heated to 65 ° C and stirred. After stirring for about 2 hours, 0.03 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added and dissolved by stirring for another 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 12 parts by weight of water, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid, 0.7 part by weight of adipic acid, benzyldimethyl ketal 1 as a photoinitiator 0.01 part by weight, 17.0 parts by weight of glycerin dimethacrylate (crosslinker light ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and 16.5 parts by weight of epoxy ester 40EM (manufactured by Kyoeisha Chemical Co., Ltd.) were added and stirred for 30 minutes. Dissolved. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition was obtained. The photosensitive resin composition had a Shore D hardness of 48 ° after ultraviolet exposure and a rebound resilience of 27%.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate 1 having a total thickness of 950 μm as an original plate for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm is reproduced. The exposure time was 4 minutes, and it was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 8>
A photosensitive resin laminate 1 was obtained in the same manner as in Example 1 except that the thickness of the photosensitive resin layer 5 was 380 μm and the total thickness was 600 μm.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate 1 as a relief printing original plate, the exposure time for reproducing 100 independent points was 3 times. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 9>
The photosensitive resin laminated body 1 was obtained like Example 1 except having changed the intermediate | middle layer 4 and the photosensitive resin layer 5 as follows respectively. For the intermediate layer 4, the polyureaurethane used as the synthetic polymer compound was changed to polyetheramide. Polyetheramide is an equimolar salt of α, ω-diaminopolyoxyethylene obtained by adding acrylonitrile to both ends of polyethylene glycol having a number average molecular weight of 600 and reducing this with hydrogen: 60 parts by weight, ε-Caprolactam: 20 parts by weight and hexamethylenediamine and adipic acid: 20 parts by weight melt polymerized to give a relative viscosity (viscosity obtained by dissolving 1 g of polymer in 100 ml of water chloral and measuring at 25 ° C.) A polyetheramide containing 2.50 ether groups was obtained. After 60 parts by weight of the obtained polyetheramide was dissolved in methanol by stirring at 60 ° C. for 1 hour, 0.015 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added to further add 30 parts. Stir to dissolve for a minute. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 18 parts by weight of water, 0.3 part by weight of ammonium sulfite, 1.0 part by weight of benzyldimethyl ketal as a photoinitiator, diglycidyl ether diacrylate (crosslinking agent epoxy ester 400EA) Further, 18.1 parts by weight of Kyoeisha Chemical Co., Ltd.) and 18.0 parts by weight of a crosslinker light acrylate HOA-MPE (Kyoeisha Chemical Co., Ltd.) were added and dissolved by stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition was obtained. Next, the photosensitive resin composition obtained after photocuring was coated on a 188 μm thick polyester film so as to have a film thickness of 100 μm and dried at 70 ° C., and then a 125 μm polyester film was further formed. A support having a 310 μm intermediate layer that was superposed and exposed to light for 60 seconds using a chemical lamp having an illuminance of 10 mw / m ² was obtained. The Shore D hardness of the formed intermediate layer 4 was 35 °.

For the photosensitive resin layer 5, the polyureaurethane used as the synthetic polymer compound was changed to polyether amide to produce a photosensitive resin layer. The photosensitive resin composition is an equimolar salt of α, ω-diaminopolyoxyethylene obtained by adding acrylonitrile to both ends of polyethylene glycol having a number average molecular weight of 600 and reducing this with hydrogen: 60 parts by weight , Ε-caprolactam: 20 parts by weight and equimolar salt of hexamethylenediamine and adipic acid: 60 parts by weight of polyetheramide obtained by melt polymerization of 20 parts by weight was dissolved in methanol by stirring at 60 ° C. for 1 hour. Thereafter, 0.015 part by weight of 1,4-naphthoquinone and 0.1 part by weight of hydroquinone monomethyl ether were added and further stirred and dissolved for 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 12 parts by weight of water, 0.3 part by weight of ammonium sulfite, 0.1 part by weight of oxalic acid, 1.0 part by weight of benzyldimethyl ketal as a photoinitiator, glycerin dimethacrylate 20.0 parts by weight (crosslinker light ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and 13.5 parts by weight of epoxy ester 40EM were further added and dissolved by stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition was obtained. The photosensitive resin composition had a Shore D hardness of 58 ° after exposure to ultraviolet light and a rebound resilience of 30%.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate 1 having a total thickness of 950 μm as an original plate for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm is reproduced. The exposure time was 6 minutes, and it was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a thin line having a width of 15 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was not observed.

<Example 10>
The photosensitive resin laminated body 1 was obtained like Example 1 except having changed the intermediate | middle layer 4 as follows. The intermediate layer 4 was produced by changing the polyureaurethane used as the synthetic polymer compound to polyurethane. 50 parts by weight of polyurethane having a number average molecular weight of 600, 10 parts by weight of 1,5-butanediol and 32.7 parts by weight of hexamethylene diisocyanate were mixed and polymerized at 150 ° C. to obtain a polyurethane containing an ether bond. After 60 parts by weight of the obtained polyurethane was dissolved in methanol by stirring at 60 ° C. for 1 hour, 0.1 part by weight of hydroquinone monomethyl ether was added and further stirred and dissolved for 30 minutes. Thereafter, 2.5 parts by weight of glycidyl methacrylate (GMA), 18 parts by weight of water, 0.3 part by weight of ammonium sulfite, 1.0 part by weight of benzyldimethyl ketal as a photoinitiator, diglycidyl ether diacrylate (crosslinking agent epoxy ester 400EA) 23.1 parts by weight of Kyoeisha Chemical Co., Ltd.) and 13.0 parts by weight of a crosslinker light acrylate HOA-MPE (manufactured by Kyoeisha Chemical Co., Ltd.) were further added and dissolved by stirring for 30 minutes. Next, the temperature was gradually raised to distill methanol and water, and the mixture was concentrated until the temperature in the kettle reached 110 ° C. At this stage, a fluid and viscous photosensitive resin composition was obtained. Next, the photosensitive resin composition thus obtained after photocuring was coated on a 188 μm thick polyester film so as to have a film thickness of 100 μm, dried at 70 ° C., and then further coated with a 125 μm polyester film. A support having a 310 μm intermediate layer 4 was obtained which was superposed and exposed to light for 60 seconds using a chemical lamp having an illuminance of 10 mw / m ² . The Shore D hardness of the formed intermediate layer 4 was 27 °.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate 1 having a total thickness of 950 μm as an original plate for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm is reproduced. The exposure time was 4 minutes, and it was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling during printing at the interface between the intermediate layer 4 and the photosensitive resin layer 5 was observed. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer 5 was observed.

<Comparative Example 1>
A photosensitive resin laminate was prepared in the same manner as in Example 1 except that a photosensitive resin layer having a thickness of 680 μm was formed without providing an intermediate layer so that the total thickness was 950 μm. As a result of evaluating the reproducibility of fine independent points in the same manner as in Example 1 using the photosensitive resin laminate thus obtained as an original plate for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm was 12 times. This was a letterpress printing original plate having a low sensitivity and a satisfactory reproducibility of independent points. About the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a line having a width of 20 μm was reproduced. Next, as in Example 1, when evaluating the presence or absence of printing fat among the thin line reproducibility, printing fat was observed. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

<Comparative example 2>
A photosensitive resin laminate was produced in the same manner as in Example 2 except that the photosensitive resin layer was formed using the same photosensitive resin composition for forming a photosensitive resin layer as in Example 1. As a result of evaluating the reproducibility of fine independent points in the same manner as in Example 1 using the photosensitive resin laminate thus obtained as an original for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm was 4 times. This was a high-sensitivity letterpress printing original plate. About the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a 10 μm wide line was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. Peeling during printing was observed at the interface between the intermediate layer and the photosensitive resin layer, and the presence or absence of peeling of the photosensitive resin layer during cylindrical molding was evaluated in the same manner as in Example 1. As a result, the photosensitive resin layer Peeling of was observed.

<Comparative Example 3>
A photosensitive resin laminate having a total thickness of 700 μm was produced in the same manner as in Example 1 except that the thickness of the intermediate layer was changed to 250 μm and the thickness of the photosensitive resin layer was changed to 240 μm. As a result of evaluating the reproducibility of fine independent points in the same manner as in Example 1 using the photosensitive resin laminate thus obtained as an original for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm was 4 times. This was a high-sensitivity letterpress printing original plate. About the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a 10 μm wide line was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. In the obtained printed matter, ink adhered to the floor portion (bottom portion) of the relief for relief printing, and ink smear occurred in the non-image portion of the printed matter, so that a satisfactory print quality could not be obtained. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

<Comparative Example 4>
A photosensitive resin laminate was prepared in the same manner as in Example 1 except that the photosensitive resin composition for forming an intermediate layer was changed to a photosensitive resin composition for forming a photosensitive resin layer having a Shore D hardness of 55 °. Produced. As a result of evaluating the reproducibility of fine independent points in the same manner as in Example 1 using the photosensitive resin laminate thus obtained as an original for letterpress printing, the exposure time for reproducing independent points having a diameter of 100 μm was 4 times. This was a high-sensitivity letterpress printing original plate. About the relief obtained at that time, when the relief reproducibility was evaluated among the fine line reproducibility, a 10 μm wide line was reproduced. The obtained printed matter does not exhibit the cushion function of the intermediate layer, and the relief layer is deformed by the printing pressure, so that the fine image is thickened and the solid portion is distorted. It was not obtained. In addition, the non-image area ink stain was not visually observed. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

<Comparative Example 5>
In the photosensitive resin composition for forming the photosensitive resin layer, only the ratio of glycerin dimethacrylate (crosslinker light ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and epoxy ester 40EM (produced by Kyoeisha Chemical Co., Ltd.) was changed, and G101P A photosensitive resin laminate was obtained in the same manner as in Example 1 except that 15.0 parts by weight and 18.5 parts by weight of epoxy ester 40EM were blended. The Shore D hardness after ultraviolet exposure of the photosensitive resin composition was 50 °, and the rebound resilience was 28%.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate as an original for letterpress printing, the exposure time to reproduce 100 μm independent points is 4 minutes. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, as in Example 1, when evaluating the presence or absence of printing fat among the thin line reproducibility, printing fat was observed. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. Further, the non-image area ink stain was not observed visually. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

<Comparative Example 6>
The photosensitive resin laminated body 1 was obtained like Example 1 except having changed the photosensitive resin layer as follows. The photosensitive resin composition for forming the photosensitive resin layer was changed by changing only the ratio of glycerin dimethacrylate (crosslinking agent light ester G101P, manufactured by Kyoeisha Chemical Co., Ltd.) and epoxy ester 40EM (produced by Kyoeisha Chemical Co., Ltd.) 29.5 parts by weight and 4.0 parts by weight of epoxy ester 40EM. The photosensitive resin composition had a Shore D hardness of 74 ° and an impact resilience of 28% after ultraviolet exposure.

As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate as an original for letterpress printing, the exposure time to reproduce 100 μm independent points is 4 minutes. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 10 μm was reproduced. Next, as in Example 1, when evaluating the presence or absence of printing fat among the thin line reproducibility, printing fat was observed. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, blurring occurred. Further, the non-image area ink stain was not observed visually. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

<Comparative Example 7>
A photosensitive resin laminate having a total thickness of 1050 μm was produced in the same manner as in Example 1 except that the thickness of the photosensitive resin layer was 740 μm. As a result of evaluating the reproducibility of fine independent points using the obtained photosensitive resin laminate as an original for letterpress printing, the exposure time to reproduce 100 μm independent points is 6 minutes. It was a relief printing original plate having high sensitivity and excellent independent point reproducibility. Regarding the relief obtained at that time, the relief reproducibility of the fine line reproducibility was evaluated. As a result, a thin line having a width of 30 μm was reproduced. Next, in the same manner as in Example 1, when the evaluation of the presence / absence of printing fat among the thin line reproducibility was evaluated, there was no printing fat. Furthermore, as a result of evaluating the printability of the solid portion in the same manner as in Example 1, there was no blur. In addition, the non-image area ink stain was not visually observed. No peeling was observed during printing at the interface between the intermediate layer and the photosensitive resin layer. Furthermore, as a result of evaluating the presence or absence of peeling of the photosensitive resin layer during cylindrical molding in the same manner as in Example 1, peeling of the photosensitive resin layer was not observed.

The configurations and results of Examples 1 to 10 and Comparative Examples 1 to 7 are shown below.

1 photosensitive resin laminate for letterpress printing plate, 2 support, 3 adhesive layer, 4 intermediate layer, 5 photosensitive resin layer, 6 mask layer, 7 flexible cover film.

Claims

A photosensitive resin laminate for a relief printing plate comprising a support, an adhesive layer, a photosensitive resin layer, and a heat-sensitive mask layer,
Between the adhesive layer and the photosensitive resin layer, it is formed of a resin having the same skeleton as the photosensitive resin constituting the photosensitive resin layer, has adhesiveness to the photosensitive resin layer, and has a photocured photosensitive property. An intermediate layer having a Shore D hardness of 5 ° or more lower than the Shore D hardness of the conductive resin layer,
A photosensitive resin laminate in which the thickness of the photosensitive resin layer is in the range of 350 to 700 μm.
2. The photosensitive resin laminate according to claim 1, wherein the total thickness is in the range of 500 to 1000 μm.
3. The photosensitive resin laminate according to claim 1 or 2, wherein the Shore D hardness of the photosensitive resin layer after photocuring is in the range of 45 to 75 °.