JPH08114915A - Photopolymerizable composition - Google Patents

Abstract

(57) [Summary] An object of the present invention is to have extremely high specific sensitivity to simultaneous action of light and heat.
A photopolymerizable composition is provided. At least an addition-polymerizable compound and light
It contains a polymerization initiation system and forms images by the simultaneous action of light and heat.
A photopolymerizable composition comprising:
Minimum dew in the range of 20 ~ 60 ℃
The reduction rate of the light amount is 0.015 or more. [Equation 1] (Where T is¹And T²Is the exposure temperature (° C), and T¹
Is 20, T²Represents 60, and E¹At a temperature of 20 ° C
Minimum exposure required for image formation (mj / cm ²)
The E²Is the minimum required for image formation at a temperature of 60 ° C.
Exposure (mj / cm ²). )

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photopolymerizable composition. In particular, it relates to a photopolymerizable composition that exhibits extremely high sensitivity by simultaneously acting light and heat.

[0002]

2. Description of the Related Art With the recent development of computer technology,
The appearance of an image forming method for directly producing a printing plate or a color image from a digital image data edited by a computer without using a silver salt filter for platemaking is strongly desired. Conventionally, as one of the promising techniques for such an image forming method, a photopolymerizable composition layer having sensitivity in the visible region was directly provided from a digital image data using a laser beam of visible light. A method for producing a printing plate or a color image (color proof) by subjecting an image forming material to scanning image exposure is already known.

However, the photopolymerizable composition used in the above-mentioned image forming method is problematic because it does not sufficiently satisfy the storage stability with time and the sensitivity to visible laser light. On the other hand, as a method for improving the above-mentioned problems, a photopolymerizable composition that induces a photocuring reaction with high sensitivity by light and heat is used, and light and heat are simultaneously applied by directly applying light and heat from digital image data. An image forming method for forming a printing plate or a color image by photo-curing the photopolymerizable composition to a desired level by changing the intensity of heat and / or heat is disclosed in JP-A-64-46745, 63-294547 and 63-294547. 63-294548, 63-278051 and the like. Since the photopolymerizable composition reported in the document can be expected to significantly improve the sensitivity due to heat when light and heat are simultaneously applied, a photopolymerization initiator having low sensitivity at room temperature can be used. However, in the image forming method, when a thermal head having a small heat capacity, which is advantageous for weight reduction and downsizing of an apparatus used in the thermal transfer image forming method, or an infrared semiconductor laser is applied as a heat source in the image forming method, the sensitivity is unsatisfactory. Enough was a problem.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have made earnest studies to overcome such problems and obtain an excellent photopolymerizable composition, and as a result, at least a compound capable of addition polymerization and a photopolymerization initiation system are included. The present invention has been accomplished by finding that a photopolymerizable composition having specific physical properties has high sensitivity and high practicality.

That is, an object of the present invention is to provide a photopolymerizable composition which is photocurable with high sensitivity by simultaneously acting light and heat. Another object of the present invention is to provide a photopolymerizable composition that enables digital direct plate making using a small heat source such as a thermal head or an infrared semiconductor laser. Another object of the present invention is to
It is an object of the present invention to provide a photopolymerizable composition which enables plate making work which is extremely advantageous in terms of cost and time.

[0006]

Accordingly, an object of the present invention is to provide a photopolymerizable composition containing at least an addition-polymerizable compound and a photopolymerization initiation system and forming an image by the simultaneous action of light and heat. In the above, the reduction ratio of the minimum exposure amount in the range of 20 to 60 ° C. of the photopolymerizable composition is 0.015 or more, and an image is formed by the simultaneous action of light and heat. Is easily achieved by a possible photopolymerizable composition.

[0007]

[Equation 2]

(Where T¹And T²Is the exposure temperature (° C)
And T¹Is 20, T²Represents 60, and E¹Is warm
The minimum exposure amount (mj
/ Cm ²), E²Is necessary for image formation at a temperature of 60 ° C.
Minimum required exposure (mj / cm ²). ) The present invention will be described in detail below.

The present invention provides a photopolymerizable composition containing at least an addition-polymerizable compound and a photopolymerization initiation system, which forms an image by the simultaneous action of light and heat. The decrease rate of the minimum exposure amount shown by the formula is 0.015
It is characterized by the above. Details of the addition-polymerizable compound and the photopolymerization initiation system will be described later, but the photopolymerizable composition containing them is not particularly limited as long as the reduction rate of the minimum exposure amount is 0.015 or more. is not.
In the present invention, the reduction rate of the minimum exposure amount is defined by the following formula.

[0010]

(Equation 3)

(In the formula, T ¹ , T ² , E ¹ and E ² have the same meanings as described above.) The reduction rate of the minimum exposure amount is preferably 0.019 or more. The numerical value calculated by the above formula is the minimum exposure amount (mj / c) per unit temperature with respect to temperature rise in the range of 20 to 60 ° C.
m ² ), which means that the exposure energy on the high temperature side is smaller when an image is formed by the simultaneous action of light and heat according to the present invention, that is, high sensitivity and low temperature. It shows that the difference in sensitivity between the high temperature side and the high temperature side is large. The addition-polymerizable compound used in the present invention has a function of significantly increasing the curing rate when light and heat are simultaneously applied to the composition containing the compound and at least a photopolymerization initiation system, and is described above. Any compound having a reduction rate of the minimum exposure amount within the above range can be used without particular limitation. As the addition-polymerizable compound exhibiting the function, physical properties such as viscosity at 20 to 60 ° C. Is preferably selected from among those that significantly change, more preferably a compound of the following formula [I] and / or
Alternatively, it can be achieved by selecting a monomer having a partial structure represented by the following formula [II].

[0012]

Embedded image

(In the formula, l is an integer of 0 to 2, m is an integer of 1 to 3, Y ¹ and Y ² represent a hydrogen atom or a methyl group, and A is a direct bond or has a carbon number of 1 to 3. Indicates an alkylene group)

Among these, as the monomer having the partial structure of the general formula [II], organic diisocyanates or their trimers are mentioned.

[0015]

Embedded image

A urethane compound obtained by the reaction (wherein A, Y ¹ , Y ² and 1 have the same meanings as defined above) can be mentioned. Preferred organic diisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, alicyclic diisocyanates such as cyclohexane diisocyanate and isophorone diisocyanate, and aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate. Further, isocyanurate compounds which are these trimers can be used in the same manner. More specific examples include the following.

[0017]

[Chemical 4]

Q represents the following structure,

[0019]

Embedded image

(N is 1 to 10, preferably 5 to 7, i is 1 to 2), and R ^{3 to} R ⁵ may be the same or different. In addition, R ^{6 to} R ⁷ are

[0021]

[Chemical 6]

(J is 1-3, preferably 1-2, k is 1
~ 2), and R⁶ ~ R⁷ Can be the same or different
And h represents 1 to 10, preferably 5 to 7. R
⁸ ~ R ⁹ Is

[0023]

[Chemical 7]

(S is 1 to 2). Further, Y ¹ and Y ² in any of the above general formula (II) in the same meaning as Y ¹ and Y ^2, n, i, j, k , h, both s is an integer. More specifically as the addition-polymerizable compound in the present invention, for example,

[0025]

Embedded image

[0026]

[Chemical 9]

[0027]

[Chemical 10]

[0028]

[Chemical 11]

[0029]

[Chemical 12]

And the like. The photopolymerization initiation system which is the second essential component of the photopolymerizable composition of the present invention will be described. The photopolymerization initiator used in the present invention is not particularly limited, but for example, it can be appropriately selected and used from those sensitive to light rays in the ultraviolet to visible region.
Examples of the photopolymerization initiator that is sensitive to ultraviolet rays include:
Benzoyl, benzoin alkyl ether, benzyl ketal, benzophenone, anthraquinone, benzyl,
Alternatively, Michler's ketone and the like can be mentioned.

Further, regarding the photopolymerizable composition containing a photopolymerization initiation system which is sensitive to light rays in the visible light region, for example, a system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377). Gazette), a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-155292), cyclic cis-α.
A system of a dicarbonyl compound and a dye (JP-A-48-841)
83), a system of substituted triazine and merocyanine dye (JP-A-54-151024), a system of ketocoumarin and an activator (JP-A-52-112681, JP-A-58-15503). JP-A-60-88005), a system of substituted triazine and a sensitizer (JP-A-58-29).
No. 803, No. 40302, and JP-A-4-318.
63, JP-A-2-189548), biimidazole, a styrene derivative, and a thiol system (JP-A-59).
-56403), a system of an organic peroxide and a dye (JP-A-59-140203 and JP-A-189340), titanocene and a xanthene dye, and an addition-polymerizable ethylenically saturated diamine having an amino group or a urethane group. A system in which a compound containing a heavy bond is combined (JP-A-4-22195).
No. 8, No. 219756) and the like.

The photopolymerization initiation system used in the above-described photopolymerizable composition of the present invention is 0.1 to 100 parts by weight, preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the addition-polymerizable compound.
It is suitable to use 5 to 50 parts by weight, more preferably 0.5 to 30 parts by weight. In the photopolymerizable composition of the present invention, it is preferable to add an organic polymer substance as a binder in addition to the above-mentioned constituents in order to modify the composition and improve physical properties after photocuring. Binder is compatible, film forming,
It may be appropriately selected depending on the improvement purpose such as developability and adhesiveness. Specifically, for example, for improving the water-based developability, an acrylic acid copolymer, a methacrylic acid copolymer, an itaconic acid copolymer,
There are partially esterified maleic acid copolymers, modified products of acidic cellulose having a carboxyl group in the side chain, polyethylene oxide, polyvinylpyrrolidone and the like. To improve the film strength and adhesiveness, a polyether of epichlorohydrin and bisphenol A; soluble nylon; alkyl polymethacrylate such as polymethylmethacrylate or alkyl polyacrylate; alkyl methacrylate and acrylonitrile,
Copolymers with acrylic acid, methacrylic acid, vinyl chloride, vinylidene chloride, styrene, etc .; Acrylonitrile with vinyl chloride, vinylidene chloride copolymers; Vinylidene chloride, chlorinated polyolefins, vinyl chloride with vinyl acetate Polyvinyl acetate; Acrylonitrile / styrene copolymer; Acrylonitrile / butadiene / styrene copolymer; Polyvinyl alkyl ether; Polyvinyl alkyl ketone; Polystyrene; Polyamide;
Examples thereof include polyurethane; polyethylene terephthalate isophthalate; acetyl cellulose and polyvinyl butyral. These binders can be added and mixed in a weight ratio of preferably 500% or less, more preferably 200% or less, with respect to the addition-polymerizable compound.

The photopolymerizable composition of the present invention may further contain a thermal polymerization inhibitor, a coloring agent, a plasticizer, a surface protective agent, a smoothing agent, if necessary.
Coating aids and other additives can be added. Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, pyrogallol, catechol, and 2,6-di-
There are t-butyl-p-cresol, β-naphthol, and the like. Examples of the colorant include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes. , There are cyanine dyes. When the binder is used, the thermal polymerization inhibitor and the colorant are added in an amount of 0.01 to 3% of the thermal polymerization inhibitor and 0 of the colorant with respect to the total weight of the addition-polymerizable compound and the binder. .1
-20% is preferable.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, and the like. When used, 10% or less of the total weight of the ethylenic compound and the binder can be added.

When using the photopolymerizable composition of the present invention,
The light-sensitive material can be prepared by forming the light-sensitive material without a solvent or dissolving it in a suitable solvent to form a solution, which is applied on a support and dried. Examples of the solvent include methyl ethyl ketone, cyclohexanone, butyl acetate, amyl acetate, ethyl propionate, toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene,
There are trichloroethane, dimethylformamide, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, bentoxone and the like, and one kind or a combination of two or more kinds can be used.

The support applied when preparing a light-sensitive material using the photopolymerizable composition of the present invention may be any of those usually used. For example, a sheet of metal such as aluminum, magnesium, copper, zinc, chromium, nickel, iron or an alloy containing them as a main component; high-quality paper, art paper,
Papers such as release paper; inorganic sheets such as glass and ceramics; polyethylene terephthalate, polyethylene, polymethylmethacrylate, vinyl chloride, vinyl chloride-vinylidene chloride copolymer, polystyrene, 6-nylon, cellulose triacetate, cellulose acetate butyrate, etc. Polymer sheets, etc.

Further, the photopolymerizable composition of the present invention is further provided with a known technique for preventing adverse effects such as sensitivity deterioration and storage stability deterioration due to oxygen, for example, providing a peelable transparent cover sheet on the photosensitive layer. Wax-like substance with low oxygen permeability,
It is also possible to provide a coating layer made of a water-soluble polymer or the like.
The exposure light source that can be applied to the composition of the present invention is not particularly limited, but includes carbon arc, high pressure mercury lamp, xenon lamp, metal halide lamp, fluorescent lamp, tungsten lamp, helium cadmium laser, argon ion laser, etc. visible light of 400 nm or more. A general-purpose light source can be used more suitably.

The heat source applicable to the composition of the present invention is not particularly limited, but a thermal head, an infrared semiconductor laser, an infrared heater using nichrome wire, ceramics, carbon, etc., a xenon lamp shielded from a sensitive wavelength,
A heat source such as a halogen lamp can be preferably used. The photopolymerizable composition of the present invention has extremely high specific sensitivity by simultaneously acting the above-mentioned light source and heat source, and can reproduce an excellent image, but the image signal is at least one of the light source and the heat source. Or it can be given to both,
In that case, the combination of the types of the light source and the heat source and the change mode may be selected.

When a heat source such as a thermal head that shields an image portion or a similar light source is used, the other light source or heat source should be devised such that it is supplied from the back surface or atmospherically. .

[0040]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist. Example 1 On a grained and anodized aluminum sheet, using a whirler, a photosensitive composition coating solution having the following composition was applied to a dry film thickness of 2 μm, and a polyvinyl alcohol aqueous solution was further applied to the surface thereof. Then, a photosensitive material sample was prepared by coating so that the dry film thickness was 3 μm.

[0041]

[Table 1] [Photosensitive composition coating liquid] Methyl methacrylate / methacrylic acid copolymer 50 parts by weight (weight average molecular weight 45000, copolymerization ratio 85/15) 50 parts by weight of monomers shown in Table 1 2,4 , 6-Tris-trichloromethyl-s-triazine 4 parts by weight Michler's ketone 2 parts by weight Ethyl cellosolve 800 parts by weight

[0042]

[Chemical 13]

Next, this photosensitive material sample was placed on a hot plate controlled at at least three various temperatures in the range of 20 to 60 ° C., and a transmission density of 1 / √2 was applied to each of the photosensitive material samples. Place different Kodak step tablets,
Through the step tablet, a 2 kW high pressure mercury lamp is used for 1 m.
Irradiation was carried out for 10 seconds to 1 minute from a remote position. The exposed sample was developed with an aqueous solution containing 1% by weight of butyl cellosolve and 1% by weight of sodium silicate, and the minimum exposure amount (minimum exposure amount mj / minimum exposure amount mj / cm ² ) was calculated to obtain data on the sensitivity of the photosensitive composition at each temperature.

Next, from these data, the decrease rate of the minimum exposure dose with respect to the unit temperature increase in the range of 20 to 60 ° C. was calculated by the above formula, and the results are shown in Table-1.

[0045]

[Table 2]

From the results shown in Table 1, the minimum exposure dose reduction rate per unit temperature is high, and the monomer having the skeleton of the present invention has a remarkably high sensitivity change due to temperature change, that is, a specific sensitivity, and therefore a remarkably excellent image. It can be seen that

[0047]

The photopolymerizable composition of the present invention has extremely high specific sensitivity to the simultaneous action of light and heat. Therefore,
The composition is useful in a wide range of application fields, for example, printing plates such as planographic printing, intaglio printing, letterpress printing, photoresists for printed wiring and IC fabrication, dry film, image formation such as relief image and image duplication, It is industrially very useful because it can be used for photocurable inks, paints, adhesives and the like.

Claims (2)

[Claims] 1. At least an addition-polymerizable compound and light
It contains a polymerization initiation system and forms images by the simultaneous action of light and heat.
A photopolymerizable composition comprising:
Minimum dew in the range of 20 ~ 60 ℃
The decrease rate of the light quantity is 0.015 or more
Photopolymerizable composition capable of forming an image by simultaneous action of light and heat
Stuff. [Equation 1](Where T is¹And T²Is the exposure temperature (° C), and T¹
Is 20, T²Represents 60, and E¹At a temperature of 20 ° C
Minimum exposure required for image formation (mj / cm ²)
The E²Is the minimum required for image formation at a temperature of 60 ° C.
Exposure (mj / cm ²). ) 2. The addition-polymerizable compound is a compound represented by the following general formula [I] or a compound having a partial structure represented by the following formula [II], wherein: A photopolymerizable composition that forms an image by the simultaneous action of light and heat. Embedded image (In the formula, 1 is an integer of 0 to 2, m is an integer of 1 to 3,
Y ¹ and Y ² represent a hydrogen atom or a methyl group, and A represents a direct bond or an alkylene group having 1 to 3 carbon atoms)