WO2001034671A1 - Ultraviolet-curable resin composition and ink-jet recording material having film based on the composition - Google Patents

Abstract

A recording material which has excellent printability with a water-based ink and can have water resistance and moisture resistance after printing; and an ultraviolet-curable resin composition which can give such a recording material. The composition is characterized by comprising the following ingredients: (a) hydrophilic acrylic monomer, (b) Cationic copolymer containing quaternary nitrogen, (c) photopolymerization initiator, (d) solvent and containing the ingredient (d) in an amount of 0 to 55 parts by weight per 100 parts by weight of the sum of the ingredients (a) and (b).

Description

 Description UV curable resin composition and recording material for ink jet having coating film based on the composition

 The present invention relates to an ultraviolet curable resin composition. In particular, the present invention relates to a film suitable for use in recording with an aqueous ink jet ink and an ultraviolet curable composition capable of forming a recording material having the same. Background art

 Recording with water-based ink has been widely used in various fields because it has little effect on the environment and health. In particular, in recent years, the ink jet recording method has become widespread, and writing to various base materials has been studied.

 The ink used here usually contains a water-soluble dye and water or a small amount of alcohol as a solvent. Therefore, if the printing surface is hydrophobic, the ink may be repelled without being absorbed, or the drying may be delayed, causing problems such as transfer and contamination of the periphery.

 Therefore, in order to make the printing surface hydrophilic and improve the ink receptivity, a coating made of a water-soluble polymer such as starch, gelatin, polyvinylpyrrolidone, polyvinyl alcohol, cellulose derivative, sodium polyacrylate, etc. is applied on the substrate surface. It has been proposed to form or mix inorganic or organic particles into the surface to make it porous. However, these methods have insufficient water resistance, such as print bleeding when water droplets adhere to the printing surface.

To improve water resistance, a method was developed to prevent ink re-elution by forming an ion complex with a water-soluble dye, which often has anionic groups such as sulfone groups, and a cationic substance. ing. Since the cationic substances used here are very hydrophilic, they can be used for substances other than water or highly hydrophilic solvents. Is difficult to dissolve, and there is a problem that such a solvent is necessary in order to use a cationic substance in a composition.

 Generally, in the process of producing a recording material for aqueous ink, a coating liquid is prepared by dissolving and mixing the above-mentioned water-soluble polymer, porous material, cationic material, and the like in a solvent. It is carried out in such a manner that it is coated on the substrate and then dried and / or cured by ultraviolet rays (Japanese Patent Application Laid-Open No. 9-245359, Japanese Patent Application Laid-Open No. 9-209609). In this case, since the coating liquid contains a solvent such as water, it was necessary to provide a drying step.

 On the other hand, attention has been paid to the application of a receptor layer having an ultraviolet-curable recording material for an ink jet to an optical recording medium such as a CD-R, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 7-44888. Has been described. When used in optical recording media, the coating liquid is required to be non-solvent in the process, but as described above, many of those containing a cationic substance contained a solvent. (Japanese Unexamined Patent Publication No. Hei 10—188345). In addition, even if a non-solvent containing a cationic substance is used (Japanese Patent Application Laid-Open No. Hei 10-77309, Japanese Patent Application No. Hei 11-179329), the ink absorbency and water resistance And the like, and there are practical problems such as poor moisture resistance of the ink.

 An object of the present invention is to provide a recording material capable of imparting excellent printing characteristics, water resistance after printing, and moisture resistance when an aqueous ink is used, and an ultraviolet light capable of providing such a recording material. An object of the present invention is to provide a curable resin composition. Disclosure of the invention

 The present inventors have conducted various studies to solve the above problems, and as a result, have found that these problems can be solved by using a composition having a specific composition, and have completed the present invention. That is, the gist of the present invention is a composition containing the following components (a) to (d), wherein component (d) is 100 parts by weight in total of components (a) and (b). 0 to 55 parts by weight with respect to the ultraviolet curable resin composition.

 (a) hydrophilic acrylic monomer

 (b) Cationic copolymer containing quaternary nitrogen

(c) Photopolymerization initiator (d) Solvent Brief description of drawings

 FIG. 1 is an example of an optical recording medium having a recording layer based on the composition of the present invention. Reference numerals in the figure, 1 denotes an optical recording medium, 12 denotes a substrate, 13 denotes a recording layer mainly composed of a dye, 14 denotes a metal reflective layer provided in close contact with the recording layer, and 15 denotes protection. Layer 17 is a recording surface layer (ink receiving layer) formed from the composition of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in detail.

 The hydrophilic acrylic monomer as the component (a) constituting the composition of the present invention can be used without any particular limitation as long as it is a monofunctional acrylic monomer having a hydrophilic group.

 In the present invention, the term “hydrophilic acrylic monomer” means that the solubility in water is 1 g / 100 g or more, among which 5 g / 100 g or more, particularly 10 g / 100 g or more. g / 100 g or more is preferable.

Examples of the hydrophilic group include a hydroxyl group, an acid amide group, a morpholino group, an alkoxy group having 1 to 4 carbon atoms, a tetrahydrofurfuryl group, and a glycidyl group. Specific examples of the hydrophilic acryl-based monomer include hydroxyxethyl acrylate, 1-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 1-hydroxybutyl acrylate, and 4-hydroxybutyl acrylate. Acrylate, hydroxy cypentyl acrylate, 2-hydroxy-1-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy_3-methoxypropyl Has a hydroxyl group such as acrylate, diethylene glycol monoacrylate, triethylene glycol monoacrylate, polyethylene glycol monoacrylate, dipropylene glycol monoacrylate, polypropylene glycol monoacrylate, and glycerin monoacrylate. Stuff, dimethyla Those having Riruami de Ya Jefferies chill § acrylic amino-de-acid Ami de group such as, Alternatively, acryloyl morpholine, N-vinylpyrrolidone, 2-ethoxyhexyl acrylate, 2-methoxyl acrylate, ethyl carbitol acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate Such highly polar monomers are exemplified.

 These hydrophilic acrylic monomers may be used alone or in combination of two or more. Esters of acrylic acid and acryloyl morpholine having a structure represented by the following general formula (2) or (3) are preferable from the viewpoints of ink absorbency and solubility of other components, and more preferably 4-hydrazine. Roxybutyl acrylate and acryloyl morpholine. When 4-hydroxybutyl acrylate and acryloyl morpholine are used, the weight ratio of 4-hydroxy butyl acrylate / acryloyl morpholine is 10/90 to 90/1. A range of 0 is preferred. When the ratio of 4-hydroxyheptyl acrylate is 10 or less, the solubility of other components is poor, and when it is 90 or more, ink absorbency may be poor. When the ratio of acryloylmorpholine is 90 or more, the water resistance of the ink is poor, and when the ratio is 10 or less, the film hardness may decrease.

CH ₂ = CH—COO—R ⁶ —OH (2) (R ⁶ : an alkylene group having 1 to 8 carbon atoms which may have a branched chain)

_{CH 2 = CH-COO-CH} 2 -CH (OH) one ^{_{CH 2 0- R 7 (3)}} (R 7: alkyl group having 1 to 8 carbon atoms, Ariru group or Ararukiru group) the composition of the present invention The cationic copolymer constituting the component (b) is a cationic copolymer containing a quaternary nitrogen, and preferably contains a structural unit derived from a quaternary ammonium salt-containing acryl-based monomer. It is particularly preferable to use a cationic copolymer containing a structural unit represented by the following general formula (1).

CH = C ¹ -COAR ² -N ⁺ (R ³ R ⁴ R ⁵ ) X- (1) where the symbols in the formula indicate the following.

R ¹ : hydrogen atom or methyl group

A: oxygen atom or imino group R ² : —CH ₂ —CH (OH) — CH ₂ — group or alkylene group having 2 to 5 carbon atoms

R ³ and R ⁴ : alkyl groups having 1 to 4 carbon atoms which may be the same or different

R ⁵ : an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group,

Or _CH ₂ CO〇C _n H _{2n + 1} (n is an integer of 1 to 4)

 X—: a halogen ion or an alkyl sulfate ion having 1 to 4 carbon atoms

 The structural unit represented by the general formula (1) is usually contained in an amount of 21 to 95 parts by weight, preferably 25 to 90 parts by weight, based on the cationic copolymer. When the content of the structural unit represented by the general formula (1) is more than 95% by weight, the resulting cationic copolymer has too high hydrophilicity, and the solubility in the hydrophilic acrylic monomer is low. On the other hand, if it is less than 20% by weight, the water resistance of the ink may deteriorate.

 The cationic copolymer containing the structural unit represented by the general formula (1) is obtained by copolymerizing a monomer having the structure represented by the general formula (1) with another copolymerizable monomer by a conventional method. By controlling the type and amount of the copolymerizable monomer, the solubility of the component (a) in the hydrophilic acrylic monomer can be controlled. Is possible.

 The cationic copolymer containing the structural unit represented by the general formula (1) has, in addition to the monomer having the structure represented by the general formula (1), an alkyl chain having 1 to 18 carbon atoms. The structural unit derived from the (meth) acrylic acid ester monomer is usually contained in the cationic copolymer in an amount of 5 to 79% by weight, preferably 10 to 75% by weight. If this content exceeds 79% by weight, the hydrophilicity of the resulting cationic copolymer will decrease, and the ink absorption and water resistance will deteriorate. If it is less than 5% by weight, the ink will have poor moisture resistance. Direction. Containing a structural unit derived from a (meth) acrylic acid ester monomer having an alkyl chain having 1 to 18 carbon atoms facilitates the solubility of the component (a) in the hydrophilic acrylic monomer. Can be controlled.

Examples of the (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, i-butyl (meth) acrylate, and t-butyl (meth). Acrylate, cyclohexyl Examples thereof include (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate, with cyclohexyl (meth) acrylate and i-butyl (meta) being preferred. Acrylate, t-butyl (meth) acrylate.

 In addition, at least one selected from the group consisting of a hydroxyl group, a morpholino group, and an alkoxy group having 1 to 4 carbon atoms for the purpose of further improving ink absorbency, moisture resistance, and solubility in a hydrophilic acrylic monomer. It is preferable to copolymerize a structural unit derived from a hydrophilic (meth) acrylic monomer or dimethylacrylamide. Their hydrophilicity

The unit derived from the (meth) acrylic monomer is preferably contained in the cationic copolymer in an amount of 5 to 70% by weight, more preferably 10 to 60% by weight. If the content exceeds 70% by weight, the resulting cationic copolymer will have too high a hydrophilicity, and the solubility of the component (a) in the hydrophilic acrylic monomer will be poor or will be produced. If the hydrophilicity of the coating becomes too high, the water resistance tends to deteriorate.

 As described above, the hydrophilic (meth) acrylic monomer refers to a (meth) acrylic monomer having a solubility in water of lg / 100 g or more, and in particular, 5 g / 100 g or more, especially 100 g / 100 g or more is preferable.

Hydrophilic (meth) acrylic monomers that can be used in the present invention include hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 1-hydroxybutyl. (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, 2-hydroxy-3- (phenoxypropyl) (meth) acrylate, 2-hydroxy-13 —Butoxypropyl (meth) acrylate, 2-hydroxy 3 —Methoxypropyl (meth) acrylate, diethyleneglycolmono (meth) acrylate, triethyleneglycolmono (meth) acrylate, polyethyleneglycolmono (meth) Acrylate, dipropylene gly Rumo Roh (meth) Akurireto, polypropylene Li glycolate one mono (meth) Akurireto, those having a hydroxyl group as glycerin mono (meth) Akurireto, Jimechirua Those having an acid amide group such as krillamidodiethylacrylamide, or acryloyl morpholine, N-vinylpyrrolidone, 2-ethoxyhexyl (meth) acrylate, 2-methoxyxyl (meth) acrylate, ethyl carb Thor

Highly polar monomers such as (meth) acrylate, glycidyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate are exemplified. Of these, preferred are acryloyl morpholine, 4-hydroxybutyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxyethyl (methyl) acrylate, dimethyl acrylamide, and getyl acrylamide. And more preferred is dimethyl acrylamide.

 The cationic copolymer constituting the composition of the present invention has a solubility in the component (a) of 5%.

(g / 100 g) or more cationic copolymers are preferred. (A) If the solubility in the component is less than 5 (g / 100 g), a large amount of solvent is required to uniformly dissolve the cationic copolymer in the coating solution. This will complicate the manufacturing process, such as installation, and will cause large amounts of organic substances to be released into the environment.

 The weight average molecular weight of the cationic copolymer constituting the composition of the present invention is usually from 5,000 to 500,000, preferably from 10,000 to 100,000. The weight-average molecular weight (hereinafter abbreviated as “Mw”) is a value measured by gel permeation chromatography (GPC) using polyoxyethylene as a standard substance. (It is preferable to use Wako Beads G-40, G-50, etc. as the column.)

 If the Mw of the cationic copolymer is higher than 500,000, the viscosity of the composition is high, and the handleability is deteriorated. If the Mw is less than 5,000, the ink absorbency and moisture resistance may be deteriorated.

In the cationic copolymer, the quaternary ammonium base in the structural unit derived from the monomer represented by the general formula (1) forms an ion complex with the anion dye in the ink, improves water resistance, and improves the molecular weight. It is considered that by setting the value to 5,000 to 500,000, the mobility of the cation portion is reduced, thereby preventing ink bleeding at high temperature and high humidity. The content ratio of the hydrophilic acrylic monomer of the component (a) and the cationic copolymer of the component (b) in the composition of the present invention is 40 / (weight ratio of (a) / (b)). It needs to be in the range of 60 to 95/5, and more preferably 50/50 to 85/15. When this ratio exceeds 95/5 and the amount of the component (a) increases, the hydrophilicity of the coating film is increased, and the water resistance of the ink may be deteriorated. On the other hand, as the ratio becomes less than 40/60, when the amount of the component (a) decreases, the viscosity of the whole composition increases, and the handleability may deteriorate.

 As the photopolymerization initiator of the component (c) constituting the composition of the present invention, a compound having a property of generating a free radical (radical) by dissociation by active energy rays such as light and ultraviolet rays is used. Examples are 2,2-Jetoxyasetov :! : Non, benzyldimethyl ketone, 2-hydroxy-1-methylpropiophenone, 1-acetophenones such as hydroxycyclohexylgenyl ketone, benzophenone, Michler's ketone, o-benzoyl methyl Benzophenones such as benzoate, benzoine alkyl ethers such as isopropyl benzone ether, thioxanthones such as 2-chlorothioxanthone, bis (2,4,6-trimethylbenzoy) B) Phenylphosphinoxide, bis (2,6-dimethoxybenzoyl) bisacylphosphinoxides such as 1,2,4,4-trimethylpentylphosphinoxide and the like.

 These photopolymerization initiators may be used alone, two or more of them may be used in combination, or a photosensitizer may be used in combination.

 The amount of the photopolymerization initiator to be used is generally 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the component (a). If the amount of the photopolymerization initiator is more than 10 parts by weight, the strength of the obtained film is reduced. On the other hand, if it is less than 0.1 part by weight, sufficient ultraviolet curability may not be obtained.

In addition, for the purpose of adjusting the viscosity of the coating solution, etc., as components (d), alcohols such as water, methanol, ethanol, isopropanol, and butanol, tetrahydrofuran, ethyl ether, Organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, hexane, and chloroform In general, 0 to 55 parts by weight, preferably 0 to 45 parts by weight can be added to 100 parts by weight of the total amount of the components (b) and (b). Since the composition of the present invention uses a cationic copolymer or the like having good solubility in a hydrophilic acryl-based monomer, there is almost no need to use a solvent. Therefore, there is an advantage that a drying step is almost unnecessary and the emission of organic substances is small.

 The ultraviolet-curable resin composition of the present invention preferably contains a hydrophilic copolymer in addition to the above-mentioned essential components in order to improve the ink absorbency, as long as the purpose is not impaired. The hydrophilic copolymer has a solubility in water of 1 g / 100 g or more, preferably 5 g / 100 g or more. Examples thereof include polyvinyl pyrrolidone, polyvinyl alcohol, and the like. Examples include homopolymers of hydroxyxethyl cellulose, hydroxypropyl cellulose, polyacrylamide, polyethylene glycol, and the like, or copolymers containing such monomer components, and solubility in other components. Polyvinyl viridone is preferred from the viewpoint of ink absorbency and the like. In the case of a copolymer, it may be a copolymer with a non-hydrophilic monomer.

 As the hydrophilic polymer, only one kind may be used, or two or more kinds may be used in combination.

 The amount of the hydrophilic polymer used is 3 to 45 parts by weight when the total amount of the component (a) and the component (b) (hereinafter sometimes referred to as “resin equivalent component”) is 100 parts by weight. It is preferable to use parts. A more preferred amount is 5 to 40 parts by weight. If the amount of the hydrophilic polymer is more than 45 parts by weight, the water resistance of the ink tends to deteriorate, and the viscosity of the resin composition may increase. On the other hand, if the amount is less than 3 parts by weight, the wettability and the absorbability of the ink of the coating may deteriorate.

 In addition, the resin composition of the present invention preferably contains an inorganic filler and / or an organic filler for the purpose of rapidly absorbing the ink and promoting drying.

Examples of inorganic fillers that can be used include silica, clay, silica, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, calcium silicate, synthetic zeolite, alumina, zinc oxide, and titanium oxide. And the like.

 Examples of organic fillers include polymer particles such as polyacrylate, polymer acrylate, styrene resin, polyester resin, polycarbonate, modified melamine resin, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, and rubber. Examples thereof include crosslinked particles of these polymers, and powders of natural polymers such as lignin, protein, cellulose, and gelatin.

 These inorganic fillers and organic fillers may be used alone, or may be used in combination according to the purpose of improving the absorbency after writing, adjusting the viscosity of the ink, or improving the color tone. The amount of these inorganic and / or organic fillers used is based on the resin equivalent

It is preferably used in an amount of 1 to 45 parts by weight, more preferably 1 to 30 parts by weight, per 100 parts by weight. If the amount of these fillers is more than 40 parts by weight, the viscosity of the composition becomes high and the strength of the obtained coating film decreases. On the other hand, if the added amount is less than 1 part by weight, sufficient ink absorbency cannot be imparted to the coating, and the viscosity of the composition may be too low.

 The composition of the present invention contains a monomer having at least two radically polymerizable double bonds in a molecule (hereinafter referred to as “multifunctional unit”) for the purpose of improving curability and increasing the strength of a film. ) Is preferably added.

Examples of such polyfunctional monomers include, for example, trimethylolpropane acrylate, triacryl isocyanurate, 1,4-butanediol diacrylate, neopentylglycol diacrylate, dicyclopentenyl genyl acrylate, and pentaerythritol Toll tetraacrylate, glycerin diacrylate, pentaerythritol triacrylate, dipentyl erythritol hexyl acrylate, ethylene glycol diacrylate, from ring-opened polymers of anhydride and propylene oxide An ester of polyester diol and acrylic acid, an ester of adipic acid and 1,6-hexane diol of polyester diol and acrylic acid, and an ester of trimellitic acid and diethylene glycol Ol and esters of Akuriru acid, to a hexamethylene Jie Société § sulfonate 1, polyurethane and 2-hydroxy-E chill § chestnut Les consisting of hexanediol to 6 — 2-Hydroxyethyla to a diisocyanate oligomer obtained by reacting a reaction product with acetonitrile or a polyesterdiol consisting of adipic acid and 1,6-hexanediol with tolylene disocinate Examples include urethane-based oligomers reacted with acrylates, and ether-based oligomers composed of esters of polypropylene glycol and acrylic acid.

 The amount of the polyfunctional monomer to be used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the resin equivalent component. You. If the amount exceeds 20 parts by weight, the ink absorbency of the resulting film will be poor. If the amount is less than 0.1 part by weight, the strength of the film may be slightly reduced.

 Further, in order to improve and adjust various physical properties such as hardness, adhesion, water resistance, and moisture resistance of the obtained film, the ultraviolet curable resin composition of the present invention further comprises, in addition to the above components, (Hereinafter collectively referred to as “copolymerizable monomers”).

 Examples of the copolymerizable monomers that can be used as described above include, for example, butyl acrylate, pentyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and phenoloxy acrylate. Rate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyshethyl acrylate, and the like.

 The amount of these copolymerizable monomers to be used is preferably 0.1 to 50 parts by weight per 100 parts by weight of the resin equivalent component, and more preferably 0.1 to 30 parts by weight. It is. If the amount is more than 50 parts by weight, the ink absorbency of the formed film will be poor, and if it is less than 0.1 part by weight, the strength of the film may be slightly weakened.

 Further, in addition to the above-mentioned components, the composition of the present invention contains a polymerization inhibitor, a preservative, a sensitizer, a defoaming agent, a dispersant, a fungicide and the like within a range that does not impair the objects and effects of the present invention. Can be added.

The method for producing the composition of the present invention is not particularly limited, and any method can be used. For example, (a) a hydrophilic acrylic monomer, (b) a cationic copolymer, and (c) an essential component of a photopolymerization initiator, and (d) a solvent to be added as necessary. A method in which a predetermined amount of a medium and other optional components are weighed and mixed and dissolved, and then an organic filler and / or an inorganic filler is added and mixed by stirring, or these components are collectively stirred and mixed. And the like.

 As the equipment for stirring and mixing, for example, a stirring tank, a dissolver, a ball mill, a kneader, a sand mill, a three-roll mill, an ultrasonic disperser, and the like can be used. The temperature at the time of mixing is preferably in the range of room temperature to 60 ° C. in order to prevent polymerization during mixing. By applying the composition of the present invention to a base material such as paper, glass, plastic, ceramic, and metal, and curing it with ultraviolet light, a high-performance ink-jet recording material can be obtained.

 The method of applying this composition on a substrate includes a spin coating method, a spray coating method, a dive method, a gravure roll method, a knife coating method, a reverse roll method, a screen printing method, a bar coating method, and the like. A method usually used for forming a film can be used without any particular limitation.

The obtained coating film is cured by irradiating ultraviolet rays to form a coating film. When a solvent is contained in the composition, the composition may be applied onto a substrate, dried to remove the solvent, formed into a coating film, and cured with ultraviolet light. The irradiation intensity of ultraviolet light for curing is 1 0 0: may be L 0 0 0 m J / cm 2 approximately.

 The thickness of the recording layer thus prepared is preferably from 1 to 100 m. More preferably, the thickness of the layer is from 5 to 40 m. If the thickness is too thick, the recording material is likely to warp or harden insufficiently. If the thickness is too thin, the ink permeability tends to decrease, and the ink absorbency after printing tends to deteriorate.

 Such a recording material can be suitably used for an ink jet as described above. Further, since this recording material can be prepared without using a solvent, it is suitable as an ink receiving layer of an optical recording medium.

FIG. 1 shows an example of an optical recording medium having such a recording layer. In FIG. 1, the optical recording medium 1 has a recording layer 13 mainly composed of a dye on a substrate 12, a metal reflective layer 14 in close contact with the recording layer 13, and a protective layer 15. In this configuration, the recording surface layer 17 is formed on the protective layer 15. The optical recording medium of the present invention A structure other than the structure shown in FIG. 1 may be adopted as long as the outer layer has an ink receiving layer formed by using the ultraviolet-curable resin composition of the present invention. Example

 Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

<Production Example 1> Production of cationic copolymer (1)

In a 30 Oml flask equipped with a stirrer and a condenser, 63 g of Solmix (alcohol-based solvent, manufactured by Nippon Kasei Co., Ltd.), 53 g of water, and 2,2-azobisisopropane as a polymerization initiator were used. After charging 0.7 g of ptyronitrile (hereinafter abbreviated as “AI BN”) and purging with nitrogen for 30 minutes, the temperature was raised to 80 ° C. Next, a mixture of 43.7 g of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution), methyl methacrylate 15 :, and 10 g of Solmix was added to the dropping port, and the mixture was added to the flask over 1 hour. The polymerization was carried out for 2 hours while maintaining the temperature at 80 ° C. After a lapse of 2 hours, the polymerization initiator AIBN was added 0.08 [], and polymerization was further performed for 4 hours. Thereafter, hot air drying and vacuum drying were performed to obtain a powder of the cationic copolymer (1). The molecular weight (Mw) of the obtained cationic copolymer (1) was 3.5 × 10 ⁴ . <Production Example 2> Production of cationic copolymer (2)

In a 300 ml flask equipped with the same stirrer and cooling tube as in Production Example 1, 37.5 g of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution), 12.5 g of dimethylacrylamide, i _ 7.5 g of butyl methyl acrylate, 117 g of Solmix as a solvent, and 0.75 g of AIBN as a polymerization initiator The temperature was raised, and polymerization was performed at that temperature for 2 hours. After 2 hours, 0.05 g of AIBN was added, and polymerization was further performed for 4 hours. The molecular weight (Mw) of the cationic copolymer (2) obtained by collecting a part of the polymerization solution was 1.73 × 10 ⁵ .

Subsequently, 0.1 g of 4-methoxyphenol was added as a polymerization inhibitor, and the mixture was stirred at 80 ° C for 4 hours while blowing in air to distill off the solvent solmix. 100 g of hydroxybutyl acrylate was charged and further stirred for 2 hours to obtain a solution of the cationic copolymer (2) in 4-hydroxybutyl acrylate.

<Production Example 3> Production of cationic copolymer (3)

A 1000 ml flask equipped with a stirrer and a condenser was charged with 300 g of Solmix as a solvent and 2.1 g of AIBN as a polymerization initiator, and after purging with nitrogen for 30 minutes, the temperature was raised to 80 ° C. Then, a mixture of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution) (12.5 g), dimethyl acrylamide (37.5 g), i-butyl methyl acrylate (22.5 g) and Solmix (51 g) was added to the dropping funnel. The mixture was dropped into the flask over 2 hours, and polymerization was carried out at 80 ° C. for 2 hours. After a lapse of 2 hours, 0.24 g of AIBN as a polymerization initiator was added, and polymerization was further performed for 4 hours. The molecular weight (Mw) of the cationic copolymer (3) was 2.8 × 10 ⁴ .

 Subsequently, 0.3 g of 4-methoxyphenol was added as a polymerization inhibitor, and the mixture was stirred at 80 ° C for 2 hours while blowing in air to distill off the solvent solmix. A rate of 150 g was charged, and the mixture was further stirred for 1 hour to obtain a 4-hydroxybutyl acrylate solution of the cationic copolymer (3).

<Production Example 4> Production of cationic copolymer (4)

In a 300 ml flask equipped with a stirrer and cooling tube similar to that used in Production Example 1, methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution) 28.12 g, 4-hydroxybutyla 20 g of acrylate, 7.5 g of t-butyl methacrylate, 37.5 g of Solmix as a solvent, 37.5 g of water, 0.5 g of AIBN as a polymerization initiator, and nitrogen replacement for 30 minutes After that, the temperature was raised to 80 ° C, and polymerization was performed for 2 hours. Thereafter, 0.05 g of AIBN as a polymerization initiator was added, and polymerization was further performed for 4 hours, followed by hot-air drying and vacuum drying to obtain a powder of a cationic copolymer (4). The molecular weight (Mw) of the cationic copolymer (4) was 1.2 × 10 ⁵ .

 <Production Example 5> Production of cationic copolymer (5)

In Production Example 4, acryloyl was used instead of 4-hydroxybutyl acrylate. A powder of the cationic copolymer (5) was obtained in the same manner except that morpholine was used, and 40 g of Solmix and 35 g of water were used as solvents. The molecular weight of the cationic co-polymer (5) (Mw) was 8. lxl 0 ^4.

<Production Example 6> Production of cationic copolymer (6)

In Production Example 4, methoxypolyethylene glycol (4) methacrylate was used in place of 4-hydroxybutyl acrylate, the solvent amounts were 70 g of Solmix and 67 g of water, and the polymerization initiator (AIBN) was used. A powder of the cationic copolymer (6) was obtained in the same manner except that the amount used was initially 0.7 g and the additional charge was 0.08 g. The molecular weight of the cationic copolymer (6) (Mw) is 2. 0 x 1 0 ⁵ der ivy.

 <Production Example 7> Production of cationic copolymer (7)

 In a 500 ml flask equipped with a stirrer and condenser, Solmix 1 as solvent

After charging 90 g and purging with nitrogen for 30 minutes, the temperature was raised to 80 ° C. Put 1.4 g of AIBN in a flask, and then put a mixture of 75 g of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution), methyl methacrylate 40 :, and 33 g of Solmix in a dropping funnel for 2 hours. The mixture was dropped into the flask, and polymerization was carried out at 80 ° C. for 2 hours. After 2 hours, 0.1 lg of AIBN was added, and polymerization was further performed for 5 hours. The molecular weight (Mw) of the cationic copolymer (7) is 2.4 X

It was 10 ⁴ .

 Subsequently, 0.2 g of 4-methoxyphenol was added as a polymerization inhibitor, and the mixture was stirred at 80 ° C for 2 hours while blowing in air to distill off the solmix of the solvent. 100 g of the rate was charged and further stirred for 1 hour to obtain a solution of the cationic copolymer (7) in 4-hydroxybutyl acrylate.

<Production Example 8>

In a 300 ml flask equipped with a stirrer and a condenser tube, 18.75 g of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution), 35 g of methyl methyl acrylate, and 150 g of Solmix as a solvent were charged and replaced with nitrogen. After 30 minutes, the temperature was raised to 56 ° C. 2,2-azobis (2,4-dimethylba (Reronitrile) (hereinafter abbreviated as V-65) 0.5 g was placed in a flask, and after 2 hours, 0.05 g of ¥ -65 was added and polymerization was carried out for 3 hours. The molecular weight (Mw) of the cationic copolymer (8) was 2.3 × 10 ⁴ .

 Subsequently, 0.2 g of 4-methoxyphenol was added as a polymerization inhibitor, and the mixture was stirred at 80 ° C for 2 hours while blowing in air to distill off the solmix of the solvent. 100 g of the rate was added, and the mixture was further stirred for 1 hour to obtain a solution of the cationic copolymer (8) in 4-hydroxybutyl acrylate.

<Production Example 9> Production of cationic copolymer (9)

 In Preparation Example 2, the amount of methyl chloride-modified dimethylaminoethyl methacrylate (80% aqueous solution) was changed to 62.5 g, and dimethylacrylamide and i-butyl methacrylate were not added. The polymerization was carried out for 2 hours + 4 hours.

Then, hot air drying and vacuum drying were performed to obtain a cationic copolymer (7) powder. The molecular weight (Mw) of the cationic copolymer (9) was 2.10 ⁴ .

<Application to polyester film substrate: Examples 1 to 11, Comparative Examples 1 to 6>

A predetermined amount of each component shown in Table 1 was blended, stirred and dispersed to prepare an ultraviolet-curable resin composition. Was coated using a # 10 bar co Isseki one on a polyester film having a thickness of 50〃M the composition, then irradiated with 33 OmJ / cm ² of ultraviolet light, a film of thickness 1 5〃M A recording material having a polyester film as a base material was prepared. The abbreviations in the table indicate the following contents.

 ACMO: Acryloylmorpholine (Nippon Kayaku Co., Ltd.)

 4HBA: 4-hydroxybutyl acrylate (Nippon Kasei Co., Ltd.)

 Irgacure 819: Photopolymerization initiator (manufactured by Ciba Specialty Co., Ltd.)

 Darocure 1 173: Photopolymerization initiator (Chivas Specialty Chemicals Co., Ltd.) 2 E HA: 2-ethylhexyl acrylate

P VP: Polyvinylpyrrolidone ESLEC KX-l: Polyvinylacetone (Sekisui Chemical Co., Ltd.) ESLEC KW-1: Polyvinylacetal (Sekisui Chemical Co., Ltd.) Poster 1002: Acryl-based crosslinkable filler (Nippon Shokubai Co., Ltd.) )

 PAA-HC1: Polyallylamine hydrochloride (Nitto Boseki Co., Ltd.)

 Fine Seal X-45: Silica (particle size: about 4〃m) (manufactured by Tokuyama Corp.) Cationic monomer: Ethyl acetate-modified dimethylaminoethyl acrylate type dye CR-95: titanium oxide (Ishihara Sangyo Co., Ltd.)

 UX 2201: Urethane acrylate oligomer (manufactured by Nippon Kayaku Co., Ltd.)

 Using the ink jet printer (EPS ON-MJ-930C), solid printing of each color of black, blue, red, and yellow was performed on the recording material obtained in the above example and comparative example, and the obtained printing sheet was obtained. Was evaluated according to the following method. The results are shown in Table 1 and below.

 (1) Ink bleed

 The ink bleeding of the printed portion was visually evaluated.

 〇: No ink bleeding

 X: Ink bleeding is seen

 (2) Ink absorption

 Two minutes after the end of printing, plain paper was brought into contact with the printed portion, and the transfer of the ink was visually evaluated.

 A: Transfer is hardly observed

 〇: There is slight transcription

 X: Transcription is clearly seen

 (3) Water resistance of the ink

 One day after printing, water was dropped on the printed portion, and two minutes later, the water was wiped off, and the state of remaining ink was visually evaluated.

 ◎: almost no change

〇: Slight decolorization X: Decoloring is remarkable

 (4) Moisture resistance of the ink

 One day after printing, the printed sample was placed in a constant temperature / humidity chamber at 30 ° C. and 90%, and the bleeding of characters was visually evaluated.

 ◎: almost no bleeding is seen

 〇: Slight bleeding is seen

 X: obvious bleeding

 (5) Film strength

 The nail was pressed against the UV cured film, and the surface was visually evaluated for scratches.

 ◎: scarcely seen

 〇: slightly scratched

X: obvious scratches

Table-1 (Part 1)

 An example

 Component (c): parts by weight based on 100 parts by weight of (a)

 Other components: parts by weight based on (a) + (b) being 100 parts by weight

Solubility: 100 g of hydrophilic acrylic monomer (4-hydroxybutyl acrylate: Nippon Kasei Co., Ltd.) at 25 ° C completely dissolves 5 g of strength copolymer or hydrophilic copolymer =以外, otherwise = x Table 1 (Part 2)

 (*): Catalog value

 (C) Parts by weight based on 100 parts by weight of component (a)

 Parts by weight based on 100 parts by weight of other components (a) + (b)

Solubility At 25 ° C, 5 g of a hydrophilic copolymer or a hydrophilic copolymer is completely dissolved in 100 _g of a hydrophilic acrylic monomer (4-hydroxybutyl acrylate: Nippon Kasei Co., Ltd.) = 〇, otherwise = X <Evaluation of results>

 (1) As shown in Table 1, the recording materials having the coatings based on the compositions of the present invention of Examples 1 to 11 all showed good results for the above evaluation items.

(2) In Comparative Examples 1 and 2, a cationic copolymer outside the scope of the present invention was used in place of the cationic copolymer (b), but the cationic copolymer was hydrophilic acrylyl. It did not dissolve in the monomer and could not form a coating.

 (3) In Comparative Example 3, an acrylic monomer containing a quaternary ammonium salt was used in place of the cationic copolymer as the component (b), but the ink had poor moisture resistance and caused bleeding.

(4) In Comparative Example 4, the weight ratio of the hydrophilic acrylic monomer of the component (a) to the cationic copolymer of the component (b) was less than the component (b) of 95/5. Also, ink bleeding occurred and the water resistance of the ink was poor.

 (5) In Comparative Examples 5 and 6, a polyvinyl acetate resin was used as the hydrophilic copolymer, but it did not dissolve in the hydrophilic acrylic monomer, and a film could not be formed.

<Application to compact disk: Examples 12 to 14, Comparative Example 7>

The components shown in Table 12 were blended in predetermined amounts, stirred and dispersed to prepare an ultraviolet-curable resin composition. This composition was screen-printed on the back side of a polycarbonate compact disk using a 30 ° mesh screen, and irradiated with 33 OmJ / cm ² ultraviolet light to obtain an optical recording having a 10 / m thick film recording layer. A medium was prepared.

 <Evaluation method>

Each color of black, blue, red and yellow was applied to the optical recording medium having a recording layer obtained in the above Examples and Comparative Examples by using an ink jet printer (Fargo: CD-Color Printer). After printing, the resulting printed sheet was evaluated for ink absorbency, ink water resistance, and ink moisture resistance. The evaluation method was the same as in Examples 1 to 11. The results are shown in Table-2. Table-2

(c) Component parts by weight when (a) is 100 parts by weight Other parts by weight when component (a) + (b) is 100 parts by weight Solubility: hydrophilic acrylic monomer at 25 ° C (4-Hydroxybutylacrylate) Nippon Kasei Co., Ltd. (100 _g ) completely dissolves 5 _g of cationic copolymer = 〇, otherwise X

Evaluation of results

 (1) As shown in Table 2, the recording materials having the coatings based on the compositions of the present invention of Examples 12 to 14 all showed good results for the above evaluation items.

(2) In Comparative Example 7, an acrylic monomer containing a quaternary ammonium salt was used instead of the cationic copolymer as the component (b), but the ink had poor moisture resistance and caused bleeding. Industrial applicability

 As described above, when the composition of the present invention is applied to a base material and cured with ultraviolet light, a film having excellent printing characteristics, water resistance, and moisture resistance when used as a recording material for printing with an aqueous ink. Can be given. In addition, since no solvent is used, emission of organic substances can be reduced during coating and curing.

Claims

The scope of the claims 1. A composition containing the following components (a) to (d), wherein the component (d) is contained in an amount of 0 to 55 parts by weight based on 100 parts by weight of the total of the components (a) and (b). An ultraviolet curable resin composition, characterized in that:  (a) Hydrophilic acrylic monomer  (b) Quaternary nitrogen-containing cationic copolymer  (c) Photopolymerization initiator  (d) Solvent 2. The ultraviolet curable resin composition according to claim 1, wherein the component (b) is a cationic copolymer having a solubility in the component (a) of 500 g or more. 3. The ultraviolet curing according to claim 1 or 2, wherein the component (b) is a cationic copolymer containing a structural unit derived from a quaternary ammonium salt-containing acrylic monomer. Resin composition. 4. The ultraviolet curing according to claim 3, wherein the component (b) is a cationic copolymer containing 21 to 95% by weight of a monomer-derived structural unit represented by the following general formula (1). Resin composition. CH ₂ = CR ¹ -COAR ² -N ⁺ (R ³ R ⁴ R ⁵ ) X "(1) However, the symbols in the formula indicate the following contents. R ¹ : hydrogen atom or methyl group  A: oxygen atom or imino group R ² : —CH ₂ —CH (OH) —CH ₂ — group or group having 2 to 5 carbon atoms  Alkylene group R ³ and R ⁴ : alkyl groups having 1 to 4 carbon atoms which may be the same or different 5: an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, Or — CH ₂ C OO C _n H _{2 n + 1} (n is an integer of 1 to 4)  X—: a halogen ion or an alkyl sulfate ion having 1 to 4 carbon atoms 5. The ultraviolet-curable composition according to any one of claims 1 to 4, wherein the weight ratio of (a) / (b) is 40/60 to 95/5. 6. A composition containing the following components (a) to (c), wherein the weight ratio of (a) / (b) is in the range of 40/60 to 95/5, and (c) The ultraviolet curable resin composition, wherein the content of the component is (a) in the range of 0.1 to 10 parts by weight per 100 parts by weight.  (a) Hydrophilic acrylic monomer  (b) It contains 21 to 95% by weight of a structural unit derived from a monomer represented by the following general formula (1), and the solubility of the component (a) in the hydrophilic acrylic monomer is 5 (g / g). 100 g) cationic copolymer having a weight average molecular weight of 500-500 CH ₂ = CR ¹ -COAR ² -N ⁺ (R ³ R ⁴ R ⁵ ) X "(1) where the symbols in the formula indicate the following contents. R ¹ : hydrogen atom or methyl group  A: oxygen atom or imino group R ² : — CH ₂ — CH (OH) — CH ₂ — group or C 2-5  Alkylene group R ³ , R ⁴ : an alkyl group having 1 to 4 carbon atoms which may be the same or different R ⁵ : an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, or —CH ₂ C OO C _n H _{2 n + 1} (n is an integer of 1 to 4) Group X—halogen ion or alkyl sulfate ion of 1 to 4 carbon atoms (c) Photopolymerization initiator 7. The method according to claim 1, wherein the component (a) is a hydrophilic acryl-based monomer containing 4-hydroxybutyl acrylate. UV curable resin composition. 8. The ultraviolet-curable resin composition according to claim 7, wherein the component (a) is a hydrophilic acryl-based monomer containing 4-hydroxybutyl acrylate and acryloyl morpholine. 9. The component (b) is a (meth) acrylate-based monomer having an alkyl group having 1 to 18 carbon atoms and 21 to 95% by weight of a structural unit derived from the monomer represented by the general formula (1). The ultraviolet-curable resin composition according to any one of claims 1 to 8, which is a cationic copolymer containing 5 to 79% by weight of a structural unit derived from a monomer. 10. The component (b) is selected from the group consisting of 21 to 95% by weight of a monomer-derived structural unit represented by the general formula (1), a hydroxyl group, a morpholino group and an alkoxy group having 1 to 4 carbon atoms. Structural units derived from hydrophilic (meth) acrylic monomers having at least one type of functional group or structural units derived from dimethylacrylamide at 5 to 70% by weight, and alkyl having 1 to 18 carbon atoms 9. The cationic copolymer according to claim 1, which is a cationic copolymer containing 5 to 79% by weight of a structural unit derived from a (meth) acrylate monomer having a group. The ultraviolet-curable resin composition according to the above. 11. In addition to the components of the composition according to any one of claims 1 to 10, in addition to the hydrophilic polymer, the inorganic filler, the organic filler, and at least 2 components in the molecule. An ultraviolet curable resin composition containing at least one selected from the group consisting of a monomer having two radically polymerizable double bonds and a copolymerizable monomer. 12. For an ink jet having an ink receiving layer composed of a cured layer obtained by curing the ultraviolet-curable fat composition according to any one of claims 1 to 11 on a substrate. Recording material. 13. An optical recording medium having a cured layer obtained by curing the ultraviolet-curable resin composition according to any one of claims 1 to 11 on a substrate. 14. The optical recording medium according to any one of claims 1 to 11, wherein the cured layer is an ink receiving layer. 15. The ultraviolet curable resin composition according to any one of claims 1 to 11 is applied to at least one surface of the substrate, and is then irradiated with an active energy ray. A method for producing an optical recording medium for curing the ultraviolet-curable resin composition.