JPH0834948A - Active energy ray curing composition for ink - Google Patents

Abstract

PURPOSE:To obtain the rapid curing composition consisting of a reaction product of an alkylene adduct of bisphenol-A, with a dibasic acid or its anhydride, etc., excellent in flow properties as an ink vehicle, having printabilities such as misting, etc., and excellent in surface hardness and solvent resistance after the curing. CONSTITUTION:This active energy ray curing composition for an ink comprises a reaction product of (A) pentaerythritol, (B) an alkyleneoxide adduct of bisphenol-A, (C) a dibasic acid or its anhydride and (D) a (metha)acrylic acid. Further, reacting with a ratio of 0.5-4.0mol component (A), 0.5-2.5mol component (B) and 3.5-17mol component (D) based on 1mol component (C) is preferable, and as a component (C) e.g. succinic acid, etc., are cited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition curable by active energy rays such as ultraviolet rays (hereinafter referred to as UV) or electron beams (hereinafter referred to as EB). The composition of the present invention is It has excellent fluidity characteristics as an ink vehicle, fast curing, excellent printability, and has excellent surface hardness as a printed matter after curing. It can be prized. In the present specification, an acryloyl group and / or a methacryloyl group is referred to as a (meth) acryloyl group, acrylic acid and / or methacrylic acid is referred to as (meth) acrylic acid, and acrylate and / or methacrylate is referred to as (meth). Expressed as acrylate.

[0002]

2. Description of the Related Art Conventionally, an ink used in offset printing or the like is a so-called high-viscosity varnish obtained by dissolving a rosin phenolic resin, a rosin maleic acid resin or an oil-modified alkyd resin in a high boiling point petroleum solvent. Ink has been used. Generally, such an ink has a slow drying property, and when the ink is used for offset rotary printing, it is necessary to perform forced drying, which requires a drying facility for this, and thus requires a large amount of cost, In addition, the printed matter obtained has the drawback of being inferior in abrasion resistance and solvent resistance. In order to improve such various drawbacks, an active energy ray-curable vehicle that does not require forced drying has been developed and put into practical use (Japanese Patent Laid-Open No. 2-77414, etc.). These include, specifically, vehicles made of diallyl phthalate, epoxy acrylate, urethane acrylate, polyester acrylate, unsaturated polyester, etc., which are dissolved by low molecular weight (meth) acrylate-based monomers as necessary. Often used as a varnish for ink. Further, a composition comprising a saturated polyester and a (meth) acrylate having two or more (meth) acryloyl groups in one molecule is also known (Japanese Patent Laid-Open No. 5-32055).
No. 5).

[0003]

However, although the conventional active energy ray-curable ink composition does not require forced drying, the curability of the composition, the surface hardness and the solvent resistance of the cured composition are not required. In addition, none of the compositions for printing ink sufficiently satisfies the so-called printability such as fluidity, pigment dispersibility and misting. In order to find a composition for active energy ray-curable ink, the present inventors have excellent printability such as curability, fluidity, pigment dispersibility, and misting, and the cured product has excellent surface hardness and solvent resistance. We conducted a thorough study.

[0004]

DISCLOSURE OF THE INVENTION The present invention comprises an activity comprising pentaerythritol, an alkylene oxide adduct of bisphenol A, a dibasic acid or an acid anhydride thereof, and a reaction product of (meth) acrylic acid. The present invention relates to an energy ray-curable ink composition. Hereinafter, the present invention will be described in detail.

Reaction product The alkylene oxide adduct of bisphenol A for obtaining the reaction product in the present invention introduces the skeleton of bisphenol A into the obtained reaction product, whereby the active energy ray curability is remarkably improved. Has the effect of improving.
Examples of the alkylene oxide adduct of bisphenol A include ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, and butylene oxide adduct of bisphenol A. The number of alkylene oxides added is
It is preferably 20 or less, more preferably 10 or less. If the number of additions exceeds 20, the curability of the composition may decrease, while if bisphenol A to which alkylene oxide is not added is used, the viscosity of the reaction product obtained is It becomes expensive and difficult to handle. Specific examples of the dibasic acid or its acid anhydride, for example, succinic acid, dodecyl succinic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid,
Examples thereof include citraconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, 4-methyltetrahydrophthalic acid and 4-methylhexahydrophthalic acid, and anhydrides thereof.

The reaction ratio of these compounds is 0.5 to 4.0 mol of pentaerythritol and 0.5 to 2 of alkylene oxide adduct of bisphenol A, based on 1 mol of dibasic acid or its acid anhydride. 0.5 mol and 3.5 to 17 mol of (meth) acrylic acid are preferable, and more preferably 1.5 to 4.0 mol of pentaerythritol and bisphenol A based on 1 mol of dibasic acid or its acid anhydride. Alkylene oxide adduct of 0.5-2.
0 mol and 10 to 16 mol of (meth) acrylic acid. If the amount is less than these ratios, the curability of the resulting composition may not be sufficient. On the other hand, if the amount exceeds these ratios, the molecular weight of the obtained reaction product will be small, resulting in pigment dispersibility. May not be enough.

The reaction product obtained by the reaction of the above-mentioned raw material compounds is presumed to consist of the compound represented by the following formula (1) and a plurality of compounds having different structures as shown in the following chemical formula 2.

[0008]

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[0009]

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[In the formula (1) and Chemical formula 2, P is a residue of pentaerythritol, B is a residue of an alkylene oxide adduct of bisphenol A, D is a residue of a dibasic acid or an acid anhydride thereof, and A means a residue of (meth) acrylic acid, and each residue is bound by an ester bond. ]

Particularly preferred reaction products in the present invention are, in addition to the compound represented by the above formula (1) as the reaction product, pentaerythritol tetra (meth) acrylate and / or the compound represented by the chemical formula 2. Only di (meth) acrylate of an alkylene oxide adduct of bisphenol A is produced, and further 100 parts by weight of the compound represented by the formula (1) is pentaerythritol tetra (meth) acrylate and / or alkylene of bisphenol A. In the ratio of each raw material compound calculated on the assumption that the oxide adduct di (meth) acrylate is theoretically produced in an amount of 10 to 150 parts by weight, and the proportion of each raw material compound is set within the above preferable reaction ratio range. It is obtained by reacting.

The above-mentioned particularly preferable reaction product is an ink composition having excellent curability and pigment dispersibility. Also, pentaerythritol tetra (meth) acrylate and / or bisphenol A for the compound represented by the formula (1)
It is also possible to add pentaerythritol tetra (meth) acrylate and / or bisphenol A alkylene oxide adduct di (meth) acrylate so as to satisfy the amount of di (meth) acrylate of alkylene oxide adduct.

Method for producing reaction product The reaction product used in the present invention is pentaerythritol, an alkylene oxide adduct of bisphenol A,
A dibasic acid or its acid anhydride and (meth) acrylic acid are dehydrated and produced by a conventional method. As an example thereof, there is a method in which the above compound is heated in an organic solvent, preferably in the presence of an acidic catalyst, with stirring to perform dehydration esterification. The reaction temperature is preferably 80 to 130 ° C.
If the reaction temperature is lower than 80 ° C., the reaction rate may be slow, while if it exceeds 130 ° C., the reaction system may become unstable or gel. Examples of the organic solvent include toluene, xylene, cyclohexane, and the like, and the compounding amount thereof is such that the NV of the reaction liquid is 10 to 9
The ratio of 0 is preferable, and more preferably 30 to 70. Examples of the acidic catalyst include sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, tungstophosphoric acid, phosphoric acid, and a strongly acidic cation-type ion exchange resin, and the addition amount thereof is the above-mentioned raw material, or a raw material and an organic solvent. 0.1 to 10 parts by weight is preferable for 100 parts by weight in total. At the time of the above reaction, it is preferable to add a small amount of a stabilizer in order to prevent thermal polymerization or maintain storage stability.
Suitable stabilizers include, for example, phenols such as hydroquinone, hydroquinone monomethyl ether, t-butyl hydroquinone, catechol and t-butyl-catechol, benzoquinone, p-benzoquinone, naphthoquinone, diphenylbenzoquinone and 2,5-t-butyl-.
Examples thereof include quinones such as hydroquinone, phenothiazine, and copper salts. The blending amount of these stabilizers is preferably 0.00001 to 0.01 parts by weight based on 100 parts by weight of the total amount of the raw material and the organic solvent or 100 parts by weight of the reaction product. These stabilizers may be added to the reaction product after the reaction is completed.

Active energy ray-curable ink composition In the active energy ray-curable ink composition of the present invention, the above reaction product can be used as it is, but various other components may be added as necessary. It can also be blended. When other components are blended, they may be mixed with the above reaction product according to a conventional method.

For example, a reactive diluent, an organic solvent and / or water can be added in order to reduce the viscosity of the composition. As a reactive diluent, in the molecule (meta)
There are compounds having an acryloyl group. As the reactive diluent, it is desirable to use one having a viscosity of 50 cps or less at 25 ° C. Specific examples of suitable compounds include tetrahydrofurfuryl acrylate (commercially available, Viscoat 150 manufactured by Osaka Organic Chemical Industry Co., Ltd.).
, Etc., phenoxyethoxyethyl acrylate [commercially available products include Aronix M101 manufactured by Toagosei Chemical Industry Co., Ltd.], neopentyl glycol diacrylate [commercially available as Osaka Organic Chemical Industry Co., Ltd.] Manufactured by Osaka Organic Chemical Industry Co., Ltd.
There is a viscoat 230, etc., etc., and two or more of these can be used. Examples of the organic solvent include ketones such as methyl ethyl ketone and methyl isobutyl ketone, acetic acid esters such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol and isopropyl alcohol, and methyl cellosolve. Examples thereof include cellosolves such as ethyl cellosolve, and cellosolve acetates such as methyl cellosolve acetate and ethyl cellosolve acetate. In addition to these, organic solvents generally used for inks can be used. These can also use 2 or more types in a composition. The content of the reactive diluent is preferably 100 parts by weight or less with respect to 100 parts by weight of the composition, and the content of the organic solvent or water is preferably the composition of the present invention and the reactive diluent (hereinafter These are preferably 100 parts by weight or less based on 100 parts by weight of the total amount of curable components).

When the composition of the present invention is cured by UV, a photoinitiator and / or a sensitizer for promoting the curing are added. As the photoinitiator used in the present invention, various photoinitiators can be used, and a typical example thereof is 2-methyl [4- (methylthio) phenyl].
Acetophenones such as 2-morpholino-1-propanone, benzyl dimethyl ketal and 1-hydroxycyclohexyl phenyl ketone, benzoin ethers such as benzoin and benzoin methyl ether, benzophenones such as benzophenone and methyl orthobenzoylbenzoate, diethyl Thioxanthones such as thioxanthone, anthraquinones and derivatives thereof, acylphosphine oxide and derivatives thereof, and benzyl. Various types of photosensitizers can be used, and representative examples thereof include amines, ureas, sulfur compounds, nitriles, phosphorus compounds, nitrogen compounds and chlorine compounds. The amount of these photoinitiators and / or sensitizers added is 0.01 to 100 parts by weight of the reaction product.
It is preferably 20 parts by weight, more preferably 0.1 to 10 parts by weight. If it is less than 0.01 part by weight, the effect of promoting the initiation of polymerization becomes insufficient, while if it exceeds 20 parts by weight, the ratio of the curable component in the composition decreases, and the properties of the cured product deteriorate. There is a fear.

In the present invention, various oligomers and / or resins may be blended in order to enhance suitability as a printing ink. Examples of the oligomer include special acrylates such as epoxy acrylate, rosin-modified epoxy acrylate, fatty acid-modified epoxy acrylate, polyester acrylate, urethane acrylate, and polyacrylate of polyol, and the resin includes diallyl phthalate resin, ketone resin, polyester, epoxy resin. , Amino resins, alkyd resins and petroleum resins. In addition to the above-mentioned components, a colorant, a pigment, a surface smoothing agent, a defoaming agent and / or a viscosity modifier may be added to the composition of the present invention.

○ Method of Use The composition of the present invention is printed on a substrate such as paper or film according to a usual printing method or coating method, and cured by irradiation with active energy rays. The composition of the present invention can also be cured by ionizing radiation such as γ-ray as an active energy ray, in addition to UV or EB. When the curing means is UV, the above-mentioned photoinitiator and sensitizer are blended in order to accelerate the curing. The curing means is EB or γ
In the case of ionizing radiation such as rays, it is not always necessary to add a photoinitiator and a sensitizer. UV the composition of the present invention
When cured by, for example, low pressure or high pressure mercury lamp, metal halide lamp, xenon lamp,
An electrodeless discharge lamp or a carbon arc lamp or the like can be used. When the composition of the present invention is cured with an electron beam, a Cockloft-Wortsine type, a Van de Graaff type, a resonance transformer type or the like can be used, and usually 50 to 1000 keV, and more preferably 100.
An electron beam with an energy of ~ 300 keV is used. The active energy ray-curable ink composition of the present invention is printed on a substrate such as paper, film or sheet according to a usual printing method or coating method, and thereafter,
The active energy ray is irradiated to cure.

[0019]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. The parts and% in each example
Is by weight unless otherwise specified. -Synthesis example 1 In a reactor equipped with a stirrer, a thermometer and a water separator, 68 parts of pentaerythritol (0.50 mol) and 203 parts of an ethylene oxide 4 mol adduct of bisphenol A (0.
50 mol), 73 parts (0.50 mol) of adipic acid, 159 parts (2.2 mol) of acrylic acid, 503 parts of toluene as a solvent, 20 parts of sulfuric acid as a catalyst, and 0.5 parts of hydroquinone as a polymerization inhibitor. After that, with stirring 110-
After reacting at 120 ° C. for 4 hours, 54 parts of water was separated. After the reaction was completed, 170 parts of water was added to the reaction solution,
After stirring at 0 ° C., the mixture was allowed to stand, and the lower layer (aqueous layer) containing unreacted acrylic acid, catalyst and the like was separated. When toluene was distilled off from the upper layer (organic layer) at 80 ° C. under reduced pressure, 390 parts of a reaction product was obtained. The viscosity was 7200 cps / 25 ° C.

Synthesis Example 2 Pentaerythritol 68 was placed in the same reactor as in Synthesis Example 1.
Parts (0.50 mol), bisphenol A ethylene oxide 10 mol adduct 335 parts (0.50 mol), tetrahydrophthalic anhydride 76 parts (0.50 mol), acrylic acid 159 parts (2.2 mol), When 638 parts of toluene, 26 parts of paratoluenesulfonic acid as a catalyst and 0.6 part of hydroquinone were charged and the reaction was carried out under the same conditions as in Synthesis Example 1, 45 parts of water was separated. After the completion of the reaction, 210 parts of water was added to the reaction solution and post-treatment was carried out in the same manner as in Synthesis Example 1 to obtain 460 parts of a reaction product. Viscosity 55
It was 00 cps / 25 ° C.

Synthesis Example 3 Pentaerythritol 68 was placed in the same reactor as in Synthesis Example 1.
Parts (0.50 mol), propylene oxide 4 mol adduct of bisphenol A, 231 parts (0.50 mol), phthalic anhydride 74 parts (0.50 mol), acrylic acid 159 parts (2.2 mol), toluene After charging 532 parts, 21 parts of paratoluene sulfonic acid and 0.5 parts of hydroquinone, the reaction was carried out under the same conditions as in Synthesis Example 1, 43
Some water was separated. After completion of the reaction, 180 parts of water was added to the reaction solution, and post-treatment was carried out in the same manner as in Synthesis Example 1.
0 part of reaction product was obtained. Viscosity is 6400cps / 25
° C.

Synthesis Example 4 Pentaerythritol 78 was placed in the same reactor as in Synthesis Example 1.
Parts (0.57 mol), ethylene oxide 4 mol adduct of bisphenol A 71 parts (0.18 mol), phthalic anhydride 27 parts (0.18 mol), acrylic acid 194 parts (2.7 mol), toluene When 370 parts, 15 parts of paratoluenesulfonic acid and 0.5 part of methoxyhydroquinone as a polymerization inhibitor were charged and the reaction was carried out under the same conditions as in Synthesis Example 1, 43 parts of water was separated. The reaction ratio of the raw materials is a ratio at which 87 parts of pentaerythritol tetraacrylate is theoretically generated with respect to 100 parts of the compound represented by the general formula (1). After the completion of the reaction, 123 parts of water was added to the reaction solution and post-treatment was carried out in the same manner as in Synthesis Example 1 to obtain 250 parts of a reaction product. Viscosity is 4200 cp
It was s / 25 ° C.

Synthesis Example 5 Pentaerythritol 78 parts (0.57 mol), Bisphenol A ethylene oxide 4 mol adduct 71 parts (0.18 mol), Tetrahydrophthalic anhydride 24 parts (0.18 mol), Acrylic Acid 194 parts (2.7 mol)
When the reaction was carried out under the same conditions as in Synthesis Example 4, except that and 367 parts of toluene were used, 43 parts of water was separated. The reaction ratio of the raw materials is a ratio at which 87 parts of pentaerythritol tetraacrylate is theoretically generated with respect to 100 parts of the compound represented by the general formula (1). After the completion of the reaction, 122 parts of water was added to the reaction solution and post-treatment was carried out in the same manner as in Synthesis Example 1 to obtain 255 parts of a reaction product. The viscosity was 7270 cps / 25 ° C.

Synthesis Example 6 Pentaerythritol 54 parts (0.40 mol), Bisphenol A ethylene oxide 4 mol adduct 134 parts (0.34 mol), phthalic anhydride 30 parts (0.20 mol), acrylic acid When the reaction was carried out under the same conditions as in Synthesis Example 4, except that 166 parts (2.3 mol) and 384 parts of toluene were used, 37 parts of water was separated. The reaction ratio of the raw materials is a ratio at which 40 parts of pentaerythritol tetraacrylate and 40 parts of diacrylate of a 4 mol ethylene oxide adduct of bisphenol A are theoretically generated with respect to 100 parts of the compound represented by the general formula (1). is there. After completion of the reaction, 128 parts of water was added to the reaction solution to prepare Synthesis Example 1
When post-treatment was carried out in the same manner as in, 274 parts of a reaction product was obtained. The viscosity was 3590 cps / 25 ° C.

Synthesis Example 7 Pentaerythritol 54 parts (0.40 mol), Bisphenol A ethylene oxide 4 mol adduct 134 parts (0.34 mol), Tetrahydrophthalic anhydride 26 parts (0.20 mol), Acrylic Acid 166 parts (2.3 mol)
When the reaction was carried out under the same conditions as in Synthesis Example 4, except that and 380 parts of toluene were used, 37 parts of water was separated. The reaction ratio of the raw materials is a ratio at which 40 parts of pentaerythritol tetraacrylate and 40 parts of diacrylate of a 4 mol ethylene oxide adduct of bisphenol A are theoretically generated with respect to 100 parts of the compound represented by the general formula (1). is there. After the completion of the reaction, 127 parts of water was added to the reaction solution and post-treatment was carried out in the same manner as in Synthesis Example 1 to obtain 270 parts of a reaction product. The viscosity was 4200 cps / 25 ° C.

Synthesis Example 4 50 parts of DAP K [diallyl phthalate manufactured by Daiso Co., Ltd.] was dissolved in 50 parts of dipentaerythritol hexaacrylate by heating at 130 ° C.

Example 1 80 parts of the reaction product obtained in Synthesis Example 1, 15 parts of Shimla Fast Yellow GTF235D [a yellow pigment manufactured by Dainippon Ink and Chemicals, Inc.] as a pigment, and talc 1
Parts and IRGACURE 651 [manufactured by Nippon Ciba Geigy Co., Ltd.] as a photoinitiator: Kayacure EPA [manufactured by Nippon Kayaku Co., Ltd.] = 7 parts: A mixture composed of 3 parts of a compound consisting of 2 parts is rolled on a three-roll mill By kneading, the composition for active energy ray-curable ink was produced. The obtained composition was evaluated according to the following. Table 1 shows the results.

UV curability: The composition obtained was applied to a paper with a film thickness of 2 μm, and 80 W / cm, 10 c from the bottom of a concentrating high-pressure mercury lamp.
It was repeatedly passed under a mercury lamp at a position of m at a conveyor speed of 40 m / min, and evaluated by the number of passes (passing number) until tack disappeared from the surface.

Misting When the incometer was operated under the condition of 1200 rpm, the state in which the ink was dispersed in the form of mist around was visually evaluated and judged. In Tables 1 and 2, ◯, Δ and × have the following meanings. ○: Does not scatter. Δ: Slightly scattered. X: Scatter.

・ Pencil hardness A coating film cured by ultraviolet rays or electron beams can be applied to JISK
Evaluation was performed according to 5400.

Solvent resistance The coating film cured by ultraviolet rays or electron beams was rubbed with a cotton swab impregnated with methyl ethyl ketone, and the number of times until the underlayer became visible was displayed.

Examples 2 and 3 An active energy ray-curable ink composition was produced in the same manner as in Example 1, except that the reaction products obtained in Synthesis Examples 2 and 3 were used. The results of evaluating the obtained composition in the same manner as in Example 1 are shown in Table 1.

Example 4 An active energy ray-curable ink composition was produced in the same manner as in Example 1 except that no photoinitiator was used. The results of evaluating the obtained composition in the same manner as in Example 1 are shown in Table 1. The EB curability was evaluated as follows.

EB Curability The composition obtained was coated on paper with a film thickness of 2 μm, and the composition was irradiated with EV under conditions of an acceleration voltage of 170 kV and evaluated by the irradiation dose required for curing.

[0035]

[Table 1]

Examples 5 to 8 Except that the reaction products obtained in Synthesis Examples 4 to 7 were used, active energy ray-curable ink compositions were produced in the same manner as in Example 1. The results of evaluation of the obtained composition in the same manner as in Example 1 are shown in Table 2.

[0037]

[Table 2]

Comparative Example 1 An active energy ray-curable ink composition was produced in the same manner as in Example 1 except that dipentaerythritol hexaacrylate was used instead of the reaction product. The results of evaluation of the obtained composition by the same method as in Example 1 are shown in Table 3.

Comparative Example 2 An active energy ray-curable ink composition was produced in the same manner as in Example 1 except that the composition of Synthesis Example 4 was used instead of the reaction product. The results of evaluation of the obtained composition by the same method as in Example 1 are shown in Table 3.

Comparative Example 3 An active energy ray-curable ink composition was prepared in the same manner as in Example 1 except that dipentaerythritol hexaacrylate was used instead of the reaction product and that no photoinitiator was used. Was manufactured. The results of evaluation of the obtained compositions by the same methods as in Examples 1 and 4 are shown in Table 3.

[0041]

[Table 3]

[0042]

The active energy ray-curable ink composition of the present invention has fast curability, excellent flow characteristics as an ink vehicle, and has so-called printability such as misting. Therefore, the surface hardness and the solvent resistance of the printed matter after curing are excellent and are extremely practical.

Claims (2)

[Claims] 1. Pentaerythritol and bisphenol A
An active energy ray-curable ink composition comprising a reaction product of the alkylene oxide adduct of 1), a dibasic acid or an acid anhydride thereof, and (meth) acrylic acid. 2. 0.5 to 4.0 mol of pentaerythritol and 0.5 to alkylene oxide adduct of bisphenol A based on 1 mol of a dibasic acid or an acid anhydride thereof.
The active energy ray-curable ink composition according to claim 1, which comprises a reaction product obtained by reacting 2.5 mol of (meth) acrylic acid with 3.5 to 17 mol.