JP5185542B2 - Active energy ray-curable ink resin composition - Google Patents

Description

  The present invention relates to a resin composition for printing ink that is suitable for printing inks such as inkjet printing ink, screen printing ink, offset printing ink, gravure printing ink, and intaglio printing ink.

Many polyfunctional acrylic monomers, which are active energy ray-curable resins, have a poor balance of physical properties when cured, and it is necessary to devise a formulation such as combining several appropriate compounds for specific applications. There are many cases. Specifically, although the curing speed is fast, the film used for the base material is not curved or the film used for the base material is not curved, but the curing speed is low and the hardness of the coating film when cured is low. It is known that there are advantages and disadvantages in various physical properties such as being easily damaged. Typical examples of such acrylic monomers include dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, ditrimethylolpropane tetraacrylate, and pentaerythritol tetraacrylate.
Development of UV / EB Curing Technology P.19-23 CMC (ed.) Radtech Study Group issued on September 29, 1989

  The polyfunctional acrylic monomer is an active energy ray-curable composition, particularly a resin composition for an ink, and is soluble in a polyester resin, a polyether resin, or the like that is used to improve adhesion and gloss when used. However, there are cases where the curing rate is slow, productivity is lowered, and the viscosity is too high depending on the use of the ink, so that the single type has various problems. Therefore, an acrylic monomer that can meet these requirements with a single compound as much as possible has long been demanded.

  As a result of intensive studies, the present inventors have obtained by reacting polyglycerin (average degree of polymerization 2 to 10) and alkylene oxide (an alkylene oxide having 2 to 4 carbon atoms and 4 to 40 added moles). It came to solve the said subject with the resin composition for active energy ray hardening-type printing inks characterized by containing the (meth) acrylate of a compound.

  Active energy ray-curable type that can improve the curing rate by adding the (meth) acrylate of the present invention and has good solubility with other polymers such as polyester added, and can keep the viscosity of the resulting composition low. A printing ink resin composition can be obtained.

  In the present invention, a (meth) acrylate of a compound obtained by reacting polyglycerin (average degree of polymerization 2 to 10) and alkylene oxide (alkylene oxide having 2 to 4 carbon atoms and 4 to 40 addition moles) is obtained. Although it is characterized by using, various compounds can be synthesize | combined by the polymerization degree of polyglycerol, the kind of alkylene oxide, the addition mole number, and the reaction ratio of (meth) acrylate, Therefore It demonstrates below.

  The polyglycerin used in the acrylate used in the present invention has an average degree of polymerization of 2 to 10 obtained from a hydroxyl group equivalent, and preferably has an average degree of polymerization of 4 to 10. When the average degree of polymerization is 1, that is, glycerin is not preferable because the curing speed is slow, and when the average degree of polymerization is larger than 10, it is not preferable because there are various problems in manufacturing such as difficulty in washing in the manufacturing process. .

  Examples of the alkylene oxide used in the acrylate used in the present invention include ethylene oxide, propylene oxide, and butylene oxide. Ethylene oxide or propylene oxide is preferable, and ethylene oxide and propylene oxide may be used alone or in combination. The number of added units of alkylene oxide is 4 to 40 mol, preferably 4 to 30 mol, per 1 mol of polyglycerol. When the number of added moles is less than 4 moles, the secondary alcohol of the polyglycerin skeleton increases, making it difficult to react with (meth) acrylate. This is not preferable because of various problems in manufacturing such as being difficult.

  About the reaction rate of the (meth) acrylate used by this invention, it is preferable to make it react 70% or more among the hydroxyl groups of the alkylene oxide adduct of polyglycerol. If it is less than 70%, the reaction rate is slow, and there are various problems in production, such as difficulty in washing with water during the production process.

  In addition, the (meth) acrylate used by this invention is normally mix | blended 30-80 weight% with respect to an ink composition. If it is less than this range, the viscosity of the ink composition is too high to make printing difficult, and if it is more, the surface gloss and adhesion tend to be poor.

  The active energy ray-curable ink resin composition of the present invention does not prevent the use of other acrylic monomers alone or in combination of two or more in addition to the acrylate used in the present invention. Examples of other acrylic monomers include tetrahydrofurfuryl (meth) acrylate, carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, acryloylmorpholine, 2-ethylhexyldiethoxy (meth) acrylate, Hydrogenated dicyclopentadiene (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, tricyclodecane di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpro Polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) ) Monomers such as acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta and hexa (meth) acrylate mixture, dipentaerythritol polyethoxyhexa (meth) acrylate, dipentaerythritol polypropoxyhexa (meth) acrylate Can be mentioned.

  The resin composition of the present invention can be cured by a known method. An active energy ray is a general term for electron beams, X-rays, ultraviolet rays, electron beams with high energy such as visible light in a low wavelength region, or electromagnetic waves, and ultraviolet rays are preferable because of the simplicity and spread of ordinary devices. There are many types of devices that can irradiate ultraviolet rays, but they can be arbitrarily selected. Moreover, it is also possible to use a blue LED as energy such as visible light on the low wavelength region side.

  In the present invention, it is necessary to use a photopolymerization initiator when curing with ultraviolet rays. The photopolymerization initiator may be any known photopolymerization initiator, but is required to have good storage stability after blending. Examples of such photopolymerization initiators include benzoins, acetophenones, thioxanthones, ketals, benzophenones, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the like, alone or in combination of two or more. be able to. When it is necessary to use a photopolymerization initiator, the amount used is usually 0.1 to 15% by weight of the composition, preferably 3 to 10% by weight.

  Examples of benzoins include benzoin ethyl ether, benzoin butyl ether, and benzoin isopropyl ether. Examples of acetophenones include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholino-propan-1-one, N, N-dimethylaminoacetophenone and the like. Examples of thioxanthones include 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and the like. Examples of ketals include benzyl dimethyl ketal and acetophenone dimethyl ketal. Examples of benzophenones include benzophenone, methylbenzophenone, 4,4'-bisdiethylaminobenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide.

  Furthermore, a photosensitizer can be used alone or in combination of two or more. Examples of the photosensitizer include tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. can give.

  The colorant used in the present invention can be arbitrarily selected from pigments and dyes, and the pigment can be arbitrarily selected from organic pigments and inorganic pigments. Examples of the colorant for the organic pigment include quinacridone pigments, phthalocyanine pigments, azo pigments, quinophthalone pigments, and isoindolinone pigments. The hue is not particularly limited, and red organic pigments, yellow organic pigments, blue organic pigments, orange organic pigments, green orange organic pigments, and the like can be used. In addition, titanium oxide, carbon black, oxalate, and the like can be used as the colorant for the inorganic pigment.

  If desired, the resin composition of the present invention comprises non-reactive polymer resins such as organic solvents such as toluene, hexane, ethyl acetate, methyl ethyl ketone, methanol and ethanol, polyester elastomers, polyurethane elastomers and acrylic polymers; polydiallyl phthalate, poly Reactive polymer resins such as diallyl isophthalate; leveling agents, antifoaming agents, silane coupling agents, antioxidants, UV absorbers, light stabilizers, polymerization inhibitors, etc .; calcium carbonate, talc, silica oxide Inorganic fillers such as barium sulfate can be used in combination.

  The composition of the present invention is prepared by mixing, heating, and dissolving the (meth) acrylate and colorant used in the present invention, and if necessary, a photopolymerization initiator, the colorant, the non-reactive polymer resin, It can be prepared by adding a reactive polymer resin, an additive, an inorganic filler, etc., and uniformly mixing, heating, and dissolving.

  A composition containing a photopolymerization initiator is applied to the surface of various substrates and then cured by irradiation with an active energy ray such as ultraviolet rays. The composition can be applied on a wide range of substrates including paper, hard and flexible plastics, metal substrates, cement, glass, stone, ceramic, wood, etc.

  The composition of the present invention is suitable for printing inks such as inkjet printing inks, screen printing inks, offset printing inks, gravure printing inks, and intaglio printing inks. Various substrates are printed to a thickness of 1 to 30 μm, and then irradiated with an active energy ray such as ultraviolet rays to be cured.

Hereinafter, the present invention will be specifically described by way of examples. In addition, this invention is not limited to a following example.
<Synthesis Example 1>
A compound obtained by adding 176 g (4 mol) of ethylene oxide to 166 g (1 mol) of diglycerin was reacted with 317 g (4.4 mol) of acrylic acid at 85 ° C. for 10 hours, and then toluene and a large amount of water and unreacted An amount of caustic to neutralize acrylic acid was added, the organic layer was taken out with a separatory funnel, and toluene was distilled off with an evaporator to obtain an acrylate reaction product of diglycerin ethylene oxide (4 mol) adduct. The viscosity of the product was 230 mPa · s (25 ° C.), and the reaction ratio of acrylic acid obtained from the saponification value was 80% with respect to the hydroxyl group. Hereinafter, the obtained compound is referred to as A1.

<Synthesis Example 2>
Except having changed ethylene oxide into 264 g (6 mol), the same reaction as in Synthesis Example 1 was performed to obtain an acrylate reaction product of diglycerin ethylene oxide (6 mol) adduct. The viscosity of the product was 240 mPa · s (25 ° C.), and the reaction ratio of acrylic acid determined from the saponification value was 87% with respect to the hydroxyl group. Hereinafter, the obtained compound is referred to as A2.

<Synthesis Example 3>
Except having changed ethylene oxide 880g (20 mol) and reaction time into 12 hours, it reacted similarly to the synthesis example 1, and obtained the acrylate reaction material of the diglycerin ethylene oxide (20 mol) addition product. The viscosity of the product was 350 mPa · s (25 ° C.), and the reaction ratio of acrylic acid determined from the saponification value was 84% with respect to the hydroxyl group. Hereinafter, the obtained compound is referred to as A3.

<Synthesis Example 4>
The same as Synthesis Example 1 except that 166 g (1 mol) of diglycerin was changed to 314 g (1 mol) of tetraglycerin, 264 g (6 mol) of ethylene oxide, 649 g (9 mol) of acrylic acid, and the reaction time was changed to 18 hours. The acrylate reaction product of tetraglycerin ethylene oxide (6 mol) adduct was obtained. The viscosity of the product was 440 mPa · s (25 ° C.), and the reaction ratio of acrylic acid determined from the saponification value was 95% with respect to the hydroxyl group. Hereinafter, the obtained compound is referred to as A4.

<Synthesis Example 5>
166 g (1 mol) of diglycerin is 758 g (1 mol) of decaglycerol, 1056 g (24 mol) of ethylene oxide, 1297 g (18 mol) of acrylic acid, and the reaction time is changed to 18 hours. Reaction was performed to obtain an acrylate reaction product of decaglycerin ethylene oxide (24 mol) adduct. The product had a viscosity of 890 mPa · s (25 ° C.), and the reaction ratio of acrylic acid determined from the saponification value was 93% with respect to the hydroxyl group. Hereinafter, the obtained compound is referred to as A5.

  Examples 1 to 8 and Comparative Examples 1 to 4 are formulated as shown in Table 1 (numerical values indicate parts by weight). Each component is mixed (in order to dissolve the resin in acrylate beforehand, the mixture is 4 at 130 ° C.). The mixture was heated for a long time and then kneaded with three rolls to prepare a resin composition (printing ink composition), and various evaluations were performed. Evaluation in the examples was performed by the following method.

  Composition viscosity: The prepared composition was measured with a rotational viscometer. The viscosity was measured at 25 ° C. using a viscometer (RB-80H; rotor No. H7) manufactured by Toki Sangyo Co., Ltd. It is preferably 50 Pa · s or less.

Compatibility: The solubility of various acrylates and diallyl phthalate resin was confirmed. The compatibility when 15 parts of diallyl phthalate resin was heated at 100 ° C. for 2 hours with respect to 60 parts of various acrylates was confirmed.
○ ・ ・ ・ Completely dissolved × ・ ・ ・ Partially undissolved resin remains

Curability: The prepared composition was applied onto a polycarbonate resin having a thickness of 100 μm by a bar coater (thickness 15 μm), and then irradiated at a position 20 cm under a light source in which a high-pressure mercury lamp (lamp output 2 kW) was arranged in parallel. Cured. The integrated light amount (mJ / cm ² ) until curing was determined.
A: Completely cured at less than 50 mJ / cm ² .
○: Completely cured at 50 mJ / cm ² or more and less than 100 mJ / cm ² .
Δ: Completely cured at 100 mJ / cm ² or more and less than 300 mJ / cm ² .
X: Completely cured at 300 mJ / cm ² or more.

Shrinkage: The warpage of the printed material cured by the above method was visually observed.
○ ····················································································································
X: Warpage is seen in the polycarbonate of the base material.

Adhesiveness: The printed material cured by the above-described method was subjected to a cross-cut-cello tape (registered trademark) peel test described in JIS K 5400.
○ ············ No peeling at 100 mm.
Δ ···· A peeling of less than 30% is observed in 100 mm.
× ········· 30% or more peeled in 100%.

  From the evaluation results of Table 1, the resin composition for printing ink of the present invention is excellent in stability and adhesiveness.

  The resin composition for printing ink of the present invention has good composition stability, little coloration of the cured product, and good adhesion.

Claims (3)

Containing (meth) acrylate of a compound obtained by reacting polyglycerin (average degree of polymerization 4 to 10) and alkylene oxide (alkylene oxide having 2 to 4 carbon atoms and 4 to 40 addition moles). A resin composition for printing ink.   2. The resin composition for printing ink according to claim 1, wherein the (meth) acrylate contains 30 to 80% by weight in the composition. The resin composition for printing inks of Claim 1 or 2 containing a photoinitiator.