JP7255055B2 - Electron beam curable composition and laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electron beam-curable composition using a rosin-modified resin and a laminate.

In the field of printing, in recent years, there has been an increasing demand for manpower saving, labor saving, automation, and speeding up of printing, and in particular, printing speed has been increasing more and more. In addition, there is a demand for inks that can stably produce high-quality prints over a long period of time under various printing conditions, and various improvements to inks have been studied.

Under such circumstances, inks and varnishes, which are active energy ray-curable compositions, are known. The active energy ray-curable composition contains a compound that is curable with respect to active energy rays (hereinafter referred to as an active energy ray-curable compound) such as an acrylic ester compound. Therefore, when the composition is irradiated with an active energy ray, the composition instantly cures to form a tough film by three-dimensional cross-linking of the active energy ray-curable compound. In addition, since the above composition cures instantly, post-processing can be performed immediately after printing. Due to these advantages, inks and varnishes, which are active energy ray-curable compositions, are suitable for package printing for packaging, which requires a strong film to improve productivity and protect designs, and form printing in the commercial field. It is used.

In these printing industries, active energy ray-curable lithographic printing inks are used as inks that are active energy ray-curable compositions.
Lithographic printing is a printing method that uses inks with relatively high viscosities, usually between 5 and 120 Pa·s. The mechanism of the printing press used in lithographic printing supplies ink from an ink fountain via multiple rollers to the image area of the plate to form a pattern, and then transfers the ink from the plate onto a substrate such as paper. image formation.
Here, in lithographic printing using dampening water when forming a pattern, dampening water is supplied to the non-image area so that the non-image area repels ink, while the dampening water is supplied to the non-image area when forming the pattern. In waterless lithographic printing that does not use , a silicone layer is formed on the non-image area so that the non-image area repels the ink.

In particular, in lithographic printing that uses dampening water when forming a pattern, the emulsification balance between ink and dampening water is important. Therefore, inks used in lithographic printing are required to have appropriate emulsification suitability and high-speed printing suitability in addition to appropriate viscosity. If the emulsified amount of the ink is too large, the ink tends to adhere to the non-printing area, resulting in staining. On the other hand, if the emulsified amount of the ink is small, dampening water tends to spit onto the surface of the ink when printing a small number of patterns. Therefore, the ink transferability between rolls and the ink transferability to the substrate are deteriorated, making it difficult to perform stable printing.

In general, active energy ray-curable lithographic printing inks are required to have printability such as emulsification suitability, scumming resistance, and initial density stability. In addition to the above printability, print film strength such as curability, glossiness, adhesion, abrasion resistance, and solvent resistance is also required.

Typically, an active energy ray-curable lithographic printing ink contains a binder (meaning a film-forming component) and a pigment as solid components. The binder contains a resin component (referred to as a binder resin) containing an active energy ray-curable compound such as a resin and an acrylic ester compound, a radical polymerization initiator, and various additives as necessary. In order to meet the above requirements, unsaturated polyester resins, epoxy acrylate resins, urethane acrylate resins, polyester acrylate resins, etc. have been studied as binder resins for active energy ray-curable lithographic printing inks.

For example, Patent Document 1 discloses a binder resin obtained by modifying a saturated polyester with an isocyanate group-containing urethane acrylate. However, since the disclosed binder resin has a highly linear structure, it is difficult to obtain sufficient ink viscoelasticity when forming an ink using the above resin. In addition, printability such as misting resistance and scumming resistance tends to deteriorate.

Further, Patent Document 2 discloses a binder resin obtained by reacting a hydroxyl-excess polyester compound containing a rosin derivative polycarboxylic acid as an essential component with acrylic acid or methacrylic acid. However, when the rosin derivative polyvalent carboxylic acid is not sufficiently specified, for example, when the amount of residual conjugated double bonds in the binder resin is large, it is susceptible to curing inhibition by oxygen in the air. As a result, when the resin is used to form an ink, the problem of insufficient print film strength in addition to curability tends to occur.

Furthermore, Patent Document 3 discloses, as a binder resin, a polyester resin containing a polyvalent carboxylic acid obtained by an addition reaction between a rosin acid and an α,β-unsaturated carboxylic acid. However, when inks are formulated using the disclosed binder resins, they tend to have poor fluidity and gloss.

Further, Patent Document 4 discloses a photocurable resin composition for lithographic printing ink, which contains a diallyl phthalate resin and a polyfunctional acrylate compound as a binder resin. However, in the photocurable resin composition (ink), if the content of the diallyl phthalate resin based on the total mass of the ink increases, the ink viscosity tends to be too high, resulting in insufficient fluidity and gloss.

Furthermore, in recent years, active energy ray curing technology in the printing industry has become popular due to the advantages of shortening the process time by instant drying, reducing environmental impact by not containing volatile components (Non-VOC), and strong coating properties by cross-linking reaction. use is expanding.

As for the use of active energy ray curing in the printing industry, inks and varnishes using ultraviolet (UV) curing and electron beam (EB) curing have been put into practical use. Curing type is the mainstream. However, the use of photopolymerization initiators required for the UV curing reaction is being regulated around the world due to concerns about their toxicity to the global environment and the human body, and their safety and continuous usability are being viewed as problems. On the other hand, the reaction form of EB curing is mainly a radical reaction like UV curing, but since it uses high-energy electron beams, it does not require a photopolymerization initiator, which reduces environmental impact and excels in business continuity. Therefore, the expansion of the use of EB curing has become an issue.

Here, as shown in Patent Document 5, conventional electron beam curable lithographic printing inks often use urethane oligomers from the viewpoint of adhesion. The emulsification balance was poor, and it was difficult to stably obtain high-quality prints over a long period of time.

Based on the above situation, it is a lithographic printing ink that has excellent curability, less curing shrinkage, excellent adhesion to substrates, and excellent printability, as well as reduced environmental impact and business continuity. From this point of view, an electron beam curable lithographic printing ink is desired as a lithographic printing ink that does not require a photopolymerization initiator, for which environmental safety and continuous usability are regarded as problematic.

JP-A-2001-348516 JP-A-2-51516 JP 2010-70743 A JP 2016-190907 A WO2020/212488

An object of the present invention is to provide an electron beam curable composition capable of forming a film having excellent curability and excellent adhesion to a substrate, and to use the electron beam curable composition. Another object of the present invention is to provide a laminated body having a thickness. A further object of the present invention is to provide an electron beam-curable composition that is excellent in printability when used as an ink.

As a result of extensive studies, the inventors of the present invention have found that the above problems can be solved by using the electron beam-curable composition described below, and have completed the present invention.

That is, the present invention includes a rosin-modified resin (A), a (meth)acrylate compound (B), and an extender pigment (C), and substantially does not contain a photopolymerization initiator. A linearly curable composition,
The rosin-modified resin (A) is a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). , and a reactant in which an ester bond is formed by the reaction of the carboxylic acid and the polyol (a3) in each of the organic acids having no conjugated double bond among the rosin acids (a1),
The (meth)acrylate compound (B) is one selected from the group consisting of alkylene oxide-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. including
The content of the extender pigment (C) is 0.1 to 10% by mass in the total mass of the composition,
Extender pigment (C) is a combination of (C1) one or more selected from the group consisting of calcium carbonate, magnesium carbonate and magnesium silicate, and (C2) silicon dioxide.

Further, in the present invention, the rosin-modified resin (A) is a mixture of an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). A compound obtained by the Diels-Alder reaction, an organic acid having no conjugated double bond among rosin acids (a1), and an organic acid or its acid anhydride (a4) (rosin acid (a1), α, β-un saturated carboxylic acid or its acid anhydride (a2)) is a reactant in which an ester bond is formed by reacting the carboxylic acid with the polyol (a3) in each of the above electron beam-curable compositions. about things.

The present invention also relates to the above electron beam curable composition, which further contains a colorant.

The present invention also relates to a laminate comprising a base material and a layer obtained by curing the above electron beam-curable composition with an electron beam.

The present invention also relates to a laminate characterized by having a layer obtained by curing the electron beam-curable composition with an electron beam on the printed surface of a printed material obtained by printing ink on a base material.

The present invention also relates to the laminate, wherein the substrate is a film substrate.

According to the present invention, an electron beam curable composition capable of forming a film having excellent curability and excellent adhesion to a substrate, and a laminate using the electron beam curable composition I could offer my body. Moreover, when using an electron beam curable composition as ink, the electron beam curable composition was able to be provided which is excellent in printability.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below, and various modifications are possible without departing from the gist of the present invention.

In addition, the “conjugated double bond” described in the present invention refers to a bond in which a plurality of double bonds are alternately connected with a single bond interposed therebetween. However, the π-electron conjugated system contained in the aromatic compound is excluded from the conjugated double bond.

<Electron beam curable composition>
The electron beam-curable composition of the present invention contains at least a rosin-modified resin (A), a (meth)acrylate compound (B), and an extender (C), and substantially does not contain a photopolymerization initiator. characterized by

<Rosin modified resin (A)>
The rosin-modified resin (A) in the present invention is a resin containing a rosin-derived skeleton in the resin skeleton. By containing a rosin-derived skeleton, curing shrinkage due to electron beam irradiation during high-speed printing can be suppressed, and smoothness of the dry film can be maintained, so glossiness and adhesion to the substrate are improved. improves.

Further, the rosin-modified resin (A) in the present invention is a Diels-Alder mixture of an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). A rosin-modified compound, which is a compound obtained by the reaction and an ester bond formed by reacting the carboxylic acid of each of the rosin acids (a1) having no conjugated double bond with the polyol (a3). Resins are preferred.

Further, the rosin-modified resin (A) in the present invention is a Diels-Alder mixture of an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). A compound obtained by the reaction, an organic acid having no conjugated double bond among rosin acids (a1), and an organic acid or an acid anhydride thereof (a4) (rosin acid (a1), α,β-unsaturated carboxylic acid Especially preferred is a rosin-modified resin which is a compound in which an ester bond is formed by reacting a carboxylic acid in each of the acids or their acid anhydrides (a2) with the polyol (a3).

<Rosin acids (a1)>
The rosin acids (a1) used for obtaining the rosin-modified resin (A) in the present invention refer to monobasic acids having a cyclic diterpene skeleton. Represents rosin acid, disproportionated rosin acid, hydrogenated rosin acid, or alkali metal salts of the above compounds, specifically, abietic acid having a conjugated double bond, and its conjugated compound, neoabietic acid, Examples include parastric acid, levopimaric acid, and pimaric acid, isopimaric acid, sandaracopimaric acid, and dehydroabietic acid that do not have a conjugated double bond. Examples of natural resins containing these rosin acids (a1) include gum rosin, wood rosin and tall oil rosin.

The amount of the rosin acids (a1) used to obtain the rosin-modified resin (A) in the present invention is preferably 15 to 70% by mass, preferably 25 to 55% by mass, based on the total amount of the resin raw materials. It is more preferable to have When the amount of rosin acids (a1) is 15% by mass or more, the glossiness of the active energy ray-curable coating varnish containing the resin is improved, and when the amount is 70% by mass or less, active energy rays The solvent resistance of the curable coating varnish composition is improved.

<α,β-unsaturated carboxylic acid or acid anhydride thereof (a2)>
The α,β-unsaturated carboxylic acid or its acid anhydride (a2) used for obtaining the rosin-modified resin (A) in the present invention includes maleic acid, fumaric acid, citraconic acid, itaconic acid, crotonic acid and isocrotonic acid. etc. and their acid anhydrides are exemplified. In view of reactivity with rosin acids (a1), maleic acid or its acid anhydride is preferred.

In the present invention, the amount of the α,β-unsaturated carboxylic acid or its acid anhydride (a2) is preferably in the range of 60 to 180 mol%, preferably 70 to 155%, based on the rosin acids (a1). It is more preferably in the range of mol %. When the blending amount of the α,β-unsaturated carboxylic acid or its acid anhydride (a2) is adjusted within the above range, it is easy to obtain a rosin-modified resin excellent in friction resistance, adhesion, and misting resistance. .

<Organic acid or acid anhydride thereof (a4) (excluding rosin acid (a1), α,β-unsaturated carboxylic acid or acid anhydride thereof (a2))>
In order to obtain the rosin-modified resin of the present invention, in addition to the rosin acids (a1), the α,β-unsaturated carboxylic acid or its acid anhydride (a2), an organic acid or its acid anhydride (a4) is used alone. Alternatively, two or more types can be used.
The amount of the organic acid or its acid anhydride (a4) is preferably 0 to 60% by mass, more preferably 0 to 50% by mass, based on the total amount of the resin raw materials.

Specific examples of the organic acid or its acid anhydride (a4) include, but are not limited to, the following.

(organic monobasic acid)
aromatic monobasic acids such as benzoic acid, methyl benzoic acid, tertiary butyl benzoic acid, naphthoic acid, and orthobenzoyl benzoic acid;
compounds having a conjugated double bond but no cyclic diterpene skeleton, such as conjugated linoleic acid, eleostearic acid, parinaric acid, and calendic acid;
Examples include fatty acids having no conjugated double bonds.

(Alicyclic polybasic acid or its acid anhydride)
1,2,3,6-tetrahydrophthalic acid, 3-methyl-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid, 1,2-cyclohexanedicarboxylic acid acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, acid anhydrides thereof, and the like.

(Other organic polybasic acids or their acid anhydrides)
Alkenyl succinic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, dodecenyl succinic acid, pentadecenyl succinic acid, o-phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid acids, acid anhydrides thereof, and the like.

<Polyol (a3)>
The polyol (a3) is a compound obtained by Diels-Alder reaction between an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2), rosin Of the acids (a1), an ester bond is formed by the reaction with the carboxylic acid of the organic acid having no conjugated double bond and the organic acid or its acid anhydride (a4).

<Divalent and trivalent polyols>
To obtain the rosin-modified resin of the present invention, divalent and trivalent polyols can be used singly or in combination of two or more. Specific examples of divalent and trivalent polyols include, but are not limited to:

(Linear alkylene dihydric polyol)
1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1 ,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1, 9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol, 1,16 -hexadecanediol, 1,2-hexadecanediol, and the like.

(Branched alkylene dihydric polyol)
2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane diol, 2,4-dimethyl-2,4-pentanediol, 2,2-dimethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dimethyloloctane, 2 -ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2 ,4-diethyl-1,5-pentanediol and the like.

(Cyclic dihydric polyol)
1,2-cycloheptanediol, tricyclodecanedimethanol, 1,2-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol , 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone and other cyclic alkylene dihydric polyols; bisphenol A, bisphenol F, bisphenol S, catechol, resorcinol, aromatic dihydric polyols such as hydroquinone, and the like.

(Other divalent polyols)
Divalent polyether polyols such as polyethylene glycol (n=2 to 20), polypropylene glycol (n=2 to 20), polytetramethylene glycol (n=2 to 20), polyester polyols, and the like can be mentioned.

(Trivalent polyol)
glycerin, trimethylolpropane, 1,2,6-hexanetriol, 3-methylpentane-1,3,5-triol, hydroxymethylhexanediol, trimethyloloctane and the like.

<Polyols other than divalent and trivalent polyols>
Moreover, in order to obtain the rosin-modified resin of the present invention, polyols having a valence of 4 or more can be used singly or in combination of two or more. Specific examples of tetravalent or higher polyols include, but are not limited to, the following.

(Tetravalent or higher polyol)
Examples include linear, branched and cyclic polyols having a valence of 4 or more, such as pentaerythritol, diglycerin, ditrimethylolpropane, dipentaerythritol, sorbitol, inositol, and tripentaerythritol.

The rosin-modified resin in the present invention preferably has a weight average molecular weight of 3,000 to 30,000, more preferably 4,000 to 15,000. A weight average molecular weight of 3,000 to 30,000 makes it possible to improve adhesion.

Also, the melting point of the rosin-modified resin is preferably 50°C or higher, more preferably in the range of 60 to 100°C. The melting point can be measured using a MeltingPoint M-565 manufactured by BUCHI under the condition of a heating rate of 0.5° C./min.

The electron beam-curable composition of the present invention preferably contains the rosin-modified resin (A) in an amount of 5 to 40% by mass, more preferably 8 to 35% by mass, and more preferably 10 to 30% by mass. It is even more preferable to have
Here, the rosin-modified resin and the (meth)acrylate compound (B) may be prepared and used in the form of a varnish, which will be described later.

As used herein, the (meth)acrylate compound (B) means a compound having a (meth)acryloyl group in the molecule.
Specific examples of the (meth)acrylate compound (B) that can be used to constitute the electron beam curable composition of the present invention include:
monofunctional (meth)acrylate compounds such as 2-ethylhexyl acrylate, methoxydiethylene glycol acrylate, ethylene glycol monophenyl ether acrylate, tetraethylene glycol monophenyl ether acrylate, acryloylmorpholine;
Ethylene glycol diacrylate, polyethylene glycol diacrylate (n = 2-20), propylene glycol diacrylate, polypropylene glycol diacrylate (n = 2-20), alkylene (4-12 carbon atoms) glycol diacrylate, alkylene (carbon atoms 4-12) Glycol ethylene oxide adduct (2-20 mol) diacrylate, alkylene (4-12 carbon atoms) glycol propylene oxide adduct (2-20 mol) diacrylate, hydroxypivalyl hydroxypivalate diacrylate, tri Cyclodecanedimethylol diacrylate, hydrogenated bisphenol A diacrylate, bisphenol A ethylene oxide adduct (2 to 20 mol) diacrylate, hydrogenated bisphenol A propylene oxide adduct (2 to 20 mol) diacrylate and other bifunctional ( meth)acrylate compounds,
Glycerin triacrylate, glycerin ethylene oxide adduct (3-30 mol) triacrylate, glycerin propylene oxide adduct (3-30 mol) triacrylate, trimethylolpropane triacrylate, trimethylolpropane ethylene oxide adduct (3-30 mol) ) trifunctional (meth)acrylate compounds such as triacrylate, trimethylolpropane propylene oxide adduct (3 to 30 mol) triacrylate,
Pentaerythritol tetraacrylate, pentaerythritol ethylene oxide adduct (4-40 mol) tetraacrylate, pentaerythritol propylene oxide adduct (4-40 mol) tetraacrylate, diglycerin tetraacrylate, diglycerin ethylene oxide adduct (4-40 mol) tetraacrylate, diglycerol propylene oxide adduct (4 to 40 mol) tetraacrylate, ditrimethylolpropane tetraacrylate, ditrimethylolpropane ethylene oxide adduct (4 to 40 mol) tetraacrylate, ditrimethylolpropane propylene oxide adduct ( 4-40 mol) tetrafunctional (meth)acrylate compounds such as tetraacrylate, and dipentaerythritol hexaacrylate, dipentaerythritol ethylene oxide adduct (6-60 mol) hexaacrylate, dipentaerythritol propylene oxide adduct (6- 60 mol) and polyfunctional (meth)acrylate compounds such as hexaacrylate.
The (meth)acrylate compound (B) may be used alone or in combination of two or more.

The (meth)acrylate compound (B) can be appropriately selected according to the desired properties of the cured film. If necessary, in addition to the above compounds, (meth)acrylate compounds such as polyester acrylate, polyurethane acrylate and epoxy acrylate can be used in combination.

From the viewpoint of curability, the (meth)acrylate compound (B) preferably contains a polyfunctional acrylate having two or more (meth)acryloyl groups in the molecule.

(Meth)acrylate compound (B) is at least one selected from the group consisting of alkylene oxide-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra (meth)acrylate, and dipentaerythritol hexa(meth)acrylate It is preferable to use seeds, and it is more preferable to use two or more kinds in combination.

The content of the (meth)acrylate compound (B) is preferably 55 to 80% by mass, more preferably 60 to 75% by mass, based on the total mass of the electron beam curable composition.

<Electron beam curing varnish>
The electron beam-curable composition of the present invention can also be produced from an electron beam-curable varnish containing a rosin-modified resin.

An electron beam curable varnish can be produced using a rosin-modified resin (A) and a (meth)acrylate compound (B). Although not particularly limited, the electron beam curable varnish contains 10 to 80% by mass of the rosin-modified resin (A) and 20 to 90% by mass of the (meth)acrylate compound (B) based on the total mass of the varnish. %, more preferably 20 to 60% by mass of the rosin-modified resin (A) and 40 to 80% by mass of the (meth)acrylate compound (B).

The electron beam-curable varnish in the present invention may contain a photopolymerization inhibitor, which will be described later, in addition to the above components. In such embodiments, photoinhibitors can be added and used in a conventional manner. When adding a photopolymerization inhibitor to the varnish, the amount is preferably 3% by mass or less based on the total quality of the electron beam curing varnish, and is used in the range of 0.01 to 1% by mass. more preferably.

The electron beam curable varnish in the present invention can be produced by mixing the above components under temperature conditions between room temperature and 160°C, for example.
For example, a varnish obtained by heating and melting a rosin-modified resin, dipentaerythritol hexaacrylate, and hydroquinone at a temperature of 100° C. can be suitably used.

<Extender Pigment (C)>
Extender pigments are pigments that do not have coloring power, and are distinguished from colored pigments, which will be described later. Specific examples of the extender pigment (C) include barium sulfate, alumina white, calcium carbonate, magnesium carbonate, aluminum silicate, magnesium silicate, silicon dioxide, and aluminum hydroxide. One of these may be used alone, or two or more may be used in combination.
The content of the extender pigment (C) in the electron beam curable composition is preferably 0.1 to 10% by mass, more preferably 0.5 to 10% by mass, even more preferably 1 to 8% by mass. By adjusting the content of the extender pigment (C) within the above range, the viscosity of the composition can be easily adjusted, and when it is used as a lithographic printing ink, the fluidity and anti-misting property can be easily improved. can. In addition, it is believed that the flexibility of the film is improved, and as a result, the curability can be easily improved.

In the present invention, the extender (C) preferably contains one or more selected from the group consisting of calcium carbonate, magnesium carbonate, magnesium silicate, and silicon dioxide, and the extender (C) contains (C1) carbonate A combination of one or more selected from the group consisting of calcium, magnesium carbonate, and magnesium silicate and (C2) silicon dioxide is preferred. The blending ratio of (C1) and (C2) is not particularly limited, but is preferably 100:1 to 100:60, more preferably 100:5 to 100:50, and 100:10 to 100:40. Especially preferred. The total content of (C1) and (C2) is the same as the content of the extender (C) described above. When (C1) and (C2) are used in combination as extender pigments, the viscosity of the composition can be easily adjusted, so that when used as a lithographic printing ink, the fluidity and anti-misting properties can be easily improved. be able to. In addition, it is believed that the flexibility of the film is improved, and as a result, the curability can be easily improved.

(Polymerization inhibitor)
The electron beam curable composition of the present invention may further contain a polymerization inhibitor in addition to the above components. In such embodiments, polymerization inhibitors can be added and used in a conventional manner. When adding a polymerization inhibitor, from the viewpoint of not inhibiting curability, the amount is preferably 3% by mass or less based on the total mass of the electron beam curable composition, and is preferably 0.01 to 1 mass. % range is more preferred.

Specific examples of polymerization inhibitors include (alkyl)phenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydrazyl, phenothiazine, p- Benzoquinone, nitrosobenzene, 2,5-di-tert-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cupferron, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, N-(3-oxyanilino -1,3-dimethylbutylidene)aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxime, cyclohexanone oxime, di-t-butyl-7-phenylquinone methide and the like. .

(Colored pigment)
The electron beam curable composition of the present invention may be a varnish or clear ink containing no colored pigment, or may be a color ink containing a colored pigment. Colored pigments may be various known and public pigments having coloring power, and inorganic pigments and organic pigments can be used. The following are examples of colored pigments that can be used to compose color inks.

Specific examples of inorganic pigments include yellow lead, zinc yellow, Prussian blue, cadmium red, titanium oxide, zinc white, red iron oxide, ultramarine blue, carbon black, graphite, and aluminum powder.

Specific examples of organic pigments include soluble azo pigments such as β-naphthol, β-oxynaphthoic acid, β-oxynaphthoic allylide, acetoacetate allylide, and pyrazolone,
Insoluble azo pigments such as β-naphthol, β-oxynaphthoic allylide, allylide acetoacetate monoazo, allylide acetoacetate disazo, and pyrazolone,
phthalocyanine pigments such as copper phthalocyanine blue, halogenated (chlorinated or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanine;
Quinacridones, dioxazines, threnes (pyranthrone, anthanthrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo, anthraquinone, perinone, perylene, etc.), isoindolinone, metal complex, quinophthalone, etc. Examples include polycyclic pigments and heterocyclic pigments.

When the electron beam curable composition of the present invention is a color ink, the content of the colored pigment is preferably 5 to 30% by mass, more preferably 5 to 25% by mass, based on the total mass of the composition.

(Various additives)
The electron beam curable composition of the present invention may further contain various additives such as a dispersant, an anti-friction agent, an antiblocking agent, and a slipping agent, depending on the purpose. Various additives can be added to the composition by conventional methods. When adding various additives to the composition, it is preferable to adjust the blending amount within a range that does not impair the effects of other components. The blending amount of various additives is preferably 15% by mass or less based on the total mass of the electron beam curable composition.

When the electron beam curable composition of the present invention is used as a lithographic printing ink, it can be produced by flushing, kneading, and mixing the above components under temperature conditions between room temperature and 120°C. . Various equipment such as a kneader, three rolls, an attritor, a sand mill, and a gate mixer are preferably used to produce the ink. In the production of ink, the rosin-modified resin (A) may be added in the form of the rosin-modified resin (A) itself, or in the form of an electron beam-curable varnish containing the rosin-modified resin (A). good too.

As various raw materials used in the electron beam curable composition of the present invention, biomass-derived raw materials using renewable resources such as plants can be preferably used from the viewpoint of carbon neutrality.

The electron beam curable composition of the present invention does not substantially contain a photopolymerization initiator. Here, "substantially free" means that the content is not intentionally added and the content due to unintentional addition is less than 1% by mass. Examples of unintentional addition include cases in which a trace amount is contained in each raw material, contamination in the manufacturing process of the composition, and the process of producing printed matter.

<Laminate>
When the electron beam curable composition is an electron beam curable ink, the laminate in the present invention is obtained by printing the electron beam curable ink on a substrate and curing with electron beams. Further, when the electron beam curable composition is an electron beam curable varnish, the electron beam curable varnish is printed on the base material, or the electron beam curable varnish is printed on a printed matter obtained by printing ink on the base material, and the electron beam curable varnish is printed. Obtained by line curing.

The base material that can be used in the present invention is preferably a film-like base material, and examples thereof include polyolefin base materials such as polyethylene and polypropylene, polyester base materials such as polyethylene terephthalate and polylactic acid, polycarbonate base materials, polystyrene, AS resins, ABS resins, and the like. Polystyrene base material, nylon base material, polyamide base material, polyvinyl chloride base material, polyvinylidene chloride base material, cellophane base material, paper base material, aluminum base material, etc., or a film-like base made of these composite materials material. In addition, a vapor deposition substrate obtained by vapor-depositing an inorganic compound such as silica, alumina, or aluminum on a polyethylene terephthalate base material or a nylon base material can also be used, and the vapor deposition-treated surface may be coated with polyvinyl alcohol or the like. . It is preferable that the surface to be printed (the surface in contact with the printed layer) of the base material is subjected to an easy-adhesion treatment, and the easy-adhesion treatment includes, for example, corona discharge treatment, ultraviolet/ozone treatment, plasma treatment, oxygen plasma treatment, Primer treatment and the like can be mentioned. Moreover, in the polyethylene terephthalate base material, if sufficient adhesion cannot be obtained, acrylic coating treatment, polyester treatment, polyvinylidene chloride treatment, or the like may be applied.

Moreover, a paper base material may be used as the base material. Usual paper, corrugated cardboard, etc. are used as the paper base material, and although the film thickness is not specified, for example, those having a thickness of 0.2 mm to 1.0 mm and 20 to 150 g/m2 can be used, and the printing surface is easy. Adhesion treatment may be performed. In addition, the surface of the paper substrate may be vapor-deposited with metal such as aluminum for the purpose of imparting design, and the surface may be coated with acrylic resin, urethane resin, polyester resin, polyolefin resin, or other resins. may be applied, and further surface treatment such as corona treatment may be applied. Examples include coated paper and art paper.

The method for printing the electron beam curable composition of the present invention is not particularly limited, and known methods can be used.
Specifically, when the electron beam curable composition is ink, offset printing, flexographic printing, gravure printing, screen printing, and the like can be used.
When the electron beam curable composition is varnish, roll coater, gravure coater, flexo coater, air doctor coater, blade coater, air knife coater, squeeze coater, impregnation coater, transfer roll coater, kiss coater, curtain coater, cast Coaters, spray coaters, die coaters, offset printing (ordinary lithography using dampening water and waterless lithography not using dampening water), flexographic printing, gravure printing, screen printing, inkjet printing and the like.

When the electron beam curable composition of the present invention is a lithographic printing ink, it is suitably used in both lithographic offset printing using dampening water and waterless lithographic printing not using dampening water. be able to.

The electron beam curable composition of the present invention is printed by various printing methods and then cured through an electron beam irradiator to form a printed layer. The irradiation dose of the electron beam is 10 to 60 kGy at an acceleration voltage of 110 kV, preferably 20 to 45 kGy at an acceleration voltage of 110 kV. After the electron beam irradiation, heating may be performed as necessary to promote curing.

The electron beam curable composition of the present invention can be used for various substrates, printed materials for forms, various printed materials for books, various printed materials for packaging such as carton paper, various printed materials for plastics, printed materials for seals/labels, printed materials for art, printed materials for metals ( It can be applied to printed matter such as art printed matter, beverage can printed matter, food printed matter such as canned food).

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. In addition, "part" as described in this specification represents a mass part, and "%" represents mass %.

Details of various measurements performed in the following examples are as follows.

(Component analysis of rosin acids)
The rosin acids used as raw materials were analyzed with a gas chromatography-mass spectrometer, and the ratio (%) of each peak area to the total rosin acid peak area of 100% was determined. More specifically, a conjugated rosin acid that is contained in rosin acids and undergoes a Diels-Alder addition reaction with an α,β-unsaturated carboxylic acid or its acid anhydride (B), and a conjugated rosin acid other than the conjugated rosin acid The content ratio was obtained from the ratio of the corresponding peak areas.

(Confirmation of the progress of the Diels-Alder addition reaction and quantification of the above-mentioned addition reaction product produced)
The reaction solution of the Diels-Alder addition reaction was analyzed with a gas chromatography mass spectrometer, and the detected peaks of the rosin acids (a1) and α,β-unsaturated carboxylic acid or its acid anhydride (a2) used as raw materials were determined. A decrease confirmed the progress of the reaction. The reaction was terminated when no change was observed in the decrease of the detected peak.

(Weight average molecular weight of rosin-modified resin (A))
The weight average molecular weight (Mw) of the rosin-modified resin (A) was measured using gel permeation chromatography (HLC-8320) manufactured by Tosoh Corporation. A calibration curve was prepared with standard polystyrene samples. Tetrahydrofuran was used as an eluent, and three columns of TSKgel SuperHM-M (manufactured by Tosoh Corporation) were used. The measurement was performed under conditions of a flow rate of 0.6 mL/min, an injection volume of 10 µL, and a column temperature of 40°C.

1. Preparation of binder resin 1-1. Preparation of Rosin-Modified Resin (A) A rosin-modified resin was prepared according to the formulation shown below.
The gum rosin used in the formulation shown below has a content of 80% by mass of a conjugated rosin acid that undergoes a Diels-Alder addition reaction with an α,β-unsaturated carboxylic acid or its acid anhydride (a2). The content other than conjugated rosin acid was 20% by mass.

(Preparation of rosin-modified resin 1)
25 parts of gum rosin and 7 parts of maleic anhydride are charged into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, and heated at 180° C. for 1 hour while blowing nitrogen gas. A reaction mixture was thus obtained. The Diels-Alder addition reaction was then confirmed to be complete by gas chromatographic mass spectrometry of the reaction mixture, as previously described.
Next, 40 parts of tert-butyl benzoic acid, 2 parts of succinic anhydride, 26 parts of neopentylglycol glycol, and 0.1 part of p-toluenesulfonic acid monohydrate as a catalyst are added to the reaction mixture. was added, and a dehydration condensation reaction was carried out at 230° C. for 14 hours to obtain a rosin-modified resin 1.

(Preparation of rosin-modified resins 2-3)
Rosin-modified resins 2 and 3 were prepared in the same manner as rosin-modified resin 1 except that the formulation of rosin-modified resin 1 was changed to the formulation shown in Table 1.

In Table 1, the amount of each monomer used in the preparation of the rosin-modified resin (A) is all parts by mass of the solid content.

In addition, commercially available resins or oligomers shown below were used for comparison.
・Daiso Dapp A made by Osaka Soda Co., Ltd.
・Mitsubishi Chemical Corporation Dianal BR116-27
· Urethane Acrylate 6328 manufactured by Sinopoly Chemical Co., Ltd. This is a varnish composed of 68 parts by mass of urethane oligomer and 32 parts by mass of EO-modified trimethylolpropane tri(meth)acrylate.

2. Preparation of electron beam curable lithographic printing ink and electron beam curable varnish







(Examples 1 to 14, Comparative Examples 1 to 5)
(Preparation of electron beam curable lithographic printing ink and electron beam curable varnish)
They were mixed so as to have the blending ratios shown in Tables 2 and 3, kneaded in a three-roll mill at 40°C, and the inks of Examples 1 to 13 and Comparative Examples 1 to 5 and the varnish of Example 14 were applied. Obtained. In addition, the thing which produced the varnish with resin and the (meth)acrylate compound beforehand was used as needed.

3. Evaluation of Electron Beam Curing Lithographic Printing Ink and Electron Beam Curing Varnish For each of the electron beam curing lithographic printing inks and varnishes prepared in Examples and Comparative Examples, a laminate was prepared according to the following method, and the print film suitability was evaluated. Printability was evaluated.

<Creation of laminate>
The electron beam curable lithographic printing inks and electron beam curable varnishes of Examples 1 to 14 and Comparative Examples 2 to 5 were applied to the film using an RI tester (a simple color development device manufactured by Akira Seisakusho Co., Ltd.). Printing was performed so that the coating amount was 1 g/m ² . The coated film after printing was immediately cured using an electron beam irradiation machine EC250/15/180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron dose of 30 kGy to obtain a laminate. In addition, for UV curing in Comparative Example 1, an air-cooled metal halide lamp of 120 W / cm manufactured by Toshiba Corporation was used instead of the electron beam, and the printed surface was irradiated with ultraviolet rays at 60 m / min to cure the laminate. got

Although the following films were used in the study, the effects of the present invention are not limited to these films.
OPP: FOR (20 μm) manufactured by Futamura Chemical Co., Ltd.
PE: white polyethylene film (50 μm)
PET: Emblet PTM (12 μm) manufactured by Unitika Ltd.
OPA: Emblem ONM (15 μm) manufactured by Unitika Ltd.

(Example 15)
The electron beam curable lithographic printing ink of Example 1 was printed on a film using an RI tester (a simple color development device manufactured by Akira Seisakusho Co., Ltd.) so that the coating amount was 1 g/m ² . The coating film after printing was immediately cured using an electron beam irradiation machine EC250/15/180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron dose of 30 kGy. Next, the electron beam curing varnish of Example 14 was applied to the obtained laminate using an RI tester (a simple color development device manufactured by Akira Seisakusho Co., Ltd.), and the coating amount was 1 g/m ² with respect to the film. I printed it out. The coated film after printing was immediately cured using an electron beam irradiation machine EC250/15/180L manufactured by Iwasaki Electric Co., Ltd. at an acceleration voltage of 110 kV and an electron dose of 30 kGy to obtain a laminate.

The laminate after curing was evaluated for surface curability, tape adhesion, and lamination resistance according to the following criteria.

(Surface Curability)
Surface curability was evaluated using the laminates obtained in Examples 1 to 15 and Comparative Examples 1 to 5. The curability was evaluated by visually observing the state when the printed surface of the laminate was rubbed with a cotton cloth, and evaluated on a scale of 5 according to the following criteria. A usable level is "3" or higher, and "4" or higher is more preferable.
5: No change in printing surface.
4: Scratches are not observed on the printed surface, but the cotton cloth is discolored.
3: Scratches are observed on part of the printed surface, but peeling is not observed.
2: Peeling is observed on a part (less than 50%) of the printed surface.
1: Peeling is observed on part (50% or more) or the entire printed surface.

(tape adhesion)
Tape adhesion was evaluated using the laminates obtained in Examples 1-15 and Comparative Examples 1-5. Measurement is performed using an adhesive tape (cellophane tape manufactured by Nichiban Co., Ltd. (width 12 mm)), attaching the tape to the printed surface, and quickly peeling it off at an angle of 180 degrees. It was evaluated in 5 stages according to the criteria of. A usable level is "3" or higher, and "4" or higher is more preferable.
5: The area of the remaining coating film is 90% or more 4: The area of the remaining coating film is 70% or more and less than 90% 3: The area of the remaining coating film is 50% or more and less than 70% 2: The area of the remaining coating film is 25% or more and less than 50% 1: The area of the remaining coating film is less than 25%

(Lamination resistance (only when used as electron beam curable lithographic printing ink))
To the laminates obtained in Examples 1 to 13 and Comparative Examples 1 to 5, an adhesive (TM-321A / TM-321B = 2/1 manufactured by Toyo-Morton Co., Ltd.) was added to ethyl acetate so that the active ingredient was 30%. The diluted adhesive solution is applied with a bar coater at room temperature so that the solid content coating amount after solvent volatilization is 2.0 to 2.5 g / m ² , and after volatilizing the solvent, the coated surface was laminated with an unstretched polypropylene film (FHK2, 30 μm, manufactured by Futamura Chemical Co., Ltd.), and left for 24 hours in an environment of 35° C. and humidity of 60% RT to 80% RT to obtain a laminate.
The obtained laminated laminate was cut into a length of 300 mm and a width of 15 mm, and was pulled using an Instron tensile tester at a peel speed of 300 mm/min in an environment of 25°C. The T-peel strength (N/15 mm) between printing ink/CPP was measured. This test was conducted 5 times, and the average value was used for evaluation in 5 stages according to the following criteria. A usable level is "3" or higher, and "4" or higher is more preferable.
5: 1.5N or more 4: 1.2N or more and less than 1.5N 3: 0.9N or more and less than 1.2N 2: 0.6N or more and less than 0.9N 1: less than 0.6N

<Evaluation of printability>
Printing tests were performed using the inks obtained in Examples 1-13 and Comparative Examples 1-5. The printing test was performed on FOR manufactured by Futamura Chemical Co., Ltd. using ComexiCI-8 (offset printer manufactured by Comexi).
In the printing test, tap water containing 3.0% SUNFOUNT S27H (manufactured by SUNCHRMICAL) was used as dampening water. In order to compare the printing state near the boundary of the condition range where normal printing is possible, printing was performed with a water dial value 2% higher than the lower limit of the water width. The "lower limit of dampening water width" means the minimum supply amount of dampening water that enables normal printing. It means a dial provided on a printing press.

(Concentration stability)
In the inks obtained in Examples 1 to 13 and Comparative Examples 1 to 5, when the density is printed as it is set to the reference value, the density fluctuation at the time of 8000m printing is measured according to the following criteria. , the initial concentration stability was evaluated in five stages. A usable level is "3" or higher, and "4" or higher is more preferable.
5: Concentration is less than ±5% of the reference value 4: Concentration is more than ±5% and less than 10% of the reference value 3: Concentration is more than ±10% and less than 15% of the reference value 2: Concentration is more than ±15% of the reference value and 20 Less than % 1: Concentration is reference value ± 20% or more

(suitability for high-speed printing)
In the inks obtained in Examples 1 to 13 and Comparative Examples 1 to 5, the printing speed was set to 100 m/min and 200 m/min, respectively, and the conditions other than the printing speed were fixed, and the density fluctuation when printing 500 m. were evaluated for initial concentration stability in 5 stages according to the following criteria. A usable level is "3" or higher, and "4" or higher is more preferable.
5: Density variation is less than ±5% 4: Density variation is ±5% or more and less than 10% 3: Density variation is ±10% or more and less than 15% 2: Density variation is ±15% or more and less than 20% 1: Density variation of ±20% or more

(Resistant to scumming)
In the above printing test, as the printing length increases, the ink gradually adheres to the roller supplying dampening water. In addition, when the amount of dampening water supplied is reduced, ink tends to adhere to the non-image area (area where ink should not adhere) where an image is formed on the printed matter. From these results, the longer the print length, the more likely the printed material will be smeared. Regarding the resistance to such stains, the water dial was printed with a water dial value 2% higher than the lower limit of the water width in the same manner as the above printing test, and the printed matter was visually confirmed. evaluated with A usable level is "3" or higher, and "4" or higher is more preferable.
5: No stains can be confirmed on the film, especially after printing for 8000 m.
4: During 8000m printing, a slight stain was observed at the edge of the film, but this was resolved by raising the water dial.
3: The water dial was raised during 8000m printing, but a slight smudge was seen at the edge of the film.
2: The stain cannot be removed unless the ink adhering to the roller is washed once during 8000m printing.
1: 8000m The stain cannot be removed unless the ink adhered to the roller is washed twice or more during printing.

As described above, according to the present invention, an electron beam-curable composition capable of forming a film having excellent curability and excellent adhesion to a substrate, and the electron beam-curable composition We were able to provide a laminate using a material. Moreover, when using an electron beam curable composition as ink, the electron beam curable composition was able to be provided which is excellent in printability.

Claims (6)

An electron beam-curable composition comprising a rosin-modified resin (A), a (meth)acrylate compound (B), and an extender (C), and substantially free of a photopolymerization initiator. There is
The rosin-modified resin (A) is a compound obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). , and a reactant in which an ester bond is formed by the reaction of the carboxylic acid and the polyol (a3) in each of the organic acids having no conjugated double bond among the rosin acids (a1),
The (meth)acrylate compound (B) is one selected from the group consisting of alkylene oxide-modified trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. including
The content of the extender pigment (C) is 0.1 to 10% by mass in the total mass of the composition,
An electron beam-curable composition, wherein the extender pigment (C) comprises (C1) one or more selected from the group consisting of calcium carbonate, magnesium carbonate, and magnesium silicate, and (C2) silicon dioxide. The rosin-modified resin (A) is obtained by a Diels-Alder reaction between an organic acid having a conjugated double bond contained in the rosin acids (a1) and an α,β-unsaturated carboxylic acid or its acid anhydride (a2). Compounds, organic acids having no conjugated double bond among rosin acids (a1), and organic acids or acid anhydrides thereof (a4) (rosin acid (a1), α,β-unsaturated carboxylic acids or acids thereof 2. The electron beam curable composition according to claim 1, which is a reactant in which an ester bond is formed by the reaction of the carboxylic acid in each of the anhydrides (a2) with the polyol (a3). . 3. The electron beam curable composition according to claim 1, further comprising a coloring agent. A laminate comprising a base material and a layer formed by curing the electron beam-curable composition according to any one of claims 1 to 3 with an electron beam. A laminate comprising a printed matter obtained by printing ink on a base material, and a layer formed by curing the electron beam-curable composition according to any one of claims 1 to 3 with an electron beam on the printed surface of the printed matter. 6. The laminate according to claim 4, wherein the substrate is a film substrate.