阅读说明：本技术 酯树脂和酯树脂的制造方法 (Ester resin and method for producing ester resin ) 是由 森田章裕 久田博之 于 2019-08-07 设计创作，主要内容包括：本发明提供一种颜料分散性、光泽性和耐磨耗性并存的油墨用酯树脂。本发明的一个实施方式涉及的酯树脂为松香类和环氧化合物的反应物与多元羧酸、多官能环氧化合物和不饱和羧酸的反应物,该环氧化合物具有三个以上的支链结构,且在上述支链结构的每一个中具有环氧基。(The invention provides an ester resin for ink, which has the advantages of pigment dispersibility, glossiness and wear resistance. An ester resin according to an embodiment of the present invention is a reaction product of a rosin and an epoxy compound, and a reaction product of a polycarboxylic acid, a polyfunctional epoxy compound, and an unsaturated carboxylic acid, wherein the epoxy compound has three or more branched structures and each of the branched structures has an epoxy group.)

1. An ester resin characterized by:

is a reaction product of a rosin and an epoxy compound (A) with a polycarboxylic acid, a polyfunctional epoxy compound (B) and an unsaturated carboxylic acid,

the epoxy compound (a) has three or more branched structures, and has an epoxy group in each of the branched structures.

2. The ester resin of claim 1, wherein:

the epoxy compound (A) is glycidyl ether type epoxy resin.

3. The ester resin of claim 2, wherein:

the glycidyl ether type epoxy resin is trimethylolpropane polyglycidyl ether.

4. An ester resin according to any one of claims 1 to 3, wherein:

the polycarboxylic acid comprises a carbocyclic ring.

5. An ester resin according to any one of claims 1 to 4, wherein:

the polyfunctional epoxy compound (B) is a bifunctional epoxy compound.

6. A method for producing an ester resin, comprising:

a first reaction step of reacting a rosin with an epoxy compound having three or more branched structures and an epoxy group in each of the branched structures;

a second reaction step of reacting the reactant obtained in the first reaction step with a polycarboxylic acid; and

and a third reaction step of reacting the reactant obtained in the second reaction step with a polyfunctional epoxy compound and an unsaturated carboxylic acid.

Technical Field

The present invention relates to an ester resin and a method for producing an ester resin.

Background

Printing inks generally contain an ink resin for uniformly dispersing a pigment and for binding the pigment to a medium such as paper. It is known that: if a rosin structure is present in the ink resin, the pigment dispersibility and gloss are improved (see, for example, patent document 1)

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-321636

Disclosure of Invention

Technical problem to be solved by the invention

However, a printing ink containing an ink resin having a rosin structure has a problem of inferior abrasion resistance to a printing ink containing a conventional epoxy acrylate as an ink resin.

The present invention has been made in view of the above problems, and an object thereof is to provide an ester resin for ink that can achieve a good balance between pigment dispersibility, gloss, and abrasion resistance.

Technical solution for solving technical problem

An ester resin according to an embodiment of the present invention is a reaction product of a rosin and an epoxy compound, and a polycarboxylic acid, a polyfunctional epoxy compound, and an unsaturated carboxylic acid, wherein the epoxy compound has three or more branched structures and each of the branched structures has an epoxy group.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an embodiment of the present invention, an ester resin for ink that can achieve all of pigment dispersibility, glossiness, and abrasion resistance can be provided.

Detailed Description

(ester resin)

An ester resin in one embodiment of the present invention will be described below. The ester resin of the present embodiment is a reaction product of a rosin and an epoxy compound, and a polycarboxylic acid, a polyfunctional epoxy compound, and an unsaturated carboxylic acid, wherein the epoxy compound has a branched structure of 3 or more and has an epoxy group in each of the branched structures. Hereinafter, each component will be described.

< rosins >

The rosin group that can be used in the present embodiment is not particularly limited, and may be, for example, a rosin obtained by subjecting a natural rosin to various known hydrogenation treatments, heat treatments, and/or refining treatments. Specifically, natural rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, purified rosin, and the like can be used, and 1 kind of them can be used alone, or 2 or more kinds can be used in combination. Furthermore, diels alder reaction products of the above-mentioned rosin and α, β unsaturated carboxylic acids (maleic rosin, hydrogenated maleic rosin, acrylic rosin, hydrogenated acrylic rosin, and the like) may also be used. Examples of the natural rosin include tall oil rosin, gum rosin, and wood rosin, and 1 kind of the natural rosin may be used alone or 2 or more kinds may be used in combination.

< epoxy compound having a branched structure of 3 or more and having an epoxy group in each of the above branched structures >

In order to obtain an ink having all of pigment dispersibility, glossiness, and abrasion resistance, an epoxy compound having 3 or more branched structures in the main chain and having an epoxy group in each of the branched structures is used as the epoxy compound that can be used in the present embodiment. By using an epoxy compound having 3 or more branched structures and an epoxy group in each of the branched structures (hereinafter referred to as an epoxy compound), when an ink containing the obtained ester resin for ink is cured, a 3-dimensional crosslinked structure can be formed, and therefore, the network becomes strong and the abrasion resistance can be improved.

Specific examples of the epoxy compound include glycidyl ether type epoxy resins, and specific examples thereof include trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and sorbitol polyglycidyl ether. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

< polycarboxylic acid >

The polycarboxylic acid that can be used in the present embodiment is not particularly limited, and examples thereof include: saturated polybasic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, 2, 6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalate, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, 1, 4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride; unsaturated polybasic acids such as maleic anhydride, fumaric acid, itaconic acid, and tetrahydrophthalic anhydride; dodecenyl succinic anhydride, tetrahydrophthalic anhydride, and the like. Among them, the use of a polycarboxylic acid containing a carbocyclic ring is preferable because the glass transition temperature and softening point of the obtained ester resin are increased, and the scratch hardness (pencil hardness) and abrasion resistance of an ink coating film containing the ester resin are increased. Here, carbocyclic means a cyclic moiety consisting only of carbon. The polycarboxylic acid may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The polycarboxylic acids are exemplified by maleic anhydride having no carbocyclic ring structure (the cyclic moiety is not composed of only carbon) and tetrahydrophthalic anhydride having a carbocyclic ring structure. Maleic anhydride has a lower structural stability than tetrahydrophthalic anhydride, and therefore has a higher reactivity to ultraviolet rays. Therefore, when an ink is prepared using maleic anhydride as a polycarboxylic acid and ultraviolet rays are irradiated to form an ink coating film, scratch hardness (pencil hardness) and abrasion resistance equivalent to those of tetrahydrophthalic anhydride having a carbocyclic structure may be exhibited.

< polyfunctional epoxy Compound >

The polyfunctional epoxy compound that can be used in the present embodiment is not particularly limited as long as it has 2 or more epoxy groups in 1 molecule, and specific examples thereof include glycidyl ether type epoxy resins such as bisphenol a diglycidyl ether, bisphenol a di β methyl glycidyl ether, bisphenol F diglycidyl ether, tetrahydroxyphenylmethane tetraglycidyl ether, resorcinol diglycidyl ether, brominated bisphenol a diglycidyl ether, chlorinated bisphenol a diglycidyl ether, novolak glycidyl ether, polyalkylene glycol diglycidyl ether, hydrogenated bisphenol a glycidyl ether, diglycidyl ether of bisphenol a alkylene oxide adduct, glycerol triglycidyl ether, pentaerythritol diglycidyl ether, and the like; glycidyl ether ester type epoxy resins such as glycidyl ether esters of p-hydroxybenzoic acid; glycidyl ester type epoxy resins such as diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, and diglycidyl dimer acid; glycidyl amine type epoxy resins such as glycidyl aniline, tetraglycidyl diaminophenylmethane, and triglycidyl isocyanurate; linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil; and alicyclic epoxy resins such as 3, 4-epoxy-6-methylcyclohexylmethyl 3, 4-epoxy-6-methylcyclohexanecarboxylate and 3, 4-epoxycyclohexylmethyl (3, 4-epoxycyclohexane) carboxylate. Among these, the use of a bifunctional epoxy compound is preferable because it can prevent the occurrence of a decrease in steric hindrance and the remaining of unreacted epoxy groups. The polyfunctional epoxy compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

< unsaturated carboxylic acid >

The unsaturated carboxylic acid that can be used in the present embodiment is not particularly limited, and examples thereof include a chain α, β -unsaturated monocarboxylic acid having 3 to 5 carbon atoms and/or an acid anhydride thereof, a chain α, β -unsaturated dicarboxylic acid having 3 to 5 carbon atoms and/or an acid anhydride thereof, and an aromatic α, β -unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, itaconic anhydride, crotonic acid, and cinnamic acid. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

(method for producing ester resin)

In the case of producing the ester resin according to the present embodiment, first, as the first reaction step, a ring-opening addition reaction based on ring opening of an epoxy group is performed by reacting a rosin with an epoxy compound having 3 or more branched structures and having an epoxy group in each of the branched structures. Then, as a second reaction step, the reaction product obtained in the first reaction step is reacted with a polycarboxylic acid to perform a ring-opening addition reaction based on condensation of a hydroxyl group generated by ring-opening of an epoxy group and a carboxyl group of the polycarboxylic acid. Further, as the third reaction step, the reaction product obtained in the second reaction step is reacted with a polyfunctional epoxy compound and an unsaturated carboxylic acid to thereby perform a ring-opening addition reaction based on ring opening of an epoxy group of the epoxy compound.

In the first reaction step, the temperature at which the rosin and the epoxy compound are reacted is usually in the range of 50 to 200 ℃. In the first reaction step, a known catalyst for promoting a ring-opening addition reaction of an epoxy group and a carboxyl group, a ring-opening addition reaction promoter, a stabilizer, and the like may be used.

The amount of the rosin and the epoxy compound used in the first reaction step is preferably such that the molar ratio of the carboxyl group to the epoxy group (COOH/epoxy group) of the rosin is in the range of 0.3 to 1.5, which allows the pigment dispersibility, gloss, and abrasion resistance of the resulting ink to be compatible.

In the second reaction step, the temperature at which the reactant obtained in the first reaction step reacts with the polycarboxylic acid is usually in the range of 50 to 200 ℃. In the second reaction step, a known catalyst, a ring-opening addition reaction accelerator, a stabilizer, or the like that accelerates a ring-opening addition reaction of a hydroxyl group generated by ring-opening of an epoxy group and a carboxyl group of a polycarboxylic acid may be used.

The amount of the polycarboxylic acid used in the second reaction step is preferably such that the molar ratio (OH/COOH) of the hydroxyl group derived from the epoxy group to the carboxyl group of the polycarboxylic acid is in the range of 0.5 to 2.0, in order to achieve the pigment dispersibility, the gloss, and the abrasion resistance of the obtained ink.

In the third reaction step, the temperature at which the reactant obtained in the second reaction step, the polyfunctional epoxy compound and the unsaturated carboxylic acid are reacted is usually in the range of 50 to 200 ℃. In the third reaction step, a known catalyst for promoting a ring-opening addition reaction of an epoxy group and a carboxyl group, a ring-opening addition reaction promoter, a stabilizer, and the like may be used.

The amount of the reactant obtained in the second reaction step, the polyfunctional epoxy compound and the unsaturated carboxylic acid used in the third reaction step is preferably such that the molar ratio (COOH/epoxy group) of the reactant obtained in the second reaction step, the carboxyl group derived from the unsaturated carboxylic acid and the epoxy group derived from the polyfunctional epoxy compound is in the range of 0.5 to 2.0, since the pigment dispersibility, the glossiness and the abrasion resistance of the obtained ink are compatible with each other.

(method for producing ink)

The ester resin for ink uses an epoxy compound having 3 or more branched structures and epoxy groups in each of the branched structures as a raw material, and has an unsaturated bond derived from an unsaturated carboxylic acid. Therefore, by producing an ink using the ester resin for ink, the pigment and the photopolymerization initiator, the obtained ink has good abrasion resistance.

The pigment is not particularly limited, and inorganic pigments and organic pigments may be mentioned. Examples of the inorganic pigment include chrome yellow, zinc yellow, prussian blue, barium sulfate, cadmium red, titanium oxide, zinc white, alumina white, calcium carbonate, ultramarine, carbon black, graphite, aluminum powder, and red iron oxide. These can be used alone in 1 kind, also can be combined with more than 2 kinds. Examples of the organic pigment include a β -naphthol pigment, a β -hydroxynaphthoic acid aniline pigment, an acetoacetanilide pigment, a soluble azo pigment such as a pyrazolone pigment, a β -naphthol pigment, a β -hydroxynaphthoic acid aniline pigment, an acetoacetanilide monoazo pigment, an acetoacetanilide disazo pigment, an insoluble azo pigment such as a pyrazolone pigment, a copper phthalocyanine blue, a halogenated (chlorinated or brominated) copper phthalocyanine blue, a sulfonated copper phthalocyanine blue, a phthalocyanine pigment such as a metal-free phthalocyanine, a quinacridone pigment, a dioxazine pigment, a threne pigment (pyranthrone, an anthanthrone, an indanthrone, an anthrapyrimidine, a xanthanthrone, a thioindigo, an anthraquinone, a perinone pigment, a perylene pigment, etc.), an isoindolinone pigment, a pigment, Polycyclic pigments such as metal complex pigments and quinophthalone pigments, and heterocyclic pigments. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

The photopolymerization initiator is not particularly limited, and examples thereof include: 2, 2-dimethoxy-1, 2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 1-cyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, bis (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide, and mixtures thereof, 2, 4, 6-trimethylbenzoyl-diphenyl-phosphine oxide, 4-methylbenzophenone, benzophenone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropanoyl) -benzyl ] phenyl } -2-methyl-propan-1-one, and the like. These can be used alone in 1 kind, also can be combined with more than 2 kinds.

The ink according to the present embodiment may further contain an active energy ray-curable monomer or a known additive, as required. The active energy ray-curable monomer is a monomer having a photopolymerizable group that can be copolymerized with the ester resin for ink by irradiation with active energy rays. Examples of the additives include a curing accelerator (such as cobalt naphthenate), a filler, a thickener, a foaming agent, an antioxidant, a light stabilizer, a heat stabilizer, and a flame retardant.

(examples)

Next, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to the following examples. For example, when synthesizing the ester resin for ink according to the present embodiment, the reaction may be carried out in a monomer. In the following, "parts" and "%" are based on mass unless otherwise specified.

< example 1 >

In a 4-neck flask equipped with a stirrer, a reflux condenser having a water separator, and a thermometer, 34.3 parts of disproportionated rosin (product name: G-100F, manufactured by Harima chemical Co., Ltd.) as a rosin was dissolved while blowing nitrogen gas, and 14.3 parts of trimethylolpropane polyglycidyl ether as an epoxy compound having 3 or more branched structures and epoxy groups in each of the branched structures and 0.3 part of triethylamine were mixed and reacted at 160 ℃ to complete a first reaction step (acid value of 7mgKOH/G or less).

The reaction product obtained in the first reaction step was mixed with 9.6 parts of maleic anhydride as a polycarboxylic acid and reacted at 160 ℃ to complete the second reaction step (acid value of 110mgKOH/g or less).

The reaction product obtained in the second reaction step was mixed with 6.9 parts of acrylic acid, 34.5 parts of bisphenol A type epoxy resin (product name: EOMIK R140, manufactured by Mitsui chemical Co., Ltd.), and 0.1 part of hydroquinone, and reacted at 160 ℃ to complete the third reaction step, whereby an ester resin for ink (hereinafter referred to as resin 1) (acid value: 16.0mgKOH/g) according to the present embodiment was obtained.

The obtained resin 1 was mixed with 39.9 parts of trimethylolpropane triacrylate (TMPTA) and 0.1 part of hydroquinone in an amount of 60.0 parts, and dissolved by heating at about 110 ℃ to obtain an ink composition (hereinafter referred to as varnish 1) according to the present embodiment.

The varnish 1 thus obtained was mixed with 43.0 parts of neutral carbon black (pigment, product name: RCF #52 manufactured by Mitsubishi chemical corporation) 20.0 parts, dipentaerythritol hexaacrylate (DPHA)20.0 parts, trimethylolpropane triacrylate (TMPTA)12.0 parts, and 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one (photopolymerization initiator, product name: Irgacure907 manufactured by BASF) 5.0 parts, and dispersed by a three-roll mill (manufactured by Mitsubishi corporation, S-43/4X 11) so that the maximum particle diameter became 5.0 μm or less. Thus, the ink according to the present embodiment (hereinafter referred to as ink 1) was obtained.

The mixing ratio of each component in the ink was adjusted so that the viscosity value after 1 minute became 8.0 to 10.0 under the condition that the roller temperature of an ink tensiometer (manufactured by Toyo Seiki Seisaku-Sho Ltd.; trade name: D-2) was 30 ℃ and 400 rpm.

< examples 2 to 7 >

Resins 2 to 7 were obtained in the same manner as in example 1, except that the compounding ratio of each component was changed to that shown in table 1. Further, varnishes 2 to 7 and inks 2 to 7 (see tables 2 and 3) were obtained in the same manner as in example 1 using the obtained resins 2 to 7. The 3-or more-functional epoxy resin in the first reaction step in table 1 is an epoxy compound having 3 or more branched structures and each of the branched structures has an epoxy group. The main component of the glycerin-type epoxy resin is 1, 2, 3-propane polyglycidyl ether or glycerol polyglycidyl ether. Further, the bisphenol a epoxy resin is a prepolymer obtained by polymerization of bisphenol a and epichlorohydrin. Further, the neopentyl glycol type epoxy resin means neopentyl glycol diglycidyl ether.

[ Table 1]

[ Table 2]

< comparative examples 1 to 4 >

Resins 8 to 11 were obtained in the same manner as in example 1, except that the compounding ratio of each component was changed to that shown in table 1. Further, varnishes 8 to 11 and inks 8 to 11 were obtained in the same manner as in example 1 using the obtained resins 8 to 11.

(ink evaluation)

The inks obtained in the examples and comparative examples were evaluated by the following methods.

< curability >

0.4mL of each ink was spread on art paper with an RI tester over the roll. Then, the substrate was irradiated with ultraviolet light 1 time under conditions of 80W/cm metal halide lamp and 24m/min transport speed using an ultraviolet irradiation apparatus (product name ESC-4011 GX manufactured by Eye Graphics Co., Ltd.).

The obtained ink coating film was judged to be dry to touch according to the following criteria.

O: by touching with a finger, no stickiness was felt at all. Good level.

And (delta): by finger touch, a slight sliminess was felt. Has a level of practicality.

X: by touching with fingers, sticky feeling was felt. There is no level of practicality.

< gloss value >

The ink was irradiated with ultraviolet light under the same conditions as those used for the evaluation of the above-mentioned curability, and the gloss value of the cured printed matter was measured with a 60 ℃ to 60 ℃ gloss meter (product name: Micro-tri-gloss, manufactured by Taiyou products Co., Ltd.).

In the above test, the obtained ink coating film was judged to have a high gloss value if it had a gloss value of 60 or more.

Hardness of pencil

The ink was irradiated with ultraviolet rays under the same conditions as those used for the evaluation of the above-mentioned curability, and the cured printed material was evaluated for the highest hardness at which the coating of the printed material did not peel off by the method in accordance with JIS K5600 (2007).

The ink coating film obtained can be judged to be usable at a level of F or more.

(hard) 2H > H > F > HB > B >2B (Soft)

< abrasion resistance >

The ink was irradiated with ultraviolet rays under the same conditions as those for the evaluation of the above-mentioned curability, and the degree of wiping off of the ink film on the surface of the printed matter was evaluated in 5 steps by a method in accordance with JIS K5701-1(2000) and by using an S-shaped friction tester (manufactured by antanji corporation) to reciprocate the cured printed matter 40 times with a load of 1816 g.

The obtained ink coating film can be judged to be usable at a level of 4 or more based on the following criteria.

5: and repeating for 40 times, and wiping off less than 20 percent.

4: repeating for 40 times, and wiping off more than 20% and less than 40%.

3: repeating for 40 times, and wiping off more than 40% and less than 60%.

2: repeating for 40 times, and wiping off more than 60% and less than 80%.

1: repeating for 40 times, and wiping off more than 80%.

< fluidity >

The inks obtained in examples and comparative examples were placed in an ink cup (1 pipette about 1.5mL) by taking 1 pipette, and the fluidity was evaluated by the distance of ink flow when the ink was placed on a glass plate inclined at 60 ° and left for 10 minutes.

The distance over which the ink flows is 80mm or more, and the ink is judged to have high fluidity.

O: over 80 mm.

△：40～80mm

X: less than 40mm

The results of the ink evaluation are shown in table 3.

[ Table 3]

As shown in table 3, the inks obtained in the examples were inks prepared using an ester resin which is a reaction product of a rosin and an epoxy compound having 3 or more branched structures and an epoxy group in each of the branched structures, and a reaction product of a polycarboxylic acid, a polyfunctional epoxy compound, and an unsaturated carboxylic acid, and therefore all the characteristics were maintained at a usable level in curability, gloss value, pencil hardness, abrasion resistance, and fluidity.