阅读说明：本技术 活性能量射线固化型喷墨油墨组合物 (Active energy ray-curable inkjet ink composition ) 是由 马越英明 上西明穗 岩佐成人 樱井哲郎 于 2019-02-27 设计创作，主要内容包括：本发明的课题在于提供一种活性能量射线固化型喷墨油墨组合物,所述活性能量射线固化型喷墨油墨组合物的粘度低,且可作为喷墨油墨喷出,且对于表面自由能低的塑料基材显示出充分的密合。本发明的活性能量射线固化型喷墨油墨组合物含有聚酯树脂(A),上述聚酯树脂(A)包含来自多元酸的结构单元(a-1)和来自多元醇的结构单元(a-2),来自多元醇的结构单元(a-2)含有20摩尔％以上且100摩尔％以下的来自氢化双酚A的结构单元,聚酯树脂(A)的数均分子量(Mn)为500～4500,酸值为5～300。(The present invention addresses the problem of providing an active energy ray-curable inkjet ink composition which has a low viscosity, can be ejected as an inkjet ink, and exhibits sufficient adhesion to a plastic substrate having a low surface free energy. The active energy ray-curable inkjet ink composition of the present invention contains a polyester resin (A), wherein the polyester resin (A) contains a structural unit (a-1) derived from a polybasic acid and a structural unit (a-2) derived from a polyhydric alcohol, the structural unit (a-2) derived from a polyhydric alcohol contains 20 to 100 mol% of a structural unit derived from hydrogenated bisphenol A, the polyester resin (A) has a number average molecular weight (Mn) of 500 to 4500, and an acid value of 5 to 300.)

1. An active energy ray-curable inkjet ink composition characterized by containing a polyester resin (A),

the polyester resin (A) comprises a structural unit (a-1) derived from a polybasic acid and a structural unit (a-2) derived from a polyhydric alcohol,

the structural unit (a-2) derived from a polyol contains 20 to 100 mol% of a structural unit derived from hydrogenated bisphenol A,

the polyester resin (A) has a number average molecular weight Mn of 500 to 4500 and an acid value of 5 to 300.

2. The active energy ray-curable inkjet ink composition according to claim 1, wherein the active energy ray-curable inkjet ink composition further contains a (meth) acrylate monomer (B).

3. The active energy ray-curable inkjet ink composition according to claim 1 or 2, wherein the active energy ray-curable inkjet ink composition further contains a polymerization initiator (C).

4. The active energy ray-curable inkjet ink composition according to any one of claims 1 to 3, wherein the viscosity of the active energy ray-curable inkjet ink composition is 5 to 20 mPas.

5. A printed matter obtained by printing the active energy ray-curable inkjet ink composition according to any one of claims 1 to 4 and irradiating the printed matter with active energy rays.

Technical Field

The present invention relates to an active energy ray-curable inkjet ink composition and a printed matter obtained by curing the composition.

Background

The active energy ray or UV curable inkjet ink is broadly classified into a radical curing type and an ion (anion and/or cation) curing type according to the curing system. In adjusting the drying rate and the physical properties of the coating film, radical curing is widely used because of its superiority in selection of various compositions.

The composition of the active energy ray-curable inkjet ink includes a UV-curable monomer, a UV-curable oligomer, a UV-curable polymer, a polymerization initiator, a colorant, and various additives. The inkjet ink sometimes does not contain a polymer component due to viscosity limitations. In addition, the polymer component is sometimes an inert polymer (inert polymer) of a non-UV curing type.

Examples of the substrate to be coated with the active energy ray-curable inkjet ink include paper, plastic, metal, and inorganic substances (e.g., glass). Among them, there are various plastics mainly composed of soft and hard plastics, but particularly, there is a case where adhesion is insufficient to a plastic substrate such as polyethylene or polypropylene having a low surface free energy, and there is a problem that peeling of a coating film may occur.

As a method for solving the insufficient adhesion to the low surface free energy base material, a method of adding a specific functional resin is included. For example, patent document 1 can solve this problem by adding a polymer. However, it is also known from the assumption that offset lithographic inks are used that compositions containing the resin have a high viscosity (several to several hundred Pa · s), and therefore cannot be applied to low viscosity inks (20mPa · s or less) such as inkjet inks.

Patent document 2 reports that an inkjet ink composition having a low viscosity adheres to a polyethylene terephthalate (PET) substrate, but the substrate is limited to PET and has no versatility, i.e., cannot widely adhere to a low surface free energy substrate.

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing an active energy ray-curable inkjet ink composition which has a low viscosity, can be ejected as an inkjet ink, and exhibits sufficient adhesion to a plastic substrate having a low surface free energy.

Means for solving the problems

The present inventors have intensively studied methods for solving the above-mentioned problems, and as a result, they have found that: an active energy ray-curable ink composition containing a polyester resin having a specific structure has excellent adhesion to a plastic substrate while maintaining low viscosity.

That is, the present invention can be described as follows.

An active energy ray-curable inkjet ink composition containing a polyester resin (A) which contains a structural unit (a-1) derived from a polybasic acid and a structural unit (a-2) derived from a polyhydric alcohol, wherein the structural unit (a-2) derived from a polyhydric alcohol contains a structural unit derived from hydrogenated bisphenol A in an amount of 20 to 100 mol%, and wherein the polyester resin (A) has a number average molecular weight (Mn) of 500 to 4500 and an acid value of 5 to 300.

Effects of the invention

A printed matter printed on a plastic substrate using the active energy ray-curable inkjet ink of the present invention exhibits high adhesion to the plastic substrate. In addition, even if the polyester resin of the present invention is blended, the viscosity of the composition can be maintained low, and therefore, the composition can be used for UV inkjet ink.

Detailed Description

The active energy ray-curable inkjet ink composition is described in detail below.

Active energy ray-curable inkjet ink composition

The active energy ray-curable inkjet ink composition of the present invention contains a polyester resin (a). The polyester resin (A) contains a structural unit (a-1) derived from a polybasic acid and a structural unit (a-2) derived from a polyhydric alcohol, and further contains a (meth) acrylate monomer (B) and a polymerization initiator (C) as required. When the active energy ray-curable inkjet ink composition of the present invention is used for a coloring ink, a colorant and the like are further added. Note that the colorless ink (in the case of being used for surface coating applications, varnish, or the like) does not add a colorant. Various additives may be added as appropriate depending on the purpose.

Polyester resin (A)

The polyester resin (A) of the present invention comprises a structural unit (a-1) derived from a polybasic acid and a structural unit (a-2) derived from a polyhydric alcohol. The structural unit (a-2) derived from a polyol contains 20 to 100 mol% of a structural unit derived from hydrogenated bisphenol A. That is, in the polyester resin (a), the structural unit derived from hydrogenated bisphenol a is 20 mol% or more and 100 mol% or less of the total structural units (a-2) derived from a polyhydric alcohol. The polyester resin (A) has a number average molecular weight of 500 to 4500 and an acid value of 5 to 300.

The polyester resin (a) contained in the active energy ray-curable inkjet ink composition of the present invention is a reaction product obtained by a reaction between a polybasic acid of a dibasic acid or higher and a polyhydric alcohol of a dibasic acid or higher. The polybasic acid may be an acid anhydride thereof, and may be used alone or in combination of two or more.

Structural unit (a-1) derived from polybasic acid

Examples of the structural unit (a-1) derived from a polybasic acid include an unsaturated polybasic acid and a saturated polybasic acid.

The unsaturated polybasic acid is not particularly limited, and known ones can be used. Examples of the unsaturated polybasic acid include maleic anhydride, fumaric acid, citraconic acid, and itaconic acid. These unsaturated polybasic acids may be used alone or in combination of plural kinds.

The saturated polybasic acid is not particularly limited, and a known one can be used. Examples of the saturated polybasic acid include structural units derived from succinic acid, glutaric acid, maleic anhydride, chloromaleic acid, mesaconic acid, adipic acid, dodecanedioic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, and the like. Among them, structural units derived from hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic acid, isophthalic acid, and terephthalic acid are preferable, and structural units derived from hexahydrophthalic anhydride and tetrahydrophthalic anhydride are more preferable.

Structural unit (a-2) derived from a polyol

The structural unit (a-2) derived from a polyol in the present invention contains at least a structural unit derived from hydrogenated bisphenol A. The hydrogenated bisphenol A may be used alone or in combination with other polyols. Examples of the polyhydric alcohol which can be used in combination include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 2-methyl-1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, 1, 9-nonanediol, 2-methyloctanediol, glycerin, 1, 10-decanediol, bisphenol A, bisphenol F, hydrogenated bisphenol F, and the like.

Among them, 1, 3-butanediol, 1, 4-butanediol and dipropylene glycol are preferable.

In the structural unit (a-2) derived from a polyol, the structural unit derived from hydrogenated bisphenol a may be in the range of 20 mol% or more and 100 mol% (for example, 20 mol% or more and 100 mol%, 20 mol% or more and 95 mol% or less, 20 mol% or more and 80 mol% or less, 20 mol% or more and 70 mol% or less) of the total structural units derived from a polyol. When the viscosity is within the above range, an ink jet ink composition having excellent adhesion to a plastic substrate while maintaining low viscosity as an ink can be obtained. Among these, the structural unit derived from hydrogenated bisphenol a contained in the structural unit derived from a polyol (a-2) is preferably 20 mol% or more and 100 mol% or less, 50 mol% or more and 100 mol% or less, 80 mol% or more and 100 mol% or less, 90 mol% or more and 100 mol% or less, 99 mol% or more and 100 mol% or less, or 100 mol%.

The number average molecular weight (Mn) of the polyester resin (A) is preferably 500 to 4500, more preferably 800 to 3000, and further preferably 800 to 2000. The weight average molecular weight (Mw) of the polyester resin (A) is not particularly limited, but is preferably 500 to 5000, and more preferably 800 to 3000. If the molecular weight is too small, the curability of the ink composition containing the plastic substrate and the polyester resin (a) decreases, and if the molecular weight is too large, the viscosity of the ink composition containing the polyester resin (a) increases, and ink jet cannot be ejected. In the present specification, "number average molecular weight" and "weight average molecular weight" were measured at 40 ℃ by gel permeation chromatography (LC-2030, Promin-i manufactured by Shimadzu corporation) and determined using a standard polystyrene calibration curve. The acid value of the polyester resin (A) may be 5 to 300, preferably 10 to 200, and more preferably 15 to 150.

The reaction for obtaining the polyester resin (a) can be synthesized by a known method using the above-mentioned raw materials. Various conditions in the synthesis need to be appropriately set depending on the raw materials used and the amounts thereof. In this reaction, a catalyst may be used as necessary. Examples of the catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. They may be used alone or in combination of plural kinds. The reaction temperature is preferably in the range of 150 to 220 ℃ and more preferably in the range of 170 to 200 ℃ in order to obtain the optimum reaction rate and yield.

The order of addition of the raw materials in obtaining the polyester resin (a) of the present invention may be appropriately adjusted depending on the polyester resin (a) having the target structure, and for example, in the case of using two kinds of the polybasic acid and the polyhydric alcohol as the polybasic acid and the polyhydric alcohol, the two kinds of the polybasic acid and the polyhydric alcohol may be added at once to carry out the reaction, and the ratio of the reaction composition of the polybasic acid and the one kind of the polyhydric alcohol may be adjusted to 1: 2 or 2: 1, and then another polybasic acid or polyhydric alcohol which determines the terminal structure is added as appropriate after the first stage reaction, to carry out the second stage reaction, whereby a polyester resin having different internal structural units and terminal structures can be obtained.

The reaction atmosphere is preferably an inert gas atmosphere such as nitrogen or argon. The reaction pressure may be either atmospheric pressure or pressurized, but is preferably atmospheric pressure in view of ease of operation. The reaction can be carried out by charging the raw materials in one or more portions in a reaction apparatus equipped with a stirring blade and then reacting the raw materials at the above-mentioned predetermined temperature.

The content of the polyester resin (a) in the active energy ray-curable inkjet ink composition may be in the range of 1 to 20% by weight, and preferably in the range of 5 to 15% by weight. If the content is 1% or less, sufficient adhesion to the substrate cannot be obtained, and if the content is 20% or more, the viscosity increases, and the ink cannot be ejected as an inkjet ink.

(meth) acrylic acid ester monomer (B)

The active energy ray-curable inkjet ink composition of the present invention contains a (meth) acrylate monomer (B) as needed.

The (meth) acrylate monomer (B) is not particularly limited as long as it can be used as an inkjet ink, but it is required to have a low viscosity. As a standard, it is sufficient that the monomer shows a degree of 5 to 20 mPas at 25 ℃, and it is usually a monofunctional or bifunctional (meth) acrylate monomer. If necessary, a small amount of a polyfunctional (meth) acrylate (e.g., trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate) may be added as long as the low viscosity can be maintained.

As examples of the (meth) acrylate monomer (B), isobornyl acrylate, 4-hydroxybutyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, phenoxyethyl acrylate, isooctyl acrylate, stearyl acrylate, cyclohexyl acrylate, 2-ethoxyethyl acrylate, benzyl acrylate, 1H, 5H-octafluoropentyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobutyl acrylate, tert-butyl acrylate, tetrahydrofurfuryl acrylate, ethylcarbitol acrylate, 2,2, 2-trifluoroethyl acrylate, 2,2,3, 3-tetrafluoropropyl acrylate, methoxytriethylene glycol acrylate, Propylene Oxide (PO) -modified nonylphenol acrylate, methyl methacrylate, ethyl methacrylate, ethylene Oxide (EO) -modified nonylphenol acrylate, Ethylene Oxide (EO) -modified 2-ethylhexyl acrylate, phenyl glycidyl ether acrylate, phenoxy diethylene glycol acrylate, Ethylene Oxide (EO) -modified phenol acrylate, Ethylene Oxide (EO) -modified cresol acrylate, methoxypolyethylene glycol acrylate, dipropylene glycol acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2-n-butyl-2-ethyl-1, 3-propanediol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, 1, 9-nonanediol diacrylate, 1, 4-butanediol diacrylate, bisphenol A Ethylene Oxide (EO) -modified diacrylate, 1, 6-hexanediol diacrylate, polyethylene glycol 200 diacrylate, bisphenol A Ethylene Oxide (EO) -modified diacrylate, 1, 6-hexanediol diacrylate, ethylene glycol 200 diacrylate, bisphenol A Ethylene Oxide (EO) -modified propylene glycol acrylate, and mixtures thereof, Neopentyl glycol hydroxypivalate diacrylate, 2-ethyl-2-butyl-propylene glycol diacrylate, polypropylene glycol diacrylate, Propylene Oxide (PO) -modified bisphenol A diacrylate, Ethylene Oxide (EO) -modified hydrogenated bisphenol A diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, gamma-butyrolactone acrylate, pentamethylpiperidyl acrylate, tetramethylpiperidyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, mevalonic lactone acrylate, dimethyltricyclodecane diacrylate, 2- (2-vinyloxyethoxy) ethyl acrylate, propylene oxide (propylene oxide), Propylene Oxide (PO) -modified bisphenol A diacrylate, Ethylene Oxide (EO) -modified hydrogenated bisphenol A diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, gamma-butyrolactone triacrylate, pentameth, 1-adamantyl methacrylate, 1-adamantyl acrylate, 2-acryloxyethyl phthalate, isobornyl acrylate, 3-acryloxypropyl acrylate, dicyclopentyl acrylate, 2-hydroxy 3-phenoxypropyl acrylate, diethylene glycol diethyl ether, N-vinylcaprolactam, N-vinylpyrrolidone and the like. Among them, isobornyl acrylate, phenoxyethyl acrylate, 1, 6-hexanediol diacrylate, 1, 9-nonanediol diacrylate and dipropylene glycol diacrylate are preferable.

In addition, as the (meth) acrylate monomer (B), a monofunctional (meth) acrylate having a homopolymer glass transition temperature of from-5 to-20 ℃ is also preferably used from the viewpoint of improving the scratch resistance. More specifically, in the polymerizable monomer component (A), it is preferable that the monofunctional (meth) acrylate having a homopolymer glass transition temperature of-5 to-20 ℃ is 6 to 50% by weight, the (meth) acrylate monomer different from the monofunctional (meth) acrylate is 50 to 94% by weight, and it is more preferable that the monofunctional (meth) acrylate having a homopolymer glass transition temperature of-5 to-20 ℃ is 15 to 45% by weight, and the (meth) acrylate monomer different from the monofunctional (meth) acrylate is 55 to 85% by weight.

As an example of the monofunctional (meth) acrylate having a homopolymer glass transition temperature of-5 to-20 ℃, examples thereof include 2-ethylhexyl methacrylate (-10 ℃), 2-hydroxyacrylate (-10 ℃), 2-hydroxyethylacrylate (-15 ℃), 2-hydroxypropylacrylate (-7 ℃), phenoxyethyl acrylate (-20 ℃), phenoxydiethylene glycol acrylate (-15 ℃), phenoxypolyethylene glycol acrylate (-20 ℃), methoxypolyethylene glycol methacrylate (-10 ℃), tetrahydrofurfuryl acrylate (-15 ℃), ethoxylated nonylphenol acrylate (-20 ℃), alkoxylated phenol acrylate (-20 ℃), and the like, and phenoxydiethylene glycol acrylate and/or tetrahydrofurfuryl acrylate are preferable. The numerical values in parentheses indicate the glass transition temperatures of the homopolymers.

One or two types of the monofunctional (meth) acrylate may be used in combination. The ratio when two or more kinds are used in combination is not particularly limited, and for example, when two kinds are used in combination, one kind of monofunctional (meth) acrylate: the ratio of the other monofunctional (meth) acrylate is 5: 95-95: 5, preferably 20: 80-80: 20, or more.

The content of the (meth) acrylate monomer (B) in the active energy ray-curable inkjet ink composition may be in the range of 50 to 1500 parts by weight, preferably 50 to 1300 parts by weight, and particularly preferably 50 to 1200 parts by weight, based on 100 parts by weight of the polyester resin (a).

Polymerization initiator (C)

The active energy ray-curable inkjet ink composition of the present invention contains a polymerization initiator as needed. In the present invention, a polymerization initiator may be used without limitation. Particularly preferably, the photopolymerization initiator is contained.

The amount of the polymerization initiator to be added to the active energy ray-curable inkjet ink composition of the present invention is preferably in the range of 0.1 to 20 parts by weight, more preferably in the range of 1 to 15 parts by weight, and particularly preferably in the range of 5 to 10 parts by weight, based on 100 parts by weight of the total of the (meth) acrylic monomer (B) and the polyester resin (a).

Examples of the photopolymerization initiator include, but are not particularly limited to, benzoins such as benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether and benzoin n-butyl ether, benzoin alkyl ethers such as benzophenone, p-methylbenzophenone, michelson, methylbenzophenone, 4 '-dichlorobenzophenone and 4, 4' -bisdiethylaminobenzophenone, benzophenones such as acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone, 1-hydroxy-cyclohexyl-phenylketone and 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-propanone, Acetophenone compounds such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and N, N-dimethylaminoacetophenone, thioxanthone compounds such as 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone and 2, 4-diisopropylthioxanthone, anthraquinone compounds such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone and 2-aminoanthraquinone, ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal, 1.2-octanedione, 1- [4- (phenylthio) -, 2- (O-benzoyl oxime) ], ethanone and 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbone Oxime esters such as oxazol-3-yl-, 1- (O-acetyloxime), acylphosphines such as 2,4, 6-trimethylbenzoyldiphenylphosphine oxide, bis (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide, and the like, phenyl disulfide, 2-nitrofluorene, butyrin, anisoin ethyl ether, azobisisobutyronitrile, and the like. Among them, acetophenones, alkylphenones, acylphosphine oxides, oxybenzenes, oxime esters and benzoins are preferable, and acetophenones and alkylphenones are more preferable. These photopolymerization initiators may be used alone, or two or more of them may be used in combination. Further, a photopolymerization initiator and a sensitizer may be used in combination.

Examples of the sensitizer include anthracene, phenothiazine, perylene, thioxanthone, and benzophenone thioxanthone.

The active energy ray for curing the active energy ray-curable inkjet ink composition of the present invention is not particularly limited as long as it is a ray that can impart necessary energy to the polymerizable component (for example, a (meth) acrylate monomer) in the composition in terms of the polymerization reaction of the polymerizable component (for example, a (meth) acrylate monomer) by ultraviolet rays, electron beams, α rays, β rays, γ rays, X rays, and the like. In particular, when a high-energy light source is used, the polymerization reaction can be allowed to proceed without using a polymerization initiator. In addition, in the case of ultraviolet irradiation, there is a strong demand for mercury-free from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light emitting device is very useful in both industrial and environmental aspects. Further, an ultraviolet light emitting diode (UV-LED) and an ultraviolet laser diode (UV-LD) are small, long in life, high in efficiency, and low in cost, and are preferable as an ultraviolet light source.

The active energy ray-curable inkjet ink composition of the present invention may contain various additives, for example, stabilizers (for example, polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, and methyl hydroquinone); colorants such as pigments (e.g., cyanine blue (cyanine), disazo yellow, Carmine 6b (Carmine 6b), lake red c (lake red c), carbon black, and titanium white), fillers, and viscosity modifiers.

Preparation of active energy ray-curable inkjet ink composition

The active energy ray-curable inkjet ink composition of the present invention can be produced using the above-mentioned various components, and the production method and conditions thereof are not particularly limited, and for example, the composition can be produced by charging a pigment, a dispersant and the like into a dispersing machine such as a ball Mill, a KT Mill (KT Mill), a disc Mill (disc Mill), a pin Mill (pin Mill), DYNO-Mill and the like, dispersing the mixture in a dispersing machine to prepare a pigment dispersion, and further mixing a (meth) acrylate monomer, a polymerization initiator, a polymerization inhibitor, a surfactant and the like with the pigment dispersion.

The viscosity of the active energy ray-curable inkjet ink composition of the present invention may be appropriately adjusted depending on the application and application, and is not particularly limited, and for example, when an ejection unit for ejecting the composition from a nozzle is used, the viscosity at 25 ℃ is preferably 1mPa · s or more and 20mPa · s or less, and is preferably 5mPa · s or more and 15mPa · s or less, as the viscosity in the range of 20 to 65 ℃. In addition, the viscosity may be adjusted to the viscosity range by adding an organic solvent or the like. The viscosity can be measured by using a MARSIII rheometer manufactured by Thermo Scientific, at a rotation speed of 10rpm, and by appropriately setting the temperature of the constant temperature circulating water in the range of 20 to 65 ℃.

Use of

The application of the active energy ray-curable inkjet ink composition of the present invention is not particularly limited as long as it is a field in which an active energy ray-curable material is generally used, and can be appropriately selected according to the purpose, and examples thereof include molding resins, coating materials, adhesives, insulating materials, release agents, coating materials, sealing materials, various resists, and various optical materials.

The active energy ray-curable inkjet ink composition of the present invention can be used not only as an ink for forming two-dimensional characters, images, and design coating films for various substrates, but also as a stereolithographic material for forming three-dimensional stereolithographic images (stereolithographic objects).

The stereolithography apparatus for stereolithography using the active energy ray-curable inkjet ink composition of the present invention may be any known apparatus, and is not particularly limited, and examples thereof include a storage unit, a supply unit, a discharge unit, and an active energy ray irradiation unit, each including the composition.

The present invention also includes a molded article obtained by processing a cured product obtained by curing an active energy ray-curable inkjet ink composition or a structure in which the cured product is formed on a substrate. The molded article is, for example, an article obtained by subjecting a cured product or a structure formed into a sheet or film to a molding process such as a hot drawing process or a press process, and is suitably used in applications requiring a post-surface-decoration molding, for example, a panel of an instrument or an operation portion such as an automobile, OA equipment, electric and electronic equipment, and a camera.

The substrate is not particularly limited and may be appropriately selected according to the purpose, and examples thereof include paper, yarn, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, and a composite material thereof, and a plastic substrate (for example, polypropylene (PP), Polyethylene (PE), Polycarbonate (PC), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and the like) is preferable from the viewpoint of processability.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples at all.

Hereinafter, materials used in examples and comparative examples described below will be described.

Polyester resin

Polyester resins were synthesized in polymerization examples described below using the materials shown below.

Tetrahydrophthalic anhydride (hereinafter referred to as THPA, RIKACIDTH manufactured by Nippon chemical Co., Ltd.)

Hydrogenated bisphenol A (hereinafter referred to as HBPA, manufactured by TCI)

1, 3-butanediol (hereinafter referred to as BG, manufactured by Wako pure chemical industries)

Polymerization example 1: synthesis of polyester resin 1

A500 ml cylindrical round-bottom flask was charged with 154g of THPA and heated to 100 ℃ to melt it. The temperature was raised to 150 ℃ and 192g of HBPA powder was put in four times while rotating at 100rpm under nitrogen at 200 ml/min. After visual inspection of the powder dissolution, the heater temperature was raised to 200 ℃, rotation at 150rpm was waited for water distillation, and after confirming that there was liquid dripping, sampling was performed every 30 minutes to measure the number average molecular weight and acid value, and at the same time, 20g in total of THPA was added to the reaction solution to stop the reaction when the target number average molecular weight and acid value were reached, and 301g of polyester resin 1 having a number average molecular weight 1280, an acid value 140, and 100 mol% of HBPA in polyol was obtained. The obtained polyester resin 1 was used in examples 1 and 6 to 8.

Polymerization example 2: synthesis of polyester resin 2

THPA92g was placed in a 500ml cylindrical round bottom flask and heated to 100 ℃ to melt. The temperature was raised to 150 ℃ and 120g of HBPA powder was put in four times while rotating at 100rpm under nitrogen at 200 ml/min. After visual inspection of the powder dissolution, the heater temperature was raised to 200 ℃, rotation at 150rpm was waited for water distillation, and after liquid dripping was confirmed, the number average molecular weight and acid value were measured at 30 minutes intervals, and 100g in total of HBPA was added to the mixture to cause reaction, and when the target number average molecular weight and acid value were reached, the reaction was stopped, and 270g of polyester resin 2 having a number average molecular weight of 800, an acid value of 23, and 100 mol% of HBPA in polyol was obtained. The obtained polyester resin 2 was used in example 2.

Polymerization example 3: synthesis of polyester resin 3

In a 500ml cylindrical round bottom flask, 280g of THPA was placed and heated to 100 ℃ to melt it. The temperature was raised to 150 ℃ and BG 80g was charged while rotating at 100rpm under nitrogen at 200 ml/min. After the dissolution was visually confirmed, the heater temperature was raised to 200 ℃ and distillation of water was waited while rotating at 150rpm, and after the liquid was confirmed to drip, a total of 70g of HBPA was added to the mixture to measure the number average molecular weight and the acid value at 30 minutes, and the reaction was stopped when the target number average molecular weight and acid value were reached, thereby obtaining 260g of polyester resin 3 having a number average molecular weight of 1020, an acid value of 130, and an HBPA content of 25 mol% in the polyol. The obtained polyester resin 3 was used in example 3.

Polymerization example 4: synthesis of polyester resin 4

150g of THPA was placed in a 500ml cylindrical round bottom flask and heated to 100 ℃ to melt it. The temperature was raised to 150 ℃ and BG 70g was charged while rotating at 100rpm under nitrogen at 200 ml/min. After the dissolution was visually confirmed, the heater temperature was raised to 200 ℃ and distillation of water was waited while rotating at 150rpm, and after the liquid was confirmed to drip, 90g in total of HBPA was added to the mixture to measure the number average molecular weight and acid value at 30 minutes intervals, and the reaction was stopped when the target number average molecular weight and acid value were reached, thereby obtaining 202g of polyester resin 4 having a number average molecular weight of 1250, an acid value of 32, and an HBPA content of 20 mol% in polyol. The obtained polyester resin 4 was used in example 4.

Polymerization example 5: synthesis of polyester resin 5

In a 500ml cylindrical round-bottom flask, 230g of THPA was charged and heated to 100 ℃ to be melted. The temperature was raised to 150 ℃ and BG 135g was charged while rotating at 100rpm under nitrogen at 200 ml/min. After the dissolution was visually confirmed, the heater temperature was raised to 200 ℃ and distillation of water was waited while rotating at 150rpm, and after the liquid was confirmed to drip, a total of 70g of HBPA was added to the mixture to measure the number average molecular weight and the acid value at 30 minutes, and the reaction was stopped when the target number average molecular weight and acid value were reached, thereby obtaining 254g of polyester resin 5 having number average molecular weight 1050, acid value 34, and 16 mol% of HBPA in polyol. The obtained polyester resin 5 was used in comparative example 2.

Preparation of polyester resin 6

50g of each of the polyester resin 1 and the polyester resin 2 obtained above was weighed and mixed to prepare a polyester resin 6. The obtained polyester resin 6 was used in example 5.

In the comparative example, ELITEL UE3350 (comparative polyester resin) manufactured by Unico, Youngco was used.

The physical property values of the respective synthetic polyester resins were measured by the following methods.

(1) GPC measurement conditions

The weight average molecular weight and the number average molecular weight were determined by GPC using a standard polystyrene calibration curve under the following conditions. The results are shown in tables 1 and 3.

The device comprises the following steps: prominence-i, LC-2030 made by Shimadzu corporation

Column: shodex LF-804X 2, protective column

Mobile phase: THF (tetrahydrofuran)

Flow rate: 1.0ml/min

Sample loading 50. mu.l

Column temperature 40 deg.C

(2) Measurement of acid value

1.5g of each of the synthesized polyester resins was weighed into an Erlenmeyer flask, and about 10ml of a solvent (toluene/methanol: 7/3 (volume ratio)) was added and dissolved. Then, 3 drops of an indicator (1% phenolphthalein/ethanol solution) was added, and titration was performed with a 0.1N potassium hydroxide aqueous solution, and the acid value was calculated by the following equation with the time point when the liquid color changed from white to peach color as an end point. The results are shown in tables 1 and 3.

Acid value (mgKOH/g) ═ A × F/S

F: coefficient of 0.1N potassium hydroxide aqueous solution (f × 5.61), f ═ 1

V: titration amount (ml) of 0.1N aqueous solution of potassium hydroxide

W: sample weight (g)

In the evaluation of the active energy ray-curable inkjet ink composition, a mixture of 90 parts by weight of dipropylene glycol diacrylate as a (meth) acrylate monomer and 10 parts by weight of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by igmesens b.v.) as a photopolymerization initiator was prepared, and a varnish composition in which 10 parts by weight of polyester resin 1 to 6 was dissolved was prepared and used for the evaluation. The dissolution is as follows: all are put into a vessel with a mixture disperser and stirred while being heated at 40 ℃ until the mixture becomes transparent by visual inspection.

The physical properties of the varnish composition were measured by the following methods.

(1) Viscosity of the oil

The viscosity of the varnish composition at 25 ℃ was measured using a MARSIII rheometer manufactured by Thermo Scientific. The cone angle was set at 2 °, and the viscosity was read at 10 rpm. The results are shown in tables 2 and 4.

(2) Tape peeling test

A6. + -.1 μm coating film was formed on a polypropylene substrate (P2161 manufactured by Toyobo Co., Ltd., biaxially stretched polypropylene, subjected to corona treatment) by using a bar coater, and passed through a metal halide light source at 200mJ/cm²The UV curable coating film is produced by the irradiation of (2). A scotch tape manufactured by miko corporation was attached thereto, and peeled off with a finger by scraping and tearing, and the state at this time was evaluated in the following five stages. The results are shown in tables 2 and 4.

5: quick peel without peeling;

4: quick peel without adhering to 50% peel tape, but with substrate peel;

3: the film is peeled off completely by quick peeling, and is not peeled off when being peeled off slowly;

2: slowly tearing and peeling 50%;

1: slowly peeled off and completely peeled off.

(3) Cut adhesion resistance test

A6. + -.1 μm coating film was formed on a polypropylene substrate (P2161 manufactured by Toyo Boseki Co., Ltd., biaxially stretched polypropylene, corona-treated) by using a bar coater, and passed through a metal halide light source at 200mJ/cm²The UV curable coating film is produced by the irradiation of (2). The coating film was cut into lattice-shaped cuts by a crosscutter according to ASTM D3359, a scotch tape manufactured by miko corporation was attached thereto, and peeled off after being rubbed with a finger, and the number of squares remaining in the substrate in 25 squares was counted. The results are shown in tables 2 and 4.

[ Table 1]

	Comparative example 1	Example 1	Example 2	Example 3	Example 4	Comparative example 2	Example 5
								Comparative polyester resin	10
Polyester resin 1		10
								Polyester resin 2			10
Polyester resin 3				10
								Polyester resin 4					10
Polyester resin 5						10
								Polyester resin 6							10
Dipropylene glycol diacrylate	90	90	90	90	90	90	90
								Irgacure 184	10	10	10	10	10	10	10
Number average molecular weight (Mn)	5,000	1,280	850	1,020	1,250	1,050	1,010
								Acid value	1	140	23	130	32	34	86
HBPA (mol%) in polyol	0	100	100	25	20	16	100

[ Table 2]

Comparative example 1 used a commercially available polyester resin, and thus had a viscosity of 35 mPas @25 ℃ which was not suitable for a high viscosity as an inkjet ink. The reason for this is considered to be that the molecular weight of the resin is too high.

According to examples 1 and 2, when the acid value of the resin containing 100 mol% of HBPA in the polyol is 20 to 140, high adhesion to the polypropylene substrate can be obtained while maintaining a low viscosity (15 mPas).

According to examples 1 and 3, if the mole% of HBPA in the structural unit derived from a polyol in the high acid value polyester resin is in the range of 25 to 100, high adhesion to a polypropylene base material can be obtained while maintaining low viscosity.

According to examples 2 and 4, if the mole% of HBPA in the polyol-derived structural unit in the low acid value polyester resin is in the range of 20 to 100, high adhesion to the polypropylene substrate can be obtained while maintaining low viscosity.

According to comparative example 2, if the HBPA in the polyol-derived structural unit in the polyester resin is 16 mol%, the viscosity is maintained low, but adhesion to the polypropylene substrate cannot be obtained.

According to example 5, the same result can be obtained even when both of the polyester resin 1 and the polyester resin 2 are mixed.

[ Table 3]