JP2006307203A - Ink composition for inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition for inkjet printers having stable dispersion stability and good ejecting property as ink for an inkjet printer, and exhibiting sufficient weatherability/durability in the case of using for forming a pattern on a siding panel of an outer wall and provide a siding panel for an outer wall printed with a pattern having high weatherability and durability and good design. <P>SOLUTION: The suitable ink composition for inkjet printers comprises a pigment, a film-forming resin comprising an acrylic copolymer containing an imide(meth)acrylate having a specific cyclic imide group as a monomer unit, and an organic solvent. A siding panel for an outer wall having good design, high durability and high weatherability can be produced by successively forming a base coating layer, a jet-ink coating layer produced by using the ink composition for inkjet printers, and a surface-protection layer on a siding substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an ink for a jet printer that is suitable for forming a design with improved design properties on an outer wall siding material using an ink jet system.
Furthermore, it is related with the manufacturing method of the siding for outer walls which forms a pattern using an ink jet system, and the siding for outer walls manufactured by this manufacturing method.

Conventionally, a method using gravure printing or roll coating is generally used to impart a pattern to a siding material for an outer wall (see Patent Document 1 and Patent Document 2). However, gravure printing uses an expensive plate, so the pattern cannot be changed easily, and it is difficult to change or modify it. Also, gravure printing and roll coating can only print on a flat surface, and it is difficult to express a three-dimensional pattern.
For this reason, printing using an ink jet system has been proposed (see Patent Document 3). When printing using the ink jet method, the design can be easily changed on demand, and even if there are irregularities on the printing surface, it can be printed, so that a design with a three-dimensional effect can be provided.
However, the properties required for jet ink used for siding for outer walls are not only the properties required for ordinary jet ink, but also high weather resistance that will not fade even when exposed to sunlight, Physical strength such as adhesion to an undercoat layer and a clear layer to be overcoated for protecting the printed portion is required.

Conventionally, as a jet printer ink capable of forming an image on a non-absorbable recording material such as a siding material, an ink in which a colorant is dissolved or dispersed in a mixed solution of a resin and a solvent is used.
Colorants include dye-based and pigment-based colorants. In general, dye-based colorants are excellent in dispersibility and color developability, but are easy to fade, so that in terms of fading and weather resistance, pigment-based colorants. Colorants are preferred. For this reason, for exterior siding, a pigment-based colorant (pigment) having good stability and good light resistance is generally used although it is difficult to disperse.
In general, as a film forming resin component of an ink composition for a jet printer, polyester resin, vinyl chloride / vinyl acetate copolymer resin, ethylene / vinyl acetate copolymer tree, polyurethane resin, acrylic resin, styrene / acrylic resin, Various resins such as polyvinyl butyral resin, rosin-modified maleic resin, nitrocellulose, and phenol resin are used alone or in combination.
However, in conventional ink compositions for jet printers using these pigments and resins, when the wall material on which the pattern is formed is used as an outer wall material, the weather resistance and durability of the drawn pattern are inferior. It was. For this reason, it was insufficient for using the conventional ink composition as an application to the outer wall.
In this way, the pigment in the ink is sufficiently finely divided and stably dispersed to such an extent that ink jet recording is possible, and when the pattern for the outer wall is formed with this ink, the pattern has excellent weather resistance. Ink compositions for jet printers that have properties and durability have not yet been put to practical use.
Japanese Patent Laid-Open No. 2001-121078 JP 2003-001749 A JP-A-10-278497

The problem to be solved by the present invention is that it has stable dispersion stability as an ink for a jet printer, and good dischargeability, and has sufficient weather resistance when used for forming a picture of an outer wall siding material. The object is to provide a durable ink composition for a jet printer.
Further, the problem to be solved by the present invention is that the decorative pattern can be easily formed even on the uneven siding surface, and the outer wall siding having excellent light resistance and durability can be manufactured. Is to provide a method.
Furthermore, the problem to be solved by the present invention is to provide a siding for an outer wall manufactured by the above manufacturing method, having a decorative pattern formed on the surface, and having excellent light resistance and durability.

  In order to solve the above-mentioned problems, the present inventors have obtained a coating film to obtain an ink that has characteristics as an ink jet recording ink and that can be used in outer wall applications that require light resistance and durability. The formation resin, colorant, dispersant, solvent, etc. were selected and earnestly studied. As a result, an ink for an ink jet containing an acrylic copolymer containing a imide (meth) acrylate having a specific cyclic imide group as a monomer unit as a film-forming resin and a pigment-based colorant as a colorant is an ink. When used as an outer wall as a siding material that has characteristics as a jet recording ink and has a pattern formed using the ink, the pattern drawn with the ink can provide sufficient light resistance and durability. As a result, they have found the present invention.

  That is, the present invention relates to an ink composition for a jet printer containing a pigment, a film-forming resin, and an organic solvent, wherein the film-forming resin is at least one of compounds represented by the general formula (1) and the general formula (2). An ink composition for a jet printer, characterized in that it is an acrylic copolymer containing as a monomer unit.

（１）
（式中Ｒ_１は水素原子またはメチル基を表し、Ｒ_２は炭素原子数２〜１２の直鎖又は分岐していても良いアルキレン基を表し、Ｒ_３及びＲ_４はそれぞれ独立して水素原子、アルキル基、アルケニル基若しくはアリール基を表しかつＲ_３とＲ_４の炭素数の和が４〜１２であるか、またはＲ_３及びＲ_４は１つとなって５員環を形成する飽和若しくは不飽和の炭化水素基を表す。）

(1)
(Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and R ₃ and R ₄ are each independently a hydrogen atom. , saturated or unsaturated alkyl group, the sum of carbon atoms in an alkenyl group or an aryl group and R ₃ and R ₄ or 4 to 12, or R ₃ and R ₄ form a 5-membered ring is one Represents a saturated hydrocarbon group.)

（２）
｛式中Ｒ_１は水素原子またはメチル基を表し、Ｒ_２は炭素原子数２〜１２の直鎖又は分岐していても良いアルキレン基を表し、Ｘは下記一般式（３）から一般式（９）で表される基からなる群より選ばれる基を表す。｝

(2)
{Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and X represents a general formula (3) from the following general formula (3): 9 represents a group selected from the group consisting of groups represented by }

（式中Ｒ_５、Ｒ_６、Ｒ_７、およびＲ_８は水素原子または炭素数１〜６のアルキル基を表す。）

(In the formula, R ₅ , R ₆ , R ₇ and R ₈ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)

Furthermore, the present invention is a siding for an outer wall in which a base coating layer, a jet ink coating layer, and a surface protective layer are sequentially laminated on a siding substrate, wherein the jet ink coating layer uses the above-described ink composition for a jet printer. The outer wall siding is provided.
Further, the present invention provides an outer wall in which a base coating layer is formed on a siding substrate, a jet ink coating layer is formed at an arbitrary position on the base coating layer by an ink jet method, and then a surface protective layer is formed thereon. A method for producing an outer wall siding, wherein the jet ink coating layer is formed using the above-described ink composition for a jet printer.

The ink composition for jet printers of the present invention contains an acrylic copolymer containing a imide (meth) acrylate having a cyclic imide group as a monomer unit as a film-forming component, and uses a pigment as a colorant. Therefore, it can be easily printed on the outer wall material such as PCM (pre-coated metal) steel plate for the outer wall with uneven surface by the ink jet method, and it is firmly bonded to the outer wall material or the base coating layer formed on the outer wall material. Can provide a siding material with sufficient durability and weather resistance.
According to the method for producing an outer wall siding of the present invention, a base coating layer is preferably formed on the entire surface of a siding substrate, and the ink composition for a jet printer having the above composition is used at an arbitrary position on the base coating layer. A jet ink coating layer is formed, and then a surface protective layer is preferably formed on the entire surface. Accordingly, it is possible to manufacture a highly designed outer wall siding that is excellent in durability and light resistance and has a fine pattern formed thereon.

The ink for a jet printer of the present invention can be produced from a pigment dispersion containing a film-forming resin, a pigment, and an organic solvent.
The film-forming resin used in the present invention is an acrylic copolymer obtained by copolymerizing an imide (meth) acrylate having a specific cyclic imide group and, if necessary, other monomers.
Examples of the imide (meth) acrylate having a cyclic imide group as the monomer unit contained in the acrylic copolymer include compounds represented by the general formula (1) and the general formula (2).

（１）
（式中Ｒ_１は水素原子またはメチル基を表し、Ｒ_２は炭素原子数２〜１２の直鎖又は分岐していても良いアルキレン基を表し、Ｒ_３およびＲ_４はそれぞれ独立して水素原子、アルキル基、アルケニル基若しくはアリール基を表しかつＲ_３とＲ_４の炭素の和が４〜１２であるか、またはＲ_３及びＲ_４は１つとなって５員環を形成する飽和若しくは不飽和の炭化水素基を表す。）

(1)
(Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and R ₃ and R ₄ are each independently a hydrogen atom. Represents an alkyl group, an alkenyl group or an aryl group, and the sum of carbons of R ₃ and R ₄ is 4 to 12, or R ₃ and R ₄ are combined to form a 5-membered ring. Represents a hydrocarbon group of

（２）
｛式中Ｒ_１は水素原子またはメチル基を表し、Ｒ_２は炭素原子数２〜１２の直鎖又は分岐していても良いアルキレン基を表し、Ｘは一般式（３）から一般式（９）で表される基からなる群より選ばれる基を表す。｝

(2)
{Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and X represents a general formula (9) ) Represents a group selected from the group consisting of groups represented by: }

（式中Ｒ_５、Ｒ_６、Ｒ_７、およびＲ_８は水素原子または炭素数１〜６のアルキル基を表す。）

一般式（１）と一般式（２）とでは一般式（２）で表される化合物の方が好ましい。Ｒ_２の炭素原子は２〜４が好ましい。Ｒ_３およびＲ_４はそれぞれ独立して水素原子、アルキル基、アルケニル基もしくはアリール基を表し、Ｒ_３とＲ_４の炭素数の和は６〜１０であることが好ましい。またＸとしては式（３）で表される基が良好な耐光性を有し好ましい。さらにＲ_５、Ｒ_６、Ｒ_７、およびＲ_８は水素原子及びメチル基が好ましい。
なお本発明の一般式（１）または一般式（２）であらわされる化合物は、単独で用いられてもよく、２種類以上を組み合わせて用いても良い。

(In the formula, R ₅ , R ₆ , R ₇ and R ₈ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)

In general formula (1) and general formula (2), the compound represented by general formula (2) is more preferable. Carbon atoms of R ₂ is 2-4 are preferable. R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group, an alkenyl group or an aryl group, and the sum of the carbon numbers of R ₃ and R ₄ is preferably 6-10. X is preferably a group represented by the formula (3) having good light resistance. R ₅ , R ₆ , R ₇ , and R ₈ are preferably a hydrogen atom and a methyl group.
In addition, the compound represented by General formula (1) or General formula (2) of this invention may be used independently, and may be used in combination of 2 or more types.

  Examples of the imide (meth) acrylate having a cyclic imide group represented by the general formula (2) include hexahydrophthalimide ethyl acrylate (Aronix M-140 manufactured by Toagosei Co., Ltd.), hexahydrophthalimide propylene acrylate, and the like. Tetrahydrophthalimidoalkyl (meth) acrylates such as hydrophthalimidoalkyl (meth) acrylate or tetrahydrophthalimidoethyl acrylate are more preferred, and among them, hexahydrophthalimidoethyl acrylate (Aronix M-140 manufactured by Toagosei Co., Ltd.) is most preferred.

The synthesis method of imide (meth) acrylate is clarified, for example, in the following known literature.
Kiyoshi Kato et al., Organic Synthetic Chemistry Association Journal 30 (10), 897, (1972),
Javier de Abajo et al., Polymer, vol 33 (5), (1992), JP-A 56-53119, JP-A 1-224269, JP-A 2001-172336

  By using an acrylic copolymer having a cyclic imide group as a film constituent of jet ink, the wettability between the pigment and the resin is improved as a characteristic of the ink, so that the dispersion stability of the pigment is improved. Further, the use of the acrylic copolymer improves the adhesion between the ink, the base coating layer used as the base, and the surface protective layer to be overcoated. And a clearing agent to be overcoated.

The other monomer copolymerized with the phthalimide (meth) acrylate having a cyclic imide group is not particularly limited, and any known copolymerizable monomer can be used.
For example, alkyl ester (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylate, ethylhexyl (meth) acrylate, lauryl (meth) acrylate, etc. The alkyl group may be branched or straight chain.
Cycloaliphatic alkyl (meth) acrylates such as isobornyl (meth) acrylate and cyclohexyl (meth) acrylate, substituted aryl (meth) acrylates such as benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl ( Alkoxy (meth) acrylates such as (meth) acrylate, hydroxyalkyl acrylates such as (meth) acrylic acid and 2-hydroxyethyl (meth) acrylate, alkoxysilyl group-containing (meth) acrylates, styrene, acrylonitrile, α-methylstyrene, etc. I can list them. These monomers may be used alone or in combination of two or more.

The mass content of the imide (meth) acrylate monomer unit having the cyclic imide group in the acrylic copolymer used in the present invention can be arbitrarily selected in the present invention. For example, when the content is 10 to 50% by mass, more preferably 15 to 45% by mass, the adhesion between the resin coating film used as the base coating layer and the ink is improved, and the ink And the surface protective layer to be overcoated are preferable in terms of good adhesion. Further, if it is 10% or more, better properties can be obtained in terms of pigment dispersibility and boiling water resistance, which is the durability of printed images in boiling water. In addition, both the adhesiveness including boiling water resistance can be maintained in good balance.
The glass transition point (Tg) of an acrylic copolymer containing an imide (meth) acrylate monomer unit having a cyclic imide group in a mass content of 10% to 50% is arbitrary, but adhesion to the substrate and resistance From the viewpoint of boiling water, Tg is preferably low, and is preferably 40 ° C to -10 ° C.
The content of the acrylic copolymer in the ink composition of the present invention can be selected as necessary. For example, the content is preferably 1 to 30% by mass and more preferably 5 to 20% by mass with respect to the total amount of the ink composition. The molecular weight of the acrylic copolymer can also be preferably selected. For example, the weight average molecular weight is preferably 5,000 to 300,000, and more preferably the weight average molecular weight is 10,000 to 60000. The physical properties of the ink composition of the present application can also be selected as necessary. For example, the viscosity of the ink composition is preferably 2 to 20 mPa · s, and more preferably 6 to 14 mPa · s. The surface tension of the ink composition is preferably 20 to 40 dyn / cm, and more preferably 25 to 35 dyn / cm.

In general, dyes, organic pigments, and inorganic pigments are used as colorants used in jet ink. The pigment used in the present invention can be arbitrarily selected, but the use of an inorganic pigment is preferable because weather resistance and durability are required for jet ink used for the siding material for the outer wall.
Specific examples include carbon black such as farnest black, channel black, thermal black, acetylene black, black iron oxide, yellow iron oxide, red iron oxide, ultramarine blue, soot, titanium oxide (rutile type and anatase type), etc. It is done. It is also possible to use organic pigments such as phthalocyanine blue having high light resistance.
The pigments used in the present invention may be used alone or in combination of two or more. The amount of the pigment used in the present invention can be selected as necessary. Preferably, the inorganic pigment is 10 to 90%, more preferably 15 to 80%, based on the solid content of the ink composition. In the case of organic pigments, 5 to 80% is preferable, and 10 to 60% is more preferable.

  These pigments are anionic, cationic, nonionic dispersants, polymer dispersants, other (amphoteric compounds, fluorine compounds, etc.) dispersants, or any known dispersion depending on the pigment properties. An auxiliary agent can be used to disperse the ink as a jet ink.

The organic solvent in which these dispersions can be dispersed is not particularly limited and can be selected as necessary. For example, alcohol solvents such as ethyl alcohol and isopropyl alcohol, glycol solvents such as ethylene glycol monoethyl ether and propylene glycol monomethyl ether, ethyl acetate, butyl acetate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-butyl acetate Ester solvents such as propylene glycol monomethyl ether acetate, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, isophorone and acetophenone, hydrocarbon solvents such as n hexane, isooctane, n octane, methyl cyclohexane and cyclopentane, toluene, Aromatic solvents such as xylene can be used.
By adjusting the viscosity, surface tension, and drying speed of the jet ink with these solvents alone or in combination of two or more, the solvent composition of the jet ink suitable for the substrate to be printed and the jet ink printer to be used can be designed. .

In order to produce a pigment dispersion from the raw materials, it can be produced, for example, by the following method.
The pigment, the organic solvent, and, if necessary, the dispersing agent are dispersed and mixed using a dispersing machine such as a dispersion stirrer, a ball mill, an attritor, a sand mill, or a bead mill. Next, the pigment is further finely dispersed using an apparatus such as a nanomill to prepare an ink base. An acrylic copolymer obtained by copolymerizing a phthalimide (meth) acrylate having a cyclic imide group and an organic solvent are added to the prepared ink base, and the mixture is mixed with a dispersion stirrer. Thereafter, the viscosity is adjusted with an organic solvent, and the mixture is filtered with a 1 micron filter to obtain an ink composition for a jet printer for an outer wall siding material.

  In addition to the components essential to the present invention, if necessary, for example, to improve concealment, extender pigments such as silica powder, aluminum silicate and calcium carbonate, anti-settling agents for pigments, thickening for viscosity adjustment Additives such as agents can be added.

  In order to manufacture the outer wall siding of the present invention, for example, it can be manufactured by the following method. After a base coating layer is formed on the entire surface of the siding substrate, a jet ink coating layer is formed thereon by the ink jet recording method using the ink composition for a jet printer. Thereafter, a surface protective layer is further formed thereon to manufacture the outer wall siding.

  The substrate for siding may be selected as necessary. For example, ceramic base materials such as cement slate plates and calcium silicate plates, plywood, and wood can be used. Furthermore, metal plates such as aluminum and steel, or these metal plates are embossed, drawn, etc. What gave unevenness, such as a tone, a tile tone, and a grain tone, can be used. In particular, when a metal siding substrate is used, the surface temperature tends to be high in an external environment, and the jet ink coating layer requires particularly high durability and weather resistance. It can be used suitably.

An undercoat layer can also be selected as necessary. For example, a paint composed of a solvent such as urethane resin, polyvinyl alcohol resin, acrylic resin, hydroxymethyl cellulose resin, acrylic resin, and / or polyamide and a solvent is applied to the siding substrate using a device such as a spray or various coaters. It can produce by drying and forming the film by a dry coating film.
As the base material for metal siding, it is possible to use a base material that has been previously coated with various resin coatings as a base coating layer, such as a PCM coating board. In this case, since the base coating layer already exists, the step of providing the base coating layer may be omitted.

The specific PCM coated plate and its substrate that can be used in the present invention can be arbitrarily selected. Examples of usable substrates include steel plates, metal plates such as titanium, copper, magnesium, and aluminum, and those coated with a metal or a nonmetal. Examples of those coated with a metal include a steel plate sprayed with metal on the surface, a steel plate plated with metal, and the like. Further, plating and thermal spraying in which an inorganic substance or an organic substance is dispersed in a metal are included in the above. Among the above-mentioned metal material plates, in particular, zinc, alloys of zinc and other metals, metal material plates covered with zinc / or zinc compounds, or steel plates thermally sprayed or plated with zinc, and further these Steel plate material plate that has been treated to form an inorganic coating such as chromate treatment or zinc phosphate treatment, or metal plates such as aluminum, steel, aluminum 55% alloy galvanium, and 5% alloy galfan. Is preferred. A resin composition containing isophthalic acid type polyester / melamine, vinylidene fluoride / acrylic / melamine / bisphenol A type epoxy containing resin composition, or terephthalic acid type polyester / melamine / bisphenol A type A PCM coated plate obtained by precoating an epoxy-containing resin composition or the like can be used.
In addition, the back side of the PCM painted board is made of phenolic resin, resin foam such as polyurethane resin, or aluminum laminated kraft paper with an inorganic material such as gypsum board to provide soundproofing and heat insulation. You may be comprised with the back surface material.

On the undercoating layer thus formed, a design can be printed using the ink composition for an ink jet printer of the present invention to form a jet ink coating layer.
The clear coating agent for the surface protective layer that can be overcoated on the jet ink coating layer can be arbitrarily selected, for example, a silicon acrylic emulsion system in an aqueous system, an acrylic emulsion system, an acrylic system, an acrylic urethane system as a solvent system, Examples include fluorine-based clear coating agents. These can be coated on the jet ink coating layer using a spray or various coaters.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to only these examples. In the following description of the examples, “part” represents “part by weight”.
<Synthesis example of phthalimide acrylate>
Methyltetrahydrophthalic anhydride compound (3 or 4-methyl-1,2,3,6-tetrahydrophthalic anhydride: manufactured by Shin Nippon Rika Co., Ltd.) in a reaction vessel equipped with a stirrer, a cooling tube, a water separator, and a nitrogen blowing tube 166.2 parts (1 mol) of Ricacid MT-500TZ) and 310 parts of toluene were charged, and 75 parts (1 mol) of n-propanolamine was added dropwise over 30 minutes. Thereafter, the temperature was raised to 90 ° C., gradually raised to 115 to 125 ° C., and the reflux temperature was maintained for 3 to 4 hours. When the acid value becomes 1 or less, the mixture is cooled, 72 parts (1 mole) of acrylic acid, 0.16 part of hydroquinone and 8.5 parts of concentrated sulfuric acid are added, and the temperature is raised again, and 115 to 125 ° C. (reflux temperature) for 4 hours. The dehydration reaction was carried out. After cooling the reaction solution, it was transferred to a separatory funnel and extracted once with 60 g of water and once with 200 g of 20% aqueous NaOH solution. The obtained organic layer was evaporated under reduced pressure to obtain 282 parts of a pale yellow liquid. It was confirmed by ¹ H-NMR and GPC that the following compound <MTIA> (methyltetrahydrophthalimidoethyl acrylate) was obtained.

<Synthesis of acrylic copolymer>
Synthesis of Acrylic Copolymer A A reaction vessel equipped with a stirrer, a condenser, a monomer tank, an initiator tank, a nitrogen blowing tube, a monomer pump, and an initiator pump was previously charged with a solvent (methacetate) in the reaction container according to Table 1. Prepared. The constituent monomers of A in Table 1 were charged into one monomer tank in each part by weight, and the initiator was charged into the initiator tank. The temperature in the reaction vessel was maintained at 95 ° C., and the monomer and initiator were added dropwise over 3 hours. The temperature was raised to 105 ° C. 2 hours after the completion of the dropping, maintained at 105 ° C. for 2 hours, and then further raised to 115 ° C. After reacting at 115 ° C. for 1.5 hours, this was cooled, and NV (nonvolatile content) and viscosity were measured. In the same manner, acrylic copolymers were synthesized in accordance with the formulations shown in Table 1, and copolymer acrylic resins A to E having the properties described in the reaction properties of Table 1 were obtained.

(Table 1)

MMA: Methyl methacrylate
Aronix M140: 2- (1,2-cyclohexanedicarboximide) ethyl acrylate (manufactured by Toagosei Co., Ltd.)
MTIA: methyltetrahydrophthalimidoethyl acrylate nBA: butyl acrylate 2EHA: 2 ethylhexyl acrylate Kayamer PM21: Nippon Kayaku Co., Ltd. ε-caprolactone-modified phosphate acrylate novomer MSD: α-methylstyrene dimer perbutyl I: Nippon Oil ( Co., Ltd. Thermal polymerization initiator Perbutyl O: Nippon Oil & Fats Co., Ltd. Thermal polymerization initiator
Viscosity (Gardner viscosity): 25 ° C Measured with a Gardner bubble viscometer
Appearance: NV by visual observation under room light: Non-volatile content 150 ° C., 30 minutes The weight before and after drying was measured and calculated in a blowing oven.

Example 1
100ED 34.0 parts (Magenta pigment manufactured by Toda Pigment)
Addispar PB-821 10.0 parts (Dispersant manufactured by Ajinomoto Fine Techno Co., Ltd.)
PMA 56.0 parts
(Solvent manufactured by Kyowa Hakko Chemical Co., Propylene Bricol Monomethyl Ether Acetate)
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 13.0 parts Acrylic resin A (including solvent) 35.0 parts PMA 14.5 parts MBA 37.5 parts (Daicel Chemical Industries solvent, methoxybutyl acetate)
As described above, the acrylic resin A and the solvent PMA / MBA were added to the pigment base, stirred with a dispersion stirrer, and then filtered with a 1 micron filter to obtain an ink composition A for a jet printer.
Ink characteristics such as viscosity, surface tension, and average particle diameter of the dispersed pigment of the obtained jet ink A are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 27 mN / m
Volume average particle size (laser diffraction / scattering particle size distribution analyzer); 220 nm

(Example 2)
FASTOGEN BLUE 5430SD 25.8 parts (Blue pigment manufactured by Dainippon Ink & Chemicals, Inc.)
Azisper PB-821 7.7 parts PMA 66.5 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 17.0 parts Acrylic resin B (including solvent) 26.6 parts PMA 6.1 parts MBA 50.3 parts Add acrylic resin B and solvent PMA / MBA to the pigment base and disperse as described above. After stirring with a stirrer, the mixture was filtered with a 1 micron filter to obtain ink composition B for jet printer.
The ink characteristics of the obtained ink composition B for jet printers are as follows.
Viscosity (E-type viscometer); 9.7 mPa · s
Surface tension (Wilhelmy surface tension meter); 27 mN / m
Volume average particle size (laser diffraction / scattering particle size distribution analyzer); 134 nm

(Example 3)
Mitsubishi Carbon Black # 960 16.7 parts (Carbon Black manufactured by Mitsubishi Chemical Corporation)
Addispar PB-821 10.0 parts PMA 73.3 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 26.3 parts Acrylic resin C (including solvent) 22.6 parts PMA 5.0 parts MBA 46.1 parts As described above, acrylic resin C and solvent PMA / MBA are added to the pigment base and dispersed. After stirring with a stirrer, the mixture was filtered with a 1 micron filter to obtain ink composition C for jet printer.
The ink characteristics of the obtained ink composition C for jet printer are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 28 mN / m
Volume average particle size (laser diffraction scattering type particle size distribution analyzer); 100 nm

Example 4
TSY-1 37.0 parts
(Yellow pigment manufactured by Toda Pigment)
Solsperse 37500 10.9 parts
(Dispersant manufactured by Lubrizol)
PMA 52.1 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 11.9 parts Acrylic resin D (including solvent) 34.7 parts PMA 12.9 parts MBA 40.5 parts Addition of acrylic resin D and solvent PMA / MBA to the pigment base as described above, dispersion stirrer After stirring, the mixture was filtered through a 1 micron filter to obtain an ink composition D for a jet printer.
The ink characteristics of the obtained ink composition D are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 27 mN / m
Volume average particle size (laser diffraction / scattering particle size distribution analyzer); 270 nm

(Comparative Example 1)
FASTOGEN BLUE 5430SD 25.8 parts Azisper PB-821 7.7 parts PMA 66.5 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 17.0 parts Acrylic resin E (including solvent) 26.1 parts PMA 6.1 parts MBA 50.8 parts Add acrylic resin A and solvent PMA / MBA to the pigment base, and after stirring with a dispersion stirrer, Filtration through a 1 micron filter gave an ink composition E for a jet printer.
The ink characteristics of the obtained ink composition E for jet printers are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 27 mN / m
Volume average particle size (laser diffraction scattering type particle size distribution analyzer); 135 nm

(Comparative Example 2)
100ED 34.0 parts Azisper PB-821 10.0 parts PMA 56.0 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 13.0 parts Acrylic resin F (including solvent) 36.0 parts PMA 14.5 parts MBA 36.5 parts Add acrylic resin F and solvent PMA / MBA to the pigment base, and stir with a dispersion stirrer. Filtration through a 1 micron filter gave an ink composition F for a jet printer.
Ink characteristics of the obtained ink composition F for jet printers are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 27 mN / m
Volume average particle size (laser diffraction / scattering particle size distribution analyzer); 230 nm

(Comparative Example 3)
FASTOGEN BLUE 5430SD 25.8 parts Azisper PB-821 7.7 parts PMA 66.5 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 17.0 parts Acrylic resin G (including solvent) 27.0 parts PMA 6.1 parts MBA 49.9 parts (Daicel Chemical Industries solvent, methoxybutyl acetate)
The acrylic resin G and the solvent PMA / MBA were added to the pigment base, stirred with a dispersion stirrer, and then filtered with a 1 micron filter to obtain an ink composition G for a jet printer.
The ink properties of the obtained ink composition G are as follows.
Viscosity (E-type viscometer); 10 mPa · s
Surface tension (Wilhelmy surface tension meter); 28 mN / m
Volume average particle size (laser diffraction / scattering particle size distribution analyzer); 140 nm

(Comparative Example 4)
Mitsubishi Carbon Black # 960 16.7 parts Ajisper PB-821 10.0 parts PMA 73.3 parts
The above compound was uniformly dispersed with a dispersion stirrer in advance, and then finely dispersed using a nanomill to prepare a pigment base.

Pigment base 26.3 parts Acrylic resin H (including solvent) 23.0 parts PMA 5.0 parts MBA 45.7 parts Add acrylic resin H and solvent PMA / MBA to the pigment base, and stir with a dispersion stirrer. Filtration through a 1 micron filter gave an ink composition H for a jet printer.
The ink properties of the obtained ink composition H are as follows.
Viscosity (E-type viscometer); 9.8 mPa · s
Surface tension (Wilhelmy surface tension meter); 28 mN / m
Average particle diameter (laser diffraction / scattering particle size distribution analyzer); 105 nm
The composition and characteristics of the inks produced in Examples 1 to 4 and Comparative Examples 1 to 4 are summarized in a list.

(Weather and durability evaluation)
Ink compositions A, B, C, and D for jet printers manufactured according to Examples 1 to 4 manufactured using an acrylic resin containing an imide (meth) acrylate having a cyclic imide group (Aronix M140) 1-4), an ink composition for jet printer E (Comparative Example 1) prepared without using an imide (meth) acrylate having a cyclic imide group, and an ink composition for jet printer prepared using a commercially available acrylic resin The following weather resistance / durability evaluation was performed using 8 points of the ink composition H for jet printer (Comparative Example 4) prepared using F, G (Comparative Examples 2 and 3) and vinyl acetate resin. It was.
The above composition is printed on a PCM steel plate (manufactured by Nippon Fine Coating Co., Ltd.), and a surface protective layer is further formed by a clear paint ("Geotech ES-T matte clear", Dainippon Ink & Chemicals, Inc. silicon acrylic emulsion paint). Was made. Then, in order to evaluate whether it can be used for an exterior wall use, the cross-cut adhesion test on a coated steel plate, a coin scratch test, pencil strength, and a boiling water test (80 degreeC 1 hour, 5 hours) were implemented.

<Cross-cut adhesion test>
A cross-cut density test was performed in accordance with JIS K5600-5-6.
Evaluation Cross-cut adhesion 80/100 or higher is acceptable and no problem.
<Coin scratch test>
; Scratch with old 500 yen coin ball (without jagged). Press it from the front and pull it from the other side.
Evaluation 5. ... No change in coating surface
4). ... Slight changes on the coating surface
3. ... Scratches on the coating but no peeling
2. ... Scratches on the coating film and slight peeling occurs. ... Based on the evaluation criteria above that the undercoat can be peeled off and the substrate can be seen, how to scratch was evaluated in 5 to 5 stages.
Three or more were considered acceptable in practical use and were accepted.
<Pencil hardness>
A pencil hardness test was conducted by a method according to JIS K5600-5-4.
Evaluation H or higher was considered acceptable because it is considered to be practically sufficient hardness.

<Boiling water test>
A Galfan steel plate manufactured by Nippon Fine Coating Co., Ltd. was used as a sample steel plate. The ink compositions A to H for jet printers corresponding to Examples 1 to 4 and Comparative Examples 1 to 4 were applied on this steel plate, and further, Geotech ES-TC (aqueous silicone) manufactured by Dainippon Ink & Chemicals, Inc. Acrylic emulsion) clear was overcoated to prepare a test steel plate.
These test steel plates were basically left in hot water at 80 degrees according to JIS K5400-8-20, and the following characteristics were measured after 1 hour and after 5 hours.
Evaluation 1. Appearance: 5 Good (No change compared before and after test) →
1 failure: Appearance abnormalities such as bleister (coating on the surface of the coating film) were evaluated according to the evaluation sample of JISK5600-8-2 in 5 to 5 stages.
Since the appearance abnormality of the surface occurs, other than 5 is rejected.
2. GR%: Gloss change rate, Gloss value before test is set to 100, and gloss reduction rate after test is evaluated. 80% or more pass and there is no problem.
3. Cross-cut adhesion: 80/100 or higher is acceptable and no problem.
The evaluation results are shown in Table 3, Table 4, and Table 5 below.

  A jet ink using an acrylic resin containing an imide acrylate having a cyclic imide group was superior in adhesion and boiling water resistance compared to other products.

As in the boiling water resistance test, the ink compositions A, B, C, and D for jet inks corresponding to Examples 1 to 4 were used, applied to a PCM steel plate, and further a sample that was overcoated with a clearing agent was used. The weather resistance was evaluated using a super UV weather resistance tester. The results are shown in Table 5.
Equipment: Iwasaki Electric Eye Super UV Tester Evaluation; Appearance: No blisters passed (no abnormalities)
GR%: Passed 80% or more.

(Table 5)

  The accelerated test with Super UV is said to have 50 hours roughly equivalent to 1 year of outdoor exposure and 500 hours to 10 years. Therefore, when samples A, B, C, and D corresponding to Examples 1 to 4 are used outdoors as siding materials, it is estimated that almost no change in appearance is observed for about 10 years.

Ink composition for jet printers that has stable dispersion stability and good ejection properties as ink for jet printers, and has sufficient weather resistance and durability when used to form patterns on siding materials for outer walls And a siding for an outer wall having a highly-designed pattern which is rich in weather resistance and durability.

Claims (9)

In the ink composition for a jet printer containing a pigment, a film-forming resin, and an organic solvent, the film-forming resin contains at least one of the compounds represented by the general formula (1) and the general formula (2) as a monomer unit. An ink composition for a jet printer, which is an acrylic copolymer.

(1)
(Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and R ₃ and R ₄ are each independently a hydrogen atom. Represents an alkyl group, an alkenyl group or an aryl group, and the sum of R ₃ + R ₄ has 4 to 12 carbon atoms, or R _{3 and} R ₄ are combined to form a 5-membered ring, a saturated or unsaturated hydrocarbon Represents a group.)

(2)
{Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a linear or branched alkylene group having 2 to 12 carbon atoms, and X represents a general formula (9) ) Represents a group selected from the group consisting of groups represented by: }

(In the formula, R ₅ , R ₆ , R ₇ and R ₈ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)   The total amount of the compound represented by the said General formula (1) and the compound represented by the said General formula (2) is 10-50 mass% of all the monomer units of the said acrylic copolymer. Ink composition for jet printer.   The ink composition for a jet printer according to claim 1 or 2, wherein the ink composition for a jet printer is used for pattern printing of a siding for an outer wall.   2. A siding for an outer wall in which a base coating layer, a jet ink coating layer, and a surface protective layer are sequentially laminated on a siding substrate, wherein the jet ink coating layer uses the ink composition for a jet printer according to claim 1. External wall siding that is formed by   Manufacture of siding for outer walls in which a base coating layer is formed on the entire surface of a siding substrate, a jet ink coating layer is formed at an arbitrary position on the base coating layer by an ink jet method, and then a surface protective layer is formed on the entire surface. It is a method, Comprising: The said jet ink coating layer is formed using the ink composition for jet printers of Claim 1, The manufacturing method of the siding for outer walls characterized by the above-mentioned.   2. The jet printer according to claim 1, wherein the acrylic copolymer contains only the compound represented by the general formula (2) among the two compounds represented by the general formula (1) and the general formula (2). Ink composition. The ink composition for jet printers of Claim 6 whose X of the compound of General formula (2) is group represented by Formula (3). The ink composition for jet printers according to claim 7, wherein R ₅ , R ₆ , R ₇ , and R ₈ are a hydrogen atom and a methyl group. The ink composition for a jet printer according to claim 1, for forming the jet ink coating layer in an outer wall siding in which a base coating layer, a jet ink coating layer, and a surface protective layer are sequentially laminated on a siding substrate. Uses of things.