JP2019131716A - Resin composition for non-water-based printing ink - Google Patents

Abstract

To provide a non-water-based printing ink composition good in adhesiveness to a substrate consisting of a polyolefin resin or a polyester resin without using a compound containing a chlorine atom.SOLUTION: There is provided a non-water-based printing ink composition containing a (meth)acrylic copolymer (A) containing a constitutional unit formed by at least one (meth)acrylic ester monomer (a) and having number average molecular weight (Mn) of 500 to 6000 and solubility parameter of 19.60 (J/cm)or more, a (meth)acrylic polymer (B) having number average molecular weight (Mn) of more than 6000 and 2000000 or less, and glass transition temperature (Tg) of 30°C to 90°C, and a solvent with boiling point of 130°C or lower.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition for non-aqueous printing ink.

Polyolefin resins or polyester resins, which are polymers of olefin monomers, have excellent mechanical properties and chemical resistance, and are easy to mold at low cost. ing. Furthermore, since these resins are also excellent in recyclability, their uses are further expanding against the background of recent global environmental problems.
However, it is known that adhesion to the surface of a polyolefin resin molding or a polyester resin molding is difficult. Therefore, when printing on the surface of a polyolefin-based substrate or polyester-based substrate, there is a method of adhering to the substrate surface using a chlorinated polyolefin having a strong adhesion to these resins as an additive for printing ink. Are known. For example, a paint resin composition having a mass ratio of chlorinated polyolefin and acrylic copolymer of 10:90 to 90:10 is disclosed as a paint having good adhesion to a polyolefin resin (for example, a patent) Reference 1).
However, the use of chlorine-containing compounds tends to be avoided due to the recent interest in environmental problems. Therefore, in recent years, a demand for a resin composition for coating composed of a compound not containing chlorine is rapidly increasing.
In Patent Document 2, as a non-chlorine compound, a method of adhering a coating primer made of acrylic resin to a polyolefin resin substrate is proposed, but there is a problem that sufficient adhesion to the substrate cannot be obtained. It was.

Japanese Examined Patent Publication No. 63-24628 JP-A-2005-97435

  The objective of this invention is providing the non-aqueous printing ink composition with favorable adhesiveness with respect to the base material which consists of polyolefin resin or polyester resin, without using the compound containing a chlorine atom.

The above problems are solved by the following non-aqueous printing ink composition.
[1] It contains a structural unit formed from at least one (meth) acrylic acid ester monomer (a), has a number average molecular weight (Mn) of 500 or more and 6000 or less, and a solubility parameter of 19.60 (J / cm ³ ) The (meth) acrylic copolymer (A) which is ^½ or more, the number average molecular weight (Mn) is larger than 6000 and 2,000,000 or less, and the glass transition temperature (Tg) is 30 ° C. or more and 90 ° C. or less ( A non-aqueous printing ink composition comprising a (meth) acrylic polymer (B) and a solvent having a boiling point of 130 ° C. or lower.
[2] The resin composition for non-aqueous printing ink according to [1], wherein the mass ratio of the (meth) acrylic polymer (A) to the (meth) acrylic polymer (B) is 10/90 to 90/10. .
[3] A non-aqueous printing ink composition, wherein the non-aqueous printing ink composition according to [1] or [2] is for at least one substrate selected from the group consisting of polyolefin resins and polyester resins.
[4] The non-aqueous printing ink composition according to any one of [1] to [3], wherein the acrylic polymer (A) has a structure of the formula (1).

(Q in the formula (1) represents a main chain portion containing a structural unit derived from the (meth) acrylate monomer (a). R in the formula (1) is a branched chain having 1 to 20 carbon atoms. , A linear or cyclic alkyl group, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 5 to 18 carbon atoms, Z is a terminal group derived from a hydrogen atom or a radical polymerization initiator. )

  The non-aqueous printing ink composition of the present invention exhibits high adhesion to a substrate mainly composed of a polyolefin resin or a polyester resin. In addition, it is environmentally friendly because it does not contain chlorine.

  Hereinafter, the present invention will be described in detail. In the present invention, (meth) acrylic acid ester means acrylic acid ester or methacrylic acid ester.

[Non-aqueous printing ink composition]
The non-aqueous printing ink composition of the present invention (hereinafter also referred to as an ink composition) includes a structural unit formed from at least one (meth) acrylic acid ester monomer (a), and has a number average molecular weight (Mn). ) Is 500 or more and 6000 or less and the solubility parameter is 19.60 (J / cm ³ ) ^1/2 or more, and the number average molecular weight (Mn) is larger than 6000 and 2000000. And a (meth) acrylic polymer (B) having a glass transition temperature (Tg) of 30 ° C. or higher and 90 ° C. or lower and a solvent having a boiling point of 130 ° C. or lower.

[(Meth) acrylic copolymer (A)]
The (meth) acrylic copolymer (A) includes a structural unit formed from at least one (meth) acrylic acid ester monomer (a), and has a number average molecular weight (Mn) of 500 or more and 6000 or less. The solubility parameter is 19.60 (J / cm ³ ) ^1/2 or more.

  Specific examples of the (meth) acrylic acid ester monomer (a) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and n-butyl. (Meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, i-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl ( Linear or branched carbonization such as (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, etc. Alkyl (meth) a having a hydrogen skeleton Lilate: Fatty cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, dicyclopentanyl (meth) acrylate, etc. Alkyl (meth) acrylate having a cyclic skeleton; glycidyl group-containing (meth) acrylic esters such as glycidyl (meth) acrylate and hydroxybutyl (meth) acrylate glycidyl ether; phenoxy (meth) acrylate, benzyl (meth) acrylate, Phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenol EO adduct (meth) acrylate, o-bif Aromatic ring-containing (meth) acrylates such as nyloxyethyl (meth) acrylate; (meth) acrylates such as ammonium (meth) acrylate, sodium (meth) acrylate, potassium (meth) acrylate; Cyclic ether-containing (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate; amino group-containing (meth) acrylates such as N-dimethylaminoethyl (meth) acrylate and N-diethylaminoethyl (meth) acrylate; (meth) acrylamide, (Meth) acrylamide diacetone acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, (meth) acryloyl (Meth) acrylamide derivatives such as morpholine; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxyethyl acid phosphate monoethanolamine salt, diphenyl ((meth) acryloyloxyethyl) phosphate, (meth) Such as acryloyloxypropyl acid phosphate, 3-chloro-2-acid phosphooxypropyl (meth) acrylate, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, acid phosphooxypolyoxypropylene glycol (meth) acrylate, etc. Phosphoric acid group-containing monomer: 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 1,2-dihydroxyethyl (meth) acrylate, 1,2-dihydroxypropyl (meth) acrylate, 1,2-dihydroxybutyl (meth) acrylate 1,2-dihydroxy5-ethylhexyl (meth) acrylate, 1,1-dihydroxyethyl (meth) acrylate, 1,1-dihydroxypropyl (meth) acrylate, 1,1-dihydroxybutyl (meth) acrylate, 1,2 , 3-trihydroxypropyl (meth) acrylate, 1,2,3-trihydroxybutyl (meth) acrylate, 1,1,2-trihydroxypropyl (meth) acrylate, 1,1,2-trihydroxybutyl (meth) ) Hides such as acrylate Aromatic ring-containing hydroxy (meth) acrylate such as 2-hydroxy-3-phenoxypropyl (meth) acrylate; hydroxy polyethylene oxide mono (meth) acrylate, hydroxy polypropylene oxide mono (meth) acrylate, hydroxy (poly Ethylene oxide-polypropylene oxide) mono (meth) acrylate, hydroxy (polyethylene oxide-propylene oxide) mono (meth) acrylate, hydroxy (polyethylene oxide-polytetramethylene oxide) mono (meth) acrylate, hydroxy (polyethylene oxide-tetramethylene oxide) Mono (meth) acrylate, hydroxy (polypropylene oxide-polytetramethylene oxide) mono (meth) a Acrylate, hydroxy (polypropylene oxide-polytetramethylene oxide) mono (meth) acrylate, 1,2-dihydroxypolyethyl oxide (meth) acrylate, 1,2-dihydroxypolypropylene oxide (meth) acrylate, polyhydroxyalkyl (meth) acrylate Hydroxyhydroxyalkylene oxide (meth) acrylates such as 1,2,3-trihydroxypropylene glycol (meth) acrylate and 1,1,2-trihydroxypropylene glycol (meth) acrylate; acrylic acid, methacrylic acid, succinic acid mono (2- (meth) acryloyloxyethyl), carboxyl group-containing (meth) acrylates such as ω-carboxy-polycaprolactone mono (meth) acrylate;

  Among these, from the viewpoint of heat resistance, adhesion and solvent solubility, alkyl (meth) acrylate having a linear or branched hydrocarbon skeleton and / or alkyl (meth) acrylate having an alicyclic skeleton is included. It is preferable that it contains at least one of methyl (meth) acrylate, t-butyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate. preferable. In addition, an acrylic ester monomer (a) may be used individually by 1 type, and may use 2 or more types together.

The (meth) acrylic copolymer (A) may contain a repeating component derived from a monomer other than the repeating unit derived from the (meth) acrylic acid ester monomer (a) in the copolymerization component. As monomer components other than the (meth) acrylic acid ester monomer (a), aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene; acrylonitrile, methacrylate Vinyl cyanide monomers such as rhonitrile, α-cyanoacrylate, dicyanovinylidene, fumaronitrile; crotonic acid, isocrotonic acid, cinnamic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, glutaconic acid, etc. Carboxyl group-containing monomers; vinyl sulfonic acid, sulfonic acid group-containing monomers such as 2-acrylamido-2-methylpropane sulfonic acid; polyfunctional monomers such as divinyl benzene, divinyl naphthalene, divinyl ether; vinyl acetate , Vinyl monomers such as vinyl propionate; 1,3-butadiene, And the like can be given; Puren, 2-chloro-1,3-butadiene, conjugated diene monomer of chloroprene. Monomer components other than these (meth) acrylic monomers may be used alone or in combination of two or more.
The (meth) acrylic copolymer (A) is a structural unit formed from the (meth) acrylic acid ester monomer (a) in view of compatibility with the (meth) acrylic polymer (B) described later. Is preferably 50% by mass or more, more preferably 80% by mass or more.

The number average molecular weight Mn measured by gel permeation chromatography (GPC) of the (meth) acrylic copolymer (A) of the present invention is 500 or more and 6000 or less. When Mn is 500 or more, sufficient adhesion can be obtained. Moreover, when Mn is 6000 or less, sufficient adhesiveness is obtained. The lower limit of Mn is more preferably 700 or more, and even more preferably 1000 or more. The upper limit of Mn is more preferably 5500 or less, and further preferably 5000 or less.
The solubility parameter (Solubility Parameter: Sp value) of the (meth) acrylic polymer (A) is 19.60 (J / cm ³ ) ^1/2 or more. If the solubility parameter is less than 19.60 (J / cm ³ ) ^1/2 , sufficient adhesion cannot be obtained.

Here, the solubility parameter is obtained by substituting the Sp value (Sp (Ui)) of the monomer unit constituting the polymer into the formula (1). Sp (Ui) is described in Polymer Engineering and Science, Vol. 14, 147 (1974). The Sp values (Sp (Ui)) of typical monomer units are shown below.
(In the formula (1), Mi represents the mole fraction of the monomer unit i component, and ΣMi = 1.)

<Sp value of representative monomer unit (Sp (Ui))>
Methyl methacrylate: 20.32 (J / cm ³ ) ^1/2
・ Ethyl methacrylate: 19.89 (J / cm ³ ) ^1/2
N-butyl methacrylate: 19.33 (J / cm ³ ) ^1/2
I-butyl methacrylate: 18.96 (J / cm ³ ) ^1/2
T-butyl methacrylate: 18.29 (J / cm ³ ) ^1/2
2-ethylhexyl methacrylate: 18.50 (J / cm ³ ) ^1/2
Isobornyl methacrylate: 19.61 (J / cm ³ ) ^1/2
・ Cyclohexyl methacrylate: 19.89 (J / cm ³ ) ^1/2
・ Methacrylic acid: 25.65 (J / cm ³ ) ^1/2
N-butyl acrylate: 19.99 (J / cm ³ ) ^1/2
Styrene: 20.09 (J / cm ³ ) ^1/2
・ 2-hydroxyethyl methacrylate: 27.56 (J / cm ³ ) ^1/2

The (meth) acrylic copolymer (A) may have any structure such as a graft copolymer or a block copolymer.
Polymerization methods for obtaining the (meth) acrylic copolymer (A) include bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and other radical polymerization, anionic polymerization, group transfer polymerization (GTP), and coordination anion. A known polymerization method such as polymerization can be employed.
There is no restriction | limiting in particular about polymerization temperature, For example, it can superpose | polymerize at the temperature of -100-250 degreeC, Preferably it is 0-200 degreeC.

In polymerizing the (meth) acrylic copolymer (A), a chain transfer agent or a radical polymerization initiator may be used. Examples of the chain transfer agent include hydrogen, mercaptans, α-methylstyrene dimer, terpenoids, cobalt chain transfer agents and the like. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types. Specific examples of suitable mercaptans used as the chain transfer agent include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and the like.
The (meth) acrylic copolymer (A) is preferably a macromonomer represented by the formula (1) having a double bond at the end of the main chain. The structure represented by the formula (1) can be obtained by using an α-substituted unsaturated compound such as a cobalt chain transfer agent or α-methylstyrene dimer as the chain transfer agent, but is not particularly limited.

Q in the formula (1) represents a main chain portion containing a structural unit formed from two or more (meth) acrylic acid ester monomers (a). R in Formula (1) is any one of a branched, straight-chain or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 18 carbon atoms, and a heterocyclic group having 5 to 18 carbon atoms.

Examples of R include a branched or straight chain alkyl group having 1 to 20 carbon atoms. Specific examples of the branched or straight chain alkyl group having 1 to 20 carbon atoms include methyl group, ethyl unit, n-propyl machine, i-propyl group, n-butyl group, t-butyl group, i-butyl group, pentyl. Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, octadecyl group, nonadecyl group and icosyl group. Among these, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, pentyl, hexyl, heptyl and octyl groups are preferred because of their availability. A methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and a t-butyl group are more preferable.
R includes, for example, a cycloalkyl group having 3 to 20 carbon atoms. Specific examples of the cycloalkyl group having 3 to 20 oxygen atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and an adamantyl group. From the viewpoint of availability, a cyclopropyl group, a cyclobutyl group, a cyclohexyl group and an adamantyl group are preferred.
R includes, for example, an aryl group having 6 to 18 carbon atoms. Specific examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a naphthyl group, and a benzophenone structure.
R includes, for example, a heterocyclic group having 5 to 18 carbon atoms. Specific examples of the heterocyclic group include γ-butyrolactone group and ε-caprolactone group.

Z is a terminal group. Examples of the terminal group include a group derived from a hydrogen atom and a radical polymerization initiator, similarly to the terminal group of a polymer obtained by known radical polymerization.
The resin composition for non-aqueous printing ink obtained by using the acrylic copolymer (A) obtained by using a cobalt chain transfer agent as the chain transfer agent has a small amount of sulfur element contained in the composition. For this reason, a resin composition for non-aqueous printing inks with low odor can be obtained, which is particularly preferable. The sulfur element content is preferably 50 ppm or less, more preferably 25 ppm or less in the ink coating film.

Examples of the radical polymerization initiator include organic peroxides and azo compounds. A radical polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
Specific examples of suitable organic peroxides used as radical polymerization initiators include t-butyl peroxypivalate, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl Peroxide, cyclohexanone peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxide -2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate and the like.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl). -4-methoxyvaleronitrile) and the like.
Among these, benzoyl peroxide, lauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, 2,2′- Azobis (2,4-dimethylvaleronitrile) and the like are preferable. The addition amount of the radical polymerization initiator is preferably 0.0001 to 10 parts by mass with respect to 100 parts by mass in total of the monomers used.

The (meth) acrylic copolymer (B) has a number average molecular weight (Mn) of more than 6000 and 2000000 or less, and a glass transition temperature (Tg) of 30 ° C. or more and 90 ° C. or less.
The same structural unit as the (meth) acrylic acid alkyl ester monomer (a) that constitutes the (meth) acrylic polymer (A) is all the single quantities that constitute the (meth) acrylic polymer (B). 10 mass% or more is preferable in a body component, and 15 mass% or more is more preferable. If it is less than 10% by mass, the compatibility of the (meth) acrylic polymer (A) and the (meth) acrylic polymer (B) is lowered, and the storage stability of the resin composition for non-aqueous printing ink is lowered. .

  The (meth) acrylic copolymer (B) is a component other than the same structural unit as the (meth) acrylic acid alkyl ester monomer (a) constituting the (meth) acrylic polymer (A) as a copolymer component. A repeating component derived from a monomer may be included. As specific examples other than the same structural unit as the (meth) acrylic acid alkyl ester monomer (a) constituting the acrylic polymer (A), the (meth) acrylic polymer (A) is constituted (meta) ) The (meth) acrylic acid alkyl ester monomer (a) described above excluding the same monomer as the acrylic acid alkyl ester monomer (a).

  The (meth) acrylic copolymer (B) may contain monomer components other than the (meth) acrylic monomer. Specific examples of monomer components other than (meth) acrylic monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, vinyltoluene and chlorostyrene; acrylonitrile, methacrylo Vinyl cyanide monomers such as nitrile, α-cyanoacrylate, dicyanovinylidene, fumaronitrile; crotonic acid, isocrotonic acid, cinnamic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, glutaconic acid, etc. Carboxyl group-containing monomers; sulfonic acid group-containing monomers such as vinyl sulfonic acid and 2-acrylamido-2-methylpropane sulfonic acid; polyfunctional monomers such as divinyl benzene, divinyl naphthalene and divinyl ether; vinyl acetate, Vinyl monomers such as vinyl propionate; 1,3-butadiene, iso Conjugated diene monomers such as prene, 2-chloro-1,3-butadiene and chloroprene; Monomer components other than these (meth) acrylic monomers may be used alone or in combination of two or more.

It is preferable that the number average molecular weight Mn measured by the gel permeation chromatograph (GPC) of the (meth) acrylic copolymer (B) is larger than 6,000 and not larger than 2,000,000. When Mn is larger than 6000, sufficient film strength can be obtained. Moreover, when Mn is 2000000 or less, printability is good. The lower limit of Mn is more preferably 10,000 or more, further preferably 30000 or more. The upper limit of Mn is more preferably 1000000 or less, and further preferably 500000 or less.
The (meth) acrylic copolymer (B) may have any structure such as a graft copolymer or a block copolymer.

Polymerization methods for obtaining the (meth) acrylic copolymer (B) include radical polymerization such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, anionic polymerization, group transfer polymerization (GTP), and coordination anion. A known polymerization method such as polymerization can be employed.
There is no restriction | limiting in particular about polymerization temperature, For example, it can superpose | polymerize at the temperature of -100-250 degreeC, Preferably it is 0-200 degreeC.

In polymerizing the (meth) acrylic copolymer (B), a chain transfer agent or a radical polymerization initiator may be used. Examples of the chain transfer agent include hydrogen, mercaptans, α-methylstyrene dimer, terpenoids, cobalt chain transfer agents and the like. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types. Specific examples of suitable mercaptans used as the chain transfer agent include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and the like.
Examples of the radical polymerization initiator include organic peroxides and azo compounds. A radical polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
Specific examples of suitable organic peroxides used as radical polymerization initiators include t-butyl peroxypivalate, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl Peroxide, cyclohexanone peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxide -2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate and the like.
Specific examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl). -4-methoxyvaleronitrile) and the like.
Among these, benzoyl peroxide, lauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, 2,2′- Azobis (2,4-dimethylvaleronitrile) and the like are preferable. The addition amount of the radical polymerization initiator is preferably 0.0001 to 10 parts by mass with respect to 100 parts by mass in total of the monomers used.
The glass transition temperature (Tg) of the (meth) acrylic polymer (B) is 30 ° C. or higher and 90 ° C. or lower. It is more preferably 40 ° C. or higher and 80 ° C. or lower, and further preferably 45 ° C. or higher and 75 ° C. or lower. When Tg is less than 30 ° C., when a plurality of substrates coated with the ink composition of the present invention are stacked and stored, the substrates are blocked by their own weight. When Tg exceeds 90 ° C., the coating film becomes brittle, so that the adhesiveness is lowered.

In the present specification, “glass transition temperature (Tg)” (unit: ° C.) is calculated by the following formula (2) Fox formula.
Wi: Mass fraction of monomer i Tgi: Tg of homopolymer of monomer i (° C.)
The Tg of the homopolymer may be a numerical value described in “Polymer Handbook 4th Edition by John Wiley & Sons”.

In the ink composition of the present invention, the mass ratio of the acrylic copolymer (A) and the acrylic copolymer (B) contained in the ink composition is preferably 10/90 to 90/10.
Sufficient adhesion can be obtained when the mass ratio of the acrylic copolymer (A) and the acrylic copolymer (B) contained in the ink composition is in the range of 10/90 to 90/10. . The range of 15/85 to 85/15 is more preferable, and the range of 20/80 to 80/20 is still more preferable.
The ink composition of the present invention is different from the (meth) acrylic copolymer (A) and the (meth) acrylic copolymer (B) as long as the adhesion to the substrate is not impaired. May be included. Although it does not specifically limit as another polymer, For example, Poly aromatic vinyl compounds, such as polystyrene; Polyester resin; Polyurethane resin; Alkyd resin; Epoxy resin; Nitrocellulose, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate And the like.

[Colorant]
The ink composition of the present invention may contain a color former. There are 5 colors in total including yellow, red, indigo, and black as process basic colors, and 3 colors of red (orange), grass (green), and purple as colors outside the process gamut. There is a color. Further, transparent yellow, peony, vermilion, brown, gold, silver, pearl, almost transparent medium for adjusting color density (including extender pigments if necessary), etc. are prepared as base colors. Other inks can be mixed with the white ink, and organic pigments, inorganic pigments, and dyes can be mixed as necessary.
Examples of the white inorganic pigment that can be used in the ink composition of the present invention include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica. Titanium oxide is preferably used for the white ink pigment from the viewpoint of coloring power, hiding power, chemical resistance, and weather resistance.
Examples of inorganic pigments other than white pigments include carbon black, aluminum, mica (mica) and the like.

Examples of colored colorants that can be used in the ink composition of the present invention include organic and inorganic pigments and dyes used in general inks, paints, and recording agents. Organic pigments that can be used in combination include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, and isoindoline. And other pigments. Indigo ink is copper phthalocyanine, and transparent yellow ink is C.I. I. Pigment No Yellow 83 is preferably used.
The colorant is preferably contained in an amount sufficient to ensure the density and coloring power of the printing ink, that is, in a proportion of 1 to 50% by mass relative to the total mass of the ink composition. These colorants can be used alone or in combination of two or more.
In order to stably disperse the pigment in the organic solvent, it is possible to disperse the resin alone in the ink composition, but it is also possible to use a dispersant in order to disperse the pigment stably. As the dispersant, anionic, nonionic, cationic, amphoteric surfactants can be used. The dispersant is preferably contained in the ink in an amount of 0.05% by mass or more based on the total mass of the ink from the viewpoint of storage stability of the ink and 5% by mass or less from the viewpoint of printability. Furthermore, it is more preferable that it is contained in the range of 0.1 to 2% by mass.

[Organic solvent]
In the ink composition of the present invention, the (meth) acrylic copolymer (A) and the (meth) acrylic copolymer (B) are soluble in order to improve the handleability and printability during production. Alternatively, an organic solvent having a boiling point of 130 ° C. or lower that is dispersible and in which other components can be dissolved or dispersed is blended. When the boiling point exceeds 130 ° C., the volatility of the solvent decreases, the solvent tends to remain in the dried coating film, and the adhesiveness decreases. The solvent having a boiling point of 130 or less is preferably 30% by mass or more, more preferably 40% by mass or more, and most preferably 80% by mass or more, based on the total solvent content in the ink composition of the present invention. If the solvent having a boiling point of 130 ° C. or less is less than 30% by mass of the total solvent content in the ink composition of the present invention, the volatility of the solvent is reduced, and the solvent tends to remain in the coated film after drying. Decreases. Examples of the solvent having a boiling point of 130 ° C. or lower include aromatic hydrocarbons such as toluene (boiling point 110.6 ° C.); alicyclic hydrocarbons such as cyclohexane (boiling point 80.7 ° C.) and methylcyclohexane (boiling point 101 ° C.). Ketones such as methyl ethyl ketone (boiling point 79.6 ° C.) and methyl isobutyl ketone (116.2 ° C.); ethyl acetate (boiling point 77.1 ° C.), i-propyl acetate (boiling point 89 ° C.), n-propyl acetate ( Esters (boiling point 96.6 ° C), n-butyl acetate (126 ° C), i-butyl acetate (118 ° C); ethanol (boiling point 78.3 ° C), n-propyl alcohol (boiling point 97.2 ° C), Alcohols such as isopropyl alcohol (boiling point 82 ° C.) and n-butanol (boiling point 117 ° C.); glycols such as propylene glycol monomethyl ether (boiling point 121 ° C.) Solvent; Miaisopa E (Exxon Chemical Co., Ltd., boiling point 114 ° C.) aliphatic hydrocarbons such as and the like. Of these, esters and alcohols are particularly preferable from the viewpoint of environmental impact due to volatile matter discharge. Moreover, these organic solvents can be used individually by 1 type or in combination of 2 or more types.

  The ink composition of the present invention may contain an organic solvent having a boiling point exceeding 130 ° C. as long as the adhesion is not impaired. Examples of the organic solvent having a boiling point exceeding 130 ° C. include ketones such as diisobutyl ketone (boiling point 168 ° C.); xylene (boiling point 144 ° C.), Swazol # 1000 (manufactured by Maruzen Petrochemical Co., Ltd., boiling point 150 ° C. or higher), Aromatic hydrocarbons such as Solvets # 150 (exxon chemistry, boiling point 190 ° C. to 210 ° C.); esters such as propylene glycol monomethyl ether acetate (boiling point 146 ° C.); cyclohexanol (boiling point 161 ° C.) Alcohols such as; glycol solvents such as ethylene glycol monobutyl ether (boiling point 171 ° C.); and aliphatic hydrocarbons such as mineral terpenes (boiling point 150 ° C. to 280 ° C.). Of these, esters and alcohols are particularly preferable from the viewpoint of environmental impact due to volatile matter discharge. Moreover, these organic solvents can be used individually by 1 type or in combination of 2 or more types.

[Other ingredients]
In the ink composition of the present invention, if necessary, conductivity imparting agents such as carbon black and ferrite; inorganic fillers, lubricants, plasticizers, organic peroxides, aluminum pastes, mica and other glittering agents; General stabilizers such as surface stabilizers, cross-linking agents, curing catalysts, pigment settling inhibitors, etc. Can be added.

[Printing ink]
The ink composition of the present invention can be suitably used as a printing ink. The printing ink can be produced by dissolving and / or dispersing a resin, a colorant and the like in an organic solvent. Specifically, by producing a pigment dispersion in which a pigment is dispersed in an organic solvent with the combination resin and the dispersant, and blending the obtained pigment dispersion with other compounds as necessary. Ink can be produced.
The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As the disperser, generally used, for example, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill, a rotation and revolution mixer, and the like can be used.
In the case where bubbles or unexpectedly large particles are included in the ink, it is preferably removed by filtration or the like in order to reduce the quality of the printed matter. A conventionally well-known filter can be used.

The ink viscosity produced by the above method is in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and being appropriately dispersed, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. preferable. The viscosity is a viscosity measured at 25 ° C. with a B-type viscometer.
The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, for example, resin, colorant, organic solvent, and the like. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.
The printing ink containing the ink composition of the present invention can be used in known printing methods such as gravure printing and flexographic printing, but is particularly suitable for gravure printing. When the printing ink containing the ink composition of the present invention is used for gravure printing, it is diluted with a diluent solvent to a suitable viscosity and concentration and used alone or in combination.

[Base material]
The ink composition of the present invention is particularly suitable for use on a substrate surface made of a polyolefin resin or a polyester resin, which has not been easily adhered by conventional techniques. Examples of the base material made of polyolefin resin include polyethylene film (PE), unstretched polypropylene film (CPP), stretched polypropylene film (OPP), ethylene / vinyl acetate copolymer film (EVA), and ethylene / vinyl alcohol copolymer. Films such as polymer films (EVOH); high-pressure polyethylene, medium-low pressure polyethylene, polypropylene, polyolefins such as poly-4-methyl-1-pentene, ethylene-propylene copolymers, ethylene-butene copolymers, propylene- Examples thereof include molded products for automobile parts and molded products for home appliances made of polyolefin resins such as butene copolymers. Examples of the base material made of polyester resin include molded parts made of polyethylene terephthalate film (PET) and polybutylene terephthalate (PBT) resin.
Furthermore, this ink composition includes not only a base material made of a polyolefin resin or a polyester resin, but also a plastic film such as an unstretched nylon film, a biaxially stretched nylon film, a polyvinylidene chloride film, a polyvinyl alcohol film; Base materials made of acrylic resins such as methacrylates and copolymers containing methyl methacrylate units, resin alloys made of polypropylene and synthetic rubber, polyamide resins, unsaturated polyester resins, polybutylene terephthalate resins, polycarbonate resins, polystyrene resins, etc. Metal substrates such as steel plates that are not surface-treated, steel plates plated with zinc or aluminum oxide film, and suitable for non-ferrous metal substrates such as copper plates, aluminum plates, aluminum alloy plates, and titanium plates be able to.
In addition, the base material printed using the ink composition of the present invention may be formed by any known molding method such as injection molding, compression molding, hollow molding, extrusion molding, and rotational molding.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited by these Examples.

<Number average molecular weight measurement (Mn)>
For the number average molecular weight measurement, a high-speed GPC apparatus HLC-8320GPC manufactured by Tosoh was used, and an RI detector was used as a detector. The columns used were TSKgel superHZM-M (4.6 mmID × 15 cmL) manufactured by Tosoh Corporation and one TSKgel HZ2000 (4.6 mmID × 15 cmL) manufactured by Tosoh Corporation. Tetrahydrofuran (containing the stabilizer dibutylhydroxytoluene) was used as the eluent, and the flow rate was 0.35 ml / min, the inlet temperature was 40 ° C., the oven temperature was 40 ° C., and the RI temperature was 40 ° C. The sample was measured by injecting 10 μl of a resin adjusted to 0.2% by mass with tetrahydrofuran.

<Synthesis of Dispersant (1)>
In a polymerization apparatus equipped with a stirrer, a condenser tube and a thermometer, 900 parts by mass of deionized water, 60 parts by mass of sodium 2-sulfoethyl methacrylate, 10 parts by mass of potassium methacrylate, 12 parts by mass of methyl methacrylate (MMA). Was added and stirred, while the inside of the polymerization apparatus was purged with nitrogen, the temperature was raised to a polymerization temperature of 50 ° C., and 0.08 parts by mass of 2,2′-azobis (2-methylpropionamidine) dihydrochloride as a polymerization initiator was added. The polymerization temperature was further raised to 60 ° C. Simultaneously with the addition of the polymerization initiator, a total of 18 parts by mass was added by continuously dropping MMA at a rate of 0.24 parts by mass / min for 75 minutes using a dropping pump. After maintaining at a polymerization temperature of 60 ° C. for 6 hours, the mixture was cooled to room temperature to obtain a dispersant (1). This dispersant (1) had a solid content of 10%.

<Synthesis of chain transfer agent (1)>
In a reaction vessel equipped with a stirrer, 2.00 g (8.03 mmol) of cobalt (II) acetate tetrahydrate (manufactured by Wako Pure Chemical Industries, Ltd., Wako Special Grade) and diphenylglyoxime (Tokyo Kasei) were added in a nitrogen atmosphere. (Trade name, EP grade) 3.86 g (16.1 mmol) and 100 ml of diethyl ether previously deoxygenated by nitrogen bubbling were added and stirred at room temperature for 2 hours. Next, 20 ml of boron trifluoride diethyl ether complex (manufactured by Tokyo Chemical Industry Co., Ltd., EP grade) was added, and the mixture was further stirred for 6 hours. The reaction product was filtered, and the solid was washed with diethyl ether and dried at 100 MPa or less at 20 ° C. for 12 hours to obtain 5.02 g (7.93 mmol, yield 99% by mass) of the chain transfer agent (1).

<Synthesis of (meth) acrylic copolymer (A)>
(Synthesis Example 1: (Meth) acrylic copolymer A-1, A-3, A-5, A′-6, A′-7)
In a polymerization apparatus equipped with a stirrer, a condenser tube and a thermometer, 145 parts by mass of deionized water, 0.10 parts by mass of sodium sulfate (Na ₂ SO ₄ ) and 0.25 part by mass of the dispersant (1) were added. Stir to a uniform aqueous solution. Next, (meth) acrylic acid ester monomer (a) in the amount shown in Table 1, 0.0022 parts by mass of chain transfer agent (1) and 1,1,3,3-tetramethylbutylperperoxide as a polymerization initiator. 0.40 part by mass of oxy-2-ethylhexanoate (manufactured by NOF Corporation, trade name: Perocta O) was added to obtain a dispersion. Thereafter, the inside of the polymerization apparatus was sufficiently purged with nitrogen, and the dispersion was heated to 80 ° C. and held for 2 hours, and further heated to 91 ° C. and held for 2 hours. Thereafter, the reaction solution was cooled to 40 ° C. to obtain a suspension containing the polymer. The suspension is filtered through a filter cloth, and the filtrate is washed with deionized water, dehydrated, dried at 40 ° C. for 16 hours, and (meth) acrylic copolymers A-1, A-3, A- 5, A′-6 and A′-7 were obtained. Table 1 shows the number average molecular weights of the (meth) acrylic copolymers A-1, A-3, A-5, A′-6, and A′-7.

(Synthesis Example 2: (Meth) acrylic copolymer A-2, A-4, A′-8)
Chain transfer agent (1) Instead of 0.008 parts by mass, 1-octanethiol (manufactured by Kanto Chemical) in the amount shown in Table 1 was used, and 0.50 parts by mass was used instead of 0.80 parts by mass of the polymerization initiator. (Meth) acrylic copolymers A-2, A-4, and A′-8 were obtained in the same manner as in Synthesis Example 1 except that they were used. Table 1 shows the number average molecular weights of the (meth) acrylic copolymers A-2, A-4, and A′-8.

The composition of the (meth) acrylic copolymer is shown in Table-1.
MMA: methyl methacrylate IBMA: i-butyl methacrylate IBXMA: isobornyl methacrylate MAA: methacrylic acid tBMA: t-butyl methacrylate nOM: n-octyl mercaptan (manufactured by Kanto Chemical)

<Synthesis of acrylic copolymer (B)>
(Synthesis Example 3: (meth) acrylic copolymers B-1, B-2, B'-3, B'-4, B'-5)
In a polymerization apparatus equipped with a stirrer, a condenser tube and a thermometer, 145 parts by mass of deionized water, 0.10 parts by mass of sodium sulfate (Na ₂ SO ₄ ) and 0.25 part by mass of the dispersant (1) were added. Stir to a uniform aqueous solution. Next, (meth) acrylic acid ester monomer in the amount shown in Table 2, 1-dodecanethiol in the amount shown in Table 2, and 1,1,3,3-tetramethylbutylperoxy-2-2 as a polymerization initiator 0.40 part by mass of ethyl hexanoate (manufactured by NOF Corporation, trade name: Perocta O) was added to prepare a dispersion. Thereafter, the inside of the polymerization apparatus was sufficiently purged with nitrogen, and the dispersion was heated to 80 ° C. and held for 2 hours, and further heated to 91 ° C. and held for 2 hours. Thereafter, the reaction solution was cooled to 40 ° C. to obtain a suspension containing the polymer. This suspension is filtered with a filter cloth, and the filtrate is washed with deionized water, dehydrated, dried at 40 ° C. for 16 hours, and acrylic copolymers B-1, B-2, B′-3, B′-4 and B′-5 were obtained. Table 2 shows the number average molecular weights of the acrylic copolymers B-1, B-2, B′-3, B′-4, and B′-5.

nDM: n-dodecyl mercaptan

<Examples 1-9 and Comparative Examples 1-8>
The amount of solvent, resin, and pigment shown in Tables 3 and 4 were mixed using a planetary mixer ("Spinning Revolving Vacuum Mixer ARV-310" manufactured by Sinky Corporation) under the conditions of 2000 rpm, room temperature, and processing time of 5 minutes. Thus, a titanium oxide dispersion solution was obtained. The corona-treated surface of the OPP film (“Pyrene Film OT P2108” manufactured by Toyobo Co., Ltd., thickness 40 μm) and the corona of the PET film (“Taiko Polyester Film FS2001” manufactured by Phutamura Chemical Co., Ltd., thickness 100 μm) It apply | coated with the bar coater (No. 6) so that the film thickness after drying might be set to 5 micrometers with respect to a process surface, and it dried at room temperature for 24 hours, and formed the coating film.

<Adhesion evaluation method>
The film on which the coating film was formed was subjected to a peeling test from the film using a cellophane tape (registered trademark), and the state of the film surface after the peeling test was visually observed and evaluated according to the following criteria.
○: Remaining paint film area 75% or more Δ: Remaining paint film area 50% or more and less than 75% ×: Remaining paint film area less than 50%

<Firability>
The both ends of the film on which the coating film was formed were grasped with both hands, and after ten times, the surface of the coating film was visually observed and evaluated according to the following criteria.
○: No peeling of coating film
×: Confirmed peeling of the coating film

<Blocking property>
The untreated surface side of the same kind of film was superimposed on the coating film side of the film on which the coating film was formed. Then, a 1 kg load was applied on the superposed film and left in a 50 ° C. hot air dryer. After 1 hour, the film was taken out of the dryer, and the resistance when the two overlapped films were peeled off was judged sensuously.
○: No resistance △: Very little resistance confirmed ×: Resistance

<Sulfur content>
The sulfur content was calculated from the charged amount.

IPA: isopropyl alcohol BGAc: ethylene glycol monobutyl ether acetate: boiling point 192 ° C.
TiO ₂ : Titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd., white pigment, Taipei C R-95)

  As shown in Tables 3 and 4, Examples 1 to 9 showed good or relatively good results for the OPP film adhesion, the PET film adhesion, the friability, and the blocking properties. On the other hand, in Comparative Example 1 using a (meth) acrylic polymer (A) having a large Mn, Comparative Example 2 using a (meth) acrylic copolymer (A) having a smaller SP value of 19.60 and In Comparative Example 3, the OPP film adhesion and the PET film adhesion could not be satisfied. In Comparative Example 4 and Comparative Example 5 in which the mass ratio of the (meth) acrylic copolymer (A) and the (meth) acrylic copolymer (B) deviates from 10/90 to 90/10, the OPP film adhesion, The PET film adhesion could not be satisfied. In Comparative Example 6 using the (meth) acrylic polymer (B) having a low glass transition temperature, the blocking property could not be satisfied. In Comparative Example 7 using the (meth) acrylic polymer (B) having a high glass transition temperature, the friability could not be satisfied.

  The ink composition of the present invention can be used when printing on a substrate made of a polyolefin resin or a polyester resin. In addition, it is environmentally friendly because it does not contain chlorine.

Claims (4)

It includes a structural unit formed from at least one (meth) acrylic acid ester monomer (a), has a number average molecular weight (Mn) of 500 or more and 6000 or less, and a solubility parameter of 19.60 (J / cm ³ ) ^{1 /} (Meth) acrylic copolymer (A) that is ² or more, (meth) acrylic that has a number average molecular weight (Mn) of more than 6000 and 2000000 or less and a glass transition temperature (Tg) of 30 ° C. or more and 90 ° C. or less. A non-aqueous printing ink composition comprising a polymer (B) and a solvent having a boiling point of 130 ° C. or lower.   The non-aqueous printing ink composition according to claim 1, wherein the mass ratio of the (meth) acrylic polymer (A) to the (meth) acrylic polymer (B) is 10/90 to 90/10.   A non-aqueous printing ink composition, wherein the non-aqueous printing ink composition according to claim 1 or 2 is for at least one substrate selected from the group consisting of polyolefin resins and polyester resins. The non-aqueous printing ink composition according to any one of claims 1 to 3, wherein the (meth) acrylic polymer (A) has a structure represented by the formula (1).
(Q in the formula (1) represents a main chain portion containing a structural unit derived from the (meth) acrylate monomer (a). R in the formula (1) is a branched chain having 1 to 20 carbon atoms. , A linear or cyclic alkyl group, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 5 to 18 carbon atoms, Z is a terminal group derived from a hydrogen atom or a radical polymerization initiator. )