JP6388131B2 - Water-based primer composition and printed matter - Google Patents

Description

  The present invention relates to a primer layer for detachment formed on a polyester substrate, and an aqueous primer composition for forming the primer layer for detachment which can easily remove the printed layer printed thereon with an alkaline aqueous solution.

In recent years, plastics such as polyethylene terephthalate (PET) products have been used in a wide variety of applications such as containers, labels, and packaging bags, and have been subjected to printing processing. From the viewpoint of resource reuse, plastics are separated and collected, recycled and used as secondary products. However, when a plastic product that has been subjected to printing processing or the like is mixed during recycling, the entire recycled product is colored, so the quality of the recycled product may be significantly reduced or may not be reused. Plastic products that have been printed in such a manner that cannot be reused are incinerated. However, in this case, harmful substances such as dioxin may be generated, which is regarded as a problem from the viewpoint of global environmental conservation. Therefore, there is a strong demand for a method that can efficiently recycle plastic products.

In particular, PET products include PET bottles, PET labels, PET containers, and the like, and the amount of usage is significantly increased from the viewpoint of light weight, transparency, and impact resistance. Of course, these products are also subjected to printing processing, and the reuse of PET is desired, but there is a problem similar to the above.

Therefore, attempts have been made to desorb (remove) the printing ink printed on the PET substrate. As a method of removing printing ink, there are a method of removing by dissolving in a solvent, and a method of removing by dissolving or decomposing with an acid or alkaline aqueous solution. Recently, many proposals have been made because the method of removing the printing ink layer with an alkaline aqueous solution is economical and efficient. For example, JP-A-11-333952 (Patent Document 1) proposes a laminate of a polymer and an ink layer obtained by crosslinking a double bond acid monomer. JP-A-2001-131484 (Patent Document 2) proposes a PET bottle label using an acrylic-modified polyester having a hydrophilic group. Japanese Patent Laid-Open No. 2002-11819 (Patent Document 3) proposes an alkali detachment label using a cross-linked acidic acrylic resin layer.

However, in the first place, compositions and printing ink compositions that form a release layer generally use hydrophobic, oily polymers such as urethane resins, acrylic resins, fiber resins, rosins, and ethylene-vinyl acetate copolymers. In many cases, the repellency phenomenon occurs even when processing with an alkaline aqueous solution, or the wettability to the oil-based ink layer is poor and the penetration is difficult. Therefore, the concentration of the alkaline aqueous solution used for the treatment is high, and the printing ink cannot be removed unless the treatment is performed at a high temperature for a long time. Therefore, the resin forming the primer layer or the ink layer is preferably hydrophilic, but it is difficult to recover because it is dissolved or finely dispersed by the treatment with the alkaline aqueous solution, and the problem of the wastewater treatment of the alkaline aqueous solution must also be taken into consideration. I must.

Further, for example, as described in Japanese Patent Application Laid-Open No. 2000-313833 (Patent Document 4), an internal addition method in which an alkali-soluble polymer or a water-swellable polymer is added to a printing ink to make the printing layer alkaline to be removed is examined. Has been. However, this method has a high possibility of lacking in printing performance and printability as a printing ink by causing aggregation and thickening of printing ink. Further, depending on the type of resin in the ink, the ink detachment becomes a fine dispersion, and in order to collect the ink detachment, it may be necessary to use an advanced filtration device.

In response to such problems, it is possible to treat a printing ink layer printed on a film or container using PET with a dilute alkaline aqueous solution, and easily and efficiently remove it to recover and recycle a PET label or PET container. This is a big issue for the time being.

Japanese Patent Application Laid-Open No. 11-333952 JP 2001-131484 A JP 2002-11819 A JP 2000-313833 A

  It is an object of the present invention to provide an aqueous primer composition for forming a primer layer that can be easily removed with an alkaline aqueous solution from a primer layer formed on a polyester substrate and a printing ink layer printed thereon. To do.

  As a result of intensive studies on the above problems, the present inventor has found that the problem can be solved by using the water-based primer composition described below, and has reached the present invention.

That is, the present invention is an aqueous primer composition for forming the release primer layer of a printed material in the order of a polyester substrate, a release primer layer, and a print layer, and is characterized by the following (1) to (3) To do.
(1) The water-based primer composition contains a polyurethane resin (A) having a carboxyl group.
(2) At least a part of the carboxyl groups of the polyurethane resin (A) is neutralized with the amine compound (a-1).
(3) The acid value before neutralization of the polyurethane resin (A) is 25 to 45 mgKOH / g.

Further, in the present invention, the polyurethane resin (A) is
At least one structural unit selected from the group consisting of a polyethylene oxide structural unit, a polypropylene oxide structural unit, a polytetramethylene oxide structural unit, and a structural unit (a-2) derived from polyester comprising adipic acid and a diol having a branched structure The water-based primer composition.

Further, the present invention is characterized in that the polyurethane resin (A) contains a polyethylene oxide structural unit and / or a structural unit derived from polyester comprising adipic acid and 3-methyl-1,5-pentanediol in the main chain. The present invention relates to an aqueous primer composition.

Furthermore, the present invention relates to the aqueous primer composition further comprising a styrene-maleic acid resin derivative (B).

Furthermore, the present invention relates to the water-based primer composition further comprising a copolymer (C) of vinyl chloride and other double bond monomers.

The present invention further includes a release primer layer on which a water-based primer composition is printed on a polyester film substrate, and further a printing ink composition printed on the release primer layer. The present invention relates to a printed matter having a layer.

  After the water-based primer composition of the present invention is applied to a polyester substrate, the printing ink composition is printed thereon, whereby the adhesion between the printed layer and the polyester substrate is good, and the water resistance is good. Furthermore, an aqueous primer composition capable of easily removing the printed layer with an alkaline aqueous solution under mild conditions could be provided.

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. The content is not limited.

That is, this invention is a water-based primer composition which forms the primer layer of the printed matter which consists of a polyester base material, a primer layer, and a printing ink layer in order, The said printing layer can be removed with alkaline aqueous solution, and following (1) (2) It is characterized by (3).
(1) The water-based primer composition contains a polyurethane resin (A) having a carboxyl group.
(2) The acid value of the polyurethane resin (A) is 25 to 45 mgKOH / g.
(3) The side chain carboxyl group in the polyurethane resin (A) is neutralized with the amine compound (a-1).

Hereinafter, the polyurethane resin (A) used in the aqueous primer composition of the present invention will be described. The polyurethane resin (A) used in the present invention comprises, for example, a polyisocyanate (b), a polymer polyol (c), and a compound (d) having a carboxyl group and at least two active hydrogen-containing groups in the molecule. A polyurethane obtained by subjecting the polyurethane as a prepolymer to a chain extension reaction with an organic diamine (e) can also be used.

As the polyisocyanate (b) used in the production of the polyurethane resin (A) used in the aqueous primer composition of the present invention, various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and carboxyl groups of dimer acid were converted to isocyanate groups. Dimer isocyanate is a typical example. These can be used alone or in admixture of two or more. Isophorone diisocyanate is preferable in terms of reactivity and the like.

The polymer polyol (c) used in the polyurethane resin (A) used in the water-based primer composition of the present invention is not particularly limited and includes known polyether polyols, polyester polyols, polycaprolactone polyols, polycarbonate polyols, and the like. Dimer diol, hydrogenated dimer diol, castor oil-modified polyol and the like may be used in combination. Of these, the use of polyether polyol and polyester polyol is preferable from the viewpoints of printability and adhesion to a substrate. The ratio of these polyols used is that a compound (d) having a carboxyl group and at least two active hydrogen-containing groups in the molecule described later is incorporated into the polyurethane resin (A) and neutralized with the amine compound (a-1). Since the solubility of the polyurethane resin (A) in water can be ensured, any ratio may be used. However, it is more preferable to include a polyether polyol from the viewpoint of further increasing the solubility in water and improving printability. preferable.

Examples of the polyether polyol include polymers or copolymers such as methylene oxide, ethylene oxide, propylene oxide, and tetrahydrofuran. These can be used alone or in admixture of two or more. As a preferred specific example, a polyethylene oxide structural unit is obtained by using polyethylene glycol, a polypropylene structural unit is obtained by using polypropylene glycol, and a polytetramethylene oxide structural unit is obtained by using polytetramethylene glycol to the polyurethane resin (A). It can be included. When polyethylene glycol is used, it is more preferable because re-solubility in water is further improved.

Examples of the polyester polyol include adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, glutaric acid, 1 Dibasic acids such as 4-cyclohexyldicarboxylic acid, dimer acid, hydrogenated dimer acid, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3 -Butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 2,4 -Diethyl-1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether, 2-monoglycerin ether These polyester polyols such as condensates obtained by esterification reaction with diols such as dimer diol and hydrogenated dimer diol can be used alone or in admixture of two or more. Furthermore, a polyol having 3 or more hydroxyl groups and a polyvalent carboxylic acid having 3 or more carboxyl groups can be used in combination.

Among these, those containing a structural unit (a-2) derived from a polyester composed of adipic acid and a diol having a branched structure are preferable, and can improve adhesion, blocking resistance, and printability with a polyester base material. . In particular, when a polyester polyol having a branched structure is used, the solubility in water at a low temperature and the adhesion to the substrate or primer layer are excellent. Examples of the diol having a branched structure include 1,2-propanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,4-pentanediol, 3-methyl-1 , 5-pentanediol, 2,5-hexanediol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propane Diol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,6-hexanediol, and the like. Polyester polyol condensed with an acid is used in the synthesis, so that a polyurethane resin (A) can be made of a polymer composed of adipic acid and a diol having a branched structure. A structural unit (a-2) derived from a reester can be contained. Among these, polyester polyols composed of 1,2-propanediol or 3-methyl-1,5-pentanediol and adipic acid are preferred, and by using these, 1,2-propanediol and adipic acid are used, respectively. The polyurethane resin (A) can contain a polyester-derived structural unit composed of polyester, and a polyester-derived structural unit composed of 3-methyl-1,5-pentanediol and adipic acid.

Polyethylene oxide structural unit, polypropylene oxide structural unit, polytetramethylene oxide structural unit, and structural unit (a-2) derived from polyester composed of adipic acid and a diol having a branched structure are attached to the side chain of the polyurethane resin (A). You may contain. Specific introduction methods include, for example, a polyisocyanate (b), a polymer polyol (c), and a polyurethane (prepolymer) obtained by reacting a carboxyl group and a compound (d) having at least two active hydrogen-containing groups in the molecule. When the polymer) is subjected to a chain extension reaction with the organic diamine (e), a macromonomer having an acrylate structure at the end of the above structure to be introduced into the side chain is subjected to Michael addition reaction with the organic diamine (e) in advance. Can be obtained by chain extension.

As a polymer polyol (c) used by this invention, a preferable number average molecular weight is 500-10000. Here, the number average molecular weight used for the polymer polyol (c) is calculated from the hydroxyl value, and the hydroxyl value is calculated by esterifying or acetylating the hydroxyl group in the resin and back titrating the remaining acid with an alkali. A value obtained by converting the amount of hydroxyl group in 1 g of the resin converted into the number of mg of potassium hydroxide according to JISK0070.

When the number average molecular weight of the polymer polyol (c) is 10,000 or less, the polyester base material is excellent in blocking resistance, and the carboxyl groups incorporated for water-solubilization can be interspersed in the polyurethane resin. Excellent solubility. Further, when the number average molecular weight of the polymer polyol (c) is 500 or more, the polyurethane resin film is excellent in flexibility and adhesiveness to a polyester substrate or primer. For the above reasons, the number average molecular weight is more preferably 1000 to 5000.

The compound (d) having a carboxyl group and at least two active hydrogen-containing groups in the molecule is not particularly limited. For example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2- Dimethylol alkanoic acid such as dimethylol butyric acid and 2,2-dimethylol valeric acid; diamine type amino acids such as glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, diaminobenzenesulfonic acid, and the like, dimethylolalkane Acid is preferred. These may be used alone or in combination of two or more, and may be used by appropriately adjusting the polyurethane resin (A) to have an acid value of 25 to 45 mgKOH / g.

In addition, the active hydrogen containing group in this invention shows the functional group which has active hydrogens, such as a hydroxyl group and an amino group, which reacts with an isocyanate group.

The polyurethane resin (A) used in the aqueous primer composition of the present invention preferably has an organic diamine-derived structural unit (e) chain-extended with the organic diamine (e). Examples of the organic diamine (e) include various known ones such as ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and dimeramine obtained by converting the carboxyl group of dimer acid into an amino group. It is done. These can be used alone or in admixture of two or more.

The polyurethane resin (A) used in the aqueous primer composition of the present invention has an organic diamine (A) when the proportion of the polyether polyol (c-1) used in 100% by weight of the polymer polyol (c) is 40% by weight or less. From the viewpoint of solubility in water, it is preferable that e) includes those having a hydroxyl group in the molecule. In this case, 40% by weight to 100% by weight of 100% by weight of the organic diamine (e) is preferably an organic diamine having a hydroxyl group.

Examples of the organic diamine having a hydroxyl group include 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, and di-2. -Hydroxypropylethylenediamine. These can be used alone or in admixture of two or more.

The acid value before neutralization of the polyurethane resin (A) used in the aqueous primer composition of the present invention is preferably 25 to 45 mgKOH / g. The acid value is a value obtained by converting the amount of acid in 1 g of resin calculated by titrating the acid with an alkali into the number of mg of potassium hydroxide, according to JISK0070. When the acid value is lower than 25 mg KOH / g, even after adding the amine compound (a-1) described later and neutralizing, the re-solubility in water is poor, and printing is likely to occur. Peeling of the printed layer becomes difficult. When the acid value is higher than 45 mgKOH / g, the adhesion to the polyester substrate or the primer layer and the blocking resistance tend to be inferior, and the water resistance of the printed matter tends to be greatly inferior.

The weight average molecular weight of the polyurethane resin (A) used in the aqueous primer composition of the present invention is preferably in the range of 5,000 to 100,000. It is excellent in the point with the blocking resistance with respect to a polyester base material, the viscosity reduction of the obtained water-system primer composition, and the solubility to water as it is in the said range.

The polyurethane resin (A) used in the water-based primer composition of the present invention can be obtained by a method using an organic solvent which is inactive with respect to isocyanate and a hydrophilic solvent, or a solvent-free synthesis method using no solvent at all. . It is possible to obtain the polyurethane resin (A) by any method, but it is inert to the isocyanate and hydrophilic because it can reduce the viscosity using an organic solvent and perform the synthesis reaction uniformly and smoothly. It is more preferable to use an organic solvent.

Examples of the inert and hydrophilic organic solvent for isocyanate include ethers such as tetrahydrofuran and dioxane, esters such as ethyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, dimethylformamide, and N-methylpyrrolidone. In order to obtain an aqueous solution of polyurethane, it is usually removed by distillation under reduced pressure (solvent removal), and water is added. Therefore, it is preferable to use a solvent having a boiling point lower than that of water. When removing the solvent, the reaction solution is neutralized by adding water and an amine compound (a-1), which will be described later, and then the temperature is raised and the solvent is distilled off under normal pressure or reduced pressure. It can be carried out.

A urethane (prepolymer) having an isocyanate group at the terminal obtained by reacting a polyisocyanate (b), a polymer polyol (c), and a compound (d) having a carboxyl group and at least two active hydrogen-containing groups in the molecule. For obtaining (hereinafter referred to as prepolymer reaction), it is preferably carried out at 50 to 100 ° C. for 30 minutes to 10 hours. The end point of the reaction is judged by viscosity measurement, NCO peak decrease by IR measurement, NCO% measurement by titration, and the like.

A catalyst can also be used for the prepolymer reaction. As the catalyst that can be used, a known metal catalyst or amine catalyst can be used. Examples of the metal catalyst include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexoate), lead 2-ethylhexoate, 2-ethylhexyl titanate, 2-ethylhexoate iron, 2- Examples thereof include ethylhexoate cobalt, zinc naphthenate, cobalt naphthenate, and tetra-n-butyltin. Examples of amine-based catalysts include tertiary amines such as tetramethylbutanediamine. These catalysts are used in the range of 0.001 to 1 mol% with respect to the polymer polyol.

When making urethane (prepolymer) and organic diamine (e) react (henceforth, chain extension reaction), it is preferable to carry out at 30-80 degreeC for 10 minutes-10 hours. The end point of the reaction is judged by viscosity measurement, reduction of NCO peak by IR measurement, amine value measurement by titration, and the like.

A reaction terminator may be used for the chain extension reaction. Examples of the reaction terminator include dialkylamines such as di-n-butylamine, monoethanolamine, diethanolamine, 2-amino-2-methyl-1-propanol, tri (hydroxymethyl) aminomethane, 2-amino. Amines having a hydroxyl group such as 2-ethyl-1,3-propanediol can also be used. Furthermore, monoamine type amino acids such as glycine, alanine, glutamic acid, taurine, aspartic acid, aminobutyric acid, valine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, sulfamic acid and the like can also be mentioned.

The carboxyl group incorporated in the polyurethane resin (A) before neutralization exhibits the solubility of the polyurethane resin (A) in water by neutralizing at least a part thereof with the amine compound (a-1). All the carboxyl groups may be neutralized. As the amine compound (a-1), ammonia, monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N- Examples thereof include organic amines such as methylmorpholine and 2-amino-2-methyl-1-propanol, and one kind or a combination of two or more kinds may be used. However, from the viewpoint of water resistance, residual odor and the like of the printed matter, those that are water-soluble and highly volatile that are easily dissociated by heat are preferable, and ammonia is particularly preferable. The amine compound (a-1) used for neutralization can evaporate after printing and drying to impart water resistance to the printed matter.

In 100% by weight of the aqueous primer composition in the present invention, the amount of the polyurethane resin (A) used is preferably 5% to 50% in terms of solid content. Within the above range, the printing layer can be easily removed with an alkaline aqueous solution, the adhesiveness to the polyester substrate is excellent, and the blocking resistance is excellent.

The aqueous primer composition of the present invention preferably contains a styrene-maleic acid resin derivative (B) in order to further promote the removal of the printed layer with an alkaline aqueous solution. The styrene-maleic acid resin derivative (B) includes a copolymer of styrene and maleic acid, and further a copolymer with other double bond monomers. The styrene-maleic acid resin derivative (B) preferably has a styrene: maleic acid copolymerization ratio (weight% ratio) of 1: 1 to 8: 1, and a preferred acid value of 50 to 500 mgKOH / g. The carboxyl group of maleic acid imparts solubility in an alkaline aqueous solution, and the styrene moiety has the effect of improving blocking resistance.

The maleic acid to be copolymerized may be an anhydride, and may be arbitrarily copolymerized such as a block copolymer, a random copolymer, or a graft copolymer. The preferred range of use of styrene: maleic acid is the same as described above.

The glass transition temperature in the styrene-maleic acid resin derivative (B) is preferably 40 ° C. to 130 ° C. in order to prevent difficult recovery due to fine dispersion of the detached printed layer when treated with an alkaline aqueous solution. For the same reason, the preferred range of the weight average molecular weight in the styrene-maleic acid resin derivative (B) is 1000 to 100,000.

Further, the styrene-maleic acid resin derivative (B) may be copolymerized with styrene, maleic acid and other double bond monomers, and among them, acrylate is preferred. In addition, the copolymerization ratio of the double bond monomer and the copolymer is preferably 20% or less from the viewpoint of maintaining solubility in water.

Examples of the acrylic ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) acrylate And octadecyl (meth) acrylate. Furthermore, the alkyl group may further have a benzene ring structure. Among these, butyl (meth) acrylate is preferable from the viewpoint that it is easy to obtain good adhesion to a polyester substrate. These can be used alone or in combination of two or more.

In addition, the acrylate ester may have a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic. (Meth) such as acid 2-hydroxybutyl, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate Glycol mono (meth) acrylic acid such as hydroxyalkyl acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate Esters, caps Lactone-modified (meth) acrylic acid esters, such as hydroxyethyl acrylamide. Among these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are more preferable because they improve solubility in water. These can be used alone or in combination of two or more.

In addition, the acrylate ester may have a functional group other than a hydroxyl group, and examples of the functional group include a carboxyl group, an amide bond group, an amino group, and an alkylene oxide group.

Examples of carboxyl group-containing acrylic esters include (meth) acrylic acid, phthalic acid monohydroxyethyl acrylate ester, p-carboxybenzyl acrylate ester, ethylene oxide modified (addition moles: 2 to 18) phthalic acid acrylate ester, phthalate Acid monohydroxypropyl acrylate, succinic acid monohydroxyethyl acrylate, β-carboxyethyl acrylate, 2- (4-benzoyl-3-hydroxyphenoxy) ethyl acrylate, maleic acid, monoethylmaleic acid, itaconic acid , Citraconic acid, fumaric acid and the like.

Examples of acrylic acid ester containing an amide bond include (meth) acrylamide, N-methylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N-dimethylamino. Examples include (meth) acrylamide-based compounds such as propyl (meth) acrylamide, diacetone acrylamide, N- (hydroxymethyl) acrylamide, and N- (butoxymethyl) acrylamide.

Moreover, what contains an amino group with an acrylic ester is, for example, (meth) acrylic acid monomethylaminoethyl, (meth) acrylic acid monoethylaminoethyl, (meth) acrylic acid monomethylaminopropyl, (meth) acrylic acid mono Examples include (meth) acrylic acid monoalkylamino esters such as ethylaminopropyl.

The acrylic ester may have an alkylene oxide unit, for example, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-phenoxyethyl acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxy Polyethylene glycol (meth) acrylic acid ester, methoxypolypropylene glycol (meth) acrylic acid ester, ethoxypolypropylene glycol (meth) acrylic acid ester, phenoxypolyethylene glycol (meth) acrylic acid ester, phenoxypolypropylene glycol (meth) acrylic acid ester, etc. Can be mentioned.

Further, the styrene-maleic acid resin derivative (B) may be further copolymerized with a double bond monomer other than an acrylate ester, and examples thereof include vinyl alcohol and vinyl acetate. Vinyl alcohol is preferred for the purpose of increasing the solubility in water or the compatibility between resins.

The maleic acid (anhydride) moiety may be partially esterified with alcohol. In the case of esterification with an alcohol, preferred alcohols include methanol, ethanol, propanol, butanol, isobutanol, hexanol, and other higher alcohols having 10 or more carbon atoms, and these may have a branched structure. From the viewpoint of adhesion to a polyester substrate, an alcohol having 10 or less carbon atoms is preferable, butanol is particularly preferable, and the acid value of the styrene-maleic acid resin derivative (B) after the esterification reaction is in the range of 50 to 500 mgKOH / g. If it is.

In the styrene-maleic acid resin derivative (B), part or all of the carboxyl group contained may be neutralized with the amine compound (a-1). The amine compound (a-1) is preferably ammonia. By neutralizing with ammonia, the solubility of the styrene-maleic acid resin derivative (B) in water is exhibited, and after printing and drying, the amine compound (a- 1) evaporates, resulting in water resistance.

In the water-based primer composition of the present invention, when the styrene-maleic acid resin derivative (B) is used, the detachment of the printed layer with an alkaline aqueous solution can be improved with a small addition. The amount used is not particularly limited, but is preferably 0.1% to 10% from the viewpoint of compatibility with the polyurethane resin (A).

As for the form of the styrene-maleic acid resin derivative (B), about half of the carboxyl groups derived from maleic acid are esterified with an alcohol having 6 or less carbon atoms, and the remaining carboxyl groups are neutralized with an amine compound (a-1). What is made into aqueous solution is preferable.

The aqueous primer composition in the present invention preferably contains a copolymer (C) of vinyl chloride and other double bond monomers. Since the dry film of the copolymer (C) has a relatively high glass transition temperature (Tg) of 50 ° C. to 80 ° C. and a strong cohesive force, the printing layer containing the aqueous primer composition in the present invention is removed with an alkaline aqueous solution. At this time, the printing layer is prevented from becoming too fine in an alkaline aqueous solution to be uncollectable.

The copolymer (C) of vinyl chloride and other double bond monomers may be a solution in a medium of water, alcohol or water mixture, or may be an emulsion (particulate). In the case of an emulsion (particulate form), the average particle diameter is preferably 500 nm or less. When it is in the range of 500 nm or less, the temporal stability of the aqueous primer composition of the present invention is also good. Here, the average particle size is a particle size at an integrated value of 50% (D50) in the particle size distribution determined by the Coulter counter method or a particle at an integrated value of 50% (D50) in the particle size distribution determined by the laser diffraction / scattering method. Means diameter.

The copolymer (C) of vinyl chloride and other double bond monomers has a glass transition temperature of 50 ° C. when the printed layer is detached with an alkaline aqueous solution in order to make it easier to collect the printed layer fragments. It is preferably ~ 100 ° C. For the same reason, the preferred range of the weight average molecular weight in the copolymer (C) of vinyl chloride and other double bond monomers is preferably 1,000 to 500,000.

In the copolymer (C) of vinyl chloride and other double bond monomers, when copolymerizing the other double bond monomers, any method such as random copolymerization, block copolymerization or graft copolymerization may be used. May be introduced. Further, in order for the copolymer (C) to have the glass transition temperature, the copolymerization ratio of vinyl chloride and other double bond monomers is preferably 70:30 to 95: 5 by weight ratio.

In the copolymer (C) of vinyl chloride and other double bond monomers, there are no particular restrictions on the other double bond monomers other than vinyl chloride, and any monomer can be used as long as it contains a double bond and can be copolymerized. However, it is preferable to copolymerize an acidic monomer such as acrylic acid, methacrylic acid, maleic acid, etc. in order to promote dissolution in an alkaline aqueous solution, and it is more preferable that the acid value is in the range of 5 to 100 mgKOH / g. .

In addition, in the copolymer (C) of vinyl chloride and other double bond monomers, the other double bond monomers are acrylic acid esters and vinyl acetate from the viewpoint of adhesion to the polyester base and blocking resistance. Etc. are preferred. Examples of the acrylate ester are the same as those described above, and preferably include butyl acrylate, hydroxyethyl acrylate, and the like, and two or more types may be used in combination.

Further, when the copolymer (C) of vinyl chloride and another double bond monomer contains a carboxyl group, a part or all of the carboxyl group may be neutralized with the amine compound (a-1). good. Amine compound (a-1) is preferably ammonia, and neutralization with ammonia increases the solubility or dispersibility of the copolymer (C) of vinyl chloride and other double bond monomers in water. When used in an aqueous primer composition, the stability of the composition is improved, and the water resistance and blocking resistance are improved since the amine compound (a-1) evaporates after printing and drying.

In the water-based primer composition of the present invention, the amount of the copolymer (C) of vinyl chloride and other double bond monomers is not particularly limited. The content is preferably 0.1% by weight to 10% by weight with respect to 100% by weight of the product.

In the aqueous primer composition of the present invention, the neutralization rate when neutralizing the carboxyl group contained in the polyurethane resin (A) with the amine compound (a-1) is particularly within the range that does not impair the solubility in water. There is no limitation and it may be partially neutralized or all may be neutralized. However, from the viewpoint of printability, it is preferable that 60 mol% or more is neutralized with an amine compound (a-1) with respect to 100 mol% of the carboxyl group of the polyurethane resin (A), and 80 mol% or more is neutralized. More preferably. The preferable range of the neutralization rate is the same when the styrene-maleic acid resin derivative (B) or the copolymer (C) of vinyl chloride and another double bond monomer has a carboxyl group.

Further, the aqueous primer composition in the present invention preferably further contains a hydrazine compound. Examples of hydrazine compounds include hydrazine, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, hydrazide dihydrazide Carboxylic acid dihydrazides, carbonic acid polyhydrazides such as carbonic acid dihydrazide, carbodihydrazide, thiocarbodihydrazide, 4,4'-oxybisbenzenesulfonylhydrazide, polyacrylic acid hydrazide, polyurethane having hydrazine functional group, bisphenol type or The adduct body of an alicyclic epoxy resin and the said hydrazine or hydrazide etc. can be mentioned. Of these, carboxylic acid dihydrazides are preferable, and adipic acid dihydrazide is more preferable from the viewpoint of water solubility. Hydrazine compounds have the property of reacting quickly with ketone groups. Therefore, it reacts with the carboxyl group contained in the polyurethane resin (A) or the styrene-maleic acid resin derivative (B) in the water-based primer composition of the present invention and further with the ketone group on the corona-treated polyester substrate, and the resin and the polyester substrate Improve the adhesion. The amount used may be small, and the blending amount of the hydrazine compound is preferably 0.01% to 2.0% in 100% by weight of the aqueous primer composition in the present invention.

Furthermore, other known crosslinking agents may be added to the aqueous primer composition of the present invention. Thereby, a cured coating film excellent in film strength and chemical resistance can be formed. For example, a polyaziridine compound, a polyepoxy compound, a polycarbodiimide compound, a metal chelate compound, a polyoxazoline compound, a polyisocyanate, a blocked polyisocyanate, a partially or completely etherified amino resin, and the like can be used as a crosslinking agent. These crosslinking reactions can be caused at room temperature, or can be promoted by heating or addition of a known reaction catalyst. Two or more kinds of crosslinking agents can be used in combination. On the other hand, polycarbonyl compounds and polyaldehyde compounds having reactivity with hydrazine compounds can be used as necessary.

The aqueous primer composition in the present invention necessarily contains water as a medium, and is preferably 50% or more in 100% by weight of the medium in the aqueous primer composition. Moreover, an organic solvent may be included in the range which does not inhibit the performance of an aqueous primer composition, and an alcohol solvent is particularly preferable. In order to improve the leveling property (wetting property), trapping property, and halftone dot reproducibility during printing, ethanol, isopropanol, normal propanol, methylpropylene glycol, etc. are particularly preferable, although there is no particular limitation, but the medium in the aqueous primer composition It is preferable to use 5 to 30% of 100% by weight of isopropanol, normal propanol or a mixture thereof.

The viscosity of the water-based primer composition of the present invention is preferably in the range of 10.0 seconds to 30.0 seconds at Zaan Cup # 4 (25 ° C.) from the viewpoint of printability during printing. It can be adjusted by appropriately selecting the type and amount of raw materials, for example, polyurethane, other resins, aqueous solutions, and the like.

  The water-based primer composition of the present invention in the present invention may contain other water-soluble / water-dispersible polymer materials, such as polyurethane resins other than the polyurethane resin (A), vinyl chloride-vinyl acetate copolymer resin, Chlorinated polypropylene resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, cellulose modified resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic acid resin, terpene Examples thereof include resins, phenol-modified terpene resins, ketone resins, butyral, and modified resins thereof. These resins can be used alone or in admixture of two or more, and the content thereof is preferably 5 to 25% by weight based on the total weight of the aqueous primer composition.

  The water-based primer composition of the present invention can appropriately contain known additives as additives, and known additives such as pigment derivatives, pigment dispersants, wetting agents, adhesion aids can be used as necessary in the production of primer compositions. Agents, leveling agents, antifoaming agents, antistatic agents, trapping agents, antiblocking agents, wax components, silica particles and the like can be used.

  The aqueous primer composition of the present invention can be produced by dissolving and / or dispersing the polyurethane resin (A) with water, a mixed solution of water and an organic solvent, and a disper. In some cases, a styrene-maleic acid resin derivative (B) or a copolymer (C) of vinyl chloride and other double bondable monomers may be used in combination. If it is difficult to dissolve in the solvent mixed solution, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill or the like may be used.

  When the water-based primer composition of the present invention contains bubbles or unexpectedly large particles, 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 aqueous primer composition of the present invention can be used in known printing methods such as gravure printing and flexographic printing. When printing, it is diluted with an aqueous solution such as ethyl alcohol, isopropyl alcohol, normal propyl alcohol, and other organic solvents and water to a viscosity and concentration suitable for gravure printing and flexographic printing. , Alone or mixed and fed to each printing unit.

The polyester base material used in the present invention is not particularly specified as a film thickness, but those having a thickness of 15 μm to 200 μm can be used, and the printing surface is preferably corona-treated. In addition, the polyester substrate may be vapor-deposited with a metal oxide such as silica or alumina for the purpose of imparting an oxygen / water vapor barrier function, and the vapor-deposited surface may be coated with polyvinyl alcohol or the like. Further, surface treatment such as corona treatment may be applied.

The printed matter of the present invention is formed by printing and drying the aqueous primer composition of the present invention on a polyester substrate using the above printing method to form a primer layer, and further printing and drying the printing ink composition thereon. Then, it can be created by forming a printing ink layer. The printing ink composition may be an oil-based ink composition or a water-based ink composition.

The printing ink composition used in the present invention comprises a pigment, a binder, a solvent, water, or the like. Examples of the binder include fiber materials such as nitrocellulose-based, cellulose acetate / propionate, chlorinated polypropylene-based, vinyl chloride- A vinyl acetate copolymer system, a polyester system, an acrylic system, a polyurethane system and an acrylic urethane system, a polyamide system, a polybutyral system, a cyclized rubber system, a chlorinated rubber system, or a binder in which these are used in combination as appropriate.

There is no restriction | limiting in particular as a pigment used for a printing ink composition, The organic and inorganic pigment currently used for general ink, a coating material, a recording agent, etc. can be used together. Organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, isoindoline, etc. These pigments are mentioned. Further, although not limited to the following examples, for example, carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthal yellow, chromophthal red, phthalocyanine blue, phthalocyanine green, dioxazine violet Quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo Bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigment, etc. Can be mentioned.

Examples of the white inorganic pigment as the pigment in the printing ink composition include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica. It is preferable to use titanium oxide for the pigment of the white ink from the viewpoint of coloring power, hiding power, chemical resistance, and weather resistance. From the viewpoint of printing performance, the titanium oxide is subjected to silica and / or alumina treatment. Is preferred.

Non-white inorganic pigments are not limited to the following examples, but include, for example, carbon black, aluminum powder, mica (mica), bronze powder, chrome vermillion, chrome lead, cadmium yellow, cadmium red, ultramarine, and bitumen. , Bengara, yellow iron oxide, iron black, titanium oxide, zinc oxide, etc., and aluminum is in the form of a powder or paste, but it is preferably used in the form of a paste from the viewpoint of handling and safety. Whether to use leafing is appropriately selected from the viewpoint of brightness and density.

Further, in the production of the printing ink composition used in the present invention, known additives as necessary, such as pigment derivatives, pigment dispersants, wetting agents, adhesion aids, leveling agents, antifoaming agents, antistatic agents, Trapping agents, antiblocking agents, wax components, silica particles, and the like can be used.

As a printing method of the aqueous primer composition and the printing ink composition for producing the printed material of the present invention, a known method can be used. Examples include gravure printing and flexographic printing. The thickness of the ink layer is preferably 0.1 μm to 100 μm. When the thickness is less than 0.1 μm, the color development of the ink is insufficient.

In general, the printed layer is detached (removed) from the printed material of the polyester base by immersing it in an aqueous alkaline solution. In the alkaline aqueous solution used for removing the printing layer in the present invention, the alkaline substance to be used is not particularly limited, and sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ₂ ). , Ammonia and the like. Preferably it is NaOH or KOH. As a method for producing an alkaline aqueous solution, NaOH, KOH, ammonia or the like may be uniformly dissolved or dispersed in water and adjusted to a specified concentration or pH as appropriate. Usually, the conditions for removing the printed layer are 10 ° C. or higher and 100 ° C. or lower, pH 11 or higher, or immersed in an alkaline aqueous solution having a concentration of 0.5 to 3.0% by weight for 30 minutes, washed with water and dried. The method of removing 90% or more is mentioned. The pH is preferably 11.0 or more, more preferably 13.0 or more. The concentration is preferably 0.5 to 3.0% by weight aqueous solution, more preferably 1.0 to 2.5% by weight aqueous solution. The immersion temperature is preferably 10 ° C. or higher and 100 ° C. or lower, more preferably 15 ° C. or higher and 90 ° C. or lower, and still more preferably 20 ° C. or higher and 80 ° C. or lower. The immersion time is within 60 minutes, more preferably within 30 minutes, and even more preferably within 20 minutes. Thereafter, the removal rate of the printed layer when washed with water and dried is preferably 90% or more, more preferably 95% or more, and still more preferably 98% or more.

The amount of the alkaline aqueous solution used is not uniform depending on the size of the printed polyester base, but it is required to be 5 to 20 times for a very large one, and 0.2 to 5 times for a small pulverized one. Further, in order to improve efficiency, circulation type washing may be performed. The washing time is preferably within 30 minutes in the recycling process. The drop-off rate of the ink layer may be 90% or more, preferably 98% or more, and more preferably 99.9% or more.

In the method of the prior art document described in the present specification, the printed layer cannot be sufficiently removed under a stirring condition in an alkaline aqueous solution for 30 minutes unless the temperature is high at 90 ° C. However, when the water-based primer composition of the present invention is used, even under low temperature conditions such as 80 ° C. to 60 ° C. within 30 minutes, 60 ° C. to 40 ° C. within 30 minutes, and 40 ° C. to 20 ° C. within 30 minutes. The removal rate of the printed layer is not significantly changed by the alkaline aqueous solution treatment, and is very good. In addition, the separated printed layer can be easily recovered without being finely dispersed.

With the printed matter of the present invention, the printed layer can be removed in an alkaline aqueous solution, washed with water and dried to obtain a regenerated polyester substrate. Further, the recycled polyester base material can be regenerated into pellets by an extruder and used.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. In the present invention, parts and% represent parts by weight and% by weight unless otherwise noted.
As the weight average molecular weight, GPC (gel permeation chromatography) “Shodex GPC System-21” manufactured by Showa Denko KK was used. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent based on the difference in molecular size. Tetrohydrofuran is used as a solvent, and the weight average molecular weight is determined in terms of polystyrene.

[Synthesis Example 1]
While introducing nitrogen gas in a reactor equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction tube, 140.0 parts of polytetramethylene glycol (hereinafter “PTMG”) having a number average molecular weight of 2000, number average 35.0 parts of polyethylene glycol (hereinafter “PEG”) having a molecular weight of 2000, 25.0 parts of 2,2-dimethylolpropionic acid (hereinafter “DMPA”) and 91.3 parts of isophorone diisocyanate (hereinafter “IPDI”) were added to methyl ethyl ketone ( (Hereinafter referred to as “MEK”) was refluxed in 72.8 parts at 80 ° C. for 6 hours to obtain a terminal isocyanate prepolymer, and then cooled to 40 ° C. to obtain a solvent solution of the terminal isocyanate prepolymer. Next, 23.3 parts of isophorone diamine (hereinafter “IPDA”), 1.0 part of dibutylamine (hereinafter “DBA”) and 663.7 parts of acetone were mixed with the obtained terminal isocyanate prepolymer solution. The solution was gradually added at room temperature and reacted at 80 ° C. for 1 hour to obtain a solvent-type polyurethane resin solution. Next, 11.3 parts of 28% ammonia water and 736.5 parts of ion-exchanged water are gradually added to the solvent-type polyurethane resin solution to neutralize it, so that it becomes water-soluble. Then, water was added to adjust the solid content to obtain a polyurethane resin PU1 having an acid value of 33.1 mg KOH / g, a solid content of 30% and a weight average molecular weight of 30000.

[Synthesis Examples 2 to 8]
Polyurethane resins (PU2 to PU8) were obtained in the same manner as in Synthesis Example 1 using the raw materials and preparation ratios shown in Table 1. In addition, the abbreviation of a raw material is represented below.
In Synthesis Example 7, the terminal isocyanate prepolymer in the procedure in Synthesis Example 1 was set to NCO / OH = 0.7 to obtain a terminal hydroxyl group polyurethane resin, and no chain extension reaction was performed.
(Here, NCO / OH is the total number of hydroxyl groups of the compound (d) having the number of moles of isocyanate groups in the polyisocyanate (b), the polymer polyol (c), and a carboxyl group and at least two active hydrogen-containing groups in the molecule). Represents the ratio of the number of moles)
PMPA: poly (3-methyl-1,5-pentaneadipate) diol PPA: poly (1,2-propylene adipate) diol PC: polycarbonate diol PPG: polypropylene glycol AEA: 2-hydroxyethylethylenediamine

[Comparative Synthesis Examples 1 to 5]
Polyurethane resins (PU9 to PU13) were obtained in the same manner as in Synthesis Example 1 with the raw materials and preparation ratios shown in Table 1.

[Comparative Synthesis Example 6: Synthesis of acrylic modified polyester resin (PESAc)]
The following was synthesized based on the examples described in Japanese Patent No. 3460946.
In a stainless steel autoclave equipped with a stirrer, thermometer and partial reflux condenser, 460 g of dimethyl terephthalate, 460 g of dimethyl isophthalate, 31 g of fumaric acid, 341 g of ethylene glycol, 650 g of 3 methylpentanediol, and tetra-n-butyl titanate. 52 g was charged and a transesterification reaction was carried out at 160 to 220 ° C. over 4 hours. Next, the temperature was raised to 250 ° C., and the pressure of the reaction system was gradually reduced, followed by reaction for 1 hour 30 minutes under a reduced pressure of 0.2 mmg to obtain a polyester resin. 75 g of the obtained polyester resin, 56 g of methyl ethyl ketone, and 19 g of isopropyl alcohol were charged and heated and stirred to dissolve the resin. To the dissolved resin, 17.5 g of methacrylic acid, 7.5 g of ethyl acrylate, and a solution of 1.2 g of azobisdimethylvaleronitrile dissolved in 10 g of methyl ethyl ketone were added dropwise at a constant rate, and the mixture was further stirred for 3 hours. Thereafter, 375 g of water and 25 parts of triethylamine were added to the reaction solution, and the mixture was further stirred for 1 hour. Next, the temperature of the solution was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off to obtain an acrylic modified polyester resin (PESAc) solid content of 25%.

[Comparative Synthesis Example 7: Synthesis of polystyrene-modified acrylic resin (STAc)]
The following was synthesized based on the examples described in Japanese Patent No. 3934292.
25 parts of acrylic acid in a reaction vessel, 54 parts of isobutyl methacrylate, 10 parts of butyl methacrylate, 10 parts of polystyrene having a molecular weight of 6000 having a methacryl group at one end (macromonomer AS-6 manufactured by Toa Gosei Co., Ltd.), 1 part of divinylbenzene, ethyl acetate 150 parts, 150 parts isopropyl alcohol, and 1. Two parts of azobisisobutyronitrile were added and mixed, and polymerized at 70 ° C. for 8 hours under a nitrogen gas atmosphere to obtain an acrylic resin (STAc) having polystyrene in the side chain. The solid content of the obtained resin solution was 25% by weight.

(Example 1: Preparation of water-based primer composition S1)
65 parts of polyurethane resin PU1, 30 parts of water, and 5 parts of isopropanol (hereinafter “IPA”) were mixed and stirred with a disper for 30 minutes to obtain an aqueous primer composition S1.

(Examples 2 to 16: Preparation of water-based primer compositions S2 to S16)
Water-based primer compositions S2 to S16 were obtained in the same manner as in Example 1 with the blending ratios of the raw materials shown in Table 2-1. Since PU12 could not be made into an aqueous solution due to insufficient solubility in water and became a gel, it was excluded from the study.
"SMA1440H" is a Sartomer styrene-maleic anhydride resin (styrene: maleic anhydride = 3: 2, molecular weight 7000) esterified with alcohol by half amount of acid value, and the contained carboxyl group is neutralized with ammonia. It has been done. (Acid value before neutralization 180 mgKOH / g, solid content 25% aqueous solution)
“Viniblanc 700” is an aqueous solution of a copolymer of vinyl chloride, acrylic acid ester, vinyl acetate and the like manufactured by Nissin Chemical Industry. (Acid value 57 mgKOH / g, solid content 30% aqueous solution)

(Comparative Examples 1-4, 7-16: Creation of water-based primer compositions T1-T4, T7-T16)
Aqueous primer compositions T1 to T4 and T8 to T16 were obtained in the same manner as in Example 1 with the blending ratios of the raw materials shown in Table 2-2.

(Comparative Examples 5 and 6: Preparation of oily primer compositions T5 and T6)
Oily primer compositions T5 and T6 were prepared using PESAc and STAc synthesized in Comparative Synthesis Examples 7 and 8.

(Preparation of printing ink composition (oil-based))
A terminal NCO urethane prepolymer obtained by reacting 10 parts of phthalocyanine indigo pigment, PPA having a molecular weight of 2000 and PPG having a molecular weight of 2000 (weight ratio of 2: 1) with IPDI at NCO / OH = 2.3 is chain-extended by IPDA. 30 parts of polyurethane resin having amino group-containing molecular weight 35000, solid content 30%, solvent composition ethyl acetate: isopropanol = 6: 4, solid content of vinyl chloride-vinyl acetate polymer (Solvine TA5R manufactured by Nisshin Chemical Co., Ltd.) 30 10 parts of a 50% ethyl acetate solution and 50 parts of a mixed solvent of ethyl acetate: isopropanol = 6: 4 were mixed and kneaded with an Eiger mill for 15 minutes to obtain an oil-based ink composition X1.

(Preparation of printing ink composition (aqueous))
10 parts of phthalocyanine indigo pigment, 40 parts of PU10, 40 parts of water and 10 parts of normal propanol were mixed and kneaded with an Eiger mill for 15 minutes to obtain a water-based ink composition Y1.
(Example 11)
<Printing of water-based primer composition and printing ink composition>
The aqueous primer composition S1 is diluted with a mixed aqueous solution (water: IPA = 7: 3) so that the viscosity is 16 seconds (25 ° C., Zaan Cup No. 3), and the oil-based ink composition X1 is mixed with a mixed solvent ( Diluted with toluene: MEK = 6: 4) to a viscosity of 16 seconds (25 ° C., Zaan Cup No. 3), and a 25 μm thick gravure printing machine equipped with a solid plate with a laser plate depth of 30 μm A corona discharge-treated polyester film “Product Name E-5100” (manufactured by Toyobo Co., Ltd.) was overprinted in the order of water-based primer S1 and oil-based ink X1 at a printing speed of 50 m / min to obtain a printed matter G1.

(Examples 12 to 30)
By the same method as in Example 11, printed materials G2 to G16 (Examples) were obtained using the aqueous primer compositions S2 to S16 described in Table 2-1. In Examples 27 to 30, the aqueous primer composition uses S13 to S16, the printing ink composition uses the aqueous ink Y1, and the mixed aqueous solution (water: IPA = 7: 3) has a viscosity of 16 seconds ( 25 degreeC, Zaan cup No.3) It diluted so that it might become, and the same overprinting was performed, and printed matter G17-G20 was obtained.

(Comparative Examples 11-30)
By the same method as in Example 11, printed materials H1 to H4 and H7 to H16 (comparative examples) were obtained using the aqueous primer compositions T1 to T4 and T7 to T16 shown in Table 2-2. The oily primer compositions T5 and T6 were diluted with a mixed solvent (toluene: MEK = 6: 4) so that the viscosity was 16 seconds (25 ° C., Zahn cup No. 3). Printing was performed to obtain printed materials H5 and H6. In Comparative Examples 27 to 30, the water-based primer composition uses T8 to T11, the printing ink composition uses water-based ink Y1, and the mixed aqueous solution (water: IPA = 7: 3) has a viscosity of 16 seconds ( It diluted so that it might become 25 degreeC and Zaan cup No.3), it printed similarly, and H17-H20 were obtained.

The printed materials G1 to G20 and H1 to H20 obtained in Examples 11 to 30 and Comparative Examples 11 to 30 were tested for tape adhesion, blocking resistance, peelability with an alkaline aqueous solution, and water resistance.

<Tape adhesiveness>
After 1 hour of printing the printed materials G1 to G20 and H1 to H20, a cellophane tape was applied to the printing surface and pressed strongly with a roller 5 times, and then the appearance of the printed film when peeled quickly in the 90 ° direction was visually determined. The determination criteria were as follows.
○ ···· Not peeled off at all.
○ Δ: 90% or more of the printed film remained on the film.
Δ: 80% of the printed film remained on the film.
Δ ×: 50% or less of the printed film remained on the film.
× ··· All peeled off.
○ and ○ △ are ranges where there is no practical problem.

<Blocking resistance>
Prints G1～G20, overlapping the film to contact the printing surface and the non-printing surface for H1～H20, applying a load of 10 kgf / cm ^2, allowed to stand for 24 hours under the environment of 40 ℃ 80% RH, after removal The state of the transfer of the ink film to the non-printing surface was evaluated in five stages. The evaluation results are shown in Table 3.
○ The amount of ink transferred to the non-printing surface is 0%.
○ △ ・ ・ ・ Transition amount less than 5%.
Δ: Transfer amount is 5% or more and less than 25%.
Δ × ··· Transition amount of 25% or more and less than 50%.
× ・ ・ ・ ・ ・ Close contact with the front.
○ and ○ △ are ranges where there is no practical problem.

<Peelability with alkaline aqueous solution>
The printed materials G1 to G20 and H1 to H20 are cut into 4 cm × 4 cm, immersed in 400 g of 2% and 1% aqueous sodium hydroxide (NaOH), and stirred at 90 ° C., 40 ° C. and 25 ° C. for up to 30 minutes, washed with water After drying, the peelability of the printed part was evaluated.
○: 100% of the printed part is peeled off within 10 minutes of stirring.
○ Δ: 100% of the printed part is peeled off within 20 minutes of stirring.
Δ: ... 50 to 80% of the printed part peeled off after 30 minutes of stirring.
Δx: 20 to 50% of the printed part peeled off after 30 minutes of stirring.
×: 0 to 20% of the printed part peeled off after 30 minutes of stirring.
(However, ○ * ... The printed part is peeled 100% or more in 10 minutes with stirring, but the printed part is finely dispersed in water and cannot be recovered.)
○ and ○ △ are ranges where there is no practical problem.

<Water resistance>
The printed materials G1 to G20 and H1 to H20 were cut out to 4 cm × 4 cm, immersed in 400 g of ion exchange, stirred at 40 ° C. and 25 ° C. for 30 minutes, washed with water and dried, and then evaluated for the peelability of the printed portion.
○ ・ ・ ・ ・ No peeling.
○ Δ ···································································································································
Δ · · · 20-30% of the printed part is peeled off.
Δ ×: 30 to 40% of the printed part is peeled off.
X: 40% or more peeling of the printed part.
○ and ○ △ are ranges where there is no practical problem.

From the evaluation results, the water-based primer composition for forming the primer layer in the printed matter printed in the order of the primer layer and the printing ink layer on the polyester substrate contains a polyurethane resin (A) having a carboxyl group. The polyurethane resin (A) is at least partially neutralized with an amine compound (a-1), and the polyurethane resin (A) has an acid value before neutralization of 25 to 45 mgKOH / g. When using an aqueous primer composition, the aqueous primer composition has excellent alkaline aqueous detachability at both high and low temperatures, and has excellent water resistance, tape adhesion and blocking resistance of the printed layer. I understood.

Claims (6)

A water-based primer composition for forming the release primer layer of a printed material in the order of a polyester substrate, a release primer layer, and a printing layer, and is characterized by the following (1) to (3).
(1) The water-based primer composition contains a polyurethane resin (A) having a carboxyl group.
(2) At least a part of the carboxyl groups of the polyurethane resin (A) is neutralized with the amine compound (a-1).
(3) The acid value before neutralization of the polyurethane resin (A) is 25 to 45 mgKOH / g. Polyurethane resin (A)
At least one structural unit selected from the group consisting of a polyethylene oxide structural unit, a polypropylene oxide structural unit, a polytetramethylene oxide structural unit, and a structural unit (a-2) derived from polyester comprising adipic acid and a diol having a branched structure The water-based primer composition of Claim 1 containing this. 3. The polyurethane resin (A) contains a polyethylene oxide structural unit and / or a structural unit derived from polyester composed of adipic acid and 3-methyl-1,5-pentanediol in the main chain. The water-based primer composition described. The aqueous primer composition according to any one of claims 1 to 3, further comprising a styrene-maleic acid resin derivative (B). The aqueous primer composition according to any one of claims 1 to 4, further comprising a copolymer (C) of vinyl chloride and other double bond monomers. 6. A desorption primer layer obtained by printing the water-based primer composition according to any one of claims 1 to 5 on a polyester film substrate, and further a printing ink composition on the desorption primer layer. Printed matter having a printed layer on which is printed.