JP6668857B2 - Laminated body and method for manufacturing the same - Google Patents

Description

The present invention relates to a laminate and a method for producing the same, and more particularly, to a laminate that achieves both the stability and re-dissolvability of an aqueous ink and the water resistance of the laminate, and a method for producing the same. is there.

In recent years, in the printing ink industry, from the viewpoints of safety and health at work, protection of environment, reduction of residual solvent in packaging materials, and the like, demands for making printing ink water-based have been increasing. However, water-based printing inks have a problem that drying is slower than solvent-based inks, adhesion and wetting to a substrate are poor, and the water resistance is low, so that the laminated product is inferior in boilability. .

  As a conventional technique for imparting water resistance of a laminate using an aqueous ink, for example, by adding a crosslinking agent to the ink as in Prior Documents 1 to 3, the carboxyl group contained in the resin in the aqueous ink and the crosslinking agent A method of forming a crosslinked structure with the carbodiimide group contained in the above. However, in such a method, since a crosslinking agent is added to the aqueous ink, a crosslinked structure is formed between the resin and the crosslinking agent in the aqueous ink, and the stability of the aqueous ink is reduced. Reuse of the ink was difficult.

Therefore, it is necessary to separately mix or separate the carboxyl group contained in the resin in the aqueous ink and the carbodiimide group contained in the crosslinking agent in order to achieve both the stability of the aqueous ink and the water resistance of the laminate. It is.

JP 2008-049706 A JP 2008-001911 A JP-A-2002-060451

SUMMARY OF THE INVENTION An object of the present invention is to provide a laminate having both the remaining wall stability and re-dissolvability of an aqueous ink and the water resistance and laminate strength of the laminate.

The present inventor has conducted intensive studies on the above problem, and as a result, by adding a crosslinking agent which has been conventionally added to the aqueous ink to the adhesive, in the laminate, the carboxyl group contained in the resin in the aqueous ink was reduced. A crosslinked structure is formed near the interface of the ink layer / adhesive layer between the carbodiimide group contained in the compound added to the adhesive, and a laminate having both water resistance of the laminate, stability of the ink, and resolubility is obtained. We found that we could provide.

That is, the present invention provides an ink layer (F2) formed from an aqueous ink (A), an adhesive layer (F3) formed from an adhesive (B), and a sealant film on a base film (F1). (F4) and the related packaging bag laminate having in this order.
However, it is characterized by satisfying the following (1) and (2).
(1) A compound (b) containing an aqueous polyurethane resin (a1) having a carboxyl group and having an acid value of 10 to 60 mgKOH / g and a hydroxyl value of 10 to 20 mgKOH / g, and having a carbodiimide group (A). Not contained.
(2) The adhesive (B) contains the compound (b) having a carbodiimide group.

The present invention relates to the laminate for a packaging bag, wherein the ratio (mol) of the carboxyl group to the carbodiimide group is carboxyl group / carbodiimide group = 1 / 0.5 to 1/6 (molar ratio).

The present invention also relates to the laminate, wherein the adhesive (B) further contains a compound (c) having an isocyanate group and a compound (d) having a hydroxyl group.

The present invention also relates to the laminate, wherein the aqueous polyurethane resin (a1) having a carboxyl group further has a hydroxyl group.

Further, the present invention has, on a base film (F1), the ink layer and (F2), and contact Chakuzaiso (F3), and a sealant film (F4) in the manufacturing method of the packaging bag laminate having in this order Further, the present invention relates to a method for producing a laminate, which includes the following steps (1) to (3).
(1) A compound containing an aqueous polyurethane resin (a1) having a carboxyl group and having an acid value of 10 to 60 mgKOH / g and a hydroxyl value of 10 to 20 mgKOH / g on a base film (F1) and having a carbodiimide group ( a step of printing an aqueous ink (A) containing no b) to form an ink layer (F2).
(2) A step of applying an adhesive (B) containing a compound (b) having a carbodiimide group on the ink layer (F2) to form an adhesive layer (F3).
(3) A step of bonding a sealant film (F4) on the adhesive layer (F3).

ADVANTAGE OF THE INVENTION According to this invention, it became possible to obtain the laminated body which made the balance of the residual wall thickness and re-dissolvability of aqueous ink, the water resistance of a laminated body, and the laminated strength compatible.

The laminate of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

The laminate of the present invention comprises, on a base film (F1), an ink layer (F2) formed from an aqueous ink (A), an adhesive layer (F3) formed from an adhesive (B), and a sealant. A laminate having a film (F4) in this order. Further, the aqueous ink (A) contains the resin (a) having a carboxyl group, does not contain the compound (b) having a carbodiimide group, and the adhesive (B) contains the compound (b) having a carbodiimide group. It is characterized by containing.

First, the water-based ink (A) will be described. In this specification, the aqueous ink (A) contains the resin (a) having a carboxyl group and does not contain the compound (b) having a carbodiimide group. Examples of the resin (a) include an aqueous polyurethane resin (a1), an aqueous acrylic resin, and an aqueous urethane / acryl composite resin. Preferably, it is an aqueous polyurethane resin (a1). The resin (a) can be used alone or in combination of two or more. The content of the resin (a) is preferably 4 to 25% by weight, more preferably 6 to 20% by weight, based on the total weight of the aqueous ink in terms of solid content.

In the present invention, the acid value of the resin (a) having a carboxyl group is preferably 10 to 60 mgKOH / g when the aqueous polyurethane resin (a1) is used. More preferably, the acid value is 25 to 45 mgKOH / g. When the acid value is 10 mgKOH / g or more, stability with time and re-dissolution tend to be improved, and when the acid value is 60 mgKOH / g or less, water resistance tends to be improved. The acid value is a value obtained by converting the amount of acid in 1 g of resin calculated by titrating an acid with an alkali into the number of mg of potassium hydroxide, and is a value measured according to JIS K0070.

The aqueous polyurethane resin (a1) includes not only an aqueous polyurethane resin having no urea bond but also an aqueous polyurethane urea resin having a urea bond. The aqueous polyurethane resin (a1) can be produced by a known method, and the production method is not limited. The aqueous polyurethane resin (a1) can be obtained, for example, by reacting a polyisocyanate, a polyol, and a compound having a carboxyl group and at least two active hydrogen-containing groups in a molecule (urethane-forming reaction). In the urethanization reaction, when a prepolymer having an isocyanate group at a terminal is produced and further reacted with an organic polyamine as a chain extender (chain extension reaction), an aqueous polyurethane urea resin can be obtained. In addition, in this specification, an "isocyanate group" means a -N = C = O group, and has the same meaning as an isocyanato group.

As the polyisocyanate that can be used when producing the aqueous polyurethane resin (a1), 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 Carboxyl group of isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate or dimer acid to isocyanate group Inverted dimer diisocyanate is a typical example. These can be used alone or in combination of two or more. Isophorone diisocyanate is preferred in terms of reactivity and the like.

The polyol can be selected from polyether polyol, polyester polyol, polycaprolactone polyol, polycarbonate polyol and the like. These can be used alone or in combination of two or more. More preferably, it is selected from polyether polyols and polyester polyols.

Examples of the polyether polyol include polymers and copolymers such as methylene oxide, ethylene oxide, propylene oxide, and tetrahydrofuran. These can be used alone or in combination of two or more. Particularly, a polymer of ethylene oxide, that is, polyethylene glycol is preferable. When polyethylene glycol is used, the resolubility becomes good. Further, polytetramethylene glycol can also be suitably used.

When polyethylene glycol is used, the content of ethylene oxide units (hereinafter abbreviated as EO%) of the aqueous polyurethane resin (a1) is preferably in the range of 4 to 30%. When the EO% is 4% or more, the resolubility tends to be improved, and when the EO% is 30% or less, the water resistance tends to be improved. In addition, EO% is a solid content weight ratio of polyethylene glycol in the aqueous polyurethane resin (a1).

Polyester polyols include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, pentanediol, 2-methyl-1,3-propanediol, neopentyl glycol, Methyl-1,5-pentanediol, hexanediol, octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, Glycols such as 2,4-butynediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, diethylene glycol, propylene glycol, dipropylene glycol, and low molecular weight polyols; Acid, phthalic acid, isophthalic acid, terephthalic acid , Maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, trimellitic acid, pyromellitic acid and other polycarboxylic acids or anhydrides thereof Dehydration condensates or polymers are mentioned. These can be used alone or in combination of two or more. As the glycols, branched glycols are preferred. In particular, a polymer of 3-methyl-1,5-pentanediol and adipic acid is preferable from the viewpoint of adhesion and lamination strength.

As the polycarbonate diol, for example, a carbonate component such as alkylene carbonate, diallyl carbonate, dialkyl carbonate or phosgene, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, pentanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol , 2-butyl-2-ethyl-1,3-propanediol, 1,4-butynediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, diethylene glycol, polypropylene glycol Lumpur include condensates of low molecular weight polyols such as dipropylene glycol. These can be used alone or in combination of two or more.

In addition to the above polyols, a low molecular polyol may be appropriately used in combination with the above polyols for the purpose of increasing the urethane bond density in the skeleton of the aqueous polyurethane resin (a1) or introducing a branched structure or a tertiary amino group into the resin. it can.

Examples of low molecular polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, , 4-cyclohexanedimethanol, octanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butylenediol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,2 4-butanetriol, 1,2,6-hexanetriol, pentaerythritol, sorbitol, triethylene glycol, N, N-bis (hydroxypropyl) aniline and the like.

As the low molecular polyol, 1,4-cyclohexanedimethanol, trimethylolpropane, and N, N-bis (hydroxypropyl) aniline are preferable from the viewpoint of water resistance.

As used herein, the term "active hydrogen-containing group" refers to a group having an active hydrogen that can react with an isocyanate group such as a hydroxyl group and an amino group.

In order to include a carboxyl group in the aqueous polyurethane resin (a1), it is preferable to use a compound having a carboxyl group and at least two active hydrogen-containing groups in the molecule. Examples of the compound having a carboxyl group and at least two active hydrogen-containing groups in the molecule include dimethylolalkanoic acids such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. Diamine-type amino acids such as glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid and diaminobenzenesulfonic acid. These can be used alone or in combination of two or more.

The aqueous polyurethane urea resin can be obtained by further reacting the aforementioned polyurethane resin with an organic diamine or the like as a chain extender (chain extension reaction). By containing a urea bond, the laminate strength and the resolubility are improved.

Examples of the chain extender include hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, nonamethylenediamine, xylylenediamine, isophoronediamine, piperazine and derivatives thereof, phenylenediamine, tolylenediamine, xylenediamine, adipic dihydrazide, and isophthalic acid. Diamines such as acid dihydrazide; and triamines such as diethylenetriamine.
Also, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate A known chain extender such as diols such as styrene and xylylene glycol; triols such as trimethylolpropane; pentaols such as pentaerythritol;

In addition, it has a hydroxyl group such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. When an organic diamine is used as a chain extender, a hydroxyl group can be introduced into a side chain in the aqueous polyurethane resin (a1). These can be used alone or in combination of two or more. When a monofunctional monoamine or monool is used in combination as a terminal terminator, the molecular weight can be controlled by terminating the chain extension.

It is preferable from the viewpoint of resolubility that the aqueous polyurethane resin (a1) having a carboxyl group further has a hydroxyl group in a side chain. In addition, when the adhesive contains a compound (c) having an isocyanate group due to having a hydroxyl group, a part of the compound (c) may be used in the vicinity of the interface between the adhesive layer (F3) and the ink layer (F2). By causing a crosslinking reaction (I) with a hydroxyl group of a side chain of the resin (a1), the crosslinking reaction (II) between the aqueous polyurethane resin (a1) and the compound (b) having a carbodiimide group is complemented, and further at the interface. Contributes to improved adhesion.

The crosslinking reaction (II) between the aqueous polyurethane resin (a1) and the compound (b) having a carbodiimide group, that is, a reaction near the interface between the adhesive layer (F3) and the ink layer (F2) is considered as follows. . When an adhesive is applied on the ink layer and the adhesive layer is formed, a low molecular weight component in the adhesive, a compound (b) having a carbodiimide group, a part of a compound (c) having an isocyanate group, and the like, It penetrates into the ink layer. If an organic solvent is used for the adhesive, the penetration and infiltration are further promoted.Therefore, near the boundary where the ink layer and the adhesive layer are in contact is not a single and clear interface, but both layers are mixed. It is presumed to be in a state. Therefore, a crosslinking reaction (II) occurs between a part of the compound (b) having a carbodiimide group in the adhesive layer (F3) and the carboxyl group of the aqueous polyurethane resin (a1) in the ink layer (F2).
When the compound (c) having an isocyanate group is present in the adhesive layer (F3), a part of the compound (c) and the hydroxyl group of the aqueous polyurethane resin (a1) in the ink layer undergo a cross-linking reaction (I) to form an interlayer. It is considered that the adhesion strength is further improved, leading to an improvement in water resistance and the like.

  The hydroxyl value of the aqueous polyurethane resin (a1) is more preferably 10 to 20 mgKOH / g. The hydroxyl value is a value obtained by converting the amount of hydroxyl group in 1 g of resin calculated by esterifying or acetylating the hydroxyl group in the resin and back-titrating the remaining acid with an alkali into mg of potassium hydroxide, according to JIS. K0070.

The weight-average molecular weight of the aqueous polyurethane resin (a1) is preferably in the range of 5,000 to 100,000. When the molecular weight of the aqueous polyurethane resin (a1) is 5,000 or more, water resistance and blocking resistance tend to be improved. When the molecular weight is 100,000 or less, the viscosity of the obtained aqueous printing ink does not increase, and And dispersion stability tend to be excellent.

Further, a catalyst can be used in the urethanization reaction. As a 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, Examples thereof include ethylhexoate cobalt, zinc naphthenate, cobalt naphthenate, and tetra-n-butyltin. Examples of the amine catalyst include tertiary amines such as tetramethylbutanediamine. These catalysts are used in the range of 0.001 to 1 mol% based on the polymer polyol.

When a solvent is used in the urethanization reaction, the reaction is not particularly limited, but is preferably performed at 50 to 100 ° C. for 10 minutes to 10 hours. When the reaction is performed without a solvent, the temperature is preferably from 90 to 180 ° C. The end point of the reaction is determined by quantification of an isocyanato group (-NCO) by viscosity measurement, IR measurement, titration or the like.

The chain extension reaction is not particularly limited, but is preferably performed at 30 to 80 ° C. for 10 minutes to 10 hours. The end point of the reaction is determined by quantification of an isocyanato group (-NCO) by viscosity measurement, IR measurement, titration or the like.

Examples of the basic compound for neutralizing the carboxyl group in the aqueous polyurethane resin (a1) include ammonia, monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, and monoethanolamine. Organic amines such as dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine and 2-amino-2-methyl-1-propanol; and inorganic alkalis such as sodium hydroxide and potassium hydroxide. One type or a combination of two or more types is used. From the viewpoints of water resistance, residual odor and the like of the printed matter, those which are water-soluble and have high volatility which easily dissociates by heat are preferable, and ammonia is particularly preferable.

As described above, the production method of the aqueous polyurethane resin (a1) is not specified, but examples thereof include an acetone method using an organic solvent that is inert to isocyanate and a hydrophilic solvent, and a solventless synthesis method using no solvent at all. Is preferably obtained by Examples of the organic solvent which is inert to isocyanate and hydrophilic 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. Amides and the like, etc., but the aqueous solution of polyurethane is usually removed by distillation under reduced pressure (desolvation), and even when used without desolvation, the drying speed is increased. Is preferred. In the case of removing the solvent, for example, after adding water and a basic compound as a neutralizing agent to the reaction solution, the temperature may be increased and the solvent may be removed under normal pressure or under reduced pressure by distilling off a necessary amount of the solvent. it can.

Examples of the aqueous acrylic resin that can be used as the resin (a) having a carboxyl group include a water-soluble acrylic resin and an emulsion acrylic resin (hereinafter, may be abbreviated as Em type). However, in any case, it is essential to include a carboxyl group. In the present invention, a water-soluble acrylic resin or an Em-type acrylic resin may be used alone, or a mixture of two or more thereof may be used.

The water-soluble acrylic resin can be obtained by solution polymerization or bulk polymerization according to a known method. For example, an organic solvent is charged into a reaction tank, and the temperature is raised in a nitrogen atmosphere. A mixture of a carboxyl group-containing ethylenically unsaturated monomer, an ethylenically unsaturated monomer containing an ethylenically unsaturated monomer copolymerizable therewith, and a radical polymerization initiator charged in the dropping layer are dropped. Any organic solvent can be used as long as it has no adverse effect on the reaction and subsequent treatment and dissolves the obtained resin. The obtained resin solution may be diluted with ion-exchanged water as it is after neutralization with a basic compound, or the organic solvent may be replaced with ion-exchanged water. Through the above steps, a water-soluble acrylic resin is obtained. However, depending on the ratio of (meth) acrylic acid, the ratio of hydrophobic monomer, the neutralization ratio, and the like, the acrylic resin may be an Em-type acrylic resin or a hydrosol-type acrylic resin.

  Examples of the carboxyl group-containing ethylenically unsaturated monomer include, for example, maleic acid, fumaric acid, itaconic acid, citraconic acid, or an alkyl or alkenyl monoester thereof, and β- (meth) acryloxyethyl monohexaphthalate. Esters, β- (meth) acryloxyethyl monosuccinate, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like.

Examples of the copolymerizable ethylenically unsaturated monomer include, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, and hexyl (meth) yl. ) Acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) ) Ethylenically unsaturated monomers containing a linear or branched alkyl group such as acrylate; styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinyl Phthalene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol acrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol acrylate, phenoxytetraethylene glycol methacrylate, phenoxyhexaethylene glycol acrylate, phenoxyhexaethylene glycol methacrylate, phenyl acrylate , An aromatic ethylenically unsaturated monomer such as phenyl methacrylate; an alicyclic alkyl group-containing ethylenically unsaturated monomer such as cyclohexyl (meth) acrylate or isobonyl (meth) acrylate; trifluoroethyl (meth) acrylate, Heptadecafluorodecyl (meta ) Fluorinated alkyl group-containing ethylenically unsaturated monomers such as acrylate; (meth) acrylamide, N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) Acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl- (meth) acrylamide, N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N- Di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) methacrylamide, N, N-di ( Butoxymethyl) acrylia N, N-butoxymethyl-N- (methoxymethyl) methacrylamide, N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) methacrylamide, N, N-dimethylaminopropyl Amide group-containing ethylenically unsaturated monomers such as acrylamide, N, N-diethylaminopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( Hydroxyl group-containing ethylenically unsaturated monomers such as (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, and allyl alcohol Diacetone (meth) acrylamide, a keto group-containing ethylenically unsaturated monomers such as acetoacetoxy (meth) acrylate; and the like.

As the radical polymerization initiator, known oil-soluble polymerization initiators can be used. For example, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate) Organic peroxides such as tert-butylperoxy-3,5,5-trimethylhexanoate and di-tert-butyl peroxide; 2,2'-azobisisobutyronitrile, 2,2'-azobis Examples include azobis compounds such as -2,4-dimethylvaleronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) and 1,1'-azobis-cyclohexane-1-carbonitrile. it can.

The basic compound used as the neutralizing agent is ammonia; monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine , N-methylmorpholine, organic amines such as 2-amino-2-ethyl-1-propanol; inorganic alkalis such as sodium hydroxide and potassium hydroxide; and one or more kinds are used in combination. However, in order to improve the water rub resistance of the printed coating film after drying, it is preferable to use a water-soluble and highly volatile one that is easily dissociated by heat, particularly ammonia, dimethylethanolamine, and trimethylamine. And triethylamine are preferred.

The acid value of the water-soluble acrylic resin is preferably 30 to 100 mgKOH / g. If the amount is less than 30 mgKOH / g, the dispersing power of the water-soluble acrylic resin is reduced, so that agglomerates are apt to be generated, and the stability of the water-based ink remains poor. On the other hand, if it exceeds 100 mgKOH / g, water resistance tends to deteriorate.

Further, the weight average molecular weight (Mw) of the water-soluble acrylic resin is preferably from 5,000 to 30,000. When the weight average molecular weight is less than 5,000, the dispersion stability of the resin fine particle dispersion tends to decrease, and the remaining wall stability of the aqueous ink tends to decrease, and the water resistance and the blocking resistance tend to deteriorate. On the other hand, even when the weight average molecular weight (Mw) exceeds 30,000, the viscosity is remarkably increased, and the remaining wall stability of the aqueous ink may decrease. The weight average molecular weight (Mw) referred to here is a value in terms of polystyrene measured by GPC (gel permeation chromatography).

Next, the Em type acrylic resin will be described. The Em-type acrylic resin can be obtained by emulsion-polymerizing an ethylenically unsaturated monomer using a surfactant or a polymer dispersant as an emulsifier. Among these, from the viewpoint of excellent film resistance of the laminate, it is preferable to use an Em-type acrylic resin using the above-mentioned water-soluble acrylic resin as an emulsifier.

A specific method for producing an Em-type acrylic resin will be described. First, an aqueous medium and the above-mentioned water-soluble acrylic resin are charged into a reaction tank, and heated to dissolve. Thereafter, a radical polymerization initiator is added while dropping the ethylenically unsaturated monomer under a nitrogen atmosphere. After the start of the reaction, the color of the solution in the reaction tank becomes pale, so that the formation of particle nuclei can be confirmed. After completion of the dropwise addition of the ethylenically unsaturated monomer, the desired Em-type acrylic resin or hydrosol-type acrylic resin can be obtained by reacting for several hours. The ethylenically unsaturated monomer may be dropped into the reaction vessel as it is, or may be dropped after being made into an emulsion in an aqueous medium in advance. The water-soluble acrylic resin functions as a protective colloid (shell component) in an aqueous medium, and stabilizes the generated particle nucleus (core component). The Em-type acrylic resin obtained by this method has a viscosity close to Newtonian and is very excellent in printability.

As the ethylenically unsaturated monomer, the above-mentioned ethylenically unsaturated monomer can be used. As the polymerization initiator, in addition to the above, a water-soluble polymerization initiator can be used. Examples of the water-soluble polymerization initiator include ammonium persulfate (APS), potassium persulfate (KPS), hydrogen peroxide, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, and the like.

When performing emulsion polymerization, a reducing agent can be used together with a polymerization initiator, if desired. Thereby, it becomes easy to accelerate the emulsion polymerization rate or to perform the emulsion polymerization at a low temperature.

Examples of such a reducing agent include reducing organic compounds such as metal salts such as ascorbic acid, ersorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, meta Examples thereof include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, Rongalit, and thiourea dioxide. These reducing agents are preferably contained in an amount of 0.05 to 5.0% based on 100% by weight of the ethylenically unsaturated monomer. It should be noted that the polymerization can be performed by a photochemical reaction, irradiation of radiation, or the like, without using the above-described polymerization initiator. The polymerization temperature is equal to or higher than the polymerization initiation temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, the temperature may be usually about 80 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate and the like may be used as a buffer, and octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan may be used as a chain transfer agent. And mercaptans such as t-dodecyl mercaptan can be used in an appropriate amount.

When the Em-type acrylic resin used in the present invention is obtained by radical polymerization, various surfactants can be used in addition to the water-soluble acrylic resin. These can be used alone or in combination of two or more.

The glass transition temperature (Tg) of the Em type acrylic resin is preferably in the range of 10 to 65 ° C. When Tg is 10 ° C. or higher, lamination strength and blocking resistance tend to be improved. On the other hand, even when the glass transition temperature is 65 ° C. or lower, the movement of the molecular chain is hardly inhibited even under low-temperature drying, the compatibility of the film formation and the core component and the shell component is increased, and the lamination strength tends to be improved. .

The acid value of the Em-type acrylic resin is preferably from 20 to 200 mgKOH / g. When it is at least 20 mgKOH / g, the stability of the Em-type acrylic resin will be improved, the crosslinking with the compound (b) having a carbodiimide group will be increased, and the water resistance tends to be improved. If it is less than 200 mgKOH / g, the water resistance tends to be good. The weight average molecular weight (Mw) is preferably in the range of 100,000 to 600,000. When the weight average molecular weight is 100,000 or more, a denser and tougher film is formed, and the laminate strength tends to be excellent. On the other hand, when it is 600,000 or less, a film is easily formed even under low-temperature drying, and the compatibility between the core component and the shell component becomes sufficient, and the laminate strength tends to be excellent.

The aqueous ink (A) can contain a pigment, a solvent, and the like, in addition to the resin (a) having a carboxyl group. In addition, if necessary, an extender, a pigment dispersant, a leveling agent, an antifoaming agent, a wax, a silane coupling agent, a plasticizer, an infrared absorber, an ultraviolet absorber, a fragrance, and a flame retardant can be included. Furthermore, resins other than the resins (a) listed above, for example, aqueous resins such as polyester resins, styrene-acrylic resins, styrene-maleic anhydride resins, rosin-modified maleic resins, cellulose resins, and chlorinated polyolefins Combinations are also possible.

Examples of the pigment include organic and inorganic pigments used in general inks, paints, recording agents, and the like. As organic pigments, azo, phthalocyanine, anthraquinone, perene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, isoindoline and the like Pigments. It is preferable to use copper phthalocyanine for the indigo ink from the viewpoint of coloring power.

Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, red iron, aluminum, mica (mica), and the like. It is preferable to use titanium oxide for the white ink, carbon black for the black ink, aluminum for the gold and silver inks, and mica for the pearl ink from the viewpoint of cost and coloring power.

The pigments can be used alone or as a mixture of two or more kinds for the purpose of adjusting hue and concentration. The pigment is contained in the aqueous ink in an amount that ensures the concentration and coloring power of the aqueous ink, preferably in an amount of 4 to 50% by weight based on the total weight of the aqueous ink.

Examples of the solvent include water and alcohol. The content of water in the aqueous ink (A) is preferably at least 5% by weight, more preferably at least 10% by weight. Examples of the alcohol system include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monoisopropyl. Ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono-n-hexyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono-n- Hexyl ether, 2 , 2,4-trimethylpentanediol-1,3-monoisobutyrate (Texanol, manufactured by Eastman Chemical Co., Ltd.) and the like, particularly isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, ethanol , Methanol is preferred. These can be used alone or in combination of two or more.

As an example of the production of the aqueous ink (A), there is a method in which a colorant and a resin (a) having a carboxyl group are kneaded (for example, a ball mill, an attritor, a sand mill, etc.), and then the additives are mixed. Can be In this case, in kneading, a pigment dispersant may be used as necessary.

Next, the adhesive (B) will be described. The adhesive (B) contains a compound (b) having a carbodiimide group. By containing the compound (b) having a carbodiimide group in the adhesive (B), the resin (a) having a carboxyl group in the aqueous ink (A), the ink layer (F2) and the adhesive layer (F3) A crosslinking reaction occurs near the interface. In the prior art, since the compound (b) having a carbodiimide group is added to the aqueous ink, the aqueous ink after printing (residual meat) increases in viscosity, gels, precipitates, and the like with the passage of time. There was a problem that the adhesiveness, lamination strength, and water resistance of the laminate using the composition were poor. According to the present invention, the compatibility between the water resistance of the laminate and the remaining wall stability of the aqueous ink (A), which has been difficult so far, is improved.

Examples of the compound (b) having a carbodiimide group include N, N'-dicyclohexylcarbodiimide, N, N'-diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, and the like. Commercially available products include, for example, Nisshinbo Co., Ltd., Carbodilite V-05, V-07, V-09, V-02, V-02-L2, SV-02, V-04, V-10, SW-12G, E-02, E-03A and the like.

The ratio (mol) between the carboxyl group and the carbodiimide group (-N = C = N-) is preferably carboxyl group / carbodiimide group = 1 / 0.5 to 1/6 (molar ratio). From the viewpoint of the water resistance of the laminate, the carboxyl group / carbodiimide group is more preferably 1/1 to 1/3 (molar ratio). When the compound (b) having a carbodiimide group is contained in the adhesive (B), a part of the compound (b) is formed in the vicinity of the interface of the adhesive layer (F3) / ink layer (F2) with the aqueous ink (A). A cross-linking reaction occurs between the resin (a) having a carboxyl group therein and the water resistance of the laminate is improved.

Since the crosslinking reaction mainly occurs near the interface between the adhesive layer (F3) and the ink layer (F2), the number of carboxyl groups (molar number) per unit volume of the ink layer (F2) is based on the unit of the adhesive layer (F3). The number (mol number) of carbodiimide groups per volume may be considered. In the vicinity of the interface, since both layers are mixed, it is considered that a compound having a carbodiimide group is added to a part of the ink and crosslinked. In the present invention, since the compound (b) having a carbodiimide group is not contained in the aqueous ink (A), the aqueous ink (A) has good residual wall stability. Therefore, the water-based ink to which the compound (b) having the conventional carbodiimide group is added has excellent water resistance and the like as compared with the remaining portion.

The adhesive (B) preferably contains a compound (c) having a known isocyanate group and a compound (d) having a hydroxyl group in addition to the compound (b) having a carbodiimide group (hereinafter, compound (c)). And the compound (d) may be referred to as a “polyurethane-based adhesive”). By including a polyurethane adhesive, lamination strength and water resistance are improved. As the compound (c) having an isocyanate group, a compound having at least two or more isocyanate groups in a molecule is preferable. Examples of the diisocyanate include 4,4′-, 2,4′- and 2,2′-diisocyanatediphenylmethane, 1,5-diisocyanatenaphthalene, 4,4′-diisocyanatedicyclohexylmethane, 1,4-diisocyanatebenzene, and / or Aromatic diisocyanate such as 2,4- or 2,6-diisocyanate toluene, 1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3-diisocyanatocyclopentane, 1,4-diisocyanatocyclohexane, 1-isocyanate- Aliphatic and alicyclic diisocyanates such as 3,3,5-trimethyl-3 or -5-isocyanate methanecyclohexane can be exemplified. Polyisocyanates can be produced from these diisocyanate monomers.

As the compound (d) having a hydroxyl group, a compound having at least two or more hydroxyl groups in the molecule is preferable, and can be appropriately selected from polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, and the like.
The compounding ratio of the compound (c) having an isocyanate group and the compound (d) having a hydroxyl group is preferably compound (c) / compound (d) = 5/1 to 1/1 from the viewpoint of lamination strength.

As the adhesive (B), various adhesives such as imine-based, polybutadiene-based, and titanate-based adhesives can be used in addition to the polyurethane-based adhesives described above. The adhesive (B) is appropriately selected depending on the laminating method, and the details of the laminating method will be described later.

  The solvent used for diluting the adhesive (B) is not particularly limited, but esters such as ethyl acetate, butyl acetate and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone and cyclohexanone, and tetrahydrofuran , Ethers such as dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as dimethyl sulfoxide, dimethyl sulfamide, methanol, ethanol, isopropanol, water, etc. Can be exemplified.

The laminate in the present invention is formed by sequentially laminating a base film (F1), an ink layer (F2), an adhesive layer (F3), and a sealant film (F4). As a method for producing the laminate, first, the aqueous ink (A) is printed on the base film (F1) by a known printing method such as gravure printing or flexographic printing to obtain a printed material. The thickness of the ink layer (F2) is preferably from 0.1 to 10 μm. At this time, gravure printing is preferred. Thereafter, an adhesive (B) is applied to the printing surface of the printed matter, an adhesive layer (F3) is provided, and subsequently, a laminating process is performed using a sealant film (F4) to form a laminate.
At this time, various lamination methods can be used, and typical examples include a non-sol lamination method (NL), a dry lamination method (DL), and an extrusion lamination method (EL). The adhesive (B) in the present invention includes an adhesive used for a non-sol laminating method (NL), a dry laminating method (DL), and an anchor coating agent used for an extrusion laminating method (EL).

The non-sol laminating method (NL) is a method in which a solvent-free adhesive is applied to the printing surface of the obtained printed matter, and is laminated by press-bonding with a sealant film. As the adhesive, a polyurethane-based adhesive is mainly used, and commercially available products include EA-N373A / EA-N373B manufactured by Toyo Morton Co., Ltd.

The dry laminating method (DL) is a method of diluting an adhesive to an appropriate viscosity with an organic solvent, applying the diluted adhesive to a printing surface of the obtained printed matter, drying the adhesive, and pressing and laminating with a sealant film. As the adhesive, a polyurethane adhesive is mainly used, and commercially available products include TM-250HV / CAT-RT86L-60, TM-550 / CAT-RT37, TM-314 / CAT-14B, etc., manufactured by Toyo Morton Co., Ltd. Can be

Extrusion lamination (EL) is a method in which a thermoplastic resin is melted on the printing surface of the obtained printed matter and extruded into a film form from a slit-shaped die called a T-die, and laminated on a substrate. is there. In many cases, an adhesive is applied to the printing surface of the printed matter before lamination. Further, the molten resin can be extruded onto the printing surface of the printed material, and a sealant film can be bonded from another unwinding machine. As the adhesive, an imine-based, butadiene-based, or polyurethane-based adhesive can be used. Examples of commercially available products include EL-420 (imine-based), EL-452 (butadiene-based), EL-530A / B (polyurethane-based), EL-540 / CAT-RT32 (polyurethane-based) manufactured by Toyo Morton Co., Ltd. Can be As the molten resin, low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer and the like can be used. Specific examples include Novatec LD LC600A (low-density polyethylene) manufactured by Japan Polyethylene Corporation.

As the base film (F1), stretched and unstretched polyolefins such as polypropylene, polyethylene and polystyrene, polyester, nylon, cellophane, vinylon and the like can be used. In the case of a polyolefin film, it is preferable to use a surface-treated polyolefin film having a functional group such as a hydroxyl group or a carbonyl group.
Further, a composite film in which a plurality of films are laminated, a vapor-deposited film having a vapor-deposited layer, a barrier film, and the like can also be used.

Examples of the sealant film (F4) include the above-mentioned various films used for the base film (F1), paper, aluminum foil, and film-like or sheet-like films made of a composite material thereof. When the laminate is used as a packaging bag, it is necessary that the sealant film surfaces be heat-sealed. For this reason, a film for imparting heat sealability is used as the innermost sealant film in the packaging bag. For example, unstretched polyolefins such as polyethylene or polypropylene are exemplified. Commercially available products include TUX-FCD (LLDPE) manufactured by Mitsui Chemicals Tohro Co., Ltd., ZK93KM (CPP) manufactured by Toray Industries, Inc. ), Toray 2203 (VMCPP) and the like. The laminate can be widely used as a packaging bag or packaging material for packaging foods, confectioneries, pharmaceuticals, pet foods and the like.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the present invention, parts and% mean parts by weight and% by weight, respectively, unless otherwise specified. The hydroxyl value is calculated by esterifying or acetylating the hydroxyl group in the resin with an excess of an acid anhydride and back-titrating the remaining acid with an alkali, and converting the amount of the hydroxyl group in 1 g of the resin into mg of potassium hydroxide. This is a value obtained according to JIS K0070. The acid value is the number of mg of potassium hydroxide required to neutralize the acid group contained in 1 g of the resin. The measuring method may be a known method, and generally according to JIS K0070 (1992). Done. The molecular weight (weight average molecular weight) of the polyurethane resin was measured using a GPC (gel permeation chromatography) apparatus (measurement solvent: tetrahydrofuran, measurement temperature: 40 ° C.), and the molecular weight distribution was measured, and polystyrene having a known molecular weight was used as a standard substance. It was obtained as a converted value.

(Synthesis of aqueous polyurethane resin)
[Synthesis Example 1]
In a four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer, polytetramethylene glycol (PTG2000, number average molecular weight 2,000, hydroxyl value 56.3) was 142.5. After charging 30.8 parts of polyethylene glycol (PEG2000, number average molecular weight 2,000, hydroxyl value 56.3) and 25.0 parts of dimethylolbutanoic acid (DMBA), the atmosphere in the flask was replaced with dry nitrogen. Then, the temperature was raised to 110 ° C. Under stirring, 82.3 parts of isophorone diisocyanate (IPDI) was added dropwise over 20 minutes, and the mixture was reacted for 3 hours while heating to 150 ° C.
Next, a mixture of 8.1 parts of ammonia water, 129.3 parts of isopropyl alcohol and 834.0 parts of distilled water was added dropwise over 30 minutes while cooling, and the acid value was 30 mgKOH / g, EO% was 10, and the weight average molecular weight was 30. 000, solid content 30%,
Thus, an aqueous polyurethane resin (a01) was obtained. The obtained resin (a01) is an aqueous polyurethane resin having a carboxyl group and no urea bond.

[Synthesis Example 2]
In a four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer, PMPA2000 (at both ends containing 3-methyl-1,5-pentanediol and adipic acid as constituent monomers) 131.8 parts of a polyester having a hydroxyl group, number average molecular weight of 2000), 31.0 parts of polyethylene glycol (PEG2000, number average molecular weight of 2,000, hydroxyl value of 56.4), 24.8 parts of DMBA, 87.8 parts of IPDI, and methyl ethyl ketone (MEK) ) 150.0 parts were charged and reacted at reflux temperature for 6 hours to obtain a prepolymer having a terminal isocyanate group. The reaction end point was determined by titration. Next, after cooling to 40 ° C., a mixture consisting of 12.9 parts of 2-hydroxyethylethylenediamine (AEA), 44 parts of isopropyl alcohol and 71 parts of MEK was added dropwise to carry out a chain extension reaction. The reaction was further performed at 80 ° C. for 1 hour to obtain a polyurethane resin solution.
Next, a mixture consisting of 9.7 parts of 28% aqueous ammonia and 863 parts of distilled water was gradually added to the polyurethane resin solution, and the entire amount of MEK was distilled off under azeotropic distillation to obtain a hydroxyl value of 25 mgKOH / g, An aqueous polyurethane resin (a02) having a value of 30 mgKOH / g, EO% of 10, weight average molecular weight of 30,000 and solid content of 30% was obtained. The obtained resin (a02) is an aqueous polyurethane resin having a carboxyl group and having a urea bond.

[Synthesis Examples 3 to 13]
In the same manner as in Synthesis Example 2, aqueous urethane resins a03 to a13 having a carboxyl group were synthesized at the compounding ratio shown in Table 1. Table 1 shows the hydroxyl value, acid value, EO%, and weight average molecular weight. The solids content is all 30%. Note that blanks in Table 1 indicate zero (no compounding).

Abbreviations of the raw materials used in the synthesis are as follows.
PMPA2000: Polyester having hydroxyl groups at both terminals using 3-methyl-1,5-pentanediol and adipic acid as constituent monomers (number average molecular weight 2000)
PTG2000: polytetramethylene glycol (number average molecular weight 2000)
PEG2000: polyethylene glycol (number average molecular weight 2000)
DMBA: dimethylol butanoic acid IPDI: isophorone diisocyanate IPDA: isophorone diamine AEA: 2-hydroxyethylethylenediamine MEK: methyl ethyl ketone

(Production of water-based ink (A))
[Production Example 1]
50.0 parts of an aqueous polyurethane resin (a01), 15.0 parts of a phthalocyanine blue pigment (Lionol Blue KLH, manufactured by Toyo Ink Co., Ltd.), 0.1 part of an antifoaming agent (SC5540, manufactured by Toray Silicone Co., Ltd.), isopropyl alcohol 5.0 parts and 29.9 parts of water were stirred with an Eiger mill (manufactured by Eiger) for 10 minutes to obtain an aqueous ink (A01). The aqueous ink (A01) was adjusted with a mixed solvent of water / isopropyl alcohol = 1/1 (weight ratio) in Zahn Cup # 3 (manufactured by Rigo Co., Ltd.) to 16 seconds, and diluted for evaluation. Ink (A01d) was obtained.

[Production Examples 2 to 13]
Aqueous inks (A02 to A13) were prepared in the same manner as in Production Example 1 at the compounding ratios shown in Table 2. Furthermore, dilution inks for evaluation (A02d to A13d) were obtained in the same manner. In addition, the blank in Table 2 shows zero (does not mix).

[Production Example 14]
Acrylic resin (a14) (Joncryl 74J manufactured by BASF, solid content: 45%, acid value: 51 mgKOH / g) 50.0 parts, phthalocyanine blue pigment (Lionol Blue KLH manufactured by Toyo Ink Co., Ltd.) 15.0 parts, defoaming 0.1 part of an agent (SC5540, manufactured by Toray Silicone Co., Ltd.), 5 parts of isopropyl alcohol, and 29.9 parts of water were stirred for 10 minutes with an Eiger mill (manufactured by Eiger) to obtain an aqueous ink (A14). The aqueous ink (A14) was adjusted with a mixed solvent of water / isopropyl alcohol = 1/1 (weight ratio) in Zahn Cup # 3 (manufactured by Rigo Co., Ltd.) so as to become 16 seconds, and diluted ink for evaluation ( A14d) was obtained.

[Production Example 15]
After obtaining an aqueous ink (A15) and a dilution ink (A15d) by the same composition and method as in Production Example 1, 5 parts of a compound having a carbodiimide group (Nisshinbo, Carbodilite E-02, carbodiimide equivalent 445) was diluted with 5 parts of a dilution ink ( A15d) Added to 150 parts. Next, using this ink, printing was performed in the same manner as the printing method described in Example 1, and the remaining ink was collected and allowed to stand at 40 ° C. for one week. This ink is a residual ink (A15d1).

(Preparation of laminate)
[Example 1]
The diluted ink (A01) prepared in Production Example 1 was coated on a gravure printing machine (plate depth 25 μm) as a base film (F1) as a nylon film (hereinafter NY, “Emblem ON-RT” manufactured by Unitika Ltd.), thickness. 15 μm) to obtain a printed material as an ink layer (F2). After applying the adhesive (B) to the printed matter to form an adhesive layer (F3), the extruded laminating machine (Musashino Kikai) was used to melt the polyethylene at a line speed of 100 m / min. ) Was melted at 320 ° C. and laminated with LLDPE (TUX-FCD, manufactured by Mitsui Chemicals Tosello Co., Ltd.) as a sealant film (F4) to obtain a laminate 1. The obtained laminate was aged at 40 ° C. for 2 days.
The adhesive (B01) was used as the adhesive (B). The adhesive (B01) was used for 18.4 parts of a polyurethane adhesive (EL-540 / CAT-RT32 = 16 parts / 2.4 parts, ethyl acetate dilution, solid content 8%, manufactured by Toyo Motor Corporation). Carbodilite V-05 (Nisshinbo Co., Ltd., carbodiimide equivalent: 261) as the compound (b) having a carbodiimide group. Here, the addition amount of the compound (b) having a carbodiimide group depends on the carboxyl group per unit volume of the ink layer (F2) formed from the aqueous ink (A01) and the adhesive layer (F3) formed from the adhesive. The compound (b) having a carbodiimide group (0.15 parts) was added so that the same number of carbodiimide groups per unit volume of (1) was obtained. In addition, the specific gravity of the urethane resin solid content, the adhesive solid content, and the cross-linking agent solid content was 1.2, and the specific gravity of the indigo pigment was 1.7.

[Examples 2 to 17]
Adhesives (B02) to (B11) were used as the diluent inks (A02d to A14d) and the adhesive (B) as the adhesive (B). In the same manner as in Example 1, according to the configuration in Table 3, laminated bodies 2 to 17 (Examples 2 to 17) were obtained. The base film and the sealant film are the same as in Example 1.
The polyurethane adhesive used for the adhesives (B02) to (B06), (B10), and (B11) is the same as the adhesive (B01), EL-540 / CAT-RT32 (= 16 parts / 2.4). Parts, diluted with ethyl acetate, solid content 8%). In the adhesives (B07) to (B09), an imine-based adhesive (EL-420 manufactured by Toyo Morton Co., Ltd., solid content: 0.7%) was used. Table 3 shows the amounts of the polyurethane adhesive, the imine adhesive, and the carbodiimide compound (b).

[Comparative Examples 1-2]
In Comparative Example 1, instead of the adhesive (B01), a polyurethane-based adhesive (EL-540 / CAT-RT32 manufactured by Toyo Motor Co., Ltd. = 16 parts / 2.4 parts, diluted with ethyl acetate, solid content 8%) A laminate 18 was obtained in the same manner as in Example 1 except that the above-described method was used. In Comparative Example 2, a laminate 19 was obtained in the same manner as in Example 1 using the remaining ink (A15d1) obtained in Production Example 15.

Using the laminate obtained above and the diluted ink used for printing, water resistance, re-dissolvability, laminate strength, and remaining wall stability were evaluated. The respective evaluation methods and criteria are described below.

[water resistant]
The laminate was formed into a bag, filled with water, sealed, and then immersed in water at 40 ° C. for 24 hours to evaluate water resistance.
：: No delamination or blister is generated (very good)
：: No delamination occurs, blisters occur only in the heat-sealed part (good)
Δ: No delamination occurs, and blisters occur in areas other than the heat-sealed portion (within practical range)
×: Delamination occurs (defective, impractical)

[Resolubility]
An impression cylinder made of NBR (nitrile butadiene rubber) having a rubber hardness of 80 Hs, a ceramic plating doctor blade having a blade edge thickness of 60 μm (base material thickness 40 μm, one side ceramic layer thickness 10 μm), chrome hardness 1050 Hv manufactured by Toyo Prepress Co., Ltd. An electronic engraving plate (a stylus angle of 120 degrees, 250 lines / inch, and the obtained printing ink were set on a gravure printing machine manufactured by Fuji Machinery Co., Ltd., and the plate was rotated at a doctor pressure of 2 kg / cm2 and a rotation speed of 100 m / min.). Is rotated for 15 minutes, and printed on the corona-treated surface of a single-sided corona-treated OPP film “FOR-AQ (manufactured by Futamura Chemical Co., Ltd.)” at a printing speed of 100 m / min and a printing pressure of 2 kg / cm ² for 60 minutes. The printed product was obtained by drying with hot air at 60 ° C. During printing, each of the components shown in Table 2 was used using a viscosity controller. The mixed solvent of the body composition is appropriately replenished to maintain a certain viscosity, and the state of the printing pattern at the start and end of printing, that is, the amount of ink transferred to the image area at the low printing plate deep part (5μ). The measurement was performed using a densitometer “X-Rite500 (manufactured by VideoJet X-Rite Co., Ltd.)” and evaluated.
A: Density change at the end of printing relative to the start of printing is less than 5%. (Very good)
：: The change in density at the end of printing with respect to the start of printing is 5% or more and less than 10%. (Good)
Δ: The change in density at the end of printing with respect to the start of printing is 10% or more and less than 15%. (Within practical range)
X: The change in density at the end of printing with respect to the start of printing is 15% or more. (Bad, not practical)

[Laminate strength]
The laminate was cut into a length of 150 mm and a width of 15 mm, opened at the ink-film interface, and the lamination strength in the 90 ° direction was measured using a Tensilon tensile tester. Note that the practical level is 2.0 N / 15 mm or more.
A: 7.0 N / 15 mm or more (very good)
〇: 4.0 N / 15 mm or more and less than 7.0 N / 15 mm (good)
Δ: 2.0 N / 15 mm or more and less than 4.0 N / 15 mm (within practical range)
×: less than 2.0 N / 15 mm (defective, impractical)

[Remaining meat stability]
The ink used for printing was subjected to a aging promotion test at 40 ° C. for one week, and it was evaluated whether or not there was a change in ink viscosity during printing and after aging. The ink viscosity was measured at 25 ° C. with Zahn Cup # 3.
A: Change in viscosity after printing and after lapse of time is less than 5% (very good)
Good: Change in viscosity after printing and after lapse of time is 5% or more and less than 10% (good)
Δ: Change in viscosity after printing and after lapse of time is 10% or more and less than 20% (within a practical range).
×: Change in viscosity after printing and after lapse of time is 20% or more (defective, impractical)

Table 3 summarizes the evaluation results. The laminates of Examples 1 to 17 in which the compound (b) having a carbodiimide group was added to the adhesive were superior to Comparative Example 1 in the water resistance and laminate strength of the laminate. In addition, the ink obtained by adding a compound having a carbodiimide group to the aqueous ink which is the conventional method from Comparative Example 2 has a remarkably reduced water resistance and resolubility when reused, and the stability of the remaining meat. Is also bad. According to the present invention, the aqueous ink can be reused, and by using the constitution of the present invention, it is possible to obtain a laminate excellent in water resistance and lamination strength of the laminate.

Claims (5)

An ink layer (F2) formed from the aqueous ink (A), an adhesive layer (F3) formed from the adhesive (B), and a sealant film (F4) are formed on the base film (F1). A laminate for a packaging bag having an order. However, it is characterized by satisfying the following (1) and (2).
(1) A compound (b) containing an aqueous polyurethane resin (a1) having a carboxyl group and having an acid value of 10 to 60 mgKOH / g and a hydroxyl value of 10 to 20 mgKOH / g, and having a carbodiimide group (A). Not contained.
(2) The adhesive (B) contains the compound (b) having a carbodiimide group. The packaging bag laminate according to claim 1, wherein the ratio (mol) of the carboxyl group to the carbodiimide group is carboxyl group / carbodiimide group = 1 / 0.5 to 1/6 (molar ratio). 3. The laminate for a packaging bag according to claim 1, wherein the adhesive (B) further comprises a compound (c) having an isocyanate group and a compound (d) having a hydroxyl group. 4. The laminate for packaging bags according to claim 2 or 3, wherein the aqueous polyurethane resin (a1) having a carboxyl group further has a hydroxyl group. On the base film (F1), the ink layer and (F2), and contact Chakuzaiso (F3), a manufacturing method of the packaging bag laminate having a sealant film (F4) in this order, the following (1 ) To (3).
(1) A compound containing an aqueous polyurethane resin (a1) having a carboxyl group and having an acid value of 10 to 60 mgKOH / g and a hydroxyl value of 10 to 20 mgKOH / g on a base film (F1) and having a carbodiimide group ( a step of printing an aqueous ink (A) containing no b) to form an ink layer (F2).
(2) A step of applying an adhesive (B) containing a compound (b) having a carbodiimide group on the ink layer (F2) to form an adhesive layer (F3).
(3) A step of bonding a sealant film (F4) on the adhesive layer (F3).