JP2009155581A - Solvent recovery/reuse type printing ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent recovery/reuse type printing ink composition which comprises a polyurethane resin having a weight-average molecular weight of 20,000 to 100,000 and an amine value of 0.5 to 20.0 mgKOH/g and a volatile component in which 90% or more of the volatile component consist of two types, an ester solvent and an alcoholic solvent. <P>SOLUTION: The solvent recovery/reuse type printing ink comprises a mixed solvent comprising two organic solvent components, wherein the mixed solvent has a specific weight-average molecular weight and an amine value. The solvent recovery/reuse type printing ink has excellent printability and is reusable by easy component adjustment of a recovered solvent as compared with a conventional ink. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solvent recovery / reuse type printing ink composition, and more particularly to a solvent recovery / reuse type printing ink composition particularly useful for coating various plastic films, plastic sheets or synthetic resin molded articles, The present invention relates to a method for selecting a raw material for recovery and reuse type printing ink.

  In recent years, problems related to air pollution, such as the destruction of the ozone layer in the destructive stratosphere of the natural environment, the damage to agricultural products and destruction of forest resources due to acid rain in the lower strata, and the adverse effects on human bodies due to photochemical oxidants have become serious. For this reason, laws related to air environment conservation, such as the enforcement of the PRTR Law to prevent this, the strengthening of regulations on the Odor Prevention Law, the reduction of carbon dioxide emissions under the Kyoto Protocol, the Air Pollution Control Law, and the Saitama Prefecture Living Environment Conservation Ordinance It is getting strict. In particular, in the gravure printing industry in which a large amount of organic solvent is used and released, interest in solvent recovery and reuse is increasing as one means for solving these problems (Non-Patent Documents 1 to 3).

  In fact, in the field of laminating adhesives and publishing gravure printing, it is already practiced to design the solvent species to a single composition and to recover and reuse the volatile solvent. This is because, if the composition is a single solvent, the recovered solvent can be obtained with a single composition, and can be easily reused as an adhesive, ink, or a diluting solvent thereof.

  On the other hand, in gravure printing (laminate, surface printing, paper, aluminum printing) for other applications, various inks are used depending on the application, and solvent is used from the standpoints of solubility of the resin used and adjustment of the drying speed. There will be multiple seeds. For this reason, when these conventional printing inks and dilution solvents are used, the recovered solvent becomes a multi-component. Therefore, in order to reuse the solvent, it is necessary to separate it into a single solvent or to add a solvent having the desired composition. there were.

As a separation method into a single solvent, distillation is first mentioned, but enormous initial cost and running cost are required. In addition, since a large amount of energy is required for distillation after all, it consumes a large amount of petroleum resources and emits a large amount of carbon dioxide. It was a problem not to become. In addition, when the components are adjusted and reused, if they are multiple components, it is necessary to add a large amount of a new solvent in order to obtain a target mixed solvent, which is not efficient (Patent Document 1).
Japanese Patent Laid-Open No. 07-247456 Hideki Yasuda, Journal of the Japan Printing Society, Vol.43, No.6, 404-410 (2006) Masato Senmoto, Journal of Japan Society of Printing Science, Vol.44, No.1, 8-14 (2007) Japan Industrial Environment Management Association 2005 Survey Report commissioned by the Ministry of Economy, Trade and Industry “Survey on Countermeasures for Environmentally Hazardous Substances (Technology Survey on Controlling Emissions of Volatile Organic Compounds (VOC))” March 2006

  An object of the present invention is to provide a printing ink and a diluting solvent that exhibit excellent printability and that can be easily adjusted and reused, and to provide a method for selecting a solvent recovery and reuse type printing ink raw material.

  As a result of intensive studies in view of the above situation, the present inventors have found that a solvent recovery reuse printing ink containing a mixed solvent composed of two organic solvents and containing a polyurethane resin with a controlled molecular weight and amine value is Thus, the present inventors have found that it has excellent printability and can be easily reused by adjusting the components of the recovered solvent as compared with conventional inks.

  That is, the present invention contains a polyurethane resin having a weight average molecular weight of 10,000 to 100,000 and an amine value of 0.5 to 20.0 mgKOH / g, and 90% or more of the volatile components are ester solvents and alcohol solvents. The present invention relates to a solvent recovery and reuse ink composition comprising two types.

Furthermore, the polyurethane resin is composed of a polymer diol and a polyisocyanate, and the solvent recovery and reuse ink composition according to claim 1,
The present invention also relates to a solvent recovery and reuse type printing ink composition, wherein the polyurethane resin comprises a chain extender and a terminal terminator.

Furthermore, regarding a laminate characterized in that it is obtained through a coating characterized by containing a printing ink composition and a plurality of coating, laminating or pressing processes,
Next, the present invention relates to a coating characterized by containing a printing ink composition and a laminate laminate characterized by being obtained through a plurality of coating, laminating or pressing processes.

  The solvent recovery and reuse printing ink provided by the present invention exhibits excellent printability as compared with conventional inks, and can easily be reused by adjusting the recovery solvent.

  Solvent recovery and reuse in the present invention means a method of separating a volatilized solvent generated in a printing drying process from one or a plurality of printing machines from air coexisting with solvent vapor, that is, a condensation method, a compression method, an absorption method. The solvent is recovered using an adsorption method, and the obtained solvent (recovered solvent) is used as a raw material for printing ink or a diluting solvent by adjusting the ratio of each solvent contained as required. .

  The solvent recovery method may be selected in consideration of the composition, physical properties, chemical properties, concentration, generation amount (treatment amount) of the solvent vapor, impurities contained, desired recovery rate, recovery solvent characteristics, etc. it can. Among these, the gas adsorption method using an adsorbent is preferable and generally used from the viewpoint of cost including the recovery rate. The solvent collected as an adsorbate in the adsorbent is desorbed by introducing a heating gas such as air, an inert gas such as nitrogen, or water vapor, and then cooled and liquefied.

  If necessary, the recovered solvent can remove water by polymer membrane such as polyimide membrane, membrane separation using ceramic membrane or zeolite membrane, adsorption using silica gel, difference in specific gravity, or distillation. .

  The solvent of the solvent recovery and reuse type printing ink composition in the present invention preferably has two components.

  When the solvent of the solvent recovery / reuse type printing ink composition is one kind, the composition of the recovery / reuse solvent becomes the same, so that the process of recovery / reuse becomes simple. However, it is difficult to ensure the performance as a printing ink with a single solvent, and it is also inconvenient that the drying adjustment performed to control the printing effect on the printing press cannot be performed.

  On the other hand, when designed with 3 or more components, often 4 to 8 in the same way as before, it is easy to ensure the performance as printing ink. However, assuming solvent recovery and reuse, the components are determined by specific gravity and refractive index. It is difficult to create a calibration curve for identification, it becomes complicated to calculate the component adjustment at the time of reuse, and depending on the ratio of the recovered solvent obtained, a large amount of adjustment solvent (not regenerated) A new solvent) is added, resulting in a recycle solvent more than necessary.

  In this way, the solvent recovery / reuse type ink is designed. However, it is expected that a multi-component mixture including moisture in the production process and the addition of a slow solvent for the purpose of improving printability will be expected. Therefore, it is necessary that 90% or more of the volatile components are composed of two organic solvent components so as not to hinder the solvent recovery and reuse process.

  As the two-component solvent used in the solvent recovery reusable printing ink composition of the present invention, aromatic organic solvents such as toluene and xylene and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone are excluded from the viewpoint of the working environment. Above, in order to ensure the solubility of various ink materials, ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, methanol, It is preferable to use alcohol solvents such as ethanol, n-propanol, isopropanol, n-butanol, propylene glycol monoethyl ether, propylene glycol monomethyl ether.

  As the ester solvent, it is preferable to select n-propyl acetate having a solubility parameter and a drying rate very close to those of toluene which has been a mainstream solvent in conventional gravure printing. Thus, it is considered that the raw materials that have been used conventionally can be used relatively easily in the solvent recovery and reuse ink of the present invention. The alcohol solvent is preferably a secondary or tertiary alcohol capable of suppressing the reaction with an isocyanate curing agent. Further, a tertiary alcohol and a relatively low molecular weight ter-butyl alcohol are solid at room temperature and are difficult to handle. Therefore, it is more preferable to use isopropyl alcohol, which is a secondary alcohol, and the drying speed of the mixed solvent is close to that of a conventional solvent system when used with n-propyl acetate.

  It is also preferable to use ethyl acetate as the ester solvent. This is because ethyl acetate is widely used as a solvent for various resin synthesis and exhibits excellent solubility in many resin systems. Ethyl acetate is slightly faster as a solvent used in gravure printing, but can be used by designing with a reduced usage rate.

  Furthermore, it is also preferable to use n-propanol as the alcohol solvent. n-Propanol is slightly slower to dry than isopropanol, and is effective in improving printability.

  The diluting solvent of the present invention is added and mixed in an optional amount to the printing ink composition every time in order to adjust the viscosity and control the printing effect and the printed matter density. Therefore, the same composition as the solvent composition of the solvent recovery and reuse type printing ink composition is preferable.

  Various resins can be selected as the resin used in the solvent recovery / reuse type printing ink composition of the present invention depending on the application and the substrate. Examples of the resin used include polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, chlorinated polypropylene resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, nitrocellulose resin, acrylic resin, polyester resin Alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic acid resin, terpene resin, phenol modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, and modified resins thereof be able to. These resins can be used alone or in combination of two or more, and the content thereof is preferably 5 to 25% by weight based on the total weight of the ink.

  Furthermore, in the printing ink for laminating, which has the largest market, among the resins used in the printing ink composition of the present invention, polyurethane resin is used as the main binder because of the reduction of the residual solvent amount in the printed ink and the suitability for extrusion laminating. Often used. Examples of the polyurethane resin used in the present invention include polyurethane resins used in general inks, paints, and recording agents.

  The polyurethane resin of the present invention can be synthesized using various known polyols that are generally used. A polyol may use together 1 type, or 2 or more types.

  The polyol in the present invention is a compound having two or more hydroxyl groups in one molecule including the above-described polymer polyol. In the present invention, a polyol having a number average molecular weight of 500 or more or a repeating unit of 5 units or more is referred to as a high molecular polyol, and a polyol having a number average molecular weight of less than 500 or consisting of a monomer is referred to as a low molecular polyol.

  In the method for synthesizing the polyurethane resin of the present invention, it is preferable to react a polyol with a polyisocyanate and a chain extender to obtain a urethane-modified polyol. The urethane-modified polyol is prepared by reacting polyol and polyisocyanate, if necessary, with an inert solvent for the isocyanate group, and if necessary, using a urethanization catalyst at a temperature of 10 to 150 ° C. A prepolymer method in which a prepolymer having a group is produced and then a chain extender and a terminal terminator are reacted with the prepolymer to obtain a polyurethane polyol resin, or an organic polyol compound, a polyisocyanate compound and a chain extender are combined in one step. It can be produced by a known method such as a one-shot method in which a polyurethane polyol resin is obtained by reaction.

  Examples of the polyol include polymer polyols such as methylene oxide, ethylene oxide, and tetrahydrofuran, or copolymer polyether polyols (1);

  Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2butyl-1,3-propanediol, 1,3-butanediol, 1,4 -Butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, polypropylene glycol, Saturated or unsaturated low molecular polyols such as dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaesitol 2);

  One or more of these low molecular weight polyols (2) and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, sperin Polyester polyols (3) obtained by dehydration condensation or polymerization of polycarboxylic acids such as acid, azelaic acid, sebacic acid, trimellitic acid, pyromellitic acid or their anhydrides;

  Polyester polyols (4) obtained by ring-opening polymerization of lactones such as cyclic ester compounds such as polycaprolactone, polyvalerolactone, poly (β-methyl-γ-valerolactone);

  Polycarbonate polyols (5) obtained by reaction of the low molecular polyols (2) and the like with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene and the like;

  Polybutadiene glycols (6); glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A (7); one or more hydroxyethyl, hydroxypropyl acrylate, acrylic hydroxybutyl, etc. in one molecule, or Acrylic polyol (8) obtained by copolymerizing these corresponding methacrylic acid derivatives and the like with, for example, acrylic acid, methacrylic acid or esters thereof; oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc. Examples thereof include polyether polyol (9) obtained by polymerizing water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin and other low molecular weight polyols as initiators.

  Among these, it is preferable to use polyester polyols (4) in order to ensure adhesion to various plastic films and blocking resistance of printed matter. From the solubility in the mixed solvent of the present invention, ethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol Those obtained by reacting one or more glycols selected from the group with adipic acid, isophthalic acid and terephthalic acid are more preferred.

  Furthermore, it is preferable that these polyester polyols (4) occupy 50% by weight or more of the polymer polyol.

  Examples of the polyisocyanate used in the urethane-modified polyol include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane resins. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 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, lysine diisocyanate, Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate Nate, dimethylene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tri Examples thereof include diisocyanate, dimerisocyanate obtained by converting a diisocyanate carboxyl group into diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and a dimer acid carboxyl group. These diisocyanate compounds can be used alone or in admixture of two or more.

  Examples of the chain extender used in the urethane-modified polyol include 2-diamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and the like. Ethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di- Amines having a hydroxyl group in the molecule such as 2-hydroxypropylpyrethylenediamine and di-2-hydroxypropylethylenediamine can also be used. These chain extenders can be used alone or in admixture of two or more.

  A monovalent active hydrogen compound can also be used as a terminal terminator for the purpose of terminating the reaction. Examples of such compounds include compounds having primary and secondary amino groups, dialkylamines such as di-n-butylamine, amino alcohols having a hydroxyl group, and alcohols such as ethanol and isopropyl alcohol. Furthermore, amino acids such as glycine and L-alanine can be used as a reaction terminator, particularly when it is desired to introduce a carboxyl group into the polyurethane resin. Among these, amino alcohols having primary and secondary amino groups need to be controlled so as to react only with amino groups while avoiding reaction at high temperature when used as a terminal terminator. These end terminators can be used alone or in admixture of two or more. Here, when an amino group is used as a chain extender, it reacts with an isocyanate group to form a urea bond, so that the resulting resin is a polyurethane / urea resin. In the present invention, these resins are also polyurethane resins. To do.

  In producing the prepolymer, the amount of polyol and polyisocyanate is such that the NCO / OH ratio, which is the ratio of the number of moles of isocyanate groups of polyisocyanate (F) to the number of moles of hydroxyl groups of the organic polyol compound, is 1.1-3. It is preferable to be in the range of 0.0. When this ratio is less than 1.1, there is a tendency that sufficient alkali resistance cannot be obtained, and when it is more than 3.0, the solubility of the resulting prepolymer tends to be lowered.

  Moreover, it is preferable from the surface of reaction control to use a solvent for reaction. As the solvent that can be used, those that dissolve the polyurethane adhesive composition are preferable. For example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as dioxane and tetrahydrofuran; aromatic hydrocarbons such as toluene and xylene And the like; esters such as ethyl acetate and butyl acetate; and halogenated hydrocarbons such as chlorobenzene and perchlene. These may be used alone or in combination as a mixed solvent.

  Furthermore, a catalyst can also be used for this urethanation reaction. Examples of catalysts that can be used include tertiary amine catalysts such as triethylamine and dimethylaniline; metal catalysts such as tin and zinc. These catalysts are usually used in the range of 0.001 to 1 mol% with respect to the polyol compound.

  The prepolymer having an isocyanate group at the terminal obtained above and the chain extender diol, diamine, triol, etc. are reacted at 10 to 80 ° C. to obtain a high molecular weight polyurethane resin containing an active hydrogen group at the terminal. It is done.

  When using an end-stopper, the end-stopper and chain extender may be used together to carry out a chain extension reaction. Thus, an end termination reaction may be performed. On the other hand, the molecular weight can be controlled without using a terminal terminator, but in this case, a method of adding a prepolymer to a solution containing a chain extender is preferable in terms of reaction control.

  End terminators are used to control molecular weight. As the amount used increases, the molecular weight of the resulting polyurethane resin decreases. This varies depending on the reactivity of the chain extender and end terminator to the prepolymer, but in general, the ratio of the number of moles of amino groups and hydroxyl groups of the chain extender to the number of moles of amino groups and hydroxyl groups of the terminal terminator A range of 0.5 to 5.0 is preferred. When this ratio exceeds 5.0, the polymer has a high molecular weight, so that the suitability for dry lamination tends to deteriorate. When it is less than 0.5, the molecular weight and the initial adhesive force tend to decrease.

The ratio of the total number of moles of amino groups and hydroxyl groups of the chain extender and terminal terminator to the equivalent of isocyanate groups in the prepolymer is 1.1 to 3.0, preferably 1.5 to 2.0. To react. When this ratio is large and the amount of chain extender or terminal terminator used is large, they remain unreacted and odor tends to remain.

The polyurethane resin of the present invention preferably has a weight average molecular weight of 20,000 to 100,000. If it is smaller than 20000, it is difficult to ensure blocking resistance and solvent resistance in the printed matter, and if it is larger than 100,000, it is difficult to ensure the printing effect because of poor solubility in the ester solvent / alcohol solvent system in the present invention.

  The polyurethane resin of the present invention is preferably a polyurethane having an amine value of 0.5 to 20.0 mgKOH / g. When the amine value is lower than 0.5, it is difficult to ensure the adhesion to the polyolefin film, and when it is greater than 20.0, it is difficult to ensure the stability of the old ink to which the isocyanate curing agent is added.

  As the hue of the printing ink containing the solvent recovery and reuse type printing ink composition of the present invention, depending on the type of colorant used, in addition to white as a process basic color, the total of yellow, red, indigo and black There are five colors, and there are three colors, red (orange), grass (green), and purple, as process gamut colors. Further, transparent yellow, peony, vermilion, brown, gold, silver, pearl, almost transparent medium for adjusting color density (including extender pigments if necessary), etc. are prepared as base colors.

  In printing ink, there is a technique for obtaining a target hue by mixing a plurality of hues as a special color, and in particular, white ink may be mixed with an operation called toning, for example, a small amount of indigo ink. The white ink in the present invention can also be mixed with other inks. In addition to mixing the ink, an organic pigment, an inorganic pigment, and a dye can be mixed with the white ink in the present invention as necessary.

  Examples of white inorganic pigments that can be used in the solvent recovery and reuse printing ink composition of the present invention include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica. Titanium oxide is preferably used for the white ink pigment from the viewpoint of coloring power, hiding power, chemical resistance, and weather resistance.

  Examples of inorganic pigments other than white pigments include carbon black, aluminum, mica (mica) and the like. Aluminum is in the form of powder or paste, but is preferably used in the form of paste from the viewpoint of handling and safety, and whether to use leafing or non-leafing is appropriately selected from the viewpoint of brightness and concentration.

Examples of the colored colorant in the printing ink composition of the present invention include organic and inorganic pigments and dyes used in general inks, paints, and recording agents. Organic pigments that can be used in combination include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, and isoindoline. And other pigments. Indigo ink is copper phthalocyanine, and transparent yellow ink is C.I. I. Pigment No Yellow 83 is preferably used.
The colorant is preferably contained in an amount sufficient to ensure the density and coloring power of the printing ink, that is, in a proportion of 1 to 50% by weight with respect to the total weight of the printing ink. These colorants can be used alone or in combination of two or more.

  In order to stably disperse the pigment in the organic solvent, it is possible to disperse the resin alone, but it is also possible to use a dispersant in order to disperse the pigment stably. As the dispersant, anionic, nonionic, cationic, amphoteric surfactants can be used. The dispersant is preferably contained in the ink in an amount of 0.05% by weight or more based on the total weight of the ink from the viewpoint of the storage stability of the ink and 5% by weight or less from the viewpoint of the suitability for lamination. Furthermore, it is more preferable that it is contained in the range of 0.1 to 2% by weight.

  The printing ink of the present invention can be produced by dissolving and / or dispersing a resin, a colorant and the like in an organic solvent. Specifically, by producing a pigment dispersion in which a pigment is dispersed in an organic solvent with the combination resin and the dispersant, and blending the obtained pigment dispersion with other compounds as necessary. Ink can be produced.

  The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As the disperser, generally used, for example, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill and the like can be used.

  In the case where bubbles or unexpectedly large particles are included in the ink, it is preferably removed by filtration or the like in order to reduce the quality of the printed matter. A conventionally well-known filter can be used.

  The ink viscosity produced by the above method is in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and being appropriately dispersed, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. preferable. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer.

  The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, for example, resin, colorant, organic solvent, and the like. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

  The printing ink containing the solvent-type printing ink composition of the present invention can be used in known printing methods such as gravure printing and flexographic printing. For example, it is diluted with a diluent solvent to a viscosity and concentration suitable for gravure printing, and is supplied to each printing unit alone or mixed.

  The coating of the present invention is obtained by applying the printing ink composition of the present invention to a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate, polycarbonate or polylactic acid, a polystyrene resin such as polystyrene, AS resin or ABS resin, nylon or polyamide. It is applied to a film or sheet substrate made of polyvinyl chloride, polyvinylidene chloride, cellophane, paper, aluminum, or a composite material thereof using the above printing method, and dried by drying in an oven. It can be obtained by fixing.

  The base material may be subjected to vapor deposition coating treatment and / or polyvinyl alcohol coating treatment on the surface of metal oxide or the like, and may further be subjected to surface treatment such as corona treatment.

  Furthermore, the normal extrusion lamination (extrusion laminating) method in which molten polyethylene resin is laminated on the printed surface of the printed material through various anchor coating agents such as imine, isocyanate, polybutadiene, and titanium, and urethane on the printed surface The laminated laminate of the present invention can be obtained by a known laminating process such as a dry laminating method in which an adhesive such as a coating is applied and a plastic film is laminated, or a direct laminating method in which a melted polypropylene is directly pressed and laminated on a printing surface. It is done.

  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. The hydroxyl value is the number of mg of potassium hydroxide required to neutralize the hydroxyl group contained in 1 g of resin, and is a value obtained according to JIS K0070. The amine value is the number of mg of potassium hydroxide equivalent to the equivalent amount of hydrochloric acid required to neutralize the amino group contained in 1 g of resin. The method for measuring the amine value was as described below. The molecular weight was determined as a polystyrene-converted molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) apparatus. The method for measuring the amine value is as follows.

[Method for measuring amine value]
Weigh 0.5-2 g of sample accurately. (Sample amount: Sg) 30 mL of neutral ethanol (BDG neutral) is added to a precisely weighed sample and dissolved. The obtained solution is titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was taken as the end point, and the amine value was determined by the following (Formula 1) using the titration amount (AmL) at this time.
(Formula 1) Amine number = (A × f × 0.2 × 56.108) / S

[Synthesis Example 1]
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, a polyester diol having a number average molecular weight of 2000 (hereinafter referred to as PMPA2000) obtained from adipic acid and 3-methyl-1,5-pentanediol. 32.977 parts, polypropylene glycol having a number average molecular weight of 2000 (hereinafter referred to as PPG2000) 16.464 parts, 8.791 parts of isophorone diisocyanate, 0.010 parts of stannous 2-ethylhexylate and n-propyl acetate 10 0.0 part was charged and reacted at 85 ° C. for 3 hours under a nitrogen stream, followed by adding 10.0 parts of n-propyl acetate and cooling to obtain 72.212 parts of a solution of a terminal isocyanate prepolymer. Next, a mixture of 1.768 parts of isophoronediamine, 92.000 parts of n-propyl acetate and 28.000 parts of isopropyl alcohol was gradually added to 78.242 parts of the resulting solvent solution of the terminal isocyanate prepolymer at room temperature. Next, the reaction is carried out at 50 ° C. for 1 hour, and a polyurethane having a solid content of 30%, a solvent composition of n-propyl acetate: isopropyl alcohol = 80: 20 (weight ratio), a weight average molecular weight of 20000, an amine value of 0.5 mgKOH / resin 1 g A resin solution (a) was obtained.

[Synthesis Examples 2, 7, and 8]
Synthesis was performed in the same manner as in Synthesis Example 1 with the blending ratios in Table 1 to obtain polyurethane resin solutions (b), (g), and (h). Details of the polyurethane resin solution are also shown in Table 1.

[Synthesis Example 3]
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube, a polyester diol having a number average molecular weight of 2000 (hereinafter referred to as PMPA2000) obtained from adipic acid and 3-methyl-1,5-pentanediol. 32.394 parts, polypropylene glycol (hereinafter referred to as PPG2000) 16.173 parts, isophorone diisocyanate 8.635 parts, stannous 2-ethylhexylate 0.010 parts and n-propyl acetate 10 0.0 part was charged, and the mixture was reacted at 85 ° C. for 3 hours under a nitrogen stream. Then, 10.0 parts of n-propyl acetate was added and cooled to obtain 77.212 parts of a solution of a terminal isocyanate prepolymer. Subsequently, 2.233 parts of isophorone diamine, 0.565 parts of di-n-butylamine, 92.000 parts of n-propyl acetate and 28.000 parts of isopropyl alcohol were mixed with a solvent solution 77 of the obtained terminal isocyanate prepolymer. .212 parts are gradually added at room temperature, followed by reaction at 50 ° C. for 1 hour, solid content 30%, solvent composition n-propyl acetate: isopropyl alcohol = 80: 20 (weight ratio), weight average molecular weight 50000, amine A polyurethane resin solution (a) having a value of 3.5 mg KOH / resin 1 g was obtained.

[Synthesis Examples 4, 5, 6, 9]
Synthesis was performed in the same manner as in Synthesis Example 2 at the blending ratio in Table 1, and polyurethane resin solutions (d) to (f) and (i) were obtained. Details of the polyurethane resin solution are also shown in Table 1.

[Example 1]
30 parts of Titanic JR-805 (manufactured by Teika), 10 parts of polyurethane resin solution (a), 10.0 parts of n-propyl acetate / isopropyl alcohol mixed solvent (weight ratio 80/20) are mixed with stirring, and the meat is mixed with a sand mill. After that, 40 parts of the polyurethane resin solution (a) and 10.0 parts of a mixed solvent of n-propyl acetate / isopropyl alcohol (weight ratio 80/20) were stirred and mixed to obtain a white printing ink (A1). To 100 parts of the obtained white printing ink (A1), 50 parts of a mixed solvent of n-propyl acetate / isopropyl alcohol (weight ratio 80/20) was added and mixed as a diluent solvent to obtain a white diluted ink (A2).
After 12 parts of copper phthalocyanine indigo blue, 20 parts of polyurethane resin solution (a) and 10 parts of n-propyl acetate / isopropyl alcohol mixed solvent (weight ratio 80/20) were stirred and mixed in a sand mill, polyurethane resin solution (A) 20 parts and 38 parts of a mixed solvent of n-propyl acetate / isopropyl alcohol (weight ratio 80/20) were stirred and mixed to obtain a deep blue printing ink (A3). To 100 parts of the obtained indigo printing ink (A3), 50 parts of n-propyl acetate / isopropyl alcohol mixed solution (weight ratio 80/20) was added and mixed as a diluent solvent to obtain indigo diluted ink (A4). . The white and indigo color inks and dilution inks obtained here are both n-propyl acetate / isopropyl alcohol = 80/20 (weight ratio).

[Examples 2 to 8]
In the mixing ratios shown in Table 3, as in Example 1, white inks (A1) to (H1) and indigo color inks (A3) to (H3) were further diluted with the same solvent composition as each ink. White diluted inks (A2) to (H2) and indigo diluted inks (A4) to (H4) were obtained and diluted.

[Comparative Examples 1-5]
Similar to the examples, the white inks (I1) to (M1) and the indigo inks (I3) to (M3) were further the same as the respective inks at the compounding ratios shown in Table 1 as in Example 1. White diluted inks (I2) to (M2) and indigo diluted inks (I4) to (M4) were obtained by diluting with a diluting solvent having a solvent composition.

[Example 1-19 and Comparative Example 1-11]
The performance of the diluted printing inks A2 to M2 and A4 to M4 obtained in Example 1-19 and Comparative Example 1-11 was evaluated as follows.

[Printability]
An NBR (nitrile butadiene rubber) rubber hardness 80Hs impression cylinder, a blade thickness of 60 μm (base material thickness 40 μm, one side ceramic layer thickness 10 μm), a chrome hardness 1050 Hv made by Toyo Prepress Co., Ltd. Fuji Machine uses an electronic engraving plate (stylus angle 120 °, for color ink: 250 lines / inch, for white ink: 200 lines / inch), and diluted printing inks obtained in Example 1-11 and Comparative Example 1-3. After setting on a gravure printing machine manufactured by Kogyo Co., Ltd. and spinning the plate for 60 minutes at a doctor pressure of 2 kg / cm @ 2 and a rotation speed of 100 m / min, corona treatment of a single-sided corona-treated OPP film "Pyrene P2161 (Toyobo Co., Ltd.)" Printed on the surface at a printing speed of 100 m / min with a printing pressure of 2 kg / cm 2 and dried with hot air at 60 ° C. To obtain things. During printing, a viscosity controller is used to appropriately replenish each dilution solvent to maintain a certain viscosity.

1. Plate fogging A printed material was pasted on black or white paper, and the amount of ink adhered to a blank portion (non-image portion) was visually evaluated according to the following criteria.
○: No ink transfer was observed in the non-image area.
○ Δ: Slight ink transfer was observed in the non-image area.
Δ: Ink transfer was observed in a small area of the non-image area.
Δ ×: Ink transfer was observed in a large area of the non-image area.
X: Ink transfer was observed over the entire non-image area.

2. Blocking resistance The printed material was sampled to 4 cm × 4 cm, and the unprinted surface of the unprinted film having the same size as the printed surface of this sample was combined, and the sample was peeled off by applying 10 kgf for 12 hours at 40 ° C. At that time, the ink was removed and the resistance was observed.
○: Ink transfer from the printed matter was not observed at all, and there was no resistance when peeled.
○ Δ: No transfer of ink was observed from the printed matter.
Δ: Slight transfer of ink from the printed material was observed.
Δ ×: Ink transfer from the printed material was recognized in an area of about 50%.
X: Ink transfer from the printed matter was observed in almost all areas.

3. Misting property The printed matter was pasted on black or white paper, and the amount of ink splashed and adhered to the blank portion (non-image portion) was visually evaluated according to the following criteria.
○: No ink transfer was observed in the non-image area.
○ Δ: Slight ink transfer was observed in the non-image area.
Δ: Ink transfer was observed in a small area of the non-image area.
Δ ×: Ink transfer was observed in a large area of the non-image area.
X: Ink transfer was observed over the entire non-image area.

4). Adhesive cellophane tape (made by Nichiban, width 12mm) was applied to the 35μm portion of the printed material and rubbed strongly with the thumb 5 times. .
○: Ink peeling was not observed at all even when pulled apart rapidly.
○ △: Slight peeling of ink was observed when pulled away rapidly.
Δ: Ink peeling was not observed at all even when pulled slowly, but peeling of ink was observed when pulled away abruptly.
Δ ×: peeling of ink having an area of about 50% was observed even when slowly separated.
X: Most ink peeling was recognized even if it pulled away slowly.

[Solvent recovery-reusability]
When the solvent was recovered and reused, the difficulty level was judged by the amount of the solvent component species. In the case of a single solvent component, the recovered solvent can be used as it is, and an insufficient amount can be added. In the case of two components, one of the deficient solvents can be added, which is a good evaluation.
◎: Solvent component is 1 component ○: Solvent component is 2 components ×: Solvent component is 3 components or more

  The evaluation results are summarized in Table 1. The printing ink of Example 1-19 exhibits excellent printability as compared with the printing ink of Comparative Example 1-11, and the recovered solvent can be easily adjusted and reused.

Claims (4)

  It contains a polyurethane resin having a weight average molecular weight of 20,000 to 100,000 and an amine value of 0.5 to 20.0 mgKOH / g, and 90% or more of the volatile components are composed of two types of ester solvent and alcohol solvent. A solvent recovery / reuse type ink composition.   2. The solvent recovery and reuse ink composition according to claim 1, wherein the polyurethane resin comprises a polymer diol and a polyisocyanate.   A solvent recovery-reusable ink composition, wherein the polyurethane resin according to claim 2 comprises a chain extender and a terminal terminator.   A laminate comprising the above-described printing ink composition according to any one of claims 1 to 3, and a laminate obtained by further performing a plurality of coating, laminating or pressing steps.