JP5056302B2 - Organic solvent recovery method - Google Patents

Description

  The present invention relates to an organic solvent recovery device and a recovery and reuse method. Specifically, the present invention relates to a recovery apparatus and a recovery method for recovering an organic solvent gas of ink generated during printing. The present invention relates to an organic solvent recovery and reuse cycle in which the recovered organic solvent is efficiently reused as a solvent for an ink raw material.

  In recent years, problems related to air pollution such as destruction of the ozone layer in the stratosphere, damage to agricultural products and forest resources due to acid rain in the lower strata, and adverse effects on human bodies due to photochemical oxidants have become serious. For this reason, laws related to the preservation of the air environment, such as the enforcement of the PRTR Law, the strengthening of the Odor Prevention Law, the reduction of carbon dioxide under the Kyoto Protocol, the Air Pollution Prevention Law, and the Saitama Prefecture Living Environment Conservation Ordinance, are becoming stricter every year. In particular, in the gravure printing industry, which uses and releases a large amount of organic solvents, interest in solvent recovery and reuse (recycling) of organic solvents is increasing as a means to solve these problems (non-patented). Literatures 1-3).

  In gravure printing, various printing inks are used depending on the application, such as laminating, surface printing, paper, aluminum printing, etc., and the types of resins and organic solvents used in each ink composition are different. It depends on the application. In particular, organic solvents are usually used in a plurality of types having 5 to 7 components from the standpoints of resin solubility and drying speed adjustment during printing (Non-Patent Documents 1 to 3).

  When printing with printing inks of various uses on the same printing press or the same office, the recovered organic solvent has a multicomponent and unstable composition ratio. When the recovered organic solvent has four or more components, there are two possible cases when reusing. One is fractionated into a single component or from two components to three components or less and reused. The other is the need to adjust the ingredients to match the desired composition of the printing ink that reuses the recovered organic solvent. In order to separate and reuse three components or less, a large-scale distillation tower must be provided, which entails a huge initial cost and running cost. In the case of multi-component adjustment, it is necessary to add a large amount of a plurality of new solvents, which is not efficient.

  Conventionally, in order to treat a gas containing an organic solvent, VOC (volatile organic compound), and other organic compounds, it is passed through a filling tank filled with activated carbon to adsorb the organic substance to the activated carbon, and then a large amount of water vapor. There is known a method in which an organic substance is heated and desorbed through inflow and incinerated. In this method, an organic solvent, VOC (volatile organic compound), and other organic compounds are prevented from being released into the atmosphere. Carbon is generated (Non-patent Document 1).

  To process organic solvent, VOC (volatile organic compound), and other organic compound gases generated from a printing press in gravure printing, the organic matter is adsorbed on the activated carbon by passing it through a filling tank filled with activated carbon. Then, a method is known in which a large amount of water vapor is passed to heat and desorb and recover the organic matter. In the method of adsorbing and recovering on activated carbon, a large amount of water vapor is circulated, so that there is a problem that a large amount of water is mixed in the obtained recovered product. In order to reduce the amount of water in the recovered material, a desorption method using air or an inert gas has been proposed for heating and desorption. Although the amount of water is reduced as compared with the case of desorption with water vapor, water contained in the air is mixed during desorption. For example, during the hot and humid rainy season, the tendency appears remarkably in the summer, and a large amount of water is mixed in the collected material. When the recovered material is reused as it is as a printing ink composition, problems occur in ink storage stability, printability, and coating film performance due to a decrease in solubility of the resin component (Patent Document 1).

  In addition, when the organic solvent used as the printing ink composition at the time of gravure printing contains an ester-based organic solvent, the ester is hydrolyzed when adsorbed on activated carbon and then heated and desorbed, and the acid component is appear. For example, when the ester solvent is ethyl acetate, there is a problem that acetic acid is generated by hydrolysis. When acid components are mixed, rust is generated in metal cans and tanks that store recovered organic solvents, which causes corrosion. Further, when the recovered organic solvent is reused as it is as a printing ink composition, the contents are adversely affected by the odor of the acid component on the printed matter and the packaging material. Therefore, when the recovered organic solvent containing the ester organic solvent is reused in the ink composition, it is necessary to remove moisture and acid.

In the past, in order to remove moisture and acid from the recovered material, the recovered organic solvent adsorbed and recovered by activated carbon was further purified by dehydration and neutralization, and the recovered organic solvent was reused. However, there are problems in that the process of refining the recovered organic solvent increases and the recovery rate (reuse rate) decreases and the purification cost increases.
JP 2005-177650 A Hideki Yasuda, Journal of Japan Printing Society Vol.43, No.6, 404-410 (2006). Masashi Senmoto, Journal of Japan Printing Society Vol.44, No.1, 8-14 (2007). Japan Industrial Environment Management Association 2005 Ministry of Economy, Trade and Industry commissioned survey report “Survey on countermeasures for environmentally hazardous substances (Survey on countermeasures to control volatile organic compound (VOC) emissions)”, March 2006.

  When collecting organic solvent generated during printing, the amount of water and acid mixed in the recovered organic solvent is reduced. After recovery, the recovered organic solvent can be easily removed without purification or neutralization such as distillation. Provided is a method that can be reused as a raw material for a printing ink composition.

  As a result of intensive studies in view of the above situation, the present inventors have adsorbed and collected the organic solvent by the adsorbent after removing the moisture contained in the gas containing the organic solvent generated during printing by the dehydrator. Then, in the step of desorbing the organic solvent from the adsorbent with a heated inert gas, and further neutralizing the acid contained in the organic solvent with a neutralizer and then cooling and liquefying the organic solvent, By using an ester solvent as an essential component, and using a printing ink composition containing three or less organic solvents selected from ester solvents, hydrocarbon solvents, ketone solvents, alcohol solvents, glycol ether solvents, Reduce the amount of moisture and acid mixed in the recovered organic solvent, and easily recover the printing ink composition without purifying or neutralizing the recovered organic solvent such as distillation. Found that can be reused as a fee, it has led to the present invention.

Dehydration apparatus (1-1) characterized by performing dehydration by membrane separation using a polymer membrane, a ceramic membrane or a zeolite membrane, an activated carbon adsorption device (1-2) for adsorbing an organic solvent, and a carbonate A recovery device (1) provided with a cooling device (1-3) having a sum function;
A heat exchanger (2-1) is provided, and heated nitrogen gas (B-1) for desorbing the organic solvent adsorbed in the activated carbon adsorbing device (1-2) from the activated carbon is converted into an activated carbon adsorbing device ( A heated gas supply device (2) for supplying to 1-2);
Using an organic solvent-containing gas treatment facility equipped with
An organic solvent (C-1) comprising an ester solvent as an essential component and including 1 to 3 types of solvents selected from hydrocarbon solvents, ketone solvents, alcohol solvents and glycol ether solvents. A method for recovering the organic solvent from a gas to be treated (A-1) comprising:
The present invention relates to a method for recovering an organic solvent, including the following (I) to (V).
(I) removing moisture in the gas to be treated (A-1) by the dehydrator (1-1);
(II) Next, the gas to be treated (A-2) from which moisture has been removed is supplied to the activated carbon adsorption device (1-2) and adsorbed by the activated carbon adsorption device;
(III) Next, by supplying heated nitrogen gas (B-1) to the activated carbon adsorption device (1-2), nitrogen gas (B) containing an organic solvent from the active stage adsorption device (1-2). -2) is obtained;
(IV) The obtained nitrogen gas (B-2) is supplied to the cooling device (1-3) having a neutralizing function, whereby the liquefied water content is 3% by weight or less, the acid value is 0.5 mgKOH / g or less organic solvent (C-2) and separated into cooled nitrogen gas;
(V) The separated nitrogen gas is supplied to the heat exchanger (2-1) to become heated nitrogen gas (B-1) again.

  When recovering organic solvents generated during printing, the amount of water and acidic components mixed in the recovered organic solvent is greatly reduced compared to conventional recovery methods, without purification or neutralization such as distillation. The recovered organic solvent can be easily reused as a raw material for the printing ink composition, and metal surfaces such as metal cans and metal tanks that store the recovered organic solvent can prevent rust caused by moisture and acidic components. Thus, the storage stability of the recovered organic solvent is excellent, the storage stability of the reused printing ink is good, and the odor of the printed matter using the printing ink reusing the recovered organic solvent is also good.

  The organic solvent recovery method of the present invention recovers volatile components generated in a printing process using a printing ink containing three or less types of solvents that require ester solvents, and makes the obtained ester solvents essential. In this method, three or less kinds of recovered organic solvents are reused as raw materials for the printing ink composition.

  As a typical solvent for gravure printing ink, an ester solvent is often contained. In particular, non-toluene type ink compositions (ink compositions that do not contain toluene) or printing inks typified by solvent recovery type reusable ink compositions mostly contain ester organic solvents. is there. When recovering these printing inks by adsorbing and recovering the organic solvent generated in the printing and drying process from one or more printers by activated carbon, the recovered solvent is mixed with moisture in the atmosphere and absorbed and recovered by the activated carbon. When the activated carbon is heated and the solvent is desorbed, the ester is hydrolyzed and an acidic component is mixed into the recovered solvent.

The present invention includes water coexisting in an organic solvent generated in a printing drying process from one or a plurality of printing presses, and an acidic component generated by hydrolysis of an ester solvent in the printing drying process and the adsorption / desorption process of activated carbon. The organic solvent is recovered after removal, and the obtained recovered organic solvent is used as a raw material for a printing ink composition by adjusting the component ratio as necessary without performing fractional distillation, dehydration and neutralization. those concerning the organic solvent recovery how reusable.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic overall configuration of an organic solvent-containing gas processing facility according to this embodiment.

As shown in FIG. 1, the organic solvent recovery device passed a prefilter (1-4) and a prefilter (1-4) for removing dust and the like in the organic solvent generated from the printing press. A dehydrator (1-1) that removes moisture coexisting in the organic solvent, an activated carbon adsorber (1-2) that adsorbs and removes the organic solvent, and an acidic component generated by the transesterification reaction when heated and desorbed. Neutralizing device (1-3) to be summed, heated gas feeding device (2) for desorbing organic solvent adsorbed by activated carbon adsorbing device (1-2) from activated carbon, and desorbed by this heated gas It consists of a recovery device that recovers organic solvents.

The prefilter (1-4) only needs to remove dust in the gas to be treated, and various commercially available dust removal filters can be used. The organic solvent that has passed through the pre-filter (1-4) is fed to the dehydrator (1-1) that removes the water coexisting in the organic solvent by the feed pump (1-5), and a plurality of the organic solvents are passed through the control valve V1. To the activated carbon adsorption device (1-2). Of course, the number of dehydration devices and activated carbon adsorption devices may be one, and the number and specifications thereof are appropriately selected depending on the amount and characteristics of the organic solvent.

  Moreover, the apparatus which remove | desorbs and collect | recovers the organic solvents adsorbed by activated carbon is provided in the downstream of the activated carbon adsorption apparatus (1-2). In this case, the relationship between the linear flow velocity (LVa) of the gas to be treated to be passed through the activated carbon and the linear velocity (LVb) of the gas when the organic matter is desorbed from the activated carbon that has adsorbed the organic matter is important. LVb / LVa = 0b to 1 / 10,000 and more preferably LVb / LVa = 1/10 to 1 / 10,000. Within this range, the organic matter adsorbed on the activated carbon can be efficiently desorbed. Specifically, a gas to be treated containing an organic solvent is passed through activated carbon at a linear velocity of 30 to 300 cm / sec, and desorption nitrogen is allowed to flow at 1/10 to 1 / 10,000 of this linear velocity. However, the organic solvent can be efficiently desorbed.

  The desorption of the organic solvent from the activated carbon adsorbed with the organic solvent was conventionally performed by supplying pressurized steam of about 1.9 atmospheres heated to about 130 ° C. In this way, if the organic solvent is benzene, toluene or xylene (so-called BTX), especially low-boiling solvents, the explosion limit may be reached with the hot air sent for drying. For example, it is difficult to work, and it is necessary to provide explosion-proof equipment and other equipment. In order to solve this problem with certainty, in this embodiment, nitrogen (B-1), which is an inert gas, is heated to about 100 ° C. and fed. Of course, other inert gases may be used instead of nitrogen.

That is, nitrogen (N ₂ ) is fed from a nitrogen container (gas or liquid nitrogen container, etc., not shown) to the heat exchanger (2-1) by the feed pump (1-6) through the control valve V4. Then, it is heated to a temperature somewhat higher than the boiling point of the organic solvent adsorbed on the activated carbon, and is sent to the activated carbon adsorption device (1-2) via the control valve V2. The heat quantity of the heat exchanger (2-1) is preferably used by supplying heat generated from other heat sources in the factory. Nitrogen may be fed directly to the high-temperature exchanger (2-1) and heated, and the feed pump may not necessarily be used to feed nitrogen, but other feed means may be used. Also good.

  The organic solvent adsorbed on the activated carbon of the activated carbon adsorption device (1-2) is desorbed by the heated nitrogen (B-1), and passes through the control valve V3 together with the nitrogen, and the cooling device (1-3) having a neutralization function. ) To obtain a liquefied organic solvent (C-2) which is neutralized and cooled. Since the organic solvent is adsorbed on the activated carbon of the activated carbon adsorption device (1-2), it is released to the outside air as clean air.

  The liquefied organic solvent (C-2) is sent to the decanter (1-7) and recovered as a high-purity organic solvent from which moisture and acidic components have been removed. The cooling device (1-3) and decanter (1-7) having a neutralizing function constitute a recovery device. However, depending on the organic solvent in the gas to be treated, the decanter (1-7) is not necessarily required, and other recovery means may be used.

Further, according to this configuration, since the organic solvent can be easily recovered, a large facility such as a distillation tower is not required. Of course, since nitrogen is used for desorption of organic substances, there is no need for water treatment compared to the case of using water vapor as in the prior art, and there is less water mixing in the recovered liquid by the dehydrator. There is also an advantage that there is little mixing of an acidic component by a sum machine.

The inert gas is nitrogen, and heat exchange is performed by passing the heating gas (B-2) desorbed from the organic solvent through a heat exchanger (2-1) for heating the nitrogen. Preferably it is.

According to this configuration, since nitrogen is inexpensive, the processing cost can be reduced, and furthermore, the heat utilization rate of the entire processing equipment can be increased and energy saving can be realized.

Further, the organic substance-containing gas treatment method according to the present invention has a characteristic configuration in which moisture in a gas to be treated containing organic substances is adsorbed and removed by a dehydrator, organic substances are adsorbed and removed by an activated carbon adsorber, and the adsorbed organic substances are removed. In the organic substance-containing gas processing method for supplying a heated gas desorbed from the activated carbon of the activated carbon adsorption device and recovering the organic matter desorbed by the heated gas, the activated carbon of the activated carbon adsorption device is used as the heating gas. To feed the inert gas.

Preferably, nitrogen is used as the inert gas, and heat exchange is performed by passing a heated gas from which the organic solvent has been removed through a heat exchanger (2-1) that heats the nitrogen.

According to this configuration, the processing cost can be reduced by using inexpensive nitrogen, and the processing cost can be lowered by increasing the heat utilization rate of the entire processing equipment.

  The dehydration method of the dehydrator (1-1) includes membrane separation using a polymer membrane, ceramic membrane or zeolite membrane (S-1), adsorption using silica gel (S-2), separation by specific gravity difference ( S-3) and distillation (S-4) are mentioned, but in the present invention, steam using a hydrophilic polymer film or ceramic film from the viewpoint of dehydration ability, heat resistance, solvent resistance, etc. in the above method. The transmission method is preferably used. As a material used for the hydrophilic polymer film, polyvinyl alcohol, polyimide, chitosan, polyethylene oxide, water-soluble cellulose acetate, carboxymethyl cellulose, zeolite, and the like are used.

  This dehydration step has the effect of reducing the amount of water mixed in the organic solvent to be recovered, and also has the effect of suppressing the generation of acidic components due to hydrolysis of the ester solvent in the desorption step.

  The cooling device (1-3) having a neutralizing function contains acidic components generated by the transesterification reaction when the ester solvent in the inert gas (B-2) containing an organic solvent is heated and desorbed. The neutralizing agent is used for the neutralization and the inert gas (B-2) containing the organic solvent is cooled to liquefy the organic solvent. The liquefaction of the organic solvent means that the state changes from gas to liquid.

  An apparatus for performing neutralization and cooling (liquefaction) at the same time, and an independent apparatus for neutralization and cooling may be used. When using an apparatus in which neutralization and cooling are independent, either order of neutralization and cooling may be used first. Either neutralizing first and then cooling (liquefaction) or conversely cooling (liquefaction) and then neutralization is possible.

  Examples of the neutralizing agent for the cooling device (1-3) having a neutralizing function include hydroxides represented by potassium hydroxide, sodium hydroxide, calcium hydroxide, and barium hydroxide, potassium carbonate, and calcium carbonate. Carbonate. It is better to use carbonate. When a hydroxide is used as the neutralizing agent, in addition to neutralizing the acidic component, the transesterification reaction is promoted as compared with the case where a carbonate is used. Therefore, it is preferable to use a carbonate.

  When the recovered organic solvent mixed with a large amount of moisture is reused as it is as a raw material for the printing ink composition, there is a risk of adverse effects such as deterioration in ink storage stability and deterioration in printability due to a decrease in the solubility of the resin. In the present invention, when the recovered organic solvent is reused as a raw material for the printing ink composition, the water content in the recovered organic solvent should be 3% or less so as not to adversely affect the storage stability and printability of the ink. More preferably, the water content in the recovered organic solvent is preferably 0%.

  Further, when a recovered organic solvent in which a large amount of acid such as acetic acid is mixed is reused as a raw material for a printing ink composition, an acid odor remains in the printed material or packaging material, which is not preferable. In the present invention, the acid value in the recovered organic solvent is preferably 0.5 mgKOH / g or less, and more preferably the acid value in the recovered organic solvent is set so as not to adversely affect the odor of the printed matter or the packaging material. 0 mg KOH / g is good.

In the present invention, the acid value is the number of mg of potassium hydroxide required to neutralize free fatty acid, resin acid and the like contained in 1 g of a sample, and the acid value is measured according to JIS K 0070 “Chemicals”. The acid value, saponification value, ester value, iodine value, hydroxyl value, and unsaponified product test method of the product "were performed.

In the present invention, the moisture content is measured according to JIS K 0068 “Moisture test of chemical products”.
The measurement was performed by the Karl Fischer titration method.

  In the present invention, the recovered organic solvent is easily reused, and the solubility of the resin is ensured, and the ester solvent is an essential component from the viewpoint of adjusting the drying of the printing ink, the ester solvent, the hydrocarbon solvent, the ketone solvent, It is preferable to use an organic solvent containing not more than three types of organic solvents selected from alcohol solvents and glycol ether solvents.

  Specifically, as the solvent used in the present invention, an organic solvent or water generally used in gravure printing and flexographic printing can be used. As the organic solvent, n-hexane, n-heptane, n- Aliphatic hydrocarbon solvents such as octane, cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane and other alicyclic hydrocarbon solvents, toluene and other aromatic hydrocarbon solvents, acetone, methyl ethyl ketone, methyl Ketone solvents such as isobutyl ketone and dimethyl carbonate, ester solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and propylene glycol monoethyl ether acetate, methanol, ethanol, n-propanol, isopropyl alcohol, butanol, etc. Alcohol solvent, of propylene glycol monomethyl ether, triethylene glycol monoethyl ether and propylene glycol monoethyl ether.

  In the present invention, when two or more types of organic solvents are selected, one type each selected from an ester solvent, a ketone solvent, and an alcohol solvent, for example, ethyl acetate, methyl ethyl ketone, and isopropyl alcohol may be selected. good. Alternatively, two to three different organic solvents can be selected from the same solvent, such as ethyl acetate, propyl acetate, n-type, such as two types from ester solvents and one type from alcohol solvents. Although three types of propanol can be selected, an ester solvent must be selected as an essential component.

  In addition, although the solvent used for the organic solvent in the present invention has been described above, a small amount of unintended solvent components present in the printing ink composition or in the printing work environment atmosphere are mixed in the recovered organic solvent. There is a case. However, if it is a grade which does not inhibit each process, such as printing and collection | recovery, it can contain the organic solvent described above.

  Further, the printing ink composition in the present invention is composed of a colorant, a resin, and a solvent, and if necessary, an extender pigment, a pigment dispersant, a leveling agent, an antifoaming agent, a crosslinking agent, a curing agent, a wax, and a silane cup. Various additives such as a ring agent, a rust inhibitor, a preservative, a plasticizer, an infrared absorber, an ultraviolet absorber, a light resistance improver, a fragrance, and a flame retardant can also be used.

  The printing ink composition of the present invention is applied to a substrate by a printing method such as gravure printing or flexographic printing, and then a solvent contained in the printing ink is volatilized by a drying device such as an oven, and an adsorbent such as activated carbon. Is sent to a collection device equipped with

  Resin used for the printing ink composition in this invention can be suitably selected with a use or a base material. Examples of the resin used in the present invention include polyurethane resin, polyurethane / urea resin, vinyl chloride-vinyl acetate copolymer resin, chlorinated polypropylene resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, nitro Cellulose resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic resin, terpene resin, phenol modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc. Can be mentioned. These resins can be used alone or in admixture of two or more.

  In the printing ink composition for laminating, which is the mainstay, among the resins used in the printing ink composition in the present invention, from the reduction of the residual solvent amount in the ink printed material and the suitability for extrusion laminating, the polymer diol, organic isocyanate The main binder is preferably a polyurethane resin comprising a compound and, if necessary, a chain extender and a terminal terminator. 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.

  It is preferable to react the polyol with a polyisocyanate and a chain extender to form a urethane-modified polyol. The urethane-modified polyol is prepared by reacting a polyol and a 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 having a group, and then reacting this prepolymer with a chain extender to obtain a polyurethane polyol resin, or by reacting an organic polyol compound, a polyisocyanate compound and a chain extender in one step. It can be produced by a known method such as a one-shot method for obtaining a polyurethane polyol resin.

Examples of the polyol include polyether polyols (i) of polymers or copolymers such as methylene oxide, ethylene oxide and tetrahydrofuran; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl- 1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexane Diol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, polypropylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexa Triol, 1,2,4-butane triol, sorbitol, low-molecular polyols, saturated or unsaturated, such as pentaerythritol (ii);
These low molecular weight polyols (ii), adipic 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, Polyester polyols (iii) obtained by dehydration condensation or polymerization of polycarboxylic acids such as sebacic acid, trimellitic acid, pyromellitic acid or their anhydrides;
Polyester polyols (iv) obtained by ring-opening polymerization of lactones such as cyclic ester compounds such as polycaprolactone, polyvalerolactone, poly (β-methyl-γ-valerolactone); the low molecular polyols (ii) And, for example, polycarbonate polyols (v) obtained by reaction with dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene and the like;
Polybutadiene glycols (vi); glycols (vii) obtained by adding ethylene oxide or propylene oxide to bisphenol A; one or more hydroxyethyl, hydroxypropacrylate, acrylichydroxybutyl, etc. in one molecule, or An acrylic polyol (viii) obtained by copolymerizing these corresponding methacrylic acid derivatives and the like, for example, acrylic acid, methacrylic acid or an ester thereof; an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc. Examples thereof include polyether polyol (ix) obtained by polymerizing water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin and the like as a low molecular weight polyol. In particular, polypropylene glycol is preferred.

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, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetra Examples include methylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimer diisocyanate obtained by converting the carboxyl group of dimer acid to an isocyanate group. It is done. 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 ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and 2-hydroxy 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-hydroxypyrroleethylenediamine and di-2-hydroxypropylethylenediamine, can also be used. These chain extenders can be used alone or in admixture of two or more.

  Moreover, a monovalent active hydrogen compound can also be used as a terminal blocking agent for the purpose of stopping the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine 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. These end blockers can be used alone or in admixture of two or more.

  In producing the prepolymer, the amount of polyol and polyisocyanate is determined by the NCO / OH ratio, which is the ratio of the number of moles of isocyanate groups contained in polyisocyanate (F) to the number of moles of hydroxyl groups contained in the organic polyol compound. It is preferable to be in the range of 1.1 to 3.0. 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 end terminator is 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.

  Further, the ratio of the total number of moles of the number of moles of amino groups and the number of moles of hydroxyl groups contained in the chain extender and the terminator with respect to the number of moles of isocyanate groups contained in the prepolymer is 1.1 to 3.0. The reaction is preferably performed in the range of 1.5 to 2.0. 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.

  As the hue of the printing ink composition of the present invention, there are a total of five colors of yellow, red, indigo and black in addition to white as a process basic color, depending on the type of colorant used. There are three colors: red (orange), grass (green), and purple. 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 the white inorganic pigment that can be used in the 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.

  The colorant is preferably contained in an amount sufficient to ensure the concentration and coloring power of the printing ink composition, that is, in a proportion of 1 to 50% by weight based on the total weight of the printing ink composition. These colorants can be used alone or in combination of two or more.

  In order to stably disperse the pigment in the organic solvent, it is possible to disperse the resin alone, 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.

  Said printing ink composition can be manufactured by melt | dissolving and / or disperse | distributing resin, a coloring agent, etc. 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 printing 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 dispersing appropriately, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. Is preferred. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer.

  The viscosity of the printing 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.

  Examples of the method for applying the printing ink composition of the present invention include printing methods such as gravure printing, flexographic printing, letterpress printing, screen printing, and offset printing, and coating methods such as roll coating, spray coating, and dip coating. For example, in the case of gravure printing, it is diluted with a diluting solvent to a viscosity and concentration suitable for printing, and is supplied alone or mixed to each printing unit. The printing ink is applied to the substrate by these printing methods and then fixed by volatilizing the solvent in an oven.

  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.

  The recovered organic solvent obtained in the present invention can be reused as it is as a diluting solvent for reusable printing inks and as a raw material for printing ink compositions.

  Furthermore, in the present invention, after analyzing the solvent composition of the recovered organic solvent obtained as necessary, the solvent is added to the recovered solvent as necessary to adjust the components, and then the diluting solvent for reusable printing ink, printing ink It can also be reused as a raw material for the composition.

  Methods for analyzing the solvent composition of the recovered organic solvent include gas chromatography measurement, liquid chromatography measurement, infrared absorption spectrum measurement, refractive index measurement, density specific gravity measurement, conductivity measurement, nuclear magnetic resonance absorption method and odor test. It is preferable to carry out by at least one method selected from the measurement methods used. The solvent for adjusting the components in addition to the recovered solvent may be a new solvent, a recovered organic solvent obtained by the above method, or a mixed solvent of the new organic solvent and the recovered organic solvent. There may be.

  EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the present invention, “part” represents “part by weight” and “%” represents “% by weight”. The molecular weight is a weight average molecular weight obtained as a polystyrene-converted molecular weight by measuring a molecular weight distribution using a GPC (gel permeation chromatography) apparatus. The methods for measuring the amine value, water content, and acid value are as follows.

[Example 1]
An example in which ethyl acetate is recovered as an organic solvent, which is an organic solvent containing one type of ester solvent, will be described. As shown in FIG. 1, exhaust gas containing ethyl acetate 720 kg / h at a flow rate of 85,000 Nm ³ / h is supplied to a dehydrator and adsorbed and removed moisture, and then four activated carbon adsorbers (1 -2) and adsorbed. The activated carbon adsorption device (1-2) includes about 20,000 activated carbon sheets and has a size of 3,000 × 4,500 × height of 1,000 mm. Nitrogen heated to about 100 ° C. is passed through the activated carbon sheet adsorbed with ethyl acetate to desorb the ethyl acetate, and a cooling device having a neutralizing function for the neutralizing agent to be potassium carbonate (1-3 ), Ethyl acetate (y1), which is a recovered organic solvent recovered from the decanter (1-7), was 684 kg / h (recovery rate of about 95%).

[Example 2]
The same procedure as in Example 1 was carried out using potassium hydroxide as the neutralizing agent of Example 1, and ethyl acetate (y2), a recovered organic solvent, was obtained (recovery rate of about 95%).

[Example 3]
The treatment gas of Example 1 was changed to n-propyl acetate, and the same procedure as in Example 1 was performed to obtain n-propyl acetate (y3) as a recovered organic solvent (recovery rate of about 95%).

[Example 4]
The gas to be treated of Example 1 was used as an organic substance-containing gas containing two types of ester solvents and alcohol solvents, and a mixed solvent having a ratio of n-propyl acetate / isopropyl alcohol (IPA) of 80/20 was used. And a mixed solvent (y4) in which the ratio of n-propyl acetate / isopropyl alcohol (IPA) as the recovered organic solvent was 86/14 was obtained (recovery rate of about 95%).

[Example 5]
As the gas to be treated of Example 1, as an organic substance-containing gas containing three types of ester solvent, alcohol solvent and glycol solvent, the ratio of n-propyl acetate / IPA / propylene glycol monomethyl ether (PGM) is 70/20. The mixed solvent (y5) of n-propyl acetate / IPA / PGM was used in the same manner as in Example 1 (recovery rate: about 95%).

[Example 6]
Number average molecular weight 2000 polyester diol 24.282 parts obtained from adipic acid and 2-butyl-2-ethylpropanediol, isophorone diisocyanate 4.317 parts, stannous 2-ethylhexylate 0.005 part and n-propyl acetate 5.0 parts was reacted at 85 ° C. for 3 hours under a nitrogen stream, and 5.0 parts of n-propyl acetate was added and cooled to obtain 38.604 parts of a solvent solution of a terminal isocyanate prepolymer. Next, a solvent solution 38 of the obtained terminal isocyanate prepolymer was prepared by mixing 1.116 parts of isophoronediamine, 0.28 parts of di-n-butylamine, 46.0 parts of n-propyl acetate and 14.0 parts of isopropyl alcohol. 604 parts are gradually added at room temperature and then reacted at 50 ° C. for 1 hour, solid content 30%, weight average molecular weight 60000, amine value 3.0 mgKOH / resin 1 g, solvent composition n-propyl acetate / isopropyl acetate A polyurethane resin solution (a1) with alcohol = 80/20 was obtained.

  Next, n-propyl acetate (y3), which is the recovered organic solvent of Example 3, and isopropyl alcohol, a new solvent, are mixed, and a mixed solvent (c1) that is a mixed solvent (y3) / isopropyl alcohol (weight ratio 80/20). ) Was adjusted.

  Further, 30 parts of Titanics JR-805 (manufactured by Teika), 10 parts of polyurethane resin solution (a1), 10.0 parts of mixed solvent (c1) were stirred and mixed in a sand mill, and then polyurethane resin solution (a1) 40 parts and 10.0 parts of mixed solvent (c1) (weight ratio 80/20) were mixed to obtain a white printing ink composition (b1). To 100 parts of the obtained white printing ink composition (b1), 50 parts of the mixed solvent (c1) was added and mixed as a diluting solvent for printing ink to obtain a white diluted ink (d1). The solvent composition of the white diluted ink (d1) obtained here was n-propyl acetate / isopropyl alcohol = 80: 20.

Next, an NBR (nitrile butadiene rubber) rubber cylinder with a hardness of 80 Hs, a blade thickness of 60 μm (base material thickness: 40 μm, one side ceramic layer thickness: 10 μm), chromium manufactured by Toyo Prepress Co., Ltd. An electronic engraving plate having a hardness of 1050 Hv (175 lines / inch, a stylus angle of 130 degrees) and the white diluted ink (d1) are set to the fifth color of a gravure five-color printing machine manufactured by Fuji Machine Industry Co., Ltd. On the corona-treated surface of “Pyrene P2161 (manufactured by Toyobo Co., Ltd.)”, printing pressure 2 kg / cm ² , doctor pressure 2 kg / cm ² , drying air volume 70 m ³ / min, drying temperature 60 ° C., printing speed printing 150 m / min. Printing was performed for 30 minutes under the conditions to obtain a printed matter (α-1). During printing, a constant viscosity was maintained by appropriately replenishing the dilution solvent using a viscosity controller. The printing width was 600 mm, the amount of white diluted ink applied was 7.5 g / m ² , and the total printing area was 2700 m ² .

[Example 7]
A mixed solvent (c2) which is a mixed solvent of n-propyl acetate / isopropyl alcohol (weight ratio 80/20) mixed with n-propyl acetate / isopropyl alcohol mixed liquid (y4) recovered in Example 4 as a new solvent. ) Was adjusted.

  It implemented like Example 6 by making mixed solvent (c1) of Example 6 into mixed solvent (c2), and printed matter ((alpha) -2) was obtained.

[Comparative Example 1]
As shown in FIG. 2, an exhaust gas containing ethyl acetate and an exhaust gas containing n-propyl acetate 720 kg / h and having a flow rate of 85,000 Nm ³ / h as an organic substance-containing gas containing one type of ester solvent as shown in FIG. The dehydration device was not fed, but was fed to four activated carbon adsorption devices (1-2) containing activated carbon sheets for adsorption. The activated carbon adsorption device (1-2) includes about 20,000 activated carbon sheets and has a size of 3,000 × 4,500 × height of 1,000 mm. Nitrogen heated to about 100 ° C. is passed through the activated carbon sheet adsorbed with ethyl acetate, and the ethyl acetate is released from the decanter without desorbing the ethyl acetate and feeding it to the neutralizer. ) Was 697 kg / h (recovery rate of about 95%).

[Comparative Example 2]
Ethyl acetate was eliminated by passing water vapor instead of nitrogen in Comparative Example 1 and the same procedure was performed to obtain ethyl acetate (z2) as a recovered organic solvent (recovery rate of about 95%).

[Comparative Example 3]
The treatment gas of Comparative Example 1 was changed to n-propyl acetate, and the same procedure as in Comparative Example 1 was carried out to obtain n-propyl acetate (z3) as a recovered organic solvent (recovery rate of about 95%).

[Comparative Example 4]
The gas to be treated of Comparative Example 1 is an organic substance-containing gas containing two types of ester solvents and alcohol solvents, and a mixed solvent having a ratio of n-propyl acetate / IPA of 80/20 is used. A mixed solvent (z4) having a ratio of n-propyl acetate / IPA, which is a recovered organic solvent, of 86/14 was obtained (recovery rate of about 95%).

[Comparative Example 5]
The gas to be treated of Comparative Example 1 is an organic substance-containing gas containing three types of ester solvent, alcohol solvent, and glycol solvent, and a mixed solvent having a ratio of n-propyl acetate / IPA / PGM of 70/20/10, The reaction was carried out in the same manner as in Comparative Example 1 to obtain a recovered organic solvent n-propyl acetate / IPA / PGM (z5) (recovery rate of about 95%).

[Comparative Example 6]
The gas to be treated of Comparative Example 1 is an organic substance-containing gas containing four types of ester solvent, alcohol solvent, hydrocarbon solvent, and ketone solvent, and n-propyl acetate / IPA / toluene / 2-butanone (MEK) A mixed solvent having a ratio of 50/30/10/10 was used in the same manner as in Comparative Example 1 to obtain a recovered organic solvent (z6) (recovery rate of about 95%).

[Comparative Example 7]
The gas to be treated of Comparative Example 1 is an organic substance-containing gas containing five solvents of ester solvent, alcohol solvent, hydrocarbon solvent, ketone solvent, and glycol solvent. N-propyl acetate / IPA / toluene / MEK / PGM A mixed solvent having a ratio of 50/30/5/10/5 was used in the same manner as in Comparative Example 1 to obtain a recovered organic solvent (z7) (recovery rate of about 95%).

[Comparative Example 8]
As the gas to be treated of Example 1 as an organic substance-containing gas containing four types of ester solvent, alcohol solvent, hydrocarbon solvent and ketone solvent, n-propyl acetate / IPA / toluene / 2-butanone (MEK) A mixed solvent having a ratio of 50/30/10/10 was used in the same manner as in Example 1 to obtain a recovered organic solvent (z8) (recovery rate of about 95%).

[Comparative Example 9]
The gas to be treated of Example 1 is an organic substance-containing gas containing five types of ester solvent, alcohol solvent, hydrocarbon solvent, ketone solvent, and glycol solvent. N-propyl acetate / IPA / toluene / MEK / PGM A mixed solvent having a ratio of 50/30/5/10/5 was used in the same manner as in Example 1 to obtain a recovered organic solvent (z9) (recovery rate of about 95%).

[Comparative Example 10]
N-Propyl acetate (z3), a recovered organic solvent of Comparative Example 3, and isopropyl alcohol, a new solvent, are mixed to prepare a mixed solvent (c3), which is a mixed solvent of (z3) / isopropyl alcohol (weight ratio 80/20). did.

  The mixed solvent (c1) of Example 6 was used as the mixed solvent (c3) in the same manner as in Example 6 to obtain a printed matter (β-1).

[Comparative Example 11]
A mixed solvent (c4) which is a mixed solvent of n-propyl acetate / isopropyl alcohol (weight ratio 80/20) mixed with n-propyl acetate / isopropyl alcohol mixed liquid (z4) recovered in Comparative Example 4 and a new solvent isopropyl alcohol. ) Was adjusted.

  The mixed solvent (c1) of Example 6 was used as the mixed solvent (c4) in the same manner as in Example 6 to obtain a printed matter (β-2).

  For the recovered organic solvents obtained in Examples and Comparative Examples, the composition of the recovered organic solvent, the amount of water in the recovered organic solvent, and the acid value were evaluated by the following methods.

(Evaluation of recovery rate)
The recovery rate represents the yield (weight ratio) of the recovered organic solvent with respect to the total weight part of the organic solvent in the supplied gas to be treated.

(Evaluation of water content of recovered organic solvent)
The moisture content of the recovered organic solvents obtained in Examples 1 to 5 and Comparative Examples 1 to 9 was determined by the Karl Fischer moisture measuring device (Hiranuma Sangyo Co., Ltd.) according to the method described in “JIS K 0068 Chemical Product Moisture Test Method”. “Hiranuma Automatic Moisture Analyzer AQV-2000”) was used. The measured values are shown in Table 1.

(Evaluation of acid value of recovered organic solvent)
The acid values of the recovered organic solvents obtained in Examples 1 to 5 and Comparative Examples 1 to 9 are “acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter test of JIS K 0070 chemical product. The method described in “Method” was used. The measured values are shown in Table 1.

(Evaluation of mixed composition of recovered organic solvent)
The mixed composition of the recovered organic solvents obtained in Examples 1 to 5 and Comparative Examples 1 to 9 was measured with a gas chromatography measuring instrument (“Gas chromatography GC-8A” manufactured by Shimadzu Corporation).

(Recovery solvent storage test)
The recovered organic solvent was put in an 18 L oil can (metal can) and sealed, and the state of rust on the inner surface of the 18 L oil can after 7 days at 40 ° C. was confirmed.
○: No rust was observed inside the 18L oil can.
○ Δ: Slight rust was observed inside the 18L oil can.
Δ: A small area of rust was observed inside the 18L oil can.
Δ ×: A large area of rust was observed inside the 18 L oil can.
X: Rust was observed on the entire surface inside the 18L oil can.

(Measuring method of amine value of resin)
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 resulting 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

(Ink storage stability)
The white printing ink and / or the white diluted ink that reused the recovered organic solvent obtained in Examples 6 to 7 and Comparative Examples 10 to 11 were allowed to stand and stored in an environment of 40 ° C. for 7 days. The presence or absence of separation after storage at 40 ° C. for 7 days and the change in viscosity before and after storage were measured.

  The viscosity of the white printing ink is Zahn Cup No. 4. The viscosity of the white diluted ink is Zahn Cup No. 3 was used. When measuring the viscosity, the white printing ink and / or the white diluted ink and the Zahn cup were previously immersed in a thermostatic bath at 25 ° C. to keep the temperature constant. Next, immerse it in white printing ink and / or white diluted ink adjusted to 25 ° C. so that the upper end of the Zaan cup is below the liquid level, and at the same time pull it up quickly with the hanging ring of the Zaan cup. I started the stopwatch. Zaan Cup No. In the case of No. 4, the end point is the point when the outflow hole looks like its size when viewed from above the Zaan cup. In the case of 3, the end point was the time when continuous outflow from the outflow hole of the white diluted ink was first interrupted.

Ink storage stability after storage at 40 ° C. for 7 days was evaluated according to the following criteria.
○: Separation of white printing ink and white diluted ink was not observed, and the change in viscosity before and after storage was less than ± 1 second.
○ △: Slight separation of white printing ink and white diluted ink was observed (less than 5% of ink level). Alternatively, the change in viscosity before and after storage was ± 1 second or more and less than ± 2 seconds.
(Triangle | delta): Separation of white printing ink and white dilution ink was recognized (5% or more of ink liquid level height and less than 10%). Or, the viscosity change before and after storage was ± 2 seconds or more and less than ± 3 seconds.
Δ: Separation of white printing ink and white diluted ink was recognized (10% or more and less than 20% of ink liquid level). Or the change in viscosity before and after storage was ± 3 seconds or more and less than ± 4 seconds.
X: Separation of white printing ink and white diluted ink was observed (20% or more of the ink level). Or the viscosity change before and after storage was ± 4 seconds or more.

(Plate fog)
The printed matter using the white diluted ink that reused the recovered organic solvent obtained in Examples 6 to 7 and Comparative Examples 10 to 11 was pasted on black paper, and the ink adhered to the blank portion (non-image portion). The amount 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.

(Print odor)
10 printed 450cc mayonnaise bottles containing 0.5m ³ were prepared for the printed matter using the white diluted ink obtained by reusing the recovered organic solvent obtained in Examples 6 to 7 and Comparative Examples 10 to 11, and 40 ° C. After heating for 30 minutes, 10 panelists evaluated the sensory odor.
○: All 10 panelists judged that there was no difference from the standard printed material.
○ Δ: One out of 10 panelists was judged to be different from the standard printed material.
Δ: It was judged that 2 to 3 out of 10 panelists were different from the standard printed matter and felt an acetic acid odor.
Δ ×: 3 to 5 out of 10 panelists were judged to have an acetic acid odor due to differences from the standard printed material.
X: It was determined that 6 or more out of 10 panelists were different from the standard printed material and felt an acetic acid odor.

  As shown in Table 1, the recovered organic solvent in which the gas to be treated obtained in Examples 1 to 3 was supplied to both the dehydration measure and the neutralization device was an organic solvent of an ester solvent. The acid value is 0.5 mgKOH / g or less, and it can be stored without causing rust, corrosion or the like inside the metal can when storing an 18 L oil can. In addition, even when the recovered organic solvent of Examples 1 to 3 is reused as a raw material for printing ink, the odor of the printed matter printed with the ink is good without dehydrating and neutralizing the components of the recovered organic solvent. The recovered organic solvent can be reused as it is. On the other hand, the recovered organic solvent obtained in Comparative Examples 1 to 3 in which the dehydrator and the neutralizer are not fed has a high water content and acid value. However, the storability was poor, the components of the recovered organic solvent were not dehydrated and neutralized, and the odor of the printed matter printed with the ink was also poor, and everything that was good was not obtained.

  As shown in Table 1, the recovered organic solvent in which the gas to be treated obtained in Examples 3 to 5 was supplied to both the dehydration measure and the neutralization device was 2% or less, and the moisture content was 3% or less. The acid value is 0.5 mgKOH / g or less, and it can be stored without causing rust, corrosion or the like inside the metal can when storing an 18 L oil can. Even when the recovered organic solvent of Examples 3 to 5 is reused as a raw material for the printing ink, the mixing ratio of each of the two and three types of mixed liquids can be adjusted without dehydrating and neutralizing the components of the recovered organic solvent. In order to match, the printed matter printed using the mixed solvent whose components are adjusted using a small amount of a new solvent has good odor, and the recovered organic solvent can be reused as the ink. On the other hand, the recovered organic solvent obtained in Comparative Examples 3 to 5 in which the dehydrator and the neutralizer are not fed has a high water content, acid value, poor storage properties, and the components of the recovered organic solvent are dehydrated. When the ink was used without being neutralized, the stability of the ink was poor, and the odor of the printed matter printed using the ink was also bad, so that everything that was good was not obtained.

  As shown in Table 1, the gas to be treated obtained in Comparative Examples 6 to 7 is an organic solvent of 4 or more types. The recovered organic solvent that does not feed the dehydrator and the neutralizer has a high water content and acid value. In order to adjust the mixing ratio of each mixture of four or more types of recovered organic solvents without dehydrating and neutralizing the components of the recovered organic solvent, it is new to adjust the components using a new solvent. A large amount of solvent must be used, and the recycling rate is reduced. When the components of the recovered organic solvent are used in ink without dehydration and neutralization, the stability of the ink is poor, the odor of the printed matter on which the ink is printed is poor, and everything that is good is obtained. Didn't exist

  The recovered organic solvent obtained in Examples 6 to 9 in which four or more kinds of organic solvents to be treated were fed to both the dehydration measure and the neutralization device had a water content of 3% or less and an acid value of 0.5 mgKOH / g or less. It is. The recovered organic solvents of Examples 1 to 3 can be stored without causing rust, corrosion, or the like inside the metal can during storage of an 18 L oil can or the like. Moreover, even when the recovered organic solvent of Examples 3 to 5 is reused as a raw material for printing ink, each of the mixed liquids of four or more recovered organic solvents is mixed without dehydrating and neutralizing the components of the recovered organic solvent. In order to adjust the ratio, adjusting the components using a new solvent requires a large amount of the new solvent, and the reuse rate is lowered, which is industrially unsuitable.

  The recovered organic solvents obtained in Comparative Examples 1 to 5 require further purification steps such as dehydration and fractional distillation after the recovery in order to reuse them. The recovered organic solvent can be dehydrated by distillation, a method using a dehydrating agent, or the like, but industrially unsuitable when considering the time and cost for dehydration.

  Similarly, neutralization of the recovered organic solvent takes time due to distillation and post-treatment of the neutralizing agent, and is industrially unsuitable in view of cost.

  It is extremely difficult to reduce the number of components contained in a mixture of four or more kinds of recovered organic solvents by fractional distillation, and the time required for fractional distillation becomes long, which is industrially unsuitable in view of costs.

    As shown in Table 2, the printed matter using the white diluted ink that reused the recovered organic solvent that was fed through the dehydrating apparatus and the neutralizing apparatus obtained in Examples 6 to 7 was stored in the ink, the plate Excellent fog and printed odor.

  On the other hand, the recycled organic solvent that does not feed the dehydration device and the neutralization device obtained in Comparative Examples 10 to 11 is reused, and the printed matter using the white diluted ink has a high water content and acid value. Inferior in storage properties, plate fogging, and print odor.

It is a conceptual diagram of the schematic whole structure of the organic solvent containing gas processing equipment. It is a conceptual diagram of the schematic whole structure of the organic solvent containing gas processing equipment which does not use a dehydrator and a neutralizer from FIG.

Explanation of symbols

(1-1) Dehydrating device (1-2) Activated carbon adsorbing device (1-3) Cooling device having neutralization function (1-4) Prefilter (1-5) Feeding pump (1-6) Feeding pump (1-7) Decanter (1-8) Cooling device (2-1) Heat exchanger (B-1) Inert gas (nitrogen)
(B-2) Inert gas (nitrogen) containing organic solvent
(C-1) Three or less kinds of organic solvents (contained in the gas to be treated) (C-2) Liquefied organic solvent (V1) Control valve (V2) Control valve (V3) Control valve (V4 ) Control valve

Claims (1)

Dehydration apparatus (1-1) characterized by performing dehydration by membrane separation using a polymer membrane, a ceramic membrane or a zeolite membrane, an activated carbon adsorption device (1-2) for adsorbing an organic solvent, and a carbonate A recovery device (1) provided with a cooling device (1-3) having a sum function;
A heat exchanger (2-1) is provided, and heated nitrogen gas (B-1) for desorbing the organic solvent adsorbed in the activated carbon adsorbing device (1-2) from the activated carbon is converted into an activated carbon adsorbing device ( A heated gas supply device (2) for supplying to 1-2);
Using an organic solvent-containing gas treatment facility equipped with
An organic solvent (C-1) comprising an ester solvent as an essential component and including 1 to 3 types of solvents selected from hydrocarbon solvents, ketone solvents, alcohol solvents and glycol ether solvents. A method for recovering the organic solvent from a gas to be treated (A-1) comprising:
A method for recovering an organic solvent comprising the following (I) to (V):
(I) removing moisture in the gas to be treated (A-1) by the dehydrator (1-1);
(II) Next, the gas to be treated (A-2) from which moisture has been removed is supplied to the activated carbon adsorption device (1-2) and adsorbed by the activated carbon adsorption device;
(III) Next, by supplying heated nitrogen gas (B-1) to the activated carbon adsorption device (1-2), nitrogen gas (B) containing an organic solvent from the active stage adsorption device (1-2). -2) is obtained;
(IV) The obtained nitrogen gas (B-2) is supplied to the cooling device (1-3) having a neutralizing function, whereby the liquefied water content is 3% by weight or less, the acid value is 0.5 mgKOH / g or less organic solvent (C-2) and separated into cooled nitrogen gas;
(V) The separated nitrogen gas is supplied to the heat exchanger (2-1) to become heated nitrogen gas (B-1) again.

Images