JP5104005B2 - Reuse method of recovered solvent - Google Patents

Description

  The present invention relates to a method for recovering and reusing a solvent generated by printing.

  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 emissions 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 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, ethyl acetate and toluene are used as a single solvent. In the field of laminating adhesives and publishing gravure printing, solvent recovery-reuse is performed, but gravure printing for other uses (for laminating, surface printing) , Paper, and aluminum printing), various inks are used depending on the application, resulting in a plurality of solvent types from the standpoints of solubility of the resin used and adjustment of the drying speed (Non-Patent Documents 1 to 3). ).

  There are attempts to simplify the composition of printing inks into two components in specific fields, such as laminating applications, and to perform solvent recovery and reuse. If two components are used, it is possible to easily adjust the components by adding either component of the recovered solvent, but ink for all uses, such as film lamination, film surface printing, paper, and aluminum printing. It is technically difficult to standardize the two components because of the difference in solubility of the resins selected according to the respective target physical properties.

  For example, as disclosed in Japanese Patent Application Laid-Open No. 07-247456, there is an invention of a solvent recovery and reuse ink in which a solvent component is composed of an ester solvent, an alcohol solvent, and a small amount of moisture. Although it is relatively easy to design inks that use polyurethane / urea resin as the main binder, which is represented by industrial inks, chlorinated rubber and chlorine used mainly to ensure adhesion to olefinic substrates Polypropylene, petroleum resin, and the like cannot obtain sufficient solubility unless a hydrocarbon-based solvent is used, and cannot ensure printability as an ink. In addition, the vinyl chloride-vinyl acetate copolymer resin cannot secure the printability of ink unless an appropriate amount of a ketone solvent is used.

When printing with various types of ink on the same printing press or at the same business location, or when collecting recovered solvent generated at various locations, using the conventional printing ink group and diluted solvent group, the recovered solvent is a multi-component and non-recoverable solvent. It becomes a stable composition ratio. For this reason, in order to separate the solvent into a single solvent, a large-scale distillation tower or the like must be provided, which requires enormous initial costs and running costs. As a result, a large amount of carbon dioxide is consumed and a large amount of carbon dioxide is discharged. Further, 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.
Japanese Patent Laid-Open No. 07-247456 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.

  An object of the present invention is to provide a method in which a mixed solvent from which volatile components generated by printing or coating are recovered can be easily reused without being separated into a single solvent. More specifically, an object of the present invention is to provide a solvent recovery and reuse method for reusing a mixed solvent recovered by a solvent recovery device installed in a printing press as a printing ink raw material and / or a diluted solvent raw material.

  As a result of intensive studies in view of the above circumstances, the inventors of the present invention designed by limiting the solvent components used in the printing ink composition group and the dilution solvent group, and generated by printing or coating using these. The mixed solvent obtained by collecting the volatile components is separated into a single solvent by reusing the single solvent and / or two or more azeotropic compositions after separating them using multistage distillation. The present invention has been found out that it can be easily reused as a printing ink raw material and / or a diluting solvent raw material.

That is, the present invention relates to a printing ink composition group in which at least three types of solvents selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, glycol ether solvents are used, and dilutions. When printing or coating is performed using a solvent group, the mixed solvent recovered by the solvent recovery device installed in the printing machine is a hydrocarbon solvent, ketone solvent, ester solvent, alcohol solvent, glycol. At least three or more types selected from ether solvents are used, and the recovered mixed solvent is subjected to a membrane separation using a polymer membrane, a ceramic membrane or a zeolite membrane , and then a single solvent is obtained by multistage distillation. And / or after separation into two or more azeotropic compositions, reuse as printing ink raw material and / or dilution solvent raw material The present invention relates to a solvent recovery and reuse how.

  Further, according to the present invention, the printing ink composition group, the dilution solvent group, and the mixed solvent recovered from these printing ink composition group and dilution solvent group are methylcyclohexane, toluene, methyl ethyl ketone, n-acetate. The present invention relates to the above-mentioned solvent recovery and reuse method, which is at least three or more selected from propyl, ethyl acetate, isopropanol, ethanol, n-propanol, and propylene glycol monomethyl ether.

  Furthermore, the present invention relates to a printing ink composition characterized by using as a raw material a single solvent and / or a solvent separated into two or more azeotropic compositions by the above method.

  In addition, the present invention relates to a diluting solvent for printing ink, characterized by using as a raw material a single solvent and / or a solvent separated into two or more azeotropic compositions by the above method.

  The recovered solvent recycling method provided by the present invention is a method of obtaining a single solvent and / or a solvent having two or more azeotropic compositions from a recovered solvent composed of volatile components generated by printing by using multistage distillation, and using this as a printing ink. It can be reused as a raw material for the composition.

  In addition, by designing various resin-based printing ink compositions with several unified solvent types, these recovered solvents generated from multiple printing machines, offices, and companies can be single or stable. Since the mixed solvent having the composition ratio can be obtained by azeotropic distillation, the reuse becomes simple.

The recovered solvent recycling method of the present invention is to provide a method in which the mixed solvent from which the volatile components generated by printing are recovered can be easily reused without being separated into a single solvent.

  As a solvent used for the printing ink in the present invention, water or an organic solvent generally used in gravure printing and flexographic printing can be used. Among these, organic solvents include aliphatic hydrocarbon organic solvents such as n-hexane, n-heptane and n-octane, and alicyclic carbonization such as cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane and cyclooctane. Hydrogen solvents, aromatic hydrocarbon solvents such as toluene, ketone organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl carbonate, methyl acetate, ethyl acetate, n-propyl acetate, butyl acetate, propylene glycol monoethyl ether Examples thereof include ester solvents such as acetate methanol, alcohol solvents such as ethanol, n-propanol, isopropanol, and butanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and the like.

  These solvents can be appropriately selected depending on the solubility of the resin system of the printing ink used and the drying adjustment related to the printing effect. However, in terms of recovery and reuse, fewer solvent types are used with less process and energy. It is preferable because separation for use is possible, and in order to design various resin-based printing inks, it is preferable that many solvent types can be used.

  For example, in gravure printing, printing for film laminating, film surface printing, paper, and aluminum is carried out roughly. From the required film properties, film laminating inks are polyurethane / urea resins, polyurethane resins, Chlorinated polypropylene resin, vinyl chloride-vinyl acetate copolymer resin, film surface printing ink is polyamide resin, paper ink is nitrocellulose resin, acrylic resin, aluminum ink is nitrocellulose resin, chlorinated rubber resin, vinyl resin It is increasingly used for main binders.

  Among them, the polyurethane resin can ensure solubility with an ester solvent / alcohol solvent. In addition, chlorinated polypropylene resins are hydrocarbon solvents, vinyl chloride-vinyl acetate copolymer resins are ketone solvents, polyamide resins are alcohol solvents, nitrocellulose resins are ester solvents, acrylic resins are hydrocarbon solvents or ester solvents. Solvent and chlorinated rubber resin can ensure solubility by using an appropriate amount of a hydrocarbon solvent. Therefore, by combining a hydrocarbon solvent, a ketone solvent, an ester solvent, and an alcohol solvent, it is possible to ensure the solubility of the main binder for inks of many uses. Furthermore, by adding the glycol ether system used to adjust the drying speed for the purpose of improving printability, and using the five solvent component systems in the present invention, it is possible to design inks for most applications. became. For these reasons, at least three types selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and glycol ether solvents are preferable.

The composition ratio of each solvent of printing ink group and diluted solvent group is
(1) The hydrocarbon solvent is 0 to 90% by weight in order to ensure solubility when rubber-based resin or petroleum-based resin is used.
(2) The ketone solvent is 0 to 90% by weight in order to ensure solubility when vinyl chloride-vinyl acetate copolymer resin is used.
(3) The ester solvent is used in an amount of 0 to 90% by weight to ensure solubility when a polyurethane resin or the like is used.
(4) If the alcoholic solvent is more than 50%, a large amount of moisture is mixed during printing, which may reduce brushing and wettability to the substrate.
(5) If the amount of the glycol ether solvent exceeds 20%, the amount remaining on the printed matter increases, affecting the subsequent process and quality.
Is preferred.

  Furthermore, since it is preferable that the type of solvent is limited, in consideration of solubility and dryness, the hydrocarbon solvent is preferably an aliphatic methylcyclohexane rather than an aromatic solvent for improving the printing work environment. However, toluene can be used as a hydrocarbon solvent alone or mixed with a hydrocarbon solvent such as methylcyclohexane.

  Also, ketone solvents have a moderate drying rate for gravure printing and have relatively good odor, and ester solvents have a drying rate and solubility parameters that are relatively close to those of toluene, which has been the mainstream in conventional gravure printing. Although n-propyl acetate is preferable, ethyl acetate can be used alone as an ester solvent or by mixing with an ester solvent such as n-propyl acetate.

  Furthermore, examples of alcohol solvents include ethanol, isopropanol and n-propanol which have an appropriate drying speed for gravure printing and relatively good odor. Isopropanol having excellent storage stability is preferred. In addition, ethanol or n-propanol can be used alone or mixed with isopropanol.

From the glycol ether solvent, it is preferable to use propylene glycol monomethyl ether which has an appropriate drying rate as a slow-release solvent and has a relatively good odor.
The above solvents are preferably at least three kinds. According to the present invention, by combining these solvents, most conventional resin-based inks can be designed, and the industrial value thereof is considered high.

  Moreover, although the solvent used for the printing ink in this invention was described above, there exists a possibility that a small amount of solvent components which are not intended by the origin of an additive, the surrounding atmosphere at the time of printing, etc. may mix. However, any type and / or amount that does not hinder each step such as printing and recovery can be contained.

  The colorant used in the printing ink in the present invention includes, as inorganic pigments, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, carbon black, aluminum, mica (mica), bengara, etc. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perinone, quinacdolin, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, and isoindoline pigments. It is done. These pigments can be used alone or in admixture of two or more for the purpose of adjusting the hue and density. A dye may be used or used in combination, but a pigment is preferred from the viewpoint of light resistance.

  Resin used for the printing ink 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 in the present invention, as necessary, extender pigment, pigment dispersant, leveling agent, antifoaming agent, crosslinking agent, curing agent, wax, silane coupling agent, rust inhibitor, preservative, plasticizer, Various additives such as an infrared absorber, an ultraviolet absorber, a light resistance improver, a fragrance, and a flame retardant can also be used.

  The printing ink in the present invention can be produced using a commonly used disperser such as a dissolver, a roller mill, a ball mill, a pebble mill, an attritor, and a sand mill. When air bubbles or unexpected coarse particles are contained in the printing 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 viscosity of the printing ink in the present invention is 10 mPa · s or more from the viewpoint of preventing pigment settling, and 1000 mPa · s or less from the viewpoint of printing suitability such as workability, plate fogging, and leveling at the time of printing ink production or printing. preferable. Furthermore, 10 to 500 mPa · s is preferable. The viscosity in the present invention is a value obtained by a method using a rotational viscometer (BM type viscometer, measured at 20 ° C.).

  Examples of the method for applying the printing ink 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.

  As the solvent recovery method of the present invention, a method of separating from air coexisting with solvent vapor, that is, a condensation method, a compression method, an absorption method, or an adsorption method can be used. These methods can be selected in consideration of the composition, physical properties, chemical properties, concentration, generation amount (processing amount) of the solvent vapor, impurities contained, desired recovery rate, recovery solvent characteristics, and the like. . Among these, the gas adsorption method using an adsorbent is preferable and generally used from the viewpoint of cost including the recovery rate.

  Examples of the adsorbent used in the above adsorption method include activated carbon, porous silica such as silica gel, zeolite, various clays, alumina, iron oxide (iron hydroxide gel), magnesium perchlorate, ion exchange resin, and the like. Among these, it is preferable to select activated carbon, porous silica such as silica gel, and zeolite having a high specific surface area. Examples of the shape of the adsorbate include particles and fibers. In the case of particles, a fluid bed, a fixed bed, and in the case of fibers, a fixed bed and a shape corresponding to the recovery system can be selected.

  The solvent collected as an adsorbate in the adsorbent is desorbed by introducing a heating gas such as air, nitrogen and other inert gases, steam, and / or reduced pressure, and is liquefied and returned to the solvent. Since this solvent generally has an increased amount of water in the process of adsorption and desorption, if distilled as it is, the solvent component azeotropes with water, and a mixed solvent containing water and an unintended component ratio is obtained. there is a possibility. Therefore, it is preferable to remove by membrane separation using a polymer membrane such as a polyimide membrane, a ceramic membrane or a zeolite membrane, adsorption using silica gel or the like, a specific gravity difference, or distillation. In addition, when moisture mixing can be suppressed by controlling operating conditions such as humidity during adsorption and desorption, moisture removal operation is not necessary.

  The components in the recovery solvent of the present invention are limited by the solvent used at the time of printing, but the component ratio varies depending on the characteristics of the recovery device. For example, in a recovery apparatus using activated carbon as an adsorbent, highly polar alcohols and the like are difficult to recover because of their low adsorption capacity, and depending on the temperature setting during desorption, high boiling point substances are difficult to desorb and difficult to recover.

  The multistage distillation in the present invention can be performed by a general distillation operation. That is, any of batch distillation and continuous distillation can be selected. In batch distillation, the situation in the column changes every moment, so it is theoretically difficult and difficult to operate, and it is difficult to obtain a stable distillate. Preferably it is done.

  Distillation towers are roughly classified into plate towers and packed towers. The former includes perforated plate towers, bubble bell towers (baffle cap towers) and valve towers, and the latter includes those using various packing materials. The perforated plate tower has a simple structure, low production costs and low pressure loss, but if the flow rate of steam is low, the liquid flows from the holes and the operation becomes unstable. The bubble tower is a type that has been used for a long time and has high production costs, high vapor pressure loss, and large vapor pressure loss, but it has the advantages of being able to operate even when the gas-liquid flow rate fluctuates. The structure of the valve tower is more complicated than that of the perforated plate tower. However, the valve gap is opened and closed according to the flow rate of the steam, so that there is no drawback as the perforated plate tower. In the packed tower, a packing such as Raschig ring is packed in the tower, and the liquid that spreads and flows down on the surface of the packing is brought into contact with the vapor that rises in the gap to exchange components. These can be selected according to the required processing capacity and cost, and further used in combination.

  The performance of the distillation column is generally indicated by the number of theoretical plates, but a higher number of plates is preferable because of higher separation ability. To increase the number of theoretical plates, it can be controlled by the shape of the distillation column, the capacity of the reboiler or condenser, and the operating conditions (heating conditions, reflux ratio, distillate amount). It can be selected according to properties such as required purity.

  Further, if necessary, another solvent or another solvent may be added to the recovered solvent to form an extractive distillation or an azeotropic distillation for separation. Extractive distillation is a method that allows separation by changing the equilibrium state by adding a non-volatile (high boiling point) liquid. For example, when concentrated nitrite is added to a nitric acid-water azeotrope to perform rectification, Concentrated nitric acid is obtained from the top of the head. Azeotropic distillation is a method that enables separation of an azeotropic mixture by adding a volatile liquid. For example, when benzene is added to an ethanol-water azeotropic mixture and rectification is performed, ethanol-water-benzene three-components are obtained. An azeotrope of By using the above method, it is possible to separate and reuse the target single solvent and / or mixed solvent.

Since the solvent obtained by distilling the recovered solvent in the present invention is obtained with a stable composition ratio, it can be reused as a raw material for producing printing ink, and can also be reused as a raw material for a diluted solvent.
The printing ink in the present invention is composed of a colorant, a resin, and a solvent, and various additives are used as necessary. After this printing ink is applied to the substrate by a printing method such as gravure printing or flexographic printing, the solvent contained in the printing ink is volatilized by a drying device such as an oven and recovered with an adsorbent such as activated carbon. Recovered with equipment. The recovered solvent has a different ratio from the components in the ink because there is a difference in adsorption capacity depending on the components. However, in the recovered solvent recycling method of the present invention, the recovered solvent is distilled to perform multistage distillation. It can be reused after being separated into a single solvent and / or two or more azeotropic compositions.

Examples of the azeotropic solvent composition by multistage distillation include the following (i) to (vi).
(I) In the case of a system of methylcyclohexane, methyl ethyl ketone, n-propyl acetate, isopropanol, and propylene glycol monomethyl ether, the top temperature is around 74 ° C., and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane = 25-40 wt%: 25-40 % By weight of a mixed solvent having a composition ratio of 25% to 40% by weight,
(Ii) In the case of methyl ethyl ketone, n-propyl acetate, isopropanol, and propylene glycol monomethyl ether, isopropyl alcohol: methyl ethyl ketone = 25 to 45% by weight: 55 to 75% by weight at a top temperature of about 75.5 ° C. The mixed solvent of composition ratio is distilled,
(Iii) In the case of a system of n-propyl acetate, isopropanol, propylene glycol monomethyl ether, a composition ratio of isopropyl alcohol: n-propyl acetate = 80 to 95 wt%: 5 to 20 wt% at a top temperature of around 76 ° C. Distilled mixed solvent,
(Iv) In the case of methyl ethyl ketone, n-propyl acetate, and propylene glycol monomethyl ether, at the top temperature of about 80 ° C, methyl ethyl ketone alone solvent is distilled.
(V) In the case of a system of n-propyl acetate and propylene glycol monomethyl ether, a solvent of n-propyl acetate alone can be recovered by distillation at a top temperature of around 102 ° C.
Also,
(Vi) Propylene glycol monomethyl ether remains in the kettle and can be recovered.

  The azeotropic composition ratio shifts depending on the conditions of the above-mentioned multistage distillation. However, if the composition analysis reveals the composition ratio and separation is possible with a stable composition ratio, a large-scale composition analysis will be performed sequentially from the next time. In addition, it is possible to reuse the mixed ink having the same composition ratio as a raw material for a printing ink composition or a diluting solvent.

  For example, when it is desired to obtain a mixed solvent of methyl ethyl ketone, n-propyl acetate and isopropanol at an arbitrary ratio, methyl ethyl ketone and n-propyl acetate obtained in (iv) and (v) are added to the mixed solvent obtained in (ii). What is necessary is just to mix | blend.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, the scope of the present invention is not limited to these description Example. In addition, the part of the following description represents a weight part,% represents weight%, and the component ratio of each solvent was calculated from the area of gas chromatography based on the analytical curve prepared beforehand.

[Example 1]
Gravure printing was carried out on multiple types of printing machines using printing inks of different types of resins whose non-volatile solvent composition was isopropyl alcohol / methyl ethyl ketone / methyl cyclohexane / n-propyl acetate / propylene glycol monomethyl ether. The water was removed by a zeolite separation membrane after collective collection with a collection device using activated carbon particles as a fluidized bed, and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane: n-propyl acetate: propylene glycol monomethyl ether = 25.0: 15.0 : A recovered solvent (A) of 5.0: 50.0: 5.0 was obtained.

  100 g of this recovered solvent (A) was charged into an Erlenmeyer flask, a distillation apparatus equipped with a distillation tower filled with Raschig rings was set, and the temperature was increased by stirring with a hot stirrer.

  Distillation was performed so that the reflux ratio was reflux (conical flask): sampling (collected solvent) = 3: 1. As a result, the top temperature was 74 ° C., and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane = 31.3: 37.0. : 31.7 (weight ratio) mixed solvent (a) 16.0 g, followed by top temperature of 75.5 ° C., isopropyl alcohol: methyl ethyl ketone = 34.3: 65.7 (weight ratio) mixed solvent (B) 13.9 g, and 16.9 g of a mixed solvent (c) of isopropyl alcohol: n-propyl acetate = 89.2: 10.8 (weight ratio) at a top temperature of 80.5 ° C. At a top temperature of 101 ° C., 48.2 g of n-propyl acetate single solvent (d) was obtained by distillation.

  Mixed solvents (a) to (c) obtained by the above, whose composition ratio can be grasped in advance because of the azeotropic composition, (d) which is a single solvent, propylene glycol monomethyl ether single solvent remaining in the Erlenmeyer flask ( e) was reused as a raw material for the printing ink composition and dilution solvent.

[Example 2]
A methyl ethyl ketone (X) weight ratio of 40 was added to the recovered solvent (A) 100 of Example 1 to prepare a mixed solvent (B).

  100 g of this mixed solvent (B) was charged into an Erlenmeyer flask, a distillation apparatus equipped with a distillation tower filled with Raschig rings was set, and the temperature was increased by stirring with a hot stirrer.

  Distillation was performed so that the reflux ratio was reflux (conical flask): sampling (collected solvent) = 3: 1. As a result, the top temperature was 74 ° C., and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane = 31.3: 37.0. : 31.7 (weight ratio) mixed solvent (a) 16.0 g, followed by top temperature of 75.5 ° C., isopropyl alcohol: methyl ethyl ketone = 34.3: 65.7 (weight ratio) mixed solvent (B) Distilling 58.0 g of a methyl ethyl ketone single solvent (f) at a top temperature of 78 ° C. and 48.2 g of a n-propyl acetate single solvent (d) at a top temperature of 101 ° C. were obtained by distillation. Obtained by distillation.

  Mixed solvent (a), (b), single solvent (d), (f), and propylene glycol monomethyl ether remaining in the Erlenmeyer flask obtained by the above, whose composition ratio can be grasped beforehand because of the azeotropic composition Solvent (e) was reused as a raw material for the printing ink composition and dilution solvent. Furthermore, the methyl ethyl ketone single solvent (f) was reused as (X) in the next distillation.

[Example 3]
Gravure printing is performed on multiple types of printing machines using a plurality of different types of printing inks whose solvent composition is isopropyl alcohol / methyl ethyl ketone / methyl cyclohexane / n-propyl acetate / propylene glycol monomethyl ether, and activated carbon particles After collecting in a collective apparatus using a fluidized bed, water was removed with a zeolite separation membrane, and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane: n-propyl acetate: propylene glycol monomethyl ether = 25.0: 15.0: 5. A recovered solvent (A) of 0: 50.0: 5.0 (weight ratio) was obtained.

  100 g of this recovered solvent (A) was charged into an Erlenmeyer flask, a distillation apparatus equipped with a distillation tower filled with Raschig rings was set, and the temperature was raised while stirring with a hot stirrer.

  Distillation was performed so that the reflux ratio was reflux (conical flask): extraction (collected solvent) = 3: 1. As a result, the top temperature was 74 ° C., and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane = 37.5: 34.2. : 18.3 g of the mixed solvent (a) of 28.3 (weight ratio), followed by the mixed solvent of isopropyl alcohol: methyl ethyl ketone = 31.8: 68.2 (weight ratio) at a top temperature of 75.5 ° C. (B) 13.9 g, and 16.4 g of a mixed solvent (c) of isopropyl alcohol: n-propyl acetate = 87.2: 12.8 (weight ratio) at a top temperature of 80.5 ° C. At a top temperature of 101 ° C., 47.2 g of n-propyl acetate sole solvent (d) was obtained by distillation.

  Mixed solvents (a) to (c) obtained by the above, whose composition ratio can be grasped in advance because of the azeotropic composition, (d) which is a single solvent, propylene glycol monomethyl ether single solvent remaining in the Erlenmeyer flask ( e) 4.2 g was reused as a raw material for the printing ink composition and dilution solvent.

[Example 4]
A methyl ethyl ketone (X) weight ratio of 40 was added to the recovered solvent (A) 100 of Example 1 to prepare a mixed solvent (B). 140 g of this mixed solvent (B) was charged into an Erlenmeyer flask, a distillation apparatus equipped with a distillation tower filled with Raschig rings was set, and the temperature was raised while stirring with a hot stirrer.

  Distillation was performed so that the reflux ratio was reflux (conical flask): extraction (collected solvent) = 3: 1. As a result, the top temperature was 74 ° C., and isopropyl alcohol: methyl ethyl ketone: methyl cyclohexane = 37.5: 34.2. : 17.4 g of mixed solvent (a) of 28.3 (weight ratio), followed by mixed solvent of isopropyl alcohol: methyl ethyl ketone = 31.8: 68.2 (weight ratio) at a top temperature of 75.5 ° C. (B) 57.1 g, and further 10 g of methyl ethyl ketone single solvent (f) at a top temperature of 78 ° C. and 49.1 g of n-propyl acetate single solvent (d) at a top temperature of 101 ° C. were obtained by distillation. Mixed solvent (a), (b), single solvent (d), (f), and propylene glycol monomethyl ether remaining in the Erlenmeyer flask obtained by the above, whose composition ratio can be grasped beforehand because of the azeotropic composition 4 g of the solvent (e) was reused as a raw material for the printing ink composition and the dilution solvent.

  Furthermore, the methyl ethyl ketone single solvent (f) was reused as (X) in the next distillation.

Claims (4)

Using a printing ink composition group and a dilution solvent group in which at least three kinds of solvents selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, glycol ether solvents are used, When performing printing or coating, the mixed solvent recovered by the solvent recovery device installed in the printing press is selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, glycol ether solvents. At least three types of the collected mixed solvent, water is removed by membrane separation using a polymer membrane, a ceramic membrane or a zeolite membrane, and further , a single solvent and / or two or more types are obtained by multistage distillation. Solvent recovery and reuse for separation as a raw material for printing ink and / or diluted solvent after separation into azeotropic composition .   The printing ink composition group, the dilution solvent group, and the mixed solvent recovered from the printing ink composition group and the dilution solvent group according to claim 1 are methylcyclohexane, toluene, methyl ethyl ketone, n-propyl acetate, ethyl acetate, isopropanol. 2. The solvent recovery and reuse method according to claim 1, wherein the solvent recovery and reuse method is at least three or more selected from ethanol, n-propanol, and propylene glycol monomethyl ether. Claim 1 or 2 printing ink composition characterized in that the solvent was separated into single solvent and / or two or more of the azeotropic composition as a starting material by the method described. Printing ink dilution solvent, which comprises a by the method of claim 1 or 2, wherein separate single solvents and / or two or more azeotropic solvents and raw materials.