JP2011131113A - Method and apparatus for drying coating liquid agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dry not only an oily coating liquid agent, but an aqueous coating liquid agent in a short and compact drying zone without reducing a running speed (≥120 m/min) in a drying oven used for a printing machine or the like. <P>SOLUTION: Many hot air blow nozzles 222 are provided to the drying part 220 of a first printing unit 200. A heating guide roll 223a is provided to a front stage and a cooling guide roll 223b is provided to a rear stage so as to correspond to the hot air jetting nozzles 222. A liquid delivery pipe 224a for injecting hot water is connected to the heating guide roll 223a, and a liquid delivery pipe 224b for injecting cooling water is connected to the cooling guide roll 223b. An introduced raw sheet 1 is heated to equal to or above the boiling point of a solvent by the heating guide roll 223a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a drying method in a drying oven such as a gravure printing machine, a dry laminating machine, a coating machine, and more specifically, a gravure solution obtained by dissolving an aqueous or solvent component in a substrate such as a packaging material. The present invention relates to a method of drying by spraying hot air on the liquid agent surface while transporting it while bringing the opposite surface of the substrate coated with the liquid agent into contact with a guide roll in a drying oven.

  A drying oven is a major component of gravure printing machines, dry laminating machines, coating machines, and the like. For example, in a multicolor gravure printing machine, ink dissolved in a solvent in a first color printing unit is applied to a substrate with a gravure roll, and then the solvent is evaporated in a drying oven to solidify only the ink on the substrate. Then, it cools and moves to the second printing unit. Subsequent printing is performed through the same process after the second printing unit, and a multicolor printed substrate is completed through the final printing unit, and is finally wound.

  In the dry laminating machine, an adhesive dissolved in a solvent is applied to the fed base A with a gravure roll, the solvent is evaporated in a drying oven, and then the base B to be bonded to the adhesive application surface is applied. Superimpose and crimp these to make a bonded product. In the coating machine, a coating solution dissolved in a solvent is applied to a substrate with a gravure roll, and the solvent is stripped off in a drying oven and cooled and wound.

  The drying oven used in each machine as described above is configured by substantially the same mechanism. That is, a large number of guide rolls are provided in the drying oven, and the substrate on which the liquid agent is applied is dried by blowing hot air while guiding the substrate on the guide roll. At that time, the substrate on which the liquid agent is applied The opposite surface is brought into contact with the guide roll and dried by heat by blowing hot air onto the surface coated with the liquid agent.

Also, in recent years, due to the problem of bad odor during working with oil-based solvents, working environment, residual solvent odor, CO ₂ reduction against global warming, it is shifting to water-soluble gravure printing and aqueous dry laminating methods that do not use solvents (for example, And Patent Documents 1 to 6).

Japanese Patent No. 3249223 Japanese Patent Laid-Open No. 2001-030611 JP 2002-096448 A JP 2000-153582 A JP 2002-88662 A JP 2005-48046 A

  However, in the conventional drying oven described above, the heat necessary for drying the substrate is provided only by hot air, so it is necessary to continue to apply heat for a certain period of time in order to provide a certain amount of heat necessary for drying. In order to dry without slowing down the production speed, the drying oven has a long traveling distance.

That is, in order to dry the liquid applied to the substrate, it is necessary to evaporate the solvent by increasing the temperature of the liquid, and to dry while compensating for the latent heat of vaporization accompanying evaporation. Even if hot air is blown onto the surface of the liquid agent, the temperature of the liquid agent cannot be increased unless the temperature of the base material is increased in order to increase the temperature of the liquid agent. Therefore, in order to increase the temperature of the base material and the temperature of the liquid agent by hot air, a certain amount of time is required because the hot air is a gas and has a small heat capacity. In particular, in water-soluble gravure printing and aqueous dry laminating methods, water having a large latent heat of vaporization compared with oil-based solvents is used, which is a very serious problem.
Table 1 shows the properties of the main solvents.

  As shown in Table 1, since the latent heat of vaporization of water is extremely large, in order to dry the aqueous coating liquid, it is necessary to give more heat than the oil-based coating liquid. Therefore, in order to dry the aqueous coating liquid, a long drying zone was used so that the residence time in the drying oven could be longer than that in the case of oiliness, or the running speed was slowed down.

  The present invention has been made to solve the above problems, and is a compact drying zone shorter than the conventional drying zone, and the running (production) speed can be achieved not only in an oily coating solution but also in an aqueous coating solution. It aims at providing the drying method and apparatus which can be dried without dropping (120 m / min or more).

  As a result of diligent research to solve the above-mentioned problems, the inventors of the present invention pay attention to the fact that the volatilization of the solvent becomes faster if the drying temperature of the coating liquid is set to a temperature equal to or higher than the boiling point of the solvent of the coating liquid. The present invention was completed by finding a means capable of quickly raising the drying temperature to the boiling point of the solvent or higher.

  That is, a guide roll provided in a drying oven is heated, and the surface of the base material introduced by the heating guide roll is heated on the side opposite to the surface on which the solvent is applied, and the temperature of the base material is determined by hot air. Is raised to the boiling point or more in a short time, and the temperature of the coating solution is raised to the boiling point or more in a short time. In addition, when the temperature of the substrate once increased by the heating guide roll is further blown with hot air for drying, the temperature further increases, and deformation such as elongation, shrinkage, and undulation occurs. Therefore, in order to prevent these deformations, it was decided to cool the rear part of the guide roll and prevent the temperature of the base material from being further increased by this cooling roll.

  As described above, among the plurality of guide rolls, a plurality of the former part is used as a heating guide roll, and a plurality of the latter part is used as a cooling guide roll, so that the temperature of the coating liquid is higher than the boiling point immediately after introduction into the drying oven. The temperature of the substrate can be efficiently dried, and can be maintained at a suitable temperature without excessively increasing the substrate temperature, thereby preventing deformation of the substrate.

  The method for drying a coating liquid according to claim 1 is a method in which a liquid agent in which an aqueous or solvent component is dissolved is uniformly applied to a substrate with a coating roll, and then a large number of opposite surfaces of the substrate on which the liquid agent is applied in a drying oven. In the method of drying by spraying hot air on the liquid surface of the base material while being brought into contact with the guide roll of the substrate, the front part of the many guide rolls is a heating guide roll, and the remaining rear part is a cooling guide roll. The substrate immediately after being introduced into the drying oven is heated with a heating guide roll to a temperature equal to or higher than the boiling point of water or solvent, and then cooled with a cooling guide roll so that the substrate can be maintained at a temperature at which it does not deform. It is configured.

  The method for drying a coating liquid according to claim 2 detects the temperature of the substrate before drying, and the cooling guide so that the temperature of the substrate after drying is substantially the same as the detected temperature of the substrate before drying. It is characterized by adjusting the temperature of the roll.

  The method for drying a coating liquid according to claim 3 is characterized in that hot water or heated oil is injected into a heating guide roll to heat it, and cooling water is injected into the cooling guide roll to cool it.

  The method for drying a coating liquid according to claim 4 is characterized in that the heating guide roll and the cooling guide roll are forcibly driven to synchronize with the transport speed of the substrate.

  The apparatus for drying a coating liquid according to claim 5 has a large number of opposite surfaces of the base material coated with the liquid agent in a drying oven after uniformly applying with a coating roll a solution in which an aqueous or solvent component is dissolved on the base material. In the drying apparatus that blows and blows hot air on the liquid surface of the base material while being brought into contact with the guide roll of the substrate, the front part of the guide roll is formed by a heating guide roll, and the remaining rear part is a cooling guide roll. It is formed as a feature.

  The apparatus for drying a coating liquid according to claim 6 is provided with detection means for detecting the temperature of the substrate before drying, inputs temperature information detected by the temperature detection means, and after drying based on the input temperature information A control unit that controls the temperature of the cooling guide roll is provided so that the substrate temperatures of the two are substantially the same.

  The apparatus for drying a coating liquid according to claim 7 is provided with heating means for injecting hot water or heating oil into the heating guide roll, and cooling means for injecting cooling water into the cooling guide roll. Has been.

  The apparatus for drying a coating liquid according to an eighth aspect is characterized in that a belt for driving the heating guide roll and the cooling guide roll and a motor for driving the belt are provided.

  In the coating liquid drying method according to the first aspect, the first stage of the plurality of guide rolls in the drying oven is constituted by a heating guide roll, and the substrate immediately after being introduced into the drying oven is heated by the heating guide roll. The temperature of the liquid agent can be set to a temperature equal to or higher than the boiling point of water or the solvent over time. Therefore, the constant rate drying period (II) of the drying characteristic curve shown in FIG. 7 can be reached in a short time, and the drying efficiency is greatly improved. This is because the solid guide roll has a larger heat capacity than the hot air gas, so that a large amount of heat can be applied to the substrate in a short time. If it is only hot air, it takes time to preheat the substrate, and this preheating time greatly affects the running speed (productivity). Moreover, since a base material is cooled with the cooling guide roll of a back | latter stage, the temperature rise of a base material can be suppressed and it can maintain at the temperature which a base material does not deform | transform. Therefore, the base material is not stretched, contracted or deformed.

  In the method for drying a coating liquid according to claim 2, the temperature of the base material before drying is detected, and cooling is performed so that the temperature of the base material after drying is substantially the same as the detected temperature of the base material before drying. Since the temperature of the guide roll is adjusted, elongation, shrinkage, deformation, etc. of the base material can be reliably prevented.

  In the method for drying the coating liquid according to claim 3, since heating water or heating oil is injected into the heating guide roll for heating and cooling water is injected into the cooling guide roll for cooling, the heating guide roll can be easily formed. While being able to heat, adjustment of heating temperature can be performed easily. In addition, the cooling guide roll can be easily cooled and the cooling temperature can be easily adjusted.

  In the coating liquid drying method according to claim 4, since the heating guide roll and the cooling guide roll are forcibly driven to synchronize with the conveyance speed of the substrate, the substrate is conveyed without sliding on the contact surface with the guide roll. I can do it.

  In the coating solution drying apparatus according to the fifth aspect, the substrate can be heated by the heating guide roll formed in the front part of the guide roll, so that the temperature of the substrate immediately after introduction and the temperature of the coating solution are reduced. The temperature can be raised over the boiling point of the solvent of the liquid agent over time. Moreover, since the base material can be cooled by the cooling guide roll formed in the rear stage portion of the guide roll, it is possible to prevent the temperature of the equipment from rising to a temperature at which expansion, contraction, deformation, etc. occur.

  In the apparatus for drying a coating liquid according to claim 6, a detecting means for detecting the temperature of the substrate before drying is provided, temperature information detected by the temperature detecting means is input, and drying is performed based on the input temperature information. Since the controller for controlling the temperature of the cooling guide roll is provided so that the subsequent substrate temperature is substantially the same, the temperature before and after the drying of the substrate can be reliably made substantially the same, and the elongation and shrinkage can be ensured. , Deformation and the like can be reliably prevented.

  In the coating liquid drying apparatus according to claim 7, since the heating means for injecting hot water or heating oil into the heating guide roll and the cooling means for injecting cooling water into the cooling guide roll are provided, the heating guide roll Can be easily heated and the heating temperature can be easily adjusted. In addition, the cooling guide roll can be easily cooled and the cooling temperature can be easily adjusted.

  In the coating liquid drying apparatus according to claim 8, since the belt for driving the heating guide roll and the cooling guide roll and the motor for driving the belt are provided, by adjusting the motor, the heating guide roll and The peripheral speed of the cooling guide roll can be matched with the transport speed of the base material, and as a result, the base material can be transported without sliding on the contact surface with the guide rope.

Schematic diagram of the entire multicolor gravure printing device Enlarged view of the first printing unit of the multicolor gravure printing device Schematic diagram of dry laminating equipment with three drying ovens in series (3 zones) Schematic showing the drying means of the first zone of the drying oven Schematic showing heating and cooling means of the guide roll in the first zone of the drying oven Schematic of a coating device with six drying ovens connected in series (6 zones) Diagram showing drying characteristics curve

  The present invention relates to a method of drying a liquid agent coated with a substrate, and this drying method is used in a drying oven constituting a main part of a gravure printing machine, a dry laminating machine, a coating machine or the like. Drying in these apparatuses is a method in which a base material coated with a liquid agent in which an aqueous or solvent component is dissolved is introduced into a drying oven, and water or solvent in the liquid agent is volatilized to fix the dissolved component to the base material. Yes, this drying speed affects the performance (productivity) of the apparatus.

  In general, drying is performed after a material preheating period (I), a constant rate drying period (II), and a reduced rate drying period (III) as shown in a drying characteristic curve shown in FIG. In the material preheating period, the moisture change during the period in which the material rises to the wet bulb temperature is small. In the constant rate drying period, the heat transfer rate from the surroundings and the evaporation rate from the material surface are in a dynamic balance, and the drying rate R is constant during this period. The decreasing rate drying period is a section below the limit moisture content at the end of the constant rate dryer period, and the moisture transfer resistance inside the material increases as the moisture decreases, and the drying rate decreases. In order to dry quickly with a short drying time, there is how fast to reach this constant rate dry state.

  The coating liquid is a liquid, and the constant-rate drying temperature corresponds to the boiling point of the solvent component. In order to bring the coating solution to the boiling temperature, it is natural that the temperature of the coated substrate must also be the boiling temperature. Conventionally, as a heat source, only hot air is blown onto the surface of the coating liquid and heated. However, since the hot air is a gas, it takes a long time to increase the temperature of the substrate because the heat capacity is small. However, if the front part of the guide roll carrying the substrate is a heating guide roll and the contacting substrate surface is heated, the heat capacity of the solid is larger than the heat capacity of the gas, so that heating can be performed quickly.

  When the liquid evaporates at a constant drying temperature (boiling point), heat is generated by the latent heat of evaporation shown in Table 1, and neither the temperature of the base material nor the temperature of the coating liquid rises above that temperature. However, since the heat absorption due to the latent heat of evaporation does not occur after passing through the constant rate drying state, the temperature of the substrate rises due to the heat of the hot air, causing elongation, shrinkage, deformation, and the like. In order to prevent this, the latter part of the guide roll is used as a cooling guide roll, and heat from the hot air is eliminated by the cooling guide roll. That is, until the constant rate drying period ends after the material preheating period, the base material is heated by a heating guide roll in a range where the deformation does not occur above the boiling point, and the constant rate drying period ends and the reduced rate drying period begins. Therefore, it is preferable that the temperature rise due to hot air is prevented and maintained within a range in which no deformation occurs.

  Of the entire guide roll in the drying oven, the composition ratio of the heating guide roll and the cooling guide roll is as follows: coating liquid type (aqueous, oily), substrate thickness, processing speed, equipment type (gravure printing, dry lamination, Depending on the coating, it is preferable to set it while performing a test under these conditions. In general, the ratio of the heating guide roll is set to 1/5 to 1/3, and suitable conditions can be set while adjusting the temperature of the heating guide roll.

  The heating guide roll is heated by injecting hot water or heating oil into the guide roll, and is set to a desired temperature by adjusting the temperature, flow rate, etc. of the hot water or heating oil. The heating temperature of the heating guide roll also varies depending on the type of coating liquid (aqueous, oily), substrate thickness, processing speed, and type of equipment (gravure printing, dry lamination, coating). It is preferable to set.

  For the injection of warm water or heated oil, for example, a liquid feed pipe is connected to the guide roll so that the warm water or heated oil circulates, and the heating unit and the flow rate for heating the warm water or heated oil can be adjusted in the middle of the liquid feed pipe. This can be done by providing a liquid feed section, and can be injected from a hot water or heated oil supply source connected to the liquid feed pipe via a pump. May be. Further, if a stop valve is provided individually connected, the heating conditions can be delicately set by turning it on and off.

  The cooling guide roll is cooled by injecting cooling water into the guide roll, and as a result, the substrate in contact with the cooling guide roll is cooled. The cooling water is injected by, for example, connecting a liquid feeding pipe so that the cooling water circulates in the guide roll, and providing a cooling part for cooling water and a liquid feeding part capable of adjusting the flow rate in the middle of the liquid feeding pipe. In addition, the cooling water can be supplied from a cooling water supply source via a pump to a liquid feeding pipe, and can be individually connected or all the cooling guide rolls can be connected.

  Preferably, the heating guide roll and the cooling guide roll are forcibly driven to synchronize with the conveyance speed of the substrate. As a means for forcibly driving the guide roll, for example, the guide roll is driven by a belt so as to coincide with the conveyance speed of the substrate. At this time, a pulley having the same diameter as the surface of the guide roll that contacts the base material is provided at the end of the guide roll, and the same belt is wound around these pulleys and driven to match the speed of the base material easily. It can be made.

  The temperature of the base material before drying is detected, and the flow rate of the cooling water injected into the guide roll can be adjusted by the detected temperature so that the base material temperature after drying is substantially the same. In order to detect the temperature of the substrate, a known temperature sensor or the like can be used, and in order to adjust the flow rate of the cooling water from the detected temperature, a control unit in which the temperature and the flow rate are set in advance is provided and detected. By sending the temperature to the control unit, the control unit controls the cooling water pump or the like to adjust the flow rate of the cooling water to be set in advance.

  An embodiment of a printing apparatus in which the coating liquid drying method of the present invention is applied to multicolor gravure printing will be described with reference to the drawings.

  FIG. 1 is an overall schematic view of a multicolor gravure printing apparatus, and FIG. 2 is an enlarged view of a first printing unit portion of the multicolor gravure printing apparatus.

  1 and 2, reference numeral 100 denotes a paper feed unit that feeds the original fabric 1 to the subsequent printing unit. 200 is a first printing unit for the first color, 300 is a second printing unit for the second color, 400 is a third printing unit for the third color, 500 is a fourth printing unit for the fourth color, and 600 is a fifth printing unit for the fifth color. The fifth printing unit.

  The first printing unit 200 of the first color is provided with a printing unit 210 that prints on the original fabric 1, a drying unit 220 that dries the printed original fabric 1, and a cooling unit 230 that cools the original fabric 1. ing. The printing unit 210 is provided with a plate cylinder 211, an impression cylinder 212, and a finisher roll 213.

  The drying unit 220 is provided with a drying box 221, and the drying box 221 is provided with a large number of hot-air ejection nozzles 222 at equal intervals. Is provided with a heating guide roll 223a, and a cooling guide roll 223b is provided at the subsequent stage. A liquid feed pipe 224a for injecting hot water and a discharge pipe (not shown) for discharging the hot water are connected to the heating guide roll 223a, and the liquid feed pipe 224a is a motor for adjusting the flow rate of the hot water. A valve 225a is connected and a heating unit 226a for heating water is connected, and a discharge pipe is connected to the opposite side of the heating unit 226a. Accordingly, the hot water circulates through the heating unit 226a, the motor valve 225a, and the heating guide roll 223a.

  The cooling guide roll 223b is connected with a liquid feeding pipe 224b for injecting cooling water and a discharge pipe (not shown) for discharging the cooling water, and the liquid feeding pipe 224b adjusts the flow rate of the cooling water. And a cooling unit 226b for cooling water are connected, and a discharge pipe is connected to the opposite side of the cooling unit 226b. Therefore, the cooling water circulates through the cooling unit 226b, the motor valve 225b, and the guide roll 223b. Reference numeral 228 denotes a hot air inlet, and 229 denotes a hot air outlet.

  The cooling unit 230 is provided with a cooling roll 231 that contacts and cools the printing surface of the original fabric 1, and this cooling roll 231 also has a motor valve 225b via a liquid feed pipe 232 in the same manner as the cooling guide roll 223b. It is connected to.

  Reference numeral 240 denotes a roll driving unit for driving the guide rolls 223a and 223b and the cooling roll 231. A driving motor 241, a belt 242 driven by the driving motor 241 and a conveying roll 243 are provided. The guide rolls 223a and 223b and the cooling roll 231 are wound around. That is, the belt 242 is hung on a pulley (not shown) having the same diameter as the guide rolls 223a and 223b, and the belt 242 is hung on a pulley (not shown) having the same diameter as the cooling roll 231 to drive the belt 242. Thus, the guide rolls 223a and 223b and the cooling roll 231 are rotated at the same peripheral speed, and this peripheral speed is set to be the same as the conveying speed of the original fabric.

  In addition, a temperature detector 250 is installed in the subsequent stage of the cooling unit 230, that is, in the previous stage of the printing unit 310 of the second printing unit 300, so that the surface temperature of the raw material coming out of the cooling unit 230 can be detected. Yes. The temperature detector 250 is connected to a control unit (not shown). The control unit uses a temperature signal from the temperature detector 250 to feed a predetermined amount of cooling water to the cooling guide roll 223b and the cooling guide roll 223b. Injecting into the roll 231.

  The second printing unit 300 for the second color, the third printing unit 400 for the third color, the fourth printing unit 500 for the fourth color, and the fifth printing unit 600 for the fifth color are also used for the first printing of the first color. As with the unit 200, plate cylinders 311, 411, 511, 611, impression cylinders 312, 412, 512, 612, finisher rolls 313, 413, 513, 613, guide rolls 321-1, 321-2, 421- 1, 421-2, 521-1, 521-2, 621-1, 621-2, and cooling rolls 331, 431, 531, 631 are provided.

  In order to perform gravure printing by the multicolor gravure printing apparatus as described above, the original 1 is fed from the paper feeding unit 100 and sent to the first printing unit 200 for the first color. The original fabric 1 sent to the printing unit 200 is first pressed against the plate cylinder 211 and the impression cylinder 212 in the printing unit 210 to print the first color (for example, white solid). The original fabric 1 is dried on the printing surface side 11 with hot air in the drying unit 220, and at the same time, the anti-printing surface side 12 is heated by the heating guide roll 223a before the suppression, and the original fabric is heated to near the boiling point of the solvent component. ing. Next, the temperature is further cooled by the subsequent cooling guide roll 223b and the temperature rise is further suppressed.

  The cooling unit 230 is wound around the cooling roll 231 and cooled from the printing surface side 11. Therefore, since the non-printing surface side 12 is already cooled by the cooling guide roll 223b and the printing surface side 11 is cooled by the cooling roll 231, the cooling guide roll 223b is cooled to suppress the temperature rise due to the hot air of the original fabric 1 and finally. Thus, the cooling roll 231 is used for effective cooling as a whole. And by this cooling, it is made to become substantially the same as the temperature of the original fabric 1 at the time of printing in the printing part 210.

  Moreover, since the heating guide roll 223a, the cooling guide roll 223b, and the cooling roll 231 are driven by the belt 242 so that the peripheral speed is the same as the conveyance speed of the original fabric 1, the original fabric 1 is the guide roll 223a, 223b and the cooling roll 231 are not rubbed, and are conveyed without being adversely affected.

  In the printing units for the second color and thereafter, the same operation is repeated, and multicolor gravure printing consisting of five colors is applied to the original fabric 1 to complete gravure printing.

  An embodiment in which the method for drying a coating solution of the present invention is applied to a dry laminate will be described with reference to the drawings.

  3 is a schematic diagram of a general dry laminating machine in which three drying ovens are connected in series (three zones), FIG. 4 is a schematic diagram of the first zone of the drying oven, and FIG. 5 is an arrangement of a heating guide roll and a cooling guide roll. FIG.

  In FIG. 3, the dry laminating machine 700 includes a base material feeding unit 710, a coating unit 720, a drying oven 730, a laminating unit 740, and a winding unit 750, and the base material fed from the base material feeding unit 710. A701 is conveyed while being sandwiched between the gravure roll 721 and the rubber roll 722 in the application unit 720, and the adhesive 702 is applied by the gravure roll 721. Reference numeral 723 denotes a doctor knife. After the base material A 701 to which the adhesive is applied is sent to the drying oven 730 and the solvent is volatilized, the heated metal roll 741 and the backup roll 742 are overlapped with the base material B 703 in the bonding unit 740. Crimped. Then, after being cooled by the cooling metal roll 743, it is wound around the winding unit 750.

  As shown in FIG. 4, the drying oven 730 is provided with a sealed box 731. The sealed box 731 is provided with a hot air inlet 732, a hot air exhaust port 733, and a hot air inlet 732. A plurality of nozzles 734 for ejecting hot air are communicated with each other. In addition, a large number of nine guide rolls 735 are provided in the transport direction of the base material A701, and four guide rolls 735 in the front stage (upstream side in the transport direction: right side in the figure) are set as the heating guide rolls 735a, and the rear stage. Five of the guide rolls 735 (downstream in the transport direction: left side in the figure) are set as cooling guide rolls 735b.

  As shown in FIG. 5, these heating guide rolls 735 a are connected in series via a pipe 736 a and connected to a hot water heating device 737 connected to a water source at the end, and are heated by the hot water heating device 737. The warm water is circulated sequentially through the heating guide roll 735a. The cooling guide roll 735b is connected in parallel via a pipe 736b, the cooling water introduction side pipe 736b is connected to the pump 738, and the cooling water discharge side pipe 736b is connected to the chiller cold water tank 739. Yes. Therefore, the chiller cold water is sent to each cooling guide roll 735b by the pump 738 to be cooled, and the cooling water whose temperature has risen through the cooling guide roll 735b is returned to the chiller cold water tank 739.

An embodiment in which the method for drying a coating solution of the present invention is applied to coating will be described with reference to the drawings.
FIG. 6 is a schematic view of a general coating machine in which six drying ovens are connected in series (six zones).

In FIG. 6, the coating machine 800 includes a base material feeding unit 810, an application unit 820, a drying oven 830, a cooling unit 840, and a winding unit 850, and the base material 801 fed out from the base material feeding unit 810 is In the application unit 820, the material is conveyed while being sandwiched between the gravure roll 821 and the rubber roll 822, and the coating agent 802 is applied by the gravure roll 821. The base material 801 to which the coating agent 802 is applied is sent to the drying oven 830 to volatilize the solvent, and then cooled by the cooling roll 841 of the cooling unit 840 and wound around the winding unit 850.
The drying oven 830 has the same configuration as the drying oven 730 in the dry laminator 700 described above.

  Hereinafter, examples in which the present invention is applied to gravure printing will be described in more detail by way of examples. However, the present invention is not limited to the examples.

  This was done by modifying an existing five-color gravure printing machine. That is, as described above, four of the nine guide rolls of the drying unit 220 are the heating guide rolls 223a, and the liquid supply pipe 224a for injecting hot water and the discharge pipe 224a for discharging the hot water are connected. did. Furthermore, it connected with the motor valve 225a so that flow volume adjustment was possible, and it connected with the heating unit 226a.

  The latter five are used as cooling guide rolls 223b, and a liquid feeding pipe 224b for injecting cooling water and a liquid feeding pipe 232 for injecting cooling water into the cooling roll 231 of the cooling unit 230 are connected together. It was connected to the motor valve 225b and the cooling unit 226b so that the flow rate could be adjusted. In addition, the drive motor 241 and the drive belt 242 were provided and modified so that the peripheral speeds of the guide rolls 223a and 223b and the cooling roll 231 were the same as the transport speed of the original fabric (base material).

A 5-mm gravure printing machine with such a modification was set with a gravure roll with a 2.0 mm grid pattern engraved on the plate cylinder by Helio's electronic engraving (175 screen lines, stylus angle 130 °). Using a water-soluble ink Hydric PRP-401 (manufactured by Nissei Kagaku Kogyo Co., Ltd.) (a pigment dispersed in an acrylic resin vehicle), a diluting solvent Hydrick 5032 solvent (methanol 50 parts, isopropyl 40 parts of alcohol (30 parts of alcohol, 20 parts of water) are added, white (pigment concentration 20%), yellow (pigment concentration 12%), red (pigment concentration 12%), blue (pigment concentration 12%), black (pigment concentration) 12%) ink was prepared.

  The printing stock 1 is printed while printing on the corona-treated surface by setting an OPP film (thickness 20 μm, width 1000 mm, 2000-m roll, single-sided corona treatment) manufactured by Tosero Co., Ltd. on the paper feeding unit 100 of a 5-color printing machine. Speed 200 m / min, tension 8.0 kg / 1000 mm width, white (first printing unit 200), yellow (second printing unit 300), red (third printing unit 400), blue (fourth printing unit 500), black The grid pattern was overprinted in the order of (fifth printing unit 600).

Hot air in the drying section 220,320,420,520,620 is, 130 ° C. in the first printing unit 200, to 70m ³ / min, even 130 ° C. in the second printing unit 300 and later, was 70m ³ / min.

  Hot water at 85 ° C. was supplied to the heating guide roll 223a via the motor valve 225a, and cooling water at 20 ° C. was supplied to the cooling guide roll 223b and the cooling roll 231 via the motor valve 225b.

  In this way, printing is performed, the temperature before entering the printing unit and the temperature at the exit of the printing unit immediately after passing through the cooling unit are measured, and the original fabric temperature during printing of each color from the first color to the fifth color is substantially the same. It was checked whether the temperature was The temperature was measured using a radiation thermometer. In addition, the printed matter was observed with the naked eye to examine whether or not the color of the grid pattern protruded (if the printing misalignment occurred, the color protruded). The measurement results are shown in Table 2.

[Original temperature during printing]
The temperature before exiting the printing unit and the exit temperature of the printing unit are substantially the same, and the heat given by the drying unit is also cooled by the cooling guide roll of the drying unit and the cooling roll of the cooling unit, and the temperature of the original fabric hardly increases. Accordingly, the original fabric temperature during printing (before entering the printing unit) is substantially the same from the first color to the fifth color.

[Visual observation of printed matter]
When the printed matter 2000 m in which white-yellow-red-blue-black prints were overprinted in the order of white-yellow-red-blue-black was observed with the naked eye, the square print was printed neatly with the black printed last from the beginning to the end. There was no protrusion. Therefore, no printing misalignment occurred.

[Print speed]
As described above, printing was performed at a printing speed of 200 m / min, but it was possible to perform printing with the same quality as before. Therefore, the printing speed is about 1.7 times that of the conventional printing speed (120 m / min).

Hereinafter, an example in which the present invention is applied to a dry laminate will be described in more detail by way of examples. However, the present invention is not limited only to the examples.
Among the 10 guide rolls in the first zone of a two-zone dry laminating machine with two existing drying ovens with a length of 3.5 m, the first four are used as heating guide rolls and are used to inject hot water. A liquid pipe and a drain pipe for discharging hot water were connected. In addition, it was connected to a motor valve and a heating unit so that the flow rate could be adjusted. The latter six guide rolls and all ten guide rolls in the second zone were used as cooling guide rolls, and a liquid feeding pipe for injecting cooling water and a discharge pipe for discharging cooling water were connected. In addition, it was connected to a motor valve and a cooling unit so that the flow rate could be adjusted. Further, the heating guide roll and the cooling guide roll were forcibly driven to provide a drive motor drive belt so as to be the same as the conveyance speed of the base material.

To the dry laminating machine that has been modified in this way, a gravure roll engraved with Helio's electronic sculpture (95 screen lines, stylus angle 130 °) is set on the plate cylinder, and urethane adhesive manufactured by Toyo Morton Co., Ltd. (Main agent: TM569, curing agent: CAT-RT37, solvent: ethyl acetate) was applied to an O-NY film (N1130, 15 μm) manufactured by Toyobo Co., Ltd. on which a 5.0 cm grid pattern was printed. The temperature was 110 ° C. and the air volume was 60 m ³ / min. The second zone was dried at a processing speed of 150 m / min at a temperature of 110 ° C. and an air volume of 20 m ³ / min. Hot water at 70 ° C. was supplied to the heating guide roll via a motor valve, and cooling water at 20 ° C. was supplied to the cooling guide roll via a motor valve. An LLDPE film (TUX-HZ, 50 μm) manufactured by Tosero Co., Ltd. was combined on the surface coated with the dried O-NY adhesive, and bonded at a linear pressure of nip pressure of 18 kg-cm.

In this way, dry lamination is performed, the gas concentration of the organic solvent (ethyl acetate) in the exhaust of the first zone and the exhaust of the second zone is measured to confirm the performance of the present invention and to reduce the amount of CO ₂ reduction. Estimated. Further, the appearance of the bonded product was observed, and the presence or absence of deformation and the size of the printed grid pattern were measured to confirm the presence or absence of expansion and contraction.

[Confirmation of performance of the present invention]
The concentration of ethyl acetate gas in the exhaust of the first zone and the exhaust of the second zone was measured using a combustible gas concentration meter RM-571A (detector GD-D8) manufactured by Riken Keiki Co., Ltd. Compared with laminator machine. The results are shown in Table 3.

  In the present invention, since the hot air temperature is high, ethyl acetate is volatilized in the first zone and does not remain in the second zone. On the other hand, the conventional method is still volatilized in the second zone. Therefore, since the conventional three-zone method can be changed to the two-zone method, the apparatus becomes compact and can be supplied at low cost.

[Estimation of CO ₂ reduction]
The total heat quantity of the hot air of the present invention and the conventional three-zone method when processed under the above conditions was calculated, and the difference was estimated as the CO ₂ reduction amount.

The present invention:
The exhaust air of 2 zones was circulated to the 1st zone, the total exhaust air volume was set to 63 m ³ / min, and the exhaust air temperature was calculated as 100 ° C. The result is shown in Equation 1.

Conventional method:
The 3rd zone exhaust air was circulated to the 2nd zone, the 2nd zone exhaust air was circulated to the 1st zone, the total exhaust air amount was 128 m ³ / min, and the exhaust air temperature was 70 ° C. The results are shown in Equation 2.

  As described above, the method of the present invention is 84,519 kcal / br with respect to the conventional three-zone method of 13,0221 kcal / br, and the difference of 13,0221-84,519 = 45,702 kcal / br Fuel (LPG gas, heavy oil) corresponding to the amount of heat can be reduced.

[Existence of deformation and shrinkage]
The appearance of the bonded product was visually observed to check for the presence or absence of deformation and the presence or absence of shrinkage by actually measuring the fixed distance before bonding of O-NY printed on a grid pattern and the fixed distance after bonding.
As a result, the appearance was normal without deformation such as curling and wrinkling. In addition, almost no shrinkage occurred. The results of shrinkage are shown in Table 4.

Hereinafter, examples applied to coating will be described in more detail by way of examples. However, the present invention is not limited to the examples.
All 10 guide rolls in the first zone of the 6-zone coating machine with 6 existing 3m-long ovens connected as heating guide rolls and the remaining 5 zone guide rolls (10 in each zone) as cooling guide rolls As in Example 2.

A 200-screen, slanted gravure roll is set on the coating machine thus modified, and a thermosetting silicone liquid (main agent: KS-847, curing agent: CAT-PL, manufactured by Shin-Etsu Chemical Co., Ltd.) −50T) was diluted with a solvent (toluene 50%, MEK 50%) to prepare a coating solution having a silicone concentration of about 1.8%. This coating solution was applied to a PET film (25 μm) manufactured by Toyobo Co., Ltd. by a reverse method, and the first zone was 100 ° C.-10 m ³ / min, the second zone was 140 ° C.-10 m ³ / min, and the third, fourth, fifth. The zone was 180 ° C.-10 m ³ / min and the sixth zone was 120 ° C.-10 m ³ / min, dried at a processing speed of 150 m / min, and finally cooled by a cooling roll and wound up. In the same manner as in Example 2, 85 ° C. warm water was supplied to the heating guide roll, and 20 ° C. cooling water was supplied to the cooling guide roll.

[Performance of coating film]
appearance;
It was transparent without whitening and was cured (whitening when uncured). Also, there was no deformation such as undulation of the film.
Measurement of peel force;
The coated PET film and Nitto Denko's adhesive tape No. 31B (50 mm width) was bonded at a nip pressure of 5 kg / 50 mm width, left at 70 ° C. for 20 hours under a load of 20 g / cm ² , and then the peel force was measured using a Tensilon tensile test. The result was 60 g / 50 mm width and a normal peeling force.

[Improved processing speed]
Since thermosetting is a chemical reaction, the higher the temperature, the faster the reaction rate (generally 2 to 3 times / 10 ° C). However, with conventional methods, increasing the hot air temperature to 150 ° C or higher increases the end of the PET film. However, the upper limit of the machining speed was 100 m / min at 150 ° C. or lower.
In the present invention, even if the hot air temperature is increased to 180 ° C., the opposite surface of the substrate is cooled, so that deformation does not occur, the processing speed can be increased to 150 m / min, and productivity can be improved. done.

DESCRIPTION OF SYMBOLS 1: Original fabric 100: Paper feeding part 200: 1st printing unit 220: Drying part 222: Hot-air ejection nozzle 223a: Heating guide roll 223b: Cooling guide roll 226a: Heating unit 226b: Cooling unit 700: Dry laminating machine 730: Heating oven 735a: Heating guide roll 735b: Cooling guide roll 800: Coating machine 830: Heating oven

Claims (8)

  After uniformly applying a liquid agent in which a water-based or solvent-based component is dissolved on the base material with an application roll, hot air is conveyed while the opposite surface of the base material on which the liquid agent is applied is brought into contact with a number of guide rolls in a drying oven. In the method of drying by spraying on the liquid surface of the base material, the front part of the many guide rolls is a heating guide roll and the remaining rear part is a cooling guide roll, and the base material immediately after being introduced into the drying oven is a heating guide. A method of drying a coating liquid, characterized by heating with a roll to a temperature equal to or higher than the boiling point of water or a solvent, and then cooling with a cooling guide roll so that the substrate can be maintained at a temperature at which the substrate does not deform.   The temperature of the substrate before drying is detected, and the temperature of the cooling guide roll is adjusted so that the temperature of the substrate after drying is substantially the same as the temperature of the substrate before drying detected. A method for drying a coating solution according to claim 1   The method of drying a coating liquid according to claim 1 or 2, wherein hot water or heated oil is injected into the heating guide roll and heated, and cooling water is injected into the cooling guide roll to cool.   4. The method of drying a coating liquid according to claim 1, wherein the heating guide roll and the cooling guide roll are forcibly driven to synchronize with the conveyance speed of the substrate.   After uniformly applying a liquid agent in which a water-based or solvent-based component is dissolved on the base material with an application roll, hot air is conveyed while the opposite surface of the base material on which the liquid agent is applied is brought into contact with a number of guide rolls in a drying oven. In a drying apparatus for spraying and drying on a liquid agent surface of a substrate, the front part of the guide roll is formed by a heating guide roll, and the remaining rear part is formed by a cooling guide roll. Drying equipment.   Detection means for detecting the temperature of the substrate before drying is provided, temperature information detected by the temperature detection means is input, and the substrate temperature after drying is substantially the same by the input temperature information. 6. A coating solution drying apparatus according to claim 5, further comprising a control unit for controlling the temperature of the cooling guide roll.   The drying of the coating liquid according to claim 5 or 6, wherein heating means for injecting warm water or heating oil into the heating guide roll and cooling means for injecting cooling water into the cooling guide roll are provided. apparatus.   8. The coating liquid drying apparatus according to claim 5, wherein a belt for driving the heating guide roll and the cooling guide roll and a motor for driving the belt are provided.

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