KR100522000B1 - Stamping foil with adhesive layer including polyamide copolymer and it's manufacturing process - Google Patents

Abstract

The present invention relates to a stamping foil in which a coating solution containing a polyamide copolymer resin having a glass transition temperature of 0 to 40 ° C. in a composition of an adhesive layer is subjected to a steam blushing process and then dried to form an adhesive layer having a thickness of 0.5 to 1.5 μm. As it is, even though the adhesive layer is coated with a thin film, it is excellent in adhesiveness at a low temperature, it is possible to ensure excellent cutting properties during stamping operations due to the thin film.

Description

Stamping foil with adhesive layer including polyamide copolymer and it's manufacturing process

The present invention relates to a stamping foil for an ink coated paper expressing a wide range of adhesive temperatures with a thin adhesive layer thickness using a solution containing a polyamide copolymer resin and a method of manufacturing the same.

In general, the structure of the stamping foil for ink coated paper is as shown in Fig. 1, the base film (1) usually made of PET film as a film for coating processing, the peeling of the polyester film and the colored layer when subjected to heat and pressure A release layer (2) for generating a color, a coloring layer (3) expressing a color by adding a dye or pigment for producing a color, a deposition layer (4) for expressing a metallic gloss by depositing a metal such as aluminum, and a subject It has a structure in which the adhesive layer (5) that serves to provide adhesion to the sequentially stacked.

As the adhesive layer of the stamping foil for ink coating paper, the main component of the ink is an acrylic resin, and therefore, acrylic resins of the same system are used a lot. However, the acrylic resin should have a thickness of at least 2.0 μm in order to maintain good adhesion due to lack of adhesion at low temperatures.

For this reason, conventional stamping foils for ink coated papers have continued to use thick adhesive coatings, and thus have a phenomenon in which accurate and clean transfer does not occur during stamping operations, that is, lack of cutting property.

Therefore, in order to satisfy the stamping working conditions in a wide adhesive temperature range while maintaining good cutting property on ink coated paper, it is necessary to apply an appropriate resin having good adhesion to ink paper and having a low glass transition temperature even at a thin coating thickness.

The present inventors have conducted a study to eliminate the above-mentioned problems in the prior art, as a result of using a resin having excellent low-temperature adhesiveness to the adhesive layer when stamping work on paper substrates, including ink coated paper, stamping excellent cutting and adhesive properties It has been found that the foil can be prepared to complete the present invention.

Accordingly, an object of the present invention is to provide a stamping foil having excellent adhesiveness to the adhesive layer and excellent cutting property when stamping to adherends of papers including ink coated paper.

It is also an object of the present invention to provide a method for producing such a stamping foil.

Stamping foil of the present invention for achieving the above object has a structure in which a base film, a release layer, a coloring layer, a deposition layer, and an adhesive layer are sequentially laminated, wherein the adhesive layer comprises a copolymerized polyamide resin, copolymerized poly The amide resin is characterized by having a glass transition temperature of 0 to 40 ° C. and a thickness of the adhesive layer of 0.5 to 1.5 μm.

The present invention will be described in more detail as follows.

The stamping foil of the present invention has the same structure as a conventional stamping foil, and has a structure in which a base film, a release layer, a coloring layer, a deposition layer, and an adhesive layer are sequentially stacked.

In the present invention, a polyester film is used as the base film; Wax, cellulose, acrylic resin, or the like is applied to the release layer to produce a release effect; Disperse | distribute and apply | coat the pigment | dye or pigment which gives a color to resin which is excellent in dispersion | dispersion of dye and chemical-resistance, and forms a colored layer; Metals such as aluminum, chromium, silver, copper, and gold are deposited thereon in a high vacuum to form a deposition layer, and an adhesive layer is applied on the metal layer.

The most characteristic part of the stamping foil of the present invention is an adhesive layer, in which the polyamide copolymer resin having a glass transition temperature of 0 to 40 ° C. is used in the present invention in place of the acrylic resin, which is often used for the adhesive layer of the existing ink coated paper. In addition, when 10 to 80 parts by weight of acrylic resin or halogenated polypropylene or vinyl resin is further added thereto, coating property and product stability may be further improved.

Specifically, the acrylic resin which can be further added to the polyamide copolymer resin is an acrylic resin having a glass transition temperature of 30 to 80 ° C. and a weight average molecular weight of 20,000 to 200,000, and a glass transition temperature of 30 to 80 ° C. and a weight average molecular weight. The low molecular weight acrylic resin of 1,000 to 20,000 can be used in 10-80 parts by weight of solids, and the vinyl resin can be used in 10 to 80 parts by weight of ethyl vinyl acetate resin having a glass transition temperature of 20 to 150 ° C. As the halogenated polypropylene resin, a polypropylene chloride having a glass transition temperature of 10 to 100 ° C. and a weight average molecular weight of 20,000 to 500,000 may be used in an amount of 10 to 80 parts by weight in terms of solid weight. When mixed with these, the polyamide copolymer resin having a glass transition temperature of 0 to 40 ° C is preferably used in an amount of 20 to 70 parts by weight based on the solid content weight ratio. If the content of the polyamide copolymer resin having a glass transition temperature of 0 to 40 ° C. is less than 20 parts by weight of the solid content ratio, there may be a problem of low temperature adhesiveness, and when added in excess of 70 parts by weight, room temperature due to the low glass transition temperature. Product stability such as tearing phenomenon occurs in the. The polyamide copolymer resin is not particularly limited and refers to one obtained from ordinary adipic acid and various diamines.

Here, the glass transition temperature was measured from the second heating zone by using differential scanning calorimeter of DSC7 manufactured by PEKIN ELMER, and the weight average molecular weight was gel permeation chromatography (Gel Permeation Chromatograph) manufactured by Waters Corporation. ) Was measured at room temperature using tetrahydrofuran as a developing solvent.

Conventionally, Kurtz Co., Ltd. already owns a patent (USP 5,981,009) for a decorative film using a polyamide copolymer resin as an adhesive layer composition, but it is used at a temperature above the glass transition temperature by using a hot melt polyamide copolymer resin. As a coating in a molten state by heating, it is intended to emphasize that different from the composition of the solution state as in the present invention.

In general, a coating method for imparting functionality on a film or sheet includes a method of using a coating head such as Dip, Reverse, Gravure, Micro-Gravure, Comma in a solution state by dissolving a resin in a solvent, and the present invention also includes the above coating. Any of the methods may be used. Since the conventional coating method is coated in a solution state, since the adhesive layer composition of the present invention is in a solution state, it can be applied regardless of the type of coating head, and thus it can be produced in an existing coating machine without additional equipment investment. .

On the other hand, the adhesive layer composition of the present invention includes a filler of an inorganic type to further improve the cutting property. As the filler, calcium, aluminum, magnesium, silicon oxides or inorganic pigments can be used. The particle size is 1 to 20 µm. In the case of silicon oxide, precipitated silica or fused silica may be used depending on the production method. . Such fillers are used in an amount of 10 to 20 parts by weight, based on the weight ratio of solids.

On the other hand, as a solvent in the adhesive layer composition, a hydrophilic solvent and a hydrophobic solvent are mixed and used, and the hydrophilic solvent is used at 10 to 90% by weight of the total solvent, and the hydrophobic solvent is used at 10 to 90% by weight of the total solvent. Mainly used hydrophilic solvents are alcohol-based compounds such as methanol, ethanol, isopropyl alcohol, butanol and the like, and hydrophobic solvents include toluene, xylene, hexane, heptane and cyclohexane.

After coating on the deposition layer with such an adhesive layer composition, before the drying after the application, after steam brushing at a relative humidity of 40 to 100%, a temperature of 60 to 100 ℃, the temperature of 100 to 180 ℃ and 2 ~ Drying under a drying condition of 30 seconds (sec) to form an adhesive layer of 0.5 to 1.5 ㎛ thickness, more preferably 0.7 to 1.0 ㎛ thickness.

When the thickness of the obtained adhesive layer is thinner than 0.5㎛ may be a non-uniform coating or poor adhesion, there may be a problem that the cutting and high speed workability is poor when thicker than 1.5㎛. In this case, the thickness of the stamping foil cut into 10cm × 10cm was folded twice, and the film thickness was measured by using an Anritsu's KG3001A (digital indicator) and K-402B (stand) thickness meter and adhesive coating. Wipe the removed area with gauze moistened with toloene five times, remove it, and fold it twice as well. Measure the film thickness by the above method. The adhesive coating thickness is calculated by subtracting the film thickness measurement after removing the adhesive layer from the film thickness measurement before removing the adhesive layer and dividing by four.

As described above, since the adhesive layer of the present invention contains a polyamide copolymer resin, the affinity with water is lower than that of the conventional acrylic resin alone, so that the adhesive layer is easily solidified by steam. Due to the low glass transition temperature, excellent adhesion to the ink coating layer can be achieved. Therefore, there is an advantage that can secure excellent cutting properties at high speed stamping work.

Here, in more detail with respect to the steam blushing process, this process is a process for forming a discontinuous film of the coating schematically shown in Figure 2, the principle is as follows.

(A) When the water vapor particles 11 fall at a relative humidity of 40 to 100% and a temperature of 60 to 100 ° C to the adhesive layer 12 (adhesive resin + hydrophilic solvent + hydrophobic solvent) before drying , (B) the remaining hydrophilic solvent The adhesive resin dissolved in the solvent precipitates as it permeates into the water vapor particles (precipitated adhesive resin 13), and when the coating layer is dried, a void 14 is formed to form a discontinuous film. In this case, if the adhesive resin has affinity with water vapor, the adhesive resin is not precipitated and is immediately dried to form a discontinuous coating film. Therefore, in the present invention, the polyamide copolymer resin is included as the adhesive resin as described above.

Steam blushing spreads the steam with a relative humidity of 40-100% and a temperature of 60-100 ° C evenly onto the surface of the coating before drying after the adhesive layer composition is coated to form a discontinuous film of the coating. When transferring the stamping foil to the landing there is an advantage that can show an advantageous effect on the cutting property by blocking the heat transfer in the transverse direction.

Hitachi's S-4300 field emission scanning electron microscope can be observed in the pores formed by steam blushing, the magnification of 1000 times and 5000 times, respectively, is shown in Figures 3a and 3b.

At this time, as shown in the depth cross-sectional view shown in the laser scanning microscope of Figure 4 there are a number of peaks on the adhesive coating surface, the number is 2 to 100 on any adhesive coating surface 25㎛ length. The number of these peaks is affected by the ratio of hydrophilic and hydrophobic solvents.

The laser scanning microscope used the LSM5 PASCAL model of ZEISS. The number of peaks measured above was measured by the following method. First, use ZEISS's PASCAL software to scan 3D scans at 3500x and 0.63㎛ intervals, then press the 3D Filled image button on the Topo graph, and adjust the image to Guassian 7 × 7, Z-threshold 5.25 and Fill-Level 8. Next, using the Profile add button and using a mouse to obtain a depth section of 25㎛ length at an arbitrary position, the number of peaks could be measured and measured, and the value was 2-100. At this time, the height of the peak can also be measured.

The stamping foil for ink coating paper of the present invention obtained through the composition and manufacturing method as described above has excellent adhesiveness at low temperature, even though the adhesive layer is coated with a thin film, and excellent cutting during high speed stamping work due to the thin film and the discontinuous coating surface. The castle can be secured.

In addition, as described above, the cutting property of the stamping foil is greatly influenced by the number and depth of the peaks generated on the surface of the adhesive layer and the distance between adjacent peaks. At least two of 100 to 100, the bottom of the peak is 1㎛ or less, at least two of the distance between adjacent peaks of 1㎛ or more are formed so that the cutting of the stamping foil is excellent to enable high-speed stamping It was.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the present invention is not limited to the following Examples.

Example 1

Paraffin wax was applied on a 12 μm polyester film at a thickness of 0.15 μm to form a release layer, and a resin comprising 60 parts by weight of polymethyl methacrylate-based acrylic resin, 15 parts by weight of nitrocellulose, and 25 parts by weight of polyurethane curing agent on the release layer. Was diluted in a methyl ethyl ketone and a cyclohexanone solvent, orange and yellow dyes were added to 10% by weight relative to the resin ratio and coated to a thickness of 1.0 μm and dried at 160 ° C. for a suitable time to form a colored layer. Then, aluminum was deposited to a thickness of 350 ° C. using a vacuum evaporator on the colored layer to form a deposition layer.

On the vapor deposition layer, polyamide copolymer resin Nylon 66/12 having a glass transition temperature of 5 ° C. was included so as to be 100 parts by weight of solids, and these were toluene (90 parts by weight in total solvent) and isopropyl alcohol (10 parts by weight in total solvent) solvent Diluted to and coated at a coating speed of 160 M / min using a gravure method, and then dried at 130 ° C. for 10 seconds to form an adhesive layer having a thickness of 0.9 μm, and the number of peaks present on an arbitrary 25 μm line on the adhesive layer surface was 0. Stamping foil was prepared to be ˜1.

Example 2

Prepare a stamping foil in the same manner as in Example 1, except that the ethylenic acetate (EVA) resin having a glass transition temperature of 30 ℃ in the adhesive layer composition as shown in Table 1 to 40 parts by weight of solids, glass transition temperature 10 ℃ 50 parts by weight of the copolymer resin Nylon 66/12 as solids, fused silica having an average particle size of 12 µm to 10 parts by weight of solids, and toluene (90 parts by weight of the total solvent) and isopropyl alcohol (10 of the total solvent) Parts by weight) and diluted with solvent.

Example 3

Prepare a stamping foil in the same manner as in Example 1, except that the adhesive layer composition as shown in Table 1 below 40 parts by weight of polypropylene chloride (CL-PP) having a glass transition temperature of 25 ℃, the weight average molecular weight of 350,000 50 parts by weight of polyamide copolymer resin Nylon 66/12 having a glass transition temperature of 10 ° C. to 50 parts by weight of solids, and fused silica having an average particle size of 12 μm to 10 parts by weight of toluene (90 parts by weight of the total solvent) And dilute in isopropyl alcohol (10 parts by weight in total solvent) solvent.

Example 4

Prepare a stamping foil in the same manner as in Example 1, except that the adhesive layer composition as shown in Table 1, the methyl methacrylate (MMA) and butyl methacrylate (BMA) having a glass transition temperature of 40 ℃ and weight average molecular weight 100,000 20 parts by weight of a copolymerized acrylic resin composed of a monomer of 20 parts by weight of an isobutyl methacrylate (IBMA) monomer having a glass transition temperature of 40 ° C. and a weight average molecular weight of 5,000. In addition, 50 parts by weight of polyamide copolymer resin Nylon 66/12 having a glass transition temperature of 10 ° C. was added to 50 parts by weight of solids, and fused silica having an average particle size of 12 μm was added to 10 parts by weight of solids. ) And dilute to isopropyl alcohol (10 parts by weight in total solvent) solvent.

Example 5

Prepare a stamping foil in the same manner as in Example 1, except that the adhesive layer composition as shown in Table 1, the methyl methacrylate (MMA) and butyl methacrylate (BMA) having a glass transition temperature of 40 ℃ and weight average molecular weight 100,000 20 parts by weight of a copolymerized acrylic resin composed of a monomer of 20 parts by weight of an isobutyl methacrylate (IBMA) monomer having a glass transition temperature of 40 ° C. and a weight average molecular weight of 5,000. In addition, 50 parts by weight of polyamide copolymer resin Nylon 66/12 having a glass transition temperature of 30 ° C. was added to 50 parts by weight of solids, and fused silica having an average particle size of 12 μm was added to 10 parts by weight of solids, and these were added to toluene (90 parts by weight of the total solvent). ) And dilute to isopropyl alcohol (10 parts by weight in total solvent) solvent. After coating at a coating speed of 160M / min using a gravure method, the steam blushing process was performed at a temperature of 50 ° C. and a relative humidity of 30%, followed by drying at 130 ° C. for 10 seconds to form an adhesive layer having a thickness of 0.9 μm. The stamping foil was prepared so that the number of the peaks which exist on the line of arbitrary 25 micrometers of adhesive layer surfaces is 2-20.

Example 6

The stamping foil was manufactured in the same manner as in Example 5, except that the steam blushing process was performed at a temperature of 90 ° C. and a relative humidity of 80% as shown in Table 1 below to determine the peak present on a line of 25 μm on the surface of the adhesive layer. Stamping foil was prepared so that the number is from 2 to 50.

Example 7

Prepare a stamping foil in the same manner as in Example 6 except changing the solvent ratio of the adhesive composition to toluene solvent (60 parts by weight of the total solvent) and isopropyl alcohol (40 parts by weight of the total solvent) as shown in Table 1 The stamping foil was manufactured so that the number of peaks which exist on the line of arbitrary 25 micrometers of an adhesive layer was 2-80.

Comparative Example 1

Prepare a stamping foil in the same manner as in Example 1, except that the ethylenic acetate acetate (EVA) resin having a glass transition temperature of 30 ° C. in an adhesive layer composition as shown in Table 1 as 90 parts by weight of solids, with an average particle size of 12 μm. The fused silica was made to contain 10 parts by weight of solids, and these were diluted by toluene (90 parts by weight in total solvent) and isopropyl alcohol (10 parts by weight in total solvent) solvent.

Comparative Example 2

Prepare a stamping foil in the same manner as in Example 1, except that the adhesive layer composition as shown in Table 1 in the glass transition temperature of 25 ℃, the weight average molecular weight of 350,000 polypropylene chloride (CL-PP) to 90 parts by weight of solids Fused silica having an average particle size of 12 µm was prepared so as to be 10 parts by weight of solids, and these were diluted by toluene (90 parts by weight in total solvent) and isopropyl alcohol (10 parts by weight in total solvent) solvent.

Comparative Example 3

Prepare a stamping foil in the same manner as in Example 1, except that the adhesive layer composition as shown in Table 1, the methyl methacrylate (MMA) and butyl methacrylate (BMA) having a glass transition temperature of 40 ℃ and weight average molecular weight 100,000 45 parts by weight of an acrylic resin (PIBMA) composed of isobutyl methacrylate (IBMA) monomer having a glass transition temperature of 40 ° C. and a weight average molecular weight of 5,000, In addition, fused silica having an average particle size of 12 µm was prepared so as to be 10 parts by weight of solids, and these were diluted by toluene (90 parts by weight in total solvent) and isopropyl alcohol (10 parts by weight in total solvent) solvent.

Comparative Example 4

The stamping foil was prepared in the same manner as in Example 1, except that the polyamide copolymer resin Nylon 66/12 included in the adhesive composition as shown in Table 2 below was used at a glass transition temperature of 50 ° C.

Comparative Example 5

The stamping foil is manufactured in the same manner as in Example 1, except that the thickness of the adhesive coating is different as shown in Table 2 below.

Comparative Example 6

Prepare a stamping foil in the same manner as in Example 5 except that the adhesive layer composition of the methyl methacrylate (MMA) and butyl methacrylate (BMA) having a glass transition temperature of 40 ℃ and a weight average molecular weight of 100,000 as shown in Table 2 45 parts by weight of an average of 45 parts by weight of an acrylic resin comprising an isobutyl methacrylate (IBMA) monomer having a glass transition temperature of 40 ° C. and a weight average molecular weight of 5,000 Fused silica having a size of 12 µm was included in an amount of 10 parts by weight of solids, and these were diluted by toluene (90 parts by weight of the total solvent) and isopropyl alcohol (10 parts by weight of the total solvent).

The adhesive layer condition table of the specific example is shown in Table 1 below.

The adhesive layer condition table of the specific comparative example is shown in Table 2 below.

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The stamping foils obtained according to the above Examples and Comparative Examples were measured at the following low temperature adhesiveness, cutting property, coating property, product stability and high speed workability, and the results are shown in Tables 3 and 4 below.

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Assessment Methods;

(1) low temperature adhesiveness

The degree of adhesion to the ink coated paper was stamped using a stamping machine at 80 ° C., 0.5 seconds, and 4 kg / cm 2.

Good: ○, Normal: △, Severe: ×

(2) cutting property

Stamping the ink coated paper using a stamping machine at 120 ° C, 0.5 seconds, 4kg / ㎠ conditions to observe the boundary between the heat and pressure and the part not to evaluate the degree of clean transfer.

Good: ○, Normal: △, Severe: ×

(3) coating property

The uniformity of the coating appearance after the coating of the adhesive layer was evaluated by observing with an electron microscope.

Good: ○, Normal: △, Severe: ×

(4) Product stability

After coating the adhesive layer was stored for 10 days at 25 ℃ to evaluate the degree of tearing.

Good: ○, Normal: △, Severe: ×

(5) high speed workability

An ink coating paper was stamped under conditions of 80 ° C., 0.25 sec, 4 kg / cm 2, 120 ° C., and 0.25 sec using a stamping machine, and the degree of adhesion and cutting property were evaluated.

Good: ○, Normal: △, Severe: ×

As described in detail above, according to the present invention, a coating solution containing a polyamide copolymer resin having a glass transition temperature of 0 to 40 ° C. in the adhesion composition was applied to perform a steam blushing process and then dried to have a thickness of 0.5 to 1.5 μm. The stamping foil having a low adhesive layer is excellent in adhesiveness at low temperatures even though the adhesive layer is coated with a thin film, thereby ensuring excellent cutting property at a high speed stamping operation.

1 is a cross-sectional view showing the structure of a stamping foil,

Figure 2 is a schematic diagram schematically showing the principle of steam brushing (Steam brushing),

Figure 3 is a field emission scanning electron microscope (Field Emission Scanning Electron Microscope) photograph of the adhesive coating surface formed by the steam blushing principle, Figure 3a is a 1000 times magnification, Figure 3b is a 5000 times magnification,

4 is a 5000 times magnification and depth profile of a Laser Scanning Microcope on an adhesive coated surface.

                   Detailed description of the major symbols

            1-base film 2-release layer

            3-colored layer 4-deposited layer

            5-Adhesion Layer 11-Water Vapor Particles

           12-adhesive layer before drying

           13-Adhesive resin precipitated by water vapor

           14-void

Claims (9)

In the stamping foil having a structure containing a base film, a release layer, a coloring layer, a deposition layer and an adhesive layer, The adhesive layer comprises a copolymerized polyamide resin, the copolymerized polyamide resin stamping foil, characterized in that the glass transition temperature of 0 to 40 ℃, the thickness of the adhesive layer is 0.5 to 1.5㎛. The stamping foil of claim 1, wherein the adhesive layer further comprises at least one resin selected from acrylic resins, halogenated polypropylenes, and vinyl resins. According to claim 1, wherein the adhesive layer is 20 to 70 parts by weight of copolymerized polyamide resin, 10 to 70 parts by weight of at least one resin selected from acrylic resin, halogenated polypropylene and vinyl resin, and 10 to 20 parts by weight of silica, based on the total solid content. Stamping foil, characterized in that it comprises a. The copolymer of methyl methacrylate and butyl methacrylate having a glass transition temperature of 30 to 80 ° C. and a weight average molecular weight of 20,000 to 200,000, and a glass transition temperature of 30 to 80 ° C. A mixture of 1,000 to 20,000 polyisobutyl methacrylate, a halogenated polypropylene is a polypropylene chloride having a glass transition temperature of 10 to 100 ° C. and a weight average molecular weight of 20,000 to 500,000, and a vinyl resin has a glass transition temperature of 20 to 150 Stamping foil, characterized in that the ethyl vinyl acetate resin. The stamping foil according to claim 1, wherein the adhesive layer has a number of peaks on the surface of 2 to 100 in an arbitrary length of 25 탆 when observed by a laser scanning microscope. Forming a release layer on the base film, dispersing and applying a dye or pigment imparting color to a resin having excellent dye resistance and chemical resistance to the release layer to form a colored layer, and forming a colored layer on the colored layer by high vacuum In the method of manufacturing a stamping foil comprising the step of forming a deposition layer by depositing under, and applying an adhesive layer on the deposition layer, The adhesive layer is formed by coating an adhesive composition comprising a copolymerized polyamide having a glass transition temperature of 0 to 40 ° C. on a deposition layer, and the thickness of the adhesive layer is 0.5 to 1.5 μm and when observed with a laser scanning microscope, the surface of the adhesive layer is 25 μm. A method of producing a stamping foil, characterized in that the length is formed so that the number of peaks is 2 to 100. The method of claim 6, wherein the adhesive composition is diluted in a mixed solvent of a hydrophobic solvent and a hydrophilic solvent, coated on the deposition layer, and then subjected to a steam blushing process, followed by drying to form voids. The method of claim 7, wherein the steam blushing is performed at a relative humidity of 50 to 80% and a temperature of 60 to 90 ° C. 9. 8. The process for producing a stamping foil according to claim 7, wherein a mixed solvent of a hydrophilic solvent and a hydrophobic solvent is obtained by mixing at a ratio of 10:90 to 90:10 by weight.