JP6242192B2 - Base film for hydraulic transfer - Google Patents

Description

  The present invention relates to a hydraulic transfer base film for forming a hydraulic transfer film for use in printing on a transfer target such as a molded article having a three-dimensional surface or curved surface with irregularities, a method for producing the same, The present invention relates to a hydraulic transfer film formed from the hydraulic transfer base film and a hydraulic transfer method using the hydraulic transfer film.

  As a means for forming a printed layer for imparting design properties or improving surface physical properties on the surface of a molded body having uneven three-dimensional surfaces or curved surfaces, it is suitable for transfer onto a water-soluble or water-swellable film surface. A method using a hydraulic transfer film on which a printing layer is formed is known. For example, in Patent Document 1, after floating on the liquid surface of a liquid represented by water with the printing surface of the hydraulic transfer film facing up, various molded bodies that are transferred bodies are pushed in from above. In addition, a method for transferring a printing layer to the surface of a transfer medium using hydraulic pressure is described.

  In the hydraulic transfer method, it is important to prevent curling when the hydraulic transfer film floats on the liquid surface. For example, in Patent Document 2, in recent years, printing of a design is multilayer printing or a printing ink having excellent durability has been used. In order to prevent curling due to differences in water absorption, etc., when manufacturing a base film for hydraulic transfer, heat treatment may be performed on the surface opposite to the surface in contact with the film forming belt or film forming drum. Have been described.

JP 54-33115 A JP 2009-1009 A

  However, the method described in Patent Document 2 is still insufficient in curling prevention effect, so that the transfer efficiency is poor. Accordingly, in the present invention, a hydraulic transfer base film that can sufficiently prevent curling when floated on the liquid surface and can form a hydraulic transfer film excellent in transfer efficiency, a manufacturing method thereof, and the hydraulic transfer An object of the present invention is to provide a hydraulic transfer film formed from a base film and a hydraulic transfer method using the hydraulic transfer film.

  As a result of intensive studies to achieve the above object, the present inventors have found that a polyvinyl alcohol (hereinafter, “polyvinyl alcohol” may be abbreviated as “PVA”) and a surfactant having a secondary alkyl group. A base film for hydraulic transfer with a small surface roughness can be easily obtained by using a film-forming stock solution containing a liquid, and a liquid film for transfer using the same is a liquid surface typified by water at the time of hydraulic transfer. Is suppressed by using a base film for hydraulic transfer containing PVA and a surfactant having a secondary alkyl group. It was found that the curling when the film is floated on the liquid surface is highly suppressed. The present inventors have further studied based on these findings and completed the present invention.

That is, the present invention
[1] Hydraulic transfer base film containing PVA and a secondary alkyl group-containing surfactant,
[2] The hydraulic transfer base film according to the above [1], comprising 0.05 to 4 parts by mass of a secondary alkyl group-containing surfactant with respect to 100 parts by mass of PVA
[3] The base film for hydraulic transfer according to the above [1] or [2], wherein the saponification degree of PVA is 80 to 98 mol%,
[4] The hydraulic transfer base film according to any one of the above [1] to [3], wherein the arithmetic average roughness (Ra) of at least one surface is 400 nm or less,
[5] A method for producing a base film for hydraulic transfer, comprising a step of forming a film using a film-forming stock solution containing PVA and a secondary alkyl group-containing surfactant.
[6] A hydraulic transfer film obtained by printing on the surface of the hydraulic transfer base film of any one of [1] to [4] above,
[7] A liquid having the step of floating the hydraulic transfer film of [6] above on the liquid surface with the printed side up, and the step of pressing the transfer medium from above the floated hydraulic transfer film Pressure transfer method,
About.

  ADVANTAGE OF THE INVENTION According to this invention, the base film for hydraulic transfer which can fully prevent the curl when it floats on the liquid surface and can form the hydraulic transfer film excellent in transfer efficiency, its manufacturing method, the said hydraulic pressure A hydraulic transfer film formed from the transfer base film and a hydraulic transfer method using the hydraulic transfer film are provided.

The present invention is described in detail below.
The base film for hydraulic transfer of the present invention contains PVA. The PVA includes one of vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, and isopropenyl acetate. What can be obtained by saponifying polyvinyl ester obtained by polymerizing 2 or more types can be used. Among the above vinyl esters, vinyl acetate is preferable from the viewpoints of ease of production of PVA, availability, cost, and the like.

  The polyvinyl ester is preferably obtained using only one or two or more vinyl esters as monomers, and more preferably obtained using only one vinyl ester as a monomer. However, as long as it does not impair the effects of the present invention, it may be a copolymer of one or more vinyl esters and other monomers copolymerizable therewith.

  Examples of other monomers copolymerizable with the vinyl ester include, for example, α-olefins having 2 to 30 carbon atoms such as ethylene, propylene, 1-butene and isobutene; (meth) acrylic acid or a salt thereof; (Meth) methyl acrylate, (meth) ethyl acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, ( (Meth) acrylic acid esters such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate; (meth) acrylamide, N-methyl ( (Meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, diacetone (meth) acryl (Meth) acrylamide derivatives such as amide, (meth) acrylamide propanesulfonic acid or salts thereof, (meth) acrylamidepropyldimethylamine or salts thereof, N-methylol (meth) acrylamide or derivatives thereof; N-vinylformamide, N-vinyl N-vinylamides such as acetamide and N-vinylpyrrolidone; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, etc. Vinyl ether; vinyl cyanide such as (meth) acrylonitrile; halogenated vinyl such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride; vinegar Allyl compounds such as allyl acid and allyl chloride; maleic acid or its salt, ester or acid anhydride; itaconic acid or its salt, ester or acid anhydride; vinylsilyl compound such as vinyltrimethoxysilane; unsaturated sulfonic acid be able to. Said polyvinyl ester can have a structural unit derived from 1 type, or 2 or more types of an above described other monomer.

  The proportion of structural units derived from the other monomers described above in the polyvinyl ester is preferably 25 mol% or less based on the number of moles of all structural units constituting the polyvinyl ester, and is 15 mol%. More preferably, it is more preferably 5 mol% or less. When the ratio exceeds 25 mol%, the affinity between the hydraulic transfer base film and the printing layer tends to be reduced.

  The PVA may be modified with one or two or more types of graft copolymerizable monomers as long as the effects of the present invention are not impaired. Examples of the graft copolymerizable monomer include unsaturated carboxylic acids or derivatives thereof; unsaturated sulfonic acids or derivatives thereof; α-olefins having 2 to 30 carbon atoms, and the like. The proportion of structural units derived from the graft copolymerizable monomer in PVA is preferably 5 mol% or less based on the number of moles of all structural units constituting PVA.

  In the PVA, a part of the hydroxyl groups may be cross-linked or may not be cross-linked. Moreover, said PVA may react with aldehyde compounds, such as acetaldehyde and a butyraldehyde, etc. to form an acetal structure, and the said PVA does not react with these compounds and does not form an acetal structure. May be.

  The polymerization degree of the PVA is preferably in the range of 500 to 3000, more preferably in the range of 700 to 2800, and still more preferably in the range of 1000 to 2500. When the degree of polymerization of PVA is less than 500, the mechanical strength of the obtained base film for hydraulic transfer may be insufficient. On the other hand, when the degree of polymerization of PVA exceeds 3000, the production efficiency in producing a hydraulic transfer base film may be reduced. In addition, the water solubility of the hydraulic transfer base film, and thus the hydraulic transfer film, may be reduced. May decrease, making it difficult to perform hydraulic transfer at an economical process speed. In addition, the polymerization degree of PVA as used in this specification means the average degree of polymerization measured according to description of JIS K6726-1994.

  The saponification degree of the PVA is preferably in the range of 80 to 98 mol%, more preferably in the range of 83 to 96 mol%, and still more preferably in the range of 85 to 90 mol%. . When the degree of saponification of PVA is less than 80 mol%, the water-solubility of the base film for hydraulic transfer, and hence the film for hydraulic transfer, decreases, making it difficult to perform hydraulic transfer at an economical process speed. There is. On the other hand, even when the degree of saponification of PVA exceeds 98 mol%, the water-solubility of the base film for hydraulic transfer and the film for hydraulic transfer is lowered, making it difficult to perform hydraulic transfer at an economical process speed. There is a case. In this specification, the degree of saponification of PVA refers to the total number of moles of structural units (typically vinyl ester units) that can be converted into vinyl alcohol units by saponification and the vinyl alcohol units of PVA. The proportion (mol%) occupied by the number of moles of vinyl alcohol units. The degree of saponification can be measured according to the description of JIS K6726-1994.

  The content of PVA in the base film for hydraulic transfer is preferably 50% by mass or more, more preferably 80% by mass or more from the viewpoint of securing basic physical properties as a base film for hydraulic transfer. More preferably, the content is 85% by mass or more. Although there is no restriction | limiting in particular in the upper limit of the said content rate, it is preferable that the said content rate is 99 mass% or less, and it is more preferable that it is 98 mass% or less.

  The base film for hydraulic transfer of the present invention contains a secondary alkyl group-containing surfactant. By including the secondary alkyl group-containing surfactant in the hydraulic transfer base film, curling when the hydraulic transfer film formed therefrom floats on the liquid surface can be sufficiently prevented. Although the present invention is not limited in any way, the reason for this is that when the hydraulic transfer film is floated on the liquid surface, the secondary alkyl group-containing surfactant is eluted to cover the liquid surface. This is presumably because the spread of the film for hydraulic transfer on the liquid surface is suppressed and the progress of curling is hindered.

  The secondary alkyl group-containing surfactant means a surfactant having at least one secondary alkyl group in its structure. Here, the secondary alkyl (group) means an alkyl (group) having at least one secondary carbon atom. The number of carbon atoms of the secondary alkyl group is preferably in the range of 3 to 20, since curling when the resulting hydraulic transfer film is floated on the liquid surface can be more effectively prevented. It is more preferable to be within the range.

  Examples of the secondary alkyl group-containing surfactant include secondary alkyl group-containing alkyl ether surfactants, secondary alkyl group-containing fatty acid ester surfactants, and secondary alcohol sulfate salts (sodium). Salt, potassium salt, ammonium salt, etc.). The secondary alkyl group-containing surfactant may be used alone or in combination of two or more. Since the secondary alkyl group-containing surfactant can more effectively prevent curling when the resulting hydraulic transfer film floats on the liquid surface, the secondary alkyl group-containing surfactant and / or Alternatively, it is preferably a secondary alkyl group-containing fatty acid ester type surfactant, and more preferably a secondary alkyl group-containing alkyl ether type surfactant.

  The alkyl ether type surfactant in the secondary alkyl group-containing alkyl ether type surfactant is an alkyl group and other organic group (for example, a hydrophilic group such as a polyoxyalkylene group) via an oxygen atom. And a surfactant having an ether-linked ((C) -O- (C)) structure. In the secondary alkyl group-containing alkyl ether surfactant, the position of the secondary alkyl group is not particularly limited, but curling when the resulting hydraulic transfer film floats on the liquid surface can be more effectively prevented. From the above, the secondary alkyl group-containing alkyl ether type surfactant has a secondary alkyl group and other organic group (for example, a hydrophilic group such as a polyoxyalkylene group) ether via an oxygen atom. It is preferable to have a bonded ((C) -O- (C)) structure.

  The fatty acid ester type surfactant in the secondary alkyl group-containing fatty acid ester type surfactant is an acyl group constituting the fatty acid and other organic groups (for example, a hydrophilic group such as a polyoxyalkylene group). Means a surfactant having a structure in which an ester bond ((acyl group) -O- (C)) is formed through an oxygen atom. The position of the secondary alkyl group in the secondary alkyl group-containing fatty acid ester type surfactant is not particularly limited, but it can more effectively prevent curling when the resulting hydraulic transfer film floats on the liquid surface. From the above, the secondary alkyl group-containing fatty acid ester type surfactant has an acyl group corresponding to the structure in which the secondary alkyl group is bonded to the carbonyl group and other organic groups (for example, hydrophilic groups such as polyoxyalkylene groups). A group having an ester bond via an oxygen atom ((acyl group) -O- (C)).

  Examples of the secondary alkyl group-containing alkyl ether surfactant include polyoxyethylene secondary alkyl ether, polyoxypropylene secondary alkyl ether, polyoxybutylene secondary alkyl ether, polyoxyoctylene second Polyoxyalkylene secondary alkyl ether such as secondary alkyl ether; polyoxyethylene secondary alkyl ether sulfate, polyoxypropylene secondary alkyl ether sulfate, polyoxybutylene secondary alkyl ether sulfate, polyoxyoctyl Polyoxyalkylene secondary alkyl ether sulfates such as len secondary alkyl ether sulfates; polyoxyethylene secondary alkyl ether phosphates, polyoxypropylene secondary alkyl ether phosphates, polyoxybutylene secondary Class alkyl -Polyoxyalkylene secondary alkyl ether phosphates such as tellurate and polyoxyoctylene secondary alkyl ether phosphates; polyoxyethylene secondary alkyl ether acetates, polyoxypropylene secondary alkyl ether acetates Salts, polyoxybutylene secondary alkyl ether acetates, polyoxyalkylene secondary alkyl ether carboxylates such as polyoxyoctylene secondary alkyl ether acetates; polyoxyethylene secondary alkyl sulfosuccinates, polyoxyethylene Examples thereof include polyoxyalkylene secondary alkylsulfosuccinates such as oxypropylene secondary alkylsulfosuccinate, polyoxybutylene secondary alkylsulfosuccinate, and polyoxyoctylene secondary alkylsulfosuccinate. In addition, when the secondary alkyl group-containing alkyl ether surfactant is a salt, for example, sodium salt, potassium salt, ammonium salt and the like can be mentioned.

  Examples of the secondary alkyl group-containing fatty acid ester surfactant include polyoxyethylene secondary fatty acid ester, polyoxypropylene secondary fatty acid ester, polyoxybutylene secondary fatty acid ester, and polyoxyoctylene. Polyoxyalkylene secondary fatty acid ester such as secondary fatty acid ester; polyoxyethylene glycerin secondary fatty acid ester, polyoxypropylene glycerin secondary fatty acid ester, polyoxybutylene glycerin secondary fatty acid ester, polyoxyoctylene Examples thereof include polyoxyalkylene glycerin secondary fatty acid esters such as glycerin secondary fatty acid esters.

  Among these secondary alkyl group-containing alkyl ether surfactants and secondary alkyl group-containing fatty acid ester surfactants, curl when the resulting film for hydraulic transfer is floated on the liquid surface is more effective. Nonionic surfactants are preferred, polyoxyalkylene secondary alkyl ethers and / or polyoxyalkylene secondary fatty acid esters are more preferred, and polyoxyalkylene secondary alkyl ethers are even more preferred.

  As said polyoxyalkylene secondary alkyl ether and polyoxyalkylene secondary fatty acid ester, the compound represented by the following formula | equation (I) can be used, for example.

In formula (I), R ¹ and R ² each represent an alkyl group having 1 to 18 carbon atoms, R ³ represents a single bond or an alkylene group having 1 to 10 carbon atoms, f represents 0 or 1, and R ⁴ represents an alkylene group having 1 to ⁴ carbon atoms, and n represents an integer of 1 to 20.

In the formula (I), the alkyl group represented by R ¹ and R ² may be linear or branched. The alkyl group has 1 to 18 carbon atoms, preferably 1 to 16 carbon atoms, and more preferably 1 to 14 carbon atoms. R ¹ and R ² may be the same as or different from each other.

In the formula (I), the alkylene group represented by R ³ may have a carbon chain that is linear or branched. The alkylene group has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms. R ³ is preferably a single bond from the viewpoints of more effectively preventing curling when the resulting film for hydraulic transfer is floated on the liquid surface and being easily available.

  In the formula (I), f is 0 or 1. When f is 0, the compound represented by formula (I) is a polyoxyalkylene secondary alkyl ether, and when f is 1, the compound represented by formula (I) is polyoxyalkylene. It becomes an alkylene secondary fatty acid ester.

In the formula (I), the alkylene group represented by R ⁴ may have a carbon chain that is linear or branched. Examples of the alkylene group include a 1,2-ethylene group, a 1,2-propylene group, a 1,2-butylene group, and the like. A 1,2-ethylene group is preferred from the standpoints that it can be effectively prevented and is easily available.

  In formula (I), n is any one of integers from 1 to 20. Among these, from the viewpoints that curl when the obtained film for hydraulic transfer is floated on the liquid surface can be more effectively prevented and is easily available, n is any one of integers of 3 to 18 It is preferable that it is any one of the integers of 5-12. Note that n may have a distribution depending on the production method of the polyoxyalkylene secondary alkyl ether and the polyoxyalkylene secondary fatty acid ester, etc., but the secondary alkyl group-containing interface used in the present invention as described above. The activator may be used alone or in combination of two or more. Therefore, even if n is a single integer and has no distribution, Alternatively, either one having a distribution of n (that is, a combination of n different from each other) may be used.

  In the formula (I), when m is the carbon number of the entire secondary alkyl group moiety, that is, the carbon number of the entire partial structure represented by the following formula (I ′), When the relationship satisfies m> n, it is possible to more effectively prevent curling when the obtained hydraulic transfer film floats on the liquid surface. From this viewpoint, m and n preferably satisfy the relationship of 1 ≦ m−n ≦ 9, and more preferably satisfy the relationship of 2 ≦ m−n ≦ 7.

In formula (I ′), R ¹ , R ² and R ³ are as defined above.

  The base film for hydraulic transfer preferably contains 0.05 to 4 parts by mass, more preferably 0.1 to 3.5 parts by mass of the secondary alkyl group-containing surfactant with respect to 100 parts by mass of PVA. More preferably, 0.5 to 3 parts by mass are included. When the content of the secondary alkyl group-containing surfactant with respect to 100 parts by mass of PVA is not less than the above lower limit, it is possible to more effectively prevent curling when the resulting hydraulic transfer film floats on the liquid surface. On the other hand, by being below the above upper limit, the surfactant can be effectively prevented from bleeding out.

  Flexibility can be imparted by adding a plasticizer to the base film for hydraulic transfer. The plasticizer is preferably a polyhydric alcohol, and specific examples thereof include ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylolpropane. The content of the plasticizer in the base film for hydraulic transfer is preferably 20 parts by mass or less, more preferably 15 parts by mass or less with respect to 100 parts by mass of PVA. If the plasticizer content exceeds 20 parts by mass, blocking may occur in the hydraulic transfer base film.

  Also, it provides the mechanical strength necessary for forming a printing layer on a hydraulic transfer base film, maintains moisture resistance when handling the hydraulic transfer base film, or the hydraulic pressure at which the printing layer is formed. Adjust the speed of softening due to liquid absorption when the transfer film floats on the liquid surface, spreadability on the liquid surface, time required for diffusion into the liquid, ease of deformation in the hydraulic transfer process, etc. For this purpose, it is preferable that the hydraulic transfer base film contains a water-soluble polymer other than starch and / or PVA.

  Examples of the starch include natural starches such as corn starch, potato starch, sweet potato starch, wheat starch, rice starch, tapioca starch, and sago starch; processed starches subjected to etherification, esterification, oxidation, etc. In particular, modified starches are preferred. The starch content in the base film for hydraulic transfer is preferably 15 parts by mass or less, more preferably 10 parts by mass or less with respect to 100 parts by mass of PVA. When the starch content exceeds 15 parts by mass, the impact resistance of the base film for hydraulic transfer and the film for hydraulic transfer is lowered and brittle, and the process passability may be reduced.

  Examples of water-soluble polymers other than PVA include, for example, dextrin, gelatin, glue, casein, shellac, gum arabic, polyacrylic acid amide, sodium polyacrylate, polyvinyl methyl ether, a copolymer of methyl vinyl ether and maleic anhydride, Examples thereof include a copolymer of vinyl acetate and itaconic acid, polyvinyl pyrrolidone, cellulose, acetyl cellulose, acetyl butyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, sodium alginate and the like. The content of the water-soluble polymer other than PVA in the base film for hydraulic transfer is preferably 15 parts by mass or less and more preferably 10 parts by mass or less with respect to 100 parts by mass of PVA. When the content of the water-soluble polymer other than PVA exceeds 15 parts by mass, the solubility and dispersibility of the hydraulic transfer film during hydraulic transfer may be lowered.

  Also, the purpose of adjusting the speed of softening due to absorption of liquid when the film for hydraulic transfer with a printed layer formed on the liquid surface, the spreadability on the liquid surface, the time required for diffusion into the liquid, etc. Thus, it is preferable that the above-mentioned base film for hydraulic transfer contains a boron compound.

  As the boron-based compound, boric acid and borax are preferable. The content of the boron-based compound in the base film for hydraulic transfer is preferably 5 parts by mass or less, more preferably 1 part by mass or less with respect to 100 parts by mass of PVA. If the boron-based compound content exceeds 5 parts by mass, the water-solubility of the hydraulic transfer base film and the hydraulic transfer film may decrease, making it difficult to perform hydraulic transfer at an economical process speed. is there.

  Moreover, the base film for hydraulic transfer may contain 1 type, or 2 or more types of surfactant other than the above-mentioned secondary alkyl group containing surfactant. There is no restriction | limiting in particular in the kind of such other surfactant, A well-known anionic surfactant, a cationic surfactant, a nonionic surfactant, etc. can be used. When the base film for hydraulic transfer contains such other surfactants, the total content of surfactants including the secondary alkyl group-containing surfactant in the base film for hydraulic transfer (all The content of the surfactant is preferably 4 parts by mass or less with respect to 100 parts by mass of PVA. When the total content of the surfactant exceeds 4 parts by mass, bleed-out may occur and handleability may deteriorate.

  In addition to the components described above, the hydraulic transfer base film may contain other components such as a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and a filler. The content of these other components is usually 10 parts by mass or less, more preferably 5 parts by mass or less with respect to 100 parts by mass of PVA, although it depends on the type. If the content of other components exceeds 10 parts by mass, the impact resistance of the hydraulic transfer base film may deteriorate.

  The moisture content of the base film for hydraulic transfer according to the present invention is preferably in the range of 2 to 6% by mass, and more preferably in the range of 3 to 5% by mass. When the moisture content is less than 2% by mass, the moisture content of the resulting hydraulic transfer film tends to be low, and the degree of curling tends to increase during the hydraulic transfer. On the other hand, when the moisture content exceeds 6% by mass, there is a tendency that problems such as a decrease in printing accuracy tend to occur.

  The thickness of the hydraulic transfer base film of the present invention may be appropriately selected in consideration of the balance between water solubility and process passability, but is usually in the range of 10 to 100 μm, preferably in the range of 20 to 80 μm. More preferably, it is in the range of 30-50 μm. If the thickness is less than 10 μm, the strength of the hydraulic transfer base film may be insufficient, resulting in a decrease in process passability. On the other hand, when the thickness exceeds 100 μm, the water-solubility of the hydraulic transfer base film and the hydraulic transfer film is lowered, and it may be difficult to perform the hydraulic transfer at an economical process speed.

  The arithmetic average roughness (Ra) of at least one surface of the base film for hydraulic transfer according to the present invention can easily form a high-definition printed pattern when printing on the surface side. When the resulting hydraulic transfer film is floated on the liquid surface, it is possible to suppress the unevenness of the dissolution rate of the hydraulic transfer film on the liquid surface and to suppress the unevenness in the printed pattern. Is preferably 350 nm or less, and particularly preferably 300 nm or less. As a minimum of the said arithmetic mean roughness (Ra), 100 nm is mentioned, for example. The hydraulic transfer base film having such an arithmetic average roughness (Ra) is obtained by using a film-forming stock solution containing PVA and a secondary alkyl group-containing surfactant as described later. It can be easily manufactured by forming a film. Although this invention is not limited at all, it is thought that this is because the secondary alkyl group-containing surfactant to be used does not easily deposit on the film surface of the hydraulic transfer base film to be formed. .

  Further, for the purpose of improving the slip property of the surface of the hydraulic transfer base film, it is also preferable that the surface of the base film for hydraulic transfer is subjected to a mat treatment. Examples of the mat treatment method include an on-line mat treatment method in which the surface of a mat on a roll or belt is transferred to a film during film formation, and a method in which an emboss treatment is performed after the formed film is once wound on a roll. The surface roughness of the mat-treated surface is preferably 0.5 μm or more, more preferably 1 μm or more in terms of arithmetic average roughness (Ra). Examples of the upper limit of the arithmetic average roughness (Ra) include 10 μm. Further, the maximum height roughness (Rz) is preferably 1 μm or more, and more preferably 3 μm or more. An example of the upper limit of the maximum height roughness (Rz) is 20 μm. As one of the preferable embodiments of the hydraulic transfer base film of the present invention, one surface of the film is a surface subjected to the mat treatment, and the other surface has an arithmetic average roughness (Ra) of 400 nm or less ( A base film for hydraulic transfer having a surface of preferably 350 nm or less, more preferably 300 nm or less) is mentioned.

  In this specification, the arithmetic average roughness (Ra) and the maximum height roughness (Rz) are the individual arithmetic average roughness (Ra) and the individual height measured at any five points on the film surface to be measured, respectively. It can be determined as an average value of the maximum height roughness (Rz). Here, each arithmetic mean roughness (Ra) and each maximum height roughness (Rz) can be measured according to JIS B0601: 2001.

  A general base film for hydraulic transfer may be a long film or a rectangular film, and in the case of a long film, the roll film is continuously rolled. The film can be printed on the surface while being fed out to form a hydraulic transfer film, and the film can be taken out as it is or once after being wound up in a roll, and continuously supplied to the hydraulic transfer. Even in the base film for hydraulic transfer according to the present invention, the shape is a rectangular film having a relatively short length (for example, each side is less than 1 m), even if the shape is a long film. In addition, it may be any, and may be a polygonal shape such as a triangle or a pentagon, or a circular shape, but a long film and a rectangular film are preferable from the viewpoint of handling at the time of hydraulic transfer, and printing or Considering the point that hydraulic transfer can be continuously performed, a long film is preferable.

  The length and width of the long film are not particularly limited, but from the viewpoint of productivity during printing, the length is preferably 1 m or more, more preferably 100 m or more, and 1000 m or more. Is more preferable. Moreover, as an upper limit of length, 10000 m is mentioned, for example. On the other hand, from the viewpoint of improving productivity during printing, the width is preferably 50 cm or more, more preferably 80 cm or more, and further preferably 100 cm or more. The width is preferably 4 m or less, more preferably 3 m or less because production of a hydraulic transfer base film having a uniform thickness is easy.

  According to the base film for hydraulic transfer of the present invention, a film for hydraulic transfer that can sufficiently prevent curling when floating on the liquid surface can be formed. The degree of curling of the hydraulic transfer film can be modeled by evaluating the degree of curling of the hydraulic transfer base film itself. In this specification, the curled area ratio is used as a method for evaluating the degree of curling of the base film for hydraulic transfer. The curled area ratio is the area of the portion of the base film for hydraulic transfer that has not floated on the surface of the water that does not come into contact with the water surface due to curling of the end of the base film for hydraulic transfer after the surface of the surface has been floated It is a ratio and is measured by the method described later. The curl area ratio means that the smaller the value, the more curling is prevented and the transfer efficiency of the hydraulic transfer film is excellent. Specifically, it is preferably 7% or less, more preferably 6% or less, 5% or less is more preferable.

  Although there is no restriction | limiting in particular in the film forming method of the base film for hydraulic transfer of this invention, Since the base film for hydraulic transfer with small surface roughness can be manufactured easily, PVA and a secondary alkyl group containing interface It is preferable to form a film using a film-forming stock solution containing an activator. Specific examples of such a film-forming stock solution include a film-forming stock solution in which PVA and a secondary alkyl group-containing surfactant are dissolved in a liquid medium, PVA, a secondary alkyl group-containing surfactant, and a liquid medium. And a film-forming stock solution in which PVA is melted.

  Examples of the liquid medium used for preparing the membrane forming stock solution include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, glycerin, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, Trimethylolpropane, ethylenediamine, diethylenetriamine and the like can be mentioned, and one or more of these can be used. Among them, water is preferably used from the viewpoint of environmental load and recoverability.

  The volatile fraction of the film-forming stock solution (content ratio of a volatile component such as a liquid medium removed by volatilization or evaporation during film formation) varies depending on the film-forming method, the film-forming conditions, etc. It is preferably 95% by mass, more preferably 55 to 90% by mass, and particularly preferably 60 to 85% by mass. If the volatile content of the membrane-forming stock solution is too low, the viscosity of the membrane-forming stock solution becomes too high, making filtration and defoaming difficult when preparing the membrane-forming stock solution, and producing a base film for hydraulic transfer with few foreign substances and defects Tend to be difficult. On the other hand, if the volatile fraction of the film-forming stock solution is too high, the concentration of the film-forming stock solution becomes too low, and it tends to be difficult to manufacture an industrial base film for hydraulic transfer.

  Examples of the film forming method when forming the base film for hydraulic transfer using the above-described film forming stock solution include a wet film forming method, a gel film forming method, a casting film forming method, and an extrusion film forming method. Can be adopted. A method based on a combination of these can also be employed. Among the film forming methods described above, the casting film forming method or the extrusion film forming method is preferably employed since a film film having a uniform thickness and width and having good physical properties can be obtained.

As a specific film forming method, a T-type slit die, a hopper plate, an I-die, a lip coater die, etc. are used to rotate the film-forming stock solution around the heated roll (or belt) positioned on the most upstream side. 1 which was uniformly discharged or cast on the surface, evaporated and dried from one surface of the film discharged or cast on this roll (or belt), and then disposed on the downstream side. Further industrially preferably adopting a method of further winding on a peripheral surface of one or a plurality of heated heated rolls or passing through a hot air drying device and further winding it with a winding device. Can do. Drying with a heated roll and drying with a hot air dryer may be performed in an appropriate combination.
The base film for hydraulic transfer after film formation may be non-stretched or uniaxially or biaxially stretched for the purpose of improving mechanical properties in accordance with transfer conditions during hydraulic transfer. Also good.

  A hydraulic transfer film can be obtained by printing on the surface of the hydraulic transfer base film of the present invention. There is no restriction | limiting in particular in the said printing method, A printing layer can be formed by employ | adopting a well-known printing system, For example, gravure printing, screen printing, offset printing, a roll coat etc. can be employ | adopted. The printing may be performed directly on the hydraulic transfer base film with printing ink, or once the printing layer is formed on another film, the printing is performed by transferring it to the hydraulic transfer base film. It can also be done. When printing directly onto the base film for hydraulic transfer with printing ink as in the former case, there may be problems such as limitations on the composition of the printing ink, problems with the drying process, and color misregistration problems during multicolor printing. Therefore, it is preferable to perform printing by once forming a printing layer on another film as in the latter and then transferring it to a base film for hydraulic transfer. A conventionally well-known thing can be used as printing ink used for printing.

  The above-described hydraulic transfer film is floated on the surface of a liquid such as water with the printed surface facing upward, and hydraulic transfer is performed by pressing a transfer target such as various molded bodies from above. it can. As a more detailed hydraulic transfer method, for example, the first step of activating the printing layer by floating the hydraulic transfer film on the liquid surface with the printed side up and spraying an ink activator, etc. Second step of pressing the transferred body from above the hydraulic transfer film floating on the liquid surface so that the transferred surface is lowered, and the printing layer of the hydraulic transfer film is the surface of the transferred body A third step of removing the hydraulic transfer base film portion of the hydraulic transfer film after sufficiently adhering to the film, and a fourth step of sufficiently drying the transferred body having the printing layer transferred to the transferred surface. A hydraulic transfer method comprising each step can be mentioned.

  There are no particular restrictions on the type of transfer material, for example, woody substrates such as wood, plywood, and particle board; various plastics; gypsum board; fiber cement boards such as pulp cement boards, slate boards, asbestos cement boards; calcium silicates Plates; Magnesium silicate plates; Glass fiber reinforced cement; Concrete; Plates of metals such as iron, stainless steel, copper, and aluminum; and composites thereof. The transferred body may have a flat surface, a rough surface, or an uneven shape, but may be a transferred object having an uneven solid surface or curved surface. It is preferable that the advantage of hydraulic transfer can be utilized more effectively.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these. In addition, each measuring method of the moisture content of the base film for hydraulic transfer, arithmetic mean roughness (Ra), and curl area rate, and the kind of surfactant used are described below.

Measurement of moisture content of hydraulic transfer base film The moisture content was measured using a Karl Fischer moisture meter.

Measurement of Arithmetic Average Roughness (Ra) of Base Film for Hydraulic Transfer Using a shape measurement laser microscope “VK-X200” manufactured by KEYENCE Corporation. Specifically, five measurement positions are arbitrarily determined on one surface of the base film for hydraulic transfer (the area of each measurement position is 20 mm ² ), and each arithmetic average roughness (Ra ) Was measured, and the average value was calculated as the arithmetic average roughness (Ra) of the base film for hydraulic transfer. The arithmetic average roughness (Ra) was calculated for both surfaces of the hydraulic transfer base film, and when the smaller value was 300 nm or less, “◯” (good), exceeding 300 nm and not exceeding 400 nm. Sometimes “Δ” (slightly good), and when exceeding 400 nm, “x” (bad) was determined.

Measurement of curl area ratio of base film for hydraulic transfer 10 liters of water was put into a container of 420 mm long × 320 mm wide × 160 mm high, adjusted to 30 ° C., and then the liquid pressure produced in the following examples or comparative examples The transfer base film (size: 200 mm × 200 mm) is made so that the surface opposite to the surface in contact with the stainless steel belt (the support on which the film forming stock solution is discharged or cast) is in contact with water. It floated on the water surface in the container. This operation usually causes the end of the hydraulic transfer base film to curl upward with respect to the water surface. The area (Amm ² ) of the portion in contact with the water surface was measured 25 seconds after the start of floating, and the curl area ratio (%) was calculated by the following formula. In addition, said area (Amm < ² >) was measured by carrying out image processing with the computer for the image data obtained by image-capturing a series of operation.

Curled area ratio (%) = [1-A / (200 × 200)] × 100

A curl area ratio of 7% or less was judged as “◯” (good), and a curl area ratio greater than 7% was judged as “x” (bad).

Types of surfactants The following surfactants were used in the following examples or comparative examples.
[Surfactant A]
Polyoxyethylene secondary alkyl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary alcohol having 12 carbon atoms. Number of oxyethylene units = 9. That is, a compound represented by the formula (I), wherein ^one of R ¹ and R ² is a pentyl group, the other is a hexyl group, R ³ is a single bond, f is 0, A compound in which R ⁴ is a 1,2-ethylene group and n is 9 (the total number of carbon atoms in the secondary alkyl group is 12).
[Surfactant B]
Polyoxyethylene secondary alkyl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary alcohol having 12 carbon atoms. Number of oxyethylene units = 7. That is, a compound represented by the formula (I), wherein ^one of R ¹ and R ² is a pentyl group, the other is a hexyl group, R ³ is a single bond, f is 0, A compound in which R ⁴ is a 1,2-ethylene group and n is 7 (the total number of carbon atoms in the secondary alkyl group is 12).
[Surfactant C]
Polyoxyethylene secondary alkyl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary alcohol having 14 carbon atoms. Number of oxyethylene units = 9. That is, a compound represented by the formula (I), wherein ^one of R ¹ and R ² is a hexyl group, the other is a heptyl group, R ³ is a single bond, f is 0, A compound in which R ⁴ is a 1,2-ethylene group and n is 9 (the total number of carbon atoms in the secondary alkyl group is 14).
[Surfactant D]
Polyoxyethylene secondary alkyl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary alcohol having 16 carbon atoms. Number of oxyethylene units = 9. That is, a compound represented by the formula (I), wherein ^one of R ¹ and R ² is a heptyl group, the other is an octyl group, R ³ is a single bond, f is 0, A compound in which R ⁴ is a 1,2-ethylene group and n is 9 (the total number of carbon atoms in the secondary alkyl group portion is 16).
[Surfactant E]
Polyoxyethylene secondary alkyl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary alcohol having 14 carbon atoms. Number of oxyethylene units = 5. That is, a compound represented by the formula (I), wherein ^one of R ¹ and R ² is a hexyl group, the other is a heptyl group, R ³ is a single bond, f is 0, A compound in which R ⁴ is a 1,2-ethylene group and n is 5 (the total number of carbon atoms in the secondary alkyl group is 14).
[Surfactant F]
Polyoxyethylene secondary fatty acid ester. Those having a structure corresponding to a structure in which ethylene oxide is added to a secondary fatty acid having 12 carbon atoms. Number of oxyethylene units = 9. That is, a compound represented by the formula (I), wherein R ¹ and R ² are both pentyl groups, R ³ is a single bond, f is 1, and R ⁴ is a 1,2-ethylene group. And n is 9 (the total number of carbon atoms in the secondary alkyl group is 11).
[Surfactant G]
Polyoxyethylene secondary alkyl ether sodium sulfate. Number of oxyethylene units = 9. _{Formula: CH (C 5 H 11)} (C 6 H 13) -O- (CH 2 CH 2 O) 9 having the structure of _-SO 3 Na.
[Surfactant H]
Polyoxyethylene lauryl ether. Those having a structure corresponding to a structure in which ethylene oxide is added to n-dodecanol. Number of oxyethylene units = 9.
[Surfactant I]
Polyoxyethylene sorbitan monolaurate. Number of oxyethylene units = 9.

[Example 1]
PVA containing 100 parts by mass of PVA (saponified product of vinyl acetate homopolymer) having a saponification degree of 88 mol% and a polymerization degree of 2400, 3 parts by mass of glycerin, 5 parts by mass of corn starch (average particle size 20 μm) and 2 parts by mass of surfactant A An aqueous solution having a concentration of 18% by mass was used as a film forming stock solution, which was cast on a stainless steel belt having a temperature of 95 ° C. and dried for 2 minutes. After drying, the surface opposite to the surface in contact with the belt was heat-treated for 8 seconds with a heat treatment roll at 80 ° C. to obtain a hydraulic transfer base film (water content: 4.0% by mass) having a thickness of 40 μm.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 2]
A base film for hydraulic transfer with a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant B was used in place of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 3]
A base film for hydraulic transfer with a thickness of 40 μm (water content: 4.0% by mass) was prepared in the same manner as in Example 1 except that the amount of surfactant A used was changed from 2 parts by mass to 1 part by mass. Obtained.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 4]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was prepared in the same manner as in Example 1 except that the amount of surfactant A used was changed from 2 parts by mass to 5 parts by mass. Obtained.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 5]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant C was used in place of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 6]
A base film for hydraulic transfer with a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant D was used instead of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 7]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant E was used instead of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Example 8]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant F was used instead of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[ Reference Example 1 ]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0 mass%) was obtained in the same manner as in Example 1 except that the surfactant G was used instead of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Comparative Example 1]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant H was used in place of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Comparative Example 2]
A base film for hydraulic transfer having a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant I was used in place of the surfactant A.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

[Comparative Example 3]
A base film for hydraulic transfer with a thickness of 40 μm (water content: 4.0% by mass) was obtained in the same manner as in Example 1 except that the surfactant A was not used.
About the obtained base film for hydraulic transfer, arithmetic mean roughness (Ra) and curl area ratio were measured according to said method. The results are shown in Table 1.

  In Examples 1 to 9, by forming a film using a film-forming stock solution containing PVA and a secondary alkyl group-containing surfactant, a base film for hydraulic transfer with a small surface roughness can be easily obtained. In addition, since the base film for hydraulic transfer contains a secondary alkyl group-containing surfactant, the curl area ratio is small, and curling when floating on the liquid surface can be sufficiently prevented, so that transfer efficiency can be prevented. It can be seen that the film was excellent in fluid pressure transfer. On the other hand, in Comparative Examples 1 to 3, since the secondary alkyl group-containing surfactant was not used, the surface roughness increased or the curled area ratio increased.

  The hydraulic transfer base film of the present invention can sufficiently prevent curling when it floats on the liquid surface, and can form a hydraulic transfer film with excellent transfer efficiency. It can be suitably used for hydraulic transfer when a printing layer is formed on the surface of the transferred material.

Claims (7)

A base film for hydraulic transfer containing polyvinyl alcohol and a secondary alkyl group-containing surfactant , wherein the secondary alkyl group-containing surfactant is represented by formula (I), and the partial structure of formula (I) A base film for hydraulic transfer, which satisfies 1 ≦ mn ≦ 9, where m is the total number of carbon atoms in the formula (I ′) .

(In formula (I), R ¹ and R ² each represent an alkyl group having 1 to 18 carbon atoms, R ³ represents a single bond or an alkylene group having 1 to 10 carbon atoms, f represents 0 or 1, R ⁴ represents an alkylene group having 1 to ⁴ carbon atoms, and n represents an integer of 1 to 20).

(In formula (I ′), R ¹ , R ² and R ³ have the same meanings as described above.)
  The base film for hydraulic transfer according to claim 1, comprising 0.05 to 4 parts by mass of a secondary alkyl group-containing surfactant with respect to 100 parts by mass of polyvinyl alcohol.   The base film for hydraulic transfer according to claim 1 or 2, wherein the saponification degree of polyvinyl alcohol is 80 to 98 mol%.   The base film for hydraulic transfer according to any one of claims 1 to 3, wherein an arithmetic average roughness (Ra) of at least one surface is 400 nm or less. A method for producing a base film for hydraulic transfer , comprising a step of forming a film using a film-forming stock solution containing polyvinyl alcohol and a secondary alkyl group-containing surfactant , wherein the secondary alkyl group-containing surfactant Of the hydraulic transfer base film satisfying 1 ≦ mn ≦ 9, where m is the total number of carbon atoms in the formula (I ′) which is represented by the formula (I) and is a partial structure of the formula (I) Production method.

(In formula (I), R ¹ and R ² each represent an alkyl group having 1 to 18 carbon atoms, R ³ represents a single bond or an alkylene group having 1 to 10 carbon atoms, f represents 0 or 1, R ⁴ represents an alkylene group having 1 to ⁴ carbon atoms, and n represents an integer of 1 to 20).

(In formula (I ′), R ¹ , R ² and R ³ have the same meanings as described above.)   The film for hydraulic transfer formed by printing on the surface of the base film for hydraulic transfer of any one of Claims 1-4. A hydraulic transfer process comprising: a step of floating the hydraulic transfer film according to claim 6 on a liquid surface with a printed surface facing upward; and a step of pressing a transfer target from above the floated hydraulic transfer film. Method.