Method for manufacturing release film, release film, and laminated film

Abstract

An alkyl pendant polymer-type non-silicone, non-fluorine release agent resin is applied to the surface of a substrate film without using organic solvents, forming a coating and release layer without the coating liquid being repelled from the surface of the substrate film. [Solution] A method for manufacturing a release film comprises, in this order, the steps of obtaining a release film precursor by applying an aqueous dispersion of a non-silicone, non-fluorine release agent resin to the first surface 11a of a base film 11 having a first surface 11a and a second surface 11b, the first surface 11a of the base film 11 having a polyester resin on the first surface 11a, and drying the release film precursor, wherein the aqueous dispersion comprises water, a release agent resin which is a non-silicone, non-fluorine release agent resin and is an alkyl pendant polymer, and a surfactant, the surfactant comprising an acetylene glycol-based nonionic surfactant having an HLB value of 11 or more.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a release film, a release film, and a laminated film. [Background technology]

[0002] Non-silicone release agent resins, such as alkyl pendant polymers, are known as release agent resins used in the release layer of release films. Patent documents 1 and 2 describe a method for forming a release layer containing a release agent resin on the surface of a polyester film, which involves applying a dispersion of the release agent resin to the surface of the polyester film and then drying the coating. Conventionally, release agent resins are applied to the surface of a base film in the form of a coating solution containing a considerable amount of organic solvent (e.g., lower alcohol). In particular, in order to impart solvent resistance to the release layer, it is necessary to further incorporate components such as crosslinking agents and binders that have the effect of fixing the release agent resin to the base film into the coating solution, and from the viewpoint of dissolving these components in the coating solution, dispersions containing organic solvents are preferably used as the coating solution. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2006-22136 [Patent Document 2] Japanese Patent Publication No. 2017-25172 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, when applying a dispersion of release agent resin, it is desirable to avoid using organic solvents from the viewpoint of environmental compatibility and work safety. However, the inventors' studies have revealed that when an alkyl pendant polymer-type non-silicone, non-fluorine release agent resin is applied to the surface of a polyester film in the form of an aqueous dispersion without the use of organic solvents, the coating is repelled from the film surface, and areas where a release layer is not formed on the film surface may occur. This phenomenon was difficult to suppress by hydrophilizing the film surface by corona treatment or the like.

[0005] The present invention provides a method for manufacturing a release film, a release film, and a laminated film, which enable the application of an alkyl pendant polymer-type non-silicone, non-fluorine release agent resin to the surface of a base film without using an organic solvent, while forming a coating film and a release layer without the coating liquid being repelled from the surface of the base film. [Means for solving the problem]

[0006] The present invention includes the following embodiments.

[0007] [1] A method for producing a release film, comprising the steps of obtaining a release film precursor by applying an aqueous dispersion of a non-silicone, non-fluorine release agent resin to the first surface of a base film having a first surface and a second surface, wherein the first surface of the base film contains a polyester resin, and drying the release film precursor, wherein the aqueous dispersion comprises water, the non-silicone, non-fluorine release agent resin which is an alkyl pendant polymer, and a surfactant, and the surfactant comprises an acetylene glycol-based nonionic surfactant having an HLB value of 11 or more. [2] The method for producing a release film according to [1], wherein the dynamic surface tension of a 0.1% by mass aqueous solution of one or more compounds of the surfactant contained in the aqueous dispersion, measured at a temperature of 23°C by the maximum bubble pressure method at bubble frequencies of 1 Hz and 10 Hz, is 30 to 60 mN / m, respectively. [3] The method for producing a release film according to [1] or [2], wherein the dynamic surface tension of a 0.1% by mass aqueous solution of one or more compounds of the surfactant contained in the aqueous dispersion, measured by the maximum bubble pressure method at a temperature of 23°C, is such that γ1 is the value at a bubble frequency of 1 Hz and γ2 is the value at a bubble frequency of 10 Hz, and γ2-γ1 is 1.0 to 7.0 mN / m. [4] The acetylene glycol-based nonionic surfactant is an alkylene oxide adduct of an acetylene glycol compound, and the acetylene glycol compound is of the following general formula (1): HO-C(R 1 )(R 2 )-C≡CC(R 1 )(R 2 )-OH(in general formula (1), R 1 and R 2 Each of the terms independently represents an alkyl group having 1 to 5 carbon atoms. The method for producing a release film according to any one of the terms [1] to [3], wherein the compound is represented by [ ]. [5] The method for producing a release film according to [4], wherein the number average value of the number of added moles of alkylene oxide in the alkylene oxide adduct of the acetylene glycol compound is 5.0 mol or more per mol of the acetylene glycol compound. [6] The method for producing a release film according to any one of [1] to [5], wherein the aqueous dispersion does not contain volatile organic compounds (VOCs) other than unavoidable impurities. [7] A method for producing a release film according to any one of [1] to [6], wherein in the step of obtaining the release film precursor, the aqueous dispersion is applied to the corona-treated first surface. [8] A method for producing a release film according to any one of [1] to [7], wherein the aqueous dispersion comprises water, the release agent resin, and one or more surfactants including the acetylene glycol-based nonionic surfactant. [9] A method for producing a release film according to any one of [1] to [8], wherein in the step of drying the release film precursor, the release film precursor is dried by heating it at a temperature of 100 to 150°C for 30 to 60 seconds.

[10] The method for producing a release film according to any one of [1] to [9], wherein in the step of obtaining the release film precursor, the base film is a biaxially oriented polyester film.

[11] The method for producing a release film according to any one of [1] to

[10] , wherein the content of the acetylene glycol-based nonionic surfactant in the aqueous dispersion is 0.02 to 5.0 parts by mass per 100 parts by mass of the total amount of water and the release agent resin.

[12] The method for producing a release film according to any one of [1] to

[11] , wherein the amount of the release agent resin in the aqueous dispersion is 0.1 to 20 parts by mass per 100 parts by mass of the total amount of water and the release agent resin.

[0008]

[13] A release film comprising a base layer containing a polyester resin on its surface, and a release layer formed on the surface of the base layer, wherein the release layer comprises a non-silicone, non-fluorine release agent resin which is an alkyl pendant polymer, and a surfactant, wherein the surfactant comprises an acetylene glycol-based nonionic surfactant having an HLB value of 11 or more.

[14] The release film according to

[13] , wherein the dynamic surface tension of a 0.1% by mass aqueous solution of one or more compounds of the surfactant contained in the release layer, measured at a temperature of 23°C by the maximum bubble pressure method at bubble frequencies of 1 Hz and 10 Hz, is 30 to 60 mN / m, respectively.

[15] The release film according to

[13] or

[14] , wherein the dynamic surface tension of a 0.1 mass% aqueous solution of one or more compounds of the surfactant contained in the release layer, measured by the maximum bubble pressure method at a temperature of 23°C, is such that γ1 is the value at a bubble frequency of 1 Hz and γ2 is the value at a bubble frequency of 10 Hz, and γ2-γ1 is 1.0 to 7.0 mN / m.

[16] The acetylene glycol-based nonionic surfactant is an alkylene oxide adduct of an acetylene glycol compound, and the acetylene glycol compound is represented by the following general formula (1): HO-C(R 1 )(R 2 )-C≡C-C(R 1 )(R 2 )-OH (in the general formula (1), R 1 and R 2 each independently represent an alkyl group having 1 to 5 carbon atoms.) The release film according to any one of

[13] to

[15] .

[17] The number average value of the added mole number of alkylene oxide in the alkylene oxide adduct of the acetylene glycol compound is 5.0 mol or more per 1 mol of the acetylene glycol compound. The release film according to

[16] .

[18] The release film according to any one of

[13] to

[17] , wherein the release layer does not contain a compound having a solubility in water at 25 ° C of less than 1 g / 100 g of water other than the alkyl pendant polymer.

[19] A laminated film comprising the release film according to any one of

[13] to

[18] , a resin layer, and a resin layer laminated in contact with the release layer of the release film.

Advantages of the Invention

[0009] According to the present invention, an alkyl pendant polymer type non-silicone non-fluorine-based release agent resin can be applied to the surface of a base film without using an organic solvent, and a coating film and a release layer can be formed without the coating liquid being repelled on the surface of the base film.

Brief Description of the Drawings

[0010] [Figure 1] It is a cross-sectional view showing an example of a release film. [Figure 2] It is a cross-sectional view showing an example of a laminated film.

Embodiments for Carrying Out the Invention

[0011] The measurement and evaluation methods described herein shall be performed under atmospheric pressure (1 atm) unless otherwise specified. The present invention will be described below based on preferred embodiments.

[0012] As shown in Figure 1, the release film 10 of this embodiment comprises a base film 11 containing a polyester resin and a release layer 12 formed on the first surface 11a of the base film 11. The release layer 12 contains a non-silicone, non-fluorine release agent resin, which is an alkyl pendant polymer, and an acetylene glycol-based nonionic surfactant with an HLB value of 11 or higher.

[0013] The method for producing the release film 10 includes, in this order, the steps of: applying an aqueous dispersion containing a release agent resin to the first surface 11a of a base film 11 to obtain a release film precursor; and drying the release film precursor. The aqueous dispersion contains water, a release agent resin, and a surfactant. The release agent resin includes an alkyl pendant polymer, a non-silicone, non-fluorine release agent resin. The surfactant includes an acetylene glycol-based nonionic surfactant with an HLB value of 11 or higher.

[0014] By using the above-described aqueous dispersion, coating can be applied to the first surface 11a of the substrate film 11 without using an organic solvent. Furthermore, even though the coating solution is an aqueous dispersion, the coating solution can form a coating film and a release layer 12 without being repelled by the first surface 11a of the substrate film 11. The above-described surfactant is excellent at reducing surface energy under dynamic conditions such as during coating, and also has an antifoaming effect.

[0015] The base film 11 has a first surface 11a and a second surface 11b. Preferably, at least the first surface 11a contains a polyester resin. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, polyarylate, and liquid crystal polymer. Preferably, the base film 11 is a biaxially oriented polyester film. Preferably, the first surface 11a to which the aqueous dispersion is applied is corona treated. The first surface 11a and the second surface 11b are opposite surfaces of each other in the thickness direction of the base film 11.

[0016] In one embodiment, the entire base film 11 may contain a polyester resin. In another embodiment, a resin other than a polyester resin may be laminated on the portion of the base film 11 other than the first surface 11a. Examples of other resins include polyolefin resins such as polyethylene (PE), polypropylene (PP), and polymethylpentene (PMP), cyclic olefin resins, acrylic resins such as polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polystyrene (PS), and polycarbonate (PC). The base film 11 is the base layer of the release film 10.

[0017] Surfactants generally have one or more hydrophilic groups and one or more hydrophobic groups in a single molecule. Adding a surfactant to a mixture of water and oil (e.g., hydrocarbons such as hexane) can form an emulsion. Either an O / W (oil-in-water) emulsion or a W / O (water-in-oil) emulsion may be formed. Whether the formed emulsion is O / W or W / O depends on the balance of hydrophilicity and hydrophobicity of the surfactant. Surfactants also have the effect of lowering the surface tension of water.

[0018] The surfactant contained in the aqueous dispersion or release layer 12 is preferably a compound whose dynamic surface tension, measured by the maximum foam pressure method at a temperature of 23°C for a 0.1% by mass aqueous solution, is within a specific range. Here, the 0.1% by mass aqueous solution of the surfactant consists only of the surfactant and water, and the surfactant concentration relative to the total volume of the aqueous solution is 0.1% by mass.

[0019] In one embodiment, the surfactant contained in the aqueous dispersion or release layer 12 may consist only of an acetylene glycol-based nonionic surfactant (and may not contain any other types of surfactants), and in another embodiment, it may consist of a mixture of an acetylene glycol-based nonionic surfactant and other types of surfactants. When the aqueous dispersion or release layer 12 contains two or more types of surfactants (there may also be cases where this applies, such as a proportional relationship not included in this embodiment), the dynamic surface tension can be measured using a 0.1% by mass aqueous solution containing the two or more (all) applicable surfactants. In this case, it is preferable that the aqueous solution used for measurement does not contain solutes other than surfactants, but it may contain other solutes, such as unintended impurities (unavoidable impurities), to the extent that it does not affect the measurement results. When the aqueous dispersion or release layer 12 contains an acetylene glycol-based nonionic surfactant and other surfactants, a 0.1% by mass aqueous solution containing all surfactants is used to measure the dynamic surface tension.

[0020] In this specification, dynamic surface tension is measured by the maximum bubble pressure method. Dynamic surface tension is measured by the maximum bubble pressure method using the "BP" series of bubble pressure dynamic surface tensile meters manufactured by KRUESS GmbH ("UE" refers to a "U" with an umlaut). (e.g., BP2, BP-D5, BP100, etc.)

[0021] When the surfactant contained in the aqueous dispersion or release layer 12 includes an acetylene glycol-based nonionic surfactant, the specific range of the dynamic surface tension of a 0.1% by mass aqueous solution of the surfactant contained in the aqueous dispersion or release layer 12 at 23°C is preferably such that γ1 is the value of the dynamic surface tension at a bubble frequency of 1 Hz and γ2 is the value of the dynamic surface tension at a bubble frequency of 10 Hz, and both γ1 and γ2 are 60 mN / m or less. Having both γ1 and γ2 at 60 mN / m or less makes it easier to suppress the phenomenon of the coating liquid being repelled from the film surface in the dynamic environment during coating.

[0022] When the surfactant contained in the aqueous dispersion or release layer 12 is a mixture of two or more compounds including an acetylene glycol-based nonionic surfactant (for example, an alkylene oxide adduct of an acetylene glycol compound), it is preferable that the dynamic surface tensions γ1 and γ2 of a 0.1% by mass aqueous solution of the mixture of the two or more compounds, i.e., a 0.1% by mass aqueous solution of all surfactants, are within the above range. The lower limits of γ1 and γ2 are not particularly limited, but in one embodiment, they may each be, for example, 30 mN / m or more. When the aqueous dispersion or release layer 12 contains two or more surfactants, as described above, the dynamic surface tension is measured for a 0.1% by mass aqueous solution of the mixture of all surfactants, and in this embodiment, it is preferable that the dynamic surface tensions γ1 and γ2 are within the above range.

[0023] Furthermore, when the surfactant contained in the aqueous dispersion or release layer 12 includes an acetylene glycol-based nonionic surfactant, it is preferable that the surfactant contained in the aqueous dispersion or release layer 12 is one compound or a mixture of two or more compounds such that the difference γ2-γ1 is 7.0 mN / m or less. When the surfactant contained in the aqueous dispersion or release layer 12 is a mixture of two or more compounds including an acetylene glycol-based nonionic surfactant, it is preferable that the difference γ2-γ1 between the dynamic surface tensions γ1 and γ2 is within the above range for a 0.1% by mass aqueous solution of the mixture of the two or more compounds, i.e., a 0.1% by mass aqueous solution of all surfactants. The lower limit of the difference γ2-γ1 is usually greater than 0 mN / m, and a smaller value is preferable, but in one embodiment it may be, for example, 1.0 mN / m or more. When the aqueous dispersion or release layer 12 contains two or more surfactants, as described above, the dynamic surface tension is measured for a 0.1% by mass aqueous solution of the mixture of all surfactants, and in this embodiment, it is preferable that the difference γ2-γ1 is within the above range.

[0024] Generally, dynamic surface tension is greater than static surface tension, and dynamic surface tension at high bubble frequencies is greater than dynamic surface tension at low bubble frequencies (γ2 > γ1). When the difference γ2 - γ1 is within the above range, the surface free energy does not change much even if the surface deformation rate increases, so a state that was stable when the surface deformation was slow will remain generally stable even when the surface deforms quickly. When the difference γ2 - γ1 is greater than the above upper limit, the surface free energy increases significantly when the surface deformation rate increases, so even if the surface is stable when the deformation is slow, it becomes unstable when the surface deforms quickly. When a coating liquid is applied to a substrate film, it is thought that the surface deformation rate will temporarily be high. When the surface free energy increases significantly at this time, it becomes energetically more advantageous to form droplets than to spread thinly on the surface of the substrate film, so it is thought that coating liquid repellency is likely to occur on the surface of the substrate film. If the difference γ2-γ1 is below the above upper limit, even if the surface deformation rate temporarily increases when applying the coating liquid to the substrate film, the increase in surface free energy is reduced, making it easier to suppress the repulsion of the coating liquid on the film surface.

[0025] Acetylene glycol-based nonionic surfactants are thought to be either dissolved in the aqueous dispersion or to form micelles in the aqueous dispersion. Examples of acetylene glycol-based nonionic surfactants include alkylene oxide adducts of acetylene glycol compounds. Furthermore, it is preferable that the acetylene glycol compound is a compound represented by the following general formula (1). HO-C(R 1 )(R 2 )-C≡CC(R 1 )(R 2 )-OH (1)

[0026] In general formula (1), R 1 and R 2Each of these independently represents an alkyl group having 1 to 5 carbon atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, and isopentyl groups. These alkyl groups may be linear or branched. 1 If they are identical, and the two R 2 Compounds with identical R have a symmetrical structure on both sides of the acetylene bond, resulting in a very stable molecular structure. 1 and R 2 These may be different alkyl groups. For example, R 1 R is a methyl group 2 It may also be an isobutyl group.

[0027] Preferred examples of acetylene glycol compounds represented by general formula (1) include 2,5,8,11-tetramethyl-6-dodecine-5,8-diol, 5,8-dimethyl-6-dodecine-5,8-diol, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 4,7-dimethyl-5-decine-4,7-diol, 2,3,6,7-tetramethyl-4-octin-3,6-diol, 3,6-diethyl-4-octin-3,6-diol, 3,6-dimethyl-4-octin-3,6-diol, 2,5-dimethyl-3-hexyn-2,5-diol, and the like. From the viewpoint of reducing surface tension even under dynamic conditions, alkylene oxide adducts of these acetylene glycol compounds can be preferably used as acetylene glycol-based nonionic surfactants. For example, an ethylene oxide adduct of 2,4,7,9-tetramethyl-5-decine-4,7-diol can be preferably used.

[0028] Examples of alkylene oxides include ethylene oxide (EO) and propylene oxide. From the viewpoint of increasing the HLB value (hydrophilic-lipophilic balance) of the acetylene glycol-based nonionic surfactant, it is preferable that the number average of the number of added moles of alkylene oxide in the alkylene oxide adduct is 5.0 mol or more per mol of acetylene glycol compound. The upper limit of the number of added moles is not particularly limited, but from the viewpoint of availability, economy, and functionality as a surfactant, it may be, for example, 50 mol or less.

[0029] The HLB (hydrophilic-lipophilic balance) value of the acetylene glycol-based nonionic surfactant is 11 or higher, and preferably 13 or higher from the viewpoint of further improving the uniformity of the coating film. If the HLB value of the acetylene glycol-based nonionic surfactant is less than 11, it becomes difficult to suppress the phenomenon of the first surface 11a of the base film 11 repelling the aqueous dispersion. By having the HLB value of the acetylene glycol-based nonionic surfactant be above the above lower limit, it becomes possible to suppress the phenomenon of the first surface 11a of the base film 11 repelling the aqueous dispersion. The upper limit of the HLB value is theoretically 20, but from the viewpoint of functionality as a surfactant, it may be, for example, 18 or lower. The HLB value of the acetylene glycol-based nonionic surfactant can be preferably adjusted, for example, by increasing or decreasing the number of moles of alkylene oxide added in the alkylene oxide adduct of the acetylene glycol compound. Furthermore, if the surfactant contained in the aqueous dispersion or release layer 12 includes an acetylene glycol-based nonionic surfactant and other nonionic surfactants, it is preferable that each nonionic surfactant component has an HLB value within the above range. In one embodiment, the surfactant contained in the aqueous dispersion or release layer 12 may consist of one or more nonionic surfactants.

[0030] In this specification, the HLB value of acetylene glycol-based nonionic surfactants refers to the value calculated by the Griffin method or the organic conceptual diagram method, and the HLB value of a mixture of two or more nonionic surfactants (mixed HLB value) is calculated as a weight average based on the additivity of the HLB values. In this specification, for nonionic surfactants for which the calculation method of HLB value is defined by the Griffin method (Griffin, WC, “Calculation of HLB Values ​​of Non-ionic Surfactants”, The Journal of the Society of Cosmetic Chemists, 1954, 5(4), 249-256), the HLB value is calculated by the Griffin method, and for other nonionic surfactants, the HLB value is calculated by the organic conceptual diagram method. For example, the HLB value of surfactants containing only polyoxyethylene chains as hydrophilic groups, such as ethylene oxide adducts of acetylene glycol, is calculated by the Griffin method using the following formula. HLB = 20 × (total molecular weight of oxyethylene moieties in the molecule) / (total molecular weight of the molecule) …(1)

[0031] The HLB values ​​of other acetylene glycol-based nonionic surfactants are calculated according to the following formula, using the organic conceptual diagram method. HLB = 10 × (Σ inorganic value / Σ organic value) …(2) In the formula, Σinorganic value / Σorganic value is called IOB (Inorganic-Organic Balance), and it is an index proposed by Fujita (Fujita, A., “Prediction of Organic Compounds by a Conceptional Diagram”, Pharmaceutical Bulletin, 1954, 2(2), 163-173, doi:10.1248 / cpb1953.2.163). IOB can be calculated as the ratio of the sums of the "inorganic value" and "organic value" of the atoms and functional groups that make up organic compounds such as surfactants, based on the "inorganic value" and "organic value" set for each atom and functional group. The table of inorganic and organic values, and the above calculation method for HLB using the organic conceptual diagram method, are also described in Horiuchi, T., "Basic Theory of Emulsification", The Journal of the Society of Cosmetic Chemists of Japan, 2010, 44(1), 2-22, doi:10.5107 / sccj.44.2.

[0032] Examples of the content of acetylene glycol-based nonionic surfactant in the aqueous dispersion include 0.02 to 5.0 parts by mass per 100 parts by mass of the total amount of water and non-silicone, non-fluorine-based release agent resin in the aqueous dispersion. For example, the content may be 0.05 to 4.0 parts by mass, or 0.1 to 2.5 parts by mass. If the content is above the lower limit, it is possible to further improve the adhesion of the coating liquid to the first surface 11a of the base film 11. If the content is below the upper limit, it is possible to further improve the uniformity of the coating film.

[0033] Alkyl pendant polymers used as non-silicone, non-fluorine release agent resins are release agent resins that do not contain silicone (organopolysiloxane structure) or fluorine (fluoro group). Alkyl pendant polymers are intrinsically hydrophobic polymers and are dispersed in water. Alkyl pendant polymers have side chains containing alkyl groups. Examples of main chains of alkyl pendant polymers include polyvinyl alcohol, ethylene-vinyl alcohol copolymers, polyethyleneimine, acrylic resins, and polyester resins. The alkyl groups in the side chains may be linear or branched. Examples of the number of carbon atoms in the alkyl groups of the side chains include 8 to 30, 10 to 24, or 12 to 18. The alkyl groups in the side chains may be one type of alkyl group or a combination of two or more alkyl groups.

[0034] The alkyl group in the side chain of the alkyl pendant polymer may be an alkyl group corresponding to a fatty acid such as a natural oil. Examples of alkyl groups corresponding to fatty acids include alkyl groups (-R) obtained by removing a carboxyl group (-COOH) from a monounsaturated fatty acid (R-COOH), and alkyl groups (R-CH2-) obtained by removing a hydroxyl group from an alcohol (R-CH2OH) obtained by reduction of a monounsaturated fatty acid (R-COOH). These operations are conceptual, and it is not necessarily required that the alkyl group be obtained by these chemical operations. For example, alkyl group (-R) may be present in the polymer as part of a fatty acid acyl group (R-CO-). The saturated fatty acid may be a saturated fatty acid obtainable from nature, or a hydrogenated unsaturated fatty acid obtainable from nature. Fatty acids derived from natural oils are usually mixtures containing two or more straight-chain fatty acids with 8 to 24 carbon atoms, and combinations of two or more straight-chain alkyl groups corresponding to this fatty acid mixture provide the oiliness required for the side-chain alkyl group of the alkyl pendant polymer type release agent resin.

[0035] Linking groups such as ester groups (-COO-), amide groups (-CONH-), ether groups (-O-), and urethane groups (-NHCOO-) may be introduced between the main chain and the alkyl group of the side chain of the alkyl pendant polymer, as needed. These linking groups may be formed by the reaction of a polymer having protic functional groups such as hydroxyl groups and amino groups in the side chain with a compound having reactive functional groups such as isocyanate groups and epoxy groups and alkyl groups. Polymers having alkyl groups in the side chain can also be synthesized by copolymerizing monomers having alkyl groups in the side chain.

[0036] The content of the non-silicone, non-fluorine release agent resin in the aqueous dispersion can be, for example, 0.1 to 20 parts by mass per 100 parts by mass of the total amount of water and the non-silicone, non-fluorine release agent resin in the aqueous dispersion. For example, the content may be 0.5 to 15 parts by mass, or 1.0 to 12 parts by mass. If the content is above the lower limit, it becomes possible to further reduce the force required for peeling (peeling force). If the content is below the upper limit, it becomes easier to improve the uniformity of the release layer in the area where the coating film is formed.

[0037] From the viewpoint of environmental compatibility and work safety, it is preferable that the aqueous dispersion is substantially free of volatile organic compounds (VOCs). VOCs are organic compounds that are gaseous when discharged into the atmosphere or dispersed into the atmosphere. That is, in one embodiment, it is preferable that the aqueous dispersion does not contain organic compounds with a boiling point of 50°C or more and less than 260°C at a pressure of 1 atm, except as unintended impurities (unavoidable impurities). In another embodiment, it is preferable that the aqueous dispersion does not contain organic compounds with a boiling point of 30°C or more and less than 260°C at a pressure of 1 atm, except as unintended impurities (unavoidable impurities). Here, "unavoidable impurities" means impurities that are unintentionally mixed into the aqueous dispersion, and examples of such impurities include trace amounts of residual organic solvents that may be contained in commercially available surfactants, and trace amounts of residual organic solvents that may be contained in aqueous dispersions of commercially available alkyl pendant polymers. In one embodiment, the total content of the above VOCs in the aqueous dispersion may be less than 100 ppm by mass, less than 50 ppm by mass, or less than 10 ppm by mass, based on the total volume of the aqueous dispersion, and may even be 0 ppm by mass. In particular, it is preferable that the aqueous dispersion does not contain any VOCs used as organic solvents.

[0038] Examples of aliphatic hydrocarbon VOCs include n-butane, isobutane, butene, butadiene, n-pentane, pentene, methylbutene, isoprene, n-hexane, cyclohexane, methylpentane, methylcyclopentane, dimethylbutane, n-heptane, heptene, methylhexane, methylcyclohexane, dimethylpentane, methylheptane, ethylcyclohexane, nonane, decane, undecane, and bicyclohexyl. Examples of aromatic hydrocarbon VOCs include benzene, toluene, xylene, styrene, ethylbenzene, cumene, mesitylene, naphthalene, and tetrahydronaphthalene. Examples of halogenated VOCs include chloromethane, dichloromethane, chloroform, chloroethane, dichloroethane, trichloroethane, vinyl chloride, dichloroethylene, trichloroethylene, tetrachloroethylene, dichloropropane, allyl chloride, epichlorohydrin, chlorobenzene, o-dichlorobenzene, tetrafluoroethylene, methyl bromide, n-propyl bromide, and others. Examples of alcohol-based VOCs include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, and benzyl alcohol. Examples of ether-based VOCs include diethyl ether, methyl tert-butyl ether, ethylene glycol monomethyl ether (also known as methyl cellosolve), ethylene glycol monoethyl ether (also known as ethyl cellosolve), propylene glycol monoethyl ether, ethylene oxide, propylene oxide, tetrahydrofuran, and dioxane. Examples of aldehyde-based VOCs include formaldehyde and acetaldehyde. Examples of ketone-based VOCs include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and isophorone. Examples of ester-based VOCs include methyl formate, ethyl acetate, vinyl acetate, propyl acetate, butyl acetate, methyl acrylate, methyl methacrylate, cellosolve acetate, and propylene glycol monomethyl ether acetate. Examples of nitrogen-based VOCs include triethylamine, cyclohexylamine, acetonitrile, acrylonitrile, dimethylformamide, methylpyrrolidone, and pyridine.

[0039] The aqueous dispersion may consist of water, a non-silicone, non-fluorine release agent resin, and one or more surfactants including an acetylene glycol-based nonionic surfactant, and may not contain any other components. The surfactant contained in the aqueous dispersion may include other surfactants in addition to the acetylene glycol-based nonionic surfactant, or it may consist solely of an acetylene glycol-based nonionic surfactant. The proportion of the acetylene glycol-based nonionic surfactant to the total amount of surfactant is preferably 50% by mass or more, more preferably 80% by mass or more, and may be 100% by mass.

[0040] In the process of obtaining the release film precursor, the method of applying the aqueous dispersion is not particularly limited, but examples include bar coating, gravure coating, air knife coating, die coating, and blade coating. The amount of release layer adhering per unit area of ​​film after drying of the aqueous dispersion is 0.2 to 1.0 g / m². 2 A range of [specified range] is preferred.

[0041] In the process of drying the release film precursor, it is preferable to heat the aqueous dispersion coating film at a temperature of 100 to 150°C for 30 to 60 seconds to dry it.

[0042] It is preferable that the release layer does not contain any compounds other than the alkyl pendant polymer that have a solubility in water of less than 1 g / 100 g water at 25°C. For example, the solubility may be less than 0.05 g / 100 g water.

[0043] It is preferable that the aqueous dispersion and release layer do not contain a binder and a crosslinking agent. A binder is a substance that can be added in the prior art when coating a release agent resin onto the surface of a film. The binder is not particularly limited, but examples include thermoplastic resins and thermosetting resins. A crosslinking agent is a substance that can be added in the prior art to cure the release agent resin on the surface of a film. The crosslinking agent is not particularly limited, but examples include isocyanate compounds, epoxy compounds, aziridine compounds, and metal chelate compounds. In embodiments in which the aqueous dispersion and release layer do not contain a crosslinking agent and a binder, an aqueous dispersion that does not contain an organic solvent is preferably used as the coating solution.

[0044] The applications of release films are not particularly limited, but include, for example, protection of adhesive surfaces of adhesive tapes and medicated patches, protection of electronic circuit boards, application substrates for adhesives, and substrates when forming resin films by casting.

[0045] Figure 2 is a schematic cross-sectional view illustrating a laminated film 100 according to one embodiment. The laminated film 100 of this embodiment comprises a release film 10 and a resin layer 20 laminated in contact with its release layer 12. The resin layer 20 may be any layer containing resin, and may also contain additives other than resin. The resin layer may be a resin layer used for the above-mentioned applications, such as an adhesive layer, a resin substrate, or a resin film. The resin contained in the resin layer is not particularly limited, but examples include thermoplastic resins, thermosetting resins, and photocurable resins. The resin layer may be a layer containing two or more resins in a mixed state, a layer containing two or more resins in a dispersed state, or a layer containing two or more resins in a laminated state. [Examples]

[0046] The present invention will be specifically described below with reference to examples.

[0047] A coating solution with the composition shown in Tables 1-2 was prepared and applied to the corona-treated surface of a polyester resin film (Toyobo Co., Ltd., E5110, 38 μm thick) using a bar coater (P0.1H17S, wire bar count: 3.8). An oven (ETAC Co., Ltd., HISPEC HT220S, exhaust air volume: 20 m³) was then used. 3 It was placed in ( / h) and dried at 130°C for 1 minute. In the table, the values ​​(parts by mass) for the release agent resin, solvent, and surfactant in the coating solution are based on the total of the release agent resin and solvent being 100 (parts by mass). The solid content (%) of each component is based on mass. Furthermore, the meaning of the abbreviations for the components used in the manufacture of the coating solution is as follows.

[0048] • Alkyl pendant polymer T-738: Manufactured by Chukyo Oil & Fat Co., Ltd., Rezem T-738 U-587: Manufactured by Chukyo Oil & Fat Co., Ltd., Rezem U-587 K-256: Manufactured by Chukyo Oils, Rezem K-256 WK-E1L: Manufactured by Wako Co., Ltd., WK-E1L

[0049] • Organic solvents IPA: Isopropyl alcohol

[0050] • Acetylene glycol-based nonionic surfactant E1004: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) E1004 (HLB=7~9, γ1=35mN / m, γ2=39mN / m, EO number average 4mol) E1006: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) E1006 (HLB=11~12, γ1=37mN / m, γ2=40mN / m, EO number average 6mol) E1010: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) E1010 (HLB=13~14, γ1=39mN / m, γ2=43mN / m, EO number average 10mol) E1020: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) E1020 (HLB=15~16, γ1=51mN / m, γ2=54mN / m, average EO number 20mol) E1030W: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) E1030W (HLB=16~17, γ1=53mN / m, γ2=56mN / m, average EO number 30mol) EXP4123: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) EXP.4123 (HLB=10~13, γ1=39mN / m, γ2=54mN / m) EXP4200: Manufactured by Nisshin Chemical Industry Co., Ltd., Olphine (registered trademark) EXP.4200 (HLB=10~13, γ1=32mN / m, γ2=42mN / m)

[0051] • Polyoxyalkylene ether-based nonionic surfactants PAE-1: Polyoxyethylene (20) oleyl ether with HLB=12.5 PAE-2: Polyoxyethylene (20) polyoxypropylene (8) cetyl with HLB=17.0

[0052] Tables 1 and 2 show the results of evaluating the adhesion amount, coating unevenness, and repellency of the obtained coating films. Coating unevenness was evaluated by visually observing the degree to which iridescent interference fringes were visible on the surface of the coating film. Repellency was evaluated by visually observing the presence or absence of areas on the surface of the substrate film where the paint was not applied at all.

[0053] [Table 1]

[0054] [Table 2]

[0055] <Evaluation (1): Measurement of peeling force> In the peel test, polyester adhesive tape No. 31B (manufactured by Nitto Denko, hereinafter referred to as "31B tape") was bonded to the release layer of the release film by passing a 2kg pressure roller back and forth once. The peel force (gf / 25mm) was then measured using a 180° peel test in accordance with JIS Z0237. 1 gf / 25mm corresponds to 9.80665 mN / 25mm. For room temperature peeling, the 31B tape was bonded to the release layer and left to stand at room temperature for 3 hours before the peel test was performed. For heated peeling, the 31B tape was bonded to the release layer and left to stand under conditions of 70°C and 2kPa for 20 hours for aging before the peel test was performed.

[0056] <Evaluation (2): Measurement of residual adhesion rate> After the peel test in evaluation (1), the 31B tape peeled from the release layer of the release film was attached to the substrate SUS304BA, and a 2kg pressure roller was passed back and forth once to adhere it to the surface of the substrate SUS304BA. Then, a 180° peel test was performed in accordance with JIS Z0237, and the adhesive strength A1 after peeling from the release layer was measured. The residual adhesive strength A0, measured by attaching a new 31B tape to the same substrate SUS304BA using the same method, was used as the reference, and the residual adhesive strength was calculated as a percentage A1 / A0 × 100 (%).

[0057] [Table 3]

[0058] Table 3 shows the results of the release test and evaluation of residual adhesive amount of the obtained release layer. In each example, an alkyl pendant polymer type non-silicone non-fluorine release agent resin could be coated onto the surface of the substrate film without using an organic solvent. Moreover, the coating liquid was able to form a coating film and a release layer without being repelled from the surface of the substrate film. [Explanation of Symbols]

[0059] 10...Release film, 11...Base film, 11a...First surface, 11b...Second surface, 12...Release layer, 20...Resin layer, 100...Laminated film.

Claims

1. A base film having a first surface and a second surface, wherein the first surface contains a polyester resin, and a step of obtaining a release film precursor by applying an aqueous dispersion of a non-silicone, non-fluorine release agent resin to the first surface of the base film, The process includes, in this order, drying the release film precursor, The aforementioned aqueous dispersion Water and, The aforementioned non-silicone, non-fluorine release agent resin is a release agent resin that is an alkyl pendant polymer, Surfactants and Includes, A method for producing a release film, characterized in that the surfactant includes an acetylene glycol-based nonionic surfactant having an HLB value of 11 or higher.

2. A method for producing a release film according to claim 1, wherein the dynamic surface tension of a 0.1% by mass aqueous solution of one or more surfactant compounds contained in the aqueous dispersion is 30 to 60 mN / m, measured at a temperature of 23°C by the maximum bubble pressure method at bubble frequencies of 1 Hz and 10 Hz.

3. The dynamic surface tension of a 0.1% by mass aqueous solution of one or more surfactant compounds contained in the aqueous dispersion, measured at a temperature of 23°C by the maximum bubble pressure method, is given by γ at a bubble frequency of 1 Hz. １ The value at a bubble frequency of 10 Hz is γ ２ as, γ ２ -γ １ A method for manufacturing a release film according to claim 1 or 2, wherein the ratio is 1.0 to 7.0 mN / m.

4. The acetylene glycol-based nonionic surfactant is an alkylene oxide adduct of an acetylene glycol compound. The acetylene glycol compound is defined by the following general formula (1) HO-C(R １ )(R ２ )-C≡C-C(R １ )(R ２ )-OH (1) (In the general formula (1), R １ and R ２ each independently represents an alkyl group having 1 to 5 carbon atoms.) The method for producing a release film according to claim 1 or 2, which is a compound represented by the above.

5. The method for producing a release film according to claim 4, wherein the number average value of the number of added moles of alkylene oxide in the alkylene oxide adduct of the acetylene glycol compound is 5.0 mol or more per mol of the acetylene glycol compound.

6. The method for producing a release film according to claim 1 or 2, wherein the aqueous dispersion does not contain volatile organic compounds (VOCs) other than unavoidable impurities.

7. A method for producing a release film according to claim 1 or 2, wherein in the step of obtaining the release film precursor, the aqueous dispersion is applied to the corona-treated first surface.

8. The aforementioned aqueous dispersion Water and, The aforementioned release agent resin, One or more surfactants including the aforementioned acetylene glycol-based nonionic surfactant A method for producing a release film according to claim 1 or 2, comprising the above.

9. A method for producing a release film according to claim 1 or 2, wherein in the step of drying the release film precursor, the release film precursor is dried by heating it at a temperature of 100 to 150°C for 30 to 60 seconds.

10. The method for producing a release film according to claim 1 or 2, wherein in the step of obtaining the release film precursor, the base film is a biaxially oriented polyester film.

11. The method for producing a release film according to claim 1 or 2, wherein the content of the acetylene glycol-based nonionic surfactant in the aqueous dispersion is 0.02 to 5.0 parts by mass per 100 parts by mass of the total amount of water and the release agent resin.

12. The method for producing a release film according to claim 1 or 2, wherein the content of the release agent resin in the aqueous dispersion is 0.1 to 20 parts by mass per 100 parts by mass of the total amount of water and the release agent resin.

13. A base layer containing a polyester resin on its surface, A release layer formed on the surface of the substrate layer, Equipped with, The aforementioned release layer Alkyl pendant polymer, non-silicone non-fluorine release agent resin, Surfactants and Includes, A release film characterized in that the surfactant comprises an acetylene glycol-based nonionic surfactant having an HLB value of 11 or higher.

14. The release film according to claim 13, wherein the dynamic surface tension of a 0.1% by mass aqueous solution of one or more surfactant compounds contained in the release layer, measured at a temperature of 23°C by the maximum bubble pressure method at bubble frequencies of 1 Hz and 10 Hz, is 30 to 60 mN / m, respectively.

15. The dynamic surface tension of a 0.1% by mass aqueous solution of one or more surfactant compounds contained in the release layer, measured at a temperature of 23°C by the maximum bubble pressure method, is given by γ at a bubble frequency of 1 Hz. １ The value at a bubble frequency of 10 Hz is γ ２ as, γ ２ -γ １ The release film according to claim 13 or 14, wherein the density is 1.0 to 7.0 mN / m.

16. The acetylene glycol-based nonionic surfactant is an alkylene oxide adduct of an acetylene glycol compound. The acetylene glycol compound is defined by the following general formula (1) HO-C(R １ )(R ２ )-C≡C-C(R １ )(R ２ )-OH (1) (In general formula (1), R １ and R ２ The release film according to claim 13 or 14, wherein each of the characters independently represents an alkyl group having 1 to 5 carbon atoms.

17. The release film according to claim 16, wherein the number average value of the number of added moles of alkylene oxide in the alkylene oxide adduct of the acetylene glycol compound is 5.0 mol or more per mol of the acetylene glycol compound.

18. The release film according to claim 13 or 14, wherein the release layer does not contain any compounds other than the alkyl pendant polymer that have a solubility in water of less than 1 g / 100 g water at 25°C.

19. The release film according to claim 13 or 14, A resin layer comprising a resin, which is laminated in contact with the release layer of the release film, A laminated film equipped with the following features.

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