JPWO2018198720A1 - the film - Google Patents

Abstract

A film having a surface roughness SRa of at least one side of 100 nm or more and 3000 nm or less, a variation of the surface roughness SRa in a 20 cm × 14 cm range of 10% or less, and a parallel line transmittance ST320 of 320 nm of 30% or more. When used as a transfer film, it is possible to uniformly transfer a low-gloss appearance, and even when a photocurable resin is used as the material to be transferred, it is possible to transfer the low-gloss appearance and fix the shape, Provided is a film having good processing process suitability in which problems such as particle dropout and slippage are less likely to occur. [Selection diagram] None

Description

The present invention relates to a film.

  2. Description of the Related Art In recent years, high-precision and high-density printed wiring boards have been developed due to the integration of circuits accompanying the expansion of smartphones and tablets. In the manufacturing process of a printed wiring board, a circuit is provided on the surface of an insulating base material (polyimide resin, polyphenylene sulfide resin, etc.), and a coverlay which is a heat-resistant resin film having an adhesive layer for the purpose of insulation and circuit protection. And press molding is performed via a release film. In this case, the release film is required to have releasability from a printed wiring board material or a press plate, shape followability, uniform moldability, transferability of matte appearance, and the like. In addition, there is an increasing need for a mat-like film as a base material to transfer a functional layer such as an insulating layer, a hard coat layer, and an electromagnetic wave shielding layer onto a circuit board surface by a hot press.

  Conventionally, as a mat-like film, processed products such as a sand mat film, a chemical mat film and a coating mat film are generally used. However, the processed product has a cost increase due to an increase in the number of steps and has a problem in quality, and improvement has been desired. Regarding these problems, superiority is recognized in a particle kneaded film manufactured by a method of extruding a large amount of particles together with a resin, but the particle kneaded film achieves a high level of low gloss appearance recently required. Is difficult. Further, since the light-transmitting film has a low light transmittance, when a photocurable resin is applied as a functional layer to be laminated, curing is insufficient, and there is a problem that the applicable range is limited.

  As a mat-like transfer substrate conventionally used, a polyester film containing inorganic particles or organic particles at a high concentration has been proposed (for example, Patent Documents 1 and 2). Further, as a film having a high matte appearance, a film having a surface provided with a resin layer by coating has been proposed (for example, Patent Document 3).

JP-A-2006-97522 JP 2014-24341 A JP 2005-24942 A

The films described in Patent Literatures 1 and 2 are not designed to ensure transparency, and the variation in surface roughness cannot be sufficiently reduced. Therefore, when a photocurable resin is applied as a functional layer. In addition, there is a problem that a low gloss surface cannot be transferred uniformly.

  In addition, the film described in Patent Document 3 has a very low gloss and excellent appearance, but when used in a transfer application, defects such as deterioration of the quality of the transfer surface and adhesion of particles due to the dropout of coarse particles. May have occurred. Also, when the release layer is provided by coating, the laminated release layer fills the concave portions on the film surface and increases the glossiness, so that the glossiness after transfer does not decrease and the desired matte appearance can be obtained. There were no challenges.

  An object of the present invention is to solve the above-mentioned problems of the conventional technology. That is, when used as a transfer film, a low gloss appearance can be transferred uniformly, and even when a photocurable resin is used as a material to be transferred, transfer and shape fixing of a low gloss appearance are possible. Another object of the present invention is to provide a film having good processing step aptitude, which is unlikely to cause a problem such as particle dropout or slippage.

In order to solve such a problem, the present invention has the following configuration.
(1) The surface roughness SRa of at least one side is 100 nm or more and 3000 nm or less, the variation of the surface roughness SRa in a range of 20 cm × 14 cm is 10% or less, and the parallel line transmittance ST320 of 320 nm is 30% or more. Some films.
(2) The film according to (1), wherein the maximum peak height (SRp) and the maximum valley depth (SRv) of the surface having the surface roughness SRa of 100 nm or more and 3000 nm or less satisfy the following formula (II).

1 ≦ SRp / SRv ≦ 3 (II)
(3) The film according to (1) or (2), wherein the center area ratio (SSr) of the surface having the surface roughness SRa of 100 nm or more and 3000 nm or less satisfies the following formula (III).

30 ≦ SSr ≦ 60 (III)
(4) The film according to any one of (1) to (3), wherein a change in thickness before and after the heat treatment at 100 ° C. for 10 minutes is 0.1% or more and 10% or less.
(5) A laminated film having a base material layer and a layer having a high concentration of particles (layer A), wherein particles having an average particle diameter of 1 μm or more and 10 μm or less are added to the A layer, The film according to any one of (1) to (4), which contains at least 40% by mass and not more than 40% by mass.
(6) The film according to any one of (1) to (5), wherein the content of ST320 is 60% or more.
(7) The film according to any one of (1) to (6), wherein a variation of the ST320 is 0.1% or more and 10% or less in a range of 20 cm × 14 cm of the film.
(8) The film according to any one of (1) to (7), wherein the film haze is 70% or less.
(9) The film according to any one of (1) to (8), wherein the surface having a surface roughness SRa of 100 nm or more and 3000 nm or less has a surface free energy of 44 mN / m or less.
(10) The film according to any one of (1) to (9), which comprises a polyester as a main component.
(11) The film according to any one of (1) to (10), which is used for transfer applications.
(12) A laminated film having a low gloss layer having a glossiness of 30 or less on at least one surface of the base material layer, wherein the surface roughness SRa of the low gloss layer surface is 100 nm or more and 3000 nm or less, and 20 cm of the film. A laminated film in which the variation of the surface roughness SRa in a range of × 14 cm is 10% or less and the parallel line transmittance ST320 at 320 nm is 30% or more.

ADVANTAGE OF THE INVENTION According to this invention, when used as a transfer film, the film excellent in the transferability of low gloss appearance and process compatibility can be provided. The film can be suitably used as a transfer film having excellent matt appearance transferability in a circuit forming step.

  As one embodiment of the film of the present invention, at least one surface has a surface roughness SRa of 100 nm or more and 3000 nm or less, and a variation of the surface roughness SRa in a 20 cm × 14 cm range is 10% or less, and a parallel line transmittance of 320 nm. A film having ST320 of 30% or more is exemplified.

  The resin used in the film of the present invention is not particularly limited.For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyester such as polyethylene naphthalate, polyarylate, polyethylene, polypropylene, polyamide, polyimide, polymethylpentene, polychlorinated chloride Vinyl, polystyrene, polymethyl methacrylate, polycarbonate, polyetheretherketone, polysulfone, polyethersulfone, fluororesin, polyetherimide, polyphenylenesulfide, polyurethane, and cyclic olefin resin can be used. Above all, it is preferable to use polyester as a main component from the viewpoints of film handling properties, dimensional stability, and economical efficiency during production. In the present invention, the expression "mainly composed of polyester" means that 50% by mass or more of the resin constituting the film is polyester. When the film of the present invention is a laminated film composed of a substrate layer and a layer containing a high concentration of particles, it is preferable that both the substrate layer and the layer containing a high concentration of particles contain polyester as a main component. In the present invention, the polyester is a generic term for polymers having a main bond in the main chain as an ester bond, and can be usually obtained by a polycondensation reaction between a dicarboxylic acid component and a glycol component.

  Examples of the dicarboxylic acid component used here include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfondicarboxylic acid, diphenoxyethanedicarboxylic acid, and 5-sodiumsulfonedicarboxylic acid. Aliphatic dicarboxylic acids such as aromatic dicarboxylic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, and fumaric acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; and paraoxybenzoic acid And other components such as oxycarboxylic acid. As the dicarboxylic acid ester derivative component, esterified products of the above dicarboxylic acid compounds, for example, dimethyl terephthalate, diethyl terephthalate, 2-hydroxyethyl methyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, adipic acid Examples of each component include dimethyl, diethyl maleate, and dimethyl dimer. In the polyester resin constituting the resin film of the present invention, the proportion of terephthalic acid and / or naphthalenedicarboxylic acid in all dicarboxylic acid components is preferably at least 95 mol%, more preferably at least 98 mol%. It is preferable from the viewpoint of productivity and productivity.

  As the glycol component, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane Diols, aliphatic dihydroxy compounds such as 2,2-dimethyl-1,3-propanediol, polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, 1,4-cyclohexanedimethanol, spiro glycol And other components such as an alicyclic dihydroxy compound such as bisphenol A and bisphenol S. Among them, ethylene glycol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, and 1,4-cyclohexanedimethanol are preferably used in terms of moldability and handleability. In the polyester resin constituting the resin film of the present invention, the proportion of ethylene glycol in all the diol components is preferably at least 65 mol% from the viewpoint of heat resistance and productivity. Two or more of these dicarboxylic acid components and glycol components may be used in combination.

  The film of the present invention is required to have a surface roughness SRa of at least one side of 100 nm or more and 3000 nm or less from the viewpoint of matt appearance transferability. If the surface roughness SRa is less than 100 nm, it is difficult to obtain a sufficient matte transferability, and if the surface roughness SRa is made larger than 3000 nm, the strength of the film is reduced. From the viewpoint of matte transferability and film strength, the surface roughness SRa of at least one side is more preferably 200 nm or more and 2000 nm or more, and most preferably 300 nm or more and 2000 nm or less.

  In the present invention, a method for reducing the surface roughness SRa of at least one surface to 100 nm or 3000 nm or less is not particularly limited. For example, a method in which particles are contained in a film at a high concentration, a method in which a shape is transferred to a film surface such as embossing, and the like are exemplified. When the surface roughness SRa of at least one surface is in the above range by a method of incorporating particles in a film at a high concentration, from the viewpoint of achieving both film strength and surface roughness, a substrate layer and a layer containing a high concentration of particles ( It is preferable that the particles to be contained in the layer A have a mean particle size of 1 μm or more and 10 μm or less, and the content is 1% by mass or more and 40% by mass with the entire A layer being 100% by mass. % Is preferable. The content of the particles to be contained in the layer A is more preferably from 3% by mass to 35% by mass, and most preferably from 5% by mass to 30% by mass. The particles contained in the layer A preferably have an average particle diameter of 2 μm or more and 10 μm or less, more preferably 3 μm or more and 9 μm or less, and most preferably 4 μm or more and 8 μm or less. In the present invention, the average particle diameter refers to a number average diameter D represented by D = ΣDi / N (Di: equivalent circle diameter of particles, N: number of particles).

  Either inorganic particles or organic particles can be used as the particles used for the high-concentration particles (A layer) of the present invention. It is also possible to use inorganic particles and organic particles in combination.

  Here, the inorganic particles and organic particles used are not particularly limited. For example, as inorganic particles, silica, aluminum silicate, alumina silicate, calcium carbonate, calcium phosphate, aluminum oxide, mica, clay, talc and the like can be used. As the organic particles, particles containing styrene, silicone, acrylic acids, methacrylic acids, polyesters, divinyl compounds, and the like as constituent components can be used. Among the inorganic particles, wet and dry silica, colloidal silica, aluminum silicate and the like are preferably used. Among the organic particles, particles containing styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene, or the like as constituent components are preferably used. From the viewpoint of mat appearance and economy, silica, aluminum silicate and alumina silicate are particularly preferably used. These particles may be used in combination of two or more.

  In addition, the film of the present invention needs to have a surface roughness SRa having a surface roughness SRa of 100 nm or more and 3000 nm or less having a surface roughness SRa variation of 10% or less in a range of 20 cm × 14 cm. The variation of the surface roughness SRa in the present invention is as follows. For a sample obtained by cutting a film at an arbitrary position into a size of 20 cm in length × 14 cm in width, the film is divided into five equal parts in the length direction and four equal parts in the width direction. It is calculated from the surface roughness SRa of 20 samples cut into a size of 4.0 cm × 3.5 cm in width by a method described later. If the variation in the surface roughness SRa is more than 10%, the matte transferability varies, resulting in a poor product appearance. In light of the appearance of the matte-finished product, the variation in the surface roughness SRa is more preferably equal to or less than 8%, and most preferably equal to or less than 6%. The present inventors have conducted intensive studies and found that, when the film of the present invention is used as a transfer film, it is better to have a certain degree of variation in the surface roughness SRa to have better peelability. At this time, it is not clear by what mechanism this phenomenon occurs, but if there is some variation in the surface roughness SRa, a large number of starting points for causing peeling are formed, It is estimated that the releasability will be good. Therefore, from the viewpoint of the releasability, the variation in the surface roughness SRa is preferably 0.1% or more, more preferably 0.5% or more, and still more preferably 1% or more.

In the present invention, there is no particular limitation on the method of setting the variation of the surface roughness SRa in the range of 20 cm × 14 cm of the surface having the surface roughness SRa of 100 nm or more and 3000 nm or less to the above range. And a layered film having a layer having a high concentration of particles (layer A), wherein the layer thickness TA (μm) of the layer A and the average particle diameter DA (μm) of the particles contained in the layer A satisfy the following formula (I). Is preferably used.
0.8 ≦ DA / TA ≦ 10.0 (I)
By satisfying the formula (I), the surface roughness SRa can be more uniformly controlled on the surface to some extent, and the variation in the surface roughness SRa can be easily controlled within the above range. From the viewpoint of the variation of the surface roughness SRa and the suppression of particle dropping, it is more preferable to satisfy the formula (I ′), more preferably the formula (I ″), and most preferably the formula (I ′ ″).
1.1 ≦ DA / TA ≦ 10.0 (I ′)
1.2 ≦ DA / TA ≦ 8.0 (I ″)
1.3 ≦ DA / TA ≦ 6.0 (I ′ ″).

  When the film of the present invention is a laminated film having a substrate layer and a layer containing a high concentration of particles (layer A), the layer A may be disposed on only one surface of the substrate layer, or may be disposed on both surfaces. It does not matter.

  When the film of the present invention is used for transfer applications, a functional layer (the surface roughness SRa of the film of the present invention is 100 nm or more and 3000 nm or less) on the film surface having a surface roughness SRa of 100 nm or more and 3000 nm or less. A transfer material layer for transferring the shape of a certain film surface is provided. A photocurable resin is suitably used as the functional layer. In order to sufficiently secure the curability of the functional layer made of a photocurable resin, the film of the present invention needs to have a parallel line transmittance ST320 of 320 nm of 30% or more. If ST320 is less than 30%, the curability of the photocurable resin will be insufficient, and the characteristics of transferring the mat appearance will be reduced. ST320 is more preferably 45% or more, and most preferably 60% or more. In light of handleability of the film, ST320 is preferably equal to or less than 95%. In general, the transmittance includes (i) transmittance in consideration of reflection and scattering (total light transmittance in which transmitted light is collected and measured by an integrating sphere), and (ii) transmission in which reflection and scattering are not considered. (Parallel ray transmittance, which measures transmittance with parallel rays). In order to sufficiently secure the curability of the functional layer made of a photocurable resin, it is necessary to increase the parallel line transmittance (ii).

  Further, in the film of the present invention, it is preferable that the variation of ST320 is 10% or less in the range of the film of 20 cm × 14 cm in order to suppress the variation of the matte transferability. By setting the variation in ST320 to 10% or less, the curability of the resin when the photocurable resin is applied becomes uniform, and the variation in the matte transferability can be suppressed. In the same manner as in the evaluation of the variation of the surface roughness SRa described above, the variation of ST320 is obtained by dividing the film into a size of 20 cm in length × 14 cm in width at an arbitrary position by dividing the film into five equal parts in the length direction and five parts in the width direction. Then, the sample is cut into a size of 4.0 cm in length × 3.5 cm in width, and is calculated from the parallel line transmittance ST320 of each sample at 320 nm. The variation of ST320 in the range of the film of 20 cm × 14 cm is preferably 8% or less, and most preferably 6% or less. On the other hand, the present inventors have conducted intensive studies and found that, when the film of the present invention is used as a transfer film, a film having a certain variation of ST320 or more has excellent peelability. At this time, it is not clear what mechanism causes this phenomenon, but if there is some variation in ST320, the part where curing proceeds and the curing in the functional layer made of a photocurable resin are A portion that does not easily advance is generated, and a portion having high hardness and a portion having low hardness are formed. As a result, it is presumed that the high hardness portion present near the low hardness portion in the functional layer made of the photocurable resin serves as a starting point for causing peeling, and the peelability is improved. Therefore, from the viewpoint of the releasability, the variation of ST320 is preferably 0.5% or more, more preferably 1% or more.

  Further, the film of the present invention preferably has a film haze of 70% or less. It is preferable that the film haze is 70% or less, because the defect inspection property is greatly improved in the structure of the laminate laminated on the material to be transferred.

  In the present invention, as a method of setting the parallel line transmittance ST320 of 320 nm to 30% or more, a laminated film having a base material layer and a layer containing a high concentration of particles (layer A) is used. Is disposed only on one side of the base material layer, and the particle concentration in the base material layer is less than 1% by mass based on the whole base material layer. The particle concentration in the substrate layer is preferably less than 0.5% by mass based on the entire substrate layer. Further, it is preferable to reduce voids around the particles in the layer (A layer) having a high concentration of particles. For example, when both the base material layer and the layer with a high concentration of particles (layer A) are made of polyester and a biaxially stretched polyester film is used, the generation of voids during the later-described stretching of the layer with a high concentration of particles (layer A) is suppressed. For this purpose, a method of increasing the stretchability of the layer having a high concentration of particles (layer A), a method of reducing the voids by performing a high-temperature treatment in a heat treatment step after the stretching described below, and the like are preferably used. The layer containing a high concentration of particles (layer A) contains a copolymerized polyethylene terephthalate resin, a polypropylene terephthalate resin and / or a copolymer thereof, a polybutylene terephthalate resin and / or a copolymer thereof in order to enhance stretchability. Is preferred.

  In the present invention, the method of controlling the variation of ST320 in the range of the film of 20 cm × 14 cm includes adjusting the stretching conditions in the film stretching step. For example, when the film of the present invention is a biaxially stretched polyester film, it is preferred that at least one of the longitudinal stretching and the width stretching is performed in two or more stages. Even in the case of simultaneous biaxial stretching in the longitudinal direction and width direction, it is preferable to perform two or more stages of stretching. In the present invention, the step stretching in two or more steps means that two or more stretching sections are provided and different stretching conditions are adopted in the two sections. It is presumed that by performing two or more stages of stretching, the strain in the vicinity of the particles is reduced, so that stretching unevenness is suppressed, and the variation of ST320 can be controlled to a preferable range. Further, setting the stretching speed to a suitable range described later is also a preferred method. It is preferable that the stretching section be at least 2 sections and at most 3 sections.

  Further, in the present invention, in order to reduce the film haze to 70% or less, a method of controlling the amount of particles contained in the film may be mentioned. When the film of the present invention is a laminated film having a base layer and a layer having a high concentration of particles (layer A), the content of particles in the base layer is less than 3% by mass based on the entire base layer. Is preferred.

The film of the present invention has a maximum peak height (SRp) and a maximum valley depth (SRv) of a surface having a surface roughness SRa of 100 nm or more and 3000 nm or less from the viewpoint of matte transferability and film peelability after transfer. It is preferable to satisfy the following formula (II).
1 ≦ SRp / SRv ≦ 3 (II)
When the maximum peak height (SRp) and the maximum valley depth (SRv) of the surface satisfy the formula (II), transfer peeling from the functional layer while having a peak shape sufficient to transfer a matt tone is achieved. Satisfactorily can be controlled. The maximum peak height (SRp) and the maximum valley depth (SRv) of the surface more preferably satisfy the formula (II) ′, and most preferably satisfy the formula (II) ″.
1.1 ≦ SRp / SRv ≦ 2.9 (II) ′
1.2 ≦ SRp / SRv ≦ 2.8 (II) ''
The method by which the maximum peak height (SRp) and the maximum valley depth (SRv) of the surface satisfy Expression (II) is not particularly limited. For example, when the film of the present invention is a laminated film having a base layer and a layer containing a high concentration of particles (layer A), the film surface is reduced by a method of reducing the particle diameter of the particles contained in the layer A and increasing the particle concentration. Is preferably used. It is preferable that the average particle diameter of the particles contained in the A layer is less than 2.5 μm, and the content is 3% by mass or more and 40% by mass or less, with the content of the entire A layer being 100% by mass. The average particle diameter of the particles contained in the layer A is more preferably less than 2.3 μm. Further, the particle content of the A layer is more preferably 5% by mass or more and 30% by mass or less.

  Further, in the film of the present invention, the center area ratio (SSr) of the surface having a surface roughness SRa of 100 nm or more and 3000 nm or less satisfies the following formula (III) from the viewpoint of improving the transfer releasability from the functional layer. Is preferred.

30 ≦ SSr ≦ 60 (III)
The center area ratio (SSr) is obtained by a measuring method described later, and is an index indicating a ratio occupying the protrusion reference area on the center plane. When the value is large, it indicates that the projections of the projections present on the film surface have a gentle shape, and when the value is small, it indicates that the projections existing on the film surface have a rugged shape. When the center area ratio (SSr) of the surface satisfies the formula (III), it is possible to satisfactorily control the transfer releasability from the functional layer while transferring the surface unevenness in a matte tone. The surface center area ratio (SSr) more preferably satisfies the formula (III) ′, and most preferably satisfies the formula (III) ″.

30 ≦ SSr ≦ 55 (III) ′
35 ≦ SSr ≦ 55 (III) ''
The method for making the center area ratio (SSr) of the surface satisfy the formula (III) is not particularly limited. For example, when the film of the present invention is a laminated film having a base material layer and a layer containing a high concentration of particles (layer A), the particle diameter of the particles contained in the layer A is reduced while increasing the particle concentration. Is preferably used. The average particle diameter of the particles contained in the layer A is less than 2.5 μm, the content is 3% by mass or more and 40% by mass or less, and the total thickness of the layer A is 100% by mass and the layer thickness of the layer A is less than 3 μm. Is preferred. The ratio (DA (μm) / TA (μm)) of the average particle diameter of the particles contained in the layer A to the layer thickness of the layer A is preferably 0.8 or more and 10 or less, and more preferably 1.1 or more and 10 or less. Is more preferable, and 1.3 to 6 is most preferable.

  In the laminated film of the present invention, the thickness change before and after the heat treatment at 100 ° C. for 10 minutes is preferably controlled to be 0.1% or more and 10% or less. When the film of the present invention is used as a transfer film, a functional layer (the surface roughness SRa of the film of the present invention is 100 nm or more and 3000 nm or less) is formed on the film surface having a surface roughness SRa of 100 nm or more and 3000 nm or less. A transfer material layer that transfers the shape of a certain film surface) is provided, but a thermal load is applied when the functional layer is coated and dried when the functional layer is provided. By controlling the dimensional change in the thickness direction of the film when a heat load is applied, that is, the thickness change before and after the heat treatment at 100 ° C. for 10 minutes to 10% or less, the film enters the functional layer at the time of coating and drying the functional layer. And transfer releasability can be better controlled. The change in thickness before and after the heat treatment at 100 ° C. for 10 minutes is more preferably 8% or less, and further preferably 6% or less. On the other hand, the present inventors have conducted intensive studies and found that when the film of the present invention is used as a transfer film, the film having a certain or more dimensional change in the thickness direction of the film when a heat load is applied is more releasable. Revealed that it was excellent. At this time, it is not clear how this phenomenon occurs, but it is better for the functional layer of the film to have a certain degree of dimensional change in the thickness direction of the film when a thermal load is applied. As a result of the fact that there is a spot where the penetration of the film is large and a spot where the penetration of the film is small, it is presumed that the place where the penetration of the film into the functional layer is small near the place where the penetration of the film into the functional layer is large becomes the starting point for causing peeling I have. Therefore, from the viewpoint of peelability, the change in thickness before and after the heat treatment at 100 ° C. for 10 minutes is preferably 0.5% or more, more preferably 1% or more. As a method of controlling the thickness change before and after the heat treatment at 100 ° C. for 10 minutes, for example, when the film of the present invention is a biaxially stretched polyester film, adjusting the stretching conditions in the film stretching step can be mentioned. The stretching ratio (area ratio = longitudinal stretching ratio × width stretching ratio) is increased to 14 times or more, preferably 16 times or more, and the heat treatment temperature after stretching is 230 ° C. or more, preferably 235 ° C. or more and 250 ° C. or less. It is mentioned as a preferable method.

  In the film of the present invention, from the viewpoint of transferability, it is preferable that the surface free energy of the surface having a surface roughness SRa of 100 nm or more and 3000 nm or less be 44 mN / m or less. By setting the surface free energy to 44 mN / m or less, the releasability from the transfer material is improved, so that the transfer and the releasability are facilitated and the transferability is improved. The surface free energy on the layer A side is more preferably 42 mN / m or less, and most preferably 15 mN / m or more and 40 mN / m or less.

  The method for controlling the surface free energy of the surface having a surface roughness SRa of 100 nm or more and 3000 nm or less of the film of the present invention within the above-mentioned range is not particularly limited, but a release agent such as a silicone compound, a wax compound, or a fluorine-based compound is used. In the film, a method of applying a release coat, and the like. In the case where the film of the present invention is a laminated film having a base material layer and a layer with a high concentration of particles (layer A), the release agent may be added to the layer with a high concentration of particles (layer A), or A layer) A method of applying a release coating on the surface is preferred.

  In the present invention, in the case of a configuration in which a release coat is applied to the surface of the layer with a high concentration of particles (layer A), the unevenness formed by the particles contained in the layer with a high concentration of particles (layer A) is changed to the surface of the release coat layer. Therefore, the thickness of the release coat layer is preferably 0.01 μm or more and 3 μm or less, more preferably 0.02 μm or more and 2 μm or less, and even more preferably 0.03 μm or more and 1.5 μm or less. Further, from the viewpoint of heat resistance at the time of heating, it is preferable that a melamine resin and a release agent are contained in the release layer. From the viewpoint of heat resistance and release stability, the content of the melamine resin in the release layer is preferably 50% by mass or more.

  Melamine resins that can be used in the present invention include melamine formaldehyde resins, methylated melamine formaldehyde resins, butylated melamine formaldehyde resins, etherified melamine formaldehyde resins, epoxy-modified melamine formaldehyde resins, and other melamine formaldehyde resins, urea melamine resins, acrylics Melamine resins and the like can be mentioned. Among them, a melamine formaldehyde resin is preferable, and a methylated melamine formaldehyde resin is particularly preferably used since it has an appropriate release property. Further, the release layer in the invention preferably contains a binder resin in addition to the binder resin and the release agent from the viewpoint of film forming properties and stretchability. As the binder resin, a polyester resin, an acrylic resin, or a urethane resin is preferably used, and an acrylic resin is particularly preferably used. Examples of the acrylic resin include a homopolymer or copolymer of an alkyl (meth) acrylate, and a (meth) acrylate copolymer having a curable functional group at a side chain and / or a main chain terminal, Examples of the curable functional group include a hydroxyl group, a carboxyl group, an epoxy group, and an amino group. Among them, an acrylic monomer copolymer obtained by copolymerizing an acrylic monomer and an acrylate having a curable functional group at a side chain and / or a main chain terminal is preferable. Further, examples of the release agent contained in the release layer of the present invention include a fluorine compound, a long-chain alkyl compound and a wax compound. These release agents may be used alone or in combination of two or more.

  The fluorine compound that can be used in the present invention is a compound containing a fluorine atom in the compound. Examples thereof include perfluoroalkyl group-containing compounds, polymers of fluorine-containing olefin compounds, and aromatic fluorine compounds such as fluorobenzene. When the release film of the present invention is used for a simultaneous transfer foil for molding and the like, a high heat load is applied at the time of transfer. Therefore, in consideration of heat resistance and contamination, the fluorine compound is preferably a polymer compound.

  The long-chain alkyl compound is a compound having a linear or branched alkyl group having 6 or more, particularly preferably 8 or more, carbon atoms. Specific examples include, but are not particularly limited to, a long-chain alkyl group-containing polyvinyl resin, a long-chain alkyl group-containing acrylic resin, a long-chain alkyl group-containing polyester resin, a long-chain alkyl group-containing amine compound, and a long-chain alkyl group. And a quaternary ammonium salt containing a long-chain alkyl group. It is preferable that the long-chain alkyl compound is a high molecular compound because transfer of the component derived from the release layer to the surface of the counterpart substrate bonded at the time of peeling the release film is preferable.

  The wax compound that can be used in the present invention is a wax selected from natural waxes, synthetic waxes, and waxes containing these waxes. Natural waxes are vegetable waxes, animal waxes, mineral waxes, and petroleum waxes. Vegetable waxes include candelilla wax, carnauba wax, rice wax, wood wax, and jojoba oil. Animal waxes include beeswax, lanolin, and whale wax. Examples of the mineral wax include montan wax, ozokerite, and ceresin. Examples of the petroleum wax include paraffin wax, microcrystalline wax, and petrolatum. Examples of the synthetic wax include a synthetic hydrocarbon, a modified wax, a hydrogenated wax, a fatty acid, an acid amide, an amine, an imide, an ester, and a ketone. As the synthetic hydrocarbons, Fischer-Tropsch wax (also known as Sazoire wax) and polyethylene wax are well known, and in addition, low molecular weight polymers (specifically, polymers having a viscosity average molecular weight of 500 to 20,000). The following polymers are also included: That is, there are polypropylene, ethylene / acrylic acid copolymer, polyethylene glycol, polypropylene glycol, and a block or graft conjugate of polyethylene glycol and polypropylene glycol. Examples of the modified wax include montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives. The derivative herein is a compound obtained by any of purification, oxidation, esterification, saponification, or a combination thereof. Hydrogenated waxes include hardened castor oil, and hardened castor oil derivatives.

  By uniformly dispersing these release agents on the surface of the release layer, the adhesive force and the peel force with the release layer to be laminated and peeled on the release layer can be set to appropriate ranges. When a long-chain alkyl compound is used as the release agent, the peeling force can be adjusted over a wide range, which is preferable in terms of application of the present invention.

  Next, a specific production method of the film of the present invention will be described with respect to an example of a laminated film having a base material layer and a layer containing a high concentration of particles (layer A), but the present invention is to be construed as being limited to such examples. is not.

  When a polyester resin is used for the substrate layer and the layer containing a high concentration of particles (layer A) of the film of the present invention, they are supplied to separate extruders and melt-extruded. At this time, it is preferable to control the resin temperature to 255 ° C. to 295 ° C. Next, through a filter or a gear pump, foreign substances are removed and the extrusion amount is leveled, and coextruded in a sheet form from a T-die onto a cooling drum to obtain a laminated sheet. At this time, an electrostatic application method in which the cooling drum and the resin are brought into close contact with each other by static electricity using an electrode to which a high voltage is applied, a casting method in which a water film is provided between the casting drum and the extruded polymer sheet, and a casting drum temperature of the polyester resin. The sheet-like polymer is brought into close contact with the casting drum by a method of sticking the extruded polymer at a glass transition point to (glass transition point −20 ° C.) or a combination of these methods, and is cooled and solidified. Among these casting methods, when polyester is used, a method of applying static electricity is preferably used from the viewpoint of productivity and flatness.

  The laminated film of the present invention is preferably a biaxially oriented film from the viewpoint of heat resistance and dimensional stability. Biaxially oriented film, after stretching the unstretched film in the longitudinal direction, stretch in the width direction, or, after stretching in the width direction, by a sequential biaxial stretching method of stretching in the longitudinal direction, or in the longitudinal direction of the film It can be obtained by performing stretching by a simultaneous biaxial stretching method in which stretching is performed substantially simultaneously in the width direction.

  The stretching ratio in such a stretching method is preferably 2.8 times or more and 5 times or less in the longitudinal direction, and more preferably 2.9 times or more and 4.5 times or less. The stretching speed is preferably 1,000% / minute or more and 200,000% / minute or less. Further, the stretching temperature in the longitudinal direction is preferably from 70 ° C. to 90 ° C. The stretching ratio in the width direction is preferably 2.8 times or more and 5 times or less, and more preferably 3 times or more and 4.5 times or less. The stretching speed in the width direction is preferably from 1,000% / min to 200,000% / min. The laminated film of the present invention is preferably stretched in two or more steps from the viewpoint of controlling the dispersion of the parallel line transmittance ST320 of 320 nm in a range of 20 cm × 14 cm of the film. In addition, the said stretching ratio shows the total stretching ratio in each direction.

  Further, the film is subjected to a heat treatment after the biaxial stretching. The heat treatment can be performed by any conventionally known method such as in an oven or on a heated roll. This heat treatment is performed at a temperature not lower than 120 ° C. and not higher than the crystal melting peak temperature of the polyester. In order to set the parallel line transmittance ST320 of 320 nm to 30% or more, voids around the particles in the layer (A layer) having a high concentration of particles are used. From the viewpoint of reducing the temperature, the heat treatment temperature is preferably set to the melting point of the high-particle-concentration content layer (A layer) −20 ° C. or higher and + 10 ° C. or lower, more preferably set to the melting point −10 ° C. or higher and −5 ° C. preferable. The heat treatment time can be arbitrarily set within a range that does not deteriorate the characteristics, and is preferably 5 seconds to 60 seconds, more preferably 10 seconds to 40 seconds, and most preferably 15 seconds to 30 seconds. Further, in order to secure stable release properties, a release layer can be coated in-line on the surface of the layer A. As a method of providing the coating layer in-line in the film manufacturing process, at least a film obtained by dispersing the coating layer composition in water on a uniaxially stretched film is uniformly applied using a metalling ring bar, a gravure roll, or the like. Then, a method of drying the coating while stretching is preferred. At that time, the thickness of the release layer is preferably 0.02 μm or more and 0.1 μm or less. Also, various additives in the release layer, for example, antioxidants, heat stabilizers, ultraviolet absorbers, infrared absorbers, pigments, dyes, organic or inorganic particles, antistatic agents, even if a nucleating agent, etc. Good.

  Further, as one embodiment of the film of the present invention, a laminated film having a low gloss layer having a glossiness of 30 or less on at least one surface of the base material layer, and the surface roughness SRa of the low gloss layer surface is 100 nm. Laminated films having a thickness of not more than 3000 nm, a variation in surface roughness SRa in a range of 20 cm × 14 cm of the film of not more than 10%, and a parallel line transmittance ST320 of 320 nm of not less than 30% are exemplified. By having a low gloss layer having a gloss of 30 or less, when used as a transfer film, a low gloss appearance can be transferred. The glossiness of the low gloss layer is more preferably 25 or less, further preferably 20 or less. The glossiness of the low gloss layer can be controlled by including the particles used in the layer (A) containing a high concentration of particles, adjusting the surface roughness of the low gloss layer, and the like. In this configuration, the low gloss layer is more preferably a layer containing a high concentration of particles (A). In addition, the glossiness in this invention represents the 60 degree mirror glossiness calculated | required by the measuring method mentioned later.

  The film of the present invention has a surface roughness SRa of at least one side of 100 nm or more and 3000 nm or less, a small variation in the surface roughness SRa in a range of 20 cm × 14 cm, and a high parallel line transmittance of 320 nm. When a photo-curable resin is used, transfer and shape fixation of a sufficiently low gloss appearance can be achieved. For this reason, it can be suitably used as a transfer film having excellent matt appearance transferability in the circuit forming step.

(1) Composition of Polyester Polyester resin and film are dissolved in hexafluoroisopropanol (HFIP), and the content of each monomer residue component and by-product diethylene glycol can be determined using ¹ H-NMR and ¹³ C-NMR. it can. In the case of a laminated film, the components constituting each layer alone can be collected and evaluated by shaving each layer of the film according to the thickness of the laminated film. In addition, about the film of this invention, the composition was calculated by calculation from the mixing ratio at the time of film manufacture.

(2) Intrinsic Viscosity of Polyester The intrinsic viscosity of the polyester resin and the film was measured at 25 ° C. by dissolving the polyester in orthochlorophenol and using an Ostwald viscometer. In the case of a laminated film, the intrinsic viscosity of each layer alone can be evaluated by shaving each layer of the film according to the laminated thickness.

(3) Film Thickness The thickness of the laminated film was measured using a dial gauge thickness meter (manufactured by Mitutoyo Corporation) having a flat tip and a diameter of 4 mm. The thickness was measured at the center of the film, at a position 4 cm (2 points) in the length direction from the center of the film, and at 4 points (2 points) in the width direction, and the average value was taken as the film thickness.

(4) Thickness of Each Layer The laminated film was embedded in an epoxy resin, and the cross section of the film was cut out with a microtome. The cross section was observed with a transmission electron microscope (TEM H7100, manufactured by Hitachi, Ltd.) at a magnification of 5000 times to determine the thickness of each layer.

(5) Average particle diameter of particles The resin constituting the film is removed from the laminated film by a plasma low-temperature incineration method (PR-503, manufactured by Yamato Scientific Co., Ltd.) to expose the particles. This was observed with a transmission electron microscope (TEM H7100, manufactured by Hitachi, Ltd.), and the image of the particles (shading of light generated by the particles) was linked to an image analyzer (QTM900, manufactured by Cambridge Instrument). The following numerical processing was performed as described above, and the number average diameter D obtained thereby was defined as the average particle diameter.
D = ΣDi / N
Here, Di is the circle equivalent diameter of the particles, and N is the number of particles.

(6) Content of particles 1 g of the polymer was put into 200 ml of a 1N-KOH methanol solution and heated under reflux to dissolve the polymer. After the dissolution was completed, 200 ml of water was added to the solution, and the liquid was centrifuged to settle particles, and the supernatant was removed. Water was further added to the particles, and washing and centrifugation were repeated twice. The particles thus obtained were dried, and the content of the particles was calculated by measuring the mass.

(7) Surface roughness SRa, maximum peak height SRp, maximum valley depth SRv, center area ratio SSr
A sample cut out to a size of 4.0 cm in length × 3.5 cm in width was used as a sample, and using a high-definition fine shape measuring instrument (three-dimensional surface roughness meter) of the stylus method in accordance with JIS B0601-1994, The surface morphology of the polyester film was measured under the following conditions.
-Measuring device: 3D fine shape measuring device (Kosaka Laboratories, ET-4000A type)
・ Analysis equipment: 3D surface roughness analysis system (TDA-31 type)
・ Stylus: 0.5 μmR at tip, 2 μm in diameter, made of diamond ・ Stylus pressure: 100 μN
・ Measurement direction: Average after measuring once each in film longitudinal direction and film width direction ・ X measurement length: 1.0 mm
・ X feed speed: 0.1 mm / s (measuring speed)
・ Y feed pitch: 5 μm (measurement interval)
・ Number of Y lines: 81 (number of measurement lines)
・ Z magnification: 20 times (vertical magnification)
・ Low frequency cutoff: 0.20mm
High frequency cutoff: R + Wmm (roughness cutoff value) R + W means that no cutoff is performed.
・ Filter method: Gaussian space type ・ Leveling: Yes (tilt correction)
・ Reference area: 1 mm ² .
The measurement was performed under the above conditions, and then the center plane average roughness SRa, the maximum peak height SRp, the maximum valley depth (SRv), and the center area ratio (SSr) were calculated using the analysis system.

(8) Variation of the surface roughness SRa in the range of 20 cm × 14 cm of the film A film is cut out at an arbitrary position into a size of 20 cm in length (parallel to the longitudinal direction) × 14 cm in width (parallel to the width direction) as a sample. The sample was further divided into five equal parts in the length direction and four equal parts in the width direction, and cut out into a size of 4.0 cm in length × 3.5 cm in width (total of 20 samples). The sample was calculated from the surface roughness SRa in the same manner as in (7), and the variation was determined as described below.
Variation (%) of surface roughness SRa = {(maximum value−minimum value) / average value} × 100
(9) Gloss According to the method specified in JIS-Z-8741 (1997), a 60 ° specular gloss was measured using a digital variable-angle gloss meter UGV-5D manufactured by Suga Test Instruments at N = 3, The average value was taken as the glossiness of the present invention.

(10) Parallel line transmittance ST320 of 320 nm
Using a spectrophotometer U-3410 (manufactured by Hitachi, Ltd.), the parallel line transmittance was measured in a wavelength range of 320 nm. The measurement was performed by irradiating light from the side having a small surface roughness (SRa) measured in (7). The measurement was performed for each sample in the same manner as in (8), and the average of a total of 20 measurement points was determined as the parallel line transmittance ST320 at 320 nm.

(11) Each sample was prepared in the same manner as the variation (8) of the parallel line transmittance ST320 of 320 nm in the 20 cm × 14 cm area of the film, and a total of 20 measurement points were measured in the same manner as in (10). The line transmittance ST320 was calculated, and the variation was determined as follows.
ST320 variation (%) = {(maximum value−minimum value) / average value} × 100
(12) A thickness-changed film before and after heat treatment at 100 ° C. for 10 minutes is cut out at an arbitrary position into a size of 10 cm in length × 10 cm in width to make a sample. From the center of the film and the center of the film in the same manner as (3) The thickness was measured at 5 points at a position of 4 cm (2 points) in the length direction and at a position of 4 cm (2 points) in the width direction, and the average value was taken as the film thickness before the heat treatment. Thereafter, the sample was held in a hot-air oven set at 100 ° C. for 10 minutes, heat-treated, and the thickness of the sample after the heat treatment was measured in the same manner at five points, and the average value was compared with the film thickness after the heat treatment. did. From the obtained thickness before and after the heat treatment, a change in thickness was calculated as follows.
Thickness change (%) = {| thickness after heat treatment−thickness before heat treatment | / thickness before heat treatment} × 100
(13) Surface free energy Four kinds of liquids, water, ethylene glycol, formamide and diiodomethane, were used as the measuring liquids, and the film surface of each liquid was measured using a contact angle meter (CA-D type manufactured by Kyowa Interface Science Co., Ltd.). The static contact angle with respect to was determined. Each liquid is measured five times, and the average contact angle (θ) and each component of the surface tension of the measurement liquid (j) are substituted into the following equations, respectively, and simultaneous equations composed of four equations are expressed as γ ^L , γ ⁺ , γ ^- solving for.
^{(Γ L γj L) 1/2 +2} (γ + γj -) 1/2 +2 (γj + γ -) 1/2
= (1 + cos θ) [γ j ^L +2 (γ j ⁺ γ j ⁻ ) ^1/2 ] / 2
Here, γ = γ ^L +2 (γ ⁺ γ ⁻ ) ^{1/2
γj = γj L +2 (γj +} γj -) 1/2
Here, γ, γ ^L , γ ⁺ , and γ ⁻ are the surface free energy of the film surface, the long-range force term, the Lewis acid parameter, and the Lewis base parameter, respectively, and γj, γj ^L , γj ⁺ , γj ⁻ Indicates the surface free energy, long-range force term, Lewis acid parameter, and Lewis base parameter of the measurement solution used, respectively. As the surface tension of each liquid used here, the value proposed by Oss ("fundamentals of adhesion", LH Lee (Ed.), P153, Plenumess, New York (1991)) was used.

(14) Peelability [I]
The film was cut into a length of 20 cm and a width of 14 cm and used. The following release layer forming solution is applied by gravure coating to the surface of the film having an SRa of 100 nm or more and 3000 nm or less (if both surfaces have SRa of 100 nm or more and 3000 nm or less, the surface has a small surface roughness (SRa)). And dried in an oven at 180 ° C. for 20 seconds. Further, the coating composition for forming a hard coat layer was applied using a slot die coater while controlling the flow rate so that the thickness after drying was 5 μm, and dried at 100 ° C. for 1 minute to remove the solvent. A laminate in which a coat layer was laminated was obtained.

An aluminum plate having a thickness of 0.2 mm / a thickness of 0.2 mm was obtained by using a press machine in which the obtained film / release layer / hard coat layer laminate was heated to a temperature of 160 ° C. for both the upper mold temperature and the lower mold temperature. 125 mm polyimide film (Toray Dupont Kapton 500H / V) /Laminate/0.125 mm thick polyimide film (Toray Dupont Kapton 500H / V) /1.5 mm thick aluminum plate Under the conditions described above for 1 hour. After the heating press, the laminate / polyimide film is taken out, and ultraviolet rays of 300 mJ / cm ² are irradiated from the laminate side using a high-pressure mercury lamp to cure the hard coat layer to obtain a sample. This sample was subjected to a peel test at the interface between the film and the release layer (film / (this interface) / release layer / hard coat layer), and the peelability was evaluated based on the following criteria.

(Solution for forming release layer)
A methylated melamine: amine paratoluenesulfonate: acrylic monomer copolymer was prepared at a mass ratio of 20: 0.4: 1, and diluted with toluene.

(Coating composition for forming hard coat layer)
The following materials were mixed and diluted with methyl ethyl ketone to obtain a coating composition for forming a hard coat layer having a solid content of 40% by mass.
30 parts by weight of toluene 25 parts by weight of polyfunctional urethane acrylate (KRM8655 manufactured by Daicel Ornex Co., Ltd.)
25 parts by mass of pentaerythritol triacrylate mixture (PET30 manufactured by Nippon Kayaku Co., Ltd.)
1 part by mass of polyfunctional silicone acrylate (EBECRYL1360 manufactured by Daicel Ornex Co., Ltd.)
3 parts by mass of photopolymerization initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals)
(Evaluation criteria)
A: Peeling was possible without resistance B: Resistance was felt at the time of peeling, but peeling was possible C: Peeling was not possible.

(15) Peelability [II]
The film was cut into a length of 20 cm and a width of 14 cm and used. The photosensitive polyimide layer forming coating composition, which is a photocurable resin, is coated by a gravure coating method with a surface having an SRa of 100 nm or more and 3000 nm or less (surface roughness (SRa) when SRa is 100 nm or more and 3000 nm or less on both surfaces). Was dried at 90 ° C. for 60 seconds in an oven to obtain a film / photosensitive polyimide layer laminate. The obtained laminate was laminated on a polyimide film (“Kapton” (registered trademark) 500H / V, manufactured by Toray DuPont) at 70 ° C./0.2 MPa, and ultraviolet light of 800 mJ / cm ² was applied from the laminate side using a high-pressure mercury lamp. Irradiated. At this time, a half (length 20 cm × width 7 cm) portion of the sample was subjected to a photomask (the portion subjected to the photomask was not subjected to UV exposure). The peel strength between the film and the photosensitive polyimide layer was measured for each of the portions with UV exposure and the portions without UV exposure, and evaluated based on the following criteria. The peel strength was determined by forming the film / photosensitive polyimide layer laminate into a strip having a length of 15 cm and a width of 5 cm, forcibly separating the film and the photosensitive polyimide layer, and performing a 180 ° peel test using a tensile tester ( Using Orientec Tensilon UCT-100), the measurement was performed at a peeling rate of 300 mm / min in an atmosphere of 25 ° C. and 50% RH. The average value of the strength between the measurement length of 50% and 100% was defined as the peel strength.
A: The difference in peel strength between the part with UV exposure and the part without UV exposure is less than 0.5 N / 50 mm B: The difference in the peel strength between the part with UV exposure and the part without UV exposure is 0.5 N / 50 mm or more and 1 N / Less than 50 mm C: The difference in peel strength between the part with UV exposure and the part without UV exposure was 1 N / 50 mm or more. D: Peeling was not possible in at least one of the part with UV exposure and the part without UV exposure.

(16) Peelability [III]
In the same manner as in (15), a film / photosensitive polyimide layer laminate was obtained. The obtained laminate was laminated at 70 ° C./0.2 MPa on a polyimide film (“Kapton” (registered trademark) 500H / V, manufactured by Toray DuPont). Then, after heat treatment was performed at 100 ° C. for 10 minutes, ultraviolet light of 800 mJ / cm ² was irradiated from the layered body side using a high-pressure mercury lamp. At this time, a half (length 20 cm × width 7 cm) portion of the sample was subjected to a photomask (the portion subjected to the photomask was not subjected to UV exposure). With respect to the UV-irradiated sample of the obtained laminate, the peel strength between the film and the photosensitive polyimide layer was measured for each of the portion with UV exposure and the portion without UV exposure, and evaluated according to the following criteria.
A: The difference in peel strength between the part with UV exposure and the part without UV exposure is less than 0.5 N / 50 mm B: The difference in the peel strength between the part with UV exposure and the part without UV exposure is 0.5 N / 50 mm or more and 1 N / Less than 50 mm C: The difference in peel strength between the part with UV exposure and the part without UV exposure is 1 N / 50 mm or more. D: Peeling was not possible in at least one of the part with UV exposure and the part without UV exposure. (17) Matte tone Transferability of appearance, uniform appearance The release layer side of the release layer obtained by the method (14) is cut out into a size of 20 cm long × 14 cm wide to obtain a sample, and the sample is further cut in the length direction. The sample was divided into five equal parts and four equal parts in the width direction, and cut into a size of 4.0 cm in length × 3.5 cm in width (total of 20 samples). The gloss of each sample was measured in the same manner as in (9), and the average value was evaluated according to the following criteria.

(Transferability of matte appearance)
A: Glossiness of 10 or less B: Glossiness of more than 10 and 20 or less C: Glossiness of more than 20 and 30 or less D: Glossiness of more than 30

(Mat-like appearance looks uniform)
Evaluation was made based on the following criteria from the difference between the maximum value and the minimum value of the glossiness at 20 points.

A: The difference between the maximum value and the minimum value of the glossiness is 2 or less B: The difference between the maximum value and the minimum value of the glossiness exceeds 2 and 4 or less C: The difference between the maximum value and the minimum value of the glossiness exceeds 4 .

(18) The haze film was cut into a square having a side of 10 cm, and the haze was measured using a haze meter NDH-5000 manufactured by Nippon Denshoku Co., Ltd. The measurement was performed at three points, and the average value was defined as the haze in the present invention.

  In the above measurements, when the longitudinal direction and the width direction of the film to be measured were unknown, the direction having the maximum refractive index in the film was regarded as the width direction, and the direction perpendicular to the width direction was regarded as the longitudinal direction.

(Manufacture of polyester)
The polyester resin used for film formation was prepared as follows.

(Polyester A)
A polyethylene terephthalate resin (intrinsic viscosity: 0.65) having 100 mol% of a terephthalic component as a dicarboxylic acid component and 100 mol% of an ethylene glycol component as a glycol component.

(Polyester B)
A copolymerized polyethylene terephthalate resin (intrinsic viscosity 0.8) in which isophthalic acid is copolymerized with a dicarboxylic acid component by 20 mol%.

(Polyester C)
A polybutylene terephthalate resin (intrinsic viscosity 1.2) in which a terephthalic component is 100 mol% as a dicarboxylic acid component and a 1,4-butanediol component is 100 mol% as a glycol component.

(Polyester D)
"Hytrel (registered trademark)" 7247 manufactured by Toray-Dupont.

(Particle Master E)
Polyethylene terephthalate particle master (intrinsic viscosity: 0.65) containing polyester A containing colloidal silica particles having an average particle diameter of 3 μm at a particle concentration of 30% by mass.

(Particle Master F)
Polyethylene terephthalate particle master (intrinsic viscosity 0.65) containing polyester A containing colloidal silica particles having an average particle diameter of 5 μm at a particle concentration of 30% by mass.

(Particle Master G)
Polyethylene terephthalate particle master (intrinsic viscosity: 0.65) containing polyester A containing alumina silicate particles having an average particle diameter of 3 μm at a particle concentration of 30% by mass.

(Particle Master H)
A polyethylene terephthalate particle master (intrinsic viscosity: 0.65) containing polyester A containing silicate alumina particles having an average particle diameter of 5 μm at a particle concentration of 30% by mass.

(Particle Master I)
Polyethylene terephthalate particle master in which colloidal silica particles having an average particle size of 2.2 μm are contained in polyester A at a particle concentration of 30% by mass (intrinsic viscosity: 0.65)
(Particle Master J)
Polyethylene terephthalate particle master (intrinsic viscosity: 0.65) containing polyester silicate alumina silicate particles having an average particle diameter of 2.4 μm at a particle concentration of 30% by mass.
(Release coating solution (water dispersion))
The following crosslinking agent: binder resin: release agent: particles were mixed at a mass ratio of 60:23:17, respectively, and adjusted by diluting with pure water such that the solid content was 1% by mass.
・ Crosslinking agent: Crosslinked resin of methylated melamine / urea copolymer (“Nikarac” (registered trademark) “MW12LF” manufactured by Sanwa Chemical Co., Ltd.)
-Binder resin I: Acrylic monomer copolymer (manufactured by Nippon Carbide)
Release agent: CF ₃ (CF ₂ ) _n CH ₂ CH ₂ OCOCH = CH ₂ (n = 5 to 11, average of n = 9) which is a perfluoroalkyl group-containing acrylate in a glass reaction vessel. 0 g, acetoacetoxyethyl methacrylate 20.0 g, dodecyl mercaptan 0.8 g, deoxygenated pure water 354.7 g, acetone 40.0 g, C ₁₆ H ₃₃ N (CH ₃ ) ₃ Cl 1.0 g and C ₈ H ₁₇ C ₆ 3.0 g of H ₄ O (CH ₂ CH ₂ O) _n H (n = 8) was added, 0.5 g of azobisisobutylamidine dihydrochloride was added, and the mixture was copolymerized at 60 ° C. for 10 hours while stirring under a nitrogen atmosphere. A copolymer emulsion obtained by the reaction.
Particles: Silica particles having a number average particle diameter of 170 nm ("Snowtex" (registered trademark) MP2040, manufactured by Nissan Chemical Industries, Ltd.) are diluted with pure water so as to have a solid concentration of 40% by weight. Water dispersion.

(Example 1)
The raw materials were respectively supplied to the extruder so that the composition and the lamination ratio were as shown in the table. The extruder cylinder temperature was set at 270 ° C, the short tube temperature was set at 275 ° C, the die temperature was set at 280 ° C, and the resin temperature was 280 ° C. Then, the mixture was discharged in a sheet form from a T-die onto a cooling drum whose temperature was controlled at 25 ° C. At that time, static electricity was applied using a wire-shaped electrode having a diameter of 0.1 mm, and the sheet was brought into close contact with a cooling drum to obtain an unstretched sheet. Subsequently, the film is stretched in the longitudinal direction at a stretching temperature of 85 ° C. as the first step by 1.5 times at a stretching speed of 50,000% / min. The film was stretched at a rate of% / min (total stretching ratio 3.3 times). Thereafter, a corona discharge treatment is performed, and a release coating solution (aqueous dispersion) is applied to the surface on the layer A side using a metaling bar so that the wet thickness becomes 13.5 μm. In the width direction, the film is stretched 1.8 times as the first stage at a stretching temperature of 100 ° C. at a stretching speed of 30,000% / minute, and stretched twice at a stretching temperature of 120 ° C. in the second stage at a stretching speed of 40,000%. / Minute (total stretching ratio 3.6 times). Thereafter, heat treatment was performed at 235 ° C. in a tenter to obtain a film having a film thickness of 16 μm (release coating layer: 0.04 μm, A layer: 3.5 μm, base layer: 12.5 μm).

(Example 2)
A film having a film thickness of 25 μm was obtained in the same manner as in Example 1 except that the composition and the lamination ratio were changed as shown in the table.

(Example 3)
A film having a film thickness of 16 μm was obtained in the same manner as in Example 1 except that the composition and the lamination ratio were changed as shown in the table.

(Example 4)
A film having a film thickness of 25 μm was obtained in the same manner as in Example 1 except that the composition and the lamination ratio were changed as shown in the table.

(Example 5)
A film having a film thickness of 16 μm was obtained in the same manner as in Example 1 except that the composition and the lamination ratio were changed as shown in the table, and that the release coating solution was not applied after stretching in the longitudinal direction.

(Example 6)
A film having a film thickness of 16 μm was obtained in the same manner as in Example 2, except that the film was stretched 3.3 times at 85 ° C. as stretching conditions in the longitudinal direction and 3.6 times at 100 ° C. as stretching conditions in the width direction. Was.

(Example 7)
A film having a film thickness of 16 μm was obtained in the same manner as in Example 1 except that the composition and the lamination ratio were changed as shown in the table, and that the release coating solution was not applied after stretching in the longitudinal direction.

(Example 8)
A film having a film thickness of 19.5 μm was obtained in the same manner as in Example 1 except that the composition, the structure, and the lamination ratio were changed as shown in the table, and that the release coating solution was not applied after stretching in the longitudinal direction.

(Example 9)
The composition and lamination ratio were changed as shown in the table, and the film was stretched 1.6 times as the first step at a stretching temperature of 85 ° C. in the longitudinal direction, and 2.4 times as the second step at a stretching temperature of 88 ° C. (total stretching ratio of 3). 0.8 times), stretched 1.9 times as the first step at a stretching temperature of 100 ° C. in the width direction, and 2.2 times stretched at a stretching temperature of 120 ° C. (total stretch ratio of 4.2 times). In the same manner as in Example 1, a film having a film thickness of 14.5 μm (release coating layer: 0.03 μm, A layer: 2 μm, substrate layer: 12.5 μm) was obtained.

(Example 10)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 11)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 12)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 13)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 14)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 15)
A film having a film thickness of 14.5 μm was obtained in the same manner as in Example 9 except that the composition and the lamination ratio were changed as shown in the table.

(Example 16)
A film having a film thickness of 9 μm was obtained in the same manner as in Example 4 except that the composition and the lamination ratio were changed as shown in the table.

(Example 17)
The film is stretched 1.7 times as the first step at a stretching temperature of 85 ° C. in the longitudinal direction, 2.4 times as the second step at a stretching temperature of 88 ° C. (total stretching ratio of 4.1 times), and stretched at a stretching temperature of 100 times in the width direction. 1.9 times stretching as the first step at 120 ° C., 2.2 times stretching at the stretching temperature of 120 ° C. (total stretching ratio of 4.2 times), and then heat treatment at 252 ° C. in a tenter. A film having a film thickness of 14.5 μm (release coating layer: 0.03 μm, A layer: 2 μm, base material layer: 12.5 μm) was obtained in the same manner as in Example 11 except that this was performed.

(Example 18)
In the longitudinal direction, the film is stretched 1.2 times as the first step at a stretching temperature of 85 ° C., stretched 1.2 times as the second step at a stretching temperature of 86 ° C., 1.6 times as the third step at a stretching temperature of 87 ° C. At 88 ° C., the film is stretched 1.7 times as the fourth stage (total stretching ratio of 3.9 times), stretched 1.2 times as the first stage at a stretching temperature of 100 ° C. in the width direction, and stretched at the second stage at a stretching temperature of 110 ° C. Example 11 was repeated except that the film was stretched 1.2 times, stretched at a stretching temperature of 115 ° C., stretched 1.6 times, and stretched at 120 ° C., stretched 1.8 times (total stretch ratio 4.1 times). A film having a film thickness of 14.5 μm (release coating layer: 0.03 μm, A layer: 2 μm, base layer: 12.5 μm) was obtained in the same manner as in Example 1.

(Comparative Example 1)
A film having a film thickness of 22.5 μm was obtained in the same manner as in Example 8, except that the composition and the lamination ratio were changed as shown in the table.

(Comparative Example 2)
A film having a film thickness of 25 μm was obtained in the same manner as in Example 4 except that the composition and the lamination ratio were changed as shown in the table.

(Comparative Example 3)
A film having a film thickness of 20.5 μm was obtained in the same manner as in Example 2 except that the composition and the lamination ratio were changed as shown in the table.

In the table, a film surface having a surface roughness SRa of 100 nm or more and 3000 nm or less is described as an A surface, and a film surface having a surface roughness SRa of not more than 100 nm and 3000 nm or less is described as a B surface. In the case of a film having a surface roughness SRa of 100 nm or more and 3000 nm or less on both surfaces, a surface having a large surface roughness is described as an A1 surface, and a surface having a low surface roughness SRa is described as an A2 surface.

The film of the present invention has a surface roughness SRa of at least one side of 100 nm or more and 3000 nm or less, a small variation in the surface roughness SRa in a range of 20 cm × 14 cm, and a high parallel line transmittance of 320 nm. When a photo-curable resin is used, transfer and shape fixation of a sufficiently low gloss appearance can be achieved. For this reason, it can be suitably used as a transfer film having excellent matt appearance transferability in the circuit forming step.

Claims (12)

A film having a surface roughness SRa of at least one side of 100 nm or more and 3000 nm or less, a variation of the surface roughness SRa in a range of 20 cm × 14 cm of 10% or less, and a parallel line transmittance ST320 of 320 nm of 30% or more. The film according to claim 1, wherein the maximum peak height (SRp) and the maximum valley depth (SRv) of the surface having the surface roughness SRa of 100 nm or more and 3000 nm or less satisfy the following formula (II).
1 ≦ SRp / SRv ≦ 3 (II) The film according to claim 1, wherein a center area ratio (SSr) of a surface having the surface roughness SRa of 100 nm or more and 3000 nm or less satisfies the following expression (III).
30 ≦ SSr ≦ 60 (III) The film according to any one of claims 1 to 3, wherein a change in thickness before and after the heat treatment at 100 ° C for 10 minutes is 0.1% or more and 10% or less. A laminated film having a base layer and a layer containing a high concentration of particles (layer A), wherein the particles having an average particle diameter of 1 μm or more and 10 μm or less in the layer A are 1% by mass or more, with the entire layer A being 100% by mass. The film according to any one of claims 1 to 4, which contains 40% by mass or less. The film according to any one of claims 1 to 5, wherein the ST320 is 60% or more. The film according to any one of claims 1 to 6, wherein a variation of the ST320 is 0.1% or more and 10% or less in a range of 20 cm x 14 cm of the film. The film according to any one of claims 1 to 7, wherein the film haze is 70% or less. The film according to any one of claims 1 to 8, wherein the surface having a surface roughness SRa of 100 nm or more and 3000 nm or less has a surface free energy of 44 mN / m or less. The film according to claim 1, comprising a polyester as a main component. The film according to any one of claims 1 to 10, which is used for transfer use. A laminated film having a low gloss layer (A layer) having a glossiness of 30 or less on at least one surface of the base material layer, wherein the surface roughness SRa of the surface of the A layer is 100 nm or more and 3000 nm or less, and 20 cm of the film. A laminated film in which the variation of the surface roughness SRa in a range of × 14 cm is 10% or less and the parallel line transmittance ST320 at 320 nm is 30% or more.