JP2019142987A - Polyester film for dry film resist substrate - Google Patents

Abstract

To provide a polyester film for a dry film resist substrate, which can be used as a substrate film in a dry film resist process for preparing a flexible printed wiring board or the like.SOLUTION: The polyester film for a dry film resist substrate has a coating layer formed from a coating liquid containing a crosslinking agent on at least one surface of a polyester film that substantially does not contain particles B having a particle diameter of 0.30 μm or more.SELECTED DRAWING: None

Description

  The present invention relates to a film that can be suitably used, for example, as a film for a substrate in a dry film resist process for producing a flexible printed circuit board or the like.

  Conventionally, polyester films represented by polyethylene terephthalate and polyethylene naphthalate have excellent mechanical properties, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, etc., and cost performance. It is used for various purposes.

  As an example of an application using a polyester film, there is a film in a dry film resist process used when a flexible printed wiring board is manufactured. The dry film resist has, for example, a three-layer structure of base film / photosensitive resin layer / protective film. As the support film, a polyester film having excellent mechanical properties, optical properties, chemical resistance, heat resistance, dimensional stability, flatness and the like is used. Briefly describing an example of use, the protective film is first peeled off, and the exposed photosensitive resin layer is brought into close contact with the conductive base material attached to the substrate. Next, a glass plate or film (referred to as a photomask) on which a circuit is printed is brought into close contact with the base film side, and light is irradiated from the photomask side. In general, ultraviolet light is used as the irradiation light. Light passes through a transparent portion of the circuit image printed on the photomask, and the photosensitive resin reacts only with the portion exposed to ultraviolet rays. The glass plate and the base film are removed, and the unexposed portion that is not exposed to ultraviolet rays in the photosensitive resin layer is removed using a suitable solvent or the like. If etching is further performed using an acid or the like, the photosensitive resin layer is removed, and a conductive base material layer is formed as a circuit.

  In recent years, miniaturization of electronic devices has demanded higher definition of flexible printed wiring boards, and there is an urgent need for further thinning of circuit patterns formed on the surface of insulating substrates. For this reason, the high quality is requested | required also with respect to the polyester film used as a base film. In the photoresist film, when exposing the photosensitive resin layer, light passes through the base film as described above. Accordingly, when the transparency of the base film is low, there arises a problem that the photosensitive resin layer is not sufficiently exposed or the resolution is deteriorated due to light scattering. For this reason, it is important for the polyester film used as a base film to have low haze and high transparency. Furthermore, when there is a scratch on the film surface, there arises a problem that the resolution is deteriorated by scattering the transmitted light.

  A polyester film having a smooth surface, high transparency, and low film haze has poor handleability in the film production process, the winding process, and the like. When such a film roll is used, there is a problem that the surface is easily damaged, the air bitten in the winding process is difficult to escape, and wrinkles are generated.

  In order to improve the handleability of such a film, or to improve the handleability and winding characteristics of the dry film resist itself, a method in which particles are usually contained in a polyester film and fine protrusions are formed on the surface is used. It has been. For this reason, a method for obtaining a polyester film satisfying transparency, scratch resistance and slipping properties has not yet been found.

  As a method for improving the slipperiness while maintaining the transparency of the film, there has been proposed a method (Patent Documents 1 and 2) in which particles are contained only in a thin surface layer of a polyester film and the content is suppressed to a low level. However, in this method, since there is no coating layer, there is a concern that the scratch resistance in the processing step is poor.

  Regarding prevention of scratches in the winding process and the processing process, a technique of adding a wax agent to the coating layer has been proposed (Patent Document 3). However, it is considered that performance is not sufficient by imparting scratch resistance only with a wax agent. In addition, this method uses a surfactant type antistatic agent, and there is a concern about contamination of the base film manufacturing process and the photoresist film manufacturing process due to bleeding out of the antistatic agent.

JP 2000-221688 A JP 2001-117237 A JP 2006-327158 A

  Hereinafter, an example of an embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below, and can be implemented with any modifications without departing from the spirit of the present invention.

  This invention is made | formed in view of the said situation, The solution subject is the polyester for dry film resist base materials which can be used conveniently as a base film in the dry film resist process which produces a flexible printed wiring board etc. The object is to provide a film (hereinafter also referred to as “film for DFR substrate”).

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the use of a laminated polyester film having a specific configuration can easily solve the above-described problems, and have completed the present invention.

  That is, the gist of the present invention is characterized in that it has a coating layer formed from a coating solution containing a crosslinking agent on at least one surface of a polyester film substantially free of particles B having a particle size of 0.30 μm or more. The present invention resides in a polyester film for a dry film resist substrate.

  According to the present invention, an ultrathin wire circuit can be formed by simultaneously satisfying transparency, scratch resistance and slipperiness as a base film in the dry film resist process. In addition, according to the present invention, since slipperiness and scratch resistance are good, the air leakage index can be reduced, and the air that is caught when the film is wound into a roll form is easily released, To provide a film for a DFR base material that can be wound in close contact with each other, prevents misalignment in the direction of the core during storage or transportation, prevents scratches due to misalignment, and prevents surface wrinkles. Can do. ADVANTAGE OF THE INVENTION According to this invention, the film for DFR base materials with higher quality can be provided, and the industrial value is high.

  The DFR substrate film according to the embodiment of the present invention has a coating layer formed from a coating solution containing a crosslinking agent on at least one surface of a polyester film substantially free of particles having a particle size of 0.30 μm or more. Have.

  A film for a DFR substrate according to an embodiment of the present invention has a coating layer formed from a coating solution containing a crosslinking agent on at least one side of a polyester film substantially free of particles having a particle size of 0.30 μm or more. Therefore, this coating layer can simultaneously satisfy the scratch resistance and slipperiness while maintaining the transparency as the base film. Moreover, since the film for DFR base materials which concerns on embodiment of this invention does not contain a particle | grain of 0.30 micrometer or more substantially in a polyester film, transparency is maintained, Furthermore, the damage prevention property of polyester film itself, While the slipperiness is maintained, the coating layer further improves the scratch resistance and slipperiness, and can further reduce circuit defects.

Polyester film The polyester film in the present invention may have a single layer structure or a multilayer structure, or may be a multilayer of two or more layers, and is not particularly limited. When adding particles to the polyester layer, three or more layers are preferable from the viewpoint of effectively imparting transparency and slipperiness, and three layers are preferable from the viewpoint of cost. In addition, in the case of three layers, from the viewpoint of effectively imparting transparency and slipperiness, particles are included in both surface layers, and two types and three layers not including particles in the intermediate layer, particles in at least one surface layer. Three types and three layers which contain and do not contain particles in the intermediate layer and the other surface layer are preferable.

  In the present invention, the polyester refers to terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, 4.4'-diphenyldicarboxylic acid, adipic acid, sebacic acid as the dicarboxylic acid component constituting the polyester. And dodecanedicarboxylic acid. In particular, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferable from the viewpoint of mechanical properties of the film. Examples of the glycol component constituting the polyester include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, polyethylene glycol, and the like. Can be illustrated. In particular, ethylene glycol is preferable from the viewpoint of the rigidity of the film.

The polyester may be a copolyester obtained by copolymerizing the dicarboxylic acid component or glycol component as the third component, and may contain a trifunctional or higher polyvalent carboxylic acid component or polyol component. It may be a polyester copolymerized in a small amount within a linear range (for example, 5 mol% or less). As the polyester used in the present invention, polyethylene terephthalate or polyethylene-2,6-naphthalate is particularly preferable. Such a polyester can be produced by a conventional method, and if the intrinsic viscosity of the polyester (in orthochlorophenol, 35 ° C.) is 0.45 or more, the mechanical properties such as the tearability and rigidity of the film are good. Therefore, it is preferable.

  There is no restriction | limiting in particular as a polymerization catalyst of polyester, A conventionally well-known compound can be used, For example, an antimony compound, a titanium compound, a germanium compound, a manganese compound, an aluminum compound, a magnesium compound, a calcium compound etc. are mentioned. Among these, titanium compounds and germanium compounds are preferable because they have high catalytic activity, can be polymerized in a small amount, and the amount of metal remaining in the film is small, so that the transparency of the film becomes high.

  When the polyester film has a multilayer structure of two or more layers, in the case of a two-layer structure, the thickness of at least one layer is preferably 1/8 or less, more preferably 1/10 or less of the thickness of the other layer. More preferably, it is 1/12 or less, and particularly preferably 1/16 or less. When the polyester film has a multilayer structure of three or more layers, the thickness of at least one surface layer (outermost layer) is preferably 1/8 or less of the thickness of a layer other than the surface layer, more preferably 1/10 or less, more preferably Is 1/12 or less, particularly preferably 1/16 or less. In the case where the polyester film has a multilayer structure of two layers or three or more layers, when the thickness of at least one surface layer is in the range of 1/8 or less of the thickness of layers other than the surface layer, the particle B described later on at least one surface layer Even if it contains, high transparency and favorable slipperiness can be made compatible.

Particle B
The polyester film preferably contains particles mainly for the purpose of imparting slipperiness and preventing scratches in each step. In this specification, the particles contained in the polyester film are referred to as particles B. The polyester film does not include particles B having a particle size of 0.30 μm or more (hereinafter, particles B having a particle size of 0.30 μm or more are referred to as “particles Bb”). In the present invention, the phrase “substantially free of particles Bb of 0.30 μm or more in the polyester film” means that the polyester film is observed using, for example, a scanning electron microscope (“S3400N” manufactured by Hitachi High-Technologies Corporation). Then, when the size of one particle is measured from the obtained image data, and there is no particle Bb having a particle size of 0.30 μm or more in the target range 200 × 200 μm ^{2 of} the image data, the particle size is It can be judged that it does not contain particles Bb of 0.30 μm or more. The DFR base film having a coating layer formed from a coating film formed from a coating liquid containing a cross-linking agent and a polyester film that does not contain particles having a particle size of 0.30 μm or more is further prevented by the coating layer. And slipperiness are improved, and circuit defects can be further reduced.

  The kind of the particle | grains B contained in a polyester film will not be specifically limited if it is a particle | grains which can provide slipperiness. Specific examples include silica, alumina, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, zirconium oxide, titanium oxide and other inorganic particles, acrylic resin, styrene resin, urea resin, phenol resin. And organic particles such as epoxy resin and benzoguanamine resin. Furthermore, precipitated particles in which a part of a metal compound such as a catalyst is precipitated and finely dispersed during the production process of the polyester film can also be used. Protrusion formation by adding particles causes UV exposure failure due to the protrusions and dents on the resist surface, resulting in reduced resolution and defects in the ultrafine wire circuit formation that has been required in recent years, and transparency of the film In some cases, sex may be reduced. Among these, by using alumina particles, organic particles, and silica particles, it is possible to obtain high transparency and scratch resistance of the polyester film, and to reduce circuit defects.

  The average particle diameter of the particles B is preferably 0.001 to 0.30 μm, more preferably 0.001 to 0.25 μm, still more preferably 0.001 to 0.2 μm, and particularly preferably 0.001 to 0.1 μm. Range. When the average particle size of the particles B contained in the polyester film is 0.001 to 0.3 μm, the proportion of the particles B having a particle size exceeding 0.30 μm contained in the polyester film is 300 ppm or less. It is possible. When the average particle size of the particles B contained in the polyester film is 0.001 to 0.30 μm, the polyester film itself can be prevented from being scratched and slippery while maintaining the transparency of the polyester film. it can. Even when the coating liquid is applied so as to be in contact with the layer containing the particles B, the smoothness of the polyester film is maintained, coating unevenness is suppressed, and the appearance of the coating layer is good. Can be. When the average particle size of the particles B contained in the polyester film exceeds 0.30 μm, the surface roughness of the polyester film becomes rough, and the unevenness of the polyester film may be transferred to the resist. When unevenness is generated in the resist, when the resist is removed by the acid edging process, the edging process degree may be affected and a circuit may be defective. Moreover, when the average particle diameter of the particle B contained in the polyester film exceeds 0.3 μm, the transparency of the polyester film is lowered, the photosensitive resin is not sufficiently exposed, and the resolution is lowered due to light scattering. If the transparency of the base film is low, the photosensitive resin layer is not sufficiently exposed, or the resolution is lowered due to light scattering, and the requirements for fine circuit formation cannot be satisfied. There is. In the present specification, the average particle size of the particles is the cumulative volume fraction in the equivalent spherical distribution obtained by measuring the powder using a centrifugal sedimentation type particle size distribution analyzer (SA-CP3 type) when the particles are powder. A particle size (d50) of 50% can be set as the average particle size. The average particle size of the particles in the film or film (for example, coating layer) is obtained by observing the powder or polyester film using, for example, a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, “S3400N”). Thus, the size of one particle can be measured, and the average value of 10 points (10 particles) can be used as the average particle size.

  The smaller the average particle size of the particles B, the higher the transparency of the polyester film, the reduction in circuit defects, and the application to applications where a finer circuit is required. The average particle size of particles B having a relatively small average particle size (hereinafter sometimes referred to as “particle B-1”) is preferably 0.001 to 0.08 μm, more preferably 0.001 to 0.00. The range is 06 μm. In order to prevent scratches in the film-forming process due to a decrease in slipperiness while maintaining the slipperiness of the polyester film, the particles B (hereinafter referred to as “Particle B-2”) having a slightly larger average particle diameter may be used. .) May be used, and the slipperiness of the polyester film may be imparted by using the particle B-2 having a slightly larger average particle diameter. The average particle diameter of the particle B-2 having a relatively large average particle diameter is The range is preferably 0.1 to 0.3 μm, more preferably 0.1 to 0.2 μm. Furthermore, two or more kinds of particles B-1 included in the range of 0.001 to 0.08 μm in average particle size and B-2 included in the range of 0.1 to 0.3 μm in average particle size B can be used in combination, and by using it together, it is possible to achieve both high transparency and good slipperiness.

  The content of the particles B in the polyester film is preferably 10000 ppm or less, more preferably 8000 ppm or less, more preferably 6000 ppm or less, and particularly preferably 4000 ppm or less. When particles B-2 having an average particle size of 0.1 to 0.3 μm are used, slipping properties can be effectively imparted in a small amount, so the content of particles B in the polyester film is preferably 3000 pm. In the following, it is more preferably 1000 ppm or less, and further preferably 500 ppm or less. The lower limit is not particularly limited, and does not include particle B, or 1 ppm or more, or 2 ppm or more. When the content of particles B in the polyester film is large, the haze increases, and a high-resolution dry film resist is insufficiently exposed to ultraviolet rays, which may cause circuit loss and resolution reduction.

  When the polyester film has a multilayer structure, the particles B are preferably contained in at least one polyester layer. When the polyester film has two polyester layers, it is preferable that at least one layer contains particles B having an average particle diameter of 0.001 to 0.3 μm. When the polyester film has a two-layer structure and at least one layer contains particles B having an average particle diameter of 0.001 to 0.3 μm, the coating layer is in contact with the layer containing the polyester film particles B. Or may be provided in contact with a layer containing no polyester film particles B. The DFR base film having a coating layer in contact with the layer containing the particles B is easy to handle in the processing process because the coating layer has good scratch resistance and slipperiness. In the dry film resist process, Easy to form a layer. On the other hand, the DFR base film having a coating layer in contact with the layer not containing the particles B is easy to handle in the processing step because the coating layer has good scratch resistance and slipperiness, and easily forms a resist layer in the dry film resist step. .

  When the polyester film has three or more polyester layers, it is preferable to contain particles B having an average particle diameter of 0.001 to 0.3 μm in at least one layer serving as a surface layer. When the polyester film has three or more polyester layers, both surface layers (both outermost layers) may contain particles B having an average particle diameter of 0.001 to 0.3 μm. When the polyester film has a multilayer structure of three or more layers, and the particles B having an average particle size of 0.001 to 0.3 μm are contained in at least one layer as a surface layer, the coating layer contains the particles B of the polyester film. You may provide in contact with the layer made to contact, and you may provide in contact with the layer which does not contain the particle | grains B of a polyester film. The DFR base film having a coating layer in contact with the layer containing the particles B is easy to handle in the processing process because the coating layer has good scratch resistance and slipperiness. In the dry film resist process, Easy to form a layer. On the other hand, the DFR base film having a coating layer in contact with the layer not containing the particles B is easy to handle in the processing step because the coating layer has good scratch resistance and slipperiness, and easily forms a resist layer in the dry film resist step. .

The shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc.
These series of particles may be used in combination of two or more as required.

  The method for adding particles to the polyester film is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage for producing the polyester constituting the film, but it is preferably added after completion of the esterification or transesterification reaction.

  In addition, the polyester film in the present invention contains conventionally known antioxidants, antistatic agents, heat stabilizers, ultraviolet absorbers, lubricants, dyes, pigments and the like as necessary in addition to the above-mentioned particles. Can do.

  The thickness of the polyester film in the present invention is not particularly limited as long as it can be formed as a film, but is preferably 1 to 300 μm, more preferably in terms of mechanical strength, handling properties, and productivity. Is preferably in the range of 5 to 50 μm, more preferably 8 to 25 μm.

  As a method for forming a polyester film, a generally known film forming method can be adopted, and there is no particular limitation. For example, when producing a biaxially stretched polyester film, the polyester raw material described above is first melt-extruded from a die using an extruder, and the molten sheet is cooled and solidified with a cooling roll to obtain an unstretched sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum, and an electrostatic application adhesion method or a liquid application adhesion method is preferably employed.

  Next, the obtained unstretched sheet is stretched in one direction by a roll or a tenter type stretching machine. The stretching temperature is usually 70 to 150 ° C., preferably 80 to 140 ° C., and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Next, the film is stretched in the direction perpendicular to the first-stage stretching direction at usually 70 to 170 ° C. and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, a method of obtaining a biaxially oriented film by performing heat treatment at a temperature of 180 to 270 ° C. under tension or under relaxation within 30% can be mentioned. In the above-described stretching, a method in which stretching in one direction is performed in two or more stages can be employed. In that case, it is preferable to carry out so that the draw ratios in the two directions finally fall within the above ranges.

Coating Layer The formation of the coating layer in the present invention will be described, and then the coating liquid for forming the coating layer and the configuration of the coating layer will be described. Regarding the formation of the coating layer, the coating layer may be formed by in-line coating, in which the coating solution is coated on the surface of the polyester film during the film formation process, and the coating solution is coated on the polyester film once manufactured outside the system. Alternatively, the coating layer may be formed by off-line coating. The coating layer is preferably formed by in-line coating from the viewpoint of ease of processing.

  In-line coating is a method of coating a coating solution that forms a coating layer in the process of manufacturing a polyester film. Specifically, any stage from melt-extrusion of polyester to heat-fixing and winding after stretching. In this method, the coating liquid is coated. Normally, the coating solution is coated on any of the unstretched sheets obtained by melting and quenching, stretched uniaxially stretched films, biaxially stretched films before heat setting, and films after heat setting and before winding. To do.

  Examples of methods for applying the coating liquid include air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, kiss roll coating, and cast coating. Conventional coating methods such as spray coating, curtain coating, calendar coating, and extrusion coating can be used.

  Although not limited to the following, for example, in sequential biaxial stretching, a coating solution is coated on a uniaxially stretched film stretched particularly in the longitudinal direction (longitudinal direction) and then stretched in the transverse direction and applied to a polyester film. A method for forming a film for a DFR substrate having a layer is excellent. According to such a method, there is an advantage in manufacturing cost because the formation of the polyester film and the formation of the coating layer can be performed simultaneously, and the thickness of the coating layer is changed depending on the stretching ratio in order to perform stretching after coating. The thin film coating can be performed more easily than the off-line coating.

  Moreover, by providing a coating layer on a polyester film before stretching, the coating layer can be stretched together with the polyester film, whereby the coating layer can be firmly adhered to the polyester film. Furthermore, in the production of a biaxially stretched polyester film, the film can be restrained in the longitudinal and lateral directions by stretching while gripping the film end with a clip, etc. High temperature can be applied while maintaining the properties.

  Therefore, since the heat treatment performed after coating can be performed at a high temperature that cannot be achieved by other methods, the film forming property of the coating layer is improved, and the coating layer and the polyester film can be more firmly adhered to each other. Furthermore, it can be set as a firm coating layer.

  Further, the coating layer may be used in combination with heat treatment and irradiation with active energy rays such as ultraviolet irradiation, if necessary, regardless of formation by off-line coating or in-line coating. Surface treatment such as chemical treatment, corona discharge treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc. on the polyester film before coating in order to improve the coating properties and adhesiveness of the coating solution that forms the coating layer. May be applied.

Coating Solution The coating solution for forming the coating layer is preferably an aqueous coating solution using water as a solvent. The coating solution may contain a small amount of an organic solvent. Examples of organic solvents include alcohols such as ethanol, isopropanol, ethylene glycol, and glycerin, ethers such as ethyl cellosolve, t-butyl cellosolve, propylene glycol monomethyl ether, and tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, and esters such as ethyl acetate. And amines such as dimethylethanolamine. These can be used alone or in combination. By appropriately selecting and containing these organic solvents in the aqueous coating solution as necessary, the stability and coating properties of the coating solution can be improved.

Crosslinking agent The coating solution for forming the coating layer contains a crosslinking agent. It has been found that by containing a crosslinking agent in the coating solution constituting the coating layer, the coating layer becomes a dense coating layer having a high crosslinking density and can impart suitable scratch resistance in the dry film resist process. . There is no restriction | limiting in particular in a crosslinking agent, A conventionally well-known crosslinking agent can be used. Examples of the crosslinking agent include melamine compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, etc. Among these, from the viewpoint of durability, the crosslinking agents are melamine compounds or oxazolines. A compound is preferable, and a melamine compound is preferable from the viewpoint of scratch resistance. Moreover, these crosslinking agents may use 2 or more types together.
A coating liquid for forming a coating layer having a high crosslinking density may contain a crosslinking agent to form a curable coating layer. In particular, when the present invention is applied to a dry film resist capable of forming an ultrafine wire circuit, it is necessary to make the surface extremely smooth in order to provide the required performance. In order to make the surface extremely smooth, it has been found that the inclusion of a cross-linking agent in the coating solution exhibits an extremely remarkable effect. Furthermore, as described above, it has also been found that the effect is more remarkable by using a specific crosslinking agent.

  The melamine compound is a compound having a melamine skeleton in the compound. For example, an alkylolized melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and these Mixtures can be used. Examples of the alkylolation include methylolation, ethylolation, isopropylolation, n-butyroylation, and isobutyrololization. Among these, methylolation is preferable from the viewpoint of reactivity. Moreover, as alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol, etc. are used suitably. From the viewpoint of improving the coating film strength and improving the adhesion between the coating layer and the substrate, it is preferably a partially etherified alkylolated melamine derivative, and is an alkylol etherified with methyl alcohol. Is more preferable. Therefore, a more preferable form is a partially etherified melamine having a methylol group and a methoxymethyl group. The etherified alkylol group is preferably 0.5 to 5 equivalents, more preferably 0.7 to 3 equivalents, relative to the non-etherified alkylol group. Moreover, as a melamine compound, either a monomer or a multimer more than a dimer may be sufficient, or a mixture thereof may be used. Further, a product obtained by co-condensing urea or the like with a part of melamine can be used, and a crosslinking catalyst can be used to increase the reactivity of the melamine compound.

  The melamine crosslinking catalyst is used to increase the reactivity of the thermosetting resin. Various known catalysts can be used, for example, amine compounds, amine compound salts, aromatic sulfonic acid compounds such as paratoluenesulfonic acid, organic acids such as phosphoric acid compounds, and salts thereof, imine compounds, and amidine compounds. , Guanidine compounds, organometallic compounds, metal salts such as zinc stearate, myristic zinc, aluminum stearate and calcium stearate. Among these, amine compounds, salts of amine compounds and paratoluenesulfonic acid are preferable, and amine compounds and salts of amine compounds are more preferable.

  The oxazoline compound is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable, and can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially. The other monomer is not limited as long as it is a monomer copolymerizable with an addition polymerizable oxazoline group-containing monomer. For example, alkyl (meth) acrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, (meth) acrylic acid esters such as n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; (meth) acrylamide, N-alkyl ( (Meth) acrylamide, N, N-dialkyl (meth) acrylamide, As the alkyl group, unsaturated amides such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group and cyclohexyl group); vinyl acetate Vinyl esters such as vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride And α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like, and one or more of these monomers can be used.

  The epoxy compound is a compound having an epoxy group in the molecule, and examples thereof include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerin, polyglycerin, bisphenol A and the like hydroxyl groups and amino groups, There are polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. Examples of the polyepoxy compound include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Examples of the polyglycidyl ether and diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , Polypropylene glycol diglycidyl ether, poly Examples of tetramethylene glycol diglycidyl ether and monoepoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidyl amine compounds such as N, N, N ′, N′-tetraglycidyl-m-xylyl. Examples include range amine and 1,3-bis (N, N-diglycidylamino) cyclohexane.

  The isocyanate compound is a compound having an isocyanate derivative structure typified by isocyanate or blocked isocyanate. Examples of the isocyanate include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate, and aromatic rings such as α, α, α ′, α′-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), isopropylidene dicyclohexyl diisocyanate Ne Alicyclic isocyanates such as bets are exemplified. Further, polymers and derivatives such as burettes, isocyanurates, uretdiones, and carbodiimide modified products of these isocyanates are also included. These may be used alone or in combination. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

  When used in the state of blocked isocyanate, the blocking agent includes, for example, bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcohols such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. Compounds, active methylene compounds such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate and acetylacetone, mercaptan compounds such as butyl mercaptan and dodecyl mercaptan, lactam compounds such as ε-caprolactam and δ-valerolactam , Amine compounds such as diphenylaniline, aniline, ethyleneimine, acetanilide, acid amide compounds of acetic acid amide, formaldehyde, acetoald Examples include oxime compounds such as oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime, and these may be used alone or in combination of two or more. Among these, an active methylene compound is preferable from the viewpoint that the peeling property hardly changes even after heating.

  In addition, the isocyanate compound in the present invention may be used alone, or may be used as a mixture or bond with various polymers. In the sense of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or a bond with a polyester resin or a urethane resin.

  In the present invention, the carbodiimide-based compound is a compound having a carbodiimide structure, and is used for improving the wet heat resistance of the coating layer. The carbodiimide compound can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and any of aromatic and aliphatic compounds can be used. Specifically, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexa Examples include methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

  A silane coupling compound is an organosilicon compound having an organic functional group and a hydrolysis group such as an alkoxy group in one molecule. For example, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4- Epoxy group) epoxy group-containing compounds such as ethyltrimethoxysilane, vinyl group-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane, styryl group-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, etc. (Meth) acrylic group-containing compound, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl)- 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N -Amino group-containing compounds such as (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, tris (trimethoxysilylpropyl) Isocyanurate, tris (triethoxysilylpropyl) Examples include isocyanurate group-containing compounds such as cyanurate, mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. It is done.

  Among the above compounds, from the viewpoint of maintaining the strength of the coating layer, epoxy group-containing silane coupling compounds, double bond-containing silane coupling compounds such as vinyl groups and (meth) acryl groups, and amino group-containing silane coupling compounds are more preferred. preferable.

  The crosslinking agent contained in the coating solution is used in a design that improves the performance of the coating layer by reacting in the drying process or the film forming process when forming the coating layer. It can be inferred that unreacted products of these crosslinking agents, compounds after the reaction, or mixtures thereof exist in the finished coating layer.

  The content of the crosslinking agent in the coating solution is preferably 5 to 85% by mass, more preferably 25 to 70% by mass, and further preferably 30 to 50% by mass with respect to all the non-volatile components in the coating solution. When the content of the crosslinking agent with respect to all the non-volatile components in the coating solution is 5 to 85% by mass, the strength of the coating layer formed from the coating solution is improved, and the anti-scratch property is further improved. Can be satisfied at the same time. Furthermore, in the case where an antistatic agent is included in the coating layer as necessary, the bleedout of the antistatic agent from the coating layer formed by the crosslinking agent is suppressed, and contamination of the film due to bleedout is suppressed, It is possible to prevent the substrate film from being damaged by adsorption of dust and the like. When the content of the crosslinking agent with respect to all nonvolatile components in the coating solution is less than 10% by mass, sufficient damage prevention performance may not be obtained.

  When the coating solution contains a crosslinking catalyst as required, the content of the crosslinking catalyst is usually 0.4 to 10% by mass, preferably 0.6 to 8%, based on the nonvolatile components in the coating solution. % By mass, more preferably 0.8 to 5% by mass. When the coating solution contains a crosslinking catalyst as necessary, a coating film having desirable scratch-preventing performance can be obtained when the content of the crosslinking catalyst is 0.4 to 10% by mass.

  The coating solution may contain an antistatic agent as necessary so as to be contained in a coating layer formed from the coating solution. The coating solution may contain a surfactant as necessary. The coating liquid preferably contains particles A. The coating solution may contain at least one release agent selected from the group consisting of a compound having a long-chain alkyl group, a wax, a fluorine compound, and a silicone compound. Moreover, the coating liquid may contain various polymers described later other than the polymer formed by crosslinking the crosslinking agent.

Coating layer It is preferable that the coating layer of the film for DFR base materials of this invention is a coating layer formed from the coating liquid by the method mentioned above.
When the polyester film has a multilayer structure, the coating layer of the DFR base film may be a coating layer formed from a coating solution applied to the surface layer containing the particles B. The coating layer formed from the coating liquid apply | coated to the layer which does not contain may be sufficient. Among the multilayered polyester films, the DFR base film having particles B in one surface layer and having a coating layer in contact with the surface layer containing the particles B is a processing step because the coating layer has good scratch resistance and slipperiness. In the dry film resist process, it is easy to form a resist layer on the layer not containing the particles B. Among the multilayered polyester films, the DFR base film having a coating layer that includes the particle B in one surface layer and is in contact with another surface layer that does not include the particle B has good scratch resistance and slipperiness due to the coating layer. Therefore, it is easy to handle in the processing process, and it is easy to form a resist layer in the dry film resist process.

  The thickness of the coating layer of the DFR substrate film (hereinafter also referred to as “coating layer thickness”) is usually 0.001 to 1 μm, preferably 0.002 to 0.5 μm, and more preferably 0.005. It is -0.2 micrometer, More preferably, it is 0.008-0.15 micrometer, More preferably, it is 0.01-0.1 micrometer, Most preferably, it is 0.01-0.08 micrometer. When the thickness of the coating layer is 0.001 to 1 μm, even when it is used as a film for a DFR base material, the coating film appearance is good and sufficient exposure is obtained, and sufficient scratch prevention performance Is obtained. The thickness of the coating layer can be measured by the method for measuring the thickness of the coating layer described in Examples described later.

Particle A
The coating layer of the DFR base film preferably contains particles A in order to improve the slipperiness of the DFR base film. The particles A are not particularly limited, and conventionally known particles can be used. Specific examples include inorganic particles such as colloidal silica, porous silica, alumina, calcium carbonate, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin and styrene resin. The particles A contained in the coating layer may be the same type of particles as the particles B contained in the polyester film, or may be different from the particles B. Colloidal silica, porous silica, and organic particles are preferred from the viewpoint of heat resistance during formation of the coating layer and availability at low cost.

  The average particle size of the particles A contained in the coating layer is preferably in the range of 0.5 to 5 times the film thickness of the coating layer in order to prevent the DFR substrate film from being scratched or contaminated. More preferably, it is in the range of 0.7 to 3.5 times the thickness of the coating layer. In the coating layer of the polyester film, if the average particle size of the particles with respect to the film thickness is large, the coating layer is rubbed in the winding or processing process, and the particles are rubbed off, or the coating film is scraped. There is a concern of contamination by the generated powder. When the average particle size of the particles A contained in the coating layer is in the range of 0.5 to 5 times the film thickness of the coating layer, scratch resistance is maintained while maintaining the transparency of the DFR substrate film. And slipperiness can be imparted.

  For example, when forming a coating layer on a polyester film having an average surface roughness (Ra) in the range of 1 to 3 nm, the average particle size is different in order to impart scratch resistance and slipperiness while maintaining transparency. It is preferable to use two or more kinds of particles A. When two or more types of particles A having different average particle sizes are used, the particle size of the particles A having the largest average particle size is in the range of 0.5 to 5 times the film thickness of the coating layer. It is preferable.

  The smaller the average particle size of the particles A, the higher the transparency of the polyester film, and the reduction of circuit defects can be reduced. The average particle size of the particles A can be applied to applications where a finer wire circuit is required. The larger one can give slipperiness. The average particle size of the particles A is usually 0.001 to 1.0 μm, preferably 0.005 to 0.5 μm, more preferably while satisfying the range of 0.5 to 5 times the thickness of the coating layer. It is in the range of 0.01 to 0.1. When the average particle diameter of the particles A is in the range of 0.001 to 1.0 μm, it is possible to prevent the DFR substrate film from being scratched or contaminated and to impart slipperiness.

  As the particles A, two or more kinds of particles A having different average particle diameters may be used. When two or more kinds of particles A are used, the average particle diameter of one kind of particles A (hereinafter also referred to as “particle A-1”) is usually 0.001 to 0.06 μm, preferably 0.005. It is -0.06 micrometer, More preferably, it is the range of 0.01-0.06 micrometer. The average particle size of the other kind of particle A (hereinafter also referred to as “particle A-2”) is usually 0.06 to 1.0 μm, preferably 0.06 to 0.5 μm, more preferably 0.06. It is -0.3 micrometer, More preferably, it is the range of 0.06-0.1 micrometer. Further, two or more kinds of particles A, a particle A-1 having an average particle size of 0.001 to 0.06 μm and a particle A-2 having an average particle size of 0.06 to 1.0 μm. By using it, it is possible to achieve both higher transparency and good slipperiness.

  Content of the particle | grains A in an application layer becomes like this. Preferably it is 1-10 mass%, More preferably, it is 1-8 mass%, More preferably, it is 2-7 mass%, More preferably, it is 2-5 mass%. When the content of the particles A in the coating layer is in the range of 1 to 10% by mass, scratch resistance and better slipperiness can be imparted while maintaining the transparency of the DFR base film. . For the content of the particles A in the coating layer, for example, after identifying the elements constituting the particles in the coating layer by elemental analysis, the size and frequency of the particles are observed with a transmission electron microscope (TEM). Can be measured. The content of the particles A in the coating solution is preferably 1 to 10% by mass, more preferably 1 to 8% by mass, still more preferably 2 to 7% by mass, and still more preferably based on the non-volatile components in the coating solution. Is 2 to 5% by mass.

Release agent It is preferable that a coating layer contains a release agent in order to improve the slipperiness of the film for DFR base materials more. The release agent is preferably at least one release agent selected from the group consisting of a compound having a long-chain alkyl group, a wax, a fluorine compound, and a silicone compound. Among these, from the viewpoint of excellent contamination, the release agent is preferably a compound having a long-chain alkyl group or a wax. From the viewpoint of preventing scratches, the release agent is preferably a wax. These release agents may be used alone or in combination. The coating layer preferably contains a wax.

  Content of the mold release agent in a coating layer is 1-10 mass% normally, Preferably it is 2-9 mass%, More preferably, it is 3-8 mass%. When the content of the release agent in the coating layer is 1 to 10% by mass, the slipperiness of the DFR base film can be further improved. It is presumed that the content of the release agent in the coating layer is approximately equal to the content of the release agent with respect to the nonvolatile components in the coating solution. The content of the release agent contained in the coating liquid for forming the coating layer is usually 1 to 10% by mass, preferably 2 to 9% by mass, and more preferably 3 to 3% by weight with respect to the nonvolatile components in the coating liquid. 8% by mass.

  The wax is at least one wax selected from natural waxes, synthetic waxes, and blended waxes thereof.

  Natural waxes are plant waxes, animal waxes, mineral waxes, and petroleum waxes. Examples of plant 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 petroleum wax include paraffin wax, microcrystalline wax, and petrolatum.

Synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, esters, and ketones. As synthetic hydrocarbons, Fischer-Tropsch wax (also known as Sazoir wax) and polyethylene wax are famous, but in addition to this, low molecular weight polymers (specifically, polymers having a viscosity number average molecular weight of 500 to 20000) Some of the following polymers are also included. That is, there are polypropylene, ethylene / acrylic acid copolymer, polyethylene glycol, polypropylene glycol, polyethylene glycol and polypropylene glycol block or graft conjugate. 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 treatment, or a combination thereof. Hydrogenated waxes include hardened castor oil and hardened castor oil derivatives.
Polyethylene wax is preferred from the viewpoint that slipperiness can be effectively imparted in a small amount.

  The compound having a long-chain alkyl group is a compound having a linear or branched alkyl group having usually 6 or more, preferably 8 or more, more preferably 12 or more carbon atoms. Examples of the alkyl group include hexyl group, octyl group, decyl group, lauryl group, octadecyl group, and behenyl group. Examples of the compound having an alkyl group include various long-chain alkyl group-containing polymer compounds, long-chain alkyl group-containing amine compounds, long-chain alkyl group-containing ether compounds, and long-chain alkyl group-containing quaternary ammonium salts. . In view of heat resistance and contamination, a polymer compound having a long-chain alkyl group in the side chain is preferable.

The polymer compound having a long-chain alkyl group in the side chain can be obtained by reacting a polymer having a reactive group with a compound having an alkyl group capable of reacting with the reactive group. Examples of the reactive group include a hydroxyl group, an amino group, a carboxyl group, and an acid anhydride.
Examples of the compound having such a reactive group include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, a reactive group-containing polyester resin, and a reactive group-containing poly (meth) acrylic resin. Among these, polyvinyl alcohol is preferable in consideration of releasability and ease of handling.

  Examples of the compound having an alkyl group capable of reacting with the reactive group include, for example, long-chain alkyl group-containing isocyanates such as hexyl isocyanate, octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, and behenyl isocyanate, hexyl chloride, and octyl chloride. Long chain alkyl group-containing acid chlorides such as decyl chloride, lauryl chloride, octadecyl chloride, and behenyl chloride, long chain alkyl group-containing amines, and long chain alkyl group-containing alcohols. Among these, long chain alkyl group-containing isocyanates are preferable, and octadecyl isocyanate is particularly preferable in consideration of releasability and ease of handling.

  In addition, a polymer compound having a long-chain alkyl group in the side chain can also be obtained by copolymerization of a long-chain alkyl (meth) acrylate polymer or a long-chain alkyl (meth) acrylate and another vinyl group-containing monomer. . Examples of the long-chain alkyl (meth) acrylate include hexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, and behenyl (meth) acrylate. It is done.

  The silicone compound is a compound having a silicone structure in the molecule, and examples thereof include silicone emulsion, acrylic graft silicone, silicone graft acrylic, amino-modified silicone, perfluoroalkyl-modified silicone, and alkyl-modified silicone. In consideration of heat resistance, it is preferable to contain a curable silicone resin. As the kind of the curable silicone resin, any of the curing reaction types such as an addition type, a condensation type, an ultraviolet curable type, and an electron beam curable type can be used.

  The fluorine compound is a compound containing a fluorine atom in the compound. Organic fluorine compounds are preferably used in terms of the appearance of coating by in-line coating, and examples thereof include perfluoroalkyl group-containing compounds, polymers of olefin compounds containing fluorine atoms, and aromatic fluorine compounds such as fluorobenzene. . From the viewpoint of releasability, a compound having a perfluoroalkyl group is preferable. Furthermore, the compound containing the long-chain alkyl compound which is mentioned later can also be used for a fluorine compound.

  Examples of the compound having a perfluoroalkyl group include perfluoroalkyl (meth) acrylate, perfluoroalkylmethyl (meth) acrylate, 2-perfluoroalkylethyl (meth) acrylate, and 3-perfluoroalkylpropyl (meth) acrylate. Perfluoroalkyl group-containing (meth) acrylates such as 3-perfluoroalkyl-1-methylpropyl (meth) acrylate and 3-perfluoroalkyl-2-propenyl (meth) acrylate, and polymers thereof, and perfluoroalkylmethyl vinyl ether 2-perfluoroalkyl ethyl vinyl ether, 3-perfluoropropyl vinyl ether, 3-perfluoroalkyl-1-methylpropyl vinyl ether, 3-perfluoroalkyl-2-propenyl vinyl Perfluoroalkyl group-containing vinyl ether and polymers thereof such as ether, and the like. In view of heat resistance and contamination, a polymer is preferable. The polymer may be a single compound or a polymer of multiple compounds. From the viewpoint of releasability, the perfluoroalkyl group preferably has 3 to 11 carbon atoms. Further, it may be a polymer with a compound containing a long-chain alkyl compound as described later. Moreover, it is preferable that it is a polymer with vinyl chloride from a viewpoint of adhesiveness with a base material.

Various polymers The coating layer may contain various polymers other than the polymer formed by crosslinking the crosslinking agent in order to improve the appearance of the coating layer and the transparency of the DFR base film.

  The content of various polymers other than the polymer obtained by crosslinking the crosslinking agent in the coating layer is usually 10 to 70% by mass, preferably 20 to 65% by mass, and more preferably 30 to 60% by mass. When the content of various polymers other than the polymer obtained by crosslinking the crosslinking agent in the coating layer is 10 to 80% by mass, the appearance and transparency of the coating layer of the DFR substrate film can be further improved. . Presumed that the content of various polymers other than the polymer formed by crosslinking the crosslinking agent in the coating layer is almost equal to the content of various polymers other than the polymer formed by crosslinking the crosslinking agent with respect to the non-volatile component in the coating solution. Is done. The content of various polymers other than the polymer formed by crosslinking the crosslinking agent contained in the coating solution for forming the coating layer is usually 10 to 70% by mass, preferably 20 to 20%, based on the nonvolatile components in the coating solution. It is 65 mass%, More preferably, it is 30-60 mass%.

  Specific examples of the various polymers include acrylic resin, polyvinyl alcohol, polyester resin, urethane resin, polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, and starches. Among these, acrylic resin and polyester resin are preferable in terms of improving the scratch prevention performance.

  The acrylic resin is a polymer composed of a polymerizable monomer including acrylic and methacrylic monomers. These may be either homopolymers or copolymers, and copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Moreover, the copolymer of these polymers and other polymers (for example, polyester, polyurethane, etc.) is also included. For example, a block copolymer or a graft copolymer. Alternatively, a polymer (possibly a mixture of polymers) obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion is also included. Similarly, a polymer obtained by polymerizing a polymerizable monomer in a polyurethane solution or a polyurethane dispersion (sometimes a mixture of polymers) is also included. Similarly, a polymer (in some cases, a polymer mixture) obtained by polymerizing a polymerizable monomer in another polymer solution or dispersion is also included. Moreover, in order to improve adhesiveness with a base material more, it is also possible to contain a hydroxyl group and an amino group.

  The polymerizable monomer is not particularly limited, but particularly representative compounds include various carboxyl groups such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Monomers, and salts thereof; such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutylhydroxy fumarate, monobutylhydroxy itaconate Various hydroxyl group-containing monomers; various (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate; Meth) acrylamide, di Various nitrogen-containing compounds such as seton acrylamide, N-methylolacrylamide or (meth) acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene, and various vinyls such as vinyl propionate Esters; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, etc .; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and biridene chloride Various conjugated dienes such as butadiene.

  The polyester resin includes, for example, those comprising the following polyvalent carboxylic acid and polyvalent hydroxy compound as main constituent components. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6 -Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutar Acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt and ester-forming derivatives thereof can be used. As polyvalent hydroxy compounds, ethylene Coal, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol , Neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol Polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate, and the like can be used. One or more compounds may be appropriately selected from these compounds, and a polyester resin may be synthesized by a conventional polycondensation reaction.

  Polyvinyl alcohol is a compound having a polyvinyl alcohol moiety. For example, conventionally known polyvinyl alcohols including modified compounds partially acetalized or butyralized with respect to polyvinyl alcohol can be used. The degree of polymerization of polyvinyl alcohol is not particularly limited, but is usually 100 or more, preferably in the range of 300 to 40,000. If the degree of polymerization is less than 100, the water resistance of the release layer may decrease. The saponification degree of polyvinyl alcohol is not particularly limited, but is usually 70 mol% or more, preferably in the range of 70 to 99.9 mol%, more preferably 80 to 97 mol%, and particularly preferably 86 to 97 mol%. A saponified polyvinyl acetate of 95 mol% is practically used.

  A urethane resin is a high molecular compound which has a urethane resin in a molecule | numerator. Usually, urethane resin is prepared by reaction of polyol and isocyanate. Examples of the polyol include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used alone or in combination.

Antistatic agent The coating layer of the film for DFR base materials may contain the antistatic agent as needed. The coating layer may not contain an antistatic agent when a coating layer having desired scratch resistance and slipperiness can be obtained by the crosslinking agent contained in the coating solution forming the coating layer. . Content of the antistatic agent in a coating layer is 45 mass% or less normally, Preferably it is 5-40 mass%, More preferably, it is 10-35 mass%, More preferably, it is 15-30 mass%. If the content of the antistatic agent in the coating layer is 45% by mass or less, the antistatic agent bleed out from the coating layer is suppressed even if the coating layer contains an antistatic agent as required. can do. In addition, if the content of the antistatic agent in the coating layer is 1% by mass or more, the surface resistance of the coating layer is lowered to prevent contamination of the base film due to bleeding out of the antistatic agent from the coating layer. Meanwhile, adsorption of dust and the like can be suppressed. The content of the antistatic agent in the coating layer can be measured, for example, by elemental analysis, fluorescent X-ray, NMR or the like. The content of the antistatic agent in the coating solution is 45% by mass or less, preferably 1 to 45% by mass or less, more preferably 5 to 40% by mass, and still more preferably 10% with respect to the nonvolatile component in the coating solution. It is -35 mass%, More preferably, it is 15-30 mass%.

  Examples of the antistatic agent include a quaternary ammonium salt, a pyridinium salt, a cationic antistatic agent having a cationic functional group such as a primary to tertiary amino group, a sulfonate group, a sulfate ester base, and a phosphate ester base. Anionic antistatic agent having an anionic functional group such as phosphonic acid group, amphoteric antistatic agent such as amino acid type and aminosulfate ester type, nonionic functional group such as polyol type, polyglycerin type and polyethylene glycol type Various polymer type antistatic agents such as an antistatic agent are listed. Further, monomers and oligomers having a tertiary amino group or a quaternary ammonium group and capable of being polymerized by ionizing radiation, such as N, N-dialkylaminoalkyl (meth) acrylate monomers, their quaternary compounds, etc. Polymerizable antistatic agents and conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used. Among these, a polymer type antistatic agent having a tertiary amino group or a quaternary ammonium group is preferable.

Surfactant The coating layer of the DFR base film may contain a surfactant as necessary. The coating layer may improve the wettability of the coating solution with respect to the polyester film by the surfactant contained in the coating solution that forms the coating layer, suppress coating unevenness, and improve the appearance of the coating layer. it can. The content of the surfactant in the coating layer is preferably 0.01 to 10% by mass, more preferably 0.05 to 5.0% by mass, still more preferably 0.10 to 3.0% by mass, and even more. Preferably it is 0.10-1.0 mass%, Most preferably, it is 0.30-1.0 mass%. If the content of the surfactant in the coating layer is 0.01 to 10% by mass, the wettability to the polyester film is improved while maintaining the transparency, scratch resistance and slipperiness of the coating layer. It is possible to suppress coating unevenness and to improve the appearance of the coating layer. When the content of the surfactant in the coating layer is less than 0.01% by mass, it becomes difficult to improve the wettability. When the content exceeds 10% by mass, the transparency of the coating layer decreases, and the DFR base material The haze value of the film may increase. It is presumed that the content of the surfactant in the coating layer is substantially equal to the content of the surfactant with respect to the nonvolatile components in the coating solution. The content of the surfactant in the coating solution is preferably 0.01 to 10% by mass, more preferably 0.05 to 5.0% by mass, and still more preferably 0.10 with respect to the nonvolatile component in the coating solution. It is -3.0 mass%, More preferably, it is 0.10-1.0 mass%, Most preferably, it is 0.30-1.0 mass%.

  As the surfactant, an anionic surfactant, a nonionic surfactant, a cationic surfactant, or an amphoteric surfactant can be used. Among these, anionic surfactants and nonionic surfactants are preferable from the viewpoint of compatibility with various resins, and anionic surfactants are particularly preferable.

  Examples of the anionic surfactant include sulfonic acid types such as alkyl sulfonates, alkyl aryl sulfonates and ester sulfonates, alkyl phosphate esters or salts thereof, polyoxyalkylene alkyl ether phosphate esters or salts thereof. And the like, phosphoric acid types such as alkyl sulfates, sulfates such as alkyl ether sulfates, and carboxylate types such as alkyl fatty acid salts. Among these, a sulfonic acid type is preferable from the viewpoint of excellent antistatic properties.

  Examples of the sulfonic acid type anionic surfactant include alkyl sulfonates such as decyl sulfonate, dodecyl sulfonate, tetradecyl sulfonate, hexadecyl sulfonate, octadecyl sulfonate, butylbenzene sulfonic acid, and the like. Salt, hexylbenzenesulfonate, octylbenzenesulfonate, decylbenzenesulfonate, dodecylbenzenesulfonate, tetradecylbenzenesulfonate, hexadecylbenzenesulfonate, octadecylbenzenesulfonate, dibutylnaphthalenesulfonate Salts, alkylaryl sulfonates such as triisopropyl naphthalene sulfonate, dibutyl sulfosuccinate ester salt, dioctyl sulfosuccinate ester salt, dodecyl sulfoacetate salt, nonylphenoxypoly Ester sulfonate salts such as Chi glycol sulfoacetate ester salts. Among these, from the viewpoint of excellent antistatic properties, the alkyl group has 8 or more carbon atoms, preferably 10 to 22 carbon atoms, more preferably 12 to 18 carbon atoms. The salt is preferably a metal salt, more preferably an alkali metal salt such as lithium, sodium or potassium, and even more preferably a sodium salt. The type is preferably an alkyl sulfonate from the viewpoint of antistatic properties.

  Examples of the phosphoric acid type anionic surfactant include butyl phosphate ester, butyl phosphate ester salt, hexyl phosphate ester, hexyl phosphate ester salt, octyl phosphate ester, octyl phosphate ester salt, decyl phosphate ester, decyl phosphate ester salt , Lauryl phosphate, lauryl phosphate, tetradecyl phosphate, tetradecyl phosphate, hexadecyl phosphate, hexadecyl phosphate, stearyl phosphate, stearyl phosphate, etc. Alkyl phosphate ester or its salt, polyoxyethylene butyl ether phosphate ester, polyoxyethylene butyl ether phosphate ester salt, polyoxyethylene hexyl ether phosphate ester, polyoxyethylene hex Ether ether phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxyethylene lauryl ether phosphorus Acid ester, polyoxyethylene lauryl ether phosphate ester salt, polyoxyethylene tetradecyl ether phosphate ester, polyoxyethylene tetradecyl ether phosphate ester salt, polyoxyethylene hexadecyl ether phosphate ester, polyoxyethylene hexadecyl ether Phosphate ester salt, polyoxyethylene stearyl ether phosphate ester, polyoxyethylene stearyl ether phosphate ester salt, polyoxy Propylene octyl ether phosphate, polyoxypropylene octyl ether phosphate, polyoxypropylene decyl ether phosphate, polyoxypropylene decyl ether phosphate, polyoxypropylene lauryl ether phosphate, polyoxypropylene lauryl ether Examples thereof include polyoxyalkylene alkyl ether phosphate esters such as phosphate ester salts or salts thereof.

  Among these, alkyl phosphate ester salts, polyoxyalkylene alkyl ether phosphate esters or salts thereof are preferable from the viewpoint of performance as a surfactant and antistatic performance.

  Regarding the alkyl phosphate ester salt, the alkyl group has a carbon number of 4 or more, preferably 4 to 22, more preferably 6 to 12, and the polyoxyalkylene alkyl ether phosphate ester or a salt thereof. The alkyl group has 4 or more carbon atoms, preferably 6-22, more preferably 8-18. Further, the salt is preferably a metal salt or an amine salt, more preferably an alkali metal salt such as lithium, sodium or potassium, an alkylamine salt or an alcoholamine salt, more preferably a sodium salt or a monoethanolamine salt.

  Nonionic surfactants include, for example, ester types in which polyhydric alcohols such as glycerin and saccharides and fatty acids are ester-bonded, ether types such as polyoxyethylene alkyl ethers and polyoxyethylene alkylphenyl ethers, fatty acids and polyhydric alcohols. Examples include an ester / ether type in which an alkylene oxide is added to a fatty acid ester, and an amide type such as a fatty acid alkanolamide in which a hydrophobic group and a hydrophilic group are connected via an amide bond. Among these, an ester type, an ether type, and an ester / ether type are preferable in consideration of heat resistance, and an ether type is preferable in consideration of antistatic performance.

  Examples of the ester type or ester / ether type nonionic surfactant include glycerol mono (di) laurate, glycerol mono (di) stearate, glycerol, glycerol mono (di) oleate, and diglycerol mono (di) stearate. Glycerin fatty acid esters such as triglycerol mono (di) stearate, polyoxyethylene glycerol mono (di) laurate, polyoxyethylene glycerol mono (di) stearate, polyoxypropylene glycerol mono (di) laurate, polyoxypropylene glycerol Polyoxyalkylene glycerin fatty acid esters such as mono (di) stearate, polyoxybutylene glycerol mono (di) laurate, polyoxybutylene glycerol mono (di) stearate, Polyoxyalkylenes such as oxyethylene mono (di) laurate, polyoxyethylene mono (di) stearate, polyoxyethylene mono (di) oleate, polyoxypropylene mono (di) laurate, polyoxypropylene mono (di) stearate Fatty acid esters, sorbitan mono (di) laurate, sorbitan mono (di) palmitate, sorbitan mono (di) stearate, sorbitan mono (di) oleate and other sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan mono Palmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, Polyoxypropylene sorbitan monolaurate, polyoxyalkylene sorbitan fatty acid esters such as polyoxypropylene sorbitan monostearate, and the like.

  Among these, glycerin fatty acid ester, polyoxyalkylene glycerin fatty acid ester, and polyoxyalkylene fatty acid ester are preferable from the viewpoint of compatibility with polyester and antistatic properties. Alkylene glycerin fatty acid esters are more preferred.

  Among these, in view of excellent antistatic properties and compatibility, the alkyl group has 8 or more carbon atoms, preferably 10 to 22 carbon atoms, more preferably 12 to 18 carbon atoms.

  Examples of ether type nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene isodecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyldodecyl ether. , Polyoxypropylene lauryl ether, polyoxypropylene cetyl ether, polyoxypropylene stearyl ether, polyoxypropylene oleyl ether, polyoxybutylene lauryl ether, polyoxybutylene cetyl ether, polyoxybutylene stearyl ether, polyoxybutylene oleyl ether, etc. Polyoxyalkylene alkyl ether, polyoxyethylene triphenyl phenyl ether, polyoxy Ethylene tribenzyl phenyl ether, polyoxyalkylene phenyl ethers of polyoxyethylene di styrene phenyl ether and the like.

  Among these, polyoxyalkylene alkyl ether is preferable from the viewpoint of antistatic properties. In view of excellent antistatic properties and compatibility, the alkyl group has 8 or more carbon atoms, preferably 10 to 22 carbon atoms, more preferably 12 to 18 carbon atoms.

  Examples of the cationic surfactant include quaternary ammonium salt types such as alkyl ammonium salts and alkyl benzyl ammonium salts, and amine salt types such as N-methylbishydroxyethylamine fatty acid ester and hydrochloride. Among these, the quaternary ammonium salt type is preferable from the viewpoint of excellent antistatic properties.

  Examples of the quaternary ammonium salt type cationic surfactant include octyltrimethylammonium salt, decyltrimethylammonium salt, lauryltrimethylammonium salt, tetradecyltrimethylammonium salt, hexadecyltrimethylammonium salt, stearyltrimethylammonium salt, octyldimethyl. Ethylammonium salt, decyldimethylethylammonium salt, lauryldimethylethylammonium salt, tetradecyldimethylethylammonium salt, hexadecyldimethylethylammonium salt, octyltriethylammonium salt, lauryltriethylammonium salt, hexadecyltriethylammonium salt, didecyldimethylammonium salt Alkylammonium salts such as octyldimethylbenzyl ammonium Alkylbenzylammonium salts such as salts, decyldimethylbenzylammonium salt, lauryldimethylbenzylammonium salt, tetradecyldimethylbenzylammonium salt, hexadecyldimethylbenzylammonium salt, stearyldimethylbenzylammonium salt, tributylbenzylammonium salt, trihexylbenzylammonium salt Etc.

  Among these, alkylammonium salts are preferable from the viewpoint of performance as a surfactant and antistatic performance.

  Moreover, carbon number of an alkyl group is the longest, and is 4 or more normally, Preferably it is 6-22, More preferably, it is the range of 8-18. In addition, examples of counter ions (counter ions) of the ammonium group include halogen ions, sulfonates, sulfates, phosphates, nitrates, carboxylates, and the like. Among these, from the viewpoint of good antistatic properties, chloride. , Sulfonate and sulfate are preferred.

  Examples of amphoteric surfactants include betaine types such as alkylbetaines, amino acid types such as alkylamino fatty acid salts, amine oxide types such as alkylamine oxides, and the like. Among these, a betaine type is preferable from the viewpoint of excellent antistatic performance.

  Examples of betaine zwitterionic surfactants include octyldimethylaminoacetic acid betaine, decyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, tetradecyldimethylaminoacetic acid betaine, hexadecyldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine. Amide propyl betaine octanoate, amide propyl betaine decanoate, amide propyl betaine laurate, amide propyl betaine tetradecanoate, amide propyl betaine hexadecanoate, amide propyl betaine stearate and the like.

Polyester film for dry film resist substrate The DFR substrate film of the present invention has a coating layer formed from a coating solution containing a crosslinking agent on at least one side of a polyester film. This DFR substrate film The average surface roughness (Ra) is preferably 1 to 10 nm, more preferably 1 to 8 nm, and still more preferably 1 to 5 nm. When the average surface roughness (Ra) of the DFR substrate film is in the range of 1 to 10 μm, the transparency can be maintained. When the average surface roughness (Ra) exceeds 10 nm, the transparency of the film for DFR base material is lowered, exposure to ultraviolet rays is insufficient, and there is a possibility that a circuit is lost or a resolution is lowered. On the other hand, when the average surface roughness (Ra) is less than 1 nm, the slipperiness deteriorates, so that scratches are likely to occur on the film surface in the process suitability, particularly in the film forming process. As a result of the surface, a high resolution dry film resist with a thin resist thickness can have a significant effect. The average surface roughness (Ra) of the film for DFR base material can be measured by the measuring method of the Example mentioned later.

  The maximum surface height (Rt) of the DFR base film is preferably 10 to 200 nm, more preferably 10 to 150 nm. When the maximum surface height of the DFR base film exceeds 200 nm, a dent is generated in the dry film resist, and this dent portion may cause a circuit defect or a resolution reduction. When the maximum surface height (Rt) is in this range, it is possible to obtain a film with less circuit loss and good resolution. The maximum surface height (Rt) of the film for DFR base material can be measured by the measuring method of the Example mentioned later.

  The haze of the DFR substrate film of the present invention is preferably 1.0% or less, more preferably 0.7% or less. A dry film resist base material that is sufficiently exposed to ultraviolet rays in a high-resolution dry film resist and that is not susceptible to circuit loss or resolution reduction because the haze of the DFR base film is 1.0% or less. Polyester film can be obtained. The haze of the DFR substrate film is preferably a small value, but is usually 0.1% or more. The haze of the film for DFR base material can be measured by the measuring method of the Example mentioned later.

  The friction coefficient of the DFR base film of the present invention is preferably 0.8 or less, more preferably 0.7 or less. When the friction coefficient is 0.8 or less, it is possible to obtain a DFR base film that hardly causes scratches during the winding process. The coefficient of friction can impart slipperiness while maintaining transparency by adding particles to the coating layer. Although it is preferable that the friction coefficient is small, the friction coefficient of the DFR base film is usually 0.1 or more. The coefficient of friction can be measured by the measurement method of the examples described later.

  The film for a DFR substrate of the present invention preferably has an air leakage index measured according to JIS P8119 of 400000 seconds or less. The air leakage index of the DFR substrate film is more preferably 350,000 seconds or less, further preferably 300000 seconds or less, and even more preferably 250,000 seconds or less. When the air leakage index of the film for DFR base material is 400000 seconds or less, the air caught when the film is wound into a roll form can be easily released, and the films can be brought into close contact with each other and rolled up, for example during storage And misalignment in the direction of the winding core during conveyance can be prevented, and damage due to misalignment or the like can be prevented. Further, when the air leakage index of the DFR substrate film is 400000 seconds or less, a winding property when the film is wound in a roll form is good, and a DFR substrate film that hardly causes surface wrinkles can be obtained. . The air leakage index of the DFR substrate film is preferably small, but if it is too small, the adhesiveness of the wound film becomes too high, and the workability may deteriorate. The air leakage index of the DFR base film is usually 8000 seconds or more, preferably 10,000 seconds or more, more preferably 30000 seconds or more.

  In this specification, the air leakage index is based on JIS P8119, for example, using a Digibeck smoothness tester (DB-2, manufactured by Toyo Seiki Seisakusho Co., Ltd.), in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50% RH. Using a vacuum vessel with a pressure device pressure of 100 kPa and a volume of 38 mL, measure the time (seconds) until 1 mL of air flows, that is, the time until the pressure in the vessel changes from 50.7 kPa to 48.0 kPa, The air leak index was 10 times the number of seconds obtained. The sample size for measurement was 70 mm × 70 mm, and 20 sheets were laminated so that the coating layer of the sample of one PDF base film and the polyester film of the other PDF base film overlapped, It can be measured by making a 5 mm diameter hole in the center of the laminated film so that the leakage is uniform.

  The DFR base film of the present invention has a coating layer on at least one side of a polyester film, but a functional layer may be provided on the other side of the polyester film. Although a functional layer is not specifically limited, A stain | pollution | contamination prevention layer, an antiblocking layer, etc. are mentioned.

  Further, the coating layer may be defoamer, coatability improver, thickener, organic lubricant, ultraviolet absorber, antioxidant, foaming agent, dye, pigment as long as the gist of the present invention is not impaired. Etc. can also be contained.

  The DFR base film of the present invention has a coating layer on at least one side of a polyester film, but a functional layer may be provided on the other side of the polyester film. Although a functional layer is not specifically limited, A stain | pollution | contamination prevention layer, an antiblocking layer, etc. are mentioned.

  The DFR base film of the present invention is obtained by applying a photosensitive resin to at least one side of the DFR base film, and laminating the photosensitive resin on the opposite release layer by pressure lamination. It can be used as a protective film.

  As the photosensitive resin, a conventional composition can be used. Usually, as the photosensitive resin for dry film resist, a negative photosensitive resin is used, and it is mainly composed of a composition containing a monomer having a polymerizable unsaturated group, a polymer, a photopolymerization initiator, and the like. The photosensitive resin generally has alkali water solubility, and a portion exposed in the dry film resist processing step forms a circuit by development, and an unexposed portion is removed by the developer.

  Although it does not specifically limit as a monomer which has a polymerizable unsaturated group, A monomer which has one polymerizable unsaturated group, a monomer which has two polymerizable unsaturated groups, a polymerizable unsaturated group The monomer which has 3 or more is mentioned, These are used individually or in combination suitably.

  Examples of the monomer having one polymerizable unsaturated group include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, propyl (meth) acrylate, and 2-hydroxypropyl (meta). ) Acrylate, butyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2 -Hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, phthalic acid derivative half (meth) acrylate, N-methylol (meth) acrylamide and the like.

  Examples of the monomer having two polymerizable unsaturated groups include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene. Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type Di (meth) acrylate, ethylene oxide / propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate Glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, propylene glycol diglycidyl di (meth) acrylate, phthalate Examples include acid diglycidyl ester di (meth) acrylate and hydroxypivalic acid-modified neopentyl glycol di (meth) acrylate. Among these, ethylene oxide-modified bisphenol A type di (meth) acrylate and ethylene oxide / propylene oxide modified bisphenol A type di (meth) acrylate are preferably used.

  Examples of the monomer having three or more polymerizable unsaturated groups include trimethylolpropane tri (meth) acrylate, trimethylolpropane tripropoxy (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta ( And (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly (meth) acrylate, and the like.

  In addition to the above, an epoxy (meth) acrylate compound, a urethane (meth) acrylate compound, a phosphorus element-containing polymerizable compound, or the like may be used.

  As the monomer having a polymerizable unsaturated group, those having two polymerizable unsaturated groups and having a weight average molecular weight of 1500 or less, preferably 300 to 1200 are preferable, and in particular, ethylene oxide-modified bisphenol A Type di (meth) acrylate and ethylene oxide / propylene oxide modified bisphenol A type di (meth) acrylate are preferably used. When the weight average molecular weight exceeds 1,500, the distance between crosslinks becomes long and sufficient curing may not be obtained, which may result in a decrease in resolution and a decrease in fine line adhesion.

  Although it does not specifically limit as a polymer contained in the photosensitive resin composition, The polymer which consists of an acryl-type and a methacryl-type polymerizable monomer is mentioned. Either a homopolymer or a copolymer, or a copolymer with a polymerizable monomer other than an acrylic or methacrylic monomer may be used. Examples of polymerizable monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, or anhydrides and half esters thereof, methyl (meth) acrylate, and ethyl (meth) acrylate. , Propyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, hydroxy (Meth) acrylates such as ethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, acrylamide, methacrylamide, acrylonitrile, methacrylonite Le, styrene, alpha-methyl styrene, vinyl acetate, alkyl vinyl ether.

  The weight average molecular weight of the above polymer is preferably 5,000 to 250,000, more preferably 10,000 to 200,000. When the weight average molecular weight is less than 5,000, the resin becomes too soft and the resin may bleed out when processed into a roll form as a photoresist film. When the weight average molecular weight exceeds 250,000, the resolution may decrease.

  The glass transition temperature (Tg) of the polymer is preferably in the range of 30 to 150 ° C. When the glass transition temperature is less than 30 ° C., the resin becomes so soft that the resin may bleed out when processed into a roll form as a photoresist film. There is a possibility that the followability to the unevenness of the substrate surface at the time is lowered.

  A conventionally well-known thing is used as a photoinitiator contained in the photosensitive resin composition. For example, benzophenone, P, P'-bis (dimethylamino) benzophenone, P, P'-bis (diethylamino) benzophenone, P, P'-bis (dibutylamino) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone Benzophenone derivatives such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin phenyl ether, benzoin isobutyl ether and other benzoin derivatives, anthraquinone, naphthoquinone and other quinone derivatives, 2-chlorothioxanthone, 2 -Thioxanthone derivatives such as methylthioxanthone and 2,4-diethylthioxanthone, dichloroacetophenone, 2,2-diethoxyacetophenone, 2,2-di Acetophenone derivatives such as rolo-4-phenoxyacetophenone, phenylglyoxylate, α-hydroxyisobutylphenone, dibenzoparone, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl-1-propanone, 2-methyl- Propanone derivatives such as [4- (methylthio) phenyl] -2-morpholino-1-propanone, sulfone derivatives such as tribromophenylsulfone and tribromomethylphenylsulfone, 2,4,6- [tris (trichloromethyl)]- 1,3,5-triazine, 2,4- [bis (trichloromethyl)]-6- (4'-methoxyphenyl) -1,3,5-triazine, 2,4- [bis (trichloromethyl)]- 6- (4′-methoxynaphthyl) -1,3,5-triazine, 2,4- [bis ( Trichloromethyl)]-6- (piperonyl) -1,3,5-triazine, 2,4- [bis (trichloromethyl)]-6- (4'-methoxystyryl) -1,3,5-triazine, etc. Triazine derivatives, acridine derivatives such as acridine and 9-phenylacridine, 2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole, 2,2 '-Bis (o-chlorophenyl) -4,5,4', 5'-tetraphenyl-1,1'-biimidazole, 2,2'-bis (o-fluorophenyl) -4,5,4 ', 5'-tetraphenyl-1,1'-biimidazole, 2,2'-bis (o-methoxyphenyl) -4,5,4 ', 5'-tetraphenyl-1,1'-biimidazole, 2, 2'-bis (p-me Xylphenyl) -4,5,4 ', 5'-tetraphenyl-1,1'-biimidazole, 2,4,2', 4'-bis [bi (p-methoxyphenyl)]-5,5'- Diphenyl-1,1'-biimidazole, 2,2'-bis (2,4-dimethoxyphenyl) -4,5,4 ', 5'-diphenyl-1,1'-biimidazole, 2,2'- Bis (p-methylthiophenyl) -4,5,4 ', 5'-diphenyl-1,1'-biimidazole, bis (2,4,5-triphenyl) -1,1'-biimidazole, etc. Hexaarylbiimidazole derivatives such as tautomers covalently bonded at 1,2'-, 1,4'-, 2,4'-, etc. disclosed in Japanese Patent Publication No. 45-37377, etc. , Benzoylbenzoic acid, methyl benzoylbenzoate, benzy Diphenyl disulfide, benzyldimethyl ketal, 2-methyl-1- [4- (methylthio) phenyl] -2-morifornopropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1 -Hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl- 1-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis ( 2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-to Limethylbenzoyl-diphenyl-phosphine oxide, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, etc. Can be given. These may be used alone or in combination of two or more. Among these, 2,2-dimethoxy-1,2-diphenylethane-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 are preferable.

  Other photosensitive resin compositions include heat crosslinking agents such as amino resins such as melamine and isocyanate compounds, crystal violet, malachite green, malachite green lake, brilliant green, patent blue, methyl violet, Victoria blue, rose aniline. , Coloring dyes such as parafuchsin and ethylene violet, adhesion promoter, plasticizer, antioxidant, thermal polymerization inhibitor, solvent, surface tension modifier, stabilizer, chain transfer agent, antifoaming agent, flame retardant, etc. Additives can be added.

  When a photosensitive resin composition is provided on a base film to form a photosensitive resin layer, a method in which an organic solvent is mixed with the photosensitive resin composition so as to have a predetermined concentration is used. Examples of the organic solvent include acetone, methyl ethyl ketone, methanol, ethanol, isopropyl alcohol, toluene, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate and the like. These may be used alone or in combination of two or more. A coating solution containing a mixture of photosensitive resin compositions is uniformly coated on one side of a carrier film by a method such as a roll coater method or a bar coater method, and is usually 50 to 130 ° C. or in an oven where the temperature is gradually increased. The photosensitive resin layered body (dry film resist) is manufactured by drying, forming the photosensitive resin layer, and winding up in roll shape.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measurement method and evaluation method used in the present invention are as follows.

(1) Measuring method of intrinsic viscosity of polyester 1 g of polyester from which other polymer components and pigments incompatible with polyester have been removed are precisely weighed, and 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) is added. And dissolved at 30 ° C.

(2) Measuring method of average particle diameter (d50) Integrated volume fraction in an equivalent spherical distribution in which particle A or particle B was measured using a centrifugal sedimentation type particle size distribution measuring device (SA-CP3 type) manufactured by Shimadzu Corporation The particle size of 50% was defined as the average particle size d50.

(3) Measuring method of average surface roughness (Ra) It calculated | required as follows using the surface roughness measuring machine (SE-3500) by a Kosaka laboratory. That is, a portion having a reference length L (2.5 mm) is extracted in the direction of the average line from the cross-sectional curve of the sample film of the DFR substrate film, the average line of the extracted portion is the x axis, and the direction of the vertical magnification is y. When expressed as a roughness curve y = f (x) as an axis, the value given by the following equation (1) is expressed in [nm]. The arithmetic average roughness was represented by the average value of the arithmetic average roughness of the extracted portion obtained from 10 roughness curves obtained from the sample film surface and obtained from these roughness curves. The tip radius of the stylus was 2 μm, the load was 30 mg, and the cutoff value was 0.08 mm.
Ra = (1 / L) ∫L0 | f (x) | dx (1)

(4) Measuring method of maximum surface height (Rt) The sampled portion of the cross-sectional curve obtained at the time of measuring the average surface roughness (Ra) of the sample film of the DFR base film is two straight lines parallel to the average line. When the extracted part is sandwiched, the distance between the two straight lines is measured in the direction of the vertical magnification of the cross-sectional curve, and the value expressed in units of micrometers (μm) is the maximum surface height (Rt) of the extracted part. did. The maximum height was expressed as an average value of the maximum heights of the extracted portions obtained from 10 cross-sectional curves obtained from the sample film surface.

(5) Method for measuring film thickness of coating layer The surface of the coating layer of the sample film of the DFR base film was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by the ultrathin section method was stained with RuO ₄ , and the cross section of the release layer was subjected to a transmission electron microscope (TEM) (H-7650, acceleration voltage 100 kV) manufactured by Hitachi High-Technologies Corporation. It measured using.

(6) Evaluation method of appearance of coating layer The surface of the coating layer of the sample film of the DFR base film is irradiated with an LED light (GF-006) manufactured by Gentos Co., Ltd. and visually observed, and coating unevenness is not seen. A is shown as A, B as slightly seen, C as seen slightly, and D as seen on the entire surface.

(7) Method for measuring film haze Using a haze meter (HM-150) manufactured by Murakami Color Research Laboratory Co., Ltd., a sample film of a DFR substrate film according to JIS-K-7136, film haze is measured. It was measured.

(8) Dynamic friction coefficient measurement method A sample film of a DFR base film is pasted on a smooth glass plate having a width of 10 mm and a length of 100 mm with the coating layer as the upper surface, and cut into a width of 18 mm and a length of 120 mm. The coating layer side of another sample film was pressed against a metal pin having a diameter of 8 mm, the metal pin was slid in the longitudinal direction of the glass plate at a load of 30 g, 40 mm / min, and the frictional force was measured. The coefficient of friction at is the dynamic coefficient of friction.

(9) Evaluation method of scratch resistance The surface of the coating layer of the DFR base film test film was rubbed five times using a rubbing tester manufactured by Taihei Rika Kogyo Co., Ltd. LED light: GF-006 is irradiated and observed visually, A is a coating layer with no scratches observed, B is a scratched area of 20% or less with respect to the total area of the test film, A sample having 50% or less was designated as C and a sample having more than 50% was designated as D.

(10) Measuring method of air leak index Digibeck smoothness tester manufactured by Toyo Seiki Co., Ltd .: DB-2 was used and measured in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH according to JIS P8119. The pressure of the pressurizer is 100 kPa, and the vacuum vessel is a small vacuum vessel with a volume of 38 ml. The time for 1 mL of air to flow, that is, the time until the pressure in the vessel changes from 50.7 kPa to 48.0 kPa (seconds) And 10 times the obtained number of seconds was taken as the air leakage index. The sample size of the DFR base film test film was 70 mm square, and 20 sheets were laminated so that the front and back of the test film (the coating layer side and the polyester film side) overlapped, and the air leakage was made uniform. A measurement was made by making a 5 mm diameter hole in the center of the film. The larger the value of the air leakage index, the more time it takes for air to leak from the gaps between the films, indicating that the films are in close contact with each other.

(11) Evaluation method of surface wrinkles A sample film of a film for a DFR substrate was wound up in a 500 m roll, and left for 16 hours in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH. A film whose surface was not wrinkled after being rolled up after 16 hours A, in the direction of the roll core of the wrinkle which was generated on the surface of the film wound up in a roll The width (hereinafter, the width of the wrinkle in the winding core direction is referred to as “horizontal width”) is 1 cm or less, B is the width of 5 cm or less, and D is the width exceeding 5 cm.

The polyester used in the examples and comparative examples was prepared as follows.
<Method for producing polyester (A)>
Using terephthalic acid as the dicarboxylic acid component and ethylene glycol as the polyhydric alcohol component, polyester (A) having an intrinsic viscosity of 0.65 dl / g was obtained by a conventional melt polymerization method.

<Method for producing polyester (B)>
In the production method of polyester (A), polyester is used in the same manner as the production method of polyester (A) except that 1.5 parts by weight of alumina particles having an average particle diameter of 0.05 μm are added as particles B before melt polymerization. (B) was obtained. When 1.5 parts by weight of alumina particles having an average particle diameter of 0.05 μm is added, it is presumed that the particles Bb having a particle diameter of 0.30 μm or more in the resulting polyester film are hardly contained.

<Method for producing polyester (C)>
In the production method of polyester (A), polyester is used in the same manner as the production method of polyester (A) except that 0.5 part by weight of styrene resin having an average particle size of 0.35 μm is added as particle B before melt polymerization. (C) was obtained.

<Method for producing polyester (D)>
In the production method of the polyester (A), the polyester is produced using the same method as the production method of the polyester (A) except that 0.2 parts by weight of silica particles having an average particle size of 2.0 μm are added as the particle B before the melt polymerization. (D) was obtained. When 0.2 part by weight of silica particles having an average particle size of 2.0 μm is added, the resulting polyester film contains particles Bb having a particle size of 0.30 μm or more.

Examples of compounds contained in the coating solution for forming the coating layer are as follows.
Crosslinking agent / melamine compound (I): hexamethoxymethylolmelamine.

Release agent / polyethylene wax (II):
An emulsification facility with an internal capacity of 1.5 L equipped with a stirrer, thermometer, temperature controller, melting point 105 ° C., acid value 16 mgKOH / g, density 0.93 g / mL, average molecular weight 5000 oxidized polyethylene wax 300 g, ion exchanged water 650 g 50 g of decaglycerin monooleate surfactant and 10 g of 48% potassium hydroxide aqueous solution were added and replaced with nitrogen, then sealed, stirred at 150 ° C for 1 hour at high speed, cooled to 130 ° C, and passed through a high-pressure homogenizer at 400 atm. A wax emulsion cooled to 40 ° C.

Particle A
Silica particles (IIIA): colloidal silica having an average particle size of 0.02 μm.

Silica particles (IIIB): colloidal silica having an average particle size of 0.045 μm.

Silica particles (IIIC): colloidal silica having an average particle size of 0.07 μm.

Silica particles (IIID): colloidal silica having an average particle size of 0.14 μm.

Various polymers and acrylic resins (IVA):
An acrylic resin copolymerized with n-butyl acrylate / n-butyl methacrylate / ethyl acrylate / ethyl methacrylate = 20/26/40/14 (mol%).

・ Polyester resin (IVB):
(Acid component) terephthalic acid / isophthalic acid / 5-sodium sulfoisophthalic acid // (diol component) ethylene glycol / 1,4-butanediol / diethylene glycol = 56/40/4 // 70/20/10 (mol%) Polyester resin aqueous dispersion copolymerized in).

Cross-linking catalyst / melamine cross-linking catalyst (V): 2-amino-2-methyl hydrochloride.

Example 1:
The mixed raw materials in which the polyesters (A) and (B) are mixed at a ratio of 80% and 20% are used as the outermost layer (surface layer) raw material, and the polyester (A) is used as the intermediate layer raw material in each of two extruders. Are melted at 285 ° C. and then coextruded and cooled on a cooling roll set to 40 ° C. in a layer configuration of two types and three layers (surface layer / intermediate layer / surface layer = 1: 14: 1 discharge amount). Solidified to obtain an unstretched sheet. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then applied to one side of the machined film and the composition shown in Table 1 below on one side of the machined film. Liquid 1 was applied, led to a tenter, stretched 4.0 times at 95 ° C. in the transverse direction, heat treated at 230 ° C., relaxed 2% in the transverse direction, and on one side of a 16 μm thick polyester film, A film for a DFR substrate having a coating layer with a thickness of 0.04 μm after drying, an average surface roughness (Ra) of 4 nm on the coating layer surface, and a maximum surface height (Rt) of 80 nm on the coating layer surface was obtained. . Since the average particle size of the particles B contained in the polyester film used for the DFR substrate film is 0.05 μm, the particle size exceeds 0.30 μm in the polyester film used for the DFR substrate film. Particles B-b are not included. The properties of the DFR base film are shown in Table 2 below. As shown in Table 2, the DFR substrate film of Example 1 had good coating appearance and film haze, and also had good dynamic friction coefficient, scratch resistance, and air leakage index.

Examples 2-9:
In Example 1, the composition of the coating layer was changed to the composition of the coating liquid having the formulation shown in Table 1, and the production was performed in the same manner as in Example 15 except that this coating liquid was used to obtain a DFR substrate film. It was. As shown in Table 2, the completed DFR substrate film had good coating appearance and film haze, and also had good dynamic friction coefficient, scratch resistance, and air leakage index.

Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except not providing a coating layer, and obtained the film. When the obtained film was evaluated, since it did not have a coating layer, it was as shown in Table 2, and was a film having a poor dynamic friction coefficient and scratch resistance.

Comparative Examples 2 and 3:
In Example 1, a film was obtained in the same manner as in Example 1 except that the coating composition of the coating layer was changed to the composition of the coating liquid having the formulation shown in Table 1. When the obtained film was evaluated, it was as shown in Table 2, and since the coating liquids 9 and 10 did not contain a crosslinking agent, the films of Comparative Examples 2 and 3 were coated although the coating appearance was good. Even a film having a layer was a film having poor scratch resistance.

Comparative Example 4:
The mixed raw materials in which the polyesters (A) and (D) are mixed in proportions of 85% and 15%, respectively, are used as the outermost layer (surface layer) raw material, and the polyester (A) is used as the intermediate layer raw material in each of the two extruders. Are melted at 285 ° C. and then coextruded and cooled on a cooling roll set to 40 ° C. in a layer configuration of two types and three layers (surface layer / intermediate layer / surface layer = 1: 14: 1 discharge amount). Solidified to obtain an unstretched sheet. Next, the film was stretched 3.2 times in the machine direction at a film temperature of 85 ° C. using the difference in peripheral speed of the roll, and then the coating liquid 4 having the composition shown in Table 1 below was applied to one side of the film. Then, the film was stretched 4.0 times at 95 ° C. in the transverse direction, heat-treated at 230 ° C., relaxed 2% in the transverse direction, and the film thickness after drying was 0.1% on one side of a 16 μm thick polyester film. A film having a coating layer of 04 μm, having an average surface roughness (Ra) of 40 nm on the coating layer surface and a maximum surface height (Rt) of 500 nm on the coating layer surface was obtained. When the obtained film was evaluated, the film of Comparative Example 4 has an average particle size of 2.0 μm of particles B contained in the polyester film. Particles Bb exceeding 30 μm were included. Since the film of Comparative Example 4 contained particles Bb having a particle size of more than 0.30 μm in the polyester film having the coating layer, the dynamic friction coefficient, scratch resistance, and air leakage index were good. The average surface roughness (Ra) was large and the film haze was high. The properties of this film are shown in Table 2 below.

  The polyester film for a dry film resist substrate of the present invention can be suitably used as a substrate film for a dry film resist used, for example, when a printed wiring board is produced.

Claims (14)

  A polyester for a dry film resist substrate, comprising a coating layer formed from a coating solution containing a crosslinking agent on at least one surface of a polyester film substantially free of particles B having a particle size of 0.30 μm or more. the film.   The polyester film for a dry film resist substrate according to claim 1, wherein the polyester film contains particles B having an average particle diameter of 0.001 to 0.1 μm.   The polyester film for a dry film resist substrate according to claim 2, wherein the polyester film has two or more polyester layers, and at least one layer contains particles B having an average particle diameter of 0.001 to 0.1 μm. .   The polyester film for a dry film resist substrate according to claim 2, wherein the polyester film has three or more polyester layers, and particles B having an average particle diameter of 0.001 to 0.1 μm are contained in at least one surface layer.   The polyester film for a dry film resist substrate according to any one of claims 1 to 4, wherein the surface having the coating layer has an average surface roughness (Ra) of 1 to 10 nm.   The polyester film for a dry film resist substrate according to any one of claims 1 to 5, wherein the surface having the coating layer has an air leakage index measured according to JIS P8119 of 400000 seconds or less.   The polyester film for a dry film resist substrate according to any one of claims 1 to 6, wherein the coating layer contains particles A.   The polyester film for a dry film resist substrate according to claim 7, wherein the average particle diameter of the particles A is in the range of 0.5 to 5 times the film thickness of the coating layer.   The polyester film for a dry film resist substrate according to any one of claims 1 to 8, wherein the coating layer contains a wax.   The polyester film for a dry film resist substrate according to any one of claims 1 to 9, wherein the crosslinking agent is a melamine compound or an oxazoline compound.   The polyester film for a dry film resist substrate according to claim 10, wherein the crosslinking agent is a melamine compound.   The polyester film for a dry film resist substrate according to any one of claims 1 to 11, wherein the content of the crosslinking agent with respect to all nonvolatile components in the coating solution is 5 to 85 mass%.   The polyester film for a dry film resist substrate according to claim 12, wherein the content of the cross-linking agent with respect to all nonvolatile components in the coating solution is 25 to 70% by mass. The dry film resist which has a photosensitive resin on the said application layer of the polyester film for dry film resist base materials of any one of Claims 1-13.