JP2017222032A - Film for photosensitive resin base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film for photosensitive resin base material, wherein the polyester film is, for example, used as a base film in a dry film resist step for making a flexible printed circuit board and the like and does not require protective films, leading to cost reduction.SOLUTION: A polyester film for photosensitive resin base material has a release layer containing a compound having a long-chain alkyl group on at least one side of a polyester film.SELECTED DRAWING: None

Description

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

  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 film has, for example, a three-layer structure of a base film / photosensitive resin layer / protective film, and a polyethylene film is conventionally used as the protective film. The dry film resist film is manufactured by drying the photosensitive resin layer coated on the base film and then laminating the protective film on the photosensitive resin layer, but the photoresist layer is flexible when laminating the protective film. The surface shape of the protective film is transferred to the photosensitive resin layer.

  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 the conductor pattern formed on the surface of the insulating substrate. Polyethylene film, which is a protective film, has many unevenness due to thickness fluctuations and fish eyes, and when this is transferred to the photosensitive resin layer, the surface of the photosensitive resin layer becomes uneven, resulting in poor adhesion of the photosensitive resin layer to the insulating substrate. Cause a decrease in yield. Therefore, the polyethylene film which is a protective film is one of the factors that hinder high definition of the flexible printed wiring board.

  A polyethylene film is formed by melt extrusion. However, since the melt viscosity is high, it is extremely difficult to filter with a high-performance filter during extrusion, and the problem that fish eyes and the like are present in the formed sheet is unavoidable. Furthermore, it is difficult to obtain a uniform thickness by the inflation method, which is a general method for forming a polyethylene film, and the problem of thickness fluctuation is unavoidable. Therefore, it has become difficult to meet the demand for higher density printed wiring boards using a polyethylene film as a protective film.

  A polyethylene film (Patent Document 1) for protecting a dry film resist with relatively few irregularities caused by fish eyes has been proposed. However, because of the extrusion laminating method, the thickness is as thick as 30 μm, the amount of polyethylene to be consumed is high, the cost is high, the laminated roll is also heavy, handling properties are lowered, and workability thereafter is also lowered. .

  A method of using a polyester film as a protective film as an alternative to a polyethylene film (Patent Document 2) has also been proposed. In order to ensure the releasability from the photosensitive resin layer, the releasability is imparted by the release layer. However, since the release property of the release layer is not sufficient, the base film is blended with a copolymer component such as a long-chain aliphatic dicarboxylic acid and / or polyolefin to give flexibility, and is as flexible as a polyethylene film. To the polyester film. However, since a special raw material is used for the base film, there is a problem that the cost of the film is increased.

  As a method for imparting releasability to a polyester film, a method of applying and laminating a silicone composition represented by polydimethylsiloxane on the surface of the polyester film (Patent Document 3) has also been proposed. However, the silicone-based release film has a problem that when the silicone component is transferred to the photosensitive resin layer and the protective film is peeled off and then bonded to the insulating substrate, the adhesive force is reduced, causing a defect. From these viewpoints, a polyester film having excellent releasability with respect to the photosensitive resin layer is required.

JP 2003-231759 A JP-A-6-297565 JP 2009-143091 A

  This invention is made | formed in view of the said situation, The solution subject can be used suitably as a base film in the dry film resist process which produces a flexible printed circuit board etc., and does not require a protective film It is providing the polyester film which can reduce cost.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the above-described problems can be easily solved by using a film for a photosensitive resin substrate having a specific configuration, and to complete the present invention. It came.

  That is, the gist of the present invention resides in a polyester film for a photosensitive resin substrate having a release layer containing a compound having a long-chain alkyl group on at least one surface of the polyester film.

  According to this invention, since it has the base film for photosensitive resins and a release layer, it can wind up in roll shape, without laminating | stacking a protective film on the photosensitive resin layer. The polyester film with reduced cost can be provided by omitting the protective film, and its industrial value is high.

  The polyester film constituting the polyester film for the photosensitive resin base material in the present invention may be a single layer structure or a multilayer structure, and other than the two-layer or three-layer structure, as long as the gist of the present invention is not exceeded, There may be four or more layers, and it is not particularly limited.

  The polyester used in the present invention is a copolyester. In the case of a homopolyester, those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Typical polyester includes polyethylene terephthalate and the like. On the other hand, the dicarboxylic acid component of the copolyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, p-oxybenzoic acid, etc.), etc. 1 type or 2 types or more are mentioned, As a glycol component, 1 type or 2 types or more, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 4-cyclohexane dimethanol, neopentyl glycol, is mentioned.

  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 and can be polymerized in a small amount, and since the amount of metal remaining in the film is small, the transparency of the film becomes high. The compound is preferable because it is inexpensive.

  In the polyester layer of the film of the present invention, particles can be blended mainly for the purpose of imparting slipperiness and preventing scratches in each step. When blending the particles, the kind of the particles to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness, and specific examples include, for example, silica, alumina, calcium carbonate, magnesium carbonate, barium carbonate. And inorganic particles such as calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, zirconium oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used. Among these, alumina particles and silica particles are preferable because high transparency and scratch resistance can be obtained.

  The average particle diameter of the particles is usually 3.0 μm or less, preferably 2.0 μm or less, more preferably 0 to 0.5 μm. When the average particle size exceeds 3.0 μm, the surface roughness of the film is so rough that the unevenness of the film may be transferred to the photosensitive resin. When unevenness is generated in the photosensitive resin, when the photosensitive resin is removed by the acid edging process, the edging process degree is affected and a circuit may be defective.

  When the polyester has a multilayer structure, the particle content when adding particles to the surface layer is usually less than 50% by weight, preferably in the range of 40% by weight, more preferably in the range of 0 to 30% by weight. If the haze is high when the particle content is high, there is a problem that the exposure of ultraviolet rays for curing the photosensitive resin becomes insufficient, resulting in a circuit loss or a decrease in resolution.

  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 layer 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 each layer, but it is preferably added after completion of esterification or transesterification.

  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 film forming method of the film of the present invention, 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.

  In the present invention, the simultaneous biaxial stretching method can be adopted for the production of the polyester film constituting the protective film. The simultaneous biaxial stretching method is a method in which the above-mentioned unstretched sheet is usually stretched and oriented in the machine direction and the width direction at a temperature controlled normally at 70 to 120 ° C., preferably 80 to 110 ° C. Is 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times in terms of area magnification. Subsequently, heat treatment is performed at a temperature of 170 to 270 ° C. under tension or relaxation within 30% to obtain a stretched oriented film. With respect to the simultaneous biaxial stretching apparatus that employs the above-described stretching method, a conventionally known stretching method such as a screw method, a pantograph method, or a linear driving method can be employed.

  Next, formation of the release layer constituting the protective film in the present invention will be described. Regarding the release layer, it may be provided by in-line coating which treats the film surface during the process of forming the polyester film, or offline coating which is applied outside the system on the once produced film may be adopted. More preferably, it is formed by in-line coating.

  In-line coating is a method of coating within the process of manufacturing a polyester film, and specifically, a method of coating at any stage from melt extrusion of a polyester to heat setting after stretching and winding up. Usually, it is coated on any of an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, and a film after heat setting and before winding.

  Although not limited to the following, for example, in sequential biaxial stretching, a method of stretching in the transverse direction after coating on a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) is particularly excellent. According to such a method, film formation and mold release layer formation can be performed at the same time, so there is an advantage in manufacturing cost. In addition, in order to perform stretching after coating, the thickness of the mold release layer can be changed depending on the stretch ratio. The thin film coating can be performed more easily than the offline coating.

  Further, by providing a release layer on the film before stretching, the release layer can be stretched together with the base film, whereby the release layer can be firmly adhered to the base 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 base film can be more firmly adhered to each other. Furthermore, a strong coating layer can be obtained.

  In the present invention, it is an essential requirement to have a release layer containing a compound having a long-chain alkyl group on at least one side of the polyester film.

  The polyester film in the present invention is used, for example, as a base film for a photosensitive resin, and has a release layer suitable for protecting the photosensitive resin.

  As a result of various studies, the present inventors have included a compound having a long-chain alkyl group in the release layer, and thus wound up in a roll shape without laminating a protective film on the photosensitive resin layer. And found that the cost can be reduced.

  The compound having a long-chain alkyl group contained in the release layer of the polyester film of the present invention is a kind of so-called release agent, and is used for improving applicability as a polyester film for a substrate. As the release agent, a compound having a long-chain alkyl group may be used alone, or a plurality of types may be used. In the case of using a plurality of types, conventionally known release agents can be used in combination, and examples thereof include waxes, fluorine compounds, and silicone compounds. However, since there is a concern about the transfer of the release agent to the photosensitive resin layer, the silicone compound is preferably a compound that does not contain a silicone compound, such as a wax and a fluorine compound, when used in combination.

  The long-chain alkyl compound 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 is preferable. Further, from the viewpoint of effectively obtaining releasability, a polymer compound having a long-chain alkyl group in the side chain is more 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 view 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 wax is a 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.

  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.

  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 type 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.

  In the formation of the coating layer of the film of the present invention, an antistatic agent, a crosslinking agent, and various polymers are used in combination for the purpose of improving the coating appearance and transparency, controlling the release property, and improving the strength of the release layer. It is possible.

  The antistatic agent is used for lowering the surface resistance of the film surface, and there is no particular limitation, and it is possible to use a conventionally known antistatic agent, but since heat resistance and heat and humidity resistance are good, It is preferably a polymer type antistatic agent. Examples of the polymer type antistatic agent include ammonium group-containing compounds, polyether compounds, sulfonic acid compounds, betaine compounds, and conductive polymers. Among these, an ammonium group-containing compound and a conductive polymer are preferable from the viewpoint that coating properties are particularly good and antistatic ability can be imparted. However, since the conductive polymer is more expensive than the ammonium group-containing compound, the ammonium group-containing compound is more preferable from the viewpoint of cost.

  The ammonium group-containing compound is a compound having an ammonium group in the molecule, and examples thereof include aliphatic amines, alicyclic amines, and ammonium compounds of aromatic amines. The ammonium group-containing compound is preferably a polymer compound. For example, an ammonium group-containing polymer compound is obtained from a polymer obtained by polymerizing a monomer containing an addition polymerizable ammonium group or a precursor of an ammonium group such as an amine. Are preferably used. As the polymer, a monomer containing an addition polymerizable ammonium group or a precursor of an ammonium group such as an amine may be polymerized alone, or it may be a copolymer of a monomer containing these and another monomer. May be.

  Specific examples of the ammonium group-containing compound include, but are not limited to, a polymer containing a component represented by the following formula (1) or the following formula (2). A single polymer or copolymer, or a plurality of other components may be copolymerized.

In the above formula (1), R ² is —O— or —NH—, R ³ is an alkylene group, or other structure capable of forming the structure of formula (1), R ¹ , R ⁴ , R ⁵ , R ⁶ Are each a hydrogen atom, an alkyl group, a phenyl group or the like, and these alkyl group and phenyl group may be substituted with the following groups. Substitutable groups include, for example, hydroxy group, amide group, ester group, alkoxy group, phenoxy group, naphthoxy group, thioalkoxy group, thiophenoxy group, cycloalkyl group, trialkylammonium alkyl group, cyano group, halogen, etc. is there.

In the above formula (2), R ¹ and R ² are each independently a hydrogen atom, an alkyl group, a phenyl group or the like, and these alkyl group and phenyl group may be substituted with the groups shown below. . Substitutable groups include, for example, hydroxyl group, amide group, ester group, alkoxy group, phenoxy group, naphthoxy group, thioalkoxy group, thiophenoxy group, cycloalkyl group, trialkylammonium alkyl group, cyano group, halogen, etc. is there. R ¹ and R ² may be chemically bonded. For example, — (CH ₂ ) _m — (m is an integer of 2 to 5), —CH (CH ₃ ) CH (CH ₃ ) —, -CH = CH-CH = CH - , - CH = CH-CH = N -, - CH = CH-N = C -, - CH 2 OCH 2 -, - (CH 2) 2 O (CH 2) 2 - Etc.

  In the case of a polymer having the structural element represented by the above formula (1) as a repeating unit, the viewpoint of improving the compatibility with other materials and improving the transparency of the resulting coating film, and further improving the releasability From the viewpoint of, it is preferable to copolymerize with other repeating units. Other repeating units include, for example, alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Can be mentioned.

  In the case of a polymer having the constituent represented by the above formula (2) as a repeating unit, it is preferably copolymerized with another repeating unit from the viewpoint of improving the releasability. Other repeating units include, for example, alkyl acrylates, alkyl methacrylates, and acrylamides such as n-methylol acrylamide.

  Further, from the viewpoint of further improving the antistatic performance, a homopolymer having the constituent represented by the above formula (2) as a repeating unit is preferable.

X ⁻ in the above formulas (1) and (2) can be appropriately selected within a range not impairing the gist of the present invention. Examples include halogen ions, sulfonates, phosphates, nitrates, alkyl sulfonates, and carboxylates.

The polymer having the component represented by the above formula (1) is excellent in transparency of the resulting coating layer, and has an advantage that the appearance is relatively good when used in combination with a release agent. In view of heat resistance and environmental aspects, X ⁻ is preferably not halogen.

  A compound represented by the above formula (2) or other ammonium base in the polymer skeleton is excellent in heat resistance and is preferable.

  In addition, the polymer in which the constituents represented by the above formulas (1) and (2) and the polyethylene glycol-containing (meth) acrylate are copolymerized has a flexible structure, and is uniform during coating and stretching. An excellent release layer is preferably obtained.

  Alternatively, a release layer having excellent uniformity can also be obtained by coating a polyethylene glycol-containing (meth) acrylate polymer in the coating solution.

  Specific examples of the polyethylene glycol-containing (meth) acrylate include polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene glycol diacrylate (the polymerization degree of polyethylene glycol units is preferably in the range of 4 to 14), and polypropylene glycol diacrylate. Acrylate, polytetramethylene glycol diacrylate, poly (ethylene glycol-tetramethylene glycol) diacrylate, poly (propylene glycol-tetramethylene glycol) diacrylate, polyethylene glycol-polypropylene glycol-polyethylene glycol diacrylate, polypropylene glycol-polybutylene glycol Monomethacrylate, methoxypolyethylene glycol Methacrylate, methoxy polyethylene glycol monoacrylate, octoxy polyethylene glycol-polypropylene glycol monomethacrylate, octoxy polyethylene glycol-polypropylene glycol monoacrylate, lauroxy polyethylene glycol monomethacrylate, lauroxy polyethylene glycol monoacrylate, stearoxy polyethylene glycol monomethacrylate, steer Examples include polymers starting from loxypolyethylene glycol monoacrylate, allyloxypolyethylene glycol monomethacrylate, allyloxypolyethylene glycol monoacrylate and the like.

  The number average molecular weight of the antistatic agent used in the release layer of the present invention is usually 1000 to 500000, preferably 2000 to 350,000, and more preferably 5000 to 200000. When the molecular weight is less than 1000, the strength of the coating film may be weak or the heat stability may be poor, and the antistatic property may not be sufficient. On the other hand, when the molecular weight exceeds 500,000, the viscosity of the coating solution increases, and the handleability and applicability may deteriorate.

  Examples of the conductive polymer include polythiophene-based, polyaniline-based, polypyrrole-based, and polyacetylene-based polymers. Among them, for example, polythiophene-based polymers using poly (3,4-ethylenedioxythiophene) in combination with polystyrene sulfonic acid. Are preferably used.

  Examples of polyether compounds include polyethylene oxide, polyether ester amide, acrylic resins having polyethylene glycol in the side chain, and the like.

  The sulfonic acid compounds are compounds containing sulfonic acid or sulfonate in the molecule, and examples thereof include polystyrene sulfonic acid.

  As the crosslinking agent, various known crosslinking agents can be used. For example, melamine compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, etc., among these, the crosslinking density is high. From the viewpoint of preventing the release layer from being transferred to the photosensitive resin, it is preferable to use a melamine compound. Moreover, these crosslinking agents may use 2 or more types together.

  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 release layer and the substrate, it is preferably an alkylolated melamine derivative partially etherified, and is an alkylol etherified with methyl alcohol. It 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 catalyst can be used to increase the reactivity of the melamine compound.

  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, 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.

  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 polyvinyl alcohol are preferable in terms of easy release control and improving the strength of the release layer.

  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, for example, 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, monobutyl hydroxyl fumarate, monobutyl hydroxy 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, Various nitrogen-containing compounds such as acetone acrylamide, N-methylol acrylamide 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.

  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.

  The polyester resin includes, for example, those composed of 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 the polyvalent hydroxy compound, ethylene Recall, 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.

  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.

  As a ratio with respect to all the non-volatile components of the release layer constituting the protective film in the present invention, the long-chain alkyl group-containing compound is usually in the range of 5 to 100% by weight, preferably in the range of 10 to 70% by weight, more preferably 20 It is in the range of -55% by weight. If the amount is less than 5% by weight, sufficient release performance may not be obtained.

  As a ratio with respect to all the non-volatile components of the release layer constituting the protective film in the present invention, the crosslinking agent is usually in the range of 90% by weight or less, preferably in the range of 10 to 70% by weight, more preferably in the range of 15 to 50% by weight. It is a range. By adding a cross-linking agent, transfer of the release agent to the photosensitive resin can be prevented.

  As a ratio with respect to all the non-volatile components of the release layer constituting the protective film in the present invention, the antistatic agent is usually 80% by weight or less, preferably 10 to 60% by weight, more preferably 25 to 60% by weight. . When the amount is more than 80% by weight, there is a possibility that the releasability cannot be obtained because there are few other components.

  As a ratio with respect to all the non-volatile components of the release layer constituting the protective film in the present invention, the polymer is usually 80% by weight or less, preferably 10 to 60% by weight, and more preferably 5 to 40% by weight.

  The peel strength of the release layer of the present invention depends on the type of photosensitive resin used. For example, the peel strength for an acrylic adhesive tape is preferably 1200 mN / cm or less, more preferably 900 mN / cm or less, particularly preferably 600 mN / cm. cm or less. Further, the lower limit of the peeling force is usually 10 mN / cm.

When an antistatic agent is used in combination with the release layer of the present invention, the surface resistance value of the release layer is preferably 5 × 10 ¹² Ω or less, more preferably 1 × 10 ¹² Ω or less, and particularly preferably 1 × 10 ^11. Ω or less. If it exceeds 5 × 10 ¹² Ω, the antistatic performance is insufficient, so that foreign matters such as dust are likely to adhere, or wrinkles are likely to occur due to static electricity in the processing step of the photosensitive resin.

  The release layer in the present invention is characterized in that it is laminated on at least one side of the polyester film, but a functional layer different from the release layer may be provided on the other side of the polyester film. The functional layer is not particularly limited, and examples thereof include an antistatic layer, an antifouling layer, and an antiblocking layer.

  The film thickness of the release layer provided on the polyester film in the present invention is usually 0.001 to 1 μm, preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.2 μm, and particularly preferably 0.00. The range is from 003 to 0.08 μm. When the film thickness exceeds 1 μm, the appearance of the coating film may be deteriorated or the release layer may be transferred to the photosensitive resin. When the film thickness is less than 0.001 μm, sufficient releasability is obtained. In some cases, the peelability from the photosensitive resin may deteriorate.

  As long as the gist of the present invention is not impaired, particles may be used in combination with the formation of the release layer of the film of the present invention for the purpose of improving blocking properties and slipping properties.

  Further, as long as it does not impair the gist of the present invention, the release layer is formed with an antifoaming agent, a coating property improver, a thickener, an organic lubricant, an ultraviolet absorber, an antioxidant, and a foaming agent as necessary. It is also possible to use dyes, pigments and the like in combination.

  Examples of the method for applying the release layer to the polyester film include air doctor coating, blade coating, rod coating, bar coating, knife coating, squeeze coating, impregnation coating, reverse roll coating, transfer roll coating, gravure coating, and kiss roll. Conventionally known coating methods such as coat, cast coat, spray coat, curtain coat, calendar coat, and extrusion coat can be used.

  Further, irrespective of off-line coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as required. In order to improve the applicability and adhesion of the release layer to the film, the film may be subjected to a surface treatment such as chemical treatment, corona discharge treatment, plasma treatment, ozone treatment, chemical treatment, or solvent treatment before coating.

  The polyester film of the present invention is used as a protective film for a photosensitive resin layer by applying a photosensitive resin on one side of a base film and laminating the photosensitive resin on the opposite release layer by pressure lamination. be able to.

  As the photosensitive resin, a conventional composition can be used. Usually, as a 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. When the glass transition temperature exceeds 150 ° C., it is used 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- 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 amino resins such as melamine and thermal crosslinking agents such as 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 product is manufactured by drying, forming a 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) Method for measuring the 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) Measurement of average particle diameter (d50) The average particle diameter d50 is the average particle diameter of 50% in the equivalent spherical distribution measured using a centrifugal sedimentation type particle size distribution measuring device (SA-CP3 type) manufactured by Shimadzu Corporation. It was.

(3) Method for measuring film thickness of release layer The surface of the release layer was dyed with RuO ₄ and embedded in an epoxy resin. Thereafter, the section prepared by ultramicrotomy stained with RuO _4, the cross section of the release layer TEM (Hitachi High Technologies Corporation H-7650, accelerating voltage 100 kV) was used for the measurement.

(4) Evaluation of release force of release layer Adhesive tape (Nitto Denko “No. 31B” base material thickness 25 μm) was applied to the surface of the release layer of the polyester film provided with the release layer with a 2 kg rubber roller. The peel force after reciprocating was measured after standing at room temperature for 1 hour. For the peeling force, “Ezgraph” manufactured by Shimadzu Corporation was used, and 180 ° peeling was performed under the condition of a tensile speed of 300 mm / min.

(5) Evaluation method of surface resistance value High resistance measuring instrument manufactured by Mitsubishi Chemical Analytech Co., Ltd .: UX MCP-HT800 is used, and the sample is conditioned in a measurement atmosphere of 23 ° C. and 50% RH for 30 minutes, and then the release layer The surface resistance value of the surface was measured.

(6) Peelability from photosensitive resin layer As the base film, the opposite side of the release layer of the polyester film described in Example 1 was used, and a photosensitive resin composition having the following composition was applied on one side. , Dried at 110 ° C. for 3 minutes to form a 40 μm photosensitive resin layer, on which the protective film of the present invention was placed so that the release layer and the photoresist layer face each other, and then pressed to release A photosensitive resin laminate protected with a layer was prepared. Thereafter, the release layer was peeled off and the peelability was evaluated. If the release is smooth and there is no transfer of the photosensitive resin to the release layer, and the surface of the photosensitive resin is not scratched, the transfer of the photosensitive resin to the release layer can be performed by paying attention to the release speed. Even if there was almost nothing, Δ was marked even if the photosensitive resin was transferred to the release layer or the surface of the photosensitive resin was damaged even if attention was paid to the peeling speed.

(7) Circuit defects The photosensitive resin surface is adhered to the surface of the copper layer laminated in the glass fiber-containing epoxy resin plate, and the glass plate on which the circuit is printed is adhered to the laminated film surface. Was exposed. Cleaning and etching were performed using an alkaline cleaning solution to form a circuit. The obtained circuit was observed using SEM (S-3400N manufactured by Hitachi High-Technologies Corporation) and evaluated for circuit defects. The case where the circuit defect was not observed by microscopic observation was indicated as ◯, the case where the circuit defect was rarely observed was indicated as Δ, and the case where the circuit defect occurred was indicated as ×.

(Composition of photosensitive resin composition)
As a monomer having a polymerizable unsaturated group, ethylene oxide-modified bisphenol A dimethacrylate having an ethylene oxide repeating number of 17 (total number of repeating units) is 30 parts, and propylene glycol diglycidyl ether diacrylate is 10 parts. A polymer having a weight average molecular weight of 170,000 polymerized at a ratio of methyl methacrylate / n-butyl methacrylate / styrene / methacrylic acid = 45/15/15/25 (weight ratio) using 10 parts of trimethylolpropane triacrylate as a polymer. 25 parts of a polymer having a weight average molecular weight of 20,000 polymerized in a ratio of styrene / acrylic acid = 75/25 (weight ratio), 2,2-dimethoxy-1,2- 2 parts of diphenylethane-1-one, (2-benzyl-2-dimethyl A mixture of 0.4 part Mino-1- (4-morpholinophenyl) -butanone-1, 75 parts methyl ethyl ketone and 25 parts isopropyl alcohol as a solvent, the weight average molecular weight of the polymer being GPC (gel permeation) This is a value obtained by measuring a THF (tetrahydrofuran) solution of a dry polymer on a polystyrene basis using a chromatography apparatus.

(8) Measurement of water droplet contact angle difference In order to evaluate the transfer of the release layer to the photosensitive resin, the following evaluation was performed. Kyowa Interface Science Co., Ltd .: Contact angle meter CA-D / A type, contact angle of the photosensitive resin (contact angle 1) by the droplet method and contact angle of the photosensitive resin after peeling the protective film ( The contact angle 2) was determined. The water used was pure water purified with a MILLI-Q REAGENT-WATER-SYSTEM device manufactured by Nippon Millipore Corporation. The time from the dropping of the droplet to the measurement was about 30 seconds. Measurement was performed 6 times and the average value was adopted.

Contact angle difference = (Contact angle 2) − (Contact angle 1)
A contact angle difference of 8 or less was evaluated as な い with little transfer, 、 １０ 10 or less as ◯ with little transfer, 15 or less as △ with little transfer, and 15 or more as × with almost transfer.

The polyester used in the examples and comparative examples was prepared as follows.
<Method for producing polyester (A)>
100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol, 30 ppm of ethyl acid phosphate with respect to the resulting polyester, and 100 ppm of magnesium acetate tetrahydrate with respect to the resulting polyester as the catalyst at 260 ° C. in a nitrogen atmosphere at 260 ° C. The reaction was allowed to proceed. Subsequently, 50 ppm of tetrabutyl titanate was added to the resulting polyester, the temperature was raised to 280 ° C. over 2 hours and 30 minutes, the pressure was reduced to 0.3 kPa in absolute pressure, and melt polycondensation was further carried out for 80 minutes. A polyester (A) having 0.65 and a diethylene glycol amount of 2 mol% was obtained.

<Method for producing polyester (B)>
In the production method of the polyester (A), the polyester (B) is produced using the same method as the production method of the polyester (A) except that 1.5 parts by weight of alumina particles having an average particle diameter of 0.05 μm is added before the melt polymerization. Got.

<Method for producing polyester (C)>
In the production method of polyester (A), polyester (C) is produced using the same method as the production method of polyester (A) except that 0.5 part by weight of an ion exchange resin having an average particle size of 0.35 μm is added before melt polymerization. )

<Method for producing polyester (D)>
In the method for producing polyester (A), polyester (D) is produced using the same method as the method for producing polyester (A) except that 0.2 parts by weight of silica particles having an average particle size of 2.0 μm is added before melt polymerization. Got.

Examples of compounds constituting the release layer and the functional layer are as follows.
・ Long chain alkyl group-containing compounds: (I)
To a four-necked flask, 200 parts of xylene and 600 parts of octadecyl isocyanate were added and heated with stirring. From the time when xylene began to reflux, 100 parts of polyvinyl alcohol having an average degree of polymerization of 500 and a degree of saponification of 88 mol% was added in small portions over a period of about 2 hours. After the addition of polyvinyl alcohol, the reaction was completed by further refluxing for 2 hours. When the reaction mixture was cooled to about 80 ° C. and added to methanol, the reaction product was precipitated as a white precipitate. This precipitate was filtered off, added with 140 parts of xylene, and heated to dissolve completely. After repeating the operation of adding methanol again to precipitate several times, the precipitate was washed with methanol and dried and ground.

Melamine compound (IIA): hexamethoxymethylol melamine.

Isocyanate compound (IIB): 1000 parts of block polyisocyanate hexamethylene diisocyanate obtained by the following production method was stirred at 60 ° C., and 0.1 part of tetramethylammonium caprylate was added as a catalyst. After 4 hours, 0.2 part of phosphoric acid was added to stop the reaction, and an isocyanurate type polyisocyanate composition was obtained. 100 parts of the obtained isocyanurate type polyisocyanate composition, 42.3 parts of methoxypolyethylene glycol having a number average molecular weight of 400, and 29.5 parts of propylene glycol monomethyl ether acetate were charged and maintained at 80 ° C. for 7 hours. Thereafter, the reaction solution temperature was kept at 60 ° C., 35.8 parts of methyl isobutanoyl acetate, 32.2 parts of diethyl malonate, and 0.88 part of 28% methanol solution of sodium methoxide were added and kept for 4 hours. 58.9 parts of n-butanol was added and held at a reaction solution temperature of 80 ° C. for 2 hours, and then 0.86 part of 2-ethylhexyl acid phosphate was added to obtain a blocked polyisocyanate.

・ Antistatic agent: (IIIA)
A polymer having a pyrrolidinium ring in the main chain polymerized at a ratio of diallyldimethylammonium chloride / dimethylacrylamide / N-methylolacrylamide = 90/5/5 (mol%). Number average molecular weight 30000

・ Antistatic agent: (IIIB)
A polymer having a number average molecular weight of 50000, wherein the counter ion is a methanesulfonate ion, comprising the structural unit of the following formula (3)

・ Acrylic resin: (IVA)
Acrylic resin copolymerized with n-butyl acrylate / n-butyl methacrylate / ethyl acrylate / ethyl methacrylate == 20/26/40/14 (mol%)

・ Polyvinyl alcohol: (IVB)
Polyvinyl alcohol having a saponification degree of 88 mol% and a polymerization degree of 500

・ Polyethylene wax: (VA)
An emulsification facility with an internal volume 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, 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. Wax emulsion cooled to 40 ° C

・ Silicone compounds: (VB)
A reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel was charged with 63 g of methylhydrogensiloxane, 15 g of α-methylstyrene, and 5.0 g of 1-dodecene while heating to 65 ° C. Mix until uniform. Next, an ethylene glycol monobutyl ether / toluene solution of platinum (IV) chloride as a hydrosilylation catalyst was added to the reaction product in the system so that the platinum concentration was 5 ppm by mass, and the reaction was carried out while cooling. When the temperature of the reaction product reached 90 ° C., 44 g of α-methylstyrene was added dropwise while cooling the reaction product so that the temperature of the reaction product became 80 to 110 ° C. After dropping, the reaction product was heated to 120 ° C. and stirred for 1 hour to react. After cooling, when the temperature of the reaction product reached 90 ° C, 42 g of 1-dodecene was added dropwise while cooling the reaction product so that the temperature of the reaction product became 80 to 110 ° C, and then 1.0 g of pentaerythritol triacrylate was added. Added. 42 g of 1-dodecene was added dropwise while cooling the reactants so that the temperature of the reactants was 80 to 110 ° C., and then the reactants were stirred at 100 ° C. for 1 hour and further at 120 ° C. for 4 hours to complete the addition reaction. It was. Thereafter, the reaction product was aerated at 120 ° C. to remove excess 1-dodecene to obtain a silicone compound. In addition, this compound used the silicone compound 1 by weight ratio, mix | blended sodium decylbenzenesulfonate in the ratio of 0.25, and used the water dispersion.

Example 1:
A mixed raw material in which polyesters (A), (B), and (C) are mixed in proportions of 64%, 6%, and 30%, respectively, is used as a raw material for the outermost layer (surface layer), and polyester (A) is used as a raw material for the intermediate layer. Each was supplied to two extruders, each melted at 285 ° C., and then two types and three layers (surface layer / intermediate layer / surface layer = 1: 14: 1 discharge amount) on a cooling roll set at 40 ° C. The unstretched sheet was obtained by co-extrusion and cooling and solidification with the layer structure. Next, the film was stretched 3.2 times in the longitudinal direction at a film temperature of 85 ° C. using the roll peripheral speed difference, and then the coating liquid 1 shown in Table 1 below was applied to one side of the longitudinally stretched film and led to a tenter. After stretching 4.0 times at 95 ° C in the transverse direction and heat-treating at 235 ° C, it is relaxed by 2% in the transverse direction, and a release layer having a coating layer thickness (after drying) of 0.03 µm is formed on one side. A film having a thickness of 16 μm and an Ra (arithmetic mean roughness) of 2 nm was obtained. When the obtained film was evaluated, the release layer and the surface resistance value of the release layer were good, and the film had good peelability with respect to the photosensitive resin. Circuit defects were rarely seen. The properties of this film are shown in Table 2 below.

Examples 2-18:
A protective film was obtained in the same manner as in Example 1 except that the composition of the release layer was changed to the coating composition shown in Table 1 in Example 1. As shown in Table 2, the finished protective film had good release force of the release layer, and good peelability, circuit defects, and contact angle difference with the photosensitive resin.

Example 19:
The mixed raw materials in which the polyesters (A) and (D) were mixed in proportions of 92% and 8%, respectively, were used as the outermost layer (surface layer) raw material, and the polyester (A) was 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 3.3 times in the longitudinal direction at a film temperature of 85 ° C. using the difference in peripheral speed of the roll, and then the coating liquid 1 shown in Table 1 below was applied to one side of the longitudinally stretched film and led to a tenter. The film was stretched 4.7 times at 100 ° C. in the transverse direction, heat treated at 230 ° C., relaxed 2% in the transverse direction, and a release layer having a coating layer thickness (after drying) of 0.03 μm on one side. A film having a thickness of 16 μm and an Ra (arithmetic mean roughness) of 15 nm was obtained. When the obtained film was evaluated, the peeling force of the release layer was good, the film was also good in peelability with respect to the photosensitive resin, and circuit defects were rarely seen. The properties of this film are shown in Table 2 below.

Examples 20-25:
In Example 19, a protective film was obtained in the same manner as in Example 19 except that the composition of the release layer was changed to the coating composition shown in Table 1. As shown in Table 2, the obtained film had good release force and surface resistance value of the release layer, and good peelability to the photosensitive resin.

Comparative Example 1:
In Example 1, it manufactured similarly to Example 1 except not providing a mold release layer, and obtained the film. When the obtained film was evaluated, it was as shown in Table 2. It was a film having poor release properties of the release layer and inferior peelability to the photosensitive resin.

Comparative Examples 2-6:
In Example 1, a film was obtained in the same manner as in Example 1 except that the coating composition of the release layer was changed to the coating composition shown in Table 1. When the obtained film was evaluated, it was as shown in Table 2. Since the release layer was inferior in releasability, the film was inferior in peelability to the photosensitive resin.

Comparative Example 7:
In Example 1, a film was obtained in the same manner as in Example 1 except that the coating composition of the release layer was changed to the coating composition shown in Table 1. When the obtained film was evaluated, it was as shown in Table 2. The film was inferior in transfer to the photosensitive resin such that the water droplet contact angle difference was large and the release agent was transferred to the photosensitive resin.

  The film for photosensitive resin base material of this invention can be utilized suitably as a base film for photosensitive resin used at the time of printed wiring board manufacture etc., for example.

Claims (3)

A polyester film for a photosensitive resin substrate, comprising a release layer containing a compound having a long-chain alkyl group on at least one side of the polyester film. The polyester film for a photosensitive resin substrate according to claim 1, wherein the release layer contains an antistatic agent. A polyester film for a photosensitive resin substrate, containing particles in polyester, and having an average particle diameter of 0.5 μm or less.