JP2005059285A - Laminated polyester film for dry film resist - Google Patents

Abstract

[Objective] To provide a high-quality film for dry film resist that has excellent resolution and prevents image defects.
[Configuration] At least one outermost layer contains 100 to 2000 ppm of crosslinked polymer particles having an average particle size of 0.1 to 1.0 μm and 10 to 500 ppm of silica particles having an average particle size of 0.1 to 3.0 μm. A dry film comprising an axially oriented laminated polyester film, wherein Ra on the surface of the outermost layer is 0.005 to 0.020 μm, Rt is less than 0.50 μm, and film haze is 2.0% or less. Laminated polyester film for resist.
[Selection figure] None

Description

  The present invention relates to a biaxially oriented laminated polyester film for dry film resist. Specifically, the present invention relates to a high-quality biaxially oriented laminated polyester film for a dry film resist that is excellent in winding characteristics and optical resolution of not only a film for a substrate but also a dry film itself and prevents image defects.

  In recent years, films for dry film resist substrates have been widely used in the production of printed wiring circuit boards. The film for a dry film resist substrate is usually a laminated structure composed of a support layer / dry film resist layer / protective layer. As the support, a polyester film having excellent mechanical properties, optical properties, chemical resistance, heat resistance, dimensional stability, flatness and the like is mainly used. The dry film resist layer is a layer made of a photosensitive resin, and a polyethylene film or a polyester film is used as the protective layer. Briefly explaining how to use the film for a dry film resist substrate, the protective layer is first peeled off, and the exposed dry film resist layer is brought into close contact with the conductive substrate attached to the substrate. The conductive substrate is generally a copper plate. Next, the glass plate on which the circuit is printed is brought into close contact with the support layer side of the dry film resist film, and light is irradiated from the glass plate side. In the circuit image printed on the glass plate, light passes through a transparent portion, and the photosensitive resin of the dry film resist layer reacts only on the exposed portion. Next, the glass plate and the support layer are removed, and the unexposed portion of the dry film resist layer is removed using an appropriate solvent or the like. Further, if etching is performed using an acid or the like, the dry film resist layer is removed and the exposed conductive base material portion is removed. Thereafter, when the dry film resist layer exposed and reacted is removed by an appropriate method, a conductive substrate layer is formed on the substrate as a circuit.

Recently, the circuits to be formed have become extremely complicated, the lines have become narrower, and the intervals between them have become narrower, and it has become necessary to have high reproducibility and resolution of image formation. For this reason, high quality has come to be requested | required also with respect to the polyester film used as a support body.
The polyester film used as the support is required to have high transparency and low film haze. In the dry film resist film, when the dry film resist layer is exposed, light passes through the support layer as described above. Therefore, if the transparency of the support is low, problems such as insufficient exposure of the dry film resist layer and deterioration of resolution due to light scattering occur.

  On the other hand, the polyester film of the support needs to have an appropriate slip property. That is, in order to improve the handleability when producing a dry film resist film by forming a dry film resist layer on the film, or to improve the handleability of the film for the dry film resist substrate itself, a good slip It is necessary to have sex. Usually, in order to satisfy such characteristics, a method is used in which particles are contained in a polyester film and fine protrusions are formed on the surface (for example, see Patent Document 1). These protrusions satisfy the adhesion between the polyester film and the glass plate on which the circuit is printed, and prevent problems such as air bubbles entering between the film and the glass plate to impair the reproducibility of the circuit image. Is necessary to do.

However, when forming protrusions by adding particles, on the other hand, the transparency of the film will be lowered, and since it has such contradictory characteristics, transparency, slipperiness, air escape properties were satisfied at the same time. A method for obtaining a film for a high-quality dry film resist substrate has not yet been found.
Japanese Patent Laid-Open No. 7-333853

  The present invention has been made in view of the above circumstances, and the problem to be solved is a high-quality dry film that has excellent resolution and prevents image defects when used as a film for a dry film resist substrate. It is providing the film for resist base materials.

  As a result of intensive studies in view of the above problems, the present inventors have found that a film having a specific configuration has excellent characteristics, and have completed the present invention.

  That is, the gist of the present invention is that at least the outermost layer on one side contains 100 to 2000 ppm of crosslinked polymer particles having an average particle size of 0.1 to 1.0 μm and 10 silica particles having an average particle size of 0.1 to 3.0 μm. A biaxially oriented laminated polyester film containing ˜500 ppm, wherein Ra on the surface of the outermost layer is 0.005 to 0.020 μm, Rt is less than 0.50 μm, and film haze is 2.0% or less. The feature resides in a laminated polyester film for dry film resist.

Hereinafter, the present invention will be described in detail.
The laminated film referred to in the present invention includes, for example, a film obtained by stretching and heat-treating a film extruded by a so-called coextrusion method in which all layers are co-melt extruded from a die of an extruder. Hereinafter, the coextruded three-layer film will be mainly described as the laminated film. However, the present invention is not limited to the coextruded three-layer film unless the gist of the present invention is exceeded, and two or more multilayers may be used. Good. The polyester constituting each layer of the laminated film of the present invention is a polyester obtained using aromatic dicarboxylic acid or its ester and glycol as main starting materials, and 80% or more of the repeating structural units are ethylene terephthalate units or ethylene-2. , Refers to polyester having 6-naphthalate units. And if it is the conditions which do not deviate from said range, the other 3rd component may be contained. As the aromatic dicarboxylic acid component, in addition to terephthalic acid and 2,6-naphthalenedicarboxylic acid, for example, isophthalic acid, phthalic acid, adipic acid, sebacic acid, 4,4′-diphenyldicarboxylic acid, oxycarboxylic acid (for example, p-oxyethoxybenzoic acid, etc.) can be used. As the glycol component, in addition to ethylene glycol, for example, one or more of diethylene glycol, triethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like can be used.

  In the laminated film of the present invention, the layer that forms at least one outermost layer contains particles, and hereinafter, the outermost layer is referred to as an A layer. The A layer is formed on at least one side of the film. In the present invention, since it is necessary to satisfy the transparency of the film to a high degree, it is preferable that the A layer that gives the slipperiness of the film is on one side. Moreover, it is preferable that layers other than A layer do not contain particle | grains substantially, or even if it contains, there is little content. However, in order to prevent the occurrence of scratches on the opposite side of the A layer and to improve the winding properties of the film, the B layer may contain a small amount of particles as the layer structure of (A / B), or (A / B / As a constitution of C), particles can be contained in the C layer. Further, by providing an A ′ layer having a thickness (A / B / A ′), that is, the same polyester composition as a raw material and having a reduced thickness on the opposite side of the A layer, a smaller number than the A layer on the surface of the A ′ layer. A method of forming the protrusions can also be used.

  The thickness of the A layer of the film of the present invention is usually 0.005 to 3 μm, preferably 0.05 to 2.5 μm, and more preferably 0.5 to 2.0 μm. If the A layer thickness exceeds 3 μm, the transparency of the film may not be highly satisfied. On the other hand, if the A layer thickness is less than 0.005 μm, the particles contained in the A layer are likely to fall off, and the wear resistance of the film may be deteriorated. If falling particles or abrasion powder is generated and enters between the film and the dry film resist layer, the reactivity of the photosensitive resin may be affected, and problems such as deterioration in reproducibility of image formation may occur.

  Examples of particles used in the present invention include inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, and crosslinked polymer particles. , Organic particles such as calcium oxalate, and precipitated particles formed during polyester polymerization. The term “deposited particles” as used herein refers to particles precipitated in a reaction system by polymerizing a system using an alkali metal or alkaline earth metal compound as a transesterification catalyst by a conventional method. Moreover, you may precipitate by adding a terephthalic acid at the time of a transesterification reaction or a polycondensation reaction. In these cases, one or more of phosphorous compounds such as phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, acidic ethyl phosphate, phosphorous acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite May be present. In addition, when the esterification process is performed, the inert substance particles can be deposited by these methods. For example, an alkali metal or alkaline earth metal compound is present before or after completion of the esterification reaction, and the polycondensation reaction is performed in the presence or absence of a phosphorus compound.

  In the present invention, among the above particles, crosslinked polymer particles or silica particles are used in order to obtain particularly high transparency and slipperiness. These particles have favorable characteristics in terms of affinity with the polyester and refractive index, so that the slipperiness can be improved without increasing the haze value of the film.

  The content of the crosslinked polymer particles in the A layer is 100 to 2000 ppm, and the content of the silica particles is 10 to 500 ppm. When three or more kinds of particles are used, the content of the crosslinked polymer particles and the silica particles is preferably larger than the content of the other particles. The average particle diameter of the silica particles is 0.1 to 3.0 μm, and the average particle diameter of the crosslinked polymer particles is 0.1 to 1.0 μm. If the average particle size of any of the particles exceeds the upper limit, excessively large protrusions will be formed on the film surface, resulting in a problem that defects occur due to insufficient adhesion to the surface of the circuit printed glass. Or the particles easily fall off from the film surface, which is not preferable because it causes deterioration of wear resistance. In addition, if the average particle size of any of the particles is below the lower limit, the formation of protrusions is insufficient, and the slipperiness of the film is insufficient, or bubbles may enter between the film and the glass when in close contact with the glass. It becomes.

  Examples of the crosslinked polymer that can be preferably used in the present invention include one or more monovinyl compounds having only one aliphatic unsaturated bond in the molecule (a) and two or more aliphatic molecules in the molecule as a crosslinking agent. The compound (b) having at least one unsaturated bond can be copolymerized by emulsion polymerization in the presence of a specific initiator. The emulsion polymerization method here refers to emulsion polymerization in a broad sense including concepts such as seed emulsion polymerization. Examples of the compound (a) include acrylic acid, methacrylic acid and alkyl or glycidyl esters thereof, maleic anhydride and alkyl derivatives thereof, vinyl glycidyl ether, vinyl acetate, styrene, alkyl-substituted styrene and the like. Examples of the compound (b) include divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate, and 1,4 butanediol diacrylate. One or more compounds (a) and (b) are used, respectively, but a compound containing a nitrogen atom or ethylene may be copolymerized. Examples of the polymerization initiator include, but are not limited to, water-soluble polymerization initiators such as potassium persulfate, potassium persulfate-sodium thiosulfate, and hydrogen peroxide.

  Depending on the combination of the above compounds or the synthesis conditions of the particles, some agglomerated particles may be generated. Therefore, the following dispersion stabilizer is preferably used in order to maintain the dispersibility of the particles. Anions such as fatty acid salts, alkyl sulfate esters, alkyl benzene sulfonates, alkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl diphenyl ether disulfonates, alkyl phosphates, polyoxyethylene alkyl or alkyl allyl sulfates Surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene derivative, polyoxyethylene-oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, Nonionic surfactants such as glycerin fatty acid esters and cationic surfactants such as alkylamine salts and quaternary ammonium salts; Rukirubetain, amphoteric surfactants such as amine oxides. Among them, anionic surfactants represented by alkyl diphenyl ether disulfonate and the like are particularly preferably used.

  The crosslinked polymer used in the present invention can be usually obtained as follows. That is, a copolymer of a monovinyl compound (A) having only one aliphatic unsaturated bond in the molecule and a compound (B) having two or more aliphatic unsaturated bonds in the molecule as a crosslinking agent Can be illustrated. In this case, the copolymer may have a group capable of reacting with the polyester.

  Examples of the compound (A) which is a component of the copolymer include acrylic acid, methacrylic acid, and methyl or glycidyl esters thereof, maleic anhydride and alkyl derivatives thereof, vinyl glycidyl ether, vinyl acetate, styrene, alkyl-substituted styrene, etc. Can be mentioned. Examples of the compound (B) include divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate and the like. One or more compounds (A) and (B) are used, respectively, but a compound having ethylene or a nitrogen atom may be copolymerized. Typical examples of these copolymers include copolymers of methyl methacrylate and divinylbenzene, and methyl acrylate and divinylbenzene.

  In addition, if the cross-linked polymer having these alkyl ester groups is saponified or copolymerized using methacrylic acid instead of methacrylic acid ester and acrylic acid instead of acrylic acid ester, the cross-linking polymer having a carboxyl group can be easily obtained. A molecule can be obtained. Since a commercially available weakly acidic cation exchange resin has a crosslinked structure and a carboxyl group, it can be suitably used as a crosslinked polymer used in the present invention. Moreover, you may utilize the crosslinked polymer which has the alkylester group which is this intermediate raw material. Furthermore, a copolymer of styrene and divinylbenzene can also be preferably used.

  These particles may be porous. For this purpose, when the compound (a) and the compound (b) are copolymerized, the compound (c) is present, and after the polymerization, the compound (c) is removed with an organic solvent. In general, the method is preferably employed. Examples of the compound (c) include hydrocarbon compounds such as n-hexane, n-heptane, cyclohexane, kerosene, toluene and xylene, alcohol compounds such as n-butanol, n-hexanol and propyl alcohol, and polystyrene, polyvinyl alcohol, poly An alkylene oxide etc. can be mentioned. As a polymerization initiator for copolymerizing the compound (a) and the compound (b), known chemical radical initiators such as azoisobutyronitrile, benzoyl peroxide, t-butyl peroxide, cumene hydro Although peroxide or the like is used or the ultraviolet irradiation method is simple, the polymerization may be started simply by heating.

These copolymers must have a crosslinked structure and be substantially insoluble, infusible and heat resistant even at high temperatures during polyester production or molding. For this purpose, the crosslinking degree of such a crosslinked polymer is preferably 6 to 50%, more preferably 7 to 45%. The degree of crosslinking is a numerical value defined by the following formula. If this value is less than 8%, pulverization tends to be difficult. Since the density of the group decreases, the bonding strength with the polyester becomes poor.
The degree of crosslinking (%) = divinyl compound weight × 100 / monomer amount Any method can be used as long as it satisfies the gist of the present invention.

  The total particle content in the A layer in the present invention is 0.01 to 0.25% by weight, more preferably 0.05 to 0.20% by weight, particularly 0.10 to 0.1% of the polyester constituting the A layer. It is desirable to be 0.15% by weight. If the amount is less than 0.01% by weight, the number of protrusions formed on the surface of the layer A tends to be insufficient, so that the film cannot be prevented from being slippery and air bubbles between the glass and the surface can be damaged during film production. This may cause problems such as deterioration of transparency. On the other hand, if the particle content in the layer A exceeds 0.25% by weight, a problem arises in the transparency of the film, resulting in a problem that the resolution tends to be lowered and defects in the circuit are likely to occur. There is a fear.

  Moreover, it is preferable that content of the particle | grains in layers other than A layer is below the content in A layer, and it is preferable that it is the minimum in the range which does not affect the handleability of a film.

  The haze of the film of the present invention is 2.0% or less, preferably less than 1.8%, more preferably less than 1.6%. If the haze exceeds 2.0%, the resolution becomes insufficient, such being undesirable.

  In the production of the polyester containing particles constituting the film of the present invention, the particles may be added during the polyester synthesis reaction or directly to the polyester. When added during the synthesis reaction, a method in which the particles are dispersed in ethylene glycol or the like as a slurry and added at any stage of the polyester synthesis is preferable. On the other hand, when adding directly to polyester, there is a method of adding and mixing to polyester using a vented twin-screw kneading extruder as dried particles or as a slurry dispersed in water or an organic solvent having a boiling point of 200 ° C. or lower. preferable. The particles to be added may be subjected to a treatment such as crushing, dispersing, classification, and filtration in advance as necessary.

  As a method for adjusting the content of particles, a master raw material containing particles at a high concentration is prepared by the above-described method, and at the time of film formation, it is diluted with a raw material that does not substantially contain particles, and the particle content is reduced. It is effective to adjust this.

  Ra of the surface of layer A of the film of the present invention is 0.005 to 0.020 μm, preferably 0.006 to 0.018 μm, and more preferably 0.007 to 0.016 μm. If Ra is less than 0.005 μm, the handleability and winding characteristics of the film will be insufficient. On the other hand, if it exceeds 0.020 μm, the resolution may decrease. Further, Rt on the surface of the A layer is less than 0.50 μm, preferably less than 0.40 μm. An Rt of 0.50 μm or more is not preferable because it causes a decrease in resolution due to poor adhesion to glass.

  The intrinsic viscosity of the polyester of the film of the present invention is preferably 0.45 to 1.0, more preferably 0.50 to 0.80. If the intrinsic viscosity exceeds 1.0, the viscosity is high and the load at the time of producing the polyester and at the time of polymer melt extrusion increases, which may cause a reduction in production efficiency. On the other hand, when the intrinsic viscosity is less than 0.45, troubles such as breakage during film production are likely to occur.

Next, the manufacturing method of the film of this invention is demonstrated concretely.
In the present invention, a coextrusion method is preferably used as a method for obtaining a laminated film. Hereinafter, the example by a coextrusion method is demonstrated. The polyester raw material which comprises each layer is supplied to the extrusion apparatus for coextrusion lamination. That is, two or three or more extruders, three or more layers of multi-manifolds or feed blocks are laminated, and extruded as a molten sheet of three or more layers from a slit-shaped die. At that time, the thickness of each layer can be set by adjusting the flow rate of the polymer with a quantitative feeder such as a gear pump installed in the melt line. Next, the molten sheet extruded from the die is rapidly cooled and solidified on the rotary cooling drum so that the temperature is equal to or lower than the glass transition temperature, thereby obtaining a substantially amorphous unoriented sheet. In this case, in order to improve the flatness of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling drum. In the present invention, the electrostatic application adhesion method and / or the liquid application adhesion method are preferably employed.

  In the present invention, the sheet thus obtained is stretched biaxially to form a film. Specifically describing the stretching conditions, the unstretched sheet is preferably 70 to 150 ° C., more preferably 75 to 130 ° C., and is first stretched in a direction by a roll or a tenter type stretching machine to 3.0 to 7 ° C. The film is stretched twice, preferably 3.2 to 6 times. Next, stretching in the direction orthogonal to the first stage is preferably 75 to 150 ° C., more preferably 80 to 140 ° C., and 3.2 to 7 times, preferably 3.5 to 6 times. An oriented film is obtained. Note that a method of performing unidirectional stretching in two or more stages can also be used, but in this case as well, it is desirable that the final stretching ratio is in the above-described range. Further, the unstretched sheet can be simultaneously biaxially stretched so that the area magnification is 10 to 40 times. The film thus obtained is heat-treated at 150 to 250 ° C. for 1 second to 5 minutes under elongation, limited shrinkage, or constant length within 30%. After biaxial stretching, a method of further re-stretching 1.05 to 2.5 times in the machine direction at a temperature of 110 ° C. to 180 ° C., followed by heat treatment may be employed. At this time, techniques such as heat fixation before re-longitudinal stretching, longitudinal relaxation after re-longitudinal stretching, and before or after re-longitudinal stretching can be appropriately employed. Similarly, restretching may be performed in the transverse direction. Moreover, you may give various surface treatments etc. in a film forming process as needed.

  The film of the present invention may be provided with a coating layer on the surface, the opposite surface or both surfaces of the A layer for the purpose of adjusting the adhesion with the dry film resist layer. Such a coating layer may be provided in the film manufacturing process, or may be applied after the film is manufactured. In particular, in view of uniformity of coating thickness and production efficiency, a method of coating after the longitudinal stretching in the film production process and before entering the lateral stretching process is preferable.

  Examples of the coating agent include resins such as polyester, polyamide, polystyrene, polyacrylate, polycarbonate, polyarylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl butyral, polyvinyl alcohol, polyurethane, and copolymers and mixtures of these resins. However, the present invention is not limited to these. In the present invention, other polymers (for example, polyethylene, polystyrene, polycarbonate, polysulfone, polyphenylene sulfide, polyamide, polyimide, etc.) of about 1% by weight or less can be contained with respect to the total amount of polyester used for film formation. Moreover, you may mix | blend additives, such as antioxidant, a heat stabilizer, an antistatic agent, a lubricant, dye, and a pigment, as needed.

  When the film of the present invention is used as a film for a dry film resist substrate, it is possible to obtain a high-quality film for a dry film resist substrate that is excellent in resolution and prevents image defects. The value is very great.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited by a following example, unless the summary is exceeded. In addition, the measurement methods and definitions of various physical properties and characteristics in the examples are as follows. In the examples and comparative examples, “parts” means “parts by weight”.

(1) Average particle diameter and particle size distribution value It measured with the Shimadzu Corporation centrifugal sedimentation type particle size distribution measuring apparatus (SP-CP3 type). In the present invention, the average particle size is defined as a particle size having an integrated volume fraction of 50% in an equivalent spherical distribution regardless of the shape.

(2) Intrinsic viscosity of polymer [η] (unit: dl / g)
Polymer-1g was dissolved in 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio) and measured at 30 ° C.

(3) Outermost layer thickness It carried out by observation of the film cross section with a transmission electron microscope (TEM). That is, a small piece of the film sample was embedded in a resin in which an epoxy resin was mixed with a curing agent and an accelerator, and a section having a thickness of about 200 nm was prepared with an ultramicrotome to obtain an observation sample. The obtained sample was taken with a transmission electron microscope H-9000 manufactured by Hitachi, Ltd., and a cross-sectional photomicrograph was taken, and the thickness of the surface layer was measured. However, the acceleration voltage was set to 300 kV, and the magnification was set in the range of 10,000 times to 100,000 times according to the outermost layer thickness. Thickness measurement was performed at 50 points, and 10 points from the thicker measurement value and 10 points from the thinner one were deleted, and 30 points were averaged to obtain a measurement value.

(4) Centerline average roughness (Ra)
It calculated | required as follows using the Kosaka Laboratory Co., Ltd. surface roughness measuring machine (SE-3F). That is, a portion having a reference length L (2.5 mm) is extracted from the film cross-sectional curve in the direction of the center line, and the roughness curve y = where the center line of the extracted portion is the x axis and the direction of the vertical magnification is the y axis. When represented by f (x), the value given by the following equation was represented by [μm]. The centerline average roughness was expressed as an average value of the centerline average roughness of the extracted portion obtained from 10 cross-sectional curves obtained from the sample film surface. 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

(5) Maximum height (Rt)
When the extracted portion of the cross-sectional curve obtained at the time of Ra measurement is sandwiched between two straight lines parallel to the average line, the interval between the two straight lines is measured in the direction of the vertical magnification of the cross-sectional curve, and the value is calculated. The value expressed in units of micrometers (μm) was defined as the maximum height Rt of the extracted portion. 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.

(6) Film haze According to JIS-K6741, the turbidity of the film was measured with the Nippon Denshoku Industries Co., Ltd. division-type turbidimeter NDH-20D.

(7) Practical properties of a film for a dry film resist substrate A film for a dry film resist substrate was produced according to a conventional method. That is, a dry film resist layer was provided on the surface opposite to the A layer, and a polyolefin film was laminated thereon as a protective layer. A printed circuit was prepared using the obtained film for a dry film resist substrate. That is, the dry film resist layer surface of the film for a dry film resist base material from which the protective layer was peeled was adhered to a copper plate provided on the glass fiber-containing epoxy resin plate. Next, the glass plate on which the circuit was printed was brought into close contact with the film for the dry film resist base material, and ultraviolet light exposure was performed from the glass plate side. Thereafter, the film for a dry film resist substrate was peeled off, and a series of development operations such as washing and etching were performed to produce a circuit. The circuit thus obtained was observed visually or using a microscope, and the following practical evaluation of the film for a dry film resist substrate was performed according to the quality.

Resolution rank 1: An extremely high resolution is obtained and a clear circuit is obtained. Rank 2: Phenomena such as slightly inferior sharpness and somewhat thicker lines are observed, but there are no practical problems. Rank 3: Sharpness is high. Inferior, cannot be used for high-density circuits

Circuit defect rank 1 ... No circuit defect is found Rank 2 ... Circuit defects are rarely seen Rank 3

Handling property Moreover, it evaluated about the handling property at the time of film production for dry film resist base materials, and use.
Rank 1… The film has sufficient slipperiness, so the handleability is good Rank 2… Slidability is slightly insufficient, so the handleability is somewhat inferior, but there is no practical problem Rank 3… Dry film because the slipperiness is insufficient There are problems in handling properties such as stopping film running during use when preparing resist film

  The manufacturing method of the raw material used in the following examples and comparative examples is as follows.

[Production of pulverized crosslinked polymer particles]
A homogeneous solution of 100 parts of methyl methacrylate, 35 parts of divinylbenzene, 32 parts of ethylvinylbenzene, 1 part of benzoyl peroxide, 100 parts of toluene and 30 parts of polystyrene having an average molecular weight of 20000 was dispersed in 700 parts of water. Next, polymerization was carried out by heating to 70 ° C. with stirring for 15 hours under a nitrogen atmosphere. The average particle size of the obtained crosslinked polymer granules was about 0.2 mm. After washing the produced polymer with water, an extraction operation was performed using 500 parts of toluene at room temperature to remove a small amount of unreacted monomer, linear monomer and polystyrene. Next, after washing with 200 parts of methanol and 500 parts of water, it was dried under reduced pressure at 80 ° C. for 24 hours. Next, the granulate is coarsely pulverized using a jet mill, and further pulverized using a sand grinder, and the average particle diameter is 0.1 μm, 0.3 μm, 1.0 μm, and 1. Crosslinked polymer particles of 2 μm were obtained.

[Production of polyester]
80 parts of dimethyl terephthalate, 20 parts of dimethyl isophthalate, 60 parts of ethylene glycol, and 0.09 part of magnesium acetate tetrahydrate are placed in a reactor, heated to a temperature and distilled off to conduct a transesterification reaction. The temperature was raised to 230 ° C. over 4 hours, and the transesterification reaction was substantially completed.
Subsequently, the previously produced ethylene glycol slurry of crosslinked polymer particles having an average particle size of 0.3 μm and ethylene glycol slurry of silica particles having an average particle size of 2.4 μm were added. After the addition of the slurry, 0.03 part of phosphoric acid and 0.04 part of antimony trioxide are further added, the reaction system is gradually reduced in pressure, the temperature is increased and the polycondensation reaction is carried out for 4 hours. Polyethylene terephthalate (A) was obtained. At this time, the concentration of the crosslinked polymer particles was 500 ppm, and the concentration of the silica particles was 300 ppm. Further, copolymer polyethylene terephthalate (B) having an intrinsic viscosity of 0.651 was obtained in the same manner as in (A) above, with only the concentration of silica particles being 150 ppm.
Further, copolymer polyethylene terephthalate (C) having an intrinsic viscosity of 0.652 was obtained in the same manner as in (A) above, with only the concentration of the crosslinked polymer particles being 1000 ppm.
Further, by using an ethylene glycol slurry of crosslinked polymer particles having an average particle diameter of 1.0 μm and an ethylene glycol slurry of silica particles having an average particle diameter of 2.4 μm by the same method as in the above (A), the intrinsic viscosity is 0.650. Copolyethylene terephthalate (D) was obtained. The concentration of the crosslinked polymer particles was 1000 ppm, and the concentration of the silica particles was 100 ppm. Further, by using an ethylene glycol slurry of crosslinked polymer particles having an average particle size of 0.3 μm and an ethylene glycol slurry of silica particles having an average particle size of 3.0 μm by the same method as in the above (A), an intrinsic viscosity of 0.649 is obtained. Copolyethylene terephthalate (E) was obtained. The concentration of the crosslinked polymer particles was 100 ppm, and the concentration of the silica particles was 500 ppm. Further, by using an ethylene glycol slurry of crosslinked polymer particles having an average particle diameter of 0.1 μm and an ethylene glycol slurry of silica particles having an average particle diameter of 0.1 μm by the same method as in the above (A), the intrinsic viscosity is 0.652. Copolymerized polyethylene terephthalate (F) was obtained. The concentration of the crosslinked polymer particles was 1000 ppm, and the concentration of the silica particles was 500 ppm. In addition, using an ethylene glycol slurry of crosslinked polymer particles having an average particle diameter of 1.0 μm and an ethylene glycol slurry of silica particles having an average particle diameter of 3.0 μm by the same method as in the above (A), an intrinsic viscosity of 0.651 is obtained. Copolymerized polyethylene terephthalate (G) was obtained. The concentration of the crosslinked polymer particles was 1000 ppm, and the concentration of the silica particles was 500 ppm. Further, copolymer polyethylene terephthalate (H) having an intrinsic viscosity of 0.650 was obtained in the same manner as in the above (A) except that the ethylene glycol slurry of silica particles having an average particle size of 2.4 μm was not added. The concentration of the crosslinked polymer particles was 500 ppm. Further, copolymer polyethylene terephthalate (I) having an intrinsic viscosity of 0.649 was obtained in the same manner as in the above (A) except that an ethylene glycol slurry of crosslinked polymer particles having an average particle size of 0.3 μm was not added. The concentration of the crosslinked polymer particles was 500 ppm.
Further, copolymer polyethylene terephthalate (J) having an intrinsic viscosity of 0.651 was obtained, which was the same as (A) except that the concentration of silica particles having an average particle size of 2.4 μm was 600 ppm. Further, copolymer polyethylene terephthalate (K) having an intrinsic viscosity of 0.652 was obtained, which was the same as (A) except that the concentration of the crosslinked polymer particles having an average particle size of 0.3 μm was 1200 ppm. Further, copolymer polyethylene terephthalate (L) having an intrinsic viscosity of 0.650 was obtained which was the same as (A) except that the concentration of the crosslinked polymer particles having an average particle diameter of 1.2 μm was 500 ppm. Further, copolymer polyethylene terephthalate (M) having an intrinsic viscosity of 0.652 was obtained, which was the same as (A) except that the concentration of silica particles having an average particle diameter of 3.5 μm was 300 ppm. Further, a transesterification reaction and a polycondensation reaction were carried out in the same manner as above except that the crosslinked polymer particles and silica particles of (A) were not added and the starting dicarboxylic acid was 100 parts of terephthalic acid. To polyethylene terephthalate (N) having an intrinsic viscosity of 0.630 and containing no inert particles. When the inside of the polyethylene terephthalates (A) to (M) was observed with a microscope, it was confirmed that the particles were uniformly dispersed.

  Using three extruders, the layer A raw material is copolymerized polyethylene terephthalate (A), the layer B raw material is polyethylene terephthalate (N), and the layer A ′ raw material is polyethylene terephthalate (A). A three-layered amorphous sheet (A / B / A ′) was obtained by melt extrusion. In addition, the twin screw extruder with a vent was used for the melt extrusion of A layer and A 'layer raw material. Next, the above amorphous sheet was stretched 3.6 times at 93 ° C. in the film flow direction (longitudinal direction) and 4.2 times at 110 ° C. in the transverse direction, heat treated at 230 ° C. for 6 seconds, and biaxially oriented. A laminated film was obtained. The total thickness of the film was 16 μm, and the thickness of the A layer was 1.5 μm. The thickness of the B layer was 14 μm, and the thickness of the A ′ layer was 0.5 μm.

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (B) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (C) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  A biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (D) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (E) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (F) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (G) was used as the raw material for the A layer and the A ′ layer in Example 1. A film was produced.

  Using two extruders, the layer A raw material is copolymerized polyethylene terephthalate (A), the layer B raw material is polyethylene terephthalate (N), and they are melt-extruded by separate melt extruders (A / B). A biaxially oriented polyester film having the structure (A / B) was produced in the same manner as in Example 1 except that a laminated amorphous sheet was obtained. The total thickness of the film was 16 μm, and the thickness of the A layer was 2.0 μm. The thickness of the B layer was 14 μm.

Comparative Example 1

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (H) was used as the raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 2

  A biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (I) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 3

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (J) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 4

  A biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (K) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 5

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (L) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 6

  Biaxially oriented laminated polyester having the structure (A / B / A ′) in the same manner as in Example 1 except that copolymer polyethylene terephthalate (M) was used as a raw material for the A layer and the A ′ layer in Example 1. A film was produced.

Comparative Example 7

  Using a single extruder, a monolayer polyester film having a thickness of 16 μm was produced using copolymerized polyethylene terephthalate (A) as a raw material.

Comparative Example 8

  Using one extruder, a monolayer polyester film having a thickness of 16 μm was produced using copolymerized polyethylene terephthalate (D) as a raw material.

  The physical properties and practical property evaluation results of the films obtained in Examples and Comparative Examples are summarized in Tables 1 and 2 below.

  The films obtained in the examples met the requirements of the present invention, and the films for dry film resist substrates using these films were of high quality showing excellent characteristics. On the other hand, the films of Comparative Examples 1 and 2 had a problem that the surface roughness was reduced due to the lack of contained particles, and the handleability was poor. Further, the films of Comparative Examples 3, 4, 5 and 6 had a problem that they were inferior in resolution and circuit defects because the roughness was too large. The films of Comparative Examples 7 and 8 are both examples of single-layer films, but if the amount of particles is decreased in order to improve transparency, the handleability is remarkably deteriorated. As a result, a high-quality film for a dry film resist substrate could not be obtained.

  The film of the present invention can be suitably used for a high-quality dry film resist substrate.

Claims (1)

Biaxially oriented laminate containing 100 to 2000 ppm of crosslinked polymer particles having an average particle size of 0.1 to 1.0 μm and 10 to 500 ppm of silica particles having an average particle size of 0.1 to 3.0 μm on at least one outermost layer Lamination for dry film resist, characterized in that Ra is 0.005 to 0.020 μm, Rt is less than 0.50 μm, and film haze is 2.0% or less, which is a polyester film. Polyester film.