JP2008133481A - Sheet - Google Patents

Abstract

The present invention provides a sheet that is excellent in flexibility at high temperatures, heat resistance, releasability, and non-contamination, and that can be easily discarded after use.
A single-layered sheet that is excellent in flexibility, heat resistance, releasability, and non-contamination properties, and can be easily discarded after use, and includes a crystalline aromatic component containing a butylene terephthalate component as a crystalline component Polyester and a polyester having a polyether skeleton in the main chain are mixed resins, the heat of crystal melting is 40 J / g or more, and the polyester having the polyether skeleton in the main chain is butanediol terephthalate polytetramethylene A sheet that is a glycol copolymer.
[Selection figure] None

Description

The present invention relates to a sheet that is excellent in flexibility at high temperatures, heat resistance, releasability, and non-contamination and that can be easily discarded after use.

In the manufacturing process of a printed wiring board, a flexible printed wiring board, a multilayer printed wiring board, etc., a release film is used when a copper-clad laminate or a copper foil is hot-pressed through a prepreg or a heat-resistant film. In addition, in the manufacturing process of a flexible printed circuit board, when the cover lay film is hot-press bonded with a thermosetting adhesive to the flexible printed circuit board body on which the electric circuit is formed, the cover lay film and the press hot plate are bonded. In order to prevent this, a method using a release film is widely performed.

As a release film used for these applications, a fluorine-based film, a silicon-coated polyethylene terephthalate film, a polymethylpentene film, a polypropylene film and the like as disclosed in Patent Document 1 and Patent Document 2 have been used. .

In recent years, due to the increasing social demands for environmental issues and safety, in addition to functions such as heat resistance that can withstand hot press molding and mold release for printed wiring boards and hot press plates, Ease of disposal processing has been demanded. Furthermore, non-contamination for copper circuits has become important for improving the product yield during hot press molding.

However, the fluorine-based film conventionally used as a release film is excellent in heat resistance, releasability, and non-contamination, but is expensive and difficult to burn in waste incineration after use. In addition, there was a problem of generating toxic gas. In addition, the silicon-coated polyethylene terephthalate film and polymethylpentene film may cause contamination of the printed wiring board, particularly the copper circuit, due to the migration of low molecular weight substances contained in the silicon and the constituent components, and there is a concern that the quality may be impaired. Also, the polypropylene film was inferior in heat resistance and insufficient in releasability.
JP-A-2-175247 Japanese Patent Laid-Open No. 5-283862

In view of the above-mentioned present situation, an object of the present invention is to provide a sheet that is excellent in flexibility at high temperatures, heat resistance, releasability, and non-contamination and that can be easily discarded after use.

The present invention is a single-layered sheet that is excellent in flexibility, heat resistance, releasability, non-contamination, and can be easily discarded after use, and includes a crystalline aromatic compound containing a butylene terephthalate component as a crystal component Polyester and a polyester having a polyether skeleton in the main chain are mixed resins, the heat of crystal melting is 40 J / g or more, and the polyester having the polyether skeleton in the main chain is butanediol terephthalate polytetramethylene It is a sheet which is a glycol copolymer.
In the present invention, the sheet means not only a sheet but also a film.
The present invention is described in detail below.

The sheet | seat of this invention consists of a resin composition which has a polar group and whose halogen content rate is 5 weight% or less.
By comprising the resin composition having a polar group, the mechanical properties of the sheet of the present invention are excellent. Further, since the halogen content in the resin composition is 5% by weight or less, no harmful substances containing halogen are generated even when incinerated. Preferably it is 3 weight% or less, More preferably, it is 1 weight% or less. If it is less than 1% by weight, substantial non-halogen substance certification in Europe can be obtained. In the present invention, having a polar group means that an ester group, an amide group, an imide group, an ether group, a thioether group, a carbonyl group, a hydroxyl group, an amino group, a carboxyl group, etc. constitute a part of the resin composition. Means that The halogen content can be measured by using a normal halogen analyzer.

The sheet of the present invention preferably comprises a resin composition having a polar group in the main chain and a halogen content of 5% by weight or less. By comprising the resin composition having a polar group in the main chain, the sheet of the present invention has extremely excellent heat resistance and mechanical properties.

The resin composition having the polar group in the main chain and having a halogen content of 5% by weight or less is not particularly limited, and examples thereof include polyester compounds, polyphenylene sulfide, polyether ether ketone, polyamide compounds, A polyimide compound etc. are mentioned. Among these, since the heteroatom is not contained in the molecule, the environmental load during the incineration treatment is reduced, and it is economically advantageous. Therefore, the crystalline aromatic polyester described below is preferably used as an essential component.

The crystalline aromatic polyester can be obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol or a high molecular weight diol.
Examples of the aromatic dicarboxylic acid or its ester-forming derivative include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, paraphenylene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, and dimethyl naphthalene dicarboxylate. And dimethyl paraphenylene dicarboxylate. These may be used alone or in combination of two or more.

Examples of the low molecular weight aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5- Examples include pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. These may be used alone or in combination of two or more.

Examples of the high molecular weight diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, and the like. These may be used alone or in combination of two or more.

Examples of the crystalline aromatic polyester composed of the above components include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, butanediol terephthalate polytetramethylene glycol copolymer, and the like. It is done. These may be used alone or in combination of two or more.

The crystalline aromatic polyester preferably contains at least butylene terephthalate as a crystal component. By including a butylene terephthalate component, the obtained sheet or film is excellent in non-staining and crystallinity.

When the crystalline aromatic polyester contains a butylene terephthalate component as a crystal component, the sheet of the present invention preferably has a heat of crystal fusion of 40 J / g or more. If it is less than 40 J / g, heat resistance that can withstand hot press molding may not be exhibited, and the dimensional change rate at 170 ° C. may increase, which may impair the circuit pattern during hot press molding. More preferably, it is 50 J / g or more. In order to improve the crystallinity and increase the heat of crystal fusion, an additive that promotes crystallization, such as a crystal nucleating agent, may be added to the resin composition. It is preferable to set it above the glass transition temperature of the aromatic polyester, and it is more preferable to set it at 70 to 150 ° C.
The heat of crystal melting can be measured by differential scanning calorimetry.

The resin composition having the polar group in the main chain and having a halogen content of 5% by weight or less is obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol. It is preferable to mix the obtained crystalline aromatic polyester with a crystalline aromatic polyester obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol and a high molecular weight diol. Such a resin composition has heat resistance and releasability by a fine dispersion of a crystalline aromatic polyester containing a high molecular weight diol component in a matrix made of a crystalline aromatic polyester containing no high molecular weight diol component. While maintaining the above, flexibility can be obtained. A sheet or film made of this resin composition has a very good balance between heat resistance and releasability and followability to uneven shapes on a substrate such as a circuit pattern or a through hole.

As the mixing ratio, the preferred lower limit of the content of the crystalline aromatic polyester obtained by reacting the aromatic dicarboxylic acid or its ester-forming derivative with a low molecular weight aliphatic diol is 50% by weight, and the upper limit is 100% by weight. The preferred lower limit of the content of the crystalline aromatic polyester obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol and a high molecular weight diol is 0% by weight, and the upper limit is 50%. %.

The crystalline aromatic polyester preferably contains a polyester having a polyether skeleton in the main chain. Thereby, the sheet | seat of this invention improves the softness | flexibility in high temperature, and the balance of high intensity | strength and high temperature softness | flexibility improves.
The polyester having the polyether skeleton in the main chain preferably has a melting point of 170 ° C. or higher. When it is lower than 170 ° C., it may be difficult to peel off when the obtained sheet is used as a release film.
The polyester having such a polyether skeleton in the main chain is not particularly limited, and examples thereof include a butanediol terephthalate polytetramethylene glycol copolymer and a butanediol terephthalate polypropylene glycol copolymer.

The content of the polyester having the polyether skeleton in the main chain in the crystalline aromatic polyester is preferably 50% by weight or less. If it exceeds 50% by weight, it may be difficult to peel off when the obtained sheet is used as a release film.

The resin composition having the polar group and having a halogen content of 5% by weight or less may contain a stabilizer.
Examples of the stabilizer include 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis {2- [ 3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, etc. Hindered phenolic antioxidants; tris (2,4-di-t-butylphenyl) phosphite, trilauryl phosphite, 2-t-butyl-α- (3-t-butyl-4-hydroxyphenyl) -P-cumenylbis (p-nonylphenyl) phosphite, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythryltetrakis (3- Uri Lucio propionate), a heat stabilizer such as ditridecyl 3,3'-thiodipropionate and the like.

The resin composition having the polar group and having a halogen content of 5% by weight or less is a fiber, an inorganic filler, a flame retardant, an ultraviolet absorber, an antistatic agent, an inorganic substance within a range not impairing practicality. Further, additives such as higher fatty acid salts may be contained.

Examples of the fibers include glass fibers, carbon fibers, boron fibers, silicon carbide fibers, alumina fibers, amorphous fibers, inorganic fibers such as silicon / titanium / carbon fibers, and organic fibers such as aramid fibers. Examples of the inorganic filler include calcium carbonate, titanium oxide, mica, talc, and the like.
Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether, and the like.

Examples of the ultraviolet absorber include pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone, and the like. Is mentioned. Examples of the antistatic agent include N, N-bis (hydroxyethyl) alkylamine, alkylallyl sulfonate, and alkyl sulfonate.
Examples of the inorganic material include barium sulfate, alumina, and silicon oxide.
Examples of the higher fatty acid salt include sodium stearate, barium stearate, sodium palmitate and the like.

The resin composition having the polar group and having a halogen content of 5% by weight or less may contain a thermoplastic resin and a rubber component in order to modify the properties.
Examples of the thermoplastic resin include polyolefin, modified polyolefin, polystyrene, polyamide, polycarbonate, polysulfone, polyester, and the like.
Examples of the rubber component include natural rubber, styrene-butadiene copolymer, polybutadiene, polyisoprene, acrylonitrile-butadiene copolymer, ethylene-propylene copolymer (EPM, EPDM), butyl rubber, acrylic rubber, and silicon rubber. , Urethane rubber, olefin thermoplastic elastomer, styrene thermoplastic elastomer, vinyl chloride thermoplastic elastomer, ester thermoplastic elastomer, amide thermoplastic elastomer, and the like.

The sheet of the present invention preferably contains an inorganic compound having a large aspect ratio. By containing an inorganic compound having a large aspect ratio, the release property at high temperatures of the sheet of the present invention can be improved, and further, bleed-out to the surface of additives and low molecular weight components is suppressed to perform hot press molding. The cleanliness of the time can be improved. Examples of the inorganic compound include layered silicates such as clay; layered double hydrates such as hydrotalcite.

The sheet of the present invention has excellent physical properties at room temperature and high temperature.
In the sheet of the present invention, the lower limit of the storage elastic modulus at 23 ° C. is 1000 MPa, and the upper limit is 5000 MPa. If it is less than 1000 MPa, the mechanical strength at room temperature decreases, so that the strength is insufficient in the peeling step after press molding, and the handling properties of the sheet or film at room temperature also decrease. If it exceeds 5000 MPa, it will adversely affect the ability to follow the irregular shape during press molding.

The sheet of the present invention has a lower storage elastic modulus at 170 ° C. of 20 MPa and an upper limit of 100 MPa. If it is less than 20 MPa, heat resistance that can withstand hot press molding cannot be exhibited. If it exceeds 100 MPa, it will not be sufficiently deformed during hot press molding, so the followability to uneven shapes on the substrate such as circuit patterns and through-holes will be reduced, for example, uniform to the circuit pattern of the coverlay film on the flexible printed circuit board Adhesion decreases. A preferred upper limit is 80 MPa.
The storage elastic modulus can be measured by dynamic viscoelasticity measurement using a viscoelastic spectrometer.

The sheet of the present invention has a tear strength at 23 ° C. of 98 N / mm or more. When it is less than 9.8 N / mm, when used as a release film, the strength is insufficient in the peeling process after press molding, and resin adhesion to the circuit may occur. Such adhesion of the resin to the circuit significantly impairs the conductivity, and the entire printed circuit board becomes a defective product.
The tear strength can be measured by a method based on JIS K 7128 C method (right angle tear method).

In the sheet of the present invention, the lower limit of 100% load at 170 ° C. is 49 mN / mm, and the upper limit is 490 mN / mm. When it is less than 49 mN / mm, heat resistance that can withstand hot press molding cannot be exhibited when used as a release film. If it exceeds 490 mN / mm, it will not be sufficiently deformed during hot press molding, so the followability to uneven shapes on the substrate such as circuit patterns and through-holes will be reduced. For example, the circuit pattern of the coverlay film on the flexible printed circuit board Uniform adhesion decreases.
The 100% elongation load is a load when the strain reaches 100% in a general tensile test, and can be measured by a method based on JIS K 7127.

The sheet of the present invention preferably has an outgas generation amount of 200 ppm or less when heated at 170 ° C. for 10 minutes. When it exceeds 200 ppm, when the sheet | seat of this invention is used as a release film, a board | substrate and an electrode may be contaminated.

The sheet of the present invention preferably has mold releasability with respect to the polyimide and / or metal foil when superimposed on the polyimide and / or metal foil and pressed at 170 ° C. and 3 MPa for 60 minutes.
In addition, having the said mold release property has low peeling force generate | occur | produced between a polyimide and / or metal foil and a sheet | seat or film after a pressurization process, and a polyimide and / or metal foil, a sheet | seat or a film are at the time of peeling. It means no damage.

The sheet of the present invention may have a single layer structure or a multilayer structure. In the case of a multilayer structure, a crystalline aromatic polyester obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol is used as a surface layer, and has excellent flexibility at high temperatures and the crystalline aromatic Resin compositions having excellent interfacial adhesion with aliphatic polyesters, for example, amorphous polyethylene terephthalate such as butanediol terephthalate polytetramethylene glycol copolymer, polyethylene-1,4-cyclohexylenedimethylene terephthalate, polyamide-poly By using a tetramethylene glycol copolymer or a styrene-based thermoplastic elastomer as an intermediate layer, flexibility can be imparted while maintaining the releasability at the time of press molding. Very good balance with follow-up to uneven shape on substrate such as through hole Sheets or films can be obtained.

When the sheet | seat of this invention is a 2 layer structure, it is preferable that the storage elastic modulus in 170 degreeC of one layer is lower than the storage elastic modulus in 170 degreeC of the other layer.
Moreover, when the sheet | seat of this invention is a multilayer structure of 3 or more layers, it is preferable that the storage elastic modulus in 170 degreeC of at least 1 layer is lower than the storage elastic modulus in 170 degreeC of a surface layer.
By adopting such a structure, flexibility can be imparted while maintaining releasability during press molding, and releasability and followability to uneven shapes on the substrate such as circuit patterns and through-holes. Can be used as a release film having an excellent balance.

When the sheet of the present invention has a two-layer structure or a multilayer structure of three or more layers, at least one surface layer has a polar group and the halogen content is 5% by weight or less. The resin composition preferably has a polar group in the main chain, more preferably a crystalline aromatic polyester, and still more preferably a crystalline aromatic polyester containing at least butylene terephthalate as a crystal component. When at least one surface layer is made of a crystalline aromatic polyester containing at least butylene terephthalate as a crystal component, the layer preferably has a heat of crystal melting of 40 J / g or more.

The surface of the sheet of the present invention preferably has smoothness, but may have been provided with slipping properties, anti-blocking properties, etc. necessary for handling, and at least for the purpose of air bleeding during hot press molding. An appropriate embossed pattern may be provided on one side.

The minimum with preferable thickness of the sheet | seat of this invention is 5 micrometers, and an upper limit is 300 micrometers. If it is less than 5 μm, the strength may be insufficient, and if it exceeds 300 μm, the thermal conductivity during hot press molding may deteriorate. A more preferred lower limit is 10 μm and an upper limit is 50 μm.

The sheet or film of the present invention can be produced by a melt molding method. The melt molding method is not particularly limited, and examples thereof include conventionally known methods for forming a thermoplastic resin film such as an air-cooled or water-cooled inflation extrusion method and a T-die extrusion method.

The sheet of the present invention may be subjected to heat treatment in order to improve heat resistance, releasability and dimensional stability. As long as the heat treatment temperature is lower than the melting point of the resin composition constituting the sheet of the present invention, the higher the temperature is, the more effective, 170 ° C. or higher is preferable, and 200 ° C. or higher is more preferable. Examples of other methods for improving the heat resistance, releasability, and dimensional stability of the sheet of the present invention include a method of stretching in a uniaxial or biaxial direction and a method of rubbing the surface with buffalo.

A sheet in which the sheet of the present invention is laminated on at least one surface of a resin film has cushioning properties and strength for applying pressure uniformly during hot press molding. For example, a coverlay film on a flexible printed circuit board It is suitable as a release film having excellent uniform adhesion to the circuit pattern. A sheet comprising a laminate in which the sheet of the present invention is laminated on at least one surface of such a resin film (hereinafter also referred to as a laminate sheet) is also one aspect of the present invention.

Although it does not specifically limit as a resin composition which comprises the said resin film, For ease of disposal after use, for example, polyethylene resin, polypropylene resin, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, etc. What consists of olefin resin is preferable. These may be used alone or in combination of two or more. Further, in order to improve the adhesiveness with the sheet or film of the present invention, a modified polyolefin such as acid-modified polyolefin or glycidyl-modified polyolefin; a resin composition constituting the sheet or film of the present invention is mixed in the resin film. May be.

The melting point of the resin composition constituting the resin film is preferably 50 ° C. in order to suppress the prepreg or thermosetting adhesive from oozing into the through-hole and to obtain uniform adhesion to the circuit pattern. The upper limit is 130 ° C.

The complex viscosity at 170 ° C. of the resin composition constituting the resin film has a preferable lower limit of 100 Pa · s and an upper limit of 10,000 Pa · s in order to obtain uniform adhesion to the circuit pattern.

The minimum of the preferable thickness of the sheet | seat of this invention laminated | stacked on the said resin film is 0.5 micrometer, and an upper limit is 100 micrometers. If it is less than 0.5 μm, the strength tends to be insufficient. If it exceeds 100 μm, the thermal conductivity may decrease and the cost will also increase.

The softening temperature of the laminate sheet of the present invention is preferably 40 ° C. and 120 for the upper limit of 120 ° C. in order to suppress the prepreg or thermosetting adhesive from penetrating into the through-hole and to obtain uniform adhesion to the circuit pattern. ° C.
In addition, the measurement of the said softening temperature can be performed based on JISK7196.

The preferable lower limit of the thickness of the laminate sheet of the present invention is 5 μm, and the upper limit is 300 μm. If it is less than 5 μm, the strength tends to be insufficient, and if it exceeds 300 μm, the thermal conductivity during hot press molding may deteriorate. A more preferred lower limit is 25 μm and an upper limit is 200 μm.

Examples of the production method of the laminate sheet of the present invention include a water-cooled or air-cooled coextrusion inflation method, a method of forming a film by a coextrusion T-die method, and a method of extruding a resin composition constituting a resin film on the sheet of the present invention Examples thereof include a method of laminating by a lamination method, a method of dry lamination of the sheet of the present invention and a resin film, and the like. Especially, the method of forming into a film by the coextrusion T die method is preferable from the point which is excellent in the thickness control of each layer.

The sheet of the present invention including the laminate sheet is excellent in flexibility at high temperatures, heat resistance, releasability, and non-contamination, and can be disposed of safely and easily. Therefore, a printed wiring board, a flexible printed wiring board, or When hot-pressing a copper-clad laminate or copper foil via a prepreg or heat-resistant film in a manufacturing process of a multilayer printed wiring board or the like, press hot plate and printed wiring board, flexible printed wiring board, or multilayer printed wiring board It is suitably used as a release film that prevents adhesion with the like. In addition, in the production process of flexible printed circuit boards, when a coverlay film is bonded with a thermosetting adhesive by hot press molding, a release film that prevents adhesion between the coverlay film and the hot press plate or between the coverlay films. Also preferably used. Furthermore, mold release when manufacturing sporting goods such as fishing rods, golf clubs and shafts and aircraft parts manufactured by curing prepregs made of glass cloth, carbon fiber, or aramid fibers and epoxy resin in an autoclave. It is also useful as a release film for producing films, polyurethane foams, ceramic sheets, electrical insulating plates and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(1) Fabrication of sheet Perprene P450B (manufactured by Toyobo Co., Ltd.) was used as a resin composition, melt plasticized at 250 ° C. using an extruder, and extrusion molded from a T die to obtain a sheet having a thickness of 50 μm.

(2) Production of resin film A low-density polyethylene resin (manufactured by Nippon Polychem Co., Ltd .: Novatec LD LE425) is melt plasticized by heating to 230 ° C with an extruder, extruded from a T-die, and a resin film having a thickness of 100 µm is obtained. Obtained.

(3) Production of copper-clad laminate A polyimide film (made by DuPont: Kapton) with a thickness of 25 μm is used as a base film, and a copper foil with a thickness of 35 μm and a width of 50 μm is an epoxy adhesive layer with a thickness of 20 μm. A bonded copper-clad laminate was obtained.

(4) Production of Coverlay Film An epoxy adhesive having a flow start temperature of 80 ° C. was applied at a thickness of 20 μm on a 25 μm thick polyimide film (manufactured by DuPont: Kapton) to obtain a coverlay film.

(5) Fabrication of flexible printed circuit board A sheet obtained by stacking the obtained sheet, copper-clad laminate, coverlay film, sheet, and resin film in this order as one set, and 32 sets were placed on a hot press, After hot press molding under the conditions of a press temperature of 170 ° C., a press pressure of 3 MPa, and a press time of 60 minutes, the press pressure was released, the resin film was removed, and the sheet was peeled off to obtain a flexible printed board.

The cover layer film of the obtained flexible printed circuit board was completely in close contact with the substrate body, and no remaining air was observed. The sheet was completely peeled from the electrode portion made of the copper foil in the portion without the coverlay film, and the copper foil was completely exposed in the electrode portion. Further, the conductivity of the copper foil in the electrode portion was sufficient, and no contamination due to adhesion of organic substances was observed. Further, the adhesive flowed out to the surface of the copper foil in the portion without the cover lay film was 0.1 mm or less from the end portion of the cover lay film, and the effect of preventing the adhesive from flowing out was sufficient. In addition, although the circuit was partially deformed, it was in a range where there was no practical problem.

(Example 2)
Example 1 except that Perprene P150B (manufactured by Toyobo Co., Ltd.) was used as the resin composition and melt-plasticized at 250 ° C. with an extruder and extruded from a T-die to produce a sheet having a thickness of 50 μm. A flexible printed circuit board was produced by the same method as described above.

(Reference Example 1)
Example 1 except that Pebax 6312 (manufactured by Toray Industries, Inc.) was used as the resin composition and melt-plasticized at 250 ° C. with an extruder and extruded from a T-die to produce a 50 μm thick sheet. A flexible printed circuit board was produced by the same method as described above.

Example 4
As a resin composition, a mixture of 70 parts by weight of Novaduran 5040ZS (manufactured by Mitsubishi Engineering Plastics) and 30 parts by weight of Perprene P90B (manufactured by Toyobo Co., Ltd.) was used. A flexible printed circuit board was produced in the same manner as in Example 1 except that a sheet having a thickness of 50 μm was produced by extrusion molding, and this was used.

(Example 5)
As a resin composition, a mixture of 70 parts by weight of Novaduran 5040ZS (Mitsubishi Engineering Plastics) and 30 parts by weight of Perprene P30B (Toyobo Co., Ltd.) was used. A flexible printed circuit board was produced in the same manner as in Example 1 except that a sheet having a thickness of 50 μm was produced by extrusion molding, and this was used.

(Reference Example 2)
Using a three-layer coextrusion machine, a 10 μm thick layer made of Novaduran 5040ZS (Mitsubishi Engineering Plastics), a 30 μm thick layer made of Perprene P90B (Toyobo Co., Ltd.), and Novaduran 5040ZS (Mitsubishi Engineering) A flexible printed circuit board was produced in the same manner as in Example 1 except that a sheet having a three-layer structure in which a 10 μm thick layer made of Plastics Co., Ltd. overlapped in this order was produced.

(Reference Example 3)
A 12.5 μm-thick stretched film made of sealer PT7001 (manufactured by DuPont), a 25 μm-thick film made of Perprene P90B (manufactured by Toyobo), and a thickness of 12.5 μm made of sealer PT7001 (manufactured by DuPont) A flexible printed circuit board was produced in the same manner as in Example 1 except that a three-layered sheet was produced by thermal lamination at a temperature of 200 ° C., and the stretched films were laminated in this order.

(Example 8)
Perprene P150B (manufactured by Toyobo Co., Ltd.) was used as the resin composition and melt plasticized at 230 ° C. using an extruder, and extrusion molding was performed from a T die to produce a sheet having a thickness of 25 μm. The obtained sheet was stacked on the resin film prepared in Example 1 (2) and heat laminated at 180 ° C. to produce a laminate sheet. A flexible printed circuit board was produced by the same method as in Example 1 except that the obtained laminate sheet was used.

(Reference Example 4)
Using a three-layer coextrusion machine, a 10 μm thick layer made of Novaduran 5040ZS (Mitsubishi Engineering Plastics), a 30 μm thick layer made of Perprene P90B (Toyobo Co., Ltd.), and Novaduran 5040ZS (Mitsubishi Engineering) A sheet having a three-layer structure in which a 10 μm-thick layer made of Plastics Co., Ltd. overlapped in this order was produced. The obtained sheet was stacked on the resin film prepared in Example 1 (2) and heat laminated at 180 ° C. to produce a laminate sheet. A flexible printed circuit board was produced by the same method as in Example 1 except that the obtained laminate sheet was used.

(Comparative Example 1)
Except for using Hytrel 4275JB (manufactured by Toray DuPont) as a resin composition, melt plasticizing at 230 ° C. with an extruder, and extruding from a T-die to produce a 50 μm thick sheet. A flexible printed circuit board was produced by the same method as in No. 1.

(Comparative Example 2)
Sealer PT7001 (manufactured by DuPont) was used as the resin composition, melt plasticized at 290 ° C. with an extruder, extruded with a T-die, then stretched twice and annealed at 230 ° C. to obtain a 50 μm sheet. A flexible printed circuit board was prepared by the same method as in Example 1 except that this was used.

(Comparative Example 3)
Using Novaduran 5040ZS (Mitsubishi Engineering Plastics) as the resin composition, melt plasticizing at 250 ° C with an extruder, extruding from a T-die to produce a sheet with a thickness of 50 µm, and carrying out except using this A flexible printed circuit board was produced in the same manner as in Example 1.

(Comparative Example 4)
Except for using Novatec PP FB3GT (manufactured by Nippon Polychem Co., Ltd.) as a resin composition, melt plasticizing at 250 ° C. with an extruder, and extruding from a T-die to produce a 50 μm thick sheet. A flexible printed circuit board was produced by the same method as in No. 1.

(Comparative Example 5)
A flexible printed circuit board was produced in the same manner as in Example 1 except that Opulan X-88B (made by Mitsui Chemicals) made of polymethylpentene having a thickness of 50 μm was used as the sheet.

About the sheet | seat and laminated sheet which were produced in Example 1, 2, 4, 5, 8, Reference Examples 1-4 and Comparative Examples 1-5, the amount of crystal melting, storage elastic modulus, tear strength, 100% by the following method. The elongation load and the outgas generation amount were measured.
Further, in the production of flexible printed boards using these sheets, the handling properties, peelability and adhesion of the sheets, electrode contamination of the flexible printed board after production, and circuit deformation were visually evaluated.
These results and the raw materials and composition of each sheet are shown in Tables 1-5.

(Measurement of heat of crystal melting)
Using a differential scanning calorimeter (DSC 2920 manufactured by TA Instruments), the measurement was performed at a heating rate of 5 ° C. per minute.

(Measurement of storage modulus)
Using a viscoelastic spectrometer (RSA-11, manufactured by Rheometric Scientific, Inc.), measurement was performed at a heating rate of 5 ° C./min, a frequency of 10 Hz, and a strain of 0.05%, and stored at 23 ° C. and 170 ° C. The elastic modulus was measured.

(Measurement of tear strength)
In accordance with JIS K 7128 C method, a right-angled tear test punched piece was measured at 23 ° C. and a test speed of 500 mm per minute.

(Measurement of 100% elongation load)
In accordance with JIS K 7127, a No. 2 punched specimen was measured at 170 ° C. and at a test speed of 500 mm per minute.

(Measurement of outgas generation amount)
Using thermal desorption GC-MS, the gas generated from the film by heating at 170 ° C. for 10 minutes was separated using a nonpolar capillary column, and the toluene equivalent of the detected peak total area was normalized by the film weight. The amount of outgas generated.

ADVANTAGE OF THE INVENTION According to this invention, the sheet | seat which is excellent in the softness | flexibility at high temperature, heat resistance, mold release property, and non-contamination property, and can be easily discarded after use can be provided.

Claims (4)

A sheet with a single layer structure that is excellent in flexibility, heat resistance, releasability, non-contamination, and easy to dispose of after use,
It consists of a mixed resin of a crystalline aromatic polyester containing a butylene terephthalate component as a crystal component and a polyester having a polyether skeleton in the main chain, and the heat of crystal fusion is 40 J / g or more,
The polyester having a polyether skeleton in the main chain is a butanediol terephthalate polytetramethylene glycol copolymer. When hot-pressing a copper-clad laminate or copper foil via a prepreg or heat-resistant film in the manufacturing process of a printed wiring board, flexible printed wiring board or multilayer printed wiring board, press hot plate and printed wiring board, flexible printing The sheet according to claim 1, wherein the sheet is a release film that prevents adhesion to a wiring board or a multilayer printed wiring board. In the manufacturing process of a flexible printed circuit board, it is a release film that prevents adhesion between a coverlay film and a heat-pressed plate or between coverlay films when the coverlay film is bonded with a thermosetting adhesive by hot press molding. The sheet according to claim 1. A laminate sheet, wherein the sheet according to claim 1 is laminated on at least one surface of a resin film.