JP5737530B2 - Metal foil laminate in which aromatic polyamideimide is laminated on metal foil - Google Patents

Description

  The present invention relates to a method for treating a long object, and more specifically, drying a long object after impregnating or coating a long object such as a film, a textile fabric, a sheet, and a metal foil with water or an organic solvent solution, and The present invention relates to a method for efficiently performing heat treatment with a high yield. The present invention also relates to a metal foil laminate excellent in performance such as dimensional stability and moisture absorption characteristics.

  Conventionally, drying and heat treatment after impregnating or coating long materials such as textile fabrics, films, sheets and metal foils with water or organic solvent solutions are usually performed continuously at a constant rate in a heating zone of a certain length. It is done by passing. However, in this method, when the boiling point of the solvent is high, curling (warping) is likely to occur during drying or heat treatment, and when the coating thickness is thick, it is difficult to dry efficiently with good yield. Met. In particular, when heat treating a metal foil laminate obtained by applying a polyimide resin solution and / or its precursor to metal foil and initially drying it as a long object, the curl is large and it is difficult to manufacture with high productivity. In addition, efficient drying was difficult. In addition, the curl is large, and the properties of the product itself such as appearance and dimensional stability are also unfavorable. Simply drying it will result in properties such as moisture absorption properties, adhesive strength, and reliability (such as adhesive strength after heat treatment). There was a disadvantage of being inferior.

  In order to solve these problems, methods such as wrapping heat treatment around a cylindrical drum have been studied so far. However, in any literature, the method is not practically high in productivity, The curl suppression was not always sufficient.

JP-A-57-50670 JP-A-60-15728 JP 55-75289 A JP-A 61-307789 JP-A-5-50547

  From the background art as described above, the object of the present invention is to heat-treat the fiber woven fabric, film, sheet, metal foil, in particular, the polyimide resin solution directly applied to the metal foil, and the initially dried metal foil laminate. A metal foil laminate that is free from curling and has excellent characteristics such as dimensional accuracy is intended to be manufactured efficiently with good yield.

As a result of diligent research to achieve the above object, the present inventors have continuously applied a polyimide resin solution to a metal foil, and when heat-treating a metal laminate obtained by initial drying, one side of a long object Or, it is possible to manufacture a metal foil laminate having no curl and excellent in dimensional stability with a high yield by continuously transporting and heat-treating a long material different from the long material as a constituent material on both surfaces. The headline and the present invention were reached.
That is, the present invention has the following configuration.
(Claim 1)
A metal foil laminate in which an aromatic polyamideimide is laminated on a metal foil, characterized by the following (a) to (c):
(A) trimellitic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as the acid component, and amine component an aromatic polyamideimide polymerized using o-tolidine or o-tolidine diisocyanate;
(B) An aromatic polyamideimide containing 5 to 99 mol% of the structural unit represented by the general formula (1) in the structural unit;
(C) A metal foil laminate that has been heat-treated using a far-infrared heater.

(Section 2)
Item 2. The metal foil laminate according to Item 1, wherein the far-infrared region is a far-infrared heater having a range of 5 µm to 1000 µm.
(Section 3)
Item 3. The metal foil laminate according to Item 1 or 2, wherein the heat treatment is performed under the following conditions (i) to (iii):
(I) Under reduced pressure of about 10 mmHg or less, or in an inert gas atmosphere of 1000 ppm or less (ii) The temperature of the heat treatment is 50 ° C. to 450 ° C. at the surface temperature of the metal laminate resin surface.
(Iii) The heat treatment time is 0.5 minutes to 100 minutes (Item 4)
Item (1) The metal foil laminate according to any one of Items 1 to 3, wherein the moisture absorption rate of the resin film layer obtained by etching and removing the metal foil from the metal foil laminate is 0.9% or less. .
(Section 5)
Item 5. The metal foil laminate according to any one of Items 1 to 4, wherein (e) the coefficient of thermal expansion (CTE) is 17 ppm or less.

  As described above, the long object of the present invention is curled by continuously transporting and heat-treating a long object different from the long object as a constituent material on one or both sides of the long object. This is industrially useful because a product excellent in dimensional stability, moisture absorption characteristics and the like can be produced with good yield.

Staggered transport system

  As long objects applied to the present invention, for example, films and sheets made of various polymers, foils made of various metals, thin plates that can be processed in a roll shape, and the like, It can be applied to various treatments such as heat treatment such as drying, ripening and curing, electric discharge treatment, electromagnetic wave treatment and the like. A particularly preferable application example is a case where a metal foil laminate obtained by applying and initially drying a polyimide resin solution and / or a precursor thereof to a metal foil is heat-treated and dried.

As the metal foil used for producing the metal foil laminate, copper foil, aluminum foil, steel foil, nickel foil, and the like can be used. A metal foil treated with the above metal can also be used. The thickness of the metal foil is not particularly limited, but a metal foil of 1 to 50 μm, preferably 3 to 35 μm, more preferably 3 to 18 μm can be suitably used. When the thickness of the metal foil is less than 1 μm, the yield at the time of conveyance is lowered, and when it is thicker than 50 μm, the winding as a long object is inferior and the winding property is inferior, and the yield is lowered.
As the polyimide-based resin to be used, any resin may be basically used as long as it has a thermal expansion coefficient equivalent to that of the metal foil and is excellent in heat resistance, but preferably aromatic polyimide or aromatic resin. Polyamideimide. The thickness of the resin is not particularly limited, but is, for example, 1 to 200 μm, preferably 5 to 75 μm, and more preferably 8 to 35 μm. When the thickness of the resin is greater than 200 μm, like a copper foil, it is unwound as a long object, is inferior in winding property, and the yield decreases. If it is less than 1 μm, there is no problem in production, but it is practically difficult to use as a metal foil laminate, for example, a printed wiring board.
The width is not limited, and a commercially available copper foil can be used as it is, for example, having a width of 250 mm to 1080 mm.

  An aromatic polyimide or an aromatic polyamideimide can be produced by a usual method, for example, an isocyanate method, an acid chloride method, a low temperature solution polymerization method, a room temperature solution polymerization method, or the like.

  Examples of raw materials used for the aromatic polyimide include the following. Examples of the acid component include pyromellitic acid, benzophenone-3,3 ′, 4,4′-tetracarboxylic acid, biphenyl-3,3 ′, 4,4′-tetracarboxylic acid, diphenylsulfone-3,3 ′, 4. , 4′-tetracarboxylic acid, diphenyl ether-3,3 ′, 4,4′-tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,2,4,5-tetracarboxylic acid A monoanhydride such as an acid, naphthalene-1,4,5,8-tetracarboxylic acid, a dianhydride, an esterified product or the like can be used alone or as a mixture of two or more. As the amine component, P-phenylenediamine, m-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 3,3′-diaminobenzanilide, 4,4′-diaminobenzanilide, 4,4′-diaminobenzophenone, 3,3′-diamino Benzophenone, 3,4'-diaminobenzophenone, 2,6-tolylenediamine, 2,4-tolylenediamine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4, 4′-diaminodiphenylpropane, 3,3′-diaminodiphenylpropane, 4, '-Diaminodiphenylhexafluoropropane, 3,3'-diaminodiphenylhexafluoropropane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylhexafluoroisopropylidene, p-xylene Diamine, m-xylenediamine, 1,4-naphthalenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, o-tolidine, 2,2'-bis (4-aminophenyl) ) Propane, 2,2'-bis (4-aminophenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-Aminophenoxy) benzene, 2,2-bis [4- ( -Aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] propane, Bis [4- (3-aminophenoxy) phenyl] hexafluoropropane, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 2,2-bis [ 4- (4-Aminophenoxy) phenyl] hexafluoropropane or a diisocyanate corresponding to these may be used alone or in combination of two or more. In addition, a resin separately polymerized by a combination of these acid component and amine component can be mixed and used.

As raw materials used for the aromatic polyamideimide, trimellitic acid anhydride, diphenyl ether-3,3 ′, 4′-tricarboxylic acid anhydride, diphenylsulfone-3,3 ′, 4′-tricarboxylic acid anhydride, Tricarboxylic acid anhydrides such as benzophenone-3,3 ′, 4′-tricarboxylic acid anhydride, naphthalene, 1,2,4-tricarboxylic acid anhydride are used alone or as a mixture, and the amine component is a diamine similar to polyimide, or The diisocyanate may be used alone or as a mixture. In addition, a resin separately polymerized by a combination of these acid component and amine component can be mixed and used. Moreover, you may use the acid component illustrated as a raw material used for an aromatic polyimide other than the said acid component.

Particularly preferred polyimide resins are aromatic polyimides and aromatic polyamideimides soluble in organic solvents, and more preferably aromatic polyamideimides containing structural units represented by the following general formula (1) or (2).
In the structural unit, the preferable content of the general formula (1) is 5 mol% to 99 mol%, more preferably 20 mol% to 90 mol%, and still more preferably 40 mol% to 70 mol%. If the content of the general formula (1) is less than 5 mol%, the curl (warpage) and dimensional accuracy of the metal laminate is inferior, and if it is more than 99 mol%, the solubility of the organic solvent becomes poor. Workability deteriorates.
One preferable structural unit is trimellitic anhydride (TMA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′- as an acid component. Biphenyltetracarboxylic dianhydride (BPDA) is used as the amine component, o-tolidine (or diisocyanate), and the component ratio of the acid component is TMA / BTDA / BPDA = 80-50 mol / 5-20 mol / 20. ~ 40 mol of polyamideimide resin.
Further, the preferable content of the general formula (2) is 1 mol% to 99 mol%, more preferably 10 mol% to 90 mol%, and still more preferably 20 mol% to 80 mol%. When the content of the general formula (2) is less than 1 mol%, the metal laminate is inferior in curl (warp) and dimensional accuracy, and when it exceeds 99 mol%, the solubility of the organic solvent becomes poor. It becomes scarce. One preferable structural unit is trimellitic anhydride (TMA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′- as an acid component. Biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic anhydride (PMA) are used as amine components and 1,5-naphthalenediamine (or diisocyanate) is used, and the composition ratio of the acid components is TMA / BTDA / BPDA / PMA = polyamideimide resin of 10 to 40 mol / 20 to 50 mol / 10 to 30 mol / 5 to 15 mol. Of course, these can also be mixed and used.

As a solvent for the polyimide resin solution, N-methyl-2-pyrrolidone, N, N′-dimethylformamide, N, N′-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, tetramethylurea, Sulfolane, dimethyl sulfoxide, γ-butyrolactone, cyclohexanone, cyclopentanone and the like, preferably N-methyl-2-pyrrolidone. Some of them can be replaced with hydrocarbon organic solvents such as toluene and xylene, ether organic solvents such as diglyme, triglyme and tetrahydrofuran, and ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone.

Any molecular weight of the polyimide resin can be used. For example, in N-methyl-2-pyrrolidone, it is preferable that the logarithmic viscosity at 30 ° C. is 0.3 to 2.5 dl / g, more preferably 1.0 to 2.0 dl / g in a polymer concentration of 0.5 g / dl. It is. If the logarithmic viscosity is less than 0.3 dl / g, mechanical properties such as bendability and resistance to edge tearing of the substrate are insufficient. If it is greater than 2.5 dl / g, the adhesive strength is insufficient, and the solution viscosity is low. Since it becomes high, a shaping | molding process becomes difficult. The number average molecular weight is preferably about 5000 to 100,000, and the molecular weight distribution is preferably about 2.0 to 5.0.

  In addition, adipic acid, azelaic acid, sebacic acid, cyclohexane-4,4′-dicarboxylic acid, butane are used as acid components within the range that does not impair heat resistance and thermal expansion coefficient in the aromatic polyimide and aromatic polyamideimide used in the present invention. Aliphatic and alicyclic dicarboxylic acids such as -1,2,4-tricarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid, Polycarboxylic acids and their monoanhydrides, dianhydrides, esterified products and the like, and as amine components, tetramethylenediamine, hexamethylenediamine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, cyclohexane-1, Aliphatic and alicyclic diamines such as 4-diamine and diaminosiloxane Aneto may be used alone or in combination of two or more. In addition, a resin separately polymerized by a combination of these acid component and amine component can be mixed and used.

  In the present invention, other resins, organic compounds, and inorganic compounds are mixed for the purpose of improving various properties of the metal foil laminate, such as mechanical properties, electrical properties, slipperiness, and flame retardancy. Or you may make it react and use together. For example, lubricant (silica, talc, silicone, etc.), adhesion promoter, flame retardant (phosphorus, triazine, aluminum hydroxide, etc.), stabilizer (antioxidant, UV absorber, polymerization inhibitor, etc.), plating activity Agents, organic and inorganic fillers (talc, titanium oxide, fluoropolymer fine particles, pigments, dyes, calcium carbide, etc.), silicone compounds, fluorine compounds, isocyanate compounds, blocked isocyanate compounds, acrylic resins, urethane resins, Resins such as polyester resin, polyamide resin, epoxy resin, phenol resin and organic compounds, or these curing agents, inorganic compounds such as silicon oxide, titanium oxide, calcium carbonate, iron oxide, etc. are within the range not hindering the object of the present invention. Can be used together.

(Initial drying process)
In the present invention, it is preferable to produce a metal foil laminate by applying a heat resistant resin solution to a metal foil and drying it first, and then further heat-treating and drying (hereinafter referred to as heat-treatment / solvent removal step). The amount of the remaining solvent is not limited, but for example, a laminate of 1% by weight to 50% by weight, preferably 10% by weight to 40% by weight, and more preferably 15% by weight to 30% by weight can be applied. When the residual solvent ratio after the initial drying is less than 1% by weight, the curl (warp) is large even after the subsequent heat treatment / solvent removal step, resulting in poor dimensional accuracy. On the other hand, when the amount is more than 50% by weight, the resin coated surface is blocked, and the yield as a long product is deteriorated. The amount of residual solvent refers to the amount of solvent in the resin system including the solvent after coating and initial drying, and is represented by Equation (2).

The initial drying is preferably performed at a temperature 70 to 130 ° C. lower than the boiling point of the solvent used for the heat resistant resin solution. If the drying temperature is higher than (boiling point of solvent−70) ° C., even if the amount of residual solvent is 1% by weight or more, unevenness of the residual solvent in the thickness direction of the resin layer becomes large. Therefore, in the subsequent heat treatment / solvent removal step, the substrate is likely to curl and productivity is lowered. On the other hand, when the temperature is lower than (boiling point of solvent−130) ° C., the drying time becomes longer and the productivity is lowered.
The preferred time for the initial drying varies depending on the set temperature and the resin thickness. For example, when the resin thickness is 25 μm (thickness after the heat treatment / desolvation step) and the temperature is 100 ° C., preferably 1 to 10 minutes, Is from 3 minutes to 7 minutes, more preferably from 4 minutes to 5 minutes. When the temperature is 70 ° C., it is 3 minutes to 15 minutes, preferably 5 minutes to 10 minutes, and more preferably 4 minutes to 8 minutes. If the drying time is less than the lower limit at each temperature, the drying property is insufficient, and the yield decreases due to blocking or the like. On the other hand, if the length is longer than the upper limit, the curl (warp) is large even after the subsequent heat treatment / solvent removal step, resulting in poor dimensional accuracy.

The initial drying method can be performed by a conventionally known method such as a roll support method or a floating method. Moreover, it does not specifically limit as a coating method, A conventionally well-known method can be applied. The viscosity of the coating solution can be adjusted by a roll coater, knife coater, doctor blade coater, gravure coater, die coater, multilayer die coater, reverse coater, reverse roll coater, etc., and then applied directly to the metal foil. The suitable solution viscosity is preferably in the range of 1 to 1000 poise in B-type viscosity at 25 ° C. The concentration of the resin solution is usually 5 to 30% by weight, more preferably 10 to 20% by weight, although it depends on the molecular weight of the resin.
The coating width is not limited and can be set according to the width of the copper foil to be used. For example, it is 250 mm to 1000 mm.

(Heat treatment / solvent removal process)
In the present invention, on one side or both sides of the long object, another long object different from the long object as a constituent material is continuously conveyed while being superposed, and when the heat treatment is performed, A material that does not deform due to shrinkage, softening, melting, or the like at the heat treatment / desolvent temperature may be selected. Preferably, a sheet such as a woven fabric or a non-woven fabric made of cellulose, glass, carbon, aramid or the like, an engineering plastic film such as polyimide or polyamideimide, a metal mesh, or the like. Also, engineering plastic films such as polyether ketone and polyparaphenylene ether can be suitably used. The thickness is preferably 5 μm or more, more preferably 10 μm or more, more preferably 20 μm or more. The upper limit is 1000 μm or less, preferably 500 μm or less, and more preferably 100 μm or less. If the amount of the residual solvent is less than 5 μm, curling is likely to occur largely when the amount of residual solvent is high, and if it is thicker than 1000 μm, the transportability, unwinding of a long object, and take-up property are poor and the productivity is low. Decreases. In the case of a metal mesh, there is no particular limitation on the size of the mesh.
In the present invention, there is no particular limitation on the method of superimposing another long material different from the long material as a constituent material. For example, as shown in FIG. It is efficient to send out different long objects and superimpose them on the long objects via nip rolls. Also, when winding after processing, as shown in FIG. Then, a method of winding with a separate winding roll is efficient. FIG. 1 is a view for superimposing a long object different from the long object on one side, but it is also possible to superimpose on a double side in the same way.
In particular, in the case where the long material to be heat-treated is a metal foil laminate obtained by applying and initial drying a polyimide resin solution and / or its precursor to a metal foil, Sheets such as woven fabric and non-woven fabric made from cellulose, glass, carbon, aramid, etc. are preferable, and on the opposite metal foil side, engineering plastic films such as polyimide films, and metal foils such as copper foil and stainless steel foil are preferable. In addition, when superimposing the long thing different from this long thing on the single side | surface of a long thing, it is preferable to superimpose on the application surface side at least.
The thickness is the same as above, but the lower limit is preferably 5 μm or more, more preferably 20 μm or more, more preferably 30 μm or more, and the upper limit is 500 μm, as long objects placed on the opposite metal foil side. Hereinafter, it is preferably 100 μm or less, more preferably 100 μm or less. When the lower limit is less than 5 μm, curl is greatly generated and productivity is lowered. On the other hand, if the upper limit is thicker than 500 μm, the transportability, unwinding and winding properties are poor and productivity is lowered.
It is preferable to superimpose a long material different from the long material as a constituent material after applying a polyimide resin solution and / or a precursor thereof to a metal foil and initial drying.

  In the present invention, the atmosphere during the heat treatment / desolvation is preferably performed under reduced pressure and / or in an inert gas atmosphere. When carried out in air, the resin layer is deteriorated or excessively cross-linked, and the curl of the substrate becomes large, or the mechanical properties of the resin layer are impaired. In addition, when heat treatment is performed in an air or oxygen atmosphere with a predetermined amount of a solvent such as N-methyl-2-pyrrolidone remaining, not only the mechanical properties of the resin layer but also the adhesion between the resin layer and the metal foil Sex is reduced. The pressure is preferably about 10 mmHg or less, or in an inert gas atmosphere of 1000 ppm or less. More preferably, it is under a reduced pressure of about 5 mmHg or less, or in an inert gas atmosphere of 100 ppm or less. More preferably, it is under a reduced pressure of about 2 mmHg or less, or in an inert gas atmosphere of 50 ppm or less. When the pressure is lower than 10 mmHg or under an inert atmosphere of 1000 ppm, the resin layer deteriorates and the curl increases.

In the present invention, the temperature and time conditions during the heat treatment and solvent removal can be arbitrarily set depending on the type of the long object. The temperature is a surface temperature of the metal laminate resin surface, and a treatment from 50 ° C. to 450 ° C. is suitable, and the conveyance speed can be changed from 1 m / min to 100 m / min in accordance with the treatment time. A preferable application range is 200 ° C. to 400 ° C., more preferably 250 ° C. to 350 ° C., and an arbitrary speed can be set for the treatment. When the temperature exceeds 450 ° C., the resin tends to deteriorate even in a nitrogen atmosphere. For example, in the case of a metal foil laminate in which a polyimide resin solution and / or its precursor is applied to a metal foil and initially dried, the laminate Characteristics, especially curl, dimensional accuracy, etc. are deteriorated. If it is less than 50 degreeC, drying efficiency is bad and productivity falls.
Strictly speaking, the preferred treatment time varies depending on the thickness of the laminated resin and the temperature, but for example, 0.5 minutes to 100 minutes, more preferably 3 minutes to 40 minutes, and even more preferably 5 minutes to 30 minutes. is there. When the heat treatment time is less than 0.5 minutes, the drying property is poor, and curling (warping), thermal dimensional accuracy, moisture absorption characteristics, adhesive strength, and reliability thereof are lowered. When the heat treatment time is longer than 100 minutes, the mechanical properties of the base film layer are deteriorated due to the thermal decomposition of the resin.
In the present invention, it is preferable to use a far infrared heater as the heating method. The type of the far infrared heater is not particularly limited, and an electric type, a steam type using steam or heat transfer oil as a heat source, an oil type, or a gas type using gas combustion heat as a heat source can be used. The wavelength range is not particularly limited and is in the far infrared range (5 μm to 1000 μm), but near infrared and / or combined use with infrared is also preferred. In particular, from the viewpoint of drying efficiency, dimensional accuracy, and the like, treatment with a combination of near infrared rays (for example, 2 μm to 20 μm) is also preferable. As the drying furnace, a conventionally known hot air circulation heating path, electric furnace, IR heater, vacuum path, or the like may be used in combination.
There is no particular limitation on the distance (irradiation distance) from the heater to the heating body (long object to be stacked), and it is sufficient that the surface temperature of the metal laminate is the above temperature. For example, it is 5 mm to 1000 mm. The heater position may be on the upper surface and / or the lower surface of the metal laminate. Also, the electric power is not particularly limited, and is usually 1000 to 10 kW.
In addition, when the resin to be used is polyimide, imidation treatment may be necessary, but the heating method is not particularly changed. Polyimide can be formed by heat treatment and solvent removal as described above after the initial drying. However, in the case of a polyimide precursor, compared with a closed ring (soluble polyimide or polyamideimide), it is easier to thermally decompose, and from the viewpoint of thermal dimensional accuracy and heat resistance, in the stage before performing the treatment with far infrared rays, It is preferable to heat-process with a heating furnace, an electric furnace, IR heater, etc.

In the present invention, the base resin laminated on the metal foil may have a laminated structure of two or more layers. The resin composition is preferably an aromatic polyimide, an aromatic polyamideimide or the like, more preferably a polyamideimide containing a repeating unit of the general formula (1) or the general formula (2), for example, in contact with a metal foil. The first layer may be a composition containing the general formula (2), and the second layer laminated thereon may be a composition containing the general formula (2).
In the general formula structural unit, the preferable content is 5 mol% to 99 mol%, more preferably 20 mol% to 90 mol%, and still more preferably 40 mol% to 70 mol in the case of the general formula (1). %. If the content of the general formula (1) is less than 5 mol%, the curl (warpage) and dimensional accuracy of the metal laminate is inferior, and if it is more than 99 mol%, the solubility of the organic solvent becomes poor. Workability deteriorates. One preferred structural unit is trimellitic anhydride (TMA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′—as the acid component. Biphenyltetracarboxylic dianhydride (BPDA) is used as the amine component, o-tolidine (or diisocyanate), and the component ratio of the acid component is TMA / BTDA / BPDA = 80-50 mol / 5-20 mol / 20. ~ 40 mol of polyamideimide resin.
Further, the preferable content of the general formula (2) is 1 mol% to 99 mol%, more preferably 10 mol% to 90 mol%, and still more preferably 20 mol% to 80 mol%. If the content of the general formula (2) is less than 1 mol%, the curl (warpage) and dimensional accuracy of the metal laminate is inferior, and if it is more than 99 mol%, the solubility of the organic solvent becomes poor. Workability deteriorates. One preferred structural unit is trimellitic anhydride (TMA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′—as the acid component. Biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic anhydride (PMA) are used as the amine component and 1,5-naphthalenediamine (or diisocyanate) as the amine component, and the component ratio of the acid component is TMA / BTDA / BPDA. / PMA = 10-40 mol / 20-50 mol / 10-10 mol / 5-15 mol polyamideimide resin.
Of course, these can also be mixed and used.
The thickness ratio of the polyamideimide resin layer containing the repeating unit of the general formula (1) and the polyamideimide resin layer containing the repeating unit of the general formula (2) is preferably general formula (1) / general formula (2) = 1. To 100 μm / 1 μm to 100 μm, preferably general formula (1) / general formula (2) = 10 to 50 μm / 5 μm to 50 μm, more preferably general formula (1) / general formula (2) = 20 to 30 μm / 10 μm to 30 μm. When the thickness of the general formula (2) is less than 1 μm, the adhesive strength and its reliability are lowered, and when it is thicker than 100 μm, the moisture absorption property is deteriorated. Further, when the thickness of the general formula (1) is less than 1 μm, the moisture absorption characteristics and dimensional accuracy are lowered, and when it is thicker than 100 μm, it is disadvantageous in terms of curling (warping).
Further, for example, the first layer in contact with the metal foil may be a composition containing the general formula (1), and the second layer laminated thereon may be a composition containing the general formula (2).

  As a method of laminating two or more layers, the first layer can be applied, and after the initial drying, the second layer can be applied, initial drying, heat treatment and desolvation. Alternatively, the first layer may be coated, initially dried, heat-treated / desolvent, and then the second layer may be coated, initially dried, heat-treated / desolved. Furthermore, after the first layer is applied, the second layer is applied, or the first layer and the second layer are applied simultaneously, and initial drying, heat treatment and solvent removal are performed. You can also.

  In the present invention, in the case of a heat treatment in a far-infrared heating furnace and a drying method as the heating method, in particular, the drying efficiency is high, and the drying speed and the drying efficiency in the thickness direction are also constant. Can do. For example, in the case of a metal foil laminate, in addition to the residual solvent rate, curl, dimensional change rate, the adhesive strength, mechanical properties of the applied resin, physical properties such as moisture absorption properties, etc. should be uniform and good. Can be obtained. In particular, when the long product of the present application is a metal foil laminate in which a polyimide resin solution and / or its precursor is applied to a metal foil and initially dried, characteristics such as adhesive strength, reliability, and moisture absorption characteristics are usually Compared to the general drying method and those obtained under the drying conditions, this is a significant improvement.

In the present invention, the continuous conveyance method of a long object at the time of heat treatment / solvent removal is preferably roll-to-roll continuous conveyance, and conventionally known methods such as a roll support method and a floating method can be applied, but a particularly preferred method is staggered conveyance. It is a method. In addition, a roll support system is a system which conveys in a form which a roll contacts only the upper surface or only the lower surface of a long thing. As shown in FIG. 1, the staggered transport method is a staggered configuration, as shown in FIG. 1, with the upper and lower surfaces of long objects alternately contacting the rolls as shown in FIG. 1. It is a method to make it. By the staggered conveyance method, a long object can be conveyed in a more constant length in the TD direction (longitudinal direction and vertical direction), and curling (warping) and dimensional accuracy in the TD direction can be reduced.
A preferable roll pitch is 50 mm or more and 10,000 mm or less, more preferably 100 mm or more and 5000 mm or less, and further preferably 200 mm or more and 1000 mm or less, but there is no particular limitation. When the roll pitch is larger than 10,000 mm, the curl becomes large depending on the long object, and when it is less than 50 mm, the transportability is inferior and the productivity tends to be lowered. Also, the curl increases. There is no particular limitation on the height difference between rolls, but there is no particular limitation, although it tends to be good at 0 mm or more and 10,000 mm or less, preferably 10 mm or more and 5000 mm or less, and more preferably 100 mm or more and 1000 mm or less. If it is 10,000 mm or more, the curl becomes large depending on the type of the long object, and the productivity tends to be lowered. Strictly speaking, the preferable range of the roll diameter is φ5 mm to φ500 mm, more preferably φ10 mm to φ100 mm, and still more preferably φ20 mm to φ60 mm, although it varies depending on the pitch. If the roll pitch is less than φ5 mm, the curl (warp) property is inferior unless the roll pitch is considerably narrowed, and if it is greater than φ500 mm, the equipment becomes large, and the productivity and efficiency that are the objects of the present invention are intended. Come different. The material of the roll is not particularly limited, but SUS or the like with less thermal expansion can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not particularly limited by the examples. The evaluation method of the characteristic value in each example is as follows.

Logarithmic viscosity Dissolved in N-methyl-2-pyrrolidone so that the polymer concentration is 0.5 g / dl. The solution viscosity and solvent viscosity of the solution were measured at 30 ° C. using an Ubellose type viscosity tube. Calculated with the formula.

Glass transition point, coefficient of thermal expansion The glass transition point of the resin film layer obtained by etching and removing the metal foil of the metal laminate of the present invention by TMA (Thermal Mechanical Analysis / manufactured by Rigaku Corporation) tensile load method was measured under the following conditions. . The film was measured for a film that was once heated to 250 ° C. and then cooled to room temperature in nitrogen at a heating rate of 10 ° C./min. The thermal expansion coefficient was an average value from 100 ° C to 200 ° C.
Load: 1g
Sample size: 4 (width) x 20 (length) mm
Temperature increase rate: 10 ° C / min Atmosphere: Nitrogen

Residual solvent ratio JIS K5400 was calculated from the following equation under the drying conditions of 250 ° C. × 1 hr.

Curling of the substrate The curling rate of the curl of the metal-clad laminate was determined from JIS C6481 for a sample (sample size 100 mm × 100 mm) conditioned for 24 hours at 25 ° C. and 65% RH.

Solder heat resistance After etching the metal foil of the metal-clad laminate and creating a circuit pattern with a width of 1 mm (multiple patterns with an inter-circuit width of 5 mm), the sample was conditioned at 40 ° C and 85% (humidity) for 5 hrs and flux washed Soldering was performed at 280 ° C. for 30 seconds, and the presence or absence of peeling or swelling was observed with a microscope. ○ indicates that there is no peeling or swelling, and × indicates that peeling or swelling has occurred.

Dimensional change rate Measured in the MD direction and TD direction by IPC-FC241 using the B method (before and after etching) and the C method (before and after heat treatment at 150 ° C. for 30 minutes).

[Hygroscopic rate]
A resin film having a length and a width of 50 ± 1 mm was measured by the following method. (If the cut surface of the sample is rough, it was finished smoothly with abrasive paper of P240 or higher as defined in JIS R 6252). Five samples were used for the measurement.
(1) The sample is allowed to stand for 24 hours in a thermostat kept at 50 ± 2 ° C.
(2) Leave the sample for 24 hours under the conditions of 25 ° C. and 90% RH so that the samples do not come into contact with each other (use the feather or brush to remove dust on the sample surface).
(3) Transfer the sample to a weighing bottle, seal it quickly with a lid, and leave it in a desiccator for about 1 hour at room temperature.
(4) The total weight of the weighing bottle and the sample is measured (W1), and then the sample is quickly taken out and the weight (W0) of only the weighing bottle is measured. (Or just leave the weighing bottle in the desiccator for more than 1 hour and measure its weight (W0) in advance)
(5) The sample in the weighing bottle is dried for 1 hour in a thermostat kept at 100 ± 5 ° C.
(6) Transfer the sample to a weighing bottle, seal it quickly with a lid, and leave it in a desiccator at room temperature for about 1 hour.
(7) The total weight of the weighing bottle and the sample is measured (referred to as W3), and then the sample is quickly taken out therefrom and the weight (W4) of only the weighing bottle is measured. (Or just leave the weighing bottle in the desiccator for 1 hour or more and measure its weight (W4) in advance)
(8) The moisture absorption rate WA (%) is calculated by the following formula.
WA = [{(W1-W0)-(W3-W4)} / (W1-W0)] × 100

Synthesis Example 1 Trimellitic anhydride 153.7 g (80 mol%), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride 40.3 g (12.5 mol%) in a synthetic reaction vessel for resin A 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride 22.1 g (7.5 mol%), o-tolidine diisocyanate 264.3 g (100 mol%), 1.0 g diazabicycloundecene , And 2500 g of N-methyl-2-pyrrolidone (purity 99.9%) were added, the temperature was raised to 100 ° C. under a nitrogen stream, and the mixture was reacted at 100 ° C. for 5 hours. Next, 1031 g of N-methyl-2-pyrrolidone (polymer concentration: 10% by weight) was added and cooled to room temperature. The logarithmic viscosity of the obtained polymer was 1.4, and the solution viscosity at 25 ° C. (measured at 10 revolutions with a B-type viscometer) was 250 poise.

Synthesis Example 2 Synthesis of Resin B In a reaction vessel, trimellitic anhydride 38.4 g (20 mol%), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride 128.9 g (40 mol%), 3 , 3 ′, 4,4′-biphenyltetracarboxylic dianhydride 58.8 g (20 mol%), pyromellitic dianhydride 21.8 g (10 mol%), 1,5-naphthalene diisocyanate 210.2 g ( 100 mol%), 1.5 g of diazabicycloundecene and 2500 g of N-methyl-2-pyrrolidone were added, the temperature was raised to 100 ° C. over 1 hr, and the mixture was further reacted at 100 ° C. for 5 hr. Next, 840 g of NMP (polymer concentration 10% by weight) was added and cooled to room temperature. The logarithmic viscosity of the obtained polymer was 1.2, and the solution viscosity at 25 ° C. (measured at 10 revolutions with a B-type viscometer) was 180 poise.

Synthesis Example 3 Trimellitic anhydride 115.3 g (60 mol%), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride 32.2 g (10 mol%), 3 , 3 ′, 4,4′-biphenyltetracarboxylic dianhydride 88.3 g (30 mol%), 264.3 g (100 mol%) o-tolidine diisocyanate, 1.0 g diazabicycloundecene, and N— 2500 g of methyl-2-pyrrolidone (purity 99.9%) was added, the temperature was raised to 100 ° C. under a nitrogen stream, and the mixture was reacted at 100 ° C. for 5 hours. Next, 1200 g of N-methyl-2-pyrrolidone (polymer concentration: 10% by weight) was added and cooled to room temperature. The logarithmic viscosity of the obtained polymer was 1.6, and the solution viscosity at 25 ° C. (measured at 10 revolutions with a B-type viscometer) was 330 poise.

Synthesis Example 4 Synthesis of resin D 43 g (50 mol%) of p-phenylenediamine, 3200 g of N-methyl-2-pyrrolidone, and 80 g (50 mol%) of 4,4′-diaminodiphenyl ether were added and cooled to 5 ° C. Then, it stirred and melt | dissolved. Next, 236 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Corporation) was gradually added and reacted at 5 ° C. for 2 hours (polymer concentration 10%). Subsequently, 1 g of 2-hydroxypyridine (2 mol% with respect to the monomer; manufactured by Nacalai Tesque) was added and reacted for 1 hour. The obtained polymer dope was light yellowish brown and transparent, and the polymer was dissolved in NMP. The logarithmic viscosity was 1.9 dl / g.

Example 1 and Reference Example 1
Each of the resin solutions obtained in Synthesis Examples 1 and 2 was subjected to solvent removal using a die coater on the treated surface of an electrolytic copper foil (USLP-SE-18 manufactured by Nihon Electrolysis Co., Ltd.) having a thickness of 18 μm and a width of 540 mm. The coating was continuously performed so that the thickness was 25 μm. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) Between the rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm) arranged in Noritake Engineering RtoR type heat treatment apparatus heat) was conveyed in a staggered manner.
Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100mm, capacity 225kW, heater dimensions 150mm x 700mm, N2 flow rate 500L / min, oxygen concentration 100ppm, the temperature in the heating furnace is 300 ° C (metal laminate surface temperature), The conveyance speed was set so that the drying time was 10 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Example 2 and Reference Example 2
Using the die coater on the treated surface of the electrolytic copper foil (F2-WS manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 18 μm and a width of 540 mm, respectively, the resin solutions obtained in Synthesis Examples 1 and 2 were removed. Was continuously coated to a thickness of 25 μm. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 130 μm (Nomex T-410, 5 mil manufactured by DuPont Teijin Ltd .; calendered) Between the rolls as shown in FIG. 1 placed in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (RtoR heat treatment apparatus manufactured by Noritake Engineering Co., Ltd.). A roll pitch of 200 mm, a roll system of 50 mmΦ, and a height difference between rolls of 300 mm) were conveyed in a staggered manner. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100mm, capacity 225kW, heater dimensions 150mm x 700mm, N2 flow rate 500L / min, oxygen concentration 100ppm, temperature in heating furnace 300 ° C (metal laminate surface temperature) The conveying speed was such that the drying time was 10 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Reference example 3
Using the die coater on the treated surface of the electrolytic copper foil (FT0-WS manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 18 μm and a width of 540 mm, respectively, the resin solutions obtained in Synthesis Examples 1 and 2 were removed. Was continuously coated to be 35 μm. Next, the film was continuously passed through a 20 m long flotation type drying furnace set at 100 ° C. at a speed of 3 m / min. The resulting metal laminate had a residual solvent ratio of 29% by weight.
A non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 180 μm (Nomex T-410, 7 mil manufactured by DuPont Teijin Ltd.) was calendered on the coated surface of the long product thus obtained. Aramid paper), and a stainless steel foil having a width of 540 mm and a thickness of 35 μm overlapped on the opposite side copper foil side, and placed in a hot air circulation type heating furnace as shown in FIG. A roll pitch of 200 mm, a roll system of 50 mmΦ, and a height difference between rolls of 300 mm) were conveyed in a staggered manner. The temperature in the heating furnace was 300 ° C. (metal laminate surface temperature), and the conveying speed was such that the drying time was 15 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Reference example 4
The resin solution obtained in Synthesis Example 2 (Resin B) was subjected to solvent removal using a die coater on the treated surface of an electrolytic copper foil having a thickness of 12 μm and a width of 540 mm (USLP-SE-18 manufactured by Nihon Denki Co., Ltd.). The coating was continuously performed so that the thickness was 20 μm. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
Subsequently, the resin solution obtained in Synthesis Example 1 (resin A) is continuously coated on the coated surface of the laminate using a die coater so that the thickness after solvent removal is 20 μm. The film was continuously passed through a 20 m long flotation type drying furnace set at 100 ° C. at a speed of 5 m / min. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) Between the rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm) arranged in Noritake Engineering RtoR type heat treatment apparatus heat) was conveyed in a staggered manner. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100mm, capacity 225kW, heater dimensions 150mm x 700mm), N2 flow rate 500L / min, oxygen concentration 100ppm, temperature in heating furnace 300 ° C (metal laminate surface temperature ) The conveyance speed was set so that the drying time was 15 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Example 5 and Reference Example 5
The resin solutions obtained in Synthesis Examples 1 and 2 were subjected to solvent removal using a die coater on the treated surface of an electrolytic copper foil (USLP-SE-18 manufactured by Nihon Electrolysis Co., Ltd.) having a thickness of 18 μm and a width of 540 mm, respectively. The coating was continuously performed so that the thickness was 25 μm. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) As shown in Fig. 1, placed between Noritake Engineering's RtoR heat treatment equipment heat) and transported between rolls (on a roll with a roll pitch of 200 mm, a roll system of 50 mmΦ, and a roll height difference of 300 mm using a roll support system). It was. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100mm, capacity 225kW, heater dimensions 150mm x 700mm, temperature in the heating furnace is 300 ° C (metal laminate surface temperature), N2 flow rate 500L / min, oxygen concentration 100ppm, The conveyance speed was set so that the drying time was 10 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Reference Example 6
Thickness after solvent removal using a die coater on the treated surface of the electrolytic copper foil (U-WZ manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 12 μm and a width of 540 mm for the resin solution obtained in Synthesis Example 2 (Resin B) Was continuously coated to a thickness of 10 μm. Subsequently, it was continuously passed through a 20 m long flotation drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
Subsequently, the resin solution obtained in Synthesis Example 3 (resin C) is continuously coated on the coated surface of the laminate using a die coater so that the thickness after solvent removal is 20 μm. The film was continuously passed through a 20 m long flotation type drying furnace set at 100 ° C. at a speed of 5 m / min. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) As shown in Fig. 1, placed between Noritake Engineering's RtoR heat treatment equipment heat) and transported between rolls (on a roll with a roll pitch of 200 mm, a roll system of 50 mmΦ, and a roll height difference of 300 mm using a roll support system). It was. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100 mm, capacity 225 kW, heater dimensions 150 mm x 700 mm, heating furnace temperature 300 ° C (metal laminate surface temperature), N2 flow rate 500 L / min, oxygen concentration 100 ppm The conveyance speed was set so that the drying time was 15 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Reference Example 7
Thickness after solvent removal using a die coater on the treated surface of the electrolytic copper foil (U-WZ manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 12 μm and a width of 540 mm for the resin solution obtained in Synthesis Example 2 (Resin B) Was continuously coated to a thickness of 10 μm. Subsequently, it was continuously passed through a 20 m long flotation drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
Subsequently, the resin solution obtained in Synthesis Example 3 (resin C) is continuously coated on the coated surface of the laminate using a die coater so that the thickness after solvent removal is 20 μm. The film was continuously passed through a 20 m long flotation type drying furnace set at 100 ° C. at a speed of 5 m / min. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) Between the rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm) arranged in Noritake Engineering RtoR type heat treatment apparatus heat) was conveyed in a staggered manner. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100 mm, capacity 225 kW, heater dimensions 150 mm x 700 mm, heating furnace temperature 300 ° C (metal laminate surface temperature), N2 flow rate 500 L / min, oxygen concentration 100 ppm The conveyance speed was set so that the drying time was 15 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Reference Example 8
Using the die coater on the treated surface of the electrolytic copper foil having a thickness of 18 μm and a width of 540 mm (USLP-SE-18 manufactured by Nihon Electrolysis Co., Ltd.), the thickness after desolvation is 25 μm. It was continuously coated so that Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 25% by weight.
The coated surface of the long product thus obtained was a non-woven fabric made of aromatic polyamide (aramid) having a width of 540 mm and a thickness of 80 μm (Nomex T-410, 3 mil manufactured by DuPont Teijin Ltd.); Aramid paper) and a polyimide film (Upilex S) with a width of 540 mm and a thickness of 50 μm are superimposed on the opposite side of the copper foil, and in a far-infrared heating furnace with a wavelength of 5.6 to 1000 μm (Co., Ltd.) As shown in Fig. 1, placed between Noritake Engineering's RtoR heat treatment equipment heat) and transported between rolls (on a roll with a roll pitch of 200 mm, a roll system of 50 mmΦ, and a roll height difference of 300 mm using a roll support system). It was. Far-infrared plate heater upper surface, lower surface arrangement, irradiation distance 100mm, capacity 225kW, heater dimensions 150mm x 700mm, the temperature in the heating furnace is 300 ° C (metal laminate surface temperature) and 350 ° C (metal laminate surface temperature) Thus, the conveyance speed was set to 15 minutes each for the drying time. The N2 flow rate was 500 L / min, and the oxygen concentration was 100 ppm. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

Comparative Example 1
Using the die coater on the treated surface of the electrolytic copper foil (F0-WS manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 18 μm and a width of 540 mm, the resin solution obtained in Synthesis Example 1 has a thickness after solvent removal of 30 μm. Was continuously coated. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 32% by weight.
The long object thus obtained is placed in a hot air circulation type heating furnace, as shown in FIG. 1, between rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm). It was transported in a zigzag pattern. The temperature in the heating furnace was 300 ° C. (metal laminate surface temperature), and the conveying speed was such that the drying time was 15 minutes. The obtained metal-clad laminate had a blocking phenomenon (scratches) on the roll, was severely curled, and was broken at both ends, and was extremely poor in quality.

Comparative Example 2
Using the die coater on the treated surface of the electrolytic copper foil (F0-WS manufactured by Furukawa Circuit Foil Co., Ltd.) having a thickness of 18 μm and a width of 540 mm, the resin solution obtained in Synthesis Example 1 has a thickness after solvent removal of 30 μm. Was continuously coated. Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The residual solvent ratio of the obtained metal laminate was 32% by weight.
The long object thus obtained is placed in a hot air circulation type heating furnace, as shown in FIG. 1, between rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm). It was transported in a zigzag pattern. The same aramid nonwoven fabric as that used in the examples was wound around the roll in advance. The temperature in the heating furnace was 300 ° C. (metal laminate surface temperature), and the conveying speed was such that the drying time was 15 minutes. The resulting metal-clad laminate was a step derived from the aramid nonwoven fabric step on the roll. Traces were seen, and both ends of the long metal laminate were partially broken, and the quality was poor.

Comparative Example 3
Using the die coater on the treated surface of the electrolytic copper foil having a thickness of 18 μm and a width of 540 mm (USLP-SE-18 manufactured by Nihon Denki Co., Ltd.), the thickness after desolvation is 20 μm. It was continuously coated so that Subsequently, the film was continuously passed through a 20 m long floating drying oven set at 100 ° C. at a speed of 5 m / min and wound up. The resulting metal laminate had a residual solvent ratio of 23% by weight.
As shown in FIG. 1, the long product thus obtained was placed in a hot air circulation type heating furnace, and between rolls (roll pitch 200 mm, roll system 50 mmΦ, height difference between rolls 300 mm) Was conveyed by a roll support method). The temperature in the heating furnace was 300 ° C. (metal laminate surface temperature), and the conveying speed was such that the drying time was 15 minutes. The solvent in the coating film of the obtained metal-clad laminate was completely removed, and the characteristics were as shown in Table 1.

    The present invention relates to a method for treating a long object, and more specifically, drying a long object after impregnating or coating a long object such as a film, a textile fabric, a sheet, and a metal foil with water or an organic solvent solution, and The present invention relates to a method for efficiently performing heat treatment with a high yield. The present invention also relates to a metal foil laminate excellent in performance such as dimensional stability and moisture absorption characteristics. In particular, the present invention relates to a method for producing a flexible metal-clad laminate obtained by applying polyimide resin or a precursor thereof to a metal foil and drying, which is useful as a flexible printed wiring board.

Claims (3)

A metal foil laminate in which an aromatic polyamideimide is laminated on a metal foil, characterized by the following (a) to (d) :
(A) trimellitic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as the acid component, and amine component an aromatic polyamideimide polymerized using o-tolidine or o-tolidine diisocyanate;
(B) An aromatic polyamideimide containing 5 to 99 mol% of the structural unit represented by the general formula (1) in the structural unit;
(C) It is a metal foil laminated body heat-processed using the far-infrared heater whose far-infrared region is the range of 5 micrometers-1000 micrometers ;
(D) The moisture absorption rate of the resin film layer obtained by etching away the metal foil from the metal foil laminate is 0.9% or less .
The metal foil laminate according to claim 1 , wherein the heat treatment is performed under the following conditions (i) to (iii).
(I) Under reduced pressure of about 10 mmHg or less, or in an inert gas atmosphere of 1000 ppm or less (ii) The temperature of the heat treatment is 50 ° C. to 450 ° C. at the surface temperature of the metal laminate resin surface.
(Iii) The heat treatment time is 0.5 minutes to 100 minutes Furthermore, (e) thermal expansion coefficient (CTE) is 17 ppm or less, The metal foil laminated body of Claim 1 or 2 characterized by the above-mentioned.