JP2008168439A - White polyimide-metal laminate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a white polyimide-metal laminate which is high in reflectance and whiteness and excellent in heat resistance. <P>SOLUTION: In the white polyimide-metal laminate, a white polyimide in which a white pigment is mixed with a polyimide prepared by reacting a diamine containing at least one selected from t-CHDA (trans-diaminocyclohexane), MBCA (methylene bis(cyclohexylamine)), and DDS (diaminodiphenylsulfone) as a main component with an aromatic tetracarboxylic acid is laminated on a metal layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal white polyimide laminate using a polyamic acid solution containing polyimide and a white pigment, and a method for producing the same. This metal white polyimide laminate can be used as heat-resistant and lightweight white material, LED (light emitting diode) reflector, metal layer laminated white film, flexible printed wiring board for mounting LED (light emitting diode) and other light emitting elements, etc. Is suitably used.

Conventionally, transparent films such as cellophane film, polyethylene film, polyester film, nylon film are mainly used for packaging applications, etc., but they are widely used in industrial products by taking advantage of the flexibility of these films. White films are also known. For example, it contains a white pigment having an average particle size of 0.1 to 2.5 μm as a biaxially oriented white copolymer polyester film useful for forming into a container after being bonded to a metal plate, and has a melting point of 210 to 245. It is made of a copolyester in the range of ° C., and is excellent in a polyester film (see Patent Document 1) in which the degree of crystal orientation in the thickness direction of the film is in the range of 0.2 to 0.6, heat resistance, and crease As a highly concealing white laminated film, a polyimide and polyester, a resin having a dispersion diameter in the film of 0.03 to 5 μm and / or a layer mainly composed of inert particles as a main constituent component is made of thermoplastic resin on at least one side. A biaxially oriented film in which the layer B is laminated, and the white laminated film in which the Tg of the resin constituting the layer A is higher than the Tg of the thermoplastic resin constituting the layer B (Patent Literature) 2), etc.) have been proposed.
In recent years, the use of these films in electronic parts has been expanding, but the above-mentioned film materials have many problems in high-temperature production and use.

For example, in a reflector for lighting, a printed wiring board for LED mounting, etc., a ceramic substrate is mainly used, and a prepreg and a metal in which a sheet-shaped glass base material is partially impregnated with a thermosetting resin containing a white pigment. Rigid metal-clad laminates obtained by hot press molding of foil have been mainly used, but electronic devices are becoming thinner and lighter in order to improve portability and the like. Correspondingly, these used ones are required to be further reduced in weight and thickness. As an example of the application, FIG. 1 shows an example in which an LED chip is mounted on a white substrate. Of the light emitted from the LED chip to the surroundings, the light that came to the white substrate side is reflected in the original color of the LED, so that the light emission color of the LED chip is not impaired and the loss due to absorption is small. it can. Dispersions or films made of aromatic polyimide or aromatic polyamic acid obtained by polycondensation reaction of aromatic tetracarboxylic dianhydride and aromatic diamine are widely used as adhesives or adhesive films with excellent heat resistance. It has been. However, although such aromatic polyimide resin has excellent heat resistance and mechanical properties, it absorbs visible light and is colored from pale yellow to reddish brown, so the resin composition mixed with the white pigment is reflective. The rate is low and the whiteness is also low.
In order to solve these problems, an aliphatic tetracarboxylic acid structure is used as a flexible metal-clad white laminate that uses a white resin composition with high reflectance and whiteness and excellent light resistance, and is easy to reduce the thickness and weight. There has been proposed a flexible metal-clad white laminate in which a white resin layer made of a resin composition obtained by mixing a white pigment with a polyimide having a repeating unit having a repeating unit is an adhesive layer of at least one metal layer (see Patent Document 3). ).
In any of the conventional techniques, there is no viewpoint on the difference between the coefficient of linear expansion between the copper foil and the polyimide layer, and as a result, in the laminate of the polyimide layer and the copper foil, peeling or warping due to heat during manufacture and use There was a problem that abnormalities such as blisters frequently occurred.
JP 05-170942 A JP 2004-098442 A JP 2006-110999 A

  An object of the present invention is to provide a white polyimide film that eliminates the problems of metal white polyimide laminates and the like that have been used in various conventional applications, eliminates defects, and has high reflectance and whiteness and excellent heat resistance. An object of the present invention is to provide a flexible metal-clad laminate and the like that are easy to make thin and light.

As a result of intensive studies to solve the above problems, a metal white polyimide laminate using a mixture of a polyamic acid and a white pigment using a specific diamine has high reflectivity and whiteness, excellent heat resistance, and machine The present inventors have found that an electronic component that is excellent in mechanical strength and that can be easily reduced in thickness and weight can be obtained.
That is, the present invention has the following configuration.
1. A diamine and an aromatic tetracarboxylic acid mainly composed of at least one selected from transdiaminocyclohexane (abbreviated as t-CHDA), methylenebis (cyclohexylamine) (abbreviated as MBCA), and diaminodiphenylsulfone (abbreviated as DDS). A white metal polyimide laminate comprising white polyimide mixed with a white pigment mixed with a metal layer obtained by reacting with a metal layer.
2. From the group in which the white pigment consists of titanium oxide, zirconium oxide, calcium oxide, silicon oxide, zinc oxide, aluminum oxide, zinc sulfide, calcium sulfate, barium sulfate, basic zinc molybdate, basic calcium zinc molybdate, molybdenum white 1. one or more selected. White polyimide film.
3. 1. Whiteness is 50 or more Or 2. Any white polyimide film.
4). Polyamic acid obtained by reacting a diamine mainly composed of at least one selected from t-CHDA (transdiaminocyclohexane), MBCA (methylenebis (cyclohexylamine)) and DDS (diaminodiphenylsulfone) with an aromatic tetracarboxylic acid. A method for producing a metal white polyimide laminate, wherein a liquid containing a white pigment is applied to a metal layer, dried and imidized.

  A diamine and a fragrance comprising at least one selected from t-CHDA (trans 1,4-diaminocyclohexane), MBCA (4,4′-methylenebis (cyclohexylamine)) and DDS (diaminodiphenylsulfone) as main components of the present invention. A liquid in which a white pigment is added to a polyamic acid obtained by reacting an aromatic tetracarboxylic acid is cast and dried on a metal layer such as a copper foil to obtain a polyimide precursor laminated copper foil, and the polyimide precursor laminated layer The metal white polyimide laminate obtained by imidizing copper foil is excellent in the adhesion between the metal layer of the metal white polyimide laminate and the polyimide by using polyimide using a specific diamine and at the time of manufacture. And there is little peeling and warping due to heat when using the laminate, and the metal white polyimide laminate is used. Excellent production efficiency of the product, it is assumed faultless and variation in performance, industrially very useful.

The metal white polyimide laminate of the present invention is composed of t-CHDA (a kind selected from isomers of transdiaminocyclohexane such as trans 1,4-diaminocyclohexane) and methylene bis (cyclohexyl) such as MBCA (4,4′-methylenebis (cyclohexylamine). Diamines and aromatic tetracarboxylic acids whose main components are at least one kind selected from isomers of amine)), DDS (one kind selected from isomers of diaminodiphenylsulfone such as 3,3′-diaminodiphenylsulfone) Is a white metal polyimide laminate in which a white polyimide mixed with a white pigment is laminated with a metal layer. The polyimide in the present invention is t-CHDA as a diamine. (Trans 1,4-dia No cyclohexane) and / or MBCA (4,4′-methylenebis (cyclohexylamine), etc.), DDS (3,3′-diaminodiphenylsulfone, etc.) are not particularly limited, It is preferable to use diamine in an amount of 70 mol% or more, more preferably 85 mol% or more.
If it is less than 30 mol% of the diamine, it may be a polyimide film using one or more diamines exemplified below in combination.

  4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (3-amino Phenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3 , 3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-di Mino diphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone,

3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, bis [ 4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1, 1-bis [4- (4-aminophenoxy) phenyl] propane, 1,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane. 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, 1,4-bis [4- (4-aminophenoxy) Phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl] butane,

2- [4- (4-Aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3- Methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4 -Aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane. 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) ) Biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- ( 4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether,

3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] Benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) ) Phenyl] propane, 3,4'-diaminodiphenyl sulfide. 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1 -Bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4 '-Bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-α) , Α-dimethylbenzyl) phenoxy] benzophenone,

  4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-Aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-Amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl ] Benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-sia) Phenoxy)-.alpha., alpha-dimethylbenzyl] benzene. 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4′-diamino-4,5′-diphenoxybenzophenone, 3, 3'-diamino-4-phenoxybenzophenone.

4,4′-diamino-5-phenoxybenzophenone, 3,4′-diamino-4-phenoxybenzophenone, 3,4′-diamino-5′-phenoxybenzophenone, 3,3′-diamino-4,4′-dibi Phenoxybenzophenone, 4,4′-diamino-5,5′-dibiphenoxybenzophenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 4, 4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis (3-amino-4- Phenoxybenzoyl) benzene, 1,4-bis (3-amino-4-phenoxybenzoyl) benzene, , 3-bis (4-amino-5-phenoxybenzoyl) benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino-4-biphenoxybenzoyl) benzene 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-bi) Phenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the above aromatic diamine are halogen atoms, particularly Some of hydrogen atoms of fluorine atom, alkyl group having 1 to 3 carbon atoms or alkoxyl group, cyano group, or alkyl group or alkoxyl group The whole can be mentioned halogenated alkyl group or an aromatic diamine substituted with an alkoxyl group having 1 to 3 carbons substituted with a halogen atom and country fluorine atom and the like.

The tetracarboxylic acid used in the present invention is preferably an aromatic tetracarboxylic anhydride.
Specific examples of aromatic tetracarboxylic acid anhydrides include the following, but pyromellitic acid anhydride of Chemical Formula 5 and 3,3 ′, 4,4 ′ biphenyltetracarboxylic acid anhydride of Chemical Formula 6 are preferable. It is a thing. Pyromellitic anhydride or 3,3 ′, 4,4′biphenyltetracarboxylic anhydride is preferably used in an amount of 70 mol% or more, more preferably 85 mol%. In addition to this pyromellitic acid anhydride and 3,3 ′, 4,4′biphenyltetracarboxylic acid anhydride, if the following aromatic tetracarboxylic acid (anhydride) or non-aromatic tetracarboxylic acid is less than 30 mol% You may use together.

  Butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, cyclobutanetetracarboxylic dianhydride, cyclopentane-1,2,3 , 4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3,5,6-tetracarboxylic dianhydride, 3- Ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3- (1,2), 5,6-tetracarboxylic Acid dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-ethylcyclohexane-1- (1,2) , 3,4-tetracarboxylic dianhydride, -Propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- (2,3) -tetracarboxylic acid Dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 1- Propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- (2,3) -tetracarboxylic acid bis Anhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2 2.2] Octane-2,3,5,6-te Rakarubon dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, and the like. These tetracarboxylic acids (dianhydrides) may be used alone or in combination of two or more.

  The solvent used when polymerizing the diamine (monomer) and the tetracarboxylic acid (monomer) to obtain the polyamic acid is not particularly limited as long as it dissolves both the raw material monomer and the polyamic acid to be produced. Polar organic solvents are preferred, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexa Examples include methylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the mass of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by mass, The amount is preferably 10 to 30% by mass.

Conventionally known conditions may be applied for the polymerization reaction for obtaining the polyamic acid (hereinafter also simply referred to as “polymerization reaction”). As a specific example, in a temperature range of 0 to 80 ° C., 10 Stirring and / or mixing continuously for 30 minutes. If necessary, the polymerization reaction may be divided or the temperature may be increased or decreased. In this case, the order of adding both monomers is not particularly limited, but it is preferable to add an aromatic tetracarboxylic acid (anhydride) to the aromatic diamine solution. The mass of the polyamic acid in the polyamic acid solution obtained by the polymerization reaction is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and the viscosity of the solution is measured with a Brookfield viscometer (25 ° C.). From the viewpoint of the stability of liquid feeding, it is preferably 10 to 2000 Pa · s, and more preferably 100 to 1000 Pa · s.
The reduced viscosity (ηsp / C) of the polyamic acid in the present invention is not particularly limited, but is preferably 2.0 dl / g or more, and more preferably 3.0 dl / g or more.

Vacuum defoaming during the polymerization reaction is effective for producing a high-quality polyamic acid organic solvent solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamine before a polymerization reaction. Examples of the end capping agent include compounds having a carbon-carbon double bond such as maleic anhydride. The amount of maleic anhydride used is preferably 0.001 to 1.0 mol per mol of aromatic diamine.
In order to form a polyimide film from a solution obtained by adding a white content to the polyamic acid obtained by the polymerization reaction, a green film is obtained by applying this solution on a support and drying, and then the green film is formed. The method of imidating reaction by using for heat processing etc. is mentioned.

A method for producing a metal white polyimide laminate by applying a solution obtained by adding a white content to polyamic acid to a metal layer, drying and imidizing is preferable as a method for producing a metal white polyimide laminate of the present invention. The application of the liquid with the white content added to the acid includes, but is not limited to, casting from a slit base, extrusion through an extruder, squeegee coating, reverse coating, die coating, applicator coating, wire bar coating, etc. A conventionally known solution coating means can be appropriately used.
In addition to this, a method in which the metal foil is pre-manufactured from the white pigment-containing polyamic acid solution and a film pre-manufactured from the white pigment-containing polyamic acid solution, a method in which the foil is preliminarily heat-pressed through an adhesive layer as necessary. Examples thereof include a method of forming a metal layer by sputtering, vapor deposition, other vapor phase methods, electroless plating, etc., and appropriately performing electrolytic plating.
Examples of the metal used for the metal layer include copper, aluminum, stainless steel, gold, silver, and nickel, and copper, aluminum, and stainless steel are preferable. Although there is no restriction | limiting in particular in the thickness of a metal layer (foil), What is necessary is just the range of 2-100 micrometers normally used. When manufacturing also by sputtering, vapor deposition and electroless plating, etc., copper, nickel, chromium, tin, cobalt, gold etc. are preferred, more preferably copper, nickel, gold, and these may be multilayered, The thickness of the metal layer in this case is not particularly limited, but is preferably 2 to 10 μm in order to take advantage of the thin film forming method.

The white pigment used in the present invention is titanium oxide, zirconium oxide, calcium oxide, silicon oxide, zinc oxide, aluminum oxide, zinc sulfide, calcium sulfate, barium sulfate, basic zinc molybdate, basic calcium zinc molybdate, molybdenum white. One or more selected from the group consisting of and the like. Among these, rutile type titanium oxide having a coating layer formed on the surface is preferable. The coating layer is treated with SiO ₂ or Al ₂ O ₃ , and the coating layer is treated with SiO ₂ or Al ₂ O _3. Then, rutile type titanium oxide which is obtained by polyol treatment or siloxane treatment is preferred.
The white pigment is usually used as a white pigment dispersion mixed in a polyamic acid solution. The blending may be performed either before or after the synthesis of the polyamic acid, during the synthesis, after the synthesis, or after the synthesis, and further after being diluted with a diluent solvent after the synthesis, but is usually performed after the synthesis.
Stirring and dispersion of the white pigment may be performed in a stirring tank equipped with a stirrer having an appropriate stirring ability, or may be performed using a device for mixing such as a ball mill or a revolving / spinning type mixing device. be able to.

The particle size of the white pigment used in the present invention is 0.05 to 5 μm, preferably 0.1 to 1 μm. When the particle size is smaller than 0.05 μm, the light reflectivity is lowered. On the other hand, when it exceeds 5 μm, the unevenness on the surface of the resin composition layer is conspicuous, resulting in poor appearance. This is not preferable because the reduction is increased. The content rate of the white pigment with respect to a polyimide is 5-60 mass% on a solid content basis, More preferably, it is 10-50 mass%. When the content exceeds 60% by mass, the mechanical properties, particularly the breaking strength, is lowered, and sufficient adhesive strength cannot be obtained, which is not preferable. On the other hand, when the content is less than 5% by mass, sufficient reflectance and whiteness cannot be obtained, which is not preferable.
The reflectance of the white polyimide film of the present invention is preferably 50% or more at 410 to 780 nm. If it is less than 50%, it is not preferable because light breakthrough occurs. Moreover, it is preferable that the whiteness degree of a white polyimide film is 50 or more. If the degree of whiteness is less than 50, light is absorbed and yellowish.

Hereinafter, the present invention will be described specifically by way of examples. In addition, this invention is not restrict | limited at all by these Examples. Evaluation in Examples and the like was performed by the method shown below.
(1) Reduced viscosity of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. using an Ubbelohde type viscosity tube.
(2) Thickness of film etc. The thickness of the film was measured using a micrometer (Finereuf Co., Ltd., Millitron (trade name) 1254D).
(3) Reflectance Using a spectral whiteness photometer ERP-80WX manufactured by Tokyo Denshoku, the spectral reflectance was measured by irradiating the resin composition layer with 450 nm and 550 nm.
(4) Whiteness Resin composition using a spectral whiteness photometer ERP-80WX manufactured by Tokyo Denshoku, and a light reflectance of 100% when a standard plate (magnesium oxide plate) is irradiated with light having a wavelength of 457 nm. The reflectivity of the layer was expressed as a percentage of the reflectivity of the standard plate.
(5) Particle size Using a laser diffraction / scattering particle size distribution measuring apparatus LA-910 manufactured by Horiba Seisakusho, water was used as a dispersion medium, and ultrasonic wave irradiation was performed until the transmittance became steady. The particle system corresponding to 50% cumulative on a volume basis was defined as the median diameter.
(6) Surface observation of metal white polyimide laminate Visually observe the surface of the polyimide layer and metal layer of the metal white polyimide laminate to observe peeling, warping, swelling, etc. A case where they were slightly observed was indicated by Δ, and a case where they were frequently observed was indicated by ×.
(7) Linear expansion coefficient (CTE) of polyimide layer
For the polyimide layer to be measured, the expansion / contraction rate is measured under the following conditions, and the expansion / contraction rate / temperature at intervals of 30 to 45 ° C, 45 to 60 ° C, ... and 15 ° C is measured, and this measurement is performed up to 300 ° C. The average value of all measured values was calculated as CTE.
Device name: TMA4000S manufactured by MAC Science
Sample length; 20mm
Sample width: 2 mm
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

(Example 1)
(Polyamide acid polymerization)
In a reaction vessel, 1140 parts by mass of trans 1,4-diaminocyclohexane was dissolved in 34,000 parts by mass of N, N-dimethylacetamide, and then stirred with 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. 2646 parts by mass of the product powder and 218 parts by mass of pyromellitic dianhydride were gradually added. When the formed salt solution was heated in an oil bath at 150 ° C. with vigorous stirring for 5 minutes, a part of the salt began to dissolve, so the reaction vessel was removed from the oil bath and stirred at room temperature for several hours. A clear and viscous polyamic acid solution (A) was obtained. A rutile type titanium oxide having an average particle size of 0.43 μm was added to the obtained polyamic acid solution so as to be 30% by mass in the polyimide film, and mixed and dispersed to obtain a white pigment-containing polyamic acid solution.
The obtained liquid was applied onto an electrolytic copper foil having a thickness of 18 μm, dried at 90 ° C. for 25 minutes, dried with hot air, heat-treated at 200 ° C. for 3 minutes, and then heated to 350 ° C. for about 20 seconds. And heat treatment at 350 ° C. for 7 minutes, and then cooled to room temperature over 5 minutes to obtain a metal white polyimide laminate.
The performance of the obtained metal white polyimide laminate is shown in Table 1.

(Example 2)
(Polyamide acid polymerization-2)
After putting 2100 parts by mass of 4,4′-methylenebis (cyclohexylamine) into a reaction vessel and dissolving in 28600 parts by mass of N-methyl-2-pyrrolidone, pyromellitic dianhydride powder 2180 is stirred with stirring in a nitrogen stream. Mass parts were gradually added and reacted at 35 ° C. for 8 hours to obtain a transparent and viscous polyamic acid solution (B). The logarithmic viscosity of the obtained polyamic acid was 1.3 dl / g. A rutile type titanium oxide having an average particle size of 0.43 μm was added to the obtained polyamic acid solution so as to be 35% by mass in the polyimide film, and mixed and dispersed to obtain a white pigment-containing polyamic acid solution.
The obtained liquid was applied onto an electrolytic copper foil having a thickness of 18 μm, dried at 90 ° C. for 25 minutes, dried with hot air, heat-treated at 200 ° C. for 3 minutes, and then heated to 350 ° C. for about 20 seconds. And heat treatment at 350 ° C. for 7 minutes, and then cooled to room temperature over 5 minutes to obtain a metal white polyimide laminate.
The performance of the obtained metal white polyimide laminate is shown in Table 1.

(Example 3)
The liquid obtained in Example 1 was used, and this liquid was applied to a surface of a polyester film (Cosmo Shine A4100 (manufactured by Toyobo Co., Ltd.)) having a thickness of 188 μm and a width of 800 mm as a support on a surface not containing a lubricant. As a drying process, the coating was dried in three hot-air drying zones at an ambient temperature of 90 ° C. × 7 minutes, 90 ° C. × 7 minutes, and 90 ° C. × 7 minutes. The precursor film that became self-supporting after drying was peeled from the support to obtain a polyimide precursor film. From one side of the obtained polyimide precursor film, 639 parts by mass of 4,4′-diaminodiphenyl ether, 12000 parts by mass of N, N-dimethylacetamide, and 990 parts by mass of 4,4′-oxydiphthalic anhydride were prepared. A laminated polyamide film having a self-supporting property was obtained by coating a yellow and viscous polyamic acid solution and drying in the same manner. This laminated precursor film was passed through a continuous drying furnace and heat-treated at 200 ° C. for 3 minutes, and then heated to 350 ° C. for about 20 seconds, heat-treated at 350 ° C. for 7 minutes, and taken for 5 minutes. And cooled to room temperature to obtain a laminated white polyimide film.
An electrolytic copper foil having a thickness of 18 μm was superposed on the surface of the laminated white polyimide film on which the polyimide from the polyamic acid solution was laminated, and thermocompression bonded with a hot press to obtain a metal white polyimide laminate.
The performance of the obtained metal white polyimide laminate is shown in Table 1.

Example 4
(Polyamide acid polymerization)
After putting 4966 parts by mass of DDS (3,3′-diaminodiphenylsulfone) in a reaction vessel and dissolving it in NMP32551 parts by mass, the vessel was cooled with water and stirred with 3,3 ′, 4,4′-biphenyltetracarboxylic acid. Acid dianhydride powder (5884 parts by mass) was gradually added. By continuing stirring for 8 hours while cooling with water, a transparent and viscous polyamic acid solution (C) was obtained. A rutile type titanium oxide having an average particle size of 0.43 μm was added to the obtained polyamic acid solution so as to be 30% by mass in the polyimide film, and mixed and dispersed to obtain a white pigment-containing polyamic acid solution.
The obtained liquid was applied onto an electrolytic copper foil having a thickness of 18 μm and dried by hot air at 80 ° C. for 7.5 minutes, and a roll produced by heating at 200 ° C. for 1 hour in an inert oven under a nitrogen atmosphere, 250 hours. After heat treatment for 1 hour at 300 ° C. for 30 minutes at 300 ° C., the mixture was cooled to room temperature to obtain a metallic white polyimide laminate.
The performance of the obtained metal white polyimide laminate is shown in Table 1.

(Comparative Example 1)
A vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 4,4′-diaminodiphenyl ether (ODA) was added. Next, dimethylacetamide (DMAC) is added and completely dissolved, and then pyromellitic dianhydride (PMDA) is added, and ODA and PMDA as monomers are polymerized in DMAC at a molar ratio of 1/1, When stirred at 25 ° C. for 5 hours, a brown viscous polyamic acid solution was obtained. 15 parts by mass of AA and 3 parts by mass of IQ are mixed with 100 parts by mass of the resulting polyamic acid solution, and further, rutile titanium oxide having an average particle size of 0.43 μm is added to the polyamic acid solution in the polyimide film. It added so that it might become 35 mass%, and it mixed and disperse | distributed and the white pigment containing polyamic acid liquid was obtained. In the same manner as in Example 1, a metal white polyimide laminate was obtained.
The performance of the obtained metal white polyimide laminate is shown in Table 1.

  The metal white polyimide laminate in which a white polyimide obtained by mixing a white pigment with a polyamic acid obtained by reacting a diamine with an aromatic tetracarboxylic acid is laminated with a metal layer, the diamine is t-CHDA (Trans 1 , 4-diaminocyclohexane), MBCA (4,4′-methylenebis (cyclohexylamine)), DDS (3,3′-diaminodiphenylsulfone) is used as a main component, and a white polyimide is used as a main component. High reflectivity and whiteness, excellent heat resistance, can be used as heat-resistant lightweight white material, LED (light emitting diode) reflector, metal layer laminated white film, LED (light emitting diode) and flexible to mount it It can be suitably used for a printed wiring board (see FIG. 1) and has great industrial significance.

Chip LED structure overview: sectional view

Explanation of symbols

1. LED element2. Electrode 3. 3. Electrode pad Bonding wire 5. White printed circuit board

Claims (4)

  A white polyimide containing a white pigment mixed with a polyimide obtained by reacting a diamine mainly composed of at least one selected from transdiaminocyclohexane, methylenebis (cyclohexylamine) and diaminodiphenylsulfone with an aromatic tetracarboxylic acid is a metal. A metal white polyimide laminate characterized by being laminated with a layer.   From the group in which the white pigment is composed of titanium oxide, zirconium oxide, calcium oxide, silicon oxide, zinc oxide, aluminum oxide, zinc sulfide, calcium sulfate, barium sulfate, basic zinc molybdate, basic calcium zinc molybdate, molybdenum white The metal white polyimide laminate according to claim 1, which is one or more selected.   The white metallic polyimide laminate according to claim 1, wherein the whiteness is 50 or more.   A liquid obtained by adding a white pigment to a polyamic acid obtained by reacting a diamine mainly composed of at least one selected from diaminocyclohexane, methylenebis (cyclohexylamine) and diaminodiphenylsulfone with an aromatic tetracarboxylic acid is used as a metal layer. A method for producing a metal white polyimide laminate, which is applied to a substrate, dried and imidized.

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