KR102309824B1 - A multilayer film - Google Patents

Abstract

The present disclosure relates to multilayer films having an L* color of less than 30 and a gloss value of less than 10 of 60 degrees. The multilayer film has a first polyimide layer and a second polyimide layer. The second polyimide layer comprises 25 to 50 wt % polyimide, 15 to 35 wt % polyimide particle matting agent, greater than 0 and less than 20 wt % of at least one submicron carbon black, and 15 to 50 wt % at least one submicron fumed metal oxide of

Description

Multilayer film {A MULTILAYER FILM}

The present disclosure relates generally to multilayer films. More specifically, the multilayer film has a first polyimide layer and a second polyimide layer containing a matting agent, submicron carbon black and submicron fumed metal oxide.

Industry has shown that polyimide films for electronic applications are matte in appearance, have a specific color, have resistance to handling and circuit handling, and when used as a coverlay for security against undesired visual inspection of electronic components protected by the coverlay. more and more wanting to provide Single layer matte gloss films do not have an L* color less than 30 which provides the deep, rich, saturated color desired by the industry. In general, the color of the film becomes weaker as the amount of matting agent increases. The effect of increasing the surface roughness by the matting agent is to dilute the pigment color, making it appear paler and less saturated. This is due to increased scattering of the specular reflectance (white light), thereby diluting the diffuse reflectance (where the pigment color is perceived). As the surface roughness increases, the gloss decreases and the scattering of specular reflectance increases. Therefore, L* (brightness) generally increases as gloss decreases. Adding more colorant does not reduce the L* color. Therefore, it is difficult to achieve low gloss and low L* color at the same time.

For the above reasons, the appearance is matte, has a deep, rich saturated color, has acceptable electrical properties (eg dielectric strength), mechanical properties, and durability to handling and circuit handling, while being visually secure when used as a coverlay. A need exists for polyimide films that provide sufficient optical density to provide

The present disclosure as a multilayer film

a. 8 to 130 comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. a micron thick first polyimide layer;

b. a second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, the second polyimide layer comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film relates to a multilayer film having an L* color of less than 30 and a gloss value of 60 degrees less than 10.

1 illustrates an adhesive layer in direct contact with a first polyimide layer opposite a second polyimide layer according to an embodiment of the present disclosure.
2 shows an adhesive layer in direct contact with the second polyimide layer on the surface of the second polyimide layer furthest from the first polyimide layer according to one embodiment of the present disclosure.

The present disclosure relates to a multilayer film that achieves a desired L* color of less than 30 and a 60 degree gloss of less than 10 while maintaining acceptable electrical properties, mechanical properties, and durability to handling and circuit handling. The multilayer film includes a first polyimide layer and a second polyimide layer.

The use of “a” or “an” is used to describe elements and components of the invention. This has been done merely for convenience and to give a general meaning of the invention. This specification is to be read as including one or at least one, and the singular also includes the plural unless it is clear to mean otherwise.

As used herein, the term “polyamic acid” is intended to include any polyimide precursor material that is derived from a combination of a dianhydride and a diamine and can be converted to a polyimide.

first polyimide layer

The first polyimide is derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. As used herein, the term “dianhydride” technically cannot be a dianhydride, but is nevertheless capable of reacting with a diamine to form a polyamic acid followed by conversion to a polyimide, precursors, derivatives or analogs thereof are intended to include As used herein, the term “diamine” technically cannot be a diamine, but nevertheless reacts with a dianhydride to form a polyamic acid, which is then converted to a polyimide precursors, derivatives or analogs thereof. are intended to include

In one embodiment, the aromatic dianhydride is

pyromellitic dianhydride;

3,3′,4,4′-biphenyl tetracarboxylic dianhydride;

3,3',4,4'-benzophenone tetracarboxylic dianhydride;

4,4'-oxydiphthalic anhydride;

3,3′,4,4′-diphenyl sulfone tetracarboxylic dianhydride;

2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane;

bisphenol A dianhydride; and

and mixtures and derivatives thereof.

In one embodiment, the aromatic dianhydride is

2,3,6,7-naphthalene tetracarboxylic dianhydride;

1,2,5,6-naphthalene tetracarboxylic dianhydride;

2,2',3,3'-biphenyl tetracarboxylic dianhydride;

2,2-bis(3,4-dicarboxyphenyl) propane dianhydride;

bis(3,4-dicarboxyphenyl) sulfone dianhydride;

3,4,9,10-perylene tetracarboxylic dianhydride;

1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride;

1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride;

bis(2,3-dicarboxyphenyl)methane dianhydride;

bis(3,4-dicarboxyphenyl)methane dianhydride;

oxydiphthalic dianhydride;

bis(3,4-dicarboxyphenyl) sulfone dianhydride; and

and mixtures and derivatives thereof.

In some embodiments, examples of suitable aliphatic dianhydrides include cyclobutane dianhydride; [1S*,5R*,6S*]-3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3-(tetrahydrofuran-2,5-dione); and mixtures thereof.

In some embodiments, the aromatic diamine is 3,4'-oxydianiline; 1,3-bis-(4-aminophenoxy)benzene; 4,4'-oxydianiline; paraphenylenediamine; 1,3-diaminobenzene; 2,2′-bis(trifluoromethyl)benzidine; 4,4'-diaminobiphenyl; 4,4'-diaminodiphenyl sulfide; 9,9'-bis(4-amino)fluorine; and mixtures and derivatives thereof.

In another embodiment, the aromatic diamine is 4,4'-diaminophenyl propane; 4,4'-diamino diphenyl methane; benzidine; 3,3'-dichlorobenzidine; 3,3'-diamino diphenyl sulfone; 4,4'-diamino diphenyl sulfone; 1,5-diamino naphthalene; 4,4'-diamino diphenyl diethylsilane; 4,4'-diamino diphenylsilane; 4,4'-diamino diphenyl ethyl phosphine oxide; 4,4'-diamino diphenyl N-methyl amine; 4,4'-diamino diphenyl N-phenyl amine; 1,4-diaminobenzene (paraphenylenediamine); 1,2-diaminobenzene; and mixtures and derivatives thereof.

In some embodiments, examples of suitable aliphatic diamines include hexamethylene diamine, dodecane diamine, cyclohexane diamine, and mixtures thereof.

In one embodiment, the first polyimide layer comprises a polyimide derived from pyromellitic dianhydride and 4,4-oxydianiline.

In some embodiments, the first polyimide layer is in between including any two of the following thicknesses: 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120 and 130 microns thick. In another embodiment, the first polyimide layer is between 8 and 130 microns thick. In another embodiment, the first polyimide layer is between 10 and 30 microns thick. In another embodiment, the first polyimide layer is 12-25 microns thick.

The first polyimide layer may optionally contain from 1 to 15 wt % of low conductivity carbon black. In some embodiments, the first polyimide layer contains between, including any two of: 1, 5, 10, and 15 wt % of low conductivity carbon black. In another embodiment, the first polyimide layer contains 2 to 9 wt % of low conductivity carbon black.

Low conductivity carbon black is intended to mean channel type black, furnace black or lamp black. In some embodiments, the low conductivity carbon black is a surface oxide carbon black. One way to evaluate the degree of surface oxidation (of carbon black) is to measure the volatile components of the carbon black. Volatile components can be determined by calculating the weight loss when calcining at 950° C. for 7 minutes. Generally speaking, highly surface oxidized carbon black (a highly volatile component) can be readily dispersed in a polyamic acid solution (polyimide precursor), which in turn leads to the (well-dispersed) filled polyimide-based polymer of the present disclosure. can be imidized. When carbon black particles (aggregates) are not in contact with each other, it is generally believed that electron tunneling, electron hopping, or other electron flow mechanisms are suppressed, resulting in lowered electrical conductivity. In some embodiments, the low conductivity carbon black has at least 1% volatile components. In some embodiments, the low conductivity carbon black has at least 5, 9, or 13% volatile components. In some embodiments, the furnace black may be surface treated to increase volatile components. Generally, low conductivity carbon blacks have a pH of less than 6.

Uniform dispersion of isolated low-conductivity carbon black particles (aggregates) tends to reduce electrical conductivity as well as produce uniform color intensity. In some embodiments, low-conductivity carbon black is milled. In some embodiments, the average particle size of the low conductivity carbon black is between (and optionally inclusive of) any two of the following sizes: 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 microns.

The first polyimide layer may optionally contain 1 to 40 wt % of a pigment or dye. In some embodiments, the first polyimide layer contains from 1 to 40 wt % of a mixture of pigment and dye. In some embodiments, the first polyimide layer contains in between, including any two of: 1, 5, 10, 15, 20, 25, 30, 35 and 40 wt % of a pigment, a dye, or mixtures thereof. In some embodiments, the first polyimide layer contains 1 to 40 wt % of a mixture of at least two of the following: low conductivity carbon black, pigment, or dye.

Virtually any pigment (or combination of pigments) can be used to practice the present invention. In some embodiments, useful pigments include, but are not limited to: barium lemon yellow, cadmium yellow lemon, cadmium yellow light, cadmium. Yellow Middle, Cadmium Yellow Orange, Scarlet Lake, Cadmium Red, Cadmium Vermillion, Alizarin Crimson, Permanent Magenta, Van Dyke Brown, Low Umber Greenish, or Burnt Umber. In some embodiments, useful black pigments include: cobalt oxide, Fe-Mn-Bi black, Fe-Mn oxide spinel black, (Fe, Mn)203 black, copper chromate black spinel, lampblack, bone black, bone ash, bone char ), hematite, black iron oxide, micaceous iron oxide, black complex inorganic pigment (CICP), (Ni, Mn, Co)(Cr, Fe)204 black, aniline black ( Aniline black, Perylene black, Anthraquinone black, Chromium Green-Black Hematite, Chromium Iron Oxide, Pigment Green 17, Pigment Black 26 , Pigment Black 27, Pigment Black 28, Pigment Brown 29, Pigment Brown 35, Pigment Black 30, Pigment Black 32, Pigment Black 33, or mixtures thereof.

In some embodiments, the pigment is lithophone, zinc sulfide, barium sulfate, cobalt oxide, iron oxide yellow, iron oxide orange, iron oxide red, iron oxide brown, hematite, iron oxide black, mica iron oxide, chromium(III) green, ultramarine blue, ultramarine violet, ultramarine pink, cyanide blue, cadmium pigment, or lead chromate pigment.

In some embodiments, the pigment is a spinel pigment, a rutile pigment, a zircon pigment, or a complex inorganic pigment (CICP) such as bismuth vanadate yellow. In some embodiments, useful spinel pigments include, but are not limited to: Zn(Fe,Cr)2O4 brown, CoAl2O4 blue, Co(AlCr)2O4 blue-green, Co2TiO4 green, CuCr2O4 black, or (Ni,Mn) ,Co)(Cr,Fe)2O4 black. In some embodiments, useful rutile pigments include, but are not limited to: Ti-Ni-Sb yellow, Ti-Mn-Sb brown, Ti-Cr-Sb buff, Zircon Pigment, or Bismuth Vanadate Yellow.

In another embodiment, the pigment is an organic pigment. In some embodiments, useful organic pigments include, but are not limited to: aniline black (Pigment Black 1), anthroquinone black, Monoazo type, Diazo type, benzimida Benzimidazolones, Diarylide yellow, Monoazo Yellow Salt, Dinitaniline Orange, Pyrazolone Orange, Azo Red, Naphthol Red, Azo Azo condensation pigments, lake pigments, copper phthalocyanine blue, copper phthalocyanine green, quinacridones, diaryl pyrrolopyrroles, aminoanthraquinone pigments, dioxazines ( Dioxazines), Isoindolinones, Isoindolines, Quinophthalones, phthalocyanine pigments, idanthrone pigments, Pigment Violet 1, Pigment Violet 3, Pigment Violet 19, or Pigment Violet 23. In another embodiment, the organic pigment is a Vat dye pigment such as, but not limited to, perylene, perylene black, perinone based or thioindigo. A uniform dispersion of isolated individual pigment particles (aggregates) tends to produce uniform color intensity. In some embodiments, the pigment is milled. In some embodiments, the average particle size of the pigment is any two of the following sizes: between (and optionally including): 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 microns. In some embodiments, luminescent (fluorescent or phosphorescent) or pearlescent pigments may be used alone or in combination with other pigments or dyes.

In some embodiments, the first polyimide layer further comprises 1 to 20 wt % of a matting agent selected from silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica, or mixtures thereof. . In another embodiment, the first polyimide layer further comprises 1 to 20 wt % of a matting agent that is carbon black having an average particle size of 2 to 9 microns. In another embodiment, the first polyimide layer further comprises 1 to 20 wt % of a matting agent, wherein the matting agent is

i) carbon black having an average particle size of 2 to 9 microns; and

ii) silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof.

In some embodiments, the first polyimide layer is a Kapton® MBC polyimide membrane manufactured by DuPont.

In some embodiments, the first polyimide layer comprises

i) 71 to 96 wt % of a chemically converted polyimide,

a. at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and

b. said chemically converted polyimide derived from at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %, and

iii) as a matting agent,

a. present in an amount from 1.6 to 10 wt %;

b. having a median particle size of 1.3 to 10 microns, and

c. a matting agent having a density of 2 to 4.5 g/cc.

In the chemical transformation process, the polyamic acid solution is submerged or mixed in the transformation (imidization) chemical. In one embodiment, the transformation chemical is a tertiary amine catalyst (promoter) and an anhydride dehydrating material. In one embodiment, The anhydride dehydrating material is acetic anhydride, which is often used in molar excess relative to the amount of amic acid (amic acid) groups in the polyamic acid, typically from about 1.2 to about 2.4 moles per equivalent polyamic acid. In one embodiment, significant amounts of tertiary amine catalysts are used.

Alternatives to acetic anhydride as an anhydride dehydrating material include: i. other aliphatic anhydrides such as propionic acid, butyric acid, valeric acid and mixtures thereof; ii. anhydrides of aromatic monocarboxylic acids; iii. mixtures of aliphatic and aromatic anhydrides; iv. carbodiimide; and v. Aliphatic ketenes (ketenes can be considered anhydrides of carboxylic acids derived from rapid acid dehydration).

In one embodiment, the tertiary amine catalysts are pyrimidine and beta-picoline, and are generally used in amounts similar to moles of anhydride dehydrating material. Depending on the desired conversion rate and catalyst used, the amount used may be less or more. Tertiary amines having the same activity as pyridine, and beta-ficolin may also be used. These include alpha-ficolin; 3,4-leutidine; 3,5-lutidine; 4-methyl pyridine; 4-isopropyl pyridine; N,N-dimethylbenzyl amine; isoquinoline; 4-benzyl pyridine; N,N-dimethyldodecyl amine; triethyl amine, and the like. Various other catalysts for imidization, such as imidazole, are known in the art and may be useful in accordance with the present disclosure.

The conversion chemistry is generally capable of reacting at about room temperature or higher to convert the polyamic acid to the polyimide. In one embodiment, the chemical conversion reaction occurs at a temperature between 15° C. and 120° C., and the reaction occurs at a high temperature and very rapid and relatively slow at low temperatures.

In one embodiment, the chemically treated polyamic acid solution can be cast or extruded onto a heated conversion surface or substrate. In one embodiment, the chemically treated polyamic acid solution may be cast onto a belt or drum. The solvent may be evaporated from the solution and the polyamic acid may be partially chemically converted to polyimide. The resulting solution takes the form of a polyamic acid-polyimide gel. Alternatively, the polyamic acid solution can be converted with or without a diluent solvent to consist of an anhydride component (dehydrating agent), a tertiary amine component (catalyst), or both. In any case, a gel film is formed, and the conversion rate of amic acid groups to imide groups in the gel film depends on the contact time and temperature, but is usually about 10-75% complete. When curing to solids levels greater than .98%, the gel film must generally be dried at an elevated temperature (from about 200° C. to about 550° C.), which tends to complete imidization. In some embodiments, it is desirable to use both a dehydrating agent and a catalyst to promote the formation of a gel film and achieve a desired conversion rate.

second polyimide layer

The second polyimide layer comprises 25 to 50 wt % derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. of polyimide. In some embodiments, the second polyimide layer contains in between, including any two of: 25, 30, 35, 40, 45 and 50 wt % of polyimide. In another embodiment, the second polyimide layer comprises 33 to 39 wt % polyimide.

In one embodiment, the aromatic dianhydride is

pyromellitic dianhydride;

3,3′,4,4′-biphenyl tetracarboxylic dianhydride;

3,3',4,4'-benzophenone tetracarboxylic dianhydride;

4,4'-oxydiphthalic anhydride;

3,3′,4,4′-diphenyl sulfone tetracarboxylic dianhydride;

2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane;

bisphenol A dianhydride; and

and mixtures and derivatives thereof.

In one embodiment, the aromatic dianhydride is

2,3,6,7-naphthalene tetracarboxylic dianhydride;

1,2,5,6-naphthalene tetracarboxylic dianhydride;

2,2',3,3'-biphenyl tetracarboxylic dianhydride;

2,2-bis(3,4-dicarboxyphenyl) propane dianhydride;

bis(3,4-dicarboxyphenyl) sulfone dianhydride;

3,4,9,10-perylene tetracarboxylic dianhydride;

1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride;

1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride;

bis(2,3-dicarboxyphenyl)methane dianhydride;

bis(3,4-dicarboxyphenyl)methane dianhydride;

oxydiphthalic dianhydride;

bis(3,4-dicarboxyphenyl) sulfone dianhydride; and

and mixtures and derivatives thereof.

In some embodiments, examples of suitable aliphatic dianhydrides include cyclobutane dianhydride; [1S*,5R*,6S*]-3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3-(tetrahydrofuran-2,5-dione); and mixtures thereof.

In some embodiments, the aromatic diamine is 3,4'-oxydianiline; 1,3-bis-(4-aminophenoxy)benzene; 4,4'-oxydianiline; paraphenylenediamine; 1,3-diaminobenzene; 2,2′-bis(trifluoromethyl)benzidine; 4,4'-diaminobiphenyl; 4,4'-diaminodiphenyl sulfide; 9,9'-bis(4-amino)fluorine; and mixtures and derivatives thereof.

In another embodiment, the aromatic diamine is 4,4'-diaminophenyl propane; 4,4'-diamino diphenyl methane; benzidine; 3,3'-dichlorobenzidine; 3,3'-diamino diphenyl sulfone; 4,4'-diamino diphenyl sulfone; 1,5-diamino naphthalene; 4,4'-diamino diphenyl diethylsilane; 4,4'-diamino diphenylsilane; 4,4'-diamino diphenyl ethyl oxidized phosphine; 4,4'-diamino diphenyl N-methyl amine; 4,4'-diamino diphenyl N-phenyl amine; 1,4-diaminobenzene (paraphenylenediamine); 1,2-diaminobenzene; and mixtures and derivatives thereof.

In some embodiments, examples of suitable aliphatic diamines include hexamethylene diamine, dodecane diamine, cyclohexane diamine, and mixtures thereof.

In one embodiment, the second polyimide layer is derived from pyromellitic dianhydride and 4,4'-oxydianiline or derived from pyromellitic dianhydride, 4,4'-oxydianiline, and paraphenylenediamine containing polyimide. In another embodiment, the second polyimide layer is derived from 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline, and paraphenylenediamine In another embodiment, the second polyimide layer comprises i) a block of pyromellitic dianhydride and 4,4'-oxydianiline, and ii) pyromellitic dianhydride and paraphenylenediamine. polyimide derived from the block of In another embodiment, the second polyimide layer is formed from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydianiline, and paraphenylenediamine. derived polyimides. In another embodiment, the first polyimide layer comprises a polyimide derived from pyromellitic dianhydride and 4,4'-oxydianiline, and the second polyimide layer comprises:

i) derived from pyromellitic dianhydride and 4.4'-oxydianiline, or

ii) derived from pyromellitic dianhydride, 4.4'-oxydianiline and paraphenylenediamine; or

iii) derived from pyromellitic dianhydride and a block of 4.4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine;

iv) polyimides derived from 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline and paraphenylenediamine.

In some embodiments, the second polyimide layer is thinner than the first polyimide layer. In general, the second polyimide layer is highly filled and the first polyimide layer must provide mechanical support. Therefore, it is desirable to have a thin second polyimide layer. In some embodiments, the second polyimide layer is 0.5 to 20 microns thick. In some embodiments, the second polyimide layer is in between including any two of the following thicknesses: 0.5, 1, 5, 10, 15 and 20 microns thick. In another embodiment, the second layer is between 0.7 and 10 microns thick. In some embodiments, the second layer is between 0.7 and 3 microns thick.

The second layer is in direct contact with the first polyimide layer. The term “direct contact” is intended to mean that two surfaces are adjacent to each other without an intervening material or adhesive layer therebetween.

The second polyimide layer comprises greater than zero and less than 20 wt % of at least one submicron carbon black. The term “submicron” is intended to mean less than one micron in all dimensions. In another embodiment, the second polyimide layer comprises 5 to 15 wt % of at least one submicron carbon black. In another embodiment, the second polyimide layer comprises greater than 7 and less than 11 wt % of at least one submicron carbon black. In another embodiment, the second polyimide layer comprises 8 to 10 wt % of at least one submicron carbon black. Submicron carbon black is intended as a colorant for the purposes of this disclosure. One of ordinary skill in the art may also contemplate the use of other colorants (pigments or dyes) to produce any desired color. In some embodiments, the same pigment or dye used in the second polyimide layer may be used in the first polyimide layer. can be used for In another embodiment, the colorant of the second polyimide layer may be different from any colorant that may be used in the first polyimide layer.

The second polyimide layer comprises from 15 to 35 wt % of the polyimide particle matting agent. In some embodiments, the second polyimide layer comprises in between, including any two of: 15, 16, 17, 18, 19, 20, 25, 30, 31, 32, 33, 34 and 35 wt % of polyimide particle matting agent. In another embodiment, the second polyimide layer comprises 19 to 31 wt % of the polyimide particle matting agent. In some embodiments, the second polyimide layer comprises a mixture of polyimide particle matting agents, or a mixture of polyimide particle matting agents and other matting agents such as silica, alumina, zirconia, boron nitride, barium sulfate, calcium phosphate and mica. include

The polyimide particle matting agent has a median particle size of 2 to 11 microns. In some embodiments, the polyimide particle matting agent has a median particle size in between, including any two of: 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 microns. In some embodiments the average particle size is between 2 and 11 microns. The particle size of the polyimide particle matting agent was measured in the slurry by laser diffraction using either a Horiba LA-930 (Horiba, Instruments, Irwin, CA) or a Malvern Mastersizer 3000 (Malvern Instruments, Westborough, Miami). can do.

The polyimide particle matting agent is derived from at least one aromatic dianhydride and at least one aromatic diamine. In one embodiment, the polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline.

In some embodiments, the polyimide particle matting agent is a colored polyimide particle matting agent. The colored polyimide particles are composed of a polyimide and a colorant. The colored polyimide particles themselves have a different color than the polyimide. Virtually any colorant may be used, including, but not limited to, inorganic pigments, complex inorganic color pigments, organic pigments, and dyes. Useful black colorants include carbon black, graphite, aniline black, and perylene black. Useful The white colorant includes titanium dioxide. The colorant may be incorporated into the polyimide particles by absorption or may be dispersed as a separate phase within the polyimide particles. Some or all of the colorant may be on the polyimide particle surface. The surface of the particles may be partially or completely covered with a colorant. Colored polyimide particles can be produced in a variety of ways, including but not limited to: incorporating a colorant into the polyimide particles during the process of forming the particles by precipitation from solution; absorbing, absorbing swelling or diffusing a colorant within the polyimide particles; Coating the colorant onto the polyimide particles. The colored polyimide particles may contain from 1 wt % to 70 wt % of a colorant. In some embodiments, the colored polyimide particles may contain from 1 wt % to 50 wt % of a colorant. Colored polyimide particle matting agents useful in this disclosure include those disclosed in US Patent Application No. 2014/0220335, the disclosure of which is incorporated herein by reference.

In some embodiments, the second polyimide layer comprises 15 to 35 wt % of the colored polyimide particle matting agent. In some embodiments, the second polyimide layer comprises in between, including any two of: 15, 16, 17, 18, 19, 20, 25, 30, 31, 32, 33, 34 and 35 wt % of colored polyimide particle matting agent. In another embodiment, the second polyimide layer comprises from 19 to 31 wt % of the colored polyimide particle matting agent.

In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline and graphite as a colorant (pigment).

In some embodiments, the polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4'-oxydianiline, and the polyimide of the second polyimide layer is pyromellitic dianhydride, 4,4'-oxide cydianiline, and paraphenylenediamine. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride, 4,4'-oxydianiline and a colorant, and the polyimide of the second polyimide layer is pyromellitic dianhydride, 4, 4'-oxydianiline, and paraphenylenediamine. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride, 4,4'-oxydianiline and graphite, and the polyimide of the second polyimide layer is pyromellitic dianhydride, 4, 4'-oxydianiline, and paraphenylenediamine.

multilayer film

As described above, the multilayer film according to the present disclosure has a first polyimide layer and a second polyimide layer. The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10, as well as durability to handling and circuit handling. L* color was measured using a HunterLab ColorQuest® XE color meter (Hunter Associates Laboratory, Inc.) in reflectance mode with specular and as L*, a*, b* on a CIELAB 10°/D65 system. An L* value of 0 is perfect black, and an L* value of 100 is perfect white. The 60 degree gloss was measured using a Micro-TRI-gloss glossmeter (manufactured by BYK-Gardner).

1 shows a multilayer film comprising an adhesive layer 60 in direct contact with a first polyimide layer 10 opposite a second polyimide layer 20, and a second polyimide layer, as an embodiment of the present disclosure. The layer comprises polyimide particle matting agent (30), submicron carbon black (40), and submicron fumed metal oxide (50). In some embodiments, the adhesive layer is an epoxy adhesive selected from the group consisting of bisphenol A type epoxy resins, cresol novolac type epoxy resins, phosphorus containing epoxy resins, and mixtures thereof. In general, the adhesive layer is equal to or thicker than the first polyimide layer or the second polyimide layer. In some embodiments, the adhesive layer is between 8 and 300 microns thick.

In some embodiments, the adhesive is a mixture of two or more epoxy resins. In some embodiments, the adhesive is a mixture of the same epoxy resins having different molecular weights.

In some embodiments, the epoxy adhesive contains a curing agent. In some embodiments, the epoxy adhesive contains a catalyst. In some embodiments, the epoxy adhesive contains an elastomeric reinforcing agent. In some embodiments, the epoxy adhesive contains a flame retardant.

In some embodiments, the multilayer film further comprises a third polyimide layer. In some embodiments, the third polyimide layer is 0.5 to 20 microns thick. In other embodiments, the third polyimide layer is in between including any two of the following thicknesses: 0.5, 1, 5, 10, 15 and 20 microns thick. In some embodiments, the third polyimide layer is between 0.7 and 10 microns thick. In some embodiments, the third polyimide layer is between 0.7 and 3 microns thick. In some embodiments, the multilayer film further comprises a third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer.

The third polyimide layer is particularly preferred when the multilayer film is co-extruded. It helps to prevent curl when the third polyimide layer is similar to or identical to the second polyimide layer. The third polyimide layer may be the same as or different from the second polyimide layer.

In some embodiments, the multilayer film further comprises a third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide; and

ii) a matting agent or mixtures thereof.

In one embodiment, the matting agent in the third polyimide layer is selected from silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof. In another embodiment, the matting agent in the third polyimide layer is carbon black having an average particle size of 2 to 9 microns. In another embodiment, the matting agent in the third polyimide layer is

i) carbon black having an average particle size of 2 to 9 microns; and

ii) silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof. In another embodiment, the matting agent in the third polyimide layer is a polyimide particle matting agent. In another embodiment, the matting agent in the third polyimide layer is a colored polyimide particle matting agent.

In another embodiment, the third polyimide layer comprises from 15 to 35 wt % of the polyimide particle matting agent. In some embodiments, the third polyimide layer comprises in between, including any two of: 15, 16, 17, 18, 19, 20, 25, 30, 31, 32, 33, 34 and 35 wt % of polyimide particle matting agent. In another embodiment, the third polyimide layer comprises 19 to 31 wt % of the polyimide particle matting agent. In some embodiments, the third polyimide layer comprises a mixture of polyimide particle matting agents, or a mixture of polyimide particle matting agents and other matting agents such as silica, alumina, zirconia, boron nitride, barium sulfate, calcium phosphate and mica. include

The polyimide particle matting agent has a median particle size of 2 to 11 microns. In some embodiments, the polyimide particle matting agent has a median particle size in between, including any two of: 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 microns. In some embodiments the average particle size is between 2 and 11 microns. The particle size of the polyimide particle matting agent was measured in the slurry by laser diffraction using either a Horiba LA-930 (Horiba, Instruments, Irwin, CA) or a Malvern Mastersizer 3000 (Malvern Instruments, Westborough, Miami). can do.

The polyimide particle matting agent is derived from at least one aromatic dianhydride and at least one aromatic diamine. In one embodiment, the polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline.

In some embodiments, the polyimide particle matting agent is a colored polyimide particle matting agent. The colored polyimide particles are composed of a polyimide and a colorant. The colored polyimide particles themselves have a different color than the polyimide. Virtually any colorant may be used, including, but not limited to, inorganic pigments, complex inorganic color pigments, organic pigments, and dyes. Useful black colorants include carbon black, graphite, aniline black, and perylene black. Useful The white colorant includes titanium dioxide. The colorant may be incorporated into the polyimide particles by absorption or may be dispersed as a separate phase within the polyimide particles. Some or all of the colorant may be on the polyimide particle surface. The surface of the particles may be partially or completely covered with colorant. Colored polyimide particles may be produced in a variety of ways, including, but not limited to: dissolving the colorant into polyimide during the process of forming the particles by precipitation from solution. incorporation into the mid particles; absorbing, absorbing swelling or diffusing a colorant within the polyimide particles; Coating the colorant onto the polyimide particles. The colored polyimide particles may contain from 1 to 70 wt % of a colorant. In some embodiments, the colored polyimide particles may contain from 1 to 50 wt % of a colorant. Colored polyimide particle matting agents useful in this disclosure include those disclosed in US Patent Application No. 2014/0220335, the disclosure of which is incorporated herein by reference.

In some embodiments, the third polyimide layer comprises 15 to 35 wt % of the colored polyimide particle matting agent. In some embodiments, the third polyimide layer comprises in between, including any two of: 15, 16, 17, 18, 19, 20, 25, 30, 31, 32, 33, 34 and 35 wt % of colored polyimide particle matting agent. In another embodiment, the second polyimide layer comprises from 19 to 31 wt % of the colored polyimide particle matting agent.

In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4-oxydianiline and graphite as a colorant (pigment).

In some embodiments, the polyimide particle matting agent is derived from pyromellitic dianhydride and 4,4'-oxydianiline, and the polyimide of the third polyimide layer is pyromellitic dianhydride, 4,4'-oxide cydianiline, and paraphenylenediamine. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride, 4,4'-oxydianiline and a colorant, and the polyimide of the third polyimide layer is pyromellitic dianhydride, 4, 4'-oxydianiline, and paraphenylenediamine. In some embodiments, the colored polyimide particle matting agent is derived from pyromellitic dianhydride, 4,4'-oxydianiline and graphite, and the polyimide of the third polyimide layer is pyromellitic dianhydride, 4, 4'-oxydianiline, and paraphenylenediamine.

In one embodiment, the third polyimide layer comprises a polyimide derived from pyromellitic dianhydride and 4,4-oxydianiline. In another embodiment, the third polyimide layer comprises a polyimide derived from pyromellitic dianhydride, 4,4-oxydianiline and paraphenylenediamine. In another embodiment, the second polyimide layer is derived from 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline, and paraphenylenediamine containing polyimide. In another embodiment, the third polyimide layer comprises a polyimide derived from i) a block of pyromellitic dianhydride and 4,4'-oxydianiline, and ii) a block of pyromellitic dianhydride and paraphenylenediamine. includes

In another embodiment, the multilayer film further comprises a third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, wherein the third polyimide layer comprises:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) 15 to 50 wt % of at least one submicron fumed metal oxide.

2 is an embodiment of the present disclosure, at the surface of the third polyimide layer 70 in direct contact with the first polyimide layer 10 , and the surface of the second polyimide layer furthest from the first polyimide layer 10 . an adhesive layer (60) in direct contact with the second polyimide layer (20), wherein the second polyimide layer and the third polyimide layer include a polyimide particle matting agent (30), submicron carbon black (40), and A multilayer film comprising submicron fumed metal oxide (50) is shown. In another embodiment, the adhesive layer 60 may be in direct contact with the third polyimide layer 70 at the surface of the third polyimide layer furthest from the first polyimide layer 10 .

In one embodiment, the multilayer film comprises:

a. 8 to 130 microns thick comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. a first polyimide layer of and

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide; and

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. 8 to 130 microns thick comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide; a first polyimide layer; and

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. An adhesive layer in direct contact with the first polyimide layer facing the second polyimide layer, wherein the adhesive layer is a bisphenol A-type epoxy resin, a cresol novolac-type epoxy resin, a phosphorus-containing epoxy resin, and mixtures thereof. an epoxy resin selected from; and

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. 8 to 130 microns thick comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide; a first polyimide layer;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a third polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide.

In one embodiment, the multilayer film comprises:

a. 8 to 130 microns thick comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. a first polyimide layer of

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a third polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

d. An adhesive layer in direct contact with the second polyimide layer on the surface of the second polyimide layer opposite the first polyimide layer, wherein the adhesive layer includes a bisphenol A-type epoxy resin, a cresol novolac-type epoxy resin, and a phosphorus-containing epoxy resin and an epoxy resin selected from the group consisting of mixtures thereof;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. 8 to 130 microns thick comprising a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide. a first polyimide layer of

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a third polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

d. An adhesive layer in direct contact with the second polyimide layer on the surface of the second polyimide layer opposite the first polyimide layer, wherein the adhesive layer includes a bisphenol A-type epoxy resin, a cresol novolac-type epoxy resin, and a phosphorus-containing epoxy resin and an epoxy resin selected from the group consisting of mixtures thereof;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. as a first polyimide layer between 8 and 130 microns thick.

i) a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide;

ii) a first polyimide layer comprising 1 to 15 wt % of low conductivity carbon black, or 1 to 40 wt % of a pigment or dye;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. as a first polyimide layer between 8 and 130 microns thick.

i) a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide;

ii) from 1 to 15 wt % of low conductivity carbon black, or from 1 to 40 wt % of a pigment or dye;

iii) a first polyimide layer comprising 1 to 20 wt % of a matting agent selected from silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. A first polyimide layer comprising:

i) a chemically converted polyimide in an amount of 71 to 96 wt %, wherein, based on the total dianhydride content of the polyimide, at least 50 mole percent aromatic dianhydride, and at least 50 moles based on the total diamine content of the polyimide chemically converted polyimides derived from a percentage of aromatic diamines;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %, and

iii) as a matting agent

a) present in an amount from 1.6 to 10 wt %;

b) has a median particle size of 1.3 to 10 microns, and

c) a first polyimide layer comprising a matting agent having a density of 2 to 4.5 g/cc;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10.

In one embodiment, the multilayer film comprises:

a. A first polyimide layer comprising:

i) a chemically converted polyimide in an amount of 71 to 96 wt %, wherein, based on the total dianhydride content of the polyimide, at least 50 mole percent aromatic dianhydride, and at least 50 moles based on the total diamine content of the polyimide chemically converted polyimides derived from a percentage of aromatic diamines;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %; and

iii) as a matting agent

a) present in an amount from 1.6 to 10 wt %;

b) has a median particle size of 1.3 to 10 microns, and

c) a first polyimide layer comprising a matting agent having a density of 2 to 4.5 g/cc;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide;

ii) a third polyimide layer comprising a matting agent or mixtures thereof;

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

a. A first polyimide layer comprising:

i) a chemically converted polyimide in an amount of 71 to 96 wt %, wherein at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 moles based on the total diamine content of the polyimide chemically converted polyimides derived from a percentage of aromatic diamines;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %; and

iii) as a matting agent

a) present in an amount from 1.6 to 10 wt %;

b) has a median particle size of 1.3 to 10 microns, and

c) a first polyimide layer comprising a matting agent having a density of 2 to 4.5 g/cc;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a third polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

a. a first polyimide layer 8 to 130 microns thick comprising a polyimide derived from pyromellitic dianhydride and 4,4'-oxydianiline;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide,

a) pyromellitic dianhydride and 4.4'-oxydianiline,

b) pyromellitic dianhydride, 4.4'-oxydianiline, and paraphenylenediamine;

c) a block of pyromellitic dianhydride and 4.4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine, or

d) polyimides derived from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydianiline and paraphenylenediamine;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15-50 wt % of at least one submicron fumed metal oxide, wherein the multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

a. A first polyimide layer comprising:

i) a chemically converted polyimide in an amount of 71 to 96 wt %, a chemically converted polyimide derived from pyromellitic dianhydride and 4,4′-oxydianiline;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %; and

iii) as a matting agent

a) present in an amount from 1.6 to 10 wt %;

b) has a median particle size of 1.3 to 10 microns, and

c) a first polyimide layer comprising a matting agent having a density of 2 to 4.5 g/cc;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide,

a) pyromellitic dianhydride and 4.4'-oxydianiline,

b) pyromellitic dianhydride, 4.4'-oxydianiline, and paraphenylenediamine;

c) a block of pyromellitic dianhydride and 4.4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine, or

d) polyimides derived from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydianiline and paraphenylenediamine;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a second polyimide layer comprising 15-50 wt % of at least one submicron fumed metal oxide, wherein the multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

a. A first polyimide layer comprising:

i) a chemically converted polyimide in an amount of 71 to 96 wt %, a chemically converted polyimide derived from pyromellitic dianhydride and 4,4′-oxydianiline;

ii) low conductivity carbon black present in an amount of 2 to 9 wt %; and

iii) as a matting agent,

a) present in an amount from 1.6 to 10 wt %;

b) has a median particle size of 1.3 to 10 microns, and

c) a first polyimide layer comprising a matting agent having a density of 2 to 4.5 g/cc;

b. A second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide,

a) pyromellitic dianhydride and 4.4'-oxydianiline,

b) pyromellitic dianhydride, 4.4'-oxydianiline, and paraphenylenediamine;

c) a block of pyromellitic dianhydride and 4.4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine, or

d) polyimides derived from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydianiline and paraphenylenediamine;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) a second polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide; and

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

c. A third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:

i) 25 to 50 wt % of a polyimide,

a) pyromellitic dianhydride and 4.4'-oxydianiline,

b) pyromellitic dianhydride, 4.4'-oxydianiline, and paraphenylenediamine;

c) a block of pyromellitic dianhydride and 4.4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine, or

d) polyimides derived from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydianiline and paraphenylenediamine;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black;

iv) a third polyimide layer comprising 15 to 50 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

a. a first polyimide layer 20-30 microns thick comprising a polyimide derived from pyromellitic dianhydride and 4,4'-oxydianiline;

b. A second polyimide layer 0.7 to 3 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from pyromellitic dianhydride, 4,4-oxydianiline and paraphenylenediamine;

ii) 19 to 31 wt % of a polyimide particle matting agent;

v) greater than 7 and less than 11 wt % of at least one submicron carbon black; and

vi) a second polyimide layer comprising 20-25 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

In one embodiment, the multilayer film comprises:

c. a first polyimide layer 20-30 microns thick comprising a polyimide derived from pyromellitic dianhydride and 4,4'-oxydianiline;

d. A second polyimide layer 0.7 to 3 microns thick in direct contact with the first polyimide layer, comprising:

i) 25 to 50 wt % of a polyimide derived from pyromellitic dianhydride, 4,4-oxydianiline and paraphenylenediamine;

ii) 19 to 31 wt % of a polyimide particle matting agent;

vii) 8 to 10 wt % of at least one submicron carbon black;

viii) a second polyimide layer comprising from 20 to 25 wt % of at least one submicron fumed metal oxide;

The multilayer film has an L* color of less than 30 and a 60 degree gloss value of less than 10.

Another embodiment of the present disclosure is a method for producing a multilayer film having an L* color of less than 30 and a gloss value of less than 10 of 60 degrees, the method comprising:

a. providing a first polyimide layer from 8 to 130 microns thick;

b. coating a second polyimide layer 0.5 to 8 microns thick to the first polyimide layer, wherein the second polyimide layer comprises:

i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;

ii) from 15 to 35 wt % of a polyimide particle matting agent;

iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and

iv) 15 to 50 wt % of at least one submicron fumed metal oxide.

The first polyimide layer and the second polyimide layer of the present disclosure may be prepared by any known method in the art for preparing a filled polyimide membrane. In some embodiments, the first polyimide layer and the second polyimide layer are prepared by a thermal conversion process (thermal imidization) in which the polyamic acid solution is heated to a temperature of typically 250° C. or higher to convert the polyamic acid to polyimide. . In another embodiment, the first polyimide layer and the second polyimide layer are prepared by a chemical transformation process (chemical imidization). In one embodiment, one such method comprises preparing a pigment slurry. The slurry may or may not be milled using a bowl mill or continuous media mill to reach the desired particle size. The slurry may or may not be filtered to remove any large residual particles. The polyamic acid prepolymer solution is prepared by reacting the dianhydride with a slight excess of diamine. The polyamic acid solution is mixed with the pigment slurry in a high shear mixer. The amount of polyamic acid solution, pigment slurry, and finishing solution can be adjusted to achieve a desired loading level of pigment and a desired viscosity for film formation. As used herein, “finishing solution” refers to a dianhydride in a polar aprotic solvent that is added to the prepolymer solution to increase molecular weight and viscosity. one of the dianhydrides). The mixture can be metered through a slot die and cast onto a smooth stainless steel belt or substrate, or cast manually to prepare a gel film. Conversion chemicals can be metered in prior to casting using a slot die. >98% Solids To convert to a level, the gel film generally has to be dried at elevated temperatures (200-300°C for convection heating, and 400-800°C for radiative heating), which tends to drive completion of imidization. Another In an embodiment, the first polyimide layer and the second polyimide layer are independently prepared by either a thermal conversion process or a chemical conversion process.

The multilayer film of the present disclosure may be prepared by a known method such as, but not limited to, coextrusion, lamination (inter-layering of single layers), coating, and combinations thereof. A description is provided in EP 0659553 A1 to Sutton et al. Coating methods include, but are not limited to, spray coating, curtain coating, knife over roll, air knife, coextrusion/slot die, gravure, reverse gravure, offset gravure, roll coating, and dipping/dipping.

In some embodiments, the multilayer film is prepared by simultaneously extruding (coextrusion) a first polyimide layer and a second polyimide layer. In some embodiments, the multilayer film is a first polyimide layer, a second polyimide layer, and a second polyimide layer. Manufactured by simultaneously extruding (co-extrusion) 3 polyimide layers. In some embodiments, the layers are extruded through a single or multi-cavity extrusion die. In other embodiments, the multilayer film is made using a single cavity die. When using a single cavity die, the laminar flow of the stream is It should be sufficiently high in viscosity to prevent mixing and to provide a uniform layer. In some embodiments, the multilayer film is made by casting from a slot die onto a moving stainless steel belt. In one embodiment, the belt is passed through a convection oven to evaporate the solvent and partially imidize the polymer to produce a “green” film. The green film can be peeled off the casting belt and wound. The green film is then placed in a tenter oven. A fully cured polyimide membrane is produced. In some embodiments, shrinkage can be minimized by tightening (ie using clips or pins) along the edges of the membrane during tentering.

In some embodiments, the multilayer film is prepared by coating the first polyimide layer with a solution of silica matting agent, submicron carbon black and submicron fumed metal oxide, and polyamic acid. The coating is dried by heating. The resulting multilayer film is placed on a pin frame to keep it flat. The coating may be cured in a batch or continuous oven capable of heating to at least 250°C. The oven temperature is raised to 320° C. for 45 to 60 minutes, then transferred to an oven at 400° C. and held there for 5 minutes. In some embodiments, a chemical imidization catalyst and/or a dehydrating agent may be added to the coating solution.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising;

a) providing a first polyimide layer or a first polyamic acid solution or a first polyamic acid green film;

b) providing a second polyamic acid solution containing polyamic acid, silica matting agent and submicron carbon black;

c) adding at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first co-extruding the polyamic acid solution; and

f) imidizing the coating formed in step d to form a second polyimide layer on the first polyimide layer, or imidizing the coating formed in step d and the first polyamic acid green film to imidize the first polyimide layer and and forming a second polyimide layer or imidizing the coextruded layer formed in step d to form a first polyimide layer and a second polyimide layer.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a first polyimide layer or a first polyamic acid solution or a first polyamic acid green film derived from pyromellitic dianhydride and 4,4'-oxydianiline;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent and submicron carbon black, wherein the polyamic acid is derived from pyromellitic dianhydride and 4,4'-oxydianiline; , 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline and paraphenylenediamine, or i) pyromellitic dianhydride and 4 , a block of 4'-oxydianiline and ii) a block of pyromellitic dianhydride and paraphenylenediamine;

c) adding 15-50 wt % of at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first co-extruding the polyamic acid solution; and

f) imidizing the coating formed in step d to form a second polyimide layer on the first polyimide layer, or imidizing the coating formed in step d and the first polyamic acid green film to imidize the first polyimide layer and forming a second polyimide layer or imidizing the coextruded layer formed in step d to form a first polyimide layer and a second polyimide layer;

The second polyimide layer is in direct contact with the first polyimide layer.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent, and submicron carbon black;

c) adding at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first forming a multilayer composite by co-extruding the polyamic acid solution; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer.

The submicron fumed metal oxide or mixture thereof may be added directly to the second polyamic acid solution, or may be added to the second polyamic acid solution after preparing a submicron fumed metal oxide slurry. In some embodiments, the second polyamic acid solution Silver may be added to the submicron fumed metal oxide slurry. In some embodiments, the polyamic acid solution formed in step c is coated on the first polyimide layer, or the polyamic acid solution formed in step c and the first polyamic acid solution are pneumatically applied. Prior to shipping, the polyimide particle matting agent, submicron carbon black and submicron fumed metal oxide (and slurries thereof) may be combined in any order.

The polyamic acid formed in step c can be prepared by methods known in the art such as spray coating, curtain coating, knife over roll, air knife, coextrusion/slot die, gravure, reverse gravure, offset gravure, roll coating, and dipping/dipping. may be coated, but is not limited thereto.

The coating or coextrusion layer may be imidized by thermal or chemical transformation as described above.

In some embodiments, the first polyamic acid solution is partially dried and partially imidized to form a first polyamic acid green film. Then, the polyamic acid solution formed in step c is coated on the first polyamic acid green film, Two layers are imidized.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent, and submicron carbon black;

c) adding at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first forming a multilayer composite by co-extruding the polyamic acid solution; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer;

The second polyimide layer is in direct contact with the first polyimide layer.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film and derived from pyromellitic dianhydride and 4,4'-oxydianiline step;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent, and submicron carbon black;

c) adding at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first polyamic acid solution forming a multi-layer composite by co-extrusion; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer.

Another embodiment is a method of reducing the amount of colorant in the multilayer film, wherein the second polyimide layer is derived from pyromellitic dianhydride and 4,4'-oxydianiline, or pyromellitic dianhydride, 4,4' -oxydianiline, and derived from paraphenylenediamine, or 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline, and paraphenylene a diamine or i) a block of pyromellitic dianhydride and 4,4'-oxydianiline and ii) a block of pyromellitic dianhydride and paraphenylenediamine.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film and derived from pyromellitic dianhydride and 4,4'-oxydianiline step;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent and submicron carbon black, wherein the polyamic acid is derived from pyromellitic dianhydride and 4,4'-oxydianiline; , derived from pyromellitic dianhydride, 4,4'-oxydianiline and paraphenylenediamine, or 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4 derived from '-oxydianiline and paraphenylenediamine, or i) a block of pyromellitic dianhydride and 4,4'-oxydianiline and ii) a block of pyromellitic dianhydride and paraphenylenediamine step that will;

c) adding at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first polyamic acid solution forming a multi-layer composite by co-extrusion; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent, and submicron carbon black;

c) adding 15-50 wt % of at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first polyamic acid solution forming a multi-layer composite by co-extrusion; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer.

Another embodiment of the present disclosure is a method of reducing the amount of colorant in a multilayer film and achieving an L* color of less than 30 and a gloss value of less than 10 of 60, the method comprising:

a) providing a component selected from the group consisting of a first polyimide layer, a first polyamic acid solution, and a first polyamic acid green film and derived from pyromellitic dianhydride and 4,4'-oxydianiline step;

b) providing a second polyamic acid solution containing polyamic acid, polyimide particle matting agent and submicron carbon black, wherein the polyamic acid is derived from pyromellitic dianhydride and 4,4'-oxydianiline; , derived from pyromellitic dianhydride, 4,4'-oxydianiline and paraphenylenediamine, or 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4 derived from '-oxydianiline and paraphenylenediamine, or i) a block of pyromellitic dianhydride and 4,4'-oxydianiline and ii) a block of pyromellitic dianhydride and paraphenylenediamine step that will;

c) adding 15-50 wt % of at least one submicron fumed metal oxide to the second polyamic acid solution;

d) coating the polyamic acid solution formed in step c on the first polyimide layer, or coating the polyamic acid solution formed in step c on the first polyamic acid green film, or the polyamic acid solution formed in step c and the first polyamic acid solution forming a multi-layer composite by co-extrusion; and

f) imidizing the composite formed in step d to produce a first polyimide layer and a second polyimide layer.

When an amount, concentration, or other value or parameter is given as one of a range, a preferred range, or a list of upper and lower preferred values, it indicates the upper or preferred limit of any range, whether or not the range is separately disclosed. It is to be understood that all ranges formed from any pair of values, and the lower limit or preferred value of any range, are specifically disclosed. It is intended to include the endpoint and all integers and fractions within this range. Numerical values are to be understood as having the precision of the number of significant digits provided. For example, the number 1 should be understood to include the range from 0.5 to 1.4, while the number 1.0 should be understood to include the range from 0.95 to 1.04, including the endpoints of the stated range. It is not intended to be limited to the specific values enumerated when defining

In describing a particular polymer, it should be understood that the polymer is sometimes referred to by either the monomers used in preparing the polymer or the amount of the monomers used in preparing the polymer. While this description may not include specific terms used to describe the final polymer or product-by-process terms, these references to monomers and amounts do not indicate or imply that the context indicates otherwise. Unless otherwise stated, it should be construed to mean that the polymer is made of these monomers.

The materials, methods, and examples herein are illustrative only, and not intended to be limiting, unless specifically stated. Although methods and materials similar or equivalent to those described herein can be used, suitable methods and materials include: described herein.

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein are defined by one of ordinary skill in the art to which this invention belongs. It has the same meanings as commonly understood. In case of conflict, the present specification, including definitions, control.

Example

Preparation and evaluation of exemplary membranes are described below.

Carbon Black Slurry (SB6 Carbon):

A carbon black slurry was prepared consisting of 82 wt % DMAC, 12 wt % carbon black powder (Special Black 6 from Orion Engineered Carbons LLC), and 6 wt % dispersant (Byk 9077 from Byk Chemie). It was thoroughly mixed in a mold disperser. The slurry was then processed in a bead mill to disperse the agglomerates and obtain the desired particle size. The median particle size was 0.14 microns.

Fumed Alumina Slurry

A fumed alumina slurry was prepared consisting of 76.3 wt % DMAC, 19.8 wt % fumed alumina powder (Alu C805 from Evonik), and 3.9 wt % dispersant (Disperbyk 180 from Byk Chemie). The slurry was then processed in a bead mill to disperse the agglomerates and obtain the desired particle size. The median particle size was 0.3 microns.

Polyimide particle slurry:

A polyimide particle slurry was prepared from a solution of PMDA/4,4'ODA polyamic acid in pyridine, and the solution was heated to precipitate the polymer. The pyridine solvent was replaced with deionized water and then milled in a high shear environment. .The deionized water was replaced with DMAc to a solids concentration of 3.6 wt%. The median size of the particles was 4.0 microns.

Colored polyimide particle slurry:

A colored polyimide particle slurry was prepared. Graphite powder was dispersed in a solution of PMDA/4,4'ODA polyamic acid in pyridine. The mixture was heated to form a precipitate of polyimide particles containing 40 wt % graphite. The pyridine solvent was replaced with deionized water, followed by grinding in a high shear environment and drying. The resulting powder was passed through a 325 mesh screen. The median particle size of the powder passed through the screen was 9.9 microns. The powder was dispersed in DMAC to form a 10 wt % dispersion of colored polyimide particles.

Kapton® MBC is an opaque matte black polyimide membrane manufactured by DuPont. It is based on PMDA/4,4'ODA polyimide and contains about 5 wt % carbon black and about 2 wt % silica matting agent. It is available in various thicknesses.

PMDA/4,4’ODA/PPD (100/70/30 molar ratio) copolyamic acid solution:

PPD was dissolved in DMAC at 40-45° C. to a concentration of about 2.27 wt %. After reducing the temperature to 30-40° C., solid PMDA was added with stirring to give a PMDA:PPD stoichometric ratio of about 0.99:1. ) was achieved. The mixture was allowed to react for 90 minutes with stirring. To this mixture was diluted to about 5.8-6.5% solids by addition of DMAC. Then 4,4'ODA was added to 70:30 4,4 'ODA:PPD molar ratio was achieved and reacted at 40-45°C for about 30 minutes. Solid PMDA was added gradually with stirring and reacted at 40-45° C. for about 2 hours to achieve a polymer viscosity of 75-250 Poise. The polyamic acid solids content was 19.5% to 20.5%. The polymer solution was stored in the refrigerator until use.

Preparation of multilayer films Examples 1 to 4:

The first polyimide layer consisted of a Kapton® MBC membrane as shown in Table 1.

A second polyimide layer was prepared using the filler slurry as described above and as shown in Table 1. As described above and as shown in Table 1, the slurry was thoroughly mixed with the polyamic acid solution in the appropriate proportions and cured. The desired composition was then produced. The resulting mixture was coated on the first polyimide layer using a stainless steel casting rod. The coating was dried on a hot plate at 100° C. until dryness was confirmed by visual inspection. The resulting multilayer film was placed on a pin frame to keep it flat and placed in an oven at 120°C. The oven temperature was raised to 320°C over 45-60 minutes, then transferred to an oven at 400°C and held for 5 minutes, then Remove from oven and cool.

The composition of the cured film was calculated from the composition of the components in the mixture taking into account the removal of water during the conversion of polyamic acid to polyimide, excluding DMAC solvent (removed during curing).

The 60 degree gloss was measured using a Micro-TRI-gloss gloss meter (manufactured by BYK-Gardner).

L* color was measured using a HunterLab ColorQuest® XE color meter (Hunter Associates Laboratory, Inc.) in reflectance mode including full reflection. The instrument was standardized prior to each use. Color data from the instrument was CIELAB 10° Reported as L*, a*, b* on the /D65 system. An L* value of 0 is completely black, and an L* value of 100 is completely white. In general, a difference in L* values of 1 unit is visually discernible. can do.

The particle size of the filler particles in the slurry is measured by laser diffraction using either a Horiba LA-930 (Horiba, Instruments, Irwin, CA) or a Malvern Mastersizer 3000 (Malvern Instruments, Westborough, Miami) particle size analyzer. did. DMAC was used as carrier fluid.

Alcohol Wipe Test: The membrane was wiped 3 times with a towel moistened with isopropyl alcohol. A “Fail” grade was rated if any colorant was observed to transfer from the membrane to the towel. It is a measure of the suitability of a membrane with respect to its durability to conditions.

The results are shown in Table 1.

The materials, methods, and examples herein are illustrative only, and not intended to be limiting, unless specifically stated. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, , suitable methods and materials are described herein.

It should be noted that not all actions described above in the general description or examples are required, some of specific actions may not be required, and additional actions other than those described may be performed. It is not necessarily in the order of performance. After reading this specification, one of ordinary skill in the art will be able to determine which action may be used for a particular need or requirement.

In the foregoing specification, the present invention has been described with reference to specific embodiments. However, it will be understood by those skilled in the art that various modifications and changes may be made therein without departing from the scope of the invention as set forth in the claims below. All features may be replaced by alternative features that serve the same, equivalent or similar purpose.

Accordingly, this specification is to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the invention.

Advantages, other advantages, and solutions to problems have been described above with respect to specific implementations. However, advantages, advantages, solutions to problems, and any advantages, advantages, or solutions to problems may arise or be more explicit. No element(s) that may be made available should be construed as being a critical, essential, or essential feature of any or all claims.

Claims (24)

As a multilayer film:
a. a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide; a first polyimide layer from 8 to 130 microns thick;
b. a second polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer, the second polyimide layer comprising:
i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;
ii) from 15 to 35 wt % of a polyimide particle matting agent;
iii) greater than zero and less than 20 wt % of at least one submicron carbon black;
iv) 15 to 50 wt % of at least one submicron fumed metal oxide;
wherein the multilayer film has an L* color of less than 30 and a gloss value of 60 degrees less than 10. The method of claim 1 , wherein the first polyimide layer comprises:
i) from 1 to 15 wt % of low conductivity carbon black, or
ii) a multilayer film further comprising 1 to 40 wt % of a pigment or dye. The method of claim 2, wherein the first polyimide layer further comprises 1 to 20 wt% of a matting agent selected from silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica, or mixtures thereof. A multilayer film containing The multilayer film of claim 2 , wherein the first polyimide layer further comprises 1 to 20 wt % of a matting agent which is carbon black having an average particle size of 2 to 9 micrometers. 3. The matting agent of claim 2, wherein the first polyimide layer further comprises 1 to 20 wt % of a matting agent, wherein the matting agent is
i) carbon black having an average particle size of 2 to 9 microns; and
ii) a multilayer film which is a mixture of silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof. The method of claim 1 , wherein the first polyimide layer comprises:
i) 2 to 9 wt % of low conductivity carbon black;
ii) as a matting agent
a. present in an amount from 1.6 to 10 wt %;
b. having a median particle size of 1.3 to 10 microns, and
c. A multilayer film further comprising a matting agent having a density of 2 to 4.5 g/cc. The polyimide of claim 1, wherein the polyimide of the first polyimide layer is derived from pyromellitic dianhydride and 4,4'-oxydianiline, and the polyimide of the second polyimide layer is
i) pyromellitic dianhydride and 4,4'-oxydianiline,
ii) pyromellitic dianhydride, 4,4'-oxydianiline, and paraphenylenediamine;
iii) a block of pyromellitic dianhydride and 4,4'-oxydianiline, and a block of pyromellitic dianhydride and paraphenylenediamine, or
iv) a multilayer film derived from 3,3',4,4'-biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydianiline and paraphenylenediamine. The method of claim 1 further comprising a third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:
i) a polyimide derived from at least 50 mole percent aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent aromatic diamine, based on the total diamine content of the polyimide; and
ii) a multilayer film comprising a matting agent or a mixture thereof. 9. The method of claim 8, wherein the matting agent in the third polyimide layer is
i) carbon black having an average particle size of 2 to 9 microns; and
ii) a multilayer film which is a mixture of silica, alumina, zirconia, boron nitride, barium sulfate, polyimide particles, calcium phosphate, mica or mixtures thereof. The method of claim 1 further comprising a third polyimide layer 0.5 to 20 microns thick in direct contact with the first polyimide layer opposite the second polyimide layer, the third polyimide layer comprising:
i) 25 to 50 wt % of a polyimide derived from at least 50 mole percent of an aromatic dianhydride, based on the total dianhydride content of the polyimide, and at least 50 mole percent of an aromatic diamine, based on the total diamine content of the polyimide;
ii) from 15 to 35 wt % of a polyimide particle matting agent;
iii) greater than zero and less than 20 wt % of at least one submicron carbon black; and
iv) 15 to 50 wt % of at least one submicron fumed metal oxide.
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