KR101985032B1 - Polyimide film incorporating polyimide powder delustrant, and manufacture thereof - Google Patents

Abstract

A multi-layer polyimide film comprising at least two polyimide layers stacked together, wherein each polyimide layer comprises a polyimide-based polymer formed by reacting diamine and dianhydride components at substantially the same molar ratio, wherein at least one The polyimide layer further comprises a polyimide powder distributed on the polyimide-based polymer, wherein the polyimide powder has a weight ratio of about 20 to about 50 wt% of the total weight of the layer into which it is incorporated. The multi-layer polyimide film has a 60 DEG gloss value of at most about 5 on at least one surface of the film. Embodiments described herein also include methods of making polyimide films and polyimide powders.

Description

POLYIMIDE FILM INCORPORATING POLYIMIDE POWDER DELUSTRANT, AND MANUFACTURE THEREOF FIELD OF THE INVENTION [0001] The present invention relates to a polyimide film,

Cross-reference to related application

The present application claims priority from Taiwan Patent Application No. 102138107, filed on October 22, 2013.

background

1. Field of the Invention

The present invention relates to a delustrant composed of a polyimide powder, a polyimide film containing a polyimide powder quencher, and a method for producing the same.

2. Description of related field

Polyimide films are widely used in electronic products. Due to the high surface flatness, the polyimide film can cause light reflections that can cause eye fatigue during uncomfortable and intensive use. This effect can be amplified in a colored film, which can make the reflected light more noticeable to the viewer.

In order to reduce the gloss of the polyimide film, some approaches may incorporate a quencher in the polyimide film to increase the surface roughness so that the incident light is scattered. Conventional quenchers can include inorganic and organic compounds.

Examples of the inorganic compound used as the quencher include silicon oxide, aluminum oxide, calcium carbonate, barium sulfate, titanium dioxide and the like. However, the inorganic particles have a relatively high dielectric constant, which can impart poor insulating properties to the film.

Examples of the organic compound used as the quencher include polycarbonate (PC), polystyrene (PS), polymethylmethacrylate (PMMA), polyethylene, polypropylene, polyethylene terephthalate (PET) . However, organic compounds are generally unable to withstand temperatures above 250 DEG C, the temperature at which chemical conversion takes place in the production of polyimide films. As a result, the use of organic compounds in the production of polyimide films can cause defects such as cracks or holes, or can result in non-uniform color spots due to uneven melting.

Therefore, there is a need for a polyimide film having desirable characteristics and low gloss, at least to solve the aforementioned problems.

summary

The present application describes a multi-layer polyimide film comprising at least two polyimide layers stacked together, each polyimide layer comprising a polyimide-based polymer formed by reacting a diamine and a dianhydride component at substantially the same molar ratio , At least one of the polyimide layers further comprises a polyimide powder distributed on the polyimide-based polymer, and the polyimide powder has a weight ratio of about 20 to about 50 wt% of the total weight of the polyimide layer containing the polyimide powder. The multi-layer polyimide film thus formed has at least one outer surface having a gloss of less than about 60 degrees.

In another embodiment, the present application describes a dual layer polyimide film comprising first and second layers stacked together. The first layer comprises a polyimide powder distributed on a polyimide-based polymer and a polyimide-based polymer, and the polyimide powder has a weight ratio of about 20 to about 50 wt% of the total weight of the first layer. The second layer comprises a polyimide powder distributed on the polyimide-based polymer and the polyimide-based polymer, and the polyimide powder has a weight ratio of about 20 wt% or less of the total weight of the second layer. In addition, at least one of the first and second layers further comprises a colored pigment.

In another embodiment, the present application describes a triple layer polyimide film comprising a first layer, a second layer and a third layer, and a second polyimide layer is interposed between the first layer and the third layer. Each layer comprises a polyimide-based polymer, and the first and third layers each comprise a polyimide powder having a weight ratio of about 20 wt% to about 50 wt% of the total weight of the layer, respectively. Furthermore, at least one of the three layers further comprises a colored pigment.

Figure 1 is a graph plotting the particle size distribution of a polyimide powder prepared according to one embodiment;
2 is a schematic view showing a double-layer polyimide film containing a polyimide powder quencher;
3 is a schematic diagram showing a triple layer polyimide film containing a polyimide powder quencher.

Detailed Description of the Embodiments

This application describes a low-gloss polyimide film comprising a polyimide-based polymer forming the main molecular structure of the film, and a polyimide powder distributed in the polyimide-based polymer. In some embodiments, the polyimide film may have a single layer structure. In another embodiment, the polyimide film may have a multi-layer structure.

The polyimide-based polymer can be obtained by reacting a diamine with a dianhydride component, and the molar ratio of the monomers of the diamine and dianhydride is substantially 1: 1. The one or more diamine components may react with one or more dianhydride components to form a polyimide-based polymer. Examples of diamine components include, but are not limited to, phenylenediamine (PDA), 2- (4-aminophenyl) -5-aminobenzimidazole (PBOA), 3,4'-oxydianiline (3,4'- , 4,4'-oxydianiline (4,4'-ODA), p-phenylenediamine (p-PDA), 2,2'-bis (trifluoromethyl) benzidine (TFMB) . Examples of dianhydrides include, but are not limited to, pyromellitic dianhydride (PMDA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride (BPADA) and the like.

By adding a polyimide powder as a quencher to the polyimide-based polymer, an uneven microstructure can be formed on the surface of the polyimide film, and / or a light-scattering structure can be formed on the polyimide film. Therefore, the incident light can be effectively scattered to reduce the gloss.

The polyimide powder used as the quencher may have an average particle size or diameter of about 0.5 [mu] m to about 15 [mu] m. More specifically, the average particle size of the polyimide powder may be about 0.7, 1, 2, 3, 5, 7, 10, 11, 12, 13, May be a median value. For example, the polyimide powder may have an average particle size of from about 1 [mu] m to about 12 [mu] m, e.g., from 2 [mu] m to 10 [

In some embodiments, the amount of added polyimide powder may have a weight ratio of about 5 wt% to about 10 wt% of the total weight of the polyimide film. For example, the weight ratio of the polyimide powder may be about 5.5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or any intermediate value between these values.

The amount and average particle size of the added polyimide powder added can be selected according to the desired application field of the film and / or the gloss value (also referred to as " 60 gloss value ") under the viewing angle of about 60 degrees desired . For example, when the 60 DEG gloss value should be about 25, the polyimide powder will have a larger amount (e.g., 1 mu m) when the average particle size is smaller (e.g., 1 mu m) May be contained in an amount of 1 to 20% by weight.

In some embodiments, the polyimide film may have a 60 DEG gloss value of about 50 or less. For example, a 60 DEG gloss value of the film can be from about 1 to about 50, such as about 1, 5, 10, 20, 25, 30, 35, 40, 45, 50, or any intermediate value between these values .

The polyimide powder can be obtained by reacting a diamine and a dianhydride component. The one or more diamine components may react with one or more dianhydride components to form a polyimide powder. Examples of diamine components include, without limitation, 4,4'-ODA, TFMB, PDA, PBOA, 3,4'-ODA or any combination thereof. Examples of dianhydride components include, without limitation, PMDA, BPDA, BPADA, or any combination thereof.

The low-gloss polyimide film may be transparent and may exhibit a hazy appearance with low gloss. In some embodiments, the polyimide film may also be a colored film, such as red, blue, black, yellow, and the like. The colored pigment may be contained in the polyimide film to exhibit the desired color. The amount of pigment can be from about 2 to about 10 wt% of the weight of the film.

The pigments may be black pigments, chrome black pigments, titanium black pigments, etc. formed by carbon micro-particles. Examples of the color pigments may include carbon black, titanium black, black black, cyanine black, acetylene black, lamp black, graphite, iron oxide black, iron black, aniline black, cyanine black and the like and these may be used individually or in combination .

In one embodiment, a black polyimide film exhibiting an increased shading rate may be formed containing carbon black, titanium black, or combinations thereof. In various embodiments, carbon black pigments having an average particle size of from about 0.1 [mu] m to about 1.5 [mu] m may also be used.

When the black polyimide film is formed by containing a polyimide powder quencher having an average particle size of more than 10 mu m or more than 10 wt%, the depth of black color can be sensitized and / It can be observed that it can be whitened. In addition, the black color of the film is unstable in large scale manufacturing, and can result in a film having uneven color. In an attempt to alleviate this problem, embodiments of the black polyimide film having a 60 DEG gloss value of about 50 or less comprise about 80 wt% to about 93 wt% of a polyimide-based polymer, about 2 wt% to about 10 wt% , And about 5 wt% to about 10 wt% of a polyimide powder having an average particle size of about 2 [mu] m to about 10 [mu] m.

The film can be obtained by condensation polymerization of monomers comprising diamines and dianhydrides. The molar ratio of diamine to dianhydride is substantially 1: 1, for example, 0.90: 1.10 or 0.98: 1.02.

The diamine and dianhydride components may be first reacted in the presence of a solvent to obtain a polyamic acid solution. The solvent may be an aprotic polarity solvent having a relatively low boiling point (e.g., below about 225 [deg.] C) so that it can be removed at a relatively low temperature. Suitable solvents include, but are not limited to, dimethylacetamide (DMAC), N, N'-dimethyl-formamide (DMF), and the like.

The polyimide powder quencher, dehydrating agent and catalyst can then be incorporated into the polyamic acid solution, which is stirred to obtain a homogeneous precursor solution. Examples of dehydrating agents include, without limitation, adipic anhydrides (such as acetic anhydride and propionic anhydride) and aromatic acid anhydrides (such as benzoic anhydride and phthalic anhydride), which can be used individually or in combination. In one embodiment, the preferred dehydrating agent may be acetic anhydride, and the amount may be about 2 to 3 moles per equivalent of polyamic acid.

Examples of catalysts include, without limitation, heterocyclic tertiary amines such as picoline, pyridine, lutidine, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, imidazole, , N-ethyl-2-pyrrolidone, N-methylpiperidine and N-ethylpiperidine), aliphatic tertiary amines (for example, triethylamine (TEA), tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, triethylenediamine, and N, N-diisopropylethylamine (DIPEA)) and aromatic tertiary amines (such as dimethylaniline), which may be used individually or in combination . In one embodiment, the preferred catalyst is picoline (e.g., alpha-picoline, beta-picoline, or gamma-picoline). The polyamic acid-dehydrating agent-catalyst molar ratio may be about 1: 2: 1. That is, about 2 moles of dehydrating agent and about 1 mole of catalyst can be used for 1 mole of polyamic acid. If necessary, colored pigments such as carbon black may be added at any of the above-mentioned steps. The pigments may be mixed with the diamine and dianhydride components at the start of the condensation polymerization or added after incorporation of a quencher, dehydrating agent or catalyst.

Other additives may also be incorporated into the solution comprising polyamic acid to impart desired properties to the polyimide film. Suitable additives, for example, may include, without limitation, processing aids, antioxidants, light stabilizers, flame retardants, antistatic agents, thermal stabilizers, ultraviolet absorbers and reinforcing agents, which may be used individually or in combination.

A layer of the precursor solution may then be coated on a glass or stainless steel flat support. The coated layer may be baked to form a low-gloss polyimide film, which may subsequently be peeled from the glass plate support. A suitable temperature range for baking is from about 90 캜 to about 350 캜. The formed polyimide film may have a thickness of from about 3 占 퐉 to about 150 占 퐉, for example, from about 3 占 퐉 to 75 占 퐉, for example, from about 5 占 퐉 to about 50 占 퐉.

The polyimide powder quenching agent can be obtained by condensation polymerization of a diamine monomer and a dianhydride monomer. To obtain a stable and desired average particle diameter, the molar ratio of diamine to dianhydride can be from about 1: 0.950 to 1: 0.995.

The diamine and dianhydride (for example, 4,4'-ODA and PMDA) having the above-mentioned molar ratio can be mixed homogeneously in a solvent to form a reaction solution. Suitable solvents include DMAC, DMF, and the like. The total amount of monomers comprising diamine and dianhydride can be from about 2 wt% to about 20 wt% of the total weight of the reaction solution. In one embodiment, the weight ratio of monomers can be from about 5 wt% to about 15 wt% of the total weight of the reaction solution.

The dehydrating agent and catalyst can then be incorporated into the reaction solution, which is stirred to obtain the reaction mixture. Dewatering agents and catalysts for the preparation of polyimide powders may be similar to those used in the production of polyimide films.

The reaction mixture may be heated to obtain a precipitate of polyimide which forms a quencher. The precipitate of polyimide can then be rinsed, filtered and dried.

Due to its excellent heat resistance, the polyimide powder quencher can maintain stable properties during chemical transformation in the temperature range of 250 ° C to 500 ° C. As a result, non-uniform color defects caused by colored spots during the production of the polyimide film can be prevented. Compared to inorganic quenching agents, polyimide powder quenching agents can lower the dielectric constant of the film to provide better color representation and higher insulation properties, which makes the film particularly suitable for applications with high insulation requirements I make it.

In some embodiments, the low-gloss polyimide film may have a multi-layer structure comprising a plurality of polyimide layers stacked together. The diamines and dianhydride monomers used may be the same or different between the layers. The multi-layer polyimide film may, for example, comprise two layers, three or more layers. The multi-layer film has a 60 DEG gloss value of less than about 5 on at least one outermost surface of the multi-layer film.

In a multi-layer film, each layer includes a polyimide-based polymer, and at least one layer contains a polyimide powder distributed on the polyimide-based polymer as a quencher. Preferably, the layer comprising the quencher is the outermost layer of the multilayer film. The polyimide powder may have a weight ratio of about 20 to about 50 wt% of the total weight of the layer. The amount of polyimide powder is defined relative to the total weight of the layer into which it is incorporated. In some embodiments, the weight ratio of polyimide powder may be 20, 21, 24, 25, 30, 35, 40, 45, 47, 49, 50 wt%, or any intermediate value between these values. For example, when the multilayer film includes first and second layers stacked on each other, the polyimide powder in the first layer may have a weight ratio of about 20-50 wt%, and the second layer may include polyimide powder Or a polyimide powder having a weight ratio of less than about 20 wt% of the total weight of the second layer.

In certain embodiments of the multi-layer polyimide film, at least one of the polyimide layers may further comprise a colored pigment. The colored pigment may be the same as described above, for example, carbon black. In one embodiment, the colored pigment contained in one layer may have a weight ratio of from about 4 to about 9 wt% of the total weight of the layer. For example, the weight ratio of colored pigments may be any intermediate value between 4, 4.1, 4.3, 4.5, 5, 5.5, 6, 6.5, 7, 8, 8.5, 8.8, 8.9, 9 wt% .

In one embodiment, a double-layer polyimide film can be produced, which includes first and second layers stacked together comprising a polyimide-based polymer. One or both of the first and second layers may comprise a color pigment such as carbon black. In addition, one of the first and second layers, e.g., the first layer, of the multi-layer polyimide film may further comprise a polyimide powder in an amount of about 20 to about 50 wt% of the total weight of the layer have. For example, the weight ratio of the polyimide powder may be 20, 21, 24, 25, 30, 35, 40, 45, 47, 49, 50 wt%, or any intermediate value between these values. The second layer may comprise no polyimide powder or may contain less than the first layer of polyimide powder. In some embodiments, the amount of polyimide powder contained in the second layer is less than about 20 wt%, such as 19, 18, 17, 15, 10, 8, 5, 3, 2, 0.5, 0.1 wt%, or any intermediate value between these values.

In another embodiment, a triple layer polyimide film can be made, which includes a first layer, a second layer and a third layer stacked on each other, and a second layer interposed between the first and third layers . Each layer of the triple layer polyimide film comprises a polyimide-based polymer, and at least one of the three layers comprises a colored pigment such as carbon black. In addition, one or both of the first and third layers may additionally comprise polyimide powder in an amount of about 20 to about 50 wt% of the total weight of the layer. The second layer may comprise polyimide powder in a reduced amount that does not include polyimide powder or does not affect the mechanical properties of the triple layer polyimide film (e.g., an excessively low elongation).

Examples of polyimide powder quenching agents and low-gloss film production will be described later.

Example

Preparation of polyimide powder

The particle size can determine the quenching effect of the applied polyimide powder as a quencher. The polyimide powder prepared by the conventional method can not be used as an effective quencher due to its wide particle size distribution. Certain monomer mole ratios and solids content can be applied to precisely control the average particle size of the polyimide powder in some embodiments of the manufacturing processes described herein.

Example 1-1

About 570 g of DMAC solvent can be added to the 3-necked flask. Thereafter, about 14.35 grams of 4,4'-ODA and about 14.86 grams of PMDA can be mixed in the DMAC solvent and stirred to allow the reaction solution to dissolve completely. The molar ratio of 4,4'-ODA and PMDA may be about 1: 0.950, and the total weight ratio of monomers may be about 5 wt% of the weight of the reaction solution. About 3.17 g of 3-picoline can then be added to the reaction solution, which is continuously stirred and heated at about 170 占 폚 for 18 hours to form a precipitate of polyimide. The precipitate is rinsed with water and ethanol, vacuum filtered and then heated in a baking oven at about 160 캜 for one hour to obtain a polyimide powder.

Examples 1-2

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 540 g of DMAC, about 28.70 g of 4,4'-ODA, about 29.72 g of PMDA, and about 6.34 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 10 wt% of the weight of the reaction solution.

Example 1-3

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 510 g of DMAC, about 43.05 g of 4,4'-ODA, about 44.58 g of PMDA, and about 9.51 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 15 wt% of the weight of the reaction solution.

Examples 1-4

The polyimide powder can be prepared similarly to Example 1-1, except that the applied amount includes about 15.41 g of PMDA, and about 3.29 g of 3-picoline. Thus, the molar ratio of 4,4-ODA to PMDA may be about 1: 0.985, and the total weight ratio of monomers may be about 5 wt% of the weight of the reaction solution.

Examples 1-5

The polyimide powder was prepared as in Example 1-4, except that the applied amount contained about 540 g of DMAC, about 28.70 g of 4,4'-ODA, about 30.81 g of PMDA, and about 6.57 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 10 wt% of the weight of the reaction solution.

Examples 1-6

The polyimide powder was prepared as in Example 1-4, except that the applied amount contained about 510 grams of DMAC, about 43.05 grams of 4,4'-ODA, about 46.22 grams of PMDA, and about 9.86 grams of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 15 wt% of the weight of the reaction solution.

Examples 1-7

The polyimide powder can be prepared similarly to Example 1-1, except that the applied amount includes about 15.57 g of PMDA, and about 3.32 g of 3-picoline. Thus, the molar ratio of 4,4-ODA to PMDA can be about 1: 0.995, and the total weight ratio of monomers can be about 5 wt% of the weight of the reaction solution.

Examples 1-8

The polyimide powder was prepared in the same manner as in Examples 1-7 and 2-6 except that the applied amount contained about 540 g of DMAC, about 28.70 g of 4,4'-ODA, about 31.14 g of PMDA, and about 6.64 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 10 wt% of the weight of the reaction solution.

Examples 1-9

The polyimide powder was prepared in the same manner as in Examples 1-7 and 2-2 except that the amount applied was about 510 g of DMAC, about 43.05 g of 4,4'-ODA, about 46.70 g of PMDA, and about 9.96 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 15 wt% of the weight of the reaction solution.

Comparative Example 1-1

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 570 g of DMAC, about 14.35 g of 4,4'-ODA, about 14.08 g of PMDA, and about 6.01 g of 3-picoline. Can be similarly prepared. Thus, the molar ratio of 4,4'-ODA to PMDA is about 1: 0.900, and the total weight ratio of monomers can be about 5 wt% of the weight of the reaction solution.

Comparative Example 1-2

The polyimide powder was prepared in the same manner as in Comparative Examples 1-1 and 2 except that the applied amount contained about 510 g of DMAC, about 43.05 g of 4,4'-ODA, about 42.23 g of PMDA, and about 18.02 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 15 wt% of the weight of the reaction solution.

Comparative Example 1-3

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 576 grams of DMAC, about 11.48 grams of 4,4'-ODA, about 11.89 grams of PMDA, and about 5.07 grams of 3-picoline. Can be similarly prepared. Thus, the molar ratio of 4,4'-ODA to PMDA is about 1: 0.950 and the total weight ratio of monomers can be about 4 wt% of the weight of the reaction solution.

Comparative Example 1-4

The polyimide powder was prepared in the same manner as in Comparative Examples 1-3 except that the applied amount contained about 504 g of DMAC, about 45.93 g of 4,4'-ODA, about 47.56 g of PMDA, and about 20.29 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 16 wt% of the weight of the reaction solution.

Comparative Example 1-5

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 576 g of DMAC, about 11.48 g of 4,4'-ODA, about 12.45 g of PMDA, and about 5.31 g of 3-picoline. Can be similarly prepared. Thus, the molar ratio of 4,4'-ODA to PMDA is about 1: 0.995, and the weight ratio of monomers can be about 4 wt% of the weight of the reaction solution.

Comparative Example 1-6

The polyimide powder was prepared in the same manner as in Comparative Examples 1-5 except that the applied amount contained about 504 g of DMAC, about 45.93 g of 4,4'-ODA, about 49.81 g of PMDA, and about 21.25 g of 3-picoline Can be similarly prepared. Thus, the total weight ratio of monomers can be about 16 wt% of the weight of the reaction solution.

Comparative Example 1-7

The polyimide powder was prepared in the same manner as in Examples 1-1 and 2 except that the applied amount contained about 570 g of DMAC, about 14.35 g of 4,4'-ODA, about 15.65 g of PMDA, and about 6.67 g of 3-picoline. Can be similarly prepared. Thus, the molar ratio of 4,4'-ODA to PMDA is about 1: 1 and the total weight ratio of monomers can be about 5 wt% of the weight of the reaction solution.

Comparative Example 1-8

The polyimide powder was prepared in the same manner as in Comparative Examples 1-7 except that the applied amount contained about 510 g of DMAC, about 43.05 g of 4,4'-ODA, about 46.95 g of PMDA, and about 20.02 g of 3-picoline. Can be similarly prepared. Thus, the total weight ratio of monomers can be about 15 wt% of the weight of the reaction solution. The reaction solution is continuously stirred and heated at about 170 占 폚 for 18 hours, but no precipitate of polyimide is formed. In other words, the polyimide powder is not formed.

Testing of polyimide powder

The polyimide powders obtained in the above Examples and Comparative Examples can be tested to determine the distribution of particle sizes.

A particle size analyzer (Horiba LA-950, sold by Horiba, Instruments) can be used to measure the particle size. The polyimide powder can be dispersed in the flow carrier DMAC and dispersed through a grinder. The particle size measured from the polyimide powder can be verified by SEM. The results are shown in Table 1 below.

In Table 1, " solids content " means the weight percentage of monomers in the reaction solution; "D50" is the median diameter. That is, there is a particle size at which the cumulative distribution percentage reaches 50% (50% with a size greater than the D50 value, and 50% with a size smaller than the D50 value); &Quot; D90 " is the particle size at which the cumulative distribution percentage reaches 90% (there are 90% of the particles having a size greater than the D90 value), which is used as a particle size index representing larger particles of the powder; The effective particle size S is defined as S = B / (A + B + C) x 100% where A is the positive percentage of particles having a size smaller than 2 탆 in the polyimide powder, Is the positive percentage of particles having a diameter of 2-10 mu m in the mid-powder, and C is the positive percentage of the particles having a size larger than 10 mu m in the polyimide powder.

1 is a graph plotting the distribution of particle sizes in the polyimide powder.

Referring to FIG. 1 and Table 1, it can be seen that the molar ratio of 4,4'-ODA to PMDA is from about 0.95 to about 0.995 and the monomer solids content is from about 5 wt.% To about 15 wt.% Of the reaction solution. 1-9, the D50 value of the polyimide powder is about 2.7 占 퐉 to about 4.9 占 퐉, the D90 value is about 5.9 占 퐉 to about 7.3 占 퐉, and the effective particle size (S) is more than 70%.

In contrast, with Comparative Samples 1-1, 1-2, 1-7 and 1-8 with a molar ratio of less than 0.95 or greater than 0.995 and a solids content of 5 wt% or 15 wt%, the effective particle size (S) reached 70% Or even particles can not be formed. Furthermore, in Comparative Examples 1-3 to 1-6 in which the molar ratio is in the range of 0.95-0.995 and the solid content is less than 5 wt% or exceeds 15 wt%, the effective particle size (S) can still not reach 70%.

Thus, controlling the molar ratio of diamine to dianhydride from about 1: 0.95 to about 1: 0.995 and the solids content from about 5 wt% to about 15 wt% can result in an effective particle size S of 70% or greater .

Preparation of single layer black polyimide film

Step 1. Preparation of polyimide powder

About 14.35 g of 4,4'-ODA, about 14.86 g of PMDA, and about 570 g of DMAC are mixed in a three-necked flask to give a reaction solution. The molar ratio of 4,4'-ODA to PMDA is about 1: 0.950, and the total weight ratio of monomers can be about 5 wt% of the reaction solution. About 3.35 g of 3-picoline can then be added to the reaction solution, which is subsequently stirred and heated at a temperature of 170 DEG C for 18 hours to form a precipitate of polyimide. The precipitate may be rinsed with water and ethanol, vacuum filtered and heated at a temperature of 160 DEG C for 1 hour, whereby about 26.7 g of polyimide powder can be obtained.

Step 2. Preparation of carbon black slurry

About 500 g of carbon black (Regal-R400, sold by CABOT Company) and about 4,000 g of DMAC can be mixed and stirred for 15 minutes. The mixture may then be processed through a grinder to obtain a carbon black slurry.

Step 3. Preparation of black polyamic acid (PAA) solution

About 833 g of polyamic acid, which was formed from the polymerization of PMDA having about 45 g of carbon black slurry, 4,4'-ODA, para-phenylenediamine (p-PDA) and a viscosity of about 150,000 cps and having a solid content of 18 wt% Solution and about 122 g of DMAC as a solvent are homogeneously mixed to obtain a black PAA solution having a solids content of about 15.49 wt% and a weight of about 1,000 g.

Step 4. Preparation of black polyimide film

Example 3-1

About 0.37 g of a polyimide powder (particle size of about 2.1 탆) obtained from Step 1, about 49.83 g of a black PAA solution obtained from Step 3, and about 15.2 g of DMAC were added to the flask and stirred for 1 to 2 hours Lt; RTI ID = 0.0 > PAA < / RTI > solution can be obtained. The low-gloss black PAA solution can be coated on a glass plate support and baked in an oven. The baking conditions may be set at a temperature of 90 DEG C for 30 minutes to remove most of the solvent, then for 4 hours at 170 DEG C to 350 DEG C to form a single layer low gloss black polyimide film. The film peeled from the glass plate support may contain 5 wt% polyimide powder having an average particle size of about 2.1 mu m.

Example 3-2

The film is prepared similarly to Example 3-1 except that the solids content of monomeric 4,4'-ODA and PMDA is about 15 wt% and the average particle size of the polyimide powder is about 5.5 μm.

Example 3-3

The film had a solids content of monomeric 4,4'-ODA and PMDA of about 15 wt%, a molar ratio of 4,4'-ODA to PMDA of about 1: 0.995, and an average particle size of polyimide powder of about 8.6 μm And can be prepared similarly to Example 3-1.

Example 3-4

The film may be prepared similarly to Example 3-1 except that the amount of added polyimide powder is about 0.78g. Thus, the low gloss black polyimide film may comprise about 10 wt% polyimide powder having an average particle size of about 2.1 mu m.

Example 3-5

The film may be prepared similarly to Example 3-2 except that the amount of added polyimide powder is about 0.78g. The polyimide powder has an average particle size of about 5.5 mu m.

Examples 3-6

The film can be prepared similarly to Example 3-3 except that the amount of added polyimide powder is about 0.78g. The polyimide powder has an average particle size of about 8.6 mu m.

Comparative Example 3-1

The film can be prepared similarly to Example 3-1 except that the amount of added polyimide powder having a particle size of about 2.1 mu m is about 0.008 g. Accordingly, the low-gloss black polyimide film contains about 1 wt% of the polyimide powder.

Comparative Example 3-2

The film can be prepared similarly to Comparative Example 3-1, except that the solids content of the monomeric 4,4'-ODA and PMDA is about 15 wt% and the average particle size of the polyimide powder is about 5.5 μm.

Comparative Example 3-3

The film had a solids content of monomeric 4,4'-ODA and PMDA of about 15 wt%, a molar ratio of 4,4'-ODA to PMDA of about 1: 0.995, and an average particle size of polyimide powder of about 8.6 μm And can be produced similarly to Comparative Example 3-1.

Comparative Example 3-4

The film may be prepared similarly to Example 3-1 except that no polyimide powder is added.

Comparative Example 3-5

The film was prepared in the same manner as in Example 3-7 except that polyimide powder was not added and about 0.37 g of SiO ₂ powder (sold by GRACE Company under the trade designation "P405") having a particle size of about 5.2 μm was used as a quencher. . ≪ / RTI >

Comparative Example 3-6

Except that polyimide powder was not added and about 0.37 g of Al ₂ O ₃ powder (sold under the name "ASFP-20" by Denka Company) having a particle size of about 5.4 μm was used as the quencher Can be prepared similarly to Example 3-7.

Optical property test of black polyimide film

The 60 ° gloss value and the total transparency of the black polyimide film prepared according to the above-mentioned Examples and Comparative Examples can be measured, and the results are shown in Table 2.

Table 2. Optical properties of black polyimide film

Gloss systems sold under the product name NIPPON DEMSHOKU PG-1M may be used to measure 60 ° gloss values, and 60 ° gloss values may be obtained as an average of three to six measurements. A turbidometer sold under the name NIPPON DEMSHOKU NDH 2000 may be used to measure the overall transparency and the overall transparency may be obtained as an average of three to six measurements.

As shown in Table 2, the low-gloss black polyimide film containing the polyimide powder quenching agent had a lower 60 ° (as compared with Comparative Example 3-4) compared to the black polyimide film formed without the addition of the quencher Can have a gloss value, and can exhibit a high shielding rate (i.e., less than 0.1% total transparency). In particular, as shown in Examples 3-1 to 3-6, the 60 ° gloss value can be reduced to 50 or less when the polyimide powder is contained in an amount of 5 wt% or more. The 60 ° gloss value can be reduced as more polyimide powder is added. Compared with the conventional quenching agents used in Comparative Examples 3-5 and 3-6, the use of the polyimide powder as the quenching agent can produce the same or better quenching effect.

When the amount of the added polyimide powder is less than 5 wt% (the case of Comparative Example 1-3), even if the average particle size of the polyimide powder is 2 탆 to 10 탆, the 60 ° gloss value of the film is still 100 Lt; / RTI > In addition, when the amount of the polyimide powder is less than 5 wt%, the 60 DEG gloss value of the film may also be more than 100, even if the average particle size is more than 10 mu m (not shown in the table).

The use of a polyimide powder having an excessively small particle size (for example, less than 0.5 mu m) can reduce the surface roughness of the film, which may cause insufficient scattering of the incident light. When higher amounts of polyimide powder are used for obtaining the desired 60 ° gloss value, the dispersion of the powder particles can be reduced and / or can even affect the properties of the film.

On the other hand, polyimide powders with excessively large particle sizes can produce film surfaces that are more quieter, especially at thinner films (e.g., less than 80 microns in thickness), which can affect surface uniformity have. In addition, the particles of the larger polyimide powder can be easily separated and contaminate subsequent processes.

Production of low-gloss polyimide film

Example 5-1

About 6.1 g of polyimide powder (about 5 탆 in particle size) and about 160.6 g of DMAC can be mixed into the flask. Thereafter, about 333.3 g of a solid content of about 18 wt.% Of the PAA solution (polymerized from 4,4'-ODA, p-PDA and PMDA having a viscosity of about 150,000 cps) had a solids content of about 13.2 wt% Can be added and stirred continuously until a PAA solution having a total weight of 500 g can be obtained. Approximately 60 g of PAA solution can then be blade coated onto a glass plate support and baked in an oven. The baking conditions were heated at a temperature of about 90 DEG C for 30 minutes to remove most of the solvent, and then at 170 DEG C to 350 DEG C to form a single layer low-gloss polyimide film containing about 10 wt% polyimide powder And heating for 4 hours.

Comparative Example 5-1

The film was carried out except that the polyimide powder was not added and about 10 wt% of Al ₂ O ₃ powder (sold by Denka Company under the trade name "ASFP-20") having a particle size of about 5.4 μm was contained as the quencher Can be prepared analogously to Example 5-1.

Comparative Example 5-2

The film was prepared in the same manner as in Example 5-1 except that polyimide powder was not added and about 10 wt% SiO ₂ powder having a particle size of about 5.2 탆 (sold by GRACE Company under the trade name of "P405") was contained as a quencher. . ≪ / RTI >

Comparative Example 5-3

The film was prepared similarly to Example 5-1 except that polyimide powder was not added and about 10 wt% TiO ₂ powder (sold by Sigma Aldrich Company) having a particle size of about 5 μm was included as a quencher .

Measurement of dielectric constant of polyimide film

ASTM D150-95 standard tests can be used to measure the dielectric constant of polyimide films prepared according to the above Examples and Comparative Examples. The impedance analyzer Agilent 4294A (clip type 16034G) can be used to determine the dielectric constant of each film, which can be an average of three measurements. The results are shown in Table 3.

Table 3. Test results of dielectric constant of low-gloss polyimide film

As shown in Table 3, as compared with conventional inorganic quenchers, the proper amount of polyimide powder inclusion can allow film formation with lower dielectric constant and better insulation properties, The branches make them particularly suitable for applications.

Preparation of multi-layer black polyimide film

Example 6-1

Step 1: Preparation of polyimide powder.

About 470 g of DMAC solvent may be added to the 3-necked flask. Thereafter, about 14.35 g of 4,4'-ODA and about 15.65 g of PMDA can be mixed in the DMAC solvent and stirred to dissolve completely in the reaction solution. The molar ratio of 4,4'-ODA and PMDA may be about 1: 1, and the total weight ratio of monomers may be about 6 wt% of the weight of the reaction solution. Approximately 500 g of the reaction solution is continuously stirred, typically heated to about 160 캜 at 2 캜 / min and heated at 160 캜 for 3 hours to form a precipitate of polyimide. The precipitate is rinsed with DMAC and ethanol, vacuum filtered and then heated in a baking oven at about 160 캜 for 1 hour to yield a polyimide powder.

Step 2: Preparation of polyamic acid (PAA) solution.

Assuming that a black double layer polyimide film is to be produced, two black PAA solutions can be prepared for each of the two polyimide layers of the film. With respect to the first black PAA solution, a polyamic acid solution having a solids content of 18 wt% can be formed from the polymerization of 4,4'-ODA and PMDA (molar ratio 1: 1). In addition, about 4 g of carbon black (SB4A sold by Degussa Company), about 20 g of polyimide powder prepared by step 1 mentioned above, and about 144 g of DMAC were mixed and stirred for 60 minutes, Lt; / RTI > The resulting mixture is then homogeneously mixed with about 496 grams of a polyamic acid solution to obtain a first black PAA solution.

With respect to the second black PAA solution, a similar polyamic acid solution having a solid content of 18 wt% can be formed from the polymerization of 4,4'-ODA and PMDA (molar ratio 1: 1). In addition, about 4 g of carbon black (SB4A, sold by Degussa Company) and about 24 g of DMAC are mixed and stirred for 60 minutes and then processed through a grinder. The resulting mixture is homogeneously mixed with about 593 g of a polyamic acid solution to obtain a second black PAA solution.

Step 3: Preparation of multi-layer polyimide film.

The second black PAA solution is coated on a glass plate support and baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent. The first black PAA solution is then coated on the second layer and baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent and then baked at 350 DEG C for 4 hours to form a double layer polyimide film. The total thickness of the double-layer polyimide film is about 13 mu m, the thickness of the first layer is 4 mu m, and the thickness of the second layer is 9 mu m.

Example 6-2

The double layer film was prepared in the same manner as in Examples 6-1 and 6-1 except that the first black PAA solution contained about 4 g of carbon black (SB4A), about 30 g of polyimide powder, about 204 g of DMAC, and about 407 g of polyamic acid solution. Can be similarly prepared.

Example 6-3

The double layer film was prepared in the same manner as in Examples 6-1 and 6-2 except that the first black PAA solution contained about 4 g of carbon black (SB4A), about 50 g of polyimide powder, about 324 g of DMAC, and about 284 g of polyamic acid solution. Can be similarly prepared.

Example 6-4

A triple layer film can be prepared based on the double layer structure obtained in Example 6-1. More specifically, the double-layer structure obtained in Example 6-1 may be peeled off from the glass plate support and then arranged so that the second layer is the top while the first layer lies in contact with the glass plate support. The first black PAA solution is then coated on the second layer to form a third layer. The structure is baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent and then baked at 350 DEG C for 4 hours to form a triple layer polyimide film. In such a triple layer structure, the first and third layers have the same composition, and the second layer is interposed between the first and third layers. In addition, the total thickness of the triple-layer polyimide film is 13 占 퐉, and the thicknesses of the first, second and third layers are 4 占 퐉, 5 占 퐉 and 4 占 퐉, respectively.

Examples 6-5

The triple layer film was prepared as in Example 6-4 except that the first black PAA solution contained about 4 grams of carbon black (SB4A), about 50 grams of polyimide powder, about 324 grams of DMAC, and about 284 grams of polyamic acid solution Can be similarly prepared.

Examples 6-6

The double layer film was prepared in the same manner as in Examples 6-1 and 6-1 except that the first black PAA solution contained about 6 g of carbon black (SB4A), about 20 g of polyimide powder, about 156 g of DMAC, and about 457 g of polyamic acid solution. Can be similarly prepared. In addition, the second black PAA solution contains about 6 grams of carbon black (SB4A), about 36 grams of DMAC, and about 580 grams of polyamic acid solution.

Examples 6-7

Step 1: Preparation of polyimide powder.

The polyimide powder can be prepared similarly to Example 6-1.

Step 2: Preparation of polyamic acid (PAA) solution.

The first black PAA solution can be prepared similarly to Example 6-1.

The second black PAA solution was prepared in the same manner as in Examples 6-1 and 6-2 except that the contained component contained about 4 g of carbon black (SB4A), about 3 g of polyimide powder, about 42 g of DMAC, and about 574 g of polyamic acid solution. Can be similarly prepared.

Step 3: Preparation of multi-layer polyimide film.

The second black PAA solution is coated on a glass plate support and baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent and then baked at 370 DEG C for 4 hours to form a second layer. The second layer is peeled from the support and inverted to expose the surface that had previously contacted the flat support. The first black PAA solution was then coated on the exposed surface of the second layer and baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent and then baked at 370 DEG C for 4 hours to form a double layer polyimide film . The total thickness of the double-layer polyimide film is about 13 mu m, and the thicknesses of the first and second layers are 4 mu m and 9 mu m, respectively.

Examples 6-8

The double layer film was prepared in the same manner as in Examples 6-7, except that the second black PAA solution contained about 4 g of carbon black (SB4A), about 10 g of polyimide powder, about 84 g of DMAC, and about 531 g of polyamic acid solution Can be similarly prepared.

Examples 6-9

The double layer film was prepared in the same manner as in Examples 6-7, except that the second black PAA solution contained about 4 g of carbon black (SB4A), about 20 g of polyimide powder, about 144 g of DMAC, and about 469 g of polyamic acid solution Can be similarly prepared.

Examples 6-10

The double layer film was prepared in the same manner as in Examples 6-7 and Comparative Example 2 except that the second black PAA solution contained about 4 g of carbon black (SB4A), about 30 g of polyimide powder, about 204 g of DMAC, and about 407 g of polyamic acid solution Can be similarly prepared.

Examples 6-11

The double layer film was prepared in the same manner as in Examples 6-9 and 6-4 except that the first black PAA solution contained about 4 grams of carbon black (SB4A), about 50 grams of polyimide powder, about 324 grams of DMAC, and about 284 grams of polyamic acid solution. Can be similarly prepared.

Examples 6-12

The double-layer film may be prepared similarly to Example 6-3 except that the second black PAA solution contains only a polyamic acid solution and no carbon black.

Examples 6-13

The double layer film was prepared as in Example 6-3 except that the first black PAA solution contained about 50 grams of polyimide powder, about 300 grams of DMAC, and about 309 grams of polyamic acid solution, and no carbon black .

Comparative Example 6-1

The double layer film was prepared in the same manner as in Examples 6-1 and 6-1 except that the first black PAA solution contained about 4 g of carbon black (SB4A), about 15 g of polyimide powder, about 114 g of DMAC, and about 500 g of polyamic acid solution. Can be similarly prepared.

Comparative Example 6-2

The double layer film was prepared in the same manner as in Examples 6-1 and 6-2 except that the first black PAA solution contained about 4 g of carbon black (SB4A), about 60 g of polyimide powder, about 384 g of DMAC, and about 222 g of polyamic acid solution. Can be similarly prepared.

Comparative Example 6-3

The double layer film was prepared in the same manner as in Examples 6-1 and 6-2 except that the first black PAA solution contained about 10 g of carbon black (SB4A), about 20 g of polyimide powder, about 180 g of DMAC, and about 432 g of polyamic acid solution. Can be similarly prepared. In addition, the second black PAA solution contains about 10 grams of carbon black (SB4A), about 60 grams of DMAC, and about 556 grams of polyamic acid solution.

Comparative Example 6-4

The double layer film was prepared similarly to Example 6-1 except that the first and second black PAA solutions each contained about 4 g of carbon black (SB4A), about 24 g of DMAC, and about 593 g of polyamic acid solution .

Comparative Example 6-5

The dual layer film was prepared in the same manner as in Example 1 except that the first and second black PAA solutions each contained about 4 grams of carbon black (SB4A), about 30 grams of polyimide powder, about 204 grams of DMAC, and about 407 grams of polyamic acid solution 6-7. ≪ / RTI >

Comparative Example 6-6

The double layer film was prepared as in Example 6-5 except that the first black PAA solution contained about 4 grams of carbon black (SB4A), about 50 grams of polyimide powder, about 324 grams of DMAC, and about 284 grams of polyamic acid solution Can be similarly prepared.

Comparative Example 6-7

About 407 g of a polyamic acid solution having a solids content of 18 wt% can be formed from the polymerization of 4,4'-ODA and PMDA (molar ratio 1: 1). In addition, about 4 g of carbon black (SB4A), about 30 g of polyimide powder and about 144 g of DMAC can be mixed with each other and stirred for 60 minutes. After being processed through a grinder, the resulting mixture is homogeneously mixed with about 407 g of a polyamic acid solution to obtain a black PAA solution.

The black PAA solution is coated on a glass plate support and baked at a temperature of about 80 DEG C for 30 minutes to remove most of the solvent and then baked at 370 DEG C for 4 hours to form a single layer polyimide film.

Comparative Example 6-8

The triple layer film was prepared as in Example 6-4 except that the first black PAA solution contained about 4 grams of carbon black (SB4A), about 60 grams of polyimide powder, about 384 grams of DMAC, and about 222 grams of polyamic acid solution Can be similarly prepared.

Comparative Example 6-9

The triple layer film may be prepared similarly to Example 6-4 except that the first black PAA solution contains about 4 grams of carbon black (SB4A), about 384 grams of DMAC, and about 593 grams of polyamic acid solution. In addition, the second black PAA solution contains about 4 grams of carbon black (SB4A), about 50 grams of polyimide powder, and about 324 grams of DMAC, and about 284 grams of polyamic acid solution.

Test of Film Properties of Multilayer Polyimide Film

The 60 DEG gloss value (GU) is measured using a gloss meter (Micro Tri Gloss-BYK Gardner). Total Transparency (TT) is measured using a Nippon Denshoku NDH 2000 turbidimeter. The elongation is measured using a universal material tester (Hounsfield H10ks) based on ASTM D288. Surface resistivity is measured using an Agilent 4339B with a 16008B Resistivity Cell. The test results are shown in Table 4.

Table 4: Properties of Multilayer Polyimide Film

In Table 4, " D " means quenching agent (i.e., polyimide powder), " C " means carbon black, " X " means no layer, " Refers to the outermost surface of a multilayer film that does not contact the flat support 2 during the manufacturing process (Fig. 2 shows an example of a double layer film 1 formed on the flat support 2, and Fig. 3 shows an example of a double- 1 "), " Surface B " refers to the outermost surface of the multi-layer film in contact with the flat support 2 during the manufacturing process (as shown in FIGS.

According to Table 4, the multilayer films of Examples 6-1 through 6-13 exhibited the desired (low) light transmittance (less than 0.2%), good elongation (greater than 30% Film properties. In Examples 6-4 and 6-5, when the first and third layers comprise 20-50 wt% polyimide powder, gloss values of both surface A and surface B are less than 5.

If the proportion of polyimide powder is too low (e.g., 15 wt% in Comparative Example 6-1), the desired gloss value can not be obtained. When the proportion of the polyimide powder is too high (for example, Comparative Examples 6-2 and 6-5 to 6-8), the mechanical properties, such as elongation, become poor.

Carbon black can also affect the electrical conductivity of the film: if the proportion of carbon black in the layer is too high (e.g., Comparative Example 6-3), the desired insulating properties can not be obtained.

Fabrication of Polyimide Film with Metal Layer

Example 7-1

A polyamic acid solution containing a solid content of 18 wt% can be formed from polymerization of 4,4'-ODA and PMDA (molar ratio 1: 1). In addition, about 4 g of carbon black (SB4A), about 10 g of polyimide powder, and about 84 g of DMAC can be mixed with each other and stirred for 60 minutes. After being processed through a grinder, the mixture is homogeneously mixed with about 519 g of a polyamic acid solution to obtain a black PAA solution.

The black PAA solution was coated on a glass plate support and baked at a temperature of about 80 캜 for 30 minutes to remove the solvent and then baked at 370 캜 for 4 hours to form a single layer polyimide film (including 10% polyimide powder) .

The black polyimide film is peeled from the glass plate support and an aluminum layer having a thickness of about 70 nm is formed on the surface in contact with the glass plate support before peeling. A metal layer may be formed by thermal evaporation under a vacuum of about 10 ^-6 torr.

Example 7-2

The film can be prepared similarly to Example 7-1 except that the aluminum layer is replaced with a silver layer having a thickness of about 70 nm.

Example 7-3

The film can be prepared similarly to Example 7-2 except that a single layer polyimide film is replaced with the double layer polyimide film of Example 6-2.

Comparative Example 7-1

The single layer polyimide film was prepared in the same manner as in Comparative Examples 6-7 except that the black PAA solution contained about 4 g of carbon black (SB4A), about 10 g of polyimide powder, about 84 g of DMAC, and about 519 g of polyamic acid solution Can be similarly prepared.

Measurement of Electromagnetic Interference (EMI) Shielding Effect.

The efficiency of EMI shielding is detected using an HP network / spectrum / impedance analyzer based on ASTM 4935. Average results of 500 MHz to 2 GHz were obtained. The results are shown in Table 5.

In Table 5, " CE " means a comparative example, " D " means a quencher (i.e., polyimide powder), " C " means carbon black, and & do.

Table 5 shows that the multi-layer polyimide film may further include a metal layer to provide about 30-50 dB of EMI shielding at frequencies of 500 MHz to 2 GHz. Thus, the application of the multilayer polyimide films described herein can include EMI shielding in the manufacture of flexible PCBs. In addition, polyimide films can have low gloss and low light transmittance (< 0.2%), and can have excellent mechanical properties and insulation.

The embodiments and examples described herein are capable of producing polyimide powders with improved light extinction effect, high insulation and good heat resistance. The polyimide powder may be used in conjunction with a carbon black pigment (e.g., in an amount of about 2-10 wt%) to produce a black polyimide film with high shielding properties, low gloss, improved insulation, and heat resistance.

Examples of applications for polyimide films include, but are not limited to, flexible printed circuit boards (FPCs), rigid printed circuit boards, flexible-rigid printed circuit boards, LCDs, LEDs, photovoltaic cells, TFT-LCDs, OLEDs, Digital cameras, laptops, e-books, tablet PCs, and the like.

The realization of films, polyimide powder quenchers and related manufacturing processes has been described in the context of certain embodiments. These embodiments are intended to be illustrative and not restrictive. Many changes, modifications, additions and improvements are possible. Other changes, modifications, additions and improvements, including these, may be within the scope of the invention as defined in the following claims.

Claims (14)

Multi-layer polyimide film including:
At least two polyimide layers stacked on each other, and
A metal layer disposed on the outer surface of the multi-layer polyimide film,
Wherein each of the polyimide layers comprises a polyimide-based polymer formed by reacting a diamine and a dianhydride component at substantially the same molar ratio, and at least one of the polyimide layers further comprises a polyimide powder distributed in the polyimide-based polymer Wherein the polyimide powder has a weight ratio of 20 to 50 wt% of the total weight of the polyimide layer containing the polyimide powder, and the polyimide powder has an average particle size of 2 to 10 mu m, and the polyimide powder has a weight ratio of 1: 0.950 to 1: Derived from diamines and dianions, the molar ratio of diamine to dianhydride,
Wherein the multi-layer polyimide film has at least one outer surface having a gloss of less than or equal to 5 degrees. The multi-layer polyimide film of claim 1, wherein at least one of the polyimide layers further comprises a colored pigment. The multilayer polyimide film of claim 2, wherein the colored pigment has a weight ratio of 4 to 9 wt% of the weight of the polyimide layer. The multi-layer polyimide film according to claim 2, wherein the colored pigment is carbon black. The multi-layer polyimide film of claim 1, wherein the polyimide powder is obtained from the reaction of oxydianiline (ODA) and pyromellitic dianhydride (PMDA). delete delete delete A double layer polyimide film comprising:
A first layer comprising a polyimide powder distributed on a polyimide-based polymer and a polyimide-based polymer, the polyimide powder having a weight ratio of 20 to 50 wt% of the total weight of the first layer; And
The second layer laminated on the surface of the first layer and the second layer comprise a polyimide powder distributed on the polyimide-based polymer and the polyimide-based polymer, and the polyimide powder contains not more than 20 wt% By weight;
Wherein at least one of the first and second layers further comprises a colored pigment, wherein the polyimide powder in the first and second layers has an average particle size of 2 [mu] m to 10 [mu] m, Derived from diamines and dianions, the molar ratio of diamines to dianions. The double-layer polyimide film according to claim 9, wherein the colored pigment is carbon black. The double-layer polyimide film of claim 9, wherein the colored pigment has a weight ratio of 4 to 9 wt% of the weight of the layer. A first layer, a second layer, and a third layer, wherein the second polyimide layer is sandwiched between a first layer and a third layer, wherein each layer comprises a polyimide-based polymer, The third layer further comprises a polyimide powder having a weight ratio of 20 wt% to 50 wt% of the total weight of the layers, at least one of the three layers further comprising a colored pigment, Wherein the polyimide powder is derived from a diamine and dianhydride having an average particle size of from 2 m to 10 m and a molar ratio of diamine to dianhydride of from 1: 0.950 to 1: 0.995. 13. The triple layer polyimide film of claim 12, wherein the colored pigment is carbon black. 13. The triple layer polyimide film of claim 12, wherein the colored pigment has a weight ratio of 4 to 9 wt% of the weight of the layer.

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