TWI870775B - Matt polyimide film and its manufacturing method (II) - Google Patents

Abstract

The present invention is a matte polyimide film and a method for manufacturing the same. The method comprises the following steps: providing an insoluble polyamide solution, which is formed by polymerization of aromatic dianhydride and aromatic diamine; providing a soluble polyimide, whose solubility is between 3% and 30%, and whose weight accounts for 5% to 25% of the film; adding the soluble polyimide to the insoluble polyamide solution to form a polyamide mixed solution; and chemically cyclizing the polyamide solution to generate phase separation to form a matte polyimide film with a 60-degree glossiness of less than 60GU.

Description

Matte polyimide film and its manufacturing method (Part 2)

The present invention is a matte polyimide film and a method for manufacturing the same, particularly a polyimide film having matte properties without adding a matte agent, which is relatively simple to manufacture and has a relatively low cost.

Polyimide films are often used as cover layers for flexible circuit boards. Matt polyimide films have special optical properties that can reduce visual discomfort caused by film reflections. They can also protect electronic components and avoid unnecessary visual inspections and damage. Therefore, they are often used in special flexible board applications.

However, the known method of manufacturing matte polyimide film mainly uses the method of adding matte particles to change the surface roughness of the film. Since the surface roughness varies with the size and addition ratio of the matte particles, it will change the angle of reflection of ambient light on the film, thereby achieving the matte effect.

Generally, matte particles can be divided into organic matte particles and inorganic matte particles. Regardless of the composition, the problem of particle dispersion must be solved in production, which not only increases the process cost, but also affects the optical properties of the finished product if the dispersion effect is poor.

In recent years, with the development trend of electronic products becoming thinner and smaller, there is still a demand for ultra-thin matte polyimide films. Therefore, the conventional method of manufacturing ultra-thin films is limited by the particle size of the matte particles themselves. If the original matte properties need to be maintained, the amount of small-sized matte particles needs to be increased, which will also affect the appearance quality of the finished product.

In order to improve the above problems, the present invention is a matte polyimide film and a method for manufacturing the same, which can have a matte effect without adding a matte agent.

The present invention is a method for manufacturing a matte polyimide film, which includes the following steps: providing an insoluble polyamide solution, which is formed by polymerization of aromatic dianhydride and aromatic diamine; providing a soluble polyimide, whose solubility is between 3% and 30%, and whose weight accounts for 5% to 25% of the film, adding the soluble polyimide to the insoluble polyamide solution to form a polyamide mixed solution; and chemically cyclizing the polyamide solution to generate phase separation to form a matte polyimide film with a 60-degree gloss less than 60GU.

S1: Provide an insoluble polyamine solution

S2: Provide a soluble polyimide

S3: Form a polyamine mixed solution

S4: Forming a polyimide precursor mixture

S5: Forming a matte polyimide film

Figure 1 is a flow chart of the method for manufacturing the matte polyimide film of the present invention.

The present invention discloses a matte polyimide film and a method for manufacturing the same, the method comprising the following steps:

An insoluble polyamide solution (S1) is provided, which is formed by polymerization of aromatic dianhydride and aromatic diamine.

Provide a soluble polyimide (S2) with a solubility of 3-30% and a weight of 5-45wt% of the film.

The soluble polyimide is added to the insoluble polyamide solution to form a polyamide mixed solution (S3).

The polyamine mixed solution is chemically cyclized to form a polyimide precursor mixed solution (S4).

The polyimide precursor mixture is coated and baked to form a matte polyimide film (S5) with a glossiness of less than 60GU at 60 degrees.

The soluble polyimide is obtained by polymerization of dianhydride and diamine, and the dianhydride can be an aromatic dianhydride or an aliphatic dianhydride. The aromatic dianhydride can be any one of 3,3',4,4'-biphenyltetracarboxylic dianhydride, hexafluorodianhydride, bisphenol A type diether dianhydride, 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride or a combination of more than one. The aliphatic dianhydride can be cyclobutanetetracarboxylic dianhydride.

The diamine of the soluble polyimide can be 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminodiphenyl ether, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 3,5-diaminobenzoic acid, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, or a combination of one or more thereof.

The matte polyimide film may also include low-conductive carbon black or pigment.

Preparation of insoluble polyamine solution

Insoluble polyamine solution is composed of aromatic dianhydride and aromatic diamine. The dianhydride component and the diamine component are polymerized in an organic solvent to form an insoluble polyamine solution.

The aforementioned aromatic dianhydride is preferably pyromellitic dianhydride (PMDA).

The aforementioned aromatic diamine is preferably p-phenylenediamine (PDA) or 4,4'-diaminodiphenyl ether (ODA).

The aforementioned organic solvents may include dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL), and N,N-dimethylformamide (DMF). The present invention uses dimethylacetamide as a solvent.

Preparation of soluble polyimide

Soluble polyamine is composed of dianhydride and diamine. The dianhydride component and the diamine component are polymerized in an organic solvent to form soluble polyamine.

The aforementioned organic solvents may include dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL), and N,N-dimethylformamide (DMF). The present invention uses dimethylacetamide as a solvent.

The aforementioned dianhydride is selected from any one or a combination of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), hexafluorodianhydride (6FDA), bisphenol A diether dianhydride (BPADA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), and cyclobutanetetracarboxylic dianhydride (CBDA).

The diamine is selected from 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 3,4'-diaminodiphenyl ether (3,4ODA), 4,4'-bis(3-aminophenoxy)diphenylsulfone (m-BAPS), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 1,4-bis(4-aminophenoxy)benzene (TPE-Q), 1,3- Bis(4-aminophenoxy)benzene (TPE-R), 1,3-bis(3-aminophenoxy)benzene (APB-N), 3,5-diaminobenzoic acid (3,5DABA), 3,3'-diaminodiphenyl sulfone (3,3DSS), 4,4'-diaminodiphenyl sulfone (4,4DDS), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (FAPB) or a combination of any one or more thereof.

The solubility of the aforementioned soluble polyimide is 3~30%. Solubility is defined as the weight of the solute that can be dissolved in every 100 grams of solvent. The generally accepted solubility value is:

Production of black pulp

Mix carbon black and dimethylacetamide in a weight ratio of 1:7 to form a solution. Stir evenly and vibrate with an ultrasonic vibrator for 1 hour to complete the black slurry.

The carbon black in the aforementioned black slurry is insulating carbon black, and Evonik SPECIAL BLACK 4A (SB4A) insulating carbon black is used in the present invention.

The weight ratio of carbon black and dimethylacetamide in the aforementioned black slurry can be adjusted according to demand. The weight ratio of carbon black is related to the penetration. The amount of carbon black added in the present invention ranges from 2 to 8 wt% of the matte polyimide film.

Preparation of matte polyimide film

The aforementioned insoluble polyamide solution, soluble polyimide and black slurry are mixed, stirred evenly, and then a catalyst and a dehydrating agent are added for chemical cyclization to obtain a polyimide precursor mixture, which is then coated on a glass substrate and baked to obtain a matte polyimide film.

In the aforementioned film-making process, in addition to glass substrates, metal plates can also be used as substrates.

The aforementioned matte polyimide film can have a film thickness of 5~100um.

The perception of the matte effect varies from person to person. The generally acceptable 60-degree glossiness is 30~80GU. The matte effect defined in the present invention is less than 60GU at 60-degree glossiness. The matte polyimide film has the effect of matte.

The aforementioned soluble polyimide accounts for at least 5wt% of the polyimide film.

The aforementioned matte polyimide film may be added with fillers, which are selected from: at least one or a combination of silicon dioxide, titanium dioxide, boron nitride, aluminum oxide, and polyimide powder.

The aforementioned catalyst can be pyridine, 3-methylpyridine, 2-methylpyridine, 4-methylpyridine, isoquinoline, quinoline, triethylamine, among which pyridine, 3-methylpyridine, 2-methylpyridine, 4-methylpyridine are preferably selected. In the present invention, 3-methylpyridine is selected as the catalyst.

The aforementioned dehydrating agent can be acetic anhydride or benzoic anhydride. In the present invention, acetic anhydride is selected as the dehydrating agent.

The present invention uses a chemical ring-closing method to obtain a matte polyimide film, and its matte effect is better than that of a thermal ring-closing method.

Add dehydrating agent and catalyst to the insoluble polyamide solution to make the insoluble polyimide solution cyclize to form insoluble polyimide. Because the insoluble polyimide cannot be dissolved in organic solvents, while soluble polyimide can be dissolved in organic solvents. The solubility of the two is different. When the organic solvent decreases during the baking process, the insoluble polyimide and the soluble polyimide are separated, resulting in a matte effect on the surface of the polyimide film.

The present invention is specifically described based on the embodiments, but the present invention is not limited thereto. Furthermore, the abbreviations and full names of the components of the present invention are as follows:

Dianhydride:

PMDA: pyromellitic dianhydride

BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride

6FDA: Hexafluorodianhydride

BPADA: Bisphenol A diether dianhydride

CBDA: Cyclobutanetetracarboxylic dianhydride

Diamine:

PDA: p-phenylenediamine

ODA: 4,4'-diaminodiphenyl ether

3,4ODA: 3,4'-diaminodiphenyl ether

TFMB: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl

m-BAPS: 4,4'-bis(3-aminophenoxy)diphenylsulfone

Solvent:

DMAc: dimethylacetamide

AA: Acetic anhydride

AP: 3-methylpyridine

Raw materials for black pulp:

Carbon black: SPECIAL BLACK 4A (SB4A), manufactured by Evonik

Solubility measurement

Solubility is measured as the weight of the solute that can be dissolved in every 100 grams of solvent. Take 3 grams and 10 grams of the soluble polyimide obtained in the following preparation example and add them to 100 grams of DMAc solvent to determine its dissolution status.

The dissolution condition is expressed as the degree using the following table codes:

<Testing method>

The various properties of the composite membranes obtained in the following examples were measured using the following methods.

Gloss: Use BYK brand, model micro-TRI-gloss gloss meter to measure gloss at 60 degrees.

[Example 1]

Preparation of soluble polyimide

Add 10.9g of TFMB to 75g of DMAc, stir and mix, add 2.003g of BPDA after TFMB is dissolved, add 12.097g of 6FDA after BPDA is dissolved, and control the temperature at 25℃ to finally obtain a polyamine solution with a solid content of 25%.

Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 260℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain soluble polyimide.

Preparation of insoluble polyamine solution

Add 8.822g of PDA to 410g of DMAc and stir to mix. After PDA is dissolved, add 14.235g of PMDA. After stirring for 60 minutes, add 30.337g of ODA. After ODA is dissolved, slowly add 35.588g of PMDA. Keep the temperature at 25℃. After stirring for two hours, use a small amount of PMDA to adjust the viscosity. Finally, an insoluble polyamide solution with a solid content of 18% and a viscosity of 157,000cps is obtained.

Preparation of carbon black slurry

Prepare a solution of 1 gram of carbon black and 7 grams of DMAc, stir evenly, and vibrate with an ultrasonic vibrator for 1 hour to prepare a black slurry.

Preparation of matte polyimide film

40 g of insoluble polyamide solution, 0.3956 g of soluble polyimide and 2.532 g of carbon black were mixed evenly, and then AA and DMAc were diluted at a weight ratio of 5:1, and AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85 ml of AA dilution and 4.17 ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

[Example 2]

The preparation of soluble polyimide is the same as Example 1

The preparation of insoluble polyamine solution is the same as Example 1

The preparation of carbon black slurry is the same as Example 1

Preparation of matte polyimide film

After 40 g of insoluble polyamide solution, 1.333 g of soluble polyimide and 2.844 g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85 ml of AA dilution and 4.17 ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

[Example 3]

The preparation of soluble polyimide is the same as Example 1

The preparation of insoluble polyamine solution is the same as Example 1

The preparation of carbon black slurry is the same as Example 1

Preparation of matte polyimide film

After 40 g of insoluble polyamide solution, 1.8947 g of soluble polyimide and 3.032 g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85 ml of AA dilution and 4.17 ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

[Example 4]

The preparation of soluble polyimide is the same as Example 1

The preparation of insoluble polyamine solution is the same as Example 1

The preparation of carbon black slurry is the same as Example 1

Preparation of matte polyimide film

After 40 g of insoluble polyamide solution, 1.8947 g of soluble polyimide and 3.032 g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85 ml of AA dilution and 4.17 ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

[Example 5]

The preparation of soluble polyimide is the same as Example 1

Preparation of insoluble polyamine solution

Add 8.031g of PDA to 410g of DMAc and stir to mix. After PDA is dissolved, add 31.213g of BPDA. After stirring for 60 minutes, add 27.616g of ODA. After it is dissolved, slowly add 22.446g of PMDA. Control the temperature at 25℃. After stirring for two hours, use a small amount of PMDA to adjust the viscosity. Finally, an insoluble polyamide solution with a solid content of 18% and a viscosity of 157,000cps is obtained.

The preparation of carbon black slurry is the same as Example 1

Preparation of matte polyimide film

After 40 g of insoluble polyamide solution, 1.333 g of soluble polyimide and 2.844 g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.24 ml of AA dilution and 3.79 ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

Immerse the glass substrate in water to peel off the matte polyimide film from the glass substrate. The film thickness is 15μm.

[Example 6]

The preparation of soluble polyimide is the same as Example 1

Preparation of insoluble polyamine solution

Add 8.787g of PDA to 410g of DMAc and stir to mix. After PDA is dissolved, add 15.040g of PMDA. Stir for 60 minutes and then add 30.218g of ODA. After it is dissolved, add 1.366g of BPDA. After it is dissolved, slowly add 33.575g of PMDA. Keep the temperature at 25℃. After stirring for two hours, use a small amount of PMDA to adjust the viscosity. Finally, an insoluble polyamide solution with a solid content of 18% and a viscosity of 207,000cps is obtained.

The preparation of carbon black slurry is the same as Example 1

Preparation of matte polyimide film

After 40 g of insoluble polyamide solution, 1.333 g of soluble polyimide and 2.844 g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.83 ml of AA dilution and 4.15 ml of AP dilution were added respectively. After uniform mixing, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300 μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

Immerse the glass substrate in water to peel off the matte polyimide film from the glass substrate. The film thickness is 15μm.

[Example 7]

Preparation of soluble polyimide

Add 10.472g of TFMB to 75g of DMAc, stir and mix, add 14.528g of 6FDA after TFMB is dissolved, and control the temperature at 25℃ to finally obtain a polyamine solution with a solid content of 25%

Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 260℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain soluble polyimide.

The preparation of insoluble polyamine solution is the same as Example 1

[00100] Preparation of carbon black slurry is the same as in Example 1

【00101】The preparation of matte polyimide film is the same as Example 1

[Example 8]

【00102】Preparation of soluble polyimide

【00103】Add 12.501 g of TFMB to 75 g of DMAc, stir and mix, add 3.828 g of CBDA after TFMB is dissolved, add 8.671 g of 6FDA after CBDA is dissolved, and control the temperature at 25°C to finally obtain a polyamine solution with a solid content of 25%.

【00104】Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 260℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain soluble polyimide.

[00105] The preparation of insoluble polyamine solution is the same as in Example 1

[00106] Preparation of carbon black slurry is the same as in Example 1

【00107】The preparation of matte polyimide film is the same as Example 1

[Example 9]

【00108】Preparation of soluble polyimide

【00109】Add 12.332g of m-BAPS to 75g of DMAc, stir and mix, add 12.668g of 6FDA after m-BAPS is dissolved, and control the temperature at 25°C to finally obtain a polyamide solution with a solid content of 25%.

【00110】Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 260℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain soluble polyimide.

[00111] The preparation of insoluble polyamine solution is the same as in Example 1

【00112】The preparation of carbon black slurry is the same as in Example 1

【00113】The preparation of matte polyimide film is the same as Example 1

[Example 10]

【00114】Preparation of soluble polyimide

【00115】Add 6.946g of 3,4ODA to 75g of DMAc, stir and mix, add 18.054g of BPADA after 3,4ODA is dissolved, and control the temperature at 25℃ to finally obtain a polyamine solution with a solid content of 25%.

【00116】Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 260℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain soluble polyimide.

[00117] The preparation of insoluble polyamine solution is the same as in Example 1

[00118] Preparation of carbon black slurry is the same as in Example 1

【00119】The preparation of matte polyimide film is the same as Example 1

【Comparison Example 1】

【00120】Preparation of soluble polyimide

【00121】Add 8.615g of ODA to 82g of DMAc, stir and mix, add 9.338g of PMDA after ODA is dissolved, and control the temperature at 25°C to finally obtain a polyamine solution with a solid content of 18%.

【00122】Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 350℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain polyimide.

【00123】The solubility test of the polyimide completed above showed that the polyimide could not be dissolved in DMAc, so the subsequent steps could not be carried out.

【Comparison Example 2】

【00124】Preparation of soluble polyimide

【00125】Add 1.764 g of PDA to 82 g of DMAc, stir and mix, add 6.067 g of ODA after PDA is dissolved, add 10.016 g of PMDA after ODA is dissolved, and control the temperature at 25°C to finally obtain a polyamide solution with a solid content of 18%.

【00126】Pour the polyamide solution onto the glass substrate and apply it using a scraper with a gap of 900μm. The applied sample is placed in an oven at 80℃ for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, then heated to 350℃ at a rate of 2.0℃/min and baked for 20 minutes to obtain a polyimide film.

【00127】The solubility test of the polyimide completed above showed that the polyimide could not be dissolved in DMAc, so the subsequent steps could not be carried out.

【Comparison Example 3】

[00128] The preparation of soluble polyimide is the same as Example 1

[00129] The preparation of insoluble polyamine solution is the same as in Example 1

【00130】Preparation of matte polyimide film

【00131】40g of insoluble polyamide solution and 0.1532g of soluble polyimide were mixed with 2.451g of carbon black slurry, and then AA and DMAc were diluted at a weight ratio of 5:1, and AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85ml of AA dilution and 4.17ml of AP dilution were added respectively. After uniform stirring, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

【00132】The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

【Comparison Example 4】

[00133] Preparation of soluble polyimide is the same as Example 1

[00134] The preparation of insoluble polyamine solution is the same as in Example 1

【00135】Preparation of matte polyimide film

【00136】After 40g of insoluble polyamide solution, 3.2727g of soluble polyimide and 3.491g of carbon black slurry were mixed evenly, AA and DMAc were diluted at a weight ratio of 5:1, AP and DMAc were diluted at a weight ratio of 1:1, and then 6.85ml of AA dilution and 4.17ml of AP dilution were added respectively. After uniform mixing, a centrifugal degasser was used for degassing, and the degassing solution was poured onto a glass substrate and coated using a scraper with a gap of 300μm. Place the coated sample in an oven at 80℃ for 20 minutes, then heat it up to 170℃ at a rate of 1.8℃/min and bake it for 20 minutes, then heat it up to 350℃ at a rate of 2.0℃/min and bake it for 20 minutes to form a matte polyimide film.

[00137] The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15μm.

【Comparison Example 5】

[00138] Preparation of soluble polyimide is the same as Example 1

[00139] The preparation of insoluble polyamine solution is the same as in Example 1

【00140】Preparation of matte polyimide film

【00141】After 40g of polyamide solution, 7.8261g of soluble polyimide and 5.009g of carbon black slurry were mixed evenly, defoamed using a centrifugal defoamer, and the defoamed solution was poured onto a glass substrate and coated using a scraper with a gap of 200μm. The coated sample was placed in an 80℃ oven for 20 minutes, then heated to 170℃ at a rate of 1.8℃/min and baked for 20 minutes, and then heated to 350℃ at a rate of 2.0℃/min and baked for 20 minutes to form a matte polyimide film.

[00142] The glass substrate was immersed in water to peel off the matte polyimide film from the glass substrate. The film thickness was 15 μm.

[00143] The results of the embodiment and the comparative example are summarized in Table 1.

【00144】It is shown in the embodiment and comparative examples 1 and 2 that a soluble polyimide with good solubility is selected and added to an insoluble polyamide solution, and a polyimide film with low gloss can be obtained after film formation by chemical cyclization.

[00145] As shown in Examples 1 to 4, the higher the proportion of soluble polyimide added within a specific range, the lower the glossiness. On the contrary, if it exceeds the specific range, the glossiness increases.

[00146] The contents of the above specific embodiments are for the purpose of describing the present invention in detail. However, such embodiments are for illustrative purposes only and are not intended to limit the present invention. A person skilled in the art can understand that various changes or modifications made to the present invention without departing from the scope defined by the scope of the attached patent application are part of the present invention.

S1: Provide an insoluble polyamine solution

S2: Provide a soluble polyimide

S3: Form a polyamine mixed solution

S4: Forming a polyimide precursor mixture

S5: Forming a matte polyimide film

Claims (9)

A method for preparing a matte polyimide film comprises the following steps: providing an insoluble polyamide solution, which is prepared by mixing aromatic dianhydride and aromatic diamine in dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL), N,N-dimethylformamide (DMF) or a combination thereof; The method comprises the steps of polymerizing in an organic solvent; providing a soluble polyimide having a solubility of 3-30% and a weight of 5-25% of the film, adding the soluble polyimide into the insoluble polyamide solution to form a polyamide mixed solution; and chemically cyclizing the polyamide solution to generate phase separation to form a 60-degree glossiness extinction polyimide film less than 60GU. As described in the first item of the patent application, the method for producing a matte polyimide film, the soluble polyimide is obtained by polymerization of dianhydride and diamine. As described in item 2 of the patent application, the method for producing a matte polyimide film, wherein the dianhydride can be an aromatic dianhydride or an aliphatic dianhydride. As described in item 3 of the patent application, the method for manufacturing a matte polyimide film, wherein the aromatic dianhydride can be any one or a combination of 3,3',4,4'-biphenyltetracarboxylic dianhydride, hexafluoro dianhydride, bisphenol A type diether dianhydride, 3,3',4,4'-dibenzophenone tetracarboxylic dianhydride. As described in item 3 of the patent application, the method for producing a matte polyimide film, wherein the aliphatic dianhydride may be cyclobutanetetracarboxylic dianhydride. The method for producing a matte polyimide film as described in item 2 of the patent application, wherein the diamine can be an aromatic diamine or an aliphatic diamine. The method for producing a matte polyimide film as described in item 6 of the patent application, wherein the aromatic diamine can be any one or more of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminodiphenyl ether, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 3,5-diaminobenzoic acid, bis-(4-amino-2-methylthio-thiazol-5-yl)-one, 1,4-bis(4-amino-2- trifluoromethylphenoxy)benzene. A matte polyimide film made by the manufacturing method of item 1 of the patent application, comprising: an insoluble polyimide formed by polymerization of aromatic dianhydride and aromatic diamine; a soluble polyimide, the weight of which accounts for at least 5-25wt% of the film; and the 60 degree gloss of the polyimide film is less than 60GU. The matte polyimide film as described in Item 8 of the patent application, wherein the film may include carbon black, and the carbon black accounts for 2-8wt% of the film.

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