Method for manufacturing polyimide film with reduced glossiness

Abstract

The invention discloses a manufacturing method of a polyimide film capable of reducing glossiness, which comprises the following steps: a diamine monomer and a dianhydride monomer are polymerized in a solvent to form a polyimide precursor solution, the diamine comprises 4, 4 '-diaminodiphenyl ether (4, 4'-diaminodiphenyl ether), and the dianhydride monomer comprises a dianhydride monomer; the diamine accounts for 10-45% of the total molar ratio of the diamine, the p-phenylenediamine (p-PDA) accounts for 90-55% of the total molar ratio of the diamine, and the dianhydride comprises pyromellitic dianhydride (PMDA) accounting for 10-50% of the total molar ratio of the dianhydride and 3, 3 ', 4, 4'-biphenyl tetracarboxylic dianhydride (BPDA) accounting for 90-50% of the total molar ratio of the dianhydride; a dehydrating agent and a catalyst are added into the polyimide precursor solution, a carrier is coated with the polyimide precursor solution, a polyimide wet film is formed, the equivalent number of the dehydrating agent ranges from 2 to 5, and the Young's modulus of the polyimide wet film ranges from 230 Kgf / mm to 350 Kgf / mm; providing an embossing wheel, and rolling the polyimide wet film at the temperature of 140-200 DEG C and the pressure of 3-10Kgf / cm < 2 >, so that a concave-convex shape is formed on the surface of the polyimide wet film; and baking the wet film to form a polyimide film with 60 glossiness less than 100.

Description

Technical Field

[0001] The present application relates to the technical field of polyimide films, and in particular to a method for manufacturing a polyimide film with reduced gloss. Background Art

[0002] Flexible copper clad laminate (FCCL) is widely used in the electronics industry as a circuit board (PCB). In addition to being light, thin and flexible, FCCL also has excellent electrical and thermal properties using polyimide film. Its low dielectric constant (Dk) allows for rapid transmission of electrical signals, good thermal properties make it easy to cool down components, and a higher glass transition temperature (Tg) allows components to operate well at higher temperatures.

[0003] However, polyimide films usually have high surface flatness, so that most of the incident light is reflected to produce high gloss. In addition, the large amount of reflected light generated by the high-gloss polyimide film irradiated on its surface may cause visual discomfort or easily cause eye fatigue when watching for a long time. In addition, low-gloss PI film is often used in the substrate and coverlay of flexible printed circuit boards, etc., and is often used for alignment in the back-end process. Such flexible printed circuit boards are widely used in 3C products, optical lens modules, LCD modules, etc.; in addition, low gloss can make the appearance of the component more textured and beautiful.

[0004] The general method to reduce the glossiness of polyimide film is to add particles as a matting agent. In addition to increasing the material cost, adding a large amount of matting agent will cause the polyimide film material itself to be brittle and crack.

[0005] Some will directly emboss the polyimide resin. This method usually requires the use of cyclized polyimide resin through thermoforming. For example, the patent TW201510000A proposes to prepare a cyclized polyimide resin from alicyclic diamines and aromatic diacids, and then make a film-like body at a temperature below 360°C, and then use embossing to form a concave-convex surface. The mechanical strength of this type of thermoplastic polyimide resin is usually low. After being processed into a film, it often cannot achieve good thermal and mechanical properties, which will cause many inconveniences in use.

[0006] Directly forming a concave-convex surface on a polyimide wet film to form a polyimide film with reduced glossiness can not only greatly reduce costs, but also will not reduce the mechanical strength of the polyimide film itself. This method is indeed a problem that the industry can consider. Summary of the invention

[0007] In order to solve the above-mentioned deficiencies in the art, the present application aims to provide a method for manufacturing a polyimide film with reduced gloss, which comprises providing a diamine monomer and a dianhydride monomer for polymerization in a solvent to form a polyimide precursor solution,

[0008] The diamine comprises 4,4'-diaminodiphenyl ether (4,4'-ODA) accounting for 10-45% of the total molar ratio of the diamine and p-phenylenediamine (p-PDA) accounting for 90-55% of the total molar ratio of the diamine.

[0009] The dianhydride comprises 10-50% of the total molar ratio of pyromellitic dianhydride (PMDA) and 90-50% of the total molar ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA);

[0010] Adding a dehydrating agent and a catalyst into the polyimide precursor solution and coating it on a carrier to form a polyimide wet film.

[0011] The Young's modulus of the polyimide wet film is 230-350Kgf / mm;

[0012] Provide an embossing wheel at a temperature of 140-200°C and a pressure of 3-10 Kgf / cm 2 rolling the polyimide wet film to form a concave-convex shape on the surface of the polyimide wet film; and

[0013] The polyimide wet film is baked to form a polyimide film with a glossiness of less than 100. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of a method for manufacturing a polyimide film with reduced glossiness. DETAILED DESCRIPTION

[0015] The technical solution of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0016] It is particularly important to point out that similar substitutions and modifications made to the present application are obvious to those skilled in the art, and they are all deemed to be included in the present application. Relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present application to implement and apply the technology of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments.

[0017] If no specific conditions are specified in this application, the preparation shall be carried out under conventional conditions or the conditions recommended by the manufacturer. The raw materials or excipients used, as well as the reagents or instruments used, for which the manufacturers are not specified, are all conventional products that can be obtained commercially.

[0018] The application is described in detail below.

[0019] The method for preparing a low-gloss polyimide film of the present invention comprises the following steps.

[0020] A diamine monomer and a dianhydride monomer are provided for polymerization in a solvent to form a polyimide precursor solution (S1), wherein the diamine includes a 4,4'-diaminodiphenyl ether (4,4'-ODA) accounting for 10-45% of the total molar ratio of the diamine and p-phenylenediamine (p-PDA) accounting for 90-55% of the total molar ratio of the diamine, and the dianhydride includes a pyromellitic dianhydride (PMDA) accounting for 10-50% of the total molar ratio of the dianhydride and a 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) accounting for 90-50% of the total molar ratio of the dianhydride.

[0021] A dehydrating agent and a catalyst are added to the polyimide precursor solution, wherein the dehydrating agent is in an equivalent amount of 2-5, and the solution is coated on a carrier to form a wet film (S2). The Young's modulus of the wet film is 230-350 Kgf / mm.

[0022] After the wet film is peeled off from the carrier, it is rolled by an embossing wheel with concave-convex shapes and totems at a temperature of 140-200°C and a pressure of 3-10Kgf / cm 2 Next (S3), a concavoconvex shape is formed on the surface of the wet film.

[0023] The wet film is baked to form a polyimide film having a glossiness of less than 100 (S4).

[0024] The solvent may be an aprotic polar solvent, such as dimethylacetamide (DMAC), N,N'-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), and the like.

[0025] The dehydrating agent may be an aliphatic anhydride (such as acetic anhydride and propionic anhydride), an aromatic anhydride (such as benzoic anhydride and phthalic anhydride), etc. The catalyst may be a heterocyclic tertiary amine (such as picoline, pyridine, etc.), an aliphatic tertiary amine (such as triethylamine (TEA)), etc.), an aromatic tertiary amine (such as xylidine, etc.), etc.

[0026] The following examples illustrate the invention in detail.

[0027] Preparation of polyimide precursor solution

[0028] The diamine monomer and the dianhydride monomer are polymerized in a solvent to form polyamic acid, thereby forming a polyimide precursor solution.

[0029] Preparation of polyimide precursor solution A:

[0030] 4.82 g (0.0446 mol) of diamine monomer PDA and 0.99 g (0.0050 mol) of ODA, 1.08 g (0.0050 mol) of dianhydride monomer PMDA and 13.11 g (0.0446 mol) of BPDA were stirred and dissolved in 80.00 g of DMAc solvent to form a polyimide precursor solution A with a solid content of 20 wt %.

[0031] Preparation of polyimide precursor solution B:

[0032] 2.93 g (0.0271 mol) of diamine monomer PDA and 4.44 g (0.0222 mol) of ODA, 5.38 g (0.0246 mol) of dianhydride monomer PMDA and 7.25 g (0.0246 mol) of BPDA were stirred and dissolved in 80.00 g of DMAc solvent to form a polyimide precursor solution B with a solid content of 20 wt %.

[0033] Example 1

[0034] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 7.02ml (2 equivalents) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 140℃, and the pressure of the embossing roller is 3Kgf / cm 2 , the embossing roller speed is 1M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 89GU.

[0035] Example 2

[0036] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 7.02ml (2 equivalents) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2, the embossing roller speed is 1M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 76GU.

[0037] Example 3

[0038] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 6.99ml (2 equivalents) of dehydrating agent and 3.60ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 140℃, and the pressure of the embossing roller is 3Kgf / cm 2 , the embossing roller speed is 1M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 95GU.

[0039] Example 4

[0040] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 6.99ml (2 equivalents) of dehydrating agent and 3.60ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 4M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 82GU.

[0041] Example 5

[0042] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 17.55ml (5 equivalents) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 15 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and roll it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 140℃, and the pressure of the embossing roller is 3Kgf / cm 2 , the embossing roller speed is 4M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 65GU.

[0043] Example 6

[0044] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 17.55ml (5 equivalents) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 15 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 4M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 59GU.

[0045] Example 7

[0046] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 17.47ml (5 equivalents) of dehydrating agent and 3.60ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 15 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 140℃, and the pressure of the embossing roller is 3Kgf / cm 2 The embossing roller speed is 4 M / min; and then the polyimide film with a glossiness of 60 and 72 GU is formed after baking at 350°C for 1 hour.

[0047] Example 8

[0048] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 17.47ml (5 equivalents) of dehydrating agent and 3.60ml (1 equivalent) of catalyst, and then coat it on a carrier or steel belt and bake it at 80℃ for 15 minutes to form a polyimide wet film; then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 4M / min; and then it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 63GU.

[0049] Comparative Example 1

[0050] Take 75 grams of polyimide precursor solution A, add 25 grams of DMAc solvent, stir and dilute to a solid content of 15wt%, add 7.02 milliliters (2 equivalents) of dehydrating agent and 3.61 milliliters (1 equivalent) of catalyst, and then coat it on a carrier or a steel belt and bake it at 80°C for 20 minutes to form a polyimide wet film. After the polyimide wet film is peeled off from the carrier or the steel belt, it is baked at 350°C for 1 hour to form a polyimide film with a glossiness of 60 and 166GU.

[0051] Comparative Example 2

[0052] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, apply it on a carrier or steel belt and bake it at 80℃ for 30 minutes to form a polyimide wet film, then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 1M / min, and film cannot be formed.

[0053] Comparative Example 3

[0054] Take 75g of polyimide precursor solution A, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 3.51ml (1 equivalent) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, apply it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film, then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 1M / min, and film cannot be formed.

[0055] Comparative Example 4

[0056] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, apply it on a carrier or steel belt and bake it at 80℃ for 30 minutes to form a polyimide wet film, then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave and convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 1M / min, and film cannot be formed.

[0057] Comparative Example 5

[0058] Take 75g of polyimide precursor solution B, add 25g of DMAc solvent, stir and dilute to a solid content of 15wt%, add 3.49ml (1 equivalent) of dehydrating agent and 3.61ml (1 equivalent) of catalyst, apply it on a carrier or steel belt and bake it at 80℃ for 20 minutes to form a polyimide wet film, then peel the polyimide wet film from the carrier or steel belt and pass it through an embossing roller with a concave-convex surface. The temperature of the embossing roller is 200℃, and the pressure of the embossing roller is 10Kgf / cm 2 , the embossing roller speed is 1M / min, and film cannot be formed.

[0059] As in the above-mentioned embodiments and comparative examples, the present invention is carried out at a temperature of 140-200°C and a pressure of 3-8 Kgf / cm 2 For the best operating conditions.

[0060] 60 degree gloss value test

[0061] According to ASTM D523, a handheld gloss meter (Micro Tri Gloss-BYKGardner) was used for testing, and the average of three independent measurements was taken.

[0062] Wet film Young's modulus test

[0063] After the wet polyimide film was peeled off from the carrier or the steel belt, the solvent content was 30 wt % and tested with a universal tensile testing machine (model: Tinius Olsen 10ST) according to ASTM D882, and the average of 5 independent measurements was taken.

[0064] Comparison table:

[0065]

[0066] Differences between the comparative example and the embodiment:

[0067] Comparative Example 1 is a polyimide film that is not rolled after film formation, Comparative Example 2 is a polyimide film that does not form a film after rolling under the condition of a thermal dead cycle, and Comparative Example 3 is a polyimide film that does not form a film after rolling under the condition of an insufficient equivalent amount of a dehydrating agent and a catalyst, and is compared with Examples 1, 2, 5, and 6.

[0068] Comparative Example 4 is under the condition of thermal dead cycle, and no film is formed after pressing and rolling; Comparative Example 5 is under the condition when the dehydrating agent and the catalyst are less than the equivalent number, and no film is formed after pressing and rolling, compared with Examples 3, 4, 7, and 8.

[0069] The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for producing a polyimide film with reduced gloss, characterized in that: Included are: A diamine monomer and a dianhydride monomer are polymerized in a solvent to form a polyimide precursor solution, wherein the diamine includes 4,4'-diaminodiphenyl ether (4,4'-ODA) accounting for 10-45% of the total molar ratio of the diamine and p-phenylenediamine (p-PDA) accounting for 90-55% of the total molar ratio of the diamine, and the dianhydride includes pyromellitic dianhydride (PMDA) accounting for 10-50% of the total molar ratio of the dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) accounting for 90-50% of the total molar ratio of the dianhydride; Adding a dehydrating agent and a catalyst into the polyimide precursor solution, wherein the dehydrating agent is 2-5 equivalents, and coating the solution on a carrier to form a polyimide wet film, wherein the Young's modulus of the polyimide wet film is 230-350 Kgf / mm; Provide an embossing wheel at a temperature of 140-200°C and a pressure of 3-10Kgf / cm 2 rolling the polyimide wet film to form a concave-convex shape on the surface of the polyimide wet film; and The polyimide wet film is baked to form a polyimide film with a glossiness of less than 100.

2. The method for producing a polyimide film with reduced glossiness according to claim 1, wherein: The solvent content of the polyimide wet film is 20-40%.

3. The method for producing a polyimide film with reduced glossiness according to claim 1, wherein: The roller speed of the embossing wheel is 1-4 M / min.

4. The method for producing a polyimide film with reduced glossiness according to claim 1, wherein: The temperature of the embossing wheel is 140-180°C and the pressure is 3-8Kgf / cm 2 .

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