Search

CN-122029217-A - Method for producing polyimide resin

CN122029217ACN 122029217 ACN122029217 ACN 122029217ACN-122029217-A

Abstract

Provided is a method for producing a polyimide resin, which can produce a polyimide resin having excellent heat resistance and excellent colorless transparency after heat treatment. A method for producing a polyimide resin, wherein a tetracarboxylic dianhydride (a) is polymerized with a diamine (b) and imidized, wherein the tetracarboxylic dianhydride (a) contains at least 1 selected from the group consisting of a compound represented by the following formula (a 1), a compound represented by the following formula (a 2), a compound represented by the following formula (a 3), a compound represented by the following formula (a 4), a compound represented by the following formula (a 5) and a compound represented by the following formula (a 6), and wherein the diamine (b) contains a compound represented by the following formula (b 1), and the content of chloride ions is less than 2.0 mass ppm relative to the compound represented by the following formula (b 1).

Inventors

  • HOSHINO SHUN
  • MURATANI TAKAHIRO

Assignees

  • 三菱瓦斯化学株式会社

Dates

Publication Date
20260512
Application Date
20241003
Priority Date
20231019

Claims (11)

  1. 1. A process for producing a polyimide resin, wherein a tetracarboxylic dianhydride a and a diamine b are polymerized and imidized, The tetracarboxylic dianhydride a contains at least 1 selected from the group consisting of a compound represented by the following formula (a 1), a compound represented by the following formula (a 2), a compound represented by the following formula (a 3), a compound represented by the following formula (a 4), a compound represented by the following formula (a 5) and a compound represented by the following formula (a 6), The diamine b contains a compound represented by the following formula (b 1), the content of chloride ions is less than 2.0 mass ppm relative to the compound represented by the following formula (b 1), 。
  2. 2. The method for producing a polyimide resin according to claim 1, comprising a step of preparing a raw material containing the compound represented by the formula (b 1) as a raw material having a chloride ion content of less than 2.0 mass ppm.
  3. 3. The method for producing a polyimide resin according to claim 1 or 2, comprising the step of measuring the content of chloride ions in a raw material containing the compound represented by the formula (b 1), and selecting a raw material having a chloride ion content of less than 2.0 mass ppm.
  4. 4. The method for producing a polyimide resin according to any one of claims 1 to 3, comprising the step of preparing a raw material containing the compound represented by the formula (b 1) in a content of 99.9% or more.
  5. 5. The method for producing a polyimide resin according to any one of claims 1 to 4, comprising the step of measuring the content of the compound represented by the formula (b 1) in a raw material containing the compound represented by the formula (b 1), and selecting a raw material having a content of the compound represented by the formula (b 1) of 99.9% or more.
  6. 6. The method for producing a polyimide resin according to any one of claims 1 to 5, comprising the steps of polymerizing a tetracarboxylic dianhydride a and a diamine b to obtain a polyamic acid or an imide-amic acid copolymer as a polyimide resin precursor, and imidizing the polyimide resin precursor to obtain a polyimide resin.
  7. 7. The method for producing a polyimide resin according to claim 6, wherein the step 1 comprises the following step 1a and the following step 1b, and is a step of obtaining an imide-amic acid copolymer as a polyimide resin precursor, Step 1a, a step of reacting tetracarboxylic dianhydride with diamine in the presence of a solvent to obtain an imide oligomer, Step 1b, mixing and polymerizing the imide oligomer obtained in step 1a with at least one selected from the group consisting of tetracarboxylic dianhydrides and diamines.
  8. 8. The method for producing a polyimide resin according to any one of claims 1 to 7, wherein the ratio of the compound represented by the formula (b 1) in the diamine b is 95 mol% or more based on the total amount of the diamine b.
  9. 9. The method for producing a polyimide resin according to any one of claims 1 to 8, wherein neither the tetracarboxylic dianhydride a nor the diamine b contains fluorine atoms.
  10. 10. A polyimide resin obtained by polymerizing a tetracarboxylic dianhydride a and a diamine b and imidizing the polymerized tetracarboxylic dianhydride a and the diamine b, The tetracarboxylic dianhydride a contains at least 1 selected from the group consisting of a compound represented by the following formula (a 1), a compound represented by the following formula (a 2), a compound represented by the following formula (a 3), a compound represented by the following formula (a 4), a compound represented by the following formula (a 5) and a compound represented by the following formula (a 6), The diamine b contains a compound represented by the following formula (b 1), the content of chloride ions is less than 2.0 mass ppm relative to the compound represented by the following formula (b 1), 。
  11. 11. A method for producing an image display device substrate, wherein the polyimide resin obtained by the method for producing a polyimide resin according to any one of claims 1 to 9 or the polyimide resin according to claim 10 is molded.

Description

Method for producing polyimide resin Technical Field The present invention relates to a method for producing a polyimide resin. Background Polyimide resins are being studied for various applications in the fields of electric/electronic parts and the like. For example, for the purpose of weight reduction and flexibility of a device, it is desired to replace a glass substrate used in an image display device such as a liquid crystal display or an OLED display with a plastic substrate, and a polyimide film suitable as the plastic substrate is being studied. Polyimide films for such applications are required to have transparency and low yellowness. In this regard, for example, patent document 1 discloses a polyimide precursor characterized by containing 2 specific amic acid structural units at specific ratios for the purpose of obtaining a polyimide film having low residual stress, less warpage, low yellowness and high elongation. Prior art literature Patent literature Patent document 1 International publication No. 2017/051827 Disclosure of Invention Problems to be solved by the invention As described above, the polyimide film for specific applications is required to have transparency and low yellowness. But in the manufacture of TFTs, the device type is LTPS (low temperature polysilicon TFT), which becomes a process temperature exceeding 400 ℃. Polyimide, which is a substrate, is required to have heat resistance to withstand a large number of treatments at a high temperature of 400 ℃ or higher, and to maintain transparency and low yellowness even in such a thermal history. Patent document 1 discloses a technique for reducing residual stress and yellowness, but is insufficient, and in particular, a polyimide film excellent in heat resistance and the like while maintaining transparency and low yellowness cannot be obtained. The present invention has been made in view of such a situation, and an object of the present invention is to provide a method for producing a polyimide resin, which can obtain a polyimide resin having excellent heat resistance and excellent colorless transparency after heat treatment. Solution for solving the problem The present inventors have found that the above problems can be solved by a method for producing a polyimide resin by polymerizing a specific tetracarboxylic dianhydride with a diamine and imidizing the resultant product, and have completed the present invention. Namely, the present invention relates to the following [1] to [11]. [1] A method for producing a polyimide resin, wherein a tetracarboxylic dianhydride (a) is polymerized with a diamine (b) and imidized, wherein the tetracarboxylic dianhydride (a) contains at least 1 selected from the group consisting of a compound represented by the following formula (a 1), a compound represented by the following formula (a 2), a compound represented by the following formula (a 3), a compound represented by the following formula (a 4), a compound represented by the following formula (a 5) and a compound represented by the following formula (a 6), and wherein the diamine (b) contains a compound represented by the following formula (b 1), and the content of chloride ions is less than 2.0 mass ppm relative to the compound represented by the following formula (b 1). [2] The method for producing a polyimide resin according to the above [1], which comprises a step of preparing a raw material containing a compound represented by the formula (b 1) as a raw material having a chloride ion content of less than 2.0 mass ppm. [3] The method for producing a polyimide resin according to the above [1] or [2], which comprises a step of measuring the content of chloride ions in a raw material containing the compound represented by the formula (b 1), and selecting a raw material having a chloride ion content of less than 2.0 mass ppm. [4] The method for producing a polyimide resin according to any one of the above [1] to [3], comprising a step of preparing a raw material containing the compound represented by the formula (b 1) in a content of 99.9% or more as a raw material containing the compound represented by the formula (b 1). [5] The method for producing a polyimide resin according to any one of the above [1] to [4], comprising the step of measuring the content of the compound represented by the formula (b 1) in a raw material containing the compound represented by the formula (b 1), and selecting a raw material having a content of the compound represented by the formula (b 1) of 99.9% or more. [6] The method for producing a polyimide resin according to any one of the above [1] to [5], which comprises a step 1 of polymerizing a tetracarboxylic dianhydride (a) and a diamine (b) to obtain a polyamic acid or an imide-amic acid copolymer as a polyimide resin precursor, and a step 2 of imidizing the polyimide resin precursor to obtain a polyimide resin. [7] The method for producing a polyimide resin according to the above [6], wherein the step 1 comprise