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JP-7855560-B2 - Polyamic acid varnish

JP7855560B2JP 7855560 B2JP7855560 B2JP 7855560B2JP-7855560-B2

Inventors

  • ミン・ソク・ヤン
  • ホ・スン・イ
  • イク・サン・イ

Assignees

  • ピーアイ・アドバンスド・マテリアルズ・カンパニー・リミテッド

Dates

Publication Date
20260508
Application Date
20231017
Priority Date
20221017

Claims (7)

  1. A particulate polyimide powder containing a cured polyamic acid varnish, The polyamic acid varnish comprises a polyamic acid having diamine monomers and dianhydride monomers as polymerization units , Multi -walled carbon nanotubes (MWCNTs) are conductive fillers , Contains organic solvents, The polyimide molded article produced by molding the aforementioned polyimide powder is a polyimide powder having a tensile strength of 80 MPa or more and an elongation of 4% or more, as measured by the ASTM D-1708 method.
  2. The polyimide powder according to claim 1, wherein the content of the conductive filler is in the range of 0.1 to 50% by weight based on the total polyamic acid varnish.
  3. The polyimide powder according to claim 1, wherein the dianhydride monomer comprises at least one compound represented by the following chemical formula 1. In the aforementioned chemical formula 1, This is a tetravalent aliphatic ring group, a tetravalent heteroaliphatic ring group, a tetravalent aromatic ring group, or a tetravalent heteroaromatic ring group, wherein the carbon atoms of the carbonyl group of chemical formula 1 are linked to the ring constituent atoms of the aliphatic ring group, heteroaliphatic ring group, aromatic ring group, or heteroaromatic ring group. The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group may be monocyclic or The rings are either fused rings or linked by linking groups that include at least one divalent substituent selected from the group consisting of single bonds, substituted or unsubstituted alkylene groups, substituted or unsubstituted alkylidene groups, substituted or unsubstituted alkenylene groups, substituted or unsubstituted alkylylene groups, substituted or unsubstituted arylene groups, -O-, -S-, -C(=O)-, -S(=O) ²- , and -Si( Rb ) ²- , where Rb is hydrogen or an alkyl group.
  4. The aforementioned X is or an aliphatic ring group, The polyimide powder according to claim 3, wherein M is at least one from the group comprising a single bond, an alkylene group, an alkylidene group, O, S, C(=O), and S(=O) 2 .
  5. The polyimide powder according to claim 1, wherein the diamine monomer comprises at least one compound represented by the following chemical formula 2. In the chemical formula 2 described above, any of B1 to B5 is an amino group ( -NH2 ), -R- NH2 , or -O-R- NH2 , where R is a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted alkenylene group, a substituted or unsubstituted alkylylene group, or a substituted or unsubstituted arylene group, and the remainder represents hydrogen, a halogen, a hydroxyl group, a carboxyl group, or an alkyl group substituted or unsubstituted to a halogen.
  6. A polyimide molded article comprising the polyimide powder described in claim 1 , The aforementioned polyimide molded article is a polyimide molded article having a tensile strength of 80 MPa or more and an elongation of 4% or more, as measured by the ASTM D-1708 method.
  7. The steps include dispersing multi-walled carbon nanotubes (MWCNTs) as conductive fillers in an organic solvent, A step of polymerizing diamine monomers and dianhydride monomers in an organic solvent in which conductive fillers are dispersed, The steps include: obtaining polyimide powder by thermal curing the polymer obtained in the polymerization step, The step includes molding the obtained polyimide powder to produce a polyimide molded product, The method for manufacturing a polyimide molded article, wherein the polyimide molded article has a tensile strength of 80 MPa or more and an elongation of 4% or more, as measured by the ASTM D-1708 method.

Description

This application relates to polyamic acid varnish, polyimide powder, polyimide molded articles, a method for producing polyamic acid varnish, a method for producing polyimide powder, and a method for producing polyimide molded articles. Generally, polyimide (PI) is a polymer of imide monomers formed by solution polymerization of dianhydride and diamine or diisocyanate. Based on the chemical stability of the imide ring, it possesses excellent mechanical properties such as strength, chemical resistance, weather resistance, and heat resistance. Furthermore, polyimide is attracting attention as a high-performance polymer material applicable to a wide range of industrial fields, including electronics, communications, and optics, due to its excellent electrical properties such as insulation and low dielectric constant. In recent years, the demand for conductive polyimide has increased in the semiconductor field due to static electricity problems in production equipment. Conventionally, conductive polyimide powder was produced by dry mixing powdered polyimide and conductive fillers, and then appropriately molded and processed according to the application. However, dry mixing has the drawback of making it difficult to achieve uniform mixing of polyimide powder and conductive filler, resulting in frequent defects during molding, reduced processability, and lower expected physical properties such as tensile strength, elongation, and modulus of elasticity. The present invention will be described in more detail below through examples and comparative examples not based on the present invention, but the scope of the present invention is not limited by the following examples. Example 1 A Dean-Stark trap was installed in a 1000 ml reactor equipped with a stirrer and a nitrogen injection/discharge pipe. While injecting nitrogen, 10% by weight of carbon black was added as a conductive filler to a solvent of N-methyl-2-pyrrolidone (NMP) and m-cresol mixed in an 8:2 weight ratio, based on the total polyamic acid varnish, and dispersed by sonication. After heating the solvent containing the dispersed conductive filler to 75°C, 100 moles of 4,4'-diaminodiphenyl ether (ODA) were added and completely dissolved. Subsequently, 80 moles of pyromellitic dianhydride (PMDA) were added per 100 moles of ODA, and 20 moles of oxydiphthalic dianhydride (OPDA) were added per 100 moles of ODA. The mixture was reacted at 75°C for 2 hours to produce a polyamic acid varnish with uniformly dispersed conductive filler. Subsequently, the polyamic acid varnish was heated to 200°C while stirring, and then heated for another 2 hours to precipitate polyimide powder. Examples 2-6 Polyimide powder was precipitated in the same manner as in Example 1, except that the monomer components, solvent, and conductive filler were adjusted as shown in Table 1 below. Comparative Examples 1-4 Polyimide powder was precipitated in the same manner as in Example 1, except that conductive fillers were not used and the monomer components, solvent, and catalyst were adjusted, as shown in Table 1 below. In Table 1 below, the methods for mixing conductive fillers are described as follows: "Dispersion mixing" in Examples 1-7 refers to the method of mixing the conductive filler with the solvent via ultrasonic treatment during the polyamic acid polymerization stage, as in Example 1. "Dry mixing" in Comparative Examples 1-4 refers to the method of polymerizing polyamic acid without using conductive fillers, imidizing it to precipitate polyimide powder, and then mechanically mixing the precipitated polyimide powder with the conductive filler. Experimental Example 1 - Processability Examples and Comparative Examples: Molded products were prepared by HCM molding of polyimide powders, and then processed into dogbon-like shapes to produce samples. The appearance of the samples was visually observed to confirm the presence or absence and number of cracks. Specifically, samples were divided into cases where no cracks occurred and cases where cracks occurred in a 10 cm x 10 cm area. If cracks occurred, the samples were further divided into "few cracks" and "many cracks" based on the number of cracks, as described below. O: No cracks △: 1-5 cracks (few cracks) X: The number of cracks exceeds 5 (there are many cracks). Experimental Example 2 - Surface Resistance The surface resistance of molded articles obtained by HCM molding of the polyimide powders of the Examples and Comparative Examples was measured using an Advanced Energy/Trek 152-1 and an ASTM D-257. The measurement temperature was set to 23±3°C, and the Source Voltage was set to 10V. Experimental Example 3 - Measurement of Elongation and Tensile Strength After HCM molding of the polyimide powders of the Examples and Comparative Examples, they were processed into dogbone shapes with a length of 38 mm and a width of 15 mm, and the elongation and tensile strength were measured using the ASTM D-1708 method with Instron UTM equipment fr