KR-20260067804-A - Method for evaluating surface resistance uniformity of polyimide molded product and polyimide molded products with uniform surface resistance

KR20260067804AKR 20260067804 AKR20260067804 AKR 20260067804AKR-20260067804-A

Abstract

The present invention relates to a method for evaluating the surface resistance uniformity of a polyimide molded article, a polyimide molded article including a conductive filler, and a method for manufacturing the same. The surface resistance uniformity of the polyimide molded article can be measured through the coefficient of variation of the surface resistance value, and provides a high-quality polyimide molded article having a low average surface resistance and a low coefficient of variation of the surface resistance value.

Inventors

이호성
이익상
김태민

Assignees

피아이첨단소재 주식회사

Dates

Publication Date: 20260513
Application Date: 20241106

Claims (9)

A method for evaluating the surface resistance uniformity of a polyimide molded article, comprising the step of measuring the average surface resistance value of the polyimide molded article and the coefficient of variation of the surface resistance value. The coefficient of variation of the above surface resistance value is calculated using the following Equation 1, Evaluation method for surface resistance uniformity of polyimide molded articles: [Equation 1] CV = Coefficient of variation of surface resistance σ = standard deviation of surface resistance μ = average surface resistance
In paragraph 1, The above average surface resistance value is the average of surface resistance values measured at 25 measurement points, which are divided into 25 equal areas based on the upper and lower surfaces where pressure is applied during molding. Method for evaluating surface resistance uniformity of polyimide molded articles.
The coefficient of variation of the surface resistance value measured by the evaluation method of paragraph 1 or 2 is 2.8 or less, and The average surface resistance is 1.0 × 10¹⁰ Ω or less, Polyimide molded product.
In paragraph 3, The coefficient of variation of the above surface resistance value is 1.22 or higher and 1.51 or lower, Polyimide molded product.
In paragraph 3, The above polyimide molded article comprises a polyimide obtained by polymerizing a dianhydride monomer and a diamine monomer, Polyimide molded product.
In paragraph 5, The above dianhydride monomer comprises pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), 4,4-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA), p-phenylenebis(trimellitate anhydride) (TAHQ), or a combination thereof, and The above diamine monomer comprises 4,4'-diaminodiphenyl ether (ODA), 1,4-diaminobenzene (PPD), 1,3-diaminobenzene (MPD), 2,4-diaminotoluene, 2,6-diaminotoluene, 4,4'-methylenediamine (MDA), 4,4-diaminobenzanilide (4,4-DABA), N,N'-bis(4-aminophenyl)benzene-1,4-dicarboxyamide (BPTPA), 2,2-dimethylbenzidine (M-TOLIDINE), 2,2-bis(trifluoromethyl)benzidine (TFDB), 1,4-bisaminophenoxybenzene (TPE-Q), bisaminophenoxybenzene (TPE-R), 2,2-bisaminophenoxyphenylpropane (BAPP), 2,2-bisaminophenoxyphenylhexafluoropropane (HFBAPP), or a combination thereof. Polyimide molded product.
In paragraph 3, The above polyimide molded article includes a conductive filler, Polyimide molded product.
In Paragraph 7, The above conductive filler is carbon nanotube, graphene, carbon black, or a combination thereof. Polyimide molded product.
In Paragraph 7, The above conductive filler is 0.1% by weight or more and 20% by weight or less based on 100% by weight of the total polyimide solid content, Polyimide molded product.

Description

Method for evaluating surface resistance uniformity of polyimide molded product and polyimide molded products with uniform surface resistance The present invention relates to a method for evaluating the uniformity of surface resistance of a polyimide molded article, a polyimide molded article having uniform surface resistance, and a method for manufacturing the same. Generally, polyimide (PI) is a polymer of imide monomers formed by solution polymerization of dianhydrides with diamines or diisocyanates, and possesses mechanical properties such as excellent strength, chemical resistance, weather resistance, and heat resistance based on the chemical stability of the imide ring. In addition, polyimide is gaining attention as a high-performance polymer material applicable to a wide range of industrial fields, such as electronics, telecommunications, or optics, due to its excellent electrical properties, such as insulation properties and low dielectric constant. Meanwhile, as mentioned above, polyimide has electrical properties such as insulating properties and low dielectric constant, but conventional polyimide molded products have a problem of being insulators with high surface resistance (>10 15 ) and a high possibility of charging. To lower the high surface resistance of such conventional polyimide molded products, a technology is being developed to introduce conductive fillers during the manufacturing of polyimide powder; however, in this case, there is a problem in that the resistance distribution of the polyimide molded product becomes uneven due to the pressure during molding. If the resistance distribution of the polyimide molded product is unbalanced and the coefficient of variation is high, the charge is not dispersed in some areas of the polyimide molded product, which may reduce the antistatic effect. In addition, since semiconductor and display production equipment parts manufactured using a portion of polyimide molded products have a direct impact on the quality of semiconductors and displays, if the coefficient of variation of the polyimide molded products is not uniform, it can cause a degradation in the quality of semiconductors and displays. Accordingly, there is a need for a method to evaluate the surface resistance uniformity of polyimide molded articles, as well as a polyimide molded article having a uniform resistance distribution, a low coefficient of variation, and an excellent antistatic effect, and a method for manufacturing the same. Figure 1 is a schematic representation of measuring the surface resistance value of a polyimide molded article. The operation and effects of the invention will be described in more detail below through specific embodiments and drawings. However, these embodiments are merely examples of the invention and do not define the scope of the invention. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Therefore, it should be understood that the configuration of the embodiments described in this specification is merely one of the most preferred embodiments of the present invention and does not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application. In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. Where various parameters in this specification are given as an enumeration of ranges, preferred ranges, preferred upper limits, and preferred lower limits, it should be understood that any pair of any upper range limit or preferred value and any lower range limit or preferred value specifically discloses all ranges formed by any pair of any upper range limit or preferred value, regardless of whether the range is disclosed separately. Where a range of numerical values is mentioned in this specification, unless otherwise described, the range is intended to include its endpoint and all integers and fractions within the range. The scope of the present invention is not intended to be limited to specific values mentioned when defining the scope. In the present specification, "a to b" and "a~b" indicating numerical ranges are defined as ≥a and ≤b. Embodiments of the present invention have been described in detail bel