Polyamic acid varnish

Abstract

To provide a polyamic acid varnish, a polyimide powder, a polyimide molded article, a method of preparing the polyamic acid varnish, a method of preparing the polyimide powder, and a method of manufacturing the polyimide molded article.SOLUTION: The present application provides a polyimide powder in which a conductive filler is uniformly dispersed within particles, and a polyamic acid varnish that is prepared from the powder and capable of implementing a polyimide molded article that not only has excellent moldability and processability, but also has excellent conductivity, tensile strength, elongation, and elastic modulus.SELECTED DRAWING: None

Description

Technical Field

[0001] This application relates to a polyamic acid varnish, a polyimide powder, a polyimide molded product, a method for producing a polyamic acid varnish, a method for producing a polyimide powder, and a method for producing a polyimide molded product.

Background Art

[0002] Generally, polyimide (PI) is a polymer of imide monomers formed by solution polymerization of dianhydrides and diamines or diisocyanates, and has excellent mechanical properties such as strength, chemical resistance, weather resistance, and heat resistance based on the chemical stability of the imide ring. Furthermore, polyimide has excellent electrical properties such as insulation properties and low dielectric constant, and has attracted attention as a high-functional polymer material applicable to a wide range of industrial fields such as electronics, communication, and optics.

[0003] In recent years, due to the electrostatic problem of production equipment in the semiconductor field, the demand for conductive polyimide has been increasing. Conventionally, a conductive polyimide powder was produced by dry-mixing powdery polyimide and a conductive filler, and this was appropriately molded and processed according to the intended use and then used.

[0004] However, dry mixing has problems in that it is difficult to uniformly mix the polyimide powder and the conductive filler, frequent defects occur during molding, the processability deteriorates, and the expected physical property values such as tensile strength, elongation, and elastic modulus become low.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application provides a polyamic acid varnish that can embody a polyimide molded product having excellent conductivity, tensile strength, elongation, and elastic modulus, as well as a polyimide powder in which conductive fillers are uniformly dispersed in particles and excellent moldability and processability, which are produced from the powder.

Means for Solving the Problems

[0007] In this specification, "room temperature" means a temperature that is neither heated nor cooled, and is within the range of approximately 10°C to 30°C, for example, a temperature of approximately 15°C or higher, 18°C ​​or higher, 20°C or higher, or approximately 23°C or higher, but not exceeding approximately 27°C. Unless otherwise specified, the unit of temperature referred to in this specification is Celsius.

[0008] Unless otherwise specified, in cases where the measurement pressure affects the physical properties referred to herein, such physical properties are those measured at normal pressure.

[0009] In this specification, the term "atmospheric pressure" refers to pressure in an unpressurized or unpressurized state, and typically means a pressure of approximately 1 atmosphere, which is at the level of atmospheric pressure.

[0010] Unless otherwise specified, in cases where the measured humidity affects the physical properties referred to herein, the physical properties are those measured at the natural humidity under normal temperature and pressure conditions.

[0011] This application relates to a polyamic acid varnish. The polyamic acid varnish according to the present invention may be a solution in which a polyimide precursor, which is imidized to polyimide through thermal curing, is dissolved in an organic solvent. In the polyamic acid varnish according to this application, polyamic acid is imidized during thermal curing and precipitated in powder form, and the precipitated polyimide powder may have conductive fillers uniformly dispersed within the particles. The polyimide powder obtained in this way not only has excellent moldability and processability during molding, but can also embody polyimide molded articles having excellent conductivity, tensile strength, elongation, and modulus of elasticity.

[0012] An exemplary polyamic acid varnish according to this application comprises a polyamic acid having diamine monomers and dianhydride monomers as polymerization units, a conductive filler, and an organic solvent. The polyamic acid varnish may be formed by polymerizing the diamine monomers and dianhydride monomers in an organic solvent in which the conductive filler is dispersed.

[0013] The polyamic acid varnish according to this application can provide a polyimide powder in which conductive fillers are dispersed within the particles during thermal curing, by introducing conductive fillers during the polymerization stage of polyamic acid. The said polyimide powder not only has excellent moldability and processability during molding, but can also embody polyimide molded articles having excellent conductivity, tensile strength, elongation, and modulus of elasticity.

[0014] The type of organic solvent may be appropriately selected considering conductive fillers and dispersibility, and as an example, it may be an aprotic polar solvent.

[0015] Examples of the aprotic polar solvents include amide solvents such as N,N'-dimethylformamide (DMF), N,N'-diethylformamide (DEF), N,N'-dimethylacetamide (DMAc), or dimethylpropanamide (DMPA); phenolic solvents such as p-chlorophenol and o-chlorophenol; and N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), or diglyme. These may be used individually or in combination of two or more. Considering the dispersibility of conductive fillers, it is preferable to use N,N'-dimethylacetamide (DMAc) or N-methyl-2-pyrrolidone (NMP) as the organic solvent.

[0016] The method for dispersing the conductive filler in the organic solvent is not particularly limited, but it is preferable to use sonication to ensure uniform dispersion. For example, the sonication may be performed using a VCX750 from Sonics & Materials for 30 minutes or more, but this is not particularly limited, and the specific conditions can be changed depending on the type of solvent and conductive filler.

[0017] Furthermore, the polyamic acid varnish according to the present invention may further contain a co-solvent to enhance reaction efficiency. The co-solvent may include at least one selected from the group consisting of m-cresol, naphtha, hexane, heptane, nonane, decane, benzene, toluene, xylene, anisole, cyclohexanone, methyl ethyl ketone, tetrahydrofuran, N-methylpyrrolidone, hexamethylphosphoramide, dioxane, tetramethylurea, triethyl phosphate, trimethyl phosphate, dimethylformamide, dimethyl sulfoxide, and dimethylacetamide.

[0018] In one example, the content of the conductive filler may be in the range of 1 to 50% by weight based on the total polyamic acid varnish. For example, the content of the conductive filler may be in the range of 1 to 45% by weight, 1 to 40% by weight, 1 to 35% by weight, 1 to 30% by weight, 1 to 25% by weight, 1 to 20% by weight, 1 to 15% by weight, 1 to 10% by weight, 3 to 50% by weight, 3 to 45% by weight, 3 to 40% by weight, 3 to 35% by weight, 3 to 30% by weight, 3 to 25% by weight, 3 to 20% by weight, 3 to 15% by weight, 3 to 10% by weight, 5 to 50% by weight, 5 to 45% by weight, 5 to 40% by weight, 5 to 35% by weight, 5 to 30% by weight, 5 to 25% by weight, 5 to 20% by weight, 5 to 15% by weight, or 5 to 10% by weight based on the total polyamic acid varnish.

[0019] The conductive filler may include at least one selected from the group consisting of carbon black, conductive carbon, graphite, conductive metal, and conductive metal oxide, and preferably the conductive filler may include at least one selected from the group consisting of carbon black, conductive carbon, and graphite.

[0020] The conductive carbon may include single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene, graphene oxide (GO), reduced graphene oxide (rGO), or mixtures thereof. Specifically, the use of SWCNTs, MWCNTs, GO, or rGO is preferred in terms of dispersibility and cost-effectiveness.

[0021] The conductive metal may be metal nanoparticles, metal wires, or metal flakes containing silver, copper, silver-plated copper, molybdenum, zinc, tungsten, nickel, iron, palladium, platinum, tin, lead, titanium, or mixtures thereof.

[0022] The conductive metal oxide may include ZnO or SnO2, etc.

[0023] In one specific example, the dianhydride monomer may be an aromatic tetracarboxylic dianhydride. For example, the dianhydride monomer includes at least one compound represented by the following chemical formula 1.

[0024] [ka]

[0025] In the aforementioned chemical formula 1, [ka] 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.

[0026] The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group are

[0027] Is it a monoring?

[0028] Is it a fused ring, or

[0029] Single bond, substituted or unsubstituted alkylene group, substituted or unsubstituted alkylidene group, substituted or unsubstituted alkenylene group, substituted or unsubstituted alkynylene group, substituted or unsubstituted arylene group, -O-, -S-, -C(=O)-, -S(=O)2- and -Si(R b The group is linked by a linking group which contains at least one divalent substituent selected from the group consisting of )2-, where R b These are hydrogen atoms or alkyl groups.

[0030] Preferably, X is [ka] or an aliphatic ring group,

[0031] The aforementioned 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.

[0032] In this specification, the term "aliphatic ring group" means an aliphatic ring group having 3 to 30 carbon atoms, 4 to 25 carbon atoms, 5 to 20 carbon atoms, or 6 to 16 carbon atoms, unless otherwise specified. Specific examples of tetravalent aliphatic ring groups include, for example, groups obtained by removing four hydrogen atoms from rings such as cyclohexane, cycloheptane, cyclodecane, cyclododecane, norbornane, isobornane, adamantane, cyclododecane, and dicyclopentane rings.

[0033] In this specification, the term "aromatic ring group" means an aromatic ring group having 4 to 30 carbon atoms, 5 to 25 carbon atoms, 6 to 20 carbon atoms, or 6 to 16 carbon atoms, unless otherwise specified. The aromatic ring may be a monoring or a fused ring. Examples of tetravalent aromatic hydrocarbon ring groups include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, or a pyrene ring from which four hydrogen atoms have been removed.

[0034] In this specification, the term "arylene group" means a divalent organic group derived from the aromatic ring group.

[0035] In this specification, the term "heterocyclic group" includes heteroaliphatic cyclic groups and heteroaromatic cyclic groups.

[0036] In this specification, the term "heteroaliphatic ring group" means a ring group in which at least one carbon atom of the aliphatic ring group is replaced by one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus.

[0037] In this specification, the term "heteroaromatic ring group" means, unless otherwise specified, a ring group in which at least one carbon atom of the aromatic ring is replaced by at least one heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus. The heteroaromatic ring group may be a monoring or a fused ring.

[0038] The aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group, or the heteroaromatic ring group may each be independently replaced with one or more substituents selected from the group consisting of halogens, hydroxyl groups, carboxyl groups, halogen-substituted or unsubstituted C1-C4 alkyl groups, and C1-C4 alkoxy groups.

[0039] In this specification, the term "condensed ring" means a ring group formed by two or more ring groups sharing and bonding two or more atoms, and means a polycyclic system formed by two or more aromatic rings joining or linking to each other. For example, it means a condensed aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring, a condensed heteroaromatic ring, or a combination thereof.

[0040] In this specification, the term "single bond" means a bond that connects two atoms without any other atoms. For example, in chemical formula 1, X is [ka] Here, if M is a single bond, both aromatic rings may be directly linked to each other.

[0041] In this specification, the term "alkyl group" means an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkyl group may have a linear, branched, or cyclic structure and may be replaced by one or more substituents as desired. Examples of such substituents include polar functional groups such as halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0042] In this specification, the term "alkenyl group" means an alkenyl group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, unless otherwise specified. The alkenyl group may have a linear, branched, or cyclic structure and may be optionally replaced by one or more substituents. Examples of such substituents include polar functional groups such as halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0043] In this specification, the term "alkynyl group" means an alkynyl group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, unless otherwise specified. The alkynyl group may have a linear, branched, or cyclic structure and may be optionally replaced by one or more substituents. Examples of substituents include polar functional groups such as halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0044] In this specification, the term "alkylene group" means an alkylene group having 2 to 30 carbon atoms, 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 10 carbon atoms, or 2 to 8 carbon atoms, unless otherwise specified. The alkylene group may have a linear, branched, or cyclic structure as a divalent organic group from which two hydrogen atoms have been removed from different carbon atoms, and may be optionally replaced by one or more substituents. Examples of such substituents include polar functional groups such as halogens, hydroxyl groups, alkoxy groups, thiol groups, or one or more substituents consisting of thioether groups.

[0045] In this specification, the term "alkylidene group" means an alkylidene group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, or 1 to 8 carbon atoms, unless otherwise specified. The alkylidene group may have a linear, branched, or cyclic structure as a divalent organic group in which two hydrogen atoms have been removed from one carbon atom, and may be optionally replaced by one or more substituents. Examples of such substituents include polar functional groups such as one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0046] In this specification, the term "alkoxy group" means an alkoxy group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkoxy group may have a linear, branched, or cyclic alkyl group, and the alkyl group may be optionally replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0047] In this specification, the term "alkylamine group" includes monoalkylamine (-NHR) or dialkylamine (-NR2) unless otherwise specified, where R independently represents an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure and may be replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0048] In this specification, the term "alkylamide" includes monoalkylamide (-C(O)NHR) or dialkylamide (-C(O)NR2) unless otherwise specified, where R independently represents an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure and may be replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0049] In this specification, the terms "thioether group" or "sulfide" mean -SR unless otherwise specified, where R independently means an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure and may be replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0050] In this specification, the term "sulfoxide" means -S(O)R unless otherwise specified, where R independently means an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure and may be replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0051] In this specification, the term "carbonyl" includes -C(O)R unless otherwise specified, where R independently represents an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure, and may be optionally replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0052] In this specification, the term "ester" includes -C(O)OR or -OC(O)R unless otherwise specified, where R independently represents an alkyl group having 1 to 30 carbon atoms, 1 to 25 carbon atoms, 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Here, the alkyl group may have a linear, branched, or cyclic structure, and may be optionally replaced by one or more substituents. Examples of such substituents include one or more substituents consisting of halogens, hydroxyl groups, alkoxy groups, thiol groups, or thioether groups.

[0053] Aliphatic tetracarboxylic dianhydrides satisfying the aforementioned chemical formula 1 include 1,2,4,5-cyclohexanetetracarboxylic dianhydride (or HPMDA), bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2:3,5:6-dianhydride (BODA), 1,2,3,4-cyclohexanetetracarboxylic dianhydride (CHMDA), bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic 2:3,5:6-dianhydride (BHDA), butane-1,2,3,4-tetracarboxylic dianhydride (BTD), and bicyclo-[2.2.2]octane. To-7-ene-2-exo,3-exo,5-exo,6-exo-2,3:5,6-dianhydride (BTA), l,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), bicyclo[4.2.0]octane-3,4,7,8-tetracarboxylic dianhydride (OTD), norbornane-2-spiro-α-cyclohexanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (ChODA), cyclopentanonebis-spironorbornanetetracarboxylic dianhydride (CpODA), bicyclo[2.2.1]Heptane-2,3,5-tricarboxyl-5-acetic acid dianhydride (BSDA), dicyclohexyl-3,3',4,4'-tetracarboxylic acid dianhydride (DCDA), dicyclohexyl-2,3'-3,4'-tetracarboxylic acid dianhydride (HBPDA), 5,5'-oxybis(hexahydro-1,3-isobenzoflangion) (HOPDA), 5,5'-methylenebis(hexahydro-1,3-isobenzoflangion) (HMDPA), 3,3'-(1,4-piperazinediyl)bis[dihydro-2,5-flangion] (PDSA), 5-(2,5-dioxotetrahydrofurfuryl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride (DOCDA), 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dianhydride Water (TDA), 3,4-dicarboxy-1,2,3,4-tetrahydro-6-methyl-1-naphthalenesuccinate dianhydride (MTDA), 3,4-dicarboxy-1,2,3,4-tetrahydro-6-fluoro-1-naphthalenesuccinate dianhydride (FTDA), 3,3,3',3'-tetramethyl-1,1'-spirobisindan-5,5',6,6'-tetracarboxylic acid anhydride (S Examples include BIDA, 4,4,4',4'-tetramethyl-3,3',4,4'-tetrahydro-2,2'-spirobio[flo[3,4-g]chromene]-6,6',8,8'-tetraone (SBCDA), or 9,10-difluoro-9,10-bis(trifluoromethyl)-9,10-dihydroanthracene-2,3,6,7-tetracarboxylic dianhydride (6FDA).

[0054] The aromatic tetracarboxylic dianhydrides satisfying the aforementioned chemical formula 1 are pyromelitic acid dianhydride (or PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (or BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (or α-BPDA), oxydiphthalic acid dianhydride (or OPDA), diphenylsulfone-3,4,3',4'-tetracarboxylic dianhydride (or DSDA), bis(3,4-dicarboxyphenyl) sulfide dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride (or BTDA), bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, and p-phenyl Examples include nilenbis(trimellitic acid monoester anhydride), p-biphenylenebis(trimellitic acid monoester anhydride), m-terphenyl-3,4,3',4'-tetracarboxylic acid dianhydride, p-terphenyl-3,4,3',4'-tetracarboxylic acid dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, or 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid dianhydride (6-FDA).

[0055] The compound represented by chemical formula 1 is preferably an aromatic tetracarboxylic dianhydride, and in particular the dianhydride may include pyromellitic dianhydride (or PMDA), oxydiphthalic dianhydride (or OPDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (or BPDA), or 2,3,3',4'-biphenyltetracarboxylic dianhydride (or α-BPDA).

[0056] As an example, the diamine monomer may contain at least one compound represented by the following chemical formula 2.

[0057] [ka]

[0058] In the above chemical formula 2, any of B1 to B5 is an amino group (-NH2), -R-NH2, or -OR-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.

[0059] Furthermore, diamine monomers that may be used in the production of polyamic acid solutions are aromatic diamines, and examples can be given by classifying them as follows.

[0060] 1) Diamines that structurally have one benzene ring, such as 1,4-diaminobenzene (or paraphenylenediamine, PPD), 1,3-diaminobenzene, 2,4-diaminotoluene, 2,6-diaminotoluene, or 3,5-diaminobenzoic acid (or DABA), and have a relatively rigid structure.

[0061] 2) Diaminodiphenyl ethers such as 4,4'-diaminodiphenyl ether (or oxydianiline, ODA), 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane (methylenediamine), 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl))-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenyl Phenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis(4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine (or o-tolidine), 2,2'-dimethylbenzidine (or m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3' -diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4'-dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, Diamines that structurally have two benzene rings, such as 4,4'-diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, or 4,4'-diaminodiphenyl sulfoxide,

[0062] 3) 1,3-bis(3-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(3-aminophenyl)benzene, 1,4-bis(4-amino)phenyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene (or TPE-Q), 1,4-bis(4-aminophenoxy)benzene (or TPE-Q), 1,3-bis(3-aminophenoxy)-4-trifluoromethylbenzene, 3,3'-diamino-4-(4-phenyl)phenoxybenzophenone, 3,3'-diamino-4,4'-di(4-phenylphenoxy)benzophenone Diamines that structurally have three benzene rings, such as 1,3-bis(3-aminophenylsulfide)benzene, 1,3-bis(4-aminophenylsulfide)benzene, 1,4-bis(4-aminophenylsulfide)benzene, 1,3-bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, 1,3-bis[2-(4-aminophenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, or 1,4-bis[2-(4-aminophenyl)isopropyl]benzene,

[0063] 4) 3,3'-bis(3-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[3-(3-aminophenoxy)phenyl] ether, bis[3-(4-aminophenoxy)phenyl] ether, bis[4-(3-aminophenoxy)phenyl] ether, bis[3-(3-aminophenoxy)phenyl] ketone, bis[3-(4-aminophenoxy) [xy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[3-(3-aminophenoxy)phenyl]sulfide, bis[3-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[3-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl 2,2-bis[3-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy]propane, 2,2-bis[4-(4-aminophenoxy] Diamines that structurally have four benzene rings, such as bis(phenyl)propane (BAPP), 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, or 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane.

[0064] The diamine monomer may be used alone or in combination of two or more as needed, and may include, for example, 4,4'-diaminodiphenyl ether (or oxydianiline, ODA), 1,4-diaminobenzene (PPD), 1,3-diaminobenzene (MPD), 2,4-diaminotoluene, 2,6-diaminotoluene, or 4,4'-methylenediamine (MDA), preferably the compound represented by chemical formula 2 is 4,4'-diaminodiphenyl ether (or oxydianiline, ODA).

[0065] This application relates to polyimide powder. The polyimide powder may be obtained when polyamic acid is imidized and precipitated in powder form during the thermal curing of the polyamic acid varnish described above.

[0066] Therefore, the polyimide powder is particulate and contains the cured (or thermoset) product of the polyamic acid varnish described above.

[0067] For example, the polyimide powder may have conductive fillers dispersed within the particles. In the polyimide powder according to the present invention, conductive fillers may be introduced during the polymerization stage of polyamic acid, resulting in the conductive fillers being dispersed within the particles. On the other hand, conventional dry mixing of polyimide powder and conductive fillers can be difficult to achieve uniformly, as the conductive fillers may be biased to certain areas or solidify during the mixing process, resulting in poor moldability and processability.

[0068] This application further relates to a polyimide molded article containing the aforementioned polyimide powder. The molded article may be produced using various molding methods from the aforementioned polyimide powder. Examples of molding methods include compression molding, injection molding, slush molding, hollow molding, extrusion molding, or spinning, and examples of molded articles include plates, rods, films, sheets, pellets, belts, or tubes.

[0069] The molded product is manufactured from polyimide powder in which the conductive filler in the particles is uniformly dispersed, so that various physical property controls can be achieved within the following numerical ranges.

[0070] The polyimide molded product according to the present application may have a surface resistance measured by the ASTM D257 method within the range of 1.0×10 2 ~1.0×10 13 Ω, for example, 1.0×10 3 ~1.0×10 13 Ω, 1.0×10 4 ~1.0×10 13 Ω, 1.0×10 5 ~1.0×10 13 Ω, 1.0×10 6 ~1.0×10 13 Ω, 1.0×10 7 ~1.0×10 13 Ω, 1.0×10 8 ~ 1.0×10 13 Ω, 1.0×10 9 ~1.0×10 13 Ω, 1.0×10 10 ~1.0×10 13 Ω, 1.0×10 11 ~1.0×10 13 Ω, 1.5×10 3 ~1.0×10 13 Ω, 1.5×10 4 ~1.0×10 13 Ω, 1.5×10 5 ~1.0×10 13 Ω, 1.5×10 6 ~1.0×10 13 Ω, 1.5×10 7 ~1.0×10 13 Ω, 1.5×10 8 ~1.0×10 13 Ω, 1.5×10 9 ~1.0×10 13 Ω, 1.5×10 10 ~1.0×10 13 Ω, 1.5×10 11 ~1.0×10 13 Ω, 1.0×10 3 ~2.0×10 12 Ω, 1.0×10 4~2.0×10 12 Ω, 1.0 × 10 5 ~2.0×10 12 Ω, 1.0 × 10 6 ~2.0×10 12 Ω, 1.0 × 10 7 ~2.0×10 12 Ω, 1.0 × 10 8 ~2.0×10 12 Ω, 1.0 × 10 9 ~2.0×10 12 Ω, 1.0 × 10 10 ~2.0×10 12 Ω, 1.0 × 10 11 ~2.0×10 12 Ω, 1.5 × 10 3 ~2.0×10 12 Ω, 1.5 × 10 4 ~2.0×10 12 Ω, 1.5 × 10 5 ~2.0×10 12 Ω, 1.5 × 10 6 ~2.0×10 12 Ω, 1.5 × 10 7 ~2.0×10 12 Ω, 1.5 × 10 8 ~2.0×10 12 Ω, 1.5 × 10 9 ~2.0×10 12 Ω, 1.5 × 10 10 ~2.0×10 12 Ω or 1.5 × 10 11 ~2.0×10 12 The surface resistance may be within the range of Ω. The surface resistance may also be measured using an Advanced Energy / Trek152-1 according to the ASTM D-257 method, and specific measurement conditions include 23±3℃ and a source voltage of 10V. The molded article according to the present invention has excellent conductivity, moldability, and processability due to having a surface resistance within the above range.

[0071] In one specific example, the polyimide molded article may have an elongation of 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, or 10% or more, as measured by the ASTM D-1708 method. There is no particular upper limit, but it may be 50% or less, 40% or less, 30% or less, or 20% or less.

[0072] Furthermore, the polyimide molded article may have a tensile strength of 65 MPa or higher, 68 MPa or higher, 70 MPa or higher, 72 MPa or higher, 74 MPa or higher, 76 MPa or higher, 78 MPa or higher, 80 MPa or higher, 85 MPa or higher, 90 MPa or higher, 90 MPa or higher, 100 MPa or higher, 150 MPa or higher, 200 MPa or higher, 250 MPa or higher, 300 MPa or higher, 350 MPa or higher, 400 MPa or higher, or 450 MPa or higher, as measured by the ASTM D-1708 method. The upper limit is not particularly limited, but may be 1000 MPa or lower, 900 MPa or lower, 800 MPa or lower, 700 MPa or lower, 600 MPa or lower, or 500 MPa or lower.

[0073] The aforementioned elongation and tensile strength can be measured by the ASTM D-1708 method using Instron UTM equipment from Instron after processing polyimide powder into a dogbone shape with a length of 38 mm and a width of 15 mm following HCM molding.

[0074] This application further relates to a method for producing polyamic acid varnish.

[0075] The above method includes the steps of dispersing a conductive filler in an organic solvent and polymerizing a diamine monomer and a dianhydride monomer in the organic solvent in which the conductive filler is dispersed. The polyamic acid varnish produced by the above method can provide a polyimide powder in which the conductive filler is dispersed within the particles during thermal curing, due to the addition of the conductive filler during the polymerization stage.

[0076] The polymerization step involves polymerizing the dianhydride monomer and the diamine monomer by heating. The heating temperature in the polymerization step is 30 to 100°C, and may be, for example, 40 to 100°C, 50 to 90°C, or 60 to 80°C.

[0077] In the polymerization step, the reaction time may be 1 to 10 hours, for example, 1 to 8 hours, 1 to 6 hours, 1 to 4 hours, or 1 to 3 hours.

[0078] In one example, the dispersion may be carried out by sonication. The sonication may be carried out by treating with Sonics & Materials' VCX750 for 30 minutes or more, and is not particularly limited; the specific conditions can be changed depending on the type of solvent and conductive filler.

[0079] A detailed explanation of the composition of the aforementioned polyamic acid varnish will be omitted below, as it would be redundant with what has already been stated.

[0080] This application further relates to a method for producing polyimide powder.

[0081] The above-mentioned manufacturing method includes the steps of: dispersing a conductive filler in an organic solvent; polymerizing a diamine monomer and a dianhydride monomer in the organic solvent in which the conductive filler is dispersed; and thermally curing the polymer produced in the polymerization step to obtain a polyimide powder.

[0082] The polymerization step is a step in which a polyamic acid having dianhydride monomers and diamine monomers as polymerization units is produced, and the polymer produced in the polymerization step may be polyamic acid. In the polymerization step, the polymerization temperature may be in the range of 30 to 100°C, 40 to 100°C, 50 to 90°C, or 60 to 80°C.

[0083] In the polymerization step, the polymerization time may be 1 to 10 hours, for example, 1 to 8 hours, 1 to 6 hours, 1 to 4 hours, or 1 to 3 hours.

[0084] During the thermal curing process, the polyamic acid may be imidized with polyimide, reducing its solubility in the solvent and potentially precipitating as a powder. For example, the curing temperature for the thermal curing may be within the temperature range of 150 to 300°C, or within the range of 160 to 280°C, 170 to 250°C, or 180 to 200°C.

[0085] The curing time for the heat curing may be 1 to 10 hours, for example, 1 to 8 hours, 1 to 6 hours, 1 to 4 hours, or 1 to 3 hours.

[0086] Explanations that overlap with those mentioned above will be omitted below.

[0087] This application relates to a method for manufacturing polyimide molded articles.

[0088] The method for manufacturing the molded article includes the steps of: dispersing a conductive filler in an organic solvent; polymerizing a diamine monomer and a dianhydride monomer in the organic solvent containing the dispersed conductive filler; thermally curing the polymer produced in the polymerization step to obtain polyimide powder; and molding the obtained polyimide powder to produce a polyimide molded article.

[0089] The polymerization step is a step in which a polyamic acid having dianhydride monomers and diamine monomers as polymerization units is produced, and the polymer produced in the polymerization step may be polyamic acid. In the polymerization step, the polymerization temperature may be in the range of 30 to 100°C, 40 to 100°C, 50 to 90°C, or 60 to 80°C.

[0090] In the polymerization step, the polymerization time may be 1 to 10 hours, for example, 1 to 8 hours, 1 to 6 hours, 1 to 4 hours, or 1 to 3 hours.

[0091] The aforementioned thermosetting is a process in which polyamic acid is imidized with polyimide and precipitated in powder form. For example, the curing temperature of the thermosetting may be within the temperature range of 150 to 300°C, or within the range of 160 to 280°C, 170 to 250°C, or 180 to 200°C.

[0092] The curing time for the heat curing may be 1 to 10 hours, for example, 1 to 8 hours, 1 to 6 hours, 1 to 4 hours, or 1 to 3 hours.

[0093] The molding method can be compression molding, injection molding, slush molding, hollow molding, extrusion molding, or spinning, and the molded product can be a plate, a rod, a film, a sheet, a pellet, a belt, or a tube.

[0094] Explanations that overlap with those mentioned above will be omitted below. [Effects of the Invention]

[0095] This application provides a polyimide powder in which conductive fillers are uniformly dispersed within the particles, and a polyamic acid varnish that can be manufactured from the powder to create polyimide molded articles that not only have excellent moldability and processability, but also excellent conductivity, tensile strength, elongation, and modulus of elasticity. [Modes for carrying out the invention]

[0096] The present invention will be described in more detail below through examples and comparative examples that do not conform to the present invention, but the scope of the present invention is not limited by the following examples.

[0097] 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) was 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.

[0098] 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.

[0099] 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.

[0100] Table 1 below describes the mixing methods for conductive fillers. "Dispersion mixing" in Examples 1 to 7 refers to a method in which the conductive filler is mixed with the solvent through ultrasonic treatment during the polyamic acid polymerization stage, as in Example 1. "Dry mixing" in Comparative Examples 1 to 4 refers to a method in which polyamic acid is polymerized without using conductive fillers, imidized to precipitate polyimide powder, and then the precipitated polyimide powder and conductive filler are mechanically mixed.

[0101] [Table 1]

[0102] Experimental Example 1 - Processability Samples were prepared by processing molded products obtained by HCM molding of the polyimide powders of the examples and comparative examples into dogbon shapes. 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 10cm x 10cm area. If cracks occurred, the samples were further divided into "few cracks" and "many cracks" based on the number of cracks, as described below.

[0103] O: No cracks △: Number of cracks: 1-5 (few cracks) X: The number of cracks exceeds 5 (too many cracks)

[0104] 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 ASTM D-257 with an Advanced Energy / Trek 152-1. The measurement temperature was set to 23±3℃ and the source voltage was set to 10V.

[0105] Experimental Example 3 - Measurement of Elongation and Tensile Strength After the polyimide powders of the examples and comparative examples were subjected to HCM molding, they were processed into dogbone shapes 38 mm in length and 15 mm in width, and their elongation and tensile strength were measured using the ASTM D-1708 method with Instron UTM equipment from Instron.

[0106] [Table 2]

Claims

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. 【Chemistry 1】 In the aforementioned chemical formula 1, 【Chemistry 2】 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 Is it a fused ring, or Single bond, substituted or unsubstituted alkylene group, substituted or unsubstituted alkylidene group, substituted or unsubstituted alkenylene group, substituted or unsubstituted alkynylene group, substituted or unsubstituted arylene group, -O-, -S-, -C(=O)-, -S(=O) ２ - and -Si(R ｂ ) ２ It is linked by a linking group which contains at least one divalent substituent selected from the group consisting of -, where R ｂ These are hydrogen atoms or alkyl groups.

4. The aforementioned X is 【Transformation 3】 or an aliphatic ring group, The above M is a single bond, an alkylene group, an alkylidene group, O, S, C(=O), and S(=O). ２ The polyimide powder according to claim 3, which is at least one from the group including the following.

5. The polyimide powder according to claim 1, wherein the diamine monomer comprises at least one compound represented by the following chemical formula 2. 【Chemistry 4】 In the chemical formula 2, B １ ~B ５ is any one of an amino group (-NH ２ ), -R-NH ２ , or -O-R-NH ２ , where the R is a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted alkenylene group, a substituted or unsubstituted alkynylene group, or a substituted or unsubstituted arylene group, and the remainder represents hydrogen, halogen, a hydroxy group, a carboxyl group, or an alkyl group substituted or unsubstituted by 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.

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