540 results about "Diaminodiphenyl ether" patented technology

A benzoxazine polymer having improved thermal properties. The properties are improved by inserting aromatic polyamines into the monomer, such as phenylenediamine, methylenedianiline, oxydianiline, diaminodiphenylsulfone, 2,2-bis(4-[aminophenoxy]phenyl)propane, 4,4'-oxydianiline, 4,4'-diaminodiphenyl sulfone, and diaminobenzanilide, to introduce internal benzoxazine groups that are crosslinking sites. The improved polymers can be converted into molding compounds, towpregs, and prepregs by being compounded with reinforcing fibers.

The invention discloses a graphene modified polyimide-based composite which is characterized in that the graphene modified polyimide-based composite comprises the following components in parts by weight: 95-105 parts of 4,4'-diaminodiphenyl ether, 110-120 parts of pyromellitic dianhydride and 1-25 parts of graphene. A preparation method comprises the steps of weighing ODA (octyl decyl adipate) and the graphene in proportion, measuring a DMAC (dimethylacetamide) solvent, adding the ODA, the graphene and the DMAC solvent to a reaction vessel, using ultrasonic till the ODA is dissolved sufficiently and the graphene is dispersed completely in the DMAC to obtain a graphene suspension, adding PMDA (pyromellitic dianhydride) in batches under high-speed stirring conditions till weak pole climbing appears, continuing to stir to allow diamine to react with dianhydride completely, and flattening an obtained graphene/PAA (poly acrylic acid) complex to obtain a composite film with uniform thickness so as to obtain a graphene polyimide composite film. The composite is 0.5 g/cm<3>-1.5 g/cm<3> in density and 60-170 KJ/m<2> in tensile strength.

The invention relates to a corona-resistant polyimide film containing high-concentration nano metal oxide, which comprises the following main components: benzenetetracarboxylic anhydride, 4, 4'-diamino diphenyl ether and nano-scale aluminum oxide, wherein the particle size of the nano-scale metal oxide is in the range from 30nm to 50nm. The film provided by the invention has the following outstanding advantages that a novel coupling agent is synthesized and is compounded with titanate coupling agent NDZ-130 to conduct surface modification on prepared alpha-Al2O3, thus the modified nano-particles can be steadily and uniformly dispersed in the substrate polyimide film with relatively high mass percentage (can reach 30wt%). By adoption of the above novel technical scheme of the invention, the technical problem that high-concentration nano-metal oxide is very difficultly doped uniformly in the corona resistant polyimide film according to the prior art is solved well, and meanwhile the mechanical strength of the film is kept from dropping.

The present invention relates to a corona-resisting insulated wire enamel for adjustable frequency motor and its preparation process. Said insulated wire enamel is formed from two portions of polyesterimine paint containing isocyanurate (THEIC) and nano material for quantum screening, and it is characterized by that its composition includes (by 100 portions) 10-20 portions of dimethyl terephthalate, 4-10 portions of glycerin, 5-20 portions of ethanediol, 5-12 portions of THEIC, 0.1-0.2 portion of catalyst, 5-15 portions of metabenzene diformic anhydride, 4-8 portions of 4,4-diaminodiphenyl ether, 0.2-0.3 portion of solidifying agent, 4-10 portions of screening agent, 0.5-2 portions of compounding agent, 15-40 portions of solvent, 10-35 portions of diluting agent and 0.5-1.5 portions of adjuvant.

A process of preparing 3ú¼4'-diamino diphenyl ether. It comprises: taking nitrodiphenyl ether as the raw material, hydrazine hydrate as the reducing agent, reducing in the presence of a catalyst, obtaining 3ú¼4'-diamino diphenyl ether at a low pressure. The invention overcomes unsafe factors in the method of high-pressure hydrogenation, avoid the step of highpressure distillation, and has mild reactive conditions. The product has good purity. So the invention is suitable for industrial production.

The present invention discloses a kind of polyimide fiber and its preparation process. The preparation process includes the following steps: 1. reacting 4, 4í»-diamino diphenyl ether and pyromellitic dianhydride in the weight ratio of 1 to 1.02 with N, N-dimethyl acetylamide solution of 15-20 % concentration at 0-5 deg.c to obtain polyamic acid solution; 2. wet spinning the polyamic acid solution and imidation reaction of the polyamic acid fiber to obtain polyimide fiber through dewatering and cyclization; and 3. mixing the polyimide fiber with acetic anhydride and triethylamide, flushing with acetone, soaking and drying to obtain the polyimide fiber. The present invention has positive effects of optimized synthesis condition of spinning solution, prolonged solidification period of initially formed fiber in the solidification bath, and fiber with ideal mechanical performance.

The invention discloses an epoxy resin curing agent, an epoxy resin pouring sealant as well as the relevant preparation methods. The epoxy resin curing agent comprises 10 to 60 diaminodiphenylmethane, 20 to 70 diaminodiphenyl ether or diaminodiphenylsulfone, and 10 to 40 multi-amine curing agent, all calculated in pbw (part by weight). The preparation method for the curing agent comprises the following steps: mixing and heating the substances, raising the temperature to 90-110 DEG C, then stirring for 1 to 3 hours in thermal insulation state, and finally simply cooling the mixture to room temperature. The curing agent is liquid under normal temperature, and mixes well with the epoxy resin. The epoxy resin pouring sealant comprises 100 pbw epoxy resin which has at least two epoxy groups and is liquid under normal temperature, and 10 to 40 pbw epoxy resin curing agent; the preparation method for the pouring sealant comprises the following steps: adding the epoxy resin curing agent into the epoxy resin, mixing for 10 to 30 minutes, then debubble in vacuum state for 10 to 30 minutes, and finally simply removing the vacuum state. The transition temperature of vitrification for the pouring sealant thus acquired is pretty high, and the compound of epoxy resin cured is excellent in electromechanical and thermal performance.

The invention relates to a bisphthalonitrile resin/aromatic amine organic montmorillonite nano composite material and a preparation method thereof, belonging to the technical field of thermosetting resin composite materials. The bisphthalonitrile resin/aromatic amine organic montmorillonite (p-BA-OMMT) nano composite material comprises the components in parts by mass: 100 parts of bisphthalonitrile monomer, 0.5-5 parts of p-BA-OMMT, and 3 parts of curing agent of 4,4'-Bisaminophenoxyphenylsulfone (p-BAPS). The method comprises the steps of montmorillonite organic treatment and composite material preparation. The bisphthalonitrile resin/p-BA-OMMT nano composite material, prepared by the preparation method, has excellent mechanical property and thermal stability, is lower in preparation cost, satisfies the application requirement of industrial production, and has broad application prospect in the fields, such as vehicles, mechanicals, aviation, aerospace and submarines.

The invention relates to a method for preparing polyimide multilayer complex films containing inorganic nanometer powder. Polyimide multilayer complex materials containing inorganic nanometer powder often reduce the mechanical property of films, and obviously reduce the property of the films especially when the nanometer powder is unevenly distributed. The method comprises the following steps of: (1) pre-processing the inorganic nanometer powder; (2) dissolving 4, 4'- diaminodiphenyl ether and pyromellitic dianhydride as raw material monomers into a solvent, and polymerizing to generate polyamic acid solution; (3) dispersing the pre-processed inorganic nanometer powder to the solvent through an ultrasound, and adding the solvent to the polyamic acid solution to prepare the polyamic acid solution containing the inorganic nanometer powder; (4) sequentially paving films on the polyamic acid solution containing the inorganic nanometer powder and the pure polyamic acid solution; and (5) putting the films in an oven for hot-imidization treatment at the temperature of 50 to 400 DEG C to obtain the polyimide hybrid multilayer complex films containing the inorganic nanometer powder. The invention is used for preparing the polyimide multilayer complex films containing the inorganic nanometer powder.

The invention relates to a biaxially oriented polyimide film for flexible printed circuit board base material and a preparation method of the biaxially oriented polyimide film. The method is characterized by mainly comprising the following steps of: (1) polymerizing: preparing a basic solution of polyimide acid according to the following proportions: 1-5% of p-phenylenediamine, 2-8% of biphenyltetracarboxylic dianhydride, 5-10% of diaminodiphenyl ether, 8-15% of pyromellitic dianhydride and 62-84% of dimethylacetylamide; (2) salivating the solution into a film; (3) longitudinally stretching the film according to the stretching ratio of 1:1.02-1.15; (4) transversely stretching the film according to the stretching ratio of 1:1.05-1.2 and carrying out imidization; (5) cutting the edge and rolling up the film; (6) postprocessing the film; and (7) cutting and packaging the film. The special biaxially oriented polyimide film material conforming to the flexible printed circuit board base material can be obtained by using the preparation method provided by the invention.

Disclosed is a biaxially oriented multilayer film comprising at least two layers A-B, wherein A and B represent separate layers at least one of which layers comprises a polyimide having a Tg of greater than about 200° C., wherein the film has a CTE of less than 35 ppm/° C., and wherein A comprises 60 wt. %-100 wt. % of amorphous polymer with 0 wt. %-40 wt. % of crystallizable polymer, and B comprises 60 wt. %-100 wt. % crystallizable polymer with 0 wt. %-40 wt. % amorphous polymer, the relative thicknesses of layer A to layer B are in a ratio in a range of between 1:5 and 1:100, and the thickness of the film is in a range of between 5 μm and 125 μm. Also disclosed is a biaxially oriented monolithic film comprising a polyimide with structural units formally derived from 3,4-diaminodiphenylether and 4,4-oxydiphthalic anhydride. Laminates comprising the films and methods for making film and laminate are also disclosed. Articles comprising a film or laminate of the invention are also disclosed.

The invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element. The invention provides a liquid crystal aligning agent which is provided with an excellent pretilt angle property by an optical alignment method, and can form a liquit crystal aligning film which does not result in poor display performance even when drived continuously for a long time. The liquit crystal aligning agent contains: (A) polyamide acid A, which is obtained by allowing tetracarboxylic dianhydride to react with diamines containing a diamine with a photoreactive structure; (B) polyamide acid B, which is obtained by allowing at least one tetracarboxylic dianhydride selected from a group composed of 1, 2, 3, 4-cyclobutane tetracarboxylic dianhydride, pyromellitic dianhydride to react with at least one diamine selected from a group composed of 2, 2'-dimethyl-4, 4'-diaminobiphenyl, p-phenylenediamine, 4, 4'-diaminodiphenylmethane, 4, 4'-diaminodiphenyl ether (with the polyamide acid A excluded).

The invention discloses a shape memory polyimide prepared by virtue of chemical imidization and a preparation method thereof. The preparation method is used for preparing the thermoplastic shape memory polyimide by synthesizing a polyamide acid prepolymer from reaction monomers 4,4'-diaminodiphenyl ether and bisphenol A dianhydride and then carrying out chemical imidization under the action of acetic anhydride, triethylamine and pyridine. The glass-transition temperature of the thermoplastic shape memory polyimide exceeds 220 DEG C, and therefore, the thermoplastic shape memory polyimide can be applied to the field of the high-temperature shape memory polymers; and the thermoplastic shape memory polyimide has excellent processability, thermal stability, mechanical properties and shape memory properties.