CN112898893A - Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb - Google Patents
Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb Download PDFInfo
- Publication number
- CN112898893A CN112898893A CN201911226698.8A CN201911226698A CN112898893A CN 112898893 A CN112898893 A CN 112898893A CN 201911226698 A CN201911226698 A CN 201911226698A CN 112898893 A CN112898893 A CN 112898893A
- Authority
- CN
- China
- Prior art keywords
- wave
- absorbing
- waterborne polyurethane
- emulsion
- parts
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004814 polyurethane Substances 0.000 title claims abstract description 144
- 238000000576 coating method Methods 0.000 title claims abstract description 91
- 229920002635 polyurethane Polymers 0.000 title claims abstract description 91
- 239000011248 coating agent Substances 0.000 title claims abstract description 86
- 239000000839 emulsion Substances 0.000 title claims abstract description 82
- 238000002360 preparation method Methods 0.000 title claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 67
- 229920001730 Moisture cure polyurethane Polymers 0.000 claims abstract description 62
- 239000011162 core material Substances 0.000 claims abstract description 39
- 239000003431 cross linking reagent Substances 0.000 claims abstract description 14
- 239000002994 raw material Substances 0.000 claims abstract description 13
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims abstract description 11
- -1 polyethylene Polymers 0.000 claims abstract description 11
- 239000000126 substance Substances 0.000 claims abstract description 11
- 239000004698 Polyethylene Substances 0.000 claims abstract description 5
- 150000002688 maleic acid derivatives Chemical class 0.000 claims abstract description 5
- 229920000768 polyamine Polymers 0.000 claims abstract description 5
- 229920000573 polyethylene Polymers 0.000 claims abstract description 5
- 239000004593 Epoxy Substances 0.000 claims abstract description 4
- 150000001252 acrylic acid derivatives Chemical class 0.000 claims abstract description 4
- 125000003368 amide group Chemical group 0.000 claims abstract description 3
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims abstract description 3
- 238000003756 stirring Methods 0.000 claims description 40
- 229940058020 2-amino-2-methyl-1-propanol Drugs 0.000 claims description 35
- CBTVGIZVANVGBH-UHFFFAOYSA-N aminomethyl propanol Chemical compound CC(C)(N)CO CBTVGIZVANVGBH-UHFFFAOYSA-N 0.000 claims description 35
- 239000002270 dispersing agent Substances 0.000 claims description 27
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 23
- 238000006243 chemical reaction Methods 0.000 claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 17
- 239000011358 absorbing material Substances 0.000 claims description 16
- 239000003795 chemical substances by application Substances 0.000 claims description 13
- 229920001577 copolymer Polymers 0.000 claims description 11
- 229910021389 graphene Inorganic materials 0.000 claims description 11
- 238000004132 cross linking Methods 0.000 claims description 8
- 239000002518 antifoaming agent Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 229920000642 polymer Polymers 0.000 claims description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 5
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 5
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 4
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 4
- 239000000194 fatty acid Substances 0.000 claims description 4
- 229930195729 fatty acid Natural products 0.000 claims description 4
- 229920000570 polyether Polymers 0.000 claims description 4
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 3
- 229920002873 Polyethylenimine Polymers 0.000 claims description 3
- 229920001400 block copolymer Polymers 0.000 claims description 3
- 239000006229 carbon black Substances 0.000 claims description 3
- 239000004917 carbon fiber Substances 0.000 claims description 3
- 239000002041 carbon nanotube Substances 0.000 claims description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 3
- 229910002804 graphite Inorganic materials 0.000 claims description 3
- 239000010439 graphite Substances 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 239000002480 mineral oil Substances 0.000 claims description 3
- 235000010446 mineral oil Nutrition 0.000 claims description 3
- 229920001610 polycaprolactone Polymers 0.000 claims description 3
- 239000004632 polycaprolactone Substances 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 3
- 229920001228 polyisocyanate Polymers 0.000 claims description 3
- 239000005056 polyisocyanate Substances 0.000 claims description 3
- 229910021529 ammonia Inorganic materials 0.000 claims description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 2
- 229920000058 polyacrylate Polymers 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 229910052710 silicon Inorganic materials 0.000 claims description 2
- 150000001336 alkenes Chemical class 0.000 claims 1
- 150000001875 compounds Chemical class 0.000 claims 1
- 239000000853 adhesive Substances 0.000 abstract description 11
- 230000001070 adhesive effect Effects 0.000 abstract description 11
- 239000002131 composite material Substances 0.000 abstract description 3
- 241000264877 Hippospongia communis Species 0.000 description 98
- 238000012360 testing method Methods 0.000 description 51
- 238000001035 drying Methods 0.000 description 39
- 239000008367 deionised water Substances 0.000 description 25
- 229910021641 deionized water Inorganic materials 0.000 description 25
- 238000001816 cooling Methods 0.000 description 21
- 238000002310 reflectometry Methods 0.000 description 20
- 238000000227 grinding Methods 0.000 description 18
- 239000006185 dispersion Substances 0.000 description 16
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical group CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 16
- 238000010521 absorption reaction Methods 0.000 description 15
- 238000000034 method Methods 0.000 description 15
- 238000004513 sizing Methods 0.000 description 14
- 239000000463 material Substances 0.000 description 11
- 230000008569 process Effects 0.000 description 11
- 238000003825 pressing Methods 0.000 description 10
- 238000005520 cutting process Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 239000002904 solvent Substances 0.000 description 9
- 230000009471 action Effects 0.000 description 8
- 238000007605 air drying Methods 0.000 description 8
- 238000007766 curtain coating Methods 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 8
- 239000004576 sand Substances 0.000 description 8
- 238000010008 shearing Methods 0.000 description 8
- 239000002002 slurry Substances 0.000 description 8
- 238000005303 weighing Methods 0.000 description 8
- 238000009775 high-speed stirring Methods 0.000 description 7
- 238000007789 sealing Methods 0.000 description 7
- 230000006378 damage Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 239000012855 volatile organic compound Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 125000000524 functional group Chemical group 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 2
- QZPSOSOOLFHYRR-UHFFFAOYSA-N 3-hydroxypropyl prop-2-enoate Chemical compound OCCCOC(=O)C=C QZPSOSOOLFHYRR-UHFFFAOYSA-N 0.000 description 2
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 2
- AEMRFAOFKBGASW-UHFFFAOYSA-N Glycolic acid Chemical compound OCC(O)=O AEMRFAOFKBGASW-UHFFFAOYSA-N 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 239000013530 defoamer Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000003002 pH adjusting agent Substances 0.000 description 2
- 229920001568 phenolic resin Polymers 0.000 description 2
- 239000005011 phenolic resin Substances 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 125000004029 hydroxymethyl group Chemical group [H]OC([H])([H])* 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000002798 polar solvent Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000011527 polyurethane coating Substances 0.000 description 1
- LLHKCFNBLRBOGN-UHFFFAOYSA-N propylene glycol methyl ether acetate Chemical compound COCC(C)OC(C)=O LLHKCFNBLRBOGN-UHFFFAOYSA-N 0.000 description 1
- 239000013557 residual solvent Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000004154 testing of material Methods 0.000 description 1
- RUELTTOHQODFPA-UHFFFAOYSA-N toluene 2,6-diisocyanate Chemical class CC1=C(N=C=O)C=CC=C1N=C=O RUELTTOHQODFPA-UHFFFAOYSA-N 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
- C09D175/04—Polyurethanes
- C09D175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/67—Unsaturated compounds having active hydrogen
- C08G18/671—Unsaturated compounds having only one group containing active hydrogen
- C08G18/672—Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/32—Radiation-absorbing paints
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Paints Or Removers (AREA)
Abstract
The invention relates to an aqueous polyurethane emulsion, an aqueous polyurethane wave-absorbing coating, a preparation method thereof and a wave-absorbing honeycomb. The waterborne polyurethane emulsion is prepared from the following raw material components in parts by weight: 60-70 parts of polyurethane prepolymer, 2-4 parts of cross-linking agent, 0.1-5 parts of active assistant and 14-34 parts of water; wherein the cross-linking agent is selected from at least one of maleic acid derivatives, polyethylene polyamines and hydroxyl-containing acrylate compounds; the chemical formula of the active assistant comprises at least one active group of double bond, hydroxyl, amido, carboxyl and epoxy. The waterborne polyurethane emulsion has good system stability, and the waterborne polyurethane wave-absorbing coating for the wave-absorbing honeycomb prepared by taking the waterborne polyurethane emulsion as the basic emulsion has strong adhesive force with a composite material honeycomb core material, effectively improves the wave-absorbing performance of the waterborne polyurethane wave-absorbing coating, and is green and environment-friendly.
Description
Technical Field
The invention relates to a wave-absorbing coating, in particular to an aqueous polyurethane emulsion, an aqueous polyurethane wave-absorbing coating, a preparation method thereof and a wave-absorbing honeycomb.
Background
Absorbing coating (also called microwave absorbing coating or radar wave absorbing coating) is a functional material which is covered on a target in a coating form to realize radar stealth. Wave-absorbing coatingThe energy of incident radar waves can be converted into heat energy to be dissipated or eliminated or weakened through a resonance effect, and the purposes of effective absorption and attenuation are achieved. The wave-absorbing coating mainly comprises a film-forming substance and an absorber, wherein the film-forming substance is an organic polymer or an inorganic adhesive, and the absorber is powder, short fiber or chiral substance which has a loss function on electromagnetic waves. The main performance characterization parameters of the wave-absorbing coating comprise reflectivity (-dB), absorption frequency bandwidth (delta f) and surface density (kg/m)2) And the like. Generally, a lower reflectance over a wider frequency band is required under the condition that the density and thickness of the coating are strictly controlled. The wave-absorbing coating can be used for reducing the radar scattering cross section (RCS) of a target, so that military targets such as aircrafts, naval vessels and the like have stealth performance, and can also be used for eliminating the electromagnetic wave interference of a radar system and the electromagnetic wave shielding of microwave equipment. The wave-absorbing coating is comprehensively applied with stealth technologies such as structural design, electronic countermeasure and the like, and can realize qualitative leap of self-protection and attack capability of weaponry such as airplanes and the like.
The wave-absorbing coating for the wave-absorbing honeycomb, namely a specific coating used in a honeycomb core material. The honeycomb structure has the characteristics of high compressive strength, high specific stiffness and the like, and is an excellent light-weight high-strength structural material. The wave-absorbing material with the honeycomb structure has excellent mechanical property and wave-absorbing property. The excellence in the adhesion of the resin to the inner wall of the honeycomb is a major cause of the influence on the compression performance of the honeycomb. Under the same sizing process condition, different formulas directly influence the honeycomb compression performance; under the condition of the same resin proportion, different sizing processes directly influence the honeycomb compression performance.
Most of the existing wave-absorbing coatings for wave-absorbing honeycombs are oil-soluble or solvent-based coatings, and the oil-soluble or solvent-based coatings contain a large amount of Volatile Organic Compounds (VOC) and pollute the environment, and when the oil-soluble or solvent-based coatings are applied to composite honeycomb core materials, residual solvents can cause the difficulty that a large amount of volatile gas is filled in the composite honeycomb core materials, and the volatile gas cannot be volatilized or discharged, so that the problems of bulging, drying cracking, stripping and the like often occur in the coatings in the application process, and the use and the stability of the wave-absorbing performance are directly influenced. With the increasing attention of people to the problem of environmental pollution, the waterborne polyurethane is gradually becoming a new favorite in the modern industry. The waterborne polyurethane is a novel polyurethane system which uses water as a medium to replace an organic solvent, and has the advantages of nonflammability, small smell, no environmental pollution, large molecular weight, relatively low viscosity, energy conservation, easy processing, high wear resistance, luster and the like. However, when the waterborne polyurethane is applied to the honeycomb core material, the adhesive force on the honeycomb core material is poor, and meanwhile, the stability of the system of the waterborne polyurethane is poor, so that the wave-absorbing performance of the waterborne polyurethane is unstable and/or the mechanical property of the waterborne polyurethane is poor.
Disclosure of Invention
Based on this, there is a need for an aqueous polyurethane emulsion. The waterborne polyurethane emulsion has good system stability, and the waterborne polyurethane wave-absorbing coating for the wave-absorbing honeycomb prepared by taking the waterborne polyurethane emulsion as the basic emulsion has strong adhesive force with a honeycomb core material, effectively improves the wave-absorbing performance of the waterborne polyurethane wave-absorbing coating, and is green and environment-friendly.
The waterborne polyurethane emulsion is prepared from the following raw material components in parts by weight:
wherein the cross-linking agent is selected from at least one of maleic acid derivatives, polyethylene polyamines and hydroxyl-containing acrylate compounds;
the chemical formula of the active assistant comprises at least one active group of double bond, hydroxyl, amido, carboxyl and epoxy.
In one embodiment, the coagent is selected from at least one of Tego 760W (sourced from or an agent of Degaco, Germany, chemical composition: polymer containing high pigment affinity groups), Tego 740W (sourced from or an agent of Degaco, Germany, chemical composition: non-ionically modified fatty acid derivative without aromatic), 2-amino-2-methyl-1-propanol, ammonia, and triethylamine.
The invention also provides a preparation method of the waterborne polyurethane emulsion, which comprises the following steps:
mixing the polyurethane prepolymer and a cross-linking agent to carry out a cross-linking reaction; and then adding the active assistant and water for continuous reaction, and adjusting the pH value of the system to 8-10.
The invention also provides a water-based polyurethane wave-absorbing coating which is prepared from the following raw material components in parts by weight:
in one embodiment, the wave-absorbing material is selected from at least one of carbon black, graphite, carbon fiber, carbon nanotube, football graphene and graphene.
In one embodiment, the dispersant is at least one selected from the group consisting of a hydrophobically modified ammonium acrylate copolymer dispersant, a pigment-philic group-containing copolymer dispersant, a polycaprolactone polyol-polyethyleneimine block copolymer dispersant, an acrylate polymer dispersant, a polyurethane polymer dispersant and a polyester polymer dispersant.
In one embodiment, the pH adjusting agent is selected from at least one of 2-amino-2-methyl-1-propanol, ammonia water, and triethylamine; and/or
The defoaming agent is selected from at least one of a mixture of organic silicon and mineral oil, fatty acid salt, polyether siloxane copolymer and organic silicon derivative; and/or
The curing agent is selected from polyisocyanates.
The invention also provides a preparation method of the waterborne polyurethane wave-absorbing coating, which comprises the following steps:
mixing a proper amount of water, the dispersing agent, the defoaming agent and the wave-absorbing material, and stirring and dispersing; then adding the pH regulator to regulate the pH of the system to 8-10, adding the basic emulsion and the rest water, and stirring and dispersing; then adding the curing agent, and stirring and dispersing; the mixture obtained is ground.
The invention also provides a wave-absorbing honeycomb which comprises a honeycomb core material and the water-based polyurethane wave-absorbing coating attached to the honeycomb core material.
Compared with the prior art, the invention has the following beneficial effects:
the waterborne polyurethane emulsion has better stability of a waterborne polyurethane emulsion system by matching the polyurethane prepolymer with a proper cross-linking agent and an active assistant, and the waterborne polyurethane wave-absorbing coating for the wave-absorbing honeycomb prepared by taking the waterborne polyurethane prepolymer as a basic emulsion has strong adhesive force with a honeycomb core material, so that the wave-absorbing performance of the waterborne polyurethane wave-absorbing coating is effectively improved, and meanwhile, the thickness of the waterborne polyurethane wave-absorbing coating can be regulated and controlled by adjusting the using amounts of the cross-linking agent and the active assistant. In addition, the waterborne polyurethane emulsion does not use an organic solvent, does not generate Volatile Organic Compounds (VOC), pollutes the environment, and does not influence the stability of the wave-absorbing coating.
The waterborne polyurethane wave-absorbing coating prepared from the waterborne polyurethane emulsion can be stably attached to a honeycomb core material, exerts an excellent and stable wave-absorbing effect, has a large molecular weight and relatively low viscosity, is highly wear-resistant, glossy and non-flammable, can be cured at a lower temperature, has appropriate construction performance, is simple in construction method, and is beneficial to production and application.
The wave-absorbing honeycomb prepared from the waterborne polyurethane wave-absorbing coating has the advantages of thin thickness, light weight, wide frequency band and strong absorption.
Drawings
Fig. 1 is a flow chart of a wave-absorbing honeycomb preparation process according to an embodiment of the invention.
Detailed Description
The aqueous polyurethane emulsion, the aqueous polyurethane wave-absorbing coating, the preparation method thereof and the wave-absorbing honeycomb of the invention are further described in detail with reference to specific embodiments.
The water used in the embodiment of the invention is deionized water, which is the deionized water from which impurities in the form of ions are removed and mainly serves as a solvent.
The embodiment of the invention provides a waterborne polyurethane emulsion which is prepared from the following raw material components in parts by weight:
wherein the cross-linking agent is selected from at least one of maleic acid derivatives, polyethylene polyamines and hydroxyl-containing acrylate compounds;
the active assistant is at least one selected from Tego 760W, Tego 740W, 2-amino-2-methyl-1-propanol, ammonia water and triethylamine.
The honeycomb core material is usually phenolic resin, the inner wall of the honeycomb core material contains reactive groups such as hydroxyl (-OH which is a common polar group), hydroxymethyl and the like, and theoretically, the reactive groups can react with reactive-NCO groups in polyurethane emulsion, so that sizing of polyurethane is realized. However, when the solvent of the polyurethane prepolymer is water, that is, the solvent is an aqueous polyurethane emulsion, in order to maintain the stability of the system, the conventional aqueous polyurethane emulsion usually does not contain a reactive-NCO group, or the content of the reactive-NCO group is very low, which is not enough to form a stable adhesion relationship with the honeycomb core material through crosslinking, and the curing effect is poor, so that the stability of the wave-absorbing coating is poor. Based on the above, the invention introduces proper cross-linking agent and active auxiliary agent into polyurethane prepolymer, introduces reactive functional group on polyurethane Prepolymer (PU) main chain or latex particle by self-crosslinking method, forms water-based PU emulsion capable of self-crosslinking at ambient temperature or water-based PU emulsion capable of further crosslinking by heat treatment, the aqueous PU emulsion can be cured by utilizing the cohesion and adhesion generated by polar groups in molecules, meanwhile, active groups (mainly comprising at least one of double-bond unsaturated groups, hydroxyl, amino, carboxyl, epoxy and other active functional groups) capable of reacting with the phenolic resin are added, the system stability of the aqueous polyurethane emulsion is enhanced, therefore, the stability and the adhesive force of the wave-absorbing coating formed after the aqueous polyurethane emulsion system is cured on the honeycomb core material are improved, and the wave-absorbing performance is enhanced. In addition, the adhesive amount of the wave-absorbing coating on the inner wall of the honeycomb core material can be regulated and controlled by controlling the using amounts of the cross-linking agent and the active assistant, so that the thickness of the wave-absorbing coating can be regulated and controlled.
In one specific embodiment, the maleic acid derivative in the crosslinking agent can be glycolic acid, the polyethylene polyamine can be diethylenetriamine, and the hydroxyl-containing acrylate compound can be hydroxypropyl acrylate. Preferably, the crosslinking agent is a hydroxyl-containing acrylate compound (such as HPA (full name: hydroxypropyl acrylate) available from Shandongtai and Water treatment science and technology Co., Ltd.), which is miscible with water in any ratio and also dissolves most of the organic solvents, which contributes to the improvement of the stability of the aqueous PU emulsion, and also is easy to polymerize and can rapidly introduce a reactive functional group.
In one particular embodiment, the co-agent is selected from at least one of Tego 760W, Tego 740W, 2-amino-2-methyl-1-propanol (AMP-95), aqueous ammonia, and triethylamine. Wherein, the AMP-95 contains relatively more active groups and types, and can further increase the reaction activity of the PU emulsion.
Preferably, the coagents are Tego 760W, Tego 740W and 2-amino-2-methyl-1-propanol. The three components are compounded for use, so that the reaction activity can be further enhanced through mutual cooperation, and the stability and the adhesive force of the wave-absorbing coating formed after the aqueous polyurethane emulsion system is cured on the honeycomb core material are improved.
In one specific embodiment, the aqueous polyurethane emulsion is prepared from the following raw materials in parts by weight:
preferably, the aqueous polyurethane emulsion is prepared from the following raw material components in parts by weight:
the raw material components in the aqueous polyurethane emulsion are reasonably compatible according to the parts by weight, so that the cohesive force and the adhesive force of a system can be enhanced, the reaction activity is ensured, and the adhesive force of a wave-absorbing coating formed by subsequent curing on a honeycomb core material is further improved.
The embodiment of the invention provides a preparation method of the waterborne polyurethane emulsion, which comprises the following steps:
mixing the polyurethane prepolymer and a cross-linking agent to carry out a cross-linking reaction; and then adding the active assistant and water for continuous reaction, and adjusting the pH value of the system to 8-10.
Specifically, the finally obtained aqueous polyurethane emulsion is translucent. According to the requirement, a pH regulator can be adopted to regulate the pH value of the system to be 8-10, and the pH regulator can be at least one selected from 2-amino-2-methyl-1-propanol, ammonia water and triethylamine, and is mainly used for regulating the pH value of the coating system and stabilizing the activity of the emulsion. Preferably, the pH adjusting agent is AMP-95.
In one specific embodiment, the temperature of the crosslinking reaction is 75-85 ℃ and the time is 0.8-1.2 h.
In one specific embodiment, the step of adding the coagent to continue the reaction comprises: adding Tego 760W and Tego 740W, and reacting for 2.5-3.5 h at the temperature of 75-85 ℃; and then, when the temperature is reduced to 35-45 ℃, adding the 2-amino-2-methyl-1-propanol.
In one specific embodiment, after the pH of the system is adjusted to 8-10, the system is further dispersed, and the method comprises the following steps: dispersing for 30min-60min under the action of high-speed (1000rpm) shearing force.
The embodiment of the invention also provides the water-based polyurethane wave-absorbing coating, which adopts the water-based polyurethane emulsion as the basic emulsion.
In one specific embodiment, the water-based polyurethane wave-absorbing coating is prepared from the following raw materials in parts by weight:
specifically, the wave-absorbing material may be a wave-absorbing material existing in the field, and is not particularly limited. However, the traditional wave-absorbing materials (such as ferrite, ceramics and the like) have the defects of high density and narrow absorption frequency, and cannot meet the following requirements: thin, light, wide and strong. In comparison, the carbon material absorbent has more excellent electromagnetic shielding and absorption characteristics, is light in weight, high in strength and hardness, low in resistivity and good in thermal conductivity, and is better in compatibility in the water-based polyurethane wave-absorbing coating system of the invention, and the curing of the coating is not influenced, so that the carbon material absorbent is preferably adopted as the wave-absorbing material and mainly comprises at least one of carbon black, graphite, carbon fibers, carbon nanotubes, football graphene and graphene (including Graphene Oxide (GO) and the like).
More preferably, the wave-absorbing material is Graphene Oxide (GO). Besides good mechanical property, mechanical property and thermal stability, the graphene oxide can also improve the ageing resistance of the coating, and can generate strong interface interaction with the aqueous polyurethane emulsion, so that the mobility of polymer molecular chains is poor, the cohesive strength and the creep resistance of the coating are enhanced, and the surface of a core material has no obvious powder removal or chapping phenomenon. In addition, graphene oxide is an amphiphilic substance, and the main reason is that the graphene sheet exhibits a property distribution from hydrophilic to hydrophobic from the edge to the center, which can exist at the interface as a surfactant and reduce the energy between the interfaces, and the graphene oxide has a large number of oxygen-containing groups on the surface and the edge, and can stably exist in an aqueous solution and a polar solvent.
In one specific embodiment, the dispersant is selected from at least one of a water-resistant polymeric dispersant (e.g., hydrophobically modified ammonium acrylate copolymer dispersant (e.g., model: H5028, Shanghai Kangji chemical Co., Ltd.) or a copolymer containing a pigment-philic group (e.g., model: BOK-3864, Guangzhou Xin Ying trade Co., Ltd.), a polycaprolactone polyol-polyethyleneimine block copolymer dispersant (e.g., propylene glycol methyl ether acetate, Qingdao Minfar New Material Co., Ltd.), an acrylate polymeric dispersant (e.g., Tego 745W, Germany Digao, or an agent thereof), a polyurethane polymeric dispersant (e.g., BYK-163, Bikk chemical), and a polyester polymeric dispersant (e.g., 1100W, Taiwan Houtch Co., Ltd.). By adopting the dispersant, the interfacial energy of a system when water is used as a solvent can be improved, the dispersion stability effect of a water-based system is greatly improved, the raw material components are stably suspended and dispersed in water, the prepared coating has moderate viscosity and good physical properties such as coating sizing rate, adhesive force and the like, and the system stability of the water-based polyurethane coating can be improved. Preferably, the dispersant is a hydrophobically modified acrylate ammonium salt copolymer dispersant, such as SN-2725, available from Shanghai deep bamboo chemical technology, Inc.
In one particular embodiment, the defoamer is selected from at least one of a mixture of silicone and mineral oil, a fatty acid salt, a polyether siloxane copolymer, and a derivative of silicone. The defoaming agent is mainly used for removing harmful foams generated in the production process of the coating. Preferably, the defoamer is a polyether siloxane copolymer (e.g., Tego 810, digao, germany, or an agent thereof).
In one specific embodiment, the curing agent is selected from polyisocyanates, which are important basic raw materials of polyurethane, and have the characteristics of easy drying, wear resistance, high hardness, good fullness, good flexibility, easy polishing, strong compatibility with solvents and stable performance. Preferably, the curing agent is Toluene Diisocyanate (TDI), which is typically a mixture of two isomers of 2,4-TDI and 2,6-TDI, which has excellent weather and temperature resistance properties, and may include 3 designations: TDI-80/20, TDI-100 and TDI-65/35. The preceding numbers indicate the content of 2,4-TDI in the composition. For example, 80 in TDI-80/20 means that the composition is 80% 2,4-TDI and 20% 2, 6-TDI. More preferably, the curing agent is TDI-80/20, has good solubility in various solvents and good compatibility with a coating system, and is beneficial to ensuring the stability of the coating system.
The preparation method of the waterborne polyurethane wave-absorbing coating comprises the following steps:
mixing a proper amount of water, the dispersing agent, the defoaming agent and the wave-absorbing material, and stirring and dispersing; then adding the pH regulator to regulate the pH of the system to 8-10, adding the basic emulsion and the rest water, and stirring and dispersing; then adding the curing agent, and stirring and dispersing; the mixture obtained is ground. The proper amount of water can be adjusted according to the dispersing effect, for example, 10-20 parts of water is added firstly.
In a specific embodiment, the grinding refers to grinding the mixture to the fineness of 1-5 microns.
The embodiment of the invention also provides a wave-absorbing honeycomb which comprises a honeycomb core material and the waterborne polyurethane wave-absorbing coating attached to the honeycomb core material.
The preparation method of the wave-absorbing honeycomb comprises the following steps:
and sizing the honeycomb core material by using the water-based polyurethane wave-absorbing coating, and then drying and curing.
In one specific embodiment, the sizing method is dipping, curtain coating or spraying.
In one specific embodiment, the drying method is air blast drying, the drying temperature is 75-85 ℃, and the drying time is 15-25 min.
In one specific embodiment, the curing temperature is 30-80 ℃ and the curing time is 3-24 hours. For example, 3 hours at 80 ℃, 10 hours at 50 ℃ and 24 hours at 30 ℃.
In the following, specific examples are shown, and all the raw materials used are commercially available ones unless otherwise specified.
In the following specific examples, in order to illustrate the performance of the aqueous polyurethane emulsion of the present invention, the aqueous polyurethane emulsion of each example is applied to the aqueous polyurethane wave-absorbing coating with the same weight part, but the application cannot be taken as a limitation of the formulation of the aqueous polyurethane wave-absorbing coating of the present invention, and the formulation of the aqueous polyurethane wave-absorbing coating of the present invention is subject to the above-mentioned content.
The performance test method of each example is as follows:
(1) flat panel reflectance test
And the transmitting antenna and the receiving antenna are symmetrically arranged on the circular arc, and the plane of the circular arc is vertical to the plane of the wave-absorbing material. The transmitting antenna generates an excitation signal to the wave-absorbing material, and the signal of the mirror reflection part is acquired by the receiving antenna. Then, an ideal conductive metal plate is used for replacing the wave-absorbing material to measure the reflected signal; finally, the reflected signals under the front and the back conditions are compared to obtain the reflectivity of the material. Test size 300mm by 300mm, test band: 2GHz-18 GHz; the microwave flat plate reflectivity test is carried out according to GJB 2038A-2011 radar absorbing material reflectivity test method, and the result is expressed by absorption intensity and-4 dB bandwidth.
The testing steps are as follows:
1) starting up the instrument for preheating, and simultaneously building a test platform;
2) the metal standard plate is placed on a test board, a time domain door range is set by utilizing the time domain function of a vector network analyzer, antenna coupling is isolated, a main reflection peak is selected, and the test dynamic range is improved.
3) After the time domain is set, setting a test plan (an example is a 10-degree semi-automatic sampling test) by using test software, and starting the test (sequentially testing the metal standard plate and the wave-absorbing material sample); after the test is finished, the absorption intensity and the-4 dB bandwidth can be obtained by processing and analyzing the test data.
(2) Plane compressive Strength test
Taking GB/T1453-2005 test method as an example:
A. preparing a sample: cutting into sample honeycomb of 60mm 5mm and 60mm 40 mm;
B. testing equipment: a universal material testing machine;
C. compressing the clamp: a fixed flat press plate and a press plate with a spherical seat (self-centering) should be used to introduce force into the test piece, the press plate is well centered and no eccentric load is applied, and the press plate surface should exceed the test piece profile. If the platens have insufficient hardness or to protect the platen surfaces, a relatively hard flat plate (parallel to the surface) may be inserted between the clamp and each end face of the respective platen.
The test method comprises the following steps: when the flat compression strength is tested, the spherical support is adjusted to enable the upper cushion block to be parallel to the lower pressing sheet of the testing machine, then the upper cushion block and the lower pressing sheet are uniformly and continuously loaded until the upper cushion block is damaged, the damage load is read, and the damage form is recorded. The recommended loading speed is 0.5 mm/min.
E. Destruction form: uniform destruction of the sample honeycomb is the only acceptable form of destruction, and compressive destruction limited to one corner or edge is ineffective.
F. Data processing: the 3 th position after the decimal point is retained, ultimate strength, P ═ F/a. Wherein P is not flat compressive strength, MPa; f is the ultimate load before failure, N; a is the cross-sectional area of the specimen, mm2。
Example 1
The embodiment is a wave-absorbing honeycomb, and the preparation method thereof is as follows (see the process flow chart in fig. 1):
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 65 parts of PU into a reaction container, adding 4 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 1.6 parts of Tego 760W and 1.2 parts of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 1.6 parts of AMP-95 and 25 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent aqueous PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-17 dB and-4 dB, and the bandwidth is 9 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 5.9 MPa.
Example 2
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 60 parts of PU into a reaction container, adding 3 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 0.1 part of Tego 760W and 0.05 part of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 0.1 part of AMP-95 and 15 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent aqueous PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 50 ℃ and the time was 10 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 5mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-15 dB and-4 dB, and the bandwidth is 8 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 5mm to be subjected to flat pressing test, and the strength is 4.6 MPa.
Example 3
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 70 parts of PU into a reaction container, adding 2 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 0.8 part of Tego 760W and 0.5 part of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 0.3 part of AMP-95 and 32 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.4 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent aqueous PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And D, drying and curing the wave-absorbing honeycomb prepared in the step C to obtain the wave-absorbing honeycomb material. Drying temperature and time: the temperature of the forced air drying area is 80 ℃, and the drying time is 20 min; the curing temperature was 30 ℃ and the time was 24 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 40mm for microwave flat plate reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-16 dB and-4 dB, and the bandwidth is 7 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 40mm to be subjected to flat pressing test, and the strength is 4.8 MPa.
Example 4
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 65 parts of PU into a reaction container, adding 4 parts of diethylenetriamine in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 1.6 parts of Tego 760W and 1.2 parts of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 1.6 parts of AMP-95 and 25 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent aqueous PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-16 dB and-4 dB, and the bandwidth is 7 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 4.8 MPa.
Example 5
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 65 parts of PU into a reaction container, adding 4 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 1.6 parts of triethylamine and 1.2 parts of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 1.6 parts of AMP-95 and 25 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent water-based PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through impregnation.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-16 dB and-4 dB, and the bandwidth is 6.5 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 4.4 MPa.
Example 6
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 65 parts of PU into a reaction container, adding 4 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 1.6 parts of Tego 760W and 1.2 parts of Tego 740W, continuing to react for 3h at 80 ℃, cooling to 40 ℃, adding 1.6 parts of AMP-95 and 25 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent aqueous PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of Tego 745W, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-15 dB and-4 dB, and the bandwidth is 6 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 4.9 MPa.
Example 7
The embodiment is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing PU emulsion: putting 65 parts of PU into a reaction container, adding 4 parts of HPA in the process of continuously stirring at normal temperature, gradually heating to 80 ℃, reacting for 1h, properly cooling, adding 2.8 parts of Tego 740W, continuously reacting for 3h at 80 ℃, cooling to 40 ℃, adding 1.6 parts of AMP-95 and 25 parts of deionized water under high-speed stirring, adjusting the pH value of the dispersion to 8-10 by using 0.1 part of AMP-95, dispersing for 30-60 min under the action of high-speed shearing force, cooling and sealing for later use, thus obtaining the semitransparent water-based PU emulsion.
1.2, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of PU emulsion and a proper amount of deionized water (10 parts), stirring at 2000rpm vigorously for 30 minutes until the emulsion is uniform, and finally adding 8 parts of TDI-80/20 and continuously stirring at 1000rpm for 20 minutes for later use;
1.3, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-17 dB and-4 dB, and the bandwidth is 8.5 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 4.8 MPa.
Comparative example 1
The comparative example is a wave-absorbing honeycomb, and the preparation method comprises the following steps:
preparation of water-based polyurethane wave-absorbing coating
1.1, preparing wave-absorbing slurry: weighing a proper amount of deionized water (20 parts) at room temperature, putting 0.6 part of SN-2725, 0.2 part of Tego 810 and 0.8 part of GO into a container in sequence, stirring at 500rpm until the GO is uniformly dispersed, adding 0.4 part of AMP-95, adjusting the pH value of the dispersion to 8-10, adding 60 parts of aqueous PU emulsion (model: FT-6001, manufacturer: Nanjing Feiteng chemical Co., Ltd.) and a proper amount of deionized water (10 parts), stirring vigorously at 2000rpm for 30 minutes until the emulsion is uniform, finally adding 8 parts of TDI-80/20, continuously stirring at 1000rpm for 20 minutes for later use;
1.2, grinding:
grinding the mixture for later use by a horizontal sand mill (2000rpm/30min) to obtain the PU wave-absorbing coating with the fineness of about 1-5 microns;
(II) preparation of wave-absorbing honeycomb
2.1 sizing
And uniformly distributing the PU wave-absorbing coating on the honeycomb core material through curtain coating.
2.2 drying and curing
And drying and curing the sized honeycomb core material to obtain the wave-absorbing honeycomb material. The drying adopts forced air drying, the zone temperature is 80 ℃, and the drying time is 20 min; the curing temperature was 80 ℃ and the time was 3 hours.
(III) test
And cutting the prepared wave-absorbing honeycomb into samples of 300mm by 15mm for microwave flat reflectivity test.
And (3) testing results: the absorption intensity in the range of 2GHz-18GHz is-17 dB and-4 dB, and the bandwidth is 6 GHz.
The sample with the tested electromagnetic parameter flat plate reflectivity is cut into sample honeycombs with the thickness of 60mm x 15mm to be subjected to flat pressing test, and the strength is 2.8 MPa.
The PU emulsion adopted by the wave-absorbing honeycombs in the embodiments 1 to 6 and the comparative example 1 and the performance test results are respectively shown in the following tables 1 to 2:
TABLE 1 PU emulsion formulation tables described in examples 1 to 6 and comparative example 1 (parts by weight)
Table 2 results of performance test of the wave-absorbing honeycomb described in examples 1 to 6 and comparative example 1
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. The waterborne polyurethane emulsion is characterized by being prepared from the following raw material components in parts by weight:
wherein the cross-linking agent is at least one selected from maleic acid derivatives, polyethylene polyamine compounds and hydroxyl-containing acrylate compounds;
the chemical formula of the active assistant comprises at least one active group of double bond, hydroxyl, amido, carboxyl and epoxy.
2. The aqueous polyurethane emulsion of claim 1, wherein the coagent is selected from at least one of Tego 760W, Tego 740W, 2-amino-2-methyl-1-propanol, ammonia, and triethylamine.
3. The aqueous polyurethane emulsion of claim 2, wherein the coagents are Tego 760W, Tego 740W and 2-amino-2-methyl-1-propanol.
4. A method for producing the aqueous polyurethane emulsion according to any one of claims 1 to 3, characterized by comprising the steps of:
mixing the polyurethane prepolymer and a cross-linking agent to carry out a cross-linking reaction; and then adding the active assistant and water for continuous reaction, and adjusting the pH value of the system to 8-10.
5. The water-based polyurethane wave-absorbing coating is characterized by being prepared from the following raw material components in parts by weight:
6. the waterborne polyurethane wave-absorbing coating of claim 5, wherein the wave-absorbing material is selected from at least one of carbon black, graphite, carbon fiber, carbon nanotube, football alkene and graphene.
7. The waterborne polyurethane wave-absorbing coating of claim 5, wherein the dispersant is at least one selected from the group consisting of a hydrophobically modified ammonium acrylate copolymer dispersant, a pigment-philic group-containing copolymer dispersant, a polycaprolactone polyol-polyethyleneimine block copolymer dispersant, an acrylate polymer dispersant, a polyurethane polymer dispersant and a polyester polymer dispersant.
8. The waterborne polyurethane wave-absorbing coating of any one of claims 5 to 7, wherein the pH regulator is at least one selected from the group consisting of 2-amino-2-methyl-1-propanol, ammonia water and triethylamine; and/or
The defoaming agent is selected from at least one of a mixture of organic silicon and mineral oil, fatty acid salt, polyether siloxane copolymer and organic silicon derivative; and/or
The curing agent is selected from polyisocyanates.
9. The preparation method of the waterborne polyurethane wave-absorbing coating of any one of claims 5 to 8, which is characterized by comprising the following steps:
mixing a proper amount of water, the dispersing agent, the defoaming agent and the wave-absorbing material, and stirring and dispersing; then adding the pH regulator to regulate the pH of the system to 8-10, adding the basic emulsion and the rest water, and stirring and dispersing; then adding the curing agent, and stirring and dispersing; the mixture obtained is ground.
10. A wave-absorbing honeycomb, which is characterized by comprising a honeycomb core material and the waterborne polyurethane wave-absorbing coating of any one of claims 5 to 8 attached on the honeycomb core material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911226698.8A CN112898893A (en) | 2019-12-04 | 2019-12-04 | Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911226698.8A CN112898893A (en) | 2019-12-04 | 2019-12-04 | Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112898893A true CN112898893A (en) | 2021-06-04 |
Family
ID=76104555
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911226698.8A Pending CN112898893A (en) | 2019-12-04 | 2019-12-04 | Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112898893A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114591645A (en) * | 2022-03-04 | 2022-06-07 | 中国人民解放军火箭军工程大学 | Carbon-based wave-absorbing coating, preparation method thereof and honeycomb sandwich structure composite wave-absorbing material |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102199333A (en) * | 2010-03-22 | 2011-09-28 | 苏州美克思科技发展有限公司 | Method for manufacturing advanced reinforced phenolic honeycomb core composite material |
| CN102690402A (en) * | 2012-05-29 | 2012-09-26 | 四川力通复合材料科技有限公司 | Preparation method for phenolic resin for modified NOMEX honeycombs |
| CN102757533A (en) * | 2011-04-28 | 2012-10-31 | 比亚迪股份有限公司 | Aqueous polyurethane emulsion, preparation method thereof and two-component aqueous silver powder coating composition |
| CN103408715A (en) * | 2013-08-09 | 2013-11-27 | 中科院广州化学有限公司 | Internal crosslinking polypropylene carbonate waterborne polyurethane emulsion and preparation method and application thereof |
| CN105461863A (en) * | 2015-12-23 | 2016-04-06 | 中山大学惠州研究院 | Acrylate modified waterborne polyurethane emulsion and preparation method thereof |
| CN107053768A (en) * | 2016-12-15 | 2017-08-18 | 中航复合材料有限责任公司 | A kind of preparation method of water soluble phenol resin comb core |
| CN107573789A (en) * | 2017-09-11 | 2018-01-12 | 宜昌市大棒科技有限公司 | A kind of hazy and illusionary camouflage veneer coating and preparation method thereof |
| CN109135530A (en) * | 2018-07-03 | 2019-01-04 | 南京理工大学 | DAPBI modified aqueous polyurethane coating and preparation method thereof |
| CN109734846A (en) * | 2019-01-23 | 2019-05-10 | 长春工业大学 | A kind of core-shell type aqueous polyurethane/acrylate composite emulsion and preparation method thereof and damping paint |
| CN109796624A (en) * | 2019-01-24 | 2019-05-24 | 大连东信微波技术有限公司 | Inhale wave honeycomb and preparation method thereof |
-
2019
- 2019-12-04 CN CN201911226698.8A patent/CN112898893A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102199333A (en) * | 2010-03-22 | 2011-09-28 | 苏州美克思科技发展有限公司 | Method for manufacturing advanced reinforced phenolic honeycomb core composite material |
| CN102757533A (en) * | 2011-04-28 | 2012-10-31 | 比亚迪股份有限公司 | Aqueous polyurethane emulsion, preparation method thereof and two-component aqueous silver powder coating composition |
| CN102690402A (en) * | 2012-05-29 | 2012-09-26 | 四川力通复合材料科技有限公司 | Preparation method for phenolic resin for modified NOMEX honeycombs |
| CN103408715A (en) * | 2013-08-09 | 2013-11-27 | 中科院广州化学有限公司 | Internal crosslinking polypropylene carbonate waterborne polyurethane emulsion and preparation method and application thereof |
| CN105461863A (en) * | 2015-12-23 | 2016-04-06 | 中山大学惠州研究院 | Acrylate modified waterborne polyurethane emulsion and preparation method thereof |
| CN107053768A (en) * | 2016-12-15 | 2017-08-18 | 中航复合材料有限责任公司 | A kind of preparation method of water soluble phenol resin comb core |
| CN107573789A (en) * | 2017-09-11 | 2018-01-12 | 宜昌市大棒科技有限公司 | A kind of hazy and illusionary camouflage veneer coating and preparation method thereof |
| CN109135530A (en) * | 2018-07-03 | 2019-01-04 | 南京理工大学 | DAPBI modified aqueous polyurethane coating and preparation method thereof |
| CN109734846A (en) * | 2019-01-23 | 2019-05-10 | 长春工业大学 | A kind of core-shell type aqueous polyurethane/acrylate composite emulsion and preparation method thereof and damping paint |
| CN109796624A (en) * | 2019-01-24 | 2019-05-24 | 大连东信微波技术有限公司 | Inhale wave honeycomb and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 吕明旭等: "聚氨酯乳液/纳米石墨微片复合导电涂料的制备及其电磁屏蔽性能", 《安全与电磁兼容》 * |
| 吕明旭等: "聚氨酯乳液/纳米石墨微片复合导电涂料的制备及其电磁屏蔽性能", 《安全与电磁兼容》, no. 06, 25 December 2008 (2008-12-25), pages 69 - 72 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114591645A (en) * | 2022-03-04 | 2022-06-07 | 中国人民解放军火箭军工程大学 | Carbon-based wave-absorbing coating, preparation method thereof and honeycomb sandwich structure composite wave-absorbing material |
| CN114591645B (en) * | 2022-03-04 | 2023-02-17 | 中国人民解放军火箭军工程大学 | Carbon-based wave-absorbing coating, preparation method thereof and honeycomb sandwich structure composite wave-absorbing material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108976986B (en) | High-solid-content graphene wave-absorbing coating and preparation method thereof | |
| CN106189602B (en) | A kind of modified white graphite alkene compound anti-oxidation coating and its preparation | |
| CN110922709A (en) | Conductive polymer composite wave-absorbing material and preparation method thereof | |
| CN112029421A (en) | Wave-absorbing adhesive film material and preparation method thereof | |
| CN109943018B (en) | Wave absorbing agent, wave absorbing material and respective preparation method | |
| CN110054942A (en) | A kind of infrared radar multi-Functional Camouflage coating of containing graphene and preparation method thereof | |
| WO2019205011A1 (en) | Aqueous wave-absorbing coating material, preparation method therefor, and use thereof | |
| EP4276152A1 (en) | Aerogel coating and preparation method therefor, and aerogel coating layer and preparation method therefor | |
| CN109760384A (en) | A kind of preparation method of high dielectric constant composite laminate | |
| CN114805882A (en) | High-strength antistatic 3D sheet and preparation method thereof | |
| CN112898893A (en) | Waterborne polyurethane emulsion, waterborne polyurethane wave-absorbing coating, preparation method of waterborne polyurethane wave-absorbing coating and wave-absorbing honeycomb | |
| CN112094109B (en) | Alumina ceramic slurry for transformer framework and preparation method and application method thereof | |
| CN109943208B (en) | Micro-nano structure coating and preparation method and application thereof | |
| CN110606698B (en) | Microwave composite dielectric substrate with high uniformity and low thermal expansion coefficient and preparation process thereof | |
| CN110951342B (en) | Radar wave-absorbing coating and preparation process thereof | |
| CN113249031A (en) | High-thermal-conductivity silica gel wave absorbing plate and preparation method thereof | |
| CN106699192B (en) | Functional ceramic gel casting slurry and preparation method thereof | |
| CN113930134B (en) | Wave-absorbing coating and preparation method thereof | |
| CN111057457B (en) | Water-resistant and environment-friendly water-based wave absorbing plate and preparation method thereof | |
| CN111218189A (en) | Resistive film and preparation method and application thereof | |
| CN114213953A (en) | Black water-based high-performance electromagnetic wave shielding coating and preparation method thereof | |
| CN109517559B (en) | Fast-curing wave-absorbing edge sealing adhesive | |
| CN116004058B (en) | Water-based paint and preparation method thereof | |
| EP4232520B1 (en) | Phthalonitrile-based high temperature resistive inks | |
| CN118185407B (en) | Preparation method of aerogel hollow glass bead heat-insulating water-based paint |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210604 |