CN117925078A - Coating suitable for compact coating and application thereof - Google Patents
Coating suitable for compact coating and application thereof Download PDFInfo
- Publication number
- CN117925078A CN117925078A CN202211253480.3A CN202211253480A CN117925078A CN 117925078 A CN117925078 A CN 117925078A CN 202211253480 A CN202211253480 A CN 202211253480A CN 117925078 A CN117925078 A CN 117925078A
- Authority
- CN
- China
- Prior art keywords
- coating
- aqueous
- water
- paint
- aqueous polyurethane
- 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
- 238000000576 coating method Methods 0.000 title claims abstract description 178
- 239000011248 coating agent Substances 0.000 title claims abstract description 158
- 239000003973 paint Substances 0.000 claims abstract description 77
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 75
- 239000004814 polyurethane Substances 0.000 claims abstract description 63
- 229920002635 polyurethane Polymers 0.000 claims abstract description 63
- 239000002966 varnish Substances 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 21
- NNOZGCICXAYKLW-UHFFFAOYSA-N 1,2-bis(2-isocyanatopropan-2-yl)benzene Chemical group O=C=NC(C)(C)C1=CC=CC=C1C(C)(C)N=C=O NNOZGCICXAYKLW-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000000203 mixture Substances 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 19
- 238000005507 spraying Methods 0.000 claims description 18
- 239000002994 raw material Substances 0.000 claims description 14
- 239000002253 acid Substances 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 7
- 239000002131 composite material Substances 0.000 claims description 6
- 125000000524 functional group Chemical group 0.000 claims description 6
- 150000001298 alcohols Chemical class 0.000 claims description 3
- 150000001412 amines Chemical class 0.000 claims description 3
- 238000006386 neutralization reaction Methods 0.000 claims description 3
- 229920005862 polyol Polymers 0.000 claims description 3
- 150000003077 polyols Chemical class 0.000 claims description 3
- 239000000126 substance Substances 0.000 abstract description 10
- 238000007665 sagging Methods 0.000 abstract description 4
- 230000006750 UV protection Effects 0.000 abstract description 3
- 230000007774 longterm Effects 0.000 abstract description 3
- 238000003756 stirring Methods 0.000 description 19
- 238000002360 preparation method Methods 0.000 description 18
- 239000000463 material Substances 0.000 description 10
- AZYRZNIYJDKRHO-UHFFFAOYSA-N 1,3-bis(2-isocyanatopropan-2-yl)benzene Chemical group O=C=NC(C)(C)C1=CC=CC(C(C)(C)N=C=O)=C1 AZYRZNIYJDKRHO-UHFFFAOYSA-N 0.000 description 9
- 238000001816 cooling Methods 0.000 description 7
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 description 6
- UEEJHVSXFDXPFK-UHFFFAOYSA-N N-dimethylaminoethanol Chemical compound CN(C)CCO UEEJHVSXFDXPFK-UHFFFAOYSA-N 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 6
- 239000008199 coating composition Substances 0.000 description 6
- 239000013530 defoamer Substances 0.000 description 6
- 239000012972 dimethylethanolamine Substances 0.000 description 6
- 238000004070 electrodeposition Methods 0.000 description 6
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 4
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 4
- 229920003180 amino resin Polymers 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000006184 cosolvent Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 239000002562 thickening agent Substances 0.000 description 4
- BWDBEAQIHAEVLV-UHFFFAOYSA-N 6-methylheptan-1-ol Chemical compound CC(C)CCCCCO BWDBEAQIHAEVLV-UHFFFAOYSA-N 0.000 description 3
- 229920003270 Cymel® Polymers 0.000 description 3
- 229960002887 deanol Drugs 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 239000012948 isocyanate Substances 0.000 description 3
- 150000002513 isocyanates Chemical class 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 description 3
- 229920005906 polyester polyol Polymers 0.000 description 3
- 239000004576 sand Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 229910002012 Aerosil® Inorganic materials 0.000 description 2
- 229920003274 CYMEL® 303 LF Polymers 0.000 description 2
- 239000005058 Isophorone diisocyanate Substances 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 125000002091 cationic group Chemical group 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical group CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 description 2
- 230000003472 neutralizing effect Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 230000004224 protection Effects 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 239000012855 volatile organic compound Substances 0.000 description 2
- LRXTYHSAJDENHV-UHFFFAOYSA-H zinc phosphate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O LRXTYHSAJDENHV-UHFFFAOYSA-H 0.000 description 2
- 229910000165 zinc phosphate Inorganic materials 0.000 description 2
- NECRQCBKTGZNMH-UHFFFAOYSA-N 3,5-dimethylhex-1-yn-3-ol Chemical compound CC(C)CC(C)(O)C#C NECRQCBKTGZNMH-UHFFFAOYSA-N 0.000 description 1
- YLZOPXRUQYQQID-UHFFFAOYSA-N 3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]propan-1-one Chemical compound N1N=NC=2CN(CCC=21)CCC(=O)N1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F YLZOPXRUQYQQID-UHFFFAOYSA-N 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- JGFZNNIVVJXRND-UHFFFAOYSA-N N,N-diisopropylethylamine Substances CCN(C(C)C)C(C)C JGFZNNIVVJXRND-UHFFFAOYSA-N 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- UKLDJPRMSDWDSL-UHFFFAOYSA-L [dibutyl(dodecanoyloxy)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCC)(CCCC)OC(=O)CCCCCCCCCCC UKLDJPRMSDWDSL-UHFFFAOYSA-L 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 239000012975 dibutyltin dilaurate Substances 0.000 description 1
- 239000000539 dimer Substances 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 229910021485 fumed silica Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- XXMIOPMDWAUFGU-UHFFFAOYSA-N hexane-1,6-diol Chemical compound OCCCCCCO XXMIOPMDWAUFGU-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 239000006115 industrial coating Substances 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- 150000007974 melamines Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- -1 neutralizer Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- ACVYVLVWPXVTIT-UHFFFAOYSA-N phosphinic acid Chemical compound O[PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-N 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 239000001038 titanium pigment Substances 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
- 238000004383 yellowing Methods 0.000 description 1
Abstract
The invention discloses a coating suitable for compact coating, a coating prepared from the coating and application thereof. The paint comprises water-based colored paint and varnish, and optionally water-based middle coating; wherein, the aqueous middle coating and the aqueous color paint both comprise one or more aqueous polyurethane; the structure of the aqueous polyurethane contains tetramethyl xylylene diisocyanate groups. When the coating meets the requirement of compact process coating, the obtained coating has excellent appearance (such as improved pinhole-free performance, sagging resistance and the like), excellent chemical resistance, ultraviolet resistance, long-term weather resistance and the like.
Description
Technical Field
The invention relates to the technical field of paint. And more particularly to a coating suitable for compact painting and its application.
Background
The production of China automobiles is rapidly increased, and the requirements of automobile coatings, the production and the demand are also large. Environmental pressures and requirements are becoming more severe and stringent, resulting in the development and growth of aqueous automotive coatings. The latest revised "atmospheric pollution control laws", the first time Volatile Organic Compounds (VOCs) are brought into the regulatory range, which puts more stringent demands on the coating industry. How to reduce the amount of organic solvents in coating systems is an important goal in terms of reducing air pollution and reducing energy consumption, which is closely related to environmental protection. The water-based paint of the original automobile factory is taken as one of the effective means for environmental protection, and is increasingly adopted in domestic host factories such as Jili automobiles, changan automobiles and the like. Compared with the traditional solvent-based colored paint, the solvent-based colored paint also brings a plurality of technical requirements for further improvement in the aspects of workability, performance and the like.
Meanwhile, in order to reduce energy consumption and improve efficiency and benefit, automobile manufacturers have abandoned the traditional three-coating and three-baking coating process basically, and gradually converted into three-coating and one-baking and two-coating and one-baking processes (commercial vehicles are especially prone to two-coating and one-baking coating processes). The intermediate coating and the colored paint layer are not fully baked at 120 ℃ or above, but dehydrated for 5-10 minutes at 60-90 ℃, then the intermediate coating and the colored paint layer are directly sprayed with wet-spraying varnish, and then the multi-coating layer is baked and crosslinked together. As the varnishes are currently substantially all solvent-borne products. When the water-based paint is not sufficiently dried and contains water, the solvent-based varnish is wet-sprayed, and the paint film tends to have defects such as pinholes, sagging, poor appearance and the like. To reduce such drawbacks, various coating technologies (including products of multiple countries such as germany, france, japan, korea, etc.) of the aqueous compact process at present often require that the applied film thickness of aqueous intercoat and paint be reduced or that the intercoat be directly dispensed with. Although the paint film can improve the problems of the paint film, the lower film thickness of the intermediate coating and the colored paint brings a plurality of problems to the coating performance of the automobile after the coating is finished, such as stone-impact resistance, impact resistance and other mechanical properties, acid resistance, alkali resistance and other chemical resistance, ultraviolet resistance, long-term weather resistance and the like.
Disclosure of Invention
Based on the above facts, an object of the present invention is to provide a coating material suitable for compact coating, which, when satisfying compact process coating, gives a coating layer having excellent appearance (e.g. having improved pinhole-free, sag resistance, etc.), while having excellent chemical resistance, uv resistance, long-term weather resistance, etc., and its use.
In one aspect, the present invention provides a coating suitable for compact coating, including aqueous paints, varnishes, optionally aqueous intercoat; wherein, the aqueous middle coating and the aqueous color paint both comprise one or more aqueous polyurethane;
The structure of the aqueous polyurethane contains tetramethyl xylylene diisocyanate groups.
Further, the aqueous intercoat comprises 20-25wt% of the aqueous polyurethane based on the total mass percent of the aqueous intercoat; and/or
The aqueous color paint comprises 8-15wt% of the aqueous polyurethane based on the total mass percentage of the aqueous color paint.
Further, the pH value of the aqueous polyurethane is 6.5-7.0, the nonvolatile matter is 39-41%, the viscosity measured under the condition of a rotary viscometer 1000s -1 is 200-300 mPa.s, and the acid value is 15-20mgKOH/g.
Further, the aqueous polyurethane is prepared by a method comprising the following steps:
Providing a mixture of alcohols comprising at least one polyol;
providing a mixture capable of reacting with isocyanate comprising an anionically formed functional group and at least an average functionality of 2;
And (3) carrying out amine neutralization on the mixture after the reaction, and dispersing the mixture in water to obtain the aqueous polyurethane.
Further, the pH value of the aqueous middle coating is 8.0-8.5, the nonvolatile matter is 40% -50%, and the viscosity measured under the condition of a rotary viscometer 250s -1 is 160-200 mPa.s.
Further, the pH value of the water-based colored paint is 8.0-8.5, the nonvolatile matter is 40% -50%, and the viscosity measured under the condition of a rotational viscometer 250s -1 is 150-190 mPa.s.
In yet another aspect, the present invention provides a coating suitable for compact coating, using the coating as described above as a starting material, using a three-coat one-bake coating process or a two-coat one-bake coating process to form a coating.
Further, the three-coating one-baking coating process comprises the following steps:
Spraying the aqueous intercoat to form an uncrosslinked and cured aqueous intercoat coating film;
spraying water-based paint on the uncrosslinked and cured water-based middle-coating film to form an uncrosslinked and cured water-based paint film;
Drying and dehydrating the obtained coating film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish coating film;
And (3) curing the obtained composite coating at one time to obtain a cured water-based intermediate coating, a cured water-based colored paint coating and a cured varnish coating.
Further, the two-coating one-baking coating process comprises the following steps:
spraying water-based paint to form an uncrosslinked and cured water-based paint film;
drying and dehydrating the non-crosslinked and solidified water-based colored paint film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish film;
and (3) curing the obtained composite coating at one time to obtain a cured water-based colored paint coating and a cured varnish coating.
In a further aspect, the present invention provides the use of a coating as provided in the first aspect above in automotive coating.
The beneficial effects of the invention are as follows:
In the coating provided by the invention, the waterborne polyurethane containing the tetramethyl xylylene diisocyanate groups is simultaneously arranged in the waterborne intercoat and the waterborne color paint, so that the waterborne intercoat and the color paint in the coating are well matched when the coating is formed by a compact spraying process, have good construction property and appearance, effectively avoid common paint film defects such as pinholes, blastholes, sagging, mixed layers and the like, and have improved mechanical properties (including stone impact property, impact property), chemical properties (including acid and alkali resistance and the like), weather resistance and the like.
Detailed Description
In order to more clearly illustrate the present invention, the present invention will be further described with reference to preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and that this invention is not limited to the details given herein.
Aiming at least at solving the problems that the paint technology of the water-based compact technology in the prior art cannot better prevent poor appearance such as pinholes and sagging and excellent chemical resistance, weather resistance and other construction properties in the process of coating the automobile body, the invention provides a paint suitable for compact coating, wherein the paint comprises water-based colored paint and varnish, and optionally water-based middle coating; wherein, the aqueous middle coating and the aqueous color paint both comprise one or more aqueous polyurethane;
The structure of the aqueous polyurethane contains tetramethyl xylylene diisocyanate groups.
In the technical scheme of the embodiment, the aqueous polyurethane is the aqueous polyurethane containing tetramethyl xylylene diisocyanate groups in the structure.
In this embodiment, the use of MDI, TDI, and other isocyanate groups instead of the tetramethylxylylene diisocyanate groups has also been studied, and this aqueous compact coating has adverse effects on weather resistance of the resulting coating such as insolation, xenon lamp, high temperature yellowing, and the like when used in an automobile body.
In the above technical solution, the optional aqueous intercoat means that the aqueous intercoat may or may not exist. For example, in a three-coat one-bake process, there is an aqueous middle coat; in the two-coating one-baking process, no aqueous intermediate coating exists.
In some examples, the aqueous polyurethane has a pH of 6.5 to 7.0, a nonvolatile matter of 39% to 41%, a viscosity of 200 to 300 mPas as measured under a rotational viscometer of 1000s -1, and an acid value of 15 to 20mgKOH/g. This can be advantageous to provide a better application appearance of the coating.
Illustratively, the aqueous polyurethane is prepared by a process comprising the steps of:
Providing a mixture of alcohols comprising at least one polyol;
Providing a mixture containing anionically formed functional groups and having at least an average functionality of 2 capable of reacting with tetramethylxylylene diisocyanate;
And (3) carrying out amine neutralization on the mixture after the reaction, and dispersing the mixture in water to obtain the aqueous polyurethane.
In some examples, the aqueous basecoat comprises from 20 to 25 weight percent of the aqueous polyurethane, based on the total mass percent of the aqueous basecoat; and/or
The aqueous color paint comprises 8-15wt% of the aqueous polyurethane based on the total mass percentage of the aqueous color paint.
The coating with excellent appearance performance is more beneficial to be obtained by limiting the dosage of the aqueous polyurethane in the coating.
In some examples, the aqueous washcoat has a pH of 8.0-8.5, a nonvolatile of 40% -50%, and a viscosity of 160-200 mPas measured with a rotational viscometer of 250s -1.
In this embodiment, the aqueous middle coating further includes other conventional components, such as amino resin, aqueous acrylic acid, thickener, dispersant, defoamer, carbon black, titanium pigment, water, neutralizer, cosolvent, and the like. The specific choice of these components may be a matter of routine in the art. For example, the raw materials can be easily obtained mature commercial finished products in China, and the main components are as follows:
(1) Amino resin Cymel 250, cymel 303 LF is selected from the group consisting of blue new resins company;
(2) The aqueous acrylic acid Setaqua 6803,6803 is selected from the group consisting of Zhan Xin resin company;
(3) The thickener Viscalex HV 30solution 9% is selected from Basoff company;
(4) Dispersing agent -DISPERSANT-192, defoamer BYKETOL-WA, leveling agent Byk-346 selected from the group of the company pick chemistry;
(5) The defoamer TEGO FOAMEX 805N, fumed silica AEROSIL R972 is selected from the group consisting of Yingchang;
(6) Carbon Black specialty Black 4 is selected from European;
(7) Titanium dioxide R-996 is selected from Chinese dragon boa company;
(8) Other components such as pure water, a neutralizing agent of dimethylethanolamine, cosolvent of ethylene glycol butyl ether, isooctanol and the like are common products.
In some examples, the aqueous color paint has a pH of 8.0-8.5, a nonvolatile of 40% -50%, and a viscosity of 150-190 mPa.s as measured by a rotational viscometer under conditions of 250s -1.
In this embodiment, the aqueous color paint further includes other conventional components, such as amino resin, aqueous acrylic acid, thickener, defoamer, leveling agent, water, neutralizer, cosolvent, and the like. The specific choice of these components may be a matter of routine in the art. For example, the raw materials can be easily obtained mature commercial finished products in China, and the main components are as follows:
(1) Amino resin Cymel 250 is selected from the group consisting of Zhanxin resins;
(2) The aqueous acrylic acid Setaqua 6803,6803 and SETAQUA 6407,6407 are selected from the group consisting of Zhan Xin resin Co;
(3) The thickener Viscalex HV 30solution 9% and acrylic emulsion Luhydran S T are selected from Basoff company;
(4) The antifoaming agent BYKETOL-WA is selected from Pick chemical company;
(5) Leveling agent TEGO Wet 505 is selected from the group consisting of winning companies;
(6) The leveling agent DYNOL 607,607 SURFACTANT, and the SURFACTANT SURFYNOL 2502SURFACTANT are selected from air chemical company;
(7) Other components such as pure water, a neutralizing agent of dimethylethanolamine, cosolvent of ethylene glycol butyl ether, isooctanol and the like are common products.
In yet another embodiment of the present invention, a coating suitable for compact coating is provided, wherein the coating is formed by using the coating as described above as a raw material, and using a three-coat one-bake coating process or a two-coat one-bake coating process.
The three-coating one-baking coating process comprises the following steps:
Spraying the aqueous intercoat to form an uncrosslinked and cured aqueous intercoat coating film;
spraying water-based paint on the uncrosslinked and cured water-based middle-coating film to form an uncrosslinked and cured water-based paint film;
Drying and dehydrating the obtained coating film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish coating film;
And (3) curing the obtained composite coating at one time to obtain a cured water-based intermediate coating, a cured water-based colored paint coating and a cured varnish coating.
Wherein, in the three-coating one-baking coating process, the water-based intermediate coating is sprayed on the electrophoretic coating.
The two-coat one-bake coating process includes the following steps:
spraying water-based paint to form an uncrosslinked and cured water-based paint film;
drying and dehydrating the non-crosslinked and solidified water-based colored paint film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish film;
and (3) curing the obtained composite coating at one time to obtain a cured water-based colored paint coating and a cured varnish coating.
In the two-coating one-baking coating process, the water-based colored paint is sprayed on the electrophoretic paint.
Further, the thickness of the aqueous intercoat after curing is 10-20 μm.
Further, the film thickness of the cured aqueous paint is 10-20 mu m.
Yet another embodiment of the present invention provides the use of a coating as described above in automotive coating.
The following describes the technical scheme of the present invention with reference to some specific embodiments:
Preparation of the aqueous polyurethane containing tetramethyl xylylene diisocyanate group (aqueous polyurethane a):
(1) Preparation of polyester polyol:
in a reaction vessel equipped with a reflux cooling device for a reaction water outlet, a thermometer, a stirring device and a nitrogen inlet pipe, the following raw materials were put into the reaction according to the following process:
The materials 1, 6-hexanediol, dimer acid 1013, hypophosphorous acid (50% aqueous solution) were added to a clean and anhydrous reaction vessel and heated to 140℃and incubated for 1 hour, and then gradually warmed to 230℃at a rate of 10-15℃per hour. Incubate until acid number <3mgKOH/g (1-3 hours reaction). Then gradually cooling to 70 ℃. In the cooling process, vacuumizing and dewatering are started when the temperature reaches 120 ℃, and the water content is measured when the temperature reaches 70 ℃ or no water basically comes out. And (3) vacuum water removal is completed until the water content is less than 0.15%. Cooling to 50 ℃, and adding 22-25 parts of butanone to adjust the solid content. Cooling to room temperature to obtain polyester polyol A with the following parameters:
Solid parts: 74-75%;
acid value: <3mgKOH/g;
coating the viscosity of the 4 cups for 60-100 seconds;
water content: <0.15%.
(2) Synthesis of aqueous polyurethane A:
In a reaction vessel equipped with a reflux cooling device for a reaction water outlet, a thermometer, a stirring device and a nitrogen inlet pipe, the following raw materials were put into the reaction according to the following process:
Adding polyester polyol A, 2-dimethylolpropionic acid, N-diisopropylethylamine, tetramethyl xylylene diisocyanate, butanone and DBTL catalyst into a clean and anhydrous reaction kettle according to the above; heating to 88+/-2 ℃, and preserving heat for 1-2 hours to react, wherein the reaction end point is that the NCO (isocyanate) content is less than 2%; 2.88 parts of trimethylolpropane is added, and the reaction is continued at 88.+ -. 2 ℃. The reaction end point is NCO (isocyanate) content less than 0.3%;5.88 parts of ethylene glycol butyl ether, and gradually and uniformly adding the ethylene glycol butyl ether into a reaction container within the time of 240 seconds to 300 seconds; and gradually adding 0.52 part of dimethylethanolamine and 14.7 parts of deionized water which are mixed in advance at a constant speed within 14-15 minutes. Then 22.1 parts of deionized water was added. Stirring was continued for 30 minutes while cooling the reaction vessel to 50-55 ℃. Vacuumizing until the water content is less than 0.5%. After the vacuum pumping is completed, the residual deionized water is added to adjust the viscosity and the solid content. The reaction vessel is cooled to room temperature to obtain the water-based polyurethane A, and the technical parameters are as follows:
the pH value is 6.5-7.0;
the nonvolatile matter is 39% -41%;
The viscosity is 200 mPas-300 mPas measured under the condition of 1000s -1 of a rotary viscometer;
The acid value is 15-20mg KOH/g.
Unless otherwise specified, the aqueous polyurethane A used in each of the following examples or comparative examples is prepared by this method, and will not be described again.
Coating preparation example section:
Preparation of aqueous intercoat:
Example 1-1
A preparation method of the aqueous middle coating comprises the following raw materials in the composition shown in the table 1. The preparation of the aqueous middle coating comprises the following steps:
Firstly, sequentially adding aqueous polyurethane A (3.47 parts) and DMEA 10% solution (0.53 parts) into a main cylinder, stirring to 300RPM by starting a TEGO FOAMEX 805N defoamer, and stirring for 15-30 minutes;
step two, sequentially adding the components into an auxiliary cylinder DISPERSANT-192 with butyl cellosolve (1.71 parts), stirring to 300RPM, stirring for 15-30 minutes; the main cylinder is in a 300RPM stirring state, and the mixture in the auxiliary cylinder is slowly added into the main cylinder within 5-7 minutes;
Thirdly, the master cylinder is in a stirring state of 300RPM, and CYMEL 303 LF Resin modified melamine resin, special Black 4, AEROSIL R972, pure water and R-996 are added in sequence. After the addition is completed, dispersing at a high speed at 800-1000RPM for 1 hour; after completion, the stirring shaft and the cylinder wall were washed with ethylene glycol butyl ether (0.63 parts), and pure water (6.94 parts). Dispersing for 15 minutes at 800-1000 RPM;
Fourth, sand the mixture in the main cylinder to a fineness of less than 5 μm by using a sand mill, and clean the sand mill pipeline by using pure water (3.74 parts);
fifthly, gradually adding aqueous polyurethane A (19.21 parts), DMEA 10% solution (1.09 parts), setaqua 6803, pure water (1.07 parts), viscalex HV 30solution 9%, CYMEL 325Resin, BYKETOL-WA defoamer, isooctanol and BYK-346 into a master cylinder under the stirring state of 300 RPM; after the addition is completed, dispersing at a high speed at 800-1000RPM for 1 hour;
Sixth, pure water (9.62 parts) and DMEA 10% solution (0.64 parts) were added to the master cylinder while stirring at 300RPM, and the viscosity and pH were adjusted.
The pH value of the aqueous middle coating is 8.0-8.5, the nonvolatile matter is 40% -50%, and the viscosity measured under the condition of a rotary viscometer 250s -1 is 160-200 mPa.s.
TABLE 1
Comparative example 1
A preparation method of the aqueous middle coating comprises the following raw materials in a composition shown in the table 1. The aqueous intercoat was prepared as in example 1-1, except that in the first step the aqueous polyurethane A was replaced with a nonvolatile equivalent amount of a racing aqueous polyurethane B (containing no TMXDI groups and containing isophorone diisocyanate groups). In the fifth step, the aqueous polyurethane A is replaced by nonvolatile equivalent competitive aqueous polyurethane B.
Examples 1 to 2
A preparation method of the aqueous middle coating comprises the following raw materials in a composition shown in the table 1. The aqueous intercoat was prepared as in example 1-1, except that in the fifth step the aqueous polyurethane A was used in an amount of 16.53% by weight and Setaqua 6803,6803 was used in an amount of 7.42% by weight. The amount of aqueous polyurethane A used is at the lower end of the range indicated above.
Examples 1 to 3
A preparation method of the aqueous middle coating comprises the following raw materials in a composition shown in the table 1. The aqueous intercoat was prepared as in example 1-1, except that in the fifth step the aqueous polyurethane A was used in an amount of 21.53% by weight and Setaqua 6803,6803 was used in an amount of 2.42% by weight. The amount of aqueous polyurethane A used is at the upper end of the range indicated above.
Preparation of the water-based colored paint:
Example 2-1
The preparation method of the water-based colored paint comprises the following raw materials in the composition shown in table 2. The preparation of the water-based colored paint comprises the following steps:
firstly, adding materials with the serial numbers of 12-17 and materials with the serial numbers of 20-21 into an auxiliary cylinder in a stirring state of 300rpm of the auxiliary cylinder, and stirring for 5min; sequentially adding materials with the serial numbers of 18-19, and stirring for 10min to obtain a mixture;
Secondly, sequentially adding materials with serial numbers of 1-11 in a stirring state of a main cylinder at 300 rpm;
thirdly, adding the mixture in the auxiliary cylinder into the main cylinder while stirring, cleaning the cylinder wall and the cylinder bottom of the auxiliary cylinder by using a material with the sequence number of 22, and mixing the mixture in the main cylinder for 15min;
fourthly, sequentially adding materials with serial numbers 23-29 into the main cylinder while stirring, and stirring for 30min;
Fifthly, adjusting the PH value to 7.8-8.5 by using a serial number 30 material; 150 mPa.s-190 mPa.s measured with a rotational viscometer adjusted with a material of serial number 31 for 250s -1;
The pH value of the obtained water-based paint is 8.0-8.5, the nonvolatile matter is 40% -50%, and the viscosity measured under the condition of a rotational viscometer 250s -1 is 150-190 mPa.s.
TABLE 2
Comparative example 2
A preparation method of the water-based colored paint comprises the following raw materials in a composition shown in the table 2. The preparation of the aqueous color paint was the same as in example 2-1, except that in the second and fourth steps the aqueous polyurethane A was replaced with a nonvolatile equivalent amount of a racing aqueous polyurethane C (containing no TMXDI groups and containing isophorone diisocyanate groups).
Example 2-2
A preparation method of the water-based colored paint comprises the following raw materials in a composition shown in the table 2. The aqueous color paint was prepared as in example 2-1, except that in the second step the amount of aqueous polyurethane A was adjusted to 5.5% by weight, the amount of Luhydran S T938T was adjusted to 14.28% wt%, and the amount of aqueous polyurethane A was the lower limit of the range described above.
Examples 2 to 3
A preparation method of the water-based colored paint comprises the following raw materials in a composition shown in the table 2. The aqueous color paint was prepared as in example 2-1, except that in the second step the amount of aqueous polyurethane A was adjusted to 12.5% by weight, the amount of Luhydran S T938T was adjusted to 2.66% by weight, and the amount of aqueous polyurethane A was the upper end of the range as described above.
Coating examples:
Example 3
Formation of coating film:
The zinc phosphate-treated passivated steel sheet was coated with an electrodeposition coating composition PN-310 (cationic electrodeposition coating composition produced by Vigorboom coating composition) until the thickness of the dried coating film was 20. Mu.m, and the steel sheet was heated at 160℃for 30 minutes to solidify the coating film and cooled to form a solidified electrodeposition coating film. All coating preparations and comparative examples were then sprayed on this electrocoat film using the three-coat one-bake process described previously. The other coatings related are shown in table 3 below. Various index tests were then performed according to the contents of table 4.
TABLE 3 Table 3
TABLE 4 Table 4
In example 3, the film was formed by spraying under a three-coat-one-bake process, and each index was measured. The results are shown in Table 5. The aqueous color paint and the aqueous middle coating have the best performance when the aqueous polyurethane A is used together. When one of them does not contain the aqueous polyurethane A, the performance is remarkably deteriorated. All without aqueous polyurethane a, the performance was the worst. The novel aqueous polyurethane A synthesized by tetramethyl-m-xylylene diisocyanate (TMXDI) has the advantages of aliphatic polyurethane and aromatic polyurethane due to the unique structure, and the aqueous coating prepared by the novel aqueous polyurethane A has the advantages of high adhesion, strength and flexibility, weather resistance, acid resistance, chemical resistance and the like. As can be seen from the test results in Table 5, the test items having high requirements for flexibility and adhesion, such as stone chips and cupping, were excellent. Meanwhile, the hardness is also good, and the toughness and hardness are shown. The chemical resistance and weather resistance are also excellent. This is mainly because the benzene rings in this structure provide higher molecular rigidity, thus making the film harder after film formation, while the urethane bonds formed after the-NCO reaction provide a large number of hydrogen bonds, thus making the coating more flexible. the-NCO functional group of the tetramethyl-m-xylylene diisocyanate (TMXDI) is far away from the benzene ring, and two methyl groups are arranged on carbon atoms connected with the-NCO functional group, and no active hydrogen atoms exist, so that the tetramethyl-m-xylylene diisocyanate is not easy to attack by other reactive functional groups, thereby reacting, and ensuring better chemical resistance and weather resistance. Coating examples 5 and 6 show the effect on the appearance of properties when the amount of TMXDI-containing aqueous polyurethane was changed. The amount of the aqueous polyurethane A in the formulation of the intermediate coating and the colored paint in the coating example 5 is lower limit, the appearance, the hardness and the toughness (cupping) are slightly reduced to a certain extent, and the aqueous polyurethane A is still in a qualified state. In coating example 6, the amount of the aqueous polyurethane A used in the formulation of the intermediate coating and the colored paint is the upper limit, and the aqueous polyurethane A has better hardness, appearance and toughness (cupping).
TABLE 5
/>
Example 4
Formation of coating film
The zinc phosphate-treated passivated steel sheet was coated with an electrodeposition coating composition PN-310 (cationic electrodeposition coating composition produced by Vigorboom coating composition) until the thickness of the dried coating film was 20. Mu.m, and the steel sheet was heated at 160℃for 30 minutes to solidify the coating film and cooled to form a solidified electrodeposition coating film. All coating preparations and comparative examples were then spray coated on this electrocoat film using the two-coat one-bake process described above. Some of the coatings associated are shown in table 6 below. Various index tests were then performed according to the contents of table 4. The results are recorded in table 7.
TABLE 6
The results showed the same trend as in example 1. Because the two-coating and one-baking process has no intermediate coating, the whole film thickness is thinner. The advantages of the water-based colored paint containing the novel water-based polyurethane A in the performance of the examples 2-1, 2-2 and 2-3 are more obvious. The obtained water-based paint can meet the performance requirement of a secondary coating and primary drying process of the intermediate coating, and can greatly save energy and reduce emission. Not only greatly improves the efficiency and benefit for the production activities of a host factory and a coating factory, but also obviously reduces the negative influence of the coating on the environment. Coating examples 7 and 8, as in coating examples 5 and 6 above, show the effect of the amount of TMXDI type waterborne polyurethane in the formulation on performance.
TABLE 7
/>
In conclusion, through the novel aqueous polyurethane, the performance of the coating obtained by coating the novel aqueous color paint under a compact process is obviously improved, the process of the water-based industrial coating in China is accelerated, and the coating engineering is helped to save more energy and reduce emission, so that greater economic benefits are generated.
It should be understood that the foregoing examples of the present invention are provided merely for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention, and that various other changes and modifications may be made therein by one skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.
Claims (10)
1. A coating suitable for compact coating, characterized in that the coating comprises water-based colored paint and varnish, and optionally water-based intermediate coating; wherein, the aqueous middle coating and the aqueous color paint both comprise one or more aqueous polyurethane;
The structure of the aqueous polyurethane contains tetramethyl xylylene diisocyanate groups.
2. The coating according to claim 1, wherein the aqueous mid-coat comprises 20-25wt% of the aqueous polyurethane, based on the total mass percent of the aqueous mid-coat; and/or
The aqueous color paint comprises 8-15wt% of the aqueous polyurethane based on the total mass percentage of the aqueous color paint.
3. The coating according to claim 1 or 2, wherein the aqueous polyurethane has a pH of 6.5 to 7.0, a nonvolatile matter of 39% to 41%, a viscosity of 200 to 300 mPa-s as measured under a rotational viscometer of 1000s -1, and an acid value of 15 to 20mgKOH/g.
4. The coating of claim 1, wherein the aqueous polyurethane is prepared by a process comprising the steps of:
Providing a mixture of alcohols comprising at least one polyol;
Providing a mixture containing anionically formed functional groups and having at least an average functionality of 2 capable of reacting with tetramethylxylylene diisocyanate;
And (3) carrying out amine neutralization on the mixture after the reaction, and dispersing the mixture in water to obtain the aqueous polyurethane.
5. The coating according to claim 1 or 2, wherein the aqueous mid-coat has a pH of 8.0-8.5, a nonvolatile content of 40% -50% and a viscosity of 160-200 mPa-s measured with a rotational viscometer of 250s -1.
6. The coating according to claim 1 or 2, wherein the aqueous color paint has a pH of 8.0-8.5, a nonvolatile matter of 40% -50% and a viscosity of 150-190 mPa-s as measured under a rotational viscometer of 250s -1.
7. A coating suitable for compact coating, characterized in that the coating is formed by using the coating as claimed in any one of claims 1-6 as a raw material and adopting a three-coating one-baking coating process or a two-coating one-baking coating process.
8. The coating of claim 7, wherein the three-coat one-bake coating process comprises the steps of:
Spraying the aqueous intercoat to form an uncrosslinked and cured aqueous intercoat coating film;
spraying water-based paint on the uncrosslinked and cured water-based middle-coating film to form an uncrosslinked and cured water-based paint film;
Drying and dehydrating the obtained coating film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish coating film;
And (3) curing the obtained composite coating at one time to obtain a cured water-based intermediate coating, a cured water-based colored paint coating and a cured varnish coating.
9. The coating of claim 7, wherein the two-coat one-bake coating process comprises the steps of:
spraying water-based paint to form an uncrosslinked and cured water-based paint film;
drying and dehydrating the non-crosslinked and solidified water-based colored paint film at 60-90 ℃ for 5-10 minutes, and then spraying varnish to form an uncured varnish film;
and (3) curing the obtained composite coating at one time to obtain a cured water-based colored paint coating and a cured varnish coating.
10. Use of a coating according to any one of claims 1 to 6 in automotive coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211253480.3A CN117925078A (en) | 2022-10-13 | 2022-10-13 | Coating suitable for compact coating and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211253480.3A CN117925078A (en) | 2022-10-13 | 2022-10-13 | Coating suitable for compact coating and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117925078A true CN117925078A (en) | 2024-04-26 |
Family
ID=90765233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211253480.3A Pending CN117925078A (en) | 2022-10-13 | 2022-10-13 | Coating suitable for compact coating and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117925078A (en) |
-
2022
- 2022-10-13 CN CN202211253480.3A patent/CN117925078A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109761834B (en) | Preparation method and application of water-dispersible polyaspartic ester resin and water-based polyurea coating | |
| KR101565940B1 (en) | Process for coating metal bands | |
| CN109354987B (en) | Polyaspartic acid ester polyurea coating with moderate surface drying time and capable of adapting to environmental change, preparation method, use method and application | |
| EP1784463B1 (en) | Aqueous coating compositions based on acrylate copolymers | |
| JP5642073B2 (en) | Water-based primer coating composition and multilayer coating film forming method | |
| EP3191232B1 (en) | Method and composition for coating substrates | |
| CZ324495A3 (en) | Aqueous dispersion of polyurethanes containing siloxane bonds, process of its preparation and its use in coating compositions | |
| EP2869939B1 (en) | Process for the production of an oem base coat/clear top coat multi-layer coating | |
| WO2013191104A1 (en) | Aqueous coating composition and coating method using same | |
| CN101831236A (en) | Aqueous metallic basecoat and preparation method thereof | |
| CN107814895A (en) | A kind of rare earth metal coordination modified aqueous polyurethane luminous resin and preparation method thereof | |
| CN110862761A (en) | Polyether amine modified polyurethane resin water-based functional coating | |
| CN110804383B (en) | Primer composition for high-film-thickness coating, primer and application thereof | |
| CN114316173B (en) | Organosilicon modified hydroxyl polyacrylate dispersion and preparation method and application thereof | |
| EP2507281A1 (en) | Chipping-resistant coating composition | |
| CN111057444A (en) | High-solid-content low-viscosity paint, preparation method thereof and paint film coating formed by same | |
| US9353285B2 (en) | Water-based two-component coating compositions | |
| CN114805733A (en) | Self-film-forming high-water-resistance solvent-free aqueous polyurethane dispersion and preparation method and application thereof | |
| CN111620984A (en) | Modified polyurethane resin and preparation method thereof, water-based paint and coating product | |
| CN117925078A (en) | Coating suitable for compact coating and application thereof | |
| CA2480675C (en) | Functionalised polyurethane | |
| KR20170023104A (en) | Polyurethane aerosol compositions, articles, and related methods | |
| WO2009013576A1 (en) | Reactive diluents for modifying thermosetting paint compositions and paint compositions in which they are used. | |
| CN110564271B (en) | Solvent high-gloss base coat for skin | |
| CN112831263A (en) | Double-component water-based automobile finishing varnish and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication |