CN102559024A - Aqueous polyurethane heat reflection coating and application thereof - Google Patents

Abstract

The invention relates to an aqueous polyurethane heat reflection coating and an application of the aqueous polyurethane heat reflection coating. The coating comprises a component A and a component B, wherein the component A comprises water, an aqueous polyurethane emulsion, a heat reflection pigment, a function filler, a wetting dispersant, a basis material wetting agent, a rheological agent, a defoaming agent, a thickening agent and a filler; and the component B comprises an isocyanate curing agent or a silane coupling agent. The aqueous polyurethane heat reflection coating has features of high heat reflection efficiency, strong adhesion and good corrosion prevention effect and meets the requirements of environmental protection. The aqueous polyurethane heat reflection coating is suitable for the surfaces of the steel structure, aluminum alloy, plastic, composite material or the like.

Description

A kind of water-based polyurethane heat-reflecting coating and its application

technical field

The invention relates to the field of chemical industry coatings, in particular to a water-based polyurethane heat-reflecting coating and its application.

Background technique

The hull paint used for ship steel structure has experienced several periods of phenolic hull paint, alkyd hull paint, chlorinated rubber hull paint, acrylic hull paint, and polyurethane hull paint. The paint film of phenolic and alkyd coatings has poor temperature resistance and poor chemical resistance. Although the performance has been improved by means of phenolic modification, chlorinated rubber modification, and acrylic modification, it is still difficult to meet actual needs. . Chlorinated rubber hull paint has good resistance and workability, but its solid content is low, and a large amount of solvent is required during construction, which seriously pollutes the environment and does not meet environmental protection requirements.

In the past ten years, there have been hull paints with thermal emission functions, such as solvent-based acrylic hull paints, polyurethane hull paints, and acrylic modified polyurethane paints (Chinese Patent Publication No. CN101550314A, title of invention: polyurethane heat-reflective hull paints) Hull paint, their performance has been greatly improved than before. However, solvent-based coatings contain a large amount of solvents and toxic substances. With the development of industry and the improvement of environmental protection requirements, the application will be more and more restricted. Therefore, it has become a trend to develop water-based coatings, improve the performance of water-based coatings, and effectively replace the current solvent-based coatings.

The basic principles of heat reflective coatings are:

The solar heat reflective coating used to reduce the internal temperature should meet the high reflection of visible light (380nm ~ 780nm wavelength) and near infrared light (780nm ~ 2500nm wavelength) and the high radiation of middle and far infrared rays (2.5um ~ 14um) .

The heat reflectance of the main index of heat reflective coating depends on the ratio of the refractive index of the pigment and the resin. When the resin has a certain refractive index (1.45-1.50), its thermal reflectance mainly depends on the refractive index of the pigment and filler, the particle size and purity of the pigment and filler, the thickness of the coating, and the PVC value. The refractive index range of pigments and fillers is generally 1.50-2.80.

The main work of developing various heat reflective coatings is: because the absorption rate of carbon black to solar heat is as high as 97%, and the reflectivity is only 3%. In order to achieve sea-gray heat-reflective coatings suitable for ship hulls, the focus of the research was on how to replace carbon black.

Contents of the invention

The present invention uses organic and inorganic red, yellow, blue and white colors to compound black to replace carbon black.

The object of the present invention is to provide a water-based polyurethane heat-reflecting coating that has excellent adhesion, can reduce the surface temperature of equipment exposed to solar radiation heat, improves construction safety and is environmentally friendly.

Another object of the present invention is to provide the application of the above-mentioned water-based polyurethane heat-reflecting coating.

In order to achieve the above object, the present invention adopts the following technical solutions:

A water-based polyurethane heat-reflecting coating, the coating formula adopts a two-component polyurethane system, which includes two components A and B:

Wherein, component A comprises (parts by weight):

Water 0-20

Water-based polyurethane emulsion 100

Heat reflective pigment 20-25

Functional filler 0.5-5

Wetting and dispersing agent 1-3

Substrate wetting agent 0.1-0.5

Rheological agent 0.1-0.5

Defoamer 0.2-0.5

Thickener 0.2-0.5

Filler 0.5-2

Described water-based polyurethane emulsion is purchased from Ocean Chemical Research Institute. They introduce polyurethane, acrylate, epoxy, and silicone resin structures into the same polymer, and combine the characteristics of several resins, so that the resulting coatings have a wide range of performance adjustments on the basis of environmental friendliness. , in order to meet different needs.

Component B is: one of silane coupling agent or isocyanate curing agent;

When the B component is a silane coupling agent, the weight ratio of the A component to the B component is 100:1～2; when the B component is an isocyanate curing agent, the A component and the B component The weight ratio is 9:1. The components A and B are mixed according to the above weight ratio.

The heat-reflecting pigment is a combination of iron oxide red, phthalocyanine green, and titanium dioxide;

The role played by the heat-reflecting pigment: the sea-gray heat-reflecting pigment system is compounded with the above-mentioned pigments, and the reflectivity to near-infrared light (780nm-2500nm wavelength) is over 70%.

The fillers are functional fillers and common fillers.

The functional filler is one or more of ultrafine (5um-15um particle size) fumed silica, hollow glass, floating beads, hollow ceramic microspheres and the like.

The function of the functional filler is to provide heat insulation, block heat transfer, and improve heat reflection performance.

The common filler is one or more of superfine (5um-15um in particle size) light calcium carbonate, talcum powder, mica powder, precipitated barium sulfate, and the like.

The function of the common filler is to reduce the cost, optimize the PVC value, and improve the heat reflection performance.

The wetting and dispersing agent is polyacrylic acid copolymer potassium salt and special modified polycarboxylate potassium salt, such as BR3, 123K and other products of Heinco.

The substrate wetting agent is a nonionic surfactant. The nonionic surfactant is polyether-modified polydimethylsiloxane, such as BYK-346 and the like.

The rheological agent is polyether modified polydimethylsiloxane, nonionic surfactant, such as BYK-333 and the like.

The defoamer is a mixture of hydrophobic solids and foam breaking polysiloxanes in polyethylene glycol. Such as BYK-024, BYK-028, Heinco 999, etc.

The thickener is non-ionic water-based polyurethane. Such as Heinco XS-71, 125P and so on.

The silane coupling agent is: a silane coupling agent containing epoxy groups; such as one of KH560, Wtlink78, Osilcoat1770 and the like.

Described isocyanate curing agent is isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), xylylene diisocyanate (XDI), tetramethylene One of the hydrophilic curing agents containing -NCO is obtained by reacting xylylene diisocyanate (TMXDI) with hydrophilic polyether. Such as 2487, 2460, 3100, 2655 of BAYER company.

The effect of the present invention: the use of water-based polyurethane emulsion, containing hydroxyl and carboxyl groups, compounded with -NCO water-based polyurethane curing agent to make the topcoat base material, has a triple cross-linking system after self-oxidation and double cross-linking, and improves the cross-linking density , improves water resistance, provides excellent weather resistance, gloss retention and color retention.

The water-based pure polyurethane emulsion modified by epoxy and silicone, compounded with the curing agent of silane coupling agent containing epoxy group as primer and topcoat base material, has double cross-linking after self-oxidation and single cross-linking. Linked system, which increases the crosslink density, improves water resistance, and provides excellent adhesion and anti-corrosion properties.

Screening of sea-gray heat-reflecting pigment system: Titanium dioxide, organic and inorganic red, and phthalocyanine green are used to compound the sea-gray heat-reflecting pigment system, which is used in water-based paint systems to provide excellent heat-reflecting properties.

The above-mentioned water-based polyurethane heat-reflecting coating is applied to the anticorrosion and decoration of the surfaces of steel structures, aluminum alloys, plastics, and composite materials. It can also be applied to the surface of large oil and natural gas storage tanks, oil pipelines, grain depots, cold storage, automobiles, buildings, etc.

The water-based polyurethane heat-reflective coating of the present invention has good heat reflection efficiency, excellent adhesion, weather resistance, and external anti-corrosion effect, and can reduce the surface temperature of the coated object and the internal environment temperature to improve the working environment, save energy and reduce consumption, and improve construction safety. and meet environmental protection requirements.

Detailed ways

Further illustrate the present invention below in conjunction with embodiment, the present invention is not limited to these embodiment.

The used raw material trade name and manufacturer of example in the implementation of the present invention are as follows:

Waterborne polyurethane heat reflective coatings are divided into component A and component B. The preparation method of component A is as follows:

Under the condition of stirring at 1000 rpm, add heat-reflecting pigments, functional fillers, wetting and dispersing agents to part of the water-based polyurethane emulsion (half to two-thirds of the formula amount), and pre-disperse evenly; grind the above materials In the equipment, at a speed of 2000-3000 rpm, grind the material to a fineness of 10um-20um, filter to obtain the required pigment and filler slurry, and then add the remaining water-based polyurethane under stirring at a low speed of 1000 rpm Emulsion, substrate wetting agent, thickener, defoamer, rheological agent. According to the construction requirements, add appropriate water to adjust the viscosity construction.

Example 1:

The proportioning of group A according to parts by weight is:

10 parts of water, 100 parts of water-based polyurethane PUA emulsion, 17.2 parts of titanium dioxide, 4.5 parts of organic perylene black, 10 parts of mica powder, 5 parts of fumed silica, 5 parts of hollow ceramic microspheres, 180.32 parts of Disponer W-, DeuAdd MB- 11 1.5 parts, NAZIA FA 379 1.5 parts, RHEOLATE 125 3.2 parts, Levaslip W-461 1.5 parts.

Component B is: 11 parts of hydrophilic curing agent BAYER 2655 containing -NCO.

The paint preparation process is as follows: mix components A and B with water in proportion, stir evenly at 300-500 rpm, adjust the viscosity for 40 seconds (coat-4), and make boards by spraying or brushing. Thickness: primer 40um, topcoat 40um.

Example 2:

The proportioning of group A according to parts by weight is:

0 parts of water, 100 parts of water-based polyurethane PUD emulsion, 17.8 parts of titanium dioxide, 3.4 parts of iron oxide red, 18 parts of iron oxide yellow, 20 parts of phthalocyanine blue, 10 parts of barium sulfate, 10 parts of hollow glass microspheres, Disponer W-19 0.32 parts, Dispenor W-519 1.7 parts, Deform W-052 0.32 parts, DeuAdd MB-16 1.5 parts, NAZIA FA 579 1.5 parts, BENTONE DY 1.5 parts.

Component B: coupling agent KH-560, added in an amount of 2% of the total weight of component A.

The paint matching process is the same as in Example 1.

Example 3:

The proportioning of group A according to parts by weight is:

0 parts of water, 100 parts of water-based polyurethane emulsion, 17.1 parts of titanium dioxide, 6.4 parts of permanent red, 0.8 parts of iron oxide yellow, 1.6 parts of phthalocyanine green, 1 part of phthalocyanine blue, 0.32 parts of Disponer W-19, 0.32 parts of Disponer W-519 9 5 parts, fumed silica 5 parts, power plant drift beads 5 parts, barium sulfate 10 parts, Deform W-0920.3 parts, RHEOLATE125 3.2 parts, DeuAdd MB-11 1.5 parts, Tamol165 5 parts.

Component B: 11 parts of hydrophilic curing agent BAYER 3100 containing -NCO.

The paint matching process is the same as in Example 1.

Example 4:

The proportioning of group A according to parts by weight is:

10 parts of water, 100 parts of water-based polyurethane PUD emulsion, 17.4 parts of titanium dioxide, 6.4 parts of permanent red, 10 parts of permanent yellow, 4.32 parts of phthalocyanine blue, 1.2 parts of Tamol 850, 2 parts of Tamol 960, 10 parts of fumed silica , 5 parts of power plant drift beads, 10 parts of barium sulfate, 0.64 parts of Deform W-092, 6.4 parts of RHEOLATE 125, 1.5 parts of DeuAdd MB-16, and 5 parts of YB-405.

Component B: coupling agent wtlink78, the addition amount is 2% of the total weight of Component A.

The paint matching process is the same as in Example 1.

Example 5:

The proportioning of group A according to parts by weight is:

20 parts of water, 100 parts of water-based polyurethane PUA emulsion, 17.6 parts of titanium dioxide, 3.4 parts of iron oxide red, 18 parts of iron oxide yellow, 4.5 parts of organic perylene black, 10 parts of mica powder, 5 parts of fumed silica, hollow ceramic microspheres 5 parts, Disponer W-18 0.32 parts, DeuAdd MB-11 1.5 parts, NAZIAFA 379 1.5 parts, RHEOLATE 125 3.2 parts, Levaslip W-461 1.5 parts.

Component B: 11 parts of hydrophilic curing agent BAYER 2487 containing -NCO.

The paint matching process is the same as in Example 1.

Embodiment 6:

The proportioning of group A according to parts by weight is:

0 parts of water, 100 parts of water-based polyurethane PUD emulsion, 17.3 parts of titanium dioxide, 3.4 parts of iron oxide red, 18 parts of iron oxide yellow, 20 parts of phthalocyanine blue, 10 parts of barium sulfate, 10 parts of hollow glass microspheres, Disponer W-19 0.32 parts, Dispenor W-519 1.7 parts, Deform W-052 0.32 parts, Troysan Polyplase AF-1 1.5 parts, NAZIA FA 579 1.5 parts, BENTONE DY 1.5 parts.

Component B: Coupling agent Osilcoat1770, added in an amount of 2% of the total weight of Component A.

The paint matching process is the same as in Example 1.

The performance test results of the heat-reflecting sea ash ship hull paint prepared by mixing components A and B in proportion are as follows:

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this field may use the technical content disclosed above to change or modify it into an equivalent implementation of equivalent changes. example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (9)

1. A water-based polyurethane heat-reflecting coating, characterized in that the coating formulation adopts a two-component polyurethane system, comprising two components of A and B: Wherein, component A comprises (parts by weight): Water 0-20 Water-based polyurethane emulsion 100 Heat Reflective Pigment 20-25 Functional filler 0.5-5 Wetting and dispersing agent 1-3 Substrate wetting agent 0.1-0.5 Rheological agent 0.1-0.5 Defoamer 0.2-0.5 Thickener 0.2-0.5 Filler 0.5-2 Described water-based polyurethane emulsion is purchased from Ocean Chemical Research Institute; Component B is: one of silane coupling agent or isocyanate curing agent; When the second component is a silane coupling agent, the weight ratio of the first and second components is 100:1～2; when the second component is an isocyanate curing agent, the weight ratio of the first and the second components is 9:1. 2. The water-based polyurethane heat-reflecting coating according to claim 1, wherein the heat-reflecting pigments include iron oxide red, phthalocyanine green, and titanium dioxide, several of which are compounded and used. 3. The water-based polyurethane heat-reflective coating according to claim 1, wherein the functional filler is ultrafine (5um to 15um in particle size) fumed silica, hollow glass, floating beads, and hollow ceramic microspheres. one or more of. 4. The water-based polyurethane heat-reflective coating according to claim 1, wherein the wetting and dispersing agent is polyacrylic acid copolymer potassium salt and special modified polycarboxylate potassium salt. 5. The water-based polyurethane heat-reflective coating according to claim 1, wherein the substrate wetting agent is a nonionic surfactant. 6. The water-based polyurethane heat-reflective coating according to claim 1, wherein the rheological agent is a polyether-modified polydimethylsiloxane or a nonionic surfactant. 7. The water-based polyurethane heat-reflective coating according to claim 1, wherein the silane coupling agent is: a silane coupling agent containing epoxy groups. 8. waterborne polyurethane heat reflective coating according to claim 1, is characterized in that, described isocyanate curing agent is isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane Diisocyanate (HMDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI) react with hydrophilic polyether to obtain one of the hydrophilic curing agents containing -NCO . 9. A water-based polyurethane heat-reflecting paint as claimed in claim 1, the application on the surface of steel structures, aluminum alloys, plastics, and composite materials.