RU2352467C2 - Method for production of heat insulation multilayer combined polymer coating (versions) - Google Patents

Abstract

FIELD: technological processes; chemistry.

SUBSTANCE: method consists in application of alternating layers of liquid-ceramic coating and layers of glass fiber cloth on surface that might have been heated previously. At that substrate may be first coated with liquid-ceramic coat from polymer composition that contains binder, mixture of hollow microspheres that differ in size and auxiliary target additives, then layer of glass fiber cloth is applied on still wet coating, and then again layers of liquid-ceramic coating, and if necessary - a layer of glass fiber cloth again. Coating may be produced by another version, when substrate is first coated with glass fiber cloth, and then liquid-ceramic coating, and later again a layer of glass fiber cloth, if required. Number of alternating layers is defined by necessary coefficient of heat conductivity.

EFFECT: high heat insulating properties of coating.

12 cl, 3 tbl, 2 ex

Description

This invention relates to the chemical industry and can be used to obtain thermal insulation coatings on various surfaces to protect them from overheating, and at the same time to protect against corrosion, from fire.

A high-quality anti-corrosion coating is of paramount importance for a number of applications. For example, when solving the problem of thermal insulation of pipelines of heat and water supply, it is extremely important to provide stable protection of pipes from external corrosion, since it is this that is the main factor limiting the time of their operation. Such coatings are equally important for protecting any building structures made of metal, wood, plastic, from the harmful effects of sunlight, precipitation, etc. At the same time, the task of preserving heat in housing and industrial construction, of course, is one of the paramount, and huge resources are allocated for its solution. To solve both the first and second problems, modern technological thought offers a wide range of solutions. In addition to the well-known mineral and basalt watts, insulating materials currently being actively offered include various foamed polymeric materials, such as foamed polystyrene, polyethylene, polyurethane, polypropylene, etc. As materials for corrosion protection, various paint materials are offered (water dispersions, paints and varnishes based on organic solvents), as well as protection of metal surfaces with metals resistant to corrosion, for example electrolytic galvanizing. Materials that would have a joint effect of protecting surfaces against corrosion and at the same time contribute to the preservation of heat and possess high adhesive properties, currently practically does not exist.

From RU 2099444, 12.20.1997, a multilayer coating for the entire surface of a metal element of a water supply network and a method for applying it are known. The multilayer coating consists of an intermediate layer and a layer of thermosetting synthetic resin. The intermediate layer is passivated with chromium or organic material containing tannic acid, and contains epoxy as a thermosetting resin. The coating is obtained as follows: an intermediate layer is applied, washing is carried out, and then a layer of thermosetting resin is applied by immersion in a bath (electrodeposition); wherein the intermediate layer is applied by chemical precipitation, after which polymerization is carried out; an additional layer of thermosetting resin can be applied by immersion in a fluidized solution or by electrostatic spraying followed by firing. The coating is applied to a metal element (cast iron) of the drinking water supply network.

From RU 2033568, 04/20/1995, a corrosion-resistant coating for a pipe is known, which is prepared as follows: a primer layer is applied to a pipe based on liquid glass, then it is coated with a flexible synthetic wrapping material and fixed to a pipe, for example, with a non-woven material “Dornit” or “ Polycarpromite ”(fix it, for example, with wire), and after that a layer of waterproofing material is applied in the form of liquid paraffin or bitumen, for example, by dipping. Depending on the requirements, the pipeline is covered with non-woven material in one, two, three layers. The resulting coating has high protective properties and provides reliable protective insulation of pipelines, but does not have the properties of a thermal insulation coating.

Corrosion-resistant roll material for protecting metal structures from corrosion is known from RU 2088835, 08.27.1997: roll material is applied on the surface of the structure in the form of a porous fabric or non-woven base with a layer of anticorrosive composition fixed from it from a mixture of glue and inorganic binders (cement) at a ratio the thicknesses of the layers of the base of the rolled material and the anti-corrosion composition 11-15. This composition can be used to protect metal structures during construction and repair, in particular when repairing small damaged sections of pipelines in the form of quick-hardening patches.

It is known from RU 2067718, 10.10.1996, a combined anti-corrosion coating for protecting pipe communications and fittings in heat conduit chambers and a method for producing it, including pretreatment of the surface to be protected and applying layers of a protective coating, while two layers of viscous are applied to the surface of the surface to be protected after pretreatment non-metallic anti-corrosion material in the form of a toluene solution of organosilicon resins, and then coated with sheets of metal foil (aluminum) so that each subsequent sheet overlaps the previous one by no more than 2.5 thicknesses of the non-metallic anticorrosion layer, while the time from the end of the deposition of non-metallic anticorrosive material to the end of the installation of the foil in the heat conduit section is no more than 15 minutes.

Known coating mainly solves the problem of corrosion protection, in addition, it is technologically difficult to perform.

From RU 2039070, 07/09/1995, a method for producing a fire-resistant coating is known, comprising applying to the surface several layers of a composition containing a binder and a filler, with intermediate drying of each layer and final heat treatment of the coating; first, heat-insulating layers from a composition containing, wt.% :

siloxane rubber 30-60 glass microspheres 40-70,

and then the fire resistant layers of the composition, containing, wt.%:

siloxane rubber 20.0-79.5 glass microspheres 20.0-60.0 boron nitride 0.5-20.0

while drying of each intermediate layer is carried out at 20-80 ° C, and the final heat treatment of the coating at 80-150 ° C, and the total thickness of the fire-resistant layers does not exceed 3 mm

However, the use of only glass microspheres with a diameter of 100-4000 microns does not provide complete thermal insulation of products.

From RU 2187433, 08.20.2002, a method for producing a heat-insulating material based on syntactic foam is known. At which the initial components are metered, two reactive components of the binder are mixed, the resulting composition is filled with microspheres, the obtained component is poured to obtain a heat-insulating material and solidified, while each of the reactive components of the binder is filled with microspheres separately, after which the filled reactive the binder components are mixed in ratios, parts by weight: first reaction component and microspheres: second reaction component and microspheres, p Awn 1: (0.1-0.4), the first reaction component: microspheres equal to 1: (0.2-0.4), the second reaction component: microspheres equal to 1: (0.2-0.4) then fill and cure.

As microspheres, hollow glass microspheres and / or polymer microspheres having a hydrostatic strength of at least 2 MPa are used.

Epoxy resins and hardeners of the amine and / or amide types are used as the reactive components of the binder. A thermal insulation coating is applied to the outer surface of the pipe, and syntactic foam is obtained by mixing the reactive components of the binder with microspheres, forming them into a stream, forming a coating on a rotating and longitudinally moving pipe and curing the coating on it, and mixing the reactive components filled with microspheres and molding the coating is carried out by means of a mixing head and a combined annular forming chamber, covering a rotating and moving pipe, p When in use, the two steps are combined into one technological method.

This known method of obtaining a heat-insulating coating is rather laborious, has limited use and does not provide full protection against overheating of various products operating in harsh conditions.

The technical task of the claimed invention is to provide heat-insulating properties of the coating of various surfaces, including metal, in particular surfaces of pipelines operating in specific, harsh conditions, while protecting them from corrosion, improving environmental properties and simplifying the technology of coating, increasing fire resistance and durability.

The stated technical problem is achieved by the claimed group of the invention, which includes a method for producing a heat-insulating multilayer combined polymer coating and its variant.

So, the stated technical problem is achieved by the method of obtaining a heat-insulating multilayer combined polymer coating, including the sequential application of alternating layers on a possibly preheated surface: first, a liquid-ceramic coating of a polymer composition comprising a binder, a mixture of hollow microspheres that vary in size from 10 to 500 microns and a bulk density in the range from 650 to 50 kg / m ^3, and auxiliary special purpose additives, followed by yet a dried layer by rytiya applied one or more layers of liquid-ceramic coating, as disclosed above, and is carried out final heat drying the coating.

In this case, before the final drying of the multilayer coating on the uncured liquid-ceramic coating (on a still not dried layer thereof), one or more layers of fiberglass are additionally applied, if necessary.

Another variant of the above-described method as an invention is a method for producing a heat-insulating multilayer combined polymer coating, comprising sequentially applying alternating layers onto a possibly preheated surface: first, fiberglass bonded to the substrate surface, either mechanically using fiberglass yarns, or using high-temperature phosphate glue, then apply one or more layers of a liquid-ceramic coating of a polymer composition containing a binder, a mixture of hollow microspheres, differing in size in the range from 10 to 500 μm and bulk density in the range from 650 to 50 kg / m ³ , and auxiliary target additives, then carry out the final thermal drying of the coating.

In this case, one or more layers of fiberglass are additionally applied, if necessary, to a still uncured (non-dried) layer of the liquid-ceramic coating.

Moreover, to implement each of the variants of the method according to the claimed invention, for the formation of a liquid-ceramic coating, a composition is used containing, as one of the auxiliary additives, flame retardant ammonium polyphosphate, for example Exolit AP422, EXFLAM APP201 (with a content of P ₂ O ₅ > 71%, N - 14.3%, particle size 10.3 microns, decomposition temperature 279.5 ° С, degree of polymerization 1200) or Exolit AP750 (with Р content - 29.7%, N - 18.5%, degree of polymerization 1000, particle size 15 microns, decomposition temperature 300 ° C.

In addition, the composition for a liquid-ceramic coating, which is one of the layers of a multilayer heat-insulating coating, may contain, as one of the auxiliary additives, Surfactants Neonol (Neonol AF9, AF-9P) ethoxylated monoalkylphenols based on propylene trimers, which serves as a thickener and thixotropic additive, and / or coalescence (coalescing) additive (glycol ethers), such as ethyl cellosolve, methyl cellosolve and others; and / or fungicidal additive, a preservative additive that prevents fungal deposits on the finished coating in wet rooms (guanidine derivatives, sodium pentachlorophenolate, etc.), as well as other target additives.

In the method according to the invention (and its variant), as compositions used to form a liquid-ceramic coating, compositions are used containing as a binder various polymer latex compositions, for example, based on styrene acrylic latex, latex butadiene-styrene copolymer, based on acrylic (co ) polymers, polyvinyl chloride latexes, polyvinyl acetate latexes, based on epoxy resins, based on glass, based on organosilicon resins, for example silicone resins (polyorganosiloxane in emulsions: polymethylphenylsiloxanes polyphenylsiloxanes in particular silicone emulsion silokofen type), and a binder may be a mixture of silicone (polyorganosiloxane) above resins with other polymeric latex compositions.

In particular, for the formation of a liquid-ceramic coating in the method according to the invention (and its variant), a composition known from and created by the author from RU 2251563, 05/10/2005, or compositions based on liquid glass — an inorganic polymer (RU 2033568) declared by the author are used ; based on epoxy resin (RU 2099444). Based on an aqueous silicone (polyorganosiloxane) emulsion (RU 2039070).

This composition, known from RU 2251563, comprises a polymer binder and hollow microspheres made of a water-suspension composition with a viscosity of 1 to 100 Pa · s, as a polymer binder the composition contains a water-based polymer latex composition containing from 10 to 90 vol.% (S ) a polymer selected from the group consisting of acrylate homopolymer, styrene acrylate copolymer, styrene butadiene copolymer, polystyrene, butadiene polymer, polyurethane polymer, vinyl acetate polymer or copolymer, or mixtures thereof from 10 to 90 vol.% water mixture and a surfactant, as hollow microspheres, the composition comprises a mixture of hollow microspheres with different sizes from 10 to 500 micrometers (μm) and different bulk density in the range from 650 to 50 kg / m ³ selected from the group comprising hollow glass microspheres, hollow ceramic microspheres, hollow polymer microspheres, hollow man-made (ash) microspheres or mixtures thereof in the following ratio of components of the water-suspension composition, vol.%:

the above polymer latex composition 5-95 the above hollow microspheres 5-95

The aqueous emulsion polymer latex composition may additionally contain various auxiliary target additives, for example, such as various white pigments, such as, for example, titanium dioxide, zinc oxide, etc., coloring (color) pigments, such as iron oxide pigments, chromium oxide pigments phthalocyanine blue, etc .; flame retardant (flame retardant) additives, such as, for example, aluminum trihydrate, ammonium polyphosphate, zinc borate, mica, asbestos, etc .; rust converters, such as, for example, a PRL-2 converter based on phosphoric acid, etc .; corrosion inhibitors, such as, for example, sodium nitrite, sodium benzoate, guanidine chromate, zinc tetraoxychromate, AKOR-1, NG-203 in amounts traditionally used in such similar aqueous dispersions.

As a polymeric binder, the composition contains, as known latexes, based on (co) polymers of acrylate, styrene, vinyl acetate, styrene-butadiene copolymer, polyurethane, polyvinyl chloride (polyvinyl chloride polymer), containing water and surfactants, for example, such as ethoxylated alkyl phenols, such as OP-6, OP-7, OP-10, praxanols based on block copolymers of hydroxyethylene and propylene and other traditionally used in water-dispersion systems; as well as various other targeted additives, such as pigments, white and coloring, corrosion inhibitors, rust converters, flame retardants, etc., also prepared directly based on the latexes of the above or mixtures thereof.

So, for example, upon receipt of the anti-corrosion and heat-insulating coating according to the invention as a polymer binder, the composition contains such latex polymer systems as latexes based on copolymers of vinyl acetate with ethylene, methyl methacrylate and methacrylic acid (the basis of paints E-BC-511, E-BC-17 ), based on a polyvinyl acetate dispersion (50%) in the form of paints E-VA-27, E-VA-0112 and others; latex systems (paints) based on styrene-butadiene copolymer SKS-65GP, BS-30, based on acrylic copolymers DMMA-65GP, as well as Dow Chem styrene acrylic copolymer, Primal 219N, acrylic MBI-5C, polyurethane.

Hollow microspheres are one of the most important fillers used in the manufacture of plastics. The spherical shape, controlled dimensions and low density make them often indispensable. An important effect of their use is to reduce the cost of expensive or scarce polymers, as well as a decrease in density. Traditionally, they have a size of 25 μm to 50 mm and a density of 100 to 700 kg / m ³ .

In the claimed invention, the use of mixtures of hollow microspheres (glass, ceramic, polymer, ash), the same or different, but with different sizes in the range from 10 to 500 microns and different bulk density in the range from 650 to 50 kg / m ³ can significantly increase the efficiency protect the surface of the processed materials (wood, concrete, plaster, metal) from corrosion and thermal insulation.

Such properties of hollow microspheres, such as low oil absorption, inertness and ease of dispersion, make them very attractive as fillers.

Hollow microspheres of glass, ceramics, polymers are mainly obtained by introducing a blowing agent into the base material, then grinding them and heating them to foam the blowing agent.

So, for example, hollow microspheres are obtained by passing small particles containing a porophore through a high-temperature zone; the particles melt or soften in the hot zone, and the blowing agent forms a cavity inside the particles, expanding them. When a sphere is cooled in air, its walls harden. Or they are obtained by foaming glass (or ceramic) particles in a burner flame, etc. As hollow microspheres, for example, microspheres of the Glace babez type, such as Microballon, are used; globumite, spherulite. Ceramic microspheres are also obtained by burning natural materials and foaming.

Polymeric hollow microspheres are obtained, as a rule, either by suspension polymerization of monomers with the addition of a blowing agent (porophore, inert gases, low boiling hydrocarbons), or by physical or chemical foaming of ready-made polymer particles. The hollow polymer microspheres in the invention use hollow microspheres, for example polystyrene, based on phenol-formaldehyde resins, silicone, urea-formaldehyde resins and others.

The composition is prepared by mixing in a certain sequence of the starting components with thorough mixing until a homogeneous and homogeneous structure is achieved, and it can be applied to various surfaces as one of the layers in the inventive method using various known methods, for example, using an airless spray gun, brush or roller, number of layers from one to five with thorough drying of each layer.

The following table 1 presents examples of compositions containing a mixture of hollow microspheres with certain parameters and used to form a liquid-ceramic coating.

To obtain a multilayer heat-insulating coating, fiberglass canvas (fiberglass) is used as one of the layers, in particular, non-woven material made of randomly spaced glass staple fibers bonded with synthetic binder reinforced with twisted glass fibers of continuous fiberglass, for example, brands BB-AM, PSX- T-450. The thickness of the fiberglass can be, for example, 0.8 ± 0.2 mm.

As a high-temperature adhesive, various phosphate adhesives (based on aluminophosphate bonds) are used.

Examples of compositions for forming a liquid-ceramic coating.

Table 1 Name of components The content of the components according to the examples, wt.% one 2 3 four 5 6 7 8 1. Polymer binder:
A. Polymer Latex Composition 20,0 50,0 40,0 60.0 - - - - Polyvinyl Acetate Latex (50%) 60.0 - 37.0 - - - - - Dimethylmethacrylate latex (DMMA-1-65-GP) - 50,0 - 30,0 - - - - B. Dispersion of methylphenylsiloxane resin (Silikofen) - - - - 5,0 95.0 20,0 - Epoxy resin (ED-20) with harden. PEPA - - - - - - - 40,0 2. A mixture of hollow microspheres: 80.0 50,0 60.0 40,0 95.0 5,0 80.0 60.0 a mixture of glass microspheres: - glass. microspheres with a size of 35 microns and a density of 650 kg / m ³ 24.0 - 30,0 - 24.0 - 24.0 - - glass. microspheres with a size of 100 microns and a density of 150 kg / m ³ 48.0 - - - 48.0 - 48.0 - - glass. microspheres with a size of 200 microns and a density of 70 kg / m ³ 8.0 - 30,0 20,0 23.0 - 8.0 - a mixture of polymer microspheres: - polystyrene microspheres with a size of 10 μm and a density of 650 kg / m ³
- polystyrene microspheres with a size of 500 microns and a density of 50 kg / m ³ -
- 15.0
5,0 -
- 20,0
- -
- 2.0
3.0 -
- 20,0
20,0 - polystyrene microspheres with a size of 50 microns and a density of 400 kg / m ³ - 30,0 - - - - - 20,0 3. Auxiliary and targeted additives: Surface-active substance: - OP-7 - 5,0 10.0 3.0 2.0 - 8.0 - - NEONOL AF 10.0 - - - - 8.0 - 4.0 Pigments and fillers: - titanium dioxide - 15.0 - - - 1,0 - - - zinc oxide - - - - 1,5 - 15.0 - Coalescing additive (cellosolve) 1,5 - 2.0 - 0.5 - 1,0 - Fire retardant: - zinc borate - - - - - - - - - ammonium polyphosphate 3.0 - 1,5 - 4.0 - 3.0 - Dispersant (sodium polyphosphate) - - - - - - 5,0 - Fungicidal supplement (sodium pentachlorophenolate) - 2.0 - - - - - - Biocidal supplement (polyhexamethylene guanidine in salt form) - - - 0.5 10.0 - - - Carboxymethyl Cellulose Thickener - - - - - - 3.0 - Water 30,0 7.0 27.5 67.0 - - - - Note: In Examples 1-8, the amount of auxiliary additives is given based on a 100% mixture of a binder and hollow microspheres.

The following are specific examples of the implementation of the method according to the invention.

Example 1

The metal cylinder (pipe) inside which the measuring thermocouple was placed was covered with two layers of PSX-T-450 fiberglass (which was fixed with fiberglass threads). Then, a single layer of Isollat-04 liquid-ceramic coating (Example 1-4) with a thickness of 0.5 mm was applied to the glass fabric. The metal cylinder with the obtained coating was heated for 2 hours at a temperature of 200 ° C. Fiberglass is bonded to the surface either using glass fibers or using phosphate glue (KFFG brand)

After that, the temperature inside the cylinder was dropped to 100 ° C.

The resulting coating was wrapped with two more layers of PSX-T-450 fiberglass (fixed in the same way). Then 5 layers of Isollat-02 were applied to the fiberglass, each 0.5 mm thick, with an interval of 30 minutes. After applying all layers, the sample was heated at 100 ° C for 2 hours.

Then the temperature was gradually raised to 400 ° C with an interval of 30 minutes.

The test results are shown in table 2.

table 2 The temperature inside the cylinder, ° C Temperature on the coating, ° С one hundred
151
201
251
303
351
397
405 29th
39
47
60
68
77
86
87

As a result of the tests, it was found that no cracking of the coating or discoloration was observed in the entire temperature range.

Example 2

On the surface, for example, pipes of heat supply, which is filled with heated water with a surface temperature of + 115 ° C, apply the composition according to example 5 (table 1) using a roller. Moreover, the composition can be applied first on a cold surface with a thin layer followed by heating to 200-250 ° C, then on a heated surface with a thin layer, then fiberglass is applied to an still not dried coating, and then one or more layers of liquid-ceramic coating from one of the compositions examples 1-8 (see table 1).

Table 3 presents some of the properties of a multilayer coating.

Table 3 The name of indicators The properties Tensile strength, kgf / cm
Elongation at break,%
Density in the liquid state, kg / dm
The density of the finished coating, kg / dm
Vapor permeability, g / m / h
Water permeability, g / m / 24 h
Light reflection,%
Light scattering,%
The coefficient of thermal resistance for the radiation component
thermal conductivity at 2 mm coverage
Thermal conductivity for the radiation component of heat transfer, V / m.S
Thermal conductivity for the contact component of heat transfer, V / m.S
Adhesion, kg / cm
Fire resistance, min 80.0
5,0
0.50
0.30
50,0
less than 30.0
82.0
92.0
up to 20.0
0.001
0,037
25.0
140-180

As follows from the above data, the resulting multilayer combined heat-insulating coatings possesses all the necessary complex of physicomechanical properties, providing, first of all, high thermal insulation properties of the protected surface.

Claims (12)

1. A method of obtaining a heat-insulating and fire-resistant multilayer combined polymer coating, comprising sequentially coating the possibly pre-heated surface of the coating layers, first with a liquid-ceramic coating from a polymer composition containing a binder, a mixture of hollow microspheres with different sizes ranging from 10 to 500 microns and a bulk density of from 650 to 50 kg / m ^3, and auxiliary special purpose additives, then not yet dried coating is applied one or more layers of glass fiber further on the surface of glass fiber is applied to one or more layers of liquid-ceramic coating, further coating is carried out final drying. 2. The method according to claim 1, characterized in that before the final drying, one or more layers of fiberglass are additionally applied to a still-dried layer of liquid-ceramic coating. 3. The method according to one of claims 1 and 2, characterized in that the liquid-ceramic coating is made of a composition containing ammonium polyphosphate as one of the auxiliary additives. 4. The method according to one of claims 1 and 2, characterized in that the liquid-ceramic coating is made of a composition containing a thickener and a thixotropic additive. 5. The method according to one of claims 1 and 2, characterized in that the liquid-ceramic coating is made of a composition containing, as one of the auxiliary additives, a coalescing additive. 6. The method according to one of claims 1 and 2, characterized in that the liquid-ceramic coating is made of a composition containing, as one of the auxiliary additives, a biocidal or fungicidal additive. 7. A method of obtaining a heat-insulating and fire-resistant multilayer combined polymer coating, comprising sequentially applying alternating layers to a possibly preheated surface, first a fiberglass layer bonded to the substrate surface, either mechanically using fiberglass yarns, or using high-temperature phosphate glue, then one or several layers of a liquid-ceramic coating of a polymer composition containing a binder, a mixture of hollow microspheres, different between a size ranging from 10 to 500 microns and a bulk density of from 650 to 50 kg / m ^3, and auxiliary special purpose additives, further coating is carried out final drying. 8. The method according to claim 7, characterized in that before the final drying, one or more layers of fiberglass are additionally applied to an still not dried layer of the liquid-ceramic coating. 9. The method according to one of claims 7 and 8, characterized in that the liquid-ceramic coating is made of a composition containing, as one of the auxiliary additives, flame retardants, ammonium polyphosphate. 10. The method according to one of paragraphs.7 and 8, characterized in that the liquid-ceramic coating is made of a composition containing a thickener and a thixotropic additive. 11. The method according to one of paragraphs.7 and 8, characterized in that the liquid-ceramic coating is made of a composition containing, as one of the auxiliary additives, a coalescing additive. 12. The method according to one of claims 7 and 8, characterized in that the liquid-ceramic coating is made of a composition containing, as one of the auxiliary additives, a biocidal or fungicidal additive.