Dispersion, method for coating objects with this dispersion, and use of the dispersion

Abstract

The invention relates to a dispersion and also to a method for coating objects, in particular heat exchanger structures, in which this dispersion is applied on a carrier structure and is crosslinked and/or made into a film with formation of a layer. Likewise, the invention relates to heat exchanger structures coated in this way. The dispersions according to the invention can likewise be used for coatings in the construction of chemical plants and also in medical technology.

1 . A dispersion comprising
 at least one porous sorbent selected from the group consisting of mesoporous alumino- and/or silicon compounds, metal-organic frameworks (M 0 Fs) and/or porous coordination polymers (PCPs), zeolite-imidazolate networks (ZiFs), mesoporous molecular sieves (MCMs), activated carbons, carbon molecular sieves, hexacyanometallates and mixtures thereof,   at least one binder from the group of polyorganosiloxanes and   at least one organic solvent.   
     
     
         2 . The dispersion according to  claim 1 ,
 wherein the at least one sorbent has nano-, meso- and/or macropores, is porous, and has a BET surface of at least 300 m 2 /g.   
     
     
         3 . The dispersion according to  claim 1 ,
 wherein the mesoporous alumino- and/or silicon compounds are selected from the group consisting of silica gels, zeolites and zeolite-like materials, aluminophosphates, silica aluminophosphates and metal aluminium phosphates.   
     
     
         4 . The dispersion according to  claim 1 ,
 wherein the at least one sorbent is water-sensitive.   
     
     
         5 . The dispersion according to  claim 1 ,
 wherein the at least one sorbent is present as a powder, with an average crystallite size of 50 nm to  20 l μm.      
     
     
         6 . The dispersion according to  claim 1 ,
 at wherein the at least one binder is selected from the group consisting of aliphatic, olefinic and aromatic mono-, di- and triorganosiloxanes which are crosslinked via a crosslinker.   
     
     
         7 . The dispersion according to  claim 1 ,
 wherein the at least one solvent is selected from the group consisting of hydrocarbons, aliphatic and aromatic hydrocarbons, benzene and alkyl-substituted benzene derivatives, such as toluene, xylenes or ethylbenzene, or from the group consisting of aliphatic or aromatic alcohols, esters, ketones such as methanol, 2-methylpropan-1-ol or 2-methoxy-1-methylethylacetate, and also mixtures of the mentioned solvents.   
     
     
         8 . The dispersion according to  claim 1 ,
 wherein in addition stabilisers, emulsifiers, low-molecular functional additives for improving the processibility, or components increasing the heat conductivity, are contained.   
     
     
         9 . The dispersion according to  claim 1 ,
 wherein the suspension, relative to the dry mass without a proportion of solvent, has the following composition:   60% to 99% by weight of the sorbent,   1 to 40% by weight of the binder, and   0 to 10% by weight of additives, selected from stabilisers, emulsifiers, low-molecular functional additives for improving the processibility, and mixtures hereof.   
     
     
         10 . The dispersion according to  claim 1 ,
 wherein the suspension is stable over a time period of at least 2 hours, up to at least 48 hours.   
     
     
         11 . A method for coating substrates in which
 a) the dispersion according to  claim 1  is formed on the substrate or is applied on the substrate after production, and   b) film formation and/or crosslinking with formation of a layer is effected at temperatures of  0 ° C. to  300 ° C.   
     
     
         12 . The method according to  claim 11 ,
 wherein the film formation and/or crosslinking is accelerated by applying a vacuum or by heating.   
     
     
         13 . The method according to  claim 11 ,
 wherein the dispersion is formed on the substrate by first applying the binder on the substrate and subsequently scattering on the sorbent in dry or moist form and subsequently drying.   
     
     
         14 . The method according to  claim 11 ,
 wherein the application of the dispersion in step b) is effected by means of manual application, immersion coating, spray coating, rotational coating or a knife-coating method.   
     
     
         15 . The method according to  claim 11 ,
 wherein the coating is produced with a layer thickness in the range of 100 nm to 10 mm.   
     
     
         16 . The method according to  claim 11 ,
 wherein the substrate consists of a metal or a metal alloy, a glass, a polymer, a ceramic or combinations thereof.   
     
     
         17 . A coated heat exchanger structure produced according to the method of  claim 11 . 
     
     
         18 . A method for the production of
 sorption layers for sorption processes with coolants, in particular in heat pumps, refrigeration machines and also for dehumidification and sorption-assisted air conditioning,   sorption layers for sorption processes for thermal storage,   protective layers and sterile layers in medical technology,   sensory or catalytically active layers, in particular for gas phase solid bed reactions, or   sorption layers for gas separation and gas storage comprising utilizing the dispersion according to  claim 1 .   
     
     
         19 . The dispersion according to  claim 2 , wherein the at least one sorbent has a BET surface of at least 300 to 5,000 m 2 g. 
     
     
         20 . The dispersion according to  claim 4 , wherein the at least one sorbent is copper(II)-trimesate (HKUST-1) or zinc terephthalate (MOF-5).