DE102016006694A1 - Internal coatings of drinking water pipes based on epoxy resin and a process for their preparation - Google Patents

Abstract

The invention relates to internal coatings of drinking water pipes based on epoxy resin, prepared by reacting a two-component system with the components A and B and a method for producing the inner coatings. The object of the invention is to provide for the inner coating of existing of metals or plastics drinking water pipes epoxy resins, which are cold-curing, cause a high blocking ability against gases and very good corrosion protection. In addition, they should meet the hygienic requirements, such as no bisphenol A-based epoxy resins and no aromatic or araliphatic amines or polyether amines as a hardener, contain no antioxidants or corrosion inhibitors as additives, and rapid curing (12 hours maximum, pot life from 30 to 90 minutes). The object is achieved with internal coatings of drinking water pipes based on epoxy resin, preparable by reacting a two-component system (A, B), wherein the component A contains (A1) based on cycloaliphatic and / or dicycloaliphatic di- or polyglycidyl ether or ester or a cyclo or dicycloaliphatic having one or more epoxide groups directly on the cycloaliphatic ring (s), (A2) an aliphatic diglycidyl ether, wherein the aliphatic chain between the glycidic groups comprises from 2 to 18 carbon atoms, (A3) silica and the component B contains (B1) one or more aliphatic and / or cycloaliphatic di- and / or polyamines, (B2) a solution of a potassium carboxylate in a glycol or a diglycidyl ether and / or a dispersion of an addition product of one or more potassium carboxylates to a nanoscale or micronized solid in a glycol or a diglycidyl ether, wherein the components A and B in Verhä Ratio of their reactive equivalents in the ratio of the epoxy to the amine groups between 1: 0.5 to 1: 5 are reacted.

Description

The invention relates to internal coatings of drinking water pipes based on epoxy resin, prepared by reacting a two-component system with the components A and B and a method for producing inner coatings of drinking water pipes based on epoxy resin by reacting a two-component system with the components A and B.

To reduce oxygen diffusion, a few approaches have been described in the patent literature. The closest to their own development comes the US-publication 2010/0160 494 A1 (Mitsubishi Gas Chemical Co. Inc., Jun. 24, 2010), according to which mixtures of epoxy resins and curing agents of an amine mixture based on xylylenediamine, polyacyl compounds, monocarboxylic acids and a carbonate compound are reacted with extended pot life. The use of the acid compounds is to be viewed critically for the intended application, since these can be leached in pipes with flowing water or can catalyze the degradation of the resins.

Another technical solution relates to three-layer systems in which a siloxane layer is built up between two epoxy resin layers ( WO 97/42027 RR Mowrer, JF Kane, CG Hull, 13.11.1997), where the siloxane or an organosilane can also be added to the epoxy resin.

Further technical solutions relate to the use of vinyl ester epoxy resins (eg. DE 60 2004 010 738 T2 Astrium SAS, 24.12.2008), mixtures of epoxy resins and silanol compounds ( DE 4008343 A1 Kansai Paint Co. Ltd., 20.09.1990), the use of certain fillers ( US 2011/00589948 A1 , 10.03.2011) or the modification of epoxy resins with elasticizing rubber particles for gas tanks ( US 2009/0255939 A1 from 15.10.2009).

Gas diffusion barriers are further prepared by inorganic layers on or in polymers, for. By hexamethyldisiloxane on PET in the arc plasma or by aluminum oxide films as intermediate layers (see eg. CA Wilson et al., Chem. Mater. 17, 5625 (2005) . MD Groner et al., Appl. Phys. Lett. 88, 051907 (2006) . AA Dameron et al., J. Phys. Chem. C 112, 4573 (2008) . R. Cooper et al., Thin Solid Films 516, 4036 (2008) ). The gas diffusion properties of polymers are described in Cozmuta et al., J. Phys. Chem. B 111, 3151-3166 (2007) respectively. Salame et al., Polym. Engng. Sci. 26 (22) (1986) examined and described.

In the US 4,943,610 describes shrinkage-free modified epoxy resins with lactone compounds and bisphenol A diglycidyl ether.

In the US 2010/0084037 describes a method and a composition for the inner coating of pipes by acrylates or epoxies with a photoinitiator, pigments antioxidants, light stabilizers and / or other additives, wherein the tube is subjected to an oxidation step before applying the coating material. In the publication of R. Kultzow and S. Foxhill, Cycloaliphatic Epoxy Resins (Meeting of the Thermoset Resin Formulators Association, Savannah, 2007) are described amine-containing and carboxylic acid-curing systems with organometallic catalysts, which despite curing catalysis> 2000 min have (Table 4). The systems based on 1-N, N- (bis-2,3-epoxypropyl) -4- (2,3-epoxypropoxy) benzene must be left at 90 ° C for at least two hours, at 150 ° C for 1 hour and at 1 hour Be cured 200 ° C.

In the US 2012/0083564 describes hardeners for epoxy resins, which consist of ethylenically unsaturated anhydrides and a vinyl compound.

In the US 2010/0292415 are described crosslinking resins of an epoxy resin mixture consisting of a cycloaliphatic epoxy resin, a cycloaliphatic anhydride and a catalyst having glass transition temperatures above 210 ° C. In the US 2011/0058948 epoxy resins for windmills are described which consist of one or more epoxy resins and one or more epoxy vinyl esters, one or more reactive diluents and at least one, amphiphilic block copolymers.

In the US 2010/0160494 Amine hardeners for epoxy resins consisting of m- or p-xylylenediamine are described. After WO 82/04256 Liquid cycloaliphatic epoxy resins are cured with diphenolic compounds. From WJ Blank, ZA He, M. Picci investigated catalysts for the epoxide-carboxyl reaction and found that amines and phosphonium compounds are active ( Lecture Int. Waterborne, High Solids and Powder Coatings Symposium, New Orleans, 21-23. 2. 2001 ). From WJ Blank, K. Dietliker, T. Jung, C. Lordelot, A. Carroy describes delayed-action catalysts which are 1,1,3-trisubstituted ureas (Lecture Basel 2008) ,

In the US 6,730,353 describes coatings for drinking water lines, which consist of epoxy resins and polyamine hardeners, wherein the amine curing agents are mixtures of one or more aromatic polyamines and one or more oligomeric polyamines.

After EP 0 767 189 Epoxy resins are cured with diamines containing primary and tertiary amino groups, the tertiary amino group is to act as a catalyst.

In EP 2 765 148 internal coatings of epoxy resin-based underfloor heating pipes are described from cycloaliphatic or aliphatic di- or triepoxides, epoxidized natural oils, silanes or siloxanes, catalysts and optionally further additives, which, however, are not suitable for the inner coating of drinking water pipes.

In the DE 10 2005 021 051 A1 there is described an epoxy two-component adhesive with thixotropic properties and a cartridge for the application of the adhesive. For internal coatings of drinking water pipes, this adhesive is not suitable because it contains harmful bisphenol A-epichlorohydrin in component A (35 wt .-%).

For interior coatings of drinking water pipes, d. H. relatively cold wall (10 to 20 ° C) of the pipe, however, in addition to he high gas barrier capacity continue to meet the hygienic requirements, d. H. no bisphenol A-based epoxy resins and no armatures or araliphatic amines or polyether amines as hardeners, no antioxidants or corrosion inhibitors as additives, and curing within a maximum of 12 hours with a pot life of 30 to 90 min required. These conditions are not met in the prior art by the available epoxy resin systems.

The object of the invention is to provide for the inner coating of existing of metals or plastics drinking water pipes epoxy resins, which are cold-curing, cause a high blocking ability against gases and very good corrosion protection. In addition, they should meet the hygienic requirements, such as no bisphenol A-based epoxy resins and no aromatic or araliphatic amines or polyether amines as a hardener, no antioxidants or corrosion inhibitors as additives, and curing within 12 hours maximum with a pot life of Allow 30 to 90 minutes.

The object is achieved according to the invention with inner coatings of drinking water pipes based on epoxy resin, prepared by reacting a two-component system with the components A and B, wherein the component A contains
(A1) a cycloaliphatic and / or dicycloaliphatic-based di- or polyglycidyl ether or ester (A1) or a cyclo- or dicycloaliphatic having one or more epoxy groups / s directly on / at the cycloaliphatic ring (s),
(A2) an aliphatic diglycidyl ether, wherein the aliphatic chain between the glycidic groups comprises 2 to 18 carbon atoms,
(A3) Silica
and component B contains
(B1) one or more aliphatic and / or cycloaliphatic di- and / or polyamines
(B2) a solution of a potassium carboxylate in a glycol or a diglycidyl ether and / or a dispersion of an addition product of one or more potassium carboxylates to a nanoscale or microvisited solid in a glycol or a diglycidyl ether,
wherein the components A and B in the ratio of their reactive equivalents in the ratio of the epoxy to the amine groups between 1: 0.3 to 1: 5 are reacted on a pipe inner surface and
a process for producing inner coatings of epoxy resin-based drinking water pipes by reacting a two-component system with components A and B, which is characterized
that component A, comprising
(A1) a cycloaliphatic and / or dicycloaliphate-based di- or polyglycidyl ether or ester or a cyclo- or dicycloaliphatic having one or more epoxy groups directly on / at the cycloaliphatic ring (s),
(A2) an aliphatic diglycidyl ether, wherein the aliphatic chain between the glycidic groups comprises 2 to 18 carbon atoms,
(A3) Silica
and component B,
full
(B1) one or more aliphatic and / or cycloaliphatic di- and / or polyamines
(B2) a solution of a potassium carboxylate in a glycol or a diglycidyl ether and / or a dispersion of an addition product of one or more potassium carboxylates to a nanoscale or micronized solid in a glycol or a diglycidyl ether, in proportion of their reactive equivalents in the ratio of the epoxy to the amine groups between 1: 0.3 to 1: 5 on a pipe inner surface to be reacted.

Advantageous developments are specified in subclaims.

Then, as component A1, glycidyl ester of 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexanedimethylene-dicarboxylic acid, 1,2-cyclohexanedimethylene-dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclohexane -endomethylene-dicarboxylic acid, the methylene-bis (4,4'-cyclohexyl-carboxylic acid) and Polyglycidether based on cycloaliphatic bodies are used, for. For example, 2,2-bis (2,3-epoxypropoxy-4-cyclohexyl) propane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, cyclohexane-1,4-dimethanol diglycidyl ether and dicyclopentadiene-based epoxides used ,

As component A2, in one embodiment, diglycidyl ethers such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butane-1,4-diol diglycidyl ether, neopentyl glycol diglycidyl ether, pentane-1,5-diol diglycidyl ether, hexane -1,6-diol diglycidyl ether, bis (2,3-epoxypropoxy) -2,2-dicyclohexyl-propane, bis (2,3-epoxypropoxy) -1,4-cyclohexane, cyclohexane-1,4-dimethanol -diglycidyl ether, triglycidyl ethers of trimethylolpropane, diglycidyl ethers of polypropylene glycols, triglycidyl ethers of oxypropylated glycerol or trimethylolpropane, polytetrahydrofuran diglycidyl ether.

As component A4, other solid additives, in particular nanoscale and / or micronized metal oxides, metal hydroxides and / or metal oxide hydroxides and / or semi-metal oxides are used, which act advantageously as reinforcing agents in the network.

Furthermore, additives are counted to the component A4, which act adsorbing or absorbing, z. As montmorillonite, bentonites, basic micronized or nanoscale bentonites, polymeric adsorbents such as acrylates, crosslinked acrylates, hydrogels, etc. These adsorbents or absorbents adsorb or absorb advantageously contained in the technical raw materials low molecular weight compounds, eg. B. from incomplete reaction of the reaction components or as undesirable impurities, so that they can not be leached by water.

In a further embodiment, the glycidyl esters A1 are combined with the glycidyl ethers A2 in a weight ratio of the two glycidyl compounds of 99.5: 0.5 to 75:25. This procedure is z. As for the preparation of coating systems in which a certain viscosity of the resin mixture at the moment of the order is required, an advantage.

As component B1 it is advantageous to use aliphatic primary diamines such as ethylenediamine, diethylenetriamine, 1,3-propanediamine, dipropylenetriamine, N-methyl-bis (3-aminopropyl) amine, 2,2,4-trimethylhexane-1,6-diamine, 2, 4,4-trimethylhexane-1,6-diamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPDA), 1,4-cyclohexanediamine, 2,2'-dimethyl-4,4'-methylene-bis (cyclohexylamine), N- (2-aminoethyl) -N-cyclohexylamine, 3- (cyclohexylamino) -propylamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethyl-1,5-pentanediamine (C11 neodiamine), 1,3-bis (aminomethyl) cyclohexane, 2,5 (2,6) bis (aminomethyl) bicyclo [2.2.1] heptane (NBDA), 3 (4), 8 ( 9) bis (aminomethyl) tricyclo [5.2.1.0 ^2,6 ] decane, aliphatic secondary diamines such as N-ethylpiperazine, N, N'-bis (sec-butyl) -4,4'-diaminodicyclohexylamine, N- Methyl-1,3-propanediamine, N-cyclohexyl-1,3-propanediamine, aliphatic triamines such as 3- (2-aminoethyl) aminopropylamine, diethylenetriamine (DETA), dipropylenetriamine (DPTA), N- (2-aminoethyl) -1, 3-propanediamine (N3-amine) , N, N'-bis (3-aminopropyl) ethylenediamine (N4-amine), N, N'-bis (3-aminopropyl) -1,4-diaminobutane, N5- (3-aminopropyl) -2-methyl- 1,5-pentanediamine, N3- (3-amino-pentyl) -1,3-pentanediamine, N5- (3-amino-1-ethyl-propyl) -2-methyl-1,5-pentanediamine and N, N'-bis (3-amino-1-ethyl-propyl) -2-methyl-1,5-pentanediamine, 4-aminomethyl-1,8-octanediamine, 1,3,5-tris (aminomethyl) -cyclohexane, tris (2-methyl) aminoethyl) amine, tris (2-aminopropyl) amine, tris (3-aminopropyl) amine, bis-hexamethylenetriamine, polyamines having primary and / or secondary amino groups such as tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA) and higher homologs linear polyethyleneamines such as polyethylenepolyamine having 5 to 7 ethyleneamine units or polyetheramines having at least 2.5 amino groups in the molecule, which are derived from trifunctional or higher-functional polyether alcohols, or mixtures thereof and
Mixtures of 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 2,2,4- / 2,4,4-trimethylhexane-1,6-diamine (TMD) in the ratio of 0.5: 99.5 to 56: 44 parts included.

The catalytically active component B2 used is potassium octoate, potassium acetate, potassium oleate, potassium formate, potassium 2-ethylhexanoate. In a particular form of the catalysis according to the invention, these metal carboxylates, such as potassium carboxylates, are brought into contact with nanoscale metal oxides or metal hydroxides or semimetal oxides, so that the metal carboxylates adsorb to the oxides. Such solid, nanoscale catalysts are particularly advantageous in the production of thin layers. By way of example, z. For example, potassium octoate in diethylene glycol with a weakly acidic silica (eg., Aerosil ^® 380 Evonik AG) are added, so that an adsorption compound is formed.

In a further embodiment, the component A with a part of the component B to form a component AB and the component B are reacted with a portion of the component A to form a component BA and then the components AB and BA with application to the pipe inner surface for implementation brought, wherein up to 30% of the equivalent amount of component B with component A and up to 30% of the equivalent amount of component A with component B to form the component AB or BA are reacted. This procedure produces a two-component system with adjustable viscosity and set pot and curing time.

The A component and the B component are preferably combined in the following proportions:
A1: 50 to 99 parts of a cycloaliphatic and / or dicycloaliphatic-based di- or polyglycidyl ether or ester,
A2: 49 to 1 part of an aliphatic diglycidyl ether, wherein the aliphatic chain between the glycidic groups comprises 2 to 18 carbon atoms,
A3: 0.01 to 10 parts of solid additives, in particular nanoscale and / or micronized metal oxides, metal hydroxides and / or metal oxide hydroxides and / or semimetal oxides,
with the proviso that the quantities contain up to 100 parts, with a B-component included
B1: one or more aliphatic and / or cycloaliphatic di-, tri- and / or polyamines
B2: 1 to 1000 ppm of a solution of a potassium carboxylate in a glycol or a diglycidyl ether and / or a dispersion of an addition product of one or more potassium carboxylates to a nanoscale or micronized solid in a glycol or a diglycidyl ether.

Then they are reacted.

In a further preferred embodiment, the mixture of the A component with 1 to 25 parts of an amine or amine mixture of one or more aliphatic and / or cycloaliphatic di- and / or polyamines at 25 to 85 ° C in 0.5 to 5 hours to Reaction brought so that a part of the epoxy groups reacts and the viscosity of the resulting product between 1000 and 20,000 mPas (25 ° C) and the amines of the B component with 1 to 25 parts of the mixture of the A component at 25 to 85 ° C in 0.5 to 5 hours reacted so that reacts a portion of the amino groups and the viscosity of the resulting product between 1000 and 20,000 mPas (25 ° C), whereby a two-component system with adjustable viscosity and set pot and curing time is produced.

It was further advantageously found that when using the inner coating according to the invention in leaching tests essentially no questionable substances in the water could be detected that the layer firmly and chemically connects to the pipe walls, that the oxygen diffusion value at about 0.1% of conventional coatings, so that corrosion of the pipe material is prevented and that the implementation of the components A and B on the inside of the drinking water pipes by the catalytic effect of the component B2 is carried out so that the pipes can be used again after 12 hours at the latest, without a thermal post cure is required.

Particularly suitable epoxy resin components are the glycidyl esters (A1) of 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexanedimethylene-dicarboxylic acid, 1,2-cyclohexanedimethylene-dicarboxylic acid and 1,3-cyclohexanedicarboxylic acid , the 1,3-cyclohexane-endomethylene-dicarboxylic acid, the methylene-bis (4,4'-cyclohexyl-carboxylic acid), etc. in question.

Alternatively, polyglycidyl ethers (A1) can be used on the basis of cycloaliphatic bodies, e.g. For example, 2,2-bis (2,3-epoxypropoxy-4-cyclohexyl) propane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane-carboxylate, 7-oxabicyclo [4.1.0] heptane-3-carboxyl-oxabicyclo [4.1.0] hept-3-ylmethyl ester, bis ((3,4-epoxycyclohexyl) methyl) adipate, 7-, 4,5-epoxytetrahydrophthalic acid diglycidyl ester, 1,4-cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylate ), Dicyclopentadiene dioxides, and dicyclopentadiene-based epoxides.

Suitable aliphatic diglycidyl ethers (A2) include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butane-1,4-diol diglycidyl ether, neopentyl glycol diglycidyl ether, pentane-1,5-diol diglycidyl ether, Hexane-1,6-diol diglycidyl ether, bis (2,3-epoxypropoxy) -2,2-dicyclohexyl-propane, bis (2,3-epoxypropoxy) -1,4-cyclohexane, triglycidyl ether of trimethylolpropane, diglycidyl ether of Polypropylene glycols, triglycidyl ethers of oxypropylated glycerol or trimethylolpropane, polytetrahydrofuran diglycidyl ether, etc.

With regard to the curing behavior and the oxygen barrier effect, it has proved advantageous to combine the cycloaliphatic glycidyl esters or ethers A1 with the aliphatic glycidyl ethers A2, wherein a weight ratio of A1 to A2 of 99.5: 0.5 to 75:25 is particularly advantageous , Due to their structure, the aliphatic glycidyl ethers act as flexibilizers in the system and increase the conversion during curing, so that higher glass transitions are already achieved in the cold-curing system. Instead of the di- or triglycidyl esters, it is also possible to use special di- or polyepoxides which fulfill the same requirement, eg. For example, 2,2-bis (2,3-epoxypropoxy-4-cyclohexyl) propane or 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane-carboxylate.

Suitable di- or polyamines (B1) according to the invention are aliphatic amines such as ethylenediamine, diethylenetriamine, 1,3-propanediamine, dipropylenetriamine, N-methyl-bis (3-aminopropyl) -amine, 2,2,4-trimethylhexane-1,6 -diamine, 2,4,4-trimethylhexane-1,6-diamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPDA), 1,4-cyclohexanediamine, 2,2'-dimethyl-4,4 '-methylene-bis (cyclohexylamine), N- (2-aminoethyl) -N-cyclohexylamine, N-ethylpiperazine, N, N'-bis (sec-butyl) -4,4'-diaminodicyclohexylamine, 3- (cyclohexylamino) propylamine etc. or mixtures thereof.

Particular preference is given to mixtures of 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 2,2,4- / 2,4,4-trimethylhexane-1,6-diamine (TMD) in the ratio of 0.5: 99.5 to 56:44 share. These amine blends are particularly advantageous in terms of corrosion protection and curing behavior. By adjusting the mixing ratio, the conversion is determined until curing is achieved. For 5 parts TMD and 95 parts IPDA z. B. with a mixture of 95 parts of cyclohexane-1,2-dicarboxylic acid diglycidester and 5 parts of pentane-1,5-diol-diglycidether a conversion up to 88% at a glass transition of 93 ° C (DSC) can be achieved.

It is a further advantage of the systems of the invention that all available pipeline materials can be coated with these materials, i. H. Metals such as steel, copper, aluminum, brass etc., plastics such as polypropylene (PP), polyethylene (HDPE, LDPE, LLDPE, HMWPE), copolymers, EPDM etc.

A problem of the aliphatic epoxy resin reaction systems is their low reaction rate, i. H. in case of long pot life, hardening takes place, which in unfavorable cases can take several days. Consequently, therefore, a variety of compounds have been studied to accelerate the cure of these systems. The proposed catalysts include, for. As tris-2,4,6- (dimethylaminomethyl) phenol, N, N'-diethylpiperazine, N-methylimidazole, zinc compounds, metal acetylacetonates, but also heterocatalysts or latent catalysts. The variety of compounds or mixtures described so far indicates a general problem.

It has now been found that certain alkali metal carboxylates also catalyze the epoxide-amine reaction. As suitable alkali metal carboxylates z. As potassium octoate, potassium acetate, potassium oleate, sodium actet, sodium formate, lithium formate, potassium 2-ethyl-hexanoate, etc. may be named. Advantageously, these metal carboxylates are dissolved in solution in a glycol, e.g. As ethylene glycol or diethylene glycol used. These solutions contain between 10 and 50% by weight of the metal carboxylate. Preference is given to solutions of potassium oleate in diethylene glycol or potassium acetate in ethylene glycol.

Preferably, these catalysts are used in very small amounts, for. Example in the range of 1 to 1000 ppm based on the hardener component (B). Particularly preferred is the range of 5 to 300 ppm based on the hardener component. Since the catalysts have a very high activity, incorporation into the resin component (the usual procedure) makes little sense, since this would lead to their instability.

Furthermore, 0.01 to 10 parts of further solid additives (A4), in particular nanoscale and / or are advantageously in the reaction systems micronized metal oxides, metal hydroxides and / or metal oxide hydroxides and / or semi-metal oxides incorporated. These serve as nucleating agents or reinforcing agents for building up the morphology, for thixotroping the systems, for coloring them (which may be prescribed by regulations) or as compatibilizers. Suitable nanoscale and / or micronized metal oxides, metal hydroxides and / or metal oxide hydroxides and / or semi-metal oxides are, for. As silicas, fumed silicas, aluminas of different degrees of drying and different particle size, magnesium oxide, magnesium hydroxide, aluminum hydroxide, aluminum oxide (boehmite), ferrous oxide, ferric oxide, magnetite, hematite, etc. It is also known metal oxide pigments or additional solids are used.

The A component is prepared by mixing the above-mentioned components in the specified mixing ratios in dissolvers, stirred reactors, kneaders, stirred kettles or by immersion stirrers in IBC. The B component is usually produced in closed stirred reactors.

For the described embodiment using partially reacted components (AB, BA) mixtures are reacted by stirring while maintaining certain temperature limits, so that a part of the reactive groups is implemented. This procedure is z. As for the preparation of coating systems in which a certain viscosity of the resin mixture at the moment of the order is required, an advantage.

For the reaction of a part of the epoxide groups of the A component (preparation of AB), the mixture of the A component from the glycidyl ester / glycidyl ether mixture is mixed with 1 to 25 parts of an amine or amine mixture of one or more aliphatic and / or cycloaliphatic diols. and / or polyamines at 25 to 85 ° C in 0.5 to 5 hours to implement. Within 2 to 24 hours, a part of the epoxy groups reacts, the viscosity is determined by the ratio of the components used and the resulting product is between 1000 and 20,000 mPas (25 ° C).

The procedure is analogous with the hardener component B (preparation of BA). Also in this part of the amino groups is reacted with epoxy groups of the resin component. Advantageously, 99 to 75 parts of the B component are reacted with 1 to 25 parts of the mixture of the A component at 25 to 85 ° C in 0.5 to 5 hours. The epoxide groups react almost quantitatively with the amino groups, whereby the viscosity of the resulting product increases to values between 1000 and 20,000 mPas (25 ° C)

embodiments

example 1

An epoxy resin system for internally coating a polypropylene drinking water pipe (25 years in service) is lined with a mixture made from an A component containing 1515 g cyclohexane-1,2-dicarboxylic acid diglycidester A1 151 g of hexane-1,6-diol diglycidyl ether A2 30 g of Aerosil ^® 380 A3 and a B component consisting of 685 g isophoronediamine (IPDA) B1 80 g of a mixture of 2,2,4- and 2,4,4-trimethyl-hexane-1,6-diamine B1 150 mg of a 20% solution of potassium octoate in diethylene glycol, B2 which are premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged into the tube (temperature 13.5 ° C) in a ratio of 2.217: 1 in 50 g shots. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 27 minutes, a significant increase in viscosity is detected, after 8 hours, the layer is cured. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.042 mg / m ² d.

Example 2

An A component is preformulated and partially implemented. This is a mixture of 4.55 kg cyclohexane-1,2-dicarboxylic acid diglycidester A1 0.45 kg of hexane-1,6-diol diglycidyl ether A2 stirred in a stirred reactor for one hour and slowly with stirring a mixture of 205 g of isophoronediamine (IPDA) B1 25 g of 2,2,4- / 2,4,4-trimethylhexane-1,6-diamine (TMD) B1 given. The temperature rises to 65 ° C within one hour. After cooling, 100 g of Aerosil ^® 380 (A3) are added to the reaction product.

The finished product AB has a viscosity of 3220 mPas (25 ° C).

Analogously, a B component is preformulated and partially reacted. This is a mixture of 1.85 kg IPDA B1 and 0.22 kg TMD B1 with 0.45 kg cyclohexane-1,2-dicarboxylic acid diglycidester A1 0.05 kg of hexane-1,6-diol diglycidyl ether A2 added with stirring. The temperature reaches 55 ° C after one hour. It is stirred for another three hours. Thereafter, 0.5 g of a 20% solution of potassium octoate (B2) in diethylene glycol are added. The reaction product (component BA) has a viscosity of 2760 mPas (25 ° C).

There are as in Example 1, the reservoir of a mixing machine filled with the components AB and BA and discharged through the described mixer in the ratio of 2.2: 1 with shots of 50 g in a polypropylene drinking water pipe and compressed air by a 300 micron thick layer generated on the pipe inner wall.

In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.058 mg / m ² d.

Example 3

An epoxy resin system for internal coating of a drinking water pipe made of polyethylene (35 years in operation) is lined with a mixture that is made of an A-component consisting of 1270 g of 3,4-epoxycyclohexanemethyl-3,4-epoxycyclohexanecarboxylate A1 258 g of cyclohexane-1,4-dimethanol diglycidyl ether A1 151 g of hexane-1,6-diol diglycidyl ether A2 27.5 g of Aerosil ^® 380 A3 and a B component consisting of 925 g isophoronediamine B1 85 g of a mixture of 2,2,4- and 2,4,4-trimethyl-hexane-1,6-diamine B1 250 mg of a 20% solution of potassium octoate in diethylene glycol, B2 which are premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and in a ratio of 1.69: 1 in Shots of 50 g in the tube (temperature 13.5 ° C) discharged. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 22 minutes, a significant increase in viscosity is detected, after 5 hours, the layer is cured. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.02 mg / m ² d.

Example 4

An epoxy resin system for internal coating of a drinking water pipe made of galvanized steel (60 years in operation) is lined with a mixture that is made of an A-component consisting of 1560 g of 1,4-cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylate) A1 718 g of hexane-1,6-diol diglycidyl ether A2 37 g of Aerosil ^® 380 A3 and a B component consisting of 935 g of isophoronediamine B1 80 g of a mixture of 2,2,4- and 2,4,4-trimethyl-hexane-1,6-diamine B1 800 mg of a 20% solution of potassium octoate in diethylene glycol, B2 which are premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged into the tube (temperature 13.5 ° C) in a ratio of 2.281: 1 in shots of 70 g. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 42 minutes, a significant increase in viscosity is detected, after 7 hours, the layer is cured. In the measurement of the oxygen diffusion, the following values were measured:
Diffusion value of the barrier layer: 0.064 mg / m ² d.

Example 5

An epoxy resin system for the internal coating of a drinking water pipe made of PVC (about 40 years in operation) is lined with a mixture that is made of an A component consisting of 1980 g 1,2-cyclohexane-endomethylene-dicarboxylic acid diglycidester A1 233 g of hexane-1,6-diol diglycidyl ether A2 37 g of Aerosil ^® 380 A3 22 g aluminum oxide hydroxide (EVONIK ALU C) A4 and a B component consisting of 997.5 g of isophoronediamine B1 79 g of N, N-bis (3-aminopropyl) N-methylamine B1 200 mg of a 20% solution of potassium octoate in diethylene glycol B2 each premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged into the tube (temperature 12.5 ° C) in a ratio of 2.111: 1 in shots of 50 g. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 35 minutes, a significant increase in viscosity is detected, after 6 hours, the layer is cured. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.048 mg / m ² d.

Example 6

An epoxy resin system for the internal coating of a drinking water pipe made of HDPE (about 33 years in operation) is lined with a mixture that is made of an A-component consisting of 1840 g bis ((3,4-epoxycyclohexyl) methyl) adipate A1 203 g of butane-1,4-diol diglycidyl ether A2 37 g of Aerosil ^® 380 A3 55 g iron oxide pigment (Kremer pigments) A4 and a B component consisting of 895 g of isophoronediamine B1 105 g of 2,2'-dimethyl-4,4'-methylenebis (cyclohexylamine) B1 95 g of N, N'-bis (sec-butyl) -4,4'-diaminodicyclohexylamine B1 700 mg of a 20% solution of potassium octoate in diethylene glycol, B2 each premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged into the tube (temperature 12.5 ° C) in a ratio of 1: 95: 1 in shots of 60 g. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 45 minutes, a significant increase in viscosity is observed, after 6.5 hours the resin has hardened to a black layer. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.032 mg / m ² d.

Example 7

An epoxy resin system for the internal coating of a drinking water pipe made of PP copolymer (about 17 years in operation) is lined with a mixture that is made of an A-component consisting of 1565 g of cyclohexane-1,2-dicarboxylic acid diglycidyl ester A1 130 g of cyclohexane-1,4-dimethanol diglycidyl ether A2 29 g of Aerosil ^® 380 A3 25 g of titanium dioxide micronized (Kremer pigments) A4 and a B component consisting of 980 g of isophoronediamine B1 55 g of 2,2'-dimethyl-4,4'-methylenebis (cyclohexylamine) B1 900 mg of a 20% solution of potassium octoate in diethylene glycol, B2 each premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged in the ratio of 1.69: 1 in shots of 40 g into the tube (temperature 14.5 ° C). By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 30 minutes, a significant increase in viscosity is detected, after 6.5 hours, the resin is cured to a white layer. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.055 mg / m ² d.

Example 8

An epoxy resin system for the internal coating of a drinking water pipe made of PP copolymer (about 17 years in operation) is lined with a mixture that is made of an A-component consisting of 1600 g of 1,4-cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylate) A1 660 g of hexane-1,6-diol diglycidyl ether A2 30 g of Aerosil ^® 380 A3 22 g titanium dioxide micronised (Kremer pigments) A4 50 g bentonite (1-2 μm particle size, pH 8-10) A4 and a B component consisting of 849 g of 4-aminomethyl-1,8-octanediamine B1 900 mg of a 20% solution of potassium octoate in diethylene glycol, B2 each premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged into the tube (temperature 14.5 ° C) in a ratio of 1.80: 1 in 40 g shots. By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 35 minutes, a significant increase in viscosity is observed, after 6.0 hours the resin has hardened to a white layer.

In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.068 mg / m ² d.

Example 9

An epoxy resin system for the internal coating of a drinking water pipe made of PP copolymer (about 17 years in operation) is lined with a mixture that is made of an A-component consisting of 1595 g of cyclohexane-1,2-dicarboxylic acid diglycidyl ester A1 110 g of hexane-1,6-diglycidyl ether A2 32 g of Aerosil ^® 380 A3 20 g of titanium dioxide micronized (Kremer pigments) A4 45 g bentonite (1-2 μm particle size, pH 8-10) A4 and a B component consisting of 790 g of 4-aminomethyl-1,8-octanediamine B1 78 g of isophoronediamine B1 900 mg of a 20% solution of potassium octoate in diethylene glycol, B2 each premixed in a 5 liter dissolver. The components are placed in a 2-component mixing machine with a combination of rotating and static mixers and discharged in a ratio of 1.75: 1 in 40 g shots into the tube (temperature 14.5 ° C). By means of compressed air, a uniform 300 μm thick layer is produced in the tube on the inner walls. After 30 minutes, a significant increase in viscosity is noted, after 5.75 hours, the resin is cured to a white layer. In the measurement of the oxygen diffusion, the following values were measured:
before coating: oxygen saturation
after coating: 0.025 mg / m ² d.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2010/0160494 A1 [0002]
• WO 97/42027 [0003]
• DE 602004010738 T2 [0004]
• DE 4008343 A1 [0004]
• US 2011/00589948 A1 [0004]
• US 2009/0255939 A1 [0004]
• US 4943610 [0006]
• US 2010/0084037 [0007]
• US 2012/0083564 [0008]
• US 2010/0292415 [0009]
• US 2011/0058948 [0009]
• US 2010/0160494 [0010]
• WO82 / 04256 [0010]
• US Pat. No. 6730353 [0011]
• EP 0767189 [0012]
• EP 2765148 [0013]
• DE 102005021051 A1 [0014]

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• R. Kultzow and S. Foxhill, Cycloaliphatic Epoxy Resins (Meeting of the Thermoset Resin Formulators Association, Savannah, 2007). [0007]
• WJ Blank, ZA He, M. Picci [0010]
• Lecture Int. Waterborne, High Solids and Powder Coatings Symposium, New Orleans, 21-23. 2. 2001 [0010]
• WJ Blank, K. Dietliker, T. Jung, C. Lordelot, A. Carroy describe delayed-action catalysts which are 1,1,3-trisubstituted ureas (Lecture Basel 2008). [0010]

Claims (13)

Internal coatings of drinking water pipes based on epoxy resin can be produced by reacting a two-component system with components A and B, containing the component A, comprising (A1) Cycloaliphatic and / or dicycloaliphate-based di- or polyglycidyl ethers or esters or cyclo- and / or dicycloaliphatic compounds having one or more epoxy groups / s directly on / at the cycloaliphatic ring (s), (A2) aliphatic diglycidyl ethers, wherein the aliphatic chain between the glycidic groups comprises from 2 to 18 carbon atoms, (A3) Silica and component B comprising (B1) one or more aliphatic and / or cycloaliphatic di-, tri- and / or polyamines having primary and / or secondary amino groups or mixtures thereof (B2) a solution of an alkali metal carboxylate in a glycol or a diglycidyl ether and / or a dispersion of an addition product of one or more potassium carboxylates to a nanoscale or micronized solid in a glycol or a diglycidyl ether, wherein the components A and B in the ratio of their reactive equivalents in the ratio of the epoxy to the amine groups between 1: 0.3 to 1: 5 are reacted. Inner coating according to claim 1, characterized in that as component A1 glycidyl ester of 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexane-endomethylene-dicarboxylic acid, 1,2-cyclohexane-endomethylene-dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,3-cyclohexane-endomethylene-dicarboxylic acid, methylenebis (4,4'-cyclohexyl-carboxylic acid) and / or 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane-carboxylate, 7-oxabicyclo [4.1 .0] heptane-3-carboxyl-oxabicyclo [4.1.0] hept-3-ylmethyl ester, bis ((3,4-epoxycyclohexyl) methyl) adipate, 4,5-epoxytetrahydrophthalic acid diglycidyl ester, 1,4-cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylates), polyglycidyl ether (A1) based on cycloaliphatic bodies, e.g. As 2,2-bis (2,3-epoxypropoxy-4-cyclohexyl) propane, dicyclopentadiene dioxide, and dicyciopentadiene based epoxides are included. Inner coating according to claim 1 or 2, characterized in that as component A2 aliphatic diglycidyl ethers such as ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butane-1,4-diol diglycidyl ether, neopentyl glycol diglycidyl ether, pentane-1 , 5-diol diglycidyl ether, hexane-1,6-diol diglycidyl ether, bis (2,3-epoxypropoxy) -2,2-dicyclohexyl-propane, bis (2,3-epoxypropoxy) -1,4-cyclohexane , Triglycidyl ethers of trimethylolpropane, diglycidyl ethers of polypropylene glycols, triglycidyl ethers of oxypropylated glycerol or trimethylolpropane, polytetrahydrofuran diglycidyl ether or pentaerythritol tetraglycidyl ether. Inner coating according to one of claims 1 to 3, characterized in that as component A4 further solid additives, in particular nanoscale and / or micronized metal oxides, metal hydroxides and / or metal oxide and / or metal oxides are contained. Inner coating according to one of claims 1 to 4, characterized in that the glycidyl esters A1 are combined with the glycidyl ethers A2 in a weight ratio of the two glycidyl compounds of 99.5: 0.5 to 75:25. Inner coating according to one of claims 1 to 5, characterized in that as component B1 aliphatic primary diamines, aliphatic secondary diamines, aliphatic triamines and polyamines with primary and / or secondary amino groups or mixtures thereof are included. Inner coating according to one of claims 1 to 6, characterized in that as component B1 mixtures of 3-aminomethyl-3,5,5-trimethylcyclohexylamine and 2,2,4- / 2,4,4-trimethylhexane-1,6-diamine (TMD) in the ratio of 0.5: 99.5 to 56:44 parts. Inner coating according to one of claims 1 to 7, characterized in that as Alkalimetallcarboxylate B2 potassium octoate, potassium acetate, potassium oleate, potassium formate and / or potassium 2-ethyl-hexanoate are included. Inner coating according to one of claims 1 to 8, characterized in that the component A with a part of the component B to form a component AB and the component B with a part Component A are reacted to form a component BA and then the components AB and BA are placed under application to a pipe inner surface for implementation. Inner coating according to one of claims 1 to 9, characterized in that up to 30% of the equivalent amount of component A with the component B and up to 30% of the equivalent amount of component B with the component A to form the component AB and BA are. Inner coating according to one of claims 1 to 10, characterized in that as component A4 additives with adsorbing or absorbing action such as montmorillonite, bentonites, basic micronized or nanoscale bentonites, polymeric adsorbents such as acrylates, crosslinked acrylates, hydrogels are included. Inner coating according to one of claims 1 to 11, characterized in that as component A4 additives with adsorbing or absorbing action such as montmorillonite, bentonites, basic micronized or nanoscale bentonites, polymeric adsorbents such as acrylates, crosslinked acrylates, hydrogels are included. Process for the preparation of internal coatings of epoxy resin-based drinking water pipes according to claims 1 to 12.