COATING COMPOSITION

Description

[0001] The present invention relates to a binder composition.

[0002] In many technical fields, a wide variety of reactive resin systems are used to achieve the desired properties for the respective application.

[0003] One application of such reactive resin systems is the coating of surfaces to protect them from solvents and oxidizing chemicals. These coating systems are used, for example, in the chemical industry, petroleum processing, refineries, wastewater treatment, ore processing plants, water protection, chemical storage facilities, reactors, pipelines, containment basins and pits, canals, etc.

[0004] Typical systems include: Asplit VEL, Asplit LF, Asplit LC, all available from REMA TipTop; Ceilcote Lining 74, Ceilcote Flakeline 232 (222, 282), all available from International Paint; Chemflake Special, available from Jotun; Bücolit V47-36, available from GBT-Bücolit; and many others. These are systems made from substances that pose health risks.

[0005] Typical uses include vinyl esters reactively diluted with monostyrene, as well as the use of furfuryl alcohol, furfural, formaldehyde or phenol.

[0006] This means that, in some cases, there are explosion risks when applying the coating due to evaporating products, and in other cases, respiratory protective equipment is often required for employees to meet safety and occupational health requirements.

[0007] Although there are a large number of suitable reactive systems available, there is still a need for systems that combine excellent properties with lower occupational safety requirements.

[0008] Desirable requirements for such coatings are: Processability in the range of 5 to 40 °C; easy processing using standard tools; no need for explosion protection measures; no need for respiratory protection equipment for employees; high resistance to organic chemicals, alkalis and acids; abrasion resistance; good adhesion; flexibility.

[0009] US 2005 / 080202 A1 discloses a family of multifunctional acrylate oligomers that are useful as pigment milling vehicles for use in radiation-curable coating formulations.

[0010] WO 2012 / 110802 A1 discloses an inkjet process in which acrylate polymers are used.

[0011] The object of the present invention was to provide binder systems that meet at least some of the requirements.

[0012] The problem is solved by a binder composition containing 50 to 70 wt.% of an acrylate ester of an epoxy-novolac resin; 30 to 49 wt.% mono-, di- or trifunctional acrylates; 0.1 to 2 wt.% starter; 0 to 10 wt.% other additives. the binder composition essentially contains no components that have a boiling point below 200 °C at normal pressure.

[0013] According to the invention, the binder composition contains 50 to 80 wt.% of an acrylate ester of an epoxy novolac resin.

[0014] If such products are supplied in mixtures, the quantity specifications refer to the content of acrylate esters of the epoxy novolac resin without taking into account the other substances in the mixture.

[0015] Preferred amounts are 60 to 70 wt.% in the binder.

[0016] Preferably, the acrylate ester in the epoxy novolac resin is a triacrylate ester. A preferred product is Ebecryl® < 9138, available from Allnex Group.

[0017] Furthermore, the binder composition contains mono-, di-, or trifunctional acrylates. These are preferably selected from 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, glycerol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol 200 dimethacrylate, butyl diglycol methacrylate, dicylopentenyloxyethyl methacrylate, dihydroxycyclopentadienyl acrylate, tetrahydrofurfuryl methacrylate, ethyl triglycol methacrylate, trimethylolpropane trimethacrylate, and mixtures thereof.

[0018] Here too, if these are offered in a mixture, only the proportion of mono-, di-, or trifunctional acrylates is considered for calculating the weight percentages. Preferred proportions are between 30 and 45 wt.%.

[0019] The above-mentioned Ebecryl®< 9138 is a mixture of 80 wt% of an acrylate ester of an epoxy-novolac resin and 20 wt% of 1,4-butanediol diacrylate. When Ebecryl®< 9138 is used, further mono-, di- or trifunctional acrylate is preferably added.

[0020] The binder composition also contains a starter. Azo- or peroxide-based starters, for example, have proven suitable, leading to a polymerization reaction within the processing temperature range specified above. The aim is to achieve curing until the surface is tack-free within a maximum of 24 hours, with processing times of at least 25 minutes. Accordingly, those skilled in the art know how to use the appropriate amount of accelerator or retarder. Thermal activation of the starter is preferred; in these cases, it is advantageous to combine the starter with the other components shortly before use. However, activation by UV radiation or electron beam is also possible in principle instead of using a starter.

[0021] The composition may also contain auxiliary substances, e.g. accelerators, retarders, viscosity modifiers, adhesion promoters, etc.

[0022] For the purposes of this application, excipients are ingredients that influence the polymerization reaction.

[0023] The binder composition according to the invention is typically used together with fillers, resulting in a coating composition. Fillers are inert with respect to the polymerization reaction but can have significant influences on the properties of the composition, particularly shrinkage, impermeability to reagents, hardness, wear resistance, and conductivity. These fillers can be, for example, glass flakes, mica, barium sulfate, or quartz flour. Alternatively, the surface can be covered with, for example, glass fiber fabrics, glass fiber mats, or glass fiber fleeces and impregnated with the binder. Carbon fibers, for example, can be used instead of glass fibers. Other fillers include, for example, pigments, barite, quartz, silica, coke, carbon black, graphite, silicon carbide, alumina, and mixtures thereof. Such coating compositions are also the subject of the invention.

[0024] If classifying a product as an additive or filler – despite the definition above – proves difficult, then substances that cannot be completely dissolved in the binder composition are fillers. Substances that do dissolve are additives.

[0025] In contrast to many prior art products, the product according to the invention contains practically no monostyrene. The monostyrene content is therefore preferably ≤0.05 wt.%, preferably below the detection limit.

[0026] The binder composition according to the invention essentially contains no components with a boiling point below 200 °C at normal pressure. "Essentially" means that the proportion of ingredients with a boiling point below 200 °C at normal pressure is <1 wt.% based on the total binder composition, preferably <0.5 wt.%. Normal pressure corresponds to 1,013 mbar.

[0027] The invention also relates to a molded body obtainable by curing the binder composition or coating composition according to the invention. Such molded bodies can be components or coatings.

[0028] The invention also relates to the use of the binder composition or coating composition according to the invention as a protective layer on substrates such as reinforced concrete or steel, as a flowable, trowelable or broadcast coating, as a synthetic resin putty for laying and grouting cladding or brickwork, as container linings or as synthetic resin masses for the production of polyconcretes.

[0029] Another object of the invention is a method for coating a substrate comprising the steps Applying the binder composition or coating composition according to the invention to obtain a coating layer; curing the coating layer.

[0030] The application can be carried out, for example, by laminating, dipping, impregnating, troweling, spraying or rolling methods.

[0031] The binder or coating composition according to the invention is typically mixed shortly before use. In a simple version, the acrylate esters of an epoxy-novolac resin, the mono-, di-, or trifunctional acrylates, additives, and fillers are premixed; only the starter is added and mixed. However, three or four components can also be mixed on-site.

[0032] Irradiation, and in particular irradiation with UV light, is preferably unnecessary for curing. Thus, coatings based on the binder according to the invention can be fully cured economically and practically over large areas at room temperature without complex additional curing measures.

[0033] The invention is further explained by the following examples: Example 1

[0034] 66.27 kg of Ebecryl 9138 containing 80 wt. % acrylate ester of an epoxynovolac resin and 20 wt. % 1,4-butanediol diacrylate were mixed with 22.22 kg of 1,4-BDDMA containing 90 wt. % butanediol dimethacrylate and 11.11 kg of dicyclopentenyloxyethyl methacrylate (FA-512 M, Hitachi Chemicals).

[0035] As excipients, 20 g of accelerator NL-53 (Akzo) containing 60-70 wt.% cobalt II-2-ethylhexanoate were added to 10 kg of the above mixture at the site and stirred. Then, 200 g of peroxide-based starter Peroxan CU-80-L (Pergan) containing 80-85 wt.% cumene hydroperoxide was added.

[0036] A mass was produced that could be applied to a pre-cleaned substrate. The layer thickness was approximately 0.8 mm. The product was workable for approximately 30 minutes; after 24 hours the surface was tack-free. The coating reached its full load-bearing capacity after 5 days. It was resistant to acids and alkalis. Example 2

[0037] The procedure was the same as in Example 1, but after adding the starter and homogenizing again, 16 kg of Millisil W4 quartz filler (Quarzwerke) was added as a filler while stirring and thoroughly mixed. This resulted in a mass that could be applied to a pre-cleaned substrate.

[0038] The layer thickness was approximately 2 mm. The product was workable for approximately 30 minutes; after 24 hours the surface was tack-free.

[0039] The product exhibited reduced shrinkage stresses compared to example 1. Example 3

[0040] The procedure was the same as in Example 2, but instead of quartz filler, two random fiber mats, each with a basis weight of less than 300 g / m², were embedded in the resin matrix along with the starter. The glass content of the total mass was 30%. After curing, a coating with higher mechanical stability was obtained.

Claims

1. A binder composition comprising - 50 to 70% by weight of an acrylate ester of an epoxy-novolac resin, - 30 to 49% by weight of mono-, di- or trifunctional acrylates, - 0.1 to 2% by weight of a starter, - 0 to 10% by weight of other auxiliaries, wherein said binder composition essentially has no components that have a boiling point below 200°C under normal pressure.

2. The binder composition according to claim 1, wherein said acrylate ester of an epoxy-novolac resin is a triacrylate ester.

3. The binder composition according to either of claims 1 to 2, wherein said mono-, di- or trifunctional acrylates are selected from 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, glycerol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol 200 dimethacrylate, butyldiglycol methacrylate, dicylopentenyloxyethyl methacrylate, dihydroxycyclopentadienyl acrylate, tetrahydrofurfuryl methacrylate, ethyltriglycol methacrylate, trimethylolpropane trimethacrylate, and mixtures thereof.

4. The binder composition according to any of claims 1 to 3, wherein said starter is an azo-based or peroxide-based starter.

5. The binder composition according to any of claims 1 to 4, wherein said auxiliaries are selected from accelerators, decelerators, viscosity modifiers, adhesion promoters, or mixtures thereof.

6. The binder composition according to any of claims 1 to 5, wherein the content of monostyrene is ≤ 0.05% by weight.

7. A coating composition comprising from 30 to 70% by weight of the binder composition according to any of claims 1 to 6, and 70 to 30% by weight of fillers.

8. The coating composition according to claim 7, wherein said fillers are selected from glass fibers, glass fabric, carbon fibers, carbon fabric, and non-wovens, glass flakes, mica, graphite flakes, pigments, baryte, quartzes, silicas, cokes, carbon blacks, graphite, silicon carbide, alumina and mixtures thereof.

9. A molded part obtainable by curing the binder composition according to any of claims 1 to 6 or the coating composition according to claim 7 or 8.

10. The molded part according to claim 9, wherein said molded part is a component or a coating.

11. Use of the binder composition according to any of claims 1 to 6 or of the coating composition according to claim 7 or 8 as a protective layer on substrates such as steel-reinforced concrete or steel, as a leveling, trowel-applied or blinded coating, as a synthetic resin putty for laying and grouting tiles or masonry, as container interior coatings or as synthetic resin compositions for preparing polyconcretes.

12. A process for coating a substrate comprising the steps of - applying the binder composition according to any of claims 1 to 6 or the coating composition according to claim 7 or 8, to obtain a coating layer, - curing said coating layer.

13. The process according to claim 12, wherein said applying is effected by laminating, dipping, soaking, trowel-applying, jet-spraying or rolling methods.