EP-4739727-A1 - CURING AGENT COMPOSITION COMPRISING SALTS OF THIOCYANATE

Abstract

The present invention relates to a curing composition comprising at least one amine which is reactive to epoxy groups and at least one salt of thiocyanate. The present invention further relates to a use of the at least one salt of thiocyanate in a multi component epoxy resin material for anchoring means. The invention further relates to a multi-component epoxy resin material, a mortar composition, and a method for the chemical fastening of construction element in boreholes.

Inventors

• BEHRENS, NICOLE

Assignees

• Hilti Aktiengesellschaft

Dates

Publication Date

20260513

Application Date

20240613

Claims (1)

1. CLAIMS 1. A curing composition comprising at least one amine which is reactive to epoxy groups and at least one salt of thiocyanate. 2. The curing composition according to claim 1, wherein the amount of the at least one salt of thiocyanate is in the range of from 0.1 to 15 weight % based on the total weight of the curing composition. 3. The curing composition according to claim 1 or 2, wherein the at least one salt of thiocyanate is selected from the group consisting of ammonium thiocyanate, sodium thiocyanate, potassium thiocyanate, imidazolinium thiocyanate, guanidin thiocyanate, copper (I) thiocyanate, tetrabutylammonium thiocyanate, calcium thiocyanate, lithium thiocyanate, magnesium thiocyanate and mixtures of two or more thereof. 4. The curing composition according to any one of claims 1 to 3, wherein the at least one amine is selected from the group consisting of aliphatic amines, alicyclic amines, araliphatic amines, aromatic amines, Mannich bases and mixtures of two or more thereof, wherein the at least one amine has on average at least two reactive hydrogen atoms per molecule which are bonded to a nitrogen atom. 5. The curing composition according to any one of claims 1 to 4, wherein the at least one amine is selected from the group consisting of isophorone diamine (IPDA), 1,3-cyclohexane bis(methylamin) (1,3-BAC), m-Xylelenediamine (mXDA), Methyldiaminocyclohexane (MDACH), 1,2-diaminocyclohexane (DCH), and mixtures of two or more thereof. 6. The curing composition according to any one of claims 1 to 5, further comprising at least one filler. 7. The curing composition according to claim 6, wherein the amount of the at least one filler is in the range of from 0.1 to 75 weight % based on total weight of the curing composition. 8. A multi-component epoxy resin material, comprising: an epoxy resin component (A) and a curing component (B) comprising the curing composition according to any one of claims 1-7, wherein the epoxy resin component (A) comprises at least one hardenable epoxy resin. 9. The multi-component epoxy resin material according to claim 8, wherein the at least one hardenable epoxy resin has one, two or more epoxy groups. 10. The multi-component epoxy resin material according to claim 8 or 9, wherein the epoxy resin component (A) comprises at least one reactive diluent. 11. The multi-component epoxy resin material according to any one of claims 8 to 10, wherein the epoxy resin component (A) comprises at least one filler. 12. The multi-component epoxy resin material according to claim 11, wherein the amount of the at least one filler is in the range of from 0.01 to 75 weight % based on total weight of the epoxy resin component (A). 13. The multi-component epoxy resin material according to any one of claim 8 to 12 in a form of a two-component system consisting of component (A) and component (B). 14. A mortar composition comprising the multi-component epoxy resin material according to any one of claims 8 to 13. 15. A use of at least one salt of thiocyanate in a multi component epoxy resin material for anchoring means to improve load values. 16. A method for the chemical fastening of construction elements in boreholes, wherein the mortar composition of claim 14 or the multi component epoxy resin material according to any one of claims 8 to 13 is used for the chemical fastening.

Description

2022P00184EP Hilti Aktiengesellschaft Principality of Liechtenstein Curing agent composition comprising salts of thiocyanate The present invention relates to a curing composition comprising at least one amine which is reactive to epoxy groups and at least one salt of thiocyanate. The present invention further relates to a use of the at least one salt of thiocyanate in a multi component epoxy resin material for anchoring means. The invention further relates to a multi-component epoxy resin material, a mortar composition, and a method for the chemical fastening of construction element in boreholes. Multi-component mortar systems based on curable epoxy resins and curing compositions comprising amines are known in the art. Such multi-component mortar systems are typically used as adhesives, spackling pastes for repairing cracks, and chemical anchors for fastening construction elements such as anchor rods, reinforcing bars, and screws in boreholes of various substrates. In the art, nitrates, triflates, bisphenols and novolac resins are used as accelerators in the curing compositions comprising amines. For example, WO 2020/058017 A1 describes compositions for anchoring means wherein nitrates and triflates are used as accelerators in epoxy resin compositions comprising isophorone diamine and 1,3-bis(aminomethyl)cyclohexane. Similarly, WO 2021/185607 A1 teaches use of nitrate and triflate salts as accelerators in epoxy resin systems comprising m-xylylenediamine, 1,2-diaminocyclohexane and 1,3- bis(aminomethyl)cyclohexane. Nitrates, like calcium nitrate-tetrahydrate used in the documents mentioned above, bring water of crystallization into the formulations which is detrimental if silanes, cement or other water-sensitive materials need to be used in the same component. Triflates are expensive and at the date of filing are not REACH registered, thereby preventing their use in the European Union. WO 2019/101563 A1 discloses bisphenols and novolac resins used as accelerators for curing an epoxy resin composition comprising m-xylylenediamine, 1,2-diaminocyclohexane, and 1,3- bis(aminomethyl)cyclohexane. Thus, there is still a need to find new accelerators for curing compositions which, when used in a mortar for fastening means, would impart an improved pullout strength/load values in dry boreholes. Further, there is also a need for new accelerators which are less expensive, REACH registered and do not contain water of crystallization. Surprisingly it has been found that salts of thiocyanate can be used instead of calcium nitrate or calcium triflate in the curing compositions comprising at least one amine which is reactive to epoxy groups. Even more surprisingly, mortar compositions comprising salts of thiocyanate in the curing composition showed an improvement in pull-out strength/load values in dry boreholes under standard conditions and at high temperature (80 °C) in comparison to mortars having calcium nitrate or calcium triflate as part of their curing compositions. Thus, the objection of the present invention is to provide a curing composition comprising an accelerator that is less expensive, without water of crystallization and REACH registered. Yet another object of the present invention is to provide a multi-component epoxy resin material suitable for fastening means that has an improved pullout strength/load values at standard conditions and at elevated temperatures (e.g.45°C to 55 °C) when used in the dry boreholes. The object of the invention is achieved by providing a curing composition according to claim 1. Preferred embodiments of the curing composition according to the present invention are provided in the dependent claims and the preferred embodiments below, which may optionally be combined with one another. The invention further relates to a multi-component epoxy resin material according to claim 9. Preferred embodiments of the multi-component epoxy resin material according to the invention are provided in the dependent claims and the preferred embodiments below, which may optionally be combined with one another. The invention further relates to a mortar composition according to claim 15, a use of at least one salt of thiocyanate according to claim 16 and a method for the chemical fastening according to claim 17. For better understanding of the invention, the following explanations of the terminology used herein are considered to be useful. Within the meaning of the invention: "a" or "an" as articles preceding a chemical compound class mean that one or more compounds falling under that chemical compound class may be meant. In a preferred embodiment, these articles mean only a single compound; “aliphatic compounds” are acyclic or cyclic, saturated or unsaturated carbon compounds, excluding aromatic compounds; “alicyclic compounds” are compounds having a carbocyclic ring structure, excluding benzene derivatives or other aromatic systems; “araliphatic compounds” are aliphatic compounds having an aromati