Additive composition for amine hardeners, use of said additive composition, and amine hardener composition containing said additive composition

Abstract

The invention relates to an additive composition, which comprises a thickener and a thixotropic agent and is characterized in that the thickener is cellulose or a derivative thereof and that the thixotropic agent is a pyrogenically produced silicic acid, the surface of which is modified with groups of general formula (I) SiR.sub.aR.sup.1.sub.bOR.sup.2.sub.c (I), in which a can equal 1, 2, or 3, b can equal 0, 1, or 2, and c can equal 0, 1, or 2, wherein a+b+c=3, and R can be a monovalent, optionally monounsaturated or polyunsaturated, optionally branched hydrocarbon group having 1 to 24 carbon atoms, R.sup.1 can be a likewise monovalent, optionally monounsaturated or polyunsaturated, optionally branched hydrocarbon group having 1 to 20 carbon atoms, and R.sup.2 can be a hydrogen atom, a monovalent, optionally monounsaturated or polyunsaturated, optionally branched hydrocarbon group having 1 to 20 carbon atoms, or a bond to another Si atom, with the stipulation that at least one of the groups R or R.sup.1 is a hydrocarbon group having more than 3 carbon atoms.

Claims

1. A hardener component for reactive resin compositions based on a binder with a resin component based on amine-hardenable compounds or on the basis of amine-hardenable compounds and radically hardenable compounds comprising at least one amine and an additive composition comprising a thickening agent and a thixotropic agent, wherein the thickening agent is a cellulose or a derivative thereof, and wherein the thixotropic agent is a fumed silica whose surface is modified with groups of the general formula (I):
SiR.sub.aR.sup.1.sub.bOR.sup.2.sub.c(I), wherein a=1, 2 or 3; b=0, 1 or 2; c=0, 1 or 2; and a+b+c=3, and wherein R is a monovalent hydrocarbon radical having 1 to 24 carbon atoms that is optionally mono- or polyunsaturated and optionally branched; R.sup.1 is a monovalent hydrocarbon radical having 1 to 20 carbon atoms that is optionally mono- or polyunsaturated and optionally branched, with the proviso that at least one of R or R.sup.1 is a monovalent hydrocarbon radical having more than 3 carbon atoms; and R.sup.2 is a hydrogen atom; a bond to another Si atom; or a monovalent hydrocarbon radical having 1 to 20 carbon atoms that is optionally mono- or polyunsaturated and optionally branched.

2. The hardener component according to claim 1, wherein at least one amine is selected from primary and/or secondary aliphatic, cycloaliphatic, aromatic and/or araliphatic amines and/or polyamines.

3. The hardener component according to claim 2, wherein at least one amine is 2-Methyl 1,5-pentanediamine.

4. The hardener component according to claim 1, wherein it further includes a radical initiator for a radically hardenable compound.

5. The hardener component according to claim 4, wherein the radical initiator is a peroxide compound.

6. The hardener component according to claim 4, wherein the peroxide is tert-butylperoxy benzoate.

7. The hardener component according to claim 1, wherein it further contains at least one inorganic filler selected from the group consisting of mineral or mineral-like fillers.

8. The hardener component according to claim 7, wherein the inorganic filler is selected from the group consisting of quartz, glass, sand, silica sand, silica powder, porcelain, corundum, ceramics, talc, silicates, clay, titanium dioxide, chalk, barite, feldspar, basalt, aluminum, granite or sandstone, polymeric fillers, hydraulically hardenable fillers, metals, mineral or organic fibers, or mixtures of two or more thereof.

Description

EMBODIMENTS

(1) To illustrate the invention, the following hardener components, and as a comparison the hardener components of the reaction resin composition according to EP 2357162 A1, are prepared, and their flow properties, once immediately after production and again after storage at +40 C. are examined over two days and over one week.

Example 1

(2) 38.9 g of 2-Methyl-1,5-pentanediamine, 6.5 g tert-butyl perbenzoate, 45.5 g of silica powder and 9.1 g of a fumed silica post-treated with octylsilane (AerosilR 805 from Evonik Industries AG or HDK H20RH from Wacker Chemie AG) are homogenized in the Speedmixer to a pasty mass.

Example 2

(3) 38.9 g 2-Methyl-1,5-pentanediamine, 6.5 g tert-butyl perbenzoate, 45.35 g of silica powder, 2.6 g of fumed silica post-treated with octylsilane (Aerosil R805 from Evonik Industries AG or HDK H20RH Wacker Chemie AG) and 5.4 g cellulose (JELUCEL HM 30, JELU plant of J. Ehrler GmbH & Co. KG) are homogenized in the Speedmixer to a pasty mass.

Comparative Example 1

(4) As a comparison, analogously to Example 1, a pasty mass is produced, with the difference that instead of 9.1 g of the fumed silica post-treated with octylsilane, 5.7 g of polydimethylsiloxane (Aerosil R202, Evonik Industries AG) is used, in accordance with the composition of the hardener component of EP 2357182 A1 from Examples 1 and 2.

Determination of Rheological Behavior of the Compositions (Time Dependence, Thixotropy)

(5) For the determination of the rheological behavior of the compositions prepared in Examples 1 and 2 and in Comparative Example 1, the freshly prepared materials as well as the mixtures were examined once after storage for 2 days, after one week and after three months. For this, the masses were each placed in a 150 ml PE beaker and stirred vigorously with a wooden tongue depressor spatula for 10 seconds. Afterward, the spatula was quickly pulled out from the sample and held horizontally. It was observed to what extent the sample runs down from the spatula. For all samples, the consistency was pasty/solid before stirring.

(6) The results are shown in Table 1.

(7) TABLE-US-00001 TABLE 1 Results of the determination of the rheological properties Example Observation Thixotropy Comparative Example 1; after stirring pasty/solid again; does not .sup.a) freshly prepared flow from the spatula Example 1; after stirring pasty/solid again; does not freshly prepared flow from the spatula Example 2; freshly after stirring again pasty/solid again; does prepared not flow from the spatula Comparative Example 1; after stirring, the sample flows from the ++.sup.D) storage 2 days + 40 C. spatula Example 1; after stirring pasty/solid again; does not storage 2 days, +40 C. flow from the spatula Example 2; after stirring pasty/solid again; does not Storage 2 days, +40 C. flow from the spatula Comparative Example after stirring the sample flows from the ++.sup.D) Storage 1 week, +40 C. spatula Example 1; after stirring pasty/solid again; does not storage 1 week, +40 C. flow from the spatula Example 2; after stirring pasty/solid again; does not storage 1 week, +40 C. flow from the spatula Comparative Example 1; after stirring, the sample flows from the ++.sup.D) storage 3 months + 40 C. spatula Example 1; after stirring pasty/solid again; does not storage, 3 months, +40 C. flow from the spatula Example 2; after stirring pasty/solid again; does not storage, 3 months, +40 C. flow from the spatula .sup.a) no thixotropy .sup.b)++: Strong thixotropy, pasty mass is again only pasty/solid after a period of one day or longer

(8) The results clearly show that composition of Comparative Example 1 after only two days of storage at +40 C. exhibits strong thixotropic behavior, that is, the mass remains liquid immediately after completion of shearing, whereas the masses according to Examples 2 and 3 exhibit no thixotropic behavior even after storage for one week at +40, that is, become pasty/solid again immediately after completion of the shearing. Even after storage for three months at +40 C, the mixture according to Example 3 displayed no thixotropic behavior, i.e., after completion of the shearing it became directly pasty/solid again. From this, the advantageous influence of the composition of the additive according to the invention becomes clear.