CS256620B1 - Low viscosity composition for effluents with reduced filler and pigment sedimentation - Google Patents

Abstract

The solution concerns the construction industry and solves the technical problem of preparing compositions for pouring materials. Its essence is a pouring material based on an epoxy acrylate binder filled with ground quartz glass. The pouring material consists of 68 to 85 parts by weight of epoxy resin, 15 to 32 parts of 2-ethylhexyl acrylate and 15 to 55 parts of ground quartz glass. The solution can be used primarily in the production of floors and terraces.

Description

The invention relates to a low viscosity flowable material with reduced sedimentation of fillers and pigments during storage and transport.

In addition to binders and surfactants, filler compositions and color pigments are also included in the compositions for the flowing compositions, particularly for the production of poured seamless floors. The role of fillers is, on the one hand, to improve certain mechanical parameters of the binder and, on the other hand, to reduce the cost of the flooring. Pigments then ensure that a pleasant color shade of the floor is achieved. In particular, pigments and often fillers show a considerable tendency to associate particles, which then sediment and solidify the sedimentation cake at an increased rate. A serious teohnical problem is the agitation of the sediment and the maintenance of the mean density of fillers and pigments for at least the time necessary to form the binder component gel. If the sedimentation rate of the filler particles and pigments cannot be managed, undesirable color changes occur on the cast surface and, on the other hand, undesirable concentration of the filler on the boundary with the substrate, which results in impaired adhesion and strength of the cast floor. This technical problem has so far been reliably overcome by the state of the art, although there are a number of methods recommended in the available literature, which, however, fail fully when using an epoxy diacrylate binder component. In the author's certificate no.

249 595 we have solved this technical problem by using suitable equalizers. However, in some cases this solution cannot be used because the compositions of the invention have a higher viscosity and a reduced flow rate. In cases where technical

The 256 620 application requires the casting material to be laid over a large area, the flowable compositions according to the present invention cannot be used because the flow rate and hence the necessary flatness of the poured floors is not achieved. The solution to this technical problem is not described in the available literature and cannot be inferred from existing knowledge ·

Based on difficult experimental work, we have found that the technical problem of achieving a low viscosity flowable material with reduced sedimentation of fillers and pigments can be solved by a flowable composition according to the invention consisting of up to 85 parts by weight of an epoxy resin with an average molecular weight of 435 to 650 and medium epoxy. 2.0, up to 32 parts of 2-ethylhexyl acrylate and up to 55 parts of ground quartz glass ·

Furthermore, the composition according to the invention is usually pigmented with inorganic pigments, in particular pigments based on iron oxides, natural ochers, zinc or titanium oxides, lithopone and others. The surface tension and wettability of the pigments and the rheological properties of the composition can be controlled by the addition of small amounts of silicone oils, low molecular weight polymers of esters of acrylic acid, fluorinated compounds or condensation products from the reaction of melamine or urea with aldehydes or other substances with similar effect. Up to 10 wt. parts of phthalic acid esters.

An important advantage of the compositions according to the invention is, on the one hand, a substantial reduction in the sedimentation of fillers and pigments, while the sedimentation cake is relatively easy to mix, and, on the other hand, a low viscosity with the known types of fillers cannot be achieved with the compositions. The significant effect is that the parameters of the cured binder significantly deteriorate with the filler used. The ground quartz glass, sometimes also referred to as ground fused quartz, is composed of vitreous amorphous quartz with a low content of crystalline alpha-SiC ^ but has a flame or spatial network formed by SiO ^ units. Silicon atoms are interconnected with oxygen atoms to form a coherent one

236 620 a polymeric network consisting of oxygen tetrahedrons surrounding each silicon atom, the tetrahedra being randomly arranged in the amorphous quartz glass network. The structure of the quartz glass is then responsible not only for the suitable properties of the filler in the epoxyacrylate binder, but also allows systems with very low thermal expansion to be obtained, which is one of the conditions for obtaining low viscosity flow systems having good mechanical properties after curing.

The technical effect achieved is a reduction in the weight of the sedimentation cake by 40 to 75%, which cake has little cohesion and is easy to mix without requiring greater mixing force. The technical effect achieved is further manifested by a relatively low viscosity of the compositions unattainable when using other types of fillers.

EXAMPLE 1 Dian epoxy resins having a mean molecular weight of 435 _{and an} average epoxy functionality of 2.0 were mixed with 15 g of 2-ethylhexyl acrylate and 50 ppm of hydroquinone at 120 ° C. The homogeneous liquid mixture has a viscosity of 850 mPa · s / 25 ° C and contains 0.472 mol / 100 g of reactive groups. 55 g of ground quartz glass with a particle size of max. 0.2 mm, g of iron red TP 303, 5 g of floated Chlumčany ocher, 2 g of zinc white 15 and 0.008 g of Lukosan M02 methylsilicone oil are mixed into the liquid. The mixture is thoroughly homogenized and the sedimentation rate of the fillers is monitored at 2 * 5 ° C:

Storage time (days) weight of sedimentation cake (g) V · pr. 1 55 g air defense 1 0.5 5.1 14 17.1 44.8 30 25.9 58.1

The viscosity of the composition is 3 * 760 mPa · s / 25 ° C, when PVC is filled, the viscosity is 8.190 mPa · s / 25 ° C. After 30 days of storage, the composition with 55 g of PVC cannot be practically stirred, whereas the composition of Example 1 is stirred within 3 minutes without exerting much effort.

256 620

The composition is mixed with 18.9 g of trimethylhexamethyleneamine. and does not cure. The cured mass has a tensile strength of 21.8 MPa, an elongation of 15.6% and an impact strength of 34.2 KJ / m ·

Example 2

Mixing 68 g of a 59µ mole epian resin melt and a mean epoxy functionality of 2.0 with 32 g of 2-ethylhexyl acrylate and 200 ppm hydroquinone yields a homogeneous mixture having a viscosity of 836 mPa · s / 25 ° C and a content of 0.401 mol /

Into this mixture, 15 g of ground silica glass having a particle size of not more than 0.1 mm, 1 g of roe, 1 g of zinc white and 3 g of ferric ocher are mixed.

The homogeneous composition has a viscosity of 1.801 mPa, s / 25 ° C and after 30 days the weight of the sedimentation cake is 6.8 g. If the composition was filled with the same amount of ground slate, the viscosity was 3.2Γ5Ο mPa.s / 25 ° C and after 30 days sedimentation cake 15.8%. The composition is mixed with 16,4 isoforms and after curing the mass has a tensile strength of 38-1 MPa, an elongation at break of 14.5% and an impact toughness of 15-2 kJ / m.

SUBJECT OF THE INVENTION

Claims (1)

SUBJECT OF THE INVENTION Low viscosity compositions for low-viscosity epoxy-based fillers and pigments based on epoxy resins and acrylates, characterized in that it consists of 68 to 85 parts of Diana epoxy resin having a mean molecular weight of 435 to 600 and an average epoxy functionality of 2.0, 15 to 32 parts of 2-ethylhexyl acrylate a 15 to 55 parts of ground quartz glass ·