CS271897B1 - Mass for reproduction devices' upper and auxiliary parts making - Google Patents

Abstract

The solution falls into the field of epoxide resins and ceramic manufacturing. The decrease in the weight and increase in the mechanical resistance especially of the coatings of ceramic duplicators is solved. The mass, according to the solution, can be prepared by homogenisation of 100 parts by weight of plasticised epoxide resins, 5 to 30 parts by weight of filling agents and 10 to 50 parts by weight of polyamine, polyaminoamide, modified and additive hardeners based on aliphatic amines. The space in the prepared female mould of the part is filled by this not yet hardened composition and it is exposed to the hardening process at a temperature of 0 to 80 degrees C, to an advantage of 20 to 30 degrees C.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for manufacturing tops and auxiliary parts of reproduction apparatuses, and more particularly to reducing the weight of shells in ceramic reproduction apparatuses.

Gypsum reproduction equipment used in the ceramics industry weighs more than 200 kg, especially in sanitary ceramics. Handling them is difficult, sometimes even dangerous, especially for women. The majority of the weight of the propagator consists of the skins with the tops. By these we understand those parts of the gypsum equipment for the production of gypsum operating molds, which the plasterer mainly handles during the assembly (preparation for casting) and disassembly of the propagation equipment (before removing the cast gypsum operating mold). The working life of the working surfaces of the reproduction equipment has been extended and the quality of the obtained operating forms has been increased by the use of elastic materials made of liquid epoxy elastomers and polyamines or polyaminoamides. It still uses gypsum reinforced with a wire armature to make the tires and tops. These parts must be handled with care to avoid damage. The wall thickness of the components (sheaths) is between 35 and 65 mm depending on the stress. After assembling the gypsum casting machine, the parts must be pulled together with metal tape, tongues, flap or carpenter pullers to prevent loosening of the plaster. Therefore, sufficient mechanical strength and durability of the individual sheath parts is required. All parts of the gypsum reproduction equipment must be separated with a varnish and a soap solution before each cast of the gypsum mold.

The service life of the top and auxiliary parts is now several times shorter than the working parts of epoxy-based reproducers. It has also been shown that the elasticity of epoxy rubbers, which is welcomed for the working surfaces of propagating devices, is not advantageous for auxiliary parts, especially if they are of larger dimensions. The use of epoxy polyester and other resins prevents its considerable shrinkage, which causes undesirable shape and size changes. Due to the high exothermic hardening reaction, a large amount of resin must be poured several times.

New material for making reproductive tops and auxiliary parts requires the lowest gypsum weight, higher mechanical strength, casting dimensional stability, easy separability by soap solution or other suitable means, minimum processing effort and minimum reaction heat per unit volume. There is little known in the literature for reducing the weight of propagating devices, where wooden segments are inserted into the encapsulation as casting inserts when casting the lower mold part.

We have now found that the major drawbacks of the prior art can be greatly improved by eliminating the top and auxiliary parts of the inventive reproduction apparatus by preparing homogenously 100 parts by weight of plasticized epoxy resins having an epoxy group content of 0.20 to 0.40 mol / 100. kg, preferably 0.24 to 0.30, up to 30 parts of fillers whose bulk density is less than 1.5 kg / liter, preferably less than 1 kg / liter, and 10 to 50 parts of polyamine, polyaminoamide, modified or aliphatic amine-based hardener additives having a minimum hydrogen equivalent weight of 40 g, in an amount of 90 to 170% of the theory relative to the epoxy group content of the composition which fills the void space in the prepared negative part and yet cures at 0 to 80 ° C preferably at 20 to 30 ° C.

The weight according to the invention results in a significant reduction in the weight of the parts, a greater impact resistance and thus a smaller volume dimension of the parts with an extended service life can be used. In terms of occupational safety, the absence of reactive solvents, which usually cause nerve, skin and other problems, is significant.

CS 271897 Bl

Plasticized epoxy resins are prepared by known methods by homogenizing a mixture of a dianed low molecular weight epoxy resin having a molecular weight of 360 to 650 with conventional external plasticizers such as dibutyl phthalate, diisoctyl phthalate, allyl naphthylate? Deň: 32 ° C.

The fillers for the process according to the invention are. natural or synthetic materials with high porosity, thereby substantially reducing the bulk density, for example, coke, pumice, cork, asbestos, foam glass, gas silicates, experite, granulated polystyrene, polyurethane or urea-formaldehyde foams and other similar materials.

Suitable hardeners are, in particular, amine compounds containing at least three reactive amine hydrogen atoms and an epoxy group, curing epoxy resins in the range of 0 to 80 [deg.] C., optionally in the presence of curing accelerators or retarders. The amount of hardener corresponds to 0.9 to 1.7 H.E, where H is the hydrogen equivalent of the hardener and E the content of epoxy groups in the resin (mol / 100 g). To reduce the reaction exotherm, it is necessary to use hardeners with a hydrogen equivalent of 40 and above. The higher the reaction heat released in the volume unit, the reaction rate is slower and the workability of the reactive composition is prolonged. The choice of hardener takes into account the size of the filled volume. For a 500 ml volume, for example, trimethylhexamethylenediamine, for a 5,000 ml solution of a polyaminoamide resin in diethylenetriamine, and for a volume of 9,000 ml, a diethylenetriamine adduct with butylglycidyl ether can be used at room temperature.

In ¹

The rheological properties of the reactive composition can be adjusted by the addition of adjuvants such as aromatic hydrocarbons, aromatic phosphoric acid esters or cyclic ethers, pigment can be dyed in kneading, and it is sometimes advisable to add flow agents.

Example 1

The space prepared for casting the 74 x 62 cm washbasin plate of the washbasin multiplier is separated and after 15 minutes filled with a homogenized reactive epoxy composition consisting of 5,470 g of epoxy resin containing 0.283 epoxy groups containing 23 wt. dibutyl phthalate, 1170 g of an aminoamide hardener with a hydrogen equivalent of 75 g and 1000 g of expertite at 24 ° C.

The mold decomposes after 16 hours. The board obtained weighs 7.5 kg at a height of 2.5 cm. The original gypsum board had a height of 4 cm and a weight of 33 kg. The compressive strength of the original gypsum mass was 25 MPa, the new composition was 43 MPa.

Claims (1)

REFLECT THE INVENTION Material for making up and auxiliary parts of propagating devices, obtainable by homogenising 100 parts by weight of plasticized epoxy resins containing epoxy groups of 0.20 to 0.40 mol / 100 g, preferably 0.24 to 0.30 mol / 100 g, 5 up to 30 parts of fillers whose bulk density is less than 1.5 kg / liter, preferably less than 1.5 kg / liter. 1 kg / liter, and 10 to 50 parts of polyamine, polyaminoamide, modified or additive hardeners based on aliphatic amines with a minimum hydrogen equivalent weight of 40 g, in an amount of 90-170% of the theoretical content of epoxy groups in the composition in the prepared negative form of the part and allowed to cure at a temperature of 0 to 80 ° C, preferably 20 to 30 ° C.