DE2012514B2 - RELEASE AGENT FROM A SOLUTION CONTAINING ALUMINUM TRISTEARATE FOR INTEGRAL MOLDED PARTS MADE OF POLYURETHANE - Google Patents

Description

The invention relates to a release agent from a solution containing aluminum tristearate to encrypt "* prevent the adhesion, YPP integral molded parts of polyurethane of shapes." ^{L u (Λ} - - "··". '' ■ J.

In the so-called integral blending of polyurethane foam, the component mixture is introduced into closed molds in such an amount that a considerably larger volume of polyurethane foam would result than the mold used for this purpose is normally able to hold. This does not arise in the Jm'egralschaumforrrrein. inconsiderable pressure ^ on the one hand 'lead reindeer density of the finished foam, on the other hand as a result of cooperation If the small foam bubbles leads to the surface of the mold cavity to form a leathery tough surface skin of the moldings * ■ ·..' to a height * ■ '''<■ -V -. "... τ"

A large number of release agents for polyurethane foam are known. Including, aluminum stearate dissolved in methylbenzene. The known release agents produce flawless despite Processability and smooth separation effect surfaces of different gloss; above all it comes often for the formation of dull areas. In some cases these areas are even discolored and whitish remind of mold spots.

An examination of these white spots on the surface of integral foam parts suggests ^ that these are microcrystals of waxes or metal soaps, some of which are already during the evaporation of the solvent after spraying the open form, sometimes only under the ' simultaneous action of pressure and heat during the reaction "in the ..gescWpsseneri. form form. '"*' '35

The present invention is intended to solve the problem of developing a release agent with which integral molded parts made of polyurethane with a smooth, uniformly glossy surface can be produced. In addition, the release agent should be easy to use, ie it must be thin. that it can be sprayed into the mold ^1. The ^x "moldings must be flawless and have sharp contours. It must not" build up "even after numerous demouldings. Furthermore, the use of only common thinners is desirable.

It has now surprisingly been found that it is possible integral foam parts smooth and demolded properly, - ancestor that ^r to form the dreaded white "spots occurs when one uses a separator made of an aluminum tristearate containing solution, which according to the invention

is characterized in that the proportion of aluminum

minium tristearate 0.5 to 1.5 weight percent loading. " That the solvent is more liquid chlorinated $ 5 Is hydrocarbon and that 0.2 to 0.8 percent by weight of magnesium oleate is added to this solution.

Magnesium oleate alone cannot properly separate integrally formed polyurethane foam parts to effect from a form. Rather, it is an optimal ratio of magnesium oleate essential to aluminum stearate. Too little addition of magnesium oleate does not prevent this Formation of white fogging, too high an addition causes a greasy surface of the after Evaporation of the solvent resulting film and thus a poorer separating effect.

The table below shows the influence of various levels of addition of magnesium oleate to aluminum stearate solution. A solution of 1% aluminum mum tristearate in triehloroethylene was used here. Experiment 1 shows the properties of the release film obtained after evaporation of the solvent of aluminum stearate alone, without the addition of magnesium oleate. The following experiments 2 to 7 show the effect of increasing additions of magnesium oleate on the consistency of the separating film formed, his Separation effect and the influence of the aluminum stearate / to magnesium oleate ratio on the formation of stains. Trials finally shows the effect

of magnesium oleate additive alone. FUm Separating
effect Flakes
education magnesium brittle moderate Strong oleat fixed Well moderate in weight
percent 1.0 percent by weight solution read •Well easy 0 Aluminum stearate ^i: tough Well weak 1. 0.01 in triehloroethylene> tough Well no 2. OiIQS-- ' ; some Well no 3. " 0.1 greasy 4th 0.5 greasy moderate no 5. 1.0 ^ greasy. moderate under 6th divorced 2.0 . "·.:. '.: .. licher 7th 2.0 -Shine 8th. without aluminum minium- ^: siearai -

From this it can be seen that with an addition of 0.5% by weight of magnesium oleate to the 10% Alumimum tristearate solution (Experiment 5) an optimal result is obtained, since the after evaporation The film obtained from the solvent is still tough and there is no longer any staining with a good release effect. The release film obtained as an attempt Allows you to effortlessly move several distances one after the other does not tend towards the so-called "building up".

The following example shows the use of a release agent according to the invention:

example

A release agent, made by dissolving 10 g of aluminum tristearai and "5" g of magnesium oleate in 1000 g of triehlorethylene, is sprayed in the usual way into a mold set up for the production of integral foam parts, after which the solvent has evaporated - Space ^{1 of} the * form filling ^ 'very thin separating film is obtained. This;. Is shiny, tough and does not need to be polished. Polyurethane foaming carried out in a known manner in a mold prepared in this way provides objects with details of the mold surface that are reproduced with sharp contours. This separating tab enables several demolding.

Claims (3)

Patent claims: 1. Release agent made from a solution containing aluminum tristearate to prevent adhesion 3 4 At least of integral molded parts made of polyurethane in this solution 0.2 to 0.8 percent by weight Ma-forms, characterized in that magnesium oleate is added.
the proportion of aluminum tristearate is 0.5 to 1.5 Ge 2. Release agent according to claim 1, characterized in that the solvent indicates that the liquid chlorinated carbon is chlorinated hydrocarbon and that hydrogen is trichlorethylene.