CS225467B1 - Agent for retardation of the polyadic reaction of polyhydroxyl compounds with isocyanates - Google Patents

Description

Poxyurethanes represent a wide group of polymeric substances formed by chemical reactions of isocyanates with substances containing active hydrogen atom.

Many important branches of plastics, adhesives, sealants, paints, etc. have been created on the basis of polyurethane chemistry. The reason for the considerable expansion of polyurethanes in these fields is the great variability of final products given the wide range of combining possibilities In general, plastics, sealants, adhesives such as hard, rigid, tough and soft and elastic, thermoplastic linear and highly structurally crosslinked with varying resistance to weathering, chemicals, water, mechanical stress and the like can be formulated. The second important feature is generally exothermic or _r little energy consuming mechanism polyurethane formation, given the high reactivity of the -N = C = O groups. Despite this high reaction capability of the isocyanate group, the reaction may need to be further accelerated in some cases. This happens in the production of special polyurethane foams for filling cavities, foamed by the reaction of isocyanates with water or carboxyl groups of reaction components and foams pumped with fluorinated low molecular weight hydrocarbons, in the manufacture of some integral types of foams and in two-component adhesives and sealants. with dynamiques or static mixing chambers ·

Catalysts having the ability to accelerate the reaction of R-NO 2 + HO-R * R-NH * 00 -OR * are a wide variety. The mechanism of action of the two groups of catalysts is different, and therefore the mixtures of amine-based catalysts and organometallic compounds suitably selected (eg, zinc naphthenate with dimethylphenylamine) exhibit a significant synergistic effect.

Technological equipment processing the catalysed mixtures has been set to working conditions for optimum conditions ensuring, with minimum variance of the input analytical data and standard thermal mode of operation of the mixer, acceptable variance of thermosetting properties during curing and after completion of chemical reaction. In normal processing, it sometimes occurs that the reaction progress is too slow. This problem can easily be solved by adding a small amount of catalyst or catalyst system.

However, a significantly different situation is when due to chemical reactions during the storage of raw materials (hydrolysis, transesterification, soap formation, etc.), adsorption processes in filled mixtures and dispersion of rheological properties and poor heat dissipation, the reaction progress is too fast and cannot be achieved by conventional techniques (by changing the ratio of components, adjusting the speed of the agitator or changing the geometry of the agitator) of the good properties of the final product, the nozzles of the device clogging the reaction product. In multi-component and pre-polymerization systems, the catalyst content can be reduced or the ratio of the components in the pre-polymerization mixture can be changed according to the reactivity of the reaction partners.

However, if the system is only a two-component system and the catalyst is incorporated into the polyol component, this state of higher reactivity presents a difficult problem which has hitherto been solved only by mixing the polyol component with higher reactivity separately with the polyol component without catalytic effect. If the processor was not also a producer of catalysed mixtures, then the problem was not solvable at all.

The above-mentioned deficiencies can be largely eliminated by admixing the amine-retarding agent, organometallic compounds or mixtures thereof with the catalysed reaction of the polyhydroxyl compounds with the isocyanates of the invention, consisting of a monohydric or dibasic aliphatic carboxylic acid having 2-24 C atoms per molecule or mixtures thereof. acids, optionally dissolved in castor oil, polyester alcohol or polyether alcohol with a hydroxyl number of 50-550 mg KOH / g, into the polyhydroxyl component of the reaction mixture,

By the slight addition of a catalysed catalysed polyaddition reaction of polyhydroxyl compounds with isocyanates (in the concentration range of 10 ' - 10 ' ' mots) a rapid decrease in reaction rate is achieved without substantially changing the rheological properties of the polyhydroxyl component The addition of the agent to retard the catalysed reaction according to the invention to 0.3 fhmoi has no significant effect on the mechanical and adhesive properties of the thermosetting plastics achieved and only slightly influences the formation and stability of the polyurethane foam.

Example 1 ha parts by weight of pelargonic acid and 50 parts by weight of castor refined oil are mixed.

Formulated to retard the polyaddition reaction of catalysed mixtures of polyhydroxyl compounds with isocyanates, given in an amount of 0.2% by weight to a polyurethane sealant, consisting of 6 parts by weight of titanium white, 65 parts by weight of a barley, ha. parts of molecular sieve type 4A, 0.2 wt. 0.2 part by weight of dibutyltin; % of triethylenediamine, dilaurate, A 21 wt. parts by weight of refined castor oil having a hydroxyl value of 162.3 mg KOH / g cured by the addition of 13 wt. parts of technical diphenylmethane diisocyanate, slows the relative reaction rate from 40 s to 80 s.

The relative reaction rate is determined as the time for which 100 g of polyurethane sealant and 13 g of technical diphenylmethane diisocyanate tempered to 25 ° C, stirred under standard conditions, reach 40 ° C. After curing, the sealant has the same mechanical properties as the material without the polyaddition retardant, and the adhesion to the ABS terpolymer and the resol baking varnish is unchanged.

Example 2 wt. % of a mixture of aliphatic acids of rapeseed oil composed of 4.5 wt. % palmitic acid, 1.7 wt. stearic acid, 0.5 wt. arachic acid, 0.3 wt. % behenic acid, 0.2 wt. % palmitoleic acid, 1.7 wt. gadoleic acid,

4.1% wt. erucic acid, 18.6 wt. linoleic acid, 8.9 wt. % linolenic acid and 59.5 wt. oleic acid, wt. adipic acid, 85 wt. parts of a polyester of glycerine, adipic acid and phthalic acid having a hydroxyl content of 389.4 mg KOH / g are mixed at 60 ° C. Upon cooling, a clear solution is formed which is a means to retard the catalysed polysaddition reaction of tolylendilocyanate with polyester and water in the production of polyurethane foam. 0.2 g to 60 g of a polyester resin consisting of 8 moles of glycerol, 5 moles of adipic acid and 1 mole of phthalic anhydride with an acid number of 14 mg KOH / g, a hydroxyl number of 389.4 mg KOH / g and a water content of 0.32% by weight, Ig of water, 0.5 g of ammonium oleate,

0.3 g of paraffin oil and 0.6 g of dimethylethanolamine, after mixing with 40 g of tolylene diisocyanate, increase the reaction time by 20%.

Claims (1)

SUBJECT TO OF THE INVENTION A composition for retarding the polyaddition reaction of polyhydroxy compounds with isocyanates of catalysed amines, organometallic compounds, or mixtures thereof, characterized in that it is a monohydric or dibasic aliphatic carboxylic acid having 2 to 24 carbon atoms or a mixture thereof, optionally dissolved in castor oil, polyester alcohol or a polyether alcohol having a hydroxyl value of 50-550 mg KOH / g.