FI74986C - Stabilized halogenated hydrocarbon mixture. - Google Patents

Description

1 74986

Stabilized halogenated hydrocarbon mixture

The invention relates to a halogenated hydrocarbon mixture stabilized against the reaction with primary and secondary polyols and consisting essentially of trichlorofluoromethane and / or trichlorotrifluoroethane.

Chlorofluoroalkanes are widely used as a blowing agent in connection with polyesters and polyethers which react with polyvalent isocyanates to form polyurethane foams. Utilized polyester and polyether pulps are mixtures of compounds formed with active hydrogen, mainly polyols and aminopolyols, which may contain even smaller molecular components such as amines and amine alcohols (as catalysts). In practice, the compounds are mixed mainly with active hydrogen by the simultaneous addition of catalysts, surfactants, flame retardants and water. To prepare the polyurethane foam, this mixture is combined and reacted with the polyisocyanate only at the point of use. For this reason, it is occasionally necessary to store this flotation system for several months under stable conditions. However, it has been shown that amino compounds containing hydroxyl groups react with chlorofluoroalkanes, in particular trichlorofluoromethane and trichlorotrifluoroethane, whereby hydrogen chloride is cleaved to form an aldehyde, as well as with chlorofluoroalkanes containing hydrogen. Such products result in discoloration of the foam-forming mixture and occasional separation of crystals, and interfere with the foaming reaction.

It is known from DE-A-1,207,626 that unsaturated compounds, such as buta-35 diene, isoprene, styrene, ot-methylstyrene or 1-alkene having 4 to 18 carbon atoms, can be used for the filling of full-fledged foams. stabilizers. Related olefin compounds such as 2-butene, vinyl acetate or methyl vinyl ketone are ineffective for the same purpose or suitably ineffective (Chapter 5 1, lines 33-39). It is known from DE 1 618 291 that p-isopropenyltoluene (= p-methyl-cK-methylstyrene) can also inhibit the reaction of an amino-containing polyol with chlorofluoroalkane.

It is known from DE 1 518 461 that the undesired reaction of trichlorofluoromethane or trichlorotrifluoroethanes with primary and secondary alcohols can be prevented by the addition of 0.1 to 5% by weight of certain olefinic compounds, for example <* - methylstyrene or anethole (para-methoxy-iso-15-propenylbenzene). The effect of these unsaturated compounds on this purpose cannot be considered as expected.

It is detrimental that the proposed substances have a relatively low flash point. According to the 20 regulations on flammable liquids, a substance used at work with a flash point below 100 ° C is required. When working on a technical scale, such substances must be handled with particular care. Some of the known stabilizers are toxicologically questionable. Finally, there is a risk that these substances will polymerize due to various effects, which may occur before or after their use in a foam-forming system.

Therefore, the task is to find a new stabilizer system that does not have these disadvantages.

It was found that the addition of 0.05 to 5% by weight (based on the weight of chlorofluoroalkane) of 2,4-diphenyl-4-methylpentene to a mixture of amines with primary and secondary aliphatic hydroxyl groups and the usual amounts of trichlorotrifluoroethane or trichlorofluoro-35 methane as a blowing agent, is suitable to prevent premature reaction of the components. 2,4-Diphenyl-4-methylpentene-1-yl 3,74986 ni consists of both isomers 2,4-diphenyl-4-methylpentene- (1) and 2,4-diphenyl-4-methylpentene- (2) and the isomer ratio pentene- (1) / pentene- ( 2) is 1: 1-9: 1. The trichlorotrifluoroethane used as a blowing agent has the formula CF2Cl-CCl2F. Instead of a mixture of both pentenes, a technical mixture can be used which, in addition to these two components, still contains a small amount of 1,1,3-trimethyl-3-phenylindan. For example, according to the method of U.S. Patent No. 2,429,719, such a mixture is available and generally contains 45 to 89% by weight of 2,4-diphenyl-4-methylpentene (1), 10 to 45% by weight. % 2,4-diphenyl-4-methylpentene- (2) and 1-20% by weight of 1,1,3-trimethyl-3-phenylindan.

Particularly preferred amounts are 50 to 60, in particular 55 to 65% by weight of pentene (1), 20 to 40, in particular 25 to 35% by weight of pentene (2) and 5 to 15% by weight of pentene (1). % of indan derivative.

The stabilizer mixture forms a colorless, virtually odorless, neutral liquid with a viscosity of 20 mPas (at 20 ° C). It is non-self-igniting, non-explosive, non-photosensitive, and has no or-20 burrs polymerized. The flash point is about 120 ° C, so that according to the German regulation on flammable liquids (VbF), the stabilizer no longer has to be classified in the hazard class.

The stabilizer is miscible in all respects with chloro-25-alkanes and can easily be contained in small concentrations in trichlorofluoromethane or trichlorotrifluoroethane. It also has good solubility in other foaming components. The stabilizer prevents the decomposition of one, but in particular more, hydroxyl-containing amino alcohols.

It is surprising that the proposed substance is suitable in the presence of amino alcohols to prevent or retard the decomposition of chlorofluoroalkanes. Another advantage of the mixture according to the invention is its oily consistency as well as good stability. Chloro-35 rifluoroalkanes are often metered into the other components by means of a piston pump, in which case they must contain a lubricant, e.g. dioctyl phthalate. Because the stabilizer acts as a lubricant, it can simultaneously fulfill this function.

The invention is further illustrated by the following examples.

5 Example 1

Mixtures of 90% by weight of triethanolamine and 10% by weight of trichlorofluoromethane are mixed with varying amounts of different stabilizers and stored at different times at 40 ° C. The results of the storage experiments are shown in Table I. The composition of the stabilizer used in Experiment 2 according to the invention is as follows: about 60% by weight of 2,4-diphenyl-4-methylpentene (1), about 30% by weight of 2,4-diphenyl- 4-methylpentene- (2) and about 10% by weight of 1,1,3-trimethyl-3-phenylindan.

The olefin compounds used as reference stabilizers in other experiments are taken from the patent literature. The amount of cleavage products (dichlorofluoromethane and hydrogen chloride) is expressed as a percentage by weight (relative to the whole mixture).

20 The expression "n.g." means that in this case the amount of degradation products was not measurable.

It can be seen from the table that the compounds shown below can be very different in suitability and even completely unsuitable.

To perform the experiment, 50 g of the mixture was weighed into each aerosol gas bottle, and these were immediately sealed gas-tight. After a given time, the mixtures were evaluated for optical appearance and, if necessary, analyzed for possible cleavage products.

30 Example 2

Mixtures of 10% by weight of trichlorofluoromethane and 90% by weight of polyol C with the following composition were tested at 40 ° C: (Polyol system C for hard PUR foam) 35 50 parts by weight of oxypropylated trimethylpropane having a hydroxyl number is 380

If 5 74986 40 parts by weight of oxypropylated ethylenediamine with a hydroxyl slip 450 10 parts by weight of triethanolamine 0.8 parts by weight of water 5 1.5 parts by weight of commercial polysiloxane 1.0 part by weight of triethylamine 0.7 parts by weight of methyl bis-dimethylaminoethylamine.

The stabilizer used in Experiment 13 according to the invention has the same composition as in Experiment 2 of Example 1. The result of the experiment is shown in Table 2.

Example 3

The response of a mixture of 95% by weight of trichlorofluoromethane and 5% by weight of inhibitor at 50 ° C (in the absence of an amine containing hydroxyl groups) is examined. The results are shown in Table 3. It appears that α-methylstyrene in a mixture with trichlorofluoromethane forms a white, fluffy precipitate after short-term storage. This precipitate redissolves again in trichlorofluoromethane after vigorous shaking, however, this white polymerizes precipitates again in the use of the solution as determined, i. when mixed with the polyol system and no longer goes into solution even after vigorous shaking. The stabilizer system used according to the invention does not have such a disadvantage.

25 Example 4

Mixtures of different polyols (90% by weight) and 10% by weight of trichlorofluoromethane were stored for 90 days at 3 ° C, and then the appearance of the mixture was evaluated. The result is shown in Table IV. Column 3 30 ("stabilizer") gives the amount of stabilizer mentioned in Experiment 2 of Example 1. Polyol B is an oxypropylated ethylenediamine having a hydroxyl number of 450. Polyol D is a polyol system for PUR cold forming foam and has the following composition.

6,74986 100 parts by weight of a glycerol / propylene oxide-ethylene oxide addition compound having a hydroxyl number of 35 and containing mainly primary hydroxyl groups 2 parts by weight of triethanolamine 5 3 parts by weight of water 0.5 parts by weight of polysiloxane foaming stabilizer 0.5 parts by weight dimethylaminoethanol 0.8 parts by weight of triethylenediamine dissolved in dipropylene glycol (33%).

The experiments show the good performance of the stabilizer system used according to the invention in the presence of trichlorofluoromethane.

Example 5

A mixture of 90% by weight of triethanolamine and 10% by weight of 1,1,2-trichloro-1,2,2-trifluoroethane was stored for 90 days at 30 ° C. The results are shown in Table V. Column 2 gives the amount of stabilizer for Experiment 2 of Example 1 (% by weight relative to 0201). It should be noted that this stabilizer is also effective in the presence of trichlorotrifluoro-20 rietane.

Example 6

Mixtures of 50% by weight of the catalyst used in Example 4, dimethylaminoethanol and 50% by weight of trichlorofluoromethane, were stored with and without the stabilizer for up to 180 days at 30 ° C. The results are shown in Table VI. It should be noted that this stabilizer also prevents the premature reaction of the halohydrocarbon with an amine containing only a single hydroxyl group.

Il 7 74986

Table I

Tissue from Varast. Inhibitor Mixture Decomposition time 1% Appearance% CHCl 2% HCl 5 days CCl 3% 1 4 without brown, paste 1,6 0,34 _female_ 2 1 2,4-diphenyl-pale, clear 0.05 0.02 4- methylpentene 4 "" ng N. G.

10 "" n.g. N. G.

18 "yellow clear 0.05 0.04 30 _" _ "_ 0.07 0.06 ^ 4 1 ct-methylstyrene light, clear approx. N. G.

ni 4 "" n.g. N. G.

10 "" n.g. N. G.

18 "Celtic samea n.g. n.g.

20 30 _ "_” _ 0.05 0.04 5 1 Camphene pale, clear n.g.

4 "" n.g. N. G.

10 "yellow, bright n.g. n.g.

18 "brown, cloudy n.g. n.g.

25 30_u __ "_ 0 ^ 2_0,11 6 1 Dicyclopentadienal, clear n.g.

ene 4 "yellow, bright n.g. n.g.

10 "brown, cloudy n.g. n.g.

18 "" n.g. N. G.

_30 _ "_ brown, pasty 0.4_0.21 7 1 Stilbene light, clear n.g. n.g.

4 "yellow, bright n.g. n.g.

10 "brown, cloudy n.g. n.g.

18 "brown, pasty n.g. n.g.

30 _ ”_” _ TjO_0.38 35 8 74986

Talukko I (continued)

Tissue from Gate. Inhibitor Mixture Decomposition products time 1% appearance% CHCl 3% HCl 5 days CCL 3 F for 8 L 2,4,4-trirretyl-pale, clear n.g. N. G.

1-pentene 4 "yellow clear n.g. n.g.

10 "brown, paste n.g. n.g.

® mainen 18 "" n.g. N. G.

30 _ "_ || _1_j6_0,34 9 4 Hexafluoropropylene, paste n.g.

_finen_mainen_ 15 10 4 Morpholine cyclocrown, pasta.g. N. G.

_hexene-1_country_ 11 30_Acrylic tr illl_brown, cloudy_I ^ J_0.36

Table II

20

Try Vcirast. Inhibitor Mixture Decomposition products time 1% appearance% CHCl 2% HCl days OCl-jFrlle 12 1 without brown, clear 0.1 0.06 3 "brown, cloudy 0.3 0.15 10" from, paste 0.7 0, 30_country_13 1 2,4-diphenyl pale, clear ng N. G.

4-methylpentene 3 "yellow clear 0.05 0.02 10" "n.g. n.g.

16 "" n.g. N. G.

_30_ || _brown, clear 0.11_0.07 14 1 t-methylstyrene light, clear n.g. N. G.

3 "yellow. Cloudy 0.05 0.02 10" yellow. samea n.g. N. G.

16 "" n.g. N. G.

_30_ || _brown, cloudy_0.10_0.06

II

9 74986

Table III

Tissue from Gate. Inhibitor Appearance of the mixture time 5 _days_ 15 1 cc-swallow 1 styrene no test result 7 "white fluffy _nau precipitated_ 16 7 2,4-diphenyl-4-pale, clear 1 0 methylpentene 30 90 _180 _" _ "_

15 Table IV

Experiment Polyol Stabilizer Mixture Decomposition Products% Appearance% CHCl 3% HCl 17 Triethanol- 0 brown, 6.0 2.0 2 <^ amine paste 18 "0.05" n.g. N. G.

19 "0.25 brown, 0.2 0.12 clear 20" 0.5 yellow. clear 0.1 0.07 25 21 "1" 0.1 0.05 22 "3 light, 0.05 0.02 clear 23 _” _ 5 _ ”_ ruc [._ n.g.

24 B 0 brown, 1.1 0.70 30 clear 25 B 0.5 Celtic. clear 0.1 0.08 26 B 1 "0.1 0.06 27 B 2 light, 0.05 0.04 _clear_ 10 74986

Table IV (continued)

Test Polyol Stabilizer Mixture Decomposition products% appearance% CHCl 3% HCl 28 C 0 brown, cloudy 0.6 0.33 29 C 0.5 yellow 0.1 0.05 30 C 1 yellow. clear 0.05 0.04 31 C 2 light, clear 0.05 0.02 _kas_ ^ 32 D 0 yellow. cloudy 0.1 0.05 33 D 0.5 light, 0.05 0.01 every 34 D 1 "n.g. n.g.

35 _D_2 _ "_ n.g._n.g.

15

Table V

Experiment Stabilizer Appearance of the mixture Decomposition products% C-HCl-F-,% HCl 20 --- 36 0 brown, pasta 3.9 1.6-like 37 0.05 "n.g. n.g.

38 0.25 brown, clear 0.3 0.15 25 39 0.5 Celtic. kirkas n.g. 0.08 40 1 "0.1 0.06 41 3 light, clear 0.05 0.02 42 _5_n__0.05 0.02 30 li 11 74986

Table VI

Tissue from Gate. Stabilizer Mixture Decomposition products time 1% appearance% CHCl 2% HCl 5 days benefits 43 1 without pale, n.g. N. G.

clear 60 "brown, 0.3 0.20 clear 10 120 _" _ ”_ 0 / 7_0.45 44 1 2,4-diphenyl-4-pale, n.g. N. G.

pentene clear 60 "" 0.05 0.02 120 "" 0.05 0.03 15 180 "yellow. 0.1 0.05 _clear_