DE1122697B - Process for the production of foams based on isocyanate - Google Patents

Description

INTERNAT. KL. C 08 g

GERMAN

PATENT OFFICE

F31174IVd / 39b

REGISTRATION DATE: MAY 6, 1960

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL: JANUARY 25, 1962

It is known to use the isocyanate polyaddition process from already higher molecular weight compounds with reactive hydrogen atoms and polyisocyanates Manufacture plastics, whereby during the formation of the high molecular structure through suitable choice of reaction partner carbon dioxide is developed, which the high molecular structure floats into a foam. For this purpose, one is of higher molecular weight having carboxyl groups Connections run out. On a large scale, however, it has been preferred to use OH groups Add water to starting materials. The latter method has from the standpoint of isocyanate consumption from the disadvantage of being not very efficient, since 1 mol of water consumes two NCO groups.

Accordingly, attempts have already been made to use polyhydroxyl compounds with polyisocyanates in the presence of haloalkanes as blowing agents using to convert small amounts of water or even without water into foams. the Foams produced by this process, especially those in which water is not used differ from those prepared in a known manner with water, but without haloalkanes Foams due to their greater softness.

In this context, it has been emphasized that the blowing process is carried out exclusively by haloalkanes to effect, expressly not only in the absence of water, but also of carboxyl groups should be worked to completely exclude the formation of carbon dioxide.

In contrast, the invention relates to a process for the production of foams based on isocyanate from polycarboxyl compounds with a molecular weight greater than 200, polyisocyanates, activators and blowing agents in the absence of water, which is characterized in that polycarboxyl compounds or mixtures of polyhydroxyl and polycarboxyl compounds with an acid number greater than 20 and a sum of acid number and hydroxyl number from 150 to 600 with less than twice the equivalent amount of polyisocyanates in the presence of halogenated unsaturated and / or saturated hydrocarbons with a ^{boiling point below 50 0} C and in the presence of activating amounts of organic or inorganic compounds with an alkaline reaction, in which the group Oj Me ^{+ is present} at least once, where Me denotes an alkali metal or a quaternary ammonium group, are reacted in the aqueous medium.

Method of manufacture
of isocyanate-based foams

Applicant:

Paint factories Bayer Aktiengesellschaft,
Leverkusen Bayerwerk

Dr. Erwin Windemuth, Leverkusen,

and Dr. Otto Bayer, Leverkusen-Bayerwerk,

have been named as inventors

In this process, the blowing effect results from the reaction with the formation of the foam an NCO group with a COOH group under Formation of a carbonamide group with simultaneous elimination of carbon dioxide. The driving effect is supported by the halogenated saturated and / or unsaturated hydrocarbons. These The mode of operation has advantages over the methods mentioned at the outset in several respects. the The fact that water is not used simplifies the entire reaction process, since the coordination the NCO-OH and NCO-water reactions in the sense of a synchronous process, which is known to often cause difficulties, no longer is required. The present method does not only bring about one result due to its simpler way of working great manufacturing reliability, it is also due to its lower use of polyisocyanate even more economical.

A very important difference between the new procedure and the process using polyhydroxyl compounds and haloalkanes work with exclusion of water, lies in the presence of the carboxyl group, which in the course of foaming converted into a carbonamide group that is particularly capable of forming secondary valence bonds will. This in turn is visibly expressed in other properties of the carbonamide foams compared to those which only contain urethane groups. The process united in other words, the advantages of isocyanate-water foams, which also enable secondary valence bonds Urea groups are formed, and the-

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those of the pure mere or higher functional polybasic carbon urethane foams driven with haloalkanes, which is characterized by a large number of economic acids, polybasic car accessible through diene syntheses with, for example, the use of isocyanates from maleic anhydride. carboxylic acids or their hydrogenation products.

When foaming polycarboxyl compounds, chloroform also used compounds with tertiary nitrogen atoms as a viscosity-reducing compound. Higher-boiling blowing agents are amines, or aminocarboxylic acids, however, are obtained ebsnfalls for satisfactory blowing effect i _n a known manner suitable polyesteramides,
less suitable because their driving effect only occurs in a die from the aforementioned or other building blocks

late stage of formation of the higher molecular weight polyesters or polyester amides available Structure and thus begins too late. In addition, with monofunctional alcohols or carbon dioxide foams produced therewith after an acidic, such. B. saturated or unsaturated fat beginning good appearance shrink. Apparently acidic, modified. Forms further suitable poly by condensation of the propellant in the case of carboxyl compounds are due to the addition of Storage of the foam at room temperature a 15 anhydrides of polybasic carboxylic acids to linear Vacuum in the cells, causing the foam or branched hydroxyl-containing components is compressed by the air pressure, which turns out to be such. B. polyesters, polyester amides, polyalkylene glycol shrinkage makes noticeable. ether or thioether, polyacetals, available. Suitable

The suitable for the process Polycarboxylver anhydrides are, for. B. maleic anhydride, amber bonds have a molecular weight greater than 20 acid anhydride, phthalic anhydride, hexahydro-200 and an acid number greater than 20. You can have phthalic anhydride, citraconic anhydride, pyro in addition to hydroxyl groups, but should have mellitic or trimellitic anhydride or the sum of the acid number and hydroxyl anhydride in the addition product of maleic anhydride to hexa range from 150 to 600. Come into consideration chlorine cyclopentadiene or its hydrogenation, for example by known condensation methods were 25 Called polyfunctional further by addition of Acrylaus alcohols, amino alcohols, _n itril to polyhydroxy compounds such. B. of linear oxycarboxylic acids, aminocarboxylic acids or polyalkylene glycol ethers or branched polyalkylene glycol ethers, of degraded basic carboxylic acids available linear or starch or acetyl cellulose, followed by branched polyesters. The higher molecular weight ratios of the components obtained by coordinating the amount of soaping of the adducts and also by the 30 polybasic carboxylic acids. Instead of the acrylonitrile, it is easily possible to conduct the condensation, and acrylic acid can sometimes also be used directly. Polyesters with carboxyl or with carboxyl and to be mentioned can also be produced by the oxidation of polyhydroxyl groups. Suitable connec- tion alkylene glycol ethers, for example in accordance with the German explanations for the production of such polyesters, are z. B. Legeschrift 1 047 442 accessible polyalkylene glycol-ethylene glycol, diethylene glycol or polyethylene 35 ethers with several free carboxyl groups. Starting glycols of the general formula materials are also those produced by copolymerization

of fumaric acid, maleic anhydride, maleic acid-HO - | - - CH ₂ —CH ₂ —O -J ₁₁ CH ₂ —CH ₂ —OH semi-esters, crotonic acid or acrylic acid with styrene,

Isobutylene, vinyl acetate, vinyl chloride, vinylidene chloride,

where η is an integer greater than 1, 40 products obtained from butadiene or isoprene, furthermore the propylene glycol, dipropylene glycol or polypropylene adducts of 2 moles of oleic acid with m-xylene, salicylic acid glycols of the general formula formaldehyde condensates, carboxymethyl cellulose,

Copolymers of acrylic acid and linoleic acid,

Addition products of thioglycol and / or Mer-45 captocarboxylic acids with compounds which _{contain double-CH 3} J _n CH ₃ bonds, e.g. B. on polymers of

Butadiene or isoprene, or on copolymers

where η is an integer greater than 1, glycols of these with other vinyl compounds.
of the general formula Also etherification products of silanols resp.

50 siloxanes with linear or branched polyesters HO [—CH ₂ -J-OH or polyethers and by known processes

accessible polyacetals containing epoxy groups

where η denotes an integer greater than 2, compounds are suitable components for producing butanediol (1,3), butanediol (2,3), 2,2-dimethylpropane in the foams.

diol- (1,3), butane-2-diol (1,4); also glycerine, tri- ₅₅ The polycarboxyl compounds should be temperature liquid in space methylolpropane, hexanetriol- (1,2,6), pentaerythritol, in order to facilitate the mechanical production of sorbitol, addition products of alkylene oxides such as the position of the foams. If the ethylene oxide, propylene oxide, 1,2- or 2,3-butylene polycarboxyl compounds are highly viscous or solid, oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, mixing with other components of the aforementioned di- and / or higher-functional components is recommended. In any case, care must be taken to ensure that the hole, lactic acid, butyrolactan, caprolactone, ricinole- that a sufficient number of carboxyl groups acid, tartaric acid, citric acid, oxalic acid, alkylene is present. The acid number must be greater than 20; dicarboxylic acids of the general formula are preferred settings with acid numbers of

ur \ nr * f iu 1 rnnu 30 to 60, but even combinations with acid numbers

IJ "65 larger than 100 can be processed with good success,

where η is an integer greater than zero, the polyisocyanates or polyisocyanate combinations

Maleic or fumaric acid, phthalic acids, due to polynations should also be liquid at room temperature be obtained from the merization of unsaturated fatty acids. It can be both simple polyisocyanates, such as

HO

CH-CH ₂ -Ol CH ₂ - CH-OH

they are directly accessible by phosgenation of appropriate amines, as well as higher molecular weight compounds with several HCO groups; n obtained by reacting compounds with reactive Hydrogen atoms are obtainable with an excess of simple polyisocyanates, are used. Suitable isocyanates are, for. B. toluene-2,4- and toluene-2,6-diisocyanate, l-methyl-3,5-diethylbenzene-2,4-diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, Diphenylmethane-4,4'-diisocyanate, naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, 4,4 ', 4 "-Triphenylmethanriisocyanat, furthermore that by reaction of 1 mole of trimethylolpropane with 3 moles High molecular weight isocyanate obtained from toluylene diisocyanate or one which is prepared by reacting one of trimethylolpropane and propylene oxide branched polyether is obtained with an excess of tolylene diisocyanate, also trimerized and polymerized isocyanates, such as those described in German patent specification 951 168. The use of monoisocyanates is not excluded, their proportion compared to the polyisocyanates however, it must be kept small. The polyisocyanates or polyisocyanate mixtures must be based on the reactive hydrogen atoms, in deficit, in an equivalent amount or in excess can be used. However, the isocyanate excess should at most be twice the equivalent amount not exceed.

The use of activators is an essential requirement. Since the carboxyl groups react more slowly than the hydroxyl groups, very reactive activators must be used. These are organic or inorganic compounds with an alkaline reaction in the aqueous medium and in which the group O] Me ^{+ is present} at least once, where Me denotes an alkali metal or a quaternary ammonium group. Alkali hydroxides, alkali metal alcoholates or phenolates, as well as alkali salts of carboxylic acids including carbonic acid may be mentioned. Aliphatic tertiary amines, such as. B. permethylated alkylenepolyamines of the tetramethylethylenediamine or permethylated diethylenetriamine type, such as dimethylpiperazine, hexahydrodimethylaniline, 1,4-diaza-bicyclo- (2,2,2) -octane, can also be used. Metal compounds soluble in an organic medium, such as. B. dibutyltin dilaurate, tin (II) oleate, have proven themselves in combination with the aforementioned "Me" activators.

Are the activators, which OH ions to are able to form, it is observed that a larger amount of carbon dioxide during the foaming process is formed as from the reaction of the carboxyl groups with isocyanate with the formation of carbonamide groups is to be expected. This effect becomes particularly clear when using an excess of isocyanate. In this fact, there is another advantage of the method over those modes of operation which carboxyl groups are not present.

It is known that foamable reaction components can be converted by metal catalysts influence. The above-mentioned special catalysts, however, have the peculiarity just that To drive COOH reaction without accelerating the reaction of the hydroxyl groups also present. However, this is currently being sought, namely the adjustment of the reaction rate the carboxyl groups in the course of the reaction, the others in the foam formation involved substances.

The halogenated saturated or unsaturated hydrocarbons, which are mixed with the other reaction components, have a boiling point lower than 50 ⁰ C. Examples include trichlorofluoromethane, dichlorodifluoromethane, chlorodifluoromethane, dichlorofluoromethane, dichloroethylene, tetrafluoroethylene, trifluorotetrafluoroethane,

ίο ethyl chloride, 1,1 - dichloroethylene, 1,2-dichloroethylene, n-propyl chloride, trichlorofluorochloroethylene, 2,2-difluoro-l, l-dichloroethylene, 3,3,3-trifluoropropene. These low-boiling liquids or liquefied Gases can be mixed with the polyisocyanate or the polycarboxyl compound or in the case of a machine Operation can be fed or injected into the current stream of components at any point.

The use of propellants, which at

Generating gases at elevated temperatures is another way of reducing the bulk density of the Foams. It can e.g. B. used are azodiisobutyronitrile, Diethyl azodicarboxylate or dinitrosopentamethylene tetramine.

Dyes, such as organic or inorganic pigments, can also be used in a known manner are like fillers such as carbon black, silica gel and metal powder. Furthermore you can the foamable reaction mixtures foam stabilizers, anion-active, cation-active or not ionic emulsifiers and fire retardants such as trichloroethyl phosphate or ammonium phosphate are added will. Occasionally bring additions of plasticizers, such as. B. of highly chlorinated paraffinic Hydrocarbons or phthalic acid esters have special effects.

The process can be carried out batchwise or in continuously operating apparatus will. In the latter case, machine facilities are used, such as those used, for. B. in the French U.S. Patent 1,074,713 and U.S. Patent 2,764,565.

The process products are semi-rigid or rigid foams, they can be used for lightweight composite structures or can be used for insulation purposes against heat, cold or sound.

example 1

700 parts of an adduct of propylene oxide and trimethylolpropane with a hydroxyl number of 350 are mixed with 300 parts of dimerized linseed oil fatty acid (acid number 180). The acid number this mixture is 54. 80 parts of this mixture are branched with 20 parts of the above Polypropylene glycol ether containing 0.18 part of sodium bound as alcoholate, 1 part of permethylated Diethylenetriamine, 1 part of a mixture of a linear and a branched phenylmethylpolysiloxane and intensively mixed with the solution of 10 parts of trichlorofluoromethane in 90 parts of tolylene diisocyanate.

The creamy reaction mixture immediately begins to foam up at a moderate rate and solidifies to form a rigid foam with a density of 25 kg / m ³ .

Example 2

65 parts of a mixture of 700 parts of castor oil and 300 parts of dimerized linseed oil fatty acid (acid

number of the mixture 56, viscosity 1530 cP / 25 ⁰ C) with 35 parts of a branched polypropylene glycol ether obtained by addition of propylene oxide to trimethylolpropane (hydroxyl number 380), containing 0.4% as alcoholate bound sodium, 1 part of the in Example 1 mentioned phenylmethylpolysiloxane and a solution of 10 parts of trichlorofluoromethane in 75 parts of toluene diisocyanate thoroughly mixed. In a moderate reaction, a semi-elastic foam with a density of 43 kg / m ^{3 is formed} .

Example 3

100 parts of a polyester prepared from 1.75 mole of adipic acid, 1.75 moles of diethylene glycol and 1 mol of glycerol (acid number 30; O H number 364, viscosity: 1120 cps / 25 ° C) with vigorous stirring with 2 parts of a 17 _^0/0 igen potassium hydroxide solution in benzyl alcohol and methyl alcohol (3: 1), 2 parts of permethylated diethylenetriamine and mixed with a solution of 40 parts of trichlorofluoromethane in 160 parts of diphenylmethane-4,4'-diisocyanate with 33% NCO groups. The reaction mixture begins to foam up at a moderate speed and solidifies in the course of about 3 minutes to form a fine-pored, rigid foam.

Example 4

100 parts of a polyester (OH number 348, acid number 28) from 5 moles of adipic acid and 5 moles of triethylene glycol and 3.34 mol of hexanetriol- (1,2,6) are mixed with 2 parts of a 17% potassium hydroxide solution in benzyl alcohol (3: 1), 1.5 parts of hexahydrodimethylaniline, 1 part of the silicon compound mentioned in Example 1 and then with the solution of 14 parts of 1,1-dichloroethylene in 150 parts of modified tolylene diisocyanate, as described in Example 5, mixed. the The reaction mixture immediately begins to foam and solidifies after a short time to a rigid one Foam with a regular pore structure and without any discoloration of the core.

Example 5

100 parts by weight of a polyester made from 1.75 moles of adipic acid, 1.75 moles of diethylene glycol and 1 mole Glycerin (acid number 30, hydroxyl number 364, viscosity 1120cP / 25 ° C are mixed with 2.5 parts of a 17% Solution of potassium hydroxide in benzyl alcohol — methanol (3: 1), 1 part of the phenylmethylpolysiloxane described in Example 1 and a mixture of 10 parts of trichlorofluoromethane in 150 parts of a modified toluene diisocyanate mixed. After intensive mixing of the components begins foam the mass immediately and solidify η a short time to a rigid, abrasion-resistant foam.

The modified tolylene diisocyanate was obtained by reacting 15 parts of a polypropylene glycol ether (hydroxyl number 365) obtained by addition of propylene oxide onto trimethylolpropane with parts of tolylene diisocyanate. The NCO content is 33.7 ° / ₀ , the viscosity 94.5 cP / 25 ° C.

Example 6

100 parts of a polyester made from 730 parts of adipic acid, 636 parts of diethylene glycol and 357 parts of trimethylolpropane (acid number 30.5; OH number 381; viscosity 919cP / 25 ° C) are mixed with 6 parts of a 17% potassium hydroxide solution in benzyl alcohol and methyl alcohol ( 3: 1), 1 part of the silicon compound described in Example 1 and a solution of 10 parts of trichlorofluoromethane in 160 parts of 4,4'-diphenylmethane diisocyanate (33 ° / ₀ NC O groups)

ao intensely mixed. The creamy mixture of the components immediately begins to foam and solidifies in the course of a few minutes to form a fine-pored, abrasion-resistant, semi-rigid foam with a very even and fine pore structure. The foam shows unusually good adhesion to the walls of the vessel. Volume weight 33 kg / m ³ .

Claims (1)

PATENT CLAIM: Process for the production of foams based on isocyanate from polycarboxyl compounds with a molecular weight greater than 200, polyisocyanates, activators and blowing agents in the absence of water, characterized in that polycarboxyl compounds, or mixtures of polyhydroxyl and polycarboxyl compounds, with an acid number greater than 20 and a sum of acid and hydroxyl number from 150 to 600 with less than twice the equivalent amount of polyisocyanates in the presence of halogenated saturated and / or unsaturated hydrocarbons with a boiling point below 50 ° C and in the presence of activating amounts of organic or alkaline reactants in the aqueous medium inorganic compounds are implemented in which the grouping up Me ^{+ is present} at least once, where Me is an alkali metal or a quaternary ammonium group. Considered publications:
German Patent No. 860 109;
French Patent No. 1,075,964;
"Rubber Age," October 1958, pp. 84, 86, 87. © 109 787/436 1.62