DE1126131B - Process for the production of polyester urethane foams - Google Patents

Description

Process for the production of polyester urethane foams additive for patent application H 31729W d / 39 b (Auslegeschrift 1117 864) The invention relates focused on a process for the production of polyester urethane foams Conversion of alkyd resins and polyisocyanates with the addition of a heat-generating gas Reaction mass and relates to an expansion of the field of application of the method for the production of polyester urethane foams by implementing one of at least containing a polyhydric alcohol and at least one polybasic carboxylic acid Alkyd resin, in which residues of adducts of a hexahalogencyclopentadiene with Unsaturated alcohols or carboxylic acid are present in such an amount that the Alkyd resin has a halogen content of at least 100 / o, with a polyisocyanate with the addition of compounds which form gas in the reaction mass and optionally customary crosslinking agents and / or emulsifiers according to patent application H 31729 IV d 139 b, in which, according to one embodiment, tertiary alcohols together with a catalytically effective amount of a concentrated acid or an acid of the Lewis type can be used as the gas generating compound. Such from tert. Alcohols and a catalytically effective amount of a concentrated acid existing gas generating Connection are advantageous because in the production of the polyester urethane foam when foaming, no water as such, that with isocyanate groups and C 0.3 development reacts, must be added. The use of water in the manufacture of Polyester urethane foams are therefore disadvantageous because water in the for Manufacture of the polyester urethane foam components that are used the alkyd resin and the polyisocyanate, is not soluble, which is why the distribution of the Water in the components or in the mixtures of these components with the aid of emulsifiers and also must be done quickly, because water already Reacts immediately with the isocyanate at room temperature. This disadvantage is now at the embodiment according to the main patent application through the use of gas-forming Connections of the type mentioned avoided. The gas-forming compounds, established from a tertiary alcohol and a catalytically effective amount of a concentrated one Acid or an acid of the Lewis type, are essentially anhydrous, so that a C02 development when mixing the components of the polyurethane foam and the Propellant at room temperature need not be feared.

However, such gas-forming compounds contain Water latently bound, that when heated, for example by elimination of water from the tert. Alcohol or by esterification of the tert. Alcohol with carboxyl groups of the alkyd resin or also by the etherification of the tert. Alcohol, is released and then with the isocyanate under CO2 formation reacts, causing foaming.

The distribution of such a gas-forming compound in the alkyd resin or in the polyisocyanate or in mixtures of these two, since such gas-forming Compounds in the components mentioned are easily soluble, can be done extremely easily. This was made possible by the complete solubility of the gas-forming compounds ensures uniform distribution of the same in the alkyd resin-polyisocyanate mixture also that the polyester urethane foams produced are largely identical Have pore size, which is why the mechanical strengths in the entire foam are the same size.

As already mentioned, the main patent application relates to the Production of polyester urethane foams from special halogen-containing alkyd resins and in the production of polyester urethane foams from such, at room temperature Highly viscous to solid alkyd resins, the alkyd resins must be in the warm state, i. H. sufficient liquid state, mixed with the other components will. At the given higher starting temperature of the mixtures In view of the large heat of reaction released during foaming, the foams, especially thick-walled foams with a low density of around 0.064 kg / m3, heated inside so much that charring occurs when the reaction of the isocyanate runs too quickly, as occurs when using water as a gas-forming compound the case is. The use of slowly releasing water only at a higher temperature thereby allowing the isocyanate to react slowly with the water gas-forming compounds from a tert. Alcohol and a catalytically active one The amount of concentrated acid removes the risk of carbonization inside thick-walled foams.

It has now been found that this embodiment of the method according to the main patent application H 31729 IV d / 39 b also for the production of foams from polyisocyanates and any alkyd resins can be used, including in this In the event that the advantages described above are fully retained, what is on the Avoidance of the use of water as such, as a gas-forming compound is.

As usable in the process according to the invention tert. Alcohols come tert. Alcohols with the formula R2 R1-C-R3 OH in which R1 is aliphatic Group means that contains at least one hydrogen atom that is directly attached to the is bonded to the carbon atom bonded to the carbinol group, while R, and Rs aliphatic or aromatic groups are in question. As such are e.g. B. to name: tert-butyl alcohol, tert. Amyl alcohol, 2-ethyl-2-butanol, 2-ethyl-2-pentanol, 2-methyl-2-pentanol, 3-methyl-3-hexanol, 4-methyl-4-heptanol, 4-propyl-4-heptanol, 4-ethyl-4-heptanol, 2,3-dimethyl-3-butanol, 2,3-dimethyl-3-pentanol, 2,3,4-trimethyl-3-pentanol, 3-ethyl-2,4-dimethyl-3-pentanol, 3-isopropyl-2,4-demethyl-3-pentanol or terpineol. Also unsaturated tert.

Alcohols can be used, e.g. B. 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-l-hexyne-3 mol, 2-methyl-3-isopropyl-4-pentyn-3-ol, l-ethenyl-1-cyclohexanol, 2-ethyl -3-penten-2-ol, 2-methyl-4-penten-2-ol, 4-methyl-l-hepten-4-ol, 2,4-dimethyl-3-isopropyl-4-pentene- 2-ol or ct-terpineol. From tert.

Aryl-alkyl alcohols come e.g. B. Consider 1 - methyl - 1 - phenylethanol, 1,1 - Diphenylethanol, 1-methyl-1,2-diphenylethanol, 1,2-dimethyl-1,2-diphenylethanol or 2-methyl-1,1,2-triphenylethanol.

In addition, aromatic tert. Alcohols, e.g. 1,1,2,2-tetraphenylethanol, be used.

As examples of in the context of the method according to the invention in the Concentrated acids used to generate gas are e.g. to mention: sulfuric acid, phosphoric acid, nitric acid, polyphosphoric acids, chlorosulfonic acid or hydrochloric acid. Strong organic acids can also be used, e.g. B. paratoluenesulfonic acid, Benzenesulfonic acid, Naphthalene sulfonic acid, 2-naphthalene sulfonic acid, picric acid, trichloroacetic acid, trifluoroacetic acid, but also acids of the Lewi type, such as aluminum chloride, boron trifluoride or boron trichloride.

The amount of the tert as a catalyst for the dehydration. Alcohol Acid required in the propellant is not critical; it can be between about 0.04 up to 0.5 g per g tert. Alcohol lying. Generally an amount of acid of 1.5 gives Weight percent of the mass to be foamed excellent results.

Large amounts do not bring any noticeable advantage, they can rather increase have a detrimental effect on the strength of the cured foam.

The amount of gas-forming compound (propellant) is not critical, it depends on the desired texture of the foam and also on the Type of propellant itself. For a very dense foam, there is only a small one and a large amount of propellant is required for a very light foam. When using a tert. Alcohol, e.g. B. of tert. Amyl alcohol, as a propellant 1.6 g are sufficient to convert 35 g of the mass to be foamed into a fire-resistant foam with a density of 0.032 to 0.04 g / cm3. More propellant can also be used be applied. Sometimes it is useful to add some residues to the alkyd resin to introduce aliphatic carboxylic acid. Residues of adipic acid are preferred for this, but also those of other acids, e.g. B. oxal, malon, amber, glutar, pimeline, Corkic or azelaic acid, or unsaturated carboxylic acids, such as maleic, fumaric, itaconic, Citraconic or aconitic acid may be included.

The alkyd resin used to make polyurethane foam is, in general terms, the reaction product of a polyhydric alcohol with a polybasic carboxylic acid or its anhydrides, chlorides or esters of monohydric low molecular weight alcohols. Such carboxylic acids are e.g. B. maleic acid, Fumaric acid, phthalic acid, tetrachlorophthalic acid and aliphatic carboxylic acids such as Oxalic, malonic, succinic, glutaric and adipic acids.

In order to achieve a correspondingly rigid foam, at least one must part of the polyhydric alcohol in the form of residues of such with at least there are three hydroxyl groups. For a stiffer final structure, alkyd resins can be used with only residues of trihydric alcohols, e.g. B. glycerin can be used. For less rigid products, a dihydric alcohol, e.g. B.

Ethylene glycol or 1,4-butanediol, be condensed. Also such with other glycols, e.g. B.

Diethylene glycol or propylene glycol are useful.

In addition to glycerine, the following polyhydric alcohols can also be considered: hexanetriol, Butanetriol, trimethylolpropane, trimethylolethane or pentaerythritol. The relationship of polyhydric alcohol to polybasic acid (hydroxyl-carboxyl ratio) can vary within wide limits. It is preferably 1.6: 1 to 2.0: 1; in The best compressive strength is achieved in this area.

Of the polyisocyanates, the aromatic ones are preferred because they are more reactive and less toxic than the aliphatic compounds. At present, there are particularly 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate and their mixtures readily available commercially.

However, other polyisocyanates can also be used, e.g. B. Diphenylmethane-4,4'-diisocyanate, 3,3'-bis-toluylene-4,4'-diisocyanate, 3,3 ' - dimethoxy -4,4-diphenylene-diisocyanate, naphthylene-1,5-diisocyanate. Both The following examples will mostly consist of a commercially available mixture 806 / o 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate were used.

The concentration of the polyisocyanate can be between about 30 and 130 Mole percent. The foam available with a higher isocyanate concentration springs. However, the elasticity decreases when the concentration of the diisocyanate is over 100 mole percent. A foam made with only 30 mole percent diisocyanate is very brittle.

A concentration of about 85 to 115 mole percent is preferred.

The starting materials used to produce the foam can be brought together in different ways. According to one embodiment the alkyd resin or a mixture thereof with a diluent into one Brought container and stirred while heating to form a viscous, homogeneous mass. The temperature is maintained at around 85 to 1150 ° C. In a second container is the diisocyanate kept at room temperature.

A third container contains the one with mineral acid as a catalyst added alcohol. These three starting materials become continuous in the desired ratio entered into a mixer, the temperature of which is kept at about 60 to 800 C. The mixture obtained in this way is brought directly into a reaction zone, where it is about Remains for 3 to 40 minutes at 40 to 600 ° C. Then the mass increases to 70 to 800 C heated, ejected through a manifold nozzle and placed in an air circulation oven at Leave 100 to 1500 C for expansion and hardening.

According to another embodiment, it is mixed with mineral acid Alcohol mixed with the mixture of alkyd resin and diisocyanate. This process has the advantage that when mixing, the temperature is considerably higher than 600 ° C can be worked without premature expansion.

Various additives can also be used to achieve certain properties be used. Antimony oxide improves z. B. Fire Resistance; the application a filler such as clay, calcium sulfate or ammonium phosphate improves the Manufacturing process economy, affects density and improves also the resistance of the product to fire. The mass can be added be colored by dyes. By adding glass fibers, asbestos or synthetic Fibers increased strength can be achieved.

Also plasticizers, such as a mixture of methyl pentachlorostearate with epoxidized soybean oil, can be added to influence the properties will.

The following example serves to explain the subject matter of the invention in more detail.

Example A commercially available alkyd resin was used as the alkyd resin, which is made from 5 moles of adipic acid, 1 mole of phthalic anhydride and 7.6 moles of glycerol was.

53.5 g of the resin were obtained by heating to 100 bis for 2 1/2 hours Dewatered 1050 C at 0.1 mm pressure. This increased the water content of the resin from 0.89 to 0.08%, the acid number (41 to 43) practically unchanged stayed.

20.0 g of the dried resin was placed in a beaker with a thermometer heated to 1000 ° C. with stirring. Then a solution of 0.3 g of dioctyl sulfosuccinate in 1.8 g of tertiary amyl alcohol with 19.8 g of an 80:20 isomer mixture of toluene-2,4- and -2,6-diisocyanate are added and the mixture is rapidly stirred at 70 to 900 C for 38 minutes, so that a homogeneous, viscous liquid was formed. After adding 3 drops more concentrated Sulfuric acid was again vigorously stirred for 30 seconds and the resultant was formed creamy mass poured into a paper container. By heating to 1150 C was the mass expands and hardens. The very fine cell product had a density of 0.108 g / cm3.

Claims (1)

PATENT CLAIM: Process for the production of polyester urethane foams by reacting residues of adducts of a hexahalogencyclopentadiene containing Alkyd resins and polyisocyanates with the addition of a reaction mass which forms gas when heated from a tertiary C atom immediately adjacent to the tertiary C atom at least one carbinol having an aliphatically bonded hydrogen atom and one catalytically effective amount of concentrated acid, as a modification of the method according to claim 4 of patent application H31729IVd / 39b, characterized in that instead of the residues of alkyd resins containing adducts of hexahalogencyclopentadiene, other alkyd resins be used. Considered publications: German Patent Specifications No. 947 833, 953 561; French patent specification No. 1 087019.