CS204880B1 - Thermoreactive mixtures with increased storage property time - Google Patents

Description

The invention relates to thermoreactive storage stable compositions over a wide range of temperatures, particularly suitable for casting and deposition, and to a process for their preparation.

The excellent mechanical and physical properties of the polyurethanes, in particular their high abrasion resistance and low temperature flexibility, with the ability to vary the polymer stiffness over a wide range depending on composition and processing, make these polymers suitable for a large number of applications. These properties are also used for the preparation of special microporous formations, especially plastic skin substitutes, especially of the shoe and haberdashery type.

Until recently, these skin substitutes were only prepared in a coagulation manner, i.e. by precipitation of the polymers in the solvent with a non-solvent. However, solvent systems have a number of economic, hygienic, environmental and safety disadvantages. Solvents are harmful to health, flammable, their regeneration is necessary for economic reasons, but also to reduce pollution of the environment.

For these reasons, it is an effort to prepare solvent-free systems that do not exhibit the above-mentioned drawbacks and have properties similar to those of the coagulation type but also to the natural ones.

Solvent-free systems are implemented either as one-component or two-component systems. Single component mixtures require blocking or masking of one of the reactive components of the mixture, i.e., the isocyanate groups of the final prepolymer or amine extender.

Two-component systems must be mixed with dosing pumps in structurally and mechanically demanding mixing heads. However, in most cases they exhibit various drawbacks and the oblique phenomenon is that the heads need to be flushed or cleaned with considerable quantities of solvents after each cycle, which increases the labor and time and material demands of the process.

One-component mixtures with blocked isocyanate prepolymers are prepared by first preparing a prepolymer of polyesters or polyethers having an isocyanate ending, which is additionally blocked by addition of suitable compounds.

These disadvantages of the prior art mixtures and processes are overcome by thermoreactive mixtures having an increased shelf life, particularly suitable for the preparation of coatings, coatings or self-supporting layers or films, containing reaction products of linear or branched polyethers or polyesters, or mixtures thereof having a hydroxyl ending 5,000 with polyisocyanates of aliphatic, aromatic, cycloaliphatic or mixtures thereof according to the process according to the invention, characterized in that the end groups are adducts of isocyanate groups with substances of the type

in a molar ratio of 1 to 1.5, where R 1 can be H, CH 3, C ₂ H 5 and R ₂ can be CH 3 or cycloaliphatic compounds of the (CH 2) _n - C = N - OH type where n = 4-6 and polyamine extender from groups of aliphatic or aromatic diamines, triamines or polyamines, preferably polyaminoimides, polyaminoimidazolines or mixtures of said compounds.

The process according to the invention does not have the disadvantages of two-component mixing head systems and, compared to the above mentioned one-component blend preparation processes, simplifies and simplifies the process for preparing blocked prepolymers which it prepares in one step by mixing polyols with polyisocyanates and suitable blocking agents. In addition to known polyamines, polyaminoimides and polyaminoimidazolines and the like, but also polyamines having one carbon dioxide molecule attached to the two amino groups, are used for the extension or crosslinking.

Said method of preparation of mixtures is suitable for the preparation of coatings, coatings, jointing or self-supporting layers or foils. Linear or branched polyethers or polyesters or mixtures thereof ending in hydroxyl groups are mixed with substances of the type

wherein R 1 can be H, CH 3, C ₂ H 5 and R ₂ can be CH 3, such as aeetonoxime, methyl ethyl ketoxime and the like or with cycloaliphatic compounds of the (GH ₂ ) _{n type} -C = N-OH where n = 4-6, such as e.g. cyclopentanone oxime, cyclohexanone oxime and the like, and at the same time polyisocyanates, which may be aromatic, such as toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, bitolyl diisocyanate, dianisidine diisocyanate, 1,5-naphthalenediisocyanate, or the like or aliphatic like 1,6-diisocyanate, etc. 2,2,4- (2,4,4-) trimethylhexamethylenediocyanate, dimeryldiisocyanate and the like, cycloaliphatic such as bisisocyanatooyclohexylmethane diisocyanate, isophorone diisocyanate and the like or arylaliphatic as xylylene diisocyanate in the ratio of isocyanate groups to isocyanate groups k hydroxyl 1,1-3,0.

These components react with stirring at 0 to 110 ° C to form an adduct which is further mixed with extenders, in particular aliphatic or aromatic diamines, triamines, possibly polyamines, but particularly preferably polyaminoimides, polyamidoimidazolines and the like, compounds or mixtures thereof, that do not react or react very slowly at room temperature, but at elevated temperatures above 100 ° C displace substances of the type

or of the type (0¾) _n -C = N-OH, thereby causing the extension or crosslinking of the released prepolymers. Preferably polyamines having one carbon dioxide molecule on two amino groups are used for the extension. In this way, a mixture with increased shelf life is prepared. To prepare the adducts of polyisocyanates, polyols, and ^R 1 ^S> C = N-OH or rZ (CH2) _n -C = N-0H can be preferably used catalysts or mixtures of catalysts containing tertiary nitrogen, such as e.g. triethylenediamine, or organometallic catalysts , such as tin octoate or dibutyltin dilaurate and the like, in an amount of 0.01 to 0.5% at 0 ° C to 110 ° C.

Said mixtures can be used for the preparation of flat structures, both light and non-light, for thermal and acoustic insulation. They can be used for haberdashery, thermal and acoustic insulation of vehicles, in clothing, for home culture, etc.

The following examples illustrate the preparation of said compositions:

Example 1

005 g of polypropylene glycol having an OH number of 56 and an acid number of 0.01 were weighed into a 3 L tempered three-necked flask equipped with a stirrer and a thermometer. The contents were heated to 100 ° C and the water contained in the polyoxypropylene glycol distilled off at about 1 mbar in about 1 hour. The polyoxypropylene glycol was then cooled to 70 ° C, 0.02 g of dibutyltin laureate, 146.5 g of acetoxime, 349 g of toluene diisocyanate was added and allowed to react until the isocyanate group content dropped to 0.0240% and did not change further.

To 1000 g of the adduct thus prepared were added 41.7 g of ethylenediamine with carbon dioxide, 130.5 g of precipitated calcium carbonate, 130.5 of pasty polyvinyl chloride having a K = 70 and 2.6 g of a silicone surfactant. Stir the mixture on a 1700 rpm mixer for 10 minutes. It was then coated with a 0.3 mm slit wiper plate onto the release coated paper. The coating was cured in an oven at 150 ° C for 2 minutes. A mechanically relatively rigid foam layer was obtained, with a very well copied relief paper release and a sufficiently smooth surface capable of being laminated to a textile backing, for example.

He did

To a tempered 3 L three-necked flask equipped with a stirrer and a thermometer was poured 1600 g of polypropylene glycol with OH number 56 and acid number 0.01 and 400 g of polypropylentriol with OH number 47.3 and acid number 0.02.

The mixture was heated to 100 ° C and dewatered as in Example 1. Then it was heated to 110 ° C, 0.02 g of diaminobicyclooctane, 168.8 g of methyl ethyl ketoxime and 337.5 toluene diisocyanate were added. The mixture reacted with stirring and heating to an isocyanate group content of 0.065% ·

To 1000 g of the adduct thus prepared was added 61.9 g of hexamethylenediamine with carbon dioxide, 118.2 g of barium sulfate and 23.6 g of silicone surfactant. The mixture was stirred for 10 min on a 1700 rpm mixer. It is then coated on a separating paper with a 0.3 mm slot. The coating was cured in an oven at 150 ° C for 2 minutes. The foam layer obtained had a thickness of 0.5 mm, mechanically strong, smooth, with a greater elastic component than the layer of Example 1.

Ex 1 to 1 and d 3

600 g of polypropylene glycol was poured into a tempered 3 L three necked flask equipped with a stirrer and a thermometer. OH 56 and acid No. 0.01 and 1200 g polypropylene glycol with s. OH 112 and acidity 0.01. Dewatering was carried out as in Example 1. Then it was cooled to 20 ° C, 12.7 g of dibutylcinlaurate, 219.3 g of acetoxime and 522.5 g of toluene diisocyanate were added. The reaction mixture contained 0.0265% free isocyanate groups. 1000 g of this mixture were mixed with 175.1 g of amine-350 polyaminoimidazoline, 133.8 g of precipitated calcium carbonate, 26.8 g of a sulfonylhydrazide type blowing agent, and 2.68 g of a silicone surfactant. The mixture was stirred for 10 minutes, 1700 rpm on a mixer and coated with a 0.3 mm slot on release paper. A solid foam layer was obtained by curing in an oven at 154 ° C.

Example 4

556 g of polypropylene glycol having an OH number of 56 and an acid number of 0.01 and 1112.1 g of polypropylene glycol having an OH number of 112 and an acid number of 0.01 were poured into a 3-neck tempered 3-L flask with stirrer and thermometer. Drainage was carried out as in the previous cases. Then, the contents of the flask were cooled to 70 ° C, 1.25 g of dibutylcinlaurate, 242.2 g of methyl ethyl ketoxime, 242.1 g of toluene diisocyanate and 347.5 diphenylmethane-4,4'-diisocyanate were added. The mixture after reaction at 70 ° C contained 0.023% of free isocyanate groups. 1000 g of this mixture was mixed with 177.9 g of amine-350 polyaminoimidazoline, 134.1 g of precipitated calcium carbonate, 2.68 g of a sulfonylhydrazide type blowing agent, and 2.68 g of a silicone surfactant.

Mix as above and apply a 0.3 mm gap on separating paper. Curing in an oven at 154 ° C resulted in a very solid, rigid foam layer 0.6 mm thick in 2 minutes.

Example 5

1 603.5 g of polypropylene glycol with OH No. 56 and acid No. 0.01 and 400.9 g of polyethylene butylene adipate with OH No. 56 were weighed into a three-necked 3 L flask and drained as in the other examples. Then the contents were cooled to 90 ° C, 349.1 g of toluene diisocyanate and 226.8 g of cyclohexanone oxime were added. The reaction mixture contained 0.04% free isocyanate groups after reaction.

To 1000 g of this mixture was added 41.9 g of diethylenetriamine, 118.7 g of precipitated calcium carbonate, 23.7 g of a sulfonylhydrazide type blowing agent, and 2.37 g of a silicone surfactant. After stirring on a mixer, the coated layer was cured in an oven at 152 ° C for 2 minutes. The foam layer was solid, rigid, with large pores.

Claims (4)

SUBJECT OF THE INVENTION 1. Thermoreactive mixtures with an increased shelf life, suitable in particular for the preparation of coatings, coatings or self-supporting layers or films, comprising reaction products of linear or branched polyethers or polyesters, or mixtures thereof with a hydroxyl terminus with a mol. weight of 300 to 5,000 with polyisocyanates of aliphatic, aromatic, cycloaliphatic or mixtures thereof, characterized in that the end groups of the reaction products are adducts of isocyanate groups with substances of a molar ratio of 1 to 1.5, where H 1 may be H, CH 2, CgH R 6 and R 8 may be CH 3 or cycloaliphatic compounds of the (CH 2) _n -C = N-OH type, wherein n = 4-6 and a polyamine extender from the group of aliphatic or aromatic diamines, triamines or polyamines, preferably polyaminoimides, polyaminoimidazolines or mixtures thereof compounds. 2. A process for the preparation of thermoreactive mixtures, characterized in that the linear or branched polyethers or polyesters or their mixtures terminated with hydroxyl groups are mixed with substances of the type EMI2.0 wherein R, can be H, CH3, C2H5 and R2 can be CH3 or cycloaliphatic compounds of type (CH2) _n ^- 6 ⁼ N-OH, where n = 4-6 and the resulting mixture is reacted with polyisocyanates, which may be aromatic, aliphatic, cycloaliphatic or arylaliphatic in an isocyanate-to-N = OH ratio of 1-1.5 and a ratio of isocyanate to hydroxyl 1,1-3,0 groups at temperatures of 0 ° C to 110 ° C until the reaction of the isocyanate groups is complete, followed by the addition of a polyamine extender, in particular from the group of aliphatic or aromatic diamines, triamines or polyamines, preferably polyaminoimides, polyaminoimidazolines or mixtures of said compounds. 3. A process according to claim 2, wherein the extender is a polyamine addition product with carbon dioxide, the polyamine having an amine number of 300 to 2300. 4. Process for the production of thermoreactive mixtures according to claim 2 or 3, characterized in that a substance or mixture of tertiary nitrogen-containing substances, in particular from the group of tertiary amines or an organometallic compound or a mixture of organometallic compounds, in particular zinc, cobalt, tin, cadmium % to 1.5 wt. per mixture.