DE4442149A1 - Prepn. of elasticised mouldings or flat goods from epoxy cpds., - Google Patents

Abstract

In prepn. of elasticised mouldings or flat good by reaction of a cpd. with more than 1 epoxy gp., opt. with mono-epoxy cpds., with a hardener and opt. other additives, the hardener is: (a) an adduct prepd. by reaction of: (1) polyalkylene ether polyols with mol. wt. 500-10,000; and (2) a mixt. of 3-isocyanatomethyl-1-methylcyclohexyl isocyanate and 4-isocyanatomethyl-1-methylcyclohexyl isocyanate, in ratio of NCO:OH of 1.5:1, and reacton of the adduct with; (3) a ketimine and/or enamine contg. OH gps., in ratio of NCO:OH of 1:1; and/or (b) amines obtd. by hydrolysis of the ketimines or enamines prepd. under (a); or (c) mixts. of (a) and/or (b) with the usual amine hardeners. Hardeners contg. the cpds. (a) require the action of water for hydrolysis of the ketimines or enamines.Also claimed is the hardener compsn.

Description

Epoxy resins have long been used Manufacture of anti-corrosion paints, wear-resistant Coatings, potting compounds and adhesives that stand out have excellent mechanical strength and good chemicals lien resistance. Due to their high network Tension density are amine-hardened epoxy resins, especially on Base of diphenylolpropane and epichlorohydrin, brittle hard with glass transition areas above 20 ° C.

In practice, the great hardness and high strength Amine hardened epoxy resins not always necessary, at the same time is often an elasticization and reduction of the brittle desired. So far there are different, but satisfactory methods have not always been used.

In principle, one can internally by reducing the network Tension-tight and the elasti externally through the addition of plasticizer Increase degree of

External elasticizers are not reactive and are not built into the duromer network. They cause The only way to expand the network is by filling up space kes. External plasticizers include tar, phthalic acid ester, high-boiling alcohols, glycols, ketone resins, vinyl polymers and the like with epoxy resins and amine hardeners non-reactive products. This type of modification is only suitable for certain applications. For elasticization it hardly contributes, since the glass softening area only is negligibly influenced, but the duromer structure is greatly disturbed.  

An internal elasticization of epoxy resins can be by reducing the functionality of the hardener, how it z. B. is described in DE-OS 22 00 717.

Have been in use for a long time and to a considerable extent long chain, low functional amino amides based dimeric and trimeric fatty acids, which is a satisfactory Achieve the property profile of soft hardeners of epoxy resins, but because of certain shortcomings they are not so universal cash as it would be desirable.

From DE-PS 10 90 803 it is also known this system to modify by using polyurethanes. A further training towards elasticized art this system has substances by means of DE-OS 21 52 606 described method found.

There has now been a process for making elastifi adorned moldings and fabrics by implementing Epoxy compounds that have more than one epoxy group per Have molecule, optionally with the use of Monoepoxy compounds, with hardening agents or hardening mixed media, optionally with the use of other additives, found that characterized is that as a curing agent or curing agent mixtures

• a) addition products, produced by implementation of
  • 1) polyalkylene ether polyols with molecular weights of 500 to 10,000, and
  • 2) a mixture of 3-isocyanatomethyl-1-methyl cyclohexyl isocyanate and 4-isocyanatomethyl-1-methyl cyclohexyl isocyanate, the ratio of NCO groups / OH groups being 1.5: 1 to 2.5: 1, and by others Implementation of the adduct thus obtained with
  • 3) ketimines and / or enamines containing hydroxyl groups,

the ratio of NCO groups / OH groups 1: 1 is, or that one

• b) amine compounds obtained by hydrolysis of the a) provided ketimines or enamines were obtained, or
• c) mixtures of the compounds mentioned under a) and b), or
• d) mixtures of the compounds mentioned in a) and / or b) with usual amine hardeners

used, wherein for the hardener mixtures, the Ver contain bonds according to a), the action of ent speaking amounts of water for hydrolysis of the ketimines or Enamine is required.

Another object of the invention are the curing agents tel for the method described above, consisting of the Components specified above under a) to d).

The terminal amine groups used according to the invention containing polyurethanes are made by reacting Isocyanate pre-adducts containing hydroxyl groups Obtain ketimines or enamines.

The isocyanate prepucts are reacted by linear or branched polyalkylene ether polyols, preferably Polypropylene oxides, obtained with di- or polyisocyanates.  

The polyalkylene ether polyols are produced by known processes manufactured and have average molecular weights between 500 and 10,000, preferably between 2000 and 5000; polypropylene oxides are particularly preferred.

A (exclusively) is preferred as the isocyanate component Mixture of 3-isocyanatomethyl-1-methyl-cyclohexyl isocyanate and 4-isocyanatomethyl-1-methyl-cyclohexyl isocyanate puts.

The polyal kylene ether polyols and the diisocyanate mixed so that a NCO / OH ratio of 1.5 to 2.5 / 1, but preferably of 2: 1, is set.

The reaction mixture is added after the addition of a suitable one Catalyst such as B. 0.1% dibutyltin dilaurate for some Heated to 50 to 100 ° C until analytical averaged isocyanate content with the calculated value matches.

Suitable ketimines or enamines containing hydroxyl groups are implemented by implementing primary or secondary alka nolamines with aldehydes or ketones and are e.g. B. in DE-OS 21 16 882 described in more detail.

The preparation of the hydroxyl group-containing ketimines is carried out in such a way that the alkanolamines, the one primary amino group and an aliphatic hydroxyl group own, with aliphatic and cyclic ketones catalyzed by acid, if necessary by heat supply or cooling, with or without solvent leads, with the corresponding water of reaction and excess carbonyl compounds removed.  

The preparation of the enamines containing hydroxyl groups is carried out in a corresponding manner by implementing the Alka nolamine, which is a secondary amino group and an aliphati own hydroxyl group, with aliphatic aldehydes or cyclic ketones.

As primary alkanolamines such. B. Ethanolamine, 1,3-Pro panolamine, 1,4-butanolamine, 1,6-hexanolamine and diglycol suitable for amine.

In the preparation of 1,2- and 1,3-alkanolamines possibly a separation of the isomeric 1,3-oxazolidines or Perhydrooxanine required.

Aliphatic or cyclic can be used as the carbonyl component Ketones such as B. methyl isobutyl ketone, diisopropyl ketone, Diisobutyl ketone, cyclohexanone and trimethylcyclohexanone Find use.

Secondary alkanolamines are, in particular, heterocy suitable products such as B. 4-hydroxypiperidine, 1- (β-hydroxyethyl) piperazine and 1- (β-hydroxypropyl) pipe razin. Cyclic components can be used here as carbonyl components Ketones such as B. Cyclopentanone, Cyclohexanone and Trime thylcyclohexanone or aldehydes, such as. B. n-butyraldehyde, Isobutyraldehyde, 2-methylpentanal and capronaldehyde be set.

The reaction is carried out so that the alkanolamine with a Excess of the carbonyl compound is mixed and after zu set of an entrainer and possibly an acidic kata lysators is heated on the water separator until the Water separation has ended. After pulling the tow by means of and the excess carbonyl component Residue distilled if necessary. The isocyanate Adducts are made with the hydroxyl-containing enamines  or cold ketimines in an NCO / OH ratio of 1: 1 mixed and stirred until in the infrared spectrum no more NCO bands can be detected.

For the use according to the invention, the ketimine or Pre-adducts containing enamine end groups directly with the Polyepoxiden or with the hardener and the polyepoxiden are mixed, the amino group being present Residual moisture or atmospheric moisture is released.

The amino groups can also be created directly in the fresh adduct by introducing water vapor or by adding set of water and heating. The Hydrolysis can be done by infrared spectroscopy using Ab follow the enamine or ketimine band.

The polyether urethanes containing amine end groups can with commercially available low molecular weight amine hardeners, the have at least two reactive amine hydrogen bonds sen, be stored stable. The viscosity the polyether urethanes significantly reduced and the reacti vity of the mixture when reacted with epoxy resins device.

The multitude of usable amine hardeners with different Chen functionalities and viscosities allows a lot wide range of processing and thermoset Properties.

Examples of common amine hardeners are: aliphatic amines, e.g. B. polyethylene polyamines and polypropylene polyamines, e.g. B. Diethylenetriamine and dipropylenetriamine; cycloaliphatic Diamines such as 1-amino-3-aminomethyl-3,5,5-trimethyl-cyclo hexane, also called isophoronediamine, 3,3′-dimethyl-4,4′- diamino-dicyclohexylmethane; heterocyclic amines, such as Piperazine; long chain polyether amines such as 1,12-diamino  4,8-dioxadodecane; aromatic amines, such as phenylenediamine, Diaminodiphenyl methane; Polyamidoamines from natural or synthetic fatty acids and polyamines; Amine adducts; Phe nolaldehyde condensates.

For the production of one-component mixtures with Epoxy resins can also be amine-releasing compounds, such as ketimines or enamines with a ketimine or enamine end group Combine pen containing polyether urethanes.

The amine hardeners can be viscous in a known manner regulators, accelerators - such as tertiary amines, triphenyl phosphite, alkylphenols - or with quick hardeners, such as Mannich bases.

The epoxy resins used in the invention are hot and can be hardened cold with these hardeners or hardener mixtures. she contain on average more than one epoxy group in the Molecule and can glycidyl ether of polyhydric alcohol len, such as B. glycerol, hydrogenated diphenylolpropane or of polyhydric phenols, such as. B. Resorcinol, Diphe nylolpropane or phenol aldehyde condensates. It can also the glycidyl esters of polyvalent carboxylic acids, such as Hexahydrophthalic acid or dimerized fatty acids are used will.

The use of liquid epoxy is particularly preferred resins based on epichlorohydrin and diphenylolpropane with a molecular weight of 340 to 450.

Optionally, with monofunctional epoxy compounds the viscosity of the mixtures can be reduced and there can be improved by processability. Examples for this are aliphatic and aromatic glycidyl ethers, such as butyl glycidyl ether, phenyl glycidyl ether or glycidyl esters such as glycidyl acrylate or epoxides such as styrene oxide.  

The combination of the long-chain, weakly networked Polyether urethane amines, polyether urethane ketimines or Polyether urethane enamines with a highly cross-linking amine formulation settings enables adjustment in a wide range the properties of the reaction mass in relation to viscose activity, reactivity u. Ä. and the properties of the thermoset in terms of elasticity, crosslink density, mechanical Strength, chemical resistance.

Examples I. Presentation of the input products

1. a) 800 g of 1- (2-hydroxyethyl) piperazine were mixed with 443 g Isobutyraldehyde and 400 ml of toluene so long Nitrogen heated up to approximately at the water separator a quantitative water yield was obtained (approx. 110 g). The reaction time was about 8-13 hours the. The solvent was removed and the back was distilled in vacuo. The distillate had a nitrogen content of 15.2% and was for the Further processing enough pure.

b) 6,754 g of a trifunctional polypropylene glycol with an OH number of 35.6 were with 855 g of a Ge mix of 3-iso-cyanato-methyl-1-methylcyclo hexyl isocanate and 4-isocyanatomethyl-1-methyl-cyclo mixed hexyl isocyanate and 2 hours with stirring warmed to 70 ° C, then at 80 ° C for 1 hour. The reaction product had an isocyanate content of 2.5% by weight.

In the product cooled to room temperature then 870 g of the enamine produced under a) stirs. After the mixture ge about 12-14 hours had stood, no infrared spectroscopy was possible Detect free insocyanate more.

Before further use as an elasticizing hardener The product was a component for polyepoxides a little more than the stoichiometric amount of water added and stirred at about 50 ° C until the infra rotspektrum the complete dismantling of the enamine group pointed to. The product had an equivalent weight from 1856.  

2. a) 390 g of 1- (2-hydroxyethyl) piperazine and 570 g 3,3,5 (3,5,5) -trimethylcyclohexanone (mixture of isomers) were ver with 300 ml of toluene and 2 ml of formic acid sets and with stirring under nitrogen at the water heated by a separator. After 16 hours, about 90% the calculated amount of water. The Solvent and excess trimethylcyclo hexanones were removed in vacuo and the residue distilled.

b) 2,000 g of a branched polypropylene glycol with the OH number 35.8 were made with 252 g of a mixture 3-isocyanatomethyl-1-methylcyclohexyl isocanate and 4- Isocyanatomethyl-1-methyl-cyclohexyl isocyanate and 0.5 g of dibutyltin dilaurate are added and the mixture is stirred warmed to 50 ° C and held at 50 ° C for 1 hour. The reaction product had an isocyanate content of 2.15%.

The product cooled to room temperature was under Stir with 300 g of the enamine produced under a) transferred. After about 12 hours, infrared spec no longer detect free isocyanate microscopically. The product had an equivalent weight of 2125.

3. A mixture of 5040 g of a branched Polypro pylene glycol with the OH number 35.6 and 631 g of a Ge mix of 3-iso-cyanatomethyl-1-methylcyclohexyl isocanate and 4-isocyanatomethyl-1-methyl-cyclohexyl Isocyanate was mixed with 5.7 g of dibutyltin dilaurate sets and for 3 hours at a temperature of 70 ° C stirred under nitrogen. The reaction product had an isocyanate content of 2.2% by weight equivalence of 1890.  

4. a) 324 g of diglycolamine were mixed with 300.5 g of methyl isobutyl ketone and 300 ml of benzene are added. Then the Mix for so long on the water separator under stick fabric heated until water separation was complete. The solvent was removed and the residue distilled in vacuo.

b) 1000 g of the Isocyanatvoradduk produced under 3. 97.8 g of the ketimine prepared under a) were added with stirring and cooling. The mixture was stirred for a further 4 hours until free isocyanate could no longer be detected in the infrared spectrum. Then a little more than the stoichiometric amount of water was added and the mixture was stirred at 50 ° C. until the ketimine band in the infrared spectrum at 1675 cm ^-1 had disappeared. The product had an equivalent weight of 2100.

II. Examples of use

5. Example of an elastic casting compound. 650 g parts by weight of that produced under 2. b) Adducts were steep with a liquid of 58 weight Diepoxides from 4,4'-dihydroxydiphenylpropane 2,2 (diphenylolpropane) and epichlorohydrin (molecular weight approx. 380) mixed. After adding 500 parts by weight Trioctyl phosphate and 70 weight steep nonylphenol approx. 230 parts by weight of highly disperse silica incorporated.

A sample was left in the absence of moisture kept unchanged for several months. One out painted sample formed within 24 hours a skin on the surface and hardened in the course of  following days through to an elastic product a Shore A hardness of approx. 20.

A test specimen stored for several weeks showed one Elongation at break of 155% at 240 N / cm² (according to DIN 53 504).

6. Example of an elasticized adhesive. 16.7 parts by weight of the diprimeric terminal amine from Example 4. b) with 50 parts by weight Polyaminoamide hardener made from dimerized tall oil fatty acid re and polyethylene amine (amine number about 400) and one Epoxy resin based on diphenylolpropane and epichlorhy mixed in (molecular weight approx. 380). Checkout steel sheet were glued together and after 7 days curing at 23 ° C the tensile shear test (DIN 53 283). Tensile shear strength 33 N / mm².

The comparative experiment without polyetheramine showed under the same conditions 24 N / mm².

7. Example of an elasticized coating agent. 55 parts by weight of a modified cycloaliphati 's amine (amine number approx. 250) with 63 Ge major parts of the diprimary polyetheramine from Bei game 4. b) mixed. After adding 100 weight Part of an epoxy resin as in 6. was a thin film, approx. 100 µm, applied to sheet metal. The film was tack-free within 7 days tet. The Erichsen cupping test (DIN 53 156) resulted in 9.2 mm. In the comparative experiment without polyetheramine only a depth of 0.4-1 mm was achieved.

Claims (3)

1. A process for the production of elasticized molded parts and fabrics by reaction of epoxy compounds which have an average of more than one epoxy group per mole, optionally with the use of monoepoxide compounds, with curing agents or hardening agent mixtures, optionally with the use of further additives, characterized in that that as a curing agent or curing agent mixtures

• a) addition products, produced by implementation of
  • 1) Polyalkylene ether polyols with molecular weights of 500 to 10,000 and
  • 2) a mixture of 3-isocyanatomethyl-1-methyl cyclohexyl isocyanate and 4-isocyanatomethyl-1-methyl-cyclohexyl isocyanate,
• the ratio of NCO groups / OH groups being 1.5: 1, and by further reaction of the adduct thus obtained with
  • 3) ketimines and / or enamines containing hydroxyl groups,
• wherein the ratio NCO groups / OH groups 1: 1 be, or that one
• b) amine compounds obtained by hydrolysis of the ketimines or enamines prepared according to a), or
• c) mixtures of the compounds mentioned under a) and b) or
• d) Mixtures of the compounds mentioned in a) and / or b) with conventional amine hardeners

used, being for the hardener mixtures that Contain compounds according to a), the action of ent speaking amounts of water for hydrolysis of the ketimines or enamine is required. 2. Hardening agent for performing the method according to claim 1, characterized in that they consist of

• a) addition products, produced by implementation of
  • 1) polyalkylene ether polyols with molecular weights of 500 to 10,000, and
  • 2) a mixture of 3-isocyanatomethyl-1-methyl cyclohexyl isocyanate and 4-isocyanatomethyl-1-methyl-cyclohexyl isocyanate
• wherein the ratio of NCO groups / OH groups is 1.5: 1 to 2.5: 1, and by further reaction of the adduct thus obtained with
  • 3) ketimines and / or enamines containing hydroxyl groups,
• wherein the ratio NCO groups / OH groups 1: 1 be, or from
• b) amine compounds obtained by hydrolysis of the ketimines or enamines prepared according to a), or from
• c) mixtures of the compounds mentioned under a) and b), or from
• d) Mixtures of the compounds mentioned in a) and / or b) with conventional amine hardeners, the curing agent mixtures containing the compounds according to a) comprising the action of appropriate amounts of water for the hydrolysis of the ketimines or enamines .