CA1252003A - Process for encapsulating glass edges with an elastic polyisocyanate addition polymerization product using an epoxy resin curing system as the adhesion- improving agent - Google Patents

Abstract

PROCESS FOR ENCAPSULATING GLASS EDGES WITH AN ELASTIC
POLYISOCYANATE ADDITION POLYMERIZATION PRODUCT USING AN
EPOXY RESIN CURING SYSTEM AS THE ADHESION-IMPROVING AGENT
Abstract of the Disclosure The invention is a process for encapsulating glass edges with an elastic polyisocyanate addition polymerization product which comprises coating an edge of glass with an adhesion-improving agent comprising an organic epoxy resin and a hardener and thereafter covering the coated edges with a polyurethane, polyurethane-polyurea or polyurea elasto-mer. The adhesion-improving agent is a two-component system comprising at least one organic epoxy resin and at least one hardener, preferably a polyamine and/or polyamine adduct, optionally dissolved in an organic solvent. A glass plate is positioned in a mold, the mold closed and the cavity between the plate of glass and the mold is injected, using a one-shot RIM process, with a reactive mixture of organic polyisocyanates, higher molecular weight compounds having at least two reactive hydrogen atoms, chain extenders and/or crosslinking agents, catalysts, and optionally auxiliaries and/or additives. The reaction mixture is allowed to cure, and the plate glass is removed.

Description

~ Case 1519 PROCESS FOR ENCAPSULATING GLASS EDGES WITH AN ELASTIC
POL~ISOCYANATE ADDITION POLY~ERIZATION PRODUCT USING AN
EPOXY RESIN CURING SYSTEM AS THE ADHESION-IMPROVIN~ AGENT
Background of the Invention 1. Field of the Invention This invention describes the use of an adhesion-improving agent in order to achieve a good adhesive bond between a plate of glass and a polyurethane, polyurethane-1~ polyurea or polyurea elastomer. Examples of a typical adhesion-improving agent are optionally modified organic polyisocyanates, polyfunctional epoxy compounds, and polyfunctional silane compounds, preferably aminoalkyltri-alkoxysilanes.
Using this process, plate glass, cut and option-ally spherically formed to fit a respective vehicle model, in particular planar side plate glass, is manufactured using, preferably, highly reactive one-shot polyurethane, polyurethane-polyurea, and polyurea elastomer systems wi~h the aid of reaction injection molding techniques in a single process step with short cycle time3, for example, mold residence times from approximately 5 to 120 second~, with good mechanical properties and high production volume.

2. Description of the Prior Art In modern tecllnology plate glass, vapor-metalized glass, and/or safety gla~s to which transparent plastic films have been applied, for example polyester, poly-,~

5;~3 urethane, films, etc., are adhesively bonded into the metal frames of transportation vehicles, in particular automotive vehicles. After being trimmed, the plate glass is subjected to an edge treating process followed by cleaning. In order to prevent U~ damage to the adhesion-improving agent and adhesive layer located between l:he plate glass and the metal frame, the plate glass is printed along its peripheral zone with a colorant which absorbs W radiation. The plate glass may then be formed at elevated temperatures to a spherical shape suitabl~ for the vehicle model. Such processes are labor-intensive and therefore expensive.
Federal Republic of Germany Patent Application P 34 32 205.1 describe~ a process for encapsulating glass edges with elastic polyisocyanate addition polymerization products in a mold. In this process, the plate glass, which may optionally be coated with an adhesion-improving agent on its periphery, is placed in the open mold, the mold is closed, the resulting space between the plate glass and the mold is charged with a reactive mixture comprising a~ an organic polyisocyanate, b) a relatively high molecular weight compound having at least two reactive hydrogen atoms c) a chain extender and a crosslinking agent and d) a catalyst, optionally, ~25~3 e) auxiliaries and/or additives, and f) curing the reac-tion mixture.

The preparation of polyurethane, polyurethane-polyurea, or polyurea elastomers is preferably performed in a one-shot process with the aid of reaction injection molding techniques (RIM). However, in this process the adhesion between the plate glass and the polyisocyanate addition polymerization products is not satisfactory.
The objective of this invention is to improve the adhesion between the plate glass and polyisocyanate addition polymerization products. Ln seeking to meet this objective, it was unexpectedly found that -this adhesion can be significantly improved by the use of a two-component epoxy resin curing sys-tem as an adhesion-improving agent. The adhesion-improving agent is a two-component system compris-ing at least one organic epoxy resin and at least one hardener, preferably a polyamine and/or polyamine adduct, optionally dissolved in an organic solvent.
The invention therefore provides a process for encapsulating glass edges with an elastic polyisocyanate addition polymerization product. This process comprises coating an edge of glass with an adhesion-improving agent comprising an organic epoxy resin and a hardener and thereafter covering the coated edge with a polyurethane, polyurethane-polyurea, or polyurea elastomer.
The objective of the invention is therefore accomplished by this process which, as noted, is for encapsulating plate glass edges coa-ted with an adhesion-improving agent with reactive mixtures in order to form a polyure-thane, polyurethane-polyurea, or polyurea ~52~i3 elastomer in a mold wherein a two-component system compris-ing at least one organic epoxy resin and at leas~ one hardener is used as the adhesion-improving agent.
Gompounds having the following structural formula:

CH2-CH-CH2~-C-~3~-CH2-~H-CH~o ~-C-~-O-CH2-C~-CH2 are used as the organic epoxy resins. Such compounds have an epoxy gram equivalent weight (defined as grams of resin containing one mole epoxy group) of from 140 to 4000, preferably ~rom 140 to 750, and more prefersbly 180 to 200.
The organic epoxy resins preferably have epoxy ratios - defined as mole epoxy/lOD g resin - of approxi-mately 0.02 to 0.8, prefersbly from 0.1 to 0.7 and more preferably from 0.5 to 0.6, and they are solid or preferably liquid at room temperature, with the liquid products having a viscosity at ~5C of approximately 7 to 220 Pa.s, prefer-ably from 80 to 1?0 Pa.s.
Other epoxy resins are also suitable, for example those based on methylol group-containing phenol, urea or melamine condensation polymerization products, or modified 'iL~$2~

epoxy resins, for example, those in which the hydroxyl groups in the structural formula cited above are completely or partially esterified with carboxylic acids or are converted with organic isocyanate groups into ur~thane groups.
In principle, organic polyfunctional compounds which react with the hydroxyl groups or terminal epoxy groups in the epoxy resins and react in such a way that the two-componen~ sy~tems possess an adequate pot time for processing and then cure as quickly as possible can be used as hardeners. Typical examples are organic, optionally modified aromatic, aliphatic, and/or cycloaliphatic polyiso-cyanates, ketimines or polyamids which may be optionally modified, for example, they may contain urethane, isocya-nurate, allophanate, biuret and/or carbodiimide groups.
However, organic polyamine adducts and/or preferably organic polyamines have proven to be particularly well sui~ed for use a~ hardeners and thus are preferably used. Aromatic, cycloaliphatic, or aliphatic difunctional and/or higher functional polyamine~ which may optionally be substituted with alkyl groups having from 1 to 4, preferably 1 to 2, carbon atoms may be used. Typical examples are aliphatic di- or polyamineq having from 2 to 20 preferably 2 to 12 carbon atoms in the linear or optionally branched alkylene radical such as ethylenediamine, 1,3-propylenediamine, 1,4 :~S~

and 1,3-butylenediamine, 2-ethyl-1,4-butylenediamine, 2-methyl-1,5-pentamethylenediamine, 1,6-hexamethylenediamine, diethylenetriamine, dipropylenetriamine, triethylene-tetramine, tripropylenetetramine, tetraethylenep~ntamine, etc., cycloaliphatic di- or polyamines having from 6 to 42, preferably 6 to 19, carbon atoms in the optionally bonded alkylene bridge member-containing cycloalkylene radical such as 1,3- and 1,4-diaminocyclohexane, 1-methyl-2,4- and 2,6-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diamino-2,2-dicyclohexylpropane, and polycyclohexylpolymethylene polyamines and aromatic di- or polyamines having from 6 to 42, preferably from 6 to 19, carbon atoms in the optionally bonded alkylene bridge member containing arylene radical, for example 1,3- and 1,4-phenylenediamine, 1-methyl-2,4- and -2,6-phenylenediamine, 1-methyl-3,5-diethyl-2,4-and 2,6 phenylenediamine, 1,3,5-triethyl-2,4-phenylenediamine, 4,4'-, 2,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodi-phenylmethane, and polyphenylpolymethylene polyamines. The organic diamines or higher functionality polyamines may be used individually or in the form of mixtures.
Reaction products of organic di- and/or poly-amines, for example the optionally alkyl-substituted aromatic, _ycloaliphatic, or aliphatic di- and/or higher funceionality polyamines described above, and organic ~s~o~

difunctional compounds which contain substituent~ which react with amino groups may be used in molecular ratios of 2:1 and greater as polyamine adducts. Typical examples of difunctional reactive organic compounds are: aliphatic, cycloaliphatic, and/or aromatic diisocyanates, dicarboxylic acid esters dicarboxylic acid dihalogenides, preferably dicarboxylic acid dichlorides and aromatic and/or alipha~ic diepoxides.
The amount of hardener which is necessary depends on the hydroxyl number - for example, when a polyisocyanate hardener is used, or preferably it depends on the epoxy ratio of the epoxy resin and the hydrogen-active equivalent weight of the hardener which is used, for example the organic polyamine and/or polyamine adduct. The water-active equivalent weight is determined by dividing the molecular weight of the hardner by the number of reactive hydrogen atoms - for example, by dividing the molecular weight of the polyamine or polyamine adduct by the number of hydrogen atoms bonded to nitrogen.
By multiplying the epoxy ratio by the hydrogen-active equivalent weight of the hardener, one can calculate the minimum amount of hardener theoretically required for 100 parts by weight organic epoxy resin. Based on equiva-lent amounts of the two-component system, it is preferable to use up to 30 percent excess hardener, preferably 8 to 20 5;~3 percent. In this way, from 3 to 55 parts by weight, preferably from 8 to 40 parts by weight, hardener are used per 100 parts by weight organic epoxy resin. Preferably a polyamine adduct and/or more preferably an organic polyamine is used as the hardener.
The two-component systems used as adhesion-improving agents in the invention, in particular those comprising one or more epoxy resin, and one or more organic polyamine, may be used solvent-free or in the form of solutions. The solvent-free systems generally have short pot times, since the absence of solvents and the high concentration of epoxy and amino groups in the system causes a highly exothermic reaction. When ketimine hardners are used, which split into active polyamine and volatile ke~one when exposed to moisture, the pot time can be extended to several hours, for example from 10 to 12 hours. Typical examples of solvents which are suitable for dissolving the two-component systems which may be used in accordance with the invention are: ketones such as acetone, methyl ethyl ketone, methylisobutylketone, methylcyclohexanone, and methoxyhexanone, organic carboxylic esters, preferably alkyl acetates such as ethyl, n-butyl, methyl glycol, ethyl glycol and isopropyl glycol acetate, and uni- or polyfunctional alcohols such as isopropanol, n-butanol, sec-butyl alcohol, methyl glycol, ethyl glycol, isopropyl glycol, butyl glycol, ~s2~

methoxyhexanol, ethyl diglycol, and butyldiglycol. ~ixtures of aromatic compounds may also be used - preferably toluene and other solvents - preferably ketones or alcohols, for example mixtures of toluene and acetone, methyl e~hyl ketone, isopropanol, sec.-butyl alcohol and n-butanol in 1:1 weight ratios.
The solution content in the two-component epoxy resin hardener system which may be used in the invention depends on the type of solvent or solvent mixture, and it can be up to 90 percent by weight based on the total weight of the solution, but is preferably from 40 to 20 percent by weight. Given the possibility of limited solubility, it may be desirable first to prepare a concentrated solution and then dilute this to the desired epoxy resin and hardener content prior to processing.
In order to accelerate hardening and/or optionally lower the hardening temperature, hardening catalysts may be incorporated in the two-component systems. Suitable for this are inorganic and organic acids or thermal cleaving ammonium or amine salts used in amounts from 0.01 to 3, preferably from 0.1 to 2 percent by weight based on ~he epoxy resin and hardening content. Typical examples are organic acids such as phosphoric acid, aliphatic carboxylic acids such as cyanoacetic acid, organic carboxylic acids or derivatives such as salicylic acid, benzoylic acid, phthalic ~5~g33 anhydride, salts such as amine borofluoride complexes, morpholine salts of para-toluenesulfonic acid, or aniline h~drochloride. The hardening temperatures may be varied within a broad range, for example 20 to 220C. Preferably temperatures of from 50 to 130C are used, more preferably from 80~ to 100C.
The two-component epoxy re~in hardener systems which may be used in the invention can optionally be combined with other adhesion-improving agents or the glass may be pretreated with other adhesion-improving agents. If such actions are taken, then preferably silane compounds having a general formula (R0)3Si-R'-X are used as the adhesion-improving agents. Here X i~ a reactive organic group such a~q an amino, mercapto, chloroalkyl, vinyl, methacrylate, or epoxy group, Rl is a (CH2-) group, in particular (CH2)3 and n is a whole number from 2 to 10 preferably from 2 to 4. Suitable silane adhesion-improving agents of the type cited here are described, for example, by ~ard Collins in Modern Plastics Encyclopedia 1977-1978), p.
163 ff.
Glass plates of various compositions may be covered around their edges. Preferably, silicate glass is used for the glass plates. However, mechanically or chemically treated gla~s plates, e.g., glass plates which have been vapor metallized or coated wi~h transparent ~s~

plastic films, for example polyamide, polycarbonate, or polyurethane films, as well as ].aminated glass may be used. The plates of glass are generally from 3 to 20 mm or more thick, preferably from 3 to 8 mm thick.
In order to achieve a good adhesive bond, the cleaned and preferably degreased peripheral zone, which may be optionally treated with adhesion-improving agents based on silane compounds, i9 coated with the two-component epoxy resin hardener system prior to being encapsulated with a polyurethane, polyurethane-polyurea, or polyurea elasto-mer. Depending on ~he chemical composition of the plate glass and the structure of the two-component system, the adhesion-improving agent is applied using various known methods, for example painting, spraying, rolling, dipping, etc., in such amounts that after the optionally used solvent evaporates the thicknesc of the layer is from 5 to 80 microns, prefera~ly from 10 to 40 microns. The adhesion-improving layer, which may be comprised of one or more coats, is generally applied in a single or multiple s~ep process, whereby the solvent is allowed to evaporate at low temperatures and the epoxy resin hardener system is allowed to cure at elevated temperatures.
In order to encapsulate the plate glass edges with reactive mixtures used to form polyurethane, polyurethane polyurea, polyurea elastomers in a mold, the following process is followed:

1. placing a plate of glass which has been coated`
on the peripheral zone with the two-component adhesion-improving system of the invention in an open mold, 2. closing the mold,

3. charging a cavity between the plate glass and the mold with a reactive mixture comprising a) an organic polyisocyanate, b) a relatively high molec~ular weight compound having at least two reactive hydrogen atoms, c) a chain extender and/or crosslinking agent, d) a catalyst, as well as, optionally, e) auxiliaries and/or additives, and

4. curing the reaction mixture.

The following describes the initial components (a) through (d) and optionally (e) used to prepare the cellular or noncellular polyure~hane, polyurethane-polyurea, or polyurea elastomer~ of the process of the invention.
Polyisocyanates Typical organic polyisocyanates which may be used are the conventionally known aliphatic, cycloaliphatic, and preferably aromatic polyfunctional isocyanates. Typical ~5;~ 3 examples are l,6-hexamethylene diisocyanate, l-isocyanato-3,3,5-trimethyl-3-isocyanatomethylcyclohexane, 2,4- and 2,6-hexahydrotoluene diisocyanate, as well as the corresponding isomer mixtures, 4,4'-, 2,2'-, and 2,4'-dicyclohexylmethane diisocyanate, as well as the corresponding isomer mixtures mixtures of 4,4'-, 2,2'~, and 2,4'-dicyclohexylme-thane diisocyanates, and polymethylen~e polycyclohexylene polyiso-cyanates, 2,4-, and 2,6-toluene diisocyanates, and the corresponding isomer mixtures' 4,4'-, 2,4'-, and 2,2'-diphenylmethane diisocyanate, and the corresponding isomer mixtures, mi~tures of 4,4'-, 2,4'-, and 2,2'-diphenylmethane diisocyanates, and polyphenylpolymethylene polyisocyanate~
(polymeric MDI), and mixtures of polymeric MDI and toluene diisocyanates.
Frequently, so called modified polyfunctional isocyanates are used, i.e. products obtained by chemically reacting the above di-and/or polyisocyanates. Typical examples are ester, urea, biuret, allophanate, and prefer-ably carbodiimide, isocyanurate, and/or urethane group-containing di- and/or polyisocyanates. Examples of resul-tant products include urethane group-containing aromatic polyisocyanates having isocyanate contents of from 15 to 33.6 percent by weight, preferably from 21 to 31 percent by weight, for example, modified 4,4'-diphenylmethane diisocya-nate or modified toluene diisocyanate. The isocyanates are modified by reacting with low molecular weight diols, triols, dialkylene glycols, trialkylene glycols, or polyoxy-alkylene glycols having molecular weights up to 800.
Typical examples of the di- or polyoxyalkylene glycols which may be used individually or as mixtures are: diethylene glycol, dipropylene glycol, polyoxyethylene glycol, polyoxy-propylene glycol, and polyoxypropylene polyoxyethylene glycols. Isocyanate group-containing prepolymers having isocyanate contents from 9 to 21 percent by weight, prefer-ably from 14 to 21 percent by weight, are also suitable. In addition, liquid carbodiimide group- and/or isocyanurate ring-containing polyisocyanates having isocyanate contents from 15 to 33.6 percent by weight, preferably from 21 to 31 percent by weight, have also proven to be effective, ~or example, those based on 4,4'-, 2,4'-, and/or 2,2'-diphenyl-methane diisocyanate and/or 2,4- and/or 2,6-toluene diisocy-anate, and preferably 2,4- and 2,6-toluene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,4'-, and 2,2'-diphenylmethane diisocyanate as well as the corresponding isomer mixtures, for example, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates, mixtures of diphenylmethane diisocyanates and polyphenyl polymethylene polyisocyanates (polymeric MDI), and mixtures of toluene diisocyanates and polymeric MDI. Preferred are urethane group, carbodiimide group, and/or isocyanurate ring-containing polyisocyanates, ~2S~

for example, those based on diphenylmethane diisocyanate and/or toluene diisocyanate, toluene diisocyanates, mixtures of polymeric MDI and toluene diisocyanates, and, more preferably, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates or mixtures of diphenylmethane diisocyanate isomers and polyphenyl polymethylene polyisocyanates.
Higher Molecular Weight Compounds For the higher molecular weight compounds, having at least two reactive hydrogen atoms, it has been found desirable to use those having a functionality of from 2 to 8, preferably from 2 to 4, and a molecular weight of from 800 to 8000, preferably from 1200 to 6000. For example, polyether polyamines and/or, preferably, polyols selected from the group comprising polyether polyols, polyester polyols, polythioether polyols, polyester amides, hydroxyl group-containing polyacetals, and hydroxyl group-containing aliphatic polycarbonates or mixtures of at least two of the cited polyols have proven to be effective. Preferably used are polyester polyols and/or polyether polyols. Suitable polyester polyols may be prepared, for example, from organic dicarboxylic acids having from 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids having from 4 to 6 carbon atoms, and polyfunctional alcoholq, preferably diols, having from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms. Typical carboxylic acids which may be used ~s~

are: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acicl, decane dicarboxylic acid, maleic acid, and fumaric acid. The dicarboxylic acids may be used individually or as mixtures with one another.
Instead of the free dicarboxylic: acids, the corresponding dicarboxlic acid derivatives may be used, for example the dicarboxylic acid esters of alcohols having from 1 to 4 carbon atoms or dicarboxylic anhydrides. Preferably used are dicarboxylic acid mixtures of succinic, glutaric, and adipic acid in quantitative ratios of, for example, 20-35:35-50:20-32 parts by weight, respectively. More preferably, adipic acid may be used alone. Typical examples of di- and polyfunctional alcohols, preferably diols, are;
ethanediol, diethylene glycol, 1,2- and 1,3-propanediol, dipropylene ~lycol, l,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, l,10-decanediol, glycerine, and trimethylol-propane. Preferably used are ethanediol, diethylene glycol, 1,4-butanediol~ 1,5-pentanediol, 1,6-hexanediol, or mixtures of at least two of the cited diols, preferably mixtures of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. In addition, polyester polyols of lactones, for example, -caprolactone, or hydroxylcarboxylic acids, for example ~-hydroxycaproic acid may be used. Preferably, the poly-ester polyols have a functionality of up to 3 and a molec-ular weight of from 800 to 3000, more preferably from 1800 to 2500.

~2~2~

Particularly preferred as polyols are polyether polyols prepared by known method~, for example, anionic polymerization using alkali hydroxides such as sodium hydroxide or potassium hydroxid~3, or alkali alcoholates ~uch as sodium methylate, sodium or potassium ethylate, or potassium isopropylate as cataly~ts, or by cationic polymer-ization using Lewis acids such as antimony pentachloride, borofluoride etherate, etc., or bleaching earth as cata-lyst4, from one or more alkylene oxides having from 2 to 4 carbon atoms in the alkylene radical, and an initiator which contains from 2 to 8, preferably from 2 to 4 reactive hydrogen atoms.
Suitable alkylene oxides are, for example, 1,3-propylene oxlde, 1,2-, and 2,3-butylene oxide, styrene oxide, epichlorohydrin, and preferably ethylene oxide and 1,2-propylene oxide. The oxides may be used individually, alternately one after another, or as mixtures. Typical intiators are: water, organic dicarboxylic acids such as succinic acid, adipic acid, phthalic acid, and terephthalic acid, aliphatic and aromatic, optionally N-mono, N,N- and N,N'-dialkyl-substituted diamines having from 1 to 4 carbon atoms in the alkyl radical such as optionally mono- and dialkyl-substituted ethylenediamine, diethylenetriamine, triethylenetetramine, 1,3-propylenediamine, 1,3- respec-tively 1,4-butylenediamine, 1,2-, 1,3-, 1,4-, 1,5-, and 1,6-hexamethylenediamine, phenylenediamines, 2,4- and 2,6-toluenediamine, and 4,4'-, 2,4'-, and 2,2'-diaminodiphenyl-methane.
Typical initiators are also alkanol amine3 such as ethanolamine, diethanolamine, N-methyl- and N-ethylethanol-amine, N-methyl- and N-ethyldiethanolamine, and triethanol-amine, ammonia, hydrazine, and hydrazides. Preferably used are polyfunctional, and more preferably di- and/or trifunc-tional alcohols such as ethanediol, 1,2- and 1,3-propane-diol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerine, trimethyolpropane, pentaerythri-tol, sorbitol, and sucro~e.
The polyether polyols preferably have a func-tionality of from 2 to 4 and molecular weights from 800 to 8000, more preferably from 1200 to 6000, and most preferably from 1800 to 4000. As with the polyester polyols, they may be used individually or in the form of mixtures. They may also be mixed with the polyester polyols as well as the hydroxyl group-containing polyester amides, polyacetals, polycarbonates, and/or polyether polyamines.
Typical hydroxyl group-containing polyacetals which may be used are compounds produced from glycols such as diethylene glycol, triethylene glycol, 4,4'-dihydroxy-ethyoxydiphenyldimethylmethane, hexanediol, and formalde-hyde. Suitable polyacetals may also be prepared by polymer-izing cyclic acetals.

~25~ 3 Hydroxyl group-containing polycarbonates which may be used are those of the essentially known type, which may be prepared, for example, through the reaction of diols such as (1,3)-propanediol, (1,4~-butanediol, and/or (1,6)-hexanediol, diethylene glycol, triethylene glycol, or tetraethylene glycol with diaryl carbonates, for example diphenyl carbonate, or phosgene. Among the polyester amides which may be used are those from polyfunctional saturated and/or unsaturated carboxylic acids or their anhydrides and polyfunctional saturated and/or unsaturated amino alcohols or mixtures of polyfunctional alcohols and amino alcohols and/or polyamines, ~referably linear condensates.
Suitable polyether polyamines may be prepared from the polyether polyols cited above using known methods.
Typical examples are the cyanoalkylation of polyoxyalkylene polyols with the subsequent hydrogenation of the nitrile which is formed (U.S. 3,267,050) or the amination of polyoxyalkylene polyols with amines or ammonia in the presence of hydrogen and catalysts (Federal Republic of Germany Patent 12,15,373).
Chain Exteners/Crosslinking Agents Di- ~o tetrafunctional, preferably difunctional, compounds having molecular weights from 60 to 600, prefer-ably from 60 to 300, from the group comprising the ali-phatic, cycloaliphatic, or araliphatic diols and/or triols, ~ 3 the secondary diamines, and preferably the primary, unsub-stituted and/or more preferably substituted aromatic di-and/or higher functionality polyamines are used as the chain extenders and/or crosslinking ac~ents.
Suitable diols or triols preferably have molecular weights less ~han 400, more pre~Eerably from 60 to 300.
Typical examples of such initiators are aliphatic, cyclo-aliphatic, and/or araliphatic diols having from 2 to 14, preferably 4 to 10 carbon atoms, such a~ ethylene glycol, 1,3-propanediol, l,10-decanediol, o-, m-, p-dihydroxycyclo-hexane, diethylene glycol, dipropylene glycol, and more preferably 1,4-butanediol, 1,6-hexanediol, and bis(2-hydroxyethyl)hydroquinone, triols such a~ 1,2,4-, 1,3,5-trihydroxycyclohexane, glycerine, and trimethylolpropane, and low molecular weight hydroxyl group-containing poly-alkylene oxides based on ethylene oxide and/or l,2-propylene oxide, and the diols and/or triols.
Typical secondary diamines which may be used are: N,N'-dialkyl-substituted aromatic diamines, which may optionally be substituted on the aromatic ring by alkyl radicals, having from 1 to 20, preferably 1 to 4, carbon atoms in the N-alkyl radical, such as N,N'-diethyl-, N,N'-di-sec-pentyl-, N,N'-di-sec-hexyl-, N,N'-di-sec-decyl-, N,N'-dicyclohexyl-p-, m-phenylenediamine, N,N'-dimethyl-, N,N'-diethyl-, N,N'-diisopropyl, N,N'-di-sec-butyl-, N,N'-dicyclohexyl-4,4'-diaminodiphenylmethane, and N,N'-di-sec-butylbenzidine.
The following may be used as unsubstituted primary aromatic diamines and/or higher functionality polyamines:
1,2-, 1,3-, and 1,4-phenylenediamine, benzidine, 4,4'- and 2,4'-diaminodiphenylmethane, 4,4'- and 2,4'-diaminodimethyl-methane, 4,4'-diaminodiphenyl ether, 1,5-naphthalenediamine, 1,8-naphthalenediamine, and polyphenyl polymethylene polyamines a3 well as mixtures of diaminodiphenylmethanes and polypheny~polymethylenepolyamineq. Also suitable are substituted primary aromatic diamines, preferably monoalkyl-substituted aromatic diamines, in which the reactivity of the amino group is not significantly affected in a negative manner by the substituents, for example 3,4-, ~,4-, and 2,6-toluenediamine.
Substituted primary aromatic diamines and/or higher functionality polyamines which are preferably used are those which are substituted in the ortho position relative to the amino groups by at least one alkyl group which reduceq the activity of the amino group due to stearic hinderance, which are liquid at room temperature, and which under the processing conditions are at leaqt partially miscible with the higher molecular weight compounds.
Succe~s has been achieved, for example, with alkyl-substi-tuted meta-phenylenediamines of formula~:

~5~ 3 R NH2 ~ NH2 H2N- ~ -R and/or ~-R

in which R3 and R2 are identical or different and are a methyl, ethyl, propyl, and isopropyl radical, and Rl i~ a linear or branched alkyl radical having from 1 to 10 carbon atoms, preferably from 4 to 6. Preferred are alkyl radi-cals Rl in which the branchin~ point is located at the C
carbon atom. Typical Rl radicals are the me~hyl, ethyl, isopropyl, l-methyloctyl, 2-ethyloctyl, l-methylhexyl, 1,1-dimethylpentyl, 1,3,3-trimethylhexyl-, l-ethylpentyl-, 2-ethylpentyl-, and preferably the cyclohexyl-, 1 methyl-n-propyl-, tert-butyl, l-ethyl-n-propyl-, l-methyl-n-butyl-, and l,l-dimethyl-n-propyl radicals.
~ypical alkyl-substituted m-phenylenediamines which may be used are: 2,4-dimethyl-6-cyclohexyl-, 2-cyclohexyl-4,6-diethyl-, 2-cyclohexyl-2,6-isopropyl-, 2,4-dimethyl-6-(1-ethyl-n-propyl)-, 2,4-dimetlhyl-6-(1,1-di-methyl-n-propyl)-l 2-(1-methyl-n-butyl)-4,6-dimethyl-1,3-phenylenediamine. Prefarably used are 1-methyl-3,~-diethyl-2,4- respectively 2,6-phenylenediamines, 2,4-dimethyl-6-tertiary butyl-, 2,4-dimethyl-6-isooctyl-, and 2,4-dimethyl-6-cyclohexyl-1,3-phenylenediamine.

Also suitable are 3,31-di- and/or 3,3',5,5'-tetra-n-alkyl substituted 4,4'-diamino-diphenylmethanes such as 3,3'-dimethyl, 3,3'-diethyl, 3,:3'-di-n-propyl, 3,3',5,5'-tetramethyl, 3,3',5,5'-tetraethyl and 3,3'5,5'-tetra-n-propyl-4,4'-diaminodiphenylme'hane.
Preferably used as alkyl-substituted 4,4'-diamino-diphenylmethane are those of fo;rmula:

~2N ~ CH2 ~ ~ 2 in which R4, R5, R6, and R7 are identical or different and are a methyl~ ethyl, propyl, isopropyl, sec-butyl, and tert-butyl radical. At least one of the radicals must be an isopropyl or a sec-butyl radical.
4,41-Diaminodiphenylmethane may also be used in mixture with isomers of formulas:

H2N R5 R6 H~2 R5 R4 ~ CH2 ~ -NH2 and/or R - ~ -CH2 ~ R6 where R4, R5, R6, and R7 have the meaning given above.
Typical examples are: 3,3',5-trimethyl-5'-isopropyl, - - -~2S~

3,3',5-triethyl-5'-isopropyl, 3,3',5-trimethyl-5'-sec-butyl, 3,3',5-triethyl-5'-sec~butyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyl-5,5'-diisopropyl, 3,3'-diethyl-5,5'-diiso-propyl, 3,3'-dimethyl-5,5'-di-sec-butyl, 3,3'-diethyl-5,5'~
di-sec-butyll 3,5-dimethyl-3',5'-diisopropyl, 3,5-diethyl-3',5'-diisopropyl, 3,5'-dimethyl-3',5-di-sec-butyl, 3,5-diethyl-3',5'-di-sec-butyl-4,4'-diaminodiphenylmethane, 3-methyl-3',5,5'-triisopropyl, 3-ethyl-3',5,5'-triisopropyl 7 3-methyl-3'5,5'-tri-sec-butyl, 3-ethyl-3',5,5'-tri-sec-butyl-4,4'-diaminodiphenylmethane, 3,3'-diisopropyl-5,5'-di-sec-butyl, 3,5-diisopropyl-3',5'-di-sec-butyl, 3-ethyl-5-sec-butyl-3',5'-diisopropyl, 3-methyl-5-tert-butyl-3',5'-diisopropyl, 3-ethyl-5-sec-butyl-3'-methyl-5'-tert-butyl, 3,3',5,5'-tertraisopropyl and 3,3',5,5'-tetra-sec-butyl-4,4'-diaminodiphenylmethane. Preferably used are 3,5-dimethyl-3',5'-diisopropyl, and 3,3',5,5'-tetraisopropyl-4,4'-diaminodiphenylmethane. The diaminodiphenylmethanes may be used individually or in the form of mixtures.
The cited chain extenders and/or crosslinking agents may be used individually or as mixtures of identical or different types. Success has been achieved, for example, with mixtures of 5 to 95 percent by weight of at least one diol and/or triol and from 5 to 95 percent by weight of at least one alkyl-substituted meta-phenylenediamine, 3,3'-~5~3 dialkyl, and/or 3,3',5,5'-tetraalkyl-substituted 4,4'-diaminodiphenylmethane, or preferably alkyl-substituted meta-phenylenediamine. The percen~s by weight are based on the total weight of the chain extender/crosslinking agent, preferably, mixtures of from 50 to 80 percent by weight 2,4-dimethyl-6-tert-butyl-1,3-phenylenediamine, 2,4-diethyl-6-methyl, and/or 2-methyl-4,6-diethyl-1,3-phenylenediamine, and from 20 to 50 percent by weight 1,3-phenylenediamine, 2,4- and/or 2,6-toluenediamine.
The chain extenders and/or crosslinking agents as well as their mixtures may be used in the process of the invention in amounts from 2 to 60 percent by weight, preferably from 8 to 50 percent by weight, and more prefer-ably from 10 to 40 percent by weight based on the weight of the higher molecular weight compound having at least two reactive hydrogen atoms.
Catalysts Preferably used as the catalyst are those com-pounds which greatly accelerate the reaction of the hydroxyl group-containing compounds of the higher molecular weight compounds having at least two reactive hydrogen and the chain extender/crosslinking components with the polyisocya~
nates. Organometallic compounds ~ay be used, preferably organic tin compounds such as tin ~II) salts of organic carboxylic acids such as ~in (II) acetate, tin (II) octoate, ~S2ç~3 tin (II) ethylhexoate, and tin (II) laurate, and the dialkyl tin (IV) salts of organic dicarboxylic acids. For example, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate, and dioctyl tin diacetate. The organo metallic compounds are used alone or, preferably, in combination with highly basic amines. Typical examples are amidines such a~
2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamin~, N-methyl, N-ethyl, N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutanedi-amine, pentamethyldiethylenetriamine, tetramethyldiamino-ethyl ether, bis(dimethylaminopropyl)urea, dimethylpiper-azine, 1,2-dimethylimidazol, 1-azobicyclo(3,3,0)octane and preferably 1,4-diazabicyclo-(2,2,2)-octane, and alkanol compounds such as triethanolamine, triisopropanolamine, N-methyl and N-ethyldiethanolamine and dimethylethanolamine.
The following may also be used as catalysts:
tri~(dialkylaminoalkyl)-s-hexahydrotriazines, more prefer-ably tris(N,N-dimethylaminopropyl)-s-hexahydrotriazine, tetraalkylammonium hydroxides such a~ tetramethyl ammonium hydroxide, alkali hydroxides such as sodium hydroxide and alkali alcoholates such as sodium methylate and pota~sium isopropylate, as well as alkali salts of long-chained fatty acids having from 10 to 20 carbon atoms and optionally hydroxyl groups on the side positions. From 0.001 to 5 - ~252~

percent by weight catalyst or catalyst combination i8 used based on the weight of the higher molecular weight compound having at least two reactive hydrogen atoms preferably from 0.05 to 2 percent by weight.
Auxiliaries/Additives Auxiliarie3 and/or aclditives may also be incor~
porated in the reaction mixture. Typical examples are blowing agents, surfactants, fillers, dyes, pigments, flame retardants, release agents, agents to prevent hydrolysis, fungistats, and bacteriostats.
Among the blowing agents which may optionally be used in the process of the invention is water, which reac's with the isocyanate groups to form carbon dioxide. The amounts of water which are most ef~ective range from 0.1 to 2 percent based on the weight of the polyisocyanate.
Other blowing agents which may be used are low boiling point liquids which evaporate as a result of he exothermic addition polymariæation reaction. Suitable agents are liquid~ which are inert toward the organic polyisocyanate and which have boiling points less than lOOC. Examples of such prefera~ly used liquids are halogenated hydrocarbons such as methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, dichloro-monofluoromethane, dichlorotetrafluoroethane, and 1,1,2-trichloro-1,2,2-trifluoroethane. Mixtures of these low-boiling point liquids with one another andJor with other substituted or unsubstituted hydrocarbons may also be used. The most desirable amount of a low boiling point liquid to be used in preparing the cellular polyurethane, polyurethane-polyurea, or polyurea elastomers depends on the desired density as well as on whether water i8 optionally used. In general, amounts from 1 to 15 parts by weight, based on lOO parts by weight organic polyisocyanate, produced satisfactory results.
Surfactants which may be used are those which aid in homogenizing the initial materials. Typical examples are emulsifiers such as the sodium salts of ca~tor oil sulfates or of fatty acids as well as salts of fatty acids with amines. For example, oleic acid, diethylamine, or stearic acid diethanolamine, salts of sulfonic acids such as alkali or ammonium salts of dodecylbenzenedisulfonic acid or dinaphthylmethanedisulfonic acid and ricinoleic acid. The surfactants are generally used in amounts from O.Ol to 5 parts by weight, based on lOO parts by weight of the higher molecular weight compound having at least two reactive hydrogen atoms.
Among the fillers, in particular reinforcing fillers, are the essentially known organic and inorganic fillers, reinforcing substances, weight-increasing sub-stances and substances to improve the wear resistance of paints and coatings. Typical examples of inorganic fillers are silicate minerals, for example, lamellar silicates such as antiqorite, serpentine, hornblends, amphibole, chriso-tile, talcum, metal oxide such a~ kaolin, aluminum oxides, titanium oxides, and iron oxides, metal salts such as chalk, heavy spar; and inorganic pigments such as cadmium sulfide, zinc sulfide, as well as powdered asbe~tos. Preferably used are kaolin (China Clay), aluminum silicate, and coprecipi-tates of barium sulfate and aluminum silicate, as well as natural and synthetic fibrous minerals like asbestos and wollastonite. Typical organic fillers which may be used are coal, melamine, pine resin, cyclopentadienyl resins, and graft polymers based on styrene acrylonitrile prepared by in situ polymerization of acrylonitrile styrene mixtures in polyether polyols as described in German patents 11 11 394, 12 22 669 (U.S. 3,304,273, 3,383,351; 3,523,093), 11 52 536 (GB 1,040,452); and 11 52 537 (GB 987,618), which may then optionally be aminated. Other organic fillers which can be used include polyoxyalkylene polyols or filler polyolyoxy-alkylene polyamines, where aqueous polymer dispersions are converted to polyoxyalkylene polyol dispersions or polyoxy-alkylene polyamine dispersions.
The inorganic and organic fillers may be used individually or in the form of mixtures. Preferably, stable filler polyoxyalkylene polyol dispersions are used in which ~Z~2~

the fillers are reduced to a particle size less than 7 ~m in situ in the presence of polyoxyalkylene polyols by mean~ of high localized energy densities and are dispersed at the same time.
The inorganic and~or organic fillers are incor-porated in the reaction mixture, preferably in amounts from O.S to 50 percent by weight, more preferably from 1 to 40 percent by weight, based on the total weight of the organic polyisocyanate, the high molecular weight compound with two reactive hydrogen atoms and the chain extender/crosslinking agent.
Further information on the further auxiliaries and additives as cited above may be found in the technical literature, for example J.H. Saunders and K.C. Frisch, Polyurethanes Chemistry and Technology, Part I Chemistry Part II Technology. High Polymers, vol. 16, New York:
Interscience Publishers, 1962, 1964, or Polyurethane.
Kunststoff Handbuch, vol. YII, 1st ed., 2nd ed. Munich:
Carl Hanser Yerlag, 1966, 1983.
To prepare the polyurethane polyurethane-polyurea, or polyrea elastomers, the organic polyisocya-nates, the higher molecular weight compounds having at least two reactive hydrogen atoms, and chain extenders and/or crosslinking agents are reacted in such amoun~q that the equivalent ratio o~ isocyanate groups in the polyisocyanate ~;2~

to the sum of reactive hydrogen atoms in the higher molec-ular weight compound having at least two reactive hydrogen atoms, chain extenders/crosslinking agents is 1:0.85 to 1:1.25 and preferably 1:0.95 to 1:1.15, more preferably 1:0.98 to 1:1.05.
The encapsulation of glass plate edges using the process of the invention is preferably performed in tempera-ture-controlled metal molds such as molds constructed of steel, cast iron, aluminum, or in plastic molds constructad of epoxy resins, or unsaturated polyester resins etc., which - have been reinforced with glass or carbon fibers. Gener-ally, multiple-part molds having an upper and a lower molding plate are used. The area between the molding plates forms a peripheral area for clamping the cut edge of the glass plate as well as a cavity for holding the reactable polyurethane, polyurethane-polyurea, or polyurea ela~tomer mixture. In order to ~eal off the cavity, which is to be filled by casting or preferably injection techniques, and to prevent the reactable elastomer from creeping along the margin of the plate glas3 due to capillary action, it is desirable to place a gasket constructed of an elastic material between the plate of glass and the mold. A gasket constructed of plastic polymers or products of condensation or addition polymerization, or some other sealing agent or device can be used. Additional fa~teners may be positioned ~s~

in the cavity so that they become connected to the plate glass in a single operation by means of the polyurethane, polyurethane-polyurea or polyurl_a elastomers. For e~ample, the surface in the cavity may be covered with release films or, preferably, decorative materials such as metallized or printed plastic films, or metal or plastic decorative molding strips.
Preferably, the plate of glass is positioned horizontally in the mold. However, other angles of inclina-tion between ~ and 90, preferably between O and 45, are possible. In addition, the closed molds containing the plate of glass may be rotated as desired about the three normal spatial axes, or the reactable elastomer mixture may be injected from below, above, and/or from the sides.
The polyurethane, polyurethane-polyurea, or polyurea elastomers are prepared by means of the prepolymer process, or pre~erably in a one-shot process - for example, by pouring the reaction mixture into the mold cavity, or preferably, by injecting the mixture with the aid of conventional reaction injection molding techniques (RIM).
This process is described, for example, by Piechota and Rohr, Integralschaumstoff, Munich: Carl Hanser Verlag, 1975, D.J. Prepelka and J.L. Wharton, Journal of Cellular Plastics, (March/April 1975): pp. 87-98, and U. Knipp, Journal of Cellular Plastic_, (March/April 1973): pp. 76-84.

When using a mixing chamber having several feed nozzles, the system components may be fed in individually and mixed intensively in the mixing chamber. It has been found to be particularly desirable to use a two-component process and to dissolve the chain extender and/or cross-linking agent, in the higher molecular weight compound having at least two reactive hydrogen atoms and to combine them with the catalysts as well as optional auxiliaries and additives in the organic polyisocyanate and to use the organic polyisocyanates as the higher molecular compound.
One advantage of this is that these components having at least two reactive hydrogen atoms may be stored separately and transported in a space-saving manner~ In processing they then only need to be mixed together in the appropriate amounts.
The amount of reaction mixture fed into the mold is established such that the polyurethane, polyurethane-polyurea, or polyurea elastomer encapsulating moldings have a density of from 0.8 to 1.4 g/cm3, preferably from 0.9 to 1.2 g/cm3. The optionally cellular elastomers may be formed by gasses trapped in the reaction mixture, in particular air, through the use of moisture-containing starting components or through the carefully controlled addition of water and/or inert physical blowing agents. The system components are mixed together at temperatures from 15 to :~2~ 3 80C, preferably from 20 to 55C, and fed into the mold~
The desired mold temperature is from 20 to 90C, preferably from 30 to 75C.
The polyurethane, polyurethane-polyurea, or polyurea elastomer encapsulated moldings of the invention possess a hardness of from Shore A 40 to Shore D 60, preferably from Shore A 40 to 80, and more preferably from Shore A 40 to 60 in accordance with DIN 53,505, a tensile strength of from 5 to 27 N/mm2, preferably Erom 5 to 16 N/mm2 in accordance with DIN 53,504, and a tear resis-tance of from 3.5 to 30 N/mm, preferably from 3.5 to 19 N/mm in accordance with DIN 53,507.
The plates of glass encapsulated with poly-urethane, polyurethane-polyurea, or polyurea elastomers are preferably used in transportation vehicles, for example railroad vehicles and, in particular, automotive vehicles.
The parts cited in the examples are based on weight.

~s~

Example 1 A 5 mm thick, grease-free plate of silicate glass was coated with an adhesion-improving two-component system on the area where the polyurethane-polyurea elastomers were to be subsequently applied. The adhe~ion-improving system comprises 100 parts by weight of an epoxy resin based on epichloro-hydrin-diphenylolpropane having a viscosity at 25C of 100-150 Pa.s, an epoxy number of 0.51-0.55, and an epoxy equivalent weight of 182-194, parts by weight 3,3'-dimethyl-4,4'-diaminodicyclo-hexylmethane, part~ by weight of a 5 percent solution of salicylic acid in isopropanol, and parts by weight toluene.
The following mixture was used as the A and components, respectively, A Component:
81.0 of a polyether polyol having a hydroxyl number of 26, which i3 prepared through the addition of 1,2-pro-pyleneoxide and the ~ubsequent addition of ethylene oxide to trimethylolpropane, 12.6 partq by weights 1,3-dimethyl-5-tert-butyl-2,4-diaminobenzene,

5.2 part~ by weight 1,3-phenylenediamine, 0.33 parts by weight 1,4-diazabicyclo-(2.2.2)octane, and 0.1 parts by weight dibutyl tin dilaurate.

B Component:
48 parts by weight of a mixture of polyoxypropylene glycol- and carbodiimide-lmodified 4,4'-diphenylmethane diisocyanate having an isocyanate content of 26.5 percent by weight.
The adhesion-improving two-componen~ system was applied using a felt applicator. The thickeness of the coating layer was 40 ~m in the liquid state. The coated plate of glaqs was then dried for 10 minutes at 100C.
The plate of silicate glass which had been pretreated in this manner was placed in a horzontal position in an aluminum mold whose temperature was requlated to 70C. The mold waq clo~ed. A mixture of polyurethane-polyurea elastomers was injected into the space between silicate glass and the inside surface of the mold at a temperature of 50C using reaction injection molding techni~ues. The mixing of components A and B, which had been heated to 50C, and the filling of the cavity in the mold with the resulting mixture of polyurethane and polyurea elastomers was performed using a Puromat~ 30 high pre~ure metering system manufactured by Elastogran Maschinenbau GmbH, 8021 Strasslach.

~S;~3 The encapsulated plate of silicate glass was removed from the mold after 30 seconds.
The resulting polyurethane-polyurea elastomer had the following mechanical properties:

Density per DIN 53 420 1.1 g/cm3 Shore D hardness per DIN 53 505 61 Tensile strength per D~N 53 504 28.0 N/mm2 Tear resistance per DIN 53 507 2a.7 N/mm The bond between the silicate glass and the polyurethane-polyurea elastomer was satisfactory.
Example 2 A 5 mm-thick, grease-free plate of silicate glass was coated with a two-component adhesion-improving system as described in Example 1. The system comprised:
100 parts by weight of an epoxy resin based on epichloro-hydrin-diphenylolpropane at a density of 1.58 g/cm3 having a processing viscosity of 22 seconds in a DIN 4 mm cup, parts by weight of a polyamine hardener (BASF Farben and Fasern AG hardener SC-0103~, and parts by weight of a xylene-containing solvent (BASF
Farben and Fasern AG solvent SV 32-0373).

~.5~ 3 The silicate glass plate which wa~ pretreated in this manner was encapsulated with the polyurethane-polyurea elastomer mixture described in Example l using the process of Example 1.
The adhesion between silicate glass and the polyurethane-polyurea elastomer wa~ good. It was not possible to manually pull off the polyurethane-polyurea elastomer .
Shear strength in accordance with R.N.U.R. 1108 ME
R.N.U.R. 1670 was 5 N/mm2.
Example 3 A 5-mm-thick, grease-free plate of silicate glass was coated with a solution of 3 parts by weight of amino-propyltrimethoxysilane in 97 parts by weight isopropane in the area where the polyurethane polyurea elastomer was to be subsequently applied. The aminopropyltrimethoxysilane solution was applied with a felt applicator at a thickness of 40 ~m in the liquid state. The coated plate of silicate glas~ was then dried for 10 minutes at 25C.
Then the adhesion-improving two-component system described in Example 2 was applied as described therein and the edges of the silicate glass plate were encapsulated with the polyurethane-polyurea elastomer mixture described in Example 1.

~2~

The adhesion between silicate gla~s and the polyurethane-polyurea elastomer was good. It wa~ not possible to manually pull off the polyurethane-polyurea elastomer.
Shear strength in accordance with R.N.U.R. 1108 ME R.N.U.R. 1670 wa~ 5 N/mm2.
The encap~ulated silicate glass plate was sub-jected to hydrolytic aging in water for 7 days at 70C. The subsequent shear strength per R.N.UR. 1108 ME R.N.U.R 1670 was 3.5 N/mm2.

-3g-

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for encapsulating glass edges with an elastic polyisocyanate addition polymerization product which comprises coating an edge of glass with an adhesion-improving agent comprising an organic epoxy resin and a hardener and thereafter covering the coated edge with a polyurethane, polyurethane-polyurea, or polyurea elastomer.

2. The process of claim 1 wherein said epoxy resin has the structural formula:

and has an epoxy equivalent weight of 140 to 4000.

3. The process of claim 1 wherein said hardener is selected from the group consisting of organic polyamines and polyamine adducts.

4. The process of claim 1 wherein said adhesion-improving agent comprises from 3 to 55 parts by weight hardener per 100 parts by weight organic epoxy resin.

5. The process of claim 1 wherein said adhesion improving agent is a solution of an organic epoxy resin and a hardener in an organic solvent.

6. The process of claim 1 wherein said adhesion improving agent is applied to a glass plate in a thickness of from 5 to 80 µm.

7. The process of claim 1 for coating and covering an edge of plate glass with an adhesion-improving agent which comprises, (a) placing said plate glass in an open mold, (b) closing said mold, (c) charging a cavity between said plate glass and said mold with a reactive mixture comprising, (1) an organic polyisocyanate, (2) a relatively high molecular weight compound having at least two reactive hydrogen atoms, (3) a chain extender and/or crosslinking agent, (4) a catalyst, and, optionally, (5) an auxiliary and/or additive, and (d) curing the reaction mixture.

8. The process of claim 7 wherein the reactive mixture is injected into a cavity formed between the plate glass and said mold by a reaction injection molding technique.

9. The process of claim 1 wherein the cured polyurethane, polyurethane-polyurea, or polyurea elastomers have a density of from 0.8 to 1.4 g/cm3, a hardness of Shore A 40 to Shore D 60, a tensile strength of from 5 to 27 N/mm2, and a tear strength of from 3.5 to 30 N/mm.

10. The process of claim 1 wherein the glass plate is made of silicate glass.