AU648099B2

AU648099B2 - Photo-hardened liquid coating composition for glass surfaces

Info

Publication number: AU648099B2
Application number: AU83314/91A
Authority: AU
Inventors: Horst Hintze-Bruning; Stephan Schunck
Original assignee: BASF Lacke und Farben AG
Current assignee: BASF Farben und Fasern AG
Priority date: 1990-09-01
Filing date: 1991-08-08
Publication date: 1994-04-14
Anticipated expiration: 2011-08-08
Also published as: NO930689D0; ES2068603T3; FI930851A0; BG60917B1; BR9106811A; EP0545969A1; LT3332B; EP0545969B1; BG97481A; LTIP531A; KR930702411A; NO930689L; DE4027770A1; YU47699B; JPH06502435A; AU8331491A; LV10463A; WO1992004391A1; DK0545969T3; LV10463B

Abstract

The invention concerns photo-hardened oligomers prepared from a) a hydroxy and/or amino compound with a hydroxy or amino number between 3 and 4 and a mean molecular weight between 500 and 4,000, b) a compound with two hydroxy and/or amino groups and a mean molecular weight between 200 and 4,000, c) a monoethylenically unsaturated compound containing a group with an active hydrogen atom and having a mean molecular weight between 116 and 1,000, d) an aliphatic and/or cycloaliphatic diisocyanate, characterized in that components (a) to (d) are used in amounts such that 1) the molar ratio of component (a) to component (b) is between 0.1 and 1.1, 2) the molar ratio of component (c) to component (a) is between 2.0 and 10, 3) the ratio by equivalent of the isocyanate groups in component (d) to the hydroxy and/or amino groups in components (a) to (c) combined is between 0.9 and 1.0.

Description

OPT DATE 30/03/92 APPLN. I D 83 14 91 P( AOJP DATE 14/05/92 PCT NUMBER PCT/EPq1/01501 INTERN.

DIE

INTERNATIONALE ZUSAMMENARBEIT AUF DEM GEBIET DES PATENTWESENS (PCT) (51) Internationale Patentklassifikation 5 (11) Internationale Ver~ffentlichungsnunimer: WO 92/04391 C08G 18/48, 18/67, 18/81 Al (43) Internatlonales Verbffentlichungsdatum: 19. Mlrz 1992 (19.03.92) (21) Internationales Akienzeichen: PCT/EP9I/01501 (74) Anwalt: LEIFERT, Elmar; BASF Lacke Farben AG, Patentabteilung, Po,;!fach 61 23, D-4400 M(Inster (DE).

(22) Internationales Anmeldedatum: 8, August 1991 (08.08.91) (81) Bestimmungsstaaten: AT (europdisches Patent), AU, BE Priori tfitsdatcn: (europflisches Patent), BG, BR, CA, CH (europaisches P 40 27 770.4 1. September 1990 (01.09.90) DE Patent), DE (europh1isches Patent), DK (europtlisches Patent), ES (europflisches Patent), Fl, FR (europffisches Patent), GB (europliisches Patent), GR (europ~1isches (71) Anmelder (fir alle Bestiminungssmtaan ausser US): BASF Patent), IT (europflisches Patent), JP, KR, LU (europdi- LACKE FARBEN AKTIENGESELLSCHAFT [DE/ sches Patent), NL (europttisches Patent), NO, SE (euro- DEJ; Max-Winkclmann-Strage 80, D-4400 MOnster p~iisches Patent), SU+, US.

(DE).

(72) Erfinder; und Veriiffentlicht Erfinder/Anmelder (nur fir US) HINTZE-BRONING, Mit internadonem RecherchenberichL Horst [DE/DEI; Karl-Immerman n-Str. 32, D-4400 MIn- Mft gndren Ansprilchen umd ErkI~iung.

ster SCHUNCK, Stephan [DE/DE]; Maximilianstr. 37, D-4400 MOnster (DE), 648099 (54)Tille: PHOTO-HARDENED LIQUID COATING COMPOSITION FOR GLASS SURFACES (54) Bezek~hnung: FLOSSIGE, STRAHLENHARTBARE OBERZUGSNIASSE FOR DIE BESCHICHTUNG VON GLAS.

OBERFLAC HEN (57) Abstract The invention concerns photo-hardened oligomers prepared from a) a hydroxy and /or amino compound with a hydroxy or amino number between 3 and 4 and a mean molecular weight between 500 and 4,000, b) a compound with two hydroxy and/or amino groups and a mean molecular weight between 200 and 4,000, c) a monoethylenically unsaturated compound containing a group with an active hydrogen atom and having a mean molecular weight between 116 and 1,000, d) an aliphatic and/or cycloaliphatic diisocyanate, characterized in that components to are used in amounts such that 1) the molar ratio of component (a) to component is between 0. 1 and 1. 1, 2) the moldr ratio of component to component is between 2.0 and 10, 3) the ratio by equivalent of the isocyanate groups in component to the hydroxy and/or amino groups in components to combined is between 0.9 and (57) Zusammenrassung Gegenstand der vorliegenden Erlindung sind strahlenhtlrtbare Oligomere, die herstellbar sind aus a) ciner hydroxi. und' oder aminorunktionellen Verbindung mit ciner Funktionalitalt zwischen 3 und 4 und einemn zanilenmittleren Moiekulargcwichit zwischen 500 und 4000, b) einer Verbindung mit zwvei Hydroxyl. und/oder Aminogruppen und cinem zahllenmittleren Molekurlargewicht zwischen 200 und 4000, c) ciner nionoethylenisch ungesalttigten Verbindung mit einer Gruppe mit cinem aktiven W\asserstoffatom und einem zahlenmittleren Molckulargewvicht zwischen 116 und 1000 und d) einem aliphatischen und/oder cycloaliphatisclien Diisocyanat, dadurch gekennzeichnet, da die Komponenten a bis d in solchen Mengen eingesetzt werden, dali 1. das Molvcrhflltnis der Komponente a zu der Komponente b zwischen 0, 1 und 1, 1 liegt, 2. das Molverhiltnis der Komponente c zu der Komponente a zwischen 2,0 und 10 Iiegt und 3. das Aquivalentverhlltnis der Isocyanatgruppen der Komponente d zu den Hy.

droxyl. und/oder Aminogruppen der Sumnme der Komponenten a bis c zwischen 0,9 und 1,0 liegt.

*Siehe R(Ickeite 1 Liquid, radiation-curable coating composition for the coating of glass surfaces The present invention relates to radiationcurable oligomers having several ethylenically unsaturated end groups and several urethane and/or urea groups per molecule, which oligomers can be prepared from a) at least one hydroxy- and/or aminofunctional compound having a functionality between 3 and 4 and a number-average molecular weight between 500 and 4000, polyester polyols being excepted, I' b) at least one compound having 2 hydroxyl and/or amino groups per molecule and a number-average molecular weight between 200 and 4000, polyesterdiols being excepted, c) at least one monoethylenically unsaturated compound having a group containing one active hydrogen atom per molecule and having a numberaverage molecular weight between 116 and 1000, S' and d) at least one aliphatic and/or cycloaliphatic diisocyanate, which comprises using components a .to d in amounts such that 1) the molar ratio of component a to component b is between 0.1:1 and 1.1:3, 2) the molar ratio of component c to component a is between 2:1 and 10:1, and 3) the equivalent ratio of the isocyanate groups of component d to the hydroxyl and/or amino groups of the sum of components a to c is between 0.9 and The present invention also relates to radiation curable coating compositions containing these radiationcurable oligomers, and to processes for the coating of glass surfaces, in particular optic glass fibers, in which S*74 35 these coating compositions are used.

2 Optic glass fibers have acquired constantly increasing importance in the communications sector as light waveguide fibers. For this particular application, it is absolutely necessary to protect their glass surface from moisture and wear. Accordingly, directly after their manufacture, the glass fibers are provided with at least one protective surface coating.

Thus it is known, for example from EP-B-114,982, to provide glass fibers first with a buffer layer (primer) which is elastic but has low hardness and low toughness and then to apply a radiation-curable top coat which has high hardness and toughness. The two-layered structure is intended to ensure good protection of the glass fibers upon exposure to mechanical stress even at low temperatures.

According to EP-B-114,982, radiation-curable coating agents based on linear urethane acrylates are used as the primer. Radiation-curable coating agents based on a linear urethane acrylate, a diethylenically unsaturated ester, a diglycidyl ether of a bisphenol and a monoethylenically unsaturated monomer, the glass transition temperature of the homopolymer prepared from this monomer being above 55 0 C, can be used as the top coat.

EP-A-223,086 furthermore discloses radiationcurable coating agents for the coating of optic glass fibers. These coating agents contain radiation-curable 3 oligomers according to the preamble of the main claim as the binder.

These radiation-curable coating agents described in EP-A-223,086 are used either as top coat or as singlelayer coating. However, they are not suitable as primer due to the excessively high modulus of elasticity value of the cured coatings.

Radiation-curable coating compositions for the coating of optic glass fibers are also described in EP-A- 209,641. These coating compositions contain a polyurethane oligomer containing acrylate end groups and based on a polyfunctional core as the binder, These coating compositions can be used not only as primer but also as top coat. Single-layer processing is also possible.

Finally, for example EP-A-208,845, EP-A-167,199, EP-A-204,161, EP-A-204,160 and EP-A-250,631 disclose radiation-curable coating compositions for the coating of optic glass fibers which contain linear urethane acrylates as binders. These coating compositions have the disadvantage of unsatisfactory ageing behavior. Furthermore, the mechanical properties of the coatings, in particular elasticity, still need to be improved upon long-term exposure.

The object of the present invention is to provide radiation-curable coating compositions for the coating of glass surfaces, in particular of optic glass fibers, which, compared with the known coating compositions, lead 4 to coatings having improved properties. In particular, the cured coatings should have improved ageing behavior and correspondingly increased long-term stability of the coated glass fibers. Furthermore, the cured coatings should have improved behavior in the Pbsorption and desorption of water. This is of particular importance for the optical damping of the coated fibers. Moreover, the cured coatings should have a good buffer effect even at low temperature. This means that the mechanical properties of the coating should deteriorate only as little as possible with decreasing temperature. In particular, the increase in the modulus of elasticity value with decreasing temperature should be as little as possible. On the other hand, the coating compositions should cure as quickly as possible. Moreover, the resulting coatings should have only very slight evolution of hydrogen upon storage and ageing and show good adhesion on the glass surface.

Surprisingly, the object is achieved by radiation-curable oligomers containing several ethylenically unsaturated end groups and several urethane and/or urea groups per molecule in dissolved form, which oligomers -ean-be prepared from a) at least one hydroxy- and/or aminofunctional compound having a functionality between 3 and 4 and a number-average molecular weight between 500 and 4000, polyeser ofolyLs b.X 3 excted, 5 b) at least one compound having 2 hydroxyl and/or amino groups per molecule and a number-average molecular weight between 200 and 4000, oPfIres-rd(ols IbetY -ep'kd, c) at least one monoethylenically unsaturated compound having a group containing one active hydrogen atom per molecule and having a number-average molecular weight between 116 and 1000, and d) at least one aliphatic and/or cycloaliphatic diisocyanate.

Components a to d are used in the radiationcurable oligomers in amounts such that 1. the molar ratio of component a to component b is between 0.1 1 and 1.1 1, preferably between 0.1 and 0.8, 2. the molar ratio of component c to component a is between 2.0 1 and 10 1, preferably between and 10, and 3. the equivalent ratio of the isocyanate groups of component d to the hydroxyl and/or amino groups of the sum of components a to c is between 0.9 and The present invention furthermore relates to radiation-curable coating compositions containing these radiation-curable oligomers and to processes for the 6 coating of glass surfaces, in particular optic glass fibers, in which these coating compositions are used.

It is surprising and was not foreseeable that radiation-curable coating compositions based on the oligomers according to the invention give coatings having improved ageing behavior compared with conventional coatings, as a result of which the glass fibers coated with these coating compositions have increased long-term stability. Moreover, the coatings prepared from the coating compositions according to the invention have improved behavior, compared with conventional coatings, in the absorption and desorption of water. Another advantage is the good buffer effect of the coatings even at low temperatures, thus solving the problem of the socalled microbends. Furthermore, the coatings according to the invention are distinguished by good mechanical properties, such as, for example, tensile strength and elongation adapted to the particular a.plication, and by only a slight evolution of hydrogen upon storage or ageing. Finally, they have good adhesion on the glass surface.

Hereinafter, first the radiation-curable oligomers according to the invention will be defined in more detail: suitable components a for the preparation of the oligomers are hydroxy- and/or aminofunctional compounds having a functionality of 3 to 4, preferably 3. These compounds have number-average molecular weights of 500 to 7 4000, preferably 750 to 2000.

Examples of suitable compounds are polyalkoxylated triols, such as, for example, ethoxylated and propoxylated triols, preferably ethoxylated triols, particularly preferably having a number-average molecular weight of greater than or equal to 1000. Examples of the triols used are glycerol and trimethylolpropane.

The corresponding aminofunctional compounds such as, for example, aminofunctional compounds derived from polyalkoxylated triols, are also suitable. Examples of such products are obtainable from Texaco under the name

JEFFAMIN"

I

for example JEFFAMIN

I

R T 403, T 3000, T 5000, C 346, DU 700 and BuD 2000.

These aminofunctional compounds can contain both primary and secondary amino groups.

In addition, compounds containing both amino and hydroxyl groups are also suitable.

Suitable components b are compounds containing two hydroxyl and/or amino groups per molecule. These compounds have number-average molecular weights of 200 to 4000, preferably 600 to 2000.

Examples of suitable compounds b are polyoxyalkylene glycols and polyoxyalkylenediomines, alkylene groups of 1 to 6 C atoms being preferred. Thus, for example, polyoxyethylene glycols having a number-average molecular weight of 1000, 1500, 2000 or 2500 and polyoxypropylene glycols having corresponding molecular weights 8 and polytetramethylene glycols are suitable.

Polyethoxylated and polypropoxylated diols can also be used, such as, for example, ethoxylated and propoxylated derivatives of butanediol, hexanediol, and the like.

-Furthcnmoro, polyesterdiols, which can bc prcpaedfo example, by reacting the already mentioned glycols with dicarboxylic acids, preferably aliphatic and/or cyc aliphatic dicarboxylic acids, such as, for ex ple, hexahydrophthalic acid, adipic acid, azelaic, se acic and glutaric acid and/or alkyl-substituted erivatives thereof, can also be used. Instead of the acids, it is possible to use their anhydrides, if t y exist.

Polycaprolactonediols can so be used. These products are obtained, for ex ple, by reacting an e-caprolactone with a roducts of this type are described in US Patent No. ,169,945.

The polylactone ols obtained by this reaction are distinguished by he presence of a terminal hydroxyl group and by recu ring polyester portions derived from the lactone. T se recurring molecular portions can have the formula 0 C (CHR)n CH2in ich n is preferably 4 to 6 and the substituent is drogen, an alkyl radical, a cycloalkyl radical or an alkoxy radical, no substituent containing more than 1^2--car-ban--tm9-and-the-t- tet-a--nuber-f--eeiabon-ateme-e--- 9 -the substitunts in-th-4aet-ene-rin-nee-eeeeedd-ng-- 2 The lactone used as starting material can be any desired lactone or any desired combination of lacton in which this lactone should contain at least 6 c rbon atoms in the ring, for example 6 to 8 carbon at s, and in which at least 2 hydrogen substituents should be present on the carbon atom. The lactone us as starting material can be described by the f lowing general formula:

CH

2

(CR

2 0 0 in which n and R are as already defined. The lactones which are preferred in he invention for the preparation of polyesterdiols e caprolactones in which n has a value of 4. The/most preferred lactone is substituted e-caprolacton in which n has a value of 4 and all R substituen are hydrogen. This lactone is particularly preferre since it is available in large amounts and gives/coatings having excellent properties. It is also po ible to use various other lactones by themselves or ombined. Examples of aliphatic diols suitable for the reaction with the lactone are the diols already mentioned abveOr -the- reaetion-wAIth-heo abey-o aeoido.----- It is of course also possible to use the corresponding diamines and compounds having an OH and an amino group as component b. Examples of suitable 10 compounds are the products available from Texaco under the name JEFFAMIN® D 230, D 400, D 2000, D 4000, ED 600, ED 900, ED 2001 and ED 4000.

A mixture comprising bl) 0 to 90 mol of at least one polyetherdiol and b 2 10 to 100 mol of at least one modified polyetherdiol composed of b 21 at least one polyetherdiol b 22 at least one aliphatic and/or cycloaliphatic dicarboxylic acid and b 23 at least one aliphatic, saturated compound having an epoxy group and 8 to 21 C atoms per molecule, in which the sum of the amounts of components bi and b 2 and the sum of the amounts of components b 21 to b 23 is in each case 100 mol is preferably used as component b.

For preparing the modified polyetherdiols by conventional methods, components b 21 to b 23 are used in amounts such that the equivalent ratio of the OH groups of component b 2 1 to the carboxyl groups of component b 22 is between 0.45 and 0.55, preferably 0.5, and that the equivalent ratio of the epoxy groups of component b 23 to the carboxyl groups of component b 22 is between 0.45 and 0.55 and preferably Examples of suitable polyetherdiols b i and b 21 are the polyoxyalkylene glycols already listed in which the alkylene groups have 1 to 6 C atoms. Polyoxypropylene glycols having a number-average molecular weight between 11 600 and 2000 are preferably used as component bI. Polyoxybutylene glycols (poly-THF) having a number-average molecular weight of 1000 are preferably used as component b 21 Aliphatic and cycloaliphatic dicarboxylic acids having 8 to 36 C atoms per molecule, such as, for example, hexahydrophthalic acid, are preferably used as component b 22 Examples of suitable components b 23 are epoxidized vinylcyclohexane compounds, epoxidized, monoolefinically unsaturated fatty acids and/or polybutadienes.

Glycidyl esters of branched monocarboxylic acids, such as, for example, the glycidyl ester of Versatic Acid, are preferably used as component b, 3 For introducing the ethylenically unsaturated groups into the polyurethane oligomer, monoethylenically unsaturated compounds having a group containing an active hydrogen atom and having a number-average molecular weight of 116 to 1000, preferably 116 to 400, are used.

Examples of suitable components c are, for example, hydroxyalkyl esters of ethylenically unsaturated carboxylic acids, such as, for example, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyamyl acrylate, hydroxyhexyl acrylate, hydroxyoctyl acrylate, and the corresponding hydroxalkyl esters of methacrylic, fumaric, maleic, itaconic, crotonic and isocrotonic acid, the hydroxyalkyl esters of acrylic acid 12 being, however, preferred.

Furthermore, adducts of caprolactone with one of the abovementioned hydroxyalkyl esters of ethylenically unsaturated carboxylic acids are suitable as component c. Adducts of the hydroxyalkyl esters of acrylic acid having a number-average molecular weight of 300 to 1000 are preferably used.

Suitable components d for the preparation of the oligomers according to the invention are aliphatic and/or cycloaliphatic diisocyanates, such as, for example, 1,3cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,2-cyclohexane diisocyanate, 4,4'-methylene-bis(cyclohexane isocyanate) and isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate and trimethyl-1,6-hexamethylene diisocyanate and the diisocyanates derived from dimeric fatty acids and described in EP-A-204,161, column 4, lines 42 to 49.

Isophorone diisocyanate and trimethyl-1,6-hexamethylene diisocyanate are preferably used.

It is essential to the invention that components a to d for preparing the oligomers are used in amounts such that 1. the molar ratio of component a to component b is between 0.1 1 and 1.1 1, preferably between 0.1 and 0.8, 13 2. the molar ratio of component c to component a is between 2:1 and 10:1, preferably between 2.5 and and 3. the equivalent ratio of the isocyanate groups of component d to the active hydrogen atoms from components a plus b plus c is between 0.9 and The oligomers according to the invention can be prepared by various methods. Thus, for example, it is possible first to react diisocyanate d with chain-lengthening agents a and b and then to react the remaining free isocyanate groups with the ethylenically unsaturated compound c.

It is also possible to prepare the oligomers by first reacting a portion of the isocyanate groups of component b with the ethylenically unsaturated compound c and then reacting the remaining free isocyanate groups with chain-lengthening agents a and b.

Furthermore, it is possible to prepare the polyurethane oligomers by the process described in EP-A-223,086 on page The polyurethane oligomers are preferably prepared by a two-step process by first carrying out the stoichiometric polyaddition reaction of components a to d until more than 85 of the NCO groups of component d have been converted. In this first process step, 14 components a to d are used in amounts such that the equivalent ratio of the NCO groups of component d to the active hydrogen atoms of components a to c is 1:1.

In a second process step, the remainder of the other components (in accordance with the desired NCO: OH ratio) is then added, and the reaction is continued up to an NCO group conversion of 99 In this second process step, it is preferred to add more of component c and to achieve the desired NCO: OH equivalent ratio by adding this component c.

The urethane oligomers according to the invention usually have number-average molecular weights of 2500 to 10000, preferably 3000 to 6000 (measured by GPC against a polystyrene standard), weight-average molecular weights of 5000 to 50000, preferably 7000 to 20000 (measured by GPC against a polystyrene standard), double-bond contents of 0.45 to 1.5, preferably 0.45 to 0.9, mol/kg and particularly preferably 0.45 to 0.63, and very particularly preferably 0.5 to 0.63 mol/kg, and a functionality of >2 to 3.5, preferably 2.2 to 2.8, in each case per statistic averaqe polymer molecule.

The oligomers according to the invention are used in radiation-curable coating compositions as film-forming component A. The coating compositions usually contain 10 to 78 by weight, preferably 15 to 75 by weight, and particularly preferably 63 to 73 by weight, in each case relative to the total weight of the coating 15 composition, of these oligomers according to the invention.

As further component, the coating compositions can contain 0 to 60 by weight, preferably 0 to 50 by weight, in each case relative to the total weight of the coating composition, of at least one further ethylenically unsaturated oligomer B. Apart from unsaturated polyesters, polyester acrylates and acrylate copolymers, in particular urethane acrylate oligomers, with the exception of the arethane acrylate oligomers used as component A, are used. The properties of the completely cured coating can be selectively adjusted by means of the typ and amount of this component B. The higher the amount of this component B, the higher in general the modulus of elasticity value of the completely cured coating. Component B is therefore added to the coating composition especially if the coating compositions are used as top coat. However, the effect of this component B on the properties of the resulting coating is known to one skilled in the art. The most favorable amount to be used in each case can therefore be simply determined by a few routine experiments. These ethylenically unsaturated polyurethanes used as component B are known. They can be obtained by reacting a di- or polyisocyanate with a chain-lengthening agent from the group of diols/polyols and/or diamines/polyamines, followed by reaction of the remaining free isocyanate groups with at least one 16 hydroxyalkyl acrylate or hydroxyalkyl ester of other ethylenically unsaturated carboxylic acids.

The amounts of chain-lengthening agent, di- or polyisocyanate and hydroxyalkyl ester of an ethylenically unsaturated carboxylic acid are selected in such a manner that 1. the equivalent ratio of the NCO groups to the reactive groups of the chain-lengthening agent (hydroxyl, amino or mercapto groups) is between 3:1 and. 1:2, preferably 2:1, and 2. the OH groups of the hydroxyalkyl esters of the ethylenically unsaturated carboxylic acids are present in a stoichiometric amount with respect to the still free isocyanate groups of the prepolymer composed of isocyanate and chain-lengthening agents.

Furthermore, it is possible to prepare the polyurethanes B by first reacting a portion of the isocyanate groups of a di- or polyisocyanate with at least one hydroxyalkyl ester of an ethylenically unsaturated carboxylic acid and then reacting the remaining isocyanate groups rith a chain-lengthening agent. In this case too, the amounts of chain-lengthening agent, isocyanate and hydroxyalkyl ester of unsaturated carboxylic acids are selected in such a manner that the equivalent ratio 17 of the NCO groups to the reactive group of the chainlengthening agent is between 3:1 and 1:2, preferably 2:1, and the equivalent ratio of the remaining NCO groups to the OH groups of the hydroxyalkyl ester is 1:1.

All intermediate forms of these two processes are of course also possible. For example, a portion of the isocyanate groups of a diisocyanate can first be reacted with a diol, a further portion of the isocyanate groups can then be reacted with the hydroxyalkyl ester of an ethylenically unsaturated carboxylic acid, and this can be followed by reacting the remaining isocyanate groups with a diamine.

These various preparation processes for polyurethanes are known (cf. for example, EP-A-204,161) and therefore need not be described in more detail.

Compounds which are suitable for the preparation of these urethane-acrylate oligomers B are the compounds already used in the preparation of component A and further the compounds mentioned in German Offenlegungsschrift 3,840,644.

Especially when the coating compositions according to the invention are used as top coat, aromatic structural components are preferably used for preparing the urethane-acrylate oligomers B. In this case, 2,4- and 2,6-toluylene diisocyanate are preferably used as isocyanate components and aromatic polyester polyols based on phthalic acid and isophthalic acid and/or polypropylene 18 glycol, ethylene glycol and diethylene glycol as chainlengthening agents.

As further component, the radiation-curable coating compositions additionally contain at least one ethylenically unsaturated monomeric and/or oligomeric compound C, usually in an amount of 20 to 50 by weight, preferably 23 to 35 by weight, in each case relative to the total weight of the coating composition.

By adding this ethylenically unsaturated compound C, the viscosity and the curing rate of the coating compositions and the mechanical properties of the resulting coating are controlled, as is known to one skilled in the art and described, for example, in EP-A-223,086 and which should be consulted for further details.

Examples of monomers which can be used are ethoxyethoxyethyl acrylate, N-vinylpyrrolidone, phenoxyethyl acrylate, dimethylaminoethyl acrylate, hydroxyethyl acrylate, butoxyethyl acrylate, isobornyl acrylate, dimethylacrylamide and dicyclopentyl acrylate. Di- and polyacrylates, such as, for example, butanediol diacrylate, hexanediol diacrylate, trimethylolpropane diand triacrylate, pentaerythritol diacrylate and the longchain linear diacrylates having a molecular weight of 400 to 4000 or preferably 600 to 2500, and described in EP-A-250,631, are also suitable. The two acrylate groups can be, for example, separated by a polyoxybutylene structure. Furthermore, 1,12-dodecyl diacrylate and the 19 reaction product of 2 mol of acrylic acid with one mol of a dimeric fatty alcohol, which in general has 36 C atoms, can also be used.

Mixtures of the monomers just described are also suitable. Phenoxyethyl acrylate, hexanediol diacrylate, N-vinylpyrrolidone and tripropylene glycol diacrylate are preferably used.

The photoinitiator usually used in the coating compositions according to the invention in an amount of 2 to 8 by weight, preferably 3 to 5 by weight, relative to the total weight of the coating composition, varies with the radiation used for curing the coating agents (UV radiation, electron radiation, visible light).

The coating compositions according to the invention are preferably cured by means of UV radiation. In this case, ketone-based photoinitiators are usually used, for example acetophenone, benzophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, hydroxypropyl phenyl ketone, m-chloroacetophenone, propiophenone, benzoin, benzil, benzil dimethyl ketal, anthraquinone, thioxanthone and thioxanthone derivatives and triphenylphosphine and the like, as well as mixtures of various photoinitiators.

Furthermore, the coating compositions can additionally contain, if desirea, customary auxiliaries and additives. These are usually used in an amount of 0 to 4 by weight, preferably 0.5 to 2.0 by weight, in each 20 case relative to the total weight of the coating composition. Examples of substances of this type are flowimproving agents, plasticizers and in particular adhesion promoters. Adhesion promoters used for this are alkoxysilanes, such as, for example, N-3-aminoethyl-7-aminopropyltrimethoxysilane, 7-aminopropyltrimethoxysilane, N-methyl-y-aminopropyltrimethoxysilane or triaminomodifled propyltrimethoxysilane (for example adhesion promoter DYNASYLAN® of "TRIAMO type", commercial product from Dynamit Nobel Chemie).

The coating compositions can be applied to the substrate by means of known application methods, such as, for example, spraying, rolling, flooding, dipping, knifeor brush-application.

The coating films are cured by means of radiation, preferably by means of UV radiation. Apparatuses and conditions for these curing methods are known from the literature (cf. for example, R. Holmes, U.V. and E.B. Curing Formulations for Printing Inks, Coatings and Paints, SITA Technology, Academic Press, London, United Kingdom 1984) and need no further description.

The coating compositions are suitable for the coating of a wide range of substrates, for example glass, wood, metal and plastic surfaces. However, they are in particular used for the coating of glass surfaces, particularly preferably of optic glass fibers.

21 Accordingly, the present invention also relates to a process for the coating of a glass surface, in which a radiation-curable coating composition is applied and cured by means of UV or electron radiation, which process comprises using the coating compositions according to the invention as the radiation-curable coating compositions.

The process according to the invention is particularly suitable for the coating of optic glass fibers.

For this purpose, the coating compositions according to the invention can be applied to the glass fibers as a primer and/or top coat of a two-layer coat. When the coating compositions are used as a primer, the completely cured coatings usually have a modulus of elasticity value (at 2.5 elongation and room temperature) of less than 10 MPa.

When the coating compositions are used as top coat, the completely cured coatings usually have a modulus of elasticity value (at 2.5 elongation and room temperature) of 500 to 1000 MPa.

The invention will be illustrated in more detail in the examples which follow. All parts and percentages given are by weight, unless stated expressly otherwise.

Preparation of a modified polvetherdiol In a boiler equipped with stirrer, inert ga.

inlet and temperature sensor, 51.1 parts of polytetrahydrofuran having a number-average molecular weight of 22 1000 and an OH number of 118 mg of KOH/g and 19.1 pars of hexahydrophthalic anhydride are heated to 120 0 C and maintained at this temperature until an acid number of 102 mg of KOH/g has been reached. 0.02 of chromium octoate, relative to the weight of the mixture composed of poly-THF, hexahydrophthalic acid and glycidyl ester of Versatic Acid, and 29.7 parts of the glycidyl ester of Versatic Acid having ar epoxy equivalent weight of 266 are then added. The mixture is heated at 120"C until the reaction product has an epoxy equivalent weight of 20,000, an acid number of 4 mg of KOH/g and an OH number of 60 mg of KOH/g.

The modified polyether diol has an average molecular weight M, of 1860 (calculated from the OH number), an M, 1500 determined by GPC and an Mw/Mn 1.67. The viscosity of an 80 strength solution in butyl acetate is 3.8 dPas (measured at 23"C with the plate/cone viscometer).

Example 1 In a boiler equipped with stirrer, inlet means, temperature sensor and air inlet, 0.35 mol of a commercially available ethoxylated trimethylolpropane having a number-average molecular weight of 1000, 0.65 mol of a commercially available polyoxypropylene glycol having a number-average molecular weight of 600, 0.65 mol of the modified polyetherdiol described above, 1.75 mol of hydroxyethyl acrylate, 0.05 of dibutyltin dilaurate 23 (relative to the total weight of the sum of components a, b, c and 0.1 of 2,6-ditert.-butylcresol (relative to the total weight of the sum of components a, b, c and d) and 30 ppm of phenothiazine (relative to the total weight of the sum of components a, b, c and d) are initially introduced, and the mixture Is heated to 60 0

C.

2.70 mol of isophorone diisocyanate are then metered in at 50 0 C over a period of 2.5 h. The mixture is then diluted with phenoxyethyl acrylate to a theoretical solids content of 90 (sum of components a to and the temperature is maintained at 60o" until an NCO value of 1 has been reached. 0.05 of dibutyltin dilaurate and 0.51 mol of a commercially available hydroxyethyl acrylate/caprolactone oligomer having a number-average molecular weight of 344 (commercial product TONE M 100 from Union Carbide) are added at a temperature of and the temperature is maintained at 80°C until an NCO value of 0.1 has been reached. The oligomer thus obtained has a double-bond content of 0.6 mol/kg and a functionality of A 40 solution (relative to the theoretical solids content) of the oligomer 1 obtained in phenoxyethyl acrylate has a viscosity of 4.9 d Pas (measured at 23*r with the plate/cone viscometer.

78.1 parts of the 90 strength solution of the urethane oligomer 1 described above, 12.1 parts of phenoxyethyl acrylate, 6.2 parts of N-vinylpyrrolidone, 24 1.6 parts of N-p-aminoethyl-y-aminopropyltrimethoxysilane and 2.0 parts of diethoxyacetophenone are used to prepare a radiation-curable coating composition 1 by mixing.

Thoroughly cleaned (in particular grease-free) glass plates (width x length 98 x 161 mm) are covered at the edge with Tesakrepp® adhesive tape No. 4432 (width 19 mm), and the coating composition 1 is applied by means of a knife (dry-film thickness 180 Am).

The curing is carried out using a UV radiation apparatus equipped with two Hg medium-pressure lamps each of 80 W/cm lamp power at a belt rate of 40 m/minute in two runs at half-load operation 40 W/cm).

The dose of this incoming radiation was 0.08 J/cm 2 (measured with the UVICURE dosimeter, system EIT from Eltosch).

This gave completely cured coatings which have very good mechanical properties and furthermore are distinguished by good resistance to ageing, good lowtemperature performance and improved performance in the absorption and desorption of water.

The results of the determination of the modulus of elasticity at 0.5 and 2.5 elongation (according to DIN Standard 53 455) and the results of the elongation at break test are listed in Table 2. The results of the measurement of the modulus of elasticity values (2.5 elongation) after various ageing treatments of the completely cured coatings are also shown in Table 2.

25 The dopendence of the modulus of elasticity value on the temperature is shown in Figure 1. The measurements were carried out using the DMTA instrument from Polymer Laboratories Ltd.

The absorption and desorption performance of the completely cured coating in contact with water is shown in Figure 2.

Comoarative Examplo 1 mol of isophorone diisocyanate and 0.05 of dibutyltin dilaurate (relative to the total weight of the sum of components a to d) are initially introduced into a boiler equipped with stirrer, inlet means, temperature sensor and air inlet, and the mixture is heated to 60 0

C.

1.30 mol of commercially available polyoxypropylene glycol having a number-average molecular weight of 600 are then metered in at 60"C over a period of 120 to 180 minutes. The temperature is maintained at 60"C until an NCO value of 5 has been reached. 0.1 of 2.6-ditert.-butylcresol (relative to the total weight of the sum of components a to d) and 40 ppm of phenothiazine (relative to the total weight of the sum of components a to d) are then added to the boiler. 1.54 mol of hydroxyethyl acrylate are then metered in at 60°C over a period of 30 minutes. Dissolution of the mixture is then started with phenoxyethyl acrylate until a theoretical solids content of 90 (relative to the total weight of the sum of components a to d) has been reached. The temperature 26 is then maintained at 60"C until an NCO content of 0.1 has been reached.

The oligomer 2 thus obtained has a double-bond content of 1.01 mol/kg and a functionality of 2.0. A 50 strength solution (relative to the theoretical solids content) of the oligomer 2 obtained in phenoxyethyl acrylate has a viscosity of 10 dPas (measured at 23°C with a plate/cone vieiometer).

Analogously to Example 1, 78.1 parts of the 90 strength solution of the urethane oligomer 2 described above, 12.1 parts of phenoxyethyl acrylate, 6.2 parts of N-vinylpyrrolidone, 1,6 parts of N-p-aminoethyl-y-aminopropyltrimethoxysilane and 2.0 parts of diethoxyacetophenone are used to prepare a radiation-curable coating composition 2 by mixing. Application of this coating composition 2 and testing of the completely cured coating is carried out analogously to Example 1. The results are shown in Table 2 and in Figures 3 and 4.

27 Table 1 Composition of the urethane oligomers (in mol) Example 1 0.35 Comparison 1 a) Ethoxylated trimethyloipropane (M 1000) bl) Polyoxypropylene glycol (Mn 600) b 2 Modified polyetherdiol (Mn 1860) c) Hydroxyethyl acrylate c) Hydroxyethyl acrylatecaprolactone oligomer d) Isophorone diisocyanate molar ratio a/b 1s Molar ratio c/a Equivalent ratio

NCO/OH

0.65 0.65 1..75 0.51 2.70 0.27 6.46 0.91 1.30 1.54 0 0.97 28 Table 2: Test results 1 Cl Elongation at break 53.1 58 in Modulus of elasticity 3.1 2.75 (0.5 elongation) in MPa Modulus of elasticity 2.9 2.6 (2.5 elongation) in MPa after 800 h, 55 0 C, 3 2.7 in MPa after 800 h, 90 0 C, 4.2 -in MPa E25 after 800 h, 120°C 7.3 18.3 in MPa 29 Example 2 2 mol of isophorone diisocyanate are initially introduced into the boiler described in Example 1, and 0.05% of dibutyltin dilaurate and 30 ppm of phenothiazine are added, and the mixture is heated to 60 0 C. 2 mol of hydroxyethyl acrylate are then added dropwise at such a rate that the temperature does not exceed 60 0 C. 1 mol of ethoxylated trimethyolpropane (sic) (20 mol of ethylene oxide per mole of trimethylolpropane) are then added dropwise also at 60°C. The mixture is maintained at until an NCO content of 0% has been reached. The intermediate 1 thus obtained is then processed further.

2 mol of isophorone diisocyanate and dibutyltin dilaurate are initially introduced, and 0.65 mol of polyoxytetramethylene glycol having a number-average molecular weight of 1,000, and 0.65 mol of the modified polyether diol are then added as a mixture, and the temperature is maintained at 60 0 C until an NCO content of 2.7% has been reached. Phenothiazine is then added as a stabilizer. A mixture of 1.05 mol of hydroxyethyl acrylate and 0.35 mol of the intermediate 1 described above is then metered in, and the temperature is maintained at 60"C until an NCO content of less than 0.1% has been reached.

The radiation-curable coating composition is prepared from 70 parts of the urethane oligomer described above, 20.0 parts of phenoxyethyl acrylate, 6.b parts of N-vinylpyrrolidone, 1.5 parts of N-p-aminoethyl-y-amino- 30 propyltrimethoxysilane and 2.0 parts of diethoxyacetophenone by mixing. The chemical properties are listed in Table 4. Thoroughly clean (in particular grease-free) glass plates (width x length 98 x 161 mm) are covered at the edge with Tesakreppe adhesive tape No. 4432 (width 19 mm), and the coating composition is applied by means of a knife (dry-film thickness 180 pm).

Curing is carried out using a UV radiation apparatus equipped with two Hg medium-pressure lamps each of 80 W/cm lamp power at a belt rate of 40 m/minute in 2 runs at half-load operation 40 W/cm).

This gave completely cured coatings which have very good mechanical properties and furthermore are distinguished by good resistance to aging, good lowtemperature performance and improved performance in the absorption and desorption of water.

The results of the determination of the modulus of elasticity at 0.5% and 2.5% elongation (according to DIN Standard 53 455) and the results of the elongation at break test are listed in Table The dependence of the modulus of elasticity value on the temperature is shown in Table 6 and Figures 5 and 7. The measurements were carried out using the DMTA instrument from Polymer Laboratories Ltd.

31 Example 3 The intermediate 1 is prepared analogously to Example 2.

2 mol of isophorone diisocyanate and dibutyltin dilaurate are initially introduced, and 0.65 mol of polyoxytetramethylene glycol having a number-average molecular weight of 1,000, and 0.65 mol of the modified polyether diol are added as a mixture, and the temperature is maintained at until an NCO content of 2.6% has been reached.

Phenothiazine is then added as a stabilizer. A mixture of 0.35 mol of hydroxyethyl acrylate and 1.05 mol of the intermediate 1 described above is then metered in, and the temperature is maintained at 60 0 C until an NCO content of less than 0.1% has been reached.

Preparation, application and curing of the radiation-curable coating agent and testing of the coating were carried out analogously to Example 2. The test results are shown in Tables 5 and 6 and in Figures and 8.

Example 4 The intermediate 1 is prepared analogously to Example 2.

2 mol of isophorone diisocyanate are initially introduced, and 1.3 mol of modified polyether diol are added.

After addition is complete, the mixture is maintained at for another 6 hours. 1.4 mol of the intermediate described above are then metered in, and the temperature 32 is maintained at 60"C until an NCO content of less than 0.1% has been reached.

Preparation, application and curing of the radiationcurable coating agent and testing of the coating were carried out analogously to Example 2.

The test results are shown in Tables 5 and S and in Figures 5 and 9.

Comparative Examples 2 and 3 Analogously to Example 2, polyurethane acrylate oligomers were prepared from the components listed in Table 3.

These urethane acrylate oligomers were used to prepare radiation-curable coating compositions analogously to Example 2. Application, curing and testing of the coatings were also carried out analogously to Example 2. The results of the determination of the modulus of elasticity at 0.5% and 2.5% elongation (according to DIN Standard 53 455) and the results of the elongation at break test are listed in Table The.dependence of the modulus of elasticity value on the temperature is shown in Figure 5 and in Table 8. The measurements were carried out using the DMTA instrument from Polymer Laboratories Ltd.

33 Table 3: Composition of the acrylate oligomers in polyurethane mol Example p-THF 1000 p 600 mod. PE eth. TMP 7 eth. TMP 20

HEA

IPDI

0.65 0.65 0.35 1.75 2.70 0.65 0.65 1.05 2.45 4 .10 1.30 1.40 2.80 4.80 0.65 0.65 0.70 2 .10 3.40 1.30 0.70 2.10 3.40 The following abbreviations were used in Table 3: p-THF 1000: 1s p 600: mod. PE: eth. TMP 7: eth. TMP 20:

HEM:

I:I

polyoxytetramethylene glycol having a numiber-average molecular weight of 1,000 polyoxypropylene glycol having a numberaverage molecular weight of 600 modified polyether diol ethoxylated trimethyloipropane having 7 ethylene oxide units per trimethylolpropane 414) ethoxylated trimethylolpropane having ethylene oxide units per trimethylo lpropane 2-hydroxyethyl acrylate isophorone diisocyanate 34 Table 4: Chemical properties of the liquid coating agents 1 2 3 4 C1 02 03 Oligomer DBC (coating a.) DBC (oligomer) C C R Funct.

DBC (coating DBC (oligomer): C C R: 1 2.07 0.67 3.39 2.5 3 2.02 0.6 3.78 2.5 4 2.02 0.61 3.73 3.5 5 1.99 0.56 4.07 4 2 2.31 2.25 2 6 1.91 0.69 2.80 3 7 2.01 0.6 3.80 3 concentration of acrylic groups in mol/kg in the coating agent concentration of acrylic groups in mol/kg in the oligomer ratio of acrylic groups of the monomers to acrylic groups of the oligomer determined in the coating agent average acrylic group functionality of the polymer Funct.: 35 Table 5: Mechanical test values of the j 1 j 2 13 coatings 4~ 102 Elongation at break Modulus of elasticity elongation) in M~a Modulus of elasticity elongation) in M~Pa 53 3.1 2.9 48 2.8 2.6 44 2.7 2.5 42 2.5 2.2 56 17 15.71 62 13.5 36 Table 6 Example 2 Example 3 T E*C] Log E 1T U too E I 1 -41 9,204 "39 9.174 .9,191 -38,5 9,161 -39 9,178 -37,5 9.148 -38,5 9,173 -36,5 9,132 -37,5 9,16 -35,5 9,122 -36,5 9.148 -35 9,107 -35,5 9,134 -34 9,092 -34,5 9,122 -32,5 9,074 -33,5 9.099 -32 9,054 -32,5 9,072 31 9,043 -31 9,063 .30 9,032 -30,5 9,045 -29 9,011 -29,5 9,035 -28,5 8,996 -28,5 8,968 -2745 8,977 -28 9,001 I -26,5 8.957 -27 8.981 1 -26 8,945 -26 8,964 I -25 8,921 8,898 -24 8.899 -24.5 8,924 -23 8,883 -23.5 8.908 -22 8,862 -22,5 8.888 -21 8.779 -21,5 8,861 1 '20,5 8,818 -21 8,849 -19.5 8,792 8,829 -18.5 8.714 -19 8.786 -18 8,745 -18 8,775 .17 8,721 -17,5 8,748 -16 8.613 -16,5 8,708 -15 8,656 -15.5 8,693 -14.5 8,636 -14,5 8,669 -13 8,587 -13,5 8,617 -12 8,556 -12,5 8,6 .11,5 8,528 37 Continuation of Table 6 Example 2 Example 3 TEoC) log E TroC) log E -11,5 8,574 .10,5 8,48 -11 8.525 -9,5 8.417 8,511 -8.5 8,415 8.448 -7.5 8,382 8,426 7" 8,327 8,403 .6 8.299 8,35 -5 8,153 -6 8.317 -4 8.205 *7 5-11 8,24 8.208 -3 8.034 -3 8,034 *2 8,109 -2 8,109 -1 8,076 -1 8,076 7.997 7,997 1 7,955 1 95 5 1.5S 7II86 7,86 2,5 7.836 7,836 I 3 7,79 3 i 7,79 4 I 7,681 4 7,681 5 7,654 7,654 6 7,618 6 I 7,618 7,5 I 7s503 7,503 8 7s464 8 7,464 S 7o425 S9 7s425 10 7,311 7,311 11 72 I11 7,275 12 7s231 12 7,231 13 7,185 13 7t185 13,5 7,15 13.5 7,15 14,5 7,099 14,S* 709915,5 7,051 7,051 16 6,999 16 6,999 17,5 6,932 17#5 6,932 18 6,891 38 Continuation of Table 6 Example 2 Example 3 I lC) w tog E LC) iogE

I/

18 6.891 18,5 6.876 18.5 6.876 20 6.815 6.815 20,5 6,796 20,5 6,796 21.5 i 6-757 21,5 0 6,757 22.5 6.735 22.5 6.735 23 6.71 23 6.71 24 6,698 24 6,698 25 6.67 6.67 26 6,638 26 6.638 26.5 6.623 26,5 6.623 28.5 6.491 28.5 6.491 1 30.5 6.483 5 6.483 1 32.5 6.501 32.5 6,501 j 34 6.514 34 ,1 6,514 37.5 6,464 37,5 6.46, 1 38 6,46 38 t, 6.46 39 6,419 39 6.419 40.5, 6.44 40.5 6.44 1 41,5 6,426 41,5 6,426 42,5 6,43 42.5 6.43 1 43 6,409 43 6,409 44 6.454 44 6, 4 5 45 6.423 6,423 46 6,364 46 6,366 47 6.453 47 6.453 1 4E" 246036 It 48 6,395 6,3 59 I 51 6.356 52 6,472 53 6,429 54 6,376 6,383 56 6.434 57,5 6.422 58,5 6.408 6,362 I

I

39 Table 7 Example 4 Example 1 0 Log ET -39 9.332 tog

E

I9 -39 9.395 "38.5 9.oZ .38 9.,33 -37 9.317 "38 9.393 -36 9,306 -36.5 9,39 9,303 o35,5 9,378 -34 9,28 -35 9,378- -33.5 9,276 -34,5 9.377 -32,5 9,265 -33.5 9,378 -31.5 9,251 -32,5 9.363 -30.5 9,232 -31,5 9,356 -29,5 9.223 -31 9,357 .29 9.208 -29,5 9.35 -27,5 9,19 -28,5 9,337 -27 9.17 -28 9,334 -26 9,146 -27,5 9.332 9.134 I -26 9.32 -24 9.119 -25 9,279 -23.5 9, -24,5 "I 9.305 -22,5 907 -24 9.303 -21.5 9,05? -22,5 9,295 -21 9,039 -21 9,267 9.008 -20,5 9.263 -19 8,981 -20 9,261 -18 8,958 "-19.5 9.256 -17,5 8,911 -18,5 9.241 -16.5 8.896 -17" 9,205 8.864 -16,5 9,202 -14.5 8,825 -16 9,199 -13,5 8,792 -15 9, 192 -13 8,765 -13.5 9,136 -12 8.654 -13 9,129 -11 8,689 -12,5 9,125 40 Continuation of Table 7 Example 4 Example I T[COQ log E cC log E 8,662 -11 9,103 8,615 -10 9,044 8,587 "9,5 9,041 8,515 "9 9,037 8,393 -6 8.892 -6 8.448 -5,5 S, 8,921 8.408 -5 8,919 -4 8.321 .5 8,64 -3 8,297 1 8,491 -2 8,22 1,5 S 8,528 -1 8,145 2 8,549 0 8,109 3 8,451 1 7,997 6 8,194 2 7954 9,5 7,827 3 7,829 10 7,94 4 7,837 12,5 7,493 7,722 13.5 7,657 6 7,673 16,5 7.273 7 7,627 17 7,328 7,579 19 7,118 9 7,464 19.5 7,143 10,5 7,364 21,5 6,932 11 7,313 22,5 6,924 12 7,247 23 6,951 13 H 7.213 25 6,817 13.5 7.156 25,5 6, 4 14,5 7a123 27,5 6,741 15.5 7,057 32 6,599 16 7,022 39 6,483 17 6,956 385 18 6,892 42 6,486 19 6.846 42,5 6,519 W 6,789 45g5 it 6.474 41 Continuation of Table 7 Example 4 Example 1 Tc E3 Tog E 7 (CI togE 20.5 0 6,759 45 H A 66477 23 ft 6.617 47,5 6,522 24.5 0 6.566 48.5 6.489 25.5 6,518 51,5 6.53 26.5 0 6.506 54.5 H 6.4-72 27. 5 0 6,491 57. 5 6.542 28.5 0 6,452 5B 6.52 29.5 30.5 N 31 32 H 6,373__ 33 6,302 33.5 6,357__ 34.5 6.329 35.5 6,286 36.5 6,283 37 6,296 38,5 6,269 39 01 6.256 11 41 42 6.247 42,5 11 6.232 43,5 "1 6.181 44 6.262 6,215 46 6.17 46,5 6,158 47,5 60166_____ 48.5 61 6.067- 49,5 11 6.081 11 51 6.07 53 53.5 6,114 54.5 6,185 6j 073 56,5 6,083__ 57 6,132 558 6,105 59 6,125 59,5 6,142 60,5 6202 1 42 Table 8 Comparative Example 2 Comparative Example 3 Comparative Example 1 T logE C1T C] logE T L'C] Log E -40,5 9.237 -38 9.363 -38.5 9.403 -41.5 9.264 -37.5 9.366 -38 9.408 9.28 -37 9.37 -37.5 9.41 -37.5 9.223 -36,5 9.37 -37 9.409 -37 9.241 J -36 9.368 -36.5 9.408 -37.5 9.257 l -35.5 9,367 -36 9.406 -38 9.267 I -34 9.341 -35 9.403 9.24 1 -33 9.334 -33.5 9.384 -33 5 9.22 -32.5 9.333 -33 9.382 -33 9.229 -32 9.33 -32.5 9.382 -31 9.203 -30.5 9.312 -32 9.38 -30.5 9.2 -28.5 9.291 -31 9.376 9.199 -28 9,294 -29,5 9.355 -29.5 9.203 -27.5 9.289 -28.5 9.353 -27.5 9.175 j -27 9.287 -28 9.354 -26,5 9.157 1 -26 9.264 -27.5 9.351 -26 9.159 I -25 9.255 -26 9.327 -25.5 9.158 1 -24.5 9.251 -24.5 9.317 -23.5 9.133 -23,5 9.251 -24 9.317 -22.5 9.116 -22 9,215 -23.5 9.317 -22 9,115 -21 9.207 -23 9 313 "-21.5 9.117 -205 9,206 -22.5 9.313 -21 9.117 I -20 .202 -21 9.279 -19 9.075 -19 9.186 -20 9,274 -18.5 H 9.071 j -17.5 9,156 -19.5 9.273 -18 9.071 -17 9,155 -19 9.271 -17,5 9.07 165 9.153 -18 9.256 -16 9,047 -15 9-125 -16.5 9.226 8.989 -14 9.1 -16 9-222 -14.5 9.02 -13.5 9.099 -15.5 9.22 -14 o 9.02 -13 9.096 -14.5 9.207 -13.5 9.02 -11.5 9.061 -13 9.165 43 Continuation of Table 8 Comparative Example 2 Comparative Example 3 Comparative Example 1 T 0 °C log E T COC 3 log E T [O°C log E -11.5 8.967 -11 9.048 -12.5 9.162 -11 8.961 -10.5 9.045 -12 9.16 -10,5 8.96 -9 9.007 -11.5 9.157 8.958 8 8.99 -9.5 9.085 8.917 1 -7.5 8.988 -8.5 9.081 8.898 -7 8.,987 *8 9.08 -7 8.894 -5.5 8.922 -7.5 9.079 8.896 -5 8.917 -6 8.998 8.846 -4.5 8.918 -5 8.982 -4 8.83 -3.5 8.91 -4.5 8.986 8.798 -1,5 8.822 -4 8,985 -3 8.825 -I 8,83 -2 8.827 -1 8.741 5 8.83 -1.5 8.886 5 8.744 1 8.757 -1 8.888 0 8.747 2 8.717 5 8.703 8.708 2.5 8,725 1 8.761 3 8,62 3 8.728 1.5 8.768 8.635 5 8.531 2 8.767 4 8.643 6 8.556 5 8.573 6 8.508 6.5 8.577 7 8.422 8.501 7 8,591 9 8.372 7 8.52 7.5 8.597 12.IL5 8.97 8,524 10.5 8.266 16.5 7,757 8.245 11 8.41 19 N 7.359 10.5 8.331 12.5 8.04 20 7,414 11 .363 14 8.164 20,5 7.468 10.5 8,389 14.5 8.209 23.5 7.158 12.5 .101 16,5 7,791 23 7.209 14 N 5,132 17 7.982 23.5 7.244 14.5 8.165 17.5 5 B.023 26 M 6.909 14 8.196 20,5 7-679 26,5 6.989 16 ._067 21 7.806 26 6.911 17 5 7,908 23'5 7.476 29.5 6.844 44 Continuation of Table 8 Comparative Example 2 Comparative Example 3 Comparative Example 1 T 0 togE T [*C1 lrj E T *log E I

F

18 7.954 24 7,534 29 6.871 18.5 8.016 26 7.256 31.5 6.685 21 7.666 27 7.229 32,5 6.698 21.5 7.722 26,5 7.289 32 6.733 21 7.774 27.5 7.297 34.5 6.391 23.5 7.488 30.5 7.011 35" 6-604 24.5 7.452 30 7.072 35.5 6.58- 7 498 30,5 7 102 38 6.464 24,5 7,541 33.5 6.79 38.5 6.554 26.5 7,363 34 6.828 38 N 6.541 27,5 N 7.?73 33.5 N 6.873 40.5 a 6.464 28 7.312 34 0 6.897 41.5 a 6.469 28.5 7.313 36 a 6.712 41 6.502 30.5 7.081 37 6.674 43 6.497 31 7,.115 36.5 6.71 45 6.449 30.5 7.162 39 6.59 44.5 6.432 33 6.988 47.5 6.299 45 6.462 34,5 6.971 50.5 6.309 47.5 6.432 34 7.013 51 6.309 48.5 6r452 37 6,85 54.5 6.299 48 A.417 38 6.831 55 6.389 51,5 6.339 37.5 6.86 58 6.29 52 6.42 38.5 6.795 57.5 6.374 51 6.368 40.5 6.767 58.5 N 6.425 54 6.421 41 6,776 6.466 40.5" 6.773 54.5 6.393 42.5 "6.744 6«19 44 6.712 6.388 44.5 6.716 58 6.394 44 N 6.714 6.382 46 6.681 58.5 6.453 47.5 6.688 47 6.668 48 50.5" 6.657 51 50.5 6.641 2 N 6 6 8 54 N 6.646 54,5 53.5 6.637 55.5N 57.5 6.644 58 6,636 57 58.5 6.676_ 60.5 6.648

Claims

1. A radiation-curable oligomer having several ethyl- enically unsaturated end groups and several urethane is and/or urea groups per molecule, which oligomer 4 iaan -be prepared from a) at least one hydroxy- and/or aminofunctional com- pound having a functionality between 3 and 4 and a number-average molecular weight of more than 750 to 4000, polyester polyols being excepted, b) at least one compound having 2 hydroxyl and/or amino groups per molecule and a number-average molecular weight between 200 and 4000, poly- esterdiols being excepted, c) at least one monoethylenically unsaturated compound having a group containing one active hydrogen atom per molecule and having a number- average molecular weight between 116 and 1000, and d) at least one aliphatic and/or cycloaliphatic diisocyanate, which comprises using components a to d in amounts such that 46 1) the molar ratio of component a to component b is between 0.1:1 and 1.1:1, 2) the molar ratio of component c to component a is between 2:1 and 10:1, and 3) the equivalent ratio of the isocyanate groups of component d to the hydroxyl and/or amino groups of the sum of components a to c is between 0.9 and

2. A radiation-curable oligomer as claimed in claim 1, wherein compounds having a functionality of 3 are used as component a.

3. 1 radiation-curable oligomer as claimed in claim 1 or 2, wherein compounds having a number-average molecular weight of more than 750 to 2000 are used as component a and/or compounds having a number-average molecular weight between 600 and 2000 are used as component b and/or compounds having a number-average molecular weight between 116 and 400 are used as component c.

4. A radiation-curable oligomer as claimed in any one of claims 1 to 3, wherein components a to d are used in amounts such that 1_7 1) the molar ratio of component a to component b is between 0.1 and 0.8 and/or 2) the molar ratio of component c to component a is between 2.5 and

5. A radiation-curable oligomer as claimed in claim 4, wherein the oligomer has an acrylic group content of 0.45 to 0.63 mol/kg.

6. A radiation-curable oligomer as claimed inT6ne of claims 1 to 5, wherein an ethoxylated triol having LO a number-average molecular weight of 1000Q a 4 belae used as component a.

7. A radiation-curable oligomer as claimed inl1ne of claims 1 to 6, wherein a mixture comprising b l b 2 b 2 1 b 2 b 23 0 to 90 mol of a polyetherdiol and 100 to 10 mol of a modified polyetherdiol composed of at least one polyetherdiol at least one aliphatic and/or cycloaliphatic dicarboxylic acid and at least one aliphatic, saturated compound having epoxy group and 8 to 21 C atoms per molecule, f-T in which the sum of the amounts of components b i and b. and the sum of the amounts of components b3 to b 23 is in each case 100 mol is pres4ably. used as component b.

8. A radiation-curable oligomer as claimed in6,ne of claims 1 to 7, which has been prepared by 1) carrying out the polyaddition reaction of com- ponents a to d up to a conversion of more than of the NCO groups, in which components a to d have been used in amounts such that the equivalent ratio of the isocyanate groups of component a to the hydroxyl and/or amino groups of components a to c is 1:1 and 2) the polyaddition reaction of components a to d has been continued with addition of more of component c up to a conversion of more than 99 of the NCO groups.

9. A radiation-curable coating composition, which contains at least one radiation-curable oligomer as claimed in ne of claims 1 to 8.

10. A radiation-curable coating composition as claimed in claim 9 iigomo a.n ol the buffer coating of optic glass fibers, which contains A) 10 to 78 of at least one radiation-curable oligomer as claimed in one of claims 1 to 8, B) 0 to 60 by weight of at least one further ethylenically unsaturated oligomer, C) 20 to 50 by weight of at least one ethylenical- ly unsaturated monomeric and/or oligomeric com- pound, D) 2 to 8 by weight of at least one photoinitiator and E) 0 to 4 by weight of conventional auxiliaries and additives, the by weight given being in each case relative to the total weight of the coating composition.

11. A radiation-curable coating composition as claimed in claim 9, which contains A) 15 to 75 of at least one radiation-curable oligomer as claimed in one of claims 1 to 8, B) 0 tio 50 by weight of at least one further ethylenically unsaturated oligomer, C) 23 to 35 by weight of at least one ethylenical- ly unsaturated monomeric and/or oligomeric compound, D) 3 to 5 by weight of at least one photoinitiator and E) 0.5 to 2.0 by weight of conventional auxilia- ries and additives, the by weight given being in each case relative to the total weight of the coating composition.

12. A radiation-curable coating composition as claimed in claim 10 or 11, which contai-J a further ethyle- nically unsaturated polyurethane as component B.

13. A process for the coating of a glass surface, 44i. partioular -C glas.io fioA, in which 1) a radiation-curable primer is applied and cured by means of UV or electron radiation and 2) a radiation-curable top coat is applied and cured by means of UV or electron radiation, 51 which comprises using a radiation-curable coating composition as claimed in any one of claims 9 to 12 as primer and/or topcoat.

14. A process as claimed in claim 13 in which the glass surface is the surface of glass fibre.

An optic glass fiber coated with a radiation- curable coating composition as claimed in any one of claims 9 to 12.

16. A radiation-curable oligomer substantially as hereinbefore described with reference to any one of the foregoing examples apart from the comparative examples.

17. A radiation-curable coating composition substantially as hereinbefore described with reference to any one of the foregoing examples apart from the comparative examples.

18. A process for the coating of a glass surface substantially as hereinbefore described with reference to any one of the foregoing examples apart from the comparative examples.

19. An optic glass fiber coated with a radiation- curable coating substantially as hereinbefore described with reference to any one of the foregoing examples apart from the comparative examples.

A radiation-curable oligomer substantially as hereinbefore described with reference to any one of the accompanying drawings.

21. A radiation-curable coating composition substantially as hereinbefore described with referenc'a to any one of the accompanying drawings. 52

22. A process for the coating of a glass surface substantially as hereinbefore described with reference to any one of the accompanying drawings.

23. An optic glass fiber coated with a radiation- curable coating substantially as hereinbefore described with reference to any one of the accompanying drawings. Dated this 28th day of January 1994 BASF LACKE FARBEN AKTIENGESELLSCHAFT By its Patent Attorneys: GRIFFITH HACK CO Fellows Institute of Patent Attorneys of Australia i i i i i t i e a at i *it DECLARATION REFERRED TO IN ARTICLE 19 The enclosed new patent claims 1 to 14 are filed, which have been delimited from the state of the art. To delimit the subject of the application from EP-A-228,854, the new claim 1 was restricted by means of a positively formulated disclaimer to radiation curable oligomers, which can be prepared with the use of at least one hydroxy- and/or amino-functional compound having a functionality of between 3 and 4 (component a) and a number-average molecular weight of more than 750. Corre- spondingly, claim 3 was also restricted to oligomers, in the preparation of which compounds naving a number- average molecular weight of more than 750 have been used as component a. To delimit the subject of the application from US-PS-4,131,602, the new claim 1 was additionally restricted by means of a disclaimer to radiation-curable oligomers, from the preparation of which polyesterpolyols as component a and as component b are excepted. The new claims 2 and 4 to 14 correspond to the originally filed patent claims 2 and .4 to 14.