GB1559319A

GB1559319A - Unsaturated polyester resin binders

Info

Publication number: GB1559319A
Application number: GB38805/76A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1975-09-18
Filing date: 1976-09-20
Publication date: 1980-01-16
Also published as: DE2541641C3; DE2541641A1; CH631476A5; DE2541641B2; NL7610299A; ATA686276A; AT356904B; JPS5238597A; FR2324669A1; IT1070724B; BE846356A; JPS5921910B2; FR2324669B1

Abstract

Unsaturated polyesters made from A) at least one alpha , beta -monoolefinically unsaturated dicarboxylic acid and/or polycarboxylic acid which is free from polymerizable aliphatic multiple bonds, B) at least one polyhydric alcohol, C) at least one co-condensable acrylic compound and D) at least one polycyclic compound which has a norbornane structure and is bonded via a functional group in the series consisting of carboxyl, hydroxyl and primary amino groups or via a majority of only similar functional groups from this series, are employed as binders in binder systems for the production of radiation-curable coatings, adhesives, knifing fillers or preferably printing inks. The printing inks produced using the binders have a good shelf life and a high curing rate on irradiation, which gives, for example, drying rates of greater than 400 m/min, the prints produced having high gloss and colour density (ink density, saturation). The unsaturated polyesters are prepared by reacting components A), B) and D) with one another in a first step, giving a polyester resin containing hydroxyl groups or carboxyl groups, and then reacting the functional groups thereof with component C), co-condensible acrylic compounds, in a second step.

Description

(54) UNSATURATED POLYESTER RESIN BINDERS (71) We, HOECHST AKTIEN GESESLLSCHAFT, a Body Corporate organised under the laws of the Federal Republic of Germany of 6230 Frankfurt/Main 80, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to radiation hardenable binders suitable for coating systems, in particular solvent-free printing inks.

In general coating systems of this kind comprise a binder which generally contains ethylenic carbon-carbon double bonds, a reactive diluent which copolymerisable therewith, at least one sensitizer and usually, in the case of printing inks, a pigment.

Coating systems of this kind should desirably harden, i.e. cross-link, rapidly under the effect of high energy radiation, preferably ultra-violet light, and in the case of printing inks should form a hard but flexible film with good adhesion, high gloss, good pigment wetting and thus a high color intensity. Furthermore, the inks should be capable of being processed satisfactorily in printing machines, particularly offset machines, and should have an adequate shelf life.

The use of radiation hardenable ethylenically unsaturated resins in coating compositions, adhesives and printing inks is known. Under the effect of high energy radiation, particularly when mixed with photosensitizers, these resins polymerise.

However, the standard commercial products frequently are unsatisfactory with regard to their pigment wetting and shelf life, in that they do not wet pigments sufficiently or they thicken when stored therewith. Moreover, the inks produced therefrom sometimes have poor printing properties. Thus, for example, acrylated epoxy resins tend to "pull", i.e. the printing ink sticks to the rollers or to the rollers and paper, and this can sometimes result in tearing of the paper.

Hardenable synthetic resins in admixture with acrylamide compounds often have the disadvantage that they have too high a viscosity. They therefore have to be mixed with a relatively large amount of reactive diluent as a result of which the drying speed suffers. Frequently, crystallisation and phase separation occurs in the printing ink making processing more difficult or impossible.

Moreover, systems based on polyacrylates obtained by reacting polyhydric alcohols with dicarboxylic acids and then reacting the product with acrylic or methacrylic acid have been proposed.

These systems generally have more satisfactory processing characteristics and have a high gloss but they do tend to have certain disadvantages, namely their drying times are too long and they thus do not meet the requirements of modern practice.

The binders for radiation hardenable polyester systems described hitherto generally have at least one easily polymerisable carbon-carbon double bond, i.e. they are a,/3-olefinically unsaturated.

However, unsaturated polyester resin systems have also been proposed in which the double bond is in an isocyclic ring.

Typical resins of this kind have a linear construction and contain substituted or unsubstituted unsaturated bicyclo-(2,2, 1)heptenyl-(2) groups either in the polymer chain or in side chains. However, when subiected to radiation, it is found that these resins harden unsatisfactorily.

Further unsaturated polyesters, hardenable by free radical polymerisation mechanisms, are known which are prepared from polyhydric alcohols and a,ss- olefinically unsaturated polycarboxylic acids, optionally a proportion of these unsaturated acids being replaced by saturated aliphatic and/or aromatic polycarboxylic acids, and which additionally comprise bi- or tricyclic dihydroxy compounds containing an endomethylene group, for example, dimethylol dicyclopentadiene and dicyclodicarboxylic acids which contain an endomethylene group, e.g.

hexachloroendomethylene tetrahydrophthalic acid. Unsaturated polyesters are also known wherein the diol rather than the acid components are partially replaced by di- or tricyclic diols, for example dimethylol bicyclo-(2,2, 1)heptane and dimethylol tricyclo-(5,2,1,026)- decane. The presence in the unsaturated polyester of these compounds containing dior tricyclic endomethylene groups brings about an increase in the hardening speed and thus a reduction in the time taken to reach a non-tacky state.

Instead of the unsaturated di- or tricyclic components, it has also been proposed to use polyesters obtained by reacting a saturated dicyclopentadiene derivative, e.g. 3(4),8(9)-dihydroxymethyltricyclo (5,2,1 ,0Z 6)-decane, with unsaturated dicarboxylic acids. These polyesters may also be processed, like styrene copolymers, to form solvent-free rapid drying enamels, but cannot be subjected to UV hardening.

Resins hardenable by the effect of high energy radication have also been described which consist of a mixture A) of an unsaturated polyester, B) a norbornene carboxylic acid derivative and C) optionally a copolymerisable vinyl monomer.

Component B) may also be esterified via the acid group with an alcohol containing a tricycloalkylene group e.g. a tricyclo (5,2,1,02-6)-dec-3-ene group. This mixture polymerises during the hardening process, whilst the copolymerisable monomer is incorporated into the resin.

Although some of the aforementioned binders have found practical application, there is still a search for products having improved properties. Thus, it is desired to improve the processability and shelf life of pigment-containing printing inks and moreover to increase the gloss of the print.

According to the present invention there is provided an unsaturated polyester binder which comprises a reaction product of A) an acid component comprising one or a mixture of a,p-mono-olefinically unsaturated dicarboxylic acids or polycarboxylic acids free from polymerisable carbon-carbon multiple bonds or functional derivatives thereof, B) a polyhydric alcohol, C) a compound containing at least one norbornane ring system with a 5 membered carbon ring fused therewith and having one or more identical substituents selected from carboxyl, hydroxy and amino groups, and D) an acrylic compound which is capable of condensing with at least one of components A) to C).

The new binders according to the invention are generally hardenable with UV radiation and have improved properties over the radiation hardenable binders used heretofore. They may be prepared by a process which comprises reacting in a first stage components A), B) and C) to produce a polyester product which is subsequently reacted in a second stage with D) an acrylic compound which is co-condensable therewith.

The polyester resin intermediate product may contain excess hydroxy groups or excess carboxyl groups as the reactive groups. In the second stage this polyester resin, which may or may not be unsaturated, undergoes an esterification, transesterification or etherification reaction between the excess reactive groups and the acrylic compound.

Polycarboxylic acids free from aliphatic carbon-carbon multiple bonds which may be used as component A) are, for example, saturated aliphatic and cycloaliphatic polycarboxylic acids with 4 to 13 carbon atoms, e.g. succinic acid, dimethylsuccinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid and hexahydrophthalic acid, and aromatic polycarboxylic acids with 8 or 9 carbon atoms, e.g. the various phthalic acids and trimellitic acid. Mono-olefinically unsaturated dicarboxylic acids which may be used are, for example, aliphatic unsaturated acids with 4 or 5 carbon atoms e.g. maleic, fumaric, itaconic, mesaconic, citraconic and chloromaleic acid.

If desired the polyesters according to the invention can be modified by incorporation of further acid components, in particular benzophenones substituted by at least one carboxyl group may be incorporated in admixture with component A) and then act as internal sensitisers, fatty oils and/or unsaturated fatty acids, those having a conjugated diene system, e.g. 9,11-ricinoleic acid and/or 10,12-linoleic acid, being preferred, and saturated fatty acids may be incorporated to act as internal plasticisers.

The proportion of modifying acid components should generally be not more than 30", preferably up to 20 , and particularly up to l0;, based on the total weight of acid component A).

Preferred polyhydric alcohols which may be used as component B) are di- to tetrafunctional, saturated or olefinically unsaturated alcohols with up to 15 carbon atoms, e.g. ethanediol, the various propane, butane-, pentane- and hexane-diols, dimethylolcyclohexane, bis-(4hydroxycyclohexyl)-methane and -propane, A2,3-butenediol- 1,4, glycerol, trimethylolethane and -propane and pentaerythritol. Mixtures of these polyhydric alcohols may also be used.

Alcohols containing only primary hydroxy groups are preferred, particularly trimethylolpropane and ethanediol.

Acrylic compounds which may be used as component D) are those which can react with the functional groups of the polyester intermediate product of components A) to C). Preferred are acrylic and methacrylic acids and their functional derivatives, for example their anhydrides and acid chlorides, and also hydroxyalkyl acrylates and methacrylates with up to 3 carbon atoms in the alkyl group, e.g. A- hydroxyethyl acrylate and ,B- and yhydroxypropyl acrylates and the corresponding methacrylates, and Nalkylolacrylamides and -methacrylamides with up to 4 carbon atoms in the alkyl group, e.g. N-methylolacrylamide.

Condensation of the acrylic compound may be effected via transesterification of the polyester intermediates containing hydroxy groups with suitable esters of acrylic and methacrylic acid, e.g. alkyl and hydroxyalkyl esters. This however, results in the alcohol group being split off and is thus less preferred. The proportion of acrylic compounds incorporated into the binder is generally from 10 to 50%, preferably more than 20% by weight, based on the reaction product of components A) to D), i.e. the polyester resin product of the second step.

Compounds which may be used as component C) of the binder are endocyclic compounds substituted with carboxyl, hydroxy and amino groups, e.g. tricyclo (5,2,1 ,026)-decan-3(4)-carboxylic acid

tricyclo-(5,2, I 6)-decan-3(4),8(9)- dicarboxylic acid

tricyclo-(5,2,1,02.6)-decan-2-carboxylic acid

8,8'-di-[tricyclo-(5,2, 1,026)-decyl] ether-4,4"- dicarboxylic acid

8-hydroxy-4(5)-hydroxymethyl-tricyclo- (5,2,1,02.6)-decane

8(9)-hydroxytricyclo-(5,2, 1,02 6)-decane

3,4,8(9)-trihydroxytricyclo-(5,2, 1 ,02,6) decane

3,4-dihydroxytncycio(5,2, 1,026)-decane

3(4)-hydroxymethyltricyclo-(5,2, 1,02.6)~ decane

3(4),8(9)-diaminomethyltricyclo-(5,2, 1 ,02.6) decane

3(4)-aminomethyl-tricyclo-(5,2, 1 ,0286) decane

and 3(4),8(9)-diaminomethyl-tricyclo (5,2, 1,026)-decane

However, compounds having a 5membered ring containing a carbon-carbon double bond fused to the norbornene ring system, for example 8(9)-hydroxy-tricyclo (5,2,1 ,026)-dec-3-ene

and 5-hydroxy-tricyclo-(5,2, 1 ,02,6)-dec-3-ene

are also suitable for the preparation of the polyester binders according to the invention.

These compounds of component C) may be used either alone or in admixture.

Generally, however, they are obtained by their normal preparative routes in the form of isomeric mixtures and are thus used in this form for the preparation of the binders according to the present invention.

The content of compounds of component C) incorporated into the binder is generally at least 0.5%, preferably from 3 to 30% by weight, based on the reaction product of components A) to D), i.e. the modified polyester resin obtained in the second step.

As discussed hereinbefore the polyester intermediate product may contain an excess of hydroxy or carboxyl groups.

The polyesters containing hydroxy groups appropriately have hydroxy numbers (determined according to DIN standard 53240) in the range from 100 to 1000, preferably from 200 to 800, most preferably from 400 to 600, and the polyester containing carboxyl groups have acid numbers (determined according to DIN standard 53402) in the range from 100 to 800, preferably from 200 to 600. At the end of the reaction with the acrylic compounds it is preferred that at least 2%, advantageously from 10 to 35% ef the reactive groups do not react. The resin is then easier to prepare since it does not have such a great tendency to cross-linking reactions and thus to undesirable premature gelatinisation and, moreover, has better pigment wetting qualities.

The viscosity of the finished polyester resin binder is generally in the range from 100 to 800 P (200 C, rotoviscosimeter) although it is also possible to use polyesters with higher viscosities, for example those with viscosities of up to 1500 P. Generally, however, a low viscosity is particularly advantageous for the further processing of the polyester.

The polyester resins are appropriately prepared in the first step under the conditions conventionally used for polycondensation resins, e.g. by condensation in a melt, by esterification with azeotropic distillation of the water formed during the reaction, or by transesterification. Towards the end of the esterification, which generally takes place at a reaction temperature in the range from 160 to 2500C, it is advisable to work under reduced pressure, at least for a short time, in order to distil off water, any unreacted volatile starting materials and low molecular weight reaction products. Subsequently, at least one acrylic compound is added to this resin and further esterification or etherification, which may be complete or partial, of any free hydroxy or carboxyl groups takes place under the conditions described further hereinafter.

Whereas, in the first step, no polycondensation catalysts are generally used, in the second step it is convenient to work in the presence of a catalyst, for example sulphuric acid, hydrochloric acid, benzenesulphonic acid, p-toluenesulphonic acid and methane-sulphonic acid. The catalysts are generally added in quantities of from 0.1 to 5%, preferably 0.5 to 2% by weight, based on the total quantity of the reaction components and are equally suitable for esterification and etherification reactions.

In the second process step, it is also advantageous to work in the presence of an entrainer, for example cyclohexane, benzene, toluene, xylene, petroleum fractions with an appropriate boiling range, e.g. n-hexane, trichloroethylene and isopropyl ether. The second stage is preferably effected at a reaction temperature in the range from 70 to 120"C, depending on the type and quantity of retarder used. It is sometimes advisable to work under reduced pressure. The course of the reaction can be monitored by determining the quantity of water formed and the reaction can be regarded as complete when more than 95 /n of the theoretical quantity of water has been separated off.

In order to avoid polymerisation reactions occurring in the second step in which unsaturated compounds are present a polymerisation inhibitor is generally added, conveniently in a quantity of 0.1 to 5%, preferably 0.5 to 2% by weight, based on the total weight of reaction components.

Typical polymerisation inhibitors are, for example, quinone derivatives e.g.

hydroquinone and p-benzoquinone, substituted phenols e.g. p-tert.butyl-phenol.

p.tert.butyl-pyrocatechol; 2,6-ditert.butylcresol and p-methoxyphenol, amines e.g. diphenylamine, sulphur and sulphur compounds e.g. thiosemicarbazide and phenothiazine.

After the reaction, any azeotropic dehydrating agent used can be distilled off under reduced pressure preferably in a thinlayer or rotary evaporator.

The binders according to the invention may be formulated into coating systems by admixture with one or more reactive diluents, sensitisers and/or pigments. Such compositions find particular application as printing inks, coating materials, adhesives and, if fillers are also added, as trowelling compounds. The binder imparts to the composition good storage properties and a high hardening speed when irradiated with UV light. Printing ink drying speeds of more than 400 m/min. can for example, be obtained, whilst the print produced therewith has high gloss and colour intensity.

Although irradiation with UV light is adequate to give a high hardening speed, irradiation with higher energy radiation sources, e.g. an electron beam, may also be used.

The viscosity of the composition can be adjusted as required for the particular intended use by adding one or more reactive diluents for example in amounts of to up to 60% by weight, based on the total composition. Acrylic and methacrylic acid esters of mono- and/or polyhydric alcohols, e.g. 2-ethylhexanol, ethane diol, the various propane- and butanediols, trimethylolpropane and pentaerythritol, are advantageously used as reactive diluents, alone or in admixture.

A sensitiser may be added to the composition to increase its hardening speed.

Typical sensitisers are, for example, ketones e.g. benzoin, benzophenone and Michler's ketone, benzoic acid esters, ethers, ketals, chlorinated aromatic compounds, and anthraquinone derivatives, combinations of benzophenone and Michler's ketone, e.g. in a 1:1 ratio, being preferred. The quantity of sensitisers is generally 2 to 20, preferably 3 to 10% by weight, based on the total composition. The addition of sensitisers can be omitted wholly or partially if an internal sensitiser has already been incorporated into the polyester as described hereinbefore. As already mentioned, benzophenones substituted with carboxyl groups are preferred for chemical incorporation.

For the preparation of printing inks and pigmented enamels from 5 to 40%, preferably 8 to 20% by weight, of pigment based on the total composition, is appropriately added. Suitable pigments are the known compounds conventionally used in the dye and printing ink industry, for example organic pigments, e.g. pigment and dyes of the azo series, complex pigments and dyes, anthraquinone dyes and quinacridone pigments, carbon black and inorganic pigments e.g. titanium dioxide, iron oxide and cadmium sulphide selenide.

The pigments may be incorporated using conventional apparatus used in the dye and printing ink industries, e.g. with a triple roller mill.

The binders according to the invention may also be combined with other resin binders in order to obtain certain special properties for example in amounts of up to 60 by weight, preferably 3 to 20% by weight, based on the total composition.

Resins with which the binders according to the invention may be combined include, for example, acrylated epoxy resins, unsaturated polyesters, acrylamide containing systems, alkyd resins, cyclorubber, hydrocarbon resins based, for example, on cyclo- or dicyclopentadiene, colophony, acrylate and/or maleate resins, phenol-modified colophony resins provided that they are high-melting types compatible with aliphatics, and phenolic resins.

Maleate resins, for example, may be added to printing inks to improve the processing characteristics in offset machines, without negatively affecting the drying speed.

The following Examples serve to illustrate the polyester binders according to the invention. The preparation of the binders and of printing inks containing them was carried out as follows:- Preparation of Binders Step 1 The carboxylic acid and the alcohol components are intimately mixed with the polycyclic compound and any other additive in a flask fitted with a stirrer, thermometer and water separator, and the mixture is kept at a temperature in the range from 160 to 2500 C, with stirring, until the theoretical quantity of water has separated off.

Step 2 The polyester resin formed in the step 1 is dissolved in an azeotropic dehydrating agent and the acrylic compound, an inhibitor and catalyst are added. The mixture is heated to 70120 C and the azeotropic dehydrating agent is then distilled off, if necessary under reduced pressure. After removal of water by azeotropic distillation, the dehydrating agent is recycled into the reaction mixture.

The catalyst is then washed out of the resin solution in known manner, after which solvent is distilled off under reduced pressure at 50 to 70"C.

Preparation of Printing Inks The viscosity of the resin binder is first adjusted to about 200 P with trimethylolpropane triacrylate and 15% of pigment and 8% by weight of a mixture of benzophenone and Michler's ketone as sensitiser are then added. The increase in viscosity produced by the incorporation of these additives is counteracted by addition of a further portion trimethylolpropane triacrylate until the viscosity is 400 P.

In the following Examples, T indicates parts by weight.

Example 1 348 T of trimethylolpropane are condensed with 292 T of adipic acid and 36 T of a compound of formula

at - 200 C, under the aforespecified conditions. 75 T of water are separated off.

100 T of the resin obtained (OH number 330) are dissolved in 150 T of toluene and 36.7 of acrylic acid, 0.75 T of 2,6-ditert.butylcresol and 1 T of conc. sulphuric acid are then added. The mixture is reacted at 950C under slightly reduced pressure. After separation of the water which forms solvent is distilled off and a yellowish resin with a viscosity of 647 P (determined at 20"C with the rotoviscosimeter made by Messrs Gebriider Haake) is obtained.

Comparison Example 1 Example I is repeated, but without adding the compound formula I. The OH number of the polyester intermediate produced is 350. A colourless resin is obtained with a viscosity of 250 P.

Comparison Example 2 Example I is repeated but instead of the compound of formula I and equimolar quantity of benzoic acid is added. The OH number of the polyester intermediate produced is 340. A light coloured resin is obtained with a viscosity of 470 P.

Comparison Example 3 Example I is repeated but instead of the compound of formula I an equimolar quantity of acetic acid is added. The OH number of the polyester intermediate produced is 340. 200 T of toluene are added in step 2 of the process. A colourless resin is obtained with viscosity of 157 P.

Example 2 450 T of trimethylolpropane are condensed with 263 T of adipic acid and 54 T of a compound of formula I at 2000C. 70 T of water are separated off. 100 g of the resin produced (OH number 490) are dissolved in 150 T toluene and 43.8 T of acrylic acid, and 0.75 T of 2,6-di-tert.-butylcresol and I T df concentrated sulphuric acid are added. The mixture is reacted as in Example 1. After azeotropic removal of the water formed, the solvent is distilled off under reduced pressure, and a slightly yellowish resin with a viscosity of 753 P is obtained.

Example 3 450 T of trimethylolpropane, 263 T of adipic acid and 58 T of a compound of formula

are condensed at 2000 C. 65 T of water are separated off. 100 T of the resin produced (OH number 560) are dissolved in 150 T of toluene and 43.8 T of acrylic acid and, after the addition of I T of 2,6-di-tert.butylcresol and 1.5 T of concentrated sulphuric acid, the mixture is reacted as in Example 1.

When no more water separates, the solvent is distilled off and a slightly yellowish resin with a viscosity of 725 P is obtained.

Example 4 472 T of hexanediol-1,6 are condensed with 876 T of adipic acid and 80 T of a compound of formula I at 200"C. under the aforespecified conditions. 132 T of water are separated off. 100 T of the resin produced (acid number 210) are dissolved in 150 T of toluene and 43.4 T of 2hydroxyethyl acrylate, 0.75 T of 2,6-ditert.butylcresol and 1.5 T of conc. sulphuric acid are added. The mixture is reacted at 95"C under slightly reduced pressure. After separation of the water formed the solvent is distilled off under reduced pressure, and a slightly yellowish resin with a viscosity of 720 P is obtained.

Example 5 118 T of hexanediol-1,6 are condensed with 124 T of ethyleneglycol, 292 T of adipic acid and 36 T of a compound of formula I at 2000C. 75 T of water are separated. 100 T of the resin produced (OH number 450) are dissolved in 150 T of toluene, and 60 T of Nmethylolacrylamide, 1.5 T of 2,6-ditert.butylcresol and 2.0 T of conc. sulphuric acid are added. The mixture is reacted at 95"C under slightly reduced pressure. After separation of the water formed, the mixture is worked up as in Example 1, and a slightly yelllowish resin with a viscosity of 850 P is obtained.

Printing inks were produced from the binders prepared in the Examples as described hereinbefore and were tested by means of the following printing tests.

Printing Tests In order to determine the drying speed of the individual printing inks, sample prints were produced on white paper with an average application of 1.5 g/m2 of printing ink and irradiating with a mercury vapour pressure lamp at 80 watts/cm at various running speeds. The drying speed is given as the radiation time required to dry i.e. crosslink, irradiated print to such an extent that when a sheet of white paper is applied.

under a contact pressure of 130 kp/cm2, there is no transfer of ink on to the white paper (the so called "off setting test", carried out using a print testing apparatus made by Messrs. Diirner, Peissenberg, Federal Republic of Germany). The gloss was assessed visually. The results of the printing tests are given in the Table which follows: TABLE Binder prepared in Pigment Drying speed Example No. C.I. number ca. m/min. Gloss Pigment Yellow 126 180 excellent Pigm. Blue 15 270 very good comparison I Pigm. Yellow 126 40 good Pigm. Blue 15 40 good comparison 2 Pigm. Yellow 126 80 satisfactory Pigm. Blue 15 80 moderate comparison 3 Pigm. Yellow 126 20 (not very good Pigm. Blue 15 20 }the print bronzes 2 Pigm. Yellow 126 240 good Pigm. Blue 15 300 good 3 Pigm . Yellow 126 190 very good Pigm.Blue 15 210 good The printing inks containing the binder prepared in Example I have a particularly high gloss and good drying properties and those containing the binder prepared in Example 2 have a good gloss and very good drying properties. In contrast, the inks containing the binders prepared in the comparison Examples have less good drying properties and some have a very inferior gloss. It makes no difference whether the binder is unmodified (comparison Example I ) or modified with an aromatic (comparison Example 2) of aliphatic (comparison Example 3) acid. The inks prepared with the binder of Example 3 have a high gloss and good drying properties.

The binders according to the invention are distinguished by high storage stability, i.e. in a six-month period they show no gel formation, no concentration and no change in viscosity. Similarly the storage stability of the mixtures prepared with the binders is also excellent.

WHAT WE CLAIM IS: I. An unsaturated polyester binder which comprises a reaction product of A) an acid component comprising one or a mixture of a,-mono-olefinically unsaturated dicarboxylic acids or polycarboxylic acids free from polymerisable carbon-carbon multiple bonds or functional derivatives thereof, B) a polyhydric alcohol, C) a compound containing at least one norbornane ring system with a 5 membered carbon ring fused therewith and having one or more identical substituents selected from carboxyl, hydroxy and amino groups, and D) an acrylic compound which is capable of condensing with at least one of components A) to C).

2. A binder as claimed in claim 1 wherein the polycarboxylic acid A) is an aliphatic dicarboxylic acid having 4 to 13 carbon atoms, hexahydrophthalic acid or an aromatic polycarboxylic acid having 8 or 9 carbon atoms.

3. A binder as claimed in claim 1 or 2 wherein the unsaturated dicarboxylic acid A) is an aliphatic dicarboxylic acid having 4 or 5 carbon atoms.

4. A binder as claimed in any one of the preceding claims wherein the polyhydric alco

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

yelllowish resin with a viscosity of 850 P is obtained.

Printing inks were produced from the binders prepared in the Examples as described hereinbefore and were tested by means of the following printing tests.

Printing Tests In order to determine the drying speed of the individual printing inks, sample prints were produced on white paper with an average application of 1.5 g/m2 of printing ink and irradiating with a mercury vapour pressure lamp at 80 watts/cm at various running speeds. The drying speed is given as the radiation time required to dry i.e. crosslink, irradiated print to such an extent that when a sheet of white paper is applied.

under a contact pressure of 130 kp/cm2, there is no transfer of ink on to the white paper (the so called "off setting test", carried out using a print testing apparatus made by Messrs. Diirner, Peissenberg, Federal Republic of Germany). The gloss was assessed visually. The results of the printing tests are given in the Table which follows: TABLE Binder prepared in Pigment Drying speed Example No. C.I. number ca. m/min. Gloss Pigment Yellow 126 180 excellent Pigm. Blue 15 270 very good comparison I Pigm. Yellow 126 40 good Pigm. Blue 15 40 good comparison 2 Pigm. Yellow 126 80 satisfactory Pigm. Blue 15 80 moderate comparison 3 Pigm. Yellow 126 20 (not very good Pigm. Blue 15 20 }the print bronzes 2 Pigm. Yellow 126 240 good Pigm. Blue 15 300 good 3 Pigm . Yellow 126 190 very good Pigm.Blue 15 210 good The printing inks containing the binder prepared in Example I have a particularly high gloss and good drying properties and those containing the binder prepared in Example 2 have a good gloss and very good drying properties. In contrast, the inks containing the binders prepared in the comparison Examples have less good drying properties and some have a very inferior gloss. It makes no difference whether the binder is unmodified (comparison Example I ) or modified with an aromatic (comparison Example 2) of aliphatic (comparison Example 3) acid. The inks prepared with the binder of Example 3 have a high gloss and good drying properties.

The binders according to the invention are distinguished by high storage stability, i.e. in a six-month period they show no gel formation, no concentration and no change in viscosity. Similarly the storage stability of the mixtures prepared with the binders is also excellent.

WHAT WE CLAIM IS: I. An unsaturated polyester binder which comprises a reaction product of A) an acid component comprising one or a mixture of a,-mono-olefinically unsaturated dicarboxylic acids or polycarboxylic acids free from polymerisable carbon-carbon multiple bonds or functional derivatives thereof, B) a polyhydric alcohol, C) a compound containing at least one norbornane ring system with a 5 membered carbon ring fused therewith and having one or more identical substituents selected from carboxyl, hydroxy and amino groups, and D) an acrylic compound which is capable of condensing with at least one of components A) to C).
2. A binder as claimed in claim 1 wherein the polycarboxylic acid A) is an aliphatic dicarboxylic acid having 4 to 13 carbon atoms, hexahydrophthalic acid or an aromatic polycarboxylic acid having 8 or 9 carbon atoms.
3. A binder as claimed in claim 1 or 2 wherein the unsaturated dicarboxylic acid A) is an aliphatic dicarboxylic acid having 4 or 5 carbon atoms.
4. A binder as claimed in any one of the preceding claims wherein the polyhydric alcohol B) is a saturated or monoolefinically unsaturated di- to tetrahydric alcohol having up to 15 carbon atoms.
5. A binder as claimed in claim 4 wherein the polyhydric alcohol B) has only primary alcohol groups.
6. A binder as claimed in claim 4 or 5 wherein the polyhydric alcohol B) is trimethylolpropane or ethanediol.
7. A binder as claimed in any one of the preceding claims wherein the compound C)

contains a carbon-carbon double bond in the 5-membered ring fused to the norbornane ring system.
8. A binder as claimed in any one of claims 1 to 6 wherein the compound C) is tricyclo-(5,2,1,026)-decane-3(4)-carboxylic acid.
9. A binder as claimed in any one of the preceding claims wherein the content of compounds C) is at least 0.5% by weight, based on the reaction product of components A) to D).
10. A binder as claimed in claim 9 wherein the content of compounds C) is from 3 to 30% by weight.
11. A binder as claimed in any one of the preceding claims wherein the acrylic compound D) is acrylic or methacrylic acid.
12. A binder as claimed in any one of the preceding claims wherein the content of acrylic compounds D) is from 10 to 50% by weight, based on the reaction product of components A) to D).
13. A binder as claimed in claim 12 wherein the content of acrylic compounds D) is more than 20% by weight.
14. A binder as claimed in any one of the preceding claims having a viscosity of up to 1500 P.
15. A binder as claimed in claim 14 having a viscosity of from 100 to 800 P.
16. A binder as claimed in any one of the preceding claims modified by at least one internal sensitizer.
17. A binder as claimed in claim 16 having an internal sensitizer wherein component A) is in admixture with a benzophenone substituted by at least one carboxyl group.
18. A binder as claimed in any one of claims I to 15 modified by at least one fatty oil, or saturated or unsaturated fatty acid.
19. A binder as claimed in claim 18 modified by 9,11-ricinoleic acid or 10,12linoleic acid.
20. A binder as claimed in any one of the claims 16 to 19 wherein the amount of the modifying component in the binder is not more than 30% by weight, based on the total weight of acid component A).
21. A binder as claimed in any of claims 1 to 10 and 12 to 20 wherein the acrylic compound D) is a hydroxyalkyl ester of acrylic or methacrylic acid having up to 3 carbon atoms in the hydroxyalkyl group.
22. A binder as claimed in any of claims I to 10 and 12 to 20 wherein the acrylic compound D) is an N-alkylolacrylamide or methacrylamide containing up to 4 carbon atoms in the alkyl group.
23. An unsaturated polyester binder according to claim 1 substantially as herein described.
24. An unsaturated polyester binder substantially as herein described with reference to any one of Examples 1 to 5.
25. A process for the preparation of an unsaturated polyester binder which comprises reacting in a first step A) an acid component comprising one or a mixture of X -mono-olefinically unsaturated dicarboxylic acids or polycarboxylic acids free from polymerisable carbon-carbon mulitple bonds or functional derivatives thereof B) a polyhydric alcohol and C) a compound containing at least one norbornane ring system with a 5 membered carbon ring fused therewith and having one or more identical substituents selected from carboxyl, hydroxy and amino groups, and reacting the product with D) an acrylic compound which is co condensable therewith.
26. A process as claimed in claim 25 wherein the first step is effected at a temperature in the range from 160 to 2500 C.
27. A process as claimed in claim 25 or 26 wherein the second step is effected at a temperature in the range from 70 to 1200C.
28. A process as claimed in any one of claims 25 to 27 wherein the product obtained in the first step has a hydroxy number in the range from 100 to 1000 (measured according to DIN 53240).
29. A process as claimed in claim 28 wherein the product obtained in the first step has a hydroxy number in the range from 200 to 800.
30. A process as claimed in claim 29 wherein the product obtained in the first step has a hydroxy number in the range from 400 to 600.
31. A process as claimed in any one of claims 25 to 27 wherein the product obtained in the first step has an acid number in the range from 100 to 800.
32. A process as claimed in claim 31 wherein the product obtained in the first step has an acid number in the range from 200 to 600.
33. A process as claimed in any one of the claims 25 to 32 wherein the second step is performed in the presence of a catalyst.
34. A process as claimed in claim 33 wherein the catalyst is sulphuric acid, hydrochloric acid, benzene sulphonic acid, p-toluene sulphonic acid or methane sulphonic acid.
35. A process as claimed in claim 33 or 34 wherein from 0.1 to 5% by weight of catalyst is used referred to the weight of the reaction components A) to D).
36. A process as claimed in claim 35 wherein from 0.5 to 2% by weight of catalyst is used.
37. A process as claimed in any one of claims 25 to 36 wherein the second step is performed in the presence of an entrainer.
38. A process as claimed in any one of claims 25 to 37 wherein the second step is performed under reduced pressure.
39. A process as claimed in any one of claims 25 to 30 and 33 to 38 wherein in the second step a hydroxy group-containing polyester product of the first reaction step is partially esterified with component D).
40. A process as claimed in any one of claims 25 to 30 and 33 to 38 wherein in the second step a hydroxy group-containing polyester product of the first reaction step is partially etherified with component D).
41. A process as claimed in claim 39 or 40 wherein at the end of the second step at least 2% of the hydroxy groups of the polyester remain unreacted.
42. A process as claimed in claim 41 wherein at the end of the second step from 10 to 35% of the hydroxy groups of the polyester remain unreacted.
43. A process as claimed in any one of claims 25 to 27 and 31 to 38 wherein in the second step a carboxyl group-containing polyester product of the first reaction step is partially esterified with component D).
44. A process as claimed in claim 43 wherein at the end of the second step at least 2% of the carboxyl groups of the polyester remain unreacted.
45. A process as claimed in claim 44 wherein at the end of the second step from 10 to 35% of the carboxyl groups of the polyester remain unreacted.
46. A process as claimed in any one of claims 25 to 45 wherein the second reaction step is performed in the presence of a polymerisation inhibitor.
47. A process as claimed in claim 46 wherein the polymerisation inhibitor is a quinone derivative, a substituted phenol, an amine, sulphur or a sulphur compound.
48. A process as claimed in claim 46 or claim 47 wherein the polymerisation inhibitor is present in an amount of from 0.1 to 5% by weight, referred to the weight of reaction components A) to D).
49. A process as claimed in claim 48 wherein the polymerisation inhibitor is present in an amount of from 0.5 to 2% by weight.
50. A process for the preparation of an unsaturated polyester binder according to claim 25 substantially as herein described.
51. A process for the preparation of an unsaturated polyester binder substantially as herein described with reference to any one of Examples 1 to 5.
52. An unsaturated polyester binder prepared by a process as claimed in any of claims 25 to 51.
53. An unsaturated polyester binder prepared by a process as claimed in any of claims 25 to 30, 33 to 42 and 46 to 49.
54. A coating composition which comprises an unsaturated polyester binder as claimed in claim I in admixture with one or more further ingredients selected from reactive diluents, sensitisers and pigments.
55. A composition as claimed in claim 54 containing a ketone, a chlorinated aromatic compound or an anthraquinone derivative as sensitiser.
56. A composition as claimed in claim 54 or 55 wherein the sensitiser consists of a combination of benzophenone and Michler's ketone.
57. A composition as claimed in any one of claims 54 to 56 containing from 2 to 20% by weight of sensitiser referred to the total composition.
58. A composition as claimed in claim 55 containing from 3 to 10% by weight of sensitiser.
59. A composition as claimed in any one of claims 54 to 58 containing up to 60% by weight of reactive diluent, referred to the total composition.
60. A composition as claimed in any one of claims 54 to 59 additionally containing a further synthetic resin in an amount of at most 60% by weight, referred to the total composition.
61. A composition as claimed in claim 60 containing from 3 to 20% by weight of the further synthetic resin.
62. A composition as claimed in claim 60 or 61 wherein the further synthetic resin is a maleate resin.
63. A composition as claimed in any one of claims 54 to 62 containing from 5 to 40% by weight of pigment, referred to the total composition.
64. A composition as claimed in claim 63 containing from 8 to 20% by weight of pigment.
65. A composition as claimed in any one of claims 54 to 64 which is a printing ink.
66. A coating composition according to claim 54 substantially as herein described.