WO1997002229A1

WO1997002229A1 - Reactive diluents

Info

Publication number: WO1997002229A1
Application number: PCT/GB1996/001568
Authority: WO
Inventors: Henry Deans; Benjamin Patrick Gracey; Christopher Hallett; Philip Kenneth Gordon Hodgson; Robert Paul Klaasen
Original assignee: Bp Chemicals Limited
Priority date: 1995-06-30
Filing date: 1996-06-28
Publication date: 1997-01-23
Also published as: AU6310896A; GB9513375D0

Abstract

This invention relates to compounds of the formula (I): [R*O.C(O)]nR' wherein R' represents at least a divalent -CH=CH- group or a -CH2-CHR5- residue in which R5 is H or a (un)saturated hydrocarbylene or hydrocarbyleneoxy group which may be the same as or different from R* and wherein R* represents an allylic hydrocarbylene or hydrocarbyloxy alkylene group having at least 5 carbon atoms and being free from non-allylic unsaturated groups other than aromatic groups, a method of making the same and use thereof as reactive diluents in paint and polymer formulations.

Description

REACTIVE DILUENTS

This invention relates to novel esters of allylic alcohols, their method of preparation and the use thereof as reactive diluents in paint and polymer formulations.

Methods of producing esters of unsaturated alcohols are well known. One such method is the direct telomerisation of butadiene with a carboxylic acid in the presence of a homogeneous catalyst comprising a noble metal compound such as eg palladium acetyacetonate and a phosphine. Such a method is described for instance in JP-A-51088907 (Mitsubishi Chemical Industries Co). In a fiirther process, octadienol is reacted with a carboxylic acid or anhydride in the presence of other catalysts (see JP- A-47046568 (Mitsubishi) which describes the use of a zinc acetate catalyst and JP-A- 04049266 (Kuraray) which describes the use of a KCN transesterification catalyst). Reactive diluents are usually compounds or mixtures of compounds of relatively low viscosity, a relatively high boiling point (i.e. low saturated vapour pressure) which act as solvents during the formulation and processing ofthe coating. A feature of reactive diluents is that such diluents can copolymerise with a resin, e.g. an alkyd resin. Hence reactive diluents may be used to replace part or all ofthe traditional solvents normally used in such formulations thereby reducing losses ofthe solvent to atmosphere on drying ofthe coating. Use of esters of di and polyhydric alcohols which have been partially etherified with allyl alcohol as reactive diluents is described for example in EP-A-0 263 474. Alkyd resins are well known components of decorative paints (see, for example, "The Technology of Paints, Varnishes and Lacquers" by Martens, C R, Ed., published by Robert Krieger Publishing (1974)) and can be prepared from polybasic acids or anhydrides, polyhydric alcohols and fatty acids or oils. US-A-3 819 720 describes methods of preparing such alkyd formulations. Alkyd resins are available commercially and are used in coating compositions which usually contain large amounts of solvents (eg mineral spirits, aromatic hydrocarbons).

It has now been found that esters of allylic alcohols which can be produced in commercially viable yields and purity have relatively low viscosity and therefore can be used as reactive diluents in a wide variety of polymer formulations. Accordingly, the present invention is a compound ofthe formula (I):

[R*O.C(O)]₂R" (I) wherein

R" represents at least a divalent -CH=CH- group or a -CH₂-CHR⁵- group in which R⁵ is H or a saturated or unsaturated hydrocarbyl(oxy) group, which may be the same as or different from R* and wherein

R* represents an allylic hydrocarbylene or hydrocarbyloxy alkylene group derived from an allylic alcohol having at least 5 carbon atoms and being free from non-allylic unsaturated groups other than aromatic groups ofthe formula:

(R⁴)(R³)C=C(R²) CH(R¹).OH (II) in which R is H, a C1-C4 alkyl group or a hydrocarbyloxy alkylene group

2

R is H, a C1-C4 alkyl group or a hydrocarbyloxy alkylene group, R is H, or a C1-C4 alkyl group,

4

R is H, or a straight or branched chain alkyl group, or, an aryl group or an aralkylene group having 2-10 carbon atoms, or, a saturated hydrocarbyloxy group having 2-10 carbon atoms and if said group is an aryloxy group it has 7-10 carbon atoms, or,

4 1

R when taken together with R forms a cyclic alkylene group with alkyl

2 substituents therein and in which case R is H,

1 4 such that at least one ofthe groups R -R is other than H. By the expression "alkylene" as used herein and throughout the specification is meant a divalent hydrocarbyl group such as eg a -CH₂-(CH₂)p group wherein p — 0 or an integer, encountered in a compound such as adipic acid.

Specific examples of allylic alcohols of formula (II) include inter alia 2-ethyl-

1 3 2 4 hex-2-en-l-ol (in which R and R are H, R is an ethyl group, and R is an n-propyl group, and which compound will hereafter be referred to as "2-ethylhexenol" for convenience); 2-ethyl allyl alcohol; hept-3-en-2-ol; 4-methyl pent-3-en-2-ol; n-oct-2- en-l-ol; n-oct-l-en-3-ol; 4-tert-butoxy but-2-en-l-ol (also called l,4-but-2-ene diol mono-tertiary butyl ether (in which R is a tertiary butoxy methylene group)); 4-(α- methylbenzyloxy) but-2-en-l-ol (also called l,4-but-2-ene-diol mono α- methylbenzyloxy ether (in which R⁴ is an α-methylbenzyloxy methylene group)); 4-(α- dimethylbenzyloxy) but-2-en-l-ol, (also called l,4-but-2-ene-diol mono α-di methylbenzyloxy ether (in which R is an α-dimethylbenzyloxy methylene group)); 4-n- butoxy but-2-en-l-ol (also called l,4-but-2-ene diol mono-n-butyl ether (in which R⁴ is a n-butoxy methylene group)); cinnamyl alcohol; and isophorol (in which R² is H, R³ is a methyl group, and R¹ and R⁴ are such that R⁴ represents a -CH₂.C(CH₃)₂.CH₂- group and forms a cyclic structure with R¹).

In the compound of formula (I) above, R* may be derived from the allylic alcohol represented by R*OH. Where R* is an allylic hydrocarbylene residue derived from the allylic alcohol as such, it may be an alkylene group, an arylene group, an alkarylene group or an aralkylene group. The reactant allylic alcohol, R*OH can be prepared in several ways known to those skilled in the art. For instance, the reactant allylic alcohol used to produce the esters ofthe present invention can be produced by the reduction ofthe corresponding α,β-unsaturated aldehyde eg by hydrogenation, which will generate a mixture ofthe allylic alcohol and its saturated analogue. Some other allylic alcohols may be produced from conjugated dienes via the well known addition reactions. Furthermore, other allylic alcohols may be produced by initially forming an unsaturated ester from an olefin and a carboxylic acid followed by hydrolysis ofthe ester to a mixture of isomeric allylic alcohols. This latter reaction may, like some ofthe other reactions mentioned above, result in a mixture of products which includes inter alia the desired allylic alcohol, isomers thereof and saturated analogues thereof. The mixtures of allylic alcohol with the saturated analogue thereof and/or the isomers thereof can be then used as such, or, after further purification to isolate the desired allylic alcohol, to prepare the esters represented by formula (I) above.

In the compounds of formula (I) above, where R" is a divalent -CH=CH- group, it may be derived from maleic acid or anhydride, fumaric acid, and dialkyi maleates, fumarates (e.g. diethyl maleate) or fumaryl chloride.

Such esters can be prepared by reacting an allylic alcohol such as eg 2-ethyl- hex-2-en-l-ol with a reactant such as a carboxylic acid and/or anhydride, an acid halide or an ester in the presence of a catalyst which does not cause undue polymerisation or rearrangement ofthe allylic groups ofthe molecule thereby giving rise to hydrocarbyl fragments capable of forming coloured products. Examples of a suitable catalysts include acidic or amphoteric catalysts, and may be homogeneous or heterogeneous. Specific examples of such catalysts include inter alia dibutyl tin oxide, stannous oxalate, zinc acetate, magnesium acetate, para-toluene sulphonic acid, methane sulphonic acid and phosphoric acid.

The esterification reaction is suitably carried out at a temperature from 80-200°C, preferably from 100-160°C. Within these temperature ranges, the viscosity the ester formed tends to increase at the higher temperatures due to resinification of the carboxylate reactant or ester product. It will be understood by those skilled in the art that the esterification ofthe allylic alcohol with a dicarboxylic acid, anhydride or halide to form the desired esters either by direct- or trans-esterification may lead to a mixture of esters under some reaction conditions. Such a mixture of esters can be due to incomplete transesterification. This will be especially true where less than one equivalent of allylic alcohol is per equivalent ofthe dicarboxylic acid/anhydride/halide used in the reaction. Thus, the reaction is suitably carried out using a molar ratio ofthe alcohol is to the dicarboxylic acid/anhydride/halide is suitably in the range of 2 : 1 to 10 : 1, preferably from 2.5 : 1 to 5 : 1. In this case, the preparative conditions employed will have a strong influence on the type of material obtained from the esterification (or transesterification) reaction, including those used for producing the esters of 2-ethyl hexenol. In addition to the degree of esterification (or transesterification) achieved, there is the possibility that samples prepared at relatively higher temperatures could isomerise to the fumarate and may have relatively higher densities due to some resinification ofthe anhydride/ester. One ofthe esters in the ester product formed contains an additional alkyleneoxy function in its structure arising from the Michael addition ofthe alcohol reactant across the unsaturated linkage ofthe unsaturated acid or anhydride or ester. In this case the ester is a compound where R" is a -CH₂-CHR⁵- group, ie the structure ofthe residue may contain additional alkyleneoxy functions. Thus for example, when 2-ethyl hexenol is reacted with maleic acid or anhydride, the resultant product may be 2-(2-ethyl hexenyloxy) di-(2-ethyl hexenyl) succinate. Esters of oct-2-en-l-ol can be formed by the esterfication ofthe corresponding n-octenol or by selective hydrogenation ofthe corresponding esters of octadienol to give eg 2-(2- octenyloxy) di-(2-octenyl) succinate, di-(2-octenyl) fumarate and di-(2-octenyl) maleate. The novel compounds described in this application can also be used as reactive diluents for paint and polymer formulations. The mixed esters formed during the esterification reaction ofthe present invention can function essentially as reactive dilutents when used in paint and polymer formulations. In this context it is not necessary to isolate the individual esters in the mixed ester product formed during the esterification reaction. The mixed ester product may be used as such, if necessary after separation ofthe catalyst, colour forming impurities, acid and excess alcohol reactant, for use as reactive diluents. Thus, curing ofthe reactive diluent after applying the formulation on a substrate surface is likely to result in the formation of a coating of hardened material. Thus, according to a further embodiment, the present invention is a formulation comprising a paint or a polymer and one or more esters selected from the group consisting of: a. 2-(2-ethyl hexenyloxy) di-(2-ethyl hexenyl) succinate, b. di-(2-ethyl hexenyl) fumarate, c. di-(2-ethyl hexenyl) maleate, d. 2-(2-octenyloxy) di-(2-octenyl) succinate, e. di-(2-octenyl) fumarate and f. di-(2-octenyl) maleate.

The esters ofthe allylic alcohols referred to in the present invention have low volatility and low viscosity eg ofthe order of 10-80 mPa.s thereby rendering them suitable for use as reactive diluents for cured paint and polymer formulations, especially for formulations comprising alkyd resins. For example, the esters of 2-ethyl hexenol have relatively low colour, and moreover, films formed from paint formulations containing esters of 2-ethyl hex-2-en-l-ol as reactive diluent show little yellowing with passage of time. The relative ratios ofthe esters used as reactive diluents to the alkyd resin in a formulation can be derived from the ranges quoted in published EP-A-0 305 006. In an example in which the reactive diluent replaces all of the traditional solvent, the ratio of reactive diluent to alkyd resin is suitably in the range from 1-50 : 99-50, eg 5-50 : 95-50, parts by weight, preferably from 5-25 : 95-75 and more preferably from 5-15 : 95-85 parts by weight. On the other hand, where used in a conventional paint formulation, such a diluent can replace all or part of a traditional solvent such as white spirit. The formulations may contain further components such as catalyst, drier, antiskinning agent, pigments, pigment stabilisers, rheology controllers (e.g. for sag control), UV and oxidation stabilisers, flow additives, microgels (e.g. to enhance hardness) and other additives. The formulations may also need to include water scavengers such as trialkyl orthoformates, molecular sieves or zeolites where the reactive diluent used is susceptible to hydrolysis such as eg some ofthe ether ester derivatives. Furthermore, where such water scavengers are used it may be necessary to use them in combination with pigment stabilizers. Where a drier (siccative) is used this may further contribute towards the solvent content ofthe formulation. For formulations comprising an oxidatively curing alkyd resin and a siccative/drier, impurities which can have a co-ordination affinity for the siccative drier can affect adversely the drying speed and stability ofthe paint. Examples of such impurities include maleic acid and triethyl amine. In particular, it has been found desirable to minimise the acidity ofthe ester mixture used as reactive diluent in such formulations to a value of < 7000 ppm, preferably < 3000 ppm, more preferably < 1000 ppm w/w of KOH.

It has also been found that when a mixture of esters, ie the succinates, fumarates and maleates, is used as a reactive diluent in such formulations comprising an oxidatively curing alkyd resins, the properties/performance ofthe diluent can be varied by changing the relative proportions ofthe three esters present in such a diluent. For example, mixtures with a relatively lower amount of maleates exhibit better hardness and drying properties compared with those having relatively higher amounts of such maleates. Moreover, it has also been observed that formulations comprising these esters display a decreased tendency especially towards wrinkling. This renders them particularly suitable when using formulations comprising high solid systems/one- coat paints have to be applied to generate a greater thickness ofthe relevant coating without impairing the ability of such thicker layers to harden through.

A further aspect ofthe present invention is that such esters when used in a relatively pure state do not cause any haze in the formulation. Where there is likely to be a risk of such haze formation, eg due to the presence of impurities such as eg resins or polymers formed during the synthesis ofthe esters used or during storage of such formulations, it is beneficial to use inhibitors such as eg butylated hydroxy-toluene (2,6-butoxy-4-methyl phenol) or 2,4,6-tert-butyl phenol. Such inhibitors not only have the advantage of preventing haze formation but also render the formulations safer to handle by inhibition of other unwanted reactions in the formulation such as eg peroxidation.

The present invention is further illustrated with reference to the following Examples. EXAMPLES: 1. Examples of the preparation of the reactive diluents

Example S 1 :

The following apparatus was assembled : A five-litre flanged flask with an insert pipe for a nitrogen sparge, a thermowell for thermocouple, and a Dean and Stark apparatus with double-walled condenser. The flask was heated with an electric heating mantle which was controlled with a eurotherm controller connected to the thermocouple. The nitrogen sparge pipe was inserted so that the nitrogen flow agitated the flask contents and provided mixing during the course of the reaction. The nitrogen flow also served to entrain out the liberated methanol and force the reaction to completion.

To the flask was added dimethyl maleate (865.7g), 2-ethylhexenol (2268.7g) and zinc acetate (32.44 g). The mixture was sparged with nitrogen for 10 minutes to remove air and the nitrogen flow was then reduced to a level which ensured efficient mixing. The mixture was then heated in stages to 120°C ( e.g. 80°C for 10 minutes, then 100°C for 10 minutes and then 120°C). The progress ofthe reaction was monitored by the methanol collected in the Dean and Stark apparatus. When 90% of the predicted methanol had been collected the reaction mixture was sampled hourly and analysed by GC. The reaction was adjudged complete when the level ofthe "half ester" (methyl 2-ethylhexenyl maleate/fumarate) fell to below 0.3% w/w and this took approximately 16 hours. At this point the heating was switched off and the reaction mixture allowed to cool to room temperature. The product from the reaction was then decanted from any solids in the reaction flask. This product was then charged to a heated decanter (40°C) with an equal volume of 5% w/w aqueous sodium hydroxide solution. The mixture was stirred for 20 minutes and then allowed to separate and the lower aqueous phase decanted. This base wash was repeated and then remaining organic phase was washed with saturated brine until the aqueous phase reached a steady pH. The organic phase was then heated (100°C) under reduced pressure (< 500 Pa (< 5mBar)) on a rotatory evaporator to remove residual water and the majority ofthe excess 2-ethylhexenol. After cooling, the product was filtered and transferred to a 5-litre three-necked round-bottomed quickfit flask . This flask was equipped with a still head condenser and reciever flask (Perkin triangle), a thermocouple, a steam inlet pipe, and a eurotherm controlled heating mantle. The apparatus was evacuated to 4000 Pa (40mBar) and the product heated to 120°C. The supply of steam was then connected and the residual traces of 2-ethylhexenol were removed. The purification was adjudged complete when the volume ofthe heads product aqueous phase increased to more than 5 times that ofthe organic phase. After cooling down, the product was then treated with activated carbon (1% w/w, 100°C, 2Hrs, < 500 Pa (< 5mBar)) on a rotatory evaporator. The cooled mixture was filtered through dried celite to obtain the final product which had the following analyses:

OH number - < 1 mg KOH/g (titration) total acid - 115 ppm KOH/g (titration) maleic acid / anhydride - < lOppm (HPLC)

Fumaric acid - <10ppm (HPLC) Zinc - <5ppm (atomic absoφtion, detection limit) sodium - <20ppm ( atomic absoφtion, detection limit) chlorine - <10ppm (atomic absoφtion detection limit)

GC "CPS.15" column - 2-ethylhexenyl methyl fumarate/ maleate 0.1% w/w di-(2-ethylhexenyl) maleate 2% w/w - di-(2-ethylhexenyl) fumarate 24% w/w

2-(2-ethylhexenoxy) di-(2-ethylhexenyl) succinate 74% w/w The GC assignment was supported by GC/MS and a 1H nmr and ¹³C nmr studies. The GC/MS used a VG Trio- 1000, operated according to the manufacturers instructions under the following conditions:

GC column 25mx0.32mm DB5 (0.25 micron film) temperature programme 40°C (3 mins) @ lOC/min to 32°0C(10min injection 1 microlitre (1% solution in acetone) on column 40°C ammonia chemical ionisation (CI) - scan range 50-800 scan rate 1/s It was found that the deduction of molecular weights from the CI spectra is rather less straightforward than is usual on account of (a) extensive rearrangements of fumarates in particular giving [M+3]⁺ and [M+20]⁺ ions in addition to the usual [M+l]⁺ and [M+l 8] ions and (b) extensive fragmentation exhibited by some species. As a result the GC peaks were assigned by inteφretation. These assignments were confirmed by H and C nmr. Table 1 gives tenative assignments ofthe observed ¹³C nmr peaks. The correspondence to the GC was again confirmed by integration ofthe nmr spectrum of several samples in which the composition varied. The products from this Example will hereafter called sample AK3R. The viscosity ofthe sample called AK3R was 23.4 mPa.s, which shows that the esters / reactive diluents of this invention have relatively low viscosity and are suitable for use as reactive diluents. In the context ofthe NMR ofthe 2-ethylhexenyl derivatives, it should be noted that 2- ethylhexenol has two isomers - a major and a minor one due to isomerism about the double bond. In some cases it is possible to identify the derivatives of both isomers but in many cases only the major species can be identified. It also contains some 2- ethylhexenol but the chemical shift of reaction products from this are listed below:

TABLE 1

2-Ethylhexenol:

6 5 4 3 2 7 8 1 CH₃.CH₂.CH₂.CH=C(CH₂.CH₃).CH₂.OH

1 2 3 4 5 6 7 8

Major 65.8 140.5 125.0 29.1 22.8 13.7 20.6 13.0

Minor 59.1 140.0 126.0 22.8 22.8 13.6 27.2 12.5

2-Ethylhexenyl fumarates/maleates: 6 5 4 3 2 7 8 1 9 10

CH₃.CH₂.CH₂.CH=C(CH₂.CH₃).CH₂.O(O=).C.C=C.C(=O).OR (R = 2-ethylhexenyl)

Fumarate/Maleate 1 2 3 4 5 6 7 8 9 10

Maleate (major isomer) 68.57 135.17 129.41 29.12 22.31 13.40 20.81 12.54 164.58 130.01

Maleate (minor isomer)* 62.10 135.03 130.19 22.60 22.60 13.61 27.58 12.23 164.77 130.01

Fumarate 68.72 136.06 130.22 29.12 22.31 13.40 20.55 12.54 164.19 133.23

Some assignments are tentative

TABLE 1 (continued)

2-Ethylhexenyl alkoxy succinate:

6 5 4 2 3 7 8 1 9 10 11 12 1' <- T - 8' ^■- 1" 2" V 8" 3" 4" 5" 6"

CH₃.CH₂.CH₂.CH=C(CH₂.CH₃).CH₂0.(0=)C.CH₂.CH.(C(=0).O.CH₂.C(CH₂.CH₃)=CH.CH₂.CH₂.CH₃).O.CH₂.C(CH₂.CH₃)=CH.CH₂.CH₂.CH₃

1 2 3 4,4^,,4" 5,5' 6,6' 7 8,8' 9 10 11 12

68.4 135.2 130.0 29.1 22.3 13.4 20.9 12.5 169.5 37.7 73.6 170.9

1' 2' 3' 7 1" 2" 3" 5" 6" 7" 8"

68.2 135.4 129.5 20.9 74.5 137.0 129.1 20.5 13.5 20.6 12.6

Alkoxy succinate- (Methyl):

6 5 4 2 3 7 8 1 9 10 11 12 1' <- 2' - 8' -> 1"

CH₃.CH₂.CH₂.CH=C(CH₂.CH₃).CH₂0.(0=)C.CH₂.CH.(C(=0).O.CH₂.C(CH₂.CH₃)=CH.CH₂.CH₂.CH₃).O.CH₃

1 2 3 4 5 6 7 8 9 10 11 12 1' 1"

68.6 135.2 130.0 29.1 22.3 13.4 20.9 12.5 169.4 37.5 76.5 170.6 68.5 58.2

Example S2: General method of reacting an acid chloride with an allylic alcohol to form an ester

The following apparatus was assembled:

A three-necked pyrex Quickfit® round-bottomed flask was equipped with two side arms, a magnetic follower and a heater stirrer mantle. The top of each ofthe three necks ofthe flask was connected respectively to a pressure equalising dropping funnel, a double condenser and a controllable source of vacuum or nitrogen top cover.

The apparatus was purged with nitrogen to displace any air and moisture, then the allylic alcohol and dry cyclohexane were added to the flask. The acid chloride was then loaded into the dropping funnel. These reactants were purged of any oxygen by means of a nitrogen sparge. Once degassed, the apparatus was evacuated by connecting it to a water pump. 0.9 Equivalents of allylic alcohol were used per carboxylic acid moiety in the reactant acid chloride.

The mixture was brought to reflux by heating to approximately 50°C under vacuum and the acid chloride was added dropwise over the period of an hour. The reactants were kept under reflux for 2 hours after the acid chloride addition had been completed. The reaction mixture was then distilled on a rotary evaporator to remove the cyclohexane, unreacted acid chloride and allylic alcohol.

The progress ofthe reaction and distillation was monitored by gas chromatography. A target of less than 5% free alcohol was set in the kettle product. Once this had been attained, the identity ofthe product was confirmed by GC, *H and ¹³C NMR analysis.

The major product of this reaction was di-(2-ethyl hexenyl) fumarate. 2. Examples of the use of the reactive diluents in paint formulations Reactive diluents, such as those ofthe present invention, must meet a range of criteria including low odour and low toxicity, low viscosity and the ability to "cut" the viscosity ofthe paint to facilitate application on the surface to be coated therewith. Furthermore, the diluent should not have a markedly adverse effect on the properties ofthe paint film such as drying speed, hardness and degree of wrinkling. The reactive diluents described above have therefore been tested in paint applications using both clear and pigmented paints. The diluents have been compared with paints formulated using white spirit, a conventional thinner. The results demonstrate the excellent performance ofthe diluents of this invention.

2.1 Tests of pigmented paint formulations NB. It is well known by those skilled in the art that day-to-day fluctuations in conditions can introduce some variability into experimental data. To minimise these errors, the tests presented below were conducted as follows: ca. five to ten paint formulations were prepared simultaneously and comprised one reference (white spirit) and about four to nine reactive diluent-based paints. These samples were tested at the same time under identical conditions. Comparison of performance data from within these groups of formulations allowed errors due to random sources to be minimised. Hence in the following examples the reader will realise that the apparent variation in performance data from some diluents results from the use of different paint formulations made on different days from the same diluent. a) Methods used to prepare pigmented paint formulations based on a high solids alkyd resin

NB. In the examples below, % reactive diluent refers to the ratio of reactive diluent to alkyd (e.g. 30% reactive diluent implies 30g diluent to every 70g alkyd). High solids alkyd reference with white spirit diluent In a mini motor mill 534 grams of a high solids alkyd (Setal® 293, ex. Akzo

Nobel Resins) and 423 grams of titanium dioxide (Kronos® 2310, ex. Kronos) were milled. Thereafter 40 grams of a combi siccative (Nuodex Combi® APB, ex. Servo) and 2.9 grams of methyl ethyl ketoxime were added and mixed thoroughly. This mixture was diluted with white spirit to an application viscosity of 0.5 Pa.s. High solids alkyd with 30 % of reactive diluent

In a mini motor mill 374 grams of a high solids alkyd (Setal® 293, ex. Akzo Nobel Resins) and 423 grams of titanium dioxide (Kronos® 2310, ex. Kronos) were milled. Thereafter 160 grams of 'AK3R' , 40 grams of a "combi siccative" (Nuodex Combi® APB, ex. Servo) and 2.9 grams of methyl ethyl ketoxime were added and mixed thoroughly. This mixture was diluted with white spirit to an application viscosity of 0.5 Pa.s.

A similar method (with appropriate adjustments to the proportions ofthe components ofthe paint) was used to prepare paints with 10 and 20% reactive diluent. Each of he pigmented paints prepared as described above was stored in two tins. One tin was kept at 23 °C for 7 days before testing. The second tin was stored at 35°C for 2 weeks before drying speed tests were performed. The results below derive from the tins stored at 23°C unless stated. b) Test methods used with pigmented paint formulations Coating viscosity was measured in accordance with the ICI Cone & Plate method (ISO2884) at 10,000 s^"1 , 23°C , 50% RH (Pa.s). Konig hardness (ISO 1522) was measured at 23 °C, 50% RH (s) of a coating film applied with a 100 μm applicator on a glass substrate.

The Fischer spherical indention test is based on ISO6441 (um) and was performed on a coating film applied with a 100 μm applicator on a glass substrate. Drying performance was determined at 10°C, 85% RH with a Beck-Koller drying recorder (hours) under daylight lamps. Films were applied to glass substrates using a 90 um applicator. The measurements quoted (in hours) are : a) For high solids alkyd resin-based pigmented paints : "phase 1", the dust drying time; b) For conventional alkyd resin-based pigmented paints : "phase 2" (touch dry time) and "phase 3" (through-dry time). c) Results of the tests of pigmented paints based on reactive diluents

Example Tl

Paints containing 30% reactive diluent were prepared from the diluent AK3R. The drying speed results in Table 3 show that paints based on the reactive diluents of this invention dry over a period which is acceptable to the industry. Furthermore, the drying speed ofthe paints remain satisfactory after storage at 35°C for 2 weeks. The Fischer indentation test and Konig hardness test results in Table 4 show that paint films containing the reactive diluents of this invention are relatively hard.

TABLE 3 (Drying performance)

Diluent Used Drying Times (Hours)

Paint stored for 1 Increase in drying time Week at 23°C when paint stored for 2 Weeks at 35°C

Ester Mix Example SI (AK3R) 7.5 1.5 TABLE 4 (^"Hardness Data)

Reactive Diluent Used Indentation (microns) Konig hardness **

Ester Mix AK3R 3.87* | 3.36# m 8#

* Film cured for 1 week at 23°C

# After 100 hours at 50°C @ After 3 weeks at 23°C

** In number of swings. Multiply by 1.4 to convert to seconds.

The results in Table 5 show the maximum thickness of paint which can be applied to a glass substrate without the appearance of unsightly wrinkles in the dried film. The reactive diluents of this invention allow relatively thick films to be applied - this is a considerable advantage for high solids and "one-coat" paints. The data in the table also show that very high solids contents can be achieved with the reactive diluents of this invention.

TABLE 5

Diluent Maximum film thickness¹* Solids content **

AK3R 300 97

* Expressed as bar coater gap width (microns) ** Solids content of paint in weight%

Example T2

Further paint formulations were prepared using the high solids resin with different concentrations of diluent (expressed as % cf. the resin, i.e. 10% means 10% diluent to 90% resin). Table 6 shows the hardness data from these samples, again demonstrating that films with good hardness can be obtained by using the diluents of this invention.

TABLE 6 (Hardness Data)

Diluent Used Indentation (microns) Konig hardness **

A K3R (10%) 1.68* 1.42# 11® 12#

AK3R (20%) 1.71* 1.45# 10® 10#

AK3R (30%) 2.59* 2.15# m 7#

White spirit 1.29* 1.1# 13® 16#

* After 1 week curing at 23°C # After 100 hours at 50°C @ After 3 weeks at 23°C

** In number of swings. Multiply by 1.4 to convert to seconds. 2.2 Tests of clearcoats (unpigmented paints) a) Methods used to prepare unpigmented "clearcoat" formulations i) Materials Used:

Unpigmented ("clearcoat") paint formulations were prepared using a high solids alkyd resin SETAL® 293 described in 2.1(a) above. In addition to the diluent, Siccatol® 938 drier (ex AKZO NOBEL) and methyl ethyl ketone- oxime (hereafter "MEK-oxime") anti-skinning agent were used. Where used, the white spirit was Exxon type 100. The nominal proportions ofthe above materials in the paint formulations were:

TABLE 7

Materials Parts by weight

Resin + Diluent 100.0

Siccatol 938 6.7

MEK-oxime 0.5

Note that, for white spirit formulations only, the proportions of drier and antiskinning agent were calculated on the basis ofthe resin only. Thus, the concentration of these components in the paint was lower than for other diluents. ii) Method of Preparation of Clearcoat Formulations

Alkyd resin and diluent were mixed in glass jars for 2 hours (eg using a Luckham multi-mix roller bed) in the proportions required to achieve a viscosity (measured via the ICI cone and plate method using a viscometer supplied by Research Equipment (London) Limited) of 0.68 ± 0.03 Pa s (6.8 ± 0.3 poise). Typically, this resulted in a mixture which was ca. 80% w/w resin. If further additions of diluent or resin were required to adjust the viscosity to

0.68 ± 0.03 Pa s (6.8 ± 0.3 poise), a further hour of mixing was allowed. The required quantity of drier was added and, after mixing (1 hour), the required amount of anti-skinning agent was added. After final mixing for at least 30 minutes, the viscosity ofthe mixture was measured to ensure that the viscosity was between 0.61 and 0.69 Pa s (6.1 and 6.9 poise).

The mixture ("formulation") was then divided into two tins and sealed so as to leave ca. 10-15% v/v headspace of air in the sealed jars. One of the tins was stored at 23 °C in darkness for 7 days before paint applications tests were performed. The second tin was stored ("aged") at 35°C in daylight for 14 days before applications tests were performed. b) Test methods used for Clearcoat Formulations: i) Application of paint film:

Thin films were applied to cleaned glass test plates using Sheen cube or draw¬ bar applicators with a nominal 75μm gap width. ii) Viscosity:

The viscosity of each formulation was measured according to BS 3900 Part A7 with an ICI cone and plate viscometer (supplied by Research Equipment (London) Limited) at 23°C and at a shear rate of 10,000 reciprocal seconds. iii) Drying Performance: Drying performance was measured using films applied to 30 cm x 2.5 cm glass strips and BK drying recorders. The BK recorders were enclosed in a Fisons controlled temperature and humidity cabinet so that the drying experiment could be performed at 10°C and at 70% relative humidity. Sample performance was assessed on the basis ofthe dust drying time, T2. NB. It is well known by those skilled in the art that day-to-day fluctuations in conditions can introduce some variability into experimental data. To minimise these errors, the tests presented below were conducted as follows: ca. five to ten paint formulations were prepared simultaneously and comprised one reference (white spirit) and four to nine reactive diluent-based paints. These samples were tested at the same time under identical conditions. Comparison of performance data from within these groups of formulations allowed errors due to random sources to be minimised. c) Drying Speed Data from clearcoats

The results in Tables 8 show that clearcoat paints based on the reactive diluents ofthe present invention reach the dust dry stage of drying within a period which is within about 4 hours of a traditional white spirit-based paint. These properties are regarded as satisfactory by the industry.

TABLE 8

Diluent Used Drying times (hours)

Paint stored for 1 week Paint stored for 2 weeks at 23°C at 35°C

AK3R 6.1 5.7

White spirit 3.9 3.8

Claims

Claims:

1. A compound ofthe formula (I):

[R*O.C(O)]„R" (I) wherein

R" represents at least a divalent -CH=CH- group or a -CH₂-CHR⁵- residue in which R⁵ is H or a saturated or an unsaturated hydrocarbyl(oxy) group, which may be the same as or different from R* and wherein

(R⁴)(R³)C=C(R²).CH(R¹).OH (II) in which

R is H, a C1-C4 alkyl group or a hydrocarbyloxy alkylene group R is H, a C1-C4 alkyl group or a hydrocarbyloxy alkylene group,

R³ is H, or a C1-C4 alkyl group, R is H, or a straight or branched chain alkyl group, or, an alkenyl group having 3-7 carbon atoms, or, an aryl group or an aralkylene group having 2-10 carbon atoms, or, a saturated hydrocarbyl(oxy) group having 2-10 carbon atoms, and if said group is an aryloxy group it has 7-10 carbon atoms, or, R when taken together with R¹ forms a cyclic alkylene group with alkyl substituents therein and in which case R is H, such that at least one ofthe groups R^!-R⁴ is other than H.

2. A compound according to Claim 1 wherein R* is derived from allylic alcohols of formula (II) selected from the group consisting of 2-ethyl-hex-2-en-l-ol; 2-ethyl allyl alcohol; hept-3-en-2-ol; 4-methyl pent-3-en-2-ol; n-oct-2-enol; 4-tert-butoxy but- 2-en-l-ol; 4-(α-methylbenzyloxy) but-2-en-l-ol; 4-(α-dimethylbenzyloxy) but-2-en-l- ol; 4-n-butoxy but-2-en-l-ol; cinnamyl alcohol; and isophorol.

3. A compound of formula (I) according to Claim 1 which is 2-(2-ethyl hexenyloxy) di-(2-ethyl hexenyl) succinate.

4. A compound of formula (I) according to Claim 1 which is di-(2-ethyl hexenyl) fumarate.

5. A compound of formula (I) according to Claim 1 which is di-(2-ethyI hexenyl) maleate.

6. A process for producing compounds ofthe formula (I) as claimed in Claim 1, said process comprising reacting an allylic alcohol or a non-allylic alcohol of formula (II) with a carboxylic acid and/or anhydride, an acid halide or an ester in the presence of a catalyst which does not cause undue polymerisation or rearrangement ofthe allylic groups in the allylic alcohol.

7. A process according to Claim 6 wherein the catalyst is an amphoteric catalyst.

8. A process according to Claim 6 or 7 wherein the catalyst is dibutyl tin oxide.

9. A paint or polmer formulation comprising a compound ofthe formula claimed in any one of Claims 1 to 5 as reactive diluent.

10. A paint or polymer formulation according to Claim 9 wherein said formulation comprises alkyd resins.

11. A paint or polymer formulation according to Claim 10 wherein the ratio of reactive diluent to alkyd resin in the paint or polymer formulation is in the range from

1-50 : 99-50 parts by weight.

12. A paint or polymer formulation according to any one ofthe preceding Claims

9-11 wherein said formulation comprises one or more further components selected from the group consisting of catalyst, drier, antiskinning agent, pigments, water scavengers and pigment stabilizers.

13. A formulation according to any one ofthe preceding Claims 9-12 wherein the acidity ofthe ester mixture used as reactive diluent in such formulations has a value of

< 7000 ppm w/w of KOH.

14. A formulation according to Claim 13 wherein the acidity ofthe ester mixture used as reactive diluent in such formulations has a value of < 1000 ppm w/w of KOH.

15. A formulation according to Claim 9 wherein said formulation comprises in addition a polymerisation inhibitor.

16. A formulation according to Claim 15 wherein the inhibitor is 2,6-butoxy-4- methyl-phenol or 2,4,6-tert-butyl phenol.