WO2006068483A1

WO2006068483A1 - Half esters and coating compositions comprising reactions products of half esters and polyepoxides

Info

Publication number: WO2006068483A1
Application number: PCT/NL2005/050088
Authority: WO
Inventors: Rolf Blaauw; Wilhelmus Johannes Mulder; Roelof Koelewijn; Gerard Boswinkel
Original assignee: Agrotechnology And Food Innovations B.V.
Priority date: 2004-12-20
Filing date: 2005-12-20
Publication date: 2006-06-29

Abstract

The present invention relates to half esters based on dicarboxylic acid derivatives and dimer fatty diols, wherein the dimer fatty dio ls are based on dimerised and/or trimerised and/or oligomerised unsaturated fatty acids. The present invention further relates to resin compositions based on the half ester and an polyepoxide. The resin composition can be used in high solids coatings, inks, adhesives, wall covering products, flooring products and plastic products.

Description

Half esters and coating compositions comprising reactions products of half esters and polyepoxides

Field of invention

This invention relates to half esters based on dicarboxylic acid derivatives, preferably 1,2-dicarboxylic acid derivatives, and dimer fatty diols, wherein the dimer fatty diols are based on dimerised unsaturated fatty acids. The invention also relates to reaction products of these half esters and a polyepoxide. These reaction products are useful in coating compositions such as high solids coatings, inks and adhesives as well as for wall and flooring applications and plastic products for which a combination of flexibility, water resistance and an ecologically friendly profile are important.

Background of invention

Half esters formed by the reaction of polyols and dicarboxylic acid derivatives, e.g. dicarboxylic acid anhydrides, are known in the art. These half esters can be used in resin and coating formulations as copolymerisable or crosslinkable agents. In the prior art basically two polymerisation routes are disclosed.

The first route is free radical addition copolymerisation with ethylenically unsaturated monomers, e.g. styrene. For instance, US 3.784.586 discloses a composition that can be polymerised by free radical initiators such as peroxides, wherein the composition consists of oligoesters having terminal carboxylic acid groups, a vinyl monomer and a polymerisation inhibitor. The oligoesters having terminal carboxylic groups are formed by reaction of maleic anhydride and saturated or unsaturated polyhydroxy compounds. The vinyl monomer may be styrene or a derivative thereof, a derivative of (meth)acrylic acid, vinyl acetate and the like.

US 4.263.413 discloses compositions that can be polymerised by free radical initiators, wherein the compositions comprise a half ester of an unsaturated polyol having terminal carboxylic groups, maleic anhydride, an ethylenically unsaturated monomer and a basic compound as catalyst. The unsaturated polyol is formed from maleic anhydride and a saturated organic polyol. The ethylenically unsaturated monomer may be styrene or a derivative thereof, a derivative of (meth)acrylic acid, vinyl acetate and the like. However, if the ethylenically unsaturated monomer is styrene or a derivative thereof, rigid products are ultimately obtained that are disadvantageous where flexibility is desired or required. Furthermore, the polyols used to prepare the half esters disclosed in US 3.784.586 and US 4.263.413 are not based on natural, renewable raw materials.

The second route is condensation polymerisation to e.g. polyesters by reaction of the carboxylic acid groups of the half ester with a polyepoxide. For example, US 4.403.093 discloses an ungelled polyester oligomer comprising reacting a 1,2- dicarboxylic anhydride with a saturated polyol to form a half ester followed by reaction of the half ester and a polyepoxide. The ungelled polyester oligomer can be used in high solid coating formulations wherein as curing agent an aminoplast (obtained by condensation of formaldehyde and an amine or amide) or a polyisocyanate is employed.

US 4.703.101 discloses a cross-linkable composition comprising an epoxy containing acrylic polymer and a polyacid as curing agent, The epoxy-containing acrylic polymer is obtained by free radical initiated copolymerisation of an ethylenically unsaturated monomer having at least one epoxy group and an ethylenically unsaturated monomer that does not contain an epoxy group. The polyacid curing agent is obtained by reacting a 1,2-dicarboxylic acid anhydride and a polyol, wherein the polyol may be a simple polyol comprising two to twenty carbon atoms, e.g. aliphatic saturated polyols or aromatic polyols such as bisphenol A, or a polymeric polyol, e.g. a polyesterpolyol or a polyurethane polyol. Again, the polyols used to prepare the half esters disclosed in US 4.403.093 and US 4.703.101 are not based on natural, renewable raw materials.

The use of polyols based on natural, renewable materials in the preparation of half esters is also known in the art. For example, the reaction between vegetable oil based polyols and 1,2-dicarboxylic acid anhydrides is disclosed in US 6.121.398. US 6.121.398 discloses a process for the manufacture of a rigid resin wherein maleic anhydride is first converted with hydroxylated plant or animal derived glycerides to a half ester. The half ester is subsequently converted with an ethylenically unsaturated monomer, e.g. styrene or a (meth)acrylate acid derivative, by free radical copolymerisation. The hydroxylated plant or animal derived glycerides comprise various reactive sites that can be used for further functionalisation. For example, the triglycerides may be oligomerised via the carbon-carbon double bonds in the fatty acid residues to materials which, however, are explicitly said to be unsuitable for high modulus liquid moulding resins (cf. US 6.121.398, column 6, lines 48 - 54 and column 7, lines 20 - 28). Instead, US 6.121.389 therefore recommends to functionalise the triglycerides prior to the reaction with maleic anhydride to the half ester, e.g. by functionalising the carbon-carbon double bonds in the fatty acid residues by for example epoxidation, maleinisation, hydroxylation and the like. Hence, US 6.121.389 is directed to the preparation of rigid resins.

US 5.798.434 discloses the oligomerisation of unsaturated fatty acids to pure dimers or mixtures of dimers and trimers, whereafter the carboxylic groups of these pure dimers or mixtures of dimers and trimers are reduced to hydroxy groups so that pure dimeric diols or mixtures of dimeric diols and trimeric triols are obtained. Alternatively, the pure dimeric diols or the mixture of dimeric diols and trimeric triols may be directly obtained by oligomerisation of unsaturated fatty alcohols. In a subsequent step, the pure dimeric diols or the mixtures of dimeric diols and trimeric triols are esterified with α,β-unsaturated carboxylic acids or transesterified with alkyl esters of α,β-unsaturated carboxylic acids. The esters so obtained may be homopolymerised or copolymerised with ethylenically unsaturated monomers, e.g. styrene or (meth)acrylic acid derivatives, by free radical initiated polymerisation (cf. US 5.798.434, column 7, lines 25 - 44). Hence, US 5.798.434 is not directed to condensation polymers such as polyesters.

DE A 4.135.664 discloses coating compositions based on renewable raw materials, where these coating compositions comprise a combination of epoxidation products of esters of unsaturated fatty acids having a chain length of C₈ to C22 with polyvalent aliphatic alcohols containing 2 to 6 carbon atoms, wherein these epoxidation products contain on average more than one epoxide group per molecule, and partial esters of polycarboxylic acids with polyether polyols, which esters contain at least two free carboxyl groups per molecule and contain a double bond in the α,β-position to the free carboxyl groups, and a hydrophobicising agent. Summary of invention

According to a first embodiment, the present invention provides a half ester obtainable by reacting a dicarboxylic acid derivative having 4 - 30 carbon atoms with a dimer fatty diol, wherein the dimer fatty diol has a number average molecular weight of about 300 to about 3000.

In this patent application a dimer fatty diol is defined as a product that can be obtained by one of the following processes that are well known in the art (cf. for example US 5.250.494, US 5.545.692, US 5.563.206, and US 5.798.434): (a) oligomerisation of an unsaturated fatty acid via carbon-carbon double bonds followed by hydrogenation of the carboxylic groups to hydroxy groups;

(b) hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols followed by oligomerisation of the unsaturated fatty alcohol;

(c) oligomerisation of an unsaturated fatty acid ester via carbon-carbon double bonds, wherein the ester is prepared from an unsaturated fatty acid and a C₁-C₂₀ alcohol, followed by hydrogeno lysis of the ester groups to hydroxy groups;

(d) oligomerisation of a dimer fatty diol with a C₂-C₂₀ diol to form a hydroxy terminated polyether diol or dimerisation or oligomerisation of a dimer fatty diol to a hydroxy terminated polyether diol; (e) oligomerisation of a dimer fatty diol with a C₂-C₂₀ dicarboxylic acid derivative or a C₁-C₄ alkyl ester of inorganic acids selected from the group consisting of carbonic acid, phosphoric acid, phosphorous acid, sulphuric acid and sulphurous acid to form hydroxy terminated polyester diols;

(f) conversion of a dimer fatty acid with a C₂-C₂₀ diol, a dimer fatty diol or a mixture thereof; and

(g) conversion of a dimer fatty acid or a dimer fatty diol with ethylene oxide, propylene oxide, a mixture of ethylene oxide and propylene oxide, hydroxy terminated polyethylene oxides, hydroxy terminated polypropylene oxides, hydroxy terminated ethyleneoxide-propyleneoxide copolymers or a mixture of these (co)polymers, wherein these copolymers have a number average molecular weight of about 100 to about 2500. According to a second embodiment, the present invention provides a resin composition comprising a reaction product obtainable by reacting a half ester according to the present invention and a polyepoxide.

Brief description of drawings

Figure 1 schematically depicts a reaction product of the reaction described in Example 1.

Figure 2 schematically depicts an embodiment of the invention wherein a dimer fatty diol, prepared by reaction of a dimer fatty acid with trimethylolpropane, is reacted with 3 or 4 equivalents of maleic acid anhydride, as described in Example 4.

Description of invention

The half ester according to the present invention is obtainable by reacting a dicarboxylic acid derivative having 4 - 30 carbon atoms with a dimer fatty diol, wherein the dimer fatty diol has a number average molecular weight of about 300 to about 3000.

According to the present invention, a "half ester" in this description means that in addition to an ester group a free carboxylic acid group is present in the molecule according to the following general formula (I):

HO(O)C-R¹ -C(O)OR² (I)

wherein R¹ represents the residue of a dicarboxylic acid derivative according to general formula (II) defined below and R² represents the residue of the dimer fatty diol also defined below. In this respect it should be noted that according to the broadest definitions for R¹ and R² included in this specification the total number of carboxylic groups in the dicarboxylic acid derivative is in the range of 2 - 6 and the total number of hydroxy groups in the dimer fatty diol is in the range of 2 - 6. Hence, as will be apparent to the person skilled in the art, the half ester according to the present invention can be a complex molecule in which the ratio of carboxylic groups and ester groups is not exactly 1 : 1. Consequently, according to the present invention, the ratio of carboxylic groups and ester groups will in general be in the range of about 2.5 : 1 to about 1 : 2.5, preferably be in the range of about 1.5 : 1 to about 1 : 1.5, more preferably about 1.2 : 1 to 1 : 1.2 and most preferably about 1.1 : 1 to about 1 : 1.1. It will further be apparent to the person skilled in the art that according to the general formula (I) the group R² may also include additional halfester groups. For example, a dimer fatty diol may be reacted with two molar equivalents of maleic anhydride to form a compound in which two half ester moieties are present.

According to the present invention, the term "carboxylic acid" and "carboxylic acid derivative" includes in general acids, esters, acid halides such as acid chlorides and anhydrides.

The dimer fatty diol

In this description reference is sometimes interchangeably made to only dimer fatty acids and dimer fatty diols. It should be understood that both products are intended where appropriate.

The dimer fatty diols used to make the half esters of the present invention are based on dimer fatty acids, a class of compounds well-known in the art. The dimer fatty diols can for example be prepared from fatty acids by processes described above.

For example, if the dimer fatty diols are prepared from fatty acids, the fatty acids are preferably C₁₂ to C₂₄, and particularly C₁₆ to C₁₈ unsaturated fatty acids. Examples of suitable fatty acids include oleic, linoleic, linolenic, palmitoleic, elaidic, calendic, erucic acid and mixtures thereof. Also suitable are the unsaturated fatty acid mixtures obtained by hydrolysis of natural fats and oils, such as sunflower oil, soybean oil, olive oil, rapeseed oil, cotton seed oil, calendula oil, and tall oil. Alternatively, if the dimer fatty diols are prepared from dimerised fatty acids, the dimerised fatty acids are prepared from iatty acids having the features described above.

Whereas dimer fatty acids are the main products of the dimerisation proces, usually varying amounts of oligomeric fatty acids ("trimer fatty acids" and higher oligomers) and isomerised monomeric fatty acids (e.g. isostearic acid) are formed as well. The fraction of dimer fatty acids can be increased by e.g. distillation. For the purposes of the present invention, no particular requirements for the purity and composition of the dimer fatty acids are necessary, although it is preferred that the fraction of isomerised monomeric fatty acid does not exceed 5%. According to an embodiment of the invention it is preferred that the dimer fatty acid comprises at least 70% pure dimer, more preferably at least 75 % pure dimer. On the other hand, if a higher degree of cross-linking is required, it may be advantageous to employ a dimer fatty acid comprising a very high amount of trimer. As will be obvious to those skilled in the art, it is preferred according to the present invention that dimer fatty diols prepared from these dimer fatty acids also comprise at least 70% pure dimer. Likewise, if the dimer fatty diols are prepared by e.g. process (b) described above, it is also preferred that the dimer content is at least 70%. But as will be apparent to the person skilled in the art, in certain applications it may be desired to employ a dimer fatty diol comprising a very high amount of trimer.

Consequently, according to this invention, the terms "dimer fatty diol" and "dimer fatty acid" are not limited to dimeric structures only but also include trimeric and oligomeric structures. However, for brevity, the term "dimer fatty diol" will be used throughout the description and include purified or unpurified product mixtures resulting from oligomerisation of the unsaturated fatty acids (cf. e.g. processes (a) - (e) described above). Commercially available dimer acids well suited for the present invention include those offered under trade names such as Pripol (ex. Uniqema), Empol (ex. Cognis) and Unidyme (ex. Arizona Chemical). Preferred examples of commercially available dimer fatty diols well-suited for the present invention include Pripol 2033, Priplast polyester polyols (Pripol and Priplast are trade names, both ex Uniqema), Sovermol (e.g. types 650 NS, 908, 909, 910 and 920), and Speziol C36/2 (Sovermol and Speziol are trade names, both ex Cognis). The term "dimer fatty diol" also includes products obtained by processes (f) and

(g) described above.

When in process (f) a C₂ - C₂₀ diol is employed, this term is meant to encompass not only the simple diols such as ethylene glycol and propylene glycol, but also simple higher polyols such as glycerol, trimethylolpropane, pentaerythritol and sorbitol. According to the invention, the total number of hydroxyl groups in the C₂ - C₂₀ diol is in the range of 2 - 6 hydroxy groups, preferably in the range of 2 - 4 hydroxy groups.

As will be apparent to those skilled in the art, other dicarboxylic acids may be used in addition to the dimer fatty acids in processes (f) and (g). Such other dicarboxylic acids are preferably C2-C2₀ hydrocarbyl dicarboxylic acids, wherein the hydrocarbylene group may be an alkylene, aralkylene, arylalkylene or arylene group. Examples of such other dicarboxylic acids are adipic acid, glutaric acid, sebacic acid, succinic acid, 1,6-cyclohexane dicarboxylic acid and terephtalic acid.

The dicarboxylic acid derivative

The dicarboxylic acid derivative to be used for reaction with the dimer fatty diol can be represented by the general formula (II):

R³OC - R¹ - COR³ (II)

wherein R¹ is an alkylene group having 2 - 28 carbon atoms, an arylalkylene group having 7 - 28 carbon atoms, an alkarylene group having 7 - 28 carbon atoms or an arylene group having 6 - 28 carbon atoms. Preferably, the alkylene group has 2 - 10 carbon atoms, the arylalkylene and alkarylene groups 7 - 10 carbon atoms and the arylene groups 6 - 10 carbon atoms, wherein R³ is selected from the group consisting of OH, X and OR⁴, wherein X is halogen, preferably chlorine or bromine, and R⁴ is a C₁ - C₁₂, preferably C₁ - C₆ alkyl group, a C₇ - C₁₂ arylalkyl group, a C₇ - C₁₂ alkaryl group or a C₆ - C₁₂ aryl group, and wherein two R³ groups may form an anhydride group. In other words, any of the carboxylic groups of the dicarboxylic acid derivative may be in the form of acid halide groups -COX wherein X is a halogen and wherin the halogen X is preferably chlorine or bromine or in the form of an ester group -COR⁴ wherein R⁴ is as defined above. The dicarboxylic acid derivative may also be in the form of an anhydride or a partial anhydride when the dicarboxylic acid derivative comprises more than two carboxylic groups. As will be apparent to the person skilled in the art, both R³ groups in formula (II) may be different.

The alkylene, arylalkylene, alkarylene and aryl groups may be substituted with one or more C₁ - C₄ alkyl groups, one or more halogen atoms or one or more carboxylic groups. The alkylene groups may be saturated or unsaturated, linear and/or branched. If the alkylene, arylalkylene, alkarylene or aryl groups are substituted with one or more carboxylic groups, it is preferred that the total number of carboxylic groups in the dicarboxylic acid derivative is in the range of 2 - 6, preferably 2 - 4. A suitable example of a dicarboxylic acid derivative having more than two carboxylic groups is citric acid and 1,2,3-propene tricarboxylic acid (cis-aconitic acid).

According to the invention, it is preferred to employ a 1,2-dicarboxylic acid derivative, in particular a 1,2-dicarboxylic acid anhydride. Suitable 1,2-dicarboxylic acid anhydrides according to the invention are succinic, dodecenylsuccinic, octadecenylsuccinic, maleic, citraconic, itaconic, citric, O-acetylcitric, phthalic, trimellitic, hexahydrophthalic, tetrahydrophthalic and methyltetrahydrophthalic acid anhydride. Preferably, the 1,2-dicarboxylic anhydride is maleic acid anhydride, citric acid anhydride or O-acetylcitric acid anhydride. The dimer fatty diol may obviously also be reacted with a combination of anhydrides.

The half ester

Reaction of the dimer fatty diol with the dicarboxylic acid derivative provides the half esters according to the present invention. The ratios in which the dimer fatty diol and the dicarboxylic acid derivative are reacted may vary. However, these ratios are selected such that the ratio of carboxylic groups and ester groups in the half esters according to the invention is in the range of about 2.5 : 1 to about 1 : 2.5, preferably about 1.5 : 1 to about 1 : 1.5, more preferably about 1.2 : 1 to 1 : 1.2 and most preferably about 1.1 : 1 to about 1 : 1.1. The person skilled in the art is well capable of calculating the corresponding ratios of the reactants that must be used which is dependent from the particular structure of the reactant. For example, one molar equivalent of dimer fatty diol may be reacted with two molar equivalents of maleic acid anhydride so that on average the half ester contains two ester groups and two carboxylic groups (ratio of carboxylic groups and ester groups is then about 1). Above it is noted that it will be apparent to the person skilled in the art in which ratios the dimer fatty diol and the dicarboxylic acid derivative have to be reacted to produce a half ester according to the invention. However, it is in general preferred that the ratio of dimer fatty diol : dicarboxylic acid derivative is in the range of 1 : 2 to 1 : 15. In case the dimer fatty diol is prepared according to any one of the processes (a) - (e) described above, it is more preferred that the ratio of dimer fatty diol : dicarboxylic acid derivative is in the range of 1 : 2 to 1 : 3. On the other hand, if the dimer fatty diol is prepared according to process (f) or (g) described above and the dimer fatty diol is a C₂ - C₂₀ diol having 2 - 6 hydroxy groups, the ratio of dimer fatty diol : dicarboxylic acid derivative is preferably 1 : 2 to 1 : 15. Obviously, if the dimer fatty diol is prepared according to process (f) or (g) described above and the dimer fatty diol is the preferred C₂ - C₂₀ diol having 2 - 4 hydroxy groups, the preferred ratio of dimer fatty diol : dicarboxylic acid derivative is then 1 : 2 to 1 : 9.

According to a first preferred embodiment of the invention, the half esters are obtainable by a process comprising the following steps:

(a) reacting a dimer fatty acid with a C₂-C₂₀ diol to form a dimer fatty diol; and

(b) reacting the dimer fatty diol with a 1,2-dicarboxylic acid derivative to form a half ester wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of about 2.5 : 1 to about 1 : 2.5, preferably about 1.5 : 1 to about 1 : 1.5, more preferably about 1.2 : 1 to 1 : 1.2 and most preferably about 1.1 : 1 to about 1 : 1.1.

The half ester according to the preferred embodiment of the invention may schematically be described by general formula (III):

HOOC - A - C(O)O - B - O(O)C - C - C(O)O - B - O(O)C - A - COOH (III)

wherein A is the dicarboxylic acid residue, B the C₂-C₂₀ diol residue and C the dimer fatty acid residue (so that B and C constitute in combination the dimer fatty diol residue as obtained in step (a)).

According to second preferred embodiment of the invention, the half esters are obtainable by a process comprising the following step:

(a) reacting a dimer fatty diol with a 1,2-dicarboxylic acid derivative to form a half ester wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of about 2.5 : 1 to about 1 : 2.5, preferably about 1.5 : 1 to about 1 : 1.5, more preferably about 1.2 : 1 to 1 : 1.2 and most preferably about 1.1 : 1 to about 1 : 1.1, and wherein the the total number of carboxylic groups in the dicarboxylic acid derivative is in the range of 2 - 6, preferably 2 - 4. An example of a half ester according to this second preferred embodiment is the half ester obtained from a dimer fatty diol and two molar equivalents of citric acid anhydride. According to a first more preferred embodiment of the present invention, the half ester is formed from a dimer fatty diol and a dicarboxylic acid derivative having a total number of 2 - 4 carboxy groups, more preferably three carboxy groups, wherein the molar ratio of the dimer fatty diol and the dicarboxylic acid derivative is about 1 : 1.5 to about 1 : 2.5, preferably about 1 : 1.8 to about 1 : 2.2, more preferably about 1 : 1.9 to about 1 : 2.1 and most preferably about 1 : 2 (in the latter case the ratio of carboxy lie groups to ester groups will be about 2 :1).

According to a second more preferred embodiment of the present invention, the half ester is formed from a dimer fatty diol and about 2.5 - 3.5, preferably 2.8 - 3.2, more preferably 2.9 - 3.1 and most preferably about 3 molar equivalents of a dicarboxylic acid derivative having a total number of two carboxylic groups, wherein the dimer fatty diol is prepared from a dimer fatty acid comprising a very high amount of trimer, preferably at least 90% by weight, based on the total weight of the dimer fatty acid, that is esterified with an equimolar amount of trimethylolpropane. According to the most preferred ratio of dimer fatty diol to dicarboxylic acid derivative , the end product will have an acid to ester ratio of about 3 : 6 = about 1 : 2.

The reaction of the dimer fatty diol and the dicarboxylic acid derivative is performed at temperatures lower than 150°C, preferably between 70° and 120°C, preferably in an inert atmosphere. Temperatures higher than 150°C are undesirable because they promote polyesterification. Temperatures lower than 50°C are generally undesirable since then the reaction proceeds too slowly. Hence, the invention also relates to a method for the preparation of a half ester, wherein the dimer fatty diol and the 1,2-dicarboxylic acid derivative are reacted at temperatures between 50° and 150°C, preferably under an inert atmosphere. Reaction times may vary, and are dependent for example on conversion, the molecular structure of the dimer fatty diol and of the 1,2-dicarboxylic acid derivative used, and the reaction temperature. Usually reaction is continued until a sample shows the desired conversion which is determined by measuring the acid value of the end product.

Reaction products of the half esters

The half esters are useful as flexible building blocks in e.g. epoxy and polyester polymerisations. The half esters are excellent curing agents or comonomers for resins, adhesives, coatings, sizing agents, inks, toners, floor coverings, etc., and other applications where a combination of flexibility, hydrophobicity and water resistance are beneficial. The invention also comprises the use of the half esters of the invention, or coating compositions derived thereof, e.g. in the above-mentioned applications. Except when processes (d) or (g) are used, no ether bonds are present, which makes the half esters of the invention more stable against thermal or UV degradation or oxidation.

According to the invention, the half esters are converted with a polyepoxide having an 1,2-epoxide equivalency (i.e. the number of epoxy groups in a single molecule) of at least 1 to about 6. The polyepoxides according to the invention are preferably selected from the group consisting of epoxidised fatty acid derivatives. According to the invention, the polyepoxide is most preferably an epoxidised fatty acid triglyceride (e.g. an epoxidised vegetable oil).

Epoxidised fatty acid derivatives are preferably C₁₂ - C₂₄, more preferably C₁₄ - C₂₂ epoxidised fatty acid derivatives. The epoxidised fatty acids may have been obtained by epoxidaton of the pure unsaturated fatty acids with peroxyacetic acid, peroxyformic acid or hydroperoxide. For example, GB B 811.852 discloses a process for the manufacture of epoxidised fatty acids. Alternatively, the epoxidised fatty acids may also have been obtained from animal or vegetable origin, i.e. that they are obtained from oils comprising unsaturated fatty acids such as epoxidised linseed oil, epoxidised soybean oil, epoxidised tall oil and the like, and will therefore constitute a mixture of epoxidised fatty acids having different carbon numbers. In this way, the resin composition may almost completely be based on materials from e.g. vegetable sources, since both the dimer fatty diol and the polyepoxide are based on vegetable oils. According to the invention, the term "epoxidised fatty acid derivatives" is also to be understood as to encompass epoxided triglycerides and oils.

Polyepoxides may also have an 1,2-epoxy equivalency greater than 1 up to about 6.. Such polyepoxides are disclosed in for example US 4.403.093. More preferably, the polyepoxides are glycidyl ethers of polyhydric phenols, cyclic polyols, glycidyl ethers of polyhydric alcohols. The polyepoxides may be prepared by the base catalysed etherification of the polyhydric phenol and an epihalohydrin, preferably epichlorohydrin. The polyphenols have preferably 6 to 20 carbon atoms. Suitable examples of polyhydric phenols include bisphenol A, l,l-bis(4-hydroxyphenyl)ethane and 2-methyl-l,l-bis(4-hydroxyphenyl)propane. Suitable examples of cyclic polyols include in particular C₆ - C₁₂ cycloaliphatic polyols such as 1,2-cyclohexane diol and 1,4-cyclohexane diol. The polyhydric alcohols are preferably C₂ - C₁₂ alcohols such as ethylene glycol, diethylene glycol, 1,2-propylene glycol and the like.

The resin compositions according to the present invention have as advantages that they are flexible or can be converted into flexible products (e.g. flexible rubbers) and may also be hydrophobic. In applications known from the art (for example DE 4.135.664), hydrophobicising agents have to be added, whereas for the resin composition of the present invention, this is usually not necessary. When polymers are formed, they have low glass transition temperatures. The resin compositions according to the present invention or the reaction products comprised by the coating compositions are very suitable for various applications. These applications include high solids coatings, inks, adhesives, flooring products and plastic products. In particular the resin compositions according to the present invention that are derived from a polyepoxide as described above are especially useful in flooring applications because of their wear-resistance, flexibility, hydrophobicity and elasticity.

Examples

Example 1: Preparation of half ester

200 parts by weight of dimer fatty diol (Pripol 2033 from Uniqema) and 73 parts by weight of maleic anhydride were reacted at 100°C under nitrogen for 1 to 2 hours. The reaction is exothermic, and an ice bath was used in case the temperature exceeded 120°C. Stirring at 100°C is continued until a sample of the mixture had an acid number between 150 and 160. The product is a moderately viscous clear liquid. Example 2: Flexible elastomer

153 parts by weight of the half ester from Example 1 and 100 parts by weight of epoxidised linseed oil (Lankroflex L from Akcros Chemicals) were mixed and cured in an oven at 150°C for 15 minutes. A clear, almost colourless flexible elastomer was formed, which had a glass transition temperature of-20°C.

Example 3: Preparation of polyol from dimer fatty acid and trimethylolpropane

3 A. With 80/20 dimer/trimer ratio. Al parts by weight of trimethylolpropane were heated under nitrogen to 150°C. 100 parts by weight of Pripol 1017 (polymerised fatty acids of Uniqema containing ca. 80% dimer and 20% trimer acid) were added dropwise. Heating and stirring was continued until about 6 parts by weight of water were collected. Acid value was 32.

3B. With 96/4 dimer/trimer ratio. 497 parts by weight of trimethylolpropane were heated under nitrogen to 170°C. 1050 parts by weight of Pripol 1006 (polymerised fatty acids of Uniqema containing ca. 96% dimer and 4% trimer acid) were slowly added dropwise. Heating and stirring was continued until about 60 parts by weight of water were collected. Acid value was 12.

Example 4: Preparation of half ester from dimer TMP-ester

4 A. 40 parts by weight of the dimer fatty polyol prepared as in Example 3 A and

15 parts by weight of maleic anhydride were heated under nitrogen to 90°C for 4 hours. The product is a dark yellow viscous liquid.

4B. 45 parts by weight of the dimer fatty polyol prepared as in Example 3 A and 22 parts by weight of maleic anhydride were heated under nitrogen to 90°C for 4 hours. The product is a brown viscous liquid.

4C. 1294 parts by weight of the dimer fatty polyol prepared as in Example 3 B were heated to 70°C. 475 parts by weight of maleic anhydride were added in small portions, during which the temperature was not allowed to exceed 100°C by means of an ice bath. Heating under nitrogen was continued at 90°C for 4 hours. The product is a slightly yellow viscous liquid. Acid number was 154. Example 5: Flexible elastomer

250 parts by weight of epoxidised linseed oil (Lankroflex L from Akcros Chemicals) and 380 parts by weight of the half ester of Example 4C were mixed. The mixture was poured into an aluminum mould and cured in an oven at 150°C for 30 minutes. A clear, slightly yellow, tack free flexible sheet of 1 mm thickness was obtained. Physical and mechanical properties: Glass transition temperature 8°C, E- modulus 9 MPa, tensile strength 4 N/mm², elongation at break 62%.

Example 6: Hydrophobic flexible paper coating

100 parts by weight of the half ester of Example 1, 65 parts by weight of epoxidised linseed oil (Lankroflex L from Akcros Chemicals) and 4 parts by weight of silica (Aerosil Rl 06 from Degussa) were mixed, and the mixture was applied on 200 g/m² Kraftliner paper with a wire bar. The coated paper was heated in an oven at 225°C for 4 min. Coating weight of the dried paper was approximately 38 g/m². The coated paper had a Cobb 1800 value of 3 g/m².

Example 7: Laser engravable printing plate

Following the procedure of Example 5, a polymer sheet of 2 mm thickness was prepared. The sheet was taped on a rubber plate cylinder. After optimisation of the focus point, a 48 lines screen was engraved in the rubber using a carbon dioxide laser device. Following the laser treatment, the engraved sheet was treated with a roller containing desk stamp ink. The image was transferred onto paper. A detailed image with good dot quality and sharpness was obtained.

Example 8: Product Properties

The compositions according to Examples 4A - 4C showed the following properties (cf. Table 1).

Table 1

^a Pa. ^b N/mm². ^c %. ^d I and II were prepared according to the method disclosed in DE A 4.135.664; I with dipropyleneglycol dimaleate and II with trimethylolpropane trimaleate.

From the data of Table 1 it appears that the products prepared according to DE A 4.135.664 have either a high modulus/high tensile strength and a low elongation at break or a low modulus/low tensile strength and a high elongation at break while the products according to the present invention have a high modulus, high tensile strength and a high elongation at break. The products according to DE A 4.135.664 also have a relatively high T_g when compared to the T_g of the compositions according to the present invention.

Claims

1. Half ester obtainable by reacting a dicarboxylic acid derivative having 4 - 30 carbon atoms with a dimer fatty diol, wherein the dimer fatty diol has a number average molecular weight of 300 to 3000.

2. Half ester according to Claim 1, wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of 2.5 : 1 to 1 : 2.5.

3. Half ester according to Claim 1 or Claim 2, wherein the dicarboxylic acid derivative is represented by the general formula (II):

R³OC - R¹ - COR³ (II)

wherein R¹ is an alkylene group having 2 - 28 carbon atoms, an arylalkylene group having 7 - 28 carbon atoms, an alkarylene group having 7 - 28 carbon atoms or an arylene group having 6 - 28 carbon atoms, the alkylene, arylalkylene, alkarylene and aryl groups optionally being substituted with one or more C₁ - C₄ alkyl groups, one or more halogen atoms or one or more carboxylic groups,, wherein R³ is selected from the group consisting of OH, X and OR⁴, wherein X is halogen, preferably chlorine or bromine, and R⁴ is a C₁ - C₁₂, preferably C₁ - C₆ alkyl group, a C₇ - C₁₂ arylalkyl group, a C₇ - C₁₂ alkaryl group or a C₆ - C₁₂ aryl group, and wherein two R³ groups may form an anhydride group.

4. Half ester according to Claim 3, wherein the total number of carboxylic groups in the dicarboxylic acid derivative is in the range of 2 - 6.

5. Half ester according to any one of Claims 1 - 4, wherein the dicarboxylic acid derivative is a 1,2-dicarboxylic acid derivative.

6. Half ester according to Claim 5, wherein the 1,2-dicarboxylic acid derivative is a 1,2-dicarboxylic acid anhydride.

7. Half ester according to Claim 6, wherein the 1,2-dicarboxylic acid anhydride is selected from the group consisting of maleic acid anhydride, citric acid anhydride or O-acetylcitric acid anhydride.

8. Half ester according to any one of Claims 1 - 7, wherein the dimer fatty diol is prepared by reacting a dimer fatty acid with a C₂-C₂₀ diol.

9. Half esters according to any one of Claims 1 - 8, obtainable by a process comprising the following steps:

(a) reacting a dimer fatty acid with a C2-C2₀ diol to form a dimer fatty diol; and

(b) reacting the dimer fatty diol with a 1,2-dicarboxylic acid derivative to form a half ester wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of about 2.5 : 1 to about 1 : 2.5.

10. Half esters according to any one of Claims 1 - 8, obtainable by a process comprising the following steps:

(a) reacting a dimer fatty diol with a 1,2-dicarboxylic acid derivative to form a half ester wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of about 2.5 : 1 to about 1 : 2.5, preferably about 1.5 : 1 to about 1 : 1.5, more preferably about 1.2 : 1 to 1 : 1.2 and most preferably about 1.1 : 1 to about 1 : 1.1, and wherein the total number of carboxylic groups in the dicarboxylic acid derivative is in the range of 2 - 6,

11. Process for the preparation of a half ester, wherein the process comprises the step of reacting a dicarboxylic acid derivative having 4 - 30 carbon atoms with a dimer fatty diol, wherein the dimer fatty diol has a number average molecular weight of 300 to 3000.

12. Process according to Claim 11, wherein the ratio of carboxylic groups and ester groups in the half ester is in the range of 2.5 : 1 to 1 : 2.5.

13. Use of the half ester according to any one of Claims 1 - 10 in the preparation of a reaction product for resin compositions.

14. Resin composition comprising a reaction product obtainable by reacting the half ester according to any one of Claims 1 - 10 with a polyepoxide.

15. Resin composition according to Claim 14, wherein the polyepoxide is selected from the group consisting of epoxidised fatty acid derivatives.

16. Resin composition according to Claim 14 or Claim 15, wherein the polyepoxide is an epoxidised fatty acid triglyceride.

17. Use of the resin composition according to any one of Claims 14 - 16 in high solids coatings, inks, adhesives, wall covering products, flooring products and plastic products.