FIELD OF INVENTION

The instant invention relates to a rosin mixture comprising a modified rosin compound having a UV-absorbing moiety, to a method for preparing said rosin mixture, to compositions comprising said rosin mixture and to the use of said compositions as an adhesive formulation or a thermoplastic road marking formulation.

BACKGROUND Rosin, also called colophony or Greek pitch [Pix grasca) , is a solid form of resin obtained from pines and some other plants, mostly conifers. Rosin comprises a mixture of resin acids such as abietic or pimaric acids, the type depending in part on the plant species. The term "rosin" as used in this invention has this generally accepted meaning.

The term "rosin compound" as used herein means a resin acid, a rosin ester or a rosin derivative.

The term "rosin derivative" means a resin acid or a rosin ester which has been subjected to at least one reaction selected from a hydrogenation, a dehydrogenat ion, a

dimerization, and an addition.

Rosin compounds are useful in numerous applications, and are included in formulations such as adhesives, inks, coatings, rubbers, sealants, asphalt, and thermoplastic road markings. However, the use of such formulations is limited in applications where they are exposed to direct sunlight because rosin compounds, and other components typically present in such formulations (e.g. polymers), can be sensitive to UV radiation. Under exposure to sunlight, materials containing rosin compounds may suffer from a deterioration of their properties over time. For instance, adhesive compositions may suffer from yellowing, tend to crack and lose their adhesion properties when exposed to UV-radiation, ink compositions may suffer from color changes and rubbers, sealants, thermoplastic road markings and coatings may generally degrade.

In order to overcome such limitations it is common practice to add UV-protecting additives, such as UV filters, UV absorbers and/or UV stabilizers, to formulations which are exposed to sunlight. A problem associated with some of such additives is that they tend to migrate, and may present a health and/or environmental hazard. For instance, an additive may migrate to the surface of a packaging polymer, putting the additive in contact with consumable food or drink products.

Further, migration may leave parts of a formulation vulnerable to UV-radiation. Another reason that UV-protecting additives are not satisfactorily used can be that the addition of separate UV- protecting additives can add complexity to the preparation of the polymer formulations. The additives can be difficult to mix, alter the properties of the final formulation or be

incompatible.

There is a need for alternative UV-protecting additives, and in particular for UV-protecting additives which do not suffer from these problems.

There is also a need for rosin compounds that are more stable in polymer-containing formulations, such as adhesives, inks, rubbers, sealants, coatings, asphalt and thermoplastic road markings, in particular when exposed to UV light.

SUMMARY OF THE INVENTION

One aspect of this invention is a rosin mixture comprising at least one of a modified rosin compound optionally in admixture with unmodified rosin compounds; the modified rosin compound is a rosin compound that is modified to have a UV- absorbing moiety. It has now been discovered that modifying a rosin compound by attaching a UV-absorbing moiety thereto results in a compound having increased UV-resistance .

Another aspect of this invention is a rosin mixture that increases the stability of formulations (e.g. adhesives, coatings, inks, rubbers, sealants, asphalt and thermoplastic road markings), in particular formulations exposed to UV- radiation. It has now been discovered that such rosin mixtures containing a modified rosin compound can function in

formulations (such as adhesives, inks, coatings, rubbers, sealants, asphalt or thermoplastic road markings) as both common rosin mixtures (e.g. as tackifier and as a binder) and as a UV- protecting additives.

Such rosin mixtures may therefore be used as multifunctional components in formulations exposed to sun light, avoiding the need for using a separate UV-absorber. An advantage of using rosin mixtures comprising a modified rosin compound having UV-absorbing moiety, is that the formulation wherein it is used advantageously may have a reduced migration of the UV- absorber.

These and other advantages will become evident from the following more detailed description of the invention.

DETAILED DESCRIPTION

The term "modified rosin compound having a UV moiety" means a rosin compound that is modified so that it contains a UV-absorbing moiety. The term "rosin compound" is as defined hereinabove. Accordingly, a modified rosin compound having a UV- absorbing moiety of the rosin mixture as described herein, can be derived from a rosin ester, a resin acid or a rosin

derivative. The term "rosin derivative" is as defined

hereinabove. Rosin mixtures comprising modified rosin derived from a rosin ester and/or a resin acid are particularly useful because rosin esters and resin acids are used in numerous applications .

The rosin mixture as described herein is obtained from mixtures of rosin compounds. The mixtures of rosin compounds comprise at least one of a rosin ester, a resin acid and a rosin derivative, as defined above.

Resin acids generally include C20 fused-ring monocarboxylic acids with a nucleus of three fused six-carbon rings and double bonds that vary in number and location.

Examples of resin acids include abietic acid, neoabietic acid, dehydroabietic acid, pimaric acid, levopimaric acid,

sandaracopimaric acid, isopimaric acid and palustrxc acid.

Rosin can be used as a source of resin acid. Rosin is a hydrocarbon secretion of many plants, particularly coniferous trees such as Pinus palustris and Pinus caribaea . Natural rosin typically consists of a mixture of seven or eight resin acids, and in minor quantities other components. Rosin is commercially available and can be obtained from pine trees by distillation of oleoresin (gum rosin being the residue of distillation) , by extraction of pine stumps (wood rosin) or by fractionation of tall oil (tall oil rosin) . Any type of rosin can be used as a source of resin acid, including tall oil rosin, gum rosin and wood rosin. Examples of commercially available rosins include rosins from Arizona Chemical (e.g. SYLVAROS™ 85, SYLVAROS™ 90, and SYLVAROS™ 95) .

Mixtures of rosin compounds comprising a rosin ester can be obtained from resin acids and alcohols by methods known in the art. For example, reference is made to the processes described in the patent document US 5,504,152, which is

incorporated herein by reference. In general, resin acids can be esterified by a thermal reaction of the resin acid with an alcohol. In order to drive the esterification reaction to completion water can be removed from the reactor, by methods, such as distillation, application of vacuum, and other techniques known to the skilled person.

Generally, any type of rosin, as described above, can be used to provide a mixture of rosin compounds comprising a rosin ester. In several embodiments the rosin ester may be obtained from fortified rosin. As it is known in the art, fortified rosin is a rosin compound which is the result of an addition reaction of a resin acid with a dienophile such as an a, β-unsaturated organic acid or the anhydride of such an acid resulting in a rosin compound with an increased number of carboxylic acid groups. The most commonly employed dienophiles are those acids and anhydrides which comprise from 3 to 10 and preferably from 3 to 6 carbon atoms, the most preferred

dienophiles being maleic acid, maleic anhydride and fumaric acid.

Several alcohols, such as glycols and other polyalcohols and monoalcohols , are suitable for reacting with a resin acid mixture, including, for instance, at least one of glycerol, pentaerythritol , ethylene glycol, diethylene glycol, triethylene glycol, sorbitol, neopentylglycol ,

trimethylolpropane , methanol, ethanol, propanol, butanol, amyl alcohol, 2-ethyl hexanol, and C ₈ -Cn branched or unbranched alkyl alcohols. In particular, glycerol, pentaerythritol, diethylene glycol, triethylene glycol, and Cs-Cn isoalkyl alcohol can be used. In one embodiment of the invention, a rosin ester- containing mixture may comprise at least one of a glycerol rosin ester, a pentaerythritol rosin ester, diethylene glycol rosin ester and triethylene glycol rosin ester.

The rosin ester-containing mixtures of rosin compounds may comprise some residual, unreacted resin acid and/or alcohol. The acid number of rosin ester-containing mixtures can be measured and gives an indication of the amount of acid present in the mixtures. Typically, mixtures comprising a rosin ester may have an acid number below 20 mg KOH/g, in particular below 15 mg KOH/g. The acid number can be determined by methods known to the skilled person, such as the standard method ASTM D974 which uses a color-indicator titration.

Commercially available rosin esters may also be used, as for example SYLVALITE™ RE100, SYLVALITE™ RE88, SYLVATAC™ RE103, SYLVATAC™ RE55, SYLVATAC™ RE85, SYLVATAC™ RE12 and

SYLVATAC™ RE5 all obtained from Arizona Chemical; Eastman ^® ester Gum 15 D- , Permalyn ^® 3100, Permalyn ^® 5110-C and Staybelite™ ester 3-E all obtained from EASTMAN; Dertoline ^® G2L, Dertoline ^® SG2, Dertoline ^® P105, Dertoline ^® P110, Dertoline ^® P2L, Dertoline ^® PL5, Dertopoline P125, Granolite SG, Granolite P, Granolite P118 and Granolite TEG all obtained from DRT (les Derives Resiniques & Terpeniques ) ; and NovaRes ^® 1100 obtained from Georgia Pacific.

Other mixtures of rosin compounds comprising rosin derivatives can be obtained by, for instance, subjecting mixtures comprising a resin acid and/or a rosin ester to at least one reaction selected from a hydrogenation, a

dehydrogenation, a dimerization, and an addition.

The rosin mixtures of this invention may comprise the rosin compounds as described herein above. The rosin mixtures obligatory contain at least one modified rosin compound. The modified rosin compound in the rosin mixtures as described herein has a UV-absorbing moiety. A UV-absorbing moiety is a group which absorbs and dissipates the light energy from UV radiation, typically by reversible intra-molecular proton transfer. The UV-absorbing moieties as described herein have a protecting effect against UV-radiation due to their ability of dissipating the light energy from UV radiation. Generally, UV- absorbing moieties have aromatic systems which are conjugated to double bonds and/or lone pairs of electrons. The modified rosin compound has at least one UV-absorbing moiety derived from a UV absorbing compound selected from a hydroxybenzophenone , an oxybenzone, a dioxybenzone , an oxanilide, a benzotriazole , a hydroxyphenylbenzotriazole , and a hydroxyphenyltriazine . These UV-absorbing compounds are compounds which have the named structure (i.e. hydroxybenzophenone, oxybenzone, dioxybenzone, oxanilide, benzotriazole, hydroxyphenylbenzotriazole, and hydroxyphenyltriazine ) as the core structure and which, as elucidated in more detail below, are provided with at least one group which is susceptible of reacting with the rosin compounds.

Rosin mixtures as described herein comprise at least 0.01 wt . % of a modified rosin compound having a UV-absorbing moiety. In several embodiments the rosin mixtures may comprise at least 0.1 wt.%, at least 0.5 wt.%, at least 1 wt.%, or at least 2 wt.% of the modified rosin compound. Maximum amounts of modified rosin compounds in the rosin mixtures can be 99 wt.%, 90 wt.%, 75 wt.%, 50 wt.%, 30 wt.%, 20 wt.% or 10 wt.%. The rosin mixtures can have an amount of modified rosin compound varying from any of the minimum weight percentage amounts to any of the maximum weight percentage amounts. In another embodiment, the rosin mixture may comprise 100 wt.% of modified rosin compounds having a UV-absorbing moiety. The percentages by weight are based on the total weight of the rosin mixture. The amount of modified rosin compound having a UV-absorbing moiety can be determined by, for instance, Gel Permeation

Chromatography (GPC) .

Generally, apart from the modified rosin compound the rosin mixture may also comprise at least one rosin compound selected from a rosin ester, a resin acid and a rosin

derivative .

The rosin mixture may comprise mixtures of different modified rosin compounds, e.g. with different number of rosin moieties and/or different UV-absorbing moieties, with different type of rosin moieties and/or different UV-absorbing moieties or both with different type and number of rosin moieties and/or different UV-absorbing moieties. Since rosin is a mixture of rosin compounds (resin acids) most embodiments of this invention will comprise such mixtures. For instance, a modified rosin compound derived from a pentaerythritol rosin ester may have 1 to 4 rosin moieties and 1 to 4 UV-absorbing moieties, the number of UV-absorbing moieties being the same or lower than the number of rosin moieties.

The rosin mixture comprising the modified rosin compound is generally obtained by reacting a mixture of rosin compounds with a UV-absorbing compound under mixing at a

temperature of at most 400 °C, in particular from 30 to 400 °C, more in particular from 50 to 350 °C, even more in particular from 80 to 300 °C, even more in particular from 160 to 250 °C, and yet more in particular from 190 to 225 °C. The reaction can be stopped (e.g. by cooling) once the reaction is completed or earlier, if desired. The reaction can be monitored by, for instance, Gel Permeation Chromatography (GPC) , and the reaction can be stopped when, for instance, changes in the peak size of the products are no longer observed. Generally, suitable

reaction times can be of at least 1 minute, 15 minutes, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 16 h or 24 h.

The reaction can be performed in the presence of a solvent. Suitable solvents include, for example,

dimethylsulfoxide (DMSO) , dimethylacetamide (DMAC) ,

dimethylformamide (DMF), toluene and trimethylbenzene .

In another embodiment, the reaction can be performed in the absence of a solvent. This advantageously avoids having to remove the solvent at a later stage, reduces the waste

production and also reduces the cycle time. The reaction may also be performed in the presence of a suitable catalyst.

The reaction product can be used as such as a UV- protecting rosin mixture or can be subjected to purification steps (e.g. to remove unreacted starting materials or side products) .

Generally, the rosin compounds and the UV-absorbing compound can be mixed in any order. In one embodiment the rosin mixture comprising the modified rosin compound is obtained by first heating a mixture of rosin compounds to a temperature of at most 400 °C, in particular from 30 to 400°C, more in particular from 50 to 350 °C, even more in particular from 80 to 300 °C, even more in particular from 160 to 250 °C, and yet more in particular from 190 to 225 °C, and then adding the UV-absorber to the mixture of rosin compounds.

The relative amount of UV-absorbing compound with respect to rosin compounds in the reaction may vary. For

instance, the total amount of the UV-absorbing compound can be from 0.01 wt . % to 75 wt . % based on the total weight of mixture of rosin compounds and UV-absorbing compound, in particular from 0.1 wt.% to 50 wt.%, 0.5 wt.% to 30 wt . % , 1 wt . % to 20 wt . % and from 2 wt.% of 10 wt.%.

The rosin source used to provide the modified rosin compound can be selected from, for example, a rosin ester, a resin acid or a rosin derivative, as described above. Such rosin compounds generally have groups which may undergo a chemical reaction, e.g. an unsaturated group (such as carbon-carbon double bonds, in particular conjugated double bonds such as dienes), an ester group or a carboxylic acid group. Rosin esters of polyalcohols (e.g. glycols, glycerol and/or pentaerythritol ) may have residual (unreacted) hydroxyl groups available for further reaction with a UV-absorbing compound. Rosin derivatives may have other groups. For instance, resin acid or rosin ester compounds can be subjected to addition reactions or to

modification of the carboxylic or ester groups to provide rosin derivatives with for instance an anhydride group or an alcohol group.

Suitable UV-absorbing compounds have a group susceptible of reacting with at least one of the groups present in the rosin compounds, referred hereinafter as a linking group. The linking group may be selected from an unsaturated group (e.g. a double bond, a triple bond and conjugated double bonds), an ester, a carboxylic acid, an amine and an alcohol. The unsaturated group may have carbon and/or heteroatoms (e.g. nitrogen, oxygen or sulfur) . In one embodiment, the unsaturated group can be a dienophile. In a particular embodiment, the dienophile may have a carbon-carbon double bond conjugated to at least one electron-withdrawing group.

Examples of suitable UV-absorbing compounds include for instance compounds having a a, β-unsaturated carbonyl group (e.g. an acryloyl functionality) , an a, β-unsaturated nitrile group, and a nitroalkene group. In particular, 2- ( 4-benzoyl-3-hydroxy- phenoxy) ethyl acrylate and (2- [3- ( 2H-benzotriazol-2-yl ) -4- hydroxyphenyl ] ethyl methacrylate can be mentioned. Suitable compounds are commercially available, such as 2- (4-benzoyl-3- hydroxyphenoxy) ethyl acrylate, (2- [3- ( 2H-benzotriazol-2-yl ) -4- hydroxyphenyl ] ethyl methacrylate, 4-allyloxy-2-hydroxybenzo- phenone, 2-hydroxy-4 -acryloylethoxy benzophenone , which is another name for 2- (4-benzoyl-3-hydroxyphenoxy) ethyl acrylate, and 2- ( 2 ' -methacryloxy-5 ' methylphenyl ) benzotriazole . Other suitable UV-absorbing compounds can be obtained by methods known to the skilled person. For instance, the preparation of UV- absorbing compounds comprising an acryloyl functionality has been described in US 4,985,559 and US 4,612,358 which contents are incorporated herein by reference. UV-absorbing oligomers or polymers comprising at least one group susceptible of reacting with rosin compounds as described above can also be used. More than one UV-absorbing compound can be used as an ingredient in the reaction.

In one embodiment the rosin mixture comprising modified rosin compound can be obtained by reacting a mixture of rosin compounds comprising a rosin ester with a UV-absorbing compound provided with an unsaturated group as the linking group, in particular the unsaturated group can be a dienophile. In another embodiment the rosin mixture comprising a modified rosin compound can be obtained by reacting a mixture of rosin compounds comprising a resin acid with a UV-absorbing compound provided with an alcohol group as the linking group.

In another embodiment a rosin mixture comprising a modified rosin compound can be obtained by reacting a mixture of rosin compounds comprising a resin acid with a UV-absorbing compound provided with an unsaturated group as the linking group to provide a rosin mixture comprising a modified resin acid. Then, the rosin mixture obtained can be reacted with an alcohol selected from at least one of glycerol, pentaerythritol , diethylene glycol, triethylene glycol, sorbitol, neopentyl- glycol, trimethylolpropane, methanol, ethanol, butanol, 2-ethyl hexanol, Ce-Cn branched and unbranched alkyl alcohols to provide a rosin mixture comprising a modified rosin ester.

Without being bound to any theory, it may be anticipated that UV-absorbing compounds provided with an unsaturated group, and in particular a dienophile, as the linking group may react with the unsaturated groups generally present in rosin compounds, and in particular with conjugated double bonds. The resulting modified rosin compound can be a Diels-Alder adduct formed between the rosin compound and the UV- absorbing compound. The resulting modified rosin compound can also be an adduct resulting from other pericyclic reactions (e.g. an ene reaction) between the unsaturated group of the UV- absorbing compound and the unsaturated group of the rosin compound .

On the other hand, UV-absorbing compounds having an ester group or an alcohol group as the linking group may react with, for instance, the carboxylic functionality present in resin acid, e.g. by esterification and transesterification .

Accordingly, the rosin compound is linked to the UV-absorbing moiety via an ester bond. UV-absorbing compounds having an amine group as the linking group may react with, for instance, the carboxylic functionality present in resin acid. Accordingly, the rosin compound is linked to the UV-absorbing moiety via an amide bond.

UV-absorbing compounds provided with a carboxylic acid as the linking group may react with a residual alcohol group present in a rosin ester of a polyalcohol such as glycerol, pentaerythritol , diethylene glycol, triethylene glycol or sorbitol, neopentylglycol , trimethylolpropane . Accordingly, the rosin compound is also linked to the UV-absorbing moiety via an ester bond.

Irrespective of the method of preparation, the rosin compound is covalently bonded to the UV-absorbing moiety.

The covalent bond between the rosin compound and UV- absorber moiety generally involves a linker and, optionally, a linking molecule.

A linker is generally present in the UV-absorbing compound, wherein the linker is attached to the UV-absorbing moiety. The linker has a linking group which is able to from a covalent bond with the rosin compound. In one embodiment the linker consist of said linking group.

A separate linking molecule is able to form a covalent bond with both the rosin compound and with the UV-absorbing compound. Accordingly, the separate linking molecule has two linking groups.

What it is described above regarding the linking group present in the UV-absorbing compound applies to the linking group described herein as part of the linker or the linking molecule. It is within the scope of the skilled person to select UV-absorbing compounds with appropriate linkers and, optionally, linking molecules to react with appropriate rosin compounds to provide

The rosin moiety and the UV-absorbing moiety in the modified rosin compound preferably have a short distance to each other. This is achieved by attaching the rosin compound to the UV-absorbing moiety by using linkers and, when applicable, separate linking molecules, of short length. The sum of the main chain (or back-bone) atoms of the linker and, if present, of the separate linking molecule, generally is from 1 to 12 atoms, in particular from 2 to 10 atoms, more in particular from 3 to 8 atoms. The number of atoms include the main-chain atoms of the linking groups of the linker and, if present, also the main- chain atoms of the linking groups of the separate linking molecule.

Modified rosin compounds as described herein generally have an average molecular weight (MW) from 600 to 2000

grams/mol, in particular from 700 to 1800, more in particular from 800 to 1600, more in particular from 900 to 1500 grams/mol.

The molecular weight can be measured by methods known in the art. For instance, the ASTM D5296-05 method for

determining the molecular weight averages and molecular weight distribution of polystyrene compositions can be used. These methods use Gel Permeation Chromatography (GPC) , also known as size-exclusion chromatography.

The rosin mixture comprising the modified rosin compound as described herein, not only has an enhanced UV- resistance itself but also enhances the UV-resistance of

compositions comprising the same.

Accordingly, in another aspect the invention relates to a composition comprising the rosin mixture as described herein. This composition can be an intermediate which can be

subsequently used to provide a formulation for end use.

Generally, the presence of a small amount of the rosin mixture is sufficient to enhance the UV-stability of compositions or formulations comprising the same. The composition as described herein may comprise at least 0.01 wt . % of the rosin mixture, based on the total weight of the composition. In other

embodiments the composition may have at least 0.1 wt . % , at least 0.5 wt.%, or at least 1 wt . % of the rosin mixture. However, because the rosin mixture can perform the same function as rosin in a common formulation (e.g. may function as a tackifier and as a binder) , the composition may comprise higher amounts of the rosin mixture than necessary to prevent degradation by UV light, such as at least 5 wt.%, in particular at least 10 wt%, more in particular at least 20 wt.%, even more in particular at least 50 wt.%, or even more in particular at least 75 wt.%, depending on the requirements of the formulation.

A rosin mixture as described herein is particularly suited for use in formulations which can be exposed to UV- radiation (e.g. for outdoor applications). In particular, the rosin mixture or compositions comprising the rosin mixture can be used in formulations together with components which can be UV-sensitive . However, the UV-protecting mixture can be used to protect any formulation from UV-radiation.

For example, the composition as described herein may comprise polymers, which may or may not suffer from long

exposures to UV-radiation. Examples of suitable polymers include polymers commonly used or suitable for use in coating, sealing or adhesive applications. For example, suitable polymers can be selected from at least one of polyacrylate , polyacrylate co ^¬ polymer, butyl rubber, chlorinated rubber, ethylene vinyl acetate, polyamide, polyester, polyisobutylene , polyolefin, polyurethane , and styrene block copolymers.

Other components that can be present in the composition as described herein include, for instance, dyes, antioxidants (such as hindered amine light stabilizers (HALS)), oils,

colorants, fillers, plasticizers, stabilizers, and in addition to a rosin mixture comprising a modified rosin compound, other UV-protecting additives including UV-absorbers , UV-filters and/or UV-stabilizers known in the art such as Ti0 ₂ and Zn0 ₂ .

However, given the presence of the UV-protecting mixture of rosin compounds, the composition generally does not require the presence of further UV-protecting additives.

Since the UV-protecting rosin as described herein surprisingly retains the properties of the original rosin compounds, e.g. as a tackifier and as a binder, the UV- protecting mixture of rosin compounds can be suitably used in compositions which typically comprise rosin mixtures. Generally, in order to improve the UV-resistance of such compositions it is sufficient to substitute all or part of the rosin mixture of the original formulation with a rosin mixture comprising a modified rosin having a UV-absorbing moiety as described herein. This advantageously facilitates the distribution of the UV-protecting agent (namely the modified rosin compound) in the final

formulation. Also, by using rosin mixture as described herein in such compositions any incompatibility issues that can be

associated to other UV-protecting additives can be avoided.

Also, since the UV-absorbing moiety is part of the modified rosin compound present in the rosin mixture, migration of the UV-absorbing moiety is prevented, reducing a health and/or environmental hazard and reducing the chances of leaving parts of a formulation vulnerable to UV-radiation .

The rosin mixture comprising a modified rosin and the compositions as described herein can suitably be used in

numerous applications, and in particular in formulations which are exposed to sun light, e.g. for outdoor applications. For instance, they can be included in adhesive formulations (e.g. for bottle labeling), ink formulations, rubber formulations, coating formulations, sealant formulations, asphalt formulations and thermoplastic road marking formulations. Further, by having the UV-absorbing moiety in the modified rosin compound a good distribution of the UV-protection can be achieved.

In particular one aspect of the invention relates to adhesive formulations and thermoplastic formulations comprising a rosin mixture as described herein. Generally, part or all of the rosin compound used as a tackifier in common adhesive formulations or as a binder in common thermoplastic road marking formulations can be

substituted by the rosin mixture as described herein. What is described above with respect to the total amounts of rosin mixture and the amounts of modified rosin compound, also applies to the adhesive formulations and thermoplastic road marking compositions as described herein.

An adhesive formulation may generally comprise 30-70 wt . % of the rosin mixture as a tackifier (e.g. comprising a rosin ester), 20-60 wt . % of a polymer (e.g. styrene-isoprene- styrene (SIS) block copolymer), 0.1-2 wt . % of an antioxidant and the remaining to 100 wt . % of a mineral oil. The weight

percentage is based on the total weight of adhesive formulation.

A thermoplastic road marking formulation may generally comprise 10-20 wt . % of the rosin mixture as a binder (e.g.

comprising a rosin ester), 1-5 wt . % of mineral oil, 0.5-1.5 wt . % of a wax (e.g. polyethylene wax), 0.5-1.5 wt . % of a

thermoplastic polymer (e.g. an ethylene vinyl acetate resin (EVA)), 0.1-0.5 wt . % of a stabilizer (e.g. stearic acid), 1-10 wt . % of a pigment (e.g. titanium dioxide), 30-40 wt . % of glass beads and the remaining to 100 wt . % of fillers (e.g. calcium carbonate) . The weight percentage is based on the total weight of thermoplastic road marking formulation.

An exemplary road marking formulation may be prepared as follows:

- charging a standard mixer with 16 g of rosin ester (obtained from Arizona Chemical), 2.8 g of mineral oil (obtained from Statoil) , 1 g of polyethylene wax (AC6 PE-wax obtained from Honeywell), 1 g of ethylene vinyl acetate resin (Elvax 22W obtained from DuPont), 0.2 g of stearic acid, 5.3 g of titanium dioxide (obtained from Kronos), 42.4 g of calcium carbonate and 37.1 g of glass beads (obtained from Swarco) - heating at 180°C and blending at low speed to avoid introducing air bubbles into the melt.

It has also been surprisingly found that the rosin mixture as described herein in addition to UV-protecting

properties has antioxidant properties. Accordingly, one aspect of the instant invention relates to the use of the rosin mixture as described herein as an antioxidant. Accordingly, the rosin mixture as described herein can be added to compositions as an antioxidant. In particular, the rosin mixture can be used as antioxidant in formulations where rosin mixtures are normally used .

As described above, for improving the UV-resistance of formulations comprising rosin compounds, to achieve the anti ^¬ oxidant effect it is sufficient to substitute all or part of the rosin mixture of the original formulation with the rosin mixture comprising a modified rosin compound as described herein.

What is described above, and in particular with regard to the amounts of the rosin mixture in the composition, and the components present in the compositions and formulations

comprising the rosin mixture as described herein, also apply to the use of the rosin mixture as an antioxidant.

The instant invention is further illustrated with the following examples without being limited thereto or thereby.

EXAMPLES :

Preparation of rosin mixture A:

A 2 liter reaction flask, equipped with a thermometer, an overhead stirrer, nitrogen purge line and a sampling port, was charged with 1200 g of commercial tall oil rosin (SYLVAROS™ 90 obtained from Arizona Chemical Company, B.V., The

Netherlands) having a softening point of 66 °C and an acid number of 171 mg KOH/g. The tall oil rosin was heated to 160 °C until molten (about 55 minutes); agitation was started when enough of the rosin was molten for the stirrer to turn. Then, 117.1 g of 2- ( -benzoyl-3-hydroxyphenoxy) ethyl acrylate Sigma- Aldrich, Germany) were added to the rosin, over 10 minutes. This is about 8.9 wt% of UV-absorbing compound, based on the total weight of UV-absorbing compound and rosin. After about 25 minutes, the temperature was set to 180 °C; and after about 55 minutes the temperature was set to 200 °C. After about 3 ¼ hours, the reaction was stopped, letting the reaction mixture cool to room temperature. The reaction product obtained had an acid value of 160.95 mg KOH/g and a softening point of 70.7 °C.

535.6 g of the product obtained, were charged into a 1 liter five necked reaction flask, equipped with a thermometer, an overhead stirrer, nitrogen purge line, a Dean and Stark with a condenser and collecting vessel, and a sampling port. The product was heated to 165 °C, until molten (about 55 minutes); agitation was started when enough of the rosin was molten for the stirrer to turn. Subsequently, 1.18 grams of TNPP

catalyst (trisnonylphenyl phosphite obtained from Sigma-Aldrich, Germany) were added. Then, 65.00 g of pentaerythritol (obtained from Perstorp, Sweden with a 99% purity or higher) was added at a rate slow enough to ensure that the temperature did not drop more than 3 °C ( a period of about 15 minutes) . After adding all the pentaerythritol, the temperature was set at 200 °C and the mixture was maintained at that temperature for about 1 hour.

Then, the temperature was increased gradually to 285 °C, by steps of about 20 °C during about 3.5 hours. The temperature of the reaction was maintained at 285 °C, until a product with an acid value of 9.51 mg KOH/g was achieved. A product was obtained (rosin mixture A) with a softening point of 90.5 °C.

The acid number was measured according to the ASTM D465 method. A sample of a known weight amount was dissolved in isopropyl alcohol. The solution was then titrated with an alcoholic solution of potassium hydroxide. The acid values obtained correspond to the amount of potassium hydroxide used to neutralize said measured amount of sample. This is generally expressed in milligrams of potassium hydroxide per gram of samp1e : mg KOH/g .

The softening point was measured according to the Ring and Ball method (ASTM E28-99) . A sample of the rosin mixture A, prepared above, was poured, when still warm, into a metal ring and then cooled. The ring was cleaned in such a way that the material fitted the ring. A steel ball was placed resting on top of the ring. The ring and ball were lowered into a beaker containing glycerol. The glycerol was heated at a rate of 5 °C per minute while stirring. When the ball dropped completely through the ring, the temperature of the glycerol was recorded. This temperature value is reported as the softening point of the rosin mixtures obtained.

Preparation of adhesive compositions :

The rosin mixture A was used as the tackifier in an adhesive composition prepared as follows.

A Z-blade (Mixer type Z from Winckworth Machinery Ltd

Staines, England) equipped with temperature controller and vacuum pump (about 50 mbar) was charged with 162 g styrene- isoprene-styrene (SIS) block copolymer with 15% polystyrene content, a total molecular weight of 220 000 and a coupling efficiency of 81% (Kraton ^® D1161NS from Kraton, The Netherlands) and with 6 g of pentaerythritol tetrakis (3- (3, 5-di-tert-butyl-4- hydroxyphenyl ) propionate ) (Irganox ^® 1010 from BASF, Switzerland). The mixture was heated to 135-145 °C. 342 g of the rosin mixture A was added to the mixture in 4 sequential steps with mixing over 1 hour. Then, 90 g of a white mineral oil (Kaydol ^® oil from Sonneborn, The Netherlands) was added in two sequential

additions followed by 10 minutes of mixing. After the second addition the formulation was mixed for 20 more minutes and the adhesive product was discharged. A reference adhesive composition was prepared as indicated above but with 342 g of pentaerythritol ester of oil rosin (SYLVALITE™ RE100S) instead of the rosin mixture Preparation of adhesive films:

Each adhesive composition was applied at 110 °C with a hotmelt coater (Laboratory Laminator LL-100 obtained from

Cheminstruments , Fairfield, Ohio, USA) as a thin film (of about 40 micron thick) onto a 50 micron thick polyethylene

terephtalate (PET) film (obtained from Adhesives Technical

Services, England) . The side of the film having the adhesive was covered with siliconized release liner paper (RP-12 roll

siliconized release paper, 13 gsm single sided siliconized obtained from Adhesives Technical Services, England) .

Evaluation of adhesive films :

The siliconized release liner paper was removed from the films. The films were then kept in a QUV machine (obtained from the Q-panel Company, UK) whilst being irradiated with a UV- A radiation. The films were irradiated on the side of the film which comprised the adhesive.

The adhesive properties and color of the films were checked every day for four days. The results are presented in table 1.

As seen in Table 1 adhesive compositions comprising the rosin mixture A display better properties than the reference adhesive composition (without the rosin mixture A) after being subjected to the same conditions.

The reference adhesive composition loses its adhesive properties after 1 day whereas the adhesive composition

comprising the rosin mixture A, only completely loses its adhesive properties on day 3.

Similarly, both the appearance of cracks and yellowing are delayed when rosin mixture A is present in the adhesive composition. Both cracks and yellowing only start appearing on the third day for adhesive compositions comprising rosin mixture A, whereas in the absence of the rosin mixture A cracking starts on the first day and yellowing on the second day.

Table 1: Evaluation of adhesive films

Adhesive composition Reference Adhesive

comprising composition

rosin mixture A

Adhesive Absence Absence Adhesive Absence Absence properties of of properties of of

cracking yellowing cracking yellowing

Day +++ +++ +++ +++ +++ +++ 0

Day ++ +++ +++ ++ +++ 1

Day + +++ +++ + ++

2

Day ++ ++ +

3

Day + +

4

Preparation and characterization of rosin mixtures B to G:

General procedure

350 g of pentaerythritol ester of tall oil rosin

(SYLVALITE™ RE100S from Arizona Chemical B.V., The Netherlands) or 350 g of glycerol ester of tall oil rosin (SYLVALITE™ RE88 from Arizona Chemical, The Netherlands) were heated at a

temperature of between 150°C and 200°C. Then either 2 wt . % or a 20 wt . % of a UV absorbing compound was added to the rosin ester (wt.% based on the total weight of rosin ester and UV absorber) . The mixture was allowed to react under mixing, and under

gradually increasing temperature. See table 2 for the starting and final temperatures used in the synthesis of each of the rosin mixtures B to G.

The following UV absorbing compounds were used:

2- ( 4 -benzoyl-3-hydroxyphenoxy ) ethyl acrylate (obtained from Sigma-Aldrich, Germany) with an absorption maximum at 325 nm and referred to in table 2 as "acrylate-hydroxybenzophenone" ;

(2- [3- (2H-benzotriazol-2-yl) -4-hydroxyphenyl ] ethyl methacrylate , (with a 99% purity obtained from Sigma-Aldrich, Germany) , with an absorption maximum at 327 nm and referred to in table 2 as "benzotriazol"; and 4 -allyloxy-2- hydroxybenzophenone (with a 99% purity obtained from Sigma- Aldrich, Germany) with an absorption maximum at 339 nm and referred to in table 2 as "allyl-hydroxybenzophenone" . The reaction time for each rosin component and UV-absorber pair is recorded in Table 2.

The reaction was monitored by Gel permeation chromatography (GPC) using a Waters HPLC system. A chromatogram was taken for each starting rosin ester, for each starting UV absorbing compound and for each reaction mixture. One sample was taken at the beginning of the reaction (i.e. after the UV absorber is mixed with the rosin ester, referred to in the tables as starting mixture) and another sample was taken at the end of the reaction. The results are shown in Table 3. The chromatogram was obtained by measuring the absorption of the samples at the region from 210 to 400 nm as explained in detail below .

The peaks for the rosin ester were generally broad indicating a mixture of species. The starting rosin esters do not show significant absorbance in the 300-400 nm region, whereas the UV-absorbers absorb in the 300-400 nm region.

The evolution of the reaction was monitored at 300-400 nm, where the UV-absorber displays absorbance. As the reaction progressed it could be observed that the peak at the retention time of the UV-absorbing compound becomes smaller. A new peak with a retention time in the region of the rosin ester was observed to appear. The new peak was generally observed to become larger with time. This indicates that the UV-absorbing moiety is built onto the rosin ester.

The yield of the reaction was provided by the UV- chromatogram. The percentage of unreacted product is based on the area of the peak observed in the 300-400 nm region, at the retention time of the UV-absorber, divided by the total area of peaks observed in the 300-400 nm region.

The percentage of reacted product is based on the area of the newly formed peak observed in the 300-400 nm region, close to the retention time of the rosin ester, divided by the total area of the peaks observed in the 300-400 nm region.

In some occasions an additional peak was observed between the retention time of the rosin ester and the UV- absorber (Examples D and E) . The product observed has a higher retention time than the rosin ester species, which possibly indicates that this product has a lower molecular weight than that of said rosin ester species. Characterization by Gel Permeation Chromatography (GPC)

Approximately 30 mg of sample were dissolved in 10 ml of tetrahydrofuran (stabilized with BHT for GPC/HPLC) . 10 μΐ of toluene were added to the solution. The sample was filtered over a polytetrafluoroethylene (PTFE) chemical-resistant filter disc for HPLC of 0.45 μπι.

100 μΐ of the sample were automatically injected to a HPLC system fitted with a Waters 717 plus autosampler; a Waters 515 HPLC pump; a Waters Column Heater Module fitted with two mixed E columns (obtained from Polymer laboratories), i.e. a 50- Angstrom column (5 μπι) and a 3 μπι guard column; a refractive index (RI) detector (Waters 2414) and a Photodiode Array (PDA) detector (Waters 996) ; and Empower software, all obtained from Waters. The detector and the column heater were set at 40 °C.

The samples were run with an isocratic solvent system over 35 minutes with the flow set at 1 ml/min. The chromatogram was registered with the PDA detector with a scanning range from 210 to 400 nm at 1.2 nm intervals.

A calibration was performed using a commercially available polystyrene standard with molecular weights from 580 grams/mol to 380000 grams/mol (PS 2 EasiCal obtained from

Polymer Laboratories, USA) .

The peaks observed were generally broad indicating the presence of a mixture of species. The retention time as recorded in Table 3 is that of the peak at its highest.

Table 2: Preparation of rosin mixtures B-G from SYLVALITE rosin esters (of type RE 100S or RE 88) and UV-absorbers

Based on the total weight of rosin ester and UV-absorber b Percentage of UV-absorber reacted with the rosin ester.

c__ The main product obtained in this reaction had a higher retention time than the rosin ester (see table 3) . Said main product represented the 73.2 % of the transformed UV-absorber. Table 3: Characterization of rosin mixtures B-G

a__ A small peak (0.01 AU) at 21.8 min was observed at 325 nm Preparation of rosin mixtures H-M

General procedure

99.5 gram of glycerol ester of tall oil rosin (SYLVALITE™ RE88 from Arizona Chemical, The Netherlands) or of a glycerol ester of a rosin fortified with 3 wt . % fumaric acid, based on the total of rosin and fumaric acid (herein after referred to as fortified rosin ester) were heated at a

temperature of 190°C. Then the UV-absorber 2- ( 4-benzoyl-3- hydroxyphenoxy) ethyl acrylate (hereinafter referred to as acrylate-hydroxybenzophenone ) was added to the rosin ester in an amount as indicated in Table 4 for each of the examples H-M. All of the acrylate-hydroxybenzophenone was added to the molten rosin ester in a single addition, with mixing under nitrogen. The reaction mixture was kept at 190°C for 24 hours after which it was cooled down to room temperature. The amount of reacted and unreacted UV-blocking agent was measured by Gel Permeation Chromatography as described above for Examples A-G. The GPC characterization data is not shown for rosin mixtures H-M.

Oxidative induction time measurement

The antioxidant properties of the rosin mixtures H-M were determined by measuring the oxidative induction time (OIT) of the rosin mixtures obtained. The oxidative induction time of the starting materials (i.e. acrylate-hydroxybenzophenone, SYLVALITE™ RE88 and fortified rosin ester) and of the samples H-M were measured using the ASTM D 5483 "Standard test Method for Oxidation Induction Time of Lubricating Greases by Pressure Differential Scanning Calorimetry" . The machine used was a DSC 2910 provided with high pressure cell (obtained from TA

Instruments) . The sample was held at 130°C and 550 psi of oxygen pressure until an exothermic auto-oxidation occurs. The oxygen used was of a purity of 99.9 wt . % . The time until onset of the exotherm was measured by differential scanning calorimetry (DSC) and was recorded as the oxidative induction time (OIT) . The results are shown in Table 5. Table 4: Preparation of rosin mixtures from acrylate- hydroxybenzophenone as the UV-absorber and from SYLVALITE™ RE (examples H-L) or fortified rosin ester (example M) at 190°C

wt.% Based on the total amount of rosin ester and UV-absorber Percentage of UV-absorber reacted with the rosin ester. Table 5: Oxidative induction time of rosin mixtures H-M

OIT = Oxidation induction time

Table 5 shows that rosin mixtures comprising a rosin compound modified with a UV-absorbing moiety as described herein have anti-oxidant properties. The higher the OIT the more stable is the product is towards oxidation. Examples H-J and the starting rosin ester material (SYLVALITE™ RE 88) display equivalent OIT values. They all are within error of the method (i.e. 5%) . Whereas, examples K and L show higher OIT numbers than the starting rosin ester, indicating improved oxidative stability over the starting material (SYLVALITE™ RE88) . The antioxidant effect is observed to a higher extent in Example M, where an increase of OIT of the 76 % with respect to the starting rosin ester.