UV absorber compositions

The invention relates to compositions of water-insoluble or very sparingly soluble uv absorbers that are stable to storage under both cold and warm storage conditions.

GB Patent 2,187,746 discloses compositions suitable for applying uv absorbers of the benzotriazole series to a substrate in the form of a dispersion in water.

Improved compositions of this type have now been found according to the present invention which surprisingly demonstrate improved stability and performance compared to those of GB 2,187,746. The compositions of the present invention comprise a 4-part composition comprising a mixture of a sparingly soluble uv absorber, water, a dispersing agent and a surfactant, whereas those of GB 2,187,746 comprise a 3-part composition, comprising the uv absorber, water and a dispersing agent. GB 2,187,746 also discloses the optional presence of non-ionic surfactants which are addition products of C1-12 alkylphenol and alkylene oxides. A preferred surfactant is the addition product of C1-12 alkylphenol (preferably nonylphenol) and a C2-3. alkyleneoxide.

The present invention provides a composition (A) comprising, based on the total weight of said composition:

a) 20 to 45% of a insoluble or sparingly soluble uv absorber of the 2-(2'-hydroxyphenyl)-benzotriazole series having an average particle size of less than 5 μm;

b) 7 to 25% of a dispersing agent which is a condensation product of a sulphonated tolylether and formaldehyde;

c) 0.5 to 10% of a non-ionic surfactant which is an addition product of ethylene oxide or propylene oxide or both ethylene oxide and propylene oxide, and a mixture of fatty alcohols, fatty acids, fatty amides or fatty esters having 7-20 carbon atoms, preferably 14-18 carbon atoms or either tristyrylphenol or distyrylphenol;

d) and water.

In a preferred embodiment of the present invention there is provided a composition (B) comprising, based on the weight of the total composition:

a) 20 to 45% of an insoluble or sparingly soluble uv absorber of the 2-(2'-hydroxyphenyl)-benztriazole series having an average particle size of less than 5 μm;

b) 7 to 20% of a dispersing agent which is a condensation product of a sulphonated tolylether and formaldehyde;

c) 1 to 6% of a non-ionic surfactant which is an addition product of ethylene oxide or propylene oxide or both ethylene and propylene oxide and tristyrylphenol;

d) and water.

In a further preferred embodiment of the present invention there is provided a composition (C) comprising, based on the weight of the total composition:

a) 20 to 45% of an insoluble or sparingly soluble uv absorber of the 2-(2-hydroxyphenol)-benzotriazole series having an average particle size of less than 5 μm;