Polysiloxane polymer

A curable coating composition comprising:

• a binder, and
• an amount of a non-crosslinked polymer sufficient to achieve at least one of improved cleanability or reduced dirt pick up of a surface coating formed from the curable coating composition relative to a surface coating formed from a curable coating composition comprising the binder but not the polymer, the polymer having a polymer main chain comprising:
• i) polysiloxane segments comprising repeating units of the formula (I)
• wherein R1 independent of each occurrence represents a hydrocarbyl group and n is an integer in the range of 6 to 150, and
• ii) non-polysiloxane segments having at least one functional group comprising at least one of hydroxyl group, acryloyl group, methacryloyl group, acetyl group, urethane group, and methyl ether group,
• wherein the number of links between non-polysiloxane segments and polysiloxane segments in the polymer is less than 9.5%, calculated on the average number of silicon atoms per polysiloxane segment, and wherein at least one non-polysiloxane segment is located between two polysiloxane segments, and
• wherein the polymer has been obtained by a process comprising:
• providing a polysiloxane having at least two Si—H groups, wherein less than 9.5% of the silicon atoms of the polysiloxane have Si—H groups,
• providing a non-polysiloxane compound having at least two ethylenically unsaturated groups per molecule,
• providing a non-polysiloxane compound having one ethylenically unsaturated group per molecule,
• wherein at least one of the non-polysiloxane compound having at least two ethylenically unsaturated groups per molecule or the non-polysiloxane compound having one ethylenically unsaturated group per molecule has at least one functional group per molecule comprising at least one of hydroxyl group, acryloyl group, methacryloyl group, acetyl group, urethane group, and methyl ether group, and
• covalently linking to the polysiloxane having at least two Si—H groups, the non-polysiloxane compound having at least two ethylenically unsaturated groups per molecule, and the non-polysiloxane compound having one ethylenically unsaturated group per molecule.

A method for achieving at least one of improved cleanability or reduced dirt pick up of a surface coating formed from a surface coating composition, the method comprising including in the surface coating composition a non-crosslinked polymer having a polymer main chain comprising

• i) polysiloxane segments comprising repeating units of the formula (I)
• wherein R1 independent of each occurrence represents a hydrocarbyl group and n is an integer in the range of 6 to 150, and
• ii) non-polysiloxane segments having at least one functional group comprising at least one of hydroxyl group, acryloyl group, methacryloyl group, acetyl group, urethane group, and methyl ether group,
• wherein the number of links between non-polysiloxane segments and polysiloxane segments in the polymer is less than 9.5%, calculated on the average number of silicon atoms per polysiloxane segment, and wherein at least one non-polysiloxane segment is located between two polysiloxane segments.