Siloxane compound and a method for preparing the same

A method for preparing the siloxane compound represented by the following formula (1), having at least two groups represented by the following formula (2) in one molecular:

• wherein R is, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, R1 is, independently of each other, a group defined for R or a group represented by the following formula (2) or (3), R2 is, independently of each other, a group represented by the following formula (2) or (3), p is an integer of 0 to 500, q is an integer of 0 to 50, provided that said formula (1) has at least two groups represented by the following formula (2), the bonding order of the siloxane units is not limited and may form a block structure or a random bonding,
• wherein R3 is a hydrogen atom or a methyl group, R4 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, L1 is a divalent hydrocarbon group having 1 to 5 carbon atoms, L2 is a divalent hydrocarbon group having 2 to 10 carbon atoms and which may contain an ether bond, and the site marked with * is a binding position to the silicon atom in formula (1),
• wherein R4, L1 and L2 are as described above, and the site marked with ** is a binding position to the silicon atom in formula (1),
• wherein the method comprises a step of reacting a siloxane compound having an amino group and represented by the following formula (5) with a lactone compound having 2 to 6 carbon atoms to obtain a compound represented by the following formula (4):
• wherein R5 is, independently of each other, a group defined for the R or a group represented by the following formula (6), R6 is, independently of each other, a group represented by the following formula (6), R, p and q are as described above, and said formula (5) has at least two groups represented by said formula (6) in one molecular,
• wherein R4 and L2 are as described above, and the site marked with *** is a binding position to the silicon atom in said formula (5),
• wherein R, p and q are as described above, R1′ is, independently of each other, the group defined for the R or the group represented by said formula (3), R2′ is, independently of each other, a group represented by said formula (3), and said formula (4) has at least two groups represented by said formula (3) in one molecular,
• and a step of reacting the compound represented by formula (4) with a (meth)acrylic acid halide to obtain the siloxane compound represented by said formula (1).