Perfluoropolyether-modified polysilazane, making method, surface treating agent, and treated article
A perfluoropolyether-modified polysilazane of silazane units of formula (1), where Q is a divalent organic group, p and q are an integer of at least 1, r and s are an integer of at least 0, and x is an integer of 1 to 3. A surface treating agent comprising the polysilazane is improved in water/oil repellency, surface slip and smear wipe-off. F(CF 2 O) p (CF 2 CF 2 O) q (CF 2 CF 2 CF 2 O) r (CF 2 CF 2 CF 2 CF 2 O) s —C x F 2x -Q-Si(NH) 1.5 (1)
1. A perfluoropolyether-modified polysilazane, consisting of silazane units of formula (1′):
F(CF 2 O) p (CF 2 CF 2 O) q —CF 2 CH 2 OC 3 H 6 —Si(NH) 1.5 (1′)
wherein p and q each are an integer of 3 to 30, p+q is 17 to 34, q/p is 0.9 to 1, and respective recurring units may be randomly bonded.
2. The polysilazane of claim 1 , which consists of the following formula:
F(CF 2 O) p′ (C 2 F 4 O) q′ —CF 2 CH 2 OC 3 H 6 —SiNH 1.5
(p′=13, q′=12),
wherein respective recurring units may be randomly bonded.
3. A method for preparing the perfluoropolyether-modified polysilazane of claim 1 , comprising the steps of:
(1) partially fluorinating a perfluoropolyether compound having carboxyl groups at both ends,
(2) modifying the carboxyl group at one end and silylating into a reactive silyl group, and
(3) converting the reactive silyl group to a silazane.
4. A surface treating agent, comprising the perfluoropolyether-modified polysilazane of claim 1 .
5. A cured film, comprising the perfluoropolyether-modified polysilazane of claim 1 .
6. An article, comprising a substrate having a surface and the cured film of perfluoropolyether-modified polysilazane of claim 5 on the substrate surface.
7. The article of claim 6 , wherein the substrate is a touch panel, anti-reflective coating, display cover glass, tempered glass, transportation vehicle glass, hardcoat film, display cover film, quartz, optical member, sanitary member, glass tableware, or building member.