PREPARATION OF FORMIC ACID ESTERS WITH A PHOSPHONIUM SALT AND ZINC BROMIDE INN,N-DIMETHYLFORMAMIDE
摘要:
When primary and secondary alcohols were treated with the phosphonium salt 1 and ZnBr2 in N,N-dimethylformamide, the corresponding formic acid esters were obtained in good yields.
Diamine compounds, which in particular are useful as precursors for the production of liquid crystal alignment layers, represented by general formula (I), wherein A1 represents an organic group of 1 to 40 carbon atoms; A2 represents a hydrogen atom or an organic group of 1 to 40 carbon atoms.
The present invention provides a compound comprising a repeating unit of formula (I)
in which:
Arepresents a nitrogen atom, a carbon atom, a group -CR1- or an aromatic or alicyclic group, wherein R1 represents a hydrogen atom or lower alkyl,
Mrepresents a repeating monomer unit;
n1 to n3each independently represent 0 or an integer having a value of from 1 to 3, with the proviso that 1 < n1 + n2 + n3 < 4;
P1, P2, P3each independently represent a photoactive group; and
B1 to B4each independently represent a residue of general formula II
as well as photoactive polymers prepared from such compounds and the use of such compounds in the preparation of liquid crystal orientation layers and structured and unstructured electro-optical elements.
Photoactive polyimides, polyamide acids or esters with side chain photocrosslinkable groups
申请人:——
公开号:US20030039768A1
公开(公告)日:2003-02-27
A photoactive polymer from the class of polyimides, polyamide acids and esters thereof comprises as a side-chain a photocrosslinkable group of the general formula (I)
1
wherein the broken line indicates the point of linkage to the polyimide main chain and wherein: B is a straight-chain or branched alkyl residue which is optionally substituted, wherein one or more non-adjacent CH
2
groups may independently be replaced by a group Q; D represents an oxygen atom or —NR
1
— wherein R
1
represents a hydrogen atom or lower alkyl; and S
3
represents a spacer unit. The polymers may be used as orientation layers for liquid crystals and in the construction of unstructured and structured optical elements and multi-layer systems.
Diamine compounds, which in particular are useful as precursors for the production of liquid crystal alignment layers, represented by general formula (I), wherein A
1
represents an organic group of 1 to 40 carbon atoms; A
2
represents a hydrogen atom or an organic group of 1 to 40 carbon atoms.
A photoactive side-chain polymer from the class of polyimides, polyamide acids and esters thereof, comprising as a side-chain a dentritic block incorporating photoactive groups at its surface. The dentritic block preferably represents a unit of formulae Ia, Ib or a combination of them, for example formulae Ic wherein the broken line symbolizes the linkage to polyimide main chain. The polymer may be used as orientation layer for liquid crystals and in the construction of unstructured and structured optical elements and multi-layer systems.