| 摘要 |
1,271,463. Microcapsule-containing coatings. CHAMPION PAPER CO. Ltd. 17 March, 1969 [29 April, 1969], No. 56217/69. Heading B2E. [Also in Division B8] An opacifyer which may be coated on to paper comprises air-containing microcapsules having shells of polymeric material containing particles of an inorganic pigment, e.g. TiO 2 , ZnO, BaSO 4 , CaCO 3 , Al 2 O 3 . 3H 2 O or clay, the microcapsules having an average diameter of less than 2 microns, preferably 0.1 to 1 micron. Numerous encapsulating materials are mentioned, examples relating to products in which a urea-formaldehyde condensate are used. The microcapsules may be made with a volatile liquid core which is removed by heating either before or after the microcapsules have been coated onto the paper. |
