| 摘要 |
1,051,262. Resorcinol-aldehyde resin solutions; mixture thereof with rubber latex. KOPPERS CO. Inc. Jan. 9, 1964 [Jan. 21, 1963], No. 1094/64. Headings C3P and C3R. [Also in Division D1] Resorcinol-aldehyde resin solutions compatible with butyl rubber latex are prepared by a two-step method comprising (a) substantially completely reacting 0.15 to 0.32 moles paraldehyde per mole resorcinol at above 120‹ C. and a pH below 1.5 (only sufficient water to dissolve the acid catalyst should be used to ensure complete reaction) and (b) reacting the condensate with 0.35 to 0.48 moles formaldehyde per mole resorcinol, the total aldehyde being 0.5 to 8 moles of which 30 to 40 mole per cent is paraldehyde. Preferably aqueous formaldehyde is used in step (b) with sufficient water to lower the boiling point of the reaction mixture to about 105‹ C.; alternatively paraformaldehyde may be used and the step performed at between 80 degrees and the boiling point. Comparative examples illustrate the effect of reversing the order of the steps, of varying the features thereof, and of using other aldehydes instead of paraldehyde. The solution may be used to prepare a tyre cord adhesive dip by incorporation of a butyl latex, additional formaldehyde, water and alkali to adjust the pH to 7.5 to 13.5 and used to coat rayon tyre cord. |
