| 摘要 |
<p>1,273,451. Thermally bondable reticulated film laminates. BOSTIK Ltd. 30 May, 1969 [31 May, 1968], No. 27547/69. Headings B5B and B5N. [Also in Division A3] A reticular film or sheet consisting of a "thermoplastic adhesive composition" is made by forming a pattern of spaced apart cuts in the film, the cuts extending therethrough, placing the film upon a supporting surface which is of such a nature it does not prevent movement of the film, heating the film to such an extent that the film material softens and shrinks away from the cuts, whereby the cuts widen to form apertures and the film acquires a reticulated structure. "Thermoplastic adhesive composition" is defined as a solvent-free adhesive composition which at normal room temperatures is in a solid condition in which it is substantially incapable of forming a strong bond with a solid surface but which can be softened and brought to a bond-forming condition by the application of heat, the composition returning to a solid condition on being allowed to cool, and the composition being capable of use in an adhesive bonding process in which the composition is heated to bondforming condition and allowed to cool. The supporting surface used in the formation of the reticulated film may be provided with a coating having "release characteristics" such as a coating of polytetrafluoroethylene or a silicone coating. The support may be a first workpiece which is to be bonded to a second workpiece by means of the web. (For details see Division A3). Preferably the pattern of spaced apart cuts is regular, all the cuts are of uniform length and parallel to one another and arranged in rows extending lengthwise of the cuts. The series of cuts in any one row is preferably staggered with respect to the series of cuts in the adjacent rows. The thermoplastic adhesive composition may comprise a condensation polymerization product of a mixture of 85 mol per cent dimerized linoleic acid and 15 mol per cent azelaic acid with a mixture of 85 mol per cent ethylene diamine and 15 mol per cent hexane diamine, the resulting polyamide containing material having a softening point (ball and ring) of 275‹ F. and a ball fall viscosity at 355‹ F. (<SP>3/</SP>32 inch falling steel ball) of 50 to 60 seconds. The composition</p> |
