Extrudable eraser compsn. with India ink solvent - contains substance swollen by solvent to prevent sepn. from PVC plastisol

摘要

Eraser compsn. with India ink solvent (I) consists of PVC or PVC/PVA copolymers (II) with plasticisers (III). It contains substance(s) (IV) which are swollen by (I) and take this up so that it is firmly anchored before mixing with the plastisol. (IV) pref. is polyvinyl alcohol, cellulose deriv., alginic acid, alginate, polysaccharide, polyvinylpyrrolidone or modified montmorillonite. In an example, the compsn. consisted of PVC, di-isononyl adipate, diethylene glycol and montmorillonite modified with organic ammonium deriv. Since (I) does not separate from the plastisol on gelation, even under press., the compsn. can be processed by extrusion, instead of by troublesome and labour-intensive casting and gelling.