Patent GB-1108118-A (GB)
Title: An ink transfer element
IPC: B01J13/02
Filed: 1965-12-08
Abstract: An ink transfer element comprises a thermo-plastic fluorinated polymer, a non-volatile plasticizer which is non-solvent for the polymer at room temperature but capable of solvating the polymer at its fusion temperature and an ink composition which is also non-solvent for the polymer and is miscible with the plasticizer. The polymer and plasticizer are combined to form a porous matrix with the ink being distributed in its pores.  The matrix is self-supporting but may be supported on a substrate, e.g. plastics, fabric or paper. The element may include 30 parts wt. of polymer, 20-50 parts wt. plasticizer and 25-60 parts wt. ink. The polymer may be P.T.F.E., fluorinated ethylenepropylene copolymer, polychlorotrifluoroethylene or polyvinylidene fluoride, the latter may have a M.W. of 300,000-600,000 and a particle size of 1-100m  before being combined in the matrix. The ink composition may be alkali blue in mineral oil, castor oil, triethylene glycol or oleic acid or it may be a commercial black system.  The plasticizer can be butylene glycol adipate, neopentyl glycol adipate, dimethyl phthalate, tributyl phosphate, tricresyl phosphate, trioctyl phosphate, cresyl diphenyl phosphate or tributoxyethyl phosphate.  The plasticizer may increase in M.W. on heating.  The element is made by dispersing the polymer in the plasticizers and ink and heating to the fusion temperature of the polymer to form the matrix, e.g. heating can be at 370 DEG  F. for 40 secs.  The dispersion may include a cross-linking agent, a heat polymerizable monomer, a porous material, e.g. a molecular sieve or porous polyethylene, a blowing agent and a stabilizer, e.g. lead phosphite, lead salicylate or lead stearate.  The transfer element can be formed as a coating 1 to 10 mils thick, thicker coatings are self-supporting. The transfer element can be in the form of a cast article, e.g. a stamp pad or ink roller.ALSO:An ink-transfer element comprises a thermoplastic fluorinated polymer, a non-volatile plasticiser which is non-solvent for the polymer at room temperature but capable of solvating the polymer at its fusion temperature and an ink composition which is also non solvent for the polymer and is miscible with the plasticiser.  The polymer and plasticiser are combined to form a porous matrix with the ink being distributed in its pores.  The matrix is self-supporting but may be supported on a substrate, e.g. plastics, fabric or paper.  The element may include 30 parts wt. of polymer, 20-50 parts wt. plasticiser and 25-60 parts wt. ink. The polymer may be P.T.F.E., fluorinated ethylene-propylene copolymer, polychlorotrifluoroethylene or polyvinylidene fluoride, the latter may have a M.W. of 300,000-600,000 and a particle size of 1-100m  before being combined in the matrix. The plasticiser may increase in M.W. on heating.  The ink composition may be alkali blue in mineral oil, castor oil, triethylene glycol or oleic acid or it may be a commercial black system.  The element is made by dispersing the polymer in the plasticiser and ink and heating to the fusion temperature of the polymer to form the matrix e.g. heating can be at 370 DEG F for 40 secs.  The dispersion may include a cross-linking agent, a heat polymerisable monomer, a porous material, e.g. a molecular sieve or porous polyethylene, a blowing agent and a stabiliser e.g. lead phosphite, lead salicylate or lead stearate. The transfer element can be formed as a coating 1 to 10 mils thick, thicker coatings are self supporting and can be stripped off the support.  The transfer element can be in the form of a cast article, e.g. a stamp pad or ink roller.