(19)
(11) EP 0 569 285 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.06.1994 Bulletin 1994/22

(43) Date of publication A2:
10.11.1993 Bulletin 1993/45

(21) Application number: 93401145.3

(22) Date of filing: 04.05.1993
(51) International Patent Classification (IPC)5: B41M 5/124, D21H 27/00, D21H 19/40, G03G 7/00
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 04.05.1992 US 878048
19.02.1993 US 19795

(71) Applicant: MINNESOTA MINING AND MANUFACTURING COMPANY
St. Paul, Minnesota 55133-3427 (US)

(72) Inventor:
  • Kraft, Keith A., c/o Minnesota Mining and
    St. Paul, Minnesota 55133-3427 (US)

(74) Representative: Warcoin, Jacques et al
Cabinet Régimbeau, 26, avenue Kléber
F-75116 Paris
F-75116 Paris (FR)


(56) References cited: : 
   
       


    (54) Colloids to increase coefficient of friction in carbonless paper pad coatings


    (57) A composition suitable for use as a pad-coat or release coating for carbonless paper constructions, the composition containing about: (a) 0.1-10.0 weight percent inorganic colloid having a particle size in the range of about 1-125 nm; (b) 0.1-5.0 weight percent abherent material; (c) 60.0-99.9 weight percent water; and (d) 0-25 weight percent binder, based upon the total weight of the coating composition. In a preferred embodiment, colloidal silica is utilized. Also disclosed is a carbonless paper construction with at least a portion of at least one outer surface having the inventive pad-coat or release coating applied thereto.
    The incorporation of inorganic colloidal particles into carbonless paper pad-coats results in an increase in the coefficient of friction of the pad coated surface; increase in toner adhesion and ink receptivity of the pad-coated surface; promotes uniform feeding of carbonless paper sheets into photocopiers and printing presses by reducing misfeeds and double feeds; and reduces feeder induced smudging. It does this without loss of the abhesive release effect provided by the pad-coat and without loss of the fan-out ability to produce form-sets.






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