Sealing liquid for safety closures

• US 8,951,382 B2
• Filed: 09/23/2011
• Issued: 02/10/2015
• Est. Priority Date: 05/29/2006
• Status: Expired due to Fees

• Current Assignee: Francotyp-Postalia GmbH (Francotyp-Postalia Holding AG)
• Original Assignee: Francotyp-Postalia GmbH (Francotyp-Postalia Holding AG)
• Inventors: Muhl, Wolfgang, Gebhardt, Thomas
• Primary Examiner(s): ORLANDO, MICHAEL N
• Application Number:
  US13/242,527
• Publication Number:
  US 20120006887A1
• Time in Patent Office: 1,236 Days
• Field of Search: 156/308.6, 156/325, 156/441.5
• US Class Current: 156/325
• CPC Class Codes: B29C 65/4895 Solvent bonding, i.e. the surfaces of the parts to be joined being treated with solvents, swelling or softening agents, without adhesives
• CPC Class Codes: B32B 27/00 Layered products comprising a layer of synthetic resin fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18
• CPC Class Codes: B32B 27/24 using solvents or swelling agents
• CPC Class Codes: B43M 5/042 for envelopes with only one flap
• CPC Class Codes: C09J 11/06 organic
• CPC Class Codes: C09J 11/08 Macromolecular additives
• CPC Class Codes: G09F 3/0341 having label sealing means
• CPC Class Codes: Y10T 156/1051 by folding

Abstract

The invention relates to a sealing liquid for sealing mailpieces containing water and a penetration agent, to the uses thereof and to letter-closing devices and franking machines containing such a sealing liquid.

Claims

1. A method of sealing a mailpiece, comprising:

providing a mailpiece envelope with a gummed flap;

applying a sealing liquid to gumming on the flap or on an area of the mailpiece envelope opposite the gumming on the folded flap according to a defined laterally inhomogeneous pattern, the sealing liquid including water and a safety additive substantially not visible by immediate observation; and

subsequently folding the flap and pressing the flap against an opposed surface of the mailpiece envelope;

wherein the sealing liquid comprises;

a) 80 to 98.9599 wt.-% water;

b) 1.0 to 20 wt.-% penetration agent;

c) 0.01 to 1.0 wt.-% wetting agent;

d) 0.01 to 2.0 wt.-% stabilizer and/or buffer;

e) 0.01 to 1.0 wt.-% dyes;

f) 0.01 to 0.1 wt.-% aromatic substances;

g) 0 to 0.1 wt.-% biocides and/or fungicides and/or other usual auxiliary substances; and

h) 0.0001 to 2.0 wt.-% safety additive.

2. The method according to claim 1, wherein the mailpiece is a letter and the mailpiece envelope is a letter envelope.

3. The method according to claim 1, which comprises performing the applying and folding steps with an automated letter-closing device.

4. The method according to claim 1, wherein component h) amounts to 0.0001 to 0.1 wt.-% safety additive.

5. The method according to claim 1, wherein the safety additive includes a luminescent substance, is substantially not visible by immediate observation, and is constituted so as to be visible or detectable using a technical mechanism.

6. A method for detecting unauthorized opening of a mailpiece, comprising:

providing a mailpiece sealed according to the steps of;

providing a mailpiece envelope with a gummed flap;

applying a sealing liquid to gumming on the flap or on an area of the mailpiece envelope opposite the gumming on the folded flap according to a defined laterally inhomogeneous pattern, the sealing liquid including water and a safety additive substantially not visible by immediate observation; and

subsequently folding the flap and pressing the flap against an opposed surface of the mailpiece envelope;

detecting a pattern of the safety additive on the mailpiece; and

comparing the detected pattern of the safety additive with a defined laterally inhomogeneous reference pattern.