“What we now propose is a new and useful business form or mailer of the type described above which uses, as the or each adhesive region, a non-tacky layer of a dry self-sealing contact adhesive which self-seals irreversibly to an opposed adhesive layer of the same kind, when the form has been folded to its folded condition, under a sealing pressure applied on that region which is a finger pressure, or alternatively stated, a pressure of 500 kPa or less or 300 kPa or less, but preferably at least 10 kPa. A form or mailer as proposed is in practice a dry seal form or mailer that can be sealed by hand without requiring the use of a sealing machine. Sealing machines are expensive, typically being engineered to exert pressures in the range 20 to 60 MPa (3000 to 8000 lb/in 2) as required by the conventional dry-seal contact adhesives. Thus, the present proposals open the way for example to small-scale use of direct mail by organisations who for one reason or another cannot run a sealing machine. The proposal also opens the way to fold, seal and return response forms which can easily be used by the ordinary recipient without the need to wet an adhesive strip – a common source of discontent.”
“1. A business form with an adhesive closure having one or more adhesive regions for holding the form on a folded condition, characterised by the use on the adhesive region of a non-tacky layer of a dry self-sealing contact adhesive, which in the folded condition self-seals irreversibly to an opposed adhesive region also carrying a said contact adhesive, the adhesive being selected to self-seal irreversibly under a pressure of 500 kPa or less. 6. A business form according to any one of the preceding claims made from a paper sheet which is laser-printable in which said contact adhesive is an elastomer latex adhesive. 7. A business form according to claim 6 in which the adhesive is a natural rubber latex adhesive stabilised with ammonia.”
“[11] One thing not mentioned expressly by Mr Morris, but which is self-evident, is that the point of this inability that he has referred to, to re-separate the bonded layers of paper in a mailer, is because one of the key uses of these mailers is for sending secure and confidential information, such as using them as pay slips. The point of this is that while one cannot prevent a third party from opening the mailer before it reaches the addressee, on the other hand, if the mailer cannot be resealed without that tampering being evident, then that will discourage the tampering. [12] Something that was not common general knowledge was a particular expedient used today to make tampering evident. This is the use of so called ‘anti-tamper slits’. Mr. Morris said the following. “22. I have been asked specifically whether mailers incorporating ‘anti-tamper slits’ or ‘tamper evident slits’ were common general knowledge in July 1998. ‘Anti-tamper slits’ are slits cut into the adhesive bearing paper of a mailer in order to create a line of weakness. The purpose of such slits is to ensure that if anyone tries to re-open a sealed mailer the paper will tear. This prevents a mailer being re-opened and re-sealed without this being evident. “22. I have been asked specifically whether mailers incorporating ‘anti-tamper slits’ or ‘tamper evident slits’ were common general knowledge in July 1998. ‘Anti-tamper slits’ are slits cut into the adhesive bearing paper of a mailer in order to create a line of weakness. The purpose of such slits is to ensure that if anyone tries to re-open a sealed mailer the paper will tear. This prevents a mailer being re-opened and re-sealed without this being evident. 23. Mastermailer started using anti-tamper slits in or around 2007 to give their mailers added security. Before this I had not seen any other products on the market in the UK that did so. For this reason I do not think that anti-tamper slits formed part of the common general knowledge at or before the priority date of the Patent. As I have mentioned above, the vast majority of mailers on the market at this time was made up of pressure seal and pressure sensitive mailers. Anti-tamper slits were not used on such mailers because the adhesives used made it very difficult to re-open them without causing damage to the unmodified paper.” ”
“The reference above to an irreversible self-seal is to be interpreted as meaning that subsequent re-separation of the layers results in disruption at least of the adhesive structure, if not also in the base material.”
“The basis material of the form is a paper sheet.”
“[28] As I have said already, [‘irreversible’] is clearly a reference back to page 3, lines 6–10 of the specification. As amended, the specification makes it clear that one needs both disruption of the adhesive structure and also disruption “in the base material”
“Re-sealing A selective number of tests pieces were attempted to [sic] re-sealed after opening. Those where there was partial adhesive transfer gave a very limited and patchy seal. Those where there was total adhesive transfer gave no seal at all.”
“On a number of mailers where paper curl was noted after opening after one hour, cursory attempts were made both by myself and Mr Poore [DMSL’s solicitor] to see if it may be possible to reverse this.”
“It was noted that on mailers where curl had occurred this could be reversed so that the mailer lay flat.”
“9. The adhesive used on the LBF Product was the sort of adhesive which would bond to itself but not to surfaces which did not have the adhesive on them. If adhesive coated onto one surface was contacted with the adhesive coated on another surface, and they were pressed together, they would bond firmly to each other. 10. I handled self sealing envelopes at the time. There were two types of self sealing envelopes that Viking sold at that time. Envelopes with release strips covering a sticky adhesive and those with an adhesive which would bond to itself but would not stick to other surfaces such as other bits of paper. The LBF Product was of that description – the envelopes without a release strip. The adhesive was dry to the touch – at least if you had dry fingers. You needed both parts. The adhesive went on three sides of each part. With pressure the adhesive bonded to itself so that, as I explained above, it would seal the mailer closed. It only needed finger pressure to seal the LBF Product closed. … 13. In relation to opening the LBF Product I would have tried everything possible to try to open it up to and including a letter opener to push between the sheets to see how safe the seal was. The seal was more than adequate. If you tried to pull the parts apart you would end up by tearing it. You might have been able to peel apart a corner, but when you went on you would end up by tearing it.”
“(ii) Self-adhesive strips, instead of laser-compatible gum was an avenue we had explored. However, the additional expense of such strips, added to the perforating and print costs, made the product very expensive in our opinion.”
“Many thanks for your fax dated1st February 1995 , in connection with our V-fold Readymade Mailers. I am delighted that you have decided to include the product in your next two catalogues May to December. … I am extremely confident that now we have upgraded the mailers to laser-compatible finger-seal (self-seal), instead of traditional moisten gum, the mailers will have an even greater appeal. I enclose a copy letter from our manufacturers of this product, Moore Paragon. The letter confirms that the self-seal pressure glue has been approved by no lesser authority than the Rank Xerox organisation.”
“Further to our telephone conversation this morning, I would like to confirm the following points in connection with One-Piece Mailers Ref.P25LBF2BL, prior to a meeting at your offices. i. It is plainly obvious that the mailers in their present format are not selling in the quantities that either of us are happy with. I think you said approximately 200 or 300 from Leicester and a further 50 or 100 from London. This is not very encouraging after three months and I think maybe this is because they are too expensive.”
“The remoist gum will reduce our gluing costs by 75%, as self-adhesive glue is very expensive to apply”. i. It is plainly obvious that the mailers in their present format are not selling in the quantities that either of us are happy with. I think you said approximately 200 or 300 from Leicester and a further 50 or 100 from London. This is not very encouraging after three months and I think maybe this is because they are too expensive.”
“In summary, I am prepared to assess the evidence relating to prior use on a flexible and proportionate basis within the overall requirement of proof on the burden of probabilities – but no more.”
“In the event that the cement employed for the sealing stripes…is of the contact type, such as a dry pressure-sensitive adhesive, it is then preferred that the stripes…continue preferably entirely along the opposite side edges of the piece so that when the panels…are folded upon each other, the engagement of said stripes of contact adhesive upon each other will immediately and permanently seal the same.”
“[103] TEVA submitted that all the claims currently sought by LEO were bad for added matter. It was an independent ground of invalidity, however I do not propose to deal with it because it does not depend on any court (at this level or on appeal) making findings of fact by resolving disputed evidence. It is primarily a matter of construction and is therefore something an appellate court would be able to resolve if necessary.”
“(3) Where an amendment of the specification of a patent has been allowed under any provisions of this Act, the court or the comptroller shall, when awarding damages or making an order for an account of profits in proceedings for an infringement of the patent committed before the decision to allow the amendment, take into account the following – … (b) whether the specification of the patent as published was framed in good faith and with reasonable skill and knowledge, (c) whether the proceedings are brought in good faith.”