US 2477344 A
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Description (OCR text may contain errors)
Patented July 26, .1949
i "PATENT OFFICE l 52,477,344
l mama-mm EABEICANDJ.0'J2HER I J- l\!IATERIALS- 1 s'a'lomon-Neumanni.LondoniZEnglarid; assignor or one-half tdfshand liyddf himitedi'hondongqllngland, a British company :NoIDrawing. ApplicatioriFebnuarstZQ;1945;582-
ariall N0..,57,8,952. 1" 1944 In GreatiZBritain. Marchll,
-%2 Claims. (Cl? ILL-A-IZZ) ri'al iscoated with adry adhesive which requires onlymoistening whenthe paper is to be applied to a wall or other surface. The invention is mainly (but not exclusively) concerned with the manufacture of pre-gummed wall-paper and other types of hanging paper, such as poster papers and bill-board papers.
It has hitherto been proposed to make pregummed wall-papers by sizing with ordinary dextrine, paste, glues or gums, but these papers have usually proved unsatisfactory, mostlybecause the applied size does not re-moisten and re-swell quickly enough, and when re-moistened, does not regain s'uflicient tackiness and slip for the proper hanging of the paper. An object of this invention is to provide an improved pregummed hanging paper which in its dry state is flexible and non-curling and in its wet state possesses good tackiness and slip characteristics so that it may readily be moved on the wall to the right position.
The invention deals with the method by which the adhesive is applied to the back of the paper or other surface to be coated. The invention provides a process for the manufacture of pregummed papers, cardboard, fabrics and like sheet materials of the type described characterised in that the adhesive is so constituted and so applied to the surface of the material to be coated that only part of the tackiness of the adhesive is developed in the application stage, thus leaving a coating of high effective concentration.
In one method of carrying the invention into efiect a water-soluble or water-swelling adhesive in powdered form is made up as a suspension in a liquid medium in which the adhesive is not soluble or only partly soluble. The suspension is then applied by spraying, brushing or in any other convenient way, and the coated material is finally dried. The suspending medium may be made by adding a proportion of water to a liquid in which the adhesive is wholly insoluble, or the adhesive may be a mixture of two or more diiierent substances, the main portion of the mixture being wholly insoluble in thesuspending medium while the remainder of the mixture is soluble. In carrying out the invention according to either of the above methods, any watersoluble or water-swelling adhesives, such as starches, starch-containing flours, chlorinated starches, dextrine, glues, gums or mixtures of crease its "slip characteristics. preventingtthe curling of the" paper may also be added "ifflesired.
' su'ch substances, may be employed. Bentonite orsim'ilar colloidal clay ofrhighswelling capacity may be embodied in theadhesive in order to in Chemicals for The following are examples of coating suspensions suitable for carrying out the invention according to the foregoing methods:
Example I The suspension comprises- Parts Alcohol 2 Light yellow dextrine 2 Bentonite 1 Water 2 Example II The suspension comprises- Parts Alcohol 2 Cold swelling paste powder (starch base) 1 Water 3 Example III The suspension comprises- Parts Acetone containing 2% cellulose acetate 2 Gum arabic 2 The above examples may be modified by increasing or decreasing the proportion of water in accordance with the thickness of film, tackiness and slip characteristics required for the individual paper.
In a further method of carrying out the invention the receiving surface of the material to be coated is first wetted with water or lightly coated with a thin film of adhesive paste, and a cold water-soluble adhesive in powdered form is then dusted over the wetted surface, after which the coatedmaterial is dried. The portions of the powder particles in contact with the Wetted surface of the material are dissolved and thus produce sufficient tackiness to hold the particles to the paper. In carrying this particular method into eiTect, any cold water-soluble adhesive, such as paste powder, soluble starch degradation products, glues and gums may be employed. As before bentonite will be added to the adhesive in order to increase the slip characteristics, and substances which are known to prevent curling of the paper or like material may also be embodied.
While, as already indicated, the invention is mainly concerned with the manufacture of wallpaper and similar hanging papers, it may also be applied to the manufacture of re-moistening tape and in general to the treatment of any material on which a pre-gummed coating is desired. I
1. A process for the manufacture of pregummed wallpaper of the type in which the rear surface of the paper carries as a dry coating, a cold-water soluble r cold-water swelling adhesive from the class consisting of dextrine and starch, which requires only moistening when the paper is to be applied to a wall or like surface, said process comprising the steps of incorporating the aforesaid adhesive in powdered form in suspension in a liquid medium made by adding Water to a liquid in which the adhesive is wholly insoluble, the liquid phase of the suspension comprising substantially equal parts by weight of water and alcohol, applying the suspension to the ,rear surface of the paper, and drying the coating.
2. A process for the manufacture of pregummed wallpaper of the type in which the rear surfaceof the paper carries as a dry coating a cold-water soluble or cold-water swelling adhesive from the class consisting of dextrine and starch, which requires only moistening when the paper is to be applied to a wall or like surface, said process comprising the steps of incorporating the aforesaid adhesive in powdered. form; in suspension in a liquid medium made by adding water to a liquid in which the adhesive is wholly insoluble, the liquid phase of the suspension comprising water and alcohol in proportions about two parts by weight alcohol to three parts by weight water, applying the suspension to the rear surface of the paper, and drying the coating.
' SALOMON NEUMANN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name 7 Date 1,733,524 Bradner Oct. 29, 1929 2,212,557 Bauer Aug. 27, 1940 2,235,676 Gardner 'Mar. 18, 1941 2,325,118 Bauer et al Aug. 10, 1943 Harris Dec. 26, 1944