US2426935A - Hectograph blanket - Google Patents

Description

Patentecl Sept. 2, 1947 HECTOGRAPH BLANKET Irwin Kramsky, Chicago, and Melville J. Holik, Berwyn, Ill., assignors to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia No Drawing. Application October 31, 1945, Serial No. 625,952

6 Claims; (01. 117-355) 1 The invention relates to composite bonded sheet material and more particularly to hectograph blankets and to methods of preparing the same. Hectograph blankets generally comprise a gelatinous copy mass secured to a flexible backing,

In one type of hectograph blanket in commercial use the backing has been secured to the copy mass by means of an intermediate layer of drying oil such as linseed oil. The drying oil may be used by itself or in a lacquer composition. In one type of blanket the backing is coated with a drying oil and then the side remote from the copy mass is coated with a lacquer such as a cellulose ester lacquer which serves as a protective coating. The success of the bond These compounds may be incorporated with all types of gelatin containing compositions for which it is desired to obtain an eflicient bond to a backing of paper, cloth, metal or the like, particu larly where the backing is coated with a compositionconsisting of or containing a drying oil such as linseed oil, poppy oil, tung oil and the like. However, our invention is particularly applicable to secure hectograph compositions to paper or cloth backings. These hectograph compositions, as is well known in the art, are gelatin between the copy mass and the drying oil coated backing has been subject to a variety of factors contingent upon (1) degree of oxidation of the drying oils (ageing); (2) humidity and temperature conditions; and (3) quality and concentration of the gelatin and glue used in the copy mass.

Anobject of this invention is to provide an improved bond between the hectograph copying mass and the intermediate layer containing a drying oil. A further object is to provide a method for bonding of a gelatin layer t a backing, which method is not so dependent upon degree of oxidation, humidity and temperature and quality and concentration of gelatin as is present with meth ods hitherto used employing drying oils as bonding agents.

Other objects and advantages of the invention will become apparent as the following detailed description progresses.

We have found a series of compounds which,

when added to a gelatin composition such as a hectograph copy mass, facilitate the adherence of the copy mass to a drying oil coated backingand otherwise accomplish the objects of our invention. These compounds consist of water soluble hydroxy aliphatic monoamines and water soluble oxygen containing heterocyclic amines which contain nitrogen in the trivalent form. Suitable compounds include, for example:

(a) Z-amino-l-butanol (b) Mono, di, and triethanolamine (0) Mixed isopropanol amines (d) Tris (hydroxymethyl) amino methane (e) 2-amino, 2-ethyl, 1,3-propanediol (f) 2-amino, Z-methyl, 1,3-propanediol (g) Z-amino, 2-methyl, l-propanol (h) Diethylaminoethanol (i) Morpholine (7') Ethyl morpholine gels containing a major proportion of a relatively non-volatile water soluble material such as glycerin. For example, hectograph blankets generally contain to 1 part by weight of gelatin, 5 to 20 parts by weight of glycerin, and from 1 to 3 parts by weight of water. The water soluble amine may be incorporated in this composition in a proportion of 1% to 50% by weight, preferably from 5% to 25% by weight. Minor proportions of tanning agents based on the gelatin are also incorporated in the mixture. Formaldehyde, aluminum alums, chrome alums and potassium and ammonium dichromates may be used. For example, .001 to .01 of potassium dichromate may be incorporated in the gelatinous mass.

To more clearly set forth the practice in accordance with the invention, and to more specifically point out the nature of the product and process contemplated thereby, several specific, illustrative examples of suitable compositions are hereinafter set forth, it being understood that these examples illustrate several embodiments which have given satisfactory results and are not intended to restrict the invention thereto.

Example I Parts 225-bloom gelatin 150 Water 200 2-amino, 2-methyl, 1,3-propanediol 15 Glycerin 1800 Q Example II Parts 225 bloom gelatin 150 Water 200 Triethanolamine 25 Glycerin 1790 Example III Parts 225 bloom gelatin 150 Water 200 Aminobutanol 25 Glycerin 1790 To prepare the gelatin I compositions, the gelatin was first soaked in the aqueous amine solution, then warmed to 53 C. and added to the glycerin, which has been preheated to 62 0.

While we do not intend to be limited to any theory as to the action of amine compounds, the following explanation is given for the purpose of aiding and'understanding "our invention:

Assuming a structure for the unsaturated, free fatty acids of the drying oils in the bonding layer to be upon oxidation, a diperoxide' structure re iree sented by the formula:

R-CH-OH- -1 3HoH-- eco-n where 0 represents nitrogen electrons and represents R electronsitmay be shown that, being soluble in water, 7

a h drated: amine of' the oxonium type" based upon a coordinate linkmvoiving a-covalent' hydrogen; called the hydrogen bond, a semi polar linkage; This linkage is semi-ionic in nature, and its resence is established from the number of covalent bonds in th'e c'omp'leted valence-shell of the atom; Onje'of the valencesorpentavalent nitrogen is an electrovalence different from the other four; The four covalences of nitrogen have a tetrahedral spatialarrangement; but thegroup held" by the electrovaience is attracted by the ammonium ion' as aunit by virtue of" the" eiec trostaticcharge without definition" of direction; This compound; then; is" capable or forminga substantially stable salt attributable to the res onance effect allied with; hydrogen bond.

This is believed to react with the peroxide por tion of the-oxidized unsaturated free fatty-acid asfollows: the-amine hydrate-forms an amine oxide hydrate from theperoxide',

' iflar=oxygenelectrons i. .7, this hydrate then forms a partial ether linkage with the ethylenic oxide,

4 Thus the conversion of trivalent nitrogen makes it possible to form a connecting bridge with the bonding layer. This is substantiated by the fact that pentavalent nitrogen compounds do not perform this function.

Since protein, e. g., gelatin org'luais a hydrophilic colloid, and the case of a; colloidal solution of a more or less linear molecule of high molecular weight, such as gelatin is assumed to be, produces an interlocking network of molecular fibers leaving a high proportion of open liquidfilled spaces which'retain their properties of electrical conductivity and difiusivity of solute, it can'logicallybe assumed that groups of a hydrophilic character, such as hydroxyl, will seek out the interstices of water and become imbedded in the colloidal solution. Thus a bridge linking the bonding layer to the protein layer is established between the amine portion of a molecule, andthehydroxyportion ofa molecule.

While we have described certain preferred em bodiment-s of our invention, many modifications thereof may be made without departing from thespirit of the invention; and we do not wish to belimited to t-he detailed examples, formulas, and proportions of ingredients herein set forth, but desire to avail-ourselves of allchanges within the scope of the appended claims,

We claim:

LA composite sheet comprising a layer of gelatin containing a: compound selectedfrom the group consisting of water soluble hydroxy all-'- phatic monoamines and water soluble-oxygen con-- taining heterocyclic monoamines containin nitrogen in a trivalent form; abacking, and an intermediate layer containing a drying oil.

2-. A heotograph blanket comprising a backing, a gelatinous copy mass comprising gelatin and containing a compound selected from the group consisting of water soluble hydroxyaliphatic monoamines and water soluble morpholines; and an'intermediat'e-bonding layer comprising a drying oil;

3. A hectograph blanket comprising a fibrous backing-,a gelatinous copy mass comprising gelatin and containing a' compound selected from thegroup consisting of water soluble hydroxy aliphatic monoamines and water soluble morpho'lines; and an intermediate bonding layer of linseed oil. 7 H i 4. A hectograph blanket comprising abacking, a gelatinous copy mass comprising gelatinand containin a hydroxyaliphaticmonoamine; and an intermediate bonding layer comprising: a dryingoil. 4

5'; A hectograph blanket comprising a backing, a. gelatinous copy. mass comprising. gelatin and containing. an ethanolamine, and an intermediate bonding layer comprising a drying oil.

6'. A liectograph blanket comprising a backing, a elatinous copy mass comprising gelatin and containingja morpholine'; a backing, and an intermediatelayercontaining a drying Oil.

IRWIN KRAMSKY.

REFERENCES CITED The following references are oirecordin" the file of this patent:

UNIT EDSI'ATES -PATEN 'ISf Number Name Date V 1,982,018 Owen Novr27,:1934