US2202765A - Bonding adhesive for an abrasive article such as sandpaper - Google Patents

Description

Patented May 28, 1940 UNITED STATES PATENT OFFICE BONDING ADHESIVE FOR AN ABRASIVE ARTICLE SUCH AS SANDPAPER sota No Drawing. Application September 11, 1930, Serial No. 481,351

20 Claim.s. (Cl. 260-29) posite structures of which forms of abrasive such as what is commonly known as sandpaper is an example.

Although I hereinafter disclose the practice of my invention in connection with abrasives such as sandpaper, it will be understood that my invention of certain features thereof has a wider field of utility.

Composite structures of the abrasive type, such as sand-paper or emery cloth, comprise generally (a) a base of sheet material which may be felted as in the case of paper or woven as in the case of cloth; (1:) a more or less finely comminuted resistant material having abrading properties such as garnet or corundum and (c) a binder generally in the form of the glue which serves to bind theabrasive to the base.

Where I have attempted to make abrasive products suitable for liquid sanding operation and having a high order of flexibility in which the binding ingredients for the abrasive particles include the water repellant properties of materials of the resinous type or resin-varnish type including 'drying oils, the new materials being of extremely complex, arbitrary nature or having varying properties due to the methods used for their production, derivation or extraction from v their natural sources, these materials have been found. to give non-uniform results or results ous or drying oil type above referred to is of such complex character that when used with thinners of solvents therefor to saturate, impregnate or otherwise coat the base or backing, uniformity is not a certainty and such factors as porosity of paper, ability to wet the abrasive due to the nature of its surface, etc., will give marked nonuniform results in the final product.

The present invention contemplates the provision of an abrasive article in the nature of sandpaper and a new binding material susceptible of application to the materials entering into an abrasive article, such as the base or backing, either cloth or paper, and the abrasive grit or layer, whether of the natural, electro-furnace type, vitreous type or baked type abrasive and 5 assure uniformity of results so far as the weight of the article is concerned, its deterioration factor throughout periods of storage, flexibility and resistance to mechanical agencies when used in dry or wet abrading operations and which properties may be obtained with great facility, without special care and permits the utilization of standard equipment in the abrasive art, such as sand- P p In its preferred form, my invention contemplates the provision of an abrasive article in the nature of sandpaper including the reaction, condensation or polymerization of products resulting when polyhydric alcohols or their anhydrides or similar compounds or when polyhydric acids or their anhydrides or similar compounds are used as components, together with another compound or compounds, with or without a modifying agent or agents to produce such compounds as commonly are called synthetic resins or condensation products and one which functions more efliciently than any other prior binder known to me; the provision of an abrasive article having a binder characterized by its uniformity of physical and chemical properties whereby any desired and predetermined degree of flexibility may be imparted to the abrasive article; the provision of an abrasive article having a binder characterized by extensibility and compressibility to accommodate itself to flexion of the base without permanent distortion, deleterious disintegration due to atmospheric conditions, temperature changes or actinic exposure; the provisions of an abrasive article having a' binder of great tensile strength and flexibility resulting from the ability of the binder to tenaciously attach itself to materials of various surface characteristics, such as natural or artificial abrasive particles and the porous base or backing and obtain uniformity of the composite article as to flexibility, abrasive resistance, and which may be conducted with an exercise of a low order of care; the provision of an abrasive article having a binder which is resistant to liquids used in sanding operations or finishing operations, whether water, organic solvents or inorganic materials, such as strong acids or alkalis; the provision of an abrasive article having a binder which may be attached to an organic base or backing material, such as paper and which may be further matured to its final stage -cluding a binder which may be modified for application to a base or backing having various porosity factors characteristic in the properties of paper when sized or unsized, or thick or thin sheets thereof and which requires no material I change to accommodate itself to abrasive particles useful for various purposes, .as may be occasioned by adopting natural or artificial abrasive; the provision of an abrasive article including a binder which may be used in any point in the composite structure of the abrasive article such as the size, back size or pre-size and a bond and sand or grit size, without material modification of the binder for the various purposes enumerated.

In the employment of my present invention for the production of sandpaper and the like (which I cite for purposes of example) I use as the base such a sheet of material (a woven web of material or a deposited or felted web of material such as paper) as will have predetermined porosity factors and serve conveniently for the employment contemplated, and as the abrasive I use such comminuted material as may be classified as natural abrasives, such as flint, garnet or corundum, or artificial abrasives such as of the character used for making argillaceous refractories or electro-furnace products, as'silicon carbide or the like of various grades and sizes, surface character, etc., as is similarly adapted to perform the function in view.

It is most desirable that the binder utilized have the functions and characteristics not only of great mechanical strength, including toughness,

resistance to tensile and shearing strains and of great binding strength, including adhesiveness and tenacity and ability to wet abrasive particles under all conditions of surface contour, but also that it be moisture resistant, unafiected by a large number of liquids which may be used in liquid sanding operations, easily worked, made of materials easily obtainable on the market, of definite chemical composition and uniformity, inexpensively and facilely worked and applied and when used with a base material which is penetrable, penetrative of such base as to form a strong union therewith and, furthermore, when built up into a plural layered composite article, retain a predetermined flexibility, free from deteriorating factors such as changes in temperature,atmospheric conditions or actinic exposure.

I have discovered that resinous materials including a polyhydric substance are preferable not only to gum, gum resins, hardened oils, but to phenolic condensation products for purposes contemplated by me, and particularly resins having as their base polyhydric substances or their anhydrides, which are peculiarly adapted for my ends for a number of reasons, including that their characteristics can not only be better controlled than in the case of the other materials first enumerated, but that batches of the desired characteristics can be readily reduplicated and the desired properties imparted to the composite article with a large variation in the basic ingredients, such as the backing and the abrasive particles, I have found that certain materials, such as polyhydric alcohols or polyhydric acids are available to give by interactions, condensation or polymerization a material which is preferred by me as a major constituent of the binder, that is, as best to attain the desired ends, viewed from certain aspects.

In carrying out my invention, in order that the resinous material may be of a known quantity and of known quality, and of predetermined ageing properties, I prefer to react, condense or polymerize polyhydric alcohols or their anhydrides or similar compounds or polyhydric acids or their anhydrides or similar compounds, used as components, together, or with another compound or compounds with which they are adapted to react, condense or polymerize to resinify, and may be further suitably modified by agents to impart additional properties of flexibility and penetrability of the base or backing or for adhesively binding the various abrasive particles. The treatment to which I subject these basic materials results in a resinifled composition, in certain aspects possessing novelty, uniformity and physical properties peculiarly useful in the sheeted abrasive art, such as freedom from gumminess or tendency to clog during intensive abrasive operations.

In producing the desired binder, I employ a number of alternative methods, each of which appears to have certain favorable characteristics and advantages. One method which has given very good results will now be described in some detail as-- Example No. 1

Grams Polyglycerine 100 Phthalic anhydride 200 are mixed together and held for a short time at a temperature of 100 to 110 C. The resulting product will produce a resinous mass which may be heated for direct application to form a size or bond or thinned for sizing. This material may be used as a paper size, sandsize, back-size, a hinder or bond for the abrasive particles. The consistency may be modified to take care of such components as porosity and penerativeness of the backsize. For instance, with paper having a low porosity and high penetrative properties I may heat the resin for only thirty minutes at 110 C. and use 35% thinners of such a nature as 50% benzol and 50% acetone together with 65% resin. On the other hand, for a paper having a high porosity and low penetrative properties I may heat the resin for, say, three hours at 110 C. and use 45% thinners and 5% resin for producingpre-size. It is evident from this that by varying the quantity of condensation and/or polymerization of the resin and varying the quantity of thinners I may be able to takecare of such factors as porosity and penetrativeness of the base. After separation of the solvent, if such is used, the resin may be matured by heating at a temperature of from to C. for a period of 19 hours or where the material is applied in fairly thin layers, a higher temperature for a shorter period of time may be utilized to set the final product.

In this type of resin particularly, this condensation resin may be combined with modifying agents such as various drying, semi-drying and non-drying oils. Though the example has been given with phthalic anhydride as the single aromatic acid, this.may be combined with an aliphatic acid, such as oleic, butyric, succinic, citric, benzoic, malic, glutaric, suberic, camphoric, adipic, linoleic and eleostearic and others.

Though I have mentioned above glycerine as the polyhydric compound, under some conditions though not as preferable, glycol and other polytreatment afterward. For certain purposes this hydric alcohols may be used, such as Dihydroxyethane 1-2 Dihydroxypropane 1-2 Dihydroxypropane 1-3 Trihydroxypropane 1-2-3 Grams Resin as produced in Example I 100 Chinese wood oil 15 are mixed and held at a temperature of about 110 C. for about 5 minutes, with continued stirring. This resinous material may now be thinned in accordance with the proportions enumerated above to vary the consistency of the solution to take care of the porosity of the base or backing and the size and character of the abrasive particles. After evaporation of the vehicle or solvent, the base with its residue may be heated to mature the same temperatures from 85 C. to 90 C. for a period of about 19 hours. In the example given, other oils which may be used are the various drying, semi-drying and non-drying oils, uch as wood oil, linseed oil, castor oil, cottonseed oil, rape seed oil and soya bean oil, within limits approximating 15% to 50% of the resin, with the modification as to the quantity depending upon the characteristics of the various oils to impart the desired flexibility to the resinous binder upon the base or backing. These oils or modifying agents act in the nature of softening agents or emolients. Gelatinizing substances, such as camphor substitutes and the heavier, less volatile solvents for the resins may also be included. Of the gelatinizing agents and high boiling solvents there may be used the gelatinizing agents or solvents used in connection with cllulosic compounds, such as nitrocellulose, cellulose ethers and esters. The camphor substitutes or gelatinizing agents referred to are particularly desirable in that they are volatile, which leave the binder or resinous base free from gumminess tending to accumulate and clog the sandpaper by the abraded particles removed in the abrading operations.

The previous examples produce materials which are usually to be preferred as a binder, sandsize or backsize. I have found it possible to produce a material admirably adapted for a paper treatment or center size by the following example:

Example No. III

Grams Diethyleneglycol l 100 Phthalic anhydride 200 are mixed together and held for from 3 to 20 hours at 110 C. The resulting product is a resinous material which at high temperatures is quite liquid, but at ordinary temperatures is a very tacky, slightly plastic resin. This resin may be put into solution with such solvents as 50% benzol and 50% alcohol in proportions of 35% resin and 65% solvents. This material may be used as a centersize or presize for paper. The paper may or may not be subjected to a baking Example N0. IV

Grams Phenol 100 Glycerol 70 Concentrated sulfuric acid are refluxed ata temperature between 160 and 190 C. until -35 g. of water have been distilled over. The sulfuric acid is neutralized with barium carbonate. Any other basic material, such as, for instance, hydroxides, carbonates or similar compounds of the alkali metals or alkali earths, are suitable. Calcium oxide may further be mentioned as another suitable neutralizing agent. This material may be used as a paper size, sandsize, backsize, a binder or bond for abrasive particles. The consistency may be modified to take care of such components as porosity and penetratlveness of the base and backing. For instance, for a material having a low porosity and low penetrative properties I may distill off only 32 g. of water and use 35% thinners such as benzol together with 65% resin for the production of a 'presize: while for a paper having a high porosity and high penetrative properties I may distill off 37 g. of water and use 45% thinners and 55% resin for producing the same action as a presize. I may use as solvents for this type of resin such solvents as acetone, alcohol, amyl-acetate or cellosolve or mixtures of these solvents.

To produce a binder, the solutions of a resin may be modified so that 35% to 15% of solvents may be added to 65% to 85% of resin. These percentages may be varied as well as the solvent to take care of the size of fineness of the grit and its character. sive, of a fineness of 280, the preferred proportions of resin to solvent are 75 to 25, in which the solvent is preferably 25. With coarser abrasive having a fineness of 220 mesh, I may use a binder mixture having resin 80%, solvent 20%. Under certain conditions it will be observed that the resinous material may be made to partial completeness and of a fluidity suflicient to be used as a bond or penetrative sizing coat directly.

Where the resinous material as above described, with or without the solvent is used for a fabric size or bond or sand size, it is preferable to set the resinous residue by heat or, where a solvent or thinner has been used, to apply the resinous material, these solvents may be recovered by suitable recovery apparatus. The resinous material, whether applied with a thinner or directly, is matured by heat in accordance with the desired flexibility, hardness and insolubility in various solvents. The higher the temperature, the more infusible and insoluble will be the final product for a given time of baking. Also, with the high- Thus using garnet as the abraer temperatures, a change to the final product takes place more readily. With a mixture as above described in Example 1, a temperature from to C. for 15 hours will produce a change to the final stage of high infusibility; a

temperature from 180 to 200 C. for 5 to 10 hours will procure approximately the same result. However, where the resinous material is applied in relatively thin layers and a highly bibulous type of paper is used, for purposes of preventing scorching of the paper and by reason of the thinness of the layer of resinous material, a high temperature may be used to quickly mature the resin to the final stage Without scorching the paper. Certain additional flexibility may be imparted to the resinous material by the addition of various oils, amongst which there may be enumerated wood oil, linseed oil, castor oil, cottonseed oil, rape seed oil, soya bean oil, as well as other semi-drying and non-drying oils. These may be added in proportions as follows:

7 Per cent Final resin Oil 20 The resinous solutions or the resin itself at the intermediate stage are best applied with the aid of pressure rolls and, additionally the final stage may be effected by heating under pressure. Also, though I have described the application of the resinous material for penetration purposes or coating in the form of a solution of the resin, or of the resin itself at the intermediate stage, its application may be facilitated by preliminarily wetting the abrasive or the backing with a solvent for the resin, eliminating the solvent at the final maturing step of the resin.

A modification of Example I may be practiced as follows:

Example No. V

Grams Glycerine Phthalic anhydride 200 are heated to about 185 C. until the evolution of water has ceased. This product is mixed with about g. of Chinese wood oil and heated in agent by precipitation with benzol, the remaining product is admirably suitable for the uses described in connection with the Examples I and. II, where solution is ,eflected by solvents such as ethyl alcohol and benzene in proportions of 50% of alcohol to 50% of benzene. Other dispersion agents may be used as follows: benzyl acetate, nitrobenzene, toluidine, benzyl alcohol, cresol, aniline, glycol diacetate, phenol-hydrazine and ortho-cresol benzoate. This material may be thinned to the consistency for producing best results for penetration of a porous base or backing, such as paper, and for wetting and tenaciously binding abrasive particles, depending upon the fineness and size of the abrasive particles and their general surface condition, due to its inherent characteristics.

For a paper of the character previously deseribed in Examples I and H, I may thin the resin above described with about 30% of a solvent such as 50% alcohol and 50% benzene. After removal of the solvent, this resin may be matured or set by heat at a temperature of from 80 to 100 C. for a period of 19 hours. A higher temperature and a lower time of exposure may be utilized where the resinous material is spread in very thin layers. As recited in the case of Examples I and II, the other polyhydric materials may be used with a certain amount of success.

Example No. VI

Grams Phthalic anhydride 200 Glycerol 100 are heated together at 100 C. for one hour. The resultant resin is dissolved in 300, g. of furfural, after which 300 g. of cresol are added. 10 g. of an alcoholic solution of hydrochloric acid serves as a catalyst for accelerating the hardening of this resin. This resin instead of requiring 20 hours to harden as is the case in Example IV required about one-half as long, or 10 hours in which to harden. This resin may be modified by various products as outlined in Examples I and II to take care of porosity, penetrativeness or particle size.

Example No. VII

This procedure will produce a slightly different resin by reacting together 200 g. of phthalic anhydride and 100 g. of glycerol as outlined in Example VI. To this I add 600 g. of a resin produced by heating Grams Furfural 300 Cresol 300 with 10 g. of an alcoholic solution of hydrochloric acid until the resin begins to polymerize and body at about the desired consistency. At this stage I add sufficient base in the form of sodium hydroxide, barium hydroxide or similar compound to neutralize the hydrochloric acid used as a catalyst. These two resins I then mix together and use as outlined in Example VI.

I may, on the other hand, introduce all of the components at one time, reacting them together and produce a resin which is different in its properties from that produced by either of the preceding methods. For instance;

Example N0. VIII Grams Phthalic anhydride 200 Glycerol 100 Furfural 200 Cresol 300 25 g. alcoholic solution of hydrochloric acid as catalyst. I heat this, mix until the desired body is produced, at which time I add suflicient quantity of base to neutralize all but 5 g. of the alcoholic solution of hydrochloric acid. This resin may also be used in the same manner as Example VI.

Although in Examples VI, VII, and VIII the proportions and constitutents have been kept identical in order to illustrate the different methods whereby the same components may be reacted together, it is to be understood that other materials may be reacted with a polyhydric substance in a similar manner.

Having thus described my invention and illus- 75 trated itsuse, what I claim as new and desire to secure by Letters Patent is- 1. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatinizing compound.

. 2. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatinizing compound, said product being dispersed in a volatile thinner.

3. A flexible adhesive coating material composition for coating and penetrating a base coat in the nature of paper for a grit or layer of abrasive particles to form therewith an article in the nature of a flexible waterproof sandpaper having low gumming and clogging characteristics during abrasive operations, said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid in a volatile thinner in the proportions of 15-45% of the volatile thinner to 85-55% of the resinifled product,

and a flexibilizing and gelatinizing compound.

4. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatinizing compound, the latter being employed in quantities comprising 15 to 50% of the resulting resinifled product.

5. A flexible adhesive coating material composition for coating and penetrating a base coat in the nature of paper for a grit or layer of abrasive particles to form therewith an article in the nature of a flexible waterproof sandpaper having low gumming and clogging characteristics during abrasive operations, said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid in a volatile thinner in the proportions of 15-45% of the volatile thinner to 85-55% of the resinifled product, and a flexibilizing and gelatinizing compound in quantities comprising 15% to 50% of the gelatinizing and flexibilizing agent to the quantity of resinifled product.

6. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the .said adhesive comprising a resinifled condensationpr'oduct of a polyhydric alcohol, a polybasic aromatic acid, and a reactive flexibilizing and gelatinizing agent comprising an unsaturated higher fatty acid.

7. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading'operations, the said adhesive comprising a resinifled condensation product of a polyhydric alcohol, a polybasic aromatic acid, and a reactive flexibilizing and gelatinizing agent comprising an unsaturated higher fatty acid, said condensation roduct being dispersed in a volatile thinner.

8. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or lawer of abrasive particles forming therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a reactive flexibilizing and gelatinizing agent comprising at least one material from the group consisting of linoleic acid, oleic acid, eleostearic acid, camphoric acid and succinic acid.

9. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatinizing agent comprising linoleic acid, thereby to provide a coated article in which the resinous material will cure without injury to the fibrous backing.

10. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article in the. nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatinizing agent comprising eleostearic acid, thereby to provide a coated article in which the resinous material cures without injury to the'fibrous back- 11. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article in the nature of flexible tinizing agent including a drying oil and a drying oil acid. I

13. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a resinifled condensation product of a polyhydric compound and an aromatic acid and a flexibilizing and gelatizing agent comprising an unsaturated higher fatty acid.

14. A flexible adhesive coating material compo- Y sition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a mixed resinifled condensation product of a polybasic acid, a glycerol, an aldehyde and a phenol and a gelatinizing agent.

15. A flexible adhesive coating material composition for coating and penetrating a base coat in the nature of paper for a grit or layer of abrasive particles to form therewith an article in the nature of a flexible waterproof sandpaper having low gumming and clogging characteristics during abrasive operations, said adhesive comprising a mixed resinifled condensation product of a polybasic acid, a glycerol, an aldehyde and a phenol, in a volatile thinner, and a gelatinizing agent.

16. A flexible adhesive coating material composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles to form therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive comprising a mixed resinifled condensation product of phthalic anhydride,

glycerol, an aldehyde and a phenol and a gelatinizing agent.

17. A flexible adhesive coating material composition for coating and penetrating a base coat in the nature of paper for a grit or layer of abrasive particles to form therewith an article in the nature of a flexible waterproof sandpaper having low gumming and clogging characteristics during abrasive operations, said adhesive comprising a mixed resinifled condensation product of phthalic anhydride, glycerol, furfural and cresol in a volatile thinner, and a gelatinizing agent.

18. A flexible adhesive coating composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive composition comprising a resinifled condensation product of a polyhydric alcohol, a polybasic acid, and a reactive flexibilizing and gelatinizing agentcomprising an unsaturated higher fatty acid, and of an aldehyde and a phenol.

19. A flexible adhesive coating composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a grit or layer of abrasive particles forming therewith an article 'in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive composition comprising a resinifled condensation product of a polyhydric alcohol, a polybasic aromatic acid, and a reactive flexibilizing and gelatinizing agent comprising an unsaturated higher fatty acid, and of an aldehyde and a phenol.

20. A flexible adhesive coating composition for coating and penetrating a fibrous base material in the nature of paper, cloth or the like for a layer of grits or abrasive particles forming therewith an article in the nature of flexible waterproof sandpaper having low gumming and clogging characteristics during abrading operations, the said adhesive composition comprising a resinifled condensation product of a polybasic acid, a polyhydric alcohol, an aldehyde, a phenol and a reactive flexibilizing and gelatinizing agent comprising an unsaturated higher fatty acid.

DURWARD OGDEN GUTH.

, CERTIFICATE OF CORRECTION. Patent No. 2,20'2T765. May 23, 191p;

' DURWARD OGDEN GU'IH. It is hereby certified that error' appears in the above numbered patent requiring correction as follows In the headingto the printed specification,

- lines 8. and 9 thereof, for "Application September 11, 1950, Serial No.-

M31551" read "Original application March 11;, 1929, Serial No. 3l 7,159." Divided and'this application September 11,1950, Serial No. h8l,551--; and" page 1,'fir st column, line 1, before the words "The present.invention",in-. sort the following paragraph p This application is a'ldivision of application Serial No.

5l 7,159, filed Manoh 11;, 1929.

t, L J I and that the said Letters Patent should be read with thisioorrection therein that the same may conformto the record of the case in the Patent Office.

Signed and sealed this 10th day of September, A. D. 191w.

v Leslie Frazer (Seal) Acting Commissioner of iatents.