US1378078A - Vegetable glue and process of making the same - Google Patents

Description

UNITED STATES PATENT OFFICE.

FREDERIC S. WILLIAMS, OF CHICAGO, ILLINOIS, AND JAMES G. B. PERKINS AND JULIUS B. B. STRYKER, OF LANSDALE, PENNSYLVANIA, ASSIGNORS TO PER- KINS GLUE COMPANY, A CORPORATION OF PENNSYLVANIA.

No Drawing.

To all whom it may concern:

Be it known that we, Fnnnnnro S. WIL- LIAMS, a citizen of the United States, and a resident of Chicago, county of Cook, in the State of Illinois, JAMES B. PERKINS, a citizen of the United States, and a resident of Lansdale, county of Montgomery, State of Pennsylvania, and JULIUS B. B. STRYKER, a citizen of the United States, and a resident of Lansdale, county of Montgomery, State of Pennsylvania, have invented certain new and useful Improvements in Vegetable'Glue and Processes of Making the Same, of which the following is a specification.

Our invention relates to improvements in vegetable glue and process of making the same. More particularly, the invention relates to a substantially neutral vegetable glue, having substantially the qualities of animal glue, for gluing up veneers, and process of making the same.

In U. S. Reissue Letters Patent No. 13436, dated July 2, 1912, and in U. S. Letters Patent Nos. 1,020,656, 1,078,691, 1,078,692 and 1,200,488, there are disclosed methods of making vegetable glue by dissolving a starchy carbohydrate with caustic alkali,

such as caustic soda, the resulting glue be-' ing markedly alkaline. Even if the percentage of caustic alkali be reduced to about line so that when applied to very thin veneers of certain woods, it will cause a discoloration of the wood veneer, which discoloration may appear on the opposite side of the wood layer from that on which the glue is applied. In many cases this discoloration is not a serious disadvantage, and with the thicker veneers it is not objectionable or does not appear at all. With certain kinds of wood and in certain cases, especially Where very thin layers of wood are being glued together, this discoloration or staming may be a detriment, which 1t is desirable to avoid.

The main object of the present invention is to provide a vegetable glue having substantially the properties of the glue described in said U. S. Letters Patent, but which is so made or treated that this dis- Specification of Letters Patent. ,Patented May 17, 1921,

Application filed October 9, 1917. Serial No. 195,544.

coloration or staining isavoided. It is also desirable to provide a vegetable glue for this purpose which is somewhat more fluid than that hitherto in use. Further objects, features and advantages will more clearly appear from the detailed description given below.

In producing the new glue, we take a suitable starchy carbohydrate, preferably the glue base resulting from the preliminary treatment describedin either of said U. S. Letters Patent. However, certain starches appear on the market which require no preliminary treatment, and these may be used, if desired. Vhether such starch is suitable may be easily determined by testing the. same. We preferably use cassava starch or tapioca flour.

To make the glue, a suitable starchy carbohydrate is preferably dissolved with about 3 parts or less by weight of water and about 3% by weight of caustic soda. the caustic soda being added in the form of a 33% solution. The starch is first thoroughly mixed with the water and then the caustic soda solution added gradually with continual stirring, until the batch is transformed from a mixture of suspended starch in water to a homogeneous colloidal solution of starch, alkali and water, having substantially the properties of good animal glue for gluing up high grade wood veneers, as described in said Letters Patent. The resulting glue, although thick and viscous, is capable of flowing through pipes 2 inches in diameter, is capable of being spread by glue applying machinery and has substantially the adhesive qualities of animal glue for this class of work.

To prevent this glue from discoloring and staining the wood, as above described, we add thereto a neutralizing agent after the alkali has acted upon the starch, so as to make the glue substantially neutral. For this purpose, we may add oxalic acid in the form of a fine powder or in the form of a solution, suflicient of the oxalic acid being added to make the glue substantially neutral. We prefer to add the acid until the glue has a faint acid reaction. Other neutralizing agents, such as acetic acid and salicylic acid may be used, as well as certain acid reacting for the making of a high grade glue for use in gluing up veneers, the h0m0geneouscharacter of the colloid must as far as possible be retained, whereas in the textile and other arts granulated, flocculated or segregated products, lacking in the high tensile strength that results from the perfect homogeneity of the colloid, may be used. We prefer, therefore, to use the organic acids forming less dissociable or ionizable salts after reaction witli the caustic soda to be neutralized, and to add them carefully so as to minimize the electrolytic fiocculating action upon the starchy carbohydrate.

While the acids may be added in the form of solutions, we prefer to add the neutralizing agent in dry form and also to mix with it about an equal weight of silicious material, such as finely ground feldspar, quartz or silica. Instead of caustic soda for dissolving the starch, other alkaline compounds may be used, such as caustic potash. Preferably. less than 12% by weight of caustic alkali is used in dissolving the starch.

While we prefer to heat the mixture during the dissolving of the starch, the temerature being carefully kept considerably elow 175 F., yet if more than 3% of caustic alkali is used, as for example, 8%, the solution of the starch may be brought about without heating the batch. By carefully regulating the heat, even less than 3% of caustic alkali may be used. If heat is used, it should be carefully regulated to pre vent local overcooking of the starch or overcooking by a long continued relatively high temperature. This may be done as described in U. S. Patent 1,251,275 issued Dec. 25, 1917.

The neutralizing agent, when added in dry form, should be very finely ground, and is preferably added to the glue when the same has cooled off and after the starch has been thoroughly dissolved by the alkali.

If, on standing a considerable time, the glue thickens up, so that it is too viscous and does not flow readily enough, it may-in most cases be brought back to proper condition by heating it up to 130-l40 F. and thoroughly stirring it.

While the amount of water used in the process may be varied somewhat, we preferably use 2% to 2} parts of water by weight, based on the dry starch base used. The neutralizing agent when added should be thoroughly stirred in, so that all parts of the batch will have an opportunity to be acted upon thereby. The addition of the silicious filler seems to increase the adhesive strength of the glue, or prevent the adhesive strength of the glue from being materially decreased. It is, of course, not necessary thatthe neutral glue be used for joining layers of wood, as it may be found advantageous for joining fabric to wood and for joining other articles.

While we have described our improvements in great detail and have given certain examples, we do not desire to be limited thereto, since many changes may be made and other reagents used, as will be understood by those skilled in the art. It is desired to cover all modifications coming within the language of the appended claims.

What we claim as new and desire to .secure by Letters Patent is:

1. The improved vegetable glue comprising a starchy carbohydrate in solution in about 3 parts or less by weight of water and containing a salt of an alkali metal and asilicious filler and being substantially neutral and having substantially the properties of animal glue for gluing up veneers.

2. The improved vegetable glue containing a starchy carbohydrate in colloidal solution with water, having substantially the adhesive, spreading and flowing qualities of animal glue for gluingup veneers and being substantially neutral.

3. The improved vegetable glue comprising a starchy carbohydrate dissolved with caustic alkali and about 3 parts or less by weight of water and being substantiall neutral and havin substantially the qualities of animal gliie for gluing up high grade veneers.

4. The improved vegetable glue comprising a starchy carbohydrate in solution in about 3 parts or less by weight of water and containing a salt of an organic acid and an alkali metal, and being substantially neutral and having substantially the properties of animal glue for gluing up veneers.

5. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with caustic alkali and' about 3 parts or less by weight of water and heat below 175 F., the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up high grade veneers, and then substantially neutralizing the glue without materially decreasing its strength or spreadabilit 6. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with an'alkaline compound and water to form a viscous alkaline glue, the carbohydrate being such that the resulting glue has substantially the properties of animal glue for gluing up veneers and adding an organic acid to substantially neutralize the glue without materially decreasing its stren th or spreadability.

7. he process of making vegetable glue which consists in dissolving a starchy carbohydrate with caustic alkali and about 3 parts or less by weight of water and heat below 175 F., the carbohydrate being such that the resulting solution has substantially the properties of animal glue for gluing up high grade veneers, and then adding a neutralizing agent to substantially neutralize the glue, and a silicious filler.

8. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with caustic alkali and about 3 parts or less by weight of water and heat below 175 F., the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up high grade veneers, and then adding a neutralizing agent to substantially neutralize the glue when it has cooled off without materially decreasing its strength or spreadability.

9. The process of making vegetable glue which consists in dissolving a starchy car-- bohydrate with about 3 parts or less by weight of water and an alkaline compound, the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up veneers and substantially neutralizing the glue without materially decreasing its strength orspreadability.

10. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with about 3 parts or less by weight of water and an alkaline compound, the carbohydrate bein such that the resulting solution has suiistantially the properties of animal glue for gluing up veneers,

and then adding a neutralizing agent to substantially neutralize the glue, and a silicious filler.

11. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with Water and an alkaline compound, the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up veneers and glue Without materially decreasing its strength or spreadability.

12. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with water and an alkaline compound, the carbohydrate being such that the resulting alkaline solution is a thick viscous mass capable of flowing through pipes two inches in diameter and of being spread by glue applying machinery and of adhesively securing layers of wood together, and adding a neutralizing agent thereto to substantially neutralize the glue without materially decreasing its strength or spreadability for Wood veneering.

In testimony whereof we have signed our names to this specification.

FREDERIC S. WILLIAMS. JAMES G. B. PERKINS. JULIUS B. B. STRYKER.

\Vitnesses as to Frederic S. lVilliams:

MARGUERITE M. MULLANY, HARRY J. RosENFELo. lVitnesses as to James G. B. Perkins and Julius B. B. Stryker:

G. H. LOVE, 1. E. Moore.

substantially neutralizing the l