US2297341A - Method of making adhesives and product thereof - Google Patents

Description

Patented Sept. 29, 1942 METHOD OF MAKING ADHESIVES AND PRODUCT THEREOF Davis Miller Wood, Tacoma, Wash.

No Drawing.

Application February 28, 1939,

Serial No. 258,947

11 Claims.

My invention relates to an improvement in the method of making an adhesive and the product thereof. My invention will be described in its relation to the manufacture of veneer panels.

U. S. Patent No. 2,088,019, dated July 27, 1937, to Jacob N. Wickert, entitled Secondary alkyl sulphates are claimed therein as neutral sulphate esters of a saturated higher branchedchain secondary ,monohydric alcohol, having at least 8 or 13 carbon atoms in its molecule and having at least one alkyl side chain directly connected with the carbon atom of the main carbon chain spaced from the carbon atom to which the sulphate group is attached. By using this product I have made a basic glue.

' Tergitol 4 and Tergitol '7 are made according to great improvement in a said patent, and are defined and described for the purposes hereof as secondary alkyl sulphates.

Tergitol 4 is -a secondary alkyl sulphate containing 14 carbon atoms and is sodium tetradecyl sulphate, and Tergitol '7 is a secondary alkyl sulphate containing 1'l carbon atoms, and is sodium heptadecyl sulphate. These are the chemical names of the Tergitols I prefer to use, and are purchasable in the open market under such names.

However, I have discovered that secondary alkyl sulphates containing as few as 12 carbon atoms produce a decided beneficial effect in the glues described herein.

It is to be understood thatmy said invention is not confined to the specific application of glueing together wood veneers to make veneer panels, but is useful in all circumstances where it is desired to secure a glue or adhesive which possesses the qualities of producing a smooth readily spreadable, long working-life glue, having great adhesiveness, a high water resistant bond, and of substantial uniform viscosity, and a glue which will avoid much checking and surface stain when applied to thin wood surfaces, and a glue which will reduce the cost while attaining great wet and dry strength.

All of these qualities appertain to a glue or glues made by my discovery, and to a far greater extent than to glues heretofore made which em.- ploy vegetable flour of a high protein content, as herein described, as a predominate ingredient in quantity.

Seed base, as used herein, is the flour or meal made from vegetable seed, beans or ,nuts from which a large portion of the oil has been extracted, and which flour or meal contains from 35% to 50%, or thereabouts, of protein.

When there is added to, or substituted for a part of, a seed base, animal proteins, such as casein or blood albumen, I will designate the composition as a blend base."

I mention soya bean flour and peanut flour as among the flours which I can use, and coming within the definition of a "seed base, but other vegetable flours having substantially the protein content above mentioned can be used. To either the seed base" or the blend base is added the following:

Lime, caustic soda, sodium silicate, carbon bisulphide or its equivalent, or carbon bisulphide and carbon tetrachloride, which I will hereafter refer to as carbon bisulphide-tetrachloride dope, and to them may be added alkali metal salt which when'used with lime by double decomposition produces causticity; and pine oil, and water. The above mentioned ingredients, or the proportions of'the above mentioned ingredients, may be varied, and the glue made therefrom come within the term basic glue.

Glues comprising the foregoing seed base or blend basefand chemicals last above mentioned I will call basic glue. To illustrate a basic glue formula now very commonly used in the. manufacture of veneer panels the following formula is given:

' Pounds Soya bean flour Lime -'l Caustic soda 9 Silicate of so 30 Carbon bisulphide-tetrachloride dope-.." 2

Waters "cs0 to 365 Another formula for basic glue is substantially as follows:

9 Pounds Soya bean flour 93.5 Trisodium phosphate 1.5 Sodium carb 5 Lime 15 to 20 Caustic soda Silicate of soda Carbon bisulphide-tetrachloride dope 2 Aldehyde compound, made according to Patent No. 1,950,060 2 Water 350 to 365 similar formulae employ peanut flour in place of some or all of the soya ,bean flour, and some have a percentage of casein or blood albumen substituted for a like percentage of flour, and some have "pine oil" added.

My invention is an improvement on all such "blend base" in the basic glue," a decided change takes place in the basic glue," (normally 0.25% to 0.5% is uniformly satisfactory) in that the texture of the basic glue is changed from a grainy nature, resembling bean soup, to a smooth and ungrainy structure, resembling varnish in texture; the applicability of the glue made according to my invention to veneers in a mechanical spreader is facilitated; the strength of the glue bond is increased as hereinafter stated; the working life of my improved glue is lengthened approximately three times that of "basic glues." As hereinafter stated the quantity of seed base or blend base to spread 1000 square feet of 3- ply panels is less thanrequired to spread 1000 square feet of 3-ply panels when using the basic glue; and the staining and checking of the panels is reduced.

Such basic glue requires from 27 lbs. to 30 lbs. of seed base or blend base" in a "basic glue to spread 1000 square feet of 3-ply panels to get its maximum stick; whereas, myfimproved glue made according to my invention, as hereinafter. set forth, will spread 1000 square feet of 3-ply panels with some lbs. to 26 lbs. of "seed base or blend base to get its maximum stick? The working life" of glue means the time during which the glue retains substantially its maximum strength and spreadability after it is tory to being put into a press. Pressing is required to bring the wood surfaces into intimate contact with the glue which has beenapplied to hold together the veneer composing the panels.

Pressure must be exerted before the glue in the lower panels of the stack loses any substantial part of its adhesive qualities, failing which there is produced an inferior or faulty panel or panels in the lower part of the stack. In plant practice frequently more than minutes is desirable to make up a stack of panels for pressing. About 10 minutes after a basic glue is applied to the panels the adhesive quality thereof commences to decrease and the ordinary time after basic glue is applied which is considered safe to insure a good joint before applying pressure is not over 30 minutes after the glue is spread upon the veneer panels. Glue made according to my improved glue and "zinc sulphate glue inventions (as hereinafter defined) retains its adhesive qualities longer (that is, the "working life), and is as strong or stronger after the panels are spread for 30 minutes and before pressure than a basic glue is after standing 10 minutes in the panels. Thus the working life of glue made according to my invention far exceeds the working life of a basic glue. This important improvement in working life has been long desired by manufacturers of veneer panels, and has been accomplished by my invention.

To obtain the maximum adhesion of a basic glue it has been heretofore required that the having been found that the finer the seed base" is ground the better adhesion is obtained in a basic glue. By means of my invention I have found that a seed base ground from to mesh produces a glue superior to a basic glue employing a seed base ground to mesh in its adhesive qualities, and ease of spreading, and otherwise, as herein pointed out. Thus there is a saving in time and expense in preparing a seed base" to be used in glue made according to my discovery over the time and expense of preparing such seed base" used in a basic glue.

A'common test to determine the water resistance of glue when panels are made up and pressed is as follows: After the glue has set test pieces of wood panels are sawn so as to permit one square inch of 3-ply panels to be used for break tests, and thereafter are subject to soaking in water for 48 hours. The panels so sawn and soaked are placed in a machine and subjected to a pull which is measured by a scale, and the strength of the glue joint is noted in pounds per square inch. For a test of dry strength a similar method is pursued, except the soaking is omitted.

By means of using a Tergitol (without water soluble metallic sulphate) I have succeeded in raising the strength of the glue bond by glue made according to my discovery above the strength of a basic glue." A basic glue, such as herein described, produces an average dry test pull of about 171.5 pounds, with a minimum of about pounds and a maximum of about 200 pounds. By means of my discovery, by the use ofTergitol alone with "basic glue, the dry test strength of a basic glue" has been raised to an average of about 232 pounds, with a minimum of about 210 pounds and a maximum of about 245 pounds.

Thus there is shown an improvement in the dry test of the glue made according to my discovery of about 60 pounds better than a basic glue, or an increase of about 35% in dry strength.

The average wet test strength of a basic glue is about 98.5 pounds, with a minimum of 80 pounds and a maximum of about 120 pounds. Glue made according to my discovery, by the use of Tergitol alone in a basic glue, has an average wet strength of- 113.5 pounds, with a minimum of 80 pounds and a maximum of pounds, thus showing an increase of average wet strength of 14%.

Instead of the glue made according to my dis- I covery by the use of Tergitol alone in a basic glue becoming less strong (as is the case with a basic glue) by the lapse of 30 minutes after being spread, the dry test strength of my glue at 30 minutes was 219 pounds, with a minimum of 185 pounds and a maximum of 265 pounds, and a wet test strength of 128 pounds, with a minimum of 115 pounds and a maximum of pounds. Thus there is shownan increase of dry strength in my glue after the panels are spread with it for 30'minutes before being pressed of 34% plus, and a wet strength of 38%. The result of the tests above given were obtained first by making a basic glue, consisting of the following:

Pounds Soya bean flour 100 Water 360 Caustic soda dissolved in 10 lbs. of water--- 8 Lime suspended in 25 lbs. of water 7 Sodium silicate 25 Carbon bisulphide-tetrachloride dope 2 seed base" be ground to 110 mesh or finer, it 75 and then by making an exactly similar basic glue to which Tergitol 4 in the amount of about 0.25 pound of 'Tergitol 4 was incorporated, by which addition the glue which I designate as improved glue is produced. 5

Other examples of glue formulae using my invention of improved glue and method of making same, which I find produces similar superior results to those above mentioned, are as follows:

As a dry mixture, viz:

Example 1 Pounds Soya bean flour 99 Tergitol 4 or Tergitol l 0.25

Example 2 Pounds Soya bean flour 98 Pine oil 1v Tergitol 4 or Tergitol 7 0.25 Example 3 Pounds Soya bean flour 98 Sodium dibromate or sodium phosphate--- 1 Tergitol 4 or Tergitol '7 0.25 Pine oil 0.9

Example 4 An example of "blend base glue which will produce superior results is as follows:

V Pounds Soya bean flour 90 Casein 5 Blood albumen 5 Tergitol 4 or Tergitol 7 0.25

Example 5 Another example of blend base glue, such as is described in Example 4, above, would be to eliminate from Example 4, 5 lbs. of the blood 4 albumen or casein and correspondingly increase the soya bean flour or peanut flour; or instead of 5 lbs. blood albumen and 5 lbs. casein, use 10 lbs. of casein or 10 lbs. blood albumen, or a lesser or greater number of pounds thereof, and cor-' respondingly modify the soya bean flour or peanut flour so that the total mixture of soya bean flour or peanut flour and casein and/or blood albumen would equal about 100 lbs.

To each of the "dry mixtures, as shown in 0 the above Examples 1 to 5, I add the following, varying the proportions somewhat if desired, viz:

Carbon bisulphide-tetrachloride dope About 2 Where a Tergitol, such as described, is incorporated in the formula of a dry mixture, as shown in the examples last above mentioned, it may be eliminated therefrom, and may be added to the water at the start, 'or during the process of mixing. In such examples peanut flour and other proteinous'flours, as described herein, may be used instead of soya flour.

The improved glue which I have made by means of incorporating one or more of the Tergitols in a basic glue I will hereinafter call my improved glue. r

I have found that by means of incorporating I sulphate glue stronger than the basic glue.

As examples of a typical glue (which I will hereinafter call zinc sulphate glue) which I have found to produce the improvement over the basic glue and improved glue, as above described, are the following:

. Pounds 'Soya bean 'flour or peanut flour 97.4 Zinc sulphate 2.5 Tergitol 4 or Tergitol 'l g 0.25 Water at roughly 70 F. (or at summer temperature. The matter of temperature is not essential, but a substantially similar temperature produces a more uniform time for chemical action than would be the case with wide variations in water temperature) 360 Caustic soda dissolved in 10 lbs. of water 8 Lime suspended in 25 lbs. of water 7 Sodium silicate 25 Carbon bisulphide-tetrachloride dope 2 An example of typical zinc sulphate glue employing a blend base which will produce com parable results is as follows:

- Pounds Soya bean flour or peanut flour 87.4 Casein 5 Blood alb n' 5 Zinc sulp 2.5

Tergitol 4 or Tergitol 7 0.25, Water at roughly 70 F.-. 360 Caustic soda dissolved in 10 lbs. of water 8 Lime suspended in 25 lbs. of water 7 Sodium silicate 25 Carbon bisulphide-tetrachloride dope 2 Another example of zinc sulphate glue 'employing a blend base would be to eliminate in the above formula 5 pounds of either casein or blood albumen, and correspondingly increase thesoya .basic glue using a seed base to which has been added one of the Tergitols and zinc sulphate made according to the formula of the foregoing example shows the average dry strength of such glue to be 265 pounds, the average wet strength of such glue to be pounds. For the purpose of comparison, the following table is set forth:

"Basic glue" Average dry strength Average wet strength 171.5 pounds 98.5 pounds Basic glue plus Tergitola (My improved glue) 232 pounds 113 pounds Basic glue plus Tergitol: and zinc sulphate (zinc sulphate glue") 265 pounds 150 pounds In the matter of the dry test strength, my zinc is approximately 64% plus In the matter of wet strength my Zinc sulphate glue" is appfoximately 51% plus stronger than the basic g ue.

In the matter of dry test strength my zinc sulphate glue is approximately 14% plus stronger than my' improved glue. 'In the matter .of wet test strength my "zinc sulphate glue is approximately 40% plus stronger than my improved glue." In addition to the increase in both dry andwet strength in my zinc sulphate glue over said basic glue and improved glue, I find that by means of employing Tergitol in the glue with the zinc sulphate I control the action of the zinc sulphate in the quantities used by me. sulphate (without the Tergitol) in the quantities used by me is used with a basic glue, its action within the glue causes an erratic and unpredictable result. On some occasions it thickens the glue too quickly for use in ordinary mill practice, whereas, with the combination of Tergitol and zinc sulphate with the basic glue," the glue is thinned as compared with. basic glue with zinc sulphate therein, and the endresult is uniform and reliable, and the beneficial effect as pointed out herein is certain and predictable.

My zinc sulphate glue will spread 1000 square feet of 3-ply panels with the use of but from to 24 pounds of seed base," whereas, the basic glue requires from 27 to 30 pounds of seed base to spread 1000 square feet of 3-ply panels. Thus my zinc sulphate glue requires 6 to 10 pounds less seed base per 1000 square feet of 3- ply panels than the basic glue requires, and effects thereby a great cost saving over "basic glue," or about of the cost of seed base. As there are used in the plywood industry hundreds of tons a month of seed base glues, and blend base glues, the aggregate saving by my improved glues is a very material consideration. My "zinc sulphate glue" has the quality of retaining its viscosity practically at a uni form level much longer than basic glue, thereby increasing its working life and avoiding waste of glue when delay occurs at the veneer plant after mixing the glue in the glue mixer.

The viscosity of my zinc sulphate glue has a range of from 60 to 85 during 3 hours on a MacMichael viscosimeter as compared under like conditions with a basic glueof from 60 to 280 in 85 minutes. The basic glues working If 'zinc salt to replace a part phates of Groups 3, 4 and 5 of the Fresenius System.

When employing zinc sulphate, for example, in my zinc sulphate glue I use quantities thereof of 1.5% to 9% of the seed base or blend base and find that a ratio of 2.5 pounds of zinc sulphate to 95 to 100 pounds of seed base or blend base will yield the numerous beneficial results herein set forth when a Tergitol is present in the amount of about 0.25% of the seed base or blend base, although a greater quantity may be used for a Tergitol is fast to lime and the acids and alkali of the glue.

It is understood that these formulae are examples only,'and that I may use instead of soya flour varying kinds of vegetable flours containirig substantially the amount of protein as above set forth, for example, peanut flour or cotton seed flour, and that I do not confine the scope of my invention to these examples only, as I may vary the proportions of any of the ingredients in either my "improved glue or in my zinc sulphate glue"; for example, I may use an alkali or all of the caustic soda and may use any one of the Tergitols as herein described, and may differ the proportions thereof to produce a glue of varying qualities to meet the requirements of the trade and the variations in the quality of the "seed base."

I have found it convenient to mix together, for instance, soya bean flour, Tergitol in dry form, and the metal sulphate of Groups 3, 4 and 5 of the Fresenius System (and pine oil, if used) approximately 3 minutes;

life is limited to about 50 minutes, whereas, my

zinc sulphate glue" has been used with satisfactory results after standing mixed in the glue pot over night. The increased working life is important in plant practice, and has long been sought by manufacturers of plywood.

In practicing my invention I prefer to use zinc sulphate because it is commercially readily available, and is likewise low in cost. However, any compound having the characteristics of zinc sulphate in a glue mix may be used with similar results. Among the many equivalents of zinc sulphate in practicing my invention are the sulphates of such metals as aluminum, iron, cad- -mium, copper, and the like.

The water soluble metallic sulphates which I have discovered improve my improved glue are designated in Groups 3, 4 and 5 of the Fresenius System. Ofthese I find iron sulphate makes the least improvement in my improved glue. For the purpose of defining such water soluble metallic sulphates in these specifications and in the claims I will use the phrase water soluble metallic sulproximately 3 minutes;

at the same time the seed base" is ground, for thus they may be packed in convenient shipping units and be readily handled in packages of appropriate size for a predetermined batch of glue.

In usual practice, the flour, Tergitol, metallic sulphate of Groups 3, 4 and 5 of the Fresenius System and sometimes alkali salts are introduced at the glue plant into a glue mixed containing about 360 pounds of water and stirred for from 3 to 5 minutes; thereafter is added the lime suspended in water, then stirred for apthereafter is added the water and stirred for thereafter is added the sodium silicate and stirred for approximately one minute; thereafter is added carbon bisulphidetetrachloride dope and stirred for approximately 5 minutes. Then the glue is ready for use, the total mixing time being about 17 minutes, thus shortening the ordinary time of mixing basic glue" by about 5 minutes.

Whenever any of the Tergitols are used in solution I find it preferable, although not imperative, to introduce the same into the water before seed flour is added.

Other modes of applying the principle of my invention may be employed instead of those explained above, the change being made as regards the details herein disclosed, provided the procaustic soda dissolved in cedure or ingredients stated or the equivalents of such stated ingredients or procedure, are employed. The particular order in which the fiour and several of the ingredients mixed in the formulas given by me in the making of glue according to my invention may be varied, and it is not necessary that the manufacture of the product be completed in a single operation.

By giving ,the explanation and illustrations aforesaid, I do not intend to limit or indicate the use of my glue as confined to the application of my glue as explained and illustrated. For a glue made in accordance with the principles of my invention may be used where. a glue is desirable having the qualities of my invention.

When I use the term carbon bisulphidetetrachloride dope in this specification it is to be understood that I mean one of the several agents used in the glue industry under that name. I prefer to use carbon bisulphide-tetrachloride dope as it is readily and cheaply obtainable, and has been quite uniformly used in the basic glues.

A typical dope is comprised of from 50 to-75 parts of carbon bisulphide and from 25 to 50 parts of carbon tetrachloride. From 1- to parts of resin, such carbon bisulphide-tetrachloride as rosin, is sometimes'used to replace an equal ride used with carbon bisulphide is introduced for the purpose of preventing its ready ignition, and a small portion of rosin may be used or not, as the theory of. using the rosin is to lessen the escapement of carbon bisulphide fumes in the mixing of the glue, but neither the carbon tetrachloride nor the rosin is essential.

Having described my invention, what I claim and desire by Letters Patent is:

1. An adhesive composition which comprises the reaction product of proteinaceous glue of at least one of the class consisting of vegetable seed flour of considerable protein content, casein, soluble blood albumin, and a secondary alkyl sulphate. of the class containing from 12 to 1'7 carbon atoms inclusive, in an amount resulting in an increased spreadability, working life, strength and water resistance of the adhesive,

and a water soluble metallic sulphate of Groups 3, 4 and 5 of the Fresenius System in an amount to increase water resistance, strength, spreadability and workinglife of the resultant adhesive.

2. "An adhesive composition which comprises the reaction product of a proteinaceous glue of at least one of the class consisting of vegetable seed flour of considerable protein content, casein, soluble blood albumin, and a secondary alkyl sulphate of the class containing from 12 to 17 carbon-atoms inclusive.

3. An adhesive composition which comprises the reaction product of a proteinaceous glue of at least one of the class consisting of vegetable seed flour of considerable protein content, caseflour of considerable protein content, casein, soluble blood albumin, and a secondary alkyl sulphate of the class containing from 12 to 17 carbon atoms inclusive, the proportion being from 0.05% to 2% to 100 pounds of the proteinaceous material in such glue, and from 2 to 5 pounds of a water soluble metallic sulphate of Groups 3, 4 and 5 of the Fresenius System to 100 pounds of the proteinaceous material. in the resultant glue.

6. A process of making an adhesive which comprises combining the reaction product of a proteinaceous glue of at least one of the class consisting of a vegetable seed flour of considerable protein content, casein, soluble blood albumin, and a secondary alkyl sulphate of the class containing from 12 to 17 carbon atoms inclusive, the proportion being 0.05 of a pound to 2 pounds in 100 pounds of proteinaceous material of the resultant glue, and 2 to 5 pounds of a water soluble metallic sulphate of groups 3, 4 and 5 of the Fresenius System to 100 pounds of the proteinaceous material in the resultant glue.

7. An adhesive composition which comprises the reaction product of a proteinaceous glue'of at least one of the class consisting of vegetable seed flour of considerable protein content, casein,

' soluble blood albumin, a small portion of a secondary alkyl sulphate of the class containing from 12 to 17 carbon atoms inclusive, and from 2 to 5 pounds of a water soluble metallic sulphate of groups 3, 4 and 5 of Fresenius System in 100 pounds of proteinaceous material in the resultant,

glue.

8. An adhesive composition which comprises the reaction product of a proteinaceous glue of at least one of the class consisting of a vegetable 0.05% to 2% of 100 pounds of the proteinaceous in, soluble blood albumin, and a secondary alkyl comisting of vegetable seed flour of considerable protein content, casein, soluble blood albumin, and a secondary alkyl sulphate of the class contaming from 12 to 1'7 carbon atoms inclusive,

the proportion thereof being 0.05 pound to v2 pounds in 100 pounds of the proteinaceous material in the resultant glue. i

5. An adhesive composition which comprises the reaction product of a proteinaceous glue of at least one of the class consisting of vegetable seed material in such glue and from 2 to 5 pounds of zinc sulphate to pounds of the proteinaceous material in the resultant glue.

9. An adhesive composition comprising adding to 99.90 pounds of soya bean flour 0.10 pound of a secondary alkyl sulphate of the class confrom 12 to 1'7 carbon atoms inclusive, about 330 pounds of water, 8 pounds of caustic soda dissolvedin 10 pounds of water, seven pounds of lime suspended in 25 pounds of water, 25 pounds of sodium silicate and 2 pounds of carbon bisulphide. v

10. An adhesive composition comprising adding to 97.4 pounds of soya bean flour 0.1 pound of a secondary alkyl sulphate of the class containing'from 12 to 17 carbon atoms inclusive, 2.5 pounds of zinc sulphate, about 360' pounds of water, 8 pounds of caustic soda dissolved in 10 pounds of water, 7 pounds of lime suspended in 25 pounds of water, 25 pounds of sodium silicate and 2 pounds of carbon bisulphide.

11. An adhesive composition which comprises adding to 87.4 pounds of soya bean flour 5 pounds of casein, 5 pounds blood albumin, 0.10 pound of a secondary alkyl sulphate of the class containing from 12 to 17 carbon atoms inclusive, 2.5 pounds of zinc sulphate, about 360 pounds of water, 8 pounds. of caustic soda dissolved in 10 pounds of water, seven pounds of lime suspended. in 25 pounds of water, 25 pounds of sodium silicate and 2 pounds of carbon bisulphide.

DAVIS MILLER WOOD.

, CERTIFICATE OF CORRECTION. Patent No. 2,297,5L 1, a September 29, 19L 2.

- DAVIS MILLER WOOD.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 2+, for "dibromate" read -dichromate---; and second column, line 5', strike out the word "pounds"; and that the said Letters Patent should be read with this correction therein that. the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of December, A. D. 1914.2.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.