US1940486A - Glue product and method for preparing the same - Google Patents

Description

Patented Dec.1 9, 1933 1 1,940,486

GLUE PRODUCT AND METHOD non PREPARING THE SAME Charles H. Campbell, Kent, Ohio No Drawing. Application MayZZ, 1933 Serial No. 672,343

9 Claims. (Cl. 13446) This invention relates to a glue product and magma, and dried the same on pans in dry to a method forpreparing the same. kilns. The objection to this method was that the Heretofo-re high grade glues have been used glue and other bases separated in'the drying, the in coating compositions such'as calcimine and glue floatingto the top of the pan, and in the r similar coating compositions in which the vesubsequent grinding a large part of the glue was 60 hicle is water. The high grade glue used for this ground separately. If the manufacturer started purpose will go into solution in water only with with a high grade glue, he found after this opgreat diificulty and only by heating the water eration the glue had lostfromtwenty-five perto temperatures from 140 to 160 F. Glues have cent to thirty-five percent of its original 10 been chemically treated in various ways to. make strength, depending upon the time of. heating 65 them more readily soluble in water but such and the temperature employed. -Moreover, he treatments of the glue affectthe adhesive qualihad not been able to really coat hisbases with ties thereof. a the glue. The microscope revealed that a por- The general ,purposejof the present invention tion of the particles of base used had particles of is to provide an improved glue product and meths ue ad i t t m y y an h b 70 ed for 'making the same whereby the physical .ance of the glue was present only in the form of properties of the natural glue are substantially a. i .When l is in Calcimine as a unaffected and yet the glue will be readily solu- ,ple miX there s y a tendency of 1 ble in water atordinary atmospheric temperaticles to agglomerate and rollinto balls when: 90 tures and even temperatures as low as 40 F. Water is added, butwhen fine base particles are 75 In particular the invention has for its object really coated h V y fine films of glue i the application of glue in very thin .orf microtendency is not present. Dic films over a base of finely divided, pref- .Other manufacturers at a somewhat later peerably inert, material or such material in a colriod ut e a l d whereby t -E 6 W s loidal state such aswhiting, gypsum-or other dissolved andmixed with the bases in a .mixer 0 materials so'that the thin films of glue on'these until thoroughlyincorporated, adding just enough base materials are readily acted upon by water, water to makea mix possible. This magma was causing the glue to jell. readily and to. go into then taken and placed; in a rotary; dryer with solution at ordinary temperatures and even temmixing arms to prevent the magma from sepperatures as low as F.- I aratingi during the drying operation. 'In using 35 It is a further object of the invention to prothis process, which is the commercial process vide a simple, effective procedure for making now, a comparatively high heat is maintained the above-described product economically by the. so as to reduce the time the glue is under heat. elimination of a numberlof steps in the usual This process reduces the test of the glue fifteen 35 process of manufacturing'glue compositions. to tWenty-five percent, depending upon thetime 0 The foregoing and other purposes of the inand temperature of the heat treatment. The vention are attained in the material and by the particles of base agglomerate and the dried mamethod set forth inthe succeeding paragraphs terial rollsfrom the dryer with many lumps. hereof. It is to be understoodthat the .inven- These lumps are quite hard, being cemented to- 0 tion is not limited to the specific form thereof gether bythe glue and are ground with diffi culty. 95 described. V r i This accounts for the fact a calcimine of this Animal glue is a colloid and is affected by heat description does not take the water Well and it and moisture, especiallyby long-continued heat, is usually necessary to strain before using. In and long, low heats with moisture are more fact, straining is .a recognizedprocedure. As

harmful than higher heats for a short time. On shown by the microscope, about one-half the 100' this account glue. and gelatin manufacturers glue in such calcimineis present in glue particles spread the chilled sheets as thin as possible in merely mixed with the othermaterials and diidrying on nets to prevent lossof strength. By ficult to dissolve and that adhesively attached this method themoisture liftsmuch more easily particles are. more or less only in the form ofparin a shorter time. 7 s

i In accordance with one-prior practice, some ing. 7 i calcimine manufacturers have taken glue and The a'bility of any calcimine to cover a given the other bases commonly used in this manuwall-surface per pound of calcimine used olefacture and after-dissolving theglue mixed it pends'upon the particlesize of the whiting or :With the bases desired, making a thin paste or other base used, The smaller the particle size tial attachment of particles and not a real coat- 1'05 of the base the greater the covering quality. Some manufacturers, although using good grades of whiting, obtain poor results due to the coarse grinding.

While many attempts have been made to produce a commercially feasible, cold water soluble calcirnine with high grade glue, a cold water soluble calcirnine hasheretofore been made only by using soluble starches or low grade glues instead of high grade animal glue. A calcimine of this sort will not second coat but pulls if the operator tries to retouch due to defective cover. ing in the first case. Many times anentire wall must be washed and redecorated. The calcimines in general use are simple mixtures'using a high grade glue as the adhesive, and requiring the use of hot water in the mixing to dissolve the glue. A high grade glue resists the absorption of water, takes time to jell before going into, solution, and requires heat. But high grade glue,

while diificult to put into solution, resists the action of water and the brush iii-second coating.

Practically all hot water: calcimines today will take a second coatbecause all contain good grades of glue. But all require hot water, and time. In new buildings the'practice is to put the calcimine into solution at night so as to avoid the delay .during the day incident to the making of the solution and strainingpreliminary to application.

In accordance with this invention a high grade glueis used that under ordinary usage couldnot be put into solution in anything but hot water. 7

properties of adhesion are not substantially damaged. The brushing quality of a calcirnine depends upon the viscosity of the glue used. It is desirable that a calcirnine when applied pull a bit on the brush, this insuring a good even spread.

' It accordingly will be understood why hot water grades have heretofore been the rule.

By first running a good grade of whiting through a colloid mill the number of particles per pound are increasedand the covering quality of, the finished calcirnine is improved. Not all of the whiting will be reduced to colloid size so as to'show a true Brownian movement under the microscope, but the particle size is reduced to a finer state of sub-division than possible by, any

glue in solution to three to eight parts of whiting used with enough water added to make the finished magma about twenty percent solids and then flash drying, a cold water soluble calcirnine containing a high grade glue is obtained with the naturalqualities of the. glue unharmed. The

resulting material consists of a very finely divided base'material, each particle of-which is coated with a thin glue film so finely divided that even a-high grade glue will go into solution in water at 46 F. If for any reason very low temperatures are desired for the finished calcirnine the percentage of base is increased, thereby reducing the film of glue on the whiting particles. 'A study of this material under the microscope shows not just the ordinary mix with some attachment ofstock.

stated without injury to the physical properties made may be particles, but a real coating of very fine base par ticles with a high grade glue that because of its exceedingly fine film size is actually soluble in cold water as low as 40 F. Ten percent or less of the glue is present as a mere mixture and this has a thin, flaky form.

.Ahigh grade hide glue such as usedin hot water calcirnine is made from hide scrap and after cleansing, washing and bleaching goes to the glue kettles and the glue is boiled out of the After this the glue liquor is settled, filtered, chilled, cut into sheets, spread on nets, dried, removed from the nets, ground, and finally packed. The drying of the glue in the thin, transparent sheet of commerce is a part of the glue cycle in. producing glue. In carrying out thisinvention it is preferred to take the glue fresh from the kettles and mix with it immediately the finely divided base and flash dry as of the glue. Asv finished dry glue may be used by preparing a thin, hot solution, but a thin, hot solution direct from the glue kettle appears to give the best results in that it gives a thinner coating of the base particles and, moreover, by'mp using the glue direct from the kettles the balance of the steps in the usual manufacture of the glue is eliminated.

It is not known with certainty why there is loss of strength of glue in ordinary drying when 10 the glue is exposed to the action of heat and moisture over a period of time. Some say the action of heat and moisture splits the particle size, and others the-efiect of oxygen in the heated currents of air used in drying, and some say 11 both. -By drying in thepresence of an inert gas such as carbon dioxide, the present inventor has found that the drying may be accomplished with less damage to the glue. An atmosphere of CO2 gas in Whole or in part may be used instead of air. However satisfactory results are secured using only air.

In carrying outthe invention in its preferred form, liquid glue such as produced by" extraction from tanner'hide scrap or bone prior to the fig usual'step of evaporation has mixed therewith whiting, gypsum, or other suitable mineral or other bases, either finely ground or in a colloidal state. The whiting or gypsum may be first passed through a colloid mill. However, the invention may be carried out with these mate- 'rials in a finely ground of pulverous state. The

proportions'of the ingredients in the batch thus 1 part. (solid content) i i .glue 3 to 5 parts whiting 12 to 20 parts water.

This usually requires that the liquid glue extracted from the tanner hide scrap or bone shall-be somewhat diluted either before or after the addition'of the'whiting or gypsum;

The batch thus made is then dried in such a wayas to prevent agglomeration of the finely ground or colloidal particles of base material.' This may be accomplished by flash or spray drying, i. e.,"the batch may be sprayed by any suitable means in a moreor less nebular'state into a hot atmosphere or against a hot surface such as the surface of a heated drum from which the material may be scraped by a doctor blade. The

material will be quickly dried with no appreciable effect upon the adhesive properties of the some air at a high temperature, for example 500 to 600 F. This will accomplish the drying in a period of from-one-iourth to one-third of a second and with no appreciable oxidation of the glue. The material thus produced is preferably quickly cooled after the drying to avoid oxidation.

The flash or spray drying may be accomplished by the use of suitable equipment resistant to abrasive action of the base materials. A diamond set nozzle may be employed for this purpose in which case the pump pressure on the liquid batch will be from 2,000 to 3,000 pounds per square inch to produce a nebular spray in which there is no appreciable tendency for the particles to agglomerate. Instead of the diamond set nozzle,

' a centrifugal disc spraying device may be emspray drying it is very necessary to prevent sponging in drying. Some types of spray dryers are impossible because this feature cannot be prevented with their usage.

The resulting material comprises fine particles of whiting or other mineral base with each particle coated with an exceedingly thin or microscopic film of glue along with a small percentage of fiaky glue particles. This glue, because of the extreme thinness of the films, is readily jelled by water and readily goes into solution therein at low temperatures.

The process may be varied by the addition of such other materials to the batch as may be desired. For example, in the production of a calcimine all the ingredients of the calcimine might be mixed in the glue and glue base solution and flash-dried therewith under the conditions prescribed. However, it is usually preferable from the standpoint of economy and handling of materials to mix the balance of the ingredients of the calcimine to the glue and glue base product after the latter has been prepared as described.

Modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. That method for making a glue product which comprises mixing with liquid glue a finely powdered, inert base, flash or spray drying the mixture in a heated atmosphere including a large proportion of an inert gas, and quickly cooling the material thusproduced whereby nonagglomerated particles of the base are produced which are coated with films of glue readily soluble in cold water.

2. That method for making a glue product which comprises mixing a finely powdered, inert base with a thin solution of glue in water and spray-drying the mix to form non-agglomerated particles of the base with thin films of glue thereon which are readily soluble in cold water.

3. That method for making a glue product which comprises mixing with a solution of glue and water a finely powdered whiting, and flashdrying the mix in an atmosphere principally of CO2.

4. That method for making a glue product which comprises mixing with a solution of glue and water a-powdered whiting, and flash-drying the mix to form non-agglomerated particles of are readily soluble in cold water.

5. That method for making a glue product which comprises mixing directly with the solution of animal glue formed by extraction in the usual way, a finely ground mineral base, and spray-drying the mix in a nebular state in an atmosphere at a high temperature whereby the particles of said mineral base do not agglomerate and are coated with thin films of glue readily soluble in cold water.

6. That method. for making a glue product which comprises mixing finely ground particles of a base'with a thin solution of glue, and spraydrying the mix in a nebular state in an atmosphere at a high temperature to produce nonagglomerated particles of the base coated with films of glue readily soluble in cold water.

7. A spray or flash-dried product of manufacture for use in calcimine and like coating compositions, said product comprising whiting of about colloidal size, the particles of which are coated with a microscopic film of extracted animal glue of a type which normally is not soluble in cold water, the films of glue on said particles being so thin as to be readily soluble in cold Water, said glue being substantially of the strength, jell and viscosity of the glue as originally extracted.

.8. A spray or flash-dried product of manufacture for use in calcimine and like coating compositions utilizing water as the vehicle thereof, said product comprising filler particles inert to glue and water and of about colloidal size, said particles being coated with microscopic films of extracted animal glue of such thinness as to be readily soluble in cold water, said glue being normally ,of a type which is insoluble in cold water said glue having substantially the chemical composition, strength, jell and viscosity of said glue in its original extracted condition.

9. A spray or flash-dried product of manufacthe base with thin films of glue thereon which v ture for use in calcimine and like coating compositions in which water is the vehicle comprising non-agglomerated particles of a filler inert in cold water, said glue having substantially its original strength and viscosity when dissolved and being of substantially its original chemical composition as obtained when said glue was originally extracted. I

CHARLES H, CAMPBELL.