US1781645A - Process for making emulsified compositions - Google Patents

Description

STATES PATENT? OFFICE LESTER KIBSCHBRAUN, OF LEONIA, NEW JERSEY PROCESS FOR MAKING EMULSIFIED COMPOSITIONS Kc Drawing. Original, application filed December 2, 152 25, Serial No. 72,818. Divided and this application filed May 6, 1927. Serial No. 189,460.

This application is a division of an application filed by me, Serial No. 72,818 on December 2nd, 1925.

In an earlier application filed by me, to-

5 wit: Serial No. 26,813 filed May 8th, 1915,

now Patent No; 1,302,810, I described a process of making an emulsified composition suitable for use with certain fibrous material. I have since discovered that in certain cases 10 it may be advantageous to make a double emulsion. Heretofore, attempts to make waterproof sheets, particularly as a continuous operation, on paper machines and the like, have experienced much diificulty in making a composition which would not stick to the machine. In said prior application, I obviate this difiiculty by making a non-sticky emulsi- .fied matrix composed of water and an emulsitying agent, such as clay of a colloidal character and a binder such as bitumen. In this matrix, the finely divided particles of the binder were in effect surrounded by a nonadhesive colloidal emulsifying agent, so that the material would pass readily over the paper machine without sticking.

I have discovered that in certain cases, it may be desirable to form what in effect may be called a double emulsion. This double emulsion seems to permit of a more minute dispersion of the asphalt particles in the water vehicle. Just exactly the action that takes place I am not at this time prepared to state.

I have ascertained however, that certain kinds of binders as for example some tars and pitches do not as readily emulsify with a clay paste as do others. Moreover, while a certain percentage of such tars or pitches might readily emulsify with the clay paste, there seemed to be a point at which no more tar or oil could be added and get a satisfactory emulsion. I have'discovered, however, that by making a double emulsion I can overcome this objection. l

The process of the present invention may be described as follows:

An adhesive waterproof binder, preferably in a hot liquid condition, is placed in'a suitable receptacle; to this liquid binder is gradually added an aqueous paste or solution. This -aqueous paste or solution may consist .of

tion from two parts upwardly of soap to 100 parts of the binder.

This first emulsion, which is a mobile liquid, is gradually added to an aqueous paste of water and material containing colloidal particles such as clay and the two thoroughly mixed together to form a second emulsion.

In forming this second emulsion, the result is an emulsified composition of a non-sticky and stable character.

I have above referred to making the first emulsion by the use of a fatty acid and later adding an alkali solution. One advantage of making an emulsion in this way is that it permits of the use of a very high melting point asphalt for a binder. For example, if an asphalt having say 300 degrees F. melting point is desired to be used with the binder, it obviously cannot be mixed with an aqueous solution when melted, for the reason that-the melting point of the bitumen will be much above the boiling point of water. However, by first adding a fatty acid to the high melt ing point binder, the latter is so softened or cut back by the fatty acid that it is a liquid at a temperature below the boiling point of water. The hot aqueous alkali solution can then be added and the alkali and fatty acid combined to form soap. This first emulsion can then be mixed with a second emulsifying agent as before stated. It will thus be seen that a very high melting point binder can be used. The-utilization of a high melting point binder permits of the formation of a' very hard and rubbery product.

After this double emulsion is formed, as above stated, it may if desired, be combined with various kinds of fillers or fibrous materials and then molded or sheeted as desired. As the water dries out of the mixture the binder will coalesce, become adhesive and form a very tough and strong product.

While it may not be true in all cases, I have found that it is most desirable that in forming the first or primary emulsion, that the aqueous solution containing the emulsifying agent be added to the binder rather than the binder to the aqueous solution, While in forming the second emulsion, the first emulsion is added to the second emulsifying agent rather than the reverse. With reference to the binders, a wide variety of binders may be employed, either asphalts, natural or artificial coal tars, water, gas tars, animal and vegetable pitches, hydrocarbon oils, drying oils, such as linseed oil, China-wood oil, wax tailings, parafiin, resin and the like. In some cases t e binder may consists of rubber dissolved in a suitable vehicle such as naphtha or benzol, which, of course, will ultimately evaporate. By the word bituminous as used in this specification and in the claims, is meant to include the various forms of binders referred to in the two preceding sentences.

Instead of carrying out the process in the manner above described, a saponifiable fluxing agent such as oleic acid, sulphonic acid, and in general substances which upon combination with soluble alkalies, act as emulsifying agents, or protective colloids may be fluxed with the bitumen and the mixture emulsified by the addition of an emulsifying agent, as for example colloidal clay, bentonite or analogous emulsifying agents. To this emulsion may be added an alkali such as sodium hydroxide or ammonium hydroxide. The result is to produce an emulsion which in certain instances, has increased stability, and is less susceptible to disturbing elements which may tend to break down the emulsion in case it is used as a paint, or applled on a paper machine.

Another advantage of this modified type of operation is that the soluble substances formed, may in certain instances act as a stabilizing agent, tending to hold the hydrogen 1on concentration fairly stable within predetermined limits. 7

In a paint, this treatment results in stabil z ng the paint while it is in an aqueous condition. Where a stabilized product is formed, such as ammonium oleate, and the dry paint film exposed to the weather, the ammonium soaps tend to break down, losing the ammonium and regenerating the saponifiable substances, which being oil soluble, tends to facllltate coalescence and engulfing of the mineral particles (clay and pigment) inasmuch as these become wet with the oil solu-.

ble saponifiable agent. The invention may be carried out substituting metallic soaps for saponifiable acids,

these soaps being fused with the pitchy binder, and then the combination emulsified as described, with clay and treated with alkali. The addition of metal soaps appears to change the interfacial tension between pitch and argilliferous emulsifying agent so as to present an optimum relationship with certain clays, and tend to produce the effect'of better dispersion.

I claim as my invention:

1. A method of making a waterproofed fibrous sheet comprising intimately mixing fibrous pulp with a normally adhesive bituminous waterproofing material dispersed in an aqueous vehicle containing soap and rendered non-adhesive by the incorporation therewith of an agent in quantity less than would substantially impair the waterproofing properties of the bituminous waterproofing material, forming a sheet from said mixture, and drying the sheet to cause the bitu' minous material to resume its adhesive condition and waterproof the fibers.

2. A method of making a waterproofed fibrous sheet comprising intimately mixing inan aqueous vehicle, fibrous pulp and an emulsion containing a heat liquefiable normally adhesive bituminous waterproofing material dispersed with soapand rendered non-adhesive by the addition thereto of a clay-like substance in quantity less than fibers.

3. A method of making a waterproofed fibrous sheet comprising intimately mixing 'in an aqueous vehicle fibrous pulp and an emulsion containing a heat liqu'efiable normally adhesive bituminous waterproofing material dispersed with soap and rendered non-adhesive by the addition thereto of material containing colloidal particles in quantity less than would substantially impair the waterproofing properties of the bituminous waterproofing material, sheeting said mixture and removing the water to cause the bituminous material to resume its normally adhesive condition and waterproof the fibers. 4. A method of making a waterproofed fibrous sheet comprising intimately mixing fibrous pulp in an aqueous medium containing a dispersion of a heat liquefiable normally adhesive waterproofing material and a water soluble dispersing agent and rendered non-adhesive by the incorporation therewith of an agentin quantity less than would substantially impair the waterproofing properties of said waterproofing material, sheeting said mixture and drying the sheet to cause' the waterproofing material to resume its normally adhesive condition and waterproof the fibers.

5. A method of makin st making a dis persion containing a normally adhesive bituminous waterproofing material in finely subdivided form, mixing said dispersion with an aqueous vehicle containing colloidal powder, incorporating fibrous pulp with said mixture, sheeting the mass and drying the sheet to cause the bituminous waterproofing materialto resume itsadhesive condition and waterproof said fibers.

6. A method of making a waterproofed fibrous sheet, which comprises first making a relatively unstable dispersion of a normal:

ly adhesive bitumlnous waterproofing material, converting said unstable emulsion to stable form by the incorporation therewith of an agent in quantity less than would substantially impair the waterproofing properties of the bituminous waterproofing material, incorporating fibrous pulp with the stabilized dispersion, sheeting the mixture and drying the sheet to cause the bituminous waterproofing material to resume its adhesive condition and waterproof said fibers.

7. A method of making a waterproofed fibrous sheet, which comprises first making a relatively unstable dispersion of a normally adhesive bituminous waterproofing material, rendering said dispersion stable by mixing said unstable dispersion with an aqueous vehicle containing colloidal material in quantity less than would substantially impair the waterproofing properties of the bituminous waterproofing material, incorporating fibrous pulp with the stabilized dispersion, sheeting the mixture and drying the sheet to cause the bituminous waterproofing material to resume its adhesive condition and waterproof the fibers,

In testimony whereof I afiix my signature.

LESTER KIRSCHBRAUN.