US1918692A - Finished surface and process for producing same - Google Patents

Description

' Patented July 18, 1933 UNITED STATES PATENT OFFICE CHARLES ELLIOTT FAWKIB, OF CHICAGO, ILLINOIS, ASSIGNOB TO PYROxYLI N PROD- UCTS, INCORPORATED, OF CHICAGO, ILLINOIS, A CORPORATION 01 ILLINOIS FINISHED SURFACE AND PROCESS FOR PRODUCING'SAME No Drawing. Application filed July 9,

This invention relates to a new type of surface finish and a process for finishing surfaces whereby a protective coating or finish is obtained which is durable, and of unusually good appearance and at a cost much below the cost of such coatings that are now in use.

Among the objects of my invention may be mentioned the finish of fibrous surfaces such as paper, imitation reed or fibre furniture, wood, and the like where the material to be finished is of a porous nature, and where in many prior instances a very large part ofthe finishing material penetrates into the object being finished, and leaves individual fibres sticking through the surface. I wish to produce in two or three coats a smooth finish on such fibrous surfaces, by applying an adhering material, glue, for example, and which material in a single coat will adhere firmly without excessive penetration, and, during drying, will pull down the individual fibres and prevent their extending through the surface.

Furthermore, I desire to apply a very cheap material for this purpose, preferably using water as a solvent. Another-object is to have this priming coat which gives a smooth surface and excellent adherence when applied to fibrous surfaces, of such a nature as to hold a subsequent finishing coat or coats firmly bound, so that there will be no danger of the bond between the final finishing coats of, for example, a lacquer enamel, and the priming coat loosening and allowing the final finish to peel or otherwise loosen and separate from the glue containing coating.

The invention is especially applicable to use in finishing such surfaces as paper, wood, paper fibre, and particularly fibre articles such as fibre or imitation reed furniture. The invention will be described more particularly with relation to its application in the fibre furniture industry, although it will be understood that it is not limited in its application to this particular purpose.

The use of glue size for porous or fibrous surfaces is well known and has long been practiced. In finishing fibre furniture, for

example. it has been customaryto dip the pieces of furniture in a tank of glue solution whereby the solution penetrates the fibre,

carrying in some of the glue. The article is then drawn out of the tank and is allowed to drain. The water is allowed to evaporate leaving a small amount of glue within the 1928. Serial No. 291,476.

fibre.v Inasmuch as the glue solution used in the clipping tank usually contains only about of glue, and the solution penetrates into the fibre, practically all of the glue size is down in the interstices, leaving the appearance of the surface practically unchanged. Furthermore, since the dipping tanks must be very large to accommodate large articles of furniture, the volume of glue solution in the tank is correspondingly large. It is necessary to hold this glue solution at temperatures above the jell point, that is, above the liquefaction point, of the glue solution. Under these conditions the glue rapidly .det-eriorates, and develops objectionable odors, so that in a few days it becomes unfit for use and must be discarded, thus increasing the cost of the sizing process.

- Even if it were vpossible to obtain a continuous glue film on a fibrous surface by the dipping process, it would not be possible to secure with glue alone good adherence between the glue surface and the subsequent coats of finishing material such as a lacquer or varnish.

I have discovered, however, that the addition to the glue of a substantially non-volatile substance that is soluble in both water and in the solvents used in lacquers or varnishes will render the glue surface capable of holding, firmly bound, other finishing materials such as lacquer, shellac, varnish, and the like. It is, of course, necessary that the substance added to the glue be one that is compatible with both the glue and the lacquer or varnish finishing coat. For example, while resorcin is soluble in bothwater and organic solvents such as are used in lacquers, it has a tendency to react with the glue to cause it to coagulate and it therefore is not preferable for my pur pose. On the other hand, monacetin or glycerol monoacetate,

romoncnoncmmccn.)

is soluble in both water and in organic solvents and is compatible with both the glue and the varnish or lacquer, and is therefore capable of producing, in a very satisfactory manner, the results which I desire to obtain, namely, a continuous coating of glueand monacetin capable of forming a bond with lacquer or varnish coatings when such coatings are applied to the said continuous coating of glue and monacetin. A feature of my process, therefore, is a priming coat consistin of a glue-like substance and a substantia ly nonvolatile material which is capable of giving to the glue-like coating the property of adhering to subsequent finishin g coats such as varnish, lacquer, shellac and the like. The process of rendering glue suitable for use in the herein described process is given in detail in my (Bo-pending application Ser. No. 251,665, filed February 3, 192-8.

It has beenpreviously mentioned that in processes heretofore known or practiced a very reat amount of glue is required, which must e applied by a multiplicity of applications to give a continuous glue film on the surface of fibrous material. Since this loads up and greatly stifiens the fibre, it is not at present the practice to use so much glue as to give a continuous film on the surface, and furthermore even if such a film were formed the adherence of subsequent finishing coats would not be satisfactory. v

According to the preferred form of my present invention, I apply a coating of suit- .able adhesive material to the surface by a hot spray, preferably with steam.- For example, a 30 to 40% water solution of glue containing the proper amount of monacetin as hereinbefore mentioned and heated to a temperature above the liquefaction point of the glue solution is sprayed onto the surface by means of a suitable spray gun such as is used for spraying varnish or lacquer. My preferred method of applying this spray of blue is to use steam instead of compressed air to atomize the glue and monacetin solution. lVhiln air that has been heated to a temperature preferably above the liquefaction point of the glue may be used, steam at a suitable pressure to give atomization has certain advantages in that the particles of glue solution emitted from the spray gun do not cool down, by evaporation or otherwise, to a temperature below the liquefaction or jell point of the glue solution before they come in contact with and attach themselves to the surface to be finished. By thus holding the warm glue solution at a temperature above its liquefaction point until it is deposited on the surface, a smoothcontinuous film of glue and monacetin is obtained. It is to be understood, of course, that other suitable substances, such as sulphonated castor oil may be substituted for monacetin.

Where a glue-like film is deposited by the above method, it jells very rapidly after being deposited, and, of course, the amount which soaks in is comparatively small. Another advantage in applying the glue-like material by a hot spray is that a comparati vcly thick film may be built up in one spraying operation or coat. In practice it has been found that a smooth glossy finish can be obtained by one coat even on such fibrous material as blotting paper, thus giving a smooth even surface for finishing with lacquer, shelterial to remain on the surface of the object as a continuous film, which may be of any desired thickness. Furthermore, should any fibres extend through the surface, where it is desirable to apply a relatively thin coat, the shrinkage during the drying stages of the glue jell tend to pull the fibres down so as to give a perfectly smooth surface, free from projecting fibres.

It has long been realized that if an inexpensive and proper finish could be put on paper, cloth, felt, straw and other fibrous material, such materials could be utilized to a greater extent in the fabrication of many articles. With my process, I can produce a finish on the surface of fibrous materials, such as the above, that compares favorably with the high grade finishes usually obtained on smooth metal surfaces. Thus cotton braid hats can be given a finish in two coats that gives them all of the appearance of the more expensive silk or rayon braid hats. Furthermore, when the second coat is a nitrocellulose containing lacquer, the braid is rendered substantially Waterproof. Straw hats can be given a glaze that has heretofore not been obtainable by any other finishing process now known. Burlap or canvas walls can be given a glossy finish by applying, by my process, one coat of my modified glue solution and one or two coats of varnish or lacquer enamel. This has not been possible heretofore, except Where a great number of coats of varnish is used, and where a nitrocellulose lacquer enamel finish is desired, it is necessary to use from six to eight coats in order to get a finish of an appearance that is equal to the appearance that can be obtained from a coat of modified glue and one coat of la"- quer according to my process. It is apparent, therefore, that my invention offers in'nnens'e economical advantages in the art of finishing.

The following paragraphs, denoted by numerals, indicate some of the considerations, conditions and requirements involved in connection with the present invention.

1. Preparation of the glue containing composzt'ion From 10 to 50 parts of glue is mixed with 50 to 90 parts of cold water and the glue allowed to swell. The swelling consists of the penetration of the water into the glue,

so that the mixture becomes jelly like. Depending upon the size of the glue particles and the grade of glue, this requires from 10 minutes to 2 hours. In practice, it is usually preferable to allow the swelling to continue until there are no hard particles of glue remaining. The swelled glue and water mixture is then warmed up until the liquefaction oint is reached, which is indicated by the ell turning from a jell to a liquid state, such as is well known in preparing gelatinjells. When the glue and water have completely liquefied, there is added, for example, from one to twenty parts of a compound such as monacetim'sulphonated castor oil, methyl or ethyl urea, and the like. If it is more convenient, the monacetin or other mutually soluble substance may be added to the water in which the glue is placed for swelling. The materials which are suitable and desirable for this purpose are preferably substantially nonvolatile. organic compounds which are mutually soluble in water and in organic solvents such as alcohol, butyl acetate, turpentine and the like. Furthermore,

as has already been mentioned, the material should be compatible with both glue and the materials used for subsequent coats of finish.

Where monacetin is used, it acts also as a plasticizing agent for the glue, so that where a glue plasticizer is desired it may not be necessary to add any additional plasticizer. In some cases, however, it is desirable to add additional glue plasticizer, in which case any of the well known glue plasticizers such as glycerin may be used. Pigments, fillers, dyes, and the like may also be added to'the glue containing solution where this is desirable.

\ Also, where it is desirable to keep the glue solution for a period of time, any of the well known glue preservatives may be used. Since, according to my process, only a relatively small amount of the above described.

modified glue solution need be held above the jell temperature during its application, the glue containing composition may be kept in cold storage over relatively long periods of time.

Various modifications are of course possible such as the addition of the material to the water used for swelling the glue, etc.

2. Application of the glue containing composition As before mentioned, it is desirable to apply the glue containing composition to the surface of the article to be finished, having only sufiicient penetration to give good adherence of the glue to the material being finished. Mypreferred method is to spraying equipments such as are used for spraying lacquers, shellac, varnish, and the like.

In any case, the most'satisfactory results are obtained when the temperature of the glue containing solution is held above its due to evaporation of water and to the trans fer of heat from the solution to the air between the time the spray leaves the spray gun nozzle and it reaches the surface being finished, I can employ pressure steam. The use of steam will be readily apparent, as it will readily be seen that the steam will not only prevent evaporation from the particles of spray by maintaining a moisture saturated atmosphere, but will give up its own heat and maintain a temperature during the whole operation above the jell point of the glue solu tion. One of my preferred methods of applying the glue cont-aining material is, there fore,"the use of pressure steam instead of air for operating the spray gun. The source of steam may be attached to any suitable spraying apparatus at the connection ordinarily used for air. The steam pressure required may be the same as the air pressure required on the spray gun to give similar atomization in the spraying of lacquers, varnishes, shellac and the like. The glue containing solution must be held at a temperature above its jell temperature at the time it enters the spray nozgle. Mixtures of steam and air may be use Under the conditions described above, the glue containing solution cools very rapidly upon striking the cold surface, and jells before it is soaked into the fibrous or porous material being finished. The amount of penetration can be controlled by the viscosity of the glue containing solution, the temperature of the surface being finished, the temperature at which the glue is applied, and by the rate of application.

3. Application of final finish has already been described, enables-me to secure extremely great adherence of such water resistant finishing materials as varnish or varnish enamels, nitrocellulose lacquers, shellac, and the like. These may be applied by any of the well known methods such as with a brush 01' with a suitable spraying equipment. It is, of course, obvious that these water resistant coatings may be of any type adapted to my particular purpose, namely the protection of the glue containing priming coat against the action of water.

It is 'to be understood that many modifications of my invention are possible both as to the choice of materials, the proportions of materials used, and the method of applying the materials to the surface being finished without departing from the spirit of the invention, or exceeding the scope of the appended claims. The herein described invention is therefore defined by the claims.

In the following claims the term surface coating is to be interpreted substantially as the equivalent of protective coating, and the term glue as intended to include any adhesive-like material having the functions and capabilities of glue in the connection herein mentioned.

What I claim is:

1. A material carrying a protective coating comprising a continuous coating of glue and a substantially non-volatile glycerol ester and one or more coats of a nitrocellulose containing finishing material applied to the glue containing priming coat.

2. A material carrying a protective coating comprising a continuous coating of glue and monacetin and one or more coats of a lacquer or varnish finishing material applied thereto.

3. A material carrying a protective coating comprising a continuous coating of glue and monacetin and one or more coats of ni tro-cellulose containing finishing material applied thereto.

4. A fibrous material carrying a tightly adhering coating containing glue and a water soluble glycerol ester and one or more coats of cellulose ester containing finishing material including a vegetable oil applied thereto.

5. A fibrous material carr ing a tightly adhering coating containing g ue and a water soluble glycerol ester and one orv more coats of nitrocellulose containing finishing material applied thereto. I

6. A woven fibre body carrying a tightly adhering coating comprising a priming coat of glue and a water soluble glycerol ester and one or more coats of nitrocellulose containing finishing material applied to said coating of glue and glycerol ester.

7. A fibrous surface carrying a tightly adhering coating comprising a priming coat of glue, a water soluble glycerol ester and a pigment, and one or more coats of nitrocellulose containing finishing material applied to said glue containing priming coat.

8. The. herein described process comprising spraying a water solution of glue and a glycerol ester to a surface as a pr1ming coat wherein steam is employed for securing atomization, allowing the glue containing coat to dry and applying thereto one or more coats a Water solution of glue an a glycerol ester A and a pigment as a priming coat on the surface of said fibre furniture and wherein steam is used to secure atomization of said glue containing solution, allowin the said priming coat to dry and ap lying t ereto one or more coats of a nitroce lulose containing finishing material.

11. The herein described process of finishing absorbent surfaces comprising making a water solution of glue and a substantially non-volatile organic substance soluble in both water and organic solvents said solution having a jell point higher than the surface to which it is to be applied, heating the said solution above its 'ell oint to cause it to .liquefy, applying t e iquefied glue containing solution in its liquid condition under such conditions of temperature that said glue solution cools and jells before it has time to be absorbed by said absorbent surface, allowing the glue containing coating to dry, and apply-ing thereto one or more coats of a nitrocellulose base finishing material.

12. The herein described process comprising applying a solution of glue and a glycerol ester to a surface, allowing the glue containing coat to dry, and apply-ing thereto one or more coats of a. cellulose ester containing finishing material. 4

13. The herein described process compris- .ing applying a. solution of glue and a glycerol ester to a surface, allowing the glue containing coat to dry, and applying thereto one or morecoats of a water resistant varnish- 14. The herein described process comprising applying a solution of glue and a glycerol ester to a surface, allowing the glue contain- 16. The herein described method of rendering glue capable of forming a bond with cellulose ester base lacquers, comprising adding to a glue a glycerol ester that is soluble both vin water and in the solvents of the lacquer.

CHARLES ELLIOTT FAWKES.