US1799004A - Cold-molded insulation - Google Patents

Description

Patented Mar. 31, 1931 UNITED STATES PATENT OFFICE ROY E. COLEMAN, OF MERIDEN, CONNECTICUT, ASSIGNOR, BY MESNE ASSTGNMENTS; TO THE MONOWATT ELECTRIC CORPORATION, OF BRIDGEPORT, CONNECTICUT, A

CORPORATION OF CONNECTICUT COLD-MOLDED INSULATION No Drawing.

My invention relates to so called cold molded insulation, and particularly to the composition of the binder and method. of llltllilng the same.

Cold molded insulation has come into cx tonsive use of late for various electrical littings and for other us It is desirable in forming a binder, which is mixed with filler material, to secure as intimate a mixture of the fluid or semi-fund ingredients as possible, to the end that a perfectlv uniform binder is formed which Wlll uniformly coat the filler particles, usually asbestos.

It is the principal object of the present invention to provide an improved cold moldable composition and method of making the same such that the fluid ingredients in the binder are widely dispersed and intimately l? mixed so that a uniform, homogeneous prod- 1 binder while hot with finely divided filler material, usually consisting of asbestos and similar material. In carrying out my present invention, 1 may follow in a general way the procedure and method outlined in the Groten patent above referred to.

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The principal feature of novelty of the present invention is in producing a very intimate mixture of the binder constituents so that a very uniform binder is formed, and so that many advantages, as Will be hereinafter set forth, are attained. By way of a specific example of a l'l'lGiJhOCl of producing a cold moldable compound embodying the present invention, I may give the following:

Linseed oil is pumped into a tank and copal chips added. The temperature of the tank is increased to, say, 400 F. and held at that temperature for several hours. The mass is mixed while hot. This mixing and heating serves to substantially dissolve and disperse Application filed August 23, 1928. Serial No. 301,699.

thegum in the oil and bodies the oil. The temperature may then be decreased to, say, 300 F. and a small quantity of drier such as manganese linoleatc may be added. After maintaining the latter temperature for some hours, the temperature may then be again raised to, say, 380 F. and an asphaltic substance such as blown asphalt added. This temperature is maintained for several hours,

during which time the asphalt ismelted and dispersed throughout the mixture. A binder made as just described will give satisfactory results.

It is the principal feature of the present invention to increase the dispersion of one or more of the binder ingredients to the end that the mixture may become almost a true solution or at least substantially a colloidal solution, so that a more uniform, binder product results. persing agents, such as the fatty acids of drying oils, and specifically linseed oil fatty acids, have the property of dispersing the binder ingredients and forming more nearly a true solution of one ingredient in another. The quantity of linseed oil fatty acids employed may vary somewhat, but I have obtained excellent results by the addition of about 1% by weight of linseed oil fatty acids in a mixture of the character described. he linseed oil fatty acid appears to have a generally beneficial effect, and particularly the resin, such as copal gum, appears to be better dispersed in the linseed oil fatty acid and the viscosity is somewhat increased. This increase of dispersion gives more nearly a true colloidal solution and even approaches a true solution. After heating and mixing the other binder ingredients with the dis persing agent, the binder is ready for use. The hot binder may then be mixed with suitable filler material such as finely divided as bestos. A small quantity of talc may also form a desirable ingredient of the binder.

If the finished product is to be colored black, n

it may be desirable to add carbon black and intimately mix the same with the filler material before the addition of the binder. Colored material may be made by adding suitable coloring agents in any suitable manner.

I have found that certain dis- I prefer to add the coloring agents in a widely dispersed condition and this dispersion may be obtained by grinding the finely divided dry coloring agents in a suitable dispersing medium such as linseed oil. This phase of the invention covering the dispersion of the coloring agents for producing coloredarticles of cold-molded insulationis more fully described and cla-imedin my copending applicatiomSerial No. 14:9,273, filed November 18, 1926.

The binder formed accordingto the pres ent invention appears to have an increased affinity for the filler material, that is,.the binder appears tohave greater wetting power for the filler particles than in those cases where the dispersing agent is not employed. After a thorough mixing of" the filler and binder, the ideal result being a thin coating ofibinder. upon each filler particle, themixture will usually'be in the form of small grains or pellets. This rather fine grained mixture; may then be cured in suitablecuring ovens or exposed to the atmosphere for a suflicient length of time, after whichthe mixture is screened and pressed in suitable presses atappropriate pressures to form articles of cold molded. insulation. These pressed articles are usually'baked at an appropriate temperature until they are hard and of permanent character.

A cold moldable compound, including a binder, the ingredients of' which are widely dispersed as above described, possesses a number of advantages. The'curing time of the powder appears to be considerably shorte ened. The finished compound before pressing appearsto be a much softer powder, thus permitting a considerable decrease in the molding pressure required for forming the molded articles. The baking ofthe'pressed articles in the oven appears to give harderand stronger product than when no dispersing agent was employed in the binder; Various other advantages appear to resultfrom the present invention, among which may be mentioned that less difficulty is experienced in molding or curing upon a change of humidity or other atmospheric conditions.

lVhile the invention has been described in considerable detail and one specificcomposi- 'tion mentioned, I do not wish to be strictly limited to the particular illustrative example given, but wish to include other'mcans for.

forming the improved binder' in'which the various ingredients or some of them are widely dispersed.

I claim: i i 1. The method of forming a coldjmoldable compound which includes forming a. binder by heating and mixing an asphaltic substance, a drying oil and a dispersing medium in-the form of a fatty acid of a, dryingoil for assisting in the dispersion and mixingof the asphaltic substance and drying oil, mixtity of dispersing medium in the form of a fatty acid of a drying oil for dispersing the. other ingredients and assisting in an 1nt1mate" mixture of the same, then mixing with filler material, and then curing the mixture.

3. The method of forming a cold moldable compound which includes, forming a binder by heating and mixing an asphaltic substance, a drying oil, a resin of the copal type and a fatty acidof a drying oil to disperse and cause an intimate admixture of the other in gredients,'mixing the binder with filler material, and then curing the mixture.

4:. The method of forming a cold moldable compound which includes, heating and mixing. an asphaltic substance, a drying oil, a resin of the copal type and adding linseed oil fatty acid to disperse the other ingredients and cause a more intimate admixture of the same, mixing the binder with filler material, and then curing the mixture.

5. The method of making a cold moldable compound which includes, mixing linseed oil with a resin of the copal type, heating the mixture, adding a drier,adding an asphaltic substance while continuing the heating and mixing, adding a small quantity of linseed oil fatty acid and continuing, the mixing, then mixing with filler material, and then curing the mixture.

Signed at Meriden, in the county of New Hayen andfSt-ate'of Connecticut, thisQ'Oth day of August, 1928-.

i ROY E. COLEMAN.