USRE18370E - Carleton ellis - Google Patents

Description

Reissued Mar. 1, 1932 uNrrEo STATES PATENT, OFFICE CARLETON ELLIS, OF MONTCLAIB, NEW JERSEY, ASSIGlN'OB '10 ELLIS-FOSTER COMPANY, A CORPORATION OF NEW JERSEY UREA ansm raonuc'r rum raocnss or MAKING SAME 1T0 Drawing. Original No. 1,685,355,.dated September 25, 1928, Serial No. 745,937, filed October 25, 1924.

Application for reissue filed December 4, 1929. Serial No. 411,702.

This invention relates to various molded or shaped products and sheeted material or plate of novel appearance and to the process of making same.

In a co-pending application, Serial No. 742,719, filed October 9, 1924, I have described the formation of striated molded articles by pressing together resin-impregnated multi-colored fragments of paper. In the present invention one object is tosecure striated products, the striations of which are of a more regular or uniform character than obtained by the process set forth in said application. Also in some cases, I deslre to obtain banded effects or parallel striation including the peculiar striped effect employed in imitating ivory. Further ob ects' include the production of hot pressed "or molded urea resin products substantially free from discoloratio In carrying out my invention for example Iimpregnate paper or other tissue; which preferably should be unsized, employing as the impregnating medium a resin, preferably a synthetic resin, having the property of hardening or setting in the mold when hot pressed at'elevated temperatures. Phenol formaldehyde resins may be employed in some cases for this operation especially for darker colors but generally speaking .I prefer a light colored base in which the striations appear-and the phenol formaldehyde resins are therefore not suitable for use in this way because of discoloration by light.

A satisfactory resin for the purpose is however made by treatment of urea with formaldehyde. Such material may be obtained in its initial stage of conversion in the form of an aqueous syrup with which the paper may be-impregnated. The urea formaldehyde resin maybe used by itself or it may be incorporated with other resins to secure a fluxing effect. One resin whichv is satisfactory for this purpose is that obtained by reacting on acetone with formaldehyde in the presence of an alkaline catalyst. A'mixture of say one part of the acetone formaldehyde resin to three or four parts of the urea formaldehyde resin may be employed to advantage.

The tissue employed may be ordinary tissue paper or parchment paper, or heavily calenclered imitation parchment paper known as glassine paper. Heavier forms of paper such as thin blotting paper may be employed in some cases, also muslinor other thin cloth. Generally speaking I prefer to obtain a translucent product and the employment of heavy paper which cannot be thoroughly impregnated to obtain translucency is objectionable for the purpose. The paper maybe dyed 7 different colors or the resin solution may be employed Withdifi'erent dyes or pigments or both the paper and the resin solution may be colored. Sheets of one color are piled one on another until the requisite thickness of that color is secured and then other sheets of a different color are piled thereon. In this way'there' may be built up .a press-board of any desired thickness.

This is exposed to a pressure of 2000 pounds per square inch in a.

7 press at 125 C. for a period of 10 minutes'or f- This method maybe continued, the article obtained by the second pressing being again out and pressed or folded and pressed to ob-,

tain still more striking effects.

The strips referred to above before pressing may be dipped in a solution of the. urea formaldehyde syrup employed for impregnation with; or *without acetone formaldehyde resin). in order-to cause thesurf'aces of the strips to better adhere on the second pressing.

Sinceinthe first pressing which preferably may take place at 125 (3., a sli ht amount of setting may occur, it is-desira le to carry out the second pressing at a somewhat hlgher temperature, say G. However if discoloration occurs at-tliat temperature a longer period at a lower temperature may be employed.

The banded sheets thus obtained are striking of appearance due to the fact that the striations or bands formed by the dark colored paper shows a vigorous contrast alongside of the uncolored paper and the latter, if the" pressboard is not too thick, are translucent yielding a product useful for various ornamental purposes such as lamp shades and the like. Instead of pressing in the form of a sheet the material may be molded into variurea are dissolved in 120 parts of aqueous formaldehyde and 3 parts of phthalic anhydride are added to the solution. The mixture is then slowly and gradually heated, the temperature being around 8090 (1., in a. flask connected with'an air condenser or a watercooled reflux condenser. he heating is continued until the contents of the flask become clear and water white. The syrup so obtained is then cooled and stored. This syrup usually contains from 45 to 55 per cent of solids. It can be diluted with water to a or per cent solution without any danger of recipitation.

mample 2Composz'te product.75 parts of urea are dissolved in 325 parts of aqueous formaldehyde and to this 25 parts of molten phenol and 10 parts of phthalic anhydride are added. The mixture is then very gradually brought to slight boiling and is maintained at this point until the milky solution which is first formed gradually becomes clear and water white. Extensive boiling as well as sharp raising of the temperature should be avoided in order to prevent the possibility of coagulation of the syrup. To the clear syrup so obtained while still warm a small amount (2 or 3'per cent) of alcohol is added. This prevents the syrup from turning milky on coolin p Exam 5e 3-Acetone resin aolutz'on.- 30 parts 0 acetone are mixed with 225 parts of aqueous 40 per cent formaldehyde in a large round bottom flask. 26 grams of per --cent aqueous solution of pure sodium hydroxide are then added and the flask is allowed to stand in the cold. In a short time an energetic exothermic reaction istaking place and a'slightly yellowish gummy resin separates on the bottom. The reaction is checked at this point by adding a large amount of cold water in order to obtain an alcohol soluble resin. The water layer. is then decanted and the resin is washed with water free from caustic and finally is dissolved in an amount of alcohol so as to form a 30 per cent solution. 7 I

The method of preparing the mixed complex solution is as follows:

(A) A 50 per cent solution of either syrup #1 or composite resin #2 is mixedwith an equal weight of 30 per cent'alcoholic solution of acetone resin #3 and the mixture used for impregnation.

(B) The same 50 per cent urea syrup #1 'could' be mixed with 30 per cent solution of other light colored products soluble either in water or alcohol, as for example a glycerol tartrate, citrate or phthalatc.

Impregnation of paper may be carried out simply by soaking, or passing the paper Or presthrough a bath of the solution. sure and vacuum methods, known to the impregnation art, may be employed in some cases,

"What I claimis:

1. -A process of making a streak-ribbed "sheet material or plastic product which comprisesimpregnating sheets of thin paper with a synthetic resin comprising urea resin, su-

perposing sheets of different colors, hot-v to weld the sheets together to a pressing thicker sheet or block, cutting such pressed synthetic resin comprising urea resin, super posing sheets of difierent colors, hot-pressing to weld the sheets together to a thicker sheet 7 or block, cutting such pressed material transversely to make strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

3. A process of making a streak-ribbed sheet material or plastic product which commaterial transversely to make thin strips, as-

prises impregnating sheets of thin paper with I a synthetic resin, superposing sheets of different colors, hot-pressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin strips, assembling the strips edgewise ina hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucentproduct. I

,4. A process of making a streak-ribbed I sheet material or plastic product which comprises impregnating sheets of paper with synthetic resin comprising urea and acetone resins, superposing sheets of different colors, hotpressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

5. A process of making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of thin paper of different colors with. a synthetic resin comprising urea resin, superposing such sheets of difierent colors, hot-pressing to wcldthe sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form av streak-ribbed or variegated partially translucent product.

6. A process of making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of paper with synthetic resins of different colors, superposing the resulting sheets of different colors, hotpressing to weld thesheets together to a thicker sheet'or block, cutting such pressed material transversely to make strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak ribbed or variegated partially translucent product.

7 A process of making a streak-ribbed sheet material or plastic product which compressing below that at which discoloration takes place w'th a synthetic resin comprising urea resin,

superposmg sheets of difierent colors, hot at a temperature above 110 C. and

in the product.

13. A process of making a streak-ribbed product which comprises-impregnating sheets of paper with synthetic resin comprising urea resins of difi'erent colors, superposing sheets of difierent colors, hot ressing at a temperature above 110 C. and elow that at which discoloration takes place,

assembling the strips, and hot pressing the assembled strips at a temperature higher than that used in the first hot pressin step.

14. In the process of making molde urea resin articles, the step of hot pressing a urea resin material at a temperature above 110 C. and below that at which substantial discoloration takes place in the product.

15. In the process of making molded urea resin articles, the step of hot pressing a ureaformaldehyde resin material at a tempera ture above 110 C. and below that at which substantial discoloration takes place in the product.

= CARLETON ELLIS.

prises impregnating sheets of paper of different colors with synthetic resins of diflerent colors, superposing such sheets of difi'erent colors, hot pressing to .weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

8. A process of making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of paper with a synthetic resin comprising urea resin, superposing sheets of 'difierent colors, hot pressing to weld the sheets together, cutting such pressed material transversely to make strips.

assembling the strips edgewise, and hot.

cutting such pressed material transversely to make str1ps,-

ioo