US1883877A - Age resister for rubber compounds - Google Patents

Description

Patented Oct. 25, 1932 UNITED STATES PATENT-OFFICE,

ALBERT M. CLIFFORD, F AKRON, OHIO, ASSIGNOR' TO THE GOODYEAR TIRE 8n RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO AGE RESISTER FOR RUBBER COMPOUNDS No Drawing.

10 ilar deteriorating agencies.

Heretofore, it has been observed that rubber, transformer oils, soaps and similar organic materials are attached by, and gradually deteriorate under the influence of, at-

sunlight, heat, etc. It has been proposed to overcome these deleterious efliects by incorporating into the com pounds certain preservatives known as antioxidants or age retarders. Although many materials have been employed for this purpose, the phenyl naphthylamines and similar secondary amines have been found by actual test to be among the most satisfactory for general use.

This invention consists in the discovery that aliphatic substituted phenyl naphthylamines such as cumidyl and xylyl naphthylamines, either of the alpha or beta form, are also excellent anti-oxidants which are practioally equal in power as preservatives to the unsubstituted amines which have heretofore been employed. Substituted amines maybe manufactured by methods analogous to those employed in the manufacture of phenyl naphthylmamines merely by subjecting the naphthol (either alpha or beta) to a temperature of 280 to 310 C. in an autoclave for a period of eight to ten hours. The reaction products may be purified by washing them with dilute alkali in order to remove any unreacted naphthol and then following this treatment with P subsequent washings with water, dilute acid, and finally with water. The product may be dried by subjecting it to distillation under vacuum. 1-3-4-xylyl beta naphthylamine Application filed April 8, 1930. Serial No. 442,713.

obtained in this manner is an orangecolored oily material having a boiling point of 238 to 240 C at a pressure of seven millimeters of mercury. Gumidyl beta naphthyla-mine is also an orange colored material having a thick sirupy consistency and having a boiling point of 215 to 230 C. under a pressure of four millimeters of mercury.- The compounds are both soluble in benzene, alcohol, acetic acid, etc, and are slightly soluble-in petroleum ether. All of the solutions are characterized by deep blue fluorescence.

Although these materials may successfully be employedas antioxidants in most of the standard rubber compounds, the following is an example of a formula which has been foundby actual test to be quite satisfactory:

Samples of compounds prepared in accordance with .the preceding formula in which cumidyl beta naphthylamine and xylyl beta naphthylamine were employed as antioxidants were subjected to vulcanization for varying periods of time. One portion of these samples was then subjected immediate- 1y to physical tests in order to ascertain the tensile strength and elasticity thereof prior to aging. I

A second set of exactly corresponding samples were then subjected to artificial aging in an oxygen bomb under pressure of 150 ounds per square inch and at a temperature of 50 C. for a period of six days. These samples were then removed from the bomb and subjected to physical tests identical with those conducted upon unaged samples.

The results of these parting from the spirit of tests are tabulated as follows Load in kgs/cm at l Tensile i i Cure Per cent 7 weight strength elong. 5007 7007 increase .kgS/cm I elong elong C'umidyl beta naphthylamine ORIGINAL a ss- 9a "890' 14 146 860 20 so r 185 820 26 92 V AGED iN oxmm BOMB 6 DAYS .a'r 50 0. i

as 104 835 15 49 .04 so 147 810 r 23 e so ".1 70 167 760 32 118 .07

I Xylyl beta naphthylamine 'joRIGINaII.

V 35 112' i 905 15 asso I 140 s50 20 5s AGED IN OXYGEN Home 6 DAYS AT 50 o.-

,as. V 117 s35 17 5e .06 50 137 785 24 87 02 70 158" 745 I as 122 :14

' It will be'observed that the samples of main which is a cumidyl group.

- April, 1930. 8

composable organic materials which comcanize in the presence of a cumidyl naph-' thylamine.

4. As anew chemical compound, a material having the formula J ,III,

In witnesswhereofll have hereunto signed my name at Akron, in the county of Summit and State of Ohio,

U; S. A., this 7th dayof" IVAL'BERTMT'OLIFFORD. I V

terial containing the new antioxidants are not materially affected by the action 'of oxygen even'under the relatively severe conditions existing in the oxygen bomb. In fact,j it would appear that the condition of the sample s is somewhatimproved, at least in certain cases, by such treatment. Under simf ilarconditions samples of material containmg no antioxidants are reduced to resinous masses-substantially devoid of elasticity and tensile strength.- a The new antioxidants may be I manufactured at relatively slight expense and trou- I -They also possess but rslight, ifany,

ble. odor and are not appreciablytoxic. They blend readily with rubberand alsowith other and soups; in fact the solubility thereofin thylamine, compounds from which they may be considered as being derived. For these mercial'materials. V

Although I have described the preferred reasons, they are highly desirable as comembodiments of the invention, it will be ap parent to those, Skilled in the art that it is notflimited thereto but that various modica fieations may be made therein without defrom the scope of the appended claims. WhatIclaim isz.

A methodof preserving rubber; transformer oils, soaps," and similar readily dethe invention or