US2609201A - Silicone elastomer golf ball core - Google Patents

Description

Sept. 2, 1952 F. s. MARTIN 2,609,20l

SILICONE ELASTOMETER GOLF BALI. com:

Filed June 26, 1947 ATTORNEY Patented Sept. 2, 1952 UNITED STATES PATENT OFFICE v Y y 2,609,201 l t SILICONE ELASTOMER GOLF' BALL conn Frank S. Martin, Cranston, R. I., assgnor to United States Rubber Company, New York,

N. Y., a; corporation of New Jersey Application Jun-eac, 1947, serial No. 757,145

The present i'nventionfrelates -to a novell golf ball core capable of' giving improved: golf ball performance.

For many years golf balls have been provided with a core of rubberfor vother yielding material about which rubber thread was tightly wound to form the golf ball body, and over this body of thread was provided a` molded balata cover.

For a number of years golf balls havefbe'en provided with a liquidi center such as paste, honey, oil or water confined within a rubber shell so that the center and shell form a core. One of the best golf balls' now on the market is a liquid center ball in' which. the core of the ball contains a pellet-formed of aspherical thin plastic container filledwithv castor oil.l This pellet or center is disposed within a relatively thick shell of vulcanized resilient rubber?.M The' core thus formed has? rubberfthread wound tightly thereupon in a i highlyv stretched condition to forni the ball body, andthis body is disposed in a balata cover asY above described;`

Experienced golfersdesire the'l followingl properties in a ball: long'iiight, goodifeelionl the club when the ball is hit, good click sound` when. the pball is hit and when itis dropped oniV ar-liardf surface, long life without getting duti of shape, and a cover that stands up welland` has a. goed white color of pleasing; appearance. The castor oil center ball above described when' made of high quality components possessesT alli of these properties toa substantial degree.

The present invention. relates* to* aiV golf". balllin' which the liquid centerlof! the! core: justA described is replaced by.V ai relativelyfnelw materialpossessing plastic' orfdoughyf properties so' that it can be workedV between theliin'gers'like.` putty, and when rolled into alball. willtb'ounce to" ap#- proximately theV same degl-eel asia go'o'dl quality solid rubber ball. This strange material v'has' beenvgiven the. name2 of' bounbingl putty and will be hereinafter described. greater detail.

Golf balls having a core'containinga center formed of this so-called bouncing putty inplace or" the liquid -center above described, but which are otherwise constructed like the liquid center balls are found to give'exc'ellent performance and to possess properties superior to otherv high grade golf balls now on the market. Experienced golfe ers are particularly pleased. with the click of this new ball and also with the feel or property of the ball to get quickly ofi' of the club.

The various features of a golfvball having a core constructed in accordance` with the present invention will be further understood from" the following description when ready in connection with the accompanyingV drawing,y wherein:

Fig. 1 shows the major portion ofv a golfball constructed in accordance-with thepresentinf vention Vin sections and a minor portion in side View; and

AFig. 2 illustrates the core alone of the ball of Fig. 1, the center of the core being shown in side view while the two' halves of the shell are shown in sectionand in spaced relation to each other. i A

The core of theV golf ball illustrated in the drawing is designated in its entirety-by the nu#Y meral Il). This corer comprises a center Il formed oi a compound containing sufficient bouncing` putty to impartl to theV center pronounced bouncing properties and also putty-like plasticity. The center Il is disposed within a relatively thick shell of vulcanized natural rubber, synthetic rubber, or! resinous material having elastic properties. The two halves ofthe shell designated. by l2Y and'` l2' inf Fig. 2 ofi the' drawing should bei vulcanized or cemented-toi gether` when iinislfiedtol flr-rrlly` unite them about thecenter Il.

After the core yIll" hasZ been constructed as' just described'rubber thread-is tightly wound about this core as' heretoforetoform abody l'3 of the desired size. A cover i4 which may bef formed of balata is then molded aboutl the' bodyV inl a well known manner. and the Vcover is painted and branded with the makers name or mark as heretofore.

The size and weight of golf balls have become st'ar'idardizedV andare followed carefully by golfball manufacturers. The diameter-ofthe -nished ball shouldj be 1168 inc'hesL The' other-T die mensions ofthe ball may vary'wi'del-y" depending upon the type of ball to be made. A golf ball constructed in accordance with the present invention and having a center ll about of an inch in diameterand` a core` I about 141% inches in diameter was' found t'o` perform ina very satisfactory manner. llher` body |31 of tightly wound rubber thread and cover' lllj having al thickness of several hundredths of an inch were constructed as heretofore. v

The so-calledY bouncingv putty used in the cen'- ter Il` is preferably the solid gel-like heat reac tion product ofV aV dimethyl silicone oil' with a minor portion of a compound of boron-such as pyroboric acid, boric anhydride or boric acid. This material has a specific gravity of about 1.03. It also' has pronounced cold flow properties in that al ball of this material will flow out into a thin disk in the course of' hours. It doesf not ow appreciably. underarapid-.blow butwillii'ow readily under the application of a low" steady pressure; it isalso stable throughoutaverywde temperature range'. This bouncing! putty iiiay'be used aloney to. form the Vcenter Il;A or itmay be used-with pigments,l fillersor plasticizers ern-r ployedtoincreaseit-sweight ortoV modifyr its plastic properties lorvfor other reasons.

One important result secured byusing plastici-zers is that plasticizers reduceV the tendency of the bouncing putty to shatter under a rapid Table I Composition Treatment Test No milling or heatlng. Heated and milled Shatter ed fairly easily.

Do. More diilicult to shatter. Do.

Do. Do.

o parts Bf P 100 B. P. and 100 zinc oxide.

100 B. P. and 10 zinc stearate.

100 B. P. and 10 Laurexl.

Composition of Table II given below.

do do l Laurex is a fatty acid activator and plasticizer and may be described as a zinc salt of a mixture of fatty acids in which laurxc acid predominates.

The above compositions, Aexcept the rst, as indicated were heated to melting during a .ten minute interval, stirred and then milled on a rubber mill for ten minutes to complete the mixing. They were tested by striking a small pellet, approximately A inch in diameter, a hard rapid blow with a hammer. Compositions 1 and 2 shattered fairly easily. vCompositions 3, 4, 5 and 6 were increasingly difficult to shatter in the order they are listed. One composition containing the above described bouncing putty which is found to produce a very satisfactory center is the following, the parts being by weight:

Examples of the zinc soaps of fatty acids are:

1. zinc soaps of coconut oil fatty acids 2. zinc soap of lauric acid 3. zinc soap of stearic acid Golf ball cores having a diameter of lg inches but different centers all about of an inch in diameter were dropped from a height of 100 inches onto a hard surface to test their rebound properties at a temperature of 80 F., with the following result. v

Table III Rebound, inches Core having center of 100% bouncing putty 67.8 Core having center of compound of above Table II 65.5 Core having oil capsule center 62.0

It is not entirely clear why a golf ball having a center formed of bouncing putty but otherwise constructed as heretofore should perform in such a satisfactory manner but professional golfers playing golf balls constructed in accordance with the present invention and unaware of the fact that it was? constructed differently from the balls they were familiar with have repeatedly commented upon the highly desirable properties of this ball, as to click, feel and flight. They have also compared its playing properties with the castor oil center ball above described and lbelieve it to .have properties superior thereto.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A golf ball core adapted to have rubber thread wound tightly thereupon to form the golf ball body; said core comprising a center formed of a mixture of a solid gel-like heat reaction product of a dimethyl silicone oil with a minor portion of a compound of'boron added thereto and having pronounced bouncing properties that are equal to those of good vulcanized elastic rubber and also having-puttyrlike plasticity, said mixture also containing at least about 5% of zinc soap based on the weight of said solid gel-like heat reaction product to substantially increase the shatter-resistant properties of the center and containing an inorganic 1lerand a shell of vulcanized rubber surrounding and coniining the center.

2. A golf ball core adapted to have rubber thread wound tightly thereupon to form the golf ball body; said core comprising a center formed of a mixture of a solid gel-like heat reaction product of a dimethyl silicone oil with a minor portion of a compound ofA boron added thereto and having pronounced bouncing properties that are equal to those of good 'vulcanized elastic rubber and also having putty-like plasticity, said mixture also containing at least about 5% of zinc stearate based on the Weight of said solid gel-like heat reaction product to substantially increase the shatter-resistant properties of the center and containing an inorganic filler, and a shell of vulcanized rubber surrounding and conning the center. n

3. A golf ball core adapted to have rubber thread wound tightly thereupon to form the golf ball body; said core comprising a center formed of a mixture of a'solid gel-like heat reaction product of a dimethyl silicone oil with a minor portion of a compound' of boron added thereto and having pronounced bouncing properties that are equal to those of good vulcanized elastic rubber and also having putty-like plasticity, said mixture also containing'at least about 5% of Zinc laurate based on the weight of said solid gel-like heat reaction product to substantially increase the shatter-resistant properties of the center and containing an inorganic llenand a shell of vulcanized rubber surrounding and confining the center.

FRANK S. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED sTATEs PATENTS OTHER REFERENCES The AmazingNew Chemical Family, pages 86-88, Oct. 6, 1945, The Oil and Gas Journal.

Claims (1)

1. A GOLF BALL CORE ADAPTED TO HAVE RUBBER THREAD WOUND TIGHTLY THEREUPON TO FORM THE GOLF BALL BODY; SAID CORE COMPRISING A CENTER FORMED OF A MIXTURE OF A SOLID GEL-LIKE HEAT REACTION PRODUCT OF A DIMETHYL SILICONE OIL WITH A MINOR PORTION OF A COMPOUND OF BORON ADDED THERETO AND HAVING PRONOUNCED BOUNCING PROPERTIES THAT ARE EQUAL TO THOSE OF GOOD VULCANIZED ELASTIC RUBBER AND ALSO HAVING PUTTY-LIKE PLASTICITY, SAID MIX-

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