DE1428816A1 - Balls with cores - Google Patents

Description

The invention relates to balls which have a core to which an outer cover is attached, in particular golf balls.

With such bales, the cover shell should be firmly attached to the core to prevent damage and wear is avoided when the ball is hit and the ball should also have the necessary plug properties.

According to the invention, a core for a solo ball has a practically impermeable blocking surface, which in the Is at least 0.2 mm and no more than 3 mm radially inward from the outer surface of the core.

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New documents for. 7 g 1 para, 2 no. Ϊ́ sentence 3 of the amendment «)« », v. 4.9. Γ

According to the invention, a solo golf core includes one Core middle part and an outer layer made of flexible thread material with a practically impermeable blocking surface, which at a distance ' is at least 0.2 and at most 5 mm radially inward from the outer surface of the compliant thread layer.

Cores formed in accordance with the invention are particularly useful for balls whose outer shell is made from a liquid polymer composition which, during manufacture, impregnates the outer surface of the core to a depth determined by the location of the practically impermeable barrier surface. In this way, the sheath is held by a mechanical wedging fixed to the core, said wedging is formed between that part of the core is impregnated by serving the sheath, and through the core. The cores are particularly useful in the manufacture of golf balls, the shell of which consists of a liquid polyurethane premix which, when applied to the core, is solidified into a solid, cross-linked shell which is resistant to cutting and abrasion treatment by the golf clubs.

The practically impermeable blocking surface is preferred formed to be 0.3 to 0.7 mm from the outer surface of the core, making the finished golf ball practical has the same flight characteristics as a golf ball, its

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Sheath is made of natural or synthetic gutta-percha or balata, with good adhesion between Shell and core is secured.

The term "partially impermeable barrier area" as used herein is intended to mean a surface which is at least 0.2 mm from the outer surface of the core, as already mentioned, whereby a noticeable penetration of a liquid polymer of the surface is prevented from inward. The surface can be designed in any way, for example it can have a barrier layer made of practically impermeable material, which forms part of the ¹ core, or it can contain a layer that was produced on the core in a dipping process during a certain process stage, whereby the Immersion takes place in a sealing composition, through which the core is impregnated and which, when drying, forms the practically impermeable barrier surface on the outermost surface.

As noted, the invention is particularly concerned with with a core for a golf ball and generally with a core thus formed and having a central center, which can consist of a sack filled with liquid or filled with a paste, but the core can also if desired be made of solid material. At a GoIf

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ball core made according to the invention becomes a Elastic band wrapped around the middle part in the usual way until the core has reached the desired size down to about 3 mm. A thin layer of rubber thread is then put on the surface of the tape is wound and another layer of tape is placed on the outer surface of these threads so that sioh neighboring. Ribbons of the ribbon, forming a handy Overlap impermeable surface. Another layer of thread is then wound onto the outer surface of this tape. The thickness of each thread layer is measured so that the surface of the tape that the impermeable barrier surface is at a distance of at least 0.2 mm from the outer surface of the core

Forms another embodiment of a golf ball the outer surface of the first layer of the tape is practically impermeable Restricted area. The outermost turns of the tape are placed so that they overlap and this surface and the core is completed by applying an outer layer of thread

of a core
Another lyp / ^ e ines Go If balls becomes a resilient one

Elastic thread wound onto the center of the core and further outside, At the point desired for the practically impermeable blocking area, a layer of tape is wound onto the rubber thread and the adjacent turns overlap, so that the impenetrable

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casual surface is formed. Another layer of thread is then applied to the tape layer to complete the core will.

In each of the embodiments of golf ball cores described in the three preceding paragraphs, the blocking area can be formed in different ways by impregnating the golf ball core with a sealing composition and not a blocking area is formed from adjacent, overlapping convolutions. " The golf ball core can for example, be made so that a flexible tape is wound onto the core center part to the desired depth and then winding a layer of thread onto the surface of the tape. When the thread is up to the desired thickness is wound, then the winding is stopped and the golf ball core is impregnated with a sealing composition. The surface formed in this way is then allowed to dry. The spaces between adjacent threads are covered with the Composition filled and they form the practically impermeable surface. The core can then be completed by winding another thread layer of the desired thickness onto the surface of the impregnated core.

Preferably the golf ball core, which is a practically impermeable Barrier layer has been made so that the winding of the thread is interrupted at a suitable point and

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.the core is then dipped in rubber latex and dried will. The core is then completed by wrapping another sheet of shuttering on its surface. As a rubber latex Natural rubber latex can be used and if desired A pre-vulcanized, natural rubber latex can also be used. Also aqueous dispersions synthetic rubbers can also be used »For the impregnation of the core, solutions made of synthetic Rubber can be used, but the solvent for the synthetic rubber should be such that it can does not swell noticeably or that other, deleterious effects on the rubber thread or the tape of the core occur. So can E.g. a solution of a pliable polypropylene oxide or a copolymer of butadiene and acrylonitrile can be used. preferably each with an intrinsic viscosity above 1.5, the solution being in a lower, aliphatic alcohol or ketone, e.g. in methyl ethyl ketone. After treatment with such a solution, the solvent is allowed to evaporate either by the application of heat or at room temperature.

In the golf ball covers should the sealing composition preferably form a resilient surface layer so that the finished ball has the desired flight characteristics.

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H28816

When the golf ball core is made of a rubber band in the usual way and a rubber thread is to be made, a rubber band is usually used, which is used in the manufacture of golf balls usual dimensions «For example, the tape can have a width of 0.317 om up to 1.9 cm and the Thickness can be, for example, 0.023 om. Usually one uses a thread with a width of 0.114 cm up to 0.165 cm and a corresponding bead of, for example, 0.051 cm

As previously stated, those are made in accordance with the invention Golf ball cores are particularly useful when the shell to be applied to the core has a liquid precursor Polyurethane contains, but cores that use other liquid polymers to form the shell are also useful became. Sin polyurethane precursor can consist of a liquid polyurethane prepolymer that is in the form of a viscous Liquid may be present. In general, the polyurethane prepolymer prepared by an organic polymer having -OH, or -SH groups with an organic polyisocyanate or polyisothiocyanate reacted · Such polymers are see p. Polyesters, polyethers or polyester amides which have at least two terminal or essentially terminal -OH groups contain. Polyethylene glycol adipate, for example, can be used and useful polyethers are, for example, polyglycols made from

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Propylene oxide and tetrahydrofuran are obtained. Typical polyisocyanates are haphthalene diisocyanate and toluene diisocyanate and diphenylmethane diisocyanate. The polyurethane prepolymer should be at least two terminal or substantially terminal -NÖO- groups so that when mixed with a crosslinking agent, for example a diol such as butanediol or by means of which an amine is converted to the solid state, forming an abrasion-resistant and cut-resistant shell. If the core with a watery If a dispersion of a natural or synthetic rubber is impregnated, then it should be practically anhydrous, before the cover made of the polyurethane prepolymer is applied, since the cover would otherwise have an undesirable quality in the finished state having. The polyurethane prepolymer can, if desired, with fillers such as mineral oils and with coloring agents Substances are mixed.

As already stated, the balls containing a core designed according to the invention have good flight properties and the shell adheres firmly to the core. This is particularly important for the long life of the ball, as well as for a real flight through the air «,

The cores of the invention are particularly useful in manufacture of golf balls by a method according to British patent application 18129/60 useful and even if the device is used to carry out the procedure,

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which are also described in British Patent Application 4816/62 is. The manufacturing process described in British Patent Application 18129/60 essentially consists in that a preformed ball core is held and that one made of one piece and without a pattern is solid Sheath made of a partially solidified, but essentially still thermoplastic polyurethane from a solidifiable Polyurethane prepolymer is formed and the coated ball is placed in a ball shape that has a patterned Has mold inner surface, whereupon the coated core is deformed into a patterned ball, while the polyurethane reshaped into a practically non-thermoplastic state. The pre-shaped core is preferably introduced into a mold, contains the supports with which a central position of the core is secured in the mold and the polyurethane prepolymer becomes injected under pressure into the mold cavity surrounding this preformed core. This can be done with either pumps or you can, as described in British patent application 18129/60, the shape due to its own weight move against a plunger so that the polyurethane prepolymer penetrates into the mold cavity. Another A method of coating the preformed core with the polyurethane prepolymer is to apply the coating while the core rotates slightly around its horizontal axis, with a doctor blade arranged so that the thickness of the coating is limited c

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- ίο -

Exemplary embodiments are a golf ball core and two golf ball shapes formed in accordance with the invention are shown in the drawing in which

. 1 shows a golf ball core in view, wherein a part is omitted, so that the schematically indicated structure of the core is visible.

2 shows a view of a golf ball with a golf ball according to FIG Figo 1 formed core, wherein a part is omitted so that the structure of the golf ball is visible.

! ig. Figure 3 is a partial view of a six-golf ball incorporating a another developed core contains "

As can be seen from Fig. 1, the core consists of a Core middle part 1 with a layer 2 of a rubber tape, which is made by winding the Kautsohukband on the surface of the core middle part 1 is formed. A layer 3 of rubber thread is made by winding the rubber thread onto the surface of the band and is outside the band. When the desired thickness of the rubber thread layer is reached, then the core is immersed in a pre-vulcanized, natural rubber latex that forms the spaces between the rubber threads fills, so that a barrier layer 4 on the surface of the

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Layer 3 is formed. Another layer 5 made of rubber threads is applied to the surface of the layer 3 to the desired thickness wound up and the free end 6 of the rubber thread is with attached to the body of the core by a latex drop.

Pig. Fig. 2 shows a golf ball made using the core shown in Fig. 1 and in which a cover 7 is applied to the core from a polyurethane composition · As can be seen from the figure, the layer 5 is sufficient Chews up to the barrier layer 4.

The golf ball shown in Fig. 3 consists of a core middle part, not shown in the drawing, and a layer of a cheesecloth band, which is also not shown and that, as in the embodiment of FIG. 1, is wound around the core middle part. A layer of chewing thread 8 is on wound the surface of the chewing tape ply and when the the desired thickness is reached, then another layer 9 of a chewing tape on the surface of the layer 8 of the Rubber thread wound so that a practically impermeable barrier layer is formed. Another layer of chewing thread 10 is then wound onto the rubber tape ply 9. The chewing thread layer 10 is impregnated and securely through the shell consisting of a polyurethane composition a mechanical locking effect is held at this layer 10

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The invention is explained below using an example j.

example

A number of golf ball cores have been made by a layer of rubber tape wound onto a core center part filled with paste, and then a chewing thread on it the tape has been wound up in the usual way until the diameter of the core was 3 »8 cm. The end of the thread was then secured by placing a drop of rubber latex on it was given.

A pre-vulcanized, natural rubber latex was made from the following ingredients?

Parts dry

Natural rubber 100

Sulfur 1

Zinc diethyl dithiocarbamate 0.8

Casein 0.05

Potassium hydroxide x 0.01

The Uaturkautaohuk was in the form of a centrifuged latex with a pesticide content of $ 60 and the sulfur

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and zinc diethyl dithiocarbamate as 50 # dispersions used in water. The casein was in the shape of a $ 12.5 Dispersion in water and the potassium hydroxide in the form of a 25 #igen dispersion (solution) in water.

The constituents were mixed with one another in the form of dispersions and ^{heated at 80 0} O for two hours, so that the pre-vulcanization took place. The resulting latex was cooled to room temperature as quickly as possible and the total solids content was 61% . The latex was then diluted with water to a total solids content of $ 17

The cores were then dipped into this precured, diluted latex and allowed to dry. The weight of one Each core gained 0.6 g after immersion.

A further layer of chewing thread was wound onto the cores treated in this way until the core became one Had a durometer of 4.06 cm and was the end of the thread attached with a drop of rubber latex.

A core produced in this way was then introduced into the mold halves of an injection mold, which was then inserted into a shell and a retaining plate was attached to one end of the sheath. The mold halves, the shell and the holding

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plate correspond to those in the British patent application 18129/60 and in Piguren 1 and 2 of this application Share.,

Titanium dioxide (anatase modification) was ^{dried at HO 0} O for 1 hour. After drying, the titanium dioxide was allowed to cool to room temperature in a closed container. The titanium dioxide was then mixed with twice its weight of methylene-bis- (ortho-chloroaniline) (MOCA) as a crosslinking agent and the mixture in a ball mill for 24 hours treated so that the aggregates of titanium dioxide broke open o The mixture of MOCA / titanium dioxide was placed in a container, which was then evacuated and heated ^{to 140 0 O in an oil bath, for example.} The MOCA melted and dissolved gas was removed. The vacuum was then broken and the mixture was stored in an oven in a closed container at 110 °. Immediately prior to use, the mixture was stirred vigorously to redisperse the titanium dioxide in the liquid MOCA.

30 parts of the prepared mixture consisting of MOCA and titanium dioxide were added at 110 ^° C. to 100 parts of a liquid polyurethane prepolymer made from polytetrahydrofuran and toluene diisocyanate, the prepolymer being at room temperature and the mixture being vigorously stirred. The polyurethane prepolymer was as little as

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possibly exposed to the Iaift, thus reacting with the humidity was avoided. The mixture was then held under vacuum for 2 minutes to remove dissolved gas

The molding apparatus was maintained at 100 ⁰ C and degassed syrup was poured into einetf transfer cavity of the mold and a plunger in said cavity employed. The mold was then turned over and it was able to lock itself against the plunger under its own weight. As a result, the syrup was pressed into the mold cavity which surrounds the core and after this cavity had been filled, it began to flow from the opening in the upper part into a hole in the holding plate. When the plunger touched the end of the transmission cavity, then the mold assembly was placed 6 1/2 minutes in a heated at 110 ⁰ C oven. The mold assembly was then ^{cooled with water to about 10 0} C and the ball removed from the mold. The preformed ball, from which the sprues had been removed, was then placed in a standard, cold golf ball mold with the usual pattern and the mold was placed between plates heated to 100 ° C. Final curing or vulcanization was continued for 10 minutes, and then the golf ball was taken out of the mold.

For comparison, a number of golf balls were combined in a corresponding manner with a corresponding polyurethane

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settlement, but the cores were not in the natural rubber latex dipped. Such balls are referred to below as comparison balls. Both types of golf balls were stored for a few days after the final deformation, so that the polyurethane shell harden and in the final state could pass over.

Plug tests were carried out with both types of balls and the results are compiled in the following table, in which the values are given in fo and are based on a value that can be achieved with a known golf ball with a gutta-percha cover «

Tabel

Scope of overall flight distraction

fo ■ <fo <fo

Comparison ball 94-102 86

Treated core ball 99.5 102 99.5

From the table above it can be seen that the balls made according to the invention are practically the same Have properties like balls with a gutta-percha cover, while those made without latex impregnation of the core Golf balls have much worse properties

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than the well-known golf balls. In the table above means
"Range" means the distance between the sole layer and the first impact, while "Total flight" means the total distance that the ball travels through the air and on the ground. "Deviation" means the amount up to which the
Ball rose

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Claims (2)

H28816 claims 1.J golf ball with a core and an outer cover layer that includes the nucleus, this nucleus being a ** j. Has inside part, which is enveloped by at least one resilient layer made of rubber tape and / or rubber thread, and wherein the cover layer is formed from a polyurethane mass, characterized in that the layer or layers are made of rubber tape and / or rubber thread (2,3,5,8,9) with a barrier layer. (4j9) is / are provided that are practically impermeable to the material is that the outer cover layer (7,11) forms that the barrier layer (4,9) »which by dipping the core is formed in a rubber latex and at a distance of at least 0.2 mm and not more than 3 mm radially inward from the outer surface of the core is firmly adhered to the core, and that at the same time the original suspension of the Core is essentially retained. 2. Golf ball according to claim 1, characterized in that the barrier layer (4,9) at a distance of 0.3 to 0.7 mm radially lying inward from the outer surface of the core 3. Golf ball according to claim 1 or 2, characterized in that the core has an outer layer made of rubber thread. 9 09818/0017