GB2192522A - Coated fly fishing line - Google Patents

Abstract

A fly fishing line comprising a core and a substantially smooth plastic surface coating, the coating comprising a plastisol and a siloxane polymer to significantly decrease the coefficient of friction of the line and thus provide a line with greater castability, shootability and resistance to tangling, without the necessity of increasing the stiffness of the line.

Description

SPECIFICATION Fly line containing a siloxane polymer Background of the Invention This invention relates to fishing lines and more particularly-to a fishing line particularly adapted for use in fly fishing.

In fly fishing a substantially weightless hooked lure, which resembles a fly or other insect, is cast upon the water. Normally the fly or artificial lure is attached to a monofilament leader which is virtually transparent in the water and which sinks just below the surface of the water, while the fly or artificial lure remains on or just below the water surface. Attached to this leader is the line, which is typically cast with the particular weight rods used for fly fishing.

In casting the fly or artificial lure, since both are extremely light, substantially all the propelling force and momentum for the lure must necessarily come from the line itself. The use of a "heavy" line is prohibited since the line must be capable of floating on the surface of the water or sinking at a desired slow rate.

A fly fishing line of high quality should be stiff enough to throw its own weight in a substantially straight line from the end of the fly rod to the target when casting; it must be sufficiently flexible to afford good throwing and laying characteristics; it should be sufficiently hard surfaced such that it has good shootability; it should have a sufficiently tough surface that it may not become cracked or broken during use; it should have sufficiently high tensile strength and stretch without permanent elongation; it should be resistant to temperature changes, i.e. be stable at 0 C and 50"C without becoming brittle or sticky; it should be water repellent such that it need not be dried after use; it should be resilient after being creased or sharply bent, i.e., not subject to "elbowing".

Of particular importance to many fishermen are the lines shootability, its resistance to tangles, and its memory. Shootability refers to the ability of a line to easily pass through the guides of the fly rod such that a line may travel a maximum distance when cast. Memory refers to the tendency of a line to retain the configuration of the spool upon which it was wound. Thus, high memory results in a line which will not hang straight when unwound off the reel, but instead will retain curls caused by being wound about the spool.

Enhanced shootability is generally important to the fly fisherman, but particularly in the case of wary fish in clear, shallow water. In such situations the fish cannot be approached closely and long lengths- of line are required to reach the fish from a distance. Shootability is also important in other situations where the fly must be cast a great distance to reach the desired target.

Prior art fishing lines have attempted to increase shootability by increasing the stiffness of the fly line. While this can enhance shootability, it also increases the tendency of a line to crack and kink. This is especially true under colder conditions. Thus, prior art lines have had to balance flexibility and shootability.

A fly line with a low memory is also important to the fly fisherman. After a line is shot from a spool, a line with high memory will exhbit the inability to lay straight in the water, with the curved portion of the line visible to the fish below the surface of the water. The curved portion also decreases what persons in the art refer to as the "touch" of the line, as there is slack between the fly and the rod. Memory is obviously an undesirable characteristic of the line. Thus, it is desirable that a fly line have little or no memory, such that it lays in a straight line after it's release from the spool. Prior art lines which have attempted to- increase shootability by increasing stiffness have also increased memory, a clearly undesirable result.

To avoid the problems associated with a stiff line discussed above, many prior art fly fishing lines are designed to be flexible, at the expense of shootability. To increase the shootability of these flexible lines, topical dressings are frequently applied to the surface of the lines. As shootability has been a prime goal for many years, such topical dressings are well known and have been extensively used by fly fishermen.

These external dressings have many disadvantages. The dressing's effectiveness is only transitory, as they wash off with use. The application of a dressing to the line is a messy and inconvenient procedure. In addition many of these dressings actually degrade the integrity of the fly line's external surface with use. Shootability has been of such importance to many fly fishermen that they have continued to apply external dressings to their fly lines for many years despite these substantial problems.

It has now been found that by compounding a siloxane polymer into the plastic surface coating of a fly line that better castability, shootability and resistance to tangling may be achieved in a flexible line, having a decreased tendency to kink and crack, and little or no memory.

Summary of the Invention In accordance with the invention, there is provided a fly fishing line comprising a core and a substantially smooth plastic surface coating, the coating comprising a plastisol and a siloxane polymer to significantly decrease the coefficient of friction of the line.

The inclusion of the silicone polymer in the fly line of this invention provides greater castability, shootahility and resistance to tangling, without the necessity of increasing the stiffness of the line. The siloxane polymer typically migrates to the surface of the line thereby replacing any siloxane removed with use. Furthermore, the inclusion of the siloxane polymer to the plastisol does not decrease the durability of the line as might be expected, but instead increases the durability.

The siloxane polymers useful in the present invention should be present in an effective amount sufficient to significantly lower the coefficient of friction of the line without degrading the integrity of the external surface. The effective amount has been found to be from about 1 to about 5 percent by weight of the plastic coating and preferably between about 2 and about 3 percent. The viscosity of the siloxane polymer should be between about 50 and about 600,000 cst and preferably between about 200,000 and about 400,000 cst. Useful siloxanes can be represented by the following formula:

wherein X, through X8 are selected from the group consisting of -H, alkyls, aryls, and fluoroalkyls; and n is between 0 and 5500.

It is preferred that X1 through X8 are selected from the group consisting of H, methyl, ethyl, phenyl and trifluoropropyl.

The plastisol of the present invention is preferably polyvinylchloride.

Detailed Description of the Invention The invention includes a fly fishing line having a core member, which is preferably made of nylon or silk filaments braided so as to form a cylinder having a substantially uniform diameter throughout its length. In the alternative, other cylindrical, stretchable based cores may be utilized.

The base core can be treated with a uniform priming coating of adhesive material to permit satisfactory bonding of a subsequently applied plastic coating. One adhesive coating suitable for use herein is a soluble synthetic acrylonitrile-butadiene copolymer dissolved in a suitable organic solvent such as methylethylketone or methylisobutylketone. Such adhesives, typically for bonding nylon with other polymers, are known and are obtainable commercially.

Other intermediate coatings can be applied as desired, such as, for example are disclosed in U.S. Pat. No. 3,830,009 and U.K. Pat. No. 1,369,256.

Superimposed upon the priming, adhesive, or other intermediate coating, if used, or directly upon the core, is a plastic coating which comprises essentially a plastic composition containing a silicone polymer. The plastic composition must be sufficiently viscous to form a relatively thick covering or coating over the core or primer coating. In addition, as taught in U.S. Pat.

4,386,132 the plastic coating composition may also contain a fluorinated polymer derived from a fluoroaliphatic radical containing vinyl monomer and a polyoxytetramethylene acrylate or methacrylate, to impart the desired characteristics as taught in said patent.

One such composition, which is a plastisol, is comprised of a dispersion of finely divided polyvinylchloride in one or more plasticizers, as is taught in U.S. Pat. No. 3,043,045. A polyvinylchloride which will form a plastisol has a very small particle size, on the order of one micron, thereby allowing it to disperse in a plasticizer, but not to dissolve therein until heated to temperatures used for fusing, for example about 180"C. One polyvinylchloride which has proved particularly satisfactory is sold under the trade designation "Geon Paste Resin 121" manufactured by B.F. Goodrich Chemical Company and described in U.S. Pat. No. 2,188,396. However, any polyvinylchloride having a small particle size such as that sold under the trade designation "VYNV3" by the Bakelite Light Division of Union Carbide Corp. or under the trade designation "VR" by the Marvenol Company has been found suitable. In addition, other plastisols may likewise be used.

A preferred system to produce a floating fly line includes the hollow microspheroids or microballoons taught in U.S. Pat. No. 3,043,045. The microspheroids or microballoons preferably have an average diameter of from about 2 to about 60 microns. Increasing sizes tend to provide roughness to the coating, are more fragile, and make coating more difficult. Smaller sizes can adversely affect the density of the line.

Microballoons are preferably of the glass bubble type, a commercial example of which are available from the 3M Company under the designation G-18/500. However, microballoons made of other material may also be used, such as the phenolic microballoons available from the Bakelite Division of Union Carbide Corp. These microballoons may be filled with air, nitrogen, helium, or other noncondensable gases.

When the addition of microballoons is desired, they are thoroughly mixed with the plastisol composition before application to the line to insure uniform distribution throughout the mass of the plastisol. The distribution of microballooons to plastisol mixture varies depending upon the specific gravity desired for the line subsequent to the coating operations. However, in a typical example, to obtain a line having a density of .85 to .90, 1890 cc or 160 grams of G-18/500 microballoons are added for each 6.5 Ibs. of plastisol.

Regardless of the specific plastic coating formulation or floating fly line manufacture (for example, microballoons, foamed core, inert gas-containing composition, fluorinated polymer, etc.) it has been found that the inclusion therein of a silicone polymer provides improved performance of the fly line; particularly the castability, shootability and resistance to tangles, without the necessity of increasing the stiffness of the line.

The siloxane polymer should be added to the plastisol in an effective amount sufficient to significantly lower the coefficient of friction of the line without adversely effecting the integrity of the external surface of the line, determined to be from about 1 to about 5 by weight of the plastisol, preferably about 2 to 3 percent by weight of the plastisol. At concentrations below about 1 percent by weight the benefits achieved by the addition of the siloxane polymer may tend to be minimal. With concentrations greater than about 5 percent by weight the integrity of the plastic coating of the fly line may be adversely affected.

Preferred silicone polymers falling within the above formula include high viscosity polydimethylsiloxanes, in particular, the Dow Corning 200 fluids covering a wide range of viscosities from 50 to 600,000 cst. Siloxanes having a viscosity of between about 200,000 to about 400,000 cst have been found to be preferred. Those siloxane polymers having viscosities in the lower range do not increase shootability as much as higher viscosity siloxane- polymers. However, those siloxane polymers of high viscosity in the range of 600,000 cst are harder to disperse in the plastic coating. In addition, phenyl siloxanes commercially available from General Electric, Co. and trifluoropropyl siloxanes available from Down Corning can also be used.

An exemplary manufacturer of a floating fishing line of our invention would involve first coating a braided line of nylon or other material having a substantially uniform diameter with an adhesion primer coating, as previously described, to provide a suitable bond for the ultimate plastisol coating. The adhesive-coated core is then passed through a coating tank containing a polyvinyl chloride plastisol/siloxane polymer mixture. This mixture could also include microballoons uniformly distributed throughout the mass thereof. The coated line would then be passed in contact with a sizing device to obtain the proper coating thickness.

After being sized as desired, the coated line would be passed through a heating zone where the temperature of the coating reaches the fusing temperature of about 1750 to about 200"C, at which ternperature the plasticizer will solvate the polyvinyl chloride particles and the plastisol will become fused. The heating of the plastisol coating at the fusing temperature causes a hardening or setting of the coating about the core without change of dimension, and provides a relatively smooth outer surface.

The following example is submitted to more clearly illustrate the present invention, without limiting same. Unless otherwise indicated parts are enumerated by weight.

Example 1 A first premix was made by heating 11 parts Drapex 4,4, a plasticizer commercially available from Witco Chemical Co. to 125"C and then adding 2 parts of FC-324, a fluorochemical commercially vailable from 3M Company and 2 parts of Uvinul D-29, a 2,2'-dihydroxy 4,4dimethoxy benzophenone commercially available from BASF Wyandotte Corp. The first premix was then allowed to cool to about 25"C.

A second premix was made by mixing the following: 18 parts plasticizer "Santicizer" S-711, Monsanto Company 27 parts plasticizer, "Monoplex" DOA, Rohm and Haas Co.

20 parts plasticizer, "Monoplex" DOS, Rohm and Haas Co.

53 parts plasticizer, "Monoplex" S-73, Rohm and Haas Co.

228 parts polyvinylchloride, "Geon" 121, B. F.

Goodrich Chemical Co.

The first premix and the second premix were then blended together, continuing to stir, at about 25to.

Two parts of the lubricant Chlorowax 4.0, commercially available from Diamond Shamrock Corp., and mineral oil were then added. Pigment was added to achieve the desired color. The density was then adjusted to the range of from .85 to .90 by adding 12 parts by weight G 18/500 microspheres, commercially available from the 3M Company, mixing until uniform in a dough-type mixer available from Bobart. Seven parts by weight Dow Corning 300,000 cst DC200 siloxane polymer was then added (3 percent by weight of the plastisol). The plastisol was then de-aerated before further processing.

Thereafter, a braided nylon core was passed through an adhesive composition comprising an acrylonitrile-butadiene copolymer in methylethylketone solvent to form a thin layer of adhesive on the core.

After heating at about IOO'C for about 2 minutes, the adhesive-coated core was passed through the plastisol and microballoon coating mixture previously described. The coating was fused by heating to produce temperatures with the coating of about 1800 to 200"C.

There has been found to be a direct correlation between a line's shootability and its coefficient of friction, which can be quite easily tested. The line of Example 1 was compared to a line of Example 1 without the siloxane polymer (control line A) and with five other commercially available lines (control lines B through F). the coefficients of friction were obtained by running the line over a steel pin, and the reported results are the average of five samples of each line.

Coefficient Sample of Friction Example 1 0.18 Control line A 0.44 Control line B 0.40 Control line C 0.25 Control line D 0.50 Control line E 0.41 Control line F 0.37 It is clear that the fly fishing line of the present invention (Example 1) has a superior coefficient of friction to other commercially available lines.

To test the durability of a line with the siloxane polymer, a line of Example 1 was compared to a line of Example 1 without the added siloxane polymer (Control line A). The test included running the line back and forth through an eyelet with a 50 gram weight attached.

Sample Cycles to Failure Example 1 38,000 Control line A 19,000 Surprisingly, the durability of the line of the present invention (Example 1) is significantly better than that of-the identical line without the added siloxane polymer (Control line A). Conventional knowledge in the polymer art teaches that the addition of the siloxane polymer would decrease the intensity of the coating of the line and would thus decrease the durability. It is believed that this may be one of the reasons that external silicone dressings have been used for years without silicones having been included in the plastic coating of a line.

Claims (10)

1. A fly fishing line having a substantially smooth plastic surface coating comprising a plastisol and an effective amount of at (east one siloxane polymer of the following formula:

wherein X, through X8 are selected from the group consisting of -H, alkyls, aryls, and fluoroalkyls; and n is between 0 and 5500.

2. The fishing line of claim 1 wherein said siloxane polymer is present in an amount between about 1 and about 5 percent by weight of said plastisol.

3. The fishing line of claim 2 wherein said siloxane polymer is present in an amount between about 2 and about 3 percent by weight of said plastisol.

4. The fishing line of claim 1 wherein the viscosity of said siloxane polymer is between about 50 and about 600,000 cst.

5. The fishing line of claim 4 wherein the viscosity of said siloxane polymer is between about 200,000 and about 400,000 cst.

6. The fishing line of claim 1 wherein said plastic coating further comprises a multiplicity of microballoons substantially uniformly distributed throughout the length and thickness thereof, said microballoons having a diameter range of from about 2 to about 60 microns.

7. The fishing line of claim 1 wherein X, through X8 are selected from the group consisting of methyl, ethyl, phenyl, and trifluoropropyl.

8. The fishing line of claim 1 wherein said plastisol is a poly(vinyl chloride).

9. The fishing line of claim 1 further comprising at least one fluorinated polymer derived from a fluoroaliphatic radical-containing vinyl monomer and a polyoxytetramethylene acrylate or methacrylate.

10. A fishing line as claimed in Claim 1 substantially as herein described with reference to the Example.