KR101656963B1 - Reinforced rubber article with tape elements - Google Patents

Abstract

A reinforced rubber article comprising a rubber product and a fiber layer embedded in the rubber product is disclosed. The fiber layer is, contains at least about 5 or more non-drawing, a uniaxial drawing a tape element of about modulus 2GPa or more, rectangular with a first layer having a 0.85g / cm ³ density of cross-section. The first layer contains a polymer selected from the group consisting of polyamides, polyesters and copolymers thereof. A method of making a reinforced rubber article is also disclosed.

Description

≪ Desc / Clms Page number 1 > REINFORCED RUBBER ARTICLE WITH TAPE ELEMENTS <

The present invention relates generally to fiber reinforced rubber products.

Reinforced rubber products are used in a wide variety of consumer and industrial applications. The performance of the reinforced molded rubber product depends on the adhesion of the stiffener to the rubber. Fabrics made of synthetic yarn tend to be difficult to bond to rubber.

Indeed, several attempts have been made to improve the adhesion, most of which involve coating the fibers and / or fabric with an adhesion promoter. For example, a spin finish can be applied that can contain an adhesion activator such as an epoxy resin when the fibers are drawn.

There is still a need for reinforced rubber products having fiber layers with improved adhesion due to fiber geometry and other physical properties in addition to adhesion promoting agents.

The reinforced rubber product contains a fiber layer embedded in the rubber product and the rubber product. Fiber layer contains a rectangular cross-section and at least about 5 or more drawing ratio, more than about 2GPa modulus, uniaxial drawn tape elements having a first layer having a 0.85g / cm ³ density or more. The first layer contains a polymer selected from the group consisting of polyamides, polyesters, and copolymers thereof. A method of making a reinforced rubber article is also disclosed.

Figure 1 schematically shows a fiber layer which is a fabric embedded in rubber.
Fig. 2 is a sectional view of a pneumatic radial tire. Fig.
Figures 3 and 4 show a reinforced rubber product that is a hose.
Figure 5 schematically illustrates one embodiment of an air spring containing a tape element.
Figure 6 schematically shows an embodiment of an exemplary tape element with one layer.
Figure 7 schematically shows an embodiment of an exemplary tape element with two layers.
Figure 8 schematically shows an embodiment of an exemplary tape element with three layers.
Figure 9 schematically illustrates an embodiment of an exemplary tape element having voids and surface crevices.
10 is a micrograph at 50,000 times magnification of the cross-section of one embodiment of fiber containing voids.
11A is a micrograph at 20,000 magnifications of a cross-section of one embodiment of a fiber containing pore and void-initiating particles, showing some diameter measurements of the pore.
11B is a micrograph at 20,000 times magnification of a cross section of one embodiment of fiber containing pore and void-evoked particles, showing some length measurements of the pores.
12 is a photomicrograph at 1,000 times magnification of the surface of one embodiment of a fiber having cracks.
13 is a micrograph at 20,000 times magnification of the surface of one embodiment of a fiber having cracks.
14 is a micrograph at 100,000 times magnification of the surface of one embodiment of a fiber having cracks.
Figure 15 schematically illustrates one embodiment of a fabric made from a tape element.

Figure 1 shows a reinforced rubber product 200 containing a fiber layer 100 embedded in a rubber 220. The fiber layer (100) contains a plurality of fibers (10). The reinforced rubber product 200 may be any rubber reinforced fiber product, such as a tire, belt, air spring, hose, and the like.

Referring now to FIG. 2, one embodiment of a reinforced rubber product 200 is shown, which is a tire including a side wall 303 connected to a tread 305 by a shoulder. The tire (200) includes a carcass (301) covered by a tread (305). In Fig. 2, the tire 200 is a radial tire. However, the present invention is not limited to radial tires, and can be applied to other tire structures. The carcass 301 is provided with one or more belt ply 334 located around the circumference of the tire cord 312 in the area of the tread 305 and a tire 314 terminated at the inner periphery of the tire at the metal bead 307 Is made of one or more plies of the cord (312). The carcass 301 is configured such that the reinforcing cords 311 extend substantially radially in the intended rotational direction R of the tire 200. The belt ply 334 is made of a relatively unstable warp material 331, such as a steel core reinforcing warp that leads to the tire in its intended rotational direction R or more typically at a slight angle thereto. The angle of the inhomogeneous warp material 331 may vary depending on the configuration or application method. A breaker 330 extends across the width of the tread 305 of the tire and terminates at an edge 332 of the tire section 220 where the tread 305 meets the side wall 303. [

A cap ply layer 343 is positioned between the belt ply 334 and the tread 305. The illustrated cap layer 343 is made of a cap ply tape 342 that is wrapped around the tire cord 312 in the direction in which the tire is rolled and extends over the edge 332 of the belt ply 334. In addition, the cap ply tape 342 of Fig. 2 can be wound around the tire cord 312 a plurality of times to reduce the imbalance effect in the tire 200 caused by overlapping overlap. Alternatively, the cap overlayer 343 may be formed from the cap ply tape 342 extending over the edge 322 of the belt ply 334, or alternatively, the cap ply layer 343 may be formed from the cap ply tape 342 in a flat spiral pattern, The cap overlayer 343 can be manufactured from the cap-folded tape 342 wound around. Some suitable cap-ply fabrics are described in U.S. Patent Nos. 7,252,129, 7,614,436 and 7,931,062, each of which is incorporated herein by reference.

Above the bead 307 is a bead apex 310 and it is the flipper 320 that at least partially surrounds the bead 307 and the apte 310. The flipper 320 is a fabric layer disposed around the bead 307 and also inside the portion of the turn-up end 330. A chipper 340 is disposed adjacent to the portion of the ply 330 wound around the bead 307. More specifically, the chippers 340 are disposed on the opposite side of the "turn-up end" 330 folds from the flipper 320. The sidewalls may also include other fabric layers not shown, such as chafer fabrics extending from the beads to the sides of the sidewalls, extending from the treads below the sidewalls, in the shoulder area, or completely covering the sidewalls, Protective fabrics or fabrics may also be wrapped around the beads. Any fabric that extends between the bead and tread is herein defined as a "sidewall fabric. &Quot; This includes a fabric, such as a flipper fabric, that also extends into the interior of the tire around the bead, as long as at least a portion of the fabric is positioned between the bead and the tread.

The tire carcass is required to have significant strength in the radial direction from the bead to the bead across the direction of rotation during use. To provide this strength, a fabric stabilizing material (also known as a tire cord) is typically formed from a pre-warp yarn that is pulled and tensioned during the fabric manufacturing process and / or finishing process, leading to a warp direction (also known as & Having a fabric with substantially inhaled, high-tenacity yarn under pressure. The fabric is then cut in the transverse machine direction (i.e., across the warp yarn). The individual fabric pieces are then rotated 90 ° and assembled together to place the high-strength warp yarns in the carcass so that they are oriented in the desired radial direction between the beads. Therefore, in the final structure, the weft yarns are oriented substantially circumferentially (i.e., in the rotational direction).

In another embodiment, the carcass stabilizing fabric is made of a warp knitted weft insertion fabric having a weft inserted yarn made of a relatively inhomogeneous reinforcing cord. Alternatively, the carcass stabilizing fabric may be a fabric having a relatively inhomogeneous reinforcing cord or a weft yarn made of laid scrim. More information on this stabilizing fabric with relatively inhomogeneous reinforcement cords in the weft direction of the fabric can be found in U.S. Patent Application No. 12 / 836,256, filed on July 14, 2010, which is incorporated herein by reference .

The fiber layer 100 of the tire (reinforced rubber product 200) of FIG. 2 may be formed from a variety of materials including, but not limited to, cap ply, carcass ply, shear ply, flipper, clipper, body ply, shoulder ply, belt ply, Belt edge wraps, or any other fiber layer in the tire.

Referring now to Figures 3 and 4, a reinforced rubber product 200 in the form of a fabric-reinforced hose is shown. One of the most widely deployed and most suitable conventional hoses is the so-called "mesh-reinforced" type, in which the fiber layer 100 is formed by a spirally wound yarn on a flexible hose forming two sets of yarns The first set of which is a fabric "mesh" having diamond-like cells superimposed on an equal number of transverse threads along parallel equidistant lines in parallel equidistant rows and arranged symmetrically about the axis of the tubular body of the hose, . Any other suitable fiber layer 100 may be used in the hose. The fiber layer 100 is embedded in the rubber 220. In addition to the hose, the fibers and fiber layers can be used to reinforce any other suitable rubber product, including power transmission belts, printer blanket, and belts such as tubes.

Some other reinforced rubber products 200 include a print blanket and a power transmission belt. In offset lithography, a typical function of a printing blanket is to transfer printing ink from a printing plate to a product, such as paper, which is printed, so that the printing blanket is repeatedly in contact with the associated printing plate and the paper to be printed. The printer blanket typically includes a fabric embedded in a rubber. Power transmission belts and other types of belts also contain rubber reinforced with fibers.

The pneumatic spring, commonly referred to as an air spring, is used to absorb shock loads applied to the axle by a wheel that hits an object in the road or falls into a recess in the road, in order to provide a buffer between moveable parts of the vehicle. . These air springs typically include a source of compressed air or other fluid and may include a flexible elastomeric sleeve or bellows having one or more pistons positioned within the flexible sleeve to cause compression and expansion when the vehicle experiences a path impact. ). The piston causes compression and expansion within the spring sleeve, and the sleeve is a flexible material that allows the piston to move axially relative to one another within the sleeve. The distal end of the sleeve is typically hermetically connected to the piston or end member and is configured to allow one or more of the end members to move axially relative to each other between the oscillated or collapsed position and the recoil or extended position without damaging the flexible sleeve Have dried ends.

It is desirable to use a braking machine or device with such an air spring to provide braking for controlling the movement of the air spring. In one embodiment, a rubber reinforced product is used for the air spring. In some embodiments, the rubber-reinforced product is used as a spacer for a piston or as a bead plate of an air spring assembly.

Fig. 5 schematically shows a reinforced rubber article 200 that is a sleeve in one type of air spring 400. Fig. The fibers 10, preferably the tape element 10, are embedded in rubber to form a sleeve 200 that serves to reduce vibration of the car and other machinery. In Figure 5, the sleeve 200 has two ends, an upper end 405 connected to the end cap 401 and a lower end 406 connected to the piston 402. One variation of the air spring 400 is shown, but the reinforced rubber article 200 can be used in any air spring structure. The cross-section of the fiber as the tape element 10 can be seen in the cut-away view of the air spring 400 as the tape element 10 is oriented in the circumferential direction within the sleeve 403. This circumferential direction of the tape element imparts stiffness to the structure.

A fiber layer (100) is formed from the fiber (10). The fibers 10 may be any fibers suitable for end use. As used herein, "fiber" is defined as a long body. The fibers may have any suitable cross-section, such as circular, multi-branched, square or rectangular (tape) and ovoid. In one embodiment, the fibers are tape elements 10. The tape element may have a rectangular or square cross section. These tape elements can also often be referred to as ribbons, strips, tapes, tape fibers, and the like.

One embodiment of a fiber that is a tape element is shown in Fig. In this embodiment, the tape element 10 contains a first layer 12 having an upper surface 12a and a lower surface 12b. In one embodiment, the tape element 10 has a rectangular cross-section. The tape element is believed to have a rectangular or square cross section, although one or more of the corners of the rectangle / square may be slightly rounded or the opposite sides may not be perfectly parallel. Having a rectangular cross-section is desirable for some applications for a variety of reasons. First, the surface that can be used for bonding is larger. Second, during the de-bonding process, the overall width of the tape is under tension and the shear point is significantly reduced or eliminated. In contrast, multifilament yarns have very few zones under tension, and there is a region where the ratio of tension to shear varies along the circumference of the fibers. In another embodiment, the cross section of the tape element 10 is square or approximately square. Having a square cross section may also be desirable in some cases, by having a smaller width and a greater thickness, thereby stacking more tapes at a given width to increase the load bearing capacity of the entire reinforcing element.

In one embodiment, the tape element has a width of about 0.1 to 6 mm, more preferably about 0.2 to 4 mm, and more preferably about 0.3 to 2 mm. In another embodiment, the tape element has a thickness of from about 0.02 to 1 mm, more preferably from about 0.03 to 0.5 mm, and more preferably from about 0.04 to 0.3 mm. In one embodiment, the tape element has a width of about 1 mm and a thickness of about 0.07 mm.

The first layer 12 of the fibers 10 can be any suitably orientable thermoplastic (meaning that the fibers can be oriented). Some thermoplastics suitable for the first layer include polyamides, co-polyamides, polyesters, co-polyesters, polycarbonates, polyimides and other orientable thermoplastic polymers. In one embodiment, the first layer contains a polyamide, a polyester and / or a copolymer thereof. In one embodiment, the first layer contains a polyamide or polyamide copolymer. Polyamides are preferred for some applications because they have high strength, high modulus, high temperature retention properties and fatigue performance. In another embodiment, the first layer contains a polyester or polyester copolymer. Polyester is preferred for some applications because it has high modulus, low shrinkage and excellent temperature performance.

In one embodiment, the first layer 12 of the tape element 10 is a blend of polyester and nylon 6. The polyester is preferably polyethylene terephthalate. Polyester is used because of its high modulus and high glass transition temperature, which has resulted in the use of polyester in tire cords and rubber-reinforced cords due mainly to its flat-spotting resistance. Nylon 6 is used for a variety of reasons. It is easier to process than nylon 6 6. One of the main reasons for incorporating nylon 6 in these embodiments is that it acts as an adhesion promoter. Nylon 6 has a surface group in which the resorcinol formaldehyde latex forms a major chemical bond through the resol group. This blend is not a physical blend but a copolymer and is incompatible with polyester and nylon 6. In one embodiment, the powder or felt of polyester and nylon 6 is simply mixed in an unmelted state to form a blend that is fed to the extruder. The tape element extruded from this physical blend provides excellent adhesion to the rubber and high modulus.

Nylon 6 polymerization also produces miscibility of polyester and nylon 6 by producing a certain amount of unreacted monomer lactam which acts as comonomer. The methylene-ester interactions allow the binary blend to tolerate a large difference in methylene content before phase separation takes place. In blends with large differences in methylene groups (as in this case), miscibility caused by entropy can occur if the fragment interaction parameter of the blend is less than the threshold value. Although some phase separation and crystallization of the phase separation element can be avoided, it appears that the majority of the tape elements can be homogeneously mixed. Nylon 6 6 is undesirable for use due to the large phase separation at a relatively low volume fraction of nylon 6 6 in the polyester. This can be attributed to several reasons. Nylon 6 6 has a higher degree of polymerization than nylon 6. Second, the crystallization rate of nylon 6 6 is much higher than that of nylon 6. This is due to the fact that the nylon 6 6 with symmetrical arrangement can be incorporated into the crystal lattice much more easily than the nylon 6 chain, which must be packed in the antiparallel chain for complete hydrogen bonding.

There is also a unique reason for the particular process utilized to advantage in extruding and drawing the blended polymer. As mentioned above, some amount of phase separation can be avoided. If the size of the extrudate is too small, as in the case of single-filament and multi-filament spinneret holes, the element can not be drawn and can not be extruded. This is not a problem in this particular process because the process is similar to the film pull process, which can tolerate a small degree of phase separation and crystallization of these phases without creating a fully separated region due to the wide slot die opening to be.

In one embodiment, the blend of polyester and nylon 6 contains about 50 to 99 wt% polyester and about 50 to 1 wt% nylon 6. More preferably, the blend of polyester and nylon 6 contains about 60 to 95 wt% polyester and about 40 to 5 wt% nylon 6. Most preferably, the blend of polyester and nylon 6 contains about 70-90 wt% polyester and about 30-10 wt% nylon 6. A weight ratio outside the specified range results in excessive phase separation and crystallization in the extrudate quench tank, so that the element is separated from the main extrudate. The weight ratios beyond these areas require special compatibilizers such as excess lactam monomer and co-polyester.

In one embodiment, the tape element is preferably preferably from about 5 or drawing ratio, a modulus of at least about 2GPa and about 1.2g / cm ³ density or more. In another embodiment, the first layer has a draw ratio of about 6 or greater. In another embodiment, the first layer has a modulus of at least about 3 GPa or at least about 4 GPa. In another embodiment, the first layer has a density of about 1.3 g / cm < ³ > or greater and a modulus of about 9 GPa. The first layer with a high modulus is desirable for better performance in applications such as tire cords, cap ply, overlay or carcass ply for tires. The lower density of these fibers is desirable for obtaining lower weights. Fiber with voids generally tends to have a lower density than fibers without voids.

In one embodiment, the fibers contain a second layer as shown in Fig. Figure 7 shows a fiber 10 having a first layer 12 having a top surface 12a and a bottom surface 12b and a second layer 14 on the top surface 12a of the first layer 12. On the lower surface 12b of the first layer 12 there can be an additional third layer 16 as shown in Fig. Although the second layer 14 and the third layer 16 are shown on the fiber 10 being a tape element of rectangular cross section, the second and / or third layer may be on any shape of the fibers . In the case where the second layer 14 and the third layer 16 are applied to the flat surface-free fibers, the upper half of the circumference is referred to as the "upper" surface and the lower half of the circumference is referred to as the "lower" surface.

The optional second layer 14 and third layer 16 may be formed simultaneously with the first layer in a process such as co-extrusion, or may be applied after the first layer 12 is formed in a process such as coating. The second and third layers preferably contain the same class of polymers as the polymers of the first layer, but may also contain additional polymers. In one embodiment, the second and / or third layer contain a block isocyanate polymer. The second layer 14 and the third layer 16 may help adhere the fibers to the rubber. Preferably, the melting point (T _m ) of the first layer 12 is higher than the T _m of the second layer 14 and the third layer 16.

In one embodiment, the fibers 10 (preferably, the tape element 10) contain a plurality of voids. Figure 9 shows a fiber 10 having a first layer 12 containing a plurality of voids 20. 10 is a micrograph at 50,000 times magnification of the cross-section of one embodiment of fiber containing voids. "Pore" is used herein to mean that there are no solid and liquid materials added, but "pores" may contain gas. Although it has been commonly accepted that fibers with voids may not have the physical properties required for use as a reinforcing material in rubber products, fibers with voids have been found to have some unique advantages. First, the existence of voids in the fibers requires sacrificing polymeric materials. This means that the density of these fibers is lower than that of fibers not having voids. The volume fraction of voids determines the percentage of fiber density that is lower than the polymer resin. Second, the void acts as a bladder for the adhesion promoter to be injected into the fiber having the voided layer / void to provide a fixing effect. Third, the shape of these pores can suppress the tip of crack propagation in the case of fatigue. The extra surface available for crack propagation reduces the loss of stress specificity in the case of periodic fatigue, including tensile and / or compressive loads. In the case of the thermoplastic polymer constituting the first layer 12 of the fibers 10, the high shear flows to the strand orientation and elongation during the excessive drawing of the layer to form regions or voids lacking the presence of the polymer. The pores may be present in any or all of the layers 12,14, 16 of the fibers 10. [ In addition, the fiber layer 100 may contain some fibers that do not have voids and some that have voids.

The pores 20 typically have a needle-like shape, which means that the diameter of the cross-section of the pores perpendicular to the fiber length is much smaller than the length of the pores due to the uniaxial orientation of the fibers. This shape is attributable to the uniaxial pullout characteristic of the fiber 10.

In one embodiment, the voids are present in the fibers in an amount of about 3 to 20% by volume. In another embodiment, the pores are present in the fibers in an amount of about 3 to 18% by volume, about 3 to 15% by volume, 5 to 18% by volume, or about 5 to 10% by volume. Density is inversely proportional to void volume. For example, if the pore volume is 10%, the density is reduced by 10%. The density reduction results in an increase in the nodal strength and modulus of the fibers, which is desirable for some applications, such as high performance tire reinforcements, because the increase in porosity is typically observed at higher draw ratios (which cause higher strengths).

In one embodiment, the size of the pores to be formed has a diameter of about 50 to 400 nm, more preferably 100 to 200 nm, and a length of about 1 to 6 microns, more preferably about 2 to 3 microns.

The voids 20 of the fibers 10 can be formed during the uniaxial orientation process without additional material, which means that the voids do not contain any pore-forming particles. The orientation of the fiber bundle is the driving factor of the origin of the voids in the fiber. Slippage between semi-molten materials is believed to result in pore formation. The number density of voids depends on the viscoelasticity of the polymer element. The uniformity of the pores along the transverse width of the oriented fibers depends on whether the complete polymer element is oriented in the drawing process along the machine direction. In order for the complete polymer element to be oriented in the drawing process, it has been found that heat must be effectively transferred from the heating element (which may be water, air, infrared, electricity, etc.) to the polymer fiber. Typically, in an industrial process using high temperature air convection heating, the possible way to keep the industrial speed while still orienting the polymer fibers is to limit the polymer fibers in terms of their width and thickness. This means that complete orientation along the machine direction can be achieved more easily when polymer fibers are extruded through a slot die or when the polymer is extruded through a film die and then slit narrowly before orientation.

In another embodiment, the fibers 10 contain pore-forming particles. The void-evolving particles can be any suitable particle. The void-inducing particles remain in the finished fiber, and the physical properties of the particles are selected according to the desired physical properties of the resulting fibers. When void-induced particles are present in the first layer 12, the stress to the layer (e.g., uniaxial orientation) increases or elongates the defects caused by the particles to cause voids around the defects in the orientation direction There is a tendency to elongate. The size and ultimate physical properties of the voids depend on the degree and balance of orientation, the stretching temperature and rate, the crystallization kinetics and the size distribution of the particles. The particles may be inorganic or organic and may have any shape, such as spherical, platelet or irregular. In one embodiment, the pore-generating particles are present in an amount of about 2 to 15 weight percent of the fibers. In another embodiment, the pore-generating particles are present in an amount of about 5 to 10 weight percent of the fibers. In another embodiment, the pore-generating particles are present in an amount of about 5 to 10 weight percent of the first layer.

In one preferred embodiment, the pore-generating particle is a nanoclay. In one embodiment, the nano-clay is a clayite having 10% of the clay has a lateral dimension of less than 2 占 퐉, 50% of the lateral dimension of less than 6 占 퐉 and 90% of the lateral dimension of less than 13 占 퐉 cloisite. The density of the nano-clay is about 1.98 g / cm ³ . Nano-clays may be desirable for some applications for a variety of reasons. First, nanoclays have excellent miscibility with various polymers, especially polyamides. Second, the high aspect ratio of nano-clay is presumed to improve some mechanical properties due to preferential orientation in the machine direction. In one embodiment, the nano-clay is present in an amount of about 5 to 10% by weight of the fibers. In another embodiment, the nanoclay is present in an amount of about 5 to 10 weight percent of the first layer. 11A is a micrograph at 20,000 magnifications of a cross-section of one embodiment containing pore and void-evoked particles, showing some diameter measurements of the pore, and FIG. 11B is a micrograph of pore and pore- Lt; RTI ID = 0.0 > 20,000 < / RTI >

The second layer 14 and the third layer 16 of the fibers 10 may have voids or may have substantially no voids. Having an outer shell layer (second layer 14 and third layer 16) that has no voids is advantageous because the outer layer reduces the ambient effect of the extrusion process on the inner first layer 12, Lt; RTI ID = 0.0 > 12 < / RTI > In one embodiment, the second layer 14 and / or the third layer 16 contain pore-generating particles, pores and surface cracks, while the first layer 12 contains pores, but the pore- .

Referring again to Figure 6, in another embodiment, the fibers 10 contain cracks 40 on one or more outermost surfaces (upper surface 10a or lower surface 10b) of the fibers 10 . The upper surface 10a of the fiber 10 corresponds to the upper surface 12a of the first layer 12 and the lower surface 10b of the fiber layer 10 corresponds to the upper surface 12a of the first layer 12. In the case where the fiber 10 contains only the first layer, Corresponds to the lower surface 12b of the first layer 12. The cracks can also be present in the second layer 14 and / or the third layer 16 forming the outermost surface of the fibers 10 if present. 12 is a photomicrograph at 1,000 times magnification of the surface of one embodiment of a fiber having cracks. 13 is a micrograph at 20,000 times magnification of the surface of one embodiment of a fiber having cracks.

Cracks, also known as bones, channels or grooves, are oriented along the length of the fibers 10 in the uniaxial orientation direction. The average size of these cracks is approximately 300 μm to 1000 μm in length and is present at a frequency of about 5 to 9 cracks / mm ² as shown in FIG. 14 taken at 100,000 times magnification. Cracks are formed when defects are present on the surface of the fiber during the drawing or orientation process. In some embodiments, nanoclay particles or agglomerated nanoclay particles can act as an induced bond. When nano-clay particles are present in the polymeric element, the orientation of the polymeric element is directed around the leading edge of the crack and is propagated along the tip in the machine orientation direction to form a crack.

In one embodiment, cracks are formed by the pore-generating particles. Preferably, the cracks are formed from nanoclay pore-generating particles. Surface defects such as cracks are typically seen as defects and are minimized or eliminated in the fiber, but when the fibers in the fiber layer are coated with an adhesion promoter, the fibers 10 with cracks 40 are excellent for the rubber when embedded in rubber Adhesive strength. Without wishing to be bound by any particular theory, it is believed that the adhesion promoter is at least partially impregnated and filled with cracks to form a solid portion and to improve the adhesion between the fiber and the rubber. In practice, when tested, the bond between the rubber and the rubber itself is destroyed before the bond between the fiber and the rubber is broken.

Referring again to FIG. 1, fiber layer 100 containing fibers 10 may be any suitable fiber layer, such as a knit, woven, non-woven and unidirectional fabric. Preferably, the fiber layer 100 has a structure that is sufficiently open to permit subsequent coatings (e.g., rubber) to pass through the fiber layer 100, thereby minimizing the formation of windowpanes.

In one embodiment, the fiber layer is a fabric, such as plain weave, water weave, twill weave, basket-weave, poplin weave, jacquard weave and crepe weave fabrics. Preferably, the fabric is a plain fabric. Weaving has been found to have excellent wear and abrasion characteristics. Twill weights have been found to have good properties in composite curves and may be desirable for rubber products as well.

In another embodiment, the fiber layer may be a knitted fabric such as a circular knitted fabric, a circular knitted fabric, a reverse plate circular knitted fabric, a double knitted fabric, a single jersey knitted fabric, a 2-terminal fleece knitted fabric, a 3-terminal fleece knitted fabric, a terry knit or a double- , Warp knitted warp knitted fabrics, warp knitted fabrics, and warp knitted fabrics with or without microdenier surfaces.

In another embodiment, the fiber layer 100 is a multiaxial fabric (knitted, woven or nonwoven), such as three-axis. In another embodiment, the fiber layer 100 is a biased fabric. In another embodiment, the fiber layer 100 is a nonwoven. The term nonwoven refers to a structure incorporating entangled / entangled or thermally fused yarn masses to provide an integrated structure having some degree of internal bonding. The nonwoven for use as the fiber layer 100 may be manufactured from a number of processes such as, for example, a melt spinning process, a hydroentangling process, a mechanical entangling process, a stitch-binding process, and the like.

In another embodiment, the fiber layer 100 is unidirectional, may have overlapping fibers, or may have gaps between fibers. In one embodiment, the fibers are continuously wound around the rubber article to form a unidirectional fiber layer. In some embodiments, a gap may be introduced between the fibers to allow the rubber to leak slightly between the fibers, which may be beneficial for adhesion.

In one example, the fiber layer 100 of FIG. 1 is a fabric (shown as a tape element 10 having a square cross section in FIG. 15) embedded in rubber such that all shown are the ends of the fibers 10.

In another embodiment, the fiber layer 100 contains yarns having different compositions, sizes and / or shapes for the fibers and / or fibers 10. These additional fibers include polyamide, aramid (including meta and para forms), rayon, PVA (polyvinyl alcohol), polyester, polyolefin, polyvinyl, nylon (including nylon 6, nylon 6,6, and nylon 4,6) , Polyethylene naphthalate (PEN), cotton, steel, carbon fiberglass, steel, polyacrylic, polytrimethylene terephthalate (PTT), polycyclohexanedimethylene terephthalate (PCT), polybutylene terephthalate ), PET modified with polyethylene glycol (PEG), polylactic acid (PLA), polytrimethylene terephthalate, nylon (including nylon 6 and nylon 6,6); Regenerated cellulose (e.g., rayon or Tencel); Elastomeric materials such as spandex; High performance fibers such as polyaramid; And polyimide natural fibers such as cotton, linen, ramie and hemp; Protein materials such as silk, wool and other animal hair, such as angora, alpaca and vicuna; But are not limited to, fiber reinforced polymers, thermoset polymers, blends thereof, and mixtures thereof. These additional fibers / yarns can be used, for example, in the warp direction of the fabric fiber layer 100, and the fibers 10 are used in the weft direction.

In one embodiment, the fibers are at least partially surrounded by an adhesion promoter. A common problem in making rubber composites is to maintain good adhesion between the rubber and the fiber and fiber layers. A common way to promote adhesion between rubber and fiber is to pre-treat the yarn with an adhesive layer typically produced from a mixture of rubber latex and phenol-formaldehyde condensation product (where phenol is almost always resorcinol). This is the so-called "RFL" (resorcinol-formaldehyde-latex) process. The resorcinol-formaldehyde latex may contain vinylpyridine latex, styrene butadiene latex, wax, filler and / or other additives. As used herein, "adhesive layer" includes RFL medications and other non-RFL rubber adhesive medications.

In one embodiment, the adhesive agent is not an RFL drug. In one embodiment, the adhesive agent does not contain formaldehyde. In one embodiment, the bonding composition comprises a non-crosslinked resorcinol-formaldehyde and / or resorcinol-furfural condensate (or a water-soluble phenol-formaldehyde condensate), a rubber latex and a 2-furylaldehyde It contains the same aldehyde component. The composition can be applied to a fabric substrate and used to improve adhesion between the treated fabric substrate and the rubber material. More information about these drugs can be found in U.S. Patent Application No. 13 / 029,293, filed on February 17, 2011, which is incorporated herein by reference.

The adhesive layer may be applied to the fibers after formation of the fiber layers prior to formation into the fiber layers or in any conventional manner. Preferably, the adhesive layer is a resorcinolic formaldehyde latex (RFL) layer or rubber adhesive layer. Generally, the adhesive layer is applied by dipping a fiber layer or fiber into the adhesive layer solution. The fiber layer or fiber is then passed through a squeeze roll and dryer to remove excess liquid. The adhesive layer is typically cured at < RTI ID = 0.0 > 150 C < / RTI >

Adhesion promoters can also be incorporated into the outer layer (second layer and / or third layer) of the fibers or can be applied to the fibers and / or the fiber layer is a free standing film. Thermoplastic films in this category are composed of various polyamides and their copolymers, polyolefins and their co-polyolefins, polyurethanes and methyl methacrylic acid. Examples of these films include 3M ™ 845 film, 3M ™ NPE-IATD 0693, and Nolax ™ A21.2242 film.

The fibers can be made in any suitable manner or manner. There are two preferred methods of making reinforced rubber products. The first is disclosed to form fibers by slit extruding the polymer (in one embodiment, the fibers are tape elements having a square or rectangular cross-section). The die typically contains 5 to 60 slits and each slit forms a fiber (a tape element). In one embodiment, each slit die has a width of about 15 mm to 50 mm and a thickness of about 0.6 to 2.5 mm. The extruded fibers typically have a width of 4 to 12 mm. The fibers having a single layer may be extruded, or the fibers may have a second layer and / or a third layer using coextrusion.

Next, the fiber is uniaxially drawn. In one embodiment, the fibers are drawn, preferably at a ratio of about 5 or more, to produce fibers having a modulus of at least about 2 GPa and a density of at least about 0.85 g / cm ³ .

Once the fibers are formed, the second and / or third layers may be applied to the fibers in any suitable manner, including, but not limited to, lamination, coating, printing and extrusion coating. This can be done before or after the uniaxial orientation step.

In one embodiment, drawing of the fibers creates pores in the fibers. In one embodiment, the voids formed are present in an amount of about 3 to 18% by volume. In another embodiment, the extrudate contains pore-forming particles which cause pores in the polymer and fibers and / or form cracks in the fiber surface.

The fibers are formed of a fibrous layer, including fabrics, non-woven fabrics, unidirectional fabrics and knitted fabrics. The fibers are then optionally coated with an adhesion promoter, such as RFL coating, and at least partially embedded (preferably fully encapsulated) in the rubber. In embodiments where the fibers contain cracks, it is preferred that the adhesive coating at least partially fills the cracks.

In the second method, the polymer is extruded into a film. The film may be extruded to have a single layer or may have a second layer and / or a third layer using coextrusion. The film is then slit into a plurality of fibers. In one embodiment, the fibers are tape elements having a square or rectangular cross-sectional shape. Then, these fibers are uniaxially drawn. In one embodiment, the fibers are preferably drawn at a ratio of at least about 5 to produce fibers having a modulus of at least about 2 GPa and a density of at least about 0.85 g / cm < ³ >.

Once the fibers are formed, they may be applied to the fibers in any suitable manner, including, but not limited to, lamination, coating, printing and extrusion coating, where a second and / or third layer is desired. This can be done before or after the uniaxial orientation step.

In one embodiment, drawing of the fibers causes voids to be generated in the fibers. In one embodiment, the voids formed are present in an amount of about 3 to 18% by volume. In another embodiment, the extrudate contains a polymer and pore-forming particles. When uniaxially oriented, this results in void formation in the fibers and / or formation of cracks on the surface of the fibers.

The fibers are formed into a fibrous layer comprising a fabric, a nonwoven, a unidirectional fabric and a knitted fabric. The fibers are then optionally coated with an adhesion promoter such as an RFL coating and at least partially embedded in the rubber. In embodiments where the fibers contain cracks, it is preferred that the adhesive coating at least partially fills the cracks.

In one embodiment, a die for extruding a film or fiber has a rectangular cross section (top, bottom and two edges) with at least one of the top or bottom sides of the die having a serrated surface. This can produce films having advantageous surface structures or surface textures.

In another embodiment, the fibers are heat treated prior to forming the fibers into a fiber layer. Heat treatment of the fibers provides several advantages, such as higher modulus, higher strength, lower elongation and especially lower shrinkage. Methods of heat treating the fibers include induction heating such as hot air convection heat treatment, steam heating, infrared heating, or stretching on a hot plate (all under tension).

Test Methods

Peel test: The T-peel test was performed on an MTS tensile tester at a rate of 12 inches / min. One end (preferably the rubber side) thereof was fixed to the lower clamp, and the fabric was fixed to the upper clamp. The peel strength of the fabric from the rubber was measured from the average force separating the layers. A release liner was added to the sample edge (1/2 inch) between the fiber and rubber to facilitate the peel test.

The peel strength measured in this test represents the force required to separate a unidirectional array of single fibers or fibers from the rubber. In all experiments, the fiber array is pulled at 180 [deg.] To the rubber sample. In all samples, the thickness of the rubber was about 3 mm.

Example

The present invention will now be described by reference to the following non-limiting examples in which all parts and percentages are by weight unless otherwise indicated.

Example  One

Example 1 was a single-filament nylon fiber having a circular cross-sectional shape with a diameter of 240 mu m. The nylon used was nylon 6,6 commercially available as Nylon 6,6 SSP-72 from Invista. The nylon was extruded in a slot die with 60 slots (each slot having a diameter of 1.1 mm). Nylon was extruded at a rate of 20 kg / hour at 300 ° C. The resulting fibers were then cooled to 32 DEG C and uniaxially oriented at a draw ratio of 5. Pulling was performed in a three-step draw line having draw ratios of 4, 1.25 and 1 in the first, second and third steps, respectively. The finished nylon fibers had a modulus of 1 GPa and a density of 1.14 g / cm < ³ >. The fibers were essentially free of voids or had no cracks on the fiber surface.

A resorcinol pre-condensate commercially available as Penacolite-2170 from Indspec Chemical Corporation and a vinyl-pyridine latex commercially available as Gentac VP 106 from Omnova Solutions Single filament nylon fibers were coated with 25 wt% (coating weight) of dry fibers in the RFL formulation used. The coated fibers were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The cured fibers were then pressed onto a rubber (commercially available as RA306 from Akron Rubber Compounding) in a mold at 300 psi so that the entire surface of the fiber was embedded in the rubber, Gt; min. ≪ / RTI > To cover 0.5 inch (1.27 cm) of rubber, seven fibers were placed at a distance of 1.7 mm to form a unidirectional fiber layer. It was performed a peeling test as described above, peel strength was 77lb _f / in. The resulting peeled fibers also had a small amount of rubber still attached. This indicated a slight bond break of the rubber (failure of the rubber adhered to the surface of the nylon fiber from the bulk rubber). This bond failure is typical when any open fabric or open fiber layer is buried due to the open structure of the fabric through which the rubber can flow and surround the fabric and adhere to the other rubber.

Example  2

Example 2 was multi-filament nylon fiber. To produce multifilament fibers, two nylon fibers having a circular cross-sectional shape of 940 denier (made from nylon available under the trade designation T-728 from Kordsa Global) Filament nylon. The multifilament twisted fibers had a modulus of 3GPa and a density of 1.14 g / cm < ³ >. The fibers were essentially free of voids or had no cracks on the fiber surface.

(Coating weight) of dry fibers in an RFL formulation using a resorcinol pre-condensate commercially available as Penacolite-2170 from Indspec Chemical Corporation and a vinyl-pyridine latex commercially available as Zinc VP 96 from Omnova Solutions, Filament < / RTI > nylon fiber. The coated fibers were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The cured fibers were then embedded in rubber (commercially available as RA306 from Akron Rubber Compounding) so that the entire surface of the fibers was embedded in the rubber, and these materials were cured at 160 DEG C for 30 minutes. To cover 0.5 inch (1.27 cm) of rubber, 7 fibers were placed spaced 1.75 mm apart to form a unidirectional fiber layer. It was performed a peeling test as described above, peel strength was 59lb _f / in. As in Example 1, a similar bond failure of the rubber was observed.

Example  3

Example 3 was a nylon film (not a fiber) having a rectangular cross-sectional shape with a width of 25 mm and a height of 200 탆. The nylon used was nylon 6,6 commercially available from INVISTA ™ as nylon 6,6 SSP-72. The nylon was extruded at a rate of 2 kg / hour at 300 ° C. The resulting film was then cooled to 32 ° C. and not drawn or oriented. The finished nylon film had a modulus of 500 MPa and a density of 1.14 g / cm ^3. The film was essentially free of voids or had no cracks on the surface of the film , And had a very high surface roughness.

(Coating weight) of the film as an RFL formulation using a resorcinol pre-condensation product commercially available as Penacolite-2170 from Indspec Chemical Corporation and a vinyl-pyridine latex commercially available as Gentac VP 106 from Omnova Solutions Nylon film was coated. The coated film was then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The cured film was then pressed onto rubber (commercially available as RA306 from Akron Rubber compounding) so that the entire surface of the film was on one side of the rubber, and these materials were cured at 160 占 폚 for 30 minutes. It was performed a peeling test as described above, peel strength was 2lb _f / in. One reason for this low value was that the RFL adhesive did not bond to the surface of the material and that the film was not fully pressed onto the rubber surface (the surface of the film was not completely filled with rubber).

Example  4

Example 4 was a single-layered nylon fiber having a rectangular cross-sectional shape of 2 mm in width and 75 占 퐉 in height. The nylon used was nylon 6,6 commercially available from INVISTA ™ as nylon 6,6 SSP-72. The polymer was extruded in a slot die with 12 slots (each slot having dimensions of 25 mm x 0.9 mm). Nylon was extruded at a rate of 20 kg / hour at 300 ° C. The resulting tape element was then cooled to 32 DEG C and uniaxially oriented with a draw ratio of 5 to 6. [ Pulling was performed in a three-step draw line having drawing ratios of 4, 1.2, and 1.1 in the first, second, and third steps, respectively. It is expected that the same modulus and strength can be obtained even if the draw ratio is distributed differently throughout the pull-out band. For example, a modulus of 6 GPa can also be obtained if the draw ratio is 1.5, 3.3 and 1.1 in the first, second and third stages, respectively. The finished nylon tape element had a modulus of 6 GPa, a density of 1.06 g / cm < ³ > and a void volume of 8 vol% (by volume) of the fibers. A micrograph of the fiber can be seen in FIG. The void extends discontinuously throughout the longitudinal section of the fiber. The size of the pores was 50 to 150 nm in width and 0 to 5 탆 in length. The density of the voids was 8% by volume. The fibers were essentially free of cracks on the fiber surface.

(Coating weight) of the dry tape with the resorcinol pre-condensation product commercially available as Penacolite-2170 from Indspec Chemical Corporation and the RFL formulation using Vinyl-Pyridine latex commercially available as Zenkup VP 106 in Omnova Solutions, (Which is a tape element). The coated tapes were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The coated fibers were then placed on rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers, so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber . They were cured at 160 DEG C for 30 minutes. In order to cover the rubber 0.5 inch (1.27 cm) strip, six rectangular fibers had to be placed. The peel test performed as described above showed rubber break at 197 lb _f / in. Peel test force results were the forces required to break the rubber in the sample. When the peel test was carried out, the fibers were not pulled out of the rubber and the rubber was broken. This represents that it was a peel strength more than 197lb _f / in, the exact value was not determined because not destroy rubber.

Example  5

Example 5 was the same as Example 4 except that the total draw ratio of the fibers was 3. The finished nylon fibers had a modulus of 3.5 GPa, a density of 1.06 g / cm < ³ > and a void volume of 8 vol% (by volume) of the fibers.

Example  6

Example 6 was the same as Example 4 except that the total draw ratio of the fibers was 4. The finished nylon fibers had a modulus of 4.1 GPa, a density of 1.06 g / cm < ³ > and a void volume of 8 vol% (by volume) of the fibers. Comparing Examples 4, 5 and 6, the modulus and strength appear to be proportional to the draw ratio.

Example  7

Example 7 was a single-layered nylon fiber having a rectangular cross-sectional shape of 4 mm in width and 130 탆 in height. The polymer used was Nylon 6,6 commercially available from INVISTA ™ as nylon 6,6 SSP-72. The nylon was extruded in a slot die with 12 slots (each slot having dimensions of 25 mm x 0.9 mm). Nylon was extruded at a rate of 60 kg / hour at 300 占 폚. The resulting tape element was then cooled to 32 DEG C and uniaxially oriented with a draw ratio of 5 to 6. [ Pulling was performed in a three-step draw line having drawing ratios of 3.1, 1.65 and 1.1 in the first, second and third steps, respectively. The finished nylon tape element had a modulus of 800 MPa and a density of 1.14 g / cm < ³ >. The fibers were essentially free of voids or had no cracks on the fiber surface. Comparing the fibers of Example 7 with those of Example 4, the fibers of Example 7 were twice as wide and nearly two layers thick, and in the same size slot die, the effluent was extruded three times. As mentioned earlier, the orientation of the fiber bundles is a driving factor in the origin of the voids in the fibers. The presence and uniformity of the pores along the transverse width of the oriented fibers depends on whether the complete polymer element is oriented in the drawing process along the machine direction. The lack of voids is due to the fact that effective heat transfer has not been achieved to completely orient it in the polymer element. An oriented region and an unoriented region were obtained on a polymer tape.

(Coating weight) of the dry tape with the resorcinol pre-condensation product commercially available as Penacolite-2170 from Indspec Chemical Corporation and the RFL formulation using Vinyl-Pyridine latex commercially available as Zenkup VP 106 in Omnova Solutions, Nylon fiber. The coated fibers were then placed on rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers, so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber . It was cured at 160 DEG C for 30 minutes. In order to cover the rubber 0.5 inch (1.27 cm) strip, six rectangular fibers had to be placed.

Example  8

The coated fibers of Example 4 were coated onto a rubber (commercially available as RA306 from Akron Rubber Compounding) in a unidirectional pattern with a spacing of 0.5 mm between the fibers so that the unidirectional fiber layer did not cover the entire surface of the rubber I left it. It was cured at 160 DEG C for 30 minutes. Six rectangular fibers were placed on a rubber 0.5 inch (1.27 cm) strip. The release film was placed between the fiber layer and the rubber at one edge for ease of peel test. The peel test performed as described above showed rubber break at 180 lb _f / in, indicating that the peel strength was greater than this value. This value was almost the same as the peel strength of the unidirectional fiber layer (Example 4) having no gap between the fibers. Since this force is an index of the breaking strength of the rubber and depends on the thickness of the rubber, it is inevitable that this value is slightly increased.

Example  9

The nylon film of Example 3 was adhesively bonded to a rubber (commercially available as RA306 from Akron Rubber compounding) using a commercially available adhesive film as 3M 845 film at 3M. The adhesive film consisted of an acrylic copolymer, an adhesive, and a vinylcarboxylic acid. The film was pressed against the rubber (the adhesive film was placed between the rubber and the nylon film) so that the entire surface of the nylon film was not covered by the rubber (so that it was not buried) and then the sample was cured at 160 DEG C for 30 minutes. As described above was performed as the peeling test, the peel strength was 27lb _f / in, an increase of the peel strength as compared to Example 3 using the RFL adhesive coating.

Example  10

The fibers of Example 10 were similar to the fibers of Example 4, but pore-forming particles were added. Example 10 was a single-layer nylon fiber having a rectangular cross-sectional shape of 2 mm in width and 75 占 퐉 in height. The polymer used was nylon 6,6 commercially available as nylon 6,6 SSP-72 in INVISTA and contained 7 wt% nano clay (chlorite) commercially available from Southern Clay Company. The nylon was extruded in a slot die with 12 slots (each slot having dimensions of 25 mm x 0.9 mm). Nylon was extruded at a rate of 20 kg / hour at 300 占 폚. The resulting fibers (which are tape elements) were then cooled to 32 DEG C and uniaxially oriented at a drawing ratio of 5 to 6. Pulling was performed in a three-step draw line having drawing ratios of 4, 1.2, and 1.1 in the first, second, and third steps, respectively. As mentioned in Example 1, even if the draw ratio is distributed differently throughout the pullout band, the same modulus and strength can also be obtained. The finished nylon fibers had a modulus of 6 GPa, a density of 1.06 g / cm < ³ > and a volume fraction of 8 vol% of the fibers. The voids of the fibers can be seen in the micrographs of FIGS. 10a and 10b. The void extends discontinuously throughout the longitudinal region of the fiber. The size of the pores was 50 to 150 nm in width and 0 to 5 탆 in length. The pore concentration was 8 vol.%. The pores were similar in shape to those obtained without the pore-initiating particles. The fibers also contained cracks on the fiber surface. The cracks present on the fiber surface were discontinuous along the longitudinal direction of the fibers, and their length was about 300 탆 to 1000 탆. Cracks on the surface of the fibers can be seen in the micrographs of FIGS. 11, 12 and 13.

(Coating weight) of dry fibers in an RFL formulation using a resorcinol pre-condensate commercially available as Penacolite-2170 from Indspec Chemical Corporation and a vinyl-pyridine latex commercially available as Zinc VP 96 from Omnova Solutions, Nylon fiber. The coated fibers were air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The coated fibers were then placed on rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers, so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber . It was cured at 160 DEG C for 30 minutes. In order to cover the rubber 0.5 inch (1.27 cm) strip, six rectangular fibers had to be placed. A release film was placed between the fiber layer and the rubber layer at one edge for ease of peel test. The peel test performed as described above showed rubber break at 197 lb _f / in, indicating that the peel strength was greater than this value.

Example  11

Example 11 was a polyester fiber having a rectangular cross-sectional shape of 2 mm in width and 60 占 퐉 in height. The polyester used was polyethylene terephthalate, commercially available as PET IV 60 from Nanya Plastics Corporation. The polyester was extruded in a slot die having 12 slots (each slot having dimensions of 25 mm x 0.9 mm). The polyester was extruded at a rate of 20 kg / hour at 300 ° C. The resulting fibers were then cooled to 32 DEG C and uniaxially oriented at a drawing ratio of 7 to 9. Pulling was performed in a three-step draw line having drawing ratios of 3.4, 2.2 and 1 in the first, second and third steps, respectively. The finished polyester tape element had a modulus of 8 GPa, a density of 1.20 g / cm < ³ > and a void volume of 8 vol% of the fibers. The fibers were essentially free of cracks on their surfaces.

The polyester fibers were coated by a two-step soak procedure using a pre-soak solution containing caprolactam blocked isocyanate commercially available as Grilbond IL-6 from EMS and cured at 225 ° C for 3 minutes And the vinyl-pyridine latex marketed as Zenkup VP 106 by OMNOBA Solutions in a Resorcinol pre-condensation product commercially available under the trade name Penacolite-2170 from Indspec Chemical Corporation was added to 25 wt% (coating weight) of the dry tape Lt; RTI ID = 0.0 > RFL < / RTI > The coated fibers were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The coated fibers were then placed on rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber. It was cured at 160 DEG C for 30 minutes. Six rectangular fibers had to be placed to cover the rubber 0.5 inch (1.27 cm) strips. When the peel test was carried out, the pulled fibers still had a large rubber mass adhered thereto. Peel test exhibits a bonding strength of the _f 120lb / in showed a cohesive failure of the rubber.

Example  12

Example 12 was a single layer fiber blend of polyester and nylon 6 having a rectangular cross-sectional shape of 1.5 mm width and 100 탆 height. The polyester used was polyethylene terephthalate, commercially available as PET IV 60 from Nanya Plastics Corporation; The nylon used was nylon 6,6 commercially available from INVISTA ™ as nylon 6,6 SSP-72. The polymer was extruded in a slot die with 12 slots (each slot having dimensions of 25 mm x 0.9 mm). The blend was physically mixed at a ratio of 90:10 (90% polyester by weight and 10% nylon by weight) and extruded at 300 ° C at a rate of 20 kg / hour. The resulting tape element was then cooled to 32 DEG C and uniaxially oriented with a draw ratio of 5 to 7. [ Pulling was performed in a three-step draw line having drawing ratios of 3, 2 and 0.9 in the first, second and third steps, respectively. It should be noted that for the various reasons, a slight over-supply is required at the final stage. Overfeed reduces fiber shrinkage and modulus relaxation [creep]. This also increases the toughness of the fibers. It is expected that the same modulus and strength can be obtained even if the draw ratio is distributed differently throughout the drawing zone. For example, a modulus of 10 GPa can be obtained even when the drawing ratio is 1.5, 3.3 and 0.9 in the first, second and third steps, respectively. The finished polyester-nylon blended tape element had a modulus of 10 GPa and a density of 1.37 g / cm < ³ >.

The polyester-nylon blend fiber was coated by a two-step soak procedure using a pre-soak solution containing caprolactam blocked isocyanate commercially available as grill bond IL-6 from EMS and cured at 225 ° C for 3 minutes And the vinyl-pyridine latex marketed as Zenkup VP 106 by OMNOBA Solutions in a Resorcinol pre-condensation product commercially available under the trade name Penacolite-2170 from Indspec Chemical Corporation was added to 25 wt% (coating weight) of the dry tape Lt; RTI ID = 0.0 > RFL < / RTI > The coated tapes were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The coated fabric was then placed on a rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber. It was cured at 160 DEG C for 30 minutes. Six rectangular fibers had to be placed to cover the rubber 0.5 inch (1.27 cm) strips. The peel test performed as described above produced a value of 143 lb _f / in.

Example  13

Example 13 was a single layer fiber blend of polyester and nylon 6 6 having a rectangular cross-sectional shape of 1.5 mm width and 100 탆 height. The polyester used was polyethylene terephthalate, commercially available as PET IV 60 from Nanya Plastics Corporation; The nylon used was nylon 6,6 commercially available from INVISTA ™ as nylon 6,6 SSP-72. The polymer was extruded in a slot die with 12 slots (each slot having dimensions of 25 mm x 0.9 mm). The blend was physically mixed at a ratio of 70:30 (70% polyester by weight and 30% nylon) and extruded at 300 ° C at a rate of 20 kg / hr. The resulting tape element was then cooled to 32 DEG C and uniaxially oriented with a draw ratio of 5 to 7. [ Pulling was performed in a three-step draw line having drawing ratios of 3, 2 and 0.9 in the first, second and third steps, respectively. It should be noted that for the various reasons, a slight over-supply is required at the final stage. Overfeed reduces fiber shrinkage and modulus relaxation (creep). This also increases the toughness of the fibers. It is expected that the same modulus and strength can be obtained even if the draw ratio is distributed differently throughout the drawing zone. For example, a modulus of 10 GPa can be obtained even when the drawing ratio is 1.5, 3.3 and 0.9 in the first, second and third steps, respectively. The finished polyester-nylon blended tape element had a modulus of 10 GPa and a density of 1.37 g / cm < ³ >.

The polyester-nylon blend fiber was coated by a two-step soak procedure using a pre-soak solution containing caprolactam blocked isocyanate commercially available as grill bond IL-6 from EMS and cured at 225 ° C for 3 minutes And the vinyl-pyridine latex marketed as Zenkup VP 106 by OMNOBA Solutions in a Resorcinol pre-condensation product commercially available under the trade name Penacolite-2170 from Indspec Chemical Corporation was added to 25 wt% (coating weight) of the dry tape Lt; RTI ID = 0.0 > RFL < / RTI > The coated tapes were then air dried and cured in an oven for 3 minutes at < RTI ID = 0.0 > 190 C. < / RTI > The coated fabric was then placed on a rubber (commercially available as RA306 from Akron Rubber compounding) in a unidirectional pattern with no gap between the fibers so that the resulting unidirectional fiber layer essentially covered the entire surface of the rubber. It was cured at 160 DEG C for 30 minutes. Six rectangular fibers had to be placed to cover the rubber 0.5 inch (1.27 cm) strips. The peel test performed as described above produced a value of 143 lb _f / in.

All references cited herein, including publications, patent applications and patents, are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and are hereby incorporated by reference in its entirety .

In describing the present invention (especially in relation to the following claims) the use of singular terms and similar citations should be considered as encompassing both singular and plural unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be considered as unspecified terms (ie, "including but not limited to") unless otherwise indicated. Citation of a range of values herein, unless otherwise indicated herein, is intended to serve as a shorthand method of simply citing each individual value falling within its scope, and each individual value is intended to refer to the individual values as if they were individually recited herein Are included in the specification. All methods described herein should be performed in any suitable order unless otherwise indicated herein or otherwise contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is intended merely to better illuminate the invention and does not limit the scope of the invention unless otherwise claimed . Terms not used in the description should be construed as indicating any non-claimed element essential to the practice of the invention.

Preferred embodiments of the present invention, including the best mode known to the inventors for carrying out the present invention, are described herein. Those skilled in the art will readily recognize modifications to these preferred embodiments after reading the above description. The inventors anticipate that, if appropriate, those skilled in the art will utilize these variations, and the inventors intend to practice the present invention contrary to what is specifically described herein. Accordingly, the invention includes all changes and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. In addition, any combination of the elements described above in all possible variations thereof is not otherwise indicated herein or otherwise covered by the present invention, unless the context clearly indicates otherwise.

Claims (19)

delete delete delete delete delete delete delete delete delete delete delete delete delete Slit extruding the tape element or extruding the film and slitting the tape element into a plurality of tape elements, wherein the tape element comprises a polymer;
Forming a plurality of voids in the fibers in an amount of 3 to 18% by volume of the fibers by uniaxially orienting the tape elements to form uniaxially drawn fibers;
Forming the uniaxially drawn fibers into a fiber layer; And
Embedding the fiber layer in a rubber
In turn, a reinforced rubber product. 15. The method of claim 14,
Wherein the fibers have a rectangular cross-section. 15. The method of claim 14,
Wherein the polymer comprises a polymer selected from the group consisting of polyamides, polyesters, and copolymers thereof. 15. The method of claim 14,
Wherein the tape element further comprises void-evoked particles. 15. The method of claim 14,
Wherein uniaxial orientation of the tape element creates a plurality of crevices in the tape element,
Wherein the method further comprises coating the tape element with an adhesion promoter before or after forming the tape element into a fiber layer to at least partially fill the plurality of cracks of the tape element. 15. The method of claim 14,
Wherein the tape element comprises a blend of polyester and nylon 6.

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