RU2574059C2 - Strengthened rubber material with ribbon elements - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: invention relates primarily to car industry, in particular, for tyre production. Strengthened rubber material represents rubber, where a fibrous layer is introduced. Fibrous layer comprises uniaxially extended ribbon elements, having rectangular cross section, and at least one the first layer characterized by extent of drawing by at least approximately 5, with a module of at least approximately 2 GPa, with density of at least 0.85 g/cm³. The first layer contains polymer selected from the group made of polyamide, polyester and their copolymers. Also methods are disclosed for strengthening of rubber material.

EFFECT: increased strength of rubber-containing cloths and accordingly tyres.

19 cl, 15 dwg

Description

Technical field

The present invention generally relates to fiber reinforced rubber products.

State of the art

Hardened rubber products are used in a wide variety of consumer and industrial applications. The characteristics of hardened molded rubber products depend on the adhesion of the hardening to the rubber. Fabrics made from synthetic yarns are generally difficult to bond with rubber.

In practice, several things are done to improve adhesion, most of which include coating fibers and / or fabrics with an adhesion promoter. For example, as the fibers are stretched, a stretch coating may be applied, which may contain an adhesion promoter, such as an epoxy resin.

There remains a need for hardened rubber products having fibrous layers with enhanced adhesion due to the geometry and other physical properties of the fibers, in addition to adhesion promoting chemicals.

SUMMARY OF THE INVENTION

A hardened rubber product comprising a rubber product and a fibrous layer embedded in a rubber product. The fibrous layer contains uniaxially elongated ribbon elements having a rectangular cross section, and at least a first layer characterized by a drawing ratio of at least about 5, a modulus of at least about 2 GPa, and a density of at least 0.85 g / cm ³ . The first layer contains a polymer selected from the group consisting of polyamide, polyester and their copolymers. Methods of obtaining a product from hardened rubber are also disclosed.

Brief Description of the Drawings

Figure 1 shows schematically a fibrous layer, which is a woven material embedded in rubber.

The figure 2 presents a sectional view of a partial view of a pneumatic radial tire.

In figures 3 and 4 presents images of products from hardened rubber, which is a hose.

Figure 5 shows schematically one embodiment of an air spring comprising belt elements.

Figure 6 shows schematically an embodiment of a typical tape element having one layer.

Figure 7 shows schematically an embodiment of a typical tape element having two layers.

Figure 8 shows schematically an embodiment of a typical tape element having three layers.

Figure 9 shows schematically an embodiment of a typical tape element having cavities and surface cracks.

Figure 10 shows a micrograph with a 50000X magnification of the cross section of one embodiment of a fiber containing cavities.

The figure On shows a micrograph with a 20,000X enlargement of the cross section of one embodiment of a fiber containing cavities and initiating cavities of the particle, indicating some sizes of diameters of the cavities.

Figure 11b shows a micrograph with a 20,000X magnification of the cross section of one embodiment of a fiber containing cavities and initiating particle cavities, indicating some sizes of cavity lengths.

Figure 12 shows a micrograph with a 1000X magnification of the surface of one embodiment of fibers having cracks.

Figure 13 shows a micrograph with a 20,000X magnification of the surface of one embodiment of fibers having cracks.

Figure 14 shows a micrograph with a 100000X magnification of the surface of one embodiment of fibers having cracks.

The figure 15 shows schematically an embodiment of a woven material obtained from tape elements.

DETAILED DESCRIPTION OF THE INVENTION

1 shows a hardened rubber article 200 comprising a fibrous layer 100 embedded in rubber 220. The fibrous layer 100 comprises a plurality of fibers 10. The hardened rubber article 200 can be any fiber reinforced rubber product, such as tires, belts, air springs, hoses and the like.

Referring now to FIG. 2, one embodiment of a hardened rubber article 200 is shown, which is a tire comprising sidewalls 303 connected to the tread 305 by shoulders. The tire 200 comprises a carcass 301 coated with 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 also be used with other tire designs. The carcass 301 is formed of one or more layers of tire cord 312 terminating at the inner periphery of the tire with metal wires 307, with at least one retaining layer 334 arranged in a circle around the tire cord 312 in the tread region 305. The carcass 301 is designed so that reinforcing cords 311 extend substantially radially to the intended direction of rotation R of the tire 200. The retaining layers 334 are obtained from relatively non-expandable base materials 331, such as steel reinforcing cord bases, which extend into an assumed direction of rotation of the tire R or more typically at a slight angle to it. The angle of the non-stretch base materials 331 may vary depending on the method of construction or application. The brackets 330 extend across the width of the tire tread 305, ending with edges 332 in the area of the tire 200, where the tread 305 passes into the side wall 303.

The protective layer 343 is located between the retaining layers 334 and the tread 305. The shown protective layer 343 is formed from a protective layer strip 342 wound around the tire cord 312 in the tire rental direction, protruding beyond the edges 332 of the retaining layers 334. In addition, the protective layer strip 342 in the figure 2 can be wound around the tire cord 312 many times to reduce the instability effect in the tire 200 caused by an overlap. Alternatively, the protective layer 343 may be formed from the protective layer strip 342 that extends beyond the edge 332 of the retaining layers 334, or the protective layer 343 may be formed from the protective layer strip 342 that is wound around the circumference around the tire carcass 301 in a plane in a spiral manner. Some suitable fabrics for the protective layer are described in US patent No. 7252129, 7614436 and 7931062, each of which is incorporated herein by reference in its entirety.

Above the wire 307 is a bead filler 310 and surrounds at least partially the wire 307, and the filler 310 is a rim tape 320. The rim tape 320 is a layer of fabric located around the wire 307 and inside part of the wrap end 330. The amplifier 340 is adjacent with a portion of the layer 330 that is wrapped around the wire 307. More specifically, the amplifier 340 is located on the back side of the portion of the “back end” layer 330 relative to the rim tape 320. The sidewall may also contain other layers of fabric not shown, for example, black leathers, heel protection fabrics, or fabrics wrapped around a wire protruding from the wire above the side of the sidewall, protruding from the tread below the sidewall, in the shoulder region or completely covering the sidewall. Any fabric protruding between the wire and the tread is defined herein as “sidewall fabric”. It includes fabrics that also protrude around the wire inside the tire, such as rim tape fabric, since at least a portion of the fabric is located between the wire and the tread.

The tire carcass, as required, has considerable radial strength, extending from wire to wire across the direction of rotation during use. To ensure this strength, the fabric stabilizing material (also known as tire cord) was typically a woven material with mainly non-stretched, pre-stretched high-strength yarns extending in the main direction (also known as “longitudinal direction”), which were stretched and stretched during fabric and / or processing. This fabric is then cut in the transverse direction (i.e. across the warp yarns). The individual pieces of fabric are then rotated 90 degrees and connected to each other for placement in the frame so that the high-strength warp yarns are oriented in the desired radial direction between the wires. Thus, in the final structure, the transverse threads are oriented mainly around the circumference (i.e., in the direction of rotation of the tire).

According to another embodiment, the formed frame-stabilizing fabric is a woven base, a weft inserted fabric having weft yarns formed from relatively unstretched reinforcing cords. Alternatively, the carcass stabilizing fabric may be a woven fabric having weft threads formed from relatively unstretchable reinforcing cords or a stacked mesh. More information about this stabilizing fabric having relatively non-stretch reinforcing cords in the direction of fabric weft can be found in U.S. Patent Application Serial No. 12/836256, filed July 14, 2010, which is incorporated herein by reference in its entirety.

The fibrous layer 100 in the tire of FIG. 2 (hardened rubber article 200) may be a protective layer, a carcass ply, a chafer, a bypass tape, an amplifier, a carcass ply, a shoulder layer, a retainer layer, a tape separation layer, a wire base, a base of the band edge or any other fibrous layer in the tire.

Referring now to figures 3 and 4, a product 200 of hardened rubber in the form of a hose with fabric gaskets is shown. One of the most common and most suitable conventional hoses is the so-called "mesh-reinforced" type, in which the fiber layer 100 is formed by threads spirally wound onto an elastic hose, forming two sets of threads, the first in parallel and equally spaced rows and superimposed on an equal number of transverse threads along similarly parallel and equidistant lines that are ordered symmetrically about the axis of the cylindrical body of the hose so as to form a “mesh” of fabric with diamond-shaped cells. Any other suitable fibrous layer 100 can also be used in hoses. The fiber layer 100 is embedded in rubber 220. In addition to hoses, fibers and fiber layers can be used to harden any suitable rubber product, including belts such as drive belts, offset blankets and pipes.

Some other hardened rubber products 200 include offset blankets and drive belts. In offset printing, the usual function of the web is to transfer the ink from the printing plate to the product, such as the paper to be printed on, while the offset web comes into contact again with the associated printing plate and the paper to be printed. Offset blankets usually contain fabric embedded in rubber. Drive belts and other types of belts also contain reinforced rubber with fibers.

Pneumatic springs, commonly called air springs, have been used in motor vehicles for many years to provide cushioning between moving parts of a vehicle, primarily to absorb shock loads produced on the vehicle’s axle by wheels that hit an object on the road or hit a pothole . These air springs usually consist of an elastic elastomeric sleeve or bellows containing a supply of compressed air or other fluid and having one or more pistons located in the elastic sleeve to cause compression and expansion when the vehicle is subjected to jolts from road bumps. Pistons cause compression and expansion in the air sleeve and, since the sleeve consists of an elastic material, allows the pistons to move axially relative to each other in the inner part of the sleeve. The ends of the sleeve are usually hermetically connected to the pistons or end elements and have one or more sealed ends that allow the end elements to move axially relative to each other between the push or position at the moment of cutting and the reverse or extended position of the piston without damaging the elastic sleeve.

It is desirable that the cushioning mechanism or device be used in combination with such air springs to provide cushioning to control the movement of the air springs. In one embodiment, the rubber hardened article is used in an air spring. According to an embodiment, the rubber hardened article is used as a gasket for a piston or side lining of an air spring assembly.

Figure 5 shows schematically a hardened rubber product 200, which is a sleeve, in the form of an air spring 400. Fibers 10, preferably tape elements 10, are embedded in the rubber forming a sleeve 200, which serves to suppress vibration in machines and other machinery. 5, sleeve 200 has two ends, upper end 405 is connected to plug 401, and lower end 406 is connected to piston 402. Although one embodiment of air spring 400 is shown, hardened rubber product 200 can be used in any air spring configuration. Cross sections of fibers being tape elements 10 can be seen in sectional view of the air spring 400, since the tape elements 10 are oriented in a circular direction in the sleeve 403. This circular direction of the tape elements gives rigidity to the structure.

The fibrous layer 100 is formed of fibers 10. The fibers 10 can be any suitable fiber for the final application. “Fiber” as used herein is defined as an elongated body. The fiber can have any suitable cross section, such as round, multi-leaf, square or rectangular (ribbon) and oval. According to one embodiment, the fibers are tape elements 10. The tape elements may have a rectangular or square cross-sectional shape. These tape elements may also sometimes be called ribbons, stripes, ribbons, tape fibers and the like.

One embodiment of a fiber being a tape member is shown in Figure 6. According to this embodiment, the tape member 10 comprises a first layer 12 having an upper surface 12a and a lower surface 12b. According to one embodiment, the tape member 10 has a rectangular section. A tape element is considered to have a rectangular or square cross section, even if one or more corners of the rectangle / square is slightly rounded, or if the opposite sides are not parallel to absolutely. The presence of a rectangular section is preferred for some applications for many reasons. First, the surface available for binding is larger. Secondly, during the bond breaking event, the entire width of the tape is under tension, and the number of shear points is significantly reduced or eliminated. In contrast, a multi-fiber yarn has a very small region under tension, and there are regions of varying tension and shear ratios along the fiber perimeter. According to another embodiment, the cross section of the tape member 10 is square or substantially square. The presence of a square cross section may also be preferable in some cases in which the width is small and the thickness is large, thus layering more ribbons in a given width, thereby increasing the allowable load of the entire reinforcing element.

In one embodiment, the tape members have a width of from about 0.1 to 6 mm, more preferably from about 0.2 to 4 mm, and more preferably from about 0.3 to 2 mm. According to another embodiment, the tape elements have 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. According to one embodiment, the tape elements have a width of about 1 mm and a thickness of about 0.07 mm.

The first layer 12 of the fiber 10 can be any suitable orientable (meaning that the fiber can be orientated) thermoplastic material. Some suitable thermoplastic materials for the first layer include polyamides, polyamide copolymers, polyesters, polyesters, polycarbonates, polyimides, and other orientable thermoplastic polymers. In one embodiment, the first layer comprises a polyamide, a polyester and / or copolymers thereof. In one embodiment, the first layer comprises a polyamide or a polyamide copolymer. Polyamides are preferred for some applications because they are characterized by high strength, high modulus, high temperature retention and fatigue resistance. According to another embodiment, the first layer comprises a polyester or a polyester copolymer. Polyesters are preferred for some applications because they are characterized by high modulus, low shrinkage and excellent temperature parameters.

In one embodiment, the first layer 12 of the tape member 10 is a mixture of polyester and nylon 6. The polyester is predominantly polyethylene terephthalate. Polyester is used because of its high modulus and high glass transition temperature, which led to the use of polyester in tire cords and cord reinforced with rubber filler, primarily because of its property of resistance to sagging. Nylon 6 is used for many reasons. It is easier to handle than nylon 66. One of the main reasons for incorporating nylon 6 in these embodiments is to function as an adhesion promoter. Nylon 6 has surface groups with which a latex containing resorcinol-formaldehyde resin can form primary chemical bonds through a resol group. This mixture is a physical mixture, not a copolymer, and the polyester and nylon 6 are immiscible in each other. According to one embodiment, the powder or granules of the polyester and nylon 6 are simply mixed in the non-molten state to form a mixture, which will then be fed to the extruder. The extruded tape elements of this physical mixture provide good adhesion to rubber and a high modulus.

Also, the polymerization of nylon 6 leads to a certain amount of unreacted monomeric lactam, which acts as a comonomer, leading to the miscibility of the polyester and nylon 6. Interactions of methylene-ester can help double mixtures to tolerate large differences in methylene content before phase separation can occur . In mixtures containing large differences in the methylene group (as in this case), entropy-induced miscibility can occur if the segmental interaction parameter of the mixture is lower than the critical value. Slight phase separation and crystallization of phase separation elements cannot be avoided; however, the bulk of the tape element appears to be uniformly mixed. Nylon 66 is not preferred for use due to strong phase separation at relatively low volumetric contents of nylon 66 in the polyester. This may be due to several reasons. Nylon 66 is characterized by a higher degree of polymerization compared to nylon 6. Secondly, the crystallization rate of nylon 66 is much higher than nylon 6. This is due to the fact that nylon 66 with its symmetrical structure can be introduced into the crystal lattice much easier. than nylon 6 chains, which should be packaged as counter chains to promote complete hydrogen bonding.

There is also a unique reason why the particular process used is beneficial for extruding and drawing the blended polymer. As indicated above, negligible phase separation cannot be avoided. An element can be non-extrudable and non-extrudable if the size of the extrudate is too small as in the case of single-filament and multi-filament bore holes. The reason why this is not a problem in this particular process is explained by its similarity to the film stretching process, in which the slit openings of the head are so wide that they can withstand a small degree of phase separation and crystallization of these phases without leading to completely unrelated regions.

According to one embodiment, the mixture of polyester and nylon 6 contains from about 50 to 99% by weight of polyester and from about 50 to 1% by weight of nylon 6. More preferably, the mixture of polyester and nylon 6 contains from about 60 to 95% by weight. polyester and from about 40 to 5 wt.% nylon b. Most preferably, the mixture of polyester and nylon 6 contains from about 70 to 90 wt.% Polyester and from about 30 to 10 wt.% Nylon 6. Mass ratios outside certain ranges will lead to excessive phase separation and crystallization in the extrudate cooling tank, resulting to the separation of the element from the main part of the extrudate. Mass ratios outside these areas require special compatibility enhancing agents, such as excess lactam monomers and polyesters.

In one embodiment, the tape elements are preferably characterized by a drawing ratio of at least about 5, a modulus of at least about 2 GPa, and a density of at least about 1.2 g / cm ³ . According to another embodiment, the first layer is characterized by a drawing ratio of at least about 6. According to another embodiment, the first layer is characterized by a modulus of at least about 3 GPa or at least about 4 GPa. According to another embodiment, the first layer is characterized by a density of at least about 1.3 g / cm ³ and a modulus of about 9 GPa. A high modulus first layer is preferred for better performance in applications such as tire cord, backing layer, tire or carcass tire layer. A lower density for these fibers will be preferable in order to give a lower mass. Fibers with cavities will generally have lower densities than their equivalents without cavities.

According to one embodiment, the fiber comprises a second layer, as shown in FIG. 7. FIG. 7 shows a fiber 10 having a first layer with an upper surface 12a and a lower surface 12b and with a second layer 14 on the upper surface 12a of the first layer 12. There may be an additional third layer 16, as shown in figure 8, on the lower surface 12b of the first layer 12. Although the second layer 14 and the third layer 16 are shown on the fiber 10, which is a tape element of rectangular cross section, the second and / or third layers can be on the fiber of any shape. If the second layer 14 and the third layer 16 are applied to the fiber without flat sides, the upper half of the circle will be called the “upper” surface, and the lower half of the circle will be called the “lower” surface.

The optional second layer 14 and the third layer 16 may be formed at the same time as the first layer in a process such as co-extrusion, or may be applied after the first layer 12 has been formed in a process such as coating. The second and third layers preferably contain a polymer of the same class as the polymer of the first layer, but may also contain additional polymers. In one embodiment, the second and / or third layers comprise a polymer, such as a block isocyanate polymer. The second and third layers 14, 16 may aid fiber adhesion to rubber. Preferably, the melting temperature (T _m ) of the first layer 12 is greater than T _{m of the} second layer 14 and the third layer 16.

According to one embodiment, the fibers 10 (preferably tape elements 10) comprise a plurality of cavities. Figure 9 shows a fiber 10 having a first layer 12 containing a plurality of cavities 20. Figure 10 shows a micrograph with a 50000X magnification of the cross section of one embodiment of a fiber containing cavities. A “cavity” is used herein to mean a space free of added solid and liquid matter, although it is likely that the “cavities” contain gas. Although it was generally accepted that fiber with cavities may not have the physical properties necessary for use as hardening in rubber products, it has been shown that fiber with cavities have some unique advantages. Firstly, the presence of cavities in the fiber is due to the mass of the polymer. This means that the density of these fibers will be lower than their equivalents without cavities. The volumetric content of the cavities will determine the percentage by which the density of this fiber will be lower than that of polymer rubber. Secondly, the cavities act as chambers for the adhesion promoter, which is introduced into the cavity layer / cavity fiber, thereby providing a fixation effect. Third, the shape of these cavities can control the propagation front of cracks in an event, such as material fatigue. The excess surface available for crack propagation will reduce the loss of the stress feature in the cyclic fatigue event, including tensile and / or compression stress. For thermoplastic polymers constituting the first layer 12 of fiber 10, flows with a high shear rate during stretching with ultra-high compressions of the layers to orient and extend the chains lead to the presence of polymer depleted regions or cavities. The cavities may be in any or all of the layers 12, 14, 16 of the fibers 10. In addition, the fibrous layer 100 may contain several fibers without a cavity, and several fibers having a cavity.

Cavities 20 are typically needle-shaped, meaning that the diameter of the cross section of the cavity perpendicular to the length of the fiber is much smaller than the length of the cavity due to the uniaxial orientation of the fiber. This shape is due to the uniaxially elongated nature of the fibers 10.

In one embodiment, the cavities are in the fiber in an amount of about 3 to 20% by volume. According to another embodiment, the cavities are in the fiber in an amount of from about 3 to 18 vol.%, From about 3 to 15 vol.%, From 5 to 18 vol.%, Or from about 5 to 10 vol.%. Density is inversely proportional to the volume of cavities. For example, if the volume of the cavities is 10%, then the density decreases by 10%. Since an increase in the number of cavities is usually observed at high degrees of drawing (which leads to high strength), a decrease in density leads to an increase in the specific strength and fiber modulus, which is desirable for some applications, such as high-quality tire hardenings.

According to one embodiment, the size of the formed cavities is characterized by a diameter in the range of from about 50 to 400 nm, more preferably from 100 to 200 nm, and from about 1 to 6 microns in length, more preferably from about 2 to 3 microns.

The cavities 20 in the fiber 10 can form during the uniaxial orientation process without additional materials, meaning that the cavities do not contain any particle initiating cavities. Orientation in a fiber bundle is a major factor in the appearance of cavities in the fibers. It is believed that the shifts between the semi-molten materials lead to the formation of cavities. The numerical density of the cavities depends on the viscoelastic properties of the polymer element. The homogeneity of the cavities along the transverse width of the oriented fiber depends on whether the entire polymer element was oriented during the drawing process along the longitudinal direction. It was noted that in order for the entire polymer element to be oriented during the drawing process, heat must be effectively transferred from the heating element (this can be water, air, infrared radiation, electricity, etc.) to the polymer fiber. Typically, in industrial processes that use convection heating with hot air, one possible way to orient the polymer fibers and, in addition, maintain industrial speed is to limit the polymer fibers with respect to their width and thickness. This means that full orientation along the longitudinal direction will be achievable more easily when the polymer fibers are extruded from the slit heads, or when the polymer is extruded through film heads and then cut into narrow thicknesses before orientation.

According to another embodiment, the fibers 10 comprise particle initiating cavities. The particle initiating cavities may be any suitable particle. The initiating particle cavities remain in the finished fiber, and the physical properties of the particles are selected according to the desired physical properties of the final fiber. When the particle-initiating cavities are in the first layer 12, exposure to the layer (such as a uniaxial orientation) typically increases or lengthens this defect caused by the particle, leading to an elongation of the cavity around this defect in the orientation direction. The size of the cavities and the final physical properties depend on the degree and balance of orientation, temperature and rate of extension, crystallization kinetics and particle size distribution. The particles can be inorganic or organic and have any shape, such as spherical, flat or complex. According to one embodiment, the particle initiating cavities are in an amount of from about 2 to 15% by weight of the fiber. According to another embodiment, the particle initiating cavities are in an amount of about 5 to 10% by weight of the fiber. According to another embodiment, the particle initiation cavities are in an amount of from about 5 to 10% by weight of the first layer.

According to one preferred embodiment, the cavity-initiating particle is a nanoclay. In one embodiment, the nanoclay is cloisite, wherein 10% of the clay has a horizontal size of less than 2 microns, 50% of less than 6 microns, and 90% of less than 13 microns. The density of the nanoclay is approximately 1.98 g / cm ³ . Nanoclay can be advantageous in some applications for a variety of reasons. Firstly, nanoclay is characterized by good miscibility with many polymers, polyamides in particular. Secondly, the high size ratio of nanoclay is supposed to improve some mechanical properties due to the preferred orientation in the longitudinal direction. In one embodiment, the nanoclay is in an amount of about 5 to 10% by weight of the fiber. According to another embodiment, the nanoclay is in an amount of about 5 to 10% by weight of the first layer. Figure 11a is a photomicrograph with a 20,000X magnification of the cross section of one embodiment of a fiber containing cavities and initiating particle cavities, indicating some sizes of cavity diameters, and Figure 11b is a micrograph with a 20,000X magnification of a cross section of one embodiment of a fiber containing cavities and initiating cavities particles indicating some sizes of cavity lengths.

The second and third layers 14, 16 of the fiber 10 may have cavities or mainly not have cavities. The presence of surface layers without cavities (second and third layers 14, 16) can help control the size and concentration of the cavities in the entire first layer 12, since the surface layers reduce the boundary effects of the extrusion process on the inner first layer 12. According to one embodiment, the second and / or the third layer 14, 16 contains the initiating cavity of the particle, cavity and surface cracks, while the first layer 12 contains the cavity, but does not contain the initiating cavity of the particle.

Referring again to FIG. 6, according to another embodiment, the fibers 10 comprise cracks 40 on at least one outer surface (upper surface 10a or lower surface 10b) of the fiber 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 lower surface 12b of the first layer 12, if the fiber 10 contains only the first layer. Cracks can also be in the second and / or third layers 14, 16 and, if present, form the outer surface of the fibers 10. Figure 12 shows a micrograph with a 1000X magnification of the surface of one embodiment of fibers having cracks. The figure 13 presents a micrograph with a 20,000X magnification of the surface of one embodiment of fibers having cracks.

Cracks, also known as hollows, channels or cuts, are oriented along the length of the fiber 10 in the direction of uniaxial orientation. The average size of these cracks is approximately somewhere in the range of 300 μm to 1000 μm in length, and they occur at a frequency of approximately 5-9 cracks / mm, as shown in Figure 14, taken at 100,000X magnification. Cracks form if there is a defect on the surface of the fiber during the drawing process or orientation. In some embodiments, the nanoclay particle or agglomerated nanoclay particles can act as introduced defects. If a nanoclay particle is in the polymer element, the polymer element is oriented around the inserted front of the crack and propagates along this front in the longitudinal direction of orientation, leading to the formation of cracks.

In one embodiment, cracks are formed by the cavity-initiating particles. Preferably, cracks form from the nanoclay particles initiating cavities. Although surface defects, such as cracks, are generally considered to be a defect and minimize or eliminate in the fibers, it has been shown that fibers 10 having cracks 40 exhibit excellent adhesion to rubber when embedded in rubber and if the fibers in the fibrous layers are coated with an adhesion promoter . Without being limited by any particular theory, it is believed that the adhesion promoter at least partially permeates and fills cracks, forming a fixative and improving adhesion between the fiber and the rubber. In fact, in testing, the cohesion between the rubber with itself weakens before the adhesion between the fiber and the rubber weakens.

Referring again to Figure 1, the fibrous layer 100 containing fiber 10 can be any suitable fibrous layer, such as knitted, woven, non-woven and unidirectional materials. Preferably, the fibrous layer 100 is sufficiently open to allow subsequent coatings (such as rubber) to pass through the fibrous layer 100, minimizing the formation of windows.

In one embodiment, the fibrous layer is a woven material, for example, plain weave, satin, twill, matting, poplin, jacquard and crepe fabrics. Preferably, the woven material is a plain weave fabric. It has been shown that plain weave has good abrasion resistance and wear resistance. Twill weaving has been shown to have good properties for complex curves, so it may also be preferred for rubber products.

According to another embodiment, the fibrous layer is a knit weave, for example, circular knit knit, reverse knit circular knit, double knit, smooth weave knit fabric, twisted knit fabric, three-knit pile fabric, terry or double knit , knitted base with weft thread inserted, knitted base and knitted base with or without microdeny surface.

According to another embodiment, the fibrous layer 100 is multiaxial, such as a triaxial fabric (knitted, woven or non-woven). According to another embodiment, the fibrous layer 100 is a filament-displaced fabric. According to another embodiment, the fibrous layer 100 is a nonwoven material. The expression non-woven refers to structures connecting a mass of threads that are tangled and / or fused with heat so as to provide a coordination structure with a degree of internal bonding. Non-woven materials for use as the fiber layer 100 can be obtained using many processes, such as, for example, melt forming, hydro-entangling processes, mechanical entangling processes, piercing, and the like.

According to another embodiment, the fibrous layer 100 is unidirectional and may have overlapping fiber or may have spacing between the fibers. According to one embodiment, the fiber is wound continuously around a rubber article to form a unidirectional fiber layer. According to some embodiments, the inclusion of the distance between the fibers can lead to slight leakage of rubber between the fibers, which may be useful for adhesion.

According to one example, the fibrous layer 100 in FIG. 1 is a woven material (shown in FIG. 15 by tape elements 10 having a square cross-sectional area) embedded in rubber so that everything shown is the ends of the fibers 10.

According to another embodiment, the fiber layer 100 contains fibers and / or filaments that have an excellent composition, size and / or shape with respect to the fibers 10. These additional fibers can contain, but are not limited to: polyamide, aramid (including meta and para forms), district, PVA (polyvinyl alcohol), polyester, polyolefin, polyvinyl, nylon (including nylon 6, nylon 66 and nylon 46), polyethylene naphthalate (PEN), cotton, steel, carbon, fiberglass, steel, polyacrylic material, polytrimethylene terephthalate (PTT) polycyclohexanedimethylene tereph thalate (PCT), polybutylene terephthalate (PBT) modified with polyethylene glycol (PEG) PET, polyacrylic acid (PAA), polytrimethylene terephthalate, nylons (including nylon 6 and nylon 66); regenerated cellulose (such as district or Tencel); elastomeric materials such as spandex; high-quality fibers, such as polyaramides, and natural polyimide fibers, such as cotton, linen, ramie and hemp, protein materials such as silk, wool and other animal hair, such as angora, alpaca and vicuna, fiber-reinforced polymers, thermosetting polymers, their compositions and mixtures thereof. These additional fibers / threads can be used, for example, in the direction of the warp of the woven fiber layer 100, while the fibers 10 are used in the weft direction.

In one embodiment, the fibers are surrounded at least partially by the adhesion promoter. A common problem when producing a rubber composite is maintaining good adhesion between rubber and fibers and fibrous layers. A common method for promoting adhesion between rubber and fibers is to pretreat the filaments with an adhesive layer, usually obtained from a mixture of rubber latex and a condensation product of phenol and formaldehyde, with phenol almost always being resorcinol. This is the so-called "RFL" method (containing latex resorcinol formaldehyde resin). The latex containing resorcinol formaldehyde resin may contain vinyl pyridine latex, styrene-butadiene latexes, waxes, fillers and / or other additives. The “adhesive layer” as used herein includes RFL-based chemicals and other RFL-free chemicals for rubber adhesion.

In one embodiment, the adhesive chemical compositions are RFL-free chemical compositions. In one embodiment, the adhesive chemical compositions do not contain formaldehyde. In one embodiment, the adhesive composition comprises a non-crosslinked resorcinol formaldehyde and / or resorcinofurfural condensate (or phenol formaldehyde condensate that is water soluble), rubber latex and an aldehyde component such as 2-furfural. The composition can be applied to fabric substrates and used to improve adhesion between treated fabric substrates and rubber materials. More information about these chemical compositions can be found in US Patent Application Serial Number 13/029293, filed February 17, 2011, which is incorporated herein in its entirety.

The adhesive layer can be applied to the fibers before being formed into the fiber layer or after the fiber layer is formed in any conventional manner. Preferably, the adhesive layer is a layer containing latex resorcinol formaldehyde resin (RFL) or a rubber adhesive layer. In general, an adhesive layer is applied by immersing the fibrous layer or fibers in a solution of the adhesive layer. The fibrous layer or fibers are then passed through squeeze rolls and a dryer to remove excess liquid. The adhesive layer is usually cured at a temperature in the range of 150 ° to 200 ° C.

The adhesion promoter can also be incorporated into the surface layer (second and / or third layer) of the fiber or can be applied to the fiber and / or fiber layer as a separate film. Thermoplastic films in this category consist of various polyamides and their copolymers, polyolefins and copolymers of polyolefins, polyurethanes and methyl methacrylic acid. Examples of these films include a 3M ™ 845.3M ™ NPE-IATD 0693 film and a Nolax ™ A21.2242 film.

The fibers may be formed by any suitable method or method. There are two preferred methods for producing a hardened rubber product. The first begins with slotted extrusion of the polymer to form fibers (according to one embodiment, the fibers are tape elements having a square or rectangular cross section). The head usually contains from 5 to 60 slots, each forming a fiber (tape element). According to one embodiment, each slot head has a width of from about 15 mm to 50 mm and a thickness of from about 0.6 to 2.5 mm. Fibers immediately after extrusion typically have a width of 4-12 mm. The fibers can be extruded as having a single layer, or they can have a second layer and / or a third layer obtained by co-extrusion.

Then the fibers are uniaxially stretched. In one embodiment, the fibers are pulled to a ratio of preferably about 5 or more, giving a fiber with a modulus of at least about 2 GPa and a density of at least about 0.85 g / cm ³ .

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

In one embodiment, elongation of the fibers causes cavities in the fiber. According to one embodiment, the formed cavities are in an amount of from about 3 to 18 vol.%. According to another embodiment, the extrudant comprises a polymer and particle initiating cavities, causing cavities in the fiber and / or cracks to form on the surface of the fiber.

Fibers are formed into a fibrous layer that contains woven materials, nonwoven materials, 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 completely embedded) into the rubber. According to embodiments in which the fibers contain cracks, it is preferred that the adhesive coating at least partially fill the cracks.

According to a second method, the polymer is extruded into a film. The film can be extruded having one layer, or it can have a second layer and / or a third layer obtained by co-extrusion. Then the film is cut into many fibers. According to one embodiment, the fibers are tape elements having square or rectangular cross-sectional shapes. These fibers are then uniaxially stretched. In one embodiment, the fibers are pulled to a ratio of preferably about 5 or more to give a fiber with a modulus of at least about 2 GPa and a density of at least about 0.85 g / cm.

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

In one embodiment, elongation of the fibers causes cavities in the fiber. According to one embodiment, the formed cavities are in an amount of from about 3 to 18 vol.%. According to another embodiment, the extrudant comprises a polymer and particle initiating cavities. With uniaxial orientation, this causes cavities in the fiber and / or cracks to form on the surface of the fiber.

Fibers are formed into a fibrous layer, which includes woven materials, non-woven materials, unidirectional fabrics and knitted fabrics. The fibers are then optionally coated with an adhesion promoter, such as an RFL coating, and at least partially embedded in rubber. According to embodiments in which the fibers contain cracks, it is preferred that the adhesive coating at least partially fill the cracks.

According to one embodiment, the head extruding the film or fiber has a rectangular cross-section (having an upper side, a lower side and 2 rib sides), wherein at least one of the upper or lower sides of the head has a serrated surface. They can produce films or films having an excellent surface structure or surface texture.

According to another embodiment, the fibers are heat treated before they are formed into a fiber layer. Heat treatment of the fibers provides several advantages, such as a higher modulus, greater strength, less elongation and, especially, less shrinkage. Fiber heat treatment methods include convection heating with hot air, steam heating, infrared heating, or conductive heating, such as stretching over hot plates, all under tension.

Test methods

Delamination Test: The delamination test was carried out on an MTS tensile tester at a speed of 12 inches / minute. One end of the sample (preferably the rubber side) was fixed on the lower clip and the fabric was fixed on the upper clip. The resistance to peeling of the fabric from rubber was measured from the average force on the separation of the layers. A coating film was added to the edge of the sample (half an inch) between the fibers and the rubber to facilitate peeling test.

The peeling resistance measured in the above test shows the force required to separate a single fiber or unidirectional mass of fibers from rubber. In all experiments, the mass of fibers is pulled in the direction of 180 degrees relative to the rubber sample. In all samples, the rubber thickness was approximately 3 mm.

Examples

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

Example 1

Example 1 was a single-stranded nylon fiber having a circular cross-sectional shape with a diameter of 240 μm. The nylon used was nylon 66, available from Invista ™ as nylon 66 SSP-72. Nylon was extruded from a slit head, which had 60 slots, each slit having a diameter of 1.1 mm. Nylon was extruded at 300 ° C at a rate of 20 kg / h. The resulting fiber was then cooled to 32 ° C and uniaxially oriented to a drawing degree 5. The drawing was carried out on a three-stage drawing line with a drawing of 4, 1.25 and 1 in the first, second and third stages, respectively. The finished nylon fiber was characterized by a module of 1 GPa, a density of 1.14 g / cm ³ . The fiber essentially did not contain cavities or cracks on the surface of the fiber.

A single-strand nylon fiber was coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry fibers. The coated fibers were then air dried and cured in an oven at 190 ° C. for three minutes. The cured fibers were then pressed into rubber (available from Akron Rubber Compounding as RA306) in a mold at 300 psi. inch, so that the entire surface of the fiber was embedded in the rubber, and the intermediate was cured at 160 ° C for 30 minutes. To cover 0.5 inches (1.27 cm) of rubber, seven fibers were placed 1.7 mm apart to form a unidirectional fiber layer. The delamination test was carried out as described above, with a delamination resistance of 77 psi. The resulting peeled fibers also had a small amount of rubber still attached. This shows a slight cohesive destruction of rubber (destruction of rubber attached to the surface of nylon fibers from the bulk of the rubber). This cohesive fracture is typical if any open tissue or open fibrous layer becomes embedded due to the open structure of the fabric through which the rubber can pass and fill the fabric, and adhere to another rubber.

Example 2

Example 2 is a multi-strand nylon fiber. To obtain a multi-strand fiber, two nylon fibers formed of nylon, available from Kordsa Global under the trade name T-728, having a circular cross-section with denier 940, were twisted together in the right direction of the strand to form a multi-strand nylon fiber with denier 1880. Multi-strand twisted fiber was characterized by a modulus of 3 GPa and a density of 1.14 g / cm ³ . The fiber essentially did not contain cavities or cracks on the surface of the fiber.

The multifilament nylon fiber was coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry fibers. The coated fibers were then air dried and cured in an oven at 190 ° C. for three minutes. The cured fibers were then pressed into rubber (available from Akron Rubber Compounding as RA306), so that the entire surface of the fiber was embedded in the rubber, and the intermediate was cured at 160 ° C for 30 minutes. To cover 0.5 inches (1.27 cm) of rubber, seven fibers were spaced 1.75 mm apart to form a unidirectional fiber layer. The delamination test was carried out as described above, with a peeling resistance of 59 psi. As in Example 1, similar cohesive failure of rubber was observed.

Example 3

Example 3 was a nylon film (not fiber) having a rectangular cross-sectional shape with a width of 25 mm and a height of 200 μm. The nylon used was nylon 66 available from Invista ™ as nylon 66 SSP-72. Nylon was extruded from a film head, which was 4 ″ wide and 1 mm high. Nylon was extruded at 300 ° C at a rate of 2 kg / h. The resulting film was then cooled to 32 ° C and not stretched or oriented. The nylon film was fragile and difficult to process, resulting in the film cracking easily. The finished nylon film was characterized by a modulus of 500 MPa and a density of 1.14 g / cm ³ . The film essentially did not contain cavities or cracks on the surface of the film, but was characterized by a very high surface roughness.

The nylon film was coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of the film. The coated film was then air dried and cured in an oven at 190 ° C. for three minutes. The cured film was then pressed into rubber (available from Akron Rubber Compounding as RA306) so that the entire surface of the film was on one side of the rubber and the intermediate was cured at 160 ° C for 30 minutes. The delamination test was performed as described above, with a peeling resistance of 2 lbf / in. One of the reasons for such a low value was explained by the inability of the RFL adhesive to bind to the surface of the material and film to completely press into the surface of the rubber (assuming that the surface of the film was not completely embedded in the rubber).

Example 4

Example 4 was a single-layer nylon fiber having a rectangular cross-section with a width of 2 mm and a height of 75 μm. The nylon used was nylon 66, available from Invista ™ as nylon 66 SSP-72. The polymer was extruded from a slit head, which had 12 slots, each slit having dimensions of 25 mm by 0.9 mm. Nylon was extruded at 300 ° C at a rate of 20 kg / h. The obtained ribbon element was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 5 to 6. The drawing was carried out on a three-stage drawing line with a drawing of 4, 1,2 and 1,1 in the first, second and third stages, respectively. It is believed that a similar modulus and strength can also be obtained if the degrees of stretch were distributed differently over the stretch zones. For example, a module of 6 GPa could also be obtained if the degrees of extraction were 1.5, 3.3, and 1.1 in the first, second, and third stages, respectively. The finished nylon tape element was characterized by a module of 6 GPa, a density of 1.06 g / cm ³ and a cavity volume of 8 vol.% (By volume) of the fiber. Micrographs of the fiber can be seen in figure 9. The cavities stretched intermittently along the longitudinal section of the fiber. The size of the cavities was in the range of 50-150 nm in width and 0-5 microns in length. The density of the cavities was 8% by volume. The fiber was substantially free of cracks on the surface of the fiber.

The resulting nylon fiber (which is a tape element) was then coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight dry tapes. The coated tapes were then air dried and cured in an oven at 190 ° C for 3 minutes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid. The delamination test was performed as described above, resulting in destruction of the rubber at 197 psi. The result of the strength of the delamination test was the force required to break the rubber in the sample. During the delamination test, the fibers were not pulled out of the rubber, so the rubber was destroyed. This shows that the peeling resistance was at least 197 psi, however, the exact number cannot be determined due to the destruction of the rubber.

Example 5

Example 5 was the same as example 4, except that the total degree of fiber drawing was 3. The finished nylon fiber was characterized by a modulus of 3.5 GPa, a density of 1.06 g / cm ³ and a cavity volume of 8 vol.% (By volume ) fibers.

Example 6

Example 6 was the same as example 4, except that the total degree of fiber drawing was 4. The finished nylon fiber was characterized by a module of 4.1 GPa, a density of 1.06 g / cm ³ and a cavity volume of 8 vol.% (By volume ) fibers. Comparing examples 4, 5, 6, the modulus and strength, as it turned out, are commensurate with the degree of drawing in proportion.

Example 7

Example 7 was a single-layer nylon fiber having a rectangular cross-section with a width of 4 mm and a height of 130 μm. The polymer used was nylon 66, available from Invista ™ as nylon 66 SSP-72. Nylon was extruded from a slit head, which had 12 slots, each slit measuring 25 mm by 0.9 mm. Nylon was extruded at 300 ° C at a rate of 60 kg / h. The obtained ribbon element was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 5 to 6. The drawing was carried out on a three-stage drawing line with a drawing of 3.1, 1.65 and 1.1 in the first, second and third stages, respectively. The finished nylon tape element was characterized by a module of 800 MPa, a density of 1.14 g / cm ³ . The fiber essentially did not contain cavities or cracks on the surface of the fiber. Comparing the fibers of Example 7 with Example 4, the fibers of Example 7 were twice as wide, almost twice as thick, and they were extruded from the same size of the slit head, but with a yield of three times that. As indicated above, orientation in the fiber bundle is a major factor for the appearance of cavities in the fibers. The presence and uniformity of the cavities along the transverse width of the oriented fiber depends on whether the entire polymer element was oriented during the drawing process along the longitudinal direction. The absence of cavities is explained by the fact that effective heat transfer did not occur in the polymer element of its full orientation. The areas of oriented and non-oriented sites were obtained in polymer tapes.

The nylon fiber was coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry tapes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid.

Example 8

The coated fibers of Example 4 were laid on rubber (available from Akron Rubber Compounding as RA306) according to a unidirectional pattern having 0.5 mm of distance between the fibers, forming a unidirectional fibrous layer that does not cover the entire surface of the rubber. They were cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers were laid. A film to be removed was placed between the fiber layer and the rubber at one end to facilitate peeling test. The delamination test was carried out as described above, leading to the destruction of the rubber at 180 pounds-force / inch, showing that the peeling resistance was greater than this value. This value was actually equal to the peeling resistance of the unidirectional fibrous layer without distance between the fibers (example 4). A slight variation in the values is inevitable, since this force is indicative of the tensile strength of the rubber and, thus, depends on the thickness of the rubber.

Example 9

The nylon film of Example 3 was adhesively bonded to rubber (available from Akron Rubber Compounding as RA306) using an adhesive film available from ZM as 3M 845 film. The adhesive film consisted of an acrylic copolymer, a tackifier and vinyl carboxylic acid. The film was pressed into the rubber (using an adhesive film between the rubber and the nylon film) so that the entire surface of the nylon film was not covered (not embedded) with rubber, and then the sample was cured at 160 ° C for 30 minutes. The delamination test was carried out as described above, with a peeling resistance of 27 pounds-force / inch, which is an increase in peeling resistance compared to example 3, in which RFL adhesive was used for coating.

Example 10

The fibers of Example 10 were similar to the fibers of Example 4, with the addition of particle-initiating cavities. Example 10 is a single-layer nylon fiber having a rectangular cross-section with a width of 2 mm and a height of 75 μm. The polymer used was nylon 66, available from Invista ™ as nylon 66 SSP-72, and contained 7% by weight of nanoclay (cloisite) available from Southern Clay Company. Nylon was extruded from a slit head, which had 12 slots, each slit measuring 25 mm by 0.9 mm. Nylon was extruded at 300 ° C. at a rate of 20 kg / h. The obtained fiber (which is a ribbon element) was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 5 to 6. The drawing was carried out on a three-stage drawing line with a drawing of 4, 1, 2 and 1.1 in the first, second and third stages, respectively . As indicated in example 1, the same modulus and strength can also be obtained if the degree of drawing was distributed differently among the drawing zones. The finished nylon fiber was characterized by a module of 6 GPa, a density of 1.06 g / cm ³ and a cavity volume of 8 vol.% Fiber. The cavities in the fiber can be seen in microphotographs of figures 10a and 10b. The cavities stretched intermittently along the longitudinal section of the fiber. The size of the cavities was in the range of 50-150 nm in width and 0-5 microns in length. The concentration of the cavities was 8% by volume. The cavities were similar in shape to those obtained without particle-initiating cavities. The fiber also contained cracks on the surface of the fiber. These cracks located on the surface of the fiber were discontinuous along the longitudinal section of the fibers, and their length ranged from about 300 microns to 1000 microns. Cracks on the surface of the fiber can be seen in microphotographs of figures 11, 12 and 13.

The nylon fiber was coated with an RFL composition using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry tapes. The coated fibers were then air-dried and cured in an oven at 190 ° C. for 3 minutes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid. A film to be removed was placed between the fiber layer and the rubber at one end to facilitate peeling test. The delamination test was performed as described above, leading to destruction of the rubber at 197 psi, indicating that the delamination resistance was greater than this value.

Example 11

Example 11 was a polyester fiber having a rectangular cross-sectional shape with a width of 2 mm and a height of 60 μm. The polyester used was polyethylene terephthalate, available from Nanya Plastics Corporation as PET IV 60. The polyester was extruded from a slit head, which had 12 slots, each slit having a size of 25 mm by 0.9 mm. The polyester was extruded at 300 ° C. at a rate of 20 kg / h. The resulting fiber was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 7-9. The hood was drawn on a three-stage hood line with a hood of 3.4, 2.2 and 1 in the first, second and third stages, respectively. The finished polyester tape element was characterized by a module of 8 GPa, a density of 1.20 g / cm ³ and a cavity volume of 8 vol.% Fiber. The fiber was substantially free of cracks on its surface.

The polyester fiber was coated with a two-step immersion procedure using a pre-immersion solution containing caprolactam-protected isocyanate, available from EMS as Grilbond IL-6, and curing at 225 ° C for three minutes, followed by immersion in a standard RFL composition using resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinyl pyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry tapes. The coated fibers were then air dried and cured in an oven at 190 ° C. for three minutes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid. In the delamination test, the elongated fibers had a large piece of rubber still attached. The delamination test resulted in a sticking force of 120 pounds-force / inch, showing cohesive failure of the rubber.

Example 12

Example 12 was a mixture of single-layer polyester and nylon 66 fibers having a rectangular cross-section with a width of 1.5 mm and a height of 100 μm. The polyester used was polyethylene terephthalate, available from Nanya Plastics Corporation as PET IV 60; the nylon used was nylon 66, available from Invista ™ as nylon 66 SSP-72. The polymer was extruded from a slit head, which had 12 slots, each slit having dimensions of 25 mm by 0.9 mm. The mixture was physically mixed in a ratio of 90:10 (90% polyester and 10% nylon by weight) and extruded at 300 ° C at a rate of 20 kg / h. The obtained ribbon element was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 5 to 7. The drawing was carried out on a three-stage drawing line with drawing 3, 2 and 0.9 in the first, second and third stages, respectively. It should be noted that submission with a slight excess is required at the last stage for a number of reasons. This excess feed reduces shrinkage and a decrease in the modulus (creep) of the fibers. It also increases the strength of the fibers. It is believed that the same modulus and strength can also be obtained if the degrees of stretch were distributed differently over the stretch zones. For example, a 10 GPa module can also be obtained if the degrees of extraction were 1.5, 3.3, and 0.9 in the first, second, and third stages, respectively. The finished tape element from a mixture of complex polyester-nylon was characterized by a modulus of 10 GPa and a density of 1.37 g / cm ³ .

Fiber from a polyester-nylon mixture by two-step immersion using a pre-immersion solution containing caprolactam-protected isocyanate, available from EMS as Grilbond IL-6, and curing at 225 ° C for three minutes, followed by immersion in a standard RFL composition, using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry tapes. The coated tapes were then air dried and cured in an oven at 190 ° C for 3 minutes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid. The delamination test was carried out as described above, resulting in a value of 143 pounds-force / inch.

Example 13

Example 13 was a mixture of single-layer polyester and nylon 66 fibers having a rectangular cross-section with a width of 1.5 mm and a height of 100 μm. The polyester used was polyethylene terephthalate, available from Nanya Plastics Corporation as PET IV 60; the nylon used was nylon 66, available from Invista ™ as nylon 66 SSP-72. The polymer was extruded from a slit head, which had 12 slots, each slit having dimensions of 25 mm by 0.9 mm. The mixture was physically mixed in a ratio of 70:30 (70% polyester and 30% nylon by weight) and extruded at 300 ° C at a rate of 20 kg / h. The obtained ribbon element was then cooled to 32 ° C and uniaxially oriented to a drawing degree of 5 to 7. The drawing was carried out on a three-stage drawing line with drawing 3, 2 and 0.9 in the first, second and third stages, respectively. It should be noted that submission with a slight excess is required at the last stage for a number of reasons. This excess feed reduces shrinkage and a decrease in the modulus (creep) of the fibers. It also increases the strength of the fibers. It is believed that the same modulus and strength can also be obtained if the degrees of stretch were distributed differently over the stretch zones. For example, a 10 GPa module can also be obtained if the degrees of extraction were 1.5, 3.3, and 0.9 in the first, second, and third stages, respectively. The finished tape element from a mixture of complex polyester-nylon was characterized by a modulus of 10 GPa and a density of 1.37 g / cm ³ .

Fiber from a polyester-nylon mixture by two-step immersion using a pre-immersion solution containing caprolactam-protected isocyanate, available from EMS as Grilbond IL-6, and curing at 225 ° C for three minutes, followed by immersion in a standard RFL composition, using a resorcinol precondensate, available from Indspec Chemical Corporation as Penacolite-2170, and vinylpyridine latex, available from Omnova Solutions as Gentac VP 106, on (coating weight) 25% by weight of dry tapes. The coated tapes were then air dried and cured in an oven at 190 ° C for 3 minutes. The coated fiber was then laid onto the rubber (available from Akron Rubber Compounding as RA306) in a unidirectional pattern without any spacing between the fibers so that the resulting unidirectional fiber layer covered virtually the entire surface of the rubber. It was then cured at 160 ° C for 30 minutes. To cover a 0.5 inch (1.27 cm) strip of rubber, six rectangular fibers had to be laid. The delamination test was carried out as described above, resulting in a value of 143 pounds-force / inch.

All references, including publications, patent publications, and patents cited herein, are hereby incorporated by reference to the extent that each reference was individually and specifically indicated to be incorporated by reference and set forth in its entirety herein.

The use of singular expressions and similar reference objects in the context of the description of the invention (in particular in the context of the following claims) should be construed as encompassing both the singular and the plural, unless otherwise indicated herein or explicitly disproved by the context. The expressions “comprising”, “having”, “including” and “covering” should be interpreted as open expressions (ie meaning “including but not limited to”) unless otherwise indicated. The enumeration of ranges of values in this document is intended only for a quick way of referring separately to each individual value falling into the range, unless otherwise specified herein, and each individual value is included in the description, as if it were separately listed in this document. All methods described herein may be performed in any suitable order unless otherwise specified herein or otherwise explicitly disproved by the context. The use of any and all examples or typical language (eg, “such as”) provided herein is intended only to better illuminate the invention and does not constitute a limitation on the scope of the present invention unless otherwise stated. No wording in the description should be construed as indicating any undeclared element as necessary for the practice of the invention.

Preferred embodiments of the present invention are described herein, including the best method known to the inventors for implementing the present invention. Variants of these preferred embodiments may become apparent to those skilled in the art upon reading the foregoing description. The inventors suggest that those skilled in the art will implement such variations as necessary, and the inventors imply that the invention may be practiced otherwise than specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the object set forth in the claims appended to the document in accordance with applicable law. In addition, any combination of the above elements in all their possible variations is encompassed by the present invention, unless otherwise indicated herein or otherwise explicitly disproved by the context.

Claims (19)

1. A hardened rubber material, which is rubber, into which a fibrous layer is embedded, wherein the fibrous layer comprises uniaxially elongated ribbon elements having a rectangular section, an upper surface and a lower surface, and wherein the ribbon elements comprise at least a first layer characterized by a degree drawing at least about 5, modulus of at least about 2 GPa, a density of at least 0.85 g / cm ^3, wherein the first layer comprises a polymer selected from the group consisting of poliami a, polyester and copolymers thereof. 2. The hardened rubber material according to claim 1, characterized in that the first layer contains many cavities. 3. The hardened rubber material according to claim 1, characterized in that the fibers also contain many cracks on at least the upper or lower surface of the fibers. 4. A tire made of the hardened rubber material according to claim 1, characterized in that the tire layer selected from the group consisting of a protective layer, a carcass layer, a chafer, a rim tape, an amplifier, a carcass layer, a shoulder layer, a retaining layer, a tape layer the separation layer, the wire base and the base of the edge of the bandage, is a fibrous layer. 5. A method of hardening a rubber material, including:
slotted extrusion of tape elements or the extrusion and cutting of a film into a plurality of tape elements, the tape elements having a rectangular cross section and at least a first layer, the first layer containing a polymer selected from the group consisting of polyamide, polyester and their copolymers having rectangular section;
the orientation of the tape elements uniaxially to a stretch of at least about 5 with the formation of uniaxially elongated tape elements having an upper surface and a lower surface and characterized by a modulus of at least about 2 GPa and a density of at least 0.85 g / cm ³ ;
the formation of uniaxially elongated tape elements in the fibrous layer and the introduction of the fibrous layer into the rubber. 6. The method according to claim 5, characterized in that the first layer further comprises initiating cavities of the particle, and the orientation of the tape elements includes the formation of many cavities. 7. The method according to claim 5, characterized in that the orientation of the fibers uniaxially forms a plurality of cracks on at least the upper or lower surface of the fibers, the method further comprising coating the fibers with an adhesion promoter at least partially filling the plurality of fiber cracks before or after the formation of the fiber into the fibrous layer. 8. A hardened rubber material, which is rubber, into which a fibrous layer is embedded, wherein the fibrous layer contains uniaxially elongated fibers having at least a first layer, an upper surface and a lower surface, the first layer containing a polymer and a plurality of cavities, wherein are in an amount of about 3 to 18 percent by volume of the first layer. 9. The hardened rubber material according to claim 8, characterized in that the first layer further comprises initiating particle cavities. 10. The hardened rubber material of claim 8, wherein the fibers further comprise a plurality of cracks on at least the upper or lower surface of the fibers. 11. The hardened rubber material according to claim 8, characterized in that the fibers have a rectangular cross-section. 12. The hardened rubber material of claim 8, wherein the first layer comprises a mixture of polyester and nylon 6. 13. A tire made of hardened rubber material according to claim 8, characterized in that the tire layer selected from the group consisting of a protective layer, a carcass layer, a chafer, a rim tape, an amplifier, a carcass layer, a shoulder layer, a retaining layer, a tape layer the separation layer, the wire base and the base of the edge of the bandage, is a fibrous layer. 14. A method of hardening a rubber material, including in order:
gap extrusion of tape elements or extrusion and cutting of a film into a plurality of tape elements, the tape elements having an upper surface and a lower surface and at least a first layer, the first layer containing a polymer;
orientation of the fibers uniaxially with the formation of uniaxially elongated fibers, forming many cavities in the first layer in an amount of from about 3 to 18 percent by volume of the first layer;
the formation of uniaxially elongated fibers in the fibrous layer and
incorporation of a fibrous layer into rubber. 15. The method according to 14, characterized in that the fibers have a rectangular cross-section. 16. The method according to 14, characterized in that the polymer of the first layer contains a polymer selected from the group consisting of polyamide, polyester and their copolymers. 17. The method according to 14, characterized in that the first layer of fibers further comprises initiating cavity particles. 18. The method according to 14, characterized in that the orientation of the fibers uniaxially forms a plurality of cracks on at least the upper or lower surface of the fibers, the method further comprising coating the fibers with an adhesion promoter, at least partially filling the plurality of fiber cracks in front of or after the formation of the fiber into the fibrous layer. 19. The method according to 14, characterized in that the first layer contains a mixture of complex polyester and nylon 6.

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