Tire having an innermost layer with an intrinsic porous sealant

Abstract

A tire having an in situ generated, internally puncturing sealant layer (102, 103) and an internal noise dampening portion (204) includes: a support tire carcass having one or more layers of ply, an outer circumferential tread (201), and a radially inner liner (203); a pair of beads; a sidewall extending radially inward from an axially outer edge of the tread portion (201) to connect a respective bead; a sealant (102, 103) including at least one sealant layer disposed radially inward from the radially inner liner (203) of the tire carcass; and an internal porous noise dampening portion (204) as an innermost layer adjacent to the sealant (102, 103). The noise dampening portion (204) has a density of less than 1.3 g / cm 3 and the sealant (102, 103) provides self-sealing properties to the tire.

Description

[0001] Cross-references to related applications

[0002] This application is a continuation-in-part claim to U.S. Patent Application SN 16 / 819,701, filed March 16, 2020, entitled “Pneumatic Tire with In-Situ Generated Sealant Composition by Chain Cessation of Ionic Butyl,” a continuation-in-part claim to U.S. Patent Application SN 14 / 991,575, filed January 8, 2016, entitled “Pneumatic Tire having Sealant Layer,” a continuation-in-part claim to U.S. Patent Application SN 14 / 572,138, filed December 16, 2014, entitled “Pneumatic Tire Having Multiple Built-In Sealant Layers and Preparation Therefore,” and is incorporated herein by reference. Background Technology

[0003] The present invention relates to a tire having one or more inner sealant layers, wherein the one or more inner sealant layers are formed from a sealant precursor layer during the tire curing step, while simultaneously forming a porous innermost layer.

[0004] Tires consist of multiple annular layers, including different blends, ply layers, and belt layers, which are applied to a forming drum before the curing process for precise alignment and higher interlayer bond strength. Bonding and aligning the layers before curing results in better uniformity and durability in the tire.

[0005] Tire punctures are an inherent problem with pneumatic rubber tires. Therefore, sealants have been developed and layered within the tire tread and ply layers to minimize the impact of punctures. The lack of suitable technology has led tire companies to apply annular sealant layers after tire curing. Inspections of recent passenger car (PCR) sealant tires from major tire manufacturers revealed the absence of cured capsule markings at the innermost sealant cap layer, indicating that annular sealant layers were applied after tire curing. Similarly, inspections of the innermost porous layers of recent PCR tires from major tire manufacturers revealed that they were based on polyurethane, suggesting that they were applied after tire curing. It is known that porous polyurethanes do not possess sufficient thermal stability to withstand the high temperatures and pressures of tire curing and will flatten and thus lose their porous structure. The presence of a suitable innermost porous layer in the tire is beneficial because it absorbs cavity noise in the dominant frequency range of 200-250 Hz, which travels inside the passenger compartment and thus generates annoying noise for vehicle occupants.

[0006] Furthermore, most commercially available PCR sealant tires expose the sealant within the tire cavity, requiring application after tire curing; otherwise, it will contaminate the cured bladder during curing. Additionally, in tires where sealant is applied to the cured tire, only physical bonding exists at the sealant-liner interface, lacking chemical bonding or interfacial cross-linking, resulting in relatively poor adhesion. Poor adhesion can lead to sealant separation from the liner, resulting in loss of peg-sealing capability. Due to poor interfacial bonding, the sealant may slip, causing tire balance problems. Similarly, in porous layers applied after curing, there is no interlayer chemical bonding, resulting in weak bonding. Therefore, the application of porous layers is limited to a narrow strip below the tread, where limited deflection exists, and if it extends beyond the belt layer edge into the sidewall, the porous layer may separate from the liner, leading to balance and other problems.

[0007] Applying sealant and porous layers to cured tires is cumbersome because the liner needs to be very clean before sealant and / or porous layer application to allow for better physical bonding between the sealant and the liner, and between the porous layer and the liner. In most tire manufacturing processes, the innermost layer is primarily contaminated with silicone from within the tire coating and / or from the lubricant used to easily remove the tire from the bladder mold. Furthermore, applying perfectly aligned sealant inside the cured tire is cumbersome and time-consuming. Tire forming machines with laser guidance help operators perfectly align layers in the tire forming drum, which is possible if a sealant precursor or porous precursor is applied before tire curing, such that the sealant precursor forms the sealant during curing, and the porous precursor forms the porous layer during tire curing.

[0008] The sealant in a cured tire needs to have a low viscosity (or low storage modulus, G') so that it can flow easily and seal puncture holes. This low-viscosity material cannot be applied directly to the tire forming drum because if applied there, it will shift, detach, or deform. Furthermore, punctures can occur at any temperature. A single-layer sealant with low viscosity works very well at low temperatures, but at high temperatures, it can achieve a very low viscosity, which would allow it to flow and leak from the tire during use, contaminating and / or damaging the road. By depleting the tire sealant, the tire loses its ability to seal punctures. Similarly, a single-layer high-viscosity sealant may work very well at high temperatures, but may be almost solid at low temperatures and therefore cannot flow to seal punctures in the tire. Therefore, a single layer of high-viscosity sealant may be good for summer tires but bad for winter tires. Likewise, a single layer of low-viscosity sealant may be good for winter tires but bad for summer tires because it may shift during use or leak from the puncture due to its very low viscosity at high temperatures. For all-season tires, a dual-layer sealant is preferred, with one layer for low-temperature puncture sealing and another for high-temperature puncture sealing. Furthermore, due to interfacial bonding, the high-viscosity sealant layer will tightly hold the low-viscosity sealant layer in place, preventing migration even when its viscosity becomes very low during the summer months. Therefore, the bonding between multiple sealant layers must be good to prevent sealant migration, especially for sealants with low viscosity. Similarly, low-density porous polyurethane, typically applied inside cured tires, has zero tack and will detach if applied to the tire molding drum. Moreover, if applied before tire curing, it does not possess sufficient thermal stability to withstand the tire curing conditions.

[0009] Tires with built-in sealant layers are known in the art. Typically, these tire sealants are formed during tire curing through the thermal degradation of a peroxide-containing butyl rubber-based sealant precursor layer, as described in U.S. Patent Nos. 4,895,610; 6,962,181; 7,073,550; 7,674,344; and 8,293,049; and U.S. Patent Publications 2005 / 0113502 and 2005 / 021568, the teachings of which are incorporated herein by reference in their entirety. The sealant layer can be black or non-black, and short fibers (e.g., polyester or polyurethane fibers) and other filler aggregates can be incorporated into the sealant layer to help seal nail holes.

[0010] Tires with a monolithic porous structure are known in the art, but currently have no commercial significance, despite attempts to push the limits. Tires with porous polyurethane applied inside the cured tire have very low densities. See, for example, application 16922641 by Majumdar et al., filed July 7, 2020, entitled "Noise Damper Bond to Tire Using Adhesives," which has a density of approximately 0.025 g / cm³. 3 The density of polyurethane is important. Applying a higher density material increases tire weight, thus increasing rolling resistance. This increased rolling resistance translates to lower fuel economy in vehicles equipped with such tires, leading to higher greenhouse gas emissions into the atmosphere and contributing to global warming. Recent global climate disasters are attributable to global warming, and countries are working together to prevent it, for example, through agreements like the Paris Agreement. Furthermore, higher-density foam inside the tire insulates against internal heat, reducing its durability. When generated inside the tire, if a lower density is still not possible, the integral foam density should preferably be less than 0.12 g / cm³. 3 US 7,694,707 / USPA 2007 / 0137752 teaches that a foaming agent with a density of 0.28 g / cm³ can be produced by using 25 phr OBSH foaming agent. 3 The foam is a single, integral foam, and its density decreases with increasing blowing agent content. OBSH produces nitrogen gas upon decomposition under tire curing conditions; the higher the gas content, the lower the foam density. Extrapolation from the teachings of US 7,694,707 / USPA 2007 / 0137752 indicates that OBSH should be at a level of 50 phr to achieve 0.12 g / cm³. 3 A reasonable foam density was achieved. Consistent with the extrapolated data from US 7,694,707, US 8,978,721 has demonstrated that a density of 0.139 g / cm³ was achieved using 50 phr azodicarbonamide. 3 Integrated bromobutyl rubber (BIIR) foam. When thermally decomposed, azodicarbonamide primarily releases nitrogen gas and some carbon monoxide. The 50 phr blowing agent used to prepare foam of reasonable density is too high for commercial purposes. Currently, there is a lack of methods to produce foam with a density of 0.12 g / cm³. 3 Or even lower density technologies for porous structures integrated with the tire, the density of which can be achieved by using a lower amount of foaming agent (e.g., 25 phr or less).

[0011] Technology for molding internal sealant tires is available. Technology for applying low-density polyurethane to the inner liner of a cured tire is also available. Therefore, by integrating the above two technologies, it is possible to produce an internal sealant with a porous polyurethane innermost layer. However, for low-density (e.g., 0.12 g / cm³)... 3 Suitable techniques for forming an intrinsic porous layer (or smaller) using a reasonable amount of foaming agent (e.g., 20 phr or less) are not applicable. Therefore, techniques for integrating an intrinsic sealant layer with an intrinsic porous layer are unavailable, but highly desirable. Summary of the Invention

[0012] This invention relates to a tire having an in-situ generated intrinsic puncture sealant layer and intrinsic noise damping portion, the tire comprising: a supporting tire carcass having one or more ply layers, an outer circumferential tread, and a radially inner layer; a pair of bead layers; sidewalls extending radially inward from the axial outer edge of the tread portion to connect to the respective bead layers; a sealant comprising at least one sealant layer disposed radially inward from the radially inner layer of the tire carcass; and an intrinsic porous noise damping portion as the innermost layer adjacent to the sealant, wherein the noise damping portion has a density of less than 1.3 g / cm³. 3 The density; and the sealant provides the tire with self-sealing properties. Attached Figure Description

[0013] The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 This is the cross-section of the tire from bead to bead of the present invention;

[0015] Figure 2 yes Figure 1 A magnified view of the tire;

[0016] Figure 3 yes Figure 1 Alternative embodiments of the tires in the example;

[0017] Figure 4 yes Figure 3 A magnified view of the tire;

[0018] Figure 5 This is a side cross-sectional view showing the orientation of two porous precursor layers applied in a tire forming drum; and

[0019] Figure 6 This is a side cross-sectional view showing the solid and porous precursor layers in the tire forming drum. Detailed Implementation

[0020] The present invention relates to a tire having one or more intrinsic (or integral or built-in) sealant layers formed during tire curing by chain scission of a conventional butyl or butyl ionomer composition catalyzed by peroxide from one or more precursor layers, the tire containing an integral porous innermost layer also formed during the tire curing step from a precursor layer containing one or more foaming agents.

[0021] sealant cap

[0022] In order for the gas formed during the chain breakage of the pre-sealant layer catalyzed by peroxide after curing to escape from the tire interlayer, the sealant capping composition should preferably have a highly permeable rubber, such as natural rubber, butadiene rubber or styrene-butadiene rubber.

[0023] Similar to most other annular layers, the ultimate goal of tire manufacturers is to apply porous precursors or low-density porous layers into the tire forming drum, resulting in a low density (less than 1.2 g / cm³). 3 The attachment of porous materials to the inner liner of a cured tire has not been achieved to date. The performance requirements for applying porous materials or precursors to porous materials in a tire forming drum are more stringent than those for application in a raw tire. For example, during the formation of a raw tire, the material must be stretchable in all directions without tearing. The material must also have good self-adhesion and liner adhesion so that the porous precursor remains attached during the expansion steps of raw (uncured) tire manufacturing. After curing, the porous material must bond well to the tire liner so that it does not detach during tire use. For example, porous silicone rubber can be applied in a raw tire, but the material does not have sufficient tensile strength to withstand the expansion in a tire forming drum. The inventors of US 7,694,707 applied a porous rubber precursor to a raw tire instead of a tire forming drum (see Examples 2 and 3 in US 7,694,707 patent). The inventor of US8,978,721 applied a foam precursor containing 50 phr of foaming agent to the tire molding drum, but could not obtain 1.2 g / cm³. 3 Or even lower densities. This patent application relates to porous precursors that can be applied to a tire forming drum and, during the tire curing step, form a low-density sound-absorbing foam with strong bonding to the liner using a reasonable amount and combination of foaming agents (<20 phr) to achieve a density below 0.12 g / cm³. 3 The foam density. As used herein, the "porous" layer is also referred to as the "foam" layer, and the terms are used interchangeably.

[0024] The three mixed compositions are shown in Table 11 (similar to US 7,694,707, except that N660 is replaced by Ashbury 3772 or Hi-Black 420B). The densities obtained in the metal molds were 0.1118 g / cm³. 3 0.1450g / cm 3 0.1012 g / cm 3 It is significantly lower than US 7,694,707 (0.49 g / cm³). 3 (containing 15 phr foaming agent). Next, capsule forming was attempted with the smooth side of the capsule in contact with the liner, and the density of the porous layer obtained was again significantly lower than that of US 7,694,707, especially in the case of compound 6C027B, where the density was 0.11 g / cm³. 3 Next, capsule molding was attempted, in which the embossed side of the capsule contacted the foam precursor (laboratory simulation of tire curing), and the foam obtained using 6C027A had a density of 0.15 g / cm³. 3 This is significantly lower than previously achieved (US 7,694,707). In the case of compound 6C033C, the density of the porous rubber obtained under metal mold and laboratory simulated tire curing conditions was 0.1012 g / cm³. 3 and 0.53g / cm 3 This indicates that the density of the formed porous material is extremely sensitive to curing conditions. Table 11 shows that by replacing the carbon black in US 7,694,707 with more conductive fillers such as Ashbury 3772 or Hi-Black® 420, the density of the obtained porous material can be reduced by 77% (0.49 g / cm³). 3 For 0.11 g / cm 3 ).

[0025]

[0026] Next, the two compositions tested are shown in Table 12, and 6C027A is very similar to US 7,694,707, both containing a large amount of N660 carbon black. The density of the foam produced in the metal mold (100% filled) was very low, and the density was still lower when the metal mold was 90% filled. During the co-curing of the liner and foam precursor with the liner in laboratory simulated tire curing in a capsule mold, the densities from both 7C026A and 7C026B were high, and this is consistent with US 7,694,707. Increasing the thickness of the precursor slightly reduced the density. However, during laboratory simulated capsule curing, the density was significantly lower when some cavitation was maintained for initial expansion. Final expansion occurs when the mold is opened to remove the cured material. This can be achieved by first laminating the liner, then co-laminating the foam precursor with die-punched holes with calendering, and then laminating the foam precursor without holes. The mold diameter was ¼ inch, and the separation from the center of each hole was 0.7 inches. The cross-section of this laminate through the die holes is shown in Figure 6 As shown in the figure. By controlling the number of pores in the laminate to optimize the initial expansion volume, the foam density can be further reduced.

[0027] Tables 11 and 12 show low-density foams formed using bromobutyl rubber with low unsaturation or double bonds. Bromobutyl rubber can be replaced by other rubbers with low unsaturation, such as chlorinated butyl rubber, butyl rubber, halogenated butyl rubber, ionic butyl rubber, or ethylene propylene diene monomer (EPDM).

[0028]

[0029] The new hybrid composition is based on Exxpro TM 1603 (a copolymer of isobutylene and 4-(bromomethyl)styrene, with no unsaturation in the main chain) without fillers and shown in Table 13. Very low-density materials are obtained even without using laminates containing porous materials. OBSH alone (p,p'-oxybis(benzenesulfonylhydrazine)) produces a density of 0.08 g / cm³ at a phr level. 3 The foam, when combined with Safoam RIC (sodium bicarbonate + citric acid foaming agent, available from REEDY ChemicalFoam), produces a density of 0.07 g / cm³. 3 The foam density can be reduced by using a combination of foaming agents. Further reduction in foam density is expected through the use of porous laminates of foam precursors (see below). In Table 13, Exxpro... TM The 1603 was originally obtained from ExxonMobile as a development sample, and its product name was changed to Exxpro after commercialization. TM3563. Table 13 also shows that by introducing a small amount (2 phr) of a secondary blowing agent (Safoam RIC) into a composition containing 15 phr of primary blowing agent (OBSH), the density of the resulting foam was further reduced by 12.5% ​​(0.08 g / cm³). 3 For 0.07 g / cm 3 ).

[0030]

[0031] Passenger car tires were molded using porous precursors 9C024DA and 9C024DB. After tire molding, the formed porous material was removed from the tire. The sound absorption coefficient was measured in four frequency ranges using a high-impedance tube, and was compared with common polyester polyurethane foam (density 0.024 g / cm³) conventionally bonded within the cured tire to reduce cavity noise. 3 The results were compared and recorded in Table 14.

[0032] The primary frequency range causing annoying noise propagation inside the vehicle compartment is in the 200-250 Hz range. Table 14 shows that when multiple pores are created on the surface of the foam facing the cavity, the noise absorption exceeds that of low-density polyurethane foam typically attached to the interior of a cured tire. Noise absorption is also high in the higher harmonic frequency range (500-1000 Hz).

[0033] This is a novel achievement demonstrating that by applying a foam precursor containing less than 20 phr of foaming agent to raw (uncured) tires, as is done in conventional tire manufacturing processes, it is possible to produce tires with a density of less than 0.1 g / cm³. 3 The internal foam will reduce cavity noise, which is higher than tires where polyurethane foam is attached inside the tire through a cumbersome process after the tire has cured. As used herein, the term "internal" refers to the application of foam noise damping before curing, rather than fixing the noise damping to the tire using adhesives after curing. The term "internal" may also be used interchangeably as built-in, embedded, or integral.

[0034]

[0035] Combination of OBSH and Expansion 930DU120 foaming agents

[0036] The foam precursor composition is shown in Table 17. When this composition is encapsulated together with the inner liner, the expansion in all directions is so high that the sample curls and can be used for sound absorption testing. Such curling is impossible in tires because the tire outer layer is strong and rigid.

[0037]

[0038] Use the following procedure to keep the sample straight so that the noise absorption coefficient can be tested from a laboratory sample without the need for a molded tire.

[0039] Capsule molding with rigid metal mesh support

[0040] A 6''×6''×0.1'' 100 BIIR base liner was placed on top of a 6-inch diameter wire mesh. Then, a 5''×5''×0.12'' foam precursor of 8C029C4 was placed on top of the liner, and the mixture was cured in a laboratory-simulated tire curing process in a capsule mold (20 minutes at 350℉ / 250psi). The cured laminate did not curl and remained straight, and was used for sound absorption testing.

[0041] Sound absorption test

[0042] Prior to the acoustic absorption test, the metal and liner were removed from the 8C029C4 sample. For the polyether polyurethane commonly used in tire interiors, normal incident acoustic absorption tests were performed using a large tube in the frequency range of 100–1600 Hz (ASTM E1050-12) and compared with 8C029C4. For the 8C029C4 sample, the acoustic absorption test was repeated after punching multiple perforations through the foam skin but not through the entire foam. Perforations were performed using a stitching device for forming one piece, with perforation intervals of 1 to 5 mm in the sample. The acoustic absorption coefficients at frequencies of 225 Hz, 450 Hz, and 675 Hz are shown in Table 18.

[0043]

[0044] At approximately the main cavity noise frequency range (225 Hz), the sound absorption of this foam is lower than that of the control polyurethane foam after perforation.

[0045] Exxpro-based with filler TM foam precursor

[0046] Previously, low-density foam was produced by simulating tire curing in a laboratory setting using capsule molds, in the case of Exxpro without fillers. TM The density of the base rubber is as low as 0.07 g / cm³. 3 (Table 13). As previously mentioned, by creating space for initial expansion, a further reduction in density is expected ( Figure 6 This technology opens up the possibility of preparing very low-density intrinsic foam inside tires, which is highly anticipated in future tires. Therefore, a composition with 15 phr blowing agent (OBSH) produces a density of 0.49 g / cm³. 3Foam (US 7,694,707). In laboratory simulations of tire curing in a capsule mold, when 10% of the volume was retained for initial expansion, compositions similar to US 7,694,707 produced a density 73.5% lower (i.e., 0.13 g / cm³). 3 The foam (7C026A in Table 12) can be further reduced by optimizing the volume retained for initial expansion during laboratory simulation of tire curing.

[0047] Table 19 shows the Exxpro-based foam precursor with filler. During capsule formation, it produces 0.11 g / cm³. 3 The low-density foam. If an initial expansion of 10% occurs during capsule formation, and if this reduces the density by 73.5% as previously stated, then extrapolation shows that a density of 0.023 g / cm³ can be prepared. 3 The foam. 0.023g / cm³ 3 Its density is even lower than that of polyurethane foam conventionally bonded inside tires (0.024-0.035 g / cm³). 3 ).

[0048]

[0049] The examples shown in Tables 11, 12, 17, and 19 use black fillers, which produce black blends with a black porous material. To prevent the porous precursor from mixing with other commonly used black tire blends, the precursor can be made non-black by using white fillers (e.g., silica, titanium dioxide) and then combined with the non-black concentrate.

[0050] There is no prior art in which an unstitched internal foam is prepared together with an integral sealant. However, there are prior art techniques in which foam is applied on top of a sealant tire, as described in US 2015 / 0107743, US 2016 / 0347127, and US 10,675,922. Prior art exists for internal sealant tires, in which the sealant is typically formed during tire curing through the thermal degradation of a peroxide-containing butyl rubber-based sealant precursor layer, for example, US Patent Nos. 4,895,610; 6,962,181; 7,073,550; 7,674,344; and 8,293,049; and US Patent Publications 2005 / 0113502 and 2005 / 021568, the teachings of which are incorporated herein by reference in their entirety. The sealant layer can be black or non-black, and short fibers (such as polyester or polyurethane fibers) and other filler aggregates can be incorporated into the sealant layer to help seal nail holes. Existing technologies exist for molding an inherent porous layer in tires, but the density of the porous layer is much higher than needed, and the amount of foaming agent used is too high to be practically meaningful.

[0051] A series of experiments were conducted on the combined in-situ generated intrinsic sealant (or multiple sealant layers) and the in-situ generated intrinsic noise damping component. The materials used are as follows:

[0052] Exxpro TM 1603 (a copolymer of isobutylene and 4-(bromomethyl)styrene, with no unsaturation in the main chain), Exxpro TM The 1603 was originally obtained from ExxonMobile as a development sample, and its product name was changed to Exxpro after commercialization. TM 3563.

[0053] OBSH is p,p'-oxobis-(benzenesulfonylhydrazine) and is obtained from Western Reserve Chemical.

[0054] Safoam RIC is a foaming agent made of sodium bicarbonate and citric acid, available from Reedy Chemical Foam.

[0055] Expancel 930du120 is a foaming agent from Nouryon Company (formerly known as Akzo Nobel).

[0056] Vul-Cup 40KE is α,α-bis(tert-butylperoxy)diisopropylbenzene, 40% by weight in an inert support. It is a product of Arkema.

[0057] SP 1045 is an octylphenol-formaldehyde resin containing hydroxymethyl and is available from SK Capital / SI Group.

[0058] Silene TM 732D is precipitated silica from PPG Industries.

[0059] The abbreviation Butyl 100, ×-Butyl RB 100, is an Arlanxeo product.

[0060] Perkalink 900 is 1,3-bis(citraconimidemethyl)benzene and is available from RheinChemie.

[0061] Duralink HTS is the disodium hexamethylene-1,6-bis(thiosulfate) available from Eastman.

[0062] Agilon 400G is a functional silica from PPG Industries.

[0063]

[0064] The inner liner compound is based on 100 phr bromobutyl rubber (BIIR rubber) typically used during tire manufacturing.

[0065]

[0066] Three layers were laminated, details of which are shown in Table 22. After lamination, they were encapsulated in a laboratory simulating tire curing process (350°F / 220psi / 12min). The normal incident sound absorption coefficients were determined at three frequencies (225Hz, 450Hz, and 675Hz) using high-impedance tubes, details of which are shown in Table 22.

[0067]

[0068] Results and discussion

[0069] The two porous precursor compositions tested are shown in Table 20. The compositions of the sealant precursor and sealant capping layer are shown in Table 21. The liner used is based on 100 phr bromobutyl rubber (BIIR), and the composition of this liner is well known to those skilled in the art. Five three-layer laminates were encapsulated and are shown in Table 22. C4 is a control sample without a porous layer and uses a sealant capping layer to protect the sealant. In samples D2 and E1, the sealant capping layer was replaced with a porous capping layer formed from a porous precursor (OC027-6) with corresponding thicknesses of 0.07” and 0.15”. In both cases, higher noise absorption coefficients were observed near the main cavity noise frequency (225 Hz) and in the higher harmonic frequency range. A similarly higher noise absorption coefficient was found when the sealant capping was replaced with a porous material formed from the OC027-2 precursor. Therefore, replacing non-porous sealant caps with porous sealant caps has led to a reduction in cavity noise that interferes with the occupants of vehicles traveling on such tires.

[0070] Figure 1 A bead-to-bead cross-section of the tire is shown, wherein the intrinsic noise damping layer 204 is applied directly on top (i.e., inside) of the intrinsic sealant layers 102, 103. As shown herein and used in this application, there may be a single sealant layer or multiple sealant layers. When the term "sealant layer" is used, it is intended to refer to a single sealant layer or a sealant layer comprising multiple sealant interlayers. As shown, the noise damping portion 204 may extend wider than the width of the sealant layers 102, 103 and serve as a capping layer. In this way, a separate capping layer is not required. Figure 1 In the diagram, 203 is the inner liner and 201 is the tread.

[0071] Figure 2 It shows Figure 1 The diagram shows a close-up view of the layers. For ease of understanding, all layers between the tread 201 and the outer layer to the inner liner 203 have been grouped into individual layers 300. These are standard versions of tire construction known in the art and are not unique to this invention. The bond between the inner liner 203 and the sealant layer(s) 102 is strong due to interfacial crosslinking 210 that occurs during curing. This interfacial bond is significantly stronger than the simple adhesives found in the typical application of noise damping portions in cured tires. Similarly, the bond between the sealant layer 102 and the foam noise damping portion 204 is strong due to interfacial crosslinking 210. The noise damping portion 204 is a foam composition containing a plurality of voids or pores 205 that contribute to noise reduction. As described above, the sealant layer 102 may be a single sealant or multiple sealants.

[0072] Figure 3 It shows Figure 1An alternative embodiment of the tire, wherein an internal porous foam noise damping layer 204 is applied on top of (i.e., inside) an internal sealant cap layer 104. As shown, the noise damping layer 204 is narrower than one or more sealant layers 102, 103, so the sealant cap layer 104 serves to prevent contamination from the tire's cured capsule.

[0073] Figure 4 It shows Figure 3 The diagram shows a close-up view of the layers. For ease of understanding, all layers between the tread 201 and the outer layer to the inner liner 203 have been grouped into individual layers 300. These are standard versions of tire construction known in the art and are not unique to this invention. As described above, the bond between the inner liner 203 and (one or more) sealant layers 102 is strong due to interfacial crosslinking 210 that occurs during curing. This interfacial bond is significantly stronger than the simple adhesive found in typical noise damping application after tire curing. Similarly, the bond between the sealant layer 102 and the sealant capping layer 104, and between the capping layer 104 and the foam noise damping portion 204, is strong due to interfacial crosslinking 210. The noise damping portion 204 includes a plurality of pores (which may also be referred to as cells or voids) 205.

[0074] Figure 5 A side view cross section showing the orientation of two porous precursor layers applied in a drum is shown, wherein the layers are self-wound such that the first end 251 and the second end 252 are separated from the midpoint 253 of the precursor layer.

[0075] like Figure 5 As shown, the present invention provides a method for manufacturing a raw tire, comprising applying a single foam precursor layer to the innermost side of an uncured tire such that the foam precursors overlap to form two or more layers of foam precursors, wherein the foam precursor layers are applied uniformly and evenly over the entire tire.

[0076] Figure 6 A side cross-sectional view showing solid and porous precursor layers is shown. The innermost layer is a foam precursor layer 304 with an inner splice 261; and the outermost layer is a perforated foam precursor layer 305, which has been machined with multiple holes 306 and has an outer splice 262.

[0077] like Figure 6 As shown, at least one of the foam precursor layers has multiple pores.

[0078] For purposes of illustration and description, the foregoing embodiments of the invention have been given. These descriptions and embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and it will be apparent that many modifications and variations are possible based on the foregoing disclosure. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to best utilize the invention in its various embodiments, with various modifications suitable for the intended particular use.

Claims

1. A tire having an in-situ formed internal puncture sealant layer and an internal noise damping portion and without splices, comprising: The tire carcass supports one or more layers of ply fabric, an outer peripheral tread, and a radial inner liner. A pair of tire beads, Sidewalls, which extend radially inward from the axial outer edge of the tread portion to connect to the corresponding bead, The sealant includes at least one sealant layer disposed radially inward from the radial inner liner of the tire carcass. an inner cellular noise damping portion as the innermost layer adjacent to the sealant, wherein the noise damping portion has a density less than 0.128 g / cm 3 and the noise damping portion is made from a noise damping portion precursor containing less than 20 phr of a blowing agent; and the sealant provides self-sealing properties to the tire.

2. The tire of claim 1, wherein the one or more sealant layers comprise two sealant layers.

3. The tire according to claim 2, wherein the two sealant layers have different viscosities.

4. The tire according to claim 1, wherein a sealant cap layer is disposed between the noise damping portion and the sealant.

5. The tire of claim 4, wherein the sealant has a width, and the noise damping portion has a width less than or equal to the width of the sealant.

6. The tire of claim 1, wherein the sealant has a width, and the noise damping portion has a width greater than or equal to the width of the sealant.

7. The tire according to claim 4, wherein the sealant capping layer is primarily composed of rubber selected from natural rubber, butadiene rubber, and styrene-butadiene rubber and combinations thereof.

8. The tire of claim 1, wherein the sealant is substantially solvent-free.

9. The tire of claim 1, wherein the sidewalls extending radially inward from the axial outer edge of the tread portion to connect the respective bead form a tire cavity, and the sealant is not exposed in the tire cavity.

10. The tire of claim 2, wherein the sealant is chemically bonded to the outermost and innermost layers of the tire.

11. The tire according to claim 1, wherein the noise damping portion has a density of 0.1 g / cm³. 3 Or even lower density.

12. The tire according to claim 1, wherein the noise damping portion has a density of 0.02 g / cm³. 3 Up to 1.2 g / cm 3 The density between.

13. The tire according to claim 1, wherein the noise damping portion is non-black.

14. The tire of claim 1, wherein the noise damping portion has a black color resulting from an additive selected from conductive graphite, conductive black, carbon black filler, and combinations thereof.

15. The tire of claim 1, wherein the noise damping portion is substantially free of any filler.

16. The tire according to claim 1, wherein the noise damping portion comprises a rubber selected from halogenated butyl rubber, brominated butyl rubber, chlorinated butyl rubber, butyl rubber, ionic butyl rubber, and ethylene propylene diene monomer and combinations thereof.

17. The tire of claim 1, wherein the noise damping portion comprises a copolymer of isobutylene and 4-(bromomethyl)styrene.

18. The tire of claim 1, wherein the noise damping portion comprises a copolymer of isobutylene and 4-(bromomethyl)styrene containing filler, the filler being selected from graphite, conductive black, carbon black, silicon dioxide, titanium dioxide, and colored pigments and combinations thereof.

19. The tire of claim 1, wherein the noise damping portion is formed by more than one foaming agent.

20. The tire of claim 19, wherein one of the foaming agents is p,p'-oxybis-(benzenesulfonylhydrazine).

21. A method for manufacturing a raw tire, comprising applying a single layer of foam precursor to the innermost side of an uncured tire such that the foam precursor overlaps itself to form two or more layers of foam precursor, wherein the foam precursor layers are applied uniformly and evenly over the entire tire.

22. The method of claim 21, wherein at least one of the foam precursor layers has a plurality of pores.

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