Patents for August 2025
Patents as compiled by the editors of Rubber World Magazine for August 2025.
Pneumatic radial tire for passenger cars
U.S. patent: 12,179,523
Issued: December 31, 2024
Inventor: Yukari Tomisaki
Assigned: Sumitomo Rubber Industries
Key statement: Provided is a pneumatic radial tire for a passenger car that exhibits both riding comfort at low temperatures and stealing stability at high speed running. The present invention is a pneumatic radial tire for a passenger car, in which: a carcass and a tread are provided; the tread is integrated into a standardized rim; when internal pressure is at a standardized internal pressure, the tire has a cross-sectional width Wt (mm) and an outer diameter Dt (mm) satisfying 1,963.4 ≤ (Dt2π/4)/Wt ≤ 2,827.4; the tread comprises at least one main groove in a running surface of the tread, extending in the circumferential direction of the tread; the land/sea ratio at the tread running surface is greater than 55% and less than 85%; and a rubber composition that forms the tread has a loss tangent (tan δ) which, when measured at a frequency of 10 Hz, an initial strain of 2% and a dynamic strain rate of 1%, is such that |20°C tan δ-50°C tan δ| is at least 0.01 and less than 0.15 and |5°C tan δ-20°C tan δ| is greater than 0.15 and less than 0.70.
Method for producing acrylic rubber
U.S. patent: 12,180,311
Issued: December 31, 2024
Inventors: Taro Ozaki, Motoki Kitagawa, Masatsugu Naitou and Ryo Okada
Assigned: Osaka Soda
Key statement: There is provided a method for more easily producing an acrylic rubber capable of providing a crosslinked rubber having excellent water resistance. A method for producing an acrylic rubber comprising the steps of subjecting a monomer to emulsion polymerization to obtain a polymerized emulsion; mixing the polymerized emulsion with a coagulant to obtain a water containing crumb; and water-washing the water containing crumb, wherein, in the step of water washing the water containing crumb, the water-containing crumb is water washed until an electrical conductivity of the washing water after water-washing the water containing crumb becomes 6.0 mS/cm or less.
Elastomer composition and sealing material
U.S. patent: 12,180,315
Issued: December 31, 2024
Inventors: Naoki Osumi, Hirohisa Imada and Tomomitsu Mochizuki
Assigned: Valqua
Key statement: Provided are an elastomer composition including a first fluoroelastomer that is a copolymer of tetrafluoroethylene and perfluoro (alkoxyvinyl ether) and a second fluoroelastomer different from the first fluoroelastomer and a sealing material including a crosslinked product of the elastomer composition.
Rubber composition, processing method thereof and braking resistant liquid product using the same
U.S. patent: 12,180,355
Issued: December 31, 2024
Inventors: Tao Xu, Zhi Sheng Fu and An Yang Wu
Assigned: Hangzhou Xingle Technologies and Shaoxing Pinghe New Material Technology
Key statement: The present invention discloses a rubber composition, a processing method thereof, and also a brake fluid resistant product using the rubber composition and a production method thereof. The rubber composition comprises, in parts by weight, 100 parts of a rubber matrix; 1.5-8 parts of a crosslinking agent; 40-140 parts of a reinforcing filler; and 0-40 parts of a plasticizer, wherein the rubber matrix comprises, based on 100 parts by weight of the rubber matrix, a branched polyethylene with a content represented as A, in which 0 < A ≤ 100 parts; an EPM with a content represented as B, in which 0 ≤ B < 100 parts; and an EPDM with a content represented as C, in which 0 ≤ C < 100 parts. The rubber composition is useful in the production of brake fluid resistant brake rubber hose and brake rubber diaphragm. The beneficial effect is that since the rubber composition comprises the branched polyethylene, the tear strength of the rubber compound is improved, thereby reducing the probability of tearing of the product during the production process and improving the overall processing performance.
Rubber composition and a tire
U.S. patent: 12,187,895
Issued: January 7, 2025
Inventors: Jerome Joel Daniel Delville, Carlo Kanz, Patrick Steiner and Marie-Laure Stephanie Milan
Assigned: Goodyear Tire & Rubber
Key statement: In a first aspect, the present invention is directed to a rubber composition comprising 70 phr to 95 phr of styrene butadiene rubber comprising at least 5 phr of a first styrene butadiene rubber having a glass transition temperature within a range of -49°C to -15°C and at least 45 phr of a second styrene butadiene rubber having a glass transition temperature within a range of -50°C to -89°C, wherein the rubber composition comprises more of the second styrene butadiene rubber than of the first styrene butadiene rubber. Moreover, the rubber composition comprises 5 phr to 30 phr of one or more of natural rubber and synthetic polyisoprene; 135 phr to 200 phr of silica; and at least 55 phr of at least one hydrocarbon resin comprising at least one terpene resin having a glass transition temperature of at least 30°C.
Rubber composition and pneumatic tire
U.S. patent: 12,187,894
Issued: January 7, 2025
Inventors: Ryota Kitago, Rie Yasuda and Shogo Hirao
Assigned: Sumitomo Rubber Industries
Key statement: The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in hardness over time. The present invention relates to a rubber composition containing a copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber composition having a heat aging resistance index defined by equation (1) of 10 or less.
Reclaimed material for manufacturing shoes and method of producing reclaimed rubber by processing recycled shoe material waste
U.S. patent: 12,195,609
Issued: January 14, 2025
Inventor: Chi-Yuan Hung
Assigned: Feng Tay Enterprises
Key statement: A method of producing a reclaimed rubber made of recycled shoe material waste includes the following steps. Step S1: collect a scrap rubber which is the shoe material waste. Step S2: grind the scrap rubber to form scrap rubber granules. Step S3: devulcanize the scrap rubber granules to form a reclaimed rubber. A reclaimed material for manufacturing shoes includes a reclaimed rubber formulation and a crosslinking agent, wherein the reclaimed rubber formulation is constituted by compounding a basic rubber formulation and the reclaimed rubber, wherein the reclaimed material for manufacturing shoes includes 65-94.8 wt.% of the basic rubber formulation, 5-30 wt.% of the reclaimed rubber and 0.2 wt.% to 5 wt.% of crosslinking agent. Mechanical properties of the reclaimed material for manufacturing shoes meet required standards of shoe outsole material. A method of consuming rubber waste produced during the shoe manufacturing process is disclosed herein.
Rubber composition and crosslinked rubber molded product
U.S. patent: 12,202,954
Issued: January 21, 2025
Inventors: Takumi Kaneko, Hiroshi Tadaoka, Ayaka Shindo and Kazuyoshi Shiga
Assigned: Sumitomo Rubber Industries
Key statement: An object of the present disclosure is to provide a rubber composition from which a crosslinked rubber molded product having good softness and excellent resilience performance can be obtained. The present disclosure provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator and (d) an organic sulfur compound, wherein (d) the organic sulfur compound includes (d1) a polythiophene compound having two or more thiophene rings in the molecule.
Wearable liquid silicone rubber product
U.S. patent: 12,193,917
Issued: January 14, 2025
Inventor: Ana Maria Teixeira Rangel
Key statement: A cured liquid silicone rubber (LSR) body having an outer surface, an inner surface opposing the outer surface, a first end, a second end opposing the first end, a non-biased body length separating the first and second ends of the cured silicone body, a pre-formed pleated portion disposed circumferentially along the body length and operably configured to enable selective and elastically biased adjustment of the non-biased body length, non-pleated portions of the LSR body forming a smooth surface of the outer surface of the LSR body and flanking the pleated portion, forming a sleeve shape with at least one enclosed opening and a sleeve channel for receiving a user’s limb and defined by the inner surface of the LSR body, and defining a plurality of perforations thereon, disposed on the non-pleated portions of the LSR body that span through the LSR body.
Polyurethane adhesive for bonding crosslinked rubber
U.S. patent: 12,195,646
Issued: January 14, 2025
Inventors: Thomas Clark, Roger Cassell, Daniel Sophiea, Sarah Mastroianni, Aaron Antwi and Huide Zhu
Assigned: DDP Specialty Electronic Materials US
Key statement: Disclosed herein are two-component polyurethane adhesive systems comprising a mixture of primary and secondary diamines.
Nitrile group containing copolymer rubber
U.S. patent: 12,202,923
Issued: January 21, 2025
Inventors: Yasuaki Watanabe and Kurihiro Goto
Assigned: Zeon
Key statement: A nitrile group-containing copolymer rubber, including 15% by weight or more and less than 28% by weight of α,β-ethylenically unsaturated nitrile monomer units (a), 10% to 50% by weight of α,β-ethylenically unsaturated monocarboxylic acid ester monomer units (b), 22% to 74% by weight of conjugated diene monomer units (c) and 1% to 10% by weight of carboxyl group-containing monomer units (d) and having an iodine value of 120 or less, wherein the conjugated diene monomer units (c) are at least partially hydrogenated, and the proportion of isoprene units in the conjugated diene monomer units (c) is 5% by weight or more and less than 33% by weight.
Rubber composition and tire
U.S. patent: 12,202,977
Issued: January 21, 2025
Inventors: Kyohei Kotani, Takafumi Asakura and Yasuhiro Shoda
Assigned: Bridgestone
Key statement: Provided is a rubber composition that can improve wear resistance and cutting resistance while having good fuel efficiency when applied to a tire. The rubber composition contains a rubber component containing natural rubber and/or synthetic isoprene rubber and syndiotactic 1,2-polybutadiene, where the syndiotactic 1,2-polybutadiene has a crystal content of 7 J/g to 40 J/g and a number-average molecular weight of 6.5 × 104 or more.
Pneumatic tire having tread with three elastomers
U.S. patent: 12,209,183
Issued: January 28, 2025
Inventors: Stacey Lynne Dean-Sioss, Brad Stephen Gulas, Kate Elizabeth Dennis-Pelcher and Paul Harry Sandstrom
Assigned: Goodyear Tire & Rubber
Key statement: A pneumatic tire comprising a vulcanizable rubber composition which comprises: 1) 100 parts by weight of elastomer consisting of 25 to 35 phr of a styrene butadiene rubber, 45 to 75 phr of a polybutadiene and 5 to 15 phr of a natural rubber or synthetic polyisoprene, wherein the styrene butadiene rubber is functionalized and has a Tg(A) ranging from -30 to -10°C; the natural rubber or synthetic polyisoprene has a Tg(B) ranging from -60 to -70°C; and the polybutadiene is a cis 1,4 polybutadiene having a Tg(C) ranging from -110 to -90°C, wherein Tg(A)-Tg(B) ≥ 25°C and Tg(B)-Tg(C) ≥ 25°C; 2) 70 to 100 phr of silica; 3) 1 to 20 phr of carbon black; 4) 1 to 15 phr of rubber processing oil; and 5) 5 to 50 phr of at least one hydrocarbon resin having a Tg ≥ 20°C and a rosin derived resin.
Tire tread rubber composition
U.S. patent: 12,215,231
Issued: February 4, 2025
Inventors: James P. Kleckner, Anthony M. Unger and Benjamin C. Galizio
Assigned: Bridgestone Americas
Key statement: Disclosed herein are tire tread rubber compositions comprising a specified elastomer component, reinforcing silica filler, a specified hydrocarbon resin, a cure package and optionally oil. The elastomer component includes styrene butadiene rubber and polybutadiene.