# US 11,441,006 B2 · Rubber composition for tires including carbon nanotubes, and method for producing same

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- Number: US 11,441,006 B2
- Document ID: US11441006B2
- Status: Granted
- Kind: B2
- Application number: 16/637,904
- Filed: 2018-08-16
- Published: 2020-07-09
- Granted: 2022-09-13
- Earliest claimed: 2017-08-16
- Assignees: Korea Kumho Petrochemical Co., Ltd.
- Applicants: Korea Kumho Petrochemical Co., Ltd.
- Inventors: Nam Sun Choi; Dong Hoon Oh; Sang Hyo Ryu; Chung Heon Jeong
- Web page: https://patentgrep.com/patent/US11441006B2

## CPC

- C01B 32/158: Carbon nanotubes
- C08K 3/041: {Carbon nanotubes}
- B60C 1/00: Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
- C01B 32/162: characterised by catalysts
- C08J 3/22: using masterbatch techniques
- C08K 3/04: Carbon
- C08K 3/08: Metals
- C08L 9/06: Copolymers with styrene
- C08L 21/00: Compositions of unspecified rubbers
- C01B 2202/06: Multi-walled nanotubes
- C01B 2202/34: Length
- C01B 2202/36: Diameter
- C01P 2002/82: by IR- or Raman-data
- C01P 2002/88: by thermal analysis data, e.g. TGA, DTA, DSC
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- C01P 2006/10: Solid density
- C08J 2309/00: Characterised by the use of homopolymers or copolymers of conjugated diene hydrocarbons
- C08J 2309/06: Copolymers with styrene
- C08J 2409/00: Characterised by the use of homopolymers or copolymers of conjugated diene hydrocarbons
- C08K 2201/002: Physical properties
- C08K 2201/011: Nanostructured additives
- C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
- C08L 2310/00: Masterbatches
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

An embodiment of the present invention provides a rubber composition for tires and a method for producing same, wherein the rubber composition for tires includes: carbon nanotubes including structural defects on at least a portion of the surface and having a thermal decomposition temperature equal to or less than 600° C.; and a rubber matrix.

## Claims

### Claim 1

A rubber composition for a tire, comprising:
carbon nanotubes having structural defects on at least a part of their surfaces and a pyrolysis temperature of 600° C. or less.

### Claim 2 (depends on 1)

The rubber composition of claim 1, wherein the carbon nanotube is a bundled carbon nanotube, which consists of multi-walled carbon nanotubes, prepared using a catalyst containing a metal component according to the following formula and having a hollow structure with an outer wall thickness of 0.5 to 10 μm:
Ma:Mb=x:y <Formula>
wherein Ma includes two or more metals selected from Ni, Co, Mn, Cr, Mo, V, W, Sn and Cu, Mb includes one or more metals selected from Mg, Al, Si and Zr, and x and y represent the mole fractions of Ma and Mb, respectively, in which x+y=10, 2.0≤x≤5.5, and 4.5≤y≤8.0.

### Claim 3 (depends on 2)

The rubber composition of claim 2, wherein the catalyst has an apparent density of 0.05 to 0.35 g/mL.

### Claim 4 (depends on 2)

The rubber composition of claim 2, wherein the catalyst has an outer wall thickness of 1 to 8 μm.

### Claim 5 (depends on 2)

The rubber composition of claim 2, wherein a hollow ratio of the hollow structure is 60 vol % or more.

### Claim 6 (depends on 2)

The rubber composition of claim 2, wherein the bundled carbon nanotube has an average bundle diameter of 0.5 to 20 μm and an average bundle length of 10 to 200 μm.

### Claim 7 (depends on 2)

The rubber composition of claim 2, wherein the multi-walled carbon nanotube has a Raman spectral intensity ratio (IG/ID) of 0.8 to 1.5.

### Claim 8 (depends on 2)

The rubber composition of claim 2, wherein the multi-walled carbon nanotube has an average diameter of 5 to 50 nm.

### Claim 9 (depends on 2)

The rubber composition of claim 2, wherein the multi-walled carbon nanotube has an apparent density of 0.005 to 0.120 g/mL.

### Claim 10 (depends on 1)

The rubber composition of claim 1, further comprising a rubber matrix including one selected from the group consisting of acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, styrene-butadiene rubber, butadiene rubber, natural rubber, isoprene rubber, butyl rubber and a combination of two or more thereof.

### Claim 11 (depends on 1)

The rubber composition of claim 1, further comprising a rubber matrix, wherein a content of the carbon nanotubes is 0.1 to 10 parts by weight with respect to 100 parts by weight of the rubber matrix.

### Claim 12

A method of preparing a rubber composition for a tire, comprising:
(a) preparing carbon nanotubes, which have structural defects on at least a part of their surfaces and a pyrolysis temperature of 600° C. or less, using a catalyst containing a metal component according to the following formula and having a hollow structure with an outer wall thickness of 0.5 to 10 μm; and (b) mixing the carbon nanotubes and a rubber:
Ma:Mb=x:y <Formula>
wherein Ma includes two or more metals selected from Ni, Co, Mn, Cr, Mo, V, W, Sn and Cu, Mb includes one or more metals selected from Mg, Al, Si and Zr, and x and y represent the mole fractions of Ma and Mb, respectively, in which x+y=10, 2.0≤x≤5.5, and 4.55≤y≤8.0.

### Claim 13 (depends on 12)

The method of claim 12, wherein the (b) step comprises (b1) preparing a master batch by mixing and pressing the carbon nanotubes and a part of the rubber, and (b2) mixing the master batch and the remainder of the rubber.