Method for producing rubber composition and rubber composition

• US 10,087,293 B2
• Filed: 08/24/2017
• Issued: 10/02/2018
• Est. Priority Date: 10/17/2013
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Nissin Kogyo Company Limited (Hitachi, Ltd.), Shinshu University National University Corporation
• Inventors: Kawamoto, Keiichi, Ueki, Hiroyuki, Noguchi, Toru, Niihara, Kenichi
• Primary Examiner(s): Uselding, John E
• Application Number:
  US15/685,635
• Publication Number:
  US 20180002494A1
• Time in Patent Office: 404 Days
• CPC Class Codes: B29B 7/56 with co-operating rollers , e.g. with repeated action, i.e. the material leaving a set of rollers being reconducted to the same set or being conducted to a next set
• CPC Class Codes: B29B 7/7485 with consecutive mixers, e.g. with premixing some of the components
• CPC Class Codes: B29B 7/90 Fillers or reinforcements , e.g. fibres
• CPC Class Codes: B29C 43/24 Calendering
• CPC Class Codes: B29C 43/245 Adjusting calender parameters, e.g. bank quantity
• CPC Class Codes: B29K 2001/00 Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
• CPC Class Codes: B29K 2007/00 Use of natural rubber as moulding material
• CPC Class Codes: B29K 2995/0062 water-soluble
• CPC Class Codes: C08J 2315/00 Characterised by the use of rubber derivatives C08J2311/00, C08J2313/00 takes precedence
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence
• CPC Class Codes: C08J 3/215 at least one additive being also premixed with a liquid phase
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 2201/014 Additives containing two or more different additives of the same subgroup in C08K
• CPC Class Codes: C08K 7/02 Fibres or whiskers
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 1/04 Oxycellulose; Hydrocellulose , e.g. microcrystalline cellulose
• CPC Class Codes: C08L 15/00 Compositions of rubber derivatives C08L11/00, C08L13/00 take precedence
• CPC Class Codes: C08L 15/005 Hydrogenated nitrile rubber
• CPC Class Codes: C08L 9/04 Latex

Abstract

A method for producing a rubber composition include a mixing step, a drying step, and a dispersion step. In the mixing step, an aqueous solution that includes at least one of oxycellulose fibers and cellulose nanofibers is mixed with rubber latex to obtain a first mixture. In the drying step, the first mixture is dried to obtain a second mixture. In the dispersion step, the second mixture is tight-milled using an open roll to obtain a rubber composition. The rubber composition does not include an aggregate that includes at least one of the oxycellulose fibers and the cellulose nanofibers, and has a diameter of 0.1 mm or more.

Claims

1. A rubber composition, comprising:

at least one of oxycellulose fibers and cellulose nanofibers that are dispersed in the rubber composition, such that all of the at least one of oxycellulose fibers and cellulose nanofibers are in an untangled state,

the rubber composition obtained by a method comprising;

a mixing step that mixes an aqueous solution that includes the at least one of oxycellulose fibers and cellulose nanofibers with rubber latex to obtain a first mixture;

a drying step that dries the first mixture to obtain a second mixture; and

a dispersion step that tight-mills the second mixture using an open roll to obtain the rubber composition,

wherein the mixing step includes repeating the following steps (1) to (4) a plurality of times;

(1) mixing the aqueous solution and the rubber latex using the open roll to obtain a mixture;

(2) removing the mixture from the open roll when the viscosity of the mixture has increased;

(3) after step (2), reducing a roll distance of the open roll; and

(4) after step (3), supplying the mixture to the open roll again,

wherein the mixing step obtains the first mixture in which at least one of the oxycellulose fibers and the cellulose nanofibers enter the space between rubber microparticles in the rubber latex by repeatedly performing the steps (1) to (4).

2. A rubber composition comprising rubber, and at least one of oxycellulose fibers and cellulose nanofibers that are dispersed in the rubber, such that all of the at least one of oxycellulose fibers and cellulose nanofibers are in an untangled state, the rubber composition not including an aggregate that includes at least one of the oxycellulose fibers and the cellulose nanofibers, and has a diameter of 0.1 mm or more, the rubber composition obtained by a method comprising:

a mixing step that mixes an aqueous solution that includes the at least one of oxycellulose fibers and cellulose nanofibers with rubber latex to obtain a first mixture;

a drying step that dries the first mixture to obtain a second mixture; and

a dispersion step that tight-mills the second mixture using an open roll to obtain the rubber composition,

wherein the mixing step includes repeating the following steps (1) to (4) a plurality of times;

(1) mixing the aqueous solution and the rubber latex using the open roll to obtain a mixture;

(2) removing the mixture from the open roll when the viscosity of the mixture has increased;

(3) after step (2), reducing a roll distance of the open roll; and

(4) after step (3), supplying the mixture to the open roll again,

wherein the mixing step obtains the first mixture in which at least one of the oxycellulose fibers and the cellulose nanofibers enter the space between rubber microparticles in the rubber latex by repeatedly performing the steps (1) to (4).

3. The rubber composition as defined in claim 2, comprising at least one of the oxycellulose fibers and the cellulose nanofibers in an amount of 0.1 to 60 parts by mass based on 100 parts by mass of the rubber.