MODIFIED LIQUID DIENE-BASED RUBBER

• Main Authors: UENO YOSHIKAZU, UEHARA YOSUKE, KASHIOKA MASAHIRO, KANEKO SHUHEI, MOTODA TETSUSHI, NOZASA YU
• Format: Patent
• Language: English; Japanese
• Published: 06.07.2023
• Subjects: ADHESIVES; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; DYES; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; POLISHES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS

To provide a modified liquid diene-based rubber excellent in pumping property, drip resistance, and reactivity, excellent in rubber elasticity of an obtained cured material, and suitably used for a sealing material, and a tyre bead filler and a composition containing the modified liquid diene-based rubber.SOLUTION: There is provided a modified liquid diene-based rubber (A) which has a functional group (a) derived from an acid anhydride and satisfies all of the following requirements (I) to (III). (I) Functional group equivalent weight of functional group (a) is in the range of 400 to 3,500 g/eq. (II) When measured by gel permeation chromatography (GPC), the polystyrene-equivalent number average molecular weight (Mn) is in the range of 5,000 to 20,000. (III) The melt viscosity at 38°C is 3 Pa s or more, and X below is 6100 K or more. X (K): A slope of the straight line passing through 2 points when the 2 points of melt viscosity η (Pa s) at 38°C and 60°C measured using a Brookfield viscometer are plotted on a graph with 1/T (K-1) on the horizontal axis, and with Ln [η/(Pa s)] on a vertical axis. (T is temperature (K).)SELECTED DRAWING: None 【課題】ポンピング性、耐液垂れ性、及び反応性に優れ、得られる硬化物のゴム弾性も優れる、シーリング材、タイヤビードフィラーなどに好適に用いられる変性液状ジエン系ゴム及び該変性液状ジエン系ゴムを含む組成物を提供する。【解決手段】酸無水物に由来する官能基（ａ）を有し、下記（Ｉ）～（ＩＩＩ）の要件をすべて満たす変性液状ジエン系ゴム（Ａ）。（Ｉ）官能基（ａ）の官能基当量が４００～３，５００ｇ／ｅｑの範囲にある。（ＩＩ）ゲルパーミエーションクロマトグラフィー（ＧＰＣ）で測定した際、ポリスチレン換算の数平均分子量（Ｍｎ）が５，０００～２０，０００の範囲にある。（ＩＩＩ）３８℃における溶融粘度が３Ｐａ・ｓ以上であり、下記Ｘが６１００Ｋ以上である。Ｘ（Ｋ）：ブルックフィールド型粘度計を用いて測定される３８℃及び６０℃における溶融粘度η（Ｐａ・ｓ）２点を、１／Ｔ（Ｋ-1）を横軸、Ｌｎ［η／（Ｐａ・ｓ）］を縦軸とするグラフにプロットした際の、該２点を通る直線の傾き。（但し、Ｔは温度（Ｋ）である。）【選択図】なし