Viscoelastic shock absorber

Abstract

The present invention provides a high-damping composition which has good processability and is capable of forming a viscoelastic body having excellent damping performance and little temperature dependency of the damping performance, and a viscoelastic damper which comprises a viscoelastic body formed from the high-damping composition, and is installed in a building and the like for use. A high attenuation composition is blended with silica and an OA-containing rosin derivative in a base polymer. The viscoelastic shock absorber comprises a viscoelastic body (1) formed from the high damping composition.

Description

[0001] This invention is a divisional application of the invention patent application with application number 202110197444.9 filed on February 22, 2021 and invention name “Viscoelastic Shock Absorber”. Technical Field

[0002] The present invention relates to a high-attenuation composition and a viscoelastic shock absorber including a viscoelastic body formed from the high-attenuation composition and installed in a building or the like for use in shock absorption or the like. Background Art

[0003] The viscoelastic body of a viscoelastic shock absorber is generally formed using a high-damping composition in which inorganic fillers such as carbon black and silica and tackifiers such as rosins and petroleum resins are blended with a base polymer (see Patent Document 1, etc.).

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-17092 Summary of the Invention

[0007] [Problems to be solved by the invention]

[0008] By adding an inorganic filler and a tackifier to the base polymer, the hysteresis loss when vibration is applied to the viscoelastic body formed from the high-damping composition can be increased, thereby improving the ability to efficiently and quickly dampen the energy of vibration, that is, the damping performance.

[0009] In order to further improve the attenuation performance compared to the current situation, it is conceivable to increase the amounts of the inorganic filler and the tackifier compared to the current situation.

[0010] However, a high-damping composition containing a large amount of inorganic filler may increase its viscosity during kneading, for example, the Mooney viscosity when the base polymer is a cross-linkable rubber, and the processability of the high-damping composition may be reduced.

[0011] Furthermore, a high-damping composition formulated with a large amount of a tackifier may have increased tackiness and may also have reduced workability.

[0012] Furthermore, in any of the above cases, it is sometimes difficult to knead the components for preparing a high attenuation composition, or to knead the high attenuation composition for producing a viscoelastic body or to shape the high attenuation composition into a desired three-dimensional shape.

[0013] Especially in the case of mass production of viscoelastic materials at a factory level, low processability significantly reduces productivity, increases the energy required for production, and further increases production costs, which is not desirable.

[0014] In addition, for example, the viscoelastic body of a viscoelastic shock absorber installed in a building, etc. is required to have low temperature dependence of the attenuation performance, even if it is installed on the outer wall of a building, etc. with a large temperature difference.

[0015] However, depending on the type of tackifier, the temperature dependency of the attenuation performance of the viscoelastic body increases, and this requirement may not be fully met.

[0016] The object of the present invention is to provide a high-attenuation composition and a viscoelastic shock absorber, wherein the high-attenuation composition has good processability and can form a viscoelastic body with excellent attenuation performance and low temperature dependence of the attenuation performance. The viscoelastic shock absorber includes a viscoelastic body formed from the high-attenuation composition and is installed in a building, etc. for use.

[0017] [Technical means to solve the problem]

[0018] The present invention is a high attenuation composition comprising:

[0019] base polymer;

[0020] silicon dioxide; and

[0021] Rosin derivatives are reaction products of rosins and oxyalkylene compounds, and one molecule of the reaction product contains two or more oxyalkylene units.

[0022] In addition, the present invention is a viscoelastic shock absorber including a viscoelastic body formed from the high-attenuation composition.

[0023] [Effects of the Invention]

[0024] According to the present invention, a high-attenuation composition and a viscoelastic shock absorber can be provided. The high-attenuation composition has good processability and can form a viscoelastic body with excellent attenuation performance and low temperature dependence of the attenuation performance. The viscoelastic shock absorber includes a viscoelastic body formed from the high-attenuation composition and is installed in a building, etc. for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an exploded perspective view showing a disassembled test body as a model of a viscoelastic body produced in order to evaluate the attenuation performance of the viscoelastic body formed from the high attenuation composition of Examples and Comparative Examples of the present invention.

[0026] Figure 2 (a) Figure 2 (b) is a diagram schematically illustrating a testing machine for displacing the test body and determining the relationship between the displacement and the load.

[0027] Figure 3 This is a graph showing an example of a hysteresis loop indicating the relationship between the displacement and the load, obtained by displacing a test body using the testing machine.

[0028] [Explanation of Symbols]

[0029] 1: Tablet

[0030] 2: Steel plate

[0031] 3: Test Subject

[0032] 4: Central fixing fixture

[0033] 5: Left and right fixing fixtures

[0034] 6: Fixed arm

[0035] 7: Connector

[0036] 8: Movable disk

[0037] 9: Connector

[0038] H: Hysteresis loop

[0039] L1: Straight line

[0040] L2: Vertical line

[0041] W: elastic strain energy

[0042] ΔW: Amount of absorbed energy DETAILED DESCRIPTION

[0043] High attenuation composite

[0044] As described above, the high attenuation composition of the present invention is characterized in that:

[0045] Contains base polymer and silica, and

[0046] Rosin derivatives are reaction products of rosins and oxyalkylene compounds, wherein one molecule of the reaction product contains two or more oxyalkylene units (hereinafter sometimes referred to as "OA (oxyalkylene)-containing rosin derivatives").

[0047] According to the high attenuation composition of the present invention, it has good processability and can be formed into a viscoelastic body having excellent attenuation performance and low temperature dependence of the attenuation performance.

[0048] This is also apparent from the results of Examples and Comparative Examples described later.

[0049] <Base polymer>

[0050] As the base polymer, a cross-linkable rubber or a non-cross-linkable thermoplastic elastomer can be used, and a cross-linkable rubber is particularly preferred.

[0051] The cross-linkable rubber is preferably at least one selected from the group consisting of, for example, natural rubber, isoprene rubber (IR), butadiene rubber (BR), and styrene butadiene rubber (SBR).

[0052] These cross-linkable rubbers are excellent in affinity with silica and dispersibility in the silica.

[0053] Furthermore, the glass transition temperature Tg of these cross-linkable rubbers does not exist near room temperature (2° C. to 35° C.).

[0054] Therefore, combined with the use of OA-containing rosin derivatives as described above, the temperature dependence of the attenuation performance of the viscoelastic body in the most common operating temperature range, i.e., near room temperature, can be reduced, and a viscoelastic body exhibiting stable attenuation performance over a wide temperature range can be formed.

[0055] Furthermore, as the cross-linkable rubber, natural rubber is preferably used because the cross-linking structure between rubber molecules in the cross-linked state is relaxed, a viscoelastic body with excellent damping performance can be formed, and natural rubber is easily available, thereby enabling the production of a high damping composition at low cost.

[0056] As the natural rubber, for example, one or more of various grades of natural rubber such as Standard Malaysian Rubber (SMR)-CV60, or various deproteinized natural rubbers can be used.

[0057] As the IR, one or two or more of various polymers having a polyisoprene structure and crosslinking properties can be arbitrarily used.

[0058] As BR, any of various BRs that include a polybutadiene structure in the molecule and have crosslinking properties can be used.

[0059] In particular, high-cis BR having a cis-1,4 bond content of 95% or more is preferred, as it can exhibit good properties as a rubber over a wide temperature range from high to low temperatures.

[0060] BR includes oil-extended BR to which extender oil is added to adjust flexibility, and non-oil-extended BR to which no extender oil is added. In the present invention, either type of BR can be used.

[0061] One or two or more of these BRs may be used.

[0062] As the SBR, any of various SBRs synthesized by copolymerizing styrene and 1,3-butadiene by various polymerization methods such as emulsion polymerization and solution polymerization can be used.

[0063] As SBR, any of high styrene type, medium styrene type, and low styrene type SBRs classified according to styrene content can be used.

[0064] Furthermore, as SBR, there are oil-extended SBR to which extender oil is added to adjust the flexibility, and non-oil-extended SBR to which no extender oil is added. In the present invention, either type of SBR can be used.

[0065] One or two or more of these SBRs may be used.

[0066] <Silicon dioxide>

[0067] Silica is dispersed in the base polymer and functions to improve the damping performance of the viscoelastic body.

[0068] As the silica, either wet-process silica or dry-process silica, which are classified according to their production methods, can be used.

[0069] Specific examples of silica are not limited thereto, and for example, one or two or more of the following various silicas may be used.

[0070] VN3, AQ, LP, NA, ER, ER-R, RS-150, NS, NS-T, NS-K, NS-KR, KP, L-300, KQ, NS-P, etc. in the NipSil (registered trademark) series manufactured by Tosoh Silica Co., Ltd.

[0071] The proportion of silica is preferably 110 parts by mass or more and 170 parts by mass or less relative to 100 parts by mass of the total amount of the base polymer.

[0072] When the ratio of silica is smaller than the above range, good damping performance may not be imparted to the viscoelastic body.

[0073] On the other hand, when the ratio of silica exceeds the above range, the viscosity of the high attenuation composition during kneading becomes too high, and workability may be reduced.

[0074] That is, it is sometimes difficult to knead the components for preparing a high attenuation composition, or to knead the high attenuation composition for producing a viscoelastic body or to shape the high attenuation composition into a desired three-dimensional shape.

[0075] On the other hand, by setting the ratio of silica in the above range, it is possible to provide good attenuation performance to the viscoelastic body while suppressing a decrease in the processability of the high attenuation composition.

[0076] <OA-containing rosin derivatives>

[0077] The OA-containing rosin derivative used in the present invention is a compound having both an oxyalkylene unit and a cyclic diterpene structure derived from rosins.

[0078] The OA-containing rosin derivative is obtained as a reaction product by reacting rosins with an alkylene oxide compound that is reactive with the rosins.

[0079] Rosins are compositions derived from trees and contain resin acids (compounds having carboxyl groups derived from trees) and / or modified forms thereof.

[0080] Examples of the resin acid include resin acids having a cyclic diterpene structure.

[0081] Examples of the resin acid having a cyclic diterpene structure include one or more of the following resin acids:

[0082] Resin acids with conjugated double bonds and cyclic diterpene structures, such as abietic acid, neoabietic acid, and palustric acid;

[0083] Resin acids such as pimaric acid and isopimaric acid that have both non-conjugated double bonds and cyclic diterpene structures.

[0084] As the resin acid, preferably, there are mentioned resin acids having both a conjugated double bond and a cyclic diterpene structure, and more preferably, there are mentioned abietic acid, neoabietic acid, and palustric acid.

[0085] Abietic acid is represented by, for example, the following formula (1), neoabietic acid is represented by, for example, the following formula (2), and palustric acid is represented by, for example, the following formula (3).

[0086] [Chemistry 1]

[0087] Chemical 1

[0088]

[0089] Examples of modified resin acids include acid-modified resin acids modified with α,β-unsaturated carboxylic acids, disproportionated resin acids, hydrogenated resin acids, and polymers obtained by polymerizing resin acids.

[0090] The resin acid and / or its modified form is included in rosins.

[0091] In other words, the rosin preferably contains a cyclic diterpene structure derived from a resin acid and / or a modified form thereof.

[0092] More specifically, examples of the rosins include unmodified rosin (unmodified rosin) and modified rosin (derivatives).

[0093] Examples of the unmodified rosin include one or two or more of tall oil rosin, gum rosin, and wood rosin containing the resin acid (unmodified form).

[0094] As the unmodified rosin, preferably, tall oil rosin is mentioned.

[0095] The modified rosin is a modified product of the unmodified rosin, and includes a modified product of the resin acid.

[0096] Examples of modified rosin include acid-modified rosin obtained by modifying unmodified rosin with α,β-unsaturated carboxylic acids, disproportionated rosin obtained by disproportionating unmodified rosin, hydrogenated rosin obtained by hydrogenating unmodified rosin, and polymerized rosin obtained by polymerizing unmodified rosin.

[0097] One or two or more of these modified rosin products may be used.

[0098] As the modified rosin, preferably, acid-modified rosin, disproportionated rosin, and hydrogenated rosin are mentioned, and more preferably, acid-modified rosin is mentioned.

[0099] One or two or more of these rosins can be used.

[0100] As rosins, from the viewpoint of cost reduction and environmental load, preferably rosins other than polymerized rosin are mentioned, and more preferably unmodified rosin, acid-modified rosin, disproportionated rosin, and hydrogenated rosin are mentioned.

[0101] Among these, unmodified rosin is more preferably used from the viewpoint of reactivity.

[0102] Examples of the oxyalkylene compound reactive with rosins include compounds having both a reactive group reactive with rosins and an oxyalkylene group (hereinafter sometimes simply referred to as a "reactive oxyalkylene compound").

[0103] Examples of the reactive group capable of reacting with rosins include:

[0104] A hydroxyl group capable of undergoing an esterification reaction with a carboxyl group of a resin acid and / or a modified form thereof; or

[0105] The conjugated double bonds of the resin acid and / or its modified form can undergo Diels-Alder reaction. s -Alder reaction) (meth) acrylic acid group, etc.

[0106] In addition, (meth)acrylic acid means acrylic acid and / or methacrylic acid.

[0107] One or two or more of these reactive groups may be used.

[0108] Examples of the oxyalkylene group include oxyalkylene groups having 2 to 4 carbon atoms, such as oxyethylene, oxypropylene (oxy-1,2-propylene), oxytrimethylene (oxy-1,3-propylene), and oxybutenyl.

[0109] One or two or more of these oxyalkylene groups may be used.

[0110] As the oxyalkylene group, preferably, an oxyalkylene group having 2 to 3 carbon atoms is used, more preferably, an oxyethylene group and an oxypropylene group are used, and further preferably, an oxyethylene group is used.

[0111] More specifically, as the reactive oxyalkylene compound, for example, there can be mentioned:

[0112] Compounds having both a hydroxyl group and an oxyalkylene group (hereinafter sometimes referred to as "hydroxyl group-containing oxyalkylene compound");

[0113] Compounds having both a (meth)acrylic acid group and an oxyalkylene group (hereinafter sometimes simply referred to as "(meth)acrylic acid group-containing oxyalkylene compound"), etc.

[0114] Examples of the hydroxyl group-containing oxyalkylene compounds include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether; diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; oxyalkylene-containing ether monools such as polyoxyethylene monoalkyl ethers having 3 to 30 oxyethylene units; diethylene glycol, triethylene glycol, polyoxyethylene glycol having 4 to 30 oxyethylene units, dipropylene glycol, tripropylene glycol, polyoxypropylene glycol having 4 to 30 oxypropylene units, and polyoxyethylene-polyoxypropylene (random / blocked) copolymer glycols. One or more of the following: an oxyalkylene-containing diol having 2 to 30 oxyalkylene units; an oxyalkylene-containing triol having 2 to 30 oxyalkylene units, such as a polyoxyethylene triol having 2 to 30 oxyalkylene units, a polyoxypropylene triol having 2 to 30 oxypropylene units, and a polyoxyethylene·polyoxypropylene (random / blocked) co-triol; and an oxyalkylene-containing tetraol having 2 to 30 oxyalkylene units, such as a polyoxyethylene tetraol having 2 to 30 oxyalkylene units, a polyoxypropylene tetraol having 2 to 30 oxypropylene units, and a polyoxyethylene·polyoxypropylene (random / blocked) co-tetraol.

[0115] The number of hydroxyl groups in one molecule of the hydroxyl group-containing oxyalkylene compound is, for example, preferably 1 or more, particularly preferably 2 or more, and preferably 6 or less, particularly preferably 4 or less, and particularly preferably 3 or less.

[0116] That is, as the hydroxyl group-containing oxyalkylene compound, preferably, oxyalkylene-containing diols, oxyalkylene-containing triols, and oxyalkylene-containing tetraols are mentioned, more preferably, oxyalkylene-containing diols and oxyalkylene-containing triols are mentioned, further preferably, oxyalkylene-containing diols are mentioned, and particularly preferably, polyoxyethylene glycol is mentioned.

[0117] The number of oxyalkylene groups in one molecule of the hydroxyl group-containing oxyalkylene compound is, for example, preferably 1 or more, particularly preferably 2 or more, and particularly preferably 4 or more, and is preferably 30 or less, particularly preferably 10 or less, and particularly preferably 9 or less.

[0118] In addition, the number average molecular weight of the hydroxyl group-containing oxyalkylene compound can be appropriately set according to the purpose and application.

[0119] As the (meth)acrylic group-containing oxyalkylene compound, for example, one or more of methoxy-diethylene glycol (meth)acrylate, methoxy-triethylene glycol (meth)acrylate, and methoxy-polyoxyethylene glycol (meth)acrylate having 4 to 30 oxyethylene units; ethoxy-diethylene glycol (meth)acrylate, ethoxy-triethylene glycol (meth)acrylate, and ethoxy-polyoxyethylene glycol (meth)acrylate having 4 to 30 oxyethylene units; oxyethylene-containing mono(meth)acrylates such as phenoxy-diethylene glycol acrylate, phenoxy-triethylene glycol acrylate, and phenoxy-polyoxyethylene glycol (meth)acrylate having 4 to 30 oxyethylene units; and oxyethylene-containing di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and polyoxyethylene glycol di(meth)acrylate having 4 to 30 oxyethylene units can be used.

[0120] The number of (meth)acrylic acid groups in one molecule of the (meth)acrylic acid group-containing oxyalkylene compound is, for example, preferably 1 or more and 6 or less, particularly preferably 4 or more, particularly preferably 2 or less, and particularly preferably 1.

[0121] Specifically, as the (meth)acrylic group-containing oxyalkylene compound, preferably, oxyethylene-containing mono(meth)acrylate is mentioned, and more preferably, methoxy-polyoxyethylene glycol (meth)acrylate having 4 to 30 oxyethylene units is mentioned.

[0122] The number of oxyalkylene groups in one molecule of the (meth)acrylic group-containing oxyalkylene compound is, for example, preferably 1 or more, particularly preferably 2 or more, particularly preferably 4 or more, and preferably 30 or less, particularly preferably 10 or less.

[0123] The number average molecular weight of the (meth)acrylic group-containing oxyalkylene compound can be appropriately set depending on the purpose and application.

[0124] One or two or more of these reactive oxyalkylene compounds may be used.

[0125] Examples of the alkylene oxide compound that can react with rosins include, in addition to the above-mentioned reactive alkylene oxide compounds, alkylene oxides.

[0126] Alkylene oxides are cyclic ethers that can undergo addition polymerization with rosins.

[0127] Examples of the alkylene oxide include one or more alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide (1,2-propylene oxide), trimethylene oxide (1,3-propylene oxide), and 1,4-butylene oxide.

[0128] As the alkylene oxide, preferably, an alkylene oxide having 2 to 3 carbon atoms is used, more preferably, ethylene oxide and 1,2-propylene oxide are used, and still more preferably, ethylene oxide is used.

[0129] One or two or more of these oxyalkylene compounds may be used.

[0130] The alkylene oxide compound reacts with rosins in the following trans form.

[0131] For example, when the alkylene oxide compound includes a hydroxyl group-containing alkylene oxide compound, the carboxyl groups of the resin acid and / or its modified form in the rosin are esterified with the hydroxyl groups of the hydroxyl group-containing alkylene oxide compound in the presence of an ester catalyst added as needed.

[0132] For example, when rosins are acid-modified and carboxyl groups are added to the resin acid, the added carboxyl groups react with hydroxyl groups of the hydroxyl-containing oxyalkylene compound in the presence of an ester catalyst added as needed for esterification.

[0133] In this case, regarding the blending ratio of the rosin and the hydroxyl-containing oxyalkylene compound, the number of moles of the hydroxyl group of the hydroxyl-containing oxyalkylene compound per 1 mol of the carboxyl group of the resin acid and / or its modified form in the rosin is, for example, preferably 0.8 mol or more, particularly preferably 0.9 mol or more, and particularly preferably 0.95 mol or more, and is preferably 5.0 mol or less, particularly preferably 3.0 mol or less.

[0134] Regarding the reaction conditions (esterification reaction conditions) of rosins and hydroxyl-containing oxyalkylene compounds, for example, under an inert gas atmosphere and at atmospheric pressure, the reaction temperature is preferably 100° C. or higher, particularly preferably 150° C. or higher, and preferably 400° C. or lower, particularly preferably 300° C. or lower.

[0135] The reaction time is preferably 2 hours or longer, particularly preferably 4 hours or longer, and is preferably 48 hours or shorter, particularly preferably 24 hours or shorter.

[0136] Thus, as a reaction product of rosins and hydroxyl-containing oxyalkylene compounds, OA-containing rosin derivatives containing a cyclic diterpene structure derived from a resin acid and / or a modified form thereof of rosins and an oxyalkylene group derived from the hydroxyl-containing oxyalkylene compound are obtained.

[0137] In addition, when the oxyalkylene compound includes an oxyalkylene compound containing a (meth)acrylic group, for example, the conjugated double bonds of the resin acid and / or its modified form in the rosin and the (meth)acrylic group of the oxyalkylene compound containing a (meth)acrylic group undergo a Diels-Alder reaction in the presence of a catalyst added as needed.

[0138] In this case, regarding the blending ratio of the rosin and the (meth)acrylic acid group-containing oxyalkylene compound, the number of moles of the (meth)acrylic acid group of the (meth)acrylic acid group-containing oxyalkylene compound relative to one unit of conjugated double bonds of the resin acid and / or its modified form in the rosin is preferably 0.2 mol or more, particularly preferably 0.4 mol or more, particularly preferably 0.7 mol or more, and particularly preferably 0.9 mol or more, and is preferably 5.0 mol or less, particularly preferably 3.0 mol or less, and particularly preferably 1.0 mol or less.

[0139] Regarding the reaction conditions of rosins and (meth)acrylic acid group-containing oxyalkylene compounds (Diels-Alder reaction conditions), for example, under an inert gas atmosphere and at atmospheric pressure, the reaction temperature is preferably 100° C. or higher, particularly preferably 150° C. or higher, and is preferably 400° C. or lower, particularly preferably 300° C. or lower.

[0140] The reaction time is preferably, for example, 2 hours or longer, particularly preferably 4 hours or longer, and is preferably 48 hours or shorter, particularly preferably 24 hours or shorter.

[0141] Thus, as a reaction product of rosins and (meth)acrylic acid group-containing oxyalkylene compounds, an OA-containing rosin derivative containing a resin acid derived from rosins and / or a cyclic diterpene structure of a modified form thereof and an oxyalkylene group derived from the (meth)acrylic acid group-containing oxyalkylene compound is obtained.

[0142] Furthermore, when the alkylene oxide compound contains an alkylene oxide, the alkylene oxide is subjected to ring-opening polymerization in the presence of a known polymerization catalyst with respect to the carboxyl groups of the resin acid and / or its modified form in the rosin.

[0143] Furthermore, if necessary, the carboxyl groups of the resin acid and / or its modified form in the rosin may be esterified with a known diol (eg, ethylene glycol, propylene glycol, etc.) to add-polymerize alkylene oxide to the terminal hydroxyl groups.

[0144] In this case, the mixing ratio of rosin and alkylene oxide is, for example, preferably 1 mol or more, particularly preferably 2 mol or more, and preferably 40 mol or less, particularly preferably 30 mol or less of alkylene oxide per 1 mol of carboxyl groups of the rosin.

[0145] Regarding the reaction conditions (addition polymerization conditions) of rosins and alkylene oxides, for example, under an inert gas atmosphere and atmospheric pressure, the reaction temperature is preferably 100°C or higher, particularly preferably 150°C or higher, and preferably 400°C or lower, particularly preferably 300°C or lower.

[0146] The reaction time is preferably, for example, 2 hours or longer, particularly preferably 4 hours or longer, and is preferably 48 hours or shorter, particularly preferably 24 hours or shorter.

[0147] Thus, as a reaction product of rosins and alkylene oxide, a compound containing a cyclic diterpene structure of a resin acid derived from rosins and / or a modified form thereof, and an oxyalkylene group derived from alkylene oxide is obtained.

[0148] Furthermore, one or two or more of these reactions (esterification reaction, Diels-Alder reaction, and addition polymerization reaction) may be used.

[0149] That is, the rosin and the alkylene oxide compound may be reacted by any one reaction method, or by two or more reaction methods. When two or more reaction methods are used in combination, the reaction order is not particularly limited and may be appropriately set.

[0150] For example, when an esterification reaction and a Diels-Alder reaction are used in combination, the rosins and the alkylene oxide compound may be first subjected to an esterification reaction and then subjected to a Diels-Alder reaction. Alternatively, the rosins and the alkylene oxide compound may be subjected to a Diels-Alder reaction and then subjected to an esterification reaction. Furthermore, the esterification reaction and the Diels-Alder reaction may be carried out simultaneously.

[0151] The same applies to the addition polymerization reaction. An esterification reaction or a Diels-Alder reaction may be used in combination with the addition polymerization reaction. Furthermore, an esterification reaction, a Diels-Alder reaction, and an addition polymerization reaction may be used in combination.

[0152] As the alkylene oxide compound, preferably a reactive alkylene oxide compound is mentioned, and more preferably a hydroxyl group-containing alkylene oxide compound is mentioned.

[0153] In other words, as the reaction between rosins and alkylene oxide compounds, preferably, an esterification reaction is mentioned.

[0154] Furthermore, in the reaction between the rosin and the oxyalkylene compound, a part or all of the carboxyl groups of the rosin may be sealed (deactivated) with an alcohol containing no oxyalkylene group, if necessary.

[0155] The alcohol is not particularly limited as long as it is a compound that does not contain an oxyalkylene group and has one or more hydroxyl groups. Examples thereof include monovalent aliphatic alcohols such as methanol, ethanol, and propanol; divalent aliphatic alcohols such as ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, and 1,8-octanediol; trivalent aliphatic alcohols such as glycerol, trimethylolethane, and trimethylolpropane; tetravalent aliphatic alcohols such as pentaerythritol and dipropylene glycol; and hexavalent aliphatic alcohols such as dipentaerythritol.

[0156] One or two or more of these alcohols may be used.

[0157] The timing of adding the alcohol is not particularly limited and can be appropriately set according to the purpose and application.

[0158] For example, before reacting the rosin with the alkylene oxide compound, a part or all of the carboxyl groups of the rosin may be subjected to an esterification reaction with an alcohol to thereby seal the rosin.

[0159] For example, when the reaction product obtained by reacting a rosin with an oxyalkylene compound has free carboxyl groups, some or all of the carboxyl groups can be esterified with an alcohol to thereby seal the carboxyl groups.

[0160] Furthermore, for example, alcohol may be added during the reaction of the rosin and the alkylene oxide compound to allow a part or all of the carboxyl groups of the rosin to undergo an esterification reaction with the alcohol for sealing.

[0161] When the carboxyl group is sealed with alcohol, the ratio of the alcohol to the carboxyl group and the reaction conditions can be appropriately set according to the purpose and application.

[0162] When the carboxyl groups are sealed with alcohol, it is preferred that the conjugated double bonds of the rosin are reacted with the (meth)acrylic acid group-containing oxyalkylene compound, and then the unreacted carboxyl groups derived from the rosin are sealed with alcohol to be inactivated.

[0163] In this way, an OA-containing rosin derivative is obtained as a reaction product of rosins and alkylene oxide compounds (and, if necessary, alcohol).

[0164] Furthermore, OA-containing rosin derivatives (ie, reaction products obtained by reaction between rosins and oxyalkylene compounds) have both a cyclic diterpene structure derived from a resin acid of rosins and / or a modified form thereof and an oxyalkylene unit derived from an oxyalkylene compound.

[0165] The number of cyclic diterpene structures contained in one molecule of the OA-containing rosin derivative (i.e., the number of moles of resin acid per 1 mole of the reaction product) is, for example, preferably 1 or more, particularly preferably 2 or more, and preferably 10 or less, particularly preferably 8 or less, particularly preferably 6 or less, particularly preferably 4 or less, and particularly preferably 2.

[0166] When the number of cyclic diterpene structures is within the above range, particularly excellent damping performance can be imparted to the viscoelastic body.

[0167] In addition, the number of oxyalkylene units (groups) contained in one molecule of the additive for the attenuating polymer (i.e., the number of moles of oxyalkylene units relative to 1 mole of the reaction product) is preferably 2 or more, preferably 3 or more, particularly preferably 4 or more, especially preferably 6 or more, particularly preferably 8 or more, and preferably 40 or less, particularly preferably 30 or less.

[0168] When the number of oxyalkylene units is within the above range, particularly excellent damping performance can be imparted to the viscoelastic body.

[0169] The weight average molecular weight (standard polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC)) of the attenuating polymer additive is preferably 500 or more, particularly preferably 800 or more, and is preferably 2500 or less, particularly preferably 2000 or less.

[0170] The OA-containing rosin derivative obtained as described above comprises a reaction product of rosins and an oxyalkylene compound reactive with the rosins. The number of oxyalkylene units in one molecule of the reaction product is 2 or more, and thus can impart particularly excellent damping properties to viscoelastic materials.

[0171] Silane compounds

[0172] The high attenuation composition of the present invention may further contain a silane compound.

[0173] As the silane compound, various silane compounds that can function as a so-called silanizing agent, a silane coupling agent, or the like can be used.

[0174] The silane compound reacts with silica to modify its surface, thereby improving the affinity and dispersibility of silica with respect to the base polymer, thereby playing a role in dispersing silica well in the high attenuation composition.

[0175] As the silane compound, an alkoxysilane compound represented by formula (a) is preferred:

[0176] R 1 n Si(OR 2 ) 4-n (a)

[0177] [Where R 1 represents a phenyl group or an alkyl group having 1 to 10 carbon atoms, R 2 represents an alkyl group having 1 to 3 carbon atoms. n represents a number of 1 to 3.

[0178] Examples of the alkoxysilane compound include one or more of methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, and decyltrimethoxysilane.

[0179] In particular, considering the provision of good damping performance to the viscoelastic body, it is preferable that R in formula (a) 1 is phenyl, R 2 is methyl, n is 1 phenyltrimethoxysilane or R in formula (a) 1 is phenyl, R 2 Phenyltriethoxysilane wherein n is 1 and ethyl is phenyltriethoxysilane.

[0180] The proportion of the silane compound is preferably 10 parts by mass or more, particularly preferably 15 parts by mass or more, and preferably 40 parts by mass or less, relative to 100 parts by mass of the total amount of the base polymer.

[0181] If the proportion of the silane compound is below the above range, the aforementioned effect of modifying the silica surface to improve affinity and dispersibility with the base polymer cannot be fully achieved, and the processability of the high attenuation composition may be reduced.

[0182] Furthermore, there are cases where it is not possible to impart good damping performance to the viscoelastic body.

[0183] On the other hand, when the ratio of the silane compound exceeds the above range, the processability of the high-attenuation composition may be reduced, or the attenuation performance of the viscoelastic body may be reduced.

[0184] On the other hand, by setting the ratio of the silane compound in the above range, it is possible to impart good attenuation performance to the viscoelastic body while suppressing a decrease in the processability of the high attenuation composition.

[0185] <Cross-linking ingredients>

[0186] When the high attenuation composition of the present invention contains a cross-linkable rubber as a base polymer, a cross-linking component for cross-linking the cross-linkable rubber is formulated into the high attenuation composition.

[0187] Examples of the cross-linking component include a cross-linking agent and a cross-linking accelerator. Among these, a sulfur-based cross-linking agent is particularly preferred as the cross-linking agent.

[0188] Examples of the sulfur-based crosslinking agent include sulfur such as powdered sulfur, oil-treated powdered sulfur, precipitated sulfur, colloidal sulfur, and dispersed sulfur; and organic sulfur-containing compounds such as tetramethylthiuram disulfide and N,N-dithiobismorpholine. Sulfur is particularly preferred.

[0189] The proportion of sulfur is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber as the base polymer.

[0190] In addition, when oil-treated powdered sulfur, dispersed sulfur, or the like is used as sulfur, for example, the above ratio is the ratio of sulfur itself as an effective component contained in each.

[0191] Examples of the cross-linking accelerator include sulfenamide-based accelerators and thiuram-based accelerators.

[0192] Since the mechanism of promoting cross-linking varies depending on the type of cross-linking accelerator, it is preferable to use two or more types in combination.

[0193] Among them, as the sulfenamide-based accelerator, for example, one or more of N-cyclohexyl-2-benzothiazolylsulfenamide, N,N-dicyclohexyl-2-benzothiazolylsulfenamide, N-oxydivinyl-2-benzothiazolylsulfenamide, and N-tert-butyl-2-benzothiazolylsulfenamide can be used.

[0194] The ratio of the sulfenamide-based accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0195] As the thiuram-based accelerator, for example, one or more of tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrakis(2-ethylhexyl)thiuram disulfide, and dipentamethylenethiuram tetrasulfide can be used.

[0196] The proportion of the thiuram-based accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0197] <Other ingredients>

[0198] In addition to the above components, the high attenuation composition of the present invention may further contain inorganic fillers other than silica, crosslinking aids, softeners, tackifiers other than OA-containing rosin derivatives, and antioxidants in appropriate proportions.

[0199] (Inorganic filler)

[0200] Examples of inorganic fillers other than silica include carbon black.

[0201] As the carbon black, one or two or more carbon blacks that can function as a filler can be used among various types of carbon black classified according to their production methods and the like.

[0202] The proportion of carbon black is preferably 1 part by mass or more and preferably 5 parts by mass or less relative to 100 parts by mass of the total amount of the base polymer such as the cross-linkable rubber.

[0203] (Crosslinking aid)

[0204] Examples of crosslinking aids include metal compounds such as zinc oxide, fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid, and one or more of other conventionally known crosslinking aids. The combined use of zinc oxide and stearic acid is particularly preferred.

[0205] Among them, the ratio of zinc oxide is preferably 1 part by mass or more and 5 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0206] The proportion of stearic acid is preferably 1 part by mass or more and 3 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0207] (Softener)

[0208] The softener is a component for further improving the processability of the high attenuation composition. Examples of the softener include liquid rubbers that are liquid at room temperature.

[0209] Examples of the liquid rubber include one or more of liquid polyisoprene rubber, liquid nitrile rubber (liquid NBR), and liquid styrene butadiene rubber (liquid SBR). Liquid polyisoprene rubber is particularly preferred.

[0210] Specific examples of liquid polyisoprene rubber include, but are not limited to, at least one of Kuraray Co., Ltd.'s Kuraprene (registered trademark) LIR-30 (number average molecular weight: 28,000) and LIR-50 (number average molecular weight: 54,000).

[0211] The liquid rubber is a component that undergoes a cross-linking reaction with the cross-linkable rubber when the cross-linkable rubber, which is solid at room temperature before cross-linking and constitutes the main body of the high attenuation composition, is cross-linked. However, since it is a softener in nature, it is not added to the total amount of the cross-linkable rubber.

[0212] The ratio of the liquid rubber is preferably 5 parts by mass or more and preferably 50 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0213] Moreover, as another softening agent, coumarone-indene resin etc. are mentioned, for example.

[0214] Examples of the coumarone-indene resin include various coumarone-indene resins that are mainly composed of a polymer of coumarone and indene, have a relatively low molecular weight of about 1000 or less, and can function as a softener.

[0215] Specific examples of the coumarone-indene resin are not limited thereto, and for example, one or two or more of the following various products may be used.

[0216] Nitto Coatings Co., Ltd. Resin) (registered trademark) series, such as coumarone G-90 [average molecular weight: 770, softening point: 90°C, acid value: 1.0 KOHmg / g or less, hydroxyl value: 25 KOHmg / g, bromine value 9 g / 100 g], G-100N [average molecular weight: 730, softening point: 100°C, acid value: 1.0 KOHmg / g or less, hydroxyl value: 25 KOHmg / g, bromine value 11 g / 100 g], V-120 [average molecular weight: 960, softening point: 120°C, acid value: 1.0 KOHmg / g or less, hydroxyl value: 30 KOHmg / g, bromine value 6 g / 100 g], and V-120S [average molecular weight: 950, softening point: 120°C, acid value: 1.0 KOHmg / g or less, hydroxyl value: 30 KOHmg / g, bromine value 7 g / 100 g].

[0217] The proportion of the coumarone-indene resin is preferably 3 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the total amount of the base polymer such as the cross-linkable rubber.

[0218] (Other tackifiers)

[0219] As other tackifiers other than the OA-containing rosin derivative, for example, one or more of the unmodified rosin or modified rosin (acid-modified rosin, disproportionated rosin, hydrogenated rosin, polymerized rosin, etc.) that have not reacted with the oxyalkylene compound can be used.

[0220] Furthermore, petroleum resin or the like may be used as the tackifier.

[0221] However, in consideration of the effect of well expressing the above-mentioned effect by blending the OA-containing rosin derivative, the ratio of the other tackifier is preferably as small as possible, and it is particularly preferred not to blend (eliminate) the other tackifier.

[0222] (Anti-aging agent)

[0223] As the anti-aging agent, for example, one or more of various anti-aging agents such as benzimidazole-based, quinone-based, polyphenol-based, and amine-based anti-aging agents can be used.

[0224] In particular, it is preferable to use a benzimidazole-based antioxidant and a quinone-based antioxidant in combination.

[0225] Among them, examples of the benzimidazole-based antioxidant include 2-mercaptobenzimidazole and the like.

[0226] The proportion of the benzimidazole-based antioxidant is preferably 0.5 parts by mass or more and preferably 5 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0227] Examples of quinone-based antioxidants include Antigen FR (aromatic ketone-amine condensate) manufactured by Maruishi Chemicals Co., Ltd.

[0228] The proportion of the quinone-based antioxidant is preferably 0.5 parts by mass or more and preferably 5 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

[0229] <High attenuation composition>

[0230] The high attenuation composition of the present invention comprising the above components can be formed into a viscoelastic body constituting a viscoelastic support for seismic isolation installed in the foundation of a building or the like, or a viscoelastic shock absorber for vibration control installed in a structure such as a building or the like.

[0231] In addition, the high-attenuation composition of the present invention can also be formed into various viscoelastic bodies used as vibration damping components for cables of suspension bridges or cable-stayed bridges, etc.; vibration isolation components for industrial machinery or aircraft, automobiles, railway vehicles, etc.; vibration isolation components for computers or their peripheral equipment, household electrical appliances, etc.

[0232] Moreover, by adjusting the types, combinations and proportions of base polymers such as cross-linkable rubber, silica, OA-containing rosin derivatives, silane compounds, cross-linking components and other components, each viscoelastic body can have excellent attenuation performance suitable for its respective application.

[0233] Viscoelastic Shock Absorber

[0234] When the high attenuation composition of the present invention is used as a forming material to form a viscoelastic body of a viscoelastic vibration damper installed in a structure such as a building, the attenuation performance of each viscoelastic vibration damper including the viscoelastic body can be improved due to the high attenuation performance of the viscoelastic body.

[0235] Therefore, even if the entire viscoelastic damper is miniaturized or the number of viscoelastic dampers installed in a building or the like is reduced, the same vibration damping performance as before can be ensured.

[0236] Furthermore, the high attenuation composition of the present invention can reduce the temperature dependence of the attenuation performance of the viscoelastic body as described above, and thus, for example, a viscoelastic damper can be installed near the outer wall of a building or the like where a large temperature difference exists.

[0237] Therefore, the degree of freedom in designing buildings and the like that utilize the vibration damping performance of the viscoelastic damper can be expanded, and designs for increasing the strength of surrounding steel materials can be omitted, thereby contributing to cost reduction.

[0238] The step of forming a viscoelastic body using the high attenuation composition can be carried out in the same manner as before.

[0239] For example, the high attenuation composition can be formed into any shape such as a sheet, the formed product can be further formed into the shape of a viscoelastic body, and then the cross-linkable rubber can be cross-linked to form the viscoelastic body.

[0240] [Example]

[0241] Hereinafter, the present invention will be further described based on Examples and Comparative Examples, but the configuration of the present invention is not limited to these Examples.

[0242] <Example 1>

[0243] (Synthesis of OA-Containing Rosin Derivative I)

[0244] 530 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and heated to melt while nitrogen gas was flowing at 5 ml / min.

[0245] Next, when the temperature reached 205°C, 240 parts by mass of methoxy-polyoxyethylene glycol acrylate [methoxypolyethylene glycol #400 acrylate, AM-90G manufactured by Shin-Nakamura Chemical Industry Co., Ltd., number of acrylic acid groups: 1, number of oxyethylene units (EO number): 9] was added dropwise over 2 hours while stirring the molten tall oil rosin.

[0246] Then, the conjugated double bonds of the resin acid in the tall oil rosin and the acrylic acid groups of the methoxy-polyoxyethylene glycol acrylate are subjected to a Diels-Alder reaction to obtain a reaction product.

[0247] Next, 230 parts by mass of 1-octanol as an alcohol not containing an oxyalkylene group was added to the reaction product, and the temperature was raised to 270° C. over 8 to 10 hours to allow the remaining carboxyl groups in the reaction product to undergo an esterification reaction with the hydroxyl groups of the 1-octanol, thereby sealing the carboxyl groups and synthesizing OA-containing rosin derivative I.

[0248] In the Diels-Alder reaction, the number of moles of acrylic acid groups per conjugated double bond unit was adjusted to 1.0 mol, so that the synthesized OA-containing rosin derivative I had a structure in which 1 mol of resin acid was added to 1 mol of methoxy-polyoxyethylene glycol acrylate.

[0249] That is, the OA-containing rosin derivative I is a compound containing one cyclic diterpene structure in one molecule and having an EO number of 9.

[0250] (Preparation of High Attenuation Composition)

[0251] As the base polymer, natural rubber [SMR-CV60], which is a cross-linkable rubber, was used.

[0252] While 100 parts by mass of the natural rubber was masticated using a closed mixer, the OA-containing rosin derivative I and the components shown in Table 1 were blended and kneaded at a kneading temperature of 160°C.

[0253] [Table 1]

[0254] Table 1

[0255] Element parts by mass Silicon dioxide 140 Rosin derivatives containing OA I 20 Silane compounds 30 Liquid polyisoprene rubber 30 carbon black 3 Two types of zinc oxide 4 stearic acid 2

[0256] The components in Table 1 are as follows: Parts by mass in the table are parts by mass relative to 100 parts by mass of natural rubber.

[0257] Silica: NipSil VN3 manufactured by Tosoh Silica Co., Ltd.

[0258] Rosin derivatives containing OA I: cyclic diterpene structure × 1, EO number × 9

[0259] Silane compound: Phenyltriethoxysilane, KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.

[0260] Liquid polyisoprene rubber: Kuraprene LIR-50 manufactured by Kuraray Co., Ltd., number average molecular weight: 54,000

[0261] Carbon black: Fast extruding furnace black (FEF), SEAST 3 manufactured by Tokai Carbon Co., Ltd.

[0262] Two types of zinc oxide: manufactured by Mitsui Mining & Smelting Co., Ltd.

[0263] Stearic acid: "Tsubaki" manufactured by NOF Corporation

[0264] Next, the cross-linking components shown in Table 2 below were added and further kneaded to prepare a high attenuation composition.

[0265] [Table 2]

[0266] Table 2

[0267] Element parts by mass 5% oil-treated powdered sulfur 1.58 Sulfenamide accelerator 1 Thiuram-based accelerators 1

[0268] The components in the table are as follows: Parts by mass in the table are parts by mass relative to 100 parts by mass of natural rubber.

[0269] 5% oil-treated powdered sulfur: crosslinking agent, manufactured by Tsurumi Chemical Industry Co., Ltd., the sulfur itself is blended at a ratio of 1.5 parts by mass

[0270] Sulfenamide-based accelerator: N-tert-butyl-2-benzothiazolylsulfenamide, Nocceler (registered trademark) NS manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0271] Thiuram-based accelerators: Tetrabutylthiuram disulfide, Nocceler TBT-n manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0272] <Example 2 to Example 5>

[0273] High attenuation compositions were prepared in the same manner as in Example 1, except that 10 parts by mass (Example 2), 20 parts by mass (Example 3), 45 parts by mass (Example 4), and 50 parts by mass (Example 5) of the OA-containing rosin derivative II synthesized below were added to 100 parts by mass of natural rubber.

[0274] (Synthesis of OA-Containing Rosin Derivative II)

[0275] 770 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0276] Next, 230 parts by mass of triethylene glycol (number of hydroxyl groups: 2, number of EO: 3) was added to the melted tall oil rosin while stirring. The temperature was then raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the triethylene glycol to undergo an esterification reaction, thereby synthesizing OA-containing rosin derivative II.

[0277] In the esterification reaction, the number of moles of hydroxyl groups was adjusted to 1.0 mole per 1 mole of carboxyl groups. The synthesized OA-containing rosin derivative II had a structure in which 2 moles of resin acid were added to 1 mole of triethylene glycol (2 moles of hydroxyl groups).

[0278] That is, the OA-containing rosin derivative II is a compound containing two cyclic diterpene structures in one molecule and having an EO number of 3.

[0279] <Example 6>

[0280] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative III synthesized below was added to 100 parts by mass of the natural rubber.

[0281] (Synthesis of OA-Containing Rosin Derivative III)

[0282] 770 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0283] Next, while stirring the molten tall oil rosin, 230 parts by mass of polyoxyethylene ether tetraol [number of hydroxyl groups: 4, number of EO: 4] was added, and the temperature was raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the polyoxyethylene ether tetraol to undergo an esterification reaction, thereby synthesizing OA-containing rosin derivative III.

[0284] In the esterification reaction, the number of moles of hydroxyl groups was adjusted to 1.0 mole per 1 mole of carboxyl groups. The synthesized OA-containing rosin derivative III had a structure in which 4 moles of resin acid were added to 1 mole of polyoxyethylene ether tetraol (4 moles of hydroxyl groups).

[0285] That is, the OA-containing rosin derivative III is a compound containing four cyclic diterpene structures in one molecule and having an EO number of 4.

[0286] <Example 7, Example 8>

[0287] High attenuation compositions were prepared in the same manner as in Example 1, except that 20 parts by mass of the OA-containing rosin derivative II was added to 100 parts by mass of the natural rubber, and the amount of silica was 110 parts by mass (Example 7) or 170 parts by mass (Example 8) per 100 parts by mass of the natural rubber.

[0288] <Example 9>

[0289] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative IV synthesized below was added to 100 parts by mass of the natural rubber.

[0290] (Synthesis of OA-Containing Rosin Derivative IV)

[0291] 830 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0292] Next, 170 parts by mass of diethylene glycol (number of hydroxyl groups: 2, number of EO: 2) was added to the melted tall oil rosin while stirring. The temperature was then raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of triethylene glycol to undergo an esterification reaction, thereby synthesizing OA-containing rosin derivative IV.

[0293] In the esterification reaction, the number of moles of hydroxyl groups was adjusted to 1.0 mole per 1 mole of carboxyl groups. The synthesized OA-containing rosin derivative IV had a structure in which 2 moles of resin acid were added to 1 mole of diethylene glycol (2 moles of hydroxyl groups).

[0294] That is, the OA-containing rosin derivative IV is a compound containing two cyclic diterpene structures in one molecule and having an EO number of 2.

[0295] <Example 10>

[0296] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative V synthesized below was added to 100 parts by mass of the natural rubber.

[0297] (Synthesis of OA-Containing Rosin Derivative V)

[0298] 590 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and heated to melt while nitrogen gas was flowing at 5 ml / min.

[0299] Next, when the temperature reached 200°C, 260 parts by mass of methoxy-polyoxyethylene glycol acrylate [methoxypolyethylene glycol #550 acrylate, AM-130G manufactured by Shin-Nakamura Chemical Industry Co., Ltd., acrylic acid group: 1, EO number: 13] was added dropwise over 2 hours while stirring the molten tall oil rosin.

[0300] Then, the conjugated double bonds of the resin acid in the tall oil rosin and the acrylic acid groups of the methoxy-polyoxyethylene glycol acrylate were subjected to a Diels-Alder reaction to obtain a reaction product, which was then cooled to 150°C.

[0301] In the Diels-Alder reaction, the number of moles of the acrylic acid group was adjusted to 1.0 mol per one unit of the conjugated double bond.

[0302] Next, the reaction product was heated to 200°C to melt, and then 60 parts by mass of diethylene glycol [number of hydroxyl groups: 2, number of EO as oxyethylene units: 2] and 90 parts by mass of triethylene glycol [number of hydroxyl groups: 2, number of EO: 3] were added. The temperature was then raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the reaction product to undergo an esterification reaction with the hydroxyl groups of diethylene glycol and triethylene glycol, thereby synthesizing OA-containing rosin derivative V.

[0303] In the esterification reaction, the number of moles of the hydroxyl group was adjusted to 1.0 mole per 1 mole of the carboxyl group.

[0304] The synthesized OA-containing rosin derivative V is a mixture of a compound containing two cyclic diterpene structures in one molecule and having an EO number of 28 and a compound containing two cyclic diterpene structures in one molecule and having an EO number of 29.

[0305] <Example 11>

[0306] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative VI synthesized below was added to 100 parts by mass of the natural rubber.

[0307] (Synthesis of OA-Containing Rosin Derivative VI)

[0308] 510 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and heated to melt while nitrogen gas was flowing at 5 ml / min.

[0309] Next, when the temperature reached 200°C, 310 parts by mass of methoxy-polyoxyethylene glycol acrylate [methoxypolyethylene glycol #550 acrylate, AM-130G manufactured by Shin-Nakamura Chemical Industry Co., Ltd., acrylic acid group: 1, EO number: 13] was added dropwise over 2 hours while stirring the molten tall oil rosin.

[0310] Then, the conjugated double bonds of the resin acid in the tall oil rosin and the acrylic acid groups of the methoxy-polyoxyethylene glycol acrylate were subjected to a Diels-Alder reaction to obtain a reaction product, which was then cooled to 150°C.

[0311] In the Diels-Alder reaction, the number of moles of the acrylic acid group was adjusted to 1.0 mol per one unit of the conjugated double bond.

[0312] Next, the reaction product was heated to 200°C to melt it, and then 80 parts by mass of triethylene glycol [number of hydroxyl groups: 2, number of EO: 3] and 100 parts by mass of polyoxyethylene glycol [number of hydroxyl groups: 2, number average molecular weight Mn: 200, number of EO: 4] were added. The temperature was raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the reaction product to undergo an esterification reaction with the hydroxyl groups of triethylene glycol and polyoxyethylene glycol, thereby synthesizing OA-containing rosin derivative VI.

[0313] In the esterification reaction, the number of moles of the hydroxyl group was adjusted to 1.0 mole per 1 mole of the carboxyl group.

[0314] The synthesized OA-containing rosin derivative VI is a mixture of a compound containing two cyclic diterpene structures in one molecule and having an EO number of 29 and a compound containing two cyclic diterpene structures in one molecule and having an EO number of 30.

[0315] <Example 12>

[0316] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative VII synthesized below was added to 100 parts by mass of the natural rubber.

[0317] (Synthesis of OA-Containing Rosin Derivative VII)

[0318] 720 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0319] Next, 280 parts by mass of polyoxyethylene glycol [number of hydroxyl groups: 2, number average molecular weight Mn: 200, number of EO: 4] was added to the melted tall oil rosin while stirring. The temperature was then raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the polyoxyethylene glycol to undergo an esterification reaction, thereby synthesizing OA-containing rosin derivative VII.

[0320] In the esterification reaction, the number of moles of hydroxyl groups was adjusted to 1.0 mole per 1 mole of carboxyl groups. The synthesized OA-containing rosin derivative VII had a structure in which 2 moles of resin acid were added to 1 mole of polyoxyethylene glycol (2 moles of hydroxyl groups).

[0321] That is, the OA-containing rosin derivative VII is a compound containing two cyclic diterpene structures in one molecule and having an EO number of 4.

[0322] <Example 13>

[0323] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the OA-containing rosin derivative VIII synthesized below was added to 100 parts by mass of the natural rubber.

[0324] (Synthesis of OA-Containing Rosin Derivative VIII)

[0325] 560 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the rosin was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0326] Next, 440 parts by mass of polyoxyethylene glycol [number of hydroxyl groups: 2, number average molecular weight Mn: 400, number of EO: 9] was added to the melted tall oil rosin while stirring. The temperature was then raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the polyoxyethylene glycol to undergo an esterification reaction, thereby synthesizing OA-containing rosin derivative VIII.

[0327] In the esterification reaction, the number of moles of hydroxyl groups was adjusted to 1.0 mole per 1 mole of carboxyl groups. The synthesized OA-containing rosin derivative VIII had a structure in which 2 moles of resin acid were added to 1 mole of polyoxyethylene glycol (2 moles of hydroxyl groups).

[0328] That is, the OA-containing rosin derivative VIII is a compound containing two cyclic diterpene structures in one molecule and having an EO number of 9.

[0329] <Comparative Example 1>

[0330] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of unmodified rosin [Hartall R-WW manufactured by Harima Chemicals Co., Ltd.] was added to 100 parts by mass of natural rubber instead of the OA-containing rosin derivative.

[0331] Comparative Example 2

[0332] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the rosin ester synthesized below was added to 100 parts by mass of the natural rubber.

[0333] (Synthesis of Rosin Ester)

[0334] 660 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0335] Next, 340 parts by mass of 1-octanol was added while stirring the melted tall oil rosin, and the temperature was raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the 1-octanol to synthesize rosin ester.

[0336] Comparative Example 3

[0337] A high attenuation composition was prepared in the same manner as in Example 1 except that 20 parts by mass of the diester rosin synthesized below was added to 100 parts by mass of the natural rubber.

[0338] (Synthesis of Diester Rosin)

[0339] 780 parts by mass of tall oil rosin as unmodified rosin was placed in a 2 L flask, and the flask was heated to 200° C. while nitrogen gas was flowing at 5 ml / min to melt the rosin.

[0340] Next, 220 parts by mass of 1,8-octanediol was added while stirring the melted tall oil rosin, and the temperature was raised to 270°C over 8 to 10 hours to allow the carboxyl groups of the resin acid in the tall oil rosin to react with the hydroxyl groups of the 1,8-octanediol to esterify, thereby synthesizing diester rosin.

[0341] <Attenuation performance test>

[0342] (Production of Test Specimens)

[0343] The high attenuation composition prepared in the examples and comparative examples was extruded into a sheet and then punched to form a sheet. Figure 1 The planar shape shown is a rectangular flat plate 1 (8 mm thick×40 mm long×40 mm wide).

[0344] Next, rectangular flat steel plates 2 with a thickness of 6 mm, a length of 44 mm, and a width of 44 mm were laminated on both the front and back surfaces of the formed flat plate 1 via a vulcanized adhesive to produce a laminate.

[0345] The laminate is then heated to 150° C. while being pressurized in the lamination direction to crosslink the high attenuation composition forming the flat plate 1 , and the flat plate 1 is vulcanized and bonded to the two steel plates 2 to produce a test body 3 for evaluating attenuation performance as a model of a viscoelastic body.

[0346] (Displacement test)

[0347] like Figure 2 As shown in (a), two test bodies 3 are prepared, and the two test bodies 3 are fixed to a central fixing fixture 4 via one of the steel plates 2, and a left and right fixing fixture 5 is fixed to the other steel plates 2 of the two test bodies 3.

[0348] Next, the central fixing jig 4 is fixed to the upper fixing arm 6 of the testing machine (not shown) via the joint 7 , and the two left and right fixing jigs 5 are fixed to the lower movable platen 8 of the testing machine via the joint 9 .

[0349] The two test bodies 3 were fixed in the above-described manner in a state where the two parallel sides of the flat plate 1 were aligned parallel to the displacement direction described below.

[0350] Next, the following operations (I) and (II) are set as one cycle, and the hysteresis loop H (refer to Figure 3 ).

[0351] (I): Such as Figure 2 As shown by the hollow arrow in (a), the movable plate 8 is displaced by pushing it upward in the direction of the fixed arm 6, so that the flat plate 1 is Figure 2 As shown in (b), the state is that the strain is deformed in a direction perpendicular to the thickness direction.

[0352] (II): From the above state, this time Figure 2 As shown by the hollow arrow in (b), the movable plate 8 is displaced and restored to its original shape by pulling downward in the direction opposite to the direction of the fixed arm 6. Figure 2 The state shown in (a).

[0353] The measurement was performed under a temperature of 23° C. by performing the above-mentioned operations (I) and (II) three times and determining the value of the third cycle.

[0354] The maximum displacement in each cycle is set so that the offset of the two steel plates 2 sandwiching the flat plate 1 in a direction perpendicular to the thickness direction of the flat plate 1 becomes 100% of the thickness of the flat plate 1 .

[0355] According to the measurement Figure 3 The hysteresis loop H is used to calculate the equivalent shear elastic modulus Geq (N / mm 2 ):

[0356] [Number 1]

[0357] Number 1

[0358]

[0359] Where, Keq (N / mm) is the maximum displacement point and the minimum displacement point of the hysteresis loop H connected in Figure 3 The slope of the straight line L1 represented by the thick solid line, T (mm) is the thickness of the plate 1, A (mm 2 ) is the cross-sectional area of ​​the plate 1.

[0360] In addition, according to Figure 3 The hysteresis loop H is used to calculate the equivalent attenuation constant Heq using formula (ii):

[0361] [Number 2]

[0362] Number 2

[0363]

[0364] The ΔW in the formula is Figure 3 The amount of absorbed energy represented by the total surface area of ​​the hysteresis loop H is shown by the middle slash line.

[0365] In addition, W is in the Figure 3 The cross-hatched line indicates the elastic strain energy represented by the surface area of ​​the region defined by a triangle formed by the straight line L1, the horizontal axis of the graph, and a vertical line L2 descending from the intersection of the straight line L1 and the hysteresis loop H toward the horizontal axis.

[0366] Then, relative values ​​of the equivalent attenuation constants Heq of the respective examples and comparative examples were determined, with the equivalent attenuation constant Heq of Comparative Example 1 being 100.

[0367] <Evaluation of Temperature Dependence of Attenuation Performance>

[0368] (Low temperature environment)

[0369] The displacement test was carried out under the same conditions as above in a low temperature environment of 0°C. Figure 3 The hysteresis loop H shown in the figure is used to determine the equivalent shear elastic modulus Geq(0℃)(N / mm 2 ).

[0370] Next, the equivalent shear elastic modulus Geq (23°C) (N / mm) of the same sample obtained under the above-mentioned temperature of 23°C was determined. 2 ) ratio Geq(0℃) / Geq(23℃).

[0371] Then, relative values ​​of the ratio Geq(0°C) / Geq(23°C) of each Example and Comparative Example were determined, with the ratio Geq(0°C) / Geq(23°C) in Comparative Example 1 being 100.

[0372] (High temperature environment)

[0373] The displacement test was carried out under the same conditions as above in a high temperature environment at 40°C. Figure 3 The hysteresis loop H shown in the figure is used to determine the equivalent shear elastic modulus Geq (40°C) (N / mm 2 ).

[0374] Next, the equivalent shear elastic modulus Geq (23°C) (N / mm) of the same sample obtained under the above-mentioned temperature of 23°C was determined. 2 ) ratio Geq(40℃) / Geq(23℃).

[0375] Then, relative values ​​of the ratio Geq(40°C) / Geq(23°C) of each Example and Comparative Example were determined, with the ratio Geq(40°C) / Geq(23°C) in Comparative Example 1 being 100.

[0376] (Temperature dependence evaluation)

[0377] Test pieces with a relative value of 105 or less in the low temperature environment and 95 or more in the high temperature environment were marked as "○", and test pieces with either or both values ​​outside the range were marked as "×" to evaluate the temperature dependence of the attenuation performance.

[0378] The results are shown in Tables 3 to 6.

[0379] [Table 3]

[0380] Table 3

[0381]

[0382] [Table 4]

[0383] Table 4

[0384] [Table 5]

[0385] Table 5

[0386]

[0387] [Table 6]

[0388] Table 6

[0389]

[0390] The results of Examples and Comparative Examples in each table show that the combined use of a base polymer, silica, and an OA-containing rosin derivative as a rosin derivative can provide a viscoelastic body having excellent damping performance and low temperature dependence of the damping performance.

[0391] Furthermore, the results of Examples 3, 7, and 8 revealed that the ratio of silica is preferably 110 parts by mass or more and 170 parts by mass or less relative to 100 parts by mass of the total amount of the base polymer.

Claims

1. A viscoelastic shock absorber, comprising: Cross-linked rubber; Silicon dioxide; and Rosin derivatives are the reaction products of rosins and oxyalkylene compounds, and one molecule of the reaction product contains two or more oxyalkylene units. The rosin derivative contains two or more and ten or less cyclic diterpene structures derived from the rosins in one molecule of the reaction product.

2. The viscoelastic shock absorber according to claim 1, wherein: The rosin derivative is contained in an amount of 10 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber.

3. The viscoelastic shock absorber according to claim 1, wherein: The cross-linkable rubber is at least one cross-linkable rubber selected from the group consisting of natural rubber, isoprene rubber, butadiene rubber and styrene butadiene rubber.

4. The viscoelastic shock absorber according to claim 1, wherein: The silica is contained in a ratio of 110 parts by mass or more and 170 parts by mass or less relative to 100 parts by mass of the total amount of the cross-linkable rubber. The viscoelastic shock absorber according to claim 1 , further comprising a silane compound.

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