Impact-absorbing resin composition

Abstract

This resin composition for impact absorption is formed by containing: an A component composed of one or more block copolymers including a polymer component A1 having a glass transition point of 30°C or higher and a polymer component A2 having a glass transition point of 0°C or lower; a B component composed of a polymer that is miscible with the polymer component A1; a C component composed of a filler that is miscible with the B component or is dispersible in the B component; and a D component composed of a polyol-based liquid component.

Description

Technical Field

[0001] The present invention relates to a resin composition for shock absorption that protects a device from shock.

Background Art

[0002] With the spread of smartphones, tablets, etc., not only miniaturization and weight reduction of devices, but also weight reduction and thinning of shock absorption sheets that protect devices from shock are required.

[0003] Conventionally, vibration damping rubbers made of vulcanized rubbers such as butyl rubber and synthetic rubbers such as silicone rubber have been used as shock absorption sheets. In recent years, however, vibration damping materials that can be expected to have high vibration damping performance and reduced manufacturing costs have been studied. Vibration damping materials convert vibration energy into thermal energy, and those that utilize the viscoelasticity of polymers are known. The attenuation of vibration by polymers utilizes the function of converting external vibration energy into thermal energy and releasing it to the outside to cause loss of vibration energy. However, conventional polymer-based vibration damping materials require a thickness of at least about several millimeters to exhibit their vibration damping performance, and there is a problem that sufficient vibration damping performance cannot be exhibited if the thickness is less than that.

[0004] In contrast, the applicant of the present application has proposed a resin composition containing a block copolymer containing a hard segment and a soft segment, which can impart excellent shock absorption even when thinned (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, as devices become smaller and lighter, there is a growing need for improved vibration damping performance in shock-absorbing sheets that protect devices from impact.

[0007] Therefore, the present invention aims to provide a shock-absorbing resin composition having even better vibration damping performance. [Means for solving the problem]

[0008] In order to solve the above problems, the present inventors conducted diligent research and found that by incorporating a liquid polyol-based component, it is possible to greatly improve shock absorption, thus completing the present invention. Specifically, the shock-absorbing resin composition of the present invention is characterized by comprising: component A, which consists of one or more block copolymers containing polymer component A1 having a glass transition temperature of 30°C or higher and polymer component A2 having a glass transition temperature of 0°C or lower; component B, which consists of a polymer compatible with polymer component A1; component C, which consists of a filler compatible with component B or dispersed in component B; and component D, which consists of a liquid polyol-based component. [Effects of the Invention]

[0009] The impact-absorbing resin composition of the present invention exhibits excellent impact absorption even when made thinner. [Brief explanation of the drawing]

[0010] [Figure 1] This graph shows the relationship between the thickness of the sheet made from the resin composition in Example 1, Comparative Example 1, and Comparative Example 2 and the impact absorption rate. [Figure 2] This graph shows the relationship between the thickness of the resin composition sheet and the impact absorption rate in Example 4, Comparative Example 7, and Comparative Example 8. [Figure 3] This graph shows the relationship between the thickness of the resin composition sheet and the impact absorption rate in Example 5, Comparative Example 9, and Comparative Example 10. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below. The shock-absorbing resin composition of the present invention is characterized by comprising: component A, which is a block copolymer containing polymer component A1 having a glass transition temperature of 30°C or higher and polymer component A2 having a glass transition temperature of 0°C or lower; component B, which is a polymer compatible with polymer component A1; component C, which is a filler compatible with component B or dispersed in component B; and component D, which is a liquid polyol-based component.

[0012] (Component A) The component A used in this invention is a block copolymer comprising polymer component A1 (hard segment) with a glass transition temperature of 30°C or higher and polymer component A2 (soft segment) with a glass transition temperature of 0°C or lower. The arrangement of polymer components A1 and A2 is not particularly limited and can take any arrangement. For example, it can be represented as (A1-A2)p, (A1-A2-A1)q, and (A2-A1-A2)r, where p, q, and r are arbitrary integers.

[0013] The polymer constituting polymer component A1 is a polymer with a glass transition temperature of 30°C or higher, and examples include styrene resins, poly(meth)acrylate resins, polyamide resins, and polyester resins. Examples of styrene resins include polystyrene, polychlorostyrene, and poly-α-methylstyrene, but polystyrene (Tg=80~100°C) is preferred. Examples of poly(meth)acrylate resins include polymethyl methacrylate (Tg=72~105°C), polyethyl methacrylate (Tg=65°C), and poly-t-butyl methacrylate (Tg=107°C). Examples of polyamide resins include polyamide 6 (Tg=50°C), polyamide 66 (Tg=50°C), and polyamide 610 (Tg=50°C). Other examples of polyester resins include polyethylene terephthalate (Tg=80℃), polybutylene terephthalate (Tg=37~53℃), and polyethylene narephthalate (Tg=113℃).

[0014] Furthermore, polymer component A2 is a polymer with a glass transition temperature of 0°C or lower, and can be selected according to polymer component A1. For example, for polystyrene, polyisoprene, polyvinylisoprene, polybutadiene, and their hydrogenated products, poly(ethylene-propylene) and poly(ethylene-butylene), can be used. For polymethyl methacrylate, polybutyl acrylate can be used. For polyamide, polyester or polyether can be used. For aromatic polyester, aliphatic polyester or polyether can be used.

[0015] Specific examples of component A include, but are not limited to, styrene-based block copolymers such as styrene-isoprene-styrene block copolymer, styrene-vinylisoprene-styrene block copolymer, and styrene-butadiene-styrene block copolymer, as well as their hydrogenated derivatives, and methyl methacrylate-butyl acrylate-methyl acrylate resin.

[0016] In the present invention, for example, the following commercially available block copolymers can be used. (1) Styrene-isoprene-styrene block copolymer (abbreviated as "SIS") Clayton D (manufactured by Clayton Corporation), JSR SIS (manufactured by JSR Corporation), Quintac (manufactured by Zeon Corporation) (2) Styrene-butadiene-styrene block copolymer (abbreviated as "SBS") Clayton D (manufactured by Clayton Corporation), Toughprene (manufactured by Asahi Kasei Corporation), and Asaprene T (manufactured by Asahi Kasei Corporation) (3) Styrene-(ethylene-propylene)-styrene block copolymer (abbreviated as "SEPS") (hydrogenated SIS) Clayton G from Clayton Corporation, Septon 2000 series from Kuraray Corporation. (4) Styrene-(ethylene-butylene)-styrene block copolymer (abbreviated as "SEBS") (hydrogenated SBS) Clayton G manufactured by Clayton, Tough Tech H manufactured by Asahi Kasei, Septon 8000 series manufactured by Kuraray (5) Styrene-butadiene-butylene-styrene block copolymer (abbreviated as "SBBS") Tough Tech P manufactured by Asahi Kasei (6) Styrene-ethylene-(ethylene-propylene)-styrene block copolymer (abbreviated as "SEEPS") Septon 4000 series manufactured by Kuraray (8) Styrene-vinyl polyisoprene-styrene block copolymer Hybrar manufactured by Kuraray (9) Triblock copolymer of methyl methacrylate-butyl acrylate-methyl methacrylate Clarity 2000 series, 3000 series, and 4000 series manufactured by Kuraray, Nanostrengths manufactured by Arkema (10) Diblock copolymer of methyl methacrylate-butyl acrylate Clarity 1000 series manufactured by Kuraray In addition, modified products such as carboxyl groups, hydroxyl groups, epoxy groups, maleic anhydride groups, etc. of the copolymers (1) to (6) above can also be used.

[0017] In addition, two or more types can be used for the A component. By combining two or more types, the flexibility and toughness can be adjusted. The combination is not particularly limited. For example, a combination of a triblock copolymer of methyl methacrylate-butyl acrylate-methyl methacrylate and a diblock copolymer of methyl methacrylate-butyl acrylate can be mentioned.

[0018] (B component) The B component is a polymer having compatibility with the polymer component A1. Here, in the present invention, the B component having compatibility with the polymer component A1 means that a polymer film can be produced by mixing the homopolymer of the polymer component A1 and the B component, and the film is visually transparent at room temperature.

[0019] Component B can be selected according to the type of polymer component A1. For example, when the above-mentioned styrene-based resin is used for polymer component A1, component B can be an aromatic hydrocarbon resin, a hydrogenated aromatic hydrocarbon resin, an alicyclic hydrocarbon resin, or a copolymer resin thereof. Alternatively, it may be an aromatic hydrocarbon oligomer, an aliphatic cyclic hydrocarbon oligomer, or a copolymer oligomer thereof. Here, in the present invention, an oligomer refers to one with a degree of polymerization of 10 or less. An aromatic hydrocarbon resin is a compound composed of a benzene ring and / or multiple fused rings, and examples include homopolymers or modified products of substituted styrenes such as styrene, α-methylstyrene, t-butylstyrene, and vinyltoluene. Furthermore, a hydrogenated aromatic hydrocarbon resin is a compound composed of a benzene ring and / or multiple fused rings, and examples include hydrogenated homopolymers of substituted styrenes such as styrene, α-methylstyrene, t-butylstyrene, and vinyltoluene. Furthermore, examples of alicyclic hydrocarbon resins include hydrogenated aromatic resins and cyclohexyl methacrylate resins. A copolymer resin is a copolymer of an aromatic resin or alicyclic resin and an aliphatic resin. Preferably, it is an aromatic hydrocarbon resin, more preferably a homopolymer of styrene or a modified product thereof, or a hydrogenated product thereof. Furthermore, oxazoline group-containing polystyrene is preferred as the modified product.

[0020] Furthermore, when the above-mentioned poly(meth)acrylate resin is used for polymer component A1, an aliphatic hydrocarbon resin can be used for component B. As the aliphatic hydrocarbon resin, polyolefin resins, poly(meth)acrylate resins, and modified versions thereof can be used. Preferably, it is a poly(meth)acrylate resin or a modified version thereof. Here, the modified version is a modified product of carboxyl groups, hydroxyl groups, epoxy groups, maleic anhydride groups, etc. In addition, the weight-average molecular weight of the poly(meth)acrylate resin or its modified version is preferably 10,000 or less.

[0021] Furthermore, when the above-mentioned polyamide resin is used for polymer component A1, an aromatic or alicyclic resin containing epoxy groups or oxazoline groups can be used for component B.

[0022] Furthermore, when the above-mentioned polyester resin is used for polymer component A1, an aromatic or alicyclic resin containing epoxy groups or oxazoline groups can be used for component B.

[0023] In the present invention, for example, the following commercially available resins can be used as component B. (Aromatic hydrocarbon resins) (1) Styrene resin FTR manufactured by Mitsui Chemicals, YS Resin SX manufactured by Yasuhara Chemical Co., Ltd., and Alphon UP-1150 manufactured by Toagosei Co., Ltd. (2) Aromatic petroleum resin ENEOS Corporation's aromatic petroleum resin, Nisseki Neopolymer; Tosoh Corporation's petroleum resin, Petocol; and Fudo Corporation's xylene resin, Nikanol. (3) Aromatic modified resins PetroTac, a petroleum resin manufactured by Tosoh Corporation, and Epocross RPS-1005, an oxazoline group-containing reactive polystyrene manufactured by Nippon Shokubai Co., Ltd. (4) Aromatic oils ENEOS Corporation's Nisseki Hyzole and Idemitsu Kosan Corporation's Diana Process Oil AC (Alicyclic hydrocarbon resin) (5) Naphthenic oils Idemitsu Kosan's Diana Process Oil NP Series and NS Series (Poly(meth)acrylate resin) (1) Polymethacrylate resin Acrypet manufactured by Mitsubishi Chemical Corporation, and Parapellets manufactured by Kuraray Corporation. (2) Polyacrylate resin Neoacrylic, a solid acrylic resin manufactured by Kusumoto Kasei Co., Ltd., and Alphon UP-1000 series, a non-functional acrylic polymer manufactured by Toagosei Co., Ltd. (3) Polyacrylate-modified resin Alphon UC-2000 series (hydroxyl group-containing acrylic polymer), Alphon UC-3000 series (carboxyl group-containing acrylic polymer), and Alphon UC-4000 series (epoxy group-containing acrylic polymer) are manufactured by Toagosei Co., Ltd. Actflow 1000 series (hydroxyl group-containing acrylic polymer) and Actflow 3000 series (carboxyl group-containing acrylic polymer) are manufactured by Soken Chemical Co., Ltd.

[0024] Furthermore, a polymer that reacts with the filler can be used as component B. By reacting with the filler, component B and filler C are more likely to exist integrally in the region where the hard segment exists, the so-called hard segment domain, thereby further improving the vibration damping performance in the hard segment domain. An example of component B that reacts with the filler is the oxazoline group-containing reactive polystyrene mentioned above. The oxazoline group reacts with the carboxylic acid group, hydroxyl group, and thiol group of the filler. Another example of component B is a polymer modified with epoxy groups, carboxylic acid groups, hydroxyl groups, etc.

[0025] (C component) The C component used in this invention is a filler, and is a compound having two or more cyclic structures selected from the group consisting of aromatic hydrocarbons, aliphatic cyclic hydrocarbons, and heteroaromatic hydrocarbons, or a metal salt of such a compound. Here, two or more cyclic structures refer to two or more monocyclic compounds directly bonded or bonded via linking groups, condensed polycyclic compounds formed by the condensation of two or more monocyclics, crosslinked cyclic compounds, or spiropolycyclic compounds. Hereinafter, unless otherwise specified, condensed polycyclic compounds, crosslinked cyclic compounds, and spiropolycyclic compounds will be referred to as polycyclic compounds.

[0026] Furthermore, compounds having two or more cyclic structures include not only low molecular weight compounds but also high molecular weight compounds. For example, if the high molecular weight is a homopolymer, it includes polymers in which two or more monocyclic compounds with repeating units are directly bonded or linked via linking groups, and polymers in which one or more monocyclic compounds with repeating units and one polycyclic compound are directly bonded or linked via linking groups. Also, if the high molecular weight is a copolymer, each repeating unit of the copolymer contains one compound selected from the group consisting of one monocyclic compound, two or more monocyclic compounds directly bonded or linked via linking groups, and one polycyclic compound.

[0027] Here, the linking groups that connect two or more monocyclic compounds are -O-, -S-, -P-, -NH-, -NR- (where R is an alkyl group with 1 to 4 carbon atoms), -Si-, -COO-, -CONH-, -(CH2) n One can be selected from the group consisting of -(n is an integer from 1 to 12), -CH=CH-, and -C≡C-. Note that -(CH2) n - If n is 2 or greater, at least one methylene group may be substituted with -O-, -S-, -P-, -NH-, -NR- (where R is an alkyl group having 1 to 4 carbon atoms), -Si-, -COO-, -CONH-, -CH=CH-, and -C≡C-.

[0028] Examples of compounds having two or more cyclic structures selected from aromatic hydrocarbons include biphenyl, diphenylamine, triphenylamine, and methylenebisphenol, which may have substituents, in which a monocyclic compound benzene is directly bonded or bonded via a linking group. Examples of polycyclic compounds may have substituents, include naphthalene, anthracene, phenanthrene, tetraphydronaphthalene, 9,10-dihydroanthracene, and acetonaphthalene.

[0029] Compounds having two or more cyclic structures selected from aliphatic cyclic hydrocarbons include monocyclic compounds such as cyclohexane, cyclopentane, cyclopropane, cyclobutane, isobornyl, or compounds in which cyclohexene, cyclopentene, cyclopropene, and cyclobutene, which have double bonds in the ring, are directly bonded or linked via linking groups. Polycyclic compounds include monocyclic, dicyclic, tricyclic, tetracyclo, and pentacyclo compounds having 5 or more carbon atoms, which may have substituents, specifically dicyclopentenyl and norbornenyl. Aliphatic cyclic hydrocarbons also include alicyclic terpenes such as α-pinene, β-pinene, limonene, caffeine, abietic acid group, terpinolene, terpinene, phellandrene, α-carotene, β-carotene, and γ-carotene. These also include terpene oils obtained from essential oil components of plants that are mainly composed of these components, and rosin and its derivatives obtained by refining pine resin. Here, the rosin derivatives include hydrogenated rosin or rosin esters, disproportionated rosin, etc., and hydrogenated rosin or rosin esters are preferred.

[0030] Examples of compounds having two or more cyclic structures selected from heteroaromatic hydrocarbons include monocyclic compounds that may have substituents, such as pyrrole, furan, thiophene, imidazole, maleimide, oxazole, thiazole, pyrazole, isoxazole, isothiazole, pyridine, pyridazine, pyrimidine, piperidine, piperazine, and morpholine. Examples of polycyclic compounds that may have substituents include benzofuran, isobenzofuran, benzothiophene, benzotriazole, isobenzothiophene, indole, isoindole, benzimidazole, benzothiazole, benzoxazole, quinazole, and naphthyridine.

[0031] Here, the two or more monocyclic compounds are not limited to being monocyclic compounds of the same type, but may also include different types of monocyclic compounds. Furthermore, examples of the substituents mentioned above include linear or branched alkyl groups having 1 to 4 carbon atoms, halogen atoms, cyano groups, hydroxyl groups, nitro groups, alkoxy groups, carboxyl groups, amino groups, amide groups, and the like.

[0032] Furthermore, examples of metal salts of compounds having two or more cyclic structures include sodium salts, magnesium salts, potassium salts, calcium salts, and the like.

[0033] Furthermore, examples of polymers or oligomers having two or more cyclic structures include the following: As a homopolymer in which two or more monocyclic compounds with repeating units are directly bonded or linked via linking groups, terpene phenol resins can be cited. In the case of copolymers, for example, coumarone-indene resins can be cited.

[0034] Furthermore, low-molecular-weight or high-molecular-weight substances that react with component B can also be used as fillers. By reacting with component B, components B and C become more readily present in the region where the hard segment exists, the so-called hard segment domain, together with component B, thereby further improving the vibration damping performance in the hard segment domain.

[0035] Examples of fillers that react with component B include, when component B is oxazoline group-containing reactive polystyrene, organic fillers containing carboxyl groups, aromatic thiol groups, phenol groups, or alcohol groups. The oxazoline group reacts with the carboxyl groups, aromatic thiol groups, phenol groups, and alcohol groups of the filler. Examples of fillers containing carboxyl groups include 4-phenylbenzoic acid and its derivatives, 1-naphthoic acid and its derivatives, and rosin containing abietic acid groups and its derivatives. Examples of fillers containing aromatic thiol groups include biphenyl-4-thiol and its derivatives, 2-naphthalenchiol and its derivatives. Examples of fillers containing phenol groups include biphenyl-4-ol, and an example of a filler containing an alcohol group is 4-hydroxymethylbiphenyl. Another example of component B is epoxy-modified acrylic resin or hydroxyl-modified acrylic resin into which functional groups such as epoxy groups or hydroxyl groups have been introduced. Preferably, the filler is a compound or polymer having two or more cyclic structures selected from aromatic hydrocarbons. More preferably, examples include diphenylamine, triphenylamine, methylenebisphenol, and rosin derivatives, which may have substituents.

[0036] When a poly(meth)acrylate resin is used as polymer component A1, an aliphatic hydrocarbon resin can be used as component B, and a polymer in which two or more monocyclic compounds with two or more repeating units are directly bonded or bonded via linking groups can be used as component C. For example, it can be a homopolymer of two or more substituted styrenes such as styrene, α-methylstyrene, t-butylstyrene, and vinyltoluene, bonded together.

[0037] When a styrene-based resin is used as polymer component A1, an alicyclic hydrocarbon resin can be used as component B, and a hydrogenated petroleum resin can be used as component C. Hydrogenated petroleum resin is obtained by hydrogenating petroleum resin using a hydrogenation catalyst. The hydrogenation catalyst consists of a metal such as cobalt, copper, nickel, palladium, or platinum supported on a carrier such as silica, alumina, or silica-alumina. Petroleum resins are not particularly limited, but can be classified into aliphatic petroleum resins, aromatic petroleum resins, cyclopentadiene petroleum resins, etc. C5 petroleum resins can be used as aliphatic petroleum resins. C9 petroleum resins can be used as aromatic petroleum resins. C5 petroleum resins are obtained by cationic polymerization of C5 petroleum fractions, such as pentene, methylbutene, isoprene, and cyclopentene. C9 petroleum resins can be obtained by cationic polymerization of C9 petroleum fractions obtained by naphtha cracking, such as styrene, vinyltoluene, and α-methylstyrene. Dicyclopentadiene-based petroleum resins are obtained by thermal polymerization or cationic polymerization of dicyclopentadiene. These petroleum resins may be modified with polar groups such as hydroxyl groups and ester groups.

[0038] (D component) Component D used in the present invention consists of a liquid polyol-based component. In the present invention, the impact absorption rate can be greatly improved by incorporating component D. Here, "liquid" means having fluidity at room temperature (25°C) and normal pressure (atmospheric pressure). Furthermore, "polyol-based component" refers to a general term for compounds containing two or more hydroxyl groups in one molecule, and includes polyether polyols, polyester polyols, modified polyols, etc. The liquid polyol-based component includes one or more selected from the group consisting of liquid polyether polyols, liquid polyester polyols, copolymers of the polyether polyol and the polyester polyol, and at least one modified product thereof. As the above modified product, at least one is selected from the group consisting of silyl group-containing polyols (i.e., silane modified products), phosphorus-containing polyols, halogen-containing polyols, and polar group-containing polyols. For example, silyl group-containing polyols (i.e., silane modified products) and phosphorus-containing polyols can be selected as modified products. In polyols containing polar groups, the polar groups may include hydroxyl groups, carboxyl groups, ester groups, nitro groups, and / or amino groups.

[0039] Examples of liquid polyether polyols include polyalkylene glycols such as polyethylene glycol, polytrimethylene glycol, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol. Preferably, polyethylene glycol, polytrimethylene glycol, or polypropylene glycol is preferred, and more preferably, polypropylene glycol. An example of a liquid polyether polyol is Preminol manufactured by AGC Inc. An example of a liquid polyester polyol is polyphosphate ester polyol.

[0040] Examples of silane-modified liquid polyether polyols include polyether polymers having hydrolyzable silyl groups at the ends of polyalkylene glycols such as polyethylene glycol, polytrimethylene glycol, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol. Examples of silane-modified liquid polyether polyols include Exester from AGC, MS Polymer and Cyryl from Kaneka Corporation.

[0041] Furthermore, liquid phosphorus-containing polyols are polyols that contain phosphorus via chemical bonds within the molecule. While not particularly limited, examples of phosphorus-containing polyols include those having phosphate groups (phosphoric acid groups) in polyalkylene glycols such as polyethylene glycol and polypropylene glycol. For example, the Exolit OP500 series manufactured by Clariant Chemicals, Inc. can be cited.

[0042] In the resin composition of the present invention, component A is 1 to 99% by weight of the total resin composition, preferably 5 to 90% by weight, and more preferably 10 to 60% by weight. This is because if it is less than 1% by weight, the film-forming ability decreases, and if it is more than 99% by weight, the vibration damping performance decreases. Component B is 0.5 to 90% by weight, preferably 1 to 50% by weight, and more preferably 10 to 40% by weight. If component B is less than 0.5% by weight, the cloud point becomes high, and if it is more than 90% by weight, the sheet becomes brittle, which is undesirable. Component C is 0.1 to 90% by weight, preferably 0.5 to 50% by weight, and more preferably 5 to 40% by weight. If component C is less than 0.1% by weight, the impact absorption rate described later decreases, and if it is more than 90% by weight, the sheet becomes brittle, which is undesirable. Component D is 0.3 to 30% by weight, preferably 5 to 20% by weight, and more preferably 10 to 20% by weight. If the D component is less than 0.3% by weight, the shock absorption rate does not improve significantly, and if it is more than 30% by weight, bleeding occurs, which is undesirable.

[0043] Furthermore, the resin composition of the present invention may contain various additives, provided that they do not reduce the impact absorption properties. Examples of such additives include antioxidants, ultraviolet absorbers, and flame retardants.

[0044] (Manufacturing method) The resin composition of the present invention can be manufactured by mixing component A with components B, C, and D by melt mixing by heating or by dissolution mixing using a solvent. For example, in order to make component C miscible with component B, or to disperse component C in component B, components B and C may be mixed beforehand, and then components A and D may be mixed into this mixture. In this case, components A and D may be mixed at a temperature lower than the temperature at which components B and C were mixed, because this makes it more difficult for components B and C to separate.

[0045] The resin composition of the present invention contains component C as a filler that is compatible with or dispersed in component B. Therefore, components B and C are present in the region where hard segments exist, the so-called hard segment domain, and vibration damping performance can be exhibited even in the hard segment domain. In the present invention, vibration damping performance can be further improved by incorporating component D.

[0046] Furthermore, the resin composition of the present invention can be molded into various shapes and used as an impact-absorbing material. For example, the resin composition can be molded into a sheet by hot pressing or the like and used as an unconstrained impact-absorbing material, or it can be laminated between deformation-resistant constrained layers and used as a constrained impact-absorbing material. It can also be used as a paint-type resin composition, applied to substrates of various shapes to form a coating film, and then composited with the substrate for use. [Examples]

[0047] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. The amounts of each component used are indicated in parts by weight.

[0048] (Component A) (1) Triblock copolymer of methyl methacrylate, butyl acrylate, and methyl methacrylate • Kuraray's Clarity LA4285 (2) Styrene-(ethylene-propylene)-styrene block copolymer • Septon 2104 manufactured by Kuraray Co., Ltd.

[0049] (B component) (1) Polyacrylate-modified resin Alphon UP-1000 and Alphon UP-1080 manufactured by Toagosei Co., Ltd. (2) Naphthenic oils Diana Process Oil NS-100 manufactured by Idemitsu Kosan Co., Ltd.

[0050] (C component) (1) Rosin • Pine Crystal KR-85 and KR-120, which are logiesters manufactured by Arakawa Chemical Industries, Ltd. (2) Terpene phenol resin YS Polystar TH130 manufactured by Yasuhara Chemical Co., Ltd. (3) Styrene resin YS Resin SX100 manufactured by Yasuhara Chemical Co., Ltd. (4) Hydrogenated petroleum resin Alcon P-100 manufactured by Arakawa Chemical Industries, Ltd.

[0051] (D component) (1) Liquid polyether polyol • Preminol S4013F (polypropylene glycol) manufactured by AGC Corporation Dow's PEG400 (2) Silane-modified liquid polyether polyols • Exestar S2410 manufactured by AGC Corporation (3) Liquid phosphorus-containing polyols • Exolit OP550 manufactured by Clariant Chemicals, Inc.

[0052] Examples 1-2 and Comparative Examples 1-4 In Examples 1-2 and Comparative Examples 1-4, component A used was a polymer in which polymer component A1 of component A was a polymethacrylate. In Example 1, component D was Exester S2410, a silane-modified liquid polyether polyol, and in Example 2, component D was PEG400, a liquid polyether polyol. Comparative Examples 1 and 3 did not contain component D, and Comparative Examples 2 and 4 did not contain component B.

[0053] Based on the compositions listed in Table 1, each component was blended and kneaded in a Laboplast Mill manufactured by Toyo Seiki Seisakusho Co., Ltd. to obtain a resin composition. This resin composition was molded using a bench press to produce a test sheet with a thickness of 200 μm. Here, for Example 1 and Comparative Examples 1 and 2, the resin composition was prepared by kneading at 180°C and 50 rpm for 3 minutes, and then by kneading at 200°C and 100 rpm for 3 minutes. For Example 2 and Comparative Examples 3 and 4, the resin composition was prepared by kneading at 180°C and 50 rpm for 3 minutes. In addition, for Example 1 and Comparative Examples 1 and 2, test sheets with thicknesses of 100 μm and 350 μm were also prepared.

[0054] Example 3 and Comparative Examples 5, 6 In Example 3 and Comparative Examples 5 and 6, component A was used in which the polymer component A1 of component A was a styrene-based resin. Note that Comparative Example 5 did not contain component D, and Comparative Example 6 did not contain component B.

[0055] Based on the compositions listed in Table 2, each component was blended and kneaded for 6 minutes at 200°C and 100 rpm using a Laboplast Mill manufactured by Toyo Seiki Seisakusho Co., Ltd. to obtain a resin composition. This resin composition was molded using a benchtop press to produce a test sheet with a thickness of 200 μm.

[0056] (Evaluation of water absorption capacity) The impact acceleration was measured when a stainless steel ball of a predetermined diameter (10 mm in diameter, 4.1 kg) was dropped from a height of 100 mm onto a 100 x 100 mm, 30 mm thick acrylic plate. The measurement was performed by attaching an acceleration sensor to the back of the acrylic plate with adhesive and using a Spectris 2250 handheld analyzer. Impact absorption performance was evaluated as impact absorption rate (%). The results are shown in Tables 2-4. Here, the impact absorption rate is defined by the following formula, and the impact transmission rate (%) was calculated by dividing the acceleration when a stainless steel ball of a predetermined diameter was dropped onto the sheet by the acceleration without the sheet. Shock absorption rate (%) = 100 (%) - Shock transmission rate (%)

[0057] [Table 1]

[0058] [Table 2]

[0059] (result) Examples 1 and 2 and Comparative Examples 1 to 4 are examples using component A, in which the polymer component A1 is polymethacrylate. As shown in Table 1, Example 1 showed a significant improvement in shock absorption rate of approximately 2.1 times compared to Comparative Example 1, which did not contain component D. This confirmed that the resin composition of the present invention has excellent vibration damping performance even when thin. As shown in Comparative Example 2, when component B was absent, the shock absorption rate was lower than that of Example 1 even when component D was added. This suggests that the inclusion of both component B and component D significantly improved the shock absorption rate. In Example 2, the shock absorption rate was also significantly improved by approximately 3.6 times compared to Comparative Example 3, which did not contain component D. As shown in Comparative Example 4, when component B was absent, the shock absorption rate was lower than that of Example 1 even when component D was added. Therefore, in Example 2 as well, it is considered that the inclusion of both component B and component D significantly improved the shock absorption rate.

[0060] Next, Examples 3 and Comparative Examples 5 and 6 are examples in which component A, a polymer constituting polymer component A1, is a styrene-based resin. As shown in Table 2, Example 3 showed a significant improvement in shock absorption rate of approximately 2.2 times compared to Comparative Example 5, which did not contain component D. This confirmed that the resin composition of the present invention has excellent vibration damping performance even when thin. As shown in Comparative Example 6, when component B was absent, the shock absorption rate was lower than in Example 3 even when component D was added. This suggests that, in the case of Example 3 as well, the inclusion of both component B and component D significantly improved the shock absorption rate.

[0061] Figure 1 is a graph showing the relationship between the thickness of the resin composition sheet and the impact absorption rate in Example 1, Comparative Example 1, and Comparative Example 2. The graph shows the relationship between the thickness of the resin composition sheet and the impact absorption rate for Example 1 and Comparative Example 1. It was confirmed that Example 1 had a higher impact absorption rate even when its thickness was reduced compared to Comparative Example 1. Furthermore, while Comparative Example 2 tended to decrease in impact absorption rate when its thickness was reduced, Example 1 tended to maintain a lower impact absorption rate even when its thickness was reduced. Therefore, it is considered that including both component B and component D allows for the highest impact absorption rate to be maintained even when the thickness is reduced, compared to Comparative Examples 1 and 2.

[0062] Examples 4 (Examples 4-1 to 4-3), Comparative Example 7 (7-1 to 7-3), and Comparative Example 8 (8-1 to 8-3) In Example 4 and Comparative Examples 7-8, component A was used in which the polymer constituting polymer component A1 of component A was polymethacrylate. In Example 4 and Comparative Example 7, polyacrylate resin was used as component B. On the other hand, component B was not used in Comparative Example 8. In Example 4 and Comparative Examples 7-8, styrene resin was used as component C. In Example 4 and Comparative Example 8, phosphorus-containing polyol was used as component D. On the other hand, component D was not used in Comparative Example 7.

[0063] Based on the compositions listed in Table 3, each component was blended and kneaded in a Laboplast Mill manufactured by Toyo Seiki Seisakusho Co., Ltd. to obtain a resin composition. This resin composition was molded using a benchtop press to produce test sheets with thicknesses of 100 μm, 200 μm, and 350 μm. The resin composition was prepared by kneading at 200°C and 50 rpm for 5 minutes.

[0064] Example 5 (Examples 5-1 to 5-3), Comparative Example 9 (9-1 to 9-3), and Comparative Example 10 (10-1 to 10-3) In Example 5 and Comparative Examples 9-10, component A was a polymer in which polymer component A1 of component A was a styrene-based resin. In Example 5 and Comparative Example 9, naphthenic oil was used as component B. On the other hand, component B was not used in Comparative Example 10. In Example 5 and Comparative Examples 9-10, hydrogenated petroleum resin was used as component C. In Example 5 and Comparative Example 10, phosphorus-containing polyol was used as component D. On the other hand, component D was not used in Comparative Example 9.

[0065] Based on the compositions listed in Table 4, each component was blended and kneaded in a Laboplast Mill manufactured by Toyo Seiki Seisakusho Co., Ltd. to obtain a resin composition. This resin composition was molded using a benchtop press to produce test sheets with thicknesses of 100 μm, 200 μm, and 350 μm. The resin composition was prepared by kneading at 200°C and 50 rpm for 5 minutes.

[0066] (Evaluation of water absorption capacity) The impact acceleration was measured when a stainless steel ball of a predetermined diameter (10 mm in diameter, 4.1 kg) was dropped from a height of 100 mm onto a 100 x 100 mm, 30 mm thick acrylic plate. The measurement was performed by attaching an acceleration sensor to the back of the acrylic plate with adhesive and using a Spectris 2250 handheld analyzer. Impact absorption performance was evaluated as impact absorption rate (%). The results are shown in Tables 3-4. Here, the impact absorption rate is defined by the following formula, and the impact transmission rate (%) was calculated by dividing the acceleration when a stainless steel ball of a predetermined diameter was dropped onto the sheet by the acceleration without the sheet. Shock absorption rate (%) = 100 (%) - Shock transmission rate (%)

[0067] [Table 3]

[0068] [Table 4]

[0069] (result) Examples 4, Comparative Example 7, and Comparative Example 8 are examples using component A, in which the polymer component A1 is polymethacrylate. As shown in Table 3, Example 4 is based on a molded article containing components A, B, C, and D. Comparative Example 7 is based on a molded article containing components A, B, and C but not component D. Comparative Example 8 is based on a molded article containing components A, C, and D but not component B. Based on Table 3 and Figure 2, comparing Example 4 and Comparative Example 8, it was found that the impact absorption rate of Example 4 was approximately 2.1 times higher than that of Comparative Example 8, which does not contain component B, when the film thickness of the molded article was 200 μm. Furthermore, comparing Comparative Example 7 and Comparative Example 8, it was found that the impact absorption rate of Comparative Example 7 was approximately 1.8 times higher than that of Comparative Example 8, which does not contain component B, when the film thickness of the molded article was 200 μm. From the above, it was found that component B makes a significant contribution to improving the impact absorption rate.

[0070] Comparing Example 4 with Comparative Example 7, it was found that the impact absorption rate of Example 4 was approximately 1.13 times higher than that of Comparative Example 7, which did not contain component D. From the above, it was found that component D, as well as component B, makes a significant contribution to ensuring further improvement in impact absorption rate.

[0071] Furthermore, as can be seen from Figure 2, in Example 4, it was confirmed that an impact absorption rate of approximately 30% could be secured even when the thickness was reduced to 100 μm compared to Comparative Examples 7 and 8. This suggests that when both component B and component D are included, the highest impact absorption rate can be maintained compared to Comparative Examples 7 and 8, even when the thickness is reduced.

[0072] (result) Examples 5, Comparative Example 9, and Comparative Example 10 are examples using component A, in which the polymer component A1 is styrene resin. As shown in Table 4, Example 5 is based on a molded article containing components A, B, C, and D. Comparative Example 9 is based on a molded article containing components A, B, and C but not component D. Comparative Example 10 is based on a molded article containing components A, C, and D but not component B. Based on Table 4 and Figure 3, comparing Example 5 and Comparative Example 10, it was found that the impact absorption rate of Example 5 was approximately 2.5 times higher than that of Comparative Example 10, which does not contain component B, when the film thickness of the molded article was 200 μm. Furthermore, comparing Comparative Example 9 and Comparative Example 10, it was found that the impact absorption rate of Comparative Example 9 was approximately 2.1 times higher than that of Comparative Example 10, which does not contain component B, when the film thickness of the molded article was 200 μm. From the above, it was found that component B makes a significant contribution to improving the impact absorption rate.

[0073] Furthermore, comparing Example 5 with Comparative Example 9, it was found that the impact absorption rate of Example 5 was approximately 1.2 times higher than that of Comparative Example 9, which did not contain component D. From the above, it was found that component D, as well as component B, makes a significant contribution to ensuring further improvement in impact absorption rate.

[0074] Furthermore, as can be seen from Figure 3, in Example 5, it was confirmed that an impact absorption rate of approximately 30% could be secured even when the thickness was reduced to 100 μm compared to Comparative Examples 9 and 10. This suggests that when both component B and component D are included, the highest impact absorption rate can be maintained compared to Comparative Examples 9 and 10, even when the thickness is reduced. [Industrial applicability]

[0075] The shock-absorbing resin composition of the present invention has excellent vibration damping performance even when thinned, and can therefore be suitably used not only as a shock-absorbing sheet for devices but also in other applications where vibration and noise are problematic.

Claims

1. Polymer component A has a glass transition temperature of 30°C or higher. １ Polymer component A has a glass transition temperature of 0°C or lower. ２ A shock-absorbing resin composition comprising component A, component B, component C, and component D, which is a polyol-based component that is liquid at room temperature (25°C) and normal pressure (atmospheric pressure), The proportion of component A is 40 to 99% by weight of the entire impact-absorbing resin composition. Polymer component A constituting component A １ A shock-absorbing resin composition in which component B is a styrene-based resin, component B is an alicyclic hydrocarbon resin, and component C is rosin or a terpene phenol resin.

2. The impact-absorbing resin composition according to claim 1, wherein the liquid polyol component comprises one or more selected from the group consisting of liquid polyether polyol, liquid polyester polyol, copolymer of the polyether polyol and the polyester polyol, and at least one modified product thereof, and the modified product is at least one selected from the group consisting of silyl group-containing polyol, phosphorus-containing polyol, halogen-containing polyol, and polar group-containing polyol.

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