JP6347615B2 - Impact absorbing resin composition - Google Patents

Description

  The present invention relates to an impact-absorbing resin composition that protects a device from impact.

  With the widespread use of smartphones, tablets, etc., not only miniaturization and weight reduction of devices, but also impact absorption sheets that protect devices from impacts are required to be lighter and thinner.

  Conventionally, anti-vibration rubber made of vulcanized rubber such as butyl rubber or synthetic rubber such as silicone rubber has been used as the impact absorbing sheet. However, in recent years, damping materials that can be expected to have high vibration damping performance and reduced manufacturing costs. Is being considered. Damping materials are materials that convert vibration energy into thermal energy, and those that utilize the viscoelasticity of polymers are known. Damping of vibration by a polymer utilizes a function of converting vibration energy from the outside into heat energy and releasing the vibration energy by releasing it to the outside. However, this damping effect is limited only to a temperature region near the glass transition temperature (Tg) of the polymer. In other words, the conventional damping material using a polymer has a problem that the usable temperature range showing a high loss coefficient (tan δ) necessary for vibration damping is narrow.

  On the other hand, two or more types of polymers having different glass transition temperatures are mixed in order to develop vibration damping properties in a wider temperature range. If the mixed polymer is incompatible, a loss coefficient peak (hereinafter referred to as a temperature peak) appears at each glass transition temperature, and a wide temperature peak cannot be obtained. If the compatibility is good, a single temperature peak is obtained. Thus, attempts have been made to select and mix semi-compatible polymers. However, although the width of the temperature peak becomes wide, there is a problem that the vibration suppression performance deteriorates because the height of the temperature peak becomes low. In addition, a method has been proposed in which two or more polymers have a mutual network structure or a compatibilizing agent is used for an incompatible resin (Patent Document 1).

  In addition, a method of adding a low molecule having three or more rings to a thermoplastic resin (Patent Document 2) and a method of adding a low molecular compound that increases a dipole moment to a polymer material (Patent Document 3) have been proposed. ing.

JP 2001-152028 A JP-A-5-112670 JP 2004-300342 A

  However, the conventional damping material needs to have a thickness of at least several millimeters in order to exhibit the damping performance, and if it is thinner than that, there is a problem that sufficient damping performance cannot be exhibited. .

  Therefore, an object of the present invention is to provide an impact-absorbing resin composition that has excellent vibration damping performance even if it is thinned.

To solve the above problems, the shock-absorbing resin composition of the present invention, the glass transition point is above 30 ° C. the polymer component A ₁ and the glass transition point block copolymer containing a 0 ℃ less of the polymer component A ₂ It comprises a polymer A, a polymer B compatible with the polymer component A1, and a filler C compatible with the polymer B or dispersed in the polymer B. .

  Moreover, the manufacturing method of the resin composition for shock absorption of this invention mixes the mixture containing the said polymer B and the said filler C with the said block copolymer A, It is characterized by the above-mentioned.

  Usually, a block copolymer containing a polymer component having a high glass transition point (hard segment) and a polymer component having a glass transition point lower than that hard segment (soft segment) is a soft segment having rubber elasticity at room temperature. Develops damping performance, and the hard segment does not directly contribute to damping performance. However, the impact-absorbing resin composition of the present invention contains the polymer B that is compatible with the hard segment and the filler C that is compatible with the polymer B or is dispersed in the polymer B. In addition, since the polymer B and the filler C exist in a region where the hard segment exists, that is, a so-called hard segment domain, it is possible to exhibit the damping performance also in the hard segment domain. Thereby, due to a synergistic effect with the soft segment having rubber elasticity, even if the thickness is reduced, it is possible to suppress the deterioration of the vibration damping performance and to impart excellent shock absorption.

It is a graph which shows the relationship between the thickness of the sheet | seat which consists of a resin composition of this invention, and an impact absorption rate.

Hereinafter, embodiments of the present invention will be described in detail.
Shock absorbing resin composition of the present invention, the block copolymer A glass transition point of more than 30 ° C. the polymer component A ₁ and the glass transition point containing a 0 ℃ following polymer components A _2, heavy It is characterized by comprising a polymer B compatible with the polymer component A ₁ and a filler C compatible with the polymer B or dispersed in the polymer B.

(Block copolymer A)
The block copolymer A used in the present invention comprises a polymer component A ₁ (hard segment) having a glass transition point of 30 ° C. or higher and a polymer component A ₂ (soft segment) having a glass transition point of 0 ° C. or lower. . Sequence of the polymer component A ₁ with the polymer component A ₂ is not limited in particular, can take any sequence. For example, it can be represented by (A ₁ -A ₂ ) p, (A ₁ -A ₂ -A ₁ ) q, (A ₂ -A ₁ -A ₂ ) r. Here, p, q, and r are arbitrary integers.

Polymer constituting the polymer component A ₁ may be mentioned a glass transition point of 30 ° C. or more polymers, styrene resins, poly (meth) acrylate resin, polyamide resin, polyester resin or the like. Examples of the styrene resin include polystyrene, polychlorostyrene, poly α-methylstyrene and the like, and polystyrene (Tg = 80 to 100 ° C.) is preferable. Examples of the poly (meth) acrylate resin include polymethyl methacrylate (Tg = 72 to 105 ° C.), polyethyl methacrylate (Tg = 65 ° C.), and poly t-butyl methacrylate (Tg = 107 ° C.). Examples of the polyamide resin include polyamide 6 (Tg = 50 ° C.), polyamide 66 (Tg = 50 ° C.), and polyamide 610 (Tg = 50 ° C.). Examples of the polyester resin include polyethylene terephthalate (Tg = 80 ° C.), polybutylene terephthalate (Tg = 37 to 53 ° C.), and polyethylene naphthalate (Tg = 113 ° C.).

In addition, the polymer component A ₂ is a polymer having a glass transition point of 0 ° C. or lower, and can be selected according to the polymer component A ₁ . For example, for polystyrene, polyisoprene, polyvinyl isoprene, polybutadiene, and hydrogenated products thereof such as poly (ethylene-propylene) and poly (ethylene-butylene) can be mentioned. Moreover, polybutyl acrylate can be mentioned with respect to polymethylmethacrylate. Also, for polyamides, mention may be made of polyesters or polyethers. For aromatic polyesters, mention may be made of aliphatic polyesters or polyethers.

  Specific examples of the block copolymer A are not particularly limited, but styrene-isoprene-styrene block copolymer, styrene-vinylisoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer. And styrene block copolymers such as hydrogenated products thereof, and methyl methacrylate-butyl acrylate-methyl acrylate resins.

In the present invention, for example, the following commercially available block copolymers can be used.
(1) Styrene-isoprene-styrene block copolymer (SIS)
Clayton D manufactured by Clayton Co., JSR SIS manufactured by JSR Co., Ltd., Quintac manufactured by Nippon Zeon Co., Ltd. (2) Styrene-butadiene-styrene block copolymer (SBS)
Clayton D made by Clayton, Toughprene made by Asahi Kasei, Asaprene T made by Asahi Kasei
(3) Styrene- (ethylene-propylene) -styrene block copolymer (SEPS) (SIS hydrogenated product)
Clayton G manufactured by Clayton Co., Septon manufactured by Kuraray Co., Ltd. (4) Styrene- (ethylene-butylene) -styrene block copolymer (SEBS) (hydrogenated product of SBS)
Clayton G manufactured by Clayton Co., Tuftec H manufactured by Asahi Kasei Co., Ltd., Septon manufactured by Kuraray Co., Ltd. (5) Styrene-butadiene-butylene-styrene block copolymer (SBBS)
Tuftec P manufactured by Asahi Kasei
(6) Styrene-ethylene- (ethylene-propylene) -styrene block copolymer (SEEPS)
Kuraray Septon (8) Styrene-vinyl polyisoprene-styrene block copolymer Kuraray Hybra (9) Methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer Kuraray Clarity, Arkema Nanostrength manufactured The modified products such as carboxyl group, hydroxyl group, epoxy group, and maleic anhydride group of the copolymers (1) to (6) can also be used.

(Polymer B)
Polymer B having compatibility with the polymer component A _1. Here, the polymer B in the present invention is a polymer component A ₁ and has a compatibility, a mixture of homopolymer of the polymer component A ₁ and the polymer B can form a film, the film is at room temperature It is transparent by visual inspection.

Polymer B can be selected depending on the type of the polymer component A _1. For example, if the polymer component A ₁ using the above styrene-based resin, the polymer B can be used aromatic hydrocarbon resins, alicyclic hydrocarbon resins, and copolymer resin thereof. Or an aromatic hydrocarbon oligomer, an aliphatic cyclic hydrocarbon oligomer, and those copolymerization oligomers may be sufficient. Here, in the present invention, the oligomer means one having a polymerization degree of 10 or less. The aromatic hydrocarbon resin is a compound composed of a benzene ring and a plurality of condensed rings. For example, a homopolymer of a substituted styrene such as styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, or a modification thereof. You can list things. Examples of the alicyclic hydrocarbon resin include hydrogenated aromatic resins and cyclohexyl methacrylate resins. The copolymer resin is a copolymer of an aromatic resin or alicyclic resin and an aliphatic resin. An aromatic hydrocarbon resin is preferable, and a homopolymer of styrene or a modified product thereof is more preferable. The modified product is preferably oxazoline group-containing polystyrene.

Further, when the polymer components A ₁ using the above poly (meth) acrylate resin, the polymer B, it is possible to use aliphatic hydrocarbon resins. As the aliphatic hydrocarbon resin, polyolefin resin, poly (meth) acrylate resin, and modified products thereof can be used. A poly (meth) acrylate resin or a modified product thereof is preferable. Here, the modified product is a modified product such as a carboxyl group, a hydroxyl group, an epoxy group, and a maleic anhydride group.

Further, when the polymer components A ₁ using the above polyamide resin, the polymer B, containing an epoxy group or oxazoline group, may be an aromatic or cycloaliphatic resins.

Further, when the polymer components A ₁ using the above polyester resin, the polymer B, containing an epoxy group or oxazoline group, may be an aromatic or cycloaliphatic resins.

In the present invention, as the polymer B, for example, the following commercially available resins can be used.
(Aromatic hydrocarbon resin)
(1) Styrenic resin FTR manufactured by Mitsui Chemicals, YS resin SX manufactured by Yasuhara Chemical, Alfon UP-1150 manufactured by Toa Gosei
(2) Aromatic petroleum resin Aromatic petroleum resin neopolymer manufactured by JX Nippon Oil & Energy, Petroleum resin Petcoal manufactured by Tosoh Corporation, Petroleum resin Petcole manufactured by Tosoh Corporation, Xylene resin Nikanol manufactured by Fudou Co., Ltd. (3) Aromatic modified resin PetroTac, a petroleum resin manufactured by Tosoh Corporation, Epocross RPS-1005, which is a reactive polystyrene containing oxazoline group, manufactured by Nippon Shokubai Co., Ltd.
(4) Aromatic oils JX Nippon Oil &Energy's Nisseki Hyzol SAS, Idemitsu Kosan Diana Process Oil AC
(Poly (meth) acrylate resin)
(1) Polymethacrylate resin Mitsubishi Rayon Acrypet, Kuraray Parapellet (2) Polyacrylate-modified resin Alfon UC-3000, a carboxyl group-containing acrylic polymer manufactured by Toa Gosei Co., Ltd.

  Moreover, the polymer which reacts with a filler can be used as the polymer B. By reacting with the filler, the polymer B and the filler C more easily exist in the region where the hard segment exists, that is, the so-called hard segment domain, integrally with the polymer B, and the damping performance in the hard segment domain is further improved. It becomes possible to improve. Examples of the polymer B that reacts with the filler include the above-mentioned oxazoline group-containing reactive polystyrene. The oxazoline group reacts with the carboxylic acid group, hydroxyl group, and thiol group of the filler. Another example of the polymer B is a polymer modified with an epoxy group, a carboxylic acid group, a hydroxyl group, or the like.

(Filler)
The filler used in the present invention 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 the compound. Here, the two or more cyclic structures are those in which two or more monocyclic compounds are bonded directly or through a linking group, condensed polycyclic compounds in which two or more monocyclic rings are condensed, A formula compound or a spiro polycyclic compound. Hereinafter, unless otherwise specified, the condensed polycyclic compound, the bridged cyclic compound, and the spiro polycyclic compound are referred to as a polycyclic compound.

  Further, the compound having two or more cyclic structures includes not only low molecules but also polymers. For example, when the polymer is a homopolymer, a polymer in which two or more monocyclic compounds having repeating units are bonded directly or via a linking group, and one monocyclic compound having one or more repeating units and one And a polycyclic compound bonded to each other via a direct bond or a linking group. Further, when the polymer is a copolymer, the repeating unit of each component of the copolymer is a compound in which one monocyclic compound or two or more monocyclic compounds are bonded directly or via a linking group. And any one compound selected from the group consisting of one polycyclic compound.

Here, as a linking group for linking two or more monocyclic compounds, -O-, -S-, -P-, -NH-, -NR- (R is an alkyl group having 1 to 4 carbon atoms), One selected from the group consisting of —Si—, —COO—, —CONH—, — (CH ₂ ) _n — (n is an integer of 1 to 12), —CH═CH—, and —C≡C—. Can be used. In addition, — (CH ₂ ) _n — means that when n is 2 or more, at least one of the methylene groups is —O—, —S—, —P—, —NH—, —NR— (R represents a carbon number of 1 to 4 alkyl group), —Si—, —COO—, —CONH—, —CH═CH—, and —C≡C—.

  As the compound having two or more cyclic structures selected from aromatic hydrocarbons, biphenyl, which is a monocyclic compound bonded directly or via a linking group, may have a substituent. , Diphenylamine, triphenylamine, and methylenebisphenol. In addition, examples of the polycyclic compound include naphthalene, anthracene, phenanthrene, tetrafidronaphthalene, 9,10-dihydroanthracene, and acetonaphthalene, which may have a substituent.

  Examples of the compound having two or more cyclic structures selected from aliphatic cyclic hydrocarbons are monocyclic compounds such as cyclohexane, cyclopentane, cyclopropane, cyclobutane, isobornyl, or cyclohexene having a double bond in the ring, Examples include cyclopentene, cyclopropene and cyclobutene bonded directly or via a linking group. In addition, examples of the polycyclic compound include monocyclo, dicyclo, tricyclo, tetracyclo, and pentacyclo, which may have a substituent, specifically dicyclopentenyl, norbornenyl, and the like. Can do. Aliphatic cyclic hydrocarbons include alicyclic terpenes such as α-pinene, β-pinene, limonene, caffeine, abietic acid group, terpinolene, terpinene, ferrandolene, α-carotene, β-carotene, and γ-carotene. Also includes. The rosin obtained by refine | purifying the terpene oil obtained from the essential oil component of the plant in which these components are main, and a rosin, and its derivative (including disproportionated rosin) are also included.

  As the compound having two or more cyclic structures selected from heteroaromatic hydrocarbons, which may be a monocyclic compound and may have a substituent, pyrrole, furan, thiophene, imidazole, maleimide, oxazole, thiazole, Examples include pyrazole, isoxazole, isothiazole, pyridine, pyridazine, pyrimidine, piperidine, piperazine and morpholine. The polycyclic compound may have a substituent, such as benzofuran, isobenzofuran, benzothiophene, benzotriazole, isobenzothiophene, indole, isoindole, benzimidazole, benzothiazole, benzoxazole, quinazole, naphthyridine, etc. Can be mentioned.

  Here, the two or more monocyclic compounds are not limited to the case of consisting of only the same type of monocyclic compound, and may include different types of monocyclic compounds. Examples of the substituent 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. it can.

  Examples of the metal salt of the compound having two or more cyclic structures include sodium salt, magnesium salt, potassium salt, calcium salt and the like.

  Examples of the polymer or oligomer having two or more cyclic structures include the following. A terpene phenol resin can be mentioned as a homopolymer in which a monocyclic compound having two or more repeating units is bonded directly or via a linking group. Moreover, in the case of a copolymer, a coumarone indene resin can be mentioned, for example.

  Moreover, the low molecule | numerator or polymer | macromolecule which reacts with the polymer B can also be used as a filler. By reacting with the polymer B, the polymer B and the filler C more easily exist in the region where the hard segment exists, that is, the so-called hard segment domain, integrally with the polymer B, and the damping performance in the hard segment domain Can be further improved. As an example of the filler which reacts with the polymer B, when the polymer B is an oxazoline group-containing reactive polystyrene, an organic filler containing a carboxyl group, an aromatic thiol group, a phenol group or an alcohol group can be exemplified. The oxazoline group reacts with the filler carboxyl group, aromatic thiol group, phenol group, and alcohol group. Examples of the filler containing a carboxyl group include 4-phenylbenzoic acid and derivatives thereof, 1-naphthoic acid and derivatives thereof, rosin containing abietic acid groups and derivatives thereof, and the like. Examples of the filler containing an aromatic thiol group include biphenyl-4-thiol and derivatives thereof, 2-naphthalenethiol and derivatives thereof, and the like. Examples of the filler containing a phenol group include biphenyl-4-ol, and examples of the filler containing an alcohol group include 4-hydroxymethylbiphenyl. Moreover, as another example of the polymer B, an epoxy group-modified acrylic resin or a hydroxyl group-modified acrylic resin into which a functional group such as an epoxy group or a hydroxyl group is introduced can be exemplified.

  The filler is preferably a compound or polymer having two or more cyclic structures selected from aromatic hydrocarbons. More preferred examples include diphenylamine, triphenylamine, and methylenebisphenol, which may have a substituent.

  In the resin composition of the present invention, the block copolymer A is 1 to 99% by weight, preferably 5 to 90% by weight, based on the entire resin composition. If the amount is less than 1% by weight, the film forming property is lowered, and if it is more than 99% by weight, the vibration damping performance is lowered. The polymer B is 0.5 to 90% by weight, preferably 1 to 50% by weight. When the amount of the polymer B is less than 0.5% by weight, the cloud point becomes high, and when it is more than 90% by weight, the sheet becomes brittle. Further, the filler C is 0.1 to 90% by weight, preferably 0.5 to 50% by weight. When the filler C is less than 0.1% by weight, the impact absorption rate described later is decreased, and when it is more than 90% by weight, the sheet becomes unfavorable.

  Moreover, you may mix | blend an additive with the resin composition of this invention in the range which does not reduce a shock absorptivity. Examples of the additive include an antioxidant, an ultraviolet absorber, and a flame retardant.

(Production method)
The resin composition of the present invention can be produced by mixing the block copolymer A with the polymer B and the filler C by melt mixing by heating or dissolution mixing using a solvent. For example, in order to make the filler C compatible with the polymer B or to disperse the filler C in the polymer B, the polymer B and the filler C are mixed in advance, and the block copolymer A is mixed with the mixture. It may be used. At that time, the block copolymer A may be mixed at a temperature lower than the temperature at which the polymer B and the filler C are mixed. This is because the polymer B and the filler C are difficult to separate.

  Since the resin composition of the present invention contains the filler C that is compatible with the polymer B or dispersed in the polymer B, the polymer B and the filler C are in a region where the hard segment exists, that is, a so-called hard segment domain. And presents damping performance even in the hard segment domain. Here, the following method can be used to confirm that the filler C is present in the hard segment domain. That is, a molded product I formed by mixing block copolymer A, polymer B and filler C, a molded product II formed by mixing polymer B and filler C, and block copolymer A and filler C. The clouding points of the three types of molded products III, which were mixed and molded, were measured. The cloud point is a temperature at which the temperature is gradually lowered by heating to a predetermined temperature to make the molded body transparent, and then the temperature is gradually lowered. The lower the cloud point, the higher the compatibility. Therefore, if the cloud point of the molded body I (A + B + C) is closer to the cloud point of the molded body II (B + C) than the cloud point of the molded body III (A + C), the filler C is hard. It can be determined that it exists in the segment domain.

  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 formed into a single sheet by hot pressing or the like and used as an unconstrained impact absorbing material, or can be laminated between constraining layers that are difficult to deform and used as a restraining impact absorbing material. It can also be used as a paint type resin composition, applied to a substrate of various shapes to form a coating film, and combined with the substrate.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail using an Example, this invention is not limited to a following example.

Example 1.
MMA resin (Acryvette VH manufactured by Mitsubishi Rayon) 60 g as polymer B and 30 g octylated diphenylamine (Nonflex OD-3 manufactured by Seiko Chemical Co., Ltd.) as filler are kneaded at 230 ° C. and 30 rpm for 10 minutes in a laboratory plasto mill. And a uniform composition was obtained. After cooling, the composition was pulverized in a mortar to obtain a fine powder. As block copolymer A, 60 g of MMA-BA block copolymer (clarity 2140e manufactured by Kuraray Co., Ltd.), which is an acrylic thermoplastic elastomer manufactured by living anion polymerization, is used at 180 ° C. and 30 rpm in a laboratory plastomill manufactured by Toyo Seiki. After melt-kneading for 5 minutes, 30 g of the above fine powder was added and kneaded at 180 ° C. and 30 rpm for 5 minutes to obtain a resin composition. This resin composition was heated and pressed at 180 ° C. to prepare a test sheet having a thickness of 0.2 mm.

Example 2.
As polymer B, 30 g of carboxyl group-containing acrylic polymer (Alfon US-3000 manufactured by Toa Gosei Co., Ltd.), 60 g of hydrogenated terpene phenol resin (YS Hara Chemical YS Polystar UH) as a filler was added. Melt kneading was performed at 180 ° C. and 30 rpm for 5 minutes. Furthermore, 0.1 g of iron (III) chloride hexahydrate was added and melt-kneaded at 180 ° C. and 30 rpm for 5 minutes to obtain a resin composition. As block copolymer A, 10 g of Kuraray Clarity 2140e was dissolved in 80 g of ethyl acetate at room temperature, 10 g of the above composition was added thereto, and mixed by stirring to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Example 3.
2,2′-methylenebis (4-ethyl-6-tert-butylphenol) (Nocrack NS-5 manufactured by Ouchi Shinsei Chemical Industry) was used as the filler in place of the hydrogenated terpene phenol resin (YS Polystar UH manufactured by Yasuhara Chemical). A test sheet was obtained using the same method as in Example 2 except for the above.

Example 4
A condenser was attached to a 200 ml separable flask, and 80 g of toluene was put into a 60 ° C. hot water bath, and stirring was started using a stirrer HS-40 manufactured by Masuda Rika Kogyo. 10 g of reactive polystyrene containing oxazoline group (Epocross RPS-1005 manufactured by Nippon Shokubai Co., Ltd.) was added as polymer B, then 10 g of disproportionated rosin (Longis R manufactured by Arakawa Chemical Industries) was added as a filler, mixed for 1 hour, and pale yellow A clear solution was obtained. After cooling this solution to room temperature, 20 g of a styrene-based thermoplastic elastomer (Kuraray Hibler 5127) was dissolved as the block copolymer A to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Example 5.
MMA resin (Acryvette VH manufactured by Mitsubishi Rayon) 60 g as polymer B and 30 g octylated diphenylamine (Nonflex OD-3 manufactured by Seiko Chemical Co., Ltd.) as filler are kneaded at 230 ° C. and 30 rpm for 10 minutes in a laboratory plasto mill. And a uniform composition was obtained. After cooling, the composition was pulverized in a mortar to obtain a fine powder. As block copolymer A, 60 g of MMA-BA block copolymer (clarity 2140e, manufactured by Kuraray Co., Ltd.), which is an acrylic thermoplastic elastomer manufactured by living anion polymerization, at 230 ° C., 30 rpm, using a Laboplast mill manufactured by Toyo Seiki. After melt-kneading for 5 minutes, 30 g of the above fine powder was added and kneaded at 230 ° C. and 30 rpm for 5 minutes to obtain a resin composition. This resin composition was heated and pressed at 180 ° C. to prepare a test sheet having a thickness of 0.2 mm.

Example 6
20 g of MMA resin (Acryvette VH manufactured by Mitsubishi Rayon) as polymer B, 60 g of MMA-BA block copolymer (Kuraray 2140e manufactured by Kuraray Co., Ltd.) as block copolymer A, and octylated diphenylamine (non-flex OD manufactured by Seiko Chemical Co., Ltd.) as filler -3) 10 g was added, and mixed at room temperature using a miller manufactured by Iwatani Corporation. The mixture was kneaded for 10 minutes at 230 ° C. and 30 rpm in a laboratory plast mill manufactured by Toyo Seiki. This resin composition was heated and pressed at 180 ° C. to prepare a test sheet having a thickness of 0.2 mm.

Example 7.
While stirring 80 g of ethyl acetate using a stirrer HS-40 manufactured by Masuda Rika Kogyo Co., Ltd., 10 g of MMA-BA block copolymer (Kuraray 2140e manufactured by Kuraray Co., Ltd.) is used as block copolymer A, and carboxyl group-containing acrylic is used as polymer B. 3.3 g of a polymer (ARUFON US-3000 manufactured by Toa Gosei Co., Ltd.) and 6.7 g of hydrogenated terpene phenol resin (YS Polystar UH manufactured by Yasuhara Chemical Co., Ltd.) as a filler were added and mixed to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Example 8
While stirring 80 g of ethyl acetate using a stirrer HS-40 manufactured by Masuda Rika Kogyo, 10 g of MMA-BA block copolymer (Kuraray 2140e, manufactured by Kuraray Co., Ltd.) as a block copolymer A and a carboxyl group as a polymer B Acrylic polymer (ARUFON US-3000 manufactured by Toa Gosei) 3.3 g, 2,2′-methylenebis (4-ethyl-6-t-butylphenol) (Nouchi NS-5 manufactured by Ouchi Shinsei Chemical Industry) as filler 6.7 g Were added and mixed to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Example 9.
A 200 ml separable flask was charged with 80 g of toluene, and stirring was started at room temperature using a stirrer HS-40 manufactured by Masuda Rika Kogyo. 20 g of a styrene thermoplastic elastomer (Kuraray Hybler 5127) was dissolved in toluene as the block copolymer A, and 10 g of reactive polystyrene containing oxazoline group (Epocross RPS-1005 from Nippon Shokubai Co., Ltd.) was charged as the polymer B. As a filler, 10 g of disproportionated rosin (Longis R, manufactured by Arakawa Chemical Industries) was added and dissolved to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Example 10.
The test was performed in the same manner as in Example 1 except that the thickness of the test sheet was 1 mm.

Example 11.
The test was performed in the same manner as in Example 1 except that the thickness of the test sheet was 2 mm.

Comparative Example 1.
Kuraray Clarity 2140e 60 g as block copolymer A and 10 g of octylated diphenylamine (Nonflex OD-3 manufactured by Seiko Chemical Co., Ltd.) as filler are kneaded at 230 ° C. and 30 rpm for 10 minutes in a Toyo Seiki lab plast mill. A composition was obtained. This resin composition was heated and pressed at 180 ° C. to prepare a test sheet having a thickness of 0.2 mm.

Comparative Example 2.
While stirring 80 g of ethyl acetate using a stirrer HS-40 manufactured by Masuda Rika Kogyo Co., Ltd., 10 g of Kuraray Clarity 2140e as block copolymer A and hydrogenated terpene phenol resin (YS Hara Chemical YS Polystar UH) as filler 6. 7 g was added and mixed to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Comparative Example 3.
2,2′-methylenebis (4-ethyl-6-tert-butylphenol) (Nocrack NS-5 manufactured by Ouchi Shinsei Chemical Industry) was used as the filler in place of the hydrogenated terpene phenol resin (YS Polystar UH manufactured by Yasuhara Chemical). Except for the above, a test sheet was obtained using the same method as in Comparative Example 2.

Comparative Example 4.
A 200 ml separable flask was charged with 80 g of toluene, and stirring was started at room temperature using a stirrer HS-40 manufactured by Masuda Rika Kogyo. 20 g of Kuraray Hybler 5127 as block copolymer A was dissolved in toluene, and then 10 g of disproportionated rosin (Longis R, manufactured by Arakawa Chemical Industries) was added and dissolved as a filler to prepare a coating solution. A coating film was prepared using this coating liquid, and the solvent was evaporated to obtain a test sheet having a thickness of 0.2 mm.

Comparative Example 5.
The test was performed in the same manner as in Comparative Example 1 except that the thickness of the test sheet was 1 mm.

Comparative Example 6.
The test was performed in the same manner as in Comparative Example 1 except that the thickness of the test sheet was 2 mm.

  Table 1 below shows the compositions of the resin compositions of Examples and Comparative Examples.

(Shock absorption evaluation)
The impact acceleration was measured when a stainless steel ball having a predetermined diameter (diameter: 10 mm, 4.1 kg) was dropped from a height of 100 mm onto an acrylic plate having a size of 100 × 100 mm and a thickness of 30 mm. The measurement was carried out by attaching an acceleration sensor to the back surface of the acrylic plate with an adhesive and measuring with a noise meter 2250 made by Bruker Care. The impact absorption performance was evaluated by the impact absorption rate (%). Here, the impact absorption rate is defined by the following equation, and the impact transmission rate (%) is calculated by dividing the acceleration when a stainless steel ball of a predetermined diameter is dropped on the sheet by the acceleration when there is no sheet. did.
Impact absorption rate (%) = 100 (%)-Impact transmission rate (%)

(Tan δ evaluation)
It measured at 23 degreeC and the frequency of 1 Hz using the dynamic viscoelasticity measuring device SDM-5500 made from Seiko Denshi Kogyo.

(Cloud point evaluation)
A sheet-like coating film was formed from a resin composition containing a solvent, and the coating film was allowed to stand for 1 day to volatilize the solvent, and used as a sample. A 50 g sample was placed in a stainless steel beaker and heated to 200 ° C. with a mantle heater, and then the heater was turned off and allowed to cool naturally. When the sheet is cooled, the sheet changes from a transparent state to an opaque state by phase separation. The change was observed visually, and the temperature at which the opaque state occurred was defined as the cloud point. The test was terminated when cooled to 30 ° C.

  The cloud point was measured at a temperature lower than 30 ° C. by the following method. The stainless beaker containing the sample is left in a constant temperature bath HIFLEX FX2050 manufactured by Enomoto Kasei Co., Ltd. at a predetermined temperature. After 8 hours, the state of the sample was visually observed, and the temperature at which the opaque state occurred was defined as the cloud point. The measurement was performed at 20 ° C., 10 ° C., 0 ° C., −10 ° C., and −20 ° C., and a transparent sample was indicated as −20 ° C. or lower even at −20 ° C.

(result)
Examples 1, 3, 10, and 11 show examples in which the polymer B and the filler C were melt-mixed and then melt-mixed with the block copolymer A. Example 2 shows an example in which the polymer B and the filler C are melt-mixed, and then the block copolymer A and the solvent are mixed. Example 4 shows an example in which the polymer B and the filler C are mixed with a solvent, and then the block copolymer A and a solvent are mixed. Example 5 is an example in which the polymer B and the filler C are melt-mixed and then the block copolymer A is melt-mixed. The temperature when the polymer B and the filler C are melt-mixed and the block afterwards An example in which the temperature when the copolymer A is melt mixed is the same. Example 6 shows an example in which the block copolymer A, the polymer B, and the filler C are melted and mixed at a time. Examples 7 to 9 show examples in which a block copolymer A, a polymer B, and a filler C are mixed with a solvent.

  Tables 2 to 5 show the cloud point, impact absorption rate, and tan δ results. FIG. 1 shows the relationship between the thickness of the test sheet and the impact absorption rate for the examples and comparative examples. In the table, “B + C” indicates a test sheet obtained from a mixture of B and C, “A + C” indicates a test sheet obtained from a mixture of A and C, and “B + C”. "+ A" refers to a test sheet obtained from a mixture of B, C and A.

  From Examples 1-4 and Comparative Examples 1-4, the cloud point of (B + C + A) is closer to the cloud point of (B + C) than the cloud point of (A + C), so filler C Was confirmed to exist in the hard segment domain.

  As is clear from Tables 2 to 4, Examples 1 to 9 gave higher impact absorption rates than Comparative Examples 1 to 4. Further, comparing Example 1 and Example 5, when the mixing temperature of “B + C + A” was made lower than the mixing temperature of “B + C”, the impact absorption rate increased. Also, comparing Example 1 and Example 6, the method of making “B + C” first and mixing “A” later is to mix “B + C + A” at once. The shock absorption rate increased compared to the manufactured method.

  FIG. 1 is a graph of the results in Table 5, and shows the relationship between the thickness of the test sheet and the impact absorption rate for the examples and comparative examples. When the thickness was 2 mm, no difference was observed, but even when the thickness was thinner than 2 mm, in the examples, the decrease in the impact absorption rate was suppressed, and excellent shock absorption was exhibited. Even at 0.2 mm, a very excellent value of 18% was obtained as compared with 4% of the comparative example.

  The impact-absorbing resin composition of the present invention has excellent vibration damping performance even if it is thinned, so it is suitable not only for impact-absorbing sheets for devices but also for other applications where vibration and noise are a problem. Can be used.

Claims (5)

Polymer glass transition temperature that is compatible with the block copolymer A, the polymer component A ₁ containing a 30 ° C. or more polymer components A ₁ and the glass transition point of 0 ℃ less polymer component A ₂ B and a filler C that is compatible with the polymer B or dispersed in the polymer B,
The polymer component A ₁ is a styrenic resin, the polymer B is an oxazoline group-containing reactive polystyrene ,
The impact-absorbing resin composition, wherein the filler C is rosin or a derivative thereof, and the content of the filler C is 0.5 to 50% by weight. The ratio of the said block copolymer A is 1 to 99 weight% of the whole resin composition, The resin composition of Claim 1 . The resin composition according to claim 1 or 2 , wherein a content of the filler C is 11 to 50% by weight. It is a manufacturing method of the resin composition for shock absorption according to claim 1 ,
A method for producing an impact-absorbing resin composition, wherein a mixture containing a polymer B and a filler C is mixed with a block copolymer A. The manufacturing method of Claim 4 which mixes with the block copolymer A at temperature lower than the temperature which mixed the said polymer B and the said filler C.

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