JP2009242671A - Heat-resistant foamed sheet and heat-resistant damping tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-resistant foamed sheet showing excellent light weight properties and having excellent heat resistance, not causing a dimensional change even at a temperature of not lower than 120°C. <P>SOLUTION: The heat-resistant foamed sheet includes a material comprising a conjugated diene-based polymer or a copolymer having a portion made by compolymerizing a conjugated diene and a crystalline resin, the copolymer ratio being in the range from 60:40 to 90:10, the crosslinkage degree (gel ratio) being in the range from 15% to 65%, and has a foaming ratio of 2 to 30. The foamed sheet specified by the above conditions is a heat-resistant foamed sheet showing excellent heat resistance and dimensional stability achieved by introduction of a heat resistant crystalline domain and a decrease in shrinkage force due to a residual stress controlled by the crosslinkage degree. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat-resistant foam sheet excellent in light weight and heat resistance, and a heat-resistant vibration damping tape using the heat-resistant foam sheet.

   Conventionally, conjugated diene polymer foam sheets have been widely used for buffer materials, heat insulating materials, electrical insulating materials, shock absorbing materials and the like. However, in general, the conjugated diene polymer foam sheet has low dimensional stability against heat due to the elastic properties of the material. Therefore, it has been difficult to apply the conjugated diene polymer foam sheet to automobile applications that require high heat resistance.

  Therefore, in order to solve the above problem, Patent Document 1 proposes a foam sheet characterized by blending a rosin-modified resin or a petroleum resin with a thermoplastic elastomer such as an ethylene-propylene-diene copolymer. The dimensional stability against heat was insufficient.

JP-A-5-214142

  The present invention provides a heat-resistant foamed sheet capable of obtaining a heat-resistant vibration-damping sheet having excellent dimensional stability against heat and exhibiting excellent vibration-damping properties by being attached to a vibrating body using an adhesive or the like. A heat-resistant vibration damping sheet using a heat-resistant foam sheet is provided.

  The heat-resistant foam sheet of the present invention is composed of 100 parts by weight of a conjugated diene polymer having a maximum loss tangent value obtained by dynamic viscoelasticity measurement of −30 to 40 ° C. and 10 to 70 parts by weight of a crystalline resin. And a gel fraction of 15 to 65% by weight and a foaming ratio of 2 to 30 times.

  The conjugated diene polymer may be any one of a homopolymer of a conjugated diene monomer, a copolymer of conjugated diene monomers, and a copolymer of a conjugated diene monomer and a monomer copolymerizable with the conjugated diene monomer. Good. Conjugated diene polymers may be used alone or in combination of two or more.

  The conjugated diene monomer is not particularly limited, and examples thereof include conjugated diene having 4 to 12 carbon atoms such as butadiene, isoprene, piperylene, and dimethylbutadiene.

  The monomer copolymerizable with the conjugated diene monomer is not particularly limited, and examples thereof include an aromatic vinyl monomer. Examples of the aromatic vinyl monomer include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, and 4-tert-butyl. Examples thereof include styrene and tert-butoxystyrene.

  The copolymer of the conjugated diene monomer and the monomer copolymerizable with the conjugated diene monomer is preferably a copolymer containing a block obtained by polymerizing the conjugated diene monomer, and the block obtained by polymerizing the conjugated diene monomer and the aromatic vinyl monomer. A block copolymer having a block obtained by polymerizing a styrene block is more preferable, and a block copolymer having a styrene block and a vinyl isoprene block shown in Chemical Formula 1 is particularly preferable. In the vinyl isoprene block shown in Chemical formula 1, n represents the degree of polymerization of the vinyl isoprene block.

  Examples of the copolymer of a conjugated diene monomer and a monomer copolymerizable with the conjugated diene monomer include, for example, styrene-isoprene-styrene triblock copolymer (SIS) and hydrogenated products thereof, styrene-ethylene-butylene-styrene. Hydrogenated diene block copolymer or random copolymer such as copolymer (SEBS), butadiene-styrene copolymer, styrene-butadiene-styrene block copolymer, styrene-butadiene-styrene radial teleblock copolymer A triblock copolymer composed of a styrene block and a vinyl isoprene block is preferable because the resulting heat-resistant foamed sheet is excellent in buffering properties and shock absorption.

  And the temperature which shows the maximum value of the loss tangent obtained by the dynamic viscoelasticity measurement in a conjugated diene type polymer (Hereafter, it may only be called "the temperature which shows the maximum value of a loss tangent.") -30-40 degreeC. It is limited to 0-35 degreeC. This is because the vibration damping performance of the automotive vibration damping sheet is deteriorated when the temperature indicating the maximum value of the loss tangent obtained by dynamic viscoelasticity measurement is outside the range of -30 to 40 ° C.

  In addition, the temperature which shows the maximum value of the loss tangent obtained by the dynamic viscoelasticity measurement in a conjugated diene polymer means what was measured in the following way. First, a test sheet (width 5 mm × length 24 mm × thickness 0.3 mm) made of a conjugated diene polymer was prepared, and the dynamic viscoelasticity of this test sheet was measured under the conditions of a strain amount of 0.1% and a frequency of 10 Hz. The temperature indicating the maximum value of the loss tangent obtained by measuring the temperature dispersion of dynamic viscoelasticity at a temperature rising rate of 3 ° C./min. In addition, the temperature which shows the maximum value of the loss tangent obtained by the dynamic viscoelasticity measurement in a conjugated diene polymer can be measured using a measuring apparatus commercially available from Rheometrics under the trade name “RSA”. .

  Further, the temperature indicating the maximum value of the loss tangent obtained by dynamic viscoelasticity measurement in the conjugated diene polymer is a method of adding a plasticizer to the conjugated diene polymer, a method of adjusting the ratio of copolymer components, It can adjust by the method of selecting a monomer, the method of adjusting the ratio of a monomer component, etc.

  The crystalline resin is not particularly limited, for example, a polyethylene resin such as high density polyethylene, an olefin resin such as a polypropylene resin such as random polypropylene, homopolypropylene or block polypropylene, a polyester resin such as polylactic acid, Polyvinyl alcohol, polyacetal, polyamide, polyvinyl chloride, polyvinylidene chloride, etc. are mentioned, but since the resulting heat-resistant foamed sheet is excellent in heat resistance and workability, polyolefin resins and polyester resins are preferred, polyethylene-based Resins, polypropylene resins and polylactic acid are preferred. In addition, crystalline resin may be used independently or 2 or more types may be used together.

  If the content of the crystalline resin in the heat-resistant foam sheet is small, the heat resistance of the heat-resistant foam sheet decreases due to a decrease in crystal domains responsible for heat resistance, and if it is large, the crystal region increases, and the heat-resistant foam sheet Therefore, it is limited to 10 to 70 parts by weight with respect to 100 parts by weight of the conjugated diene polymer, and preferably 25 to 45 parts by weight.

  It is preferable that crystalline resin contains crystalline resin whose melting | fusing point measured by differential scanning calorimetry (DSC) is 120-200 degreeC. When the melting point of the crystalline resin is lower than 120 ° C., the crystal melts at a high temperature (120 ° C. or higher), the strength and dimensional stability of the heat-resistant foamed sheet are lowered, and the heat resistance is inferior. This is because blocking occurs in the heat-resistant foamed sheet to be produced. When the melting point of the crystalline resin exceeds 200 ° C., it is preferable from the viewpoint of the heat resistance of the heat-resistant foamed sheet, but in the kneading process for producing the heat-resistant foamed sheet, the foaming agent is easily decomposed by shearing heat generation, and the uniform This is because it is difficult to obtain a heat-resistant foam sheet having a cell structure, which is not preferable.

  The crystalline resin preferably contains a crystalline resin with a crystal component having a crystal melting energy of 20 mJ / mg or more, and more preferably 50 to 200 mJ / mg. When the crystal melting energy is less than 20 mJ / mg, the crystalline domain responsible for the heat resistance of the synthetic resin constituting the heat resistant foam sheet is reduced, and the shrinkage force caused by residual strain remaining when the heat resistant foam sheet is formed is reduced. This is because it becomes difficult to withstand, and the dimensional stability of the heat-resistant foam sheet is lowered.

  The crystalline resin preferably contains a crystalline resin having a melting point measured by differential scanning calorimetry (DSC) of 120 to 200 ° C. and a crystal melting energy of 20 mJ / mg or more.

  When the content of the crystalline resin having a melting point measured by differential scanning calorimetry (DSC) of 120 to 200 ° C. and a crystal melting energy of 20 mJ / mg or less in the heat resistant foam sheet is small, the heat resistant foam sheet Since the heat resistance of the resin may decrease, 50 to 100% by weight is preferable.

  Here, in the crystalline component of the crystalline resin, the melting point and crystal melting energy measured by differential scanning calorimetry (DSC) are measured as follows. First, a predetermined amount of crystalline resin is sampled and used as a sample. This sample is heated to 220 ° C. using a differential scanning calorimeter and completely melted, and then the sample is heated to −50 ° C. at 10 ° C./min. After cooling, the sample was heated and heated at a rate of 10 ° C./min, and the melting point and heat of fusion were measured. In addition, melting | fusing point was made into the point where absorption heat amount becomes the maximum, and fusion | melting heat amount was taken as the value calculated from the obtained endothermic peak area. In addition, the differential scanning calorimeter can use what is marketed by the brand name "SSC / 5200 type | mold" from SII company, for example.

  In addition to the conjugated diene polymer and the crystalline resin, other synthetic resins (hereinafter referred to as “third synthetic resin”) are used for the purpose of improving extrudability or imparting buffering. May be included).

  The third synthetic resin is not particularly limited, but nitrile-butadiene rubber (NBR), styrene-butadiene copolymer rubber (SBR), ethylene-propylene copolymer rubber (EPR), ethylene-propylene-diene- Preferred are rubber components such as methylene rubber (EPDM), flexible polyolefin resins such as low density polyethylene and ethylene-vinyl acetate copolymer, and low density polyethylene and ethylene-acetic acid from the viewpoint of cost and fluidity. A vinyl copolymer is more preferable.

  If the content of the third synthetic resin in the heat-resistant foamed sheet is small, the heat-resistant foamed sheet may not exhibit the effect of improving the buffering properties and extrudability. If the content is large, the heat resistance of the heat-resistant foamed sheet will be reduced. Therefore, the amount is preferably 5 to 60 parts by weight and more preferably 20 to 50 parts by weight with respect to 100 parts by weight of the crystalline resin.

  If the gel fraction of the heat-resistant foam sheet is low, the strength of the heat-resistant foam sheet decreases and drawdown occurs during molding. If the gel fraction is high, the elastic properties of the synthetic resin constituting the heat-resistant foam sheet increase. However, since the dimensional stability of the heat-resistant foam sheet at a high temperature is lowered, it is limited to 15 to 65% by weight and preferably 25 to 55% by weight.

In addition, the gel fraction of a heat resistant foam sheet can be measured in the following way. First, the heat-resistant foamed sheet is weighed and immersed in xylene at 120 ° C. for 24 hours, the insoluble matter is filtered through a 200-mesh wire mesh, the residue on the wire mesh is vacuum-dried, and the weight of the dried residue is measured. Measured (Bg) and calculated by the following formula.
Gel fraction (% by weight) = (B / A) × 100

  If the expansion ratio of the heat-resistant foam sheet is low, the light weight of the heat-resistant foam sheet may be reduced. If it is high, the shape of the air bubbles in the heat-resistant foam sheet will be uneven, and the heat-resistant foam sheet will be produced stably. Since it may not be possible, it is limited to 2 to 30 times. The expansion ratio of the heat-resistant foam sheet is a value measured according to JIS K6767.

  The heat-resistant foam sheet has an antioxidant, a filler, a stabilizer, an ultraviolet absorber, a pigment, a flame retardant, an antistatic agent, if necessary, as long as the effects of the present invention are not impaired. Conventionally known additives such as plasticizers may be added.

  Next, the manufacturing method of a heat resistant foam sheet is demonstrated. As a method for producing a heat-resistant foam sheet, a conjugated diene polymer, a crystalline resin, a foaming agent, and additives such as a crosslinking agent, a crosslinking aid, and an antioxidant that are added as necessary are blended. A method of producing a heat-resistant foamed sheet by preparing a foamable sheet from the obtained foamable resin composition, and crosslinking and foaming the foamable sheet.

  As a procedure for producing the foamable sheet, the resin composition is heated to a temperature lower than the decomposition temperature of the foaming agent using a kneading apparatus such as a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader mixer, a roll, or a plast mill. And a method of preparing a foamable resin composition by melt-kneading and molding the foamable resin composition into a sheet.

  Examples of the method of crosslinking the foamable sheet include a method of irradiating the foamable sheet with ionizing radiation, and a method of crosslinking the foamable sheet by adding a crosslinking agent to the foamable sheet. Examples of the ionizing radiation include α rays, β rays, γ rays, and electron beams. Examples of the crosslinking agent include organic peroxides, sulfur, sulfur compounds and the like.

  The foaming agent is not particularly limited, and examples thereof include azodicarbonamide, benzenesulfonylhydrazide, dinitrosopentamethylenetetramine, toluenesulfonylhydrazide, 4,4-oxybis (benzenesulfonylhydrazide), and the like. Two or more of them may be used in combination.

  If the content of the foaming agent in the foamable resin composition is small, the foamable sheet may not be sufficiently foamed. If it is large, the bubbles formed by foaming are not stable, and the cell structure of the heat-resistant foamed sheet. 1 to 30 parts by weight is preferable with respect to 100 parts by weight of the total amount of the synthetic resin in the foamable resin composition.

  A pressure-sensitive adhesive layer can be laminated and integrated on one surface or both surfaces of the heat-resistant foamed sheet in a general manner to obtain a heat-resistant vibration-damping tape, and this heat-resistant vibration-damping tape exhibits excellent vibration-damping performance. In addition, it does not specifically limit as an adhesive which comprises an adhesive layer, An acrylic adhesive and a urethane type adhesive are preferable.

  The heat-resistant damping tape is adhered to the surface of the vibrating body with the adhesive, and the heat-resistant foam sheet exhibits excellent damping performance, suppressing vibration of the vibrating body and reducing vibration noise. Can do. Furthermore, the damping performance of the heat resistant damping tape can be improved by laminating and integrating a synthetic resin sheet or a metal sheet on the other surface of the heat resistant damping tape.

  The heat-resistant foam sheet of the present invention is composed of 100 parts by weight of a conjugated diene polymer having a maximum loss tangent value obtained by dynamic viscoelasticity measurement of −30 to 40 ° C. and 10 to 70 parts by weight of a crystalline resin. And a gel fraction of 15 to 65% by weight and a foaming ratio of 2 to 30 times, so that it is excellent in light weight and heat resistance.

  A heat-resistant vibration-damping tape can be obtained by laminating and integrating a pressure-sensitive adhesive layer on one side of a heat-resistant foam sheet. This heat-resistant vibration-damping tape has excellent vibration-damping performance and requires heat resistance. It can be suitably used for automobile applications.

It is the graph which showed the measurement result of the loss factor of the heat-resistant damping tape obtained by the example and the comparative example.

Example 1
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.), styrene Styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 10 parts by weight, random polypropylene (Trade name “EG8” manufactured by Nippon Polypro Co., Ltd., melting point: 145 ° C., crystal melting energy: 64.6 mJ / mg) 30 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4.5 weight And phenolic antioxidants (Ciba Specialty Chemicals Co., Ltd.) The name "Irganox 1010") and 2.0 parts by weight was supplied to an extruder and melt-kneaded to prepare extrusion, a foamed sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foamed sheet having a thickness of 2.13 mm.

(Example 2)
A heat-resistant foam sheet having a thickness of 1.89 mm was obtained in the same manner as in Example 1 except that 1.0 Mrad was irradiated with an electron beam instead of 2.0 Mrad.

(Example 3)
A heat-resistant foam sheet having a thickness of 1.94 mm was obtained in the same manner as in Example 1 except that the electron beam was irradiated with 4.0 Mrad instead of 2.0 Mrad.

Example 4
A heat-resistant foam sheet having a thickness of 2.64 mm was obtained in the same manner as in Example 1 except that 10.0 parts by weight of azodicarbonamide was used instead of 4.5 parts by weight.

(Example 5)
51.4 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 26.7 ° C.) Styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 8.6 wt. Parts, random polypropylene (trade name “EG8” manufactured by Nippon Polypro Co., Ltd., melting point: 145 ° C., crystal melting energy: 64.6 mJ / mg), azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4.5 parts by weight, phenolic antioxidant (Ciba Specialty Chemicals) A product name “Irganox 1010”) 2.0 parts by weight was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 1.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foam sheet having a thickness of 1.92 mm.

(Example 6)
68.6 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 26.7 ° C.) A styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 11.4 weight Parts, random polypropylene (trade name “EG8” manufactured by Nippon Polypro Co., Ltd., melting point: 145 ° C., crystal melting energy: 64.6 mJ / mg), azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals) 2.0 parts by weight of “Irganox 1010” manufactured by the company was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 1.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foamed sheet having a thickness of 1.94 mm.

(Example 7)
77.1 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 26.7 ° C.) , Styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 12.9 weight Parts, random polypropylene (trade name “EG8” manufactured by Nippon Polypro Co., Ltd., melting point: 145 ° C., crystal melting energy: 64.6 mJ / mg), 10 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals) 2.0 parts by weight of “Irganox 1010” manufactured by the company was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 0.75 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat resistant foamed sheet having a thickness of 2.04 mm.

(Example 8)
77.1 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 26.7 ° C.) , Styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 12.9 weight Parts, polylactic acid (trade name “TP-4000”, manufactured by Unitika Ltd., melting point: 167.3 ° C., crystal melting energy: 34.8 mJ / mg), 10 parts by weight, azodicarbonamide (trade name “SO-” manufactured by Otsuka Chemical Co., Ltd.) 20 ") 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals" Irganox 1010 ") 2.0 parts by weight was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat resistant foamed sheet having a thickness of 1.83 mm.

Example 9
68.6 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 26.7 ° C.) A styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 11.4 weight Parts, polylactic acid (trade name “TP-4000” manufactured by Unitika Ltd., melting point: 167.3 ° C., crystal melting energy: 34.8 mJ / mg), 20 parts by weight, azodicarbonamide (trade name “SO-” manufactured by Otsuka Chemical Co., Ltd.) 20 ") 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals" Irganox 1010 ") 2.0 parts by weight was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foam sheet having a thickness of 2.03 mm.

(Example 10)
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.), styrene Styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 3.0 ° C.) 10 parts by weight, polylactic acid (Trade name “TP-4000” manufactured by Unitika Ltd., melting point: 167.3 ° C., crystal melting energy: 34.8 mJ / mg) 30 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4 .5 parts by weight and phenolic antioxidant (“Irgano” manufactured by Ciba Specialty Chemicals) 2.010 parts by weight was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 1.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat resistant foamed sheet having a thickness of 1.85 mm.

Example 11
51.4 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 26.7 ° C.) Styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 8.6 wt. Parts, polylactic acid (trade name “TP-4000” manufactured by Unitika Ltd., melting point: 167.3 ° C., crystal melting energy: 34.8 mJ / mg), 40 parts by weight, azodicarbonamide (trade name “SO-” manufactured by Otsuka Chemical Co., Ltd.) 20 ”) and 4.5 parts by weight of a phenolic antioxidant (Ciba Specialty Chemicals“ I Luganox 1010 ") 2.0 parts by weight was supplied to an extruder, melted and kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 1.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat resistant foamed sheet having a thickness of 1.72 mm.

Example 12
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.), styrene 10 parts by weight of a styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.), high density 30 parts by weight of polyethylene (trade name “HB530R”, manufactured by Nippon Polyethylene Co., Ltd., melting point: 134.4 ° C., crystal melting energy: 194 mJ / mg), azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 4.5 Part by weight and phenolic antioxidant (Ciba Specialty Chemicals) "Irganox 1010") 2.0 parts by weight was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the resulting foamable sheet with 3.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foamed sheet having a thickness of 2.26 mm.

(Example 13)
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.), styrene Styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 10 parts by weight, homopolypropylene (Trade name “J-2003GP” manufactured by Prime Polymer Co., Ltd., melting point: 167 ° C., crystal melting energy: 96.8 mJ / mg), 30 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 5 parts by weight and phenolic antioxidant (Ciba Specialty Chemical) "Irganox 1010" manufactured by KK, was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foam sheet having a thickness of 3 mm. An acrylic pressure-sensitive adhesive was applied to both sides of the obtained heat-resistant foamed sheet using a coating machine and dried, and a 0.08 mm pressure-sensitive adhesive layer was laminated and integrated to obtain a heat-resistant damping tape.

(Example 14)
72 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.), styrene Styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 3.0 ° C.) 13 parts by weight, polyethylene ( Product name “HB-530R” manufactured by Nippon Polyethylene Co., Ltd., melting point: 134.4 ° C., crystal melting energy: 194 mJ / mg, 15 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 2.0 Part by weight and phenolic antioxidant (Ciba Specialty Chemicals) "Irganox 1010") 2.0 parts by weight was supplied to an extruder, melted and kneaded and extruded to obtain a foamable sheet having a thickness of 0.6 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foam sheet having a thickness of 1.4 mm. A urethane pressure-sensitive adhesive was applied to both sides of the obtained heat-resistant foamed sheet using a coating machine and dried, and a 0.08 mm pressure-sensitive adhesive layer was laminated and integrated to obtain a heat-resistant damping tape.

(Example 15)
56 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 26.7 ° C.), styrene Styrene-vinylisoprene-styrene triblock copolymer having a block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 9 parts by weight, polylactic acid (Trade name “TP-4000” manufactured by Unitika Ltd., melting point: 167.3 ° C., crystal melting energy: 34.8 mJ / mg) 35 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 2 0.0 part by weight and phenolic antioxidant (“Irganotto” manufactured by Ciba Specialty Chemicals) Was supplied to an extruder, melt-kneaded and extruded to obtain a foamable sheet having a thickness of 0.6 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foam sheet having a thickness of 0.9 mm. A urethane pressure-sensitive adhesive was applied to both sides of the obtained heat-resistant foamed sheet using a coating machine and dried, and a 0.08 mm pressure-sensitive adhesive layer was laminated and integrated to obtain a heat-resistant damping tape.

(Example 16)
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer (trade name “HIBLER 5127” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 26.7 ° C.), styrene-vinylisoprene-styrene triblock copolymer 10 parts by weight (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 3.0 ° C.), homopolypropylene (trade name “900GV” manufactured by Nippon Polypro Co., Ltd., melting point: 171 ° C., crystal melting Energy: 90.4 mJ / mg) 20 parts by weight, ethylene-vinyl acetate copolymer (trade name “Evalate H1011” manufactured by Sumitomo Chemical Co.), azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) ) 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals, Inc., trade name “Irganock”) S10 ") 2.0 parts by weight was supplied to an extruder, melt kneaded and extruded to produce a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foamed sheet having a thickness of 2.23 mm.

(Example 17)
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer (trade name “HIBLER 5127” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 26.7 ° C.), styrene-vinylisoprene-styrene triblock copolymer 10 parts by weight (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 3.0 ° C.), homopolypropylene (trade name “900 GV” manufactured by Nippon Polypro Co., Ltd.) Energy: 90.4 mJ / mg) 20 parts by weight, ethylene-propylene-diene-methylene rubber (EPDM) (trade name “EPT 3012P” manufactured by Mitsui Chemicals), 10 parts by weight, azodicarbonamide (trade name “manufactured by Otsuka Chemical Co., Ltd.” SO-20 ") 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals) Trade name "Irganox 1010") and 2.0 parts by weight was supplied to the extruder melt kneaded and extruded to produce a foamable sheet with a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foamed sheet having a thickness of 2.31 mm.

(Example 18)
60 parts by weight of styrene-vinylisoprene-styrene triblock copolymer (trade name “HIBLER 5127” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 26.7 ° C.), styrene-vinylisoprene-styrene triblock copolymer 10 parts by weight (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature indicating the maximum value of loss tangent: 3.0 ° C.), homopolypropylene (trade name “900GV” manufactured by Nippon Polypro Co., Ltd., melting point: 171 ° C., crystal melting Energy: 90.4 mJ / mg) 25 parts by weight, ethylene-vinyl acetate copolymer (trade name “Evertate H1011” manufactured by Sumitomo Chemical Co., Ltd.) 5 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) ) 4.5 parts by weight and phenolic antioxidant (Ciba Specialty Chemicals, Inc., trade name "Irganox") 1010 ") 2.0 parts by weight were supplied to an extruder, melt-kneaded and extruded to produce a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to be foamed to obtain a heat-resistant foam sheet having a thickness of 2.35 mm.

(Comparative Example 1)
Styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature showing maximum value of loss tangent: 26.7 ° C.) 85.7 parts by weight , A styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “HIBLER 5125” manufactured by Kuraray Co., Ltd., temperature showing the maximum value of loss tangent: 3.0 ° C.) 14.3 wt. Part, 4.5 parts by weight of azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) and 2.0 parts by weight of phenolic antioxidant (“Irganox 1010” manufactured by Ciba Specialty Chemicals) It was supplied to a machine, melted and kneaded and extruded to obtain a foamable sheet having a thickness of 1.0 mm.

  The foamable sheet was crosslinked by irradiating the obtained foamable sheet with 2.0 Mrad of an electron beam at an acceleration voltage of 500 keV. Thereafter, the foamable sheet was supplied into a foaming furnace and heated to 230 ° C. to obtain a heat-resistant foamed sheet having a thickness of 2.05 mm.

(Comparative Example 2)
Except that the electron beam was irradiated at 0.6 Mrad instead of 2.0 Mrad, an attempt was made to produce a heat-resistant foam sheet in the same manner as in Example 1, but the foamability was poor and a heat-resistant foam sheet could be obtained. There wasn't.

(Comparative Example 3)
Except that the electron beam was irradiated at 5.0 Mrad instead of 2.0 Mrad, an attempt was made to produce a heat resistant foam sheet in the same manner as in Example 1, but the foamability was poor and a heat resistant foam sheet could be obtained. There wasn't.

(Comparative Example 4)
A heat-resistant foam sheet having a thickness of 2.03 mm was obtained in the same manner as in Example 6 except that the electron beam was irradiated with 3.5 Mrad instead of 2.0 Mrad.

(Comparative Example 5)
10 parts by weight of styrene-vinylisoprene-styrene triblock copolymer having a styrene block and a vinylisoprene block (trade name “Hibler 5127” manufactured by Kuraray Co., Ltd., temperature indicating maximum value of loss tangent: 26.7 ° C.), 10 parts by weight 8. Density polyethylene (trade name “LE520H” manufactured by Nippon Polyethylene Co., Ltd., melting point: 110.5 ° C., crystal melting energy: 120 mJ / mg), 90 parts by weight, azodicarbonamide (trade name “SO-20” manufactured by Otsuka Chemical Co., Ltd.) 0 parts by weight and 2.0 parts by weight of a phenolic antioxidant (“Irganox 1010” manufactured by Ciba Specialty Chemicals) were supplied to the extruder, and the thickness of the foamable sheet was changed to 1.0 mm instead of 1.0 mm. A heat-resistant vibration-damping tape having a thickness of 3 mm was obtained in the same manner as in Example 13 except that the thickness was 6 mm.

  The expansion ratio and gel fraction of the heat-resistant foam sheets obtained in Examples 1 to 18 and Comparative Examples 1 to 4 were measured in the above manner, and the dimensional stability was measured in the following manner. It was shown to. In Comparative Examples 2 and 3, since a heat-resistant foam sheet was not obtained, the expansion ratio and dimensional stability could not be measured.

  The vibration damping properties of the heat-resistant foam sheets obtained in Examples 13 to 15 and Comparative Example 5 were measured in the following manner, and the results are shown in Table 4 and FIG.

(Dimensional stability)
A test piece of a desired size was cut out from the obtained heat-resistant foamed sheet, and after measuring the dimension L ₁ in the extrusion direction of the test piece, the test piece was cured at 120 ° C. for 22 hours, and the dimension L ₂ after curing was determined. Measured, and the dimensional change rate in the extrusion direction was calculated based on the following formula.
Dimensional change rate (%) = 100 × (L ₂ −L ₁ ) / L ₁

  Next, the dimensional change rate in the direction orthogonal to the extrusion direction of the test piece is calculated in the same manner as described above, and the arithmetic average value of the dimensional change rate in the extrusion direction and the dimensional change rate in the direction orthogonal to the extrusion direction. Was used as an index of dimensional stability.

(Vibration control performance)
The damping performance of the heat resistant damping tape was measured by the central excitation method. Assuming joining of members, a vibrating body was obtained by laminating and integrating two flat rectangular SPCC steel plates having a length of 15.0 mm, a width of 250 mm, and a thickness of 1.0 mm using a double-sided tape (damping tape). And the loss factor was measured on 25 degreeC conditions using the measuring apparatus (Rion company make brand name "SA-01").

Claims (8)

The gel contains 100 parts by weight of a conjugated diene polymer having a maximum loss loss tangent obtained by dynamic viscoelasticity measurement of −30 to 40 ° C. and 10 to 70 parts by weight of a crystalline resin. A heat-resistant foam sheet having a fraction of 15 to 65% by weight and an expansion ratio of 2 to 30 times. The heat-resistant foam sheet according to claim 1, wherein the conjugated diene polymer is a copolymer containing a block obtained by polymerizing a conjugated diene monomer. The crystalline resin contains a crystalline resin having a melting point of 120 to 200 ° C. measured by differential scanning calorimetry (DSC) and a crystal melting energy of 20 mJ / mg or more. The heat-resistant foam sheet described in 1. The heat-resistant foam sheet according to claim 1, wherein the crystalline resin contains one or both of a polyolefin resin and a polyester resin. The heat resistant foamed sheet according to claim 4, wherein the crystalline resin is a polyethylene resin, a polypropylene resin, or polylactic acid. The heat-resistant foam sheet according to claim 1, wherein the conjugated diene polymer contains a block copolymer having a styrene block and a vinyl isoprene block. A heat-resistant damping tape, wherein an adhesive layer is laminated and integrated on at least one surface of the heat-resistant foam sheet according to any one of claims 1 to 6. The heat-resistant vibration-damping tape according to claim 7, wherein the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive or a urethane pressure-sensitive adhesive.

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