JPH06170997A - Damping reinforcing structural body for vehicle - Google Patents

Abstract

PURPOSE:To provide a lightweight structural body for a vehicle wherein high damping performance and high rigidity are given by laminating a spacer layer having specified composition, the sheet layer of damping material and the sheet layer of restriction material on a vibration base plate having wide area. CONSTITUTION:A damping reinforcing structural body for a vehicle is provided by successively laminating three layers of a spacer layer consisting of an expandable thermosetting resin sheet, the sheet layer of damping material and the sheet layer of restriction material on a vibration base plate having wide area. The spacer layer consists of a sheet which is semigelled by heating the following mixture at the temperature not higher than the generation temperature of decomposable gas. The mixture contains 10-200 pts.wt. methacrylic resin having <=300mum mean particle diameter, 0.5-20 pts.wt. foaming agent wherein the generation temperature of decomposable gas is regulated to 100-220 deg.C and 0.05-5 pts.wt. surfactant per 100 pts.wt. epoxy resin containing at least one piece of epoxy group in a molecule. At least a tackifier having 10<3>-10<5>cps viscosity at 20 deg.C is added in 10-100 pts.wt. to 100 pts.wt. butyl rubber and the mixture is used for the sheet layer of damping material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle vibration damping device which is integrated by fusion molding on a wide area substrate such as a front panel, a fender panel, a door panel, a ceiling panel of a vehicle which is easily vibrated and has low robustness. The present invention relates to a reinforcing structure.

[0002]

2. Description of the Related Art A heat-fusible reinforcing material containing an epoxy resin as a main component is fused and used on a vibrating substrate surface such as a front panel of a vehicle, a fender panel, a door panel, a ceiling panel, etc. There are many. Further, in recent years, a metal sheet such as a glass cloth or an aluminum plate is laminated as a restraint material on the upper surface of these epoxy resin-based reinforcement materials to improve rigidity as a restraint-type reinforcing structure. More recently, attempts have been made to further improve rigidity performance by foaming a reinforcing material sheet containing an epoxy resin as a main component. However, these reinforcing structures have the following problems. That is, in the double-layer type reinforcing structure in which the substrate is reinforced only by the heat-sealing type reinforcing sheet containing epoxy resin as a main component, it is necessary to increase the thickness in order to improve the reinforcing performance. Despite the increase, the level of improvement in the rigidity of the structure is not so great. Further, recently, a technique for making the reinforcing material sheet containing the epoxy resin as a main component foamable to suppress the increase in the weight has started to be widely used, but the actual expansion ratio is 1.5 to 2.0.
It is about double and the improvement of the reinforcing performance in the practical weight range is not significant. In addition, a metal sheet such as a steel plate or an aluminum plate or an uncured thermosetting resin sheet is placed on the epoxy resin-based reinforcing material sheet as a restraining material sheet on the reinforcing material sheet containing epoxy resin as a main component. When the sandwich type reinforcement structure is integrated by heating, the rigidity is improved compared to the double layer reinforcement structure, but the restraint sheet requires a considerable thickness to significantly improve its performance. Therefore, even in this case, the vehicle weight is increased. In the practical thickness range, more effective reinforcement performance, that is, rigidity, can be obtained than the double layer type reinforcement structure, but since these reinforcement structures have almost no vibration damping performance, recent noise reduction in the vehicle interior From the point of view of the above, the current situation is that the performance is becoming insufficient.

[0003]

In order to solve these problems, a composition comprising a vinyl chloride resin for paste, a plasticizer, a foaming agent, etc., containing a liquid epoxy resin and a heat-activatable curing agent, has a foaming property. There is also a proposal of a so-called thermosetting foam spacer-equipped vibration damping reinforcing structure using a semi-gelated sheet as a spacer (for example, Japanese Patent Application No. 4-7313).
9). This is a lightweight and excellent vibration-damping reinforcing structure despite having high vibration-damping property and rigidity, but since it contains a vinyl chloride resin in its composition, for example, it is used in an automobile production line. There is a problem that the resin may be thermally decomposed at a high temperature such as an electrodeposition coating process. Under the circumstances, the present invention provides a vehicle structure that is lightweight and has high vibration damping performance and high rigidity, and has good heat resistance. For example, it can withstand an electrodeposition coating process. An object of the present invention is to provide a vehicle structure having the above composition.

[0004]

According to the present invention, a spacer layer (I) made of a foamable thermosetting resin sheet laminated on a wide area vibration substrate in a vehicle and a vibration damping laminated on the spacer layer. A vehicle comprising three material sheet layers (II) and a restraining material sheet layer (III) laminated on the damping material layer, wherein the spacer layer (I) is foamed. In a vibration-damping and reinforcing structure for a vehicle, a spacer layer (I) comprises (A) methacryl having an average particle diameter of 300 μm or less per 100 parts by weight of a liquid epoxy resin containing one or more epoxy groups in one molecule. System resin 10 to 200 parts by weight, (C) epoxy resin curing agent 0.5 to 20 parts by weight, (D) decomposition gas generation temperature 10
0.5 to 20 parts by weight of a foaming agent at 0 to 220 ° C. and (E)
A sheet made of 0.05 to 5 parts by weight of a surfactant, which is semi-gelled by heating at a temperature below the decomposition gas generation temperature of the foaming agent (D), wherein the damping material sheet layer (II) is 100 parts by weight of butyl rubber. 10 parts by weight of a tackifier having a viscosity of 10 ³ to 10 ⁵ cps at 20 ° C. to at least 10 parts by weight, and the constraining material sheet layer (III) has a composition containing a tackifier resin. The present invention provides a vibration-damping and reinforcing structure for a vehicle, characterized in that it is made of a thermosetting plastic, or a metal sheet.

Further, according to the present invention, the structure is fused and integrated with a vibration substrate of a vehicle so that excellent vibration damping performance can be imparted and rigidity can be improved in a range where a weight increase of the vehicle is small. It provides a structure. Furthermore, for this type of vehicle structure, it is necessary to complete the reaction, foaming, fusion bonding, etc. of each layer by heat treatment in a drying step such as painting, and moreover, there is a material with little deterioration in physical properties even at a relatively high temperature. Although required as preferable properties, the structure according to the present invention correctly meets these requirements.

Hereinafter, each constituent layer relating to the present invention will be described. The spacer layer (I) used in the present invention is a foamable thermosetting resin sheet, and imparts a function as a spacer in a vibration damping reinforcing structure, and has preferable properties as a spacer in a vehicle vibration damping reinforcing structure. Is
Light weight, high rigidity, little change in physical properties due to temperature changes,
In addition, it is adhered and fixed to the vibrating substrate in the coating drying process and the like, and has a high-magnification foaming action in this process. In the spacer composition of the present invention, the liquid epoxy resin used as the component (A) contains one or more epoxy groups in the molecule. Examples of such liquid resins include bisphenol A and bisphenol F. Or resorcin-based glycidyl ether, polyglycidyl ether of phenol novolac resin or cresol novolac resin, glycidyl ether of hydrogenated bisphenol A, glycidyl amine type, linear aliphatic epoxide type, phthalic acid, hexahydrophthalic acid or tetrahydro Epoxy equivalents such as glycidyl ether of phthalic acid are preferably 100 to 300.
The following are listed. These liquid epoxy resins may be used alone or in combination of two or more, and are added with ethylene oxide or propylene oxide addition type phenol A type in order to impart toughness to the resulting foam. A flexible epoxy resin such as an epoxy resin, a dimer acid type epoxy resin, or an epoxy modified NBR may be used in combination.

In the spacer composition of the present invention, a methacrylic resin having an average particle diameter of 300 μm or less is used as the component (B). As the methacrylic resin, polymethylmethacrylate or a copolymer resin of methylmethacrylate containing methylmethacrylate as a predominant amount and a copolymerizable monomer such as ethylacrylate or acrylonitrile is used. The preferred degree of polymerization of the methacrylic resin is such that the degree of polymerization in terms of polymethylmethacrylate is in the range of 2,000 to 30,000. If the polymerization degree is less than 2000, the melt viscosity at the time of processing becomes low, and it becomes difficult to form a dense cell structure due to flow breakage of the foam cells. Further, when the degree of polymerization exceeds 30,000, the meltability during processing deteriorates and a high expansion ratio cannot be obtained, and the effect of the present invention is reduced, which is not preferable. Also,
The methacrylic resin has an average particle size of 300 μm or less,
It is preferably 100 μm to 1 μm. When it exceeds 300 μm, the uniform dispersibility with other compositions is deteriorated, which is not preferable. The amount of the methacrylic resin added is 10 to 2 per 100 parts by weight of the liquid epoxy resin as the component (A).
The range is 00 parts by weight, preferably 20 to 100 parts by weight. When the amount is less than 10 parts by weight, the viscosity during processing depends on the viscosity of the epoxy resin as the component (A), but the viscosity at the time of processing becomes too low to cause a flow cell breakage of the foamed cells or the like, resulting in a dense cell structure,
If it exceeds 200 parts by weight, the meltability at the time of processing deteriorates and it becomes difficult to obtain a high expansion ratio.

In the composition of the present invention, 0.5 to 20 parts by weight of a curing agent for epoxy resin is used as the component (C). This curing agent preferably has an exothermic peak temperature in the range of 100 to 220 ° C. in combination with an epoxy resin, and examples of such a curing agent include dicyandiamide, 4,4′-diaminodiphenylsulfone and 2-n.
-Imidazole derivatives such as heptadecyl imidazole, isophthalic dihydrazide, N, N'-dialkylurea derivatives, N, N'-dialkylthiourea derivatives, acid anhydrides such as tetrahydrophthalic anhydride, isophoronediamine, N-amino Examples thereof include ethylpiperazine, trifluoroboric acid complex compound, trisdimethylaminomethylphenol and the like. One of these curing agents may be used, or two or more thereof may be used in combination, and the addition amount thereof is 0.5 to 20 parts by weight per 100 parts by weight of the (A) component epoxy resin. It is a range of parts. If this amount is less than 0.5 parts by weight, the curing will be insufficient and the rigidity of the foam will be insufficient, and if it exceeds 20 parts by weight, the rigidity of the foam will not improve for that amount, which is economically disadvantageous. Not only does it have a technical meaning. The curing temperature here means the temperature of the medium at which the heat generated by curing reaches a peak when a mixture of an epoxy resin and a curing agent at room temperature is heated with an oil bath or a heater. Further, a preferable combination of the amount and type of the epoxy resin and the curing agent depending on the heating conditions can be easily determined by conducting a test in advance. In the present invention, together with the curing agent of the component (C), if necessary, as a curing accelerator, for example, alcohol type, phenol type, mercaptan type, dimethylurea type, aliphatic type, further imidazole type, monuron, Chlorotoluene or the like can be used.

In the present invention, a foaming agent having a decomposition gas generation temperature of 100 to 220 ° C. is used as the component (D). As such a high temperature decomposition type foaming agent, an organic foaming agent, an inorganic foaming agent, a high temperature expansion type microcapsule or the like can be used. If the decomposition gas generation temperature is less than 100 ° C., foaming may start before producing a semi-gelled sheet,
When the resin is heated and foamed, the melting of the resin is insufficient and the gas escapes and the expansion ratio does not increase, or it is difficult to obtain a homogeneous foam. On the other hand, if the temperature exceeds 220 ° C., the processing temperature of the composition becomes too high and the composition is deteriorated, which makes it difficult to obtain a foam having good quality. Examples of the organic foaming agent include azodicarbonamide, p-toluenesulfonyl hydrazide, dinitrosopentamethylenetetramine, 4,4′-
Examples thereof include oxybisbenzenesulfonyl hydrazide. The decomposition temperature of these organic foaming agents can be arbitrarily adjusted by adding an appropriate amount of urea, a zinc compound, a lead compound or the like. Examples of the inorganic foaming agent include sodium hydrogen carbonate and sodium borohydride, and examples of the high temperature expansion type microcapsules include those in which a low boiling point hydrocarbon is encapsulated with vinylidene chloride resin.

As the component (D) of the present invention, any of the above-mentioned organic foaming agents, inorganic foaming agents, high temperature expansion type microcapsules and the like can be used, but from the viewpoints of expansion ratio and economical efficiency, the organic foaming agent is used. Is preferred. These foaming agents may be used alone or in combination of two or more, and the addition amount thereof is the liquid epoxy resin 10 which is the component (A).
It is selected in the range of 0.5 to 20 parts by weight with respect to 0 parts by weight. If the amount added is less than 0.5 parts by weight, the expansion ratio will be insufficient, and if it exceeds 20 parts by weight, the expansion ratio will not improve for the amount added, which is economically disadvantageous. Further, in order to obtain a dense foam having a uniform foam cell diameter and a rigid cell membrane, it is advantageous to use a foaming agent having a small particle diameter, for example, to obtain a 0.5 mm cell diameter. It is preferable that the foaming agent has a uniform average particle size of 20 μm or less, preferably 1.0 μm or less and a uniform particle size distribution. In the present invention, a foaming accelerator may be used in combination with the foaming agent, if necessary. Examples of the foaming accelerator include zinc oxide, zinc stearate, lead stearate, calcium stearate, barium stearate, sodium and potassium compounds, urea and the like.

In the present invention, a surfactant is used as the component (E). This surfactant plays a role in improving the foam cell structure. Examples of the surfactant include alkyl sulfate salts such as sodium lauryl sulfate and sodium myristyl sulfate, alkyl allyl sulfonates such as sodium dodecylbenzenesulfonate and potassium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate, dihexylsulfosuccinate. Anionic surfactants such as sulfosuccinate salts such as sodium acid salt, ammonium laurate, fatty acid salts such as potassium stearate, polyoxyethylene alkyl sulfate ester salts, polyoxyethylene alkylallyl sulfate ester salts, and rosinate are preferable. Examples thereof include sorbitan monooleate, sorbitan esters such as polyoxyethylene sorbitan monostearate, and polyoxyethylene. Alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters of the nonionic surfactant and cetyl pyridinium chloride, cationic surfactants such as cetyltrimethylammonium bromide may also be used.

These surfactants may be used alone or in combination of two or more, and the addition amount thereof is from 0.05 to 100 parts by weight of the liquid epoxy resin as the component (A). 5 parts by weight, preferably 0.2 to 3 parts by weight. If the added amount is less than 0.05 parts by weight, the effect of homogenizing the foamed cells is poor, and if the added amount exceeds 5 parts by weight, not only the added amount of the foamed cells does not become uniform, but also the resin It is not preferable because it lowers thermal stability. Further, in the present invention, a plasticizer may be added as necessary in order to adjust the melt viscosity and the affinity between the epoxy resin as the component (A) and the methacrylic resin as the component (B). . Examples of the plasticizer include phthalic acid esters such as di-2-ethylhexyl phthalate and dibutyl phthalate, phosphoric acid esters such as tricresyl phosphate, fatty acid esters such as dioctyl adipate, and adipic acid condensation of ethylene glycol. Known substances such as a body, a trimellitic acid ester, a glycolic acid ester, a chlorinated paraffin, and an alkylbenzene can be used.

Further, in the present invention, for the purpose of facilitating the initial mixing, increasing the addition amount of the filler and the like,
A diluent for epoxy resin may be added if necessary. As the diluent, for example, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, reactive diluents such as persatic acid glycidyl ether, dibutyl phthalate, tricresyl phosphate, butyl benzyl phthalate, Acetyl tributyl citrate, aromatic process oil, pine oil,
Mention may be made of non-reactive diluents such as 2,2,4-trimethyl-1,3-pentadiol isobutyrate.
These diluents are usually 5 to 150 parts by weight, preferably 1 to 100 parts by weight of the component (A) liquid epoxy resin.
It is selected in the range of 0 to 100 parts by weight. In the present invention, a thixotropic agent, a filler, a pigment or the like may be added as necessary in order to adjust coating properties such as workability and viscosity and to reduce costs. Examples of the thixotropic agent include silicic acid anhydride such as silicic acid anhydride and hydrous silicic acid, bentonite such as organic bentonite, asbestos such as silodex, and organic such as dibenzylidene sorbitol. These thixotropic agents are usually used in an amount of 1 to 2 per 100 parts by weight of the liquid epoxy resin as the component (A).
It is selected in the range of 0 parts by weight. Examples of the filler include calcium carbonate, mica, talc, kaolin clay, celite, asbestos, perlite, baryta, silica, silica sand, scaly graphite, gypsum, and metal powder.

In the structure of the present invention, the foamable thermosetting resin sheet composition is used as a semi-gelled sheet. That is, the above-prepared composition is molded into a semi-gelled sheet at a temperature below the decomposition temperature of the foaming agent, usually at a relatively low temperature of about 100 to 150 ° C., and then the vibration damping sheet (II) and the restraining material sheet. (III)
After being laminated, in the next heating step, for example, a coating drying step, the resin foams at 120 ° C. to 200 ° C. and is cured by the crosslinking of the epoxy resin. The expansion ratio of the foamable thermosetting resin sheet is 2 to 30 times, preferably 3 to 10 times. Of course, a foaming ratio of 2 or less can function as a spacer, but it is not the object of the present invention from the viewpoint of lightness and heat insulation property.
If the expansion ratio is doubled or more, the strength of the foam cells is insufficient, and the compression resistance strength may be insufficient depending on the use part of the vehicle, so that it may not be practically usable. The thickness of the spacer layer after foaming is 1 to 50 mm, preferably 2 to 30 mm.
Is. When it is 1 mm or less, it cannot fulfill its effective function as a spacer, and when it is 50 mm or more, it is not practical in the vehicle application which is the object of the present invention, and it becomes unpractical and a heating step such as a coating drying step. However, when it is attached to a vertical surface such as a door panel, a deviation occurs or a uniform foaming property cannot be obtained.

The damping material sheet (II) provided for the structure of the present invention imparts a damping function in this structure and has a viscosity of 10 ^{3 at} 20 ° C. with respect to 100 parts by weight of butyl rubber. It is formed by adding at least a tackifier of 10 ⁵ cps. The butyl rubber used here is not particularly limited and may be a commonly used one having an unsaturation degree of about 0.5 to 3.0, and halogenated butyl rubber may be used, and a mixture thereof may be used. Of course it does not matter if you use it. 20 used in the present invention
The tackifier having a viscosity of 10 ³ to 10 ⁵ cps at ℃ is
It has a function as a plasticizer for setting the temperature dispersion of the loss coefficient in a predetermined temperature range, and has appropriate viscoelasticity and adhesion to the spacer sheet layer (I) and the restraining material sheet layer (III) suitable for the purpose of the present invention. The adhesiveness and the adhesiveness are given to prevent the deviation in the heating step even when it is attached to a vertical surface such as a door panel.

The viscosity of this tackifier is 10 ³ to 10 ⁵ cps at 20 ° C. If the viscosity is less than 10 ³ cps, it depends on the type and amount of addition, but 40 to 50 ° C
The loss factor in the above high temperature region is reduced, and the adhesiveness and the adhesiveness that prevent the deviation during heating when the tape is attached to a vertical surface such as a door panel are insufficient. Further, when the viscosity is 10 ⁵ cps or more, this also relates to the kind and the addition amount, but the loss coefficient at low temperature decreases. Examples of such a tackifier include petroleum hydrocarbons such as polybutene, polymerized polyester, atactic polypropylene, liquid polybutadiene, and low molecular weight butyl rubber,
Examples thereof include rosin derivatives such as hydrogenated rosin methyl ester, hydrogenated rosin triethylene glycol ester, and turpentine derivatives. Furthermore, this addition amount is
Butyl rubber 100
10 to 100 parts by weight, preferably 20 to 7 parts by weight
0 parts by weight. When the amount is 10 parts by weight or less, the loss coefficient at low temperature decreases, and the adhesion and the adhesiveness with the spacer sheet layer (I) and the restraining material sheet layer (III) may be insufficient. The function of preventing misalignment during the heating process is insufficient. Further, when the amount is 100 parts by weight or more, the loss coefficient at high temperature is lowered, and the viscosity of the composition is lowered, so that it is difficult to obtain a good vibration-damping material sheet having a uniform thickness by a usual processing method. .

The thickness of the vibration damping material sheet is not particularly specified, but considering that it is formed as a structure for a vehicle, it is preferably 3 mm or less, preferably 1 mm or less. When the thickness is 3 mm or more, it is against the weight reduction which is one of the objects of the present invention, and it is economically disadvantageous because an effective loss coefficient cannot be obtained for the thickness.
When it is attached to a panel having a vertical surface such as a door, the weight of the panel easily causes a deviation in the heating process. Moreover, the lower limit of the thickness is not set. This is because the structure of the present invention has a constrained type vibration damping structure, and therefore the function can be exhibited even if the vibration damping sheet layer (II) is thin. In the composition of the vibration-damping material sheet of the present invention, in addition to the above-mentioned composition, the function as the vibration-damping material is not impaired, and the moldability and the like are not deteriorated as long as there is no hindrance during the formation of the floor panel of the vehicle or the like. For the purpose of improvement, other softeners, reinforcing agents such as carbon, inorganic fillers such as calcium carbonate, talc, clay and calcium sulfate, halogen compounds, antimony oxide, zinc borate hydrate, aluminum hydroxide, etc. A flame retardant, a heat stabilizer, a lubricant, an anti-blocking agent, a colorant, an anti-UV agent and the like can be used.
Further, in order to improve durability, a vulcanizing agent such as sulfur may be added within a range that does not hinder baking on the vibration substrate during molding. The method for molding the vibration-damping material sheet according to the present invention is not particularly limited, but generally, after kneading with a Banbury mixer or the like, sheet molding may be performed with a calendar or the like.

The restraining material sheet (III) provided for the structure of the present invention restrains the deformation of the damping material sheet (II) due to the vibration, and imparts a large loss coefficient by causing the shearing deformation to act on the damping material sheet (II). In addition to providing high rigidity. It is preferable that the material used for the restraint material sheet has a high elastic modulus and does not impair the function as a vehicle material. Materials satisfying such conditions include rosin-based resins, terpene-based resins, aliphatic petroleum resins,
Thermosetting resin sheet containing a tackifier such as aromatic petroleum resin, alkylphenol-acetylene resin, xylene-based resin, coumarone-indene-based resin or rubber such as butadiene rubber or styrene-butadiene rubber as a base polymer A flexible plastic sheet and a metal sheet such as a steel plate and an aluminum plate are suitable. The thermoplastic resin sheet containing the tackifier resin has a relatively high elastic modulus in the temperature range of about 0 to 60 ° C., which is the state of use of the vehicle, depending on the type and content of the tackifier resin, and coating and drying the vehicle. It is possible to design a material that becomes a low-viscosity melt in the temperature range of about 120 to 200 ° C., which is the temperature of the process, and can follow a complicated uneven shape together with the spacer layer (I) and the damping material sheet layer (II). It's easy. Further, the thickness of the binding material sheet is not particularly limited, and the suitable thickness may vary depending on the type of material, but as a sheet formed on a vertical surface of a door panel or the like, it is resistant to slippage at high temperatures. From the same viewpoint as the spacer layer (I) and the damping material sheet layer (II) in consideration of the weight that affects, for example, the resin constraining material sheet is about 0.5 to 3 mm, and the metallic constraining material is Is in the range of about 0.05 to 1 mm. Metallic restraint sheets such as steel plates and aluminum sheets originally have a high elastic modulus, and therefore have desirable characteristics when applied to restraint sheets.

The production of such a structure according to the present invention is carried out by the spacer sheet layer (I) and the damping material sheet layer (I).
I), each layer of the restraining material sheet layer (III) is individually stuck on a wide area vibration substrate of a vehicle, and the substrate, the spacer sheet layer (I), and the damping material sheet layer (II) are heated by heating in a coating drying step or the like. ), The constraining material sheet layer (III) may be fused and foamed with each other, or the spacer sheet layer (I), the damping material sheet layer (II), and the constraining material sheet layer (I
The layered product of II) may be fused and foamed on the substrate by heating in a coating drying step or the like. Further, of course, the spacer sheet layer (I) and the damping material sheet layer (II), or the damping material sheet layer (II) and the restraining material sheet layer (III) may be combined.

[0020]

As described above, the vibration damping reinforcing structure for a vehicle according to the present invention is attached to a vertical vibration substrate surface having a relatively large area of a vehicle such as a vehicle door panel, a front panel and a fender panel. By heating, each layer and the substrate can be firmly fixed. The structure thus obtained is a constrained type vibration damping reinforcement structure with a spacer, which has rigidity and good heat resistance and has a dense cell structure with a high expansion ratio in the lower layer, so that it has excellent vibration damping over a wide temperature range. The structure has both functions and high rigidity, and is not only suitable as a material for reducing vehicle interior noise, but also provides a vehicle panel with robustness and a structure with excellent heat insulation.

[0021]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples. The materials and test methods used in the test are as follows. (1) Test material Vibrating substrate: Steel plate having a thickness of 1.0 mm Spacer sheet A spacer composition having a compounding ratio shown in Table 1 was mixed for 20 minutes by a Hobart mixer, and then coated on a release paper with a predetermined thickness. . This was heated at 120 ° C. for 100 seconds to prepare a semi-gelled sheet.

[0022]

[Table 1]

Damping Material Sheet After the damping material composition was kneaded in a kneader at the compounding ratio shown in Table 2, it was further roll-kneaded, and the obtained roll sheet was pressed to a predetermined thickness.

[0024]

[Table 2]

Restraint Material Sheet The restraint material composition having the compounding ratio shown in Table 3 was melted and mixed in an autoclave at 200 ° C., and the obtained mixture was hot-pressed to have a predetermined thickness.

[0026]

[Table 3]

Further, in the case of the restraining material sheet made of the thermosetting plastic sheet, the one having the compounding ratio shown in Table 4 was kneaded with a roll to have a predetermined thickness.

[0028]

[Table 4]

Further, the metal sheets shown in Table 5 were also used as the restraining material sheet.

[0030]

[Table 5]

(2) Test method The shear resistance of the structure upon heating (1) The unfoamed semi-gelled sheet, damping material sheet, restraint material sheet, etc. are placed on a steel plate having a thickness of 1.0 mm. After mounting, the example structures as shown in Table 6 and the comparative example structures as shown in Table 7 were prepared, and these were vertically fixed, and a steel plate when heat-foamed at 150 ° C. for 30 minutes. The degree of misalignment between the foam, the damping material, and the restraining material was determined according to the following criteria. The size of the test body used in this test is 70 × 110 mm. ⊚: Deviation is within 1 mm, and there is almost no deviation from the initial sticking position. ◯: The deviation is 1 to 2 mm, and although there is some deviation, there is no problem in use. Δ: The deviation is 2 to 5 mm, which may cause a problem in use depending on the site. X: The deviation is 5 mm or more, which is a problem in use. XX: Completely peeled.

[0032]

[Table 6]

[0033]

[Table 7]

Foaming ratio, foamed cell shape, denseness of cells (1) An unfoamed semi-gelized sheet, a damping material sheet, a restraining material sheet, etc. were placed on a steel plate having a thickness of 1.0 mm. , After creating the structures shown in Table 6 and Table 7,
The shape and the denseness of the foamed cells when this was fixed horizontally and heated and foamed at 150 ° C. for 30 minutes were determined according to the following criteria. A: The cells are uniform and dense, and most of them are closed cells. ◯: The cell is relatively uniform and dense, with some open cells. Δ: The cells are relatively nonuniform and coarse, and most of them are open cells. X: The cells are non-uniform and coarse, and most of them are open cells. The expansion ratio was calculated by dividing the thickness of the entire foam layer by the thickness of the semi-gel sheet.

Loss factor of structure, rigidity ratio (1) The unfoamed semi-gelized sheet, damping material sheet, restraint material sheet, etc. were placed on a steel plate having a thickness of 1.0 mm, and Table 6 , After creating the structure as shown in Table 7,
A test structure was prepared by heating at 150 ° C. for 30 minutes, foaming and adhering each layer. The size of the test body at this time is 30
The loss factor and the rigidity ratio were measured in an atmosphere of 20 ° C., 40 ° C. and 60 ° C. The loss coefficient was calculated from the half width of the mechanical impedance at the resonance point, and the loss coefficient at 200 Hz was obtained by the interpolation method. The measurement frequency range is 1 to 1000 Hz. The rigidity was calculated by the following formula in the form of the ratio to the rigidity of the vibration substrate, that is, the rigidity ratio.

[0036]

[Formula 1] Rigidity ratio = (f ₀ / f) ² · {(m ₁ + m ₂ ) / m ₁ }

Here, f ₀ : Resonance frequency in the case of a multi-layer structure (Hz) f: Resonance frequency in the case of a single steel plate (Hz) m ₁ : Area density in the case of a single steel plate (kg / m ² ) m ₂ : Area density (kg / m ² ) when a multilayer structure is formed.

(3) Test Results Table 8 shows the test results of the examples, and Table 9 shows the test results of the comparative examples.

[0039]

[Table 8]

[0040]

[Table 9]

As shown in Tables 8 and 9, in the structures according to Examples 1 to 13 of the present invention, the foam cell shape is uniform and dense, and most of them are composed of closed cells. As for the deviation, almost no deviation was observed, and the soundproofing performance (loss coefficient) and the rigidity were good. On the other hand, in the structures according to the comparative examples, the structures according to the comparative examples 1 and 2 had all the above-mentioned performances. There is a problem in that Comparative Example 3 is inferior in soundproofness, Comparative Example 4 is in rigidity, and Comparative Examples 5 to 8 are all inferior in shear resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigenori Kazama 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Takamitsu Mikuni 1-2-1, Yokou, Kawasaki-ku, Kanagawa Research and Development Center Co., Ltd.

Claims (2)

[Claims] 1. A spacer layer (I) made of a foamable thermosetting resin sheet laminated on a vibration substrate of a vehicle, a damping material sheet layer (II) laminated on the spacer layer, and the damping material layer. Restraint sheet layer (II
I) three layers, wherein the spacer layer (I) is foamed, in a vibration damping reinforcing structure for a vehicle, the spacer layer (I) is in one molecule of (A). Liquid epoxy resin 100 containing one or more epoxy groups
(B) 10 to 200 parts by weight of a methacrylic resin having an average particle size of 300 μm or less, (C) 0.5 to 20 parts by weight of a curing agent for epoxy resin, and (D) a decomposition gas generation temperature of 100 to 100 parts by weight. It was composed of 0.5 to 20 parts by weight of a blowing agent at 220 ° C. and 0.05 to 5 parts by weight of (E) a surfactant, and was semi-gelled by heating below the decomposition gas generation temperature of the blowing agent (D). It is a sheet, and the damping material sheet layer (II) is 20 ° C. with respect to 100 parts by weight of butyl rubber.
The viscosity of 10 ³ to 10 ⁵ cps tackifier is 10
At least 100 parts by weight of the vibration damping reinforcing structure for a vehicle is added. 2. The vibration damping reinforcement structure for a vehicle according to claim 1, wherein the restraint material sheet layer (III) is any one of a tackifier resin sheet, a thermosetting plastic sheet, and a metal sheet. body.