JPH0755549B2 - Vehicle structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicle such as a floor panel, a dash panel, a door panel, a ceiling panel or the like of a vehicle, which is easily vibrated, and is integrated by heat fusion. The present invention relates to an excellent vibration control structure.

[Prior Art] On a vibration base material surface of a vehicle floor panel, dash panel, wheel house, or the like, a heat-bonding damping material containing asphalt as a main component is fused by using heating in a drying process of coating. It is often done.

In recent years, a metal sheet such as a steel plate or an aluminum plate is provided as a restraint material on the upper surface of an asphalt damping material, or a thermosetting resin such as an epoxy resin, a diallyl phthalate resin, or an acrylic resin is laminated to restrain the damping material. The structure is being improved in vibration damping performance and rigidity.

Furthermore, recently, attempts have been made to improve the vibration damping performance by a method of foaming a vibration damping material containing asphalt as a main component.

[Problems to be Solved by the Invention] However, these damping structures have the following problems. That is, in the double-layer type vibration damping structure in which the vibration base material is damped only by the heat-fusible sheet containing asphalt as a main component, it is necessary to increase the thickness in order to improve the vibration damping performance. Will increase the vehicle weight and hardly improve the rigidity of the structure.

Further, in the case of a sandwich type vibration damping structure in which a steel plate, an aluminum plate or the like is laminated on the upper surface of the asphalt-based heat-sealing damping material, the damping performance as a structure is improved, but the rigidity is high as a constraining layer. In order to bring it into close contact with the heat-fusible damping sheet, it is necessary to mechanically fix it to a highly rigid vibrating base material such as a steel plate, or fix it with screws such as bolts. . However, since vehicle floor boards and the like are generally press-formed in an uneven shape for the purpose of imparting rigidity, it is necessary to form the restraining metal plate in a shape complementary to this, and an extra step is required. In addition, there is a problem that it is not easy to correctly position it at a predetermined position when mounting.

In addition, a method of placing an uncured thermosetting resin on a damping material and curing it in the drying process of coating to use it as a restraining material, or a thermoplastic resin using a tackifier resin as a base material There is also a method in which it is placed on a material and heat-bonded in a coating and drying step to be used as a restraining material.

The method of using these hard resin materials as a restraint material is certainly effective in improving the loss coefficient, and
There is an advantage that the rigidity of the structure can be expected to some extent.
However, the restraint type vibration control structure using the hard resin restraint material has a problem that the temperature range in which the high loss coefficient can be obtained is relatively narrow in a practical range without a large weight increase. It is not possible to obtain high loss factors all over the temperature range.

[Means for Solving the Problems] The present invention is to improve such problems, and includes a spacer layer (1) made of a foamable thermosetting resin sheet laminated on a vibration substrate of a vehicle, A vehicle structure comprising a vibration damping sheet (2) laminated on a spacer, the contact surfaces of these sheets and the vibration substrate are integrally fused by heating and the spacer layer is foamed. It is about.

Further, an object of the present invention is to provide a superior loss coefficient in a range where a weight increase is small and to improve rigidity by fusing and integrating the structure with a vibration substrate of a vehicle. To provide a panel.

Furthermore, for this type of vehicle structure, it is necessary to adhere to the uneven vibration substrate by heat treatment in the drying process such as painting and complete reaction, foaming, fusion bonding, etc. of each layer. A material which is less likely to be deteriorated in physical properties even at an extremely high temperature is required as a preferable property, but the structure according to the present invention exactly meets these requirements.

When the vehicle structure according to the present invention is schematically illustrated,
The figure is a cross-sectional view before heat fusion foaming, in which a spacer layer (1) is laminated on a vibrating substrate (3), and a limiting sheet (2) is laminated on the spacer (1). FIG. 2 shows a state in which the substrate and the sheet surface are integrally fused by heating and the spacer layer is foamed. FIG. 3 shows a state after heating when a foamable vibration damping sheet is used as the vibration damping sheet (3), and the foamable vibration damping sheet is also foamed.

As described above, the present invention provides the double-layer type vibration damping structure with spacers to the vibration substrate of the vehicle. Hereinafter, each constituent layer relating to the present invention will be described.

The spacer layer (1) used in the present invention imparts a function as a spacer in the double layer type vibration damping structure. That is, the preferable properties as a spacer for a double-layer type vibration damping structure for vehicle use are light weight, high rigidity, less deterioration of physical properties due to temperature change, and closely adhered / fixed to an uneven vibration substrate during the coating drying process. It has a high-magnification foaming action in the process. From this point of view, the foamable thermosetting resin sheet is suitable for the purpose. Among them, the epoxy resin, the vinyl chloride resin, the plasticizer and the foaming agent are contained, and the vinyl chloride resin is in a semi-gelled state. The product is excellent in shape retention as a sheet state, storage property, adhesiveness to a vertical vibration substrate, rigidity and the like.

Here, the vinyl chloride resin is in a semi-gelled state,
The epoxy resin does not undergo a curing reaction, and only the vinyl chloride resin refers to a state in which the plasticizer has penetrated into the interior and gelation has started.

The epoxy resin foaming composition to be provided to this spacer sheet has at least a vinyl chloride resin, a plasticizer, a foaming agent, an epoxy resin, a heat-activatable curing agent for epoxy resin as an essential component, and other optional cell regulator, filler, A composition consisting of a viscosity modifier, a heat stabilizer, a pigment, etc., which has been previously molded into a sheet at a temperature not higher than the decomposition temperature of the foaming agent, in the next heating step, for example, a coating drying step,
It is capable of foaming at 120 to 200 ° C and being cured by crosslinking of an epoxy resin.

As the vinyl chloride resin, not only vinyl chloride homopolymer but also vinyl chloride, vinyl acetate, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester,
Known copolymers with maleic acid, fumaric acid, maleic acid ester, fumaric acid ester, itaconic acid, vinylidene chloride, vinyl ether and the like can be used alone or in combination. The vinyl chloride polymer (including a copolymer) may be produced by any known method such as emulsion polymerization or suspension polymerization, but is particularly produced by emulsion polymerization for paste or fine suspension polymerization. It is preferable to use one alone or in combination with one obtained by suspension polymerization, from the viewpoint of easy sheet formation and a cell structure during foaming.

Examples of the plasticizer include phthalates such as dioctyl phthalate and dibutyl phthalate, phosphates such as tricresyl phosphate, fatty acid esters such as dioctyl adipate and dioctyl sebacate, for example, a condensate of adipic acid and ethylene glycol. Known vinyl chloride plasticizers such as various polyesters, trimellitic acid esters such as trioctyl trimellitate, chlorinated paraffins, alkylbenzenes, and high molecular weight aromatics can be used alone or in combination. The amount of plasticizer blended is
Although not particularly limited, it is preferably mixed in an amount of more than 10 parts by weight and 150 parts by weight or less with respect to 100 parts by weight of vinyl chloride. If the compounding amount is 10 parts by weight or less, the expansion ratio does not improve, and if it exceeds 150 parts by weight, the hardness does not increase and the reinforcing effect becomes small.

As the foaming agent, a high temperature decomposition type organic or inorganic foaming agent, a high temperature expansion type microcapsule and the like are used. Organic blowing agents include azodicarbonamide, paratoluenesulfonyl hydrazide, dinitrosopentamethylenetetramine, 4,
4'-oxybisbenzenesulfohydrazide and the like are used. The decomposition temperature of organic foaming agents is urea, zinc compounds,
It can be optionally adjusted with a lead compound or the like. Examples of the inorganic foaming agent include sodium bicarbonate and sodium borohydride. As the high temperature expansion type microcapsules, those obtained by encapsulating a low boiling point hydrocarbon with vinylidene can be used. In the present invention, any foaming agent can be applied, but especially the decomposition temperature is 100 ° C. or more and the organic foaming agent is easy to form into a sheet,
It is more preferable from the viewpoint of the appearance of the foam, uniform foaming and denseness. If the decomposition temperature is 100 ° C. or less, foaming will start when it is formed into a sheet, or the resin will be insufficiently melted at the time of foaming in a heating furnace so that gas will not escape and the expansion ratio will not rise, and it will be difficult to obtain a uniform foam. Further, an inorganic foaming agent or microcapsules can be used, but there is a problem in terms of expansion ratio and economical efficiency. The blending amount of foaming agent is vinyl chloride resin 100
It is preferably 0.5 to 15 parts by weight with respect to parts by weight. If the compounding amount is less than 0.5 part by weight, foaming is insufficient, and if it exceeds 15 parts by weight, the foaming degree does not change, and it is economically wasteful to add excessively.

Examples of the epoxy resin applicable to the present invention include usual glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and aliphatic epoxide type epoxy resins, and desired foams. They can be used alone or in combination depending on the physical properties of. The compounding amount of the epoxy resin is in the range of 20 to 500 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. If the blending amount is less than 20 parts by weight, it is difficult to obtain a hard foam, and if it exceeds 500 parts by weight, the heat generated during curing is large, so that the decomposition of vinyl chloride occurs or the expansion due to the decomposition gas of the foaming agent is suppressed. This causes problems such as difficulty in obtaining a high-magnification foam.

As the heat-activatable curing agent for the epoxy resin, a usual curing agent exhibiting a curing action by heating can be used. A preferred curing agent is a curing agent having an exothermic peak temperature in the range of 100 ° C to 200 ° C in combination with an epoxy resin.
Examples of the curing agent include dicyandiamide, 4,4′-diaminodiphenylsulfone, imidazole derivative such as 2-n-heptadecylimidazole, isophthalic acid dihydrazide, N, N-dialkylurea derivative, N, N-dialkylthiourea derivative. Acid anhydrides such as tetrahydrophthalic anhydride, isophoronediamine, metaphenylenediamine, N-aminoethylpiperazine, boron trifluoride complex compounds, trisdimethylaminomethylphenol and the like. The curing agents can be used alone or in combination as desired. Epoxy resin 10
It is preferably 1 to 20 parts by weight with respect to 0 parts by weight. If the blending amount is less than 1 part by weight, the rigidity of the foam is insufficient due to insufficient curing. On the other hand, if the blending amount is more than 20 parts by weight, the rigidity of the foam does not change, and excessive addition is economically wasteful.

The curing temperature referred to here is 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 by an oil bath, a heater, or the like.

The preferred combination and amount 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, in addition to these essential ingredients, for example, fillers such as calcium carbonate, talc and clay, heat stabilizers,
A bubble regulator and a coloring agent can be added. The compounding amount of each of the above-mentioned compounding agents is in the range of 0 to 200 parts by weight for the filler, 0 to 10 parts by weight for the heat stabilizer, and 0 to 10 parts by weight for the cell regulator with respect to 100 parts by weight of the vinyl chloride resin. . When blending each compounding agent, if the filler is more than 200 parts by weight, the fineness of foaming is lost, the expansion ratio does not increase, and even if the heat stabilizer and the cell regulator are more than 10 parts by weight. No effect.

The expandable resin composition applied to the spacer sheet includes a vinyl chloride resin, a plasticizer, a foaming agent, an epoxy resin, a curing agent for an epoxy resin, and a bubble regulator, a filler, a heat stabilizer, if necessary. A colorant and the like are added and the mixture is homogenized and adjusted by a generally known kneader.

The expansion ratio of such a spacer 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 lightweight,
From the viewpoint of heat insulation and the like, this is not the subject of the present invention, and if the foaming ratio is 30 times or more, the strength of the foamed cells may be insufficient, and there may be a problem in durability depending on the vehicle use site.

The thickness of the spacer sheet after foaming is 1 to 50.
mm, preferably 3 to 30 mm. If it is 1 mm or less, it cannot function effectively as a spacer, and if it is 50 mm or more, it is not practical in the vehicle application which is the object of the present invention and the space inside the vehicle becomes narrow and it is a heating step such as a coating drying step. In that case, a uniform foaming property cannot be obtained.

The vibration-damping sheet used in the present invention may be rubber-based, resin-based, asphalt-based, etc., and the type is not particularly limited, but the adhesion (heat fusion) to the spacer sheet, the heating by From the viewpoint of cost performance, the asphalt type vibration damping sheet and foamed asphalt type are superior in the required performance for vehicle applications such as conformability to uneven vibration substrate and the characteristics as a damping material suitable for double layer type damping structure. The vibration damping sheet is excellent and suitable for this purpose.

The thickness of the vibration damping sheet is not particularly limited, but from the practical viewpoint, it is in the range of about 0.5 to 10 mm. With a thickness of 0.5 mm or less, the loss factor cannot be effectively expressed as a feature of the double layer type vibration damping structure,
Further, if the thickness of the vibration damping sheet is 10 mm or more, the weight becomes extremely large, which is outside the scope of the present invention.

To manufacture such a structure related to the present invention, two layers of a spacer sheet and a vibration damping sheet are separately placed on a vibration substrate of a vehicle, and the vibration substrate, the spacer sheet and the vibration damping substrate are heated by heating in a drying process of coating. The sheets may be fused to each other and the spacer sheet may be foamed to simultaneously follow the unevenness of the vibration substrate. Alternatively, the spacer sheet and the damping sheet may be laminated in advance on the vibration substrate during the coating drying process. The spacer sheet may be foamed and the spacer sheet may be foamed at the same time so as to follow the irregularities of the vibrating substrate.

[Effects of the Invention] As described above, the vehicle structure according to the present invention is
Place it on a vibration board such as a vehicle floor panel, dash panel, wheel house, etc., and heat it to foam the spacer sheet or the vibration damping sheet if necessary, and firmly fix the vibration board, the spacer and the vibration damping sheet. In addition, the spacer sheet and the vibration damping sheet can be made to follow the uneven shape of the vibration substrate.

The structure obtained in this way is a double-layer type vibration damping structure in which the spacer layer uses a foamable thermosetting resin sheet with little change in physical properties due to temperature change, so that it can cover a wide temperature range. In addition to exhibiting excellent vibration damping function, it has a structure with high rigidity to a certain extent, and is not only suitable as a material for reducing vehicle interior noise, but also provides a solid feeling of the vehicle and a structure with excellent heat insulation. Become.

[Examples] Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.
The materials and test methods used in the test are as follows.

I. Test material Vibration substrate: 0.8 mm thick steel plate Spacer layer (expandable thermosetting resin sheet) Prepared by mixing the expandable thermosetting resin composition in a Hobart mixer for 20 minutes at the compounding ratio shown in Table 1. Then, it was applied on a release paper with a predetermined thickness. This was heated at 120 ° C. for 90 seconds to prepare a sheet in which only the paste resin was semi-gelled.

Damping sheet 1. Asphalt damping sheet (trade name: Melsheet, manufactured by Nippon Special Coating Co., Ltd.) The thickness was adjusted in advance with a press.

It is shown as type C of material in Table 3.

2. Foamed asphalt damping sheet (trade name: Melsheet,
Made by Nippon Special Coating Co., Ltd. In Table 3, the material type D is shown.

II. Test method (1) Vibration damping performance test Each spacer layer and damping sheet layer is 150 x 300
mm, 0.8 mm thick steel plate (0.8 mm thick) was combined to create a damping structure, and the rigidity of each structure was measured at 20 ° C, 40 ° C and 60 ° C. For laminating and foaming each layer, a damping material and a restraining material were laminated on a steel plate, and heat treatment was performed in an oven under the condition of 150 ° C. × 30 minutes to fuse each layer and to foam. The loss factor was calculated from the half-width of the mechanical impedance at the resonance point, and the loss factor at 200Hz was obtained by interpolation. still,
The measurement frequency range is 1 to 1000 Hz.

The rigidity ratio was calculated based on the following formula.

Rigidity ratio = (f ₀ / f) ² · {(m ₁ + m ₂ ) / m ₁ } where f ₀ is the resonance frequency when a damping material or restraint material is attached, and f is the vibrating substrate 0.8 mm The resonance frequency of the thick steel plate, m ₁ is the mass per unit area of the steel plate, and m ₂ is the mass per unit area of the damping material and the restraining material.

The results are shown in Table 2.

(2) Shape-following test on uneven plate Each of the above-mentioned asphalt damping material and each restraint material has a width of 20
mm, 250 mm in length, placed on a steel plate with a corrugated shape shown in Fig. 4 and a wave height of 7.8 mm so as to be orthogonal to the direction of the wave and placed in an oven at 150 ° C for 30 minutes. A heating test was performed at 4 to observe the conformability to uneven shapes. The results are shown in Table 2. However, in the judgment, those that were in close contact with each other without a gap were rated as “◯”, those that were slightly left but could not cause any problems in use were rated as “△”, and those that remained with a gap and remained a problem in use were rated as “x”.

III. Test structure and performance Table 2 shows the configurations and test results of the examples of the present invention and comparative examples.

As can be seen from the above test results, the structure of the present invention is excellent in vibration damping characteristics and also has good conformability to unevenness on the vibration substrate by being melted by heating, and can also improve rigidity. It has superior characteristics to the vehicle vibration control structure.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vehicle structure according to the present invention before heat treatment, FIG. 2 is a cross-sectional view of the same after heat treatment, and FIG. FIG. 4 (a) and FIG. 4 (b) are a front view and a side view, respectively, of a steel plate used in the follow-up test when a sheet is used and after heating. (1) …… Spacer layer, (2) …… Vibration damping sheet, (3) …… Vibration substrate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takamitsu Mikuni 1-2-1, Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Zeon Corporation R & D Center (72) Yutaka Kagoshima Yakou, Kawasaki-ku, Kawasaki-shi, Kanagawa 1-2-1 Research & Development Center, Nippon Zeon Co., Ltd. (72) Inventor Noboru Hino 1-2-1 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa (72) Research & Development Center, Nippon Zeon Co., Ltd. (72) Inventor Hirukawa Adult Tokyo Zeon Kasei Co., Ltd. 1-10-7 Hatchobori, Chuo-ku, Tokyo

Claims (3)

[Claims] 1. A foamable thermosetting resin sheet to be laminated on a vibration substrate in a vehicle, which contains an epoxy resin, a vinyl chloride resin, a plasticizer, and a foaming agent, and is epoxy based on 100 parts by weight of the vinyl chloride resin. A resin is 20 to 500 parts by weight, and a spacer layer (1) in which a vinyl chloride resin is in a semi-gelled state, and a vibration damping sheet (2) laminated on the spacer are used. A vehicle structure characterized in that a contact surface of a vibrating substrate is integrally fused by heating and a spacer layer is foamed. 2. The vehicle structure according to claim 1, wherein the damping sheet (2) is made of an asphalt damping material. 3. The vehicle structure according to claim 1, wherein the vibration damping sheet (2) is made of a foamable asphalt vibration damping material.