JPH0473139A - Laminated structure for vehicle - Google Patents

Abstract

PURPOSE:To obtain excellent damping function and high rigidity by integrally welding a lower layer sheet composed of a foamable thermosetting resin sheet, an intermediate sheet composed of a damping sheet, a restricting material sheet and a vibration substrate by heating and foaming the lower layer sheet. CONSTITUTION:A laminated structure for a vehicle is formed by laminating a lower layer sheet 1 to a vibration substrate 4 and laminating an intermediate sheet 2 to the lower layer sheet 1 and laminating a restricting material sheet 3 to the intermediate sheet 2. The restricting material sheet 3 contains a stickiness imparting resin and the intermediate sheet 2 is composed of an asphalt type damping material. The lower layer sheet 1 contains a vinyl chloride resin, an epoxy resin, a plasticizer, an epoxy resin curing agent and a foaming agent and the amount of the epoxy resin is 20 - 500pts.wt. per 100pts.wt. of the vinyl chloride resin and the vinyl chloride resin is in a semi-gelled state. When the structure is prepared, the lower layer sheet, the intermediate sheet and the restricting material sheet are individually placed on the vibration substrate of the vehicle and mutually welded and foamed by heating in a painting and drying process so as to follow the unevenness of the vibration substrate at the same time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a vehicle control system that is integrated by heat fusion molding onto a substrate that easily vibrates, such as a floor panel, tack panel, door panel, or ceiling panel of a vehicle. This relates to vibration and high rigidity structures.

[Conventional technology] Heat-adhesive damping materials containing asphalt as a main component are often used on vibration base material surfaces such as vehicle floor panels, dash panels, door panels, and wheel houses. .

In addition, in recent years, restraint-type vibration damping has been developed by providing metal sheets such as steel plates and aluminum plates as restraining materials on the top surface of asphalt-based vibration damping materials, or by laminating thermosetting resins such as epoxy resins, diallyl phthalate resins, and acrylic resins. Efforts are also being made to improve the vibration damping performance and rigidity of the structure.

Furthermore, recently, attempts have been made to particularly improve the damping performance by foaming a damping material whose main component is asphalt.

[Problems to be Solved by the Invention] However, these vibration damping structures have the following problems. In other words, in a double-layer damping structure in which the vibration of a vibrating base material is damped using only a heat-adhesive damping sheet mainly composed of asphalt, the thickness must be increased in order to improve its damping performance. However, this increases the weight of the vehicle and hardly improves the rigidity of the structure.

In addition, technology has recently begun to be used to suppress the weight increase by making the asphalt-based vibration damping material foamable, but the improvement in loss coefficient is not large within a practical range.

In addition, in the case of a sandwich-type damping structure in which a steel plate, aluminum plate, etc. is laminated on the top surface of an asphalt-based thermally adhesive damping sheet, the vibration damping performance as a structure is improved, but a highly rigid metal is used as a restraining layer. In order to adhere the plate to the heat-adhesive damping sheet, it is necessary to fix it mechanically to a highly rigid vibration base material such as a steel plate, or by screwing it with bolts, etc. There is. However, since the floorboards of vehicles are generally press-formed into an uneven shape for the purpose of imparting rigidity, it is necessary to form the restraining metal plate into a complementary shape, which requires an extra process. Another problem is that it is not easy to correctly position the device at a predetermined position during installation.

In addition, there is a method in which uncured thermosetting resin is placed on a damping material and cured during the drying process of painting to be used as a restraining material, and a method in which a thermoplastic resin with a base agent such as tackifier resin is used as a damping material. Another method is to use it as a restraining material by placing it on a material and heat-sealing it during the coating drying process.

Although the method of using these hard resin materials as a restraining material is certainly effective in improving the loss coefficient and rigidity, it is still difficult to use from the viewpoint of reducing noise inside a car. The current situation is that the range of improvement in loss coefficient and rigidity when using a resin restraining material is insufficient within a practical range.

[Means for Solving the Problems] The present invention improves these problems and includes a lower layer sheet (1) made of a foamable thermosetting resin sheet laminated on a vibration substrate in a vehicle, and a lower layer sheet (1) made of a foamable thermosetting resin sheet, Intermediate sheet (2) consisting of a damping sheet laminated on sheet (1)
and a restraining material sheet laminated on the intermediate sheet (
3), the contact surfaces of these sheets and the vibrating substrate are integrally fused by heating, and the lower sheet (1) is foamed.

Further, the present invention provides a vehicle panel that can provide an excellent loss coefficient with a small increase in weight and dramatically improve rigidity by integrally fusing the structure with a vibration board of a vehicle. It provides:

Furthermore, as a panel structure for this type of vehicle, it is necessary to adhere to the uneven vibrating substrate by heat treatment during the drying process such as painting, and to complete the reaction 9 foaming, fusing, etc. of each layer. A material that exhibits less deterioration in physical properties even at relatively high temperatures is required as a desirable property, and the structure related to the invention exactly meets these requirements.

The laminated structure for a vehicle according to the present invention is schematically illustrated as follows:
Figure 1 is a cross-sectional view before heat fusion and foaming, in which the lower layer sheet (1) is laminated on the vibrating substrate (4), the intermediate sheet (2) is laminated on the lower layer sheet (1), and the intermediate sheet (
2) A restraining material sheet (3) is laminated on top.

FIG. 2 shows a state in which the vibrating substrate and the contact surfaces of each sheet are integrally fused by heating, and the lower sheet is foamed.

Further, FIG. 3 shows a state in which the intermediate sheet r (2) using a foamable damping sheet is also foamed by heating.

Each constituent layer related to the present invention will be explained below.

The lower layer sheet (1) used in the present invention has the function of a spacer.1. The preferred properties for a spacer for vehicle applications are that it is lightweight, has high rigidity, has little physical property deterioration due to temperature changes, can be tightly attached and fixed to the uneven vibrating substrate during the paint drying process, and has a high-magnification foaming effect during this process. It is. From this point of view, foamable thermosetting resin sheets are suitable for the purpose, among them vinyl chloride resin, epoxy resin, epoxy resin curing agent,
A composition containing a plasticizer and a foaming agent and containing a vinyl chloride resin in a semi-gelled state (hereinafter referred to as an epoxy foam composition) has excellent shape retention in a sheet state, storage stability, and ability to be applied to a vertically vibrating substrate. Excellent in terms of adhesion, etc.

Here, when vinyl chloride resin is in a semi-gelled state,
It is assumed that the epoxy resin has not undergone a curing reaction, and only the vinyl chloride resin is in a state where the plasticizer has penetrated into the inside and gelation has begun.

The epoxy resin foaming composition that spreads over this lower layer sheet is a composition consisting of a cell regulator, a filler, a viscosity regulator, a heat stabilizer, a pigment, etc. as other optional components, and is prepared in advance at a temperature below the decomposition temperature of the foaming agent. In the next heating process, for example, the coating drying process,
It foams at ~200°C and can be cured by crosslinking with an epoxy resin.

Vinyl chloride resins include not only vinyl chloride homopolymers, but also vinyl chloride, vinyl acetate, acrylic acid, methacrylic acid, acrylic esters, methacrylic esters,
maleic acid, fumaric acid.

Maleic acid ester, phthalic acid ester, itaconic acid,
Known copolymers with vinylidecychloride, vinyl ether, etc. can be used alone or in combination. Vinyl chloride polymers (including copolymers) can be produced by any known method such as emulsion polymerization or suspension polymerization, but in particular, vinyl chloride polymers produced by emulsion polymerization or fine suspension polymerization for pastes can be used. It is preferable to use these materials alone or in combination with those obtained by suspension polymerization from the viewpoint of ease of sheet formation and cell structure during foaming.

Examples of plasticizers include phthalic acid esters such as dioctyl phthalate and cyphthyl phthalate, phosphoric acid esters such as tribrezyl phosphate, fatty acid esters such as cyctyl adipate and dioctyl sebacate, and condensates of adipic acid and ethylene glycol. Known plasticizers for vinyl chloride, such as polyesters such as, trimellitic acid esters such as trioctyl trimellitate, chlorinated paraffins, and alkylbenzene high molecular weight aromatics, can be used alone or in combination. The amount of the plasticizer to be blended is not particularly limited, but it is preferably blended in a range of more than 10 parts by weight and not more than 150 parts by weight per 100 parts by weight of vinyl chloride.

If the blending amount is less than 10 parts by weight, the foaming ratio will not improve and 1
If it exceeds 50 parts by weight, the hardness will not increase and the reinforcing effect will be reduced.

As the foaming agent, a high temperature decomposition type organic or inorganic foaming agent, high temperature expansion type microcapsules, etc. are used.

Examples of the organic blowing agent that can be used include asocyclocarbonamide, valatoluenesulfonylhydracinte, dinitrosopentamethinetetracin, and 4,4'-oxyhishecyzenesulfonylhydracinth.

The decomposition temperature of the organic blowing agent can be arbitrarily adjusted using urea, a zinc compound, a lead compound, or the like. Examples of inorganic blowing agents include sodium bicarbonate and sodium borate hydride. As high-temperature expansion type microcapsules, low-boiling hydrocarbons encapsulated with dihahiniritene can be used. In the invention, any blowing agent can be applied, but especially blowing agents with a decomposition temperature of 10
An organic blowing agent having a temperature of 0° C. or higher is more preferable in terms of ease of forming into a sheet, appearance of the foam, uniformity of foaming, and denseness.

If the decomposition temperature is below 100°C, foaming may begin when forming into a sheet, the resin may not be sufficiently melted during foaming in a heating furnace, the foaming ratio may not increase when gas is removed, and it may be difficult to obtain a uniform foam. Inorganic foaming agents and microcapsules can also be used, but they have drawbacks in terms of expansion ratio and economic efficiency. The amount of the blowing agent to be blended is preferably 0.5 to 15 parts by weight per 100 parts by weight of the vinyl chloride resin.

If the amount is less than 0.5 parts by weight, foaming will be insufficient, and if it exceeds 15 parts by weight, the degree of foaming will not change, and adding too much is economically wasteful.

Examples of epoxy resins that can be applied to the present invention include ordinary glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and aliphatic epoxide type epoxy resins. They can be used alone or in combination depending on their physical properties. The blending amount of the epoxy resin is in the range of 20 to 500 parts by weight per 100 parts by weight of the vinyl chloride resin. When the amount is less than 20 parts by weight, it is difficult to obtain a hard foam, and when it exceeds 500 parts by weight, heat generation during curing is large, resulting in decomposition of vinyl chloride and suppressing expansion due to decomposed gas of the blowing agent. This causes problems such as difficulty in obtaining a foam with a high magnification.

As the heat-activated curing agent for epoxy resins, any ordinary curing agent that exhibits curing action when heated can be used. A preferred curing agent is one having an exothermic peak temperature in the range of 100°C to 200°C in combination with the epoxy resin. Examples of curing agents include dicyandiamide, 4,
4”-diaminodiphenylsulfone, imidazole derivatives such as 2-n-hephtadecyl imidazole, isophthalic acid dihydrazide, N,N-dialkyl urea derivatives,
Examples include N,N-dialkylthiourea derivatives, acid anhydrides such as tetrahydrophthalic anhydride, isophoronediamine, metaphenylenediamine, N-aminoethylpiperazine, boron trifluoride complex compounds, trisdimethylaminomethylphenol, and the like. Curing agents can be used alone or in combination as desired. The amount of the curing agent blended is preferably 1 to 20 parts by weight per 100 parts by weight of the epoxy resin.

If the amount is less than 1 part by weight, curing will be insufficient and the rigidity of the foam will be insufficient.On the other hand, if more than 20 parts by weight is added, the rigidity of the foam will not change, and adding too much is economically wasteful.

The curing temperature in the term "curing temperature" refers to the temperature of the medium at which the heat generated by curing acts as a heater when a mixture of epoxy resin and curing agent is heated at room temperature using an oil bath, heater, etc.

A preferred combination and amount of epoxy resin and curing agent depending on the heating conditions can be easily determined by testing in advance.

In the present invention, in addition to these essential ingredients, fillers such as calcium carbonate, talc, and clay, heat stabilizers,
Foam regulators, colorants, etc. can be added. The blending amounts of each of the above ingredients are 0 to 200 parts by weight of the filler, 0 to 10 parts by weight of the heat stabilizer, and 0 to 10 parts by weight of the bubble regulator, per 100 parts by weight of the vinyl chloride resin. . When blending each compounding agent, if the amount of filler exceeds 200 parts by weight, the fineness of foaming will be lost or the expansion ratio will not increase, and if the amount of filler exceeds 10 parts by weight, the foaming ratio will not increase. It's not effective.

The foamable resin composition applied to the present invention includes a vinyl chloride resin, a plasticizer, a blowing agent, an epoxy resin, a curing agent for epoxy resin, and, if necessary, a cell regulator, a filler, a heat stabilizer, and a coloring agent. The mixture is homogenized and adjusted using a commonly known kneading machine.

The expansion ratio of such a lower layer sheet is 2 to 30 times, preferably about 5 to 10 times. Those with a foaming ratio of 2@ or less can of course function as a spacer, but from the viewpoint of lightness, heat insulation, etc., this is not the purpose of the present invention.
If the foaming ratio is greater than 30@, the strength of the foamed cells will be insufficient and there may be problems with durability depending on the parts of the vehicle used.

Moreover, the thickness of such a spacer sheet after foaming is 1 to 5.
0 mm, preferably 3 to 30 mm. If it is less than 1mm, it can function effectively as a spacer.5
If it is 0 mm or more, in the vehicle application which is the object of the present invention, the interior space of the vehicle becomes narrow and it becomes impractical, and homogeneous foaming properties cannot be obtained in the heating process such as the paint drying process.

The intermediate sheet (2) provided in the present invention functions as a vibration damping sheet, and may be made of rubber-based, resin-based, asphalt-based, etc., but is not particularly limited in type; h(3), any material may be used as long as it satisfies the performance requirements for vehicle use, such as adhesion (thermal adhesion) with the lower layer sheet b(1) and followability to the uneven vibration substrate due to heating.

Asphalt-based vibration damping materials and foamed asphalt-based vibration damping materials are excellently suited for this purpose in view of satisfying such required performance and in terms of damping performance, cost, etc.

The thickness of such an intermediate sheet is preferably 10 mm or less. 1
If the diameter is 0 mm or more, the weight becomes extremely large, and this is not the gist of the present invention. Further, there is no particular lower limit to the thickness. This is because, since the structure of the present invention is a constrained vibration damping structure, the intermediate seam i is thin (although it can sufficiently exhibit its function).

The upper layer sheet (3) applied to the present invention is a restraining material for restraining deformation due to vibration of the vibration damping sheet, which is the intermediate seam b, and imparting a large loss factor to the structure by applying shear deformation to the intermediate sheet. It is.

The material used for this restraining material sheet is also an intermediate sheet.

Adhesion (thermal adhesion) with the intermediate sheet as well as the lower layer sheet,
It is desirable that the elastic modulus is as high as possible, which satisfies the requirement of followability to the uneven vibration substrate due to heating.

Desirable materials that meet these conditions include rosin resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, alkyl phenolic resins, xylene resins, coumaron intene resins, etc. Thermoplastic resin sheets and thermosetting plastic sheets containing tackifiers are suitable.

For thermoplastic resin sheets containing tackifier resin, there is Japanese Patent Application No. 1-16398, and for thermosetting plastic sheets, there are combs such as tutadiene comb and styrene-butadiene rubber made of hese polymers. be.

In particular, thermoplastic resin sheets containing a tackifier resin are used depending on the type and content of the tackifier resin, depending on the usage condition of the vehicle.
It has a relatively high elastic modulus in a temperature range of about 60℃,
The structure according to the present invention is particularly useful because it becomes a low-viscosity molten material in the temperature range of about 120 to 160°C, which is the temperature of the vehicle painting process, and it is easy to design the material so that it can follow complex uneven shapes. It is suitable for use in restraining material sheets, and since it does not contain any reactants, it is easy to handle from the viewpoint of storage stability.

The thickness of the restraining material sheet is not particularly limited, but from the same viewpoint as the lower layer and intermediate sheet, the thickness of the sheet formed on the floor panel of a vehicle is usually 0.5 to 3 mm. A certain range is sufficient.

To manufacture such a structure according to the present invention, each layer of a lower sheet, an intermediate sheet, and a restraining material sheet is individually placed on a vibrating substrate of a vehicle, and the vibrating substrate, lower sheet, and intermediate sheet are heated in a coating drying process, etc. The sheet and the restraining material sheet may be fused and foamed to each other and simultaneously made to follow the irregularities of the vibration board, or the three sheets of the lower layer sheet, the intermediate sheet, and the restraining material sheet may be laminated in advance and then painted and dried. Fusion to the vibrating substrate, foaming, etc. may be performed in the process. Also,
Of course, combinations of the upper layer sheet and the intermediate sheet, or the lower layer sheet and the intermediate sheet may also be used.

[Effects of the Invention] As explained above, the laminated structure for a vehicle according to the present invention is placed on a vibrating substrate such as a floor panel or a dance panel of a vehicle, and is heated to form a lower layer seam or as needed. In addition to foaming the intermediate sheet, a force λ can be applied to firmly define the space between each layer and the vibrating substrate and to follow the uneven shape of the vibrating substrate.

The structure obtained in this way has a constrained vibration damping structure in which a spacer with little temperature change is added to the lower layer, so it not only exhibits an excellent vibration damping function over a wide temperature range. This structure also has high rigidity, and is not only suitable as a material for reducing noise inside a vehicle, but also provides a solid feeling to the vehicle panel and has excellent heat insulation properties.

[Examples] The present invention will be explained below using Examples and Comparative Examples. The materials and test methods used in the test are as follows.

■Test material■ Vibrating substrate: 0.8 mm thick steel plate■ Foamable thermosetting resin sheet (lower layer sheet) A foamable thermosetting resin composition was mixed in a Hobart mixer at the mixing ratio shown in Table 1 for 20 minutes. After preparing the film, it was coated on release paper to a predetermined thickness. This was heated at 120° C. for 90 seconds to create a sheet in which only the paste resin was semi-gelled.

The following margins ■ Vibration damping sheet (intermediate sheet) 1. Asphalt-based vibration damping sheet (trade name: Melsheet, manufactured by Nippon Tokushu Toyo Co., Ltd.), the thickness of which was adjusted in advance using a press.

It is shown in Table 4 as material type C.

2. Foaming asphalt-based vibration damping sheet (trade name Melsheet, manufactured by Nippon Tokushu Toyo Co., Ltd.) Table 4 shows the types of materials.

■ Restraint material sheet (upper layer sheet) A thermoplastic composition having the compounding ratio shown in Table 2 is melted and mixed in an autoclave heated to 200°C, and the resulting mixture is adjusted to a predetermined thickness using a hot press. did.

Further, the thermosetting plastic sheet (F) was prepared by kneading a thermosetting resin composition having the compounding ratio shown in Table 3 using a roll and forming it into a sheet with a predetermined thickness.

Below is the margin (1)
, Test method (vibration damping performance test) A vibration damping structure was created by combining each spacer layer, damping sheet layer, and restraint sheet layer with a steel plate (L50 x 300 mm, 0.8 mm thick) (thickness 0, 8 mm). Then, the loss coefficient of each structure was measured at 20°C, 40°C, and 60°C. For bonding 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 at 150° C. for 30 minutes to fuse and foam each layer.

The loss coefficient was calculated from the half-width from the resonance point of the mechanical impedance, and the loss coefficient of 200)1z was determined by interpolation. Note that the measurement frequency range is 1 to 1000 Hz.

In addition, the stiffness ratio was calculated based on the following formula.

Rigidity ratio - (fo/f) 2. ((m, *m 7m1)
Here, fo is the resonant frequency when damping material and restraint material are attached, f is the resonant frequency of the 0.8 mm thick steel plate serving as the vibration substrate, and ml is the mass per unit area of the steel plate.

m2 is the mass per unit area of the damping material and the restraining material combined.

(2) Test structures and performance Table 4 shows the structures and test results of the inventive examples and comparative examples.

As can be seen from the test results below with a margin of 4° or more, the structure of the present invention has excellent vibration damping properties and rigidity, and is superior in suitability to conventional structures for vehicles.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a laminated structure for a vehicle according to the present invention before heat treatment, FIG. 2 is a sectional view of the same after heat treatment, and FIG.
The figure is a sectional view after heat treatment when a foamable asphalt-based vibration damping sheet is used as the vibration damping sheet (2). (1)...Lower sheet. (2)...Intermediate sheet. (3)...Restraint material sheet. (4)... Vibration board. Patent applicant: Nippon Zeon Co., Ltd. Zeon Kasei Co., Ltd.

Claims (1)

[Claims] 1. A lower layer sheet (1) made of a foamable thermosetting resin sheet laminated on a vibration substrate in a vehicle, and an intermediate layer made of a vibration damping sheet laminated on the lower layer sheet (1). Consisting of a sheet (2) and a restraining material sheet (3) laminated on the intermediate sheet, the contact surfaces of these sheets and the vibration substrate are fused together by heating, and the lower sheet (1) is A laminated structure for vehicles characterized by foaming. 2. The lower sheet (1) contains a vinyl chloride resin, an epoxy resin, a plasticizer, an epoxy resin curing agent, and a foaming agent, and the epoxy resin is 20 to 500 parts by weight per 100 parts by weight of the vinyl chloride resin; The laminated structure for a vehicle according to claim 1, wherein the vinyl chloride resin is in a semi-gelled state. 3. The laminated structure for a vehicle according to claim 1, wherein the intermediate sheet (2) is made of an asphalt-based damping material. 4. The laminated structure for a vehicle according to claim 1, wherein the intermediate sheet (2) is made of a foamable asphalt-based vibration damping material. 5. The laminated structure for a vehicle according to claim 1, wherein the restraining material sheet (3) is a restraining material sheet containing a tackifier resin. 6. The laminated structure for a vehicle according to claim 1, wherein the restraining material sheet (3) is made of a thermosetting plastic sheet.