JPH069865B2 - Construction method of heat restoration sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a construction method for filling a soundproof material sheet or a heat insulating material sheet into a void of, for example, an automobile body or a building material panel.

[Conventional technology]

In a body or building material panel of an automobile, for example, as shown in FIG. 2, an outer shell is assembled with two steel materials 1a and 1b such as iron plates or stainless steel plates, and polyurethane foam, felt, glass fiber, etc. A soundproof material 2 made of a sheet is inserted to improve sound absorption and sound insulation and further improve heat insulation.

[Problems to be solved by the invention]

By the way, since the weight reduction of the car body has recently been particularly emphasized, the steel material 1a to which the soundproof material 2 should be charged,
The gap between 1b is also getting narrower to about a few mm. As a result, it becomes difficult to fill and install the soundproofing material 2 in such a narrow space, and there is a problem in that workability is lowered and productivity is lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a construction method capable of easily inserting and filling a soundproof material sheet or a heat insulating material sheet even in a narrow space.

[Means for solving problems]

The method for applying a heat-restorable sheet according to the present invention is to impregnate a flexible polyurethane foam sheet with a mixed solution obtained by mixing 5 to 55 parts by weight (solid content) of a thermoplastic resin emulsion with 100 parts by weight (solid content) of asphalt emulsion. The heat-resilient sheet that has been dried and then compressed at a temperature of 30 ° C. or lower and is kept in a compressed state has a thickness smaller than that of the internal void of the outer shell made of a plate material such as a steel plate. After being inserted into the space, it is heated and expanded to fill the space.

As the asphalt emulsion in the present invention, those obtained by a known emulsification technique such as mechanically stirring and dispersing asphalt in water using a cationic or anionic surfactant may be used. In this case, the asphalt may be either natural asphalt, or straight asphalt obtained as a residue obtained by distilling asphalt base crude oil, or blown asphalt which has been subjected to chemical polymerization by feeding heated air into the asphalt. The one with a low penetration is preferable.

The thermoplastic resin emulsion according to the present invention includes E
VA resin emulsion (ethylene / vinyl acetate copolymer resin emulsion), polyethylene resin emulsion,
Vinyl acetate resin emulsion, nylon resin emulsion and the like can be used. In the present invention, a flexible polyurethane foam is impregnated with a mixed emulsion obtained by adding and mixing the thermoplastic resin emulsion to the asphalt emulsion, and the mixing ratio of both emulsions is 100 parts by weight of the solid content of the asphalt emulsion. The solid content is in the range of 5 to 55 parts by weight. The reason for this limitation will be described in the section of the operation described later. The preferable mixing amount of these thermoplastic resin emulsions is 7.0 to 30 parts by weight with respect to 100 parts by weight of the asphalt emulsion.

The impregnated amount of the above mixed emulsion may be appropriately increased or decreased depending on the use, but it is generally in the range of 300 to 1500% by weight in terms of solid content of the mixed emulsion.

In the present invention, the compressibility of the flexible polyurethane foam impregnated with the mixed emulsion is 50% of the original thickness.
Approximately 90%.

[Work]

In the present invention, a soft urethane foam is impregnated with a mixed emulsion of an asphalt emulsion and a thermoplastic resin emulsion and dried to obtain a urethane foam in which particles of the asphalt and the thermoplastic resin are attached to the inner wall surfaces of the open cells of the urethane foam. can get.
In this impregnated urethane foam, the elasticity and restoring force are partially lost due to the asphalt and thermoplastic resin particles contained in the cells.

Therefore, as shown in FIG. 1 (A), when the impregnated urethane foam 10 is cold-pressed by a press machine kept at a temperature of 30 ° C. or less, the impregnated urethane foam partially loses its restoring force. The foam 10 is fixed in a state of being thinly compressed as shown in FIG. 3B due to the caking property of the asphalt and the particles of the thermoplastic resin contained inside.

The sheet 11 obtained by compression as described above has a small volume and is therefore easy to carry, and at normal temperature, it loses the resilience peculiar to urethane foam, but when heated, It becomes a heat-restorable sheet with the property of restoring the original thickness.

In this case, the asphalt and the thermoplastic resin act synergistically with each other to suppress the resilience of the urethane foam. Therefore, the solid content of the thermoplastic resin emulsion in the mixed emulsion is 1% of the solid content of the asphalt.
When the amount is less than 5 parts by weight with respect to 00 parts by weight, the recoverability is good even at a relatively low temperature (40 ° C. to 60 ° C.), and the product is restored at the time of high temperature inventory storage and transportation. On the other hand, if the amount is more than 55 parts by weight, the characteristics of the asphalt particles such as sound absorbing property, sound insulating property and heat insulating property become small. It is for this reason that the mixing ratio of the asphalt emulsion and the thermoplastic resin emulsion is limited as described above in the present invention.

Next, as shown in FIG. 1 (C), two steel materials 1a and 1b are used.
The heat-restorable sheet 11 having a thickness smaller than that of the void is inserted into the internal void of the outer shell assembled in (1). This work is remarkably easy as compared with the conventional case of inserting and filling a sheet that is substantially the same as or slightly thicker than the void, and the workability can be improved. Then, when the inserted heat-restorable sheet 11 is heated, the sheet 11 expands and fills the internal voids of the outer shell as shown in FIG. It will be installed in a state in which it can exert an effect. The heating temperature for this purpose is about 100 to 150 ° C. when the time for restoration is taken into consideration.

It should be noted that in the case of an automobile body, painting and baking steps are carried out after inserting and filling the soundproofing material, so that the inserted heat-restorable sheet 11 is sufficiently heated in these steps.
Therefore, it is not necessary to take special heating means when applying the heat-restorable sheet produced by the present invention.

〔Example〕

 Examples of the present invention will be described below.

A flexible polyurethane foam sheet having a specific gravity of 0.016 and a thickness of 5 mm and having open cells was impregnated with a mixed solution of an asphalt emulsion and an ethylene / vinyl acetate copolymer resin in a ratio of 100: 15 by a dipping method. The impregnated amount was adjusted by a roll to be 800 parts by weight with respect to 100 parts by weight of the urethane foam.

Then, after heating and drying, cold pressing was performed with a pressing machine kept at a temperature of 25 ° C. to a thickness of 2 mm. The obtained sheet maintained a thickness of 2 mm at room temperature.

Next, the 2 mm thick heat-restorable sheet thus obtained is
As shown in FIG. 1 (C), it was inserted and filled into the internal space (thickness: 4 mm) of the outer shell assembled from the two steel materials 1a and 1b. Then, the two steel materials 1a and 1b were both left in an oven maintained at 150 ° C. to heat the heat-restorable sheet 11 inserted therein. As shown in FIG. It expanded and filled the inner voids of the outer shell.

[Effects of the Invention] As described in detail above, according to the present invention, a heat-restorable sheet having properties suitable for a soundproofing material and a heat insulating material can be easily filled and installed even in a narrow space. It is possible to obtain various effects.

[Brief description of drawings]

1 (A) to 1 (D) are cross-sectional views for explaining a method for applying a heat-restorable sheet according to the present invention, and FIG. Is. 1a, 1b ... Steel plate, 10 ... Impregnated urethane foam, 11
… Heat recovery sheet

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Claims (1)

[Claims] 1. A thermoplastic resin emulsion 5 to 55 relative to 100 parts by weight (solid content) of an asphalt emulsion.
A soft polyurethane foam sheet is impregnated with a mixed solution in which 1 part by weight (solid content) is mixed, dried, and further compressed at a temperature of 30 ° C. or less to retain a compressed state in a heat-resilient sheet, such as a steel plate. A method for constructing a heat-restorable sheet, which comprises inserting the outer shell formed of the plate material into an inner void with a thickness thinner than the void, and then thermally expanding the void to fill the void.