JP2002079955A - Gap filler and gap filler fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gap filler hardly drooping in the step of heating and foaming, and to arrange simply the gap filler in an internal space such as a pillar of an automobile or the like. SOLUTION: In embodiment samples 1-3, a board-like gap filler B is formed by mixing a polymer, an inorganic filler, a crosslinking agent and a foaming agent respectively so that the weight of the whole composition becomes 100 g. As the polymer, a polyolefin of MI(melt index): 0.2, an EVA(ethylene vinyl acetate copolymer) of MI: 1.5, and an EPM (ethylene propylene rubber) of MI: 3.5 are used respectively in each embodiment sample 1-3. The formed gap filler B is placed on a nylon board N, and heated at 180 deg.C for 20 minutes and foamed. As a result, excellently foaming fluidity at the baking time is obtained in the case where the value of the MI is in the range of 0.2-3.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gap filling material for filling gaps by heating and foaming.

[0002]

2. Description of the Related Art Conventionally, a gap filling material which improves sound insulation and vibration damping characteristics by filling an internal space of a filling object such as a pillar of an automobile has been widely known. The mainstream of this kind of void filler is a thermosetting foamable material which comprises at least a polymer such as a resin, a foaming agent, and a crosslinking agent, and when heated, hardens after foaming.

[0003] As such a gap filling material, for example, a material whose outside shape is formed into a plate shape as shown in FIG. 4A (a gap filling material 200) is known. The gap filling material 200 is applied to the inner wall of the pillar 300 by the adhesive 21.
It is fixed by 0 or the like, and when heated from outside the pillar 300, it is filled so as to fill the internal space of the pillar 300 by foaming.

[0004]

However, the inventors of the present invention have made various studies and found that some of the void fillers have a remarkably low viscosity in the initial stage of foaming, so that the void fillers hang down below the pillars. It turned out that there was something that was deformed.

[0005] In such a case, the internal space of the pillar may not be completely filled, and as a result, the sound insulation / damping characteristics may not be sufficiently secured. Also,
In particular, in the latter case, in order to fill the internal space of the pillar, it is sufficient to use a large amount of the void filler in consideration of the amount of the filler that hangs down. However, as shown in the right figure of FIG. 4 (a), there is a problem that unnecessary portions increase, which is one of the causes of increasing the manufacturing cost including the void filler.

On the other hand, as shown in FIG. 4 (b), in order to slightly reduce the drooping downward inside the pillar, each pillar 300 has a shape along the cross-sectional shape of the pillar 300 and has a predetermined interval. Two restraining plates 220 fixed with a gap
It is also conceivable to arrange the gap filling material 200 and then fix the constraint plate 220 to the side wall of the pillar 300 in the internal space.

However, such a constraining plate 220 is unnecessary after the interior of the pillar 300 is filled, and the use of the constraining plate 220 increases the cost. When the restraint plate 220 is arranged inside the pillar 300,
When vibration is applied from the outside of the pillar 300 or the like, the restraint plate 220 resonates, and there is a possibility that sufficient sound insulation / damping characteristics may not be obtained.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a gap filling material that is less likely to sag downward at the stage of heating and foaming as compared with the related art. It is another object of the present invention to achieve the above object and to easily arrange the gap filling material in an internal space of an object to be filled such as a pillar of an automobile.

[0009]

Means for Solving the Problems and Effects of the Invention The invention according to claim 1, which has been made to achieve the above object, comprises at least a polymer, a foaming agent, and a cross-linking agent. A void filling material configured to fill the internal space by being foamed by heating and increasing in volume after being placed, wherein the polymer has an MI (melt index) of 0.2 ≦ 0.2 It is characterized in that a material in the range of MI ≦ 3.5 is used.

Here, examples of the polymer include a thermoplastic resin.
Polyolefin, EVA (ethylene vinyl acetate copolymer), EPM (ethylene propylene rubber), S
BS (styrene butadiene styrene block copolymer) and the like.

Further, MI is such a polymer,
The number of grams extruded in 10 minutes from an orifice having a diameter of 2.1 mm and a length of 8 mm when subjected to a force of 2160 g at a temperature of 190 ° C. In the void filler according to the present invention (claim 1), the polymer as a constituent member is
MI was defined so that 0.2 ≦ MI ≦ 3.5. This is a value obtained as a result of various experiments including an experiment described in Examples described later. When the value is in the range of 0.2 ≦ MI ≦ 3.5, the gap filling material is heated to When filling the internal space, at the stage of foaming and curing, the internal space is reliably filled without causing a decrease in viscosity so that the void filler itself drips down inside the object to be filled. It becomes possible.

[0012] Further, since all the void fillers can be filled so as to efficiently shield the internal space of the object to be filled,
Since the useless portion does not exist, the cost can be reduced as compared with the related art. If the MI is smaller than 0.2, the viscosity in the foaming / curing stage does not sufficiently decrease,
If it is larger than 3.5, the viscosity in the foaming / curing stage becomes too low. For this reason, when the MI is smaller than 0.2 or larger than 3.5, foaming of the void filler due to foaming becomes insufficient in any case, and the internal space of the filling object as described above is filled. You will not be able to do it. On the other hand, if the MI is larger than 3.5, the viscosity becomes too low to increase the fluidity, and as a result, there is a risk of dropping before curing.

According to various experiments carried out by the present inventors,
It was found that when the MI was 1.5, the viscosity was optimum for foaming, and that the highest expansion ratio was exhibited. Here, the expansion ratio is a value obtained by dividing the volume after foaming (in other words, the volume after foaming and curing) by the volume before foaming.

In order to fill the internal space of the object to be filled with such a space filling material, as shown in FIGS. 4A and 4B, the space filling material is provided on the inner wall of the object to be filled. May be arranged and heated, but may be arranged as described in claim 2.

That is, the present invention (Claim 2) is a resin-made void filler fixing tool for arranging the void filler before heating in the internal space of the object to be filled, A base for attaching and holding the gap filling material around, a support leg protruding from the base, extending from a tip of the support leg, and opening outward toward the base. A check piece, the check piece is elastically deformed when inserted into a through hole formed in the side wall of the filling object, and is configured to engage with the opening periphery of the through hole. It is characterized by being.

That is, when the gap filling material fixing device of the present invention (claim 2) is used, when the gap filling material is arranged in the internal space of the filling object, for example, two steel plates are welded to each other. Before forming an object to be filled such as a pillar of an automobile, it is only necessary to insert and engage a check piece into a through hole formed in one of the steel plates on the inner space side of the object to be filled. , The task is extremely simple. Then, if heating is performed thereafter, the internal space of the object to be filled can be reliably filled.

Here, as a material for forming the space filler fixing device, for example, a resin having high heat resistance and a light weight (for example, nylon 6, 6) can be used.

[0018]

Embodiments of the present invention (embodiments 1 to 3) will be described below. In addition, Examples 1 to
In No. 3, as will be described later, the composition is varied, and a void filler is formed so as to have a plate shape.
Comparative evaluation of fluidity (fluidity during baking) when the formed void filler was heated to a predetermined temperature was performed. The contents will be described below with reference to FIG. (Examples 1 to 3 and Comparative Examples 1 and 2) First, the contents of Examples 1 to 3 and Comparative Examples 1 and 2 will be described.

In Examples 1 to 3, a polymer, an inorganic filler, a cross-linking agent, and a foaming agent were mixed so that the total weight of the composition was 100 g, and as shown in the upper diagram in FIG. A plate-shaped void filler B having a width of 40 mm × a depth of 40 mm × a thickness of 2 mm was formed.

In each of the embodiments, the inorganic filler, the crosslinking agent, and the foaming agent were used in an amount of 36.0% by weight, 0.9% in the total composition.
wt% and 9.0 wt%, and the amount of the polymer was adjusted.
The blending amounts were adjusted so that the total composition was 54.1 wt%.

In Examples 1 to 3, polyolefin, EVA (ethylene vinyl acetate copolymer), and EPM (ethylene propylene rubber) were used as the polymers. The MI (melt index) of each polymer was determined in Example 1 (polyolefin):
0.2, Example 2 (EVA): 1.5, Example 3 (EP
M): The one that resulted in 3.5 was used.

On the other hand, as the inorganic filler, the crosslinking agent and the foaming agent, calcium carbonate, a well-known peroxide and azodicarbonamide were used in each of the examples. Among them, as the inorganic filler, besides calcium carbonate, barium sulfate, ferrite, silica and the like can be used.
Further, as the blowing agent, dinitropentamethylenetetramine and the like can be used in addition to azodicarbonamide.

The thus formed void filler B was placed on a nylon (nylon 6.6) plate N having a width of 10 mm, a depth of 40 mm and a thickness of 3 mm. At this time, the gap filling material B was placed so that the width direction thereof was along the longitudinal direction of the nylon plate N. Next, the void filler B in this state was heated at a temperature of 180 ° C. for 20 minutes to actually foam.

In this case, since the viscosity of the void filler B is reduced by heating, the void filler B flows to some extent. In each of the embodiments, the position of the lower surface in contact with the nylon plate N in the gap filler B is used as a reference, and after the flow (after heating), the reference position and one end in the longitudinal direction (FIG.
(B) Middle left end) By measuring the distance from the lower position, it was clarified how the fluidity (fluidity during baking) differs depending on the MI value of the polymer.

For comparison with Examples 1 to 3, the types and amounts of inorganic fillers, crosslinking agents, and foaming agents, and the shapes were exactly the same as in Examples 1 to 3, and the MI of the polymer was Comparative Examples 1 and 2 having the values of 0 and 6.0 were performed. In Comparative Example 1, SBS having a MI value of 0 was used as a polymer.
(Styrene butadiene styrene block copolymer), and in Comparative Example 2, EVA having a MI value of 6.0 was used. Further, in the same manner as in Examples 1 to 3, it was clarified how the fluidity during baking differs.

In Examples 1 to 3 and Comparative Examples 1 and 2,
The criteria for evaluating the fluidity during baking were specified as shown below. (Evaluation Criteria)…: When heated, fluidity to the extent that foaming proceeds quickly is obtained.

…: When heated, fluidity is obtained to such an extent that foaming does not proceed. Δ: When heated, the viscosity is not sufficiently reduced, and fluidity that makes foaming difficult is obtained.

X: When heated, the viscosity becomes too low, and fluidity is obtained in which the void filler B falls from the nylon plate N. As a result, as shown in FIG. 1A, in the case of Example 2 in which the MI value of the polymer was 1.5, the best fluidity for foaming (fluidity during baking) was obtained. Do you get it. Also, from the results of Comparative Example 1, it was found that when the value of MI of the polymer was 0, the viscosity did not decrease sufficiently, and as a result, foaming did not occur sufficiently.
Was 6.0, the viscosity was too low and the fluidity was high, and as a result, it was found that the particles dropped during foaming and curing.

As described above, from the results of Examples 1 to 3 and Comparative Examples 1 and 2, when the value of MI is in the range of 0.2 to 3.5 as the void filler, good results are obtained. It was found that fluidity for foaming (fluidity during baking) was obtained. In addition, it was found that especially when the value of MI was 1.5, the fluidity capable of foaming was obtained best.

Next, use examples 1 to 3 in which the internal spaces of various pillars of an automobile were actually filled with the gap filling material of the present invention.
Will be described based on FIG. 2 and FIG. (Usage Example 1) In this usage example, the gap filler 10 is disposed in the middle of the center pillar 102 of the automobile 100 shown in FIG. The gap filling material 10 is attached to the gap filling material fixing device 20 and arranged in the inner space of the center pillar 102 as shown in FIG. Have been. Further, the gap filling material 10 is formed with the same composition as in the case of the above-described second embodiment, and only the outer shape is different from that of the second embodiment.

The gap filling material fixing device 20 is provided with the gap filling material 10.
A rod-shaped base 22 for attaching and holding the surroundings,
It has a bar-shaped support leg 24 protruding from the base 22 and an umbrella-shaped check piece 26 extending from the tip of the support leg 24 and opening outward toward the base 22. Further, the entire space filler fixing device 20 is integrally formed of nylon 6 and 6, and has elasticity as a whole.

The base 22 is provided with a center pillar 102.
Is arranged in the space near the center of
Is mounted so as to cover the periphery of the base 22 so as to form a shape along the internal space shape of the center pillar 102 and to have a slightly plate shape as a whole.

On the other hand, the center pillar 102 is formed by welding both end portions of two steel plates to each other so as to form a cylindrical shape as a whole. A slit 104 is formed in the side wall of the center pillar 102 on the inner side of the vehicle 100. The check piece 26 of the gap filler fixing device 20 has both ends of the support leg 2.
In a state where it is elastically deformed so as to approach the fourth side, it is inserted through the slit 104 from the inside of the center pillar 102 to the outside.
Are supported in a state in which both end portions thereof are in contact with a side wall (outer wall) of the center pillar 102. Thus, the space filler fixing device 20 is supported by the center pillar 102.

Here, with respect to the center pillar 102,
In order to actually arrange the gap filling material fixing device 20 with the gap filling material 10 attached thereto, for example, the above-described slit 104 is formed in one steel plate (the steel plate 102a in the upper part in FIG. 2B) before welding. And the check piece 26 of the gap filling material fixing device 20 is inserted from the plate surface on the side corresponding to the inside of the center pillar 102, so that the gap filling material fixing device 20 is You only need to support it.

Next, the center pillar 102 is formed by welding the steel plate 102a in this state and the other steel plate 102b. The center pillar 102 thus formed includes:
As shown in FIG. 2B, the gap filler 10 is arranged in the internal space by the gap filler fixture 20.

After that (for example, after assembling the body of the automobile 100), by heating the body, the gap filling material 10 foams. In addition, the gap filling material 10 does not hang down below the center pillar 102, and is uniformly foamed from the portion near the center thereof in all directions, so that the space filling material 10 is hardened in a state where it is securely filled so as to cover the internal space. .

Further, the space filler 10 is provided on the center pillar 1.
In order to arrange the base 22 in the inner space of the center pillar 102, the base 22 may be arranged near the center of the center pillar 102. However, it is not necessary to arrange the base 22 so precisely, and the base 22 may be arranged at a position slightly eccentric from the center. It may be.

(Usage Example 2) In this usage example, the gap filling material 30 is disposed in the middle of the roof rail 106 of the automobile 100 shown in FIG. FIG. 3 is a cross-sectional view taken along the line YY shown in FIG.
As shown in (a), it is attached to the space filler fixing device 40 and is arranged in the internal space of the roof rail 106. Further, the gap filling material 30 is formed with the same composition as in the above-described second embodiment, and only the outer shape is different from that of the second embodiment.

As in the case of the gap filler fixing device 20 of Use Example 1, the gap filler fixing device 40 includes a rod-shaped base 42,
Although a bar-shaped support leg 44 and a check piece 46 are provided, the size (length) of the base 42 and the support leg 44 is different from that of the gap filler fixing device 20. Further, the base 42 is disposed in a space slightly lower right (lower right side in FIG. 3A) of the roof rail 106, and the gap filler 30 has a shape substantially conforming to the internal space shape of the roof rail 106. The cover 42 covers the periphery of the base 42 so as to form a plate, and is mounted so as to have a slightly plate shape as a whole.

On the other hand, the roof rail 106 is formed by welding both end portions of two steel plates to each other so as to form a cylindrical shape as a whole. A slit 108 similar to that drilled in the center pillar 102 is provided to support the (gap filler fixing device 40).

Here, in order to actually arrange the gap filling material fixing device 40 with the gap filling material 30 attached to the roof rail 106, it is necessary to fix the gap filling material fixing device 20 to the center pillar 102. Just follow the same procedure. By doing so, the roof rail 10
6, as shown in FIG.
0 places the void filler 30 in its interior space.

Then, when the vehicle body is heated (for example, after assembling the vehicle body of the automobile 100), the gap filling material 30 is uniformly foamed in all directions without dripping below the roof rail 106, and the internal space is reduced. It will cure completely in the filled state so as to cover it completely.

(Usage Example 3) In this usage example, the void filler 50 is arranged in the middle of the rear pillar 110 of the automobile 100 shown in FIG. This gap filling material 5
0 is a ZZ cross section shown in FIG.
As shown in (2), it is attached to the space filler fixing device 60 and is disposed in the internal space of the rear pillar 110. Further, the gap filler 50 is formed with the same composition as in the case of the above-described embodiment 2, and only the outer shape is the same as that of the embodiment 2.
It is different from the case.

The gap filler fixing device 60 is similar to the gap filler fixing devices 20 and 40 of the first and second use examples, and is similar to the base 62.
, A bar-shaped support leg 64, and a check piece 66. In the gap filler fixing device 60, two support legs 64 are provided at a distance from one base 62 at an interval. A check piece 66 is provided at one end (left side in FIG. 3B) of each support leg 64.

The base 62 is arranged in a space near the center of the rear pillar 110, and
Slightly narrow space in the interior space (upper in Fig. 3 (b))
Is formed so as to have a rod shape, and in a slightly wide place (the lower part in FIG. 3B) is formed as a plate shape.

Here, the present inventors have conducted various studies, and found that, for example, in an internal space having a rectangular cross-sectional shape such that the length of each of the vertical and horizontal sides exceeds 100 mm,
It has been found that if the base is formed in a plate shape, it is possible to hold a gap filler capable of sufficiently filling the internal space. In addition, when the length of the vertical and horizontal sides was 100 mm or less, it was found that if the base was formed in a rod shape, it would be possible to hold a sufficiently fillable void filler.

The gap filling material 50 is formed by the rear pillar 1
The base 62 is mounted so as to cover the periphery of the base 62 so as to substantially conform to the internal space shape of the base 10 and to have a slightly plate shape as a whole. On the other hand, the rear pillar 110 is formed by welding both ends of two steel plates to each other so as to form a cylindrical shape as a whole.
00, a center pillar 102 is provided on the inner side wall to support the check piece 66 (the gap filler fixing device 60).
And two slits 112 similar to those formed in the roof rail 106.

Here, the gap filler fixing device 6 with the gap filler 50 attached to the rear pillar 110 is used.
In order to actually arrange the space fillers 0, the same procedure as that in the case where the space filler fixing members 20 and 40 are fixed to the center pillar 102 and the roof rail 106 may be used. By doing so, the gap filler 50 is arranged in the inner space of the rear pillar 110 by the gap filler fixing device 60 as shown in FIG. 3B.

After that (for example, after assembling the body of the automobile 100), if the body is heated, it does not droop below the rear pillar 110, and the gap filling material 5
0 is uniformly foamed in all directions, and hardens in a filled state so as to completely cover the internal space.

As described above, each of the above use examples 1 to 3
By using the space filler fixing devices 20, 40, and 60 shown in (1), the space fillers 10, 30, and 5 can be easily provided in the internal space of each pillar.
0 can be arranged. Moreover, in order to attach the gap filler fixing members 20, 40, 60 to the pillars, for example, in a steel plate before welding, it is only necessary to insert the slit fillers 104, 108, 112 from the plate surface on the side corresponding to the inside. The task is very simple.

The present invention is not limited to the above-described embodiment and use examples, but may be modified as follows. Even in such a case, the same operation and effect as those of the above-described embodiments and use examples are obtained. be able to. For example, as shown in the above Examples 1 to 3, the polymer having the composition of the void filler is replaced by the M
By setting the numerical value of I (melt index) in the range of 0.2 to 3.5, fluidity (fluidity during baking) that can be favorably foamed can be obtained.

When forming the void filler, the compounding amount of the polymer is 40 to 95 wt%, the compounding amount of the crosslinking agent is 0.2 to 5.0 wt%, and the compounding amount of the foaming agent is as a whole composition. It has been found that when the content is 4.0 to 20.0 wt%, a fluidity capable of more excellent foaming can be obtained.

On the other hand, if the compounding amount of the foaming agent is less than 4.0 wt%, the formed void filler does not foam sufficiently, and as a result, it becomes impossible to fill the internal space of the pillar.
If the amount of the foaming agent is larger than 20.0 wt%, the foaming is easy to occur, but the calorific value of the void filler increases accordingly, and as a result, the crosslinking between the polymers (or between the molecules) is abrupt. And hardens during foaming, and the interior space of the pillar cannot be filled.

If the amount of the crosslinking agent is less than 0.2 wt%, a void-filling material having low heat resistance will be formed and will be damaged at the temperature during foaming. On the other hand, if the blending amount of the crosslinking agent is larger than 5.0 wt%, the viscosity at the time of foaming becomes high, so that the foam can be sufficiently foamed, and as a result, the internal space of the pillar cannot be filled.

In the above-mentioned use examples 1 to 3, the interior space of the pillar is filled with the gap filling material. However, the invention is not limited to this. You may make it comprise as what fills an internal space.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining evaluation contents of a void filler in Examples 1 to 3 and Comparative Examples 1 and 2.

FIG. 2 is an explanatory diagram for explaining usage example 1;

FIG. 3 is an explanatory diagram for explaining usage examples 2 and 3;

FIG. 4 is an explanatory diagram for explaining a conventional gap filling material.

[Explanation of symbols]

B, 10, 30, 50: gap filling material, 20, 40, 60
... Void filling material fixing device, 22, 42, 62 ... Base, 24,
44, 64 ... support legs, 26, 46, 66 ... check pieces, 10
2,110 ... pillar (object to be filled), 104,108,
112: slit (through hole); 106: roof rail (object to be filled).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D003 AA01 BB02 CA32 CA34 4J002 AA011 BB001 BB061 BB151 BP011 EK007 EQ016 ES006 FD147 FD326 GN00

Claims (2)

[Claims] 1. After being arranged in an internal space of an object to be filled, it is made of at least a polymer, a foaming agent, and a crosslinking agent, and then foamed by heating to increase the volume.
A void filling material configured to fill the internal space, wherein the polymer has an MI (melt index) in the range of 0.2 ≦ MI ≦ 3.5. Characteristic void filler. 2. A resin-made space filler fixing device for arranging the space filler before heating in an internal space of the object to be filled, wherein the resin space filler is disposed in the internal space and surrounds the space filler. A base for attaching and holding the base, a support leg protruding from the base, and a check piece extending from a tip of the support leg and opening outward toward the base, A gap filling member configured to elastically deform when the stop piece is inserted into a through hole formed in a side wall of the filling object and to engage with a peripheral edge of an opening of the through hole. Fixture.