JP2003105118A - Thermosetting foaming/filling resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting foaming/filling resin composition not suffering burns due to heat generated during the foaming/setting reaction, capable of sufficiently filling hollow parts, various pipes, etc., for the enhancement of their structural strength, and capable of providing them with excellent features relative to noise, vibration, and heat isolation. SOLUTION: The resin composition contains (A) a thermosetting resin, (B) an organic foaming agent, (C) a thixotropy giving agent, (D) a crystal water containing inorganic filling agent, and (E) hollow micrograins, and has a density of 1.0 g/cm<3> or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow part or various pipes composed of a closed cross-section structural member, for example, a thin plate member such as a door of an automobile, to fill the voids thereof to improve the structural strength and to prevent noise. The present invention relates to a thermosetting foam-fillable resin composition used for imparting properties such as heat resistance, vibration resistance, and heat insulation.

[0002]

2. Description of the Related Art In automobiles, home electric appliances, industrial machines, etc., the parts thereof are hollow because they are made of a thin plate member in order to reduce the weight of the products. Examples of such hollow parts include automobile doors, roofs, fenders,
Examples include trunks and various pipes. However, from the viewpoint of safety and comfort, products such as automobiles are required to have characteristics such as a certain level of structural strength, soundproofing, vibration damping, and heat insulating properties. Therefore, in the above hollow parts and the like, a reinforcing member made of an iron member and a foam filling member for filling the hollow portion are used.

As the foam filling member, a rubber type foam sheet has been conventionally used. By sticking this rubber-based foamed sheet to the voids such as the hollow parts, the products such as automobiles are provided with soundproofing, heat insulating and vibration damping properties. However, this rubber foam sheet
Since it is flexible, it cannot be expected to improve the structural strength of the above components. Therefore, recently, a urethane-based two-component curable foamable resin composition or a sheet-like or putty-like thermosetting foamable resin composition has been used as a reinforcing material.

The above-mentioned urethane-based two-component curable foamable resin composition is a liquid composition prepared by mixing a two-component curable urethane resin with a foaming agent. For example, this liquid resin composition is applied to the inner peripheral surface of a thin plate member of an automobile door to be cured, and at the same time foamed and expanded by the action of the foaming agent to fill voids in the door or the like. If this urethane-based two-component curable resin composition is used, the structural strength of parts will be improved by the action of the cured product, and since the cured product is foamed, it will be sound-proof, heat-insulating, and vibration-proof. It becomes possible to add the characteristics of. However, this urethane-based two-component curable resin composition has a problem of dripping during coating.
That is, since the resin composition is in the liquid state as described above, when the resin composition is applied to the standing thin plate member or the like, the resin composition flows by its own weight. Therefore, the use of this urethane-based two-component curable resin composition is limited to the surface to be coated in a horizontal state, a bag-shaped hollow component such that the liquid does not flow out even in a standing state, and the like.

On the other hand, the thermosetting foam-filling resin composition is a thermosetting resin blended with a heating foaming agent.
It is used after being formed into a putty or sheet. Since the cured product of this thermosetting foam-fillable resin composition has excellent rigidity, it is possible to remarkably improve the structural strength of the hollow parts, various pipes and the like by using this. Further, also in this resin composition, since the heating foaming agent is used, the cured product foams and expands, the soundproofing,
It is also possible to add properties of heat insulation and vibration isolation.

[0006]

However, even in such a high-performance thermosetting foam-filling resin composition,
During foaming and curing reaction, the heat generated may be accumulated in the central part to cause kogation. This kogation portion is brittle, and it is not possible to obtain satisfactory properties as a reinforcing material.

The present invention has been made in view of the above circumstances, and does not cause kogation due to heat generated during the foaming and curing reaction, and sufficiently fills voids in hollow parts and various pipes. Improve the structural strength of various pipes,
Further, it is an object of the present invention to provide a thermosetting foam-fillable resin composition capable of imparting excellent soundproofing, vibrationproofing, and heat insulating properties to these.

[0008]

The present inventors have conducted a series of studies to prevent the occurrence of kogation in thermosetting foam-filling resin compositions. Then, by adding an inorganic filler containing crystal water to the thermosetting foam-fillable resin composition, only the portion where the temperature rises too much during the thermosetting reaction can release the crystal water from the filler and prevent the temperature rise. Found.

That is, the thermosetting foam-fillable fat composition of the present invention contains the following components (A) to (E), and the density of the resin composition is set to 1.0 g / cm ³ or less. Take the configuration. (A) Thermosetting resin (B) Organic foaming agent (C) Thixotropy imparting agent (D) Water-containing inorganic filler (E) Micro hollow particles

Next, the present invention will be described in detail.

The thermosetting foamable filling resin composition of the present invention comprises a thermosetting resin (component A), an organic foaming agent (component B), a thixotropy imparting agent (component C), and a crystal water-containing inorganic filler ( D component) and fine hollow particles (E component).

The thermosetting resin (component A) is the main component of the thermosetting, foaming and filling resin composition of the present invention. This thermosetting resin is not particularly limited,
For example, glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type,
Examples thereof include various alicyclic epoxide type epoxy resins and modified epoxy resins thereof, melamine-based resins, polyester-based resins, phenol-based resins, urea-based resins, and the like, which may be used alone or in combination of two or more kinds. Among these, the above-mentioned epoxy resin and its modified epoxy resin which are excellent in adhesiveness to metal are preferable.

Further, the thermosetting resin (component A) contains
Usually, a heat-activated curing agent (hereinafter referred to as “curing agent”) that exerts a curing action by heating (80 to 200 ° C.) is added. Examples of the curing agent include epoxy resin curing agents such as dicyandiamide, 4,4'-diaminodiphenylsulfone, phenol, various acids or acid anhydrides, and polyamide. And a hardening accelerator may be mix | blended with the said thermosetting resin (A component).
As the curing accelerator, imidazole derivatives such as 2-n-heptadecylimidazole, isophthalic acid or adipic acid dihydrazide, guanidine series, N, N-dialkylthiourea derivatives and the like are used. The amounts of these curing agents and curing accelerators used are, for example, epoxy resin 10
The amount of the above curing agent is 3 to 30 parts, and the amount of the curing accelerator is 5 parts or less with respect to 0 parts by weight (hereinafter abbreviated as “part”).

Next, the organic foaming agent (component B) is
It is added to the resin composition in order to impart heat-foamability. Examples of the organic foaming agent include azo compounds such as azodicarbonamide and azobisisobutyronitrile, nitroso compounds such as dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide, 4,4 '.
And hydrazide compounds such as oxybenzenesulfonyl hydrazide. These organic foaming agents can be used alone or in combination of two or more kinds.
Of these, those having a decomposition and foaming temperature of 80 ° C. or higher are preferable from the viewpoint of storage stability and stability of the thermosetting foam-fillable resin composition. In addition, the blending amount of this organic foaming agent,
2 to 20 relative to 100 parts of the thermosetting resin (component A)
Parts, preferably 3 to 15 parts. If the blending amount of the foaming agent is less than 2 parts, the foaming ratio may be low and it may not be possible to efficiently fill the voids.
This is because if the content of the component exceeds 0 part, the resulting cured resin composition will have excessive foaming and the reinforcing property will tend to decrease.

A foaming aid may be used in combination with the organic foaming agent (component B). Examples of the foaming aid include inorganic foaming aids such as zinc white, metal soaps such as zinc stearate, and urea compounds.

The above-mentioned thixotropic agent (component C) is usually
In a putty-like or sheet-like thermosetting foam-fillable resin composition, it is added in order to prevent dripping during coating or deviation or peeling of the sheet during sticking. Further, by the addition of this thixotropic agent, the foam cells of the resin composition after curing and foaming become minute and uniform, so that the structural strength is improved, and the properties such as soundproofing, vibration damping, and heat insulating properties are excellent. The advantage is that Examples of the thixotropic agent include aerosil, asbestos fiber, and organic bentonite. Of these, organic bennatonite is most suitable. That is, among the above thixotropy-imparting agents, the organic bentonite is most excellent in imparting thixotropy, uniformity of foamable cells, and minuteness. The above organic bentonite usually has an average particle size of 1 to 5 μm.
m is used.

The mixing ratio of the thixotropy-imparting agent is generally in the range of 5 to 20 parts, preferably in the range of 5 to 15 parts, and optimally 8 to 100 parts of the thermosetting resin (component A).
It is in the range of 13 parts. That is, when the mixing ratio of the thixotropic agent is less than 5 parts, the thixotropy imparting to the resin composition becomes insufficient, and when the resin composition is applied, dripping or sheet misalignment, after curing This is because there is a possibility that peeling of the material will occur. On the contrary, the mixing ratio of the thixotropic agent,
If it exceeds 20 parts, foaming of the resin composition after curing becomes insufficient, and desired properties such as improvement in structural strength, soundproofness, heat insulation, and vibration isolation may not be obtained.

Next, an inorganic filler containing water of crystallization (component D)
Is to release water of crystallization by heating, and to prevent temperature rise due to release of water of crystallization from the filler only in a portion where the temperature rises too much during the thermosetting reaction of the thermosetting foam filling resin composition. It is a thing. Examples of the crystal water-containing inorganic filler include aluminum hydroxide, magnesium hydroxide, zinc hydroxide, calcium hydroxide, tin hydroxide and the like. Of these, aluminum hydroxide is most suitable from the viewpoint of the temperature of releasing water of crystallization.

The blending ratio of the above-mentioned water-containing inorganic filler is
Generally 5 to 100 parts of the thermosetting resin (component A)
It is in the range of 50 parts, preferably in the range of 5 to 30 parts.
That is, if the blending ratio of the water of crystallization-containing inorganic filler is less than 5 parts, the effect of suppressing the temperature rise may be insufficient. Further, if it exceeds 50 parts, the foamability of the thermosetting foam-filling resin composition may be deteriorated, and both are not preferable.

Next, the fine hollow particles (component E) used in the present invention will be described. Examples of the hollow particles include inorganic particles such as alumina silicate, glass and silica, and organic particles such as phenol, vinylidene chloride, vinylidene chloride-acrylonitrile copolymer and melamine resin. Among these, from the viewpoint of rigidity and density, alumina silicate, vinylidene chloride type, and the like are preferable, and alumina silicate is most preferable. Further, the particle size of the fine hollow particles is generally 5 to 300 μm.
m, optimally, in the range of 30 to 150 μm. The density of the fine hollow particles is preferably from 0.8 g / cm ³ or less, and optimally, a range of 0.04~0.7g / cm ^3. The shape of the fine hollow particles is not particularly limited, but is preferably spherical.

One of the purposes of blending the fine hollow particles (component E) is to adjust the density of the resin composition before curing. That is, when the thixotropy-imparting agent is blended in the above-mentioned predetermined ratio, it becomes possible to achieve both the impartation of thixotropy and the foamability. However, for example, under severe conditions such as the case where the surface to be coated is in an upright state and the width of the void is 20 to 30 mm, even when the thixotropy-imparting agent is blended in the above ratio, the thixotropic property-imparting agent may be mixed in Dripping, sheet misalignment, peeling, etc. occur. Therefore, in the present invention, the thixotropy imparting agent is blended and the density of the resin composition is 1.0
By specifying g / cm ³ or less, the problems such as dripping or peeling can be solved. From such a point of view, the mixing ratio of the fine hollow particles is such that the density of the resin composition before curing is 1.0 g / cm ³ or less, and preferably,
0.9 g / cm ³ or less, optimally 0.5 to 0.8 g /
It is set to be cm ³ .

The density of the resin composition before curing is
The values are measured and calculated as follows. That is, a sample resin composition is prepared by kneading a mixture prepared by mixing components A to D, which are compounding components of the resin composition, and other additives in a predetermined ratio in a mixing pot while vacuum defoaming. . Then, in accordance with JIS K 6830, this is an item among them [5. Specific Gravity] The aluminum frame plate 10 (see FIG. 4) shown in FIG. 1 is prepared. The mass (g) (W1) of the aluminum frame plate 10 in water and the mass (g) (W2) of the aluminum frame plate 10 in air are measured. Then, first, the sample is filled in the groove 10a of the aluminum frame plate 10 for measuring the specific gravity so that air does not enter. Then, with the aluminum frame plate 10 filled with the sample, the mass in the air by a chemical balance [W4: aluminum frame plate 10
And the mass (g) of the sample in the air] are weighed, and then immersed in methanol and taken out quickly. Immediately thereafter, the mass in distilled water at 20 ± 2 ° C. [W3: mass of aluminum frame plate 10 and sample in water (g)] is weighed to obtain the above W.
JIS K 6830 [5. specific gravity〕
Specific gravity D according to the formula described in (2) of Item 5.3
To calculate. The value (specific gravity D) thus measured and calculated is the density of the resin composition before curing.

Further, the addition of the fine hollow particles (component E) is effective not only for preventing the resin composition from dripping but also for forming fine cells. That is, even with these minute hollow particles, uniform minute cells are formed in the resin composition after curing and foaming, and the effect of improving the structural strength of hollow parts and the like, excellent soundproofing, vibration damping, heat insulating properties, etc. can be obtained. You can

The means for adjusting the density of the thermosetting foam-filling resin composition is not limited to the adjustment by the fine hollow particles (component E), but also the type of each main component such as the thermosetting resin and the foaming agent. It can also be adjusted by selecting. However, from the viewpoint of ease of adjustment, adjustment using the fine hollow particles (component E) is preferable.

Next, the thermosetting foam-fillable resin composition of the present invention is produced, for example, as follows, using the components A to E. That is, the thermosetting resin (A
Components) are melt-mixed with a mixer such as a heating mixer. Then, an organic foaming agent (B component), a thixotropy imparting agent (C component), a crystal water-containing inorganic filler (D component), and minute hollow particles (E) are added to the melt-blended thermosetting resin (A component). Ingredients) and, if necessary, additives such as a curing accelerator and a foaming aid are blended in a predetermined ratio. Then, by kneading this mixture using a mixing roll or the like, a putty-like thermosetting foam-fillable resin composition can be produced. Further, this putty-like thermosetting foam-filling resin composition is subjected to hot press molding at a temperature not higher than the decomposition temperature of the foaming agent through a release paper to give a sheet-like thermosetting foam-filling resin composition. Obtainable. The thickness of the sheet-shaped thermosetting foam-filling resin composition is generally 2 to 15
mm, preferably 3 to 10 mm.

The putty-like or sheet-like thermosetting foam-fillable resin composition thus obtained is used as follows. That is, in the case of putty-like parts, such as voids of parts made of thin plate members such as automobile doors,
It is applied by the spatula method or the like, or when it is formed into a sheet, it is attached. At this time, because the densities of the thixotropic agent (component C) and the resin composition are specified, even if the surface to be coated or adhered is the thin plate member or the pipe inner peripheral surface in the standing state, dripping or No deviation or peeling of the sheet occurs. Then, when heated to a predetermined temperature (usually 80 ° C. or higher), the thermosetting resin (component A) contained
The resin composition is cured and foamed and expanded by the curing by the above and the foaming by the organic foaming agent (component B), and the voids are filled without any gap. Furthermore, even when the heat generated during the foaming curing reaction is stored in the central portion of the resin composition, the crystal water can be released from the crystal water-containing inorganic filler (D component), and the temperature rise can be prevented, which may cause burns. Occurrence can be prevented. In this way, it becomes possible to improve the structural strength of hollow parts such as automobile doors and various pipes, and to impart excellent properties such as soundproofing, vibration damping, and heat insulating properties.

[0027]

As described above, the thermosetting foam-filling resin composition of the present invention has a density of the resin composition before curing set to a specific value or less, and a thixotropy-imparting agent, an organic foaming agent, and a thermosetting agent. By blending the curable foam filling resin composition and the micro hollow particles, the heat generated during the foam curing reaction can be performed without inhibiting the foamability and the dripping during coating or the deviation of the sheet during sticking. It solves the problem of kogation. For this reason, when the thermosetting foam-fillable resin composition of the present invention is used as a reinforcing material for hollow parts and various pipes having a void with a width of 20 to 30 mm or more in an upright state, the gap of the sheet or the like in the void. It becomes possible to adhere or even coat without causing any trouble. When the coated or adhered thermosetting foam-fillable resin composition of the present invention is heated, it is sufficiently cured and foam-expanded, so that the voids of the hollow parts and the like can be filled without gaps. . Further, during foaming and curing reaction, kogation can be prevented even if the heat generated is stored in the central portion of the resin composition, and a sufficient strength as a reinforcing material is secured. As described above, the thermosetting foam-fillable resin composition of the present invention has excellent curability and foam expansion, and is not limited to the object to be coated or attached. Therefore, if the thermosetting foam-fillable resin composition of the present invention is used as a reinforcing material for automobile doors, for example, by simple coating and sticking work, the structural strength is remarkably increased without impairing the weight reduction of the door. It is possible to improve and impart excellent properties such as soundproofing, vibration damping and heat insulation.

Next, examples will be described together with comparative examples.

Example 1 As thermosetting resin (component A), 60 parts of bisphenol A type liquid epoxy resin (Epicoat # 828, manufactured by Yuka Shell Co., Ltd.) and bisphenol A type solid epoxy resin (Epicoat # 1002, oil type). (Manufactured by Shell Co.) and 40 parts thereof were prepared and melt-mixed in a mixing pot. Then, to 100 parts of this molten mixture (A component), 5 parts of a hydrazide-based foaming agent (OBSH: 4,4'-oxybenzenesulfonyl hydrazide) and organic bentonite (C component).
(Average particle size 3 μm) 10 parts, aluminum hydroxide (high dilite) (D component) 10 parts, alumina silicate (E component) [density 0.6 to 0.7 g / cm ³ ] 70 parts,
5 parts of dicyandiamide (curing agent) was blended, and these were kneaded using a mixing roll. Then, the obtained resin block was hot-pressed (condition: press temperature 60 ° C.) through a release paper to obtain a sheet-shaped thermosetting foam-filling resin composition having a thickness of 6 mm.

Comparative Example 1 A sheet-shaped thermosetting foam-filling resin composition was prepared in the same manner as in Example 1 except that 10 parts of aluminum hydroxide (Hydrite) (component D) was not added.

The product of Example and the product of Comparative Example thus obtained were subjected to a void filling test and a rigidity test, and their properties and kogation properties were examined. The results are shown in Table 1 below. The various tests described above were carried out by the following methods. In addition, the density of each resin composition before curing shown in Table 1 is measured according to the above-mentioned measuring method according to JIS K 683.
It was measured and calculated according to 0.

[Gap Filling Test] Metal Square Pipe (30
mm × 30 mm × 100 mm height) and a sheet-shaped thermosetting foam filling resin composition (30 mm × 80 mm × 6 mm thickness) were prepared. Then, as shown in FIGS. 1A and 1B, the two sheet-shaped thermosetting foamable filling resin compositions 1 were attached to the inner peripheral surface of the metal square pipe 2. Figure 1
FIG. 1 (A) is a perspective view showing a state of being stuck, and FIG.
(B) is the sectional drawing. In this state, the metal square pipe 2 is placed in an oven at 180 ° C. for 20 minutes for heat treatment, and is then taken out of the oven to visually observe the foam filling state of the resin composition 1 inside the metal square pipe 2. did. Then, those that were completely filled were marked with ◯, and those that were insufficiently filled, that the resin dropped or shifted, or those that had insufficient foam expansion were marked with x.

The foamed filling at this time was cut in half and the kogation property of the central portion was visually observed. The case where no kogation was observed was marked with ◯, and the case where kogation was observed was indicated with x.

[Rigidity Test] As shown in FIG. 2A, the test steel plates 3a and 3b (25 mm × 150 mm × 0.8 mm)
(Thickness) is prepared, and a sheet-shaped thermosetting foam-fillable resin composition (25 mm × 120 mm × 4) is provided on one of the test steel plates 3 b.
(mm thickness) was attached. Then, as shown in the drawing, another test steel plate 3a is inserted through the spacer 4 (height: 12 mm).
It was arranged on the above-mentioned stuck sheet-like thermosetting foam-filling resin composition. In this state, the test steel plates 3a, 3b and the sheet-shaped thermosetting foam-filling resin composition 1 were placed in an oven at 180 ° C. for 20 minutes for heat treatment, and as shown in FIG. The thermosetting foamed resin composition was foamed and expanded, and this was used as a test piece for a rigidity test. A bending test was performed on this test piece as shown in FIG. That is, as shown in the figure, the test piece is placed on the two support bases 5a and 5b, and in this state, the rod-shaped member is lowered (bending speed: 5
(mm / min) and the bending strength was measured. In the figure, L is a distance (span distance) 10 between the support bases 5a and 5b.
It is 0 mm.

[0035]

[Table 1]

From Table 1 above, an inorganic filler containing water of crystallization (D
Component) the sheet-shaped thermosetting foam filling resin composition of the example product containing aluminum hydroxide is compared with the sheet thermosetting foam filling resin composition of the comparative example product in which this is not added, It can be seen that the kogation property is further improved while having the same void filling property and rigidity.

[Brief description of drawings]

FIG. 1 (A) is a perspective view showing a state in which a sheet-shaped thermosetting foamable filling resin composition is attached to the inner peripheral surface of a metal square pipe in a void filling test, and FIG. FIG.

FIG. 2A is a cross-sectional view showing a state before heat treatment of a test steel plate and a sheet-shaped thermosetting foam-filling resin composition in a rigidity test, and FIG. 2B is a state after heat treatment. FIG.

FIG. 3 is a configuration diagram showing a state in which bending strength is measured in a rigidity test.

FIG. 4 is a perspective view showing an aluminum frame plate for measuring specific gravity used when measuring the density of a resin composition before curing.

Claims (4)

[Claims] 1. A thermosetting foam-filling resin composition containing the following components (A) to (E) and having a resin composition density of 1.0 g / cm ³ or less. object. (A) Thermosetting resin (B) Organic foaming agent (C) Thixotropy imparting agent (D) Water-containing inorganic filler (E) Micro hollow particles 2. The thermosetting foam-fillable resin composition according to claim 1, wherein the thixotropy-imparting agent of the component (C) is organic bentonite. 3. The thermosetting foam-filling resin composition according to claim 1, wherein the inorganic water-containing filler of the component (D) is aluminum hydroxide. 4. The thermosetting foam-fillable resin composition according to claim 1, wherein the fine hollow particles of the component (E) have a density of 0.9 g / cm ³ or less.