JPH09316169A - Epoxy resin composition for reinforcing automotive body and method for reinforcing automotive body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin compsn. for reinforcing an automotive body which enables an automotive body frame to be reinforced and enables the improvement in comfortableness in riding and the reduction in noise or vibration to be expected and to provide a method for reinforcing an automotive body usig the same. SOLUTION: This compsn. is prepd. by compounding 10 pts.wt. epoxy resin derived from bisphenol A and/or bisphenol F with 10-100 pts.wt. acrylate or methacrylate polymer powder, 3-30 pts.wt. thermally activatable curative for an epoxy resin, 0.5-100 pts.wt. thermally decomposable blowing agent, and 3-150 pts.wt. inorg. filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel epoxy resin composition for reinforcing a vehicle body and a method for reinforcing a vehicle body using the composition. Particularly, since the vehicle body skeleton can be lightly reinforced, the vehicle body can be reinforced. The present invention relates to an epoxy resin-based composition for car body reinforcement, which can be expected to improve the riding comfort of the car, and to reduce noise and vibration, and a car body reinforcement method using the composition.

[0002]

2. Description of the Related Art Generally, in the body structure of an automobile, the skeleton of each part of the body is firmly formed from the viewpoint of improving riding comfort and reducing noise and vibration. The conventional body frame has a box-shaped closed cross-section structure and is manufactured in various cross-sectional shapes.
Due to the social demand to improve fuel efficiency from the viewpoint of depletion of fossil fuels and the atmospheric environment, in order to reduce the weight of the car body, both structures have a thin plate thickness, and metal reinforcements are used to compensate for the strength reduction. Is common.

On the other hand, a vehicle body structure of an automobile has been proposed in which a rigid urethane foam is filled inside the closed cross section to reinforce the vehicle body structure (Japanese Patent Laid-Open No. 48-2631). The foam filling has a high effect of suppressing wall buckling, and significantly improves the strength of the box-shaped member, so that the vehicle body weight is not significantly increased as compared with the method of reinforcing the vehicle body by the metal reinforcing material. The rigidity can be improved.

[0004] As a resin foam type filler,
In addition to urethane-based, olefin resin foam filler (Sea Clastomer 240 manufactured by Japan Seeker Co., Ltd.) and epoxy foam filler (OROTEX manufactured by Iida Sangyo Co., Ltd.)
815) and the like. All of these fillers are of the type that foams / fills in the vehicle body painting process.

[0005]

However, in the method of strengthening with the urethane resin, the urethane from the small hole of the box-shaped member and the joint of the box-shaped member with the closed cross-section during the injection and foaming of the undiluted urethane solution into the box-shaped closed cross-section member in the construction Since a considerable amount of material leaks, it is necessary to take measures to prevent it, and it is considered difficult to apply it to automobile production lines. In addition, from the viewpoint of improving the working environment, in recent years, the foaming method using freon has been replaced with a foaming method using water.However, the water foaming method achieves more uniform foaming than the freon foaming method. There is a problem that it is difficult to do.

Further, in the olefin resin foam material, low molecular weight polyethylene wax or the like is used as the base olefin resin, so that the rigidity / strength of the material is not sufficient, and the box type member is filled with the box type member. The effect of improving the strength / rigidity of the member is not sufficient.

On the other hand, in the epoxy resin type foam material, first,
The disadvantage of the poor impact resistance of epoxy resins must be compensated for. The load input to the car body is not always static, and impact load may act on the car body due to unevenness of the road surface during traveling.Therefore, even the car body reinforcements are shock resistant enough to withstand such a shock load. Toughness and toughness are required.

The method of improving the impact resistance is roughly classified into a method of improving the chemical structure of the epoxy resin itself and a method of adding a separately prepared impact resistance improving agent to the epoxy resin. The epoxy resin which can sufficiently satisfy the impact resistance cannot be obtained only by the above method. On the other hand, in the latter method, (1) a soluble elastomer monomer is added to an uncured epoxy resin, and both are simultaneously polymerized, (2)
A method of adding a compatible elastomeric polymer,
(3) A method of dispersing a fine particle impact resistance improving polymer is known.

However, the method (1) is known as an interpenetrating network structure: IPN (Inter-Penetrating Network). However, this method generally lowers the softening point of the product and causes variations in mechanical strength. It has drawbacks such as In the method (2), various examples have been proposed in which an elastomer component such as a butadiene-acrylonitrile copolymer rubber (CTBN or ATBN) having a carboxyl group or an amino group at the terminal is added to modify the rubber. Although it has been put to practical use, the product obtained by this method cannot be said to be sufficiently satisfactory in terms of impact resistance and toughness for use in reinforcing the rigidity of the vehicle body. Furthermore, (3)
In this method, many impact modifiers including polyamide resins have been proposed, but all of these methods have the drawback of insufficient pseudo-curability.

The term "pseudo-curability" as used herein refers to the property of solidifying to a non-adhesive or sticky state at a temperature lower than the temperature at which a liquid or paste epoxy resin composition is heat-cured, and has the following advantages. Have That is, in the conventional foamed filler, when disposing the uncured material on the steel plate of the vehicle body, it is necessary to use a dedicated clip or adhesive,
When it is installed on a preformed steel plate of a vehicle body, it may cause problems such as setting of clip holes and dropping due to defective adhesive. On the other hand, by coating the steel sheet and then heating it in a short time to form a pseudo-cured material, it is possible to prevent the falling off and contamination of the pretreatment liquid for coating.

In general, when a rubber component having a glass transition temperature of -30 ° C. or lower is added as an impact resistance improver for plastics, it acts to relieve external stress and the impact resistance is greatly improved. It is known that many of these rubber components have a dispersibility that is easily affected by mixing conditions when a liquid epoxy is used as a base material, and the resulting composition has unstable storage properties. However, it is not practical for automobile production applications that require long-term stability.

Further, when the viscosity of the resin sharply decreases in the foaming temperature range, it is difficult to hold the gas generated from the foaming agent in the resin, and it becomes difficult to break the foam to form a foam. . In order for the foam cells to exist stably in the foam, the resin viscosity in the foaming temperature range must be controlled. For this purpose, it is necessary to add an elastomer having high compatibility with the epoxy resin to control the temperature dependence of the viscosity, or to control the temperature dependence of the viscosity by physical crosslinking.

However, the method of controlling the viscosity by adding an elastomer has a drawback that the rigidity originally possessed by the epoxy composition is lowered, and when the viscosity is controlled by crosslinking accompanied by a chemical reaction, the crosslinking is Since the density depends on the reaction conditions and cannot be strictly controlled, the viscosity is too high and the foaming is insufficient, so that the box-shaped member of an automobile may not be sufficiently filled.

[0014]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have focused on an ionic crosslinked structure that is a reversible crosslink by heat, and have focused on a core-shell type acrylate or methacrylate system. By ion-crosslinking the copolymer resin particles, while preventing the swelling phenomenon of the epoxy resin base material due to the particles, to give an epoxy resin composition having impact resistance, this composition is applied to a preformed steel sheet. After heat-treating it is pseudo-cured to prevent dripping, and after assembling a box-shaped member using this steel plate, it is foamed and filled in the baking process during car body electrodeposition coating, or this composition is pseudo-cured. After it is made into a sheet, it is trimmed to the shape of the car body and attached to a steel plate to assemble a box-shaped member, then foamed and filled in the baking process of electro-deposition of the car body to make it lighter. Found that it is possible to reinforce the vehicle body skeleton, we have reached the present invention.

The above objects of the present invention are: (A) 10 to 100 parts by weight of powdered acrylate or methacrylate polymer, based on 100 parts by weight of an epoxy resin derived from bisphenol A and / or bisphenol F; Containing 3 to 30 parts by weight of (C) heat-activatable curing agent for epoxy resin, (D) 0.5 to 100 parts by weight of thermal decomposition type foaming agent, and (E) 3 to 150 parts by weight of inorganic filler And an epoxy resin composition for vehicle body reinforcement, and a method for reinforcing a vehicle body using this composition.

In the present invention, the above composition comprises (B)
An acrylate or methacrylate polymer (a) a core component composed of an acrylate or methacrylate polymer having a glass transition temperature of −30 ° C. or lower; and (b) (a)
The glass transition temperature obtained from the acrylate or methacrylate polymer, (b) a radically polymerizable unsaturated carboxylic acid monomer having a carboxyl group having 3 to 8 carbon atoms and (c) a crosslinkable monomer is 70 ° C. A monovalent or divalent metal cation is added to the copolymer resin particles composed of the above-mentioned copolymer and a shell component and having a core component / shell component weight ratio of 10/1 to 1/4. It is preferable that the resin powder particles are added and ionically crosslinked.

Further, the above object of the present invention is to apply the above composition to a preformed steel sheet and then heat treat it to pseudo-cure it so as to prevent it from falling off or flowing out, and to assemble a box-shaped member using the above steel sheet. After that, it was achieved by a method of reinforcing a vehicle body, which comprises foaming in a baking step during electrodeposition coating of the vehicle body and filling the box-shaped structural member of the vehicle body to improve rigidity.

Hereinafter, the present invention will be described in more detail. Specific examples of the epoxy resin derived from bisphenol A used as the component (A) in the composition of the present invention include those represented by the following chemical formula 1.

[0019]

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Specific examples of the epoxy resin derived from bisphenol F include those represented by the following chemical formula 2.

[0021]

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Although n in the above Chemical Formulas 1 and 2 is a number of 0 or more, those having an average value of less than 1 are preferable because they are liquid at room temperature. In addition to the resins of Chemical Formulas 1 and 2 described above being mixed and used, as the bisphenol chain portion of Chemical Formula 1 or Chemical Formula 2, a chain having a mixture of a bisphenol A unit and a bisphenol F unit is also preferably used. it can.

The core-shell type resin particles used as the component (B) in the composition of the present invention are obtained by ion-crosslinking by adding a monovalent or divalent metal cation to the core-shell type acrylate or methacrylate type copolymer resin particles. It is a thing.

In producing the resin powder particles of the component (B), first, the glass transition temperature (T) of the core component (a) is used.
g) Prepare a rubber-like seed polymer composed of an acrylate or methacrylate polymer having a temperature of −30 ° C. or lower. Examples of the (meth) acrylate-based monomer that gives a polymer having Tg of −30 ° C. or lower include n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-decyl methacrylate, and n-decyl methacrylate. Can be mentioned. These (meth) acrylate-based monomers may be used alone or in combination of two or more.

If desired, a crosslinkable monomer may be added to the (meth) acrylate-based monomer to enhance the rubber property. As the crosslinkable monomer for this purpose, those having two or more double bonds having substantially the same reactivity, for example, ethylene glycol, diacrylate, ethylene glycol dimethacrylate, butylene glycol diacrylate, butylene glycol dimethacrylate, Trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, hexanediol diacrylate, hexanediol methacrylate, oligoethylene diacrylate, oligoethylene dimethacrylate,
Further, aromatic divinylbenzene derivatives such as divinylbenzene, triallyl trimellitate, triallyl isocyanurate and the like can be mentioned.

These crosslinkable monomers may be used alone in the range where the Tg of the obtained polymer is −30 ° C. or lower, or two or more kinds may be used in combination, and the amount thereof is used. It is preferably in the range of 0.01 to 5% by weight based on the total weight of the monomers.

Furthermore, the (meth) acrylate-based monomer and the crosslinkable monomer may be used in combination with other copolymerizable monomers, if necessary. Examples of other copolymerizable monomers include styrene, vinyltoluene, aromatic vinyl compounds such as α-methylstyrene, acrylonitrile, vinyl cyanide compounds such as methacrylonitrile, and vinylidene cyanide.
2-hydroxyl ethyl acrylate, 2-hydroxyl ethyl methacrylate, 3-hydroxybutyl acrylate, 2-hydroxyethyl fumarate, hydroxybutyl vinyl ether, monobutyl maleate, glycidyl methacrylate, butoxyethyl methacrylate and the like can be mentioned. These monomers may be used alone or in combination of two or more. It is necessary to select the amount of the monomer used in such a range that the Tg of the obtained polymer is −30 ° C. or lower, but it is usually preferable that the amount is 50% by weight or lower based on the total weight of the monomer. .

Next, using the (meth) acrylate polymer particles thus obtained as a core, (a) a (meth) acrylate monomer and (b) a carboxyl group-containing 3 to 8 carbon atom. Second-stage emulsification for forming a shell made of a copolymer having a glass transition temperature of 70 ° C. or higher by glast-polymerizing a radically polymerizable unsaturated carboxylic acid monomer and (c) a crosslinkable monomer Polymerize. In this case, as the (meth) acrylate-based monomer of the raw material component (a) used, for example, an alkyl group such as ethyl acrylate, n-butyl acrylate, methyl methacrylate, or butyl methacrylate having 1 to 4 carbon atoms ( (Meth) acrylate is mentioned. These monomers may be used alone or in combination of two or more, and of these, methyl methacrylate is particularly preferable.

Examples of the radically polymerizable unsaturated carboxylic acid monomer having a carboxyl group and having 3 to 8 carbon atoms used as the raw material component (b) include acrylic acid,
Unsaturated monocarboxylic acids such as methacrylic acid, ethacrylic acid, crotonic acid, cinnamic acid, maleic acid, itaconic acid,
Unsaturated dicarboxylic acids such as fumaric acid, citraconic acid, chloromaleic acid and their anhydrides, methyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monomethyl itaconate, monoethyl itaconate, itaconic acid Examples thereof include monoesters of unsaturated dicarboxylic acids such as monobutyl and derivatives thereof. These monomers may be used alone,
Two or more kinds may be used in combination, but acrylic acid, methacrylic acid, maleic acid, maleic anhydride and fumaric acid are particularly preferable.

On the other hand, as the crosslinkable monomer of (c) the raw material component, one kind may be used from the examples exemplified in the description of the (meth) acrylate polymer forming the core, or two kinds thereof may be used. The above may be used in combination. The amount of the crosslinkable monomer used, based on the total amount of the monomer, usually,
It is preferably in the range of 0.01 to 10% by weight.

Further, in the present invention, the above (a),
Other copolymerizable monomers may be used together with the components (b) and (c). Examples of the other copolymerizable monomer include aromatic vinyl compounds such as styrene, vinyltoluene and α-methylstyrene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, and vinylidene siadide. , 2-hydroxyl ethyl acrylate, 2-hydroxyl ethyl methacrylate, 3-hydroxybutyl acrylate, 2-hydroxyethyl fumarate, hydroxybutyl vinyl ether, monobutyl maleate, glycidyl methacrylate, butoxyethyl methacrylate and the like.
These monomers may be used alone or in combination of two or more. The amount used is usually preferably 50% by weight or less based on the total weight of the monomers.

The resin particles thus obtained have a carboxyl group-containing copolymer at least in the shell part, and this copolymer has a carboxyl group-containing monomer unit per one molecule of the copolymer. , On average, combine one or more,
Further, those containing a monomer unit having a carboxyl group in a proportion of 0.01 to 20 parts by weight per 100 parts by weight of this copolymer are preferable. The content of this monomer unit is 0.
If it is less than 01 parts by weight, the effect of modifying the particle surface by ionic cross-linking is hardly exerted, and if it exceeds 20 parts by weight, no improvement in the effect of modifying the particle surface is observed, and rather the mechanical properties inherent to the base resin are not observed. The characteristics deteriorate. Tg of the (meth) acrylate-based copolymer having the shell is 70 ° C.
It is preferable that it is above. When the temperature is lower than 70 ° C, the storage stability becomes insufficient when mixed with an epoxy resin.

The weight of the shell portion of the core-shell type resin particles thus obtained is such that the (meth) acrylate-based monomer as the component (a) and the radically polymerizable unsaturated carboxylic acid having a carboxyl group as the component (b). It is represented by the weight of the copolymer produced during the graft copolymerization of the acid monomer, the crosslinkable monomer of the component (c) and other copolymerizable monomer used as necessary. In the present invention, the core component /
The weight ratio of the shell component is preferably in the range of 10/1 to 1/4. If the weight ratio deviates from this range, the object of the present invention cannot be fully achieved.

Monovalent or divalent metal cations are added to the core-shell type resin particles for ion-crosslinking. Examples of the monovalent or divalent metal cations include potassium, sodium, lithium and cesium. Examples thereof include monovalent metal ions and divalent metal ions such as calcium, zinc, tin, chromium, and lead, and monovalent or divalent ions of metals belonging to Group I to III of the periodic table are particularly preferable.

Examples of the metal cation supplier include oxides, hydroxides, phosphates, carbonates, nitrates, sulfates, chlorides, nitrites, and sulfites of monovalent or divalent metal ions of the above metals. Salt, and further octylic acid, stearic acid,
Organic acid salts such as oleic acid, capric acid, formic acid, succinic acid, erucic acid, linolenic acid, palmitic acid, propionic acid, acetic acid, adipic acid, butyric acid, naphthenic acid and thiocarboxylic acid, acetylacetone salts, alcoholates such as ethosid and methoxide. And so on.

In the case of an acid salt, it is preferable that the acid dissociation constant pKa is 4 or more. Among these cation donors,
Particularly, monovalent metal hydroxides and carboxylates are effective from the viewpoint of the reaction efficiency of ionic crosslinking and the mechanical strength of the heat-formed product. A monovalent or divalent cation supplier does not require heating for a relatively long time when performing a cross-linking reaction unlike a trivalent or higher cation supplier. It has a feature that a crosslinking reaction within a range is possible.

Examples of the heat-activatable curing agent for epoxy resin used as the component (C) in the composition of the present invention include dicyandiamide, 4,4'-diaminodiphenylsulfone, and 2-n-heptadecylimidazole. Imidazole derivative, isophthalic acid dihydrazide,
N, N-dialkylurea derivatives, N, N-dialkylthiourea derivatives, acid anhydrides such as tetrahydrophthalic anhydride, isophoronediamine, m-phenylenediamine,
N-aminoethylpiperazine, melamine, guanamine,
Examples thereof include boron trifluoride complex compounds and trisdimethylaminomethylphenol.

One of these curing agents may be used, or two or more thereof may be used in combination. Among these, dicyandiamide is particularly preferable. In this case, in order to perform sufficient foaming, the baking temperature of the electrodeposition coating is preferably set in the range of 140 to 210 ° C., and the baking time is preferably set in the range of 10 to 30 minutes.

The compounding amount of the heat-activatable curing agent as the component (C) is not particularly limited, but is usually in the range of 3 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A). is there. If the compounding amount is less than 3 parts by weight, the composition will not be sufficiently cured, resulting in a significant decrease in rigidity / strength.
If the amount exceeds 0 parts by weight, an excessive exothermic reaction is caused during curing and partial decomposition or thermal deterioration is caused, which causes a significant deterioration in the mechanical strength of the composition.

Examples of the thermal decomposition type foaming agent used as the component (D) in the composition of the present invention include azo compounds such as azodicarbonamide and azobisisobutyronitrile, and dinitrosopentamethylenetetramine. Organic decomposing type foaming agents such as nitroso compounds, p-toluenesulfonyl hydrazide, sulfohydrazide compounds such as 4,4'-oxybenzenesulfonyl hydrazide, sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, magnesium carbonate Inorganic thermal decomposition type foaming agents such as ammonium nitrite, ferrous oxalate and sodium borohydride. These foaming agents may be used alone or in combination of two or more, and among these, azodicarbonamide is particularly preferable.

When an organic pyrolyzable foaming agent is used, usually, as a foaming aid for controlling the proper foaming temperature, calcium carbonate, zinc white, zinc nitrate, lead phthalate,
Inorganic salts of lead carbonate, tribasic lead phosphate, tribasic lead sulfate, etc., metal soaps such as zinc fatty acid soap, lead fatty acid soap, cadmium fatty acid soap, acids such as boric acid, oxalic acid, succinic acid, adipic acid, etc. , Urea, biurea, ethanolamine, glycol, glycerin, and the like.

The amount of the thermal decomposition type foaming agent as the component (D) to be added is not particularly limited, but is usually in the range of 0.5 to 100 parts by weight based on 100 parts by weight of the epoxy resin as the component (A). is there. When the blending amount is less than 0.5 part by weight,
If the foaming is insufficient and, on the contrary, more than 100 parts by weight, the foamed cells become too large and stable mechanical properties cannot be obtained.

Examples of the inorganic filler used as the component (E) in the composition of the present invention include calcium carbonate, talc, clay, mica, aluminum hydroxide,
Examples thereof include glass beads and shirasu balloon. These inorganic fillers may be used alone or in combination of two or more, and among these, calcium carbonate is particularly preferable.

The amount of the inorganic filler used as the component (E) is not particularly limited, but is usually in the range of 3 to 150 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A). preferable. If the blending amount is less than 3 parts by weight, a sufficient reinforcing effect cannot be obtained. On the contrary, if the blending amount exceeds 150 parts by weight, the viscosity is remarkably increased and it becomes difficult to apply the composition, and the composition becomes brittle and mechanical. It causes a significant loss of strength.

The epoxy resin composition of the present invention comprises the epoxy resin of component (A), acrylate or methacrylate resin powder particles of component (B), a heat-activatable curing agent of component (C), and thermal decomposition of component (D). It can be adjusted by blending the mold foaming agent, the inorganic filler of the component (E), and an additive component used as necessary, and uniformly mixing them.
Examples of the additive component to be added to the composition of the present invention include a plasticizer, a (reactive) diluent, a stabilizer, an emulsifier, a toughening agent, a colorant, an antioxidant, an ultraviolet absorber, a lubricant, and a thixotropic property. Agents, curing accelerators and the like.

[0046]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention. The physical properties of the composition were evaluated by the methods described below.

(1) Pseudo-hardening property An untreated cold-rolled steel sheet is applied by using an application gun,
After pseudo curing with hot air at 110 ° C for 20 seconds, 160 ° C
The epoxy resin composition was allowed to stand for 20 minutes in the hot air drying oven of No. 1 to foam, and evaluated according to the following criteria. ◯: The gelled composition does not fall off and is sufficiently foamed Δ: The gelled composition falls off or is insufficiently foamed ×: Does not gel

(2) Tensile Shear Strength The adhesive strength was evaluated in accordance with JIS K6850 by baking an untreated cold-rolled steel sheet under the same conditions as above.

(3) Impact Test A 700 mm long C-shaped cold-rolled steel sheet pre-press-formed to have a cross-sectional size of 50 mm × 50 mm was used, and a length of 7
Apply using an application gun for over 100 mm. 11
Sheets formed by pseudo-curing with hot air at 0 ° C. for 20 seconds or pre-curing are 700 mm × 50 m
It was cut to a size of m and attached via an adhesive. The U-shaped steel plate member is integrated with a closing plate by spot welding to form a box-shaped cross-section member, which is
The epoxy resin composition was left to stand in a hot air drying oven at 60 ° C. for 20 minutes to foam and fill the epoxy resin composition.

Using the box-shaped cross-section member assembled in this way, a hemispherical dropper having a weight of 5 kgf of 7 m / sec was used by using the same test piece as the one subjected to the bending test by the drop type impact tester. It was made to collide at a speed and the presence or absence of breakage of the foam material was evaluated according to the following criteria. ○: No destruction of the foam Δ: Part of the foam is destroyed ×: The foam is completely destroyed

(4) Member rigidity Using the same box-shaped cross-section member as used in (3),
A bending test as shown in FIG. 1 was performed, the epoxy resin composition was compared with an unfilled box-shaped cross-section member, and the rigidity was evaluated according to the following criteria. ◯: Stiffness sufficiently improved to a satisfactory level Δ: Stiffness improved but not at a satisfactory level ×: Stiffness not improved

Example 1 47 parts by weight of n-butyl acrylate was added to have 12 to 18 carbon atoms.
Using 1.0 part by weight of sodium alkyl fate as an emulsifier, 0.1 part by weight of potassium persulfate catalyst was added, and water 1
Emulsion polymerization was carried out by stirring for 180 minutes at a polymerization temperature of 70 ° C. in 50 parts by weight to prepare a polyn-butyl acrylate core part fine particle dispersion polymerization liquid, and subsequently, 47 parts by weight of methyl methacrylate was added to the polymerization liquid. Was continuously added over 180 minutes to carry out core / shell emulsion polymerization for forming a shell portion on the surface of the core particle.

50% polymerization of the methyl methacrylate
At the time of reaching 5 parts by weight of methacrylic acid and tetraethylene glycol dimethacrylate (TE
0.5 parts by weight of GDMA) was continuously added to complete the copolymerization.

To the latex after polymerization, 2 parts by weight of a 1% by weight aqueous solution of potassium hydroxide was added at room temperature, and the mixture was stirred for 30 minutes. Next, this solution was spray-dried using hot air of 150 ° C. to obtain reinforcing resin particles having an average particle size in the range of 0.2 to 0.3 μm.

Reinforcing agent resin particles thus obtained,
Liquid bisphenol A type epoxy resin, curing agent dicyandiamide, organic foaming agent azodicarbonamide, and inorganic filler calcium carbonate were mixed at a ratio shown in Table 1 at room temperature using a planetary mixer to prepare an epoxy composition. It was adjusted. Table 1 shows the results of evaluation using the box-shaped cross-section member assembled in this manner.

COMPARATIVE EXAMPLE 1 Polymerization was carried out in exactly the same manner as in Example 1, and potassium hydroxide was not added to the copolymerized latex obtained, and drying and mixing were carried out in the same manner as in Example 1 except that the epoxy composition was used. The material was adjusted and the member evaluation was performed in the same manner as in Example 1.
Table 1 shows the results.

Examples 2 and 3 Polymerization was carried out in exactly the same manner as in Example 1, and the copolymer latex thus obtained was supplied with calcium acetate in Example 2 and zinc acetate in Example 3 as a divalent cation supplier. Except for adding 2 parts by weight of a 1% by weight aqueous solution, the epoxy composition was prepared by drying and mixing in the same manner as in Example 1, and the same member evaluation as in Example 1 was performed. Table 1 shows the results.

Comparative Example 2 Polymerization was carried out in exactly the same manner as in Example 1 except that 2 parts by weight of 1% by weight aqueous solution of aluminum hydroxide was not added to the obtained copolymerized latex as a trivalent cation supplier. ,
Drying and mixing were performed in the same manner as in Example 1 to adjust the epoxy composition, and the same member evaluation as in Example 1 was performed.
Table 1 shows the results.

Comparative Example 3 Polymerization was carried out in exactly the same manner as in Example 1, and 2 parts by weight of 1% by weight aqueous solution of ammonium hydroxide was added to the obtained copolymerized latex as a monovalent non-metal cation supplier. Was dried and mixed in the same manner as in Example 1 to adjust the epoxy composition, and the same member evaluation as in Example 1 was performed. Table 1 shows the results.

Comparative Example 4 49.5 parts by weight of n-butyl acrylate was added to have 12 to 12 carbon atoms.
Polymerization was carried out by an emulsion polymerization method under the same polymerization conditions as in Example 1, using 1.0 part by weight of sodium alkylfate of 18 as an emulsifier to produce a poly (n-butyl acrylate) core particle dispersion polymerization liquid. Then, 49.5 parts by weight of methyl methacrylate was continuously added to this polymerization liquid over 180 minutes, and core / shell emulsion polymerization for forming a shell portion on the surface of core portion particles was performed. In this polymerization, tetraethylene glycol dimethacrylate (TE) was added when the amount of methyl methacrylate added reached 50%.
0.5 parts by weight of GDMA) was continuously added to complete the copolymerization.

2 parts by weight of a 1% by weight aqueous solution of potassium hydroxide was added to the latex after polymerization at room temperature, and the mixture was stirred for 30 minutes. Next, this solution was spray-dried using hot air at 150 ° C. to obtain reinforcing resin particles. The reinforcing agent resin particles, the liquid bisphenol A type epoxy resin, the curing agent dicyandiamide, the organic foaming agent azodicarbonamide, and the inorganic filler calcium carbonate thus obtained were mixed in a planetary mixer at a ratio shown in Table 1. The mixture was used at room temperature to prepare an epoxy composition.

A cross-sectional size of this composition was previously set to 50 mm ×
700mm length pressed to 50mm
Was applied to the U-shaped cold-rolled steel sheet for 700 mm in length using an application gun, and was pseudo-cured with hot air at 110 ° C. for 20 seconds. The U-shaped steel plate member is integrated with a closing plate by spot welding to form a box-shaped cross-section member, which is left in a hot-air drying oven at a temperature of 160 ° C. for 20 minutes to foam and fill the epoxy resin composition. It was

A bending test as shown in FIG. 1 was conducted using the box-shaped cross-section member assembled in this manner, and the epoxy resin composition was improved in rigidity and strength as compared with the unfilled box-shaped cross-section member. confirmed. Table 1 shows the results.

Examples 4 and 5 In the same manner as in Example 1, the core portion was polymerized, and when the shell portion was polymerized, the amount of methyl methacrylate added was 50.
%, Maleic acid in Example 4 and Example 5
5 parts by weight of acrylic acid and tetraethylene glycol dimethacrylate (TEGDMA) 0.
5 parts by weight were continuously added and polymerized under the same conditions as in Example 1 to complete a copolymer having a different carboxylic acid monomer type from Example 1.

2 parts by weight of a 1% by weight aqueous solution of kalimu hydroxide was added to the polymerized latex at room temperature, and the same procedure as in Example 1 was carried out to obtain reinforcing resin particles. The reinforcing agent resin particles, the liquid bisphenol A type epoxy resin, the curing agent dicyandiamide, the organic foaming agent azodicarbonamide, and the inorganic filler calcium carbonate thus obtained were mixed in a planetary mixer at a ratio shown in Table 1. The mixture was used at room temperature to prepare an epoxy composition.

This composition was previously prepared to have a cross-sectional size of 50 mm ×
700mm length pressed to 50mm
Was applied to the U-shaped cold-rolled steel sheet for 700 mm in length using an application gun, and was pseudo-cured with hot air at 110 ° C. for 20 seconds. The U-shaped steel plate member is integrated with a closing plate by spot welding to form a box-shaped cross-section member, which is left in a hot-air drying oven at a temperature of 160 ° C. for 20 minutes to foam and fill the epoxy resin composition. It was

A bending test as shown in FIG. 1 was conducted using the box-shaped cross-section member assembled in this manner, and the epoxy resin composition was improved in rigidity and strength as compared with the unfilled box-shaped cross-section member. confirmed. Table 1 shows the results.

Comparative Example 5 An epoxy resin composition was prepared in the same manner as in Example 1 except that the crosslinking component was not used, and the evaluation of members was performed. Table 1 shows the results.

Examples 6 and 7 In the same manner as in Example 1, the core portion was polymerized, and when the shell portion was polymerized, the amount of methyl methacrylate added was 50.
%, Triaryl trimethate was used in Example 6 and trimethylol propane trimethacrylate (TMPT) was used in Example 7 as a cross-linking agent in an amount of 0.5 parts by weight, respectively. Copolymers of different types were completed.

1% by weight of potassium hydroxide in this latex
2 parts by weight of an aqueous solution was added at room temperature, and the same procedure as in Example 1 was carried out to obtain reinforcing resin particles. The reinforcing agent resin particles, the liquid bisphenol A type epoxy resin, the curing agent dicyandiamide, the organic foaming agent azodicarbonamide, and the inorganic filler calcium carbonate thus obtained were mixed in a planetary mixer at a ratio shown in Table 1. The mixture was used at room temperature to prepare an epoxy composition.

This composition was previously prepared to have a cross-sectional dimension of 50 mm ×
700mm length pressed to 50mm
Was applied to the U-shaped cold-rolled steel sheet for 700 mm in length using an application gun, and was pseudo-cured with hot air at 110 ° C. for 20 seconds. A closing plate was integrated by spot welding with this U-shaped steel plate member to form a box-shaped cross-section member, which was left in a hot air drying oven at a temperature of 160 ° C. for 20 minutes to foam and fill the epoxy resin composition. .

A bending test as shown in FIG. 1 was conducted using the box-shaped cross-section member assembled in this way, and the epoxy resin composition was improved in rigidity and strength as compared with the unfilled box-shaped cross-section member. confirmed. The results of Example 6 are shown in Table 1, and the results of Example 7 are shown in Table 2.

Example 8 An epoxy resin composition was prepared in exactly the same manner as in Example 1 except that 2-ethylhexyl acrylate was used instead of n-butyl acrylate used for the polymerization of the core part,
The box-shaped member was evaluated. The results are shown in Table 2.

Comparative Examples 6 and 7 In Comparative Example 6, the core portion was not polymerized as in Example 1, but the shell portion was directly polymerized by emulsion polymerization using methyl methacrylate, methacrylic acid and TEGDAM. In Comparative Example 7, conversely, the shell portion was not polymerized, and a copolymer latex of n-butyl acrylate, methacrylic acid and TEGDAM was prepared, and the epoxy resin composition was prepared by the same procedure as in Example 1. I went to
Since no pseudo-hardening was observed, the box-shaped member was not evaluated.

Comparative Example 8 An epoxy resin composition was prepared in exactly the same manner as in Example 1 except that n-butyl methacrylate was used instead of methyl methacrylate as the shell polymerization monomer.
The box-shaped member was evaluated. The results are shown in Table 2.

Examples 9 and 10 Polymerization of the acrylic core / shell type reinforcing resin particles was carried out in exactly the same manner as in Example 1. The addition of a cation supplier to the obtained polymer latex and spray drying were also carried out in Example 1.
And went exactly the same. Regarding the blending of the epoxy resin used in the subsequent step of adjusting the adhesive composition, in Example 9, a mixture of a bisphenol A type epoxy resin and a bisphenol F type epoxy resin in a ratio of 7: 3 was used. For, the bisphenol A type epoxy resin was completely replaced with the bisphenol F type epoxy resin. The performance evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

Examples 11 and 12 In Example 1, the case where the type of the inorganic filler was replaced with calcium carbonate by talc is Example 11, and the case where silica was substituted by Example 12. The performance evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Examples 9 and 10 The core / shell of Example 1 was changed to 47/47 by changing the addition ratio of each monomer of the core and the shell at the time of producing the acrylic core / shell type reinforcing agent resin particles. Comparative Example 1 was used as Comparative Example 9 in which the core / shell was 90/4 parts by weight with respect to 47 parts by weight.
0 is the core / shell = 14/80 parts by weight. The amounts of methacrylic acid, TEGDMA and the cation supplier added are as shown in Table 2, and spray drying and adjustment of the adhesive composition were carried out in exactly the same manner as in Example 1.
The evaluation results are shown in Table 2.

Examples 13 and 14 Polymerization of the acrylic core / shell type reinforcing agent resin particles was carried out in the same manner as in Example 1 except that the acrylic type core / shell type reinforcing agent resin was mixed with the epoxy resin. In Example 13, the content of the particles was set to 20 parts by weight with respect to 200 parts by weight of the epoxy resin. Example 1
No. 4 was adjusted such that the compounding amount of the acrylic core / shell type reinforcing agent resin particles was 200 parts by weight with respect to 200 parts by weight of the epoxy resin.

Comparative Examples 11 and 12 Polymerization of the acrylic core / shell type reinforcing agent resin particles was carried out in the same manner as in Example 1, except that the acrylic core / shell type reinforcing agent resin was mixed with the epoxy resin. In Comparative Example 11, the content of the particles was set to 10 parts by weight with respect to 200 parts by weight of the epoxy resin. Comparative Example 12
Was adjusted so that the blending amount of the acrylic core / shell type reinforcing agent resin particles was 220 parts by weight with respect to 200 parts by weight of the epoxy resin.

Examples 15 and 16 Polymerization of acrylic core / shell type reinforcing agent resin particles was carried out in exactly the same manner as in Example 1. When forming the composition, the compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles are exactly the same as in Example 1, and the compounding amount of the dicyandiamide as the curing agent is 10 parts by weight with respect to 200 parts by weight of the epoxy resin. Example 15 is a case where parts are arranged. In Example 16 as well, the compounding amount of the acrylic core / shell type reinforcing agent resin particles with respect to the epoxy resin is exactly the same as in Example 1, and the compounding amount of dicyandiamide as a curing agent is 50 parts by weight with respect to 200 parts by weight of the epoxy resin. It was adjusted so that

Comparative Examples 13 and 14 Polymerization of acrylic core / shell type reinforcing agent resin particles was carried out in exactly the same manner as in Example 1. The compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles in forming the composition are exactly the same as in Example 1, and the compounding amount of the dicyandiamide as the curing agent is 4 parts by weight with respect to 200 parts by weight of the epoxy resin. Comparative Example 1 was prepared so that the amount was parts by weight.
3. In Comparative Example 14 as well, the compounding amount of the acrylic core / shell type reinforcing agent resin particles with respect to the epoxy resin was the same as in Example 1.
In the same manner as described above, the amount of dicyandiamide as a curing agent was adjusted to 70 parts by weight with respect to 200 parts by weight of epoxy resin.

Examples 17 and 18 Polymerization of acrylic core / shell type reinforcing agent resin particles was carried out in exactly the same manner as in Example 1. The compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles in forming the composition are exactly the same as in Example 1, and the compounding amount of azodicarbonamide which is a foaming agent with respect to 200 parts by weight of the epoxy resin. Example 17 is such that the amount is 2 parts by weight. In Example 18, the amount of acrylic core / shell type reinforcing agent resin particles mixed with the epoxy resin was exactly the same as in Example 1, and the amount of azodicarbonamide as a foaming agent was 200 parts by weight based on 200 parts by weight of the epoxy resin. It is adjusted so that it becomes a part.

Comparative Examples 15 and 16 Polymerization of acrylic core / shell type reinforcing resin particles was carried out in exactly the same manner as in Example 1. The compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles in forming the composition are exactly the same as in Example 1, and the compounding amount of azodicarbonamide which is a foaming agent with respect to 200 parts by weight of the epoxy resin. Is 15 parts by weight in Comparative Example 15. In Comparative Example 15, foaming of the composition was insufficient and filling of the box-shaped cross-section member was insufficient. In Comparative Example 16 as well, the compounding amount of the acrylic core / shell type reinforcing agent resin particles with respect to the epoxy resin is exactly the same as that of Example 1, and the compounding amount of azodicarbonamide as a foaming agent is 250 with respect to 200 parts by weight of the epoxy resin. It was adjusted so that it would be part by weight. In Comparative Example 16,
Since the composition overflowed from both open surfaces of the box-shaped cross-section member, the composition was removed and evaluated.

Examples 19 and 20 Polymerization of the acrylic core / shell type reinforcing agent resin particles was carried out in exactly the same manner as in Example 1. When forming the composition, the compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles were exactly the same as in Example 1, and the compounding amount of the filler calcium carbonate was 200 parts by weight of the epoxy resin. Although the amount was set to 10 parts by weight, Example 1 was used.
9 Also in Example 20, the blending amount of the acrylic core / shell type reinforcing agent resin particles with respect to the epoxy resin was the same as in Example 1
In the same manner as above, the blending amount of calcium carbonate as a filler is adjusted to 300 parts by weight with respect to 200 parts by weight of the epoxy resin.

Comparative Examples 17 and 18 Polymerization of acrylic core / shell type reinforcing resin particles was carried out in exactly the same manner as in Example 1. When forming the composition, the compounding amounts of the epoxy resin and the acrylic core / shell type reinforcing agent resin particles were exactly the same as in Example 1, and the compounding amount of the filler calcium carbonate was 200 parts by weight of the epoxy resin. Comparative Example 1 was prepared so as to be 2 parts by weight.
7 In Comparative Example 18 as well, the compounding amount of the acrylic core / shell type reinforcing agent resin particles with respect to the epoxy resin was the same as in Example 1.
In the same manner as described above, the blending amount of calcium carbonate as a filler is adjusted to 400 parts by weight with respect to 200 parts by weight of epoxy resin. In Comparative Example 18, the viscosity of the composition was high, and the coating property on the steel sheet was deteriorated.

Example 21 47 parts by weight of n-butyl acrylate was added to have 12 to 18 carbon atoms.
Using 1.0 part by weight of sodium alkyl fate as an emulsifier, 0.1 part by weight of potassium persulfate catalyst is added, and water 15
Emulsion polymerization was carried out by stirring for 180 minutes at a polymerization temperature of 70 ° C. in 0 part by weight to prepare a poly (n-butyl acrylate) core part fine particle dispersion polymerization liquid, and subsequently 47 parts by weight of methyl methacrylate was added to this polymerization liquid. Core for forming a shell part on the particle surface by continuously adding
Shell emulsion polymerization was performed. In this polymerization, when the polymerization of the methyl methacrylate reached 50%, 5 parts by weight of methacrylic acid and 0.5 parts by weight of tetraethylene glycol dimethacrylate (TEGDMA) as a cross-linking agent were continuously added to carry out copolymerization. Was completed.

To the latex after polymerization, 2 parts by weight of a 1% by weight aqueous solution of potassium hydroxide was added at room temperature, and the mixture was stirred for 30 minutes. Next, this solution was spray-dried using hot air of 150 ° C. to obtain reinforcing resin particles having an average particle size in the range of 0.2 to 0.3 μm. The reinforcing agent resin particles, liquid bisphenol A type epoxy resin, curing agent dicyandiamide, inorganic foaming agent sodium bicarbonate and inorganic filler calcium carbonate thus obtained were mixed in a planetary mixer at the ratios shown in Table 1. The mixture was used at room temperature to prepare an epoxy composition. Table 1 shows the results of evaluation using the box-shaped cross-section member assembled in this manner.

Example 22 The same polymerization as in Example 1 was carried out to obtain reinforcing resin particles. The reinforcing resin particles thus obtained, the liquid bisphenol A type epoxy resin, the curing agent dicyandiamide, the organic foaming agent azodicarbonamide, and the inorganic filler calcium carbonate were mixed in a planetary mixer at the ratios shown in Table 5. The mixture was used at room temperature to prepare an epoxy composition. This epoxy resin composition was pseudo-cured into a sheet having a thickness of 4 mm using an extruder set at 110 ° C., cut into a size of 50 mm × 700 mm, and then a butyl-based adhesive was used. Evaluation was performed using a box-shaped cross-section member that was bonded to a steel plate having a U-shaped cross section similar to that used in Example 1 and assembled using this steel plate. The results are shown in Table 5.

Comparative Example 19 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 1, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. The results are shown in Table 5.

Examples 23 and 24 The composition of the epoxy resin composition is exactly the same as that of Examples 2 and 3, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. Table 5 shows the results.

Comparative Example 20 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 2, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. The results are shown in Table 5.

Comparative Example 21 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 3, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. The results are shown in Table 5.

Comparative Example 22 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 4, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. The results are shown in Table 5.

Examples 25 and 26 The composition of the epoxy resin composition is exactly the same as that of Examples 4 and 5, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. Table 5 shows the results.

Comparative Example 23 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 5, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. The results are shown in Table 5.

Examples 27 and 28 The composition of the epoxy resin composition is exactly the same as that of Examples 6 and 7, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. The results of Example 27 are shown in Table 5, and the results of Example 28 are shown in Table 6.

Example 29 The composition of the epoxy resin composition is exactly the same as that of Example 8, but a sheet in which the epoxy resin composition was pseudo-cured was prepared and cut out in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. Table 6 shows the results.

Comparative Examples 24 and 25 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 6 and 7, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. The respective results are shown in Table 6.

Comparative Example 26 The composition of the epoxy resin composition is exactly the same as that of Comparative Example 8, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl series. The evaluation was performed using a box-shaped cross-section member assembled using steel plates bonded with an adhesive. Table 6 shows the results.

Examples 30 and 31 The composition of the epoxy resin composition is exactly the same as that of Examples 9 and 10, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. The respective results are shown in Table 6.

Examples 32 and 33 The composition of the epoxy resin composition is exactly the same as that of Examples 11 and 12, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 6.

Comparative Examples 27 and 28 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 9 and 10, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. The evaluation was performed using a box-shaped cross-section member that was assembled by using a steel sheet that was cut out and adhered via a butyl-based pressure-sensitive adhesive. The respective results are shown in Table 6.

Examples 34 and 35 The composition of the epoxy resin composition is exactly the same as that of Examples 13 and 14, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 7.

Comparative Examples 29 and 30 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 11 and 12, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 6.

Examples 36 and 37 The composition of the epoxy resin composition is exactly the same as that of Examples 15 and 16, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 7.

Comparative Examples 31 and 32 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 13 and 14, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 7.

Examples 38 and 39 The composition of the epoxy resin composition is exactly the same as that of Examples 17 and 18, but a sheet in which the epoxy resin composition is pseudo-cured is prepared and cut out as in Example 22. The evaluation was performed using a box-shaped cross-section member assembled using steel sheets bonded with a butyl adhesive. Table 7 shows each result.
Shown in

Comparative Examples 33 and 34 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 15 and 16, but a sheet in which the epoxy resin composition was pseudo-cured was prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The results of Comparative Example 33 are shown in Table 7, and the results of Comparative Example 34 are shown in Table 8.

Examples 40 and 41 The composition of the epoxy resin composition is exactly the same as that of Examples 19 and 20, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, Evaluation was performed using a box-shaped cross-section member that was cut out and assembled using a steel plate that was adhered via a butyl-based pressure-sensitive adhesive. The respective results are shown in Table 8.

Comparative Examples 35 and 36 The composition of the epoxy resin composition is exactly the same as that of Comparative Examples 17 and 18, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22. Cut out,
The evaluation was performed using a box-shaped cross-section member assembled using a steel sheet bonded via a butyl adhesive. The respective results are shown in Table 8.

Example 42 The composition of the epoxy resin composition is exactly the same as that of Example 21, but a sheet in which the epoxy resin composition is pseudo-cured is prepared in the same manner as in Example 22, cut out, and cut into butyl. The evaluation was performed using a box-shaped cross-section member assembled by using steel plates bonded with a system adhesive. Table 8 shows the results.

Example 43 Center pillar / waist portion of vehicle body and roof rail /
On the preformed steel plate that constitutes the center pillar joint,
As shown in FIG. 2, the epoxy resin composition of the present invention was applied using a coating gun and pseudo-cured by hot air at 110 ° C. for 20 seconds. Then, after assembling a car body using the steel sheet, the car body is washed with a caustic treatment solution to improve the adhesion of the coating film on the car body, and the car body is immersed in an electrodeposition bath for rust prevention at 170 ° C. , Bake the electrodeposition coating under the condition of 20 minutes,
At the same time, the epoxy resin composition was foamed and cured to fill the box-shaped structural member of the vehicle body and improve the rigidity. At this time, since the foamed material was preliminarily pseudo-cured, no outflow or falling out was observed in the washing / electrodeposition immersion step.

Example 44 Center pillar / waist portion of vehicle body and roof rail /
On the preformed steel plate that constitutes the center pillar joint,
As shown in FIG. 3, the epoxy resin composition of the present invention
The sheet pseudo-cured by hot air at 0 ° C. for 20 seconds was trimmed into a vehicle body shape, and the sheet was placed via an adhesive. Then, after assembling a car body using the steel sheet, the car body is washed with a caustic treatment solution to improve the adhesion of the coating film on the car body, and the car body is immersed in an electrodeposition bath for rust prevention at 170 ° C. Two
The electrodeposition coating film was baked under the condition of 0 minutes, and at the same time, the epoxy resin composition was foamed and cured to fill the box-shaped structural member of the vehicle body and improve the rigidity. At this time, since the foam material has been pseudo-cured beforehand,
No outflow or omission was observed in the electrodeposition dipping process.

[0115]

[Table 1]

[0116]

[Table 2]

[0117]

[Table 3]

[0118]

[Table 4]

[0119]

[Table 5]

[0120]

[Table 6]

[0121]

[Table 7]

[0122]

[Table 8]

[0123]

As described above, according to the epoxy resin composition for vehicle body reinforcement of the present invention and the vehicle body reinforcement method using the composition, the vehicle body skeleton can be lightly reinforced. Further, it is expected that the ride comfort of the vehicle will be improved and the noise and vibration will be reduced. Further, by filling the box-shaped cross-section member with a highly rigid foam, it is possible to improve the energy absorption at the time of a vehicle collision.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for measuring the rigidity improving effect of a box-shaped cross-section member by filling with an epoxy resin composition according to the present invention.

FIG. 2 is a process diagram showing a method for reinforcing a vehicle body, which is pseudo-cured after applying the epoxy resin composition according to the present invention.

FIG. 3 is a process diagram showing a method for reinforcing a vehicle body in which the epoxy resin composition according to the present invention is pseudo-cured in advance to form a sheet, which is then cut out and attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Epoxy resin composition 2 Box-shaped sectional member

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C08K 5/00 NKY C08K 5/00 NKY C08L 63/00 NJN C08L 63/00 NJN NJP NJP C09J 163/00 JFM C09J 163/00 JFM JFP JFP

Claims (4)

[Claims] 1. For (A) 100 parts by weight of an epoxy resin derived from bisphenol A and / or bisphenol F, (B) 10 to 100 parts by weight of powdered acrylate or methacrylate polymer, (C) for epoxy resin It is characterized by containing 3 to 30 parts by weight of a heat-activatable curing agent, 0.5 to 100 parts by weight of (D) a thermal decomposition type foaming agent, and 3 to 150 parts by weight of an inorganic filler (E). Epoxy resin composition for vehicle body reinforcement. 2. A core component comprising (B) an acrylate or methacrylate polymer (a) an acrylate or methacrylate polymer having a glass transition temperature of −30 ° C. or lower, and (b) (a) an acrylate or methacrylate polymer. And (b) 3 to 3 carbon atoms having a carboxyl group
8. A shell component composed of a copolymer having a glass transition temperature of 70 ° C. or higher obtained from the radically polymerizable unsaturated carboxylic acid monomer of 8 and (c) a crosslinkable monomer, and a core component / Resin powder particles obtained by ion-crosslinking copolymer resin particles having a weight ratio of shell components in the range of 10/1 to 1/4 with addition of monovalent or divalent metal cations. The epoxy resin composition for vehicle body reinforcement according to claim 1. 3. A box-shaped structural member for a vehicle body.
Alternatively, after the composition described in 2 is applied to a preformed steel plate, it is pseudo-cured by heating so as to prevent it from falling off or flowing out, and after assembling a box-shaped member using the steel plate, it may be used for vehicle body electrodeposition coating. A method of reinforcing a vehicle body, which comprises foaming in a baking process and filling the box-shaped structural member of the vehicle body to improve rigidity. 4. A box-shaped structural member for a vehicle body.
Alternatively, after the composition according to 2 is pseudo-cured by heating and trimmed into a vehicle body shape, it is adhered to a preformed steel plate via a catch such as an adhesive or a clip to prevent falling or outflow, A method for reinforcing a vehicle body, comprising assembling a box-shaped member using a steel sheet, followed by foaming in a baking step during electrodeposition coating of the vehicle body, and filling the box-shaped structural member of the vehicle body to improve rigidity.