JP2006240134A - Structural member for car and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structural member for a car which is improved in car body rigidity and crash safety. <P>SOLUTION: The structural member comprises a closed cross section filled with a foamed filler. As regards the foamed filler, a foamed epoxy filler (A) and a foamed urethane filler (B) are laminated and packed. The volume ratio of the foamed epoxy filler to the foamed urethane filler is 100:100-1,900. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automotive structural member in which a foam filler is filled in a structure having a closed space composed of an outer panel and an inner panel and / or an inner panel, such as a body side sill, a floor member, and a pillar of a vehicle body. More specifically, at least a part of the foam filler is composed of an epoxy foam filler and a urethane foam filler, and the volume ratio of the epoxy foam filler to the urethane foam filler is an epoxy foam. This is a urethane foam filler 100 to 1,900 with respect to the filler 100, and relates to a structural member for an automobile having improved vehicle body rigidity and collision safety.

  In general, the body structure of an automobile has a strong skeleton for each part of the body in terms of handling stability, ride comfort, noise and vibration performance. Many conventional vehicle body structural members have a closed cross-sectional structure composed of an outer panel and an inner panel. However, due to social demands to prevent depletion of fossil fuels, air pollution, and improved fuel efficiency, In order to reduce the thickness, it is common to use a method of reducing the thickness of the plate and adding a metal reinforcement or increasing the thickness of the plate to compensate for the corresponding decrease in rigidity.

  For example, a vehicle body structure has been proposed in which a rigid urethane foam filler is filled into a structural member having a closed cross section to reinforce a vehicle body skeleton (Patent Document 1). According to the publication, the use of a hard urethane foam filler can absorb impact energy even in the case of an automobile collision, and the front energy can be prevented from being transmitted backward by the sandwich structure.

The foam filler has a high buckling suppression effect, and can significantly improve the rigidity when the structural member is a box-type member. In comparison, the rigidity can be improved without significantly increasing the weight of the vehicle body. Examples of the resin-made foam filler include the olefin-based foam filler (Nihon Seika Co., Ltd., Sea Calastomer 240) and the epoxy-based foam filler (Oidatex RF-10, manufactured by Iida Sangyo Co., Ltd.) in addition to the urethane type. They can be used after being foamed and cured in the baking process of the electrodeposition coating process.
JP-A-48-2631

  However, in the reinforcing method using the urethane-based foam filler, impact energy can be effectively absorbed by a flexible urethane bond, but since the buckling suppression effect is small, the rigidity of the vehicle body is reduced when the structural member is filled. The expected effect on improvement may not be obtained.

  In addition, low-molecular weight polyethylene wax, polypropylene wax, etc. are used as the base olefin resin in olefin-based foam fillers, so the material rigidity is not sufficient, and even when structural members are filled, the rigidity of the vehicle body is improved. The expected effect may not be obtained.

  In addition, the epoxy foam filler has sufficient strength derived from the three-dimensional cross-linked structure of the epoxy resin and can significantly improve the rigidity of the structural member, but once the structural member buckles, the epoxy foam filling If cracks occur in the material, the cracks progress continuously, so that deformation of the structural member may not be suppressed.

  The present invention has been made in view of such a problem, and provides an automotive structural member having a closed cross section, which is excellent in vehicle body rigidity and collision safety, and a method for manufacturing the same. Objective.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in a structural member for an automobile having a closed cross section filled with a foam filler, at least a part of the foam filler is an epoxy-based foam filler and a urethane. It is possible to reduce the weight by limiting the volume ratio of the epoxy foam filler to the urethane foam filler to a specific range, and to improve the rigidity and collision safety of the vehicle body. As a result, the present invention has been completed.

  That is, the automotive structural member of the present invention is an automotive structural member having a closed cross section filled with a foam filler, wherein the foam filler is (A) an epoxy foam filler and (B) a urethane foam filler. And the volume ratio of the epoxy foam filler to the urethane foam filler is from urethane foam filler 100 to 1,900 with respect to the epoxy foam filler 100. And

  Furthermore, the ratio (p / q) of the compression elastic modulus q (MPa) of the (B) urethane-based foam filler to the compression elastic modulus p (MPa) of the (A) epoxy-based foam filler is 2.0 or more. And the compression strength of the (A) epoxy-based foam filler is 5 MPa or more.

  In addition, (A) the epoxy resin composition before foaming / curing of the epoxy foam filler is derived from (a) an epoxy resin having at least two epoxy groups in the molecule, and (b) an amino group. And (a) the epoxy equivalent of the epoxy resin is α, and the active hydrogen equivalent of the amino compound is β (β). The urethane-based resin composition before the foaming / curing of the (B) urethane-based foam filler includes (b) the amino compound 150β / α to 1,000β / α parts by mass with respect to 100 parts by mass of the epoxy resin. (C) an isocyanate resin having at least two or more isocyanate groups in the molecule, and (d) a hydrolyzate having at least two or more active hydrogens derived from a hydroxyl group or amino group in the molecule. When the isocyanate equivalent of (c) isocyanate resin is γ and the active hydrogen equivalent of (d) hydroxy compound or amino compound is θ, (c) 100 parts by mass of isocyanate resin On the other hand, it is characterized by containing (d) 30θ / γ to 90θ / γ parts by mass of a hydroxy compound or an amino compound.

  In addition, the foam filler has a two-layer structure of the (A) epoxy foam filler and the (B) urethane foam filler laminated inside the vehicle.

  In the method for manufacturing a structural member for an automobile of the present invention, the closed cross section is constituted by an outer panel, an inner panel, and / or a reinforcement, and the (A) epoxy resin composition is installed inside the outer panel. Then, a closed space is formed using the inner panel and / or the reinforcement, and the epoxy resin composition (A) is foamed and cured by baking of the electrodeposition coating treatment, and then the outer panel, the inner panel and / or the rain The urethane-based resin composition (B) is further injected into the unfilled portion of the foam filler between the force and foamed and cured.

  The automotive structural member of the present invention can achieve both excellent energy absorption and high rigidity with a minimum weight increase. Furthermore, the weight of the vehicle body can be reduced with respect to the metal reinforcement method, and the steering stability and the ride comfort can be improved, and the noise and vibration can be reduced.

  A first aspect of the present invention is an automotive structural member having a closed cross section filled with a foam filler, wherein the foam filler is formed by laminating (A) an epoxy foam filler and (B) a urethane foam filler. The volume ratio of the epoxy foam filler to the urethane foam filler is urethane foam filler 100 to 1,900 with respect to the epoxy foam filler 100. It is a structural member.

  (A) Epoxy foam filler and (B) urethane foam filler are filled so that the volume of the urethane foam filler is 100-1900 with respect to the volume of the epoxy foam filler 100. Then, an impact load can be reduced and buckling of a structural member can be suppressed. In the present invention, “automobile structural member having a closed cross-section” refers to an automotive structure in which the outermost layer of the cross-section of the structural member forms an irregular annular structure and forms a closed space in which the interior does not leak. It is a member. Examples of the structural member for an automobile that has such a closed cross-section include a body side sill, a floor member, and a pillar. Such an automobile structural member has a fixed mounting direction, and the urethane foam filler (B) is preferably laminated on the vehicle side of the automobile structural member. Due to the laminated structure, there is an epoxy foam filler with a large elastic modulus at the part that is bent by the input of impact load and enters the inside of the vehicle (buckling part). And buckling of the structural member can be suppressed. Further, even when the structural member is buckled, the urethane foam filler provided on the inner side of the vehicle can effectively absorb the impact energy and suppress the deformation of the structural member. In particular, a laminated structure of the urethane foam fillers 100 to 1,900 with respect to the epoxy foam filler 100 is preferable in terms of volume ratio. If the urethane foam filler 100 is equal to or greater than the epoxy foam filler 100, the impact energy can be absorbed without a sudden drop in load after the structural member buckles. On the other hand, if the urethane foam filler is 1,900 or less with respect to the epoxy foam filler 100, it is possible to increase the load during buckling without increasing the plate pressure of the structural member.

  The ratio (p / q) of the compression elastic modulus q (MPa) of the (B) urethane-based foam filler to the compression elastic modulus p (MPa) of the (A) epoxy-based foam filler is 2.0 or more. In addition, it is preferable that the compression strength of the (A) epoxy-based foam filler is 5 MPa or more.

  If the compressive strength of the epoxy foam filler is 5 MPa or more and the compressive modulus p of the epoxy foam filler is 2.0 times or more of the compressive modulus q of the urethane foam filler, a local impact will occur. Even if a load is input, buckling can be suppressed to the maximum without increasing the thickness of the structural member, and even if the structural member buckles and undergoes large deformation locally, the surface of the structural member The impact energy can be effectively absorbed without generating cracks in the urethane foam and cracks in the urethane foam filler. In this specification, “compressive strength” and “compressive modulus” are values measured by the method described in the examples.

  The epoxy resin composition before foaming / curing of the epoxy foam filler (A) is (a) an epoxy resin having at least two epoxy groups in the molecule, and (b) an activity derived from an amino group. An amino compound having at least two hydrogen atoms in the molecule, wherein (a) the epoxy equivalent of the epoxy resin is α, and (b) the active hydrogen equivalent of the amino compound is β, (a) the epoxy resin 100 parts by mass of the urethane-based resin composition before (b) the amino compound 150β / α to 1,000β / α parts by mass and before the foaming / curing of the (B) urethane-based foam filler, c) an isocyanate resin having at least two or more isocyanate groups in the molecule, and (d) a hydroxylation having at least two or more active hydrogens derived from a hydroxyl group or an amino group in the molecule. Or (c) the isocyanate equivalent of the isocyanate resin is γ, and the active hydrogen equivalent of the (d) hydroxy compound or amino compound is θ, And (d) 30θ / γ to 90θ / γ parts by mass of a hydroxy compound or an amino compound. The “epoxy equivalent” of the epoxy resin is the number of epoxy groups present in the molecule divided by the molecular weight of the epoxy resin. The same applies to the “active hydrogen equivalent” of the hydroxy compound and amino compound and the “isocyanate equivalent” of the isocyanate resin, which are obtained by dividing the number of hydroxyl groups, amino groups, and isocyanate groups present in the molecule by the molecular weight.

  The (a) epoxy resin constituting the epoxy resin composition of the present invention is not particularly limited as long as it has at least two epoxy groups in the molecule, and is appropriately selected according to the purpose of use and conditions. be able to. Preferably, it has 2 to 6 epoxy groups in the molecule. The epoxy equivalent (molecular weight per epoxy group) of the epoxy resin is usually 50 to 1,000, preferably 100 to 500. When the epoxy equivalent is 50 or more, the epoxy resin composition exhibits excellent storage stability. If the epoxy equivalent is 1,000 or less, a dense three-dimensional crosslinked structure can be formed, and the resulting (A) epoxy-based foam filler has excellent adhesion and mechanical strength to the steel sheet. Indicates. (A) Examples of the epoxy resin having at least two epoxy groups in the molecule include the following (a-1) to (a-5).

(A-1) Glycidyl ether type (i) Diglycidyl ether of 6 to 30 carbon dihydric phenols such as bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, bisphenol AD diglycidyl ether, bisphenol S diglycidyl Ether, halogenated bisphenol A diglycidyl ether, tetrachlorobisphenol A diglycidyl ether, catechin diglycidyl ether, resorcinol diglycidyl ether, hydroquinone diglycidyl ether, 1,5-dihydroxynaphthalenediglycidyl ether, dihydroxybiphenyl diglycidyl ether, octachloro -4,4'-dihydroxybiphenyl diglycidyl ether, tetramethylbiphenyl diglycidyl ether, 9, '- bis (4-hydroxyphenyl) furo diglycidyl ether, a diglycidyl ether obtained from bisphenol A2 moles and 3 moles of epichlorohydrin in the reaction.

  (Ii) polyglycidyl ethers of polyhydric phenols having a molecular weight of 300 to 5,000, such as pyrogallol triglycidyl ether, dihydroxynaphthylcresol triglycidyl ether, tris (hydroxyphenyl) methane triglycidyl ether, dinaphthyltriol triglycidyl ether, Trismethyl-tert-butyl-butylhydroxymethane triglycidyl ether, 4,4′-oxybis (1,4-phenylethyl) tetracresol tetraglycidyl ether, bis (dihydroxynaphthalene) tetraglycidyl ether, phenol or cresol novolac resin (number average) Glycidyl ether having a molecular weight of 500 to 5,000, polyphenol obtained by condensation reaction of phenol and formaldehyde And the like polyglycidyl ether, and resorcinol and the polyglycidyl ethers of polyphenols having a number average molecular weight of 500 to 5,000 obtained by the condensation reaction of acetone average molecular weight 500 to 5,000).

  (Iii) Diglycidyl ether of a diol having a molecular weight of 180 to 5,000 and having 2 to 100 carbon atoms, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, 1,6-hexanediol di Glycidyl ether, polyethylene glycol (molecular weight 180-5,000) diglycidyl ether, polypropylene glycol (molecular weight 180-5,000) diglycidyl ether, polytetramethylene glycol (molecular weight 200-5,000) diglycidyl ether, neopentyl glycol Diglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide [ethylene oxide or propylene oxide (1 to 20 mol)] adduct, etc. That.

  (Iv) Glycidyl ethers of polyhydric alcohols having a molecular weight of 100 to 5,000, such as trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol hexaglycidyl ether, poly (n = 2 to 5) ) Glycerol polyglycidyl ether.

(A-2) Glycidyl ester type Glycidyl ester of an aromatic polycarboxylic acid having 6 or more carbon atoms and 2 or more carbon atoms, and a glycidyl ester of an aliphatic or alicyclic polycarboxylic acid having 6 or more carbon atoms and 2 or more carbon atoms. Including.

  (I) Aromatic polycarboxylic acids such as glycidyl esters of phthalic acids include phthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, trimellitic acid triglycidyl ester, and the like.

  (Ii) As the glycidyl ester of the aliphatic or alicyclic polycarboxylic acid, the aromatic nucleus water additive of the above-mentioned phenolic glycidyl ester, diglycidyl oxalate, diglycidyl malate, diglycidyl succinate, diglycidyl glutata Examples thereof include (co) polymers (degree of polymerization of 2 to 10), tricarballylic acid triglycidyl ester, and the like of rate, diglycidyl adipate, diglycidyl pimelate, glycidyl acrylate, and glycidyl methacrylate.

(A-3) Glycidylamine type of aromatic glycidylamine and aliphatic, alicyclic or heterocyclic amines having 6 to 20 or more carbon atoms and having 2 to 10 or more active hydrogen atoms Includes glycidylamine and the like.

  (I) Glycidylamines of aromatic amines such as N, N-diglycidylaniline, N, N-diglycidyltoluidine, N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane, N, N, N ′ , N′-tetraglycidyldiaminodiphenylsulfone, N, N, N ′, N′-tetraglycidyldiethyldiphenylmethane, and the like.

  (Ii) Glycidylamines of aliphatic amines such as N, N, N ', N'-tetraglycidylxylylenediamine, N, N, N', N'-tetraglycidylhexamethylenediamine and the like.

  (Iii) Glycidylamines of alicyclic amines such as hydrogenated compounds of N, N, N ', N'-tetraglycidylxylylenediamine; glycidylamines of heterocyclic amines; trisglycidylmelamine and the like.

(A-4) Chain aliphatic epoxides A chain aliphatic epoxide having 6 to 50 or more carbon atoms and having 2 to 6 or more valences, for example, an epoxidized polybutadiene having an epoxy equivalent of 100 to 1,000 (number average molecular weight 180) ˜2,500) and epoxidized soybean oil (molecular weight 300˜2,500).

(A-5) Alicyclic epoxides Aliphatic epoxides having 6 to 50 or more carbon atoms, a molecular weight of 100 to 2500, and 2 to 4 or more epoxy groups, such as vinylcyclohexene dioxide, dicyclopentadiene Dioxide, ethylene glycol bisepoxy dicyclopentyl ether, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, and bis (3,4-epoxy-6-methylcyclohexylmethyl) butylamine. Moreover, the aromatic nucleus hydrogenated thing of the epoxy compound of the said phenols is also included.

  In addition, even if it is other than (a-1) to (a-5), any epoxy resin having at least two epoxy groups capable of reacting with active hydrogen in the molecule can be used. Moreover, these epoxy resins may be used individually by 1 type, and may use 2 or more types together. Among these, in order for the (A) epoxy foam filler of the present invention to exhibit excellent curability and mechanical strength, preferably (a-1) glycidyl ether type, (a-2) glycidyl ester Type, more preferably (a-1) glycidyl ether type. (A-1) Of the glycidyl ether types, diglycidyl ethers of dihydric phenols and dihydric aliphatic alcohols are preferred.

  The (b) amino compound of the present invention is not particularly limited as long as it is a compound having two or more active hydrogens derived from an amino group in the molecule, and can be appropriately selected according to the purpose and conditions. A compound having 2 to 10 active hydrogens derived from an amino group in the molecule is preferable, and a compound having 3 to 6 active hydrogens is more preferable. The active hydrogen equivalent (molecular weight per active hydrogen) of the amino compound is usually 20 to 1,000, preferably 30 to 300. When the active hydrogen equivalent is 20 or more, the epoxy resin composition exhibits excellent storage stability. If the active hydrogen equivalent is 1,000 or less, a dense three-dimensional crosslinked structure is formed, and the resulting (A) epoxy-based foam filler exhibits excellent adhesion and mechanical strength to the steel sheet. . (B) Examples of the amino compound having at least two active hydrogens derived from an amino group in the molecule include the following (b-1) to (b-5).

(B-1) Aliphatic polyamines The aliphatic polyamines have 2 to 18 carbon atoms, preferably 2 to 7 functional groups, and a molecular weight of 60 to 500, and additionally include alicyclic rings and heterocyclic rings. May be.

  (I) As an aliphatic polyamine, an alkylene diamine having 2 to 6 carbon atoms such as ethylene diamine, propylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine and the like; polyalkylene (2 to 6 carbon atoms) polyamine such as, for example, Examples include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. (Ii) these alkyl (carbon number 1 to 4) or hydroxyalkyl (carbon number 2 to 4) substitution products, for example, [dialkyl carbon number 1 to 3] aminopropylamine, trimethylhexamethylenediamine, aminoethylethanol There are amines. In addition, (iii) alicyclic or heterocyclic-containing aliphatic polyamines such as 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane can be used. Furthermore, (iv) aromatic ring-containing aliphatic amines (8 to 15 carbon atoms), for example, xylylenediamine and the like.

(B-2) Alicyclic polyamine The alicyclic polyamine preferably has 4 to 15 carbon atoms and 2 to 3 functional groups. For example, there are 1,3-diaminocyclohexane, isophorone diamine, 4,4′-methylene dicyclohexane diamine (hydrogenated methylene dianiline) and the like.

(B-3) Heterocyclic polyamine The heterocyclic polyamine preferably has 4 to 15 carbon atoms and 2 to 3 functional groups. For example, there are piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine and the like.

(B-4) Aromatic polyamines The aromatic polyamines preferably have 6 to 20 carbon atoms, 2 to 3 functional groups, and a molecular weight of 100 to 1,000.

  (I) unsubstituted aromatic polyamines such as 1,2-, 1,3- and 1,4-phenylenediamine, 2,4′- and 4,4′-diphenylmethanediamine, diaminodiphenylsulfone, thiodianiline, 2, Examples include 6-diaminopyridine, m-aminobenzylamine, and naphthylenediamine.

  (Ii) In the aromatic polyamine having a nucleus-substituted alkyl group, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, n-, i-propyl, and butyl. -And 2,6-tolylenediamine, crude tolylenediamine, diethyltolylenediamine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-bis (o-toluidine), 1,3 -Dimethyl-2,4-diaminobenzene, 1,3-diethyl-2,4-diaminobenzene, 1,3-dimethyl-2,6-diaminobenzene, 1,4-diethyl-2,5-diaminobenzene, 1 , 4-Diisopropyl-2,5-diaminobenzene, 1,4-dibutyl-2,5-diaminobenzene, 1,3,5-triethyl-2,4-diamino , 1,3,5-triisopropyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diamino Benzene, 2,3-dimethyl-1,4-diaminonaphthalene, 2,6-dimethyl-1,5-diaminonaphthalene, 2,6-diisopropyl-1,5-diaminonaphthalene, 2,6-dibutyl-1,5 -Diaminonaphthalene, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5′-tetraisopropyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetrabutyl-4,4′-diaminodiphenylmethane, 3,5-die 3'-methyl-2 ', 4-diaminodiphenylmethane, 3,5-diisopropyl-3'-methyl-2', 4-diaminodiphenylmethane, 3,3'-diethyl-2,2'-diaminodiphenylmethane, 4 , 4′-diamino-3,3′-dimethyldiphenylmethane, 3,3 ′, 5,5′-tetraethyl-4,4′-diaminobenzophenone, 3,3 ′, 5,5′-tetraisopropyl-4,4 '-Diaminobenzophenone, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenyl ether, 3,3 ', 5,5'-tetraisopropyl-4,4'-diaminodiphenylsulfone, etc.), and There are mixtures of various proportions of these isomers.

(Iii) Nuclear-substituted electron-withdrawing group-containing aromatic polyamine Examples of the nucleus-substituted electron-withdrawing group include halogens such as Cl, Br, I, and F; alkoxy groups such as methoxy and ethoxy; nitro groups and the like. Examples of the aromatic polyamine containing a nucleus-substituted electron withdrawing group include methylene bis-o-chloroaniline, 4-chloro-o-phenylenediamine, 2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline, 4- Bromo-1,3-phenylenediamine, 2,5-dichloro-1,4-phenylenediamine, 5-nitro-1,3-phenylenediamine, 3-dimethoxy-4-aminoaniline; 4,4′-diamino-3 , 3′-dimethyl-5,5′-dibromo-diphenylmethane, bis (4-amino-3-chlorophenyl) oxide, bis (4-amino-2-chlorophenyl) propane, bis (4-amino-2-chlorophenyl) sulfone Bis (4-amino-3-methoxyphenyl) decane, bis (4-aminophenyl) sulfide, bis (4-a Nophenyl) telluride, bis (4-aminophenyl) selenide, bis (4-amino-3-methoxyphenyl) disulfide, 4,4'-methylenebis (2-iodoaniline), 4,4'-methylenebis (2-bromoaniline) ), 4,4′-methylenebis (2-fluoroaniline), 4-aminophenyl-2-chloroaniline and the like.

(Iv) Aromatic polyamine having a secondary amino group A part or all of —NH ₂ of the aromatic polyamines (i) to (iii) above is —NH—R ′ (R ′ is an alkyl group such as methyl, ethyl For example, 4,4′-di (methylamino) diphenylmethane.

(B-5) Polyamide polyamine Obtained by condensation with dicarboxylic acid (such as dimer acid) and excess (more than 2 moles per mole of acid) polyamine (such as alkylene diamine and polyalkylene polyamine having 2 to 7 functional groups). Polyamide polyamines (number average molecular weight 200 to 1,000).

(B-6) Polyether polyamines Polyether polyols, for example, hydrides (molecular weights of 100 to 1,000) of cyanoethylated products such as the above-mentioned polyalkylene glycols.

(B-7) Epoxy-added polyamine For example, an epoxy-added polyamine (molecular weight: 100 to 1) obtained by adding 1 to 30 mol of an epoxy compound (A) to 1 to 30 mol of a polyamine (the alkylene diamine, polyalkylene polyamine, etc.). , 000).

(B-8) Cyanoethylated polyamines There are cyanoethylated polyamines (molecular weight: 100 to 500) obtained by addition reaction of acrylonitrile and polyamines (the above-mentioned alkylenediamine, polyalkylenepolyamine, etc.).

(B-9) Other polyamine compounds (i) Hydrazines (hydrazine, monoalkylhydrazine, etc.); (ii) Dihydrazides (succinic acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, etc.); (iii) There are guanidines (butyl guanidine, 1-cyanoguanidine, etc.); (iv) dicyandiamide, etc .; and a mixture of two or more of these.

  In addition, compounds other than (b-1) to (b-9) can be used as long as they are amino compounds having two or more active hydrogens derived from amino groups in the molecule. Moreover, these amino compounds may be used individually by 1 type, and may use 2 or more types together. Among these, in order for (A) the epoxy foam filler to exhibit excellent curability and mechanical strength, (b-4) aromatic polyamines, (b-9) other polyamine compounds are preferred. And (b-9) other polyamine compounds are more preferable. (B-9) Among other polyamine compounds, dihydrazides and dicyandiamide are preferable.

  The blending amount of the (a) epoxy resin and (b) amino compound of the present invention is not particularly limited, but preferably (a) the epoxy equivalent of the epoxy resin is α, and (b) the active hydrogen equivalent of the amino compound is β When (a) 100 parts by mass of the epoxy resin is usually (b) the amino compound 150β / α to 1,000β / α parts by mass, preferably (b) the amino compound 200β / α to 500β / α. Part by mass. Within this range, an epoxy resin composition in which the compressive strength of the epoxy foam filler is 5 MPa or more can be obtained. Moreover, if it is the said range, ratio (p / q) of the compression elastic modulus q (MPa) of (B) urethane type foaming filler with respect to the compression elastic modulus p (MPa) of (A) epoxy type foaming filler will be 2. An epoxy resin composition of 0.0 or more can be obtained, and the resulting epoxy foam filler can exhibit excellent curability, adhesion, water resistance, and chemical resistance.

  In addition to (a) epoxy resin and (b) amino compound, the epoxy resin composition used in the present invention includes (e) a curing acceleration catalyst and (f) a pyrolytic organic foaming agent as necessary. May be.

  The (e) curing accelerating catalyst is not particularly limited as long as it is a catalyst for accelerating the reaction between (a) an epoxy resin and (b) an amino compound, and can be appropriately selected according to the purpose and conditions. A tertiary amino compound having at least one tertiary amino group in the molecule is preferable. Examples of the curing accelerating catalyst include the following (e-1) to (e-3).

  (E-1) Aliphatic tertiary amine: trimethylamine, triethylamine, dimethylcyclohexylamine, dimethylbenzylamine, 1,2-dimethylimidazole, tetraethylmethylenediamine, tetramethylpropane-1,3-diamine, tetramethylhexane-1, 6-diamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetramethylguanidine, dimethylpiperazine, N-methyl-N '-(2-dimethylamino) -ethylpiperazine, N-methylmorpholine, N- (N', N '-Dimethylaminoethyl) morpholine, dimethylaminoethanol and the like.

  (E-2) Phenol nucleus-containing aliphatic tertiary amine: N, N-dimethylaminomethylphenol (DMP-10, manufactured by Rohm & Haas), Tris (N, N-dimethylaminomethylphenol (DMP-30, Rohm) & Haas).

  (E-3) Nitrogen-containing heterocyclic compound: 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU, manufactured by San Apro), 1,5-diazabicyclo (4,3,0) -nonene- 5 (DBN, manufactured by San Apro), 6-dibutylamino-1,8-diazabicyclo (5,4,0) -undecene-7 (DBA-DBU, manufactured by San Apro), triethylenediamine, hexamethylenetetramine and the like.

  It should be noted that a catalyst other than (e-1) to (e-3) can be used as long as it is a curing accelerating catalyst for accelerating the reaction between (a) an epoxy resin and (b) an amino compound. Further, two or more of these curing accelerating catalysts can be used in combination. Of these, (e-1) an aliphatic tertiary amine is preferable in order for the (A) epoxy foam filler of the present invention to exhibit excellent curability and mechanical strength. (E-1) Among aliphatic tertiary amines, imidazoles and piperazines are preferable.

  (E) The compounding quantity of a hardening acceleration | stimulation catalyst is not specifically limited, Usually, it is 0.1-15 mass parts with respect to 100 mass parts of (a) epoxy resins. When the blending amount of the (e) curing accelerating catalyst is 0.1 parts by mass or more, the (A) epoxy-based foam filler of the present invention can exhibit excellent curability due to the accelerating effect. When the blending amount of the (e) curing accelerating catalyst is 15 parts by mass or less, the epoxy resin composition of the present invention exhibits excellent storage stability.

  (F) The pyrolytic organic foaming agent is not particularly limited as long as it thermally decomposes and foams, for example, when the epoxy resin composition is baked in the electrodeposition coating treatment. It can be selected as appropriate according to the conditions. Preferably, from the viewpoint of storage stability of the epoxy resin composition, the decomposition / foaming start temperature is 80 ° C. or higher. Examples of the (f) pyrolytic organic foaming agent include the following (f-1) to (f-4).

  (F-1) Azo compounds: azodicarbonamide (ADCA), azobisisobutyronitrile (AIBN) and the like.

(F-2) Nitroso compounds: dinitrosopentamethylenetetramine (DPT) and the like.
(F-3) Sulfohydrazide compounds: p, p′-oxybisbenzenesulfonyl hydrazide (OBSH), p-toluenesulfonyl hydrazide (TSH), and the like.

  (F-4) Other compounds: hydrazodicarbonamide (HDCA) and the like.

  It should be noted that other than (f-1) to (f-4) can be used as long as they are thermally decomposed and foamed in the baking process of the electrodeposition coating process. These pyrolyzable organic foaming agents can be used in combination of two or more. Of these, (f-1) an azo compound is preferred in order to foam the epoxy resin composition of the present invention uniformly and stably. (F-1) Of the azo compounds, azodicarbonamide (ADCA) is preferable.

  The blending amount of the (f) pyrolytic organic foaming agent is not particularly limited, and is usually 0.5 to 20 parts by mass with respect to 100 parts by mass of the (a) epoxy resin. If the blending amount of the (f) pyrolyzable organic foaming agent is 0.5 parts by mass or more, the foaming ratio of the (A) epoxy foam filler of the present invention is constant, so that the performance is stable. Can be expressed. If the blending amount of the (f) pyrolytic organic foaming agent is 20 parts by mass or less, the mechanical strength of the (A) epoxy foam filler of the present invention is excellent without causing scorching due to the decomposition heat. Can be expressed.

  The (f) pyrolytic organic foaming agent may be used in combination with a foaming aid in order to control the proper foaming temperature. Foaming aids include inorganic salts such as zinc white, zinc nitrate, lead phthalate, lead carbonate, tribasic lead phosphate, tribasic lead sulfate, metals such as zinc fatty acid soap, lead fatty acid soap, cadmium fatty acid soap Examples include soaps, acids such as boric acid, oxalic acid, succinic acid, and adipic acid, urea, biurea, ethanolamine, glycol, glycerin, and the like. These foaming aids can be used in combination of two or more.

  As a manufacturing method of the epoxy resin composition of the present invention, (a) an epoxy resin, (b) an amino compound, (e) a curing accelerating catalyst, (f) a thermally decomposable organic foaming agent, and, if necessary, The method is not particularly limited as long as other additives can be mixed and uniformly dispersed, and examples thereof include the following methods. In a suitable container such as a glass beaker, can, or plastic cup, knead by hand with a stirring bar or spatula, or a device with a double helical ribbon blade, gate blade, universal mixer, planetary mixer, bead mill, 3 bottles Although it can knead | mix with a conventionally well-known mixing apparatus, such as a roll and an extruder type kneading extruder, Preferably, it is a mixing apparatus, such as a universal mixer.

  Examples of the additives include (1) antioxidants such as hindered amines, hydroquinones, hindered phenols, and sulfur-containing compounds, and (2) ultraviolet absorption of benzophenones, benzotriazoles, salicylic acid esters, metal complexes, and the like. Agents, (3) metal soaps, inorganic and organic salts of heavy metals (eg, zinc, tin, lead, cadmium, etc.), weathering stabilizers such as organic tin compounds, (4) phthalates, phosphates, fatty acid esters , Plasticizers such as epoxidized soybean oil, castor oil, liquid paraffin alkyl polycyclic aromatic hydrocarbons, (5) paraffin wax, microcrystalline wax, polymer wax, beeswax, whale wax, low molecular weight (for example, number average molecular weight 300) ~ 2,000) Waxes such as polyolefin, (6) n-butylglycidy Reactive diluents such as aliphatic glycidyl ethers such as ether, aromatic monoglycidyl ethers such as phenyl glycidyl ether, (7) Calcium carbonate, kaolin, talc, mica, bentonite, clay, sericite, asbestos, glass fiber, aramid fiber , Nylon fiber, Acrylic fiber, Glass balloon, Shirasu balloon, Coal powder, Acrylic resin powder, Phenol resin powder, Ceramic powder, Zeolite, Slate powder and other fillers, (8) Deodorants such as activated carbon, zeolite, silica sol, silica gel (9) Carbon black, titanium oxide, red iron oxide, red lead, para red, bitumen and other pigments, (10) antifoaming agent, (11) dehydrating agent, (12) antistatic agent, (13) antibacterial agent, (14) Add fungicides, (15) perfumes, (16) flame retardants, etc. Door can be. Two or more of these additives can be used in combination. The compounding amount of these additives is usually 0.1 to 200 parts by mass with respect to 100 parts by mass of (a) epoxy resin, and preferably 1 to 100 parts by mass with respect to 100 parts by mass of (a) epoxy resin. is there.

  The curing mechanism of the epoxy resin composition of the present invention is as follows. First, (f) a pyrolytic organic foaming agent is thermally decomposed and foamed by baking in an electrodeposition coating process, and (a) an epoxy resin and (b) amino A compound is reacted to form and cure a three-dimensional crosslinked structure. In this case, the storage and use form of the epoxy resin composition includes (a) an epoxy resin, (b) an amino compound, (e) a curing accelerating catalyst, (f) a pyrolytic organic foaming agent and an additive in advance. It can be stored in the form of a liquid and given a heat load just before use to be foamed and cured.

  The (c) isocyanate resin constituting the urethane-based resin composition of the present invention is not particularly limited as long as it has at least two isocyanate groups in the molecule, and is appropriately selected according to the purpose and conditions. Can do. Preferably, it has 2 to 6 isocyanate groups in the molecule. The isocyanate equivalent (molecular weight per isocyanate group) of the isocyanate resin is usually 50 to 1,000, preferably 100 to 500. When the isocyanate equivalent is 50 or more, the urethane resin composition of the present invention exhibits excellent curability. If the isocyanate equivalent is 1,000 or less, the (B) urethane-based foam filler of the present invention exhibits excellent mechanical strength. (C) Examples of the isocyanate resin having at least two or more isocyanate groups in the molecule include the following (c-1) to (c-4).

  (C-1) aromatic isocyanate; 1,3- or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, diphenylmethane-2,4'- and And / or -4,4'-diisocyanate (MDI), polymethylene polyphenyl isocyanate (crude MDI), naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate.

  (C-2) Aliphatic or alicyclic isocyanate; isophorone diisocyanate, 1,6-hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexylene diisocyanate, 2,2,4-trimethylhexamethylene There are diisocyanates.

  (C-3) aromatic aliphatic isocyanates such as xylylene diisocyanate and tetramethyl xylylene diisocyanate.

  (C-4) Other isocyanates; modified products (trimethylolpropane, castor oil, sucrose and other polyol addition modified products, carbodiimide modified products, allophanate modified products, urea modified products, burette modified products, isocyanurate modified products, oxazolidone modified products And the like, and a terminal NCO group-containing urethane prepolymer obtained by reaction of polyols with an excess of a polyisocyanate compound.

  It should be noted that, other than (c-1) to (c-4), any isocyanate resin having at least two isocyanate groups capable of reacting with active hydrogen in the molecule can be used. These isocyanate resins can be used in combination of two or more. Among these, in order for the (B) urethane foam filler of the present invention to exhibit excellent curability and mechanical strength, preferably (c-1) aromatic isocyanate, (c-4) and others Isocyanates. Of (c-1) aromatic isocyanate and (c-4) other isocyanates, MDI, crude MDI, sucrose-modified TDI, and carbodiimide-modified MDI are preferable.

  (D) The hydroxy compound or amino compound is not particularly limited as long as it is a compound having two or more active hydrogens derived from a hydroxyl group or amino group in the molecule, and can be appropriately selected according to the purpose and conditions. A compound having 2 to 10 active hydrogens derived from a hydroxyl group or an amino group in the molecule is preferable, and a compound having 3 to 6 active hydrogens is more preferable. The active hydrogen equivalent (molecular weight per active hydrogen) of the hydroxyl group or amino compound is usually 20 to 1,000, preferably 30 to 300. When the active hydrogen equivalent is 20 or more, the (B) urethane-based foam filler of the present invention exhibits excellent curability. When the active hydrogen equivalent is 1,000 or less, the (B) urethane foam filler of the present invention exhibits excellent adhesiveness and mechanical strength. (B) Examples of the hydroxy compound or amino compound having at least two active hydrogens derived from a hydroxyl group or amino group in the molecule include the following (d-1) to (d-7).

  (D-1) polyhydric alcohols; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, cyclohexylene glycol and other dihydric alcohols, trimethylolpropane, glycerin, etc. There are tetrahydric or higher alcohols such as trihydric alcohol, pentaerythritol, sorbitol, methylglycoside, diglycerin, sorbitol, sucrose.

  (D-2) Bisphenols; hydroquinone, 1,4-bis (hydroxyethoxy) benzene, bisphenol A, bisphenol F, bisphenol S, 4,4′-dihydroxybiphenyl, 2,2′-bis (4-hydroxyphenyl) There are hexafluoropropane and the like.

  (D-3) Aliphatic amine; ammonia, monoethanolamine, diethanolamine, triethanolamine, polymethylenediamine (ethylenediamine, diaminobutane, diaminopropane, hexanediamine, dodecanediamine, etc.), polyethylene polyamine (diethylenetriamine, triethylenetetramine, etc.) ) And polyether diamine.

  (D-4) Aromatic amine; 2,4- or 2,6-diaminotoluene (TDA), crude TDA, 1,2-, 1,3- or 1,4-phenylenediamine, diethyltolylenediamine, 4 , 4′-diaminodiphenylmethane (MDA), crude MDA, 1,5-naphthylenediamine, 3,3′-dichloro-4,4′-diaminodiphenylmethane, 3,3′-dimethyl-4,4′-diaminodiphenyl There is cyclohexane.

  (D-5) Aliphatic amine having an aromatic ring; 1,2-, 1,3- or 1,4-xylenediamine and the like.

  (D-6) Alicyclic amine; 4,4′-diaminodicyclohexylmethane, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, 3-amino-1-cyclohexylaminopropane, bis (aminomethyl) Examples include cyclohexane, isophoronediamine, norbornanediamine, mensendiamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (-5,5-) undecane.

  (D-7) Other polyol compounds: oligomers having two or more hydroxyl groups, such as polyester polyol (condensate of polycarboxylic acid and polyhydroxyl compound), polycarbonate polyol, polycaprolactone polyol, polybutadiene polyol, acrylic polyol, ethylene Polymer polyol modified with a polymerizable unsaturated monomer.

  In addition, compounds other than (d-1) to (d-7) can be used as long as they are hydroxy compounds or amino compounds having two or more active hydrogens derived from a hydroxyl group or an amino group in the molecule. These hydroxy compounds or amino compounds can be used in combination of two or more. Among these, in order for the (B) urethane foam filler of the present invention to exhibit excellent curability and mechanical strength, preferably (d-1) polyhydric alcohol, (d-7) other A polyol compound, more preferably (d-1) a polyhydric alcohol. (D-1) Among the polyhydric alcohols, a polyether polyol obtained by an addition reaction of an alkylene oxide (for example, one or more of ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, etc.) is preferable.

  (D) The compounding amount of the hydroxy compound or amino compound is not particularly limited. When (c) the isocyanate equivalent of the isocyanate resin is γ, and (d) the active hydrogen equivalent of the hydroxy compound or amino compound is θ, (c) Isocyanate resin: 100 parts by mass Usually, (d) hydroxy compound or amino compound: 30θ / γ to 90θ / γ part by mass, preferably (d) hydroxy compound or amino compound: 50θ / γ to 80θ / γ Part by mass. Within this range, the ratio (p / q) of the compression elastic modulus q (MPa) of (B) urethane-based foam filler to the compression elastic modulus p (MPa) of (A) epoxy-based foam filler is 2.0 or more. A urethane resin composition can be obtained, and the obtained urethane foam filler (B) can exhibit excellent curability, adhesion, and mechanical strength.

  In addition to (c) the isocyanate resin, (d) the hydroxy compound or the amino compound, the two-component urethane resin composition of the present invention may contain (g) a curing accelerating catalyst as necessary.

  (G) The curing accelerating catalyst is not particularly limited as long as it is a catalyst for accelerating the reaction between (c) an isocyanate resin and (d) a hydroxy compound or an amino compound, and is appropriately selected according to the purpose and conditions. Can do. A tertiary amino compound having at least one tertiary amino group in the molecule is preferable. Examples of the (g) curing accelerating catalyst include the following (g-1) to (g-4).

  (G-1) Aliphatic tertiary amine: trimethylamine, triethylamine, dimethylcyclohexylamine, dimethylbenzylamine, 1,2-dimethylimidazole, tetraethylmethylenediamine, tetramethylpropane-1,3-diamine, tetramethylhexane-1, 6-diamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, tetramethylguanidine, dimethylpiperazine, N-methyl-N '-(2-dimethylamino) -ethylpiperazine, N-methylmorpholine, N- (N', N '-Dimethylaminoethyl) morpholine, dimethylaminoethanol and the like.

  (G-2) Phenol nucleus-containing aliphatic tertiary amine: N, N-dimethylaminomethylphenol (DMP-10, manufactured by Rohm & Haas), Tris (N, N-dimethylaminomethylphenol (DMP-30, Rohm) & Haas).

  (G-3) Nitrogen-containing heterocyclic compound: 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU, manufactured by San Apro), 1,5-diazabicyclo (4,3,0) -nonene- 5 (DBN, manufactured by San Apro), 6-dibutylamino-1,8-diazabicyclo (5,4,0) -undecene-7 (DBA-DBU, manufactured by San Apro), triethylenediamine, hexamethylenetetramine and the like.

  (G-4) Organometallic compounds: stannous octylate, dibutyltin dilaurate, lead octylate and the like.

  Any catalyst other than (g-1) to (g-4) can be used as long as it is a catalyst for promoting the reaction between (c) an isocyanate resin and (d) a hydroxy compound or an amino compound. Further, two or more of these curing accelerating catalysts can be used in combination. Among these, in order for the (B) urethane foam filler of the present invention to exhibit excellent curability and mechanical strength, (g-3) a nitrogen-containing heterocyclic compound is preferable. (G-3) Among the nitrogen-containing heterocyclic compounds, 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU), triethylenediamine, and hexamethylenetetramine are preferable.

  (G) The compounding quantity of a hardening acceleration | stimulation catalyst is not specifically limited, Usually, it is 0.0001-10 mass parts with respect to 100 mass parts of (c) isocyanate resin. If the blending amount of the (g) curing accelerating catalyst is 0.0001 part by mass or more, the urethane foam filler (B) can exhibit excellent curability due to the accelerating effect. On the other hand, if the blending amount of the (g) curing accelerating catalyst is 10 parts by mass or less, the (B) urethane-based foam filler exhibits excellent mechanical strength.

  As a method for producing the urethane resin composition, (c) an isocyanate resin, (d) a hydroxy compound or an amino compound, (g) a curing accelerating catalyst and, if necessary, an additive can be mixed and dispersed uniformly. If it is, it will not specifically limit, For example, the following method is mentioned. In a suitable container such as a glass beaker, can, or plastic cup, knead by hand with a stirring bar or spatula, or a device with a double helical ribbon blade, gate blade, universal mixer, planetary mixer, bead mill, 3 bottles Kneading can be carried out by a conventionally known mixing apparatus such as a roll or an extruder type kneading extruder, but a method using a mixing head for RIM (Reaction Injection Molding) molding is preferred. This method is a method in which a liquid urethane resin composition that is a raw material for a urethane-based foam filler is collided and mixed under high pressure, and then the mixed solution is discharged from a nozzle. Therefore, the liquid mixture can be immediately cured and foamed, and the filling of the urethane foam filler can be completed in a relatively short working time.

  The additive that can be used in the urethane resin composition is the same as the additive that can be used in the epoxy resin composition, and two or more of them can be used in combination. The compounding amount of these additives is usually 0.1 to 200 parts by mass with respect to 100 parts by mass of (c) isocyanate resin, and preferably 1 to 100 parts by mass with respect to 100 parts by mass of (c) isocyanate resin. is there.

  The curing mechanism of the urethane-based resin composition is as follows. First, (c) the isocyanate resin and (d) water contained in the hydroxy compound or amino compound react to generate / foam carbon dioxide, and almost (c) ) The isocyanate resin and (d) the hydroxy compound or amino compound react immediately to form and cure a urethane bond. Accordingly, the urethane resin composition is stored and used in the form of an independent two-component solution comprising (c) an isocyanate resin and (d) a mixture of a hydroxy compound or amino compound and (g) a curing accelerating catalyst. The two liquids are mixed immediately before foaming and curing. In addition, an additive component can also be previously contained in (c) isocyanate resin and / or (d) hydroxy compound or amino compound.

  In the automotive structural member of the present invention, the foam filler filled in the closed cross section forms a laminated structure of an epoxy foam filler and a urethane foam filler, and in particular, the urethane foam filler is inside the vehicle. It is preferable to have a two-layer structure laminated with an epoxy-based foam filler.

  According to the laminated structure, in order to form a laminated structure in which the epoxy foam filler and the urethane foam filler are in contact with each other, the amino compound contained in the epoxy foam filler and the urethane foam filler The isocyanate resin contained can form a urethane bond. As a result, the epoxy foam filler and the urethane foam filler form a strong adhesive interface, and the rigidity of the vehicle body can be further improved.

  2nd of this invention is a manufacturing method of the said structural member for motor vehicles, Comprising: The said closed cross-section is comprised from an outer panel, an inner panel, and / or a reinforcement, The said (A) epoxy type is carried out inside the said outer panel. A resin composition is installed, a closed space is formed using an inner panel and / or a reinforcement, and the epoxy resin composition (A) is foamed and cured by baking in an electrodeposition coating treatment, and then the outer panel and the inner The urethane resin composition (B) is further injected into the unfilled portion of the foam filler between the panel and / or the reinforcement, and is foamed and cured.

  For example, after the epoxy resin composition is placed on the inner side of the outer panel, it is foamed and filled, and the foam filler is not filled between the outer panel / reinforce or the outer panel / inner panel inside the automobile structural member. The method is not particularly limited as long as it is a method in which a urethane-based resin composition is injected into a part and foamed and cured, and examples thereof include the following methods. First, an epoxy resin composition is molded into a sheet by a method such as casting, compression molding, or extrusion molding, and the obtained sheet is placed inside an outer panel of an automotive structural member that has been molded in advance. Next, a closed cross-section structure is assembled using an inner panel and / or a reinforce constituting the vehicle inner portion of the closed cross section, and the sheet is foamed and cured by baking in an electrodeposition coating process. Furthermore, in the vehicle body assembly process, the urethane resin composition is injected between the outer panel / reinforce, or between the outer panel / inner panel in the automobile structural member, and the foam filler is not filled, immediately after injection. The structural member for automobiles is completed by foaming and curing.

  In the manufacturing method of the structural member for automobiles, since the sheet made of the epoxy resin composition of the present invention is semi-solid or solid, workability is very good. In the method for manufacturing a structural member for an automobile, the formation of the closed space by the outer panel and the inner panel and / or the inner panel is not limited to the above. For example, the outer space is formed after the structural members are assembled to form the closed space. You may install a sheet | seat inside a panel. The method for setting the sheet formed by molding the epoxy resin composition of the present invention inside the outer panel is not particularly limited as long as the sheet can be fixed to the panel, and examples thereof include the following methods. The sheet can be installed by a conventionally known method such as a method of directly attaching a sheet with a hand or a roller, an adhesive or an adhesive material, or a method of indirectly attaching with a locking clip, but preferably an adhesive material or It is a method of installing with a stop clip. The baking process of the electrodeposition coating treatment is not particularly limited as long as the sheet formed by molding the epoxy resin composition of the present invention can be uniformly foamed and cured inside the structural member, depending on the purpose and conditions. It can be selected appropriately. Preferably, heating is performed at 140 ° C. to 230 ° C. for 10 to 30 minutes. If the heating temperature is 140 ° C. or higher, the epoxy resin composition forms a dense three-dimensional crosslinked structure, and (A) the epoxy foam filler has excellent adhesion and mechanical strength to the panel. Can be expressed. When the heating temperature is 230 ° C. or lower, the curing shrinkage of the (A) epoxy-based foam filler is small and cracks do not occur. If the heating time is 10 minutes or longer, the epoxy resin composition forms a dense three-dimensional cross-linked structure, and (A) the epoxy foam filler has excellent adhesion and mechanical strength to the panel. Can be expressed. When the heating time is 30 minutes or less, the (A) epoxy foam filler can exhibit excellent mechanical strength without causing thermal deterioration. Furthermore, the method for injecting the urethane resin composition of the present invention into the structural member is not particularly limited as long as the urethane resin composition can be uniformly foamed and cured, and can be injected by a conventionally known method. However, it is preferable to use the above-mentioned mixing nozzle for RIM molding. The injection conditions for the urethane-based resin composition are not particularly limited as long as the urethane-based resin composition can be uniformly foamed and filled inside the structural member, and can be appropriately selected according to the purpose and conditions. Preferably, the injection temperature of the urethane resin composition is 10 ° C to 90 ° C. If the injection temperature is 10 ° C. or higher, the fluidity of the urethane-based resin composition is good and can be uniformly filled up to the details inside the structural member. If the injection temperature is 90 ° C. or less, the urethane resin composition can be foamed and cured immediately after injection without causing thermal decomposition.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

(Production Example 1)
(A) 100 parts by mass of a bisphenol A type liquid epoxy resin (Epicoat 828, manufactured by Japan Epoxy Resin; epoxy equivalent 190) as an epoxy resin, (b) Dicyandiamide (DICY15, manufactured by Japan Epoxy Resin Co., Ltd .; active hydrogen equivalent 22) ) 30 parts by mass, (e) 1 part by mass of imidazole (2-methylimidazole, manufactured by BASF Japan) as a curing accelerating catalyst, and (f) azodicarbonamide (Cermic CE, Sankyo Kasei Co., Ltd.) as a pyrolytic organic foaming agent. Product), 10 parts by mass of butadiene-acrylonitrile rubber (NBR) with three rolls at room temperature, and further 70 parts by mass of calcium carbonate (NS-200, manufactured by Nitto Flour Chemical Co., Ltd.) as a filler, glass beads ( UBS-0020L (manufactured by Union)) 30 parts by mass, as pigment Over carbon black 3 parts by weight was added, a planetary mixer having a volume 10L, 12rpm, 45 ℃ × 30 minutes, and stirred until homogeneous. This is poured into a polypropylene container 100 mm long x 100 mm wide x 15 mm deep, defoamed with a vacuum degassing apparatus at 25 ° C for 3 minutes, and cured at 25 ° C for 3 hours to fill with foam of 3 mm thickness A sheet formed by molding the material composition was obtained (referred to as an epoxy resin composition P).

(Production Example 2)
(A) 100 parts by mass of a bisphenol A type liquid epoxy resin (Epicoat 828, manufactured by Japan Epoxy Resin; epoxy equivalent 190) as an epoxy resin, (b) Dicyandiamide (DICY15, manufactured by Japan Epoxy Resin Co., Ltd .; active hydrogen equivalent 22) ) 10 parts by mass, (e) 1 part by mass of imidazole (2-methylimidazole, manufactured by BASF Japan) as a curing accelerating catalyst, and (f) azodicarbonamide (Cermic CE, Sankyo Kasei Co., Ltd.) as a pyrolytic organic foaming agent. ), 10 parts by mass of styrene-butadiene rubber (SBR) at room temperature with three rolls, and further 100 parts by mass of calcium carbonate (NS-200, manufactured by Nitto Flour Chemical Co., Ltd.) as a filler and carbon as a pigment. Add 3 parts by weight of black, and use a planetary mixer with a capacity of 10L. 12 rpm, 45 ° C. × 30 minutes, and stirred until homogeneous. This is poured into a polypropylene container of length 100 mm x width 100 mm x depth 15 mm, defoamed at 25 ° C for 3 minutes with a vacuum degassing device, and cured at 25 ° C for 3 hours. A sheet formed by molding the material composition was obtained (referred to as epoxy resin composition Q).

(Production Example 3)
(D) 100 parts by mass of trimethylolpropane-modified polyether triol (Sanix TE-300, manufactured by Sanyo Chemical Industries, Ltd .; active hydrogen equivalent 100) as a hydroxy compound or amino compound, (g) an aliphatic tertiary amine as a curing accelerating catalyst (Pentamethylenediethyltetramine, manufactured by Mitsui Chemicals) 2 parts by mass, a planetary mixer with a capacity of 5 L in which 0.2 parts by mass of pure water was previously dried as a blowing agent, until 12 rpm, 25 ° C. × 15 minutes, until uniform Stir. The obtained mixed solution was stored as “curing agent”, (c) 100 parts by mass of modified MDI (Cosmonate M-100, manufactured by Mitsui Takeda Chemical Co., Ltd .; isocyanate equivalent 134) as an isocyanate resin as “main agent”. (Referred to as urethane resin composition R).

Example 1
In the same manner as in Production Examples 1 and 2, the epoxy resin compositions P and Q were obtained in the form of a sheet having a thickness of 30 mm. The obtained sheet was directly affixed on a steel plate, heated and maintained in a coating oven at 170 ° C. for 20 minutes, then removed from the oven and cooled to room temperature. After cooling, each foam filler was cut into a 50 mm × 50 mm × 50 mm cube, and the specific gravity, compressive strength, and compressive elastic modulus were measured as epoxy foam filler P and epoxy foam filler Q, respectively. In addition, the liquid temperature of the urethane-based resin composition R prepared in Production Example 3 becomes 70 ° C. using a two-liquid mixing device (H-2000, manufactured by Gasmer) and a mixing head (GX-7, manufactured by Gasmer). Then, the mixture was mixed at a volume ratio of main agent: curing agent = 1: 1, and quickly discharged onto a steel plate to be foamed and cured. After cooling to room temperature, the obtained urethane foam filler was cut into a 50 mm × 50 mm × 50 mm cube, and the urethane foam filler R was similarly measured for specific gravity, compressive strength, and compression modulus. The results are shown in Table 1.

  A pre-molded hat-shaped automotive structural member shown in FIG. 1 was used. As shown in FIG. 3, the epoxy resin composition molded in Production Example 1 inside the outer panel (material: SP150-440, plate thickness: 1.0 mm) 1 of a hat-shaped automotive structural member molded in advance. After directly attaching the P sheet, the reinforcement (material: SP150-440, plate thickness: 0.6 mm) 3 and the inner panel (material: SP150-440, plate thickness: 1.0 mm) 2 are shown in FIG. Assemble as shown and spot welded to the fringe section at 50 mm pitch. The assembled automotive structural member (hat part: 60 mm × 60 mm, flange width: 10 mm, length: 220 mm) was heated and held at 170 ° C. for 20 minutes in a coating oven, then taken out of the oven and cooled to room temperature. After cooling, the urethane-based resin composition R prepared in Production Example 3 is mixed with the two-component mixing device (H-2000, manufactured by Gasmer) and the mixing head (GX-) at the unfilled portion of the foam filler between the outer panel and the reinforcement. (7, manufactured by Gasmer Co., Ltd.) was used until the liquid temperature reached 70 ° C., and then the mixture of the main agent: curing agent = 1: 1 in a volume ratio was quickly discharged to open the outer panel φ10 mm Were injected into the foam filling material unfilled portion through the small holes and foamed and cured. The volume ratio of the urethane foam filler to the epoxy foam filler was 100: 500. After cooling to room temperature, a dynamic three-point bending test and a torsional rigidity test were performed. The results are shown in Table 2.

(Example 2)
Using the epoxy resin composition Q obtained in Production Example 2 and the urethane resin composition R in Production Example 3, the volume ratio of the urethane foam filler to the epoxy foam filler is 100: 220. Thus, as shown in FIG. 4, a structural member for an automobile was manufactured in the same manner as in Example 1 except that each foam filler was filled. After cooling to room temperature, a dynamic three-point bending test and a torsional rigidity test were performed. The results are shown in Table 2.

(Example 3)
Using the epoxy resin composition Q obtained in Production Example 2 and the urethane resin composition R in Production Example 3, the volume ratio of the urethane foam filler to the epoxy foam filler is 100: 430. Thus, the structural member for automobiles was manufactured by the same method as in Example 1 except that each foaming filler was filled as shown in FIG. After cooling to room temperature, a dynamic three-point bending test and a torsional rigidity test were performed. The results are shown in Table 2.

Example 4
A pre-molded hat-shaped structural member for an automobile composed of the outer panel 1 and the inner panel 2 shown in FIG. 2 was used. Using the epoxy resin composition P obtained in Production Example 1 and the urethane resin composition R in Production Example 3, the volume ratio of the urethane foam filler to the epoxy foam filler is 100: 900. Thus, as shown in FIG. 6, a structural member for an automobile was manufactured in the same manner as in Example 1 except that each foam filler was filled. After cooling to room temperature, a dynamic three-point bending test and a torsional rigidity test were performed. The results are shown in Table 2.

(Example 5)
A pre-molded hat-shaped structural member for an automobile composed of the outer panel 1 and the inner panel 2 shown in FIG. 2 was used. Using the epoxy resin composition Q obtained in Production Example 2 and the urethane resin composition R in Production Example 3, the volume ratio of the urethane foam filler to the epoxy foam filler is 100: 130. Thus, a structural member for an automobile was manufactured in the same manner as in Example 1 except that each foam filler was filled as shown in FIG. After cooling to room temperature, a dynamic three-point bending test and a torsional rigidity test were performed. The results are shown in Table 2.

(Comparative Example 1)
The pre-molded hat-shaped automotive structural member shown in FIG. 1 was used, and spot welding was performed on the fringe portion at a 50 mm pitch in the same manner as in Example 1 without filling the foam filler as shown in FIG. . About this thing, it carried out similarly to Example 1, and implemented the dynamic three-point bending test and the torsional rigidity test. The results are shown in Table 2.

(Comparative Example 2)
The pre-molded hat-shaped automotive structural member shown in FIG. 2 was used, and spot welding was performed on the fringe portion at a 50 mm pitch in the same manner as in Example 1 without filling the foam filler as shown in FIG. . About this thing, it carried out similarly to Example 1, and implemented the dynamic three-point bending test and the torsional rigidity test. The results are shown in Table 2.

(Comparative Example 3)
Without using the urethane foam filler R, only the epoxy resin composition Q obtained in Production Example 2 was filled, and the automobile structural member shown in FIG. About this thing, it carried out similarly to Example 1, and implemented the dynamic three-point bending test and the torsional rigidity test. The results are shown in Table 2.

(Comparative Example 4)
An epoxy resin composition was not used, and only the urethane foam filler R obtained in Production Example 3 was filled, and the automobile structural member shown in FIG. About this thing, it carried out similarly to Example 1, and implemented the dynamic three-point bending test and the torsional rigidity test. The results are shown in Table 2.

(Comparative Example 5)
An epoxy resin composition was not used, and only the urethane foam filler R obtained in Production Example 3 was filled, and the automobile structural member shown in FIG. About this thing, it carried out similarly to Example 1, and implemented the dynamic three-point bending test and the torsional rigidity test. The results are shown in Table 2.

(Measuring method)
The above measurement was performed by the following method.

[specific gravity]
The dimensions and weights of the epoxy foam fillers P and Q and the urethane foam filler R were measured with a caliper and an electronic balance, respectively, and the specific gravity was calculated.

[Compressive strength]
From one direction of samples of epoxy foam fillers P and Q and urethane foam filler R, which have been cut into 50 mm × 50 mm × 50 mm cubes in advance, a speed of 10 mm / min by autograph (AG-IS 250 kN, manufactured by Shimadzu Corporation) The average value of the initial peak strength (yield point load) at the time of compression was taken as the compressive strength (MPa). Each sample was measured three times and the average value was calculated.

[Compressive modulus]
From one direction of samples of epoxy foam fillers P and Q and urethane foam filler R, which have been cut into 50 mm × 50 mm × 50 mm cubes in advance, a speed of 10 mm / min by autograph (AG-IS 250 kN, manufactured by Shimadzu Corporation) The average value of the initial slope in the stress-strain curve (SS curve) was taken as the compression modulus (MPa). Each sample was measured three times and the average value was calculated.

[Volume ratio]
The hat member previously filled with the foam filler was cut in the cross-sectional direction, and the area ratio in the cross section was calculated to obtain the volume ratio of the epoxy foam filler to the urethane foam filler.

[weight]
The weight of the hat member previously filled with the foam filler was measured with an electronic balance. The total weight of the hat member including the foam filler was evaluated as follows.

(Weight evaluation)
◎: When the total weight of the hat member is less than 2,900 g ○: When the total weight of the hat member is 2,900 g or more and less than 3,200 g Δ: The total weight of the hat member is 3,200 g or more and less than 3,500 g In the case of x: When the total weight of the hat member is 3,500 g or more [energy absorption amount]
A dynamic three-point bending test was performed using a hat member previously filled with an epoxy foam filler and a urethane foam filler. The bending wedge radius is 70 mm, the load is 500 kgw, the support radius is 30 mm, the distance between fulcrums is 500 mm, the bending speed is 25 km / h, and the absorbed energy of the hat member at 0 to 30 mm displacement is the energy. Absorption amount.

[Maximum load]
A dynamic three-point bending test was performed using a hat member previously filled with an epoxy foam filler and a urethane foam filler. Bending test was performed at a pressure wedge radius of 70 mm, a load of 500 kgw, a support radius of 30 mm, a distance between fulcrums of 500 mm, a bending speed of 25 km / h, and the maximum load (yield point) at 0 to 30 mm displacement. Load) was the maximum load.

[Torsional rigidity]
A torsional rigidity test was carried out using a hat member previously filled with an epoxy foam filler and a urethane foam filler. Steel plates (100 mm × 100 mm × 5 mm) were arc welded to both cross sections of the hat member, and the test was started by fixing the mounted steel plate and the device with bolts. A test was performed at a load torque of 500 N · m, and the maximum axial force when the hat member shifted from elastic deformation to plastic deformation was defined as torsional rigidity.

  From the results of Table 2, from the results of Comparative Example 1 and Example 1, at least a part of the foam filler is composed of an epoxy-based foam filler and a urethane-based foam filler at a constant volume ratio. As a result, it was possible to improve the energy absorption and swing rigidity with a minimum weight increase. This tendency is the same in the comparison between Comparative Example 2 and Example 3, and is not limited to the case where the structural member for an automobile forms a closed cross section by the outer panel and the inner panel, and further includes a reinforcement. The same excellent effect was observed.

  In particular, as apparent from comparison between Example 1 and Comparative Example 3, energy absorption is achieved even when the filling weight is reduced by combining the epoxy foam filler and the urethane foam filler in a predetermined volume ratio. Both quantity and maximum load could be increased. A similar tendency was also observed in Example 2 in which the amount of the urethane-based foam filler was halved from that of Example 1.

  Further, as is clear from the comparison between Comparative Example 4 and Example 4, both the energy absorption amount and the maximum load could be significantly increased by using the epoxy foam filler as the filler. This tendency was similarly observed in Example 5 in which the use ratio of the urethane-based foam filler was reduced as compared with Example 4.

It is a figure which shows the structural member for motor vehicles containing an outer panel, an inner panel, and a reinforcement. It is a figure which shows the structural member for motor vehicles which consists of an outer panel and an inner panel. It is a figure which shows the closed cross section of the structural member for motor vehicles of Example 3. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of Example 4. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of Example 5. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of Example 6. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of Example 7. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of the comparative example 1. FIG. It is a figure which shows the closed cross section of the structural member for motor vehicles of the comparative example 2. It is a figure which shows the closed cross section of the structural member for motor vehicles of the comparative example 3. It is a figure which shows the closed cross section of the structural member for motor vehicles of the comparative example 4. It is a figure which shows the closed cross section of the structural member for motor vehicles of the comparative example 5. FIG.

Explanation of symbols

1: outer panel,
2: Inner panel,
3: Reinforce,
4: Spot welding,
5P: Epoxy foam filler P,
5Q: Epoxy foam filler Q,
6: Urethane foam filler R.

Claims (5)

  In an automotive structural member having a closed cross-section filled with a foam filler, the foam filler is laminated and filled with (A) an epoxy-based foam filler and (B) a urethane-based foam filler. The automotive structural member, wherein the volume ratio of the filler to the urethane foam filler is urethane foam fillers 100 to 1,900 with respect to the epoxy foam filler 100.   The ratio (p / q) of the compression elastic modulus q (MPa) of the (B) urethane-based foam filler to the compression elastic modulus p (MPa) of the (A) epoxy-based foam filler is 2.0 or more, 2. The structural member for automobile according to claim 1, wherein the compression strength of the (A) epoxy foam filler is 5 MPa or more.   The epoxy resin composition before foaming / curing of the epoxy foam filler (A) is (a) an epoxy resin having at least two epoxy groups in the molecule, and (b) an activity derived from an amino group. An amino compound having at least two hydrogen atoms in the molecule, wherein (a) the epoxy equivalent of the epoxy resin is α, and (b) the active hydrogen equivalent of the amino compound is β, (a) the epoxy resin 100 parts by mass of the urethane-based resin composition before (b) the amino compound 150β / α to 1,000β / α parts by mass and before the foaming / curing of the (B) urethane-based foam filler, c) an isocyanate resin having at least two or more isocyanate groups in the molecule, and (d) a hydroxylation having at least two or more active hydrogens derived from a hydroxyl group or an amino group in the molecule. Or (c) the isocyanate equivalent of the isocyanate resin is γ, and the active hydrogen equivalent of the (d) hydroxy compound or amino compound is θ, The automotive structural member according to claim 1, further comprising (d) 30θ / γ to 90θ / γ parts by mass of a hydroxy compound or an amino compound.   The automobile foam structure according to any one of claims 1 to 3, wherein the foam filler (B) is a urethane foam filler laminated on a vehicle inner side of the automobile structural member. Element. 5. The method for manufacturing a structural member for an automobile according to claim 1, wherein the closed cross section includes an outer panel and an inner panel and / or a reinforcement, and the epoxy resin (A) is disposed inside the outer panel. The composition is installed, a closed space is formed using an inner panel and / or a reinforcement, and the epoxy resin composition (A) is foamed and cured by baking of an electrodeposition coating treatment, and then the outer panel and the inner panel A method for producing a structural member for an automobile, wherein the urethane resin composition (B) is further injected into a foam filler unfilled portion between and / or the reinforcement, and foamed and cured.