JP2000345138A - Formable sealing material composition and sealing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a formable sealing material composition capable of securing water tightness in connection of an outer plate of vehicle, providing a coated face of sealing material having the same qualities of coating film appearance and durability of coating film as those of other common outer plate parts, and to provide a sealing method for using the formable sealing material composition. SOLUTION: This formable sealing material composition comprises (a) 100 pts.wt. of a liquid epoxy resin, (b) 5-100 pts.wt. of a thermal activation type curing agent for an epoxy resin, (c) 10-50 pts.wt. of polymer powder consisting essentially of a 1-12C alkyl group-containing acrylic acid ester and/or methacrylic acid ester and (d) 10-250 pts.wt. of an inorganic filler. In the sealing method comprising arranging a formable sealing material on a connection part of an outer plate of vehicle which is undercoated or undercoated followed by intermediate coating, coating the whole connection part and sealing the connection part, a process for extending the formable sealing material composition, then preheating the composition to give a pseudo-curable sheet as a formable sealing material, arranging the formable sealing material on a connection part of an outer plate, applying an external force to the formable sealing material, leveling the formable sealing material and carrying out a coating is included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded sealing material composition and a sealing method, and more particularly to a molded sealing material composition applied to a vehicle outer panel joint which has been subjected to an undercoating or an undercoating followed by an intermediate coating. After placing, it is a sealing method that paints the entire joint and secures the watertightness of the joint, while securing the watertightness of the outer panel joint, the painted surface of the sealing part is equivalent to other general outer panel parts The present invention relates to a sealing method and a molded sealing material composition having coating film appearance quality and coating durability.

[0002]

2. Description of the Related Art In the manufacture of automobiles, outer panels are generally joined by welding. Since the welded outer panel joint is not sufficiently watertight by simply painting, it is necessary to secure the watertightness by some means to prevent rainwater and the like from entering and preventing rust.

[0003] For this reason, at the joint portion of the outer panel, a sealing material is applied after a base coat is applied, and a middle coat and a top coat are applied to the entire joint, or a middle coat is applied after the base coat. A method in which a sealing material is applied afterwards and a top coat is applied to the entire joint is widely adopted. As the intermediate coating used here, polyester melamine resin is often used, and as the top coating, acrylic melamine resin is often used, and as the sealing material, a sealing material mainly containing a sol of polyvinyl chloride resin is generally used. After the sealing material is applied to the joint portion, it is calcined in a dedicated oven before being coated, or is baked together with the coating in a coating oven to cure and secure water tightness.

[0004] Similarly, welding of a roof outer panel of a vehicle is generally performed by welding, and it is necessary to ensure watertightness of the joint. The joint of the roof skin is located on the outermost surface of the vehicle,
Since it is a part that is easily visible, appearance quality is particularly required. For this reason, when the sealing surface is the outermost surface, the coating surface of the sealing portion also needs to have the same coating film appearance quality and coating film durability as those of the other general outer plate portion coating surfaces.

However, after applying a sealing material mainly composed of a polyvinyl chloride resin sol, a method of performing intermediate coating and top coating, or a sealing material mainly composed of a polyvinyl chloride resin sol is applied. Later, in the method of performing top coating, it is difficult to apply the sealing material smoothly and uniformly, and there is a concern that cracks and discoloration of the coating film on the sealing material due to changes in physical properties of the sealing material over time may occur. The coated surface could not have the same coating appearance quality and coating durability as the other general outer panel coated surfaces.

[0006] Therefore, in the joint portion of the roof outer plate, it is often devised not to expose the sealing surface to the outermost surface of the vehicle. When joining the roof skin, the joint has a groove-shaped cross-sectional structure, a sealing material is applied to the joint where the undercoat has been applied, intermediate coating and topcoating are applied, and then the groove at the roof joint is A double-sided adhesive tape is used to attach a resin molding, or apply a sealing material to the joint where the intermediate coating is applied following the undercoating, apply a topcoat, and then apply it to the groove of the roof joint. It is common to attach a resin molding using a double-sided adhesive tape or the like.

[0007] However, in the case of a joint portion of an outer panel, such as a roof outer panel of a vehicle, which particularly requires appearance quality, the joint portion has a groove-like cross-sectional shape, and the joint portion provided with an undercoat is sealed. After applying the material, applying intermediate coating and top coating, attaching a resin molded product to the groove of the roof joint using double-sided adhesive tape, etc., joining undercoating followed by intermediate coating After applying a sealing material to the part and applying a top coat, attaching a resin molded article to the groove of the roof joint using double-sided adhesive tape etc. increases the number of parts and the installation work also occurs, There has been a problem that the production cost is increased, and the production of the vehicle is restricted in order to secure the width of the groove.

[0008] Therefore, in order to alleviate restrictions on vehicle manufacturing and reduce manufacturing costs, watertightness is ensured at the time of joining vehicle outer plates, and the painted surface of the sealing portion is equivalent to that of other general outer plate portions. It is expected that a sealing material composition and a sealing method which can be used on the outermost surface of a vehicle and have a coating film appearance quality and a coating film durability can be developed.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and ensures watertightness at the time of joining a vehicle outer panel, and a painted surface of a sealing portion is the same as other general outer panel portions. An object of the present invention is to provide a sealing method and a sealing material composition having coating film appearance quality and coating film durability.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that undercoating or a joint of a vehicle outer panel to which undercoating has been applied, After placing the molded sealing material, in the method of coating the entire joint and ensuring watertightness, by using a molded sealing material having a specific composition, the watertightness of the outer plate joint is ensured and the sealing part coating The inventors have found that the surface has the same coating film appearance quality and coating durability as those of other general outer plate parts, and have reached the present invention.

That is, the molded sealing material composition according to claim 1 comprises (1) (a) 100 parts by weight of a liquid epoxy resin, (b) 5 to 100 parts by weight of a heat-active curing agent for an epoxy resin, and (c) 10 to 50 parts by weight of a polymer powder containing an acrylate and / or methacrylate having an alkyl group having 1 to 12 carbon atoms as a main component and (d) an inorganic filler 10 to 250
It is characterized by containing parts by weight.

[0012] The molded sealing material composition according to claim 2 is the molded sealing material composition according to claim 1,
(c) The polymer powder mainly containing an acrylate and / or methacrylate having an alkyl group having 1 to 12 carbon atoms has a primary average particle diameter of 0.03 to 5.0 μm.
It is characterized by being.

According to a third aspect of the present invention, there is provided a molded sealing material composition according to the first or second aspect, further comprising a fatty acid and / or an aromatic phosphate.

[0014] The molded sealing material composition according to claim 4 is disposed on a joint of an outer plate of a vehicle which has been subjected to an undercoating or an undercoating followed by an intermediate coating. In a sealing method of coating and bonding the joint, the sealing material composition according to any one of claims 1 to 3 is applied, and then preheated to obtain a pseudo-curable sheet as a molded sealing material. The method is characterized in that after the molded sealing material is arranged on the outer plate joint, a step of applying an external force to level the molded sealing material, and then performing coating is performed.

According to a fifth aspect of the present invention, in the sealing method of the fourth aspect, in producing the pseudo-curable sheet, after the molded sealing material composition is spread, a maintenance cloth is further laminated and impregnated. It is characterized by including a step.

According to a sixth aspect of the present invention, in the sealing method of the fourth or fifth aspect, in producing the pseudo-curable sheet, the preheating is performed at a temperature lower than the reaction temperature of the heat activated curing agent (b) and 70%. It is carried out at a temperature of at least ℃.

According to a seventh aspect of the present invention, in the sealing method according to any one of the fourth to sixth aspects, the molded sealing material liquid composition is spread to a thickness of 0.5 to 5.0 mm, and is leveled. Is carried out with an external force of 0.1 to 2.0 kgf / cm ² .

The sealing method according to claim 8 is the sealing method according to any one of claims 4 to 7, wherein the molded sealing material composition is spread on release paper, and the molded sealing material is joined to an outer plate joint. In this case, the release paper is disposed as an outer surface, and after leveling, the release paper is peeled off and coating is performed.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The molded sealing material composition of the present invention comprises (a) 100 parts by weight of a liquid epoxy resin, (b) 5 to 100 parts by weight of a heat-active curing agent for an epoxy resin, and (c) 1 carbon atom.
Acrylic acid ester having an alkyl group of from 1 to 12 and / or
Or polymer powder 1 containing methacrylic acid ester as a main component
The essential components are 0 to 50 parts by weight and 10 to 250 parts by weight of the inorganic filler (d).

The epoxy resin (a) used in the present invention is preferably a liquid or paste epoxy resin at normal temperature, such as bisphenol condensate, hydantoin type epoxy resin, novolak type epoxy resin, aliphatic epoxy resin and dimer acid. It includes a wide variety of conventional epoxy resins, such as modified epoxy resins, NBR modified epoxy resins, and urethane modified epoxy resins.

Particularly preferred epoxy resins include, for example, an initial condensate obtained by reacting bisphenol A or bisphenol F with an epoxy group-containing compound such as epichlorohydrin. An epoxy resin derived from a compound obtained by adding 2 to 20 moles of ethylene oxide or propylene oxide to bisphenol A can also be used.

Further, the epoxy resin used in the present invention may be mixed with a solid epoxy resin. The mixture is liquid at room temperature, and the epoxy equivalent of the mixture is in the range of 150 to 600. If you can use it. In particular, a bisphenol A type liquid epoxy resin having an epoxy equivalent of 180 to 210 is excellent in workability, curability and the like, and is particularly preferably used.

As the heat-active curing agent (b) for epoxy resin used in the present invention, those which are stable at the time of storage, exhibit activity at high temperature, and have high adhesive strength to the substrate after curing are used. Organic acid hydrazides such as adipic acid dihydrazide, isophthalic acid dihydrazide and derivatives thereof; imidazole derivatives such as dicyandiamide, 4,4'-diaminodiphenyl sulfone, 2-n-heptadecyl imidazole; 2-methylimidazole triazine Imidazole derivatives having a triazine ring in the molecule such as salts; N, N-dialkylurea derivatives;
N, N-dialkylthiourea derivatives; acid anhydrides such as tetrahydrophthalic anhydride and trimellitic anhydride;
Polyamines such as isophoronediamine, m-phenylenediamine, ethylenediamine, hexamethylenediamine, m-xylenediamine, diethylenetriamine, triethylenetetremin, and tetraethylenepentamine; bis (aminomethyl) cyclohexane, N-aminoethylpiverazine; Trisdimethylaminomethylphenol,
3,9-bis (3-aminopropyl) -2,4,8,1
Aminoalkyl cyclic compounds such as 0-tetraoxaspiro (5,5) undecane; melamine; boron trifluoride complex compounds; polyamidoamines comprising adducts of various dimer acids with amines; May be used, or two or more kinds may be used in combination.

In particular, dicyandiamide is used for storage stability after dispersion blending in the liquid epoxy resin (a), curability,
It is suitable in that it has excellent adhesion to a substrate. The heat-active curing agent for epoxy resin (b) used in the present invention must be in a proportion of 5 to 100 parts by weight based on 100 parts by weight of the liquid epoxy resin (a). When the compounding amount is less than 5 parts by weight, poor curability and insufficient adhesive strength of the molded sealing material composition occur, while when the compounding amount exceeds 100 parts by weight,
The unreacted curing agent remains in the cured product in an excessive amount, or causes partial decomposition or thermal deterioration due to excessive exothermic reaction at the time of molding, resulting in a decrease in adhesive strength and durability and discoloration. The result is a reduction in the excellent properties possessed.

[0025] If necessary, a curing accelerator can be used in combination. As a curing accelerator, 3- (3,4-
Alicyclic dimethylurea such as dichlorophenyl) dimethylurea, aromatic dimethylurea, alkylaminophenol derivative, 1,8-diazabicyclo (5,4,
0) imidazole derivatives such as undecene and 2-ethyl 4-methylimidazole;

The acrylate and / or methacrylate having an alkyl group having 1 to 12 carbon atoms used in the present invention (hereinafter, acrylate and / or methacrylate is abbreviated as (meth) acrylate) The polymer powder (c) is, for example, a fine powder obtained by polymerizing a (meth) acrylate monomer using a radical initiator and then drying. Here, the main component means that the content is 50% by weight or more. Examples of (meth) acrylate monomers include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, n-octyl methacrylate, n-decyl methacrylate and lauryl methacrylate; methyl acrylate, propyl acrylate, butyl acrylate, n-
Alkyl acrylates such as octyl acrylate and 2-ethylhexyl acrylate; butoxyethyl (meth) acrylate, alkyl glycol (meth) acrylate, and alkylene glycol mono (meth) acrylate. A particularly preferred (meth) acrylate is methyl methacrylate.

Further, ethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, and trimethylolpropane di (meth) are used as crosslinkable monomers for adjusting the degree of polymerization of the polymer powder (c).
Acrylate, trimethylolpropane tri- (meth)
Acrylate, hexanediol di (meth) acrylate, oligoethylene di (meth) acrylate, polyfunctional (meth) acrylate such as polyethylene glycol di (meth) acrylate, aromatic divinyl monomer such as divinylbenzene, and triallyl trimellitate And triallyl isocyanurate can be used in combination.

If desired, styrene, vinyl acrylate, and / or methacrylate having an alkyl group having 1 to 12 carbon atoms used in the present invention may be used as the main copolymerizable monomer. toluene,
aromatic vinyl compounds such as α-methylsterene; vinyl cyanide compounds such as acrylonitrile, methacrylonitrile, vinylidene cyanide; conjugated diene compounds such as butadiene, isoprene, 1,3-pentadiene, cyclopentadiene; 1,4-hexadiene Non-conjugated diene compounds; unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid; unsaturated polycarboxylic acids such as maleic acid, itaconic acid, fumaric acid, citraconic acid and chloromaleic acid Acids and their anhydrides; unsaturated polycarboxylic acid partial esters such as monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monomethyl itaconate, monoethyl itaconate and monobutyl itaconate; Examples include 2-hydroxyethyl fumarate, hydroxybutyl vinyl ether, monobutyl maleate, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, butoxyethyl methacrylate, and dimethylaminoethyl methacrylate.

In the present invention, the method for producing the polymer powder as the component (c) is not particularly limited, and methods conventionally used for producing fine resin powders such as polymethyl methacrylate, for example, fine suspensions, may be used. A suspension polymerization method, an emulsion polymerization method, a seeded emulsion polymerization method, or the like can be used. Among these methods, a polymerization method in which the particle diameter is not extremely fine and a spherical one is obtained is preferable. The average particle diameter is 0.1 to 5.0 μm, and more preferably 0.2. The thickness is preferably from 3.0 to 3.0 μm from the viewpoint of the viscosity suitable for coating the sealing material composition.

In the fine suspension polymerization method, an oil-soluble initiator is used as a radical initiator, and the particle diameter of the monomer oil droplets is adjusted by a homogenization treatment before the polymerization is started, so that the emulsion droplet diameter is adjusted. It is a way to make it.

Examples of the oil-soluble radical initiator include diacyl peroxides such as benzoyl peroxide, di-3,5,5-trimethylhexanoyl peroxide and dilauroyl peroxide; diisopropyl peroxydicarbonate, diisopropyl peroxide and the like. -Peroxy dicarbonates such as sec-butyl peroxy dicarbonate and di-2-ethylhexyl peroxy dicarbonate; peroxy esters such as t-butyl peroxy pivalate and t-butyl peroxy neodecanoate; Alternatively, organic peroxides such as acetylcyclohexylsulfonyl peroxide and disuccinic acid peroxide, furthermore, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2'-Azobi An azo compound such as dimethylvaleronitrile can be used. These initiators can be used alone or in combination of two or more. The amount used can be appropriately selected depending on the type and amount of the monomer, the preparation method, and the like.
It is preferable to use it in the range of 01 to 5.0 parts by weight from the viewpoint of controlling the reaction temperature of the polymerization reaction.

In the fine suspension polymerization method, usually, a surfactant and a dispersant are used. As the surfactant, for example, sodium lauryl sulfate, alkyl sulfate salts such as sodium myristyl sulfate,
Alkyl aryl sulfonates such as sodium dodecylbenzenesulfonate and potassium dodecylbenzenesulfonate; sulfosuccinates such as sodium dioctylsulfosuccinate and sodium dihexylsulfosuccinate; fatty acid salts such as ammonium laurate and potassium stearate; polyoxyethylene Alkyl sulfates, polyoxyethylene alkylaryl sulfates, and anionic surfactants such as sodium dodecyl diphenyl ether disulfonate; sorbitan monooleate, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers Nonionic surfactants such as cetylpyridinium chloride and cetyltrimethylammonium bromide; And the like thione soluble surface active agents. These surfactants and dispersants can be used alone or in combination of two or more. The amount used can be appropriately selected depending on the type and amount of the monomer, the preparation method, and the like. It is preferable to appropriately select from the range of from 4 to 4 parts by weight in view of the stability of the monomer emulsion droplets and the control of the particle size of the polymer particles.

In the case of the fine suspension polymerization, first, the above-mentioned oil-soluble initiator, the above-mentioned monomer, the above-mentioned surfactant and, if necessary, higher fatty acids and higher alcohols are used in an aqueous medium. The mixture is premixed with a polymerization aid and other additives, and homogenized by a homogenizer or the like to adjust the particle diameter of the oil droplets. As a homogenizer,
For example, a colloid mill, a vibration stirrer, a two-stage high-pressure pump, high-pressure ejection from a nozzle or an orifice, ultrasonic stirring, or the like can be used. Further, the adjustment of the particle size of the oil droplets is affected by the control of the shearing force in the homogenization treatment, the stirring conditions during the polymerization, the type of the reactor, the amounts of the surfactants and additives, and the like. The average particle size is preferably 0.1 to 5.0 μm, and the average is 0.2 to 5.0 μm.
3.0 μm is more preferred.

Next, the liquid homogenized in this manner is transferred to a polymerization apparatus, and the temperature is increased while stirring slowly.
The polymerization is usually carried out at a temperature in the range from 30 to 80C. Emulsion polymerization method usually uses an anionic surfactant as an emulsifier,
This is a method in which micelles, which are aggregates of an emulsifier dispersed in an aqueous medium, are formed, monomers are solubilized in the micelles to form a reaction site, and a polymerization reaction is started with a water-soluble radical initiator. In a typical emulsion polymerization, a large number of polymer particles are generated by adding an emulsifier all at once, so that the particle size of the particles is 0.05 to 0.1.
Very small, 1 μm. In order to increase the particle size, there is a method in which the initial emulsifier is reduced in a small amount to suppress the number of generated particles, and a minimum and necessary emulsifier necessary for stabilization is additionally supplied as the particles grow as the polymerization proceeds. By doing so, the generation of fine particles is limited, and the polymerization reaction proceeds while maintaining the number of polymer particles generated at the initial stage.
A polymer latex having a large average particle size of 2 to 0.6 μm is obtained.

Further, as a method for obtaining polymer particles having a larger particle diameter, polymer particles having an average of 0.05 to 0.7 μm prepared in advance by emulsion polymerization or fine suspension polymerization are used as nuclei.
The monomer is coated and polymerized using a water-soluble radical initiator, and the surface of the particles, which enlarges as the polymerization proceeds, is continuously coated with anionic surfactant or nonionic surfactant so as not to be excessive. Polymerization is carried out while stabilizing the particles by adding them intermittently or intermittently.
A seeded emulsion polymerization method for obtaining a latex in which polymer particles of 5 μm are dispersed is also useful.

Examples of the water-soluble radical initiator include potassium persulfate, ammonium persulfate, potassium perphosphate, ammonium perphosphate, hydrogen peroxide and the like, and organic hydroperoxides such as cumene hydroperoxide and ethylenediaminetetraacetic acid. And a redox initiator in combination with a reducing agent.

The polymer of the polymer powder of the component (C) in the present invention is a particle which is a single polymer layer from the center to the surface of the above-mentioned particles in terms of the structure of the polymer particles. The core may be a (meth) acrylate polymer having a glass transition temperature of -30 ° C or lower, and the shell may be a (meth) acrylate.
Core / shell particles may be a copolymer of an acrylate monomer and a carboxyl group-containing unsaturated carboxylic acid monomer, wherein the carboxyl groups are ionically cross-linked with a monovalent or divalent metal cation. The production of core / shell particles is described in JP-A-5-65391 or JP-A-5-21431.
No. 0 publication may be used. The polymer latex obtained by the polymerization is usually made into a polymer powder by spray drying with a nitrogen stream or by salting out, coagulation, dehydration and fluid drying.

The primary average particle diameter of the polymer powder (c) containing acrylate and / or methacrylate as a main component obtained by the above-mentioned polymerization and then drying is 0.1 to 5.0 μm. Is more preferably in the range of 0.2 to 3.0 μm. When the polymer powder has a primary average particle size of less than 0.1 μm, the viscosity of the liquid mixture comprising the components (a), (b), (c), and (d) of the present invention significantly increases. However, it is difficult to apply a thin film on release paper. If the average primary particle diameter of the polymer powder exceeds 5.0 μm, the speed of pseudo-curing by heating tends to be significantly reduced. The primary average particle size was measured by dispersing 0.5 g of the polymer powder in 200 ml of water, applying the mixture to an ultrasonic shaker having an oscillation frequency of 50 kHz for 1 minute, and then allowing the suspension to stand still for 3 minutes. It is applied to a particle size measuring device by a turbidity method, and is obtained as a particle size that becomes 50% of the cumulative particle size distribution. The weight average molecular weight of the polymer powder is
It can be adjusted to a desired value by a reaction temperature or a polymerization degree regulator, and is usually 500,000 to 8,000,000.

As a method for obtaining the polymer powder (c) of the present invention from a polymer emulsion or suspension, spray drying using a multi-blade rotating disk type, a disk type rotating disk type, a nozzle type or the like is usually used. It is preferable that the polymer emulsion or the suspension is coagulated and separated by a salting-out method or a freeze-out method, and a wet cake prepared by dehydration is dried by a fluidized bed or the like to obtain aggregated particles.

The amount of the polymer powder (c) containing a (meth) acrylate monomer as a main component monomer used in the present invention is 10 to 100 parts by weight of the liquid epoxy resin (a).
Must be ~ 50 parts by weight. If the blending amount of the (meth) acrylic polymer powder (c) is less than 10 parts by weight, a pseudo-cured molded product having a desired strength cannot be obtained by heating, and the (meth) acrylic polymer powder Exceeds 50 parts by weight, the viscosity of the liquid mixture comprising the components (a), (b), (c), and (d) of the present invention increases, causing the mixing operation and the mixture to fall on release paper. It becomes difficult to spread the thin film.

In the molded sealing composition of the present invention, it is necessary to use an inorganic filler (d) in combination, and the type thereof is not particularly limited. By using inorganic filler,
When spread in a thin film on release paper, it forms an appropriate coating viscosity, prevents curing shrinkage of the sealing material after final heat molding in the overcoating process, and can impart desired mechanical properties and hardness. The adhesion strength between the coating material and the sealing material can be maintained.

Examples of the inorganic filler include fused silica, crystalline silica, mica, alumina, calcium silicate, kaolin clay, calcium carbonate, talc, barium sulfate, magnesium oxide, titanium oxide, zinc oxide, gypsum, aluminum hydroxide, trialuminum, and the like. Examples include antimony oxide and flake graphite. These may be used alone or in combination of two or more.

The amount of the inorganic filler (d) to be added is 10 to 250 parts by weight, preferably 30 to 220 parts by weight, based on 100 parts by weight of the liquid epoxy resin (a), and the above performance is exhibited. Preferred above. When the addition amount is less than 10 parts by weight, the liquid composition comprising the components (a), (b), (c) and (d) of the present invention is spread on a release paper at a desired coating speed. In such a case, a proper thixotropy cannot be obtained, and if it exceeds 250 parts by weight, the viscosity of the liquid composition increases, and it becomes difficult to apply a thin film on release paper or the like.

If necessary, the surface of these inorganic fillers may be treated with a silane coupling agent, a titanium coupling agent, a fatty acid, a resin acid, a surfactant or the like.

Further, in order to improve the adhesion of the molded sealing material to the joint of the outer panel of the vehicle which has been subjected to the undercoating or the undercoating followed by the intermediate coating, fatty acids and / or
Alternatively, an aromatic phosphate (e) can be added. These phosphate esters have a molecular weight of 180.
460 are preferable, and tricresyl phosphate is particularly preferable. It is particularly preferable to use 2 to 10 parts by weight based on 100 parts by weight of the liquid epoxy resin (a).

In addition, if desired, pigments, flame retardants, antioxidants, antioxidants, diluents, plasticizers, stabilizers, foaming agents, and the like can also be used within the range usually employed by those skilled in the art. Can be added.

The liquid molded sealing material composition of the present invention is prepared by first mixing the above components with a kneader such as various kneaders, three rolls, disperser, paddle mixer, and planetary mixer.

Next, the sealing material composition was applied to a thickness of 0.5
It is spread on, for example, release paper to a thickness of about 5.0 mm, and is subjected to primary processing in advance at a temperature not higher than the reaction temperature of the heat-active curing agent (b) and not lower than 70 ° C. to obtain a pseudo-curable sheet. 0.5 thickness
The reason for setting the thickness to 5.0 mm is from the viewpoint of uniform heating suitability.
For example, when a heat-active curing agent for an epoxy resin having a curing temperature of 130 ° C. or more is blended, 5 to 2 at 90 to 110 ° C.
By heating for 0 minutes, the polymer powder used in the present invention
(c) is swollen by the liquid epoxy resin (a), and can be easily pseudo-cured to form a gel-like flexible sheet. Since the heating conditions are lower than the temperature (reaction temperature) at which the heat-active curing agent for epoxy resin (b) exhibits activity, the liquid epoxy resin (a) and the heat-active curing agent for epoxy resin (b) are used. Does not cause a curing reaction.

Further, for the purpose of increasing the strength of the sealing material of the present invention, a fiber cloth can be used as a core material of the sealing material. In the step of producing a pseudo-curable sheet used as the sealing material, (a) of the present invention,
Immediately after the liquid composition comprising the components (b), (c), and (d) is spread on release paper, the reinforcing fibers can be easily compounded by laminating and impregnating the fiber cloth. . As the fiber cloth, for example, glass fiber, polymer fiber, natural fiber, or the like can be used, and it is preferable to use a coarse cloth or mesh.

Therefore, (a), (b), (c) and (d) of the present invention
Is cast to a uniform thickness on, for example, release paper,
After heating at 0 ° C. for 10 minutes and pseudo-curing to form a sheet, slit processing or punching processing can be performed to obtain a molded sealing material having a predetermined shape.

Using the molded sealing material thus obtained, the molded sealing material is arranged along the joint of the undercoated outer plate, and then the intermediate coating, the top coating is applied, or the undercoat is applied. After disposing the molded sealing material along the outer plate joint where the intermediate coating has been applied following the coating, it is possible to apply the top coating, but after disposing the molded sealing material, leveling ( Smoothing)
It is important to take action.

As the leveling method, a tape-shaped sealing material prepared by slitting or punching from a pseudo-cured sheet with release paper is subjected to an undercoating or an outer plate joining which has been subjected to an intermediate coating followed by an intermediate coating. Attached along the upper part, with the release paper side facing outward.
A method in which an external force of 1 to 2.0 kgf / cm ² is applied from the release paper to perform leveling is preferable. At that time, a method of applying smoothing with a constant weight roller or the like from the release paper is simple and accurate in operation. The leveling pressure condition is 0.1
When an external force of less than kgf / cm ² is used, the sealing material may cause poor adhesion and watertightness may be reduced. Also, when an external force exceeding 2.0 kgf / cm ² is used as the same pressing condition, the release paper laminated on the sealing material tends to enter the gap of the outer plate joint or cause lateral displacement. .

Thereafter, after releasing the release paper or the like, a smooth coating surface is easily formed on the upper surface of the molded sealing material by performing a top coating after the middle coating or by performing a top coating. The molded sealing material is baked in a dedicated oven, or is baked together with painting in a painting oven after spraying the paint, so that a sufficient adhesive strength can be formed at the joint.

[0054]

The present invention will be described with reference to the following examples and comparative examples. Examples 1-5 Bisphenol A type epoxy resin (Epicoat 828, Yuka Shell Epoxy Co., Ltd. epoxy equivalent 190),
Dicyandiamide (EH3636AS, manufactured by Asahi Denka Kogyo Co., Ltd.) as a thermally active curing agent for epoxy resin, 2-heptadecyl imidazole (C17Z, Shikoku Kasei Co., Ltd.) as a curing accelerator, and calcium carbonate as an inorganic filler (White luster A, Shiroishi Industry Co., Ltd. average particle size 1 μm)
An epoxy resin-containing methyl methacrylate polymer (Zeon Acrylic Resin F301, manufactured by Zeon Kasei Co., Ltd.) or a methyl methacrylate polymer as an acrylic resin powder;
(Zeon Acrylic Resin F320, Zeon Kasei Co., Ltd.
) Or a core-shell acrylate polymer (Zeon Acrylic Resin F351, manufactured by Zeon Kasei Co., Ltd.)
In accordance with the composition shown in the above, kneading was performed with a kneader while defoaming at -5 mmHg under reduced pressure to obtain molded sealing material compositions 1 to 5. Note • Zeon acrylic resin F301: contains 90% by weight or more of methyl methacrylate, primary average particle diameter 1.2 μm • Zeon acrylic resin F320: contains 100% by weight of methyl methacrylate, primary average particle diameter 1.4 μm • Zeon acrylic resin F351: methyl methacrylate Containing 50% by weight or more, core part glass transition temperature about -5
0 ° C, shell part glass transition temperature about 110 ° C, primary average particle size 0.3μm

Each of the obtained sealing material compositions 1 to 5 was applied to a wax-treated release paper having a thickness of 0.15 mm using a doctor knife so as to have a thickness of 3.0 mm.
After baking at 110 ° C for 10 minutes and pseudo-curing, length 1
Each release paper was cut out to a size of 00 mm and a width of 20 mm to obtain each molded sealing material. Next, each of these molded sealing materials was placed on the electrodeposition coated steel plate having a length of 150 mm, a width of 70 mm, and a thickness of 0.8 mm with the release paper on the non-contact side, along the outer plate joint, Smoothing was performed on the release paper using a metal roller weighing 500 g. Next, after releasing the release paper, an intermediate coating containing polyester melamine resin as a main component is sprayed to a dry film thickness of 30 μm.
Bake at 40 ° C. for 20 minutes. Further, a white top coat mainly composed of acrylic melamine resin is applied to a dry film thickness of 30 μm.
And baked at 140 ° C. for 20 minutes to perform sealing.

Example 6 For the molded sealing material obtained in Example 3, 150
An intermediate coat made by spraying an intermediate coat mainly composed of polyester melamine resin onto a 30 mm thick, 70 mm wide, 0.8 mm thick electrodeposited coated steel sheet to a dry film thickness of 30 μm and baking at 140 ° C. for 20 minutes. The release paper is placed on the board along the outer plate joint with the non-contact surface side, and smoothing is performed using a metal roller having a weight of 500 g from above the release paper, and the main component is an acrylic melamine resin. Spray white top coat paint to a dry film thickness of 30 μm,
For 20 minutes.

[0057]

[Table 1]

Comparative Examples 1 and 2 As comparative examples, sealing material compositions 6 and 7 containing a polyvinyl chloride resin as a main component were produced. The sealing material compositions 6 and 7 include a polyvinyl chloride resin (ZEST38).
J and ZESTB51J, both new Daiichi PVC Co., Ltd.
), Diisononyl phthalate, and calcium carbonate (Whiteton H, Shiraishi Calcium Co., Ltd.
Kamishima Chemical Co., Ltd.) and an adhesion-imparting material (ACR Epoxy R
1735-2, ACR urethane PR-9311, AC
R epoxy R-82, both manufactured by AC R Co., Ltd.) and a diluent (mineral spirit A, Nippon Petrochemical Co., Ltd.) were manufactured according to the composition shown in Table 2. Sealant composition Production of 6 and 7 was carried out by preparing a sol by suspending a polyvinyl chloride resin in diisononyl phthalate, adding and kneading calcium carbonate, and further adding and kneading an adhesion promoter and a diluent. The viscosity of the liquid sealing material was measured using a BH type viscometer (rotor # 7, rotor # 2).
0 rpm), the viscosity of the sealing material composition 6 was 136 Pa · s, and the viscosity of the sealing material composition 7 was 11
It was 2 Pa · s. After applying these liquid sealing material compositions to a length of 150 mm, a width of 70 mm, and a thickness of 0.8 mm on an electrodeposition coated steel sheet to a length of 100 mm, a width of 20 mm, and a thickness of 3.0 mm, a polyester melamine resin is applied. Spray the middle coat paint as the main component to a dry film thickness of 30 μm.
Baked at 40 ° C. for 20 minutes. Furthermore, a white top coat mainly composed of an acrylic melamine resin is applied with a dry film thickness of 30 μm.
m and baked at 140 ° C. for 20 minutes for sealing.

[0059]

[Table 2]

Test Examples The test pieces sealed in Examples 1 to 6 and Comparative Examples 1 and 2 were evaluated under the following test conditions, and the results are shown in Table 3. (1) Appearance The coated surface after the overcoating was visually observed to check for cracks, blisters, and discoloration. In addition, it was examined whether the painted surface of the sealing portion could be aligned with other general outer plate portions. (2) Adhesion with electrodeposition coating The adhesion between the sealing material and the electrodeposition coating was evaluated by a nail peel test. A case where the sealing material undergoes cohesive failure is regarded as acceptable.

(3) Adhesion with intermediate coat and top coat (adhesion with intermediate coat, top coat composite coating film and top coat film) 25 crosscut hatches of 2 mm width were cut with a cutter knife on the coated surface after top coating. A peeling test was performed using a cellophane adhesive tape having a width of 24 mm (Cellotape, manufactured by Nichiban Co., Ltd.). A case where there was no peeling and all 25 grids remained remained as a pass. (4) Hot water immersion test Each of the top-coated test pieces was placed in hot water at 40 ° C for 336 hours.
After soaking for a period of time and taking out, water droplets were wiped off, and the appearance, adhesion to the middle coat and top coat were evaluated.

(5) Thermal Aging Test The top-coated test piece was left in an atmosphere of 90 ° C. for 336 hours, taken out, and evaluated for appearance, adhesion to the middle coat and top coat. (6) Heat cycle test The test specimen coated with the top coat was left under the following heat cycle conditions (temperature and humidity conditions), and after taking out, the appearance, intermediate coat, and adhesion to the top coat were evaluated. Thermal cycle conditions: 90 ° C 4 hours → room temperature 0.5 hours →
-40 ℃ 1.5 hours → room temperature 0.5 hours → 70 ℃ 9
5% room temperature 3 hours → room temperature 0.5 hours → −40 ° C.
5 hours → room temperature 0.5 hours was defined as one cycle, and 10 cycles were performed.

(7) Weather resistance test A sunshine weather meter (WEL-SUN-HMC type, manufactured by Suga Test Instruments Co., Ltd.)
After leaving for 2,000 hours, remove the test piece,
The adhesion with the middle coat was evaluated. The test conditions are shown below. Black panel temperature: 63 ± 3 ° C, spray cycle:
18 minutes during irradiation for 120 minutes, spray pressure: 0.1 MPa
It is.

[0064]

[Table 3]

[0065]

The sealing method using the sealing material composition according to the present invention is a method of arranging a molded sealing material on a joint of a vehicle outer panel to which an undercoating or an undercoating is applied followed by an intermediate coating. By coating the whole, it is possible to ensure the watertightness of the outer panel joint, and to obtain the same coating appearance quality and coating durability as the coating part of the sealing part with other general outer plate parts, The sealing part can be used on the outermost surface of the vehicle.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B05D 7/14 B05D 7/14 L B29B 11/14 B29B 11/14 15/10 15/10 B62D 65/00 B62D 65 / 00 Q (72) Inventor Tadashi Ashida 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Toshio Nagase 1-2-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term in Zeon Chemical Co., Ltd. (Reference) 3D114 AA17 AA20 BA01 CA10 4D075 AC52 AE04 BB05Z BB22Z CA33 DA33 DB02 DC12 EA39 EB22 EB33 EC01 EC13 EC37 4F072 AA07 AB03 AB04 AB05 AB09 AB30 AD25 AD28 AD34 AE00 AE01 AE23 AF03 AB03 AB03 AB03 AB03 AB03 AB03 AB04 BC01 BC12 BD10 BM11 4H017 AA04 AA12 AA31 AA39 AB01 AB08 AC03 AC16 AD05 AD06 AE05

Claims (8)

[Claims] (1) (1) (a) 100 parts by weight of a liquid epoxy resin,
(b) 5 to 100 parts by weight of a heat-active curing agent for an epoxy resin,
(c) 10 to 50 parts by weight of a polymer powder containing an acrylate ester and / or methacrylate ester having an alkyl group having 1 to 12 carbon atoms as a main component of a constituent monomer, and (d) 10 to 250 inorganic filler. A molded sealing material composition comprising parts by weight. 2. The molded sealing material composition according to claim 1, wherein (c) a polymer powder mainly containing an acrylate ester and / or a methacrylate ester having an alkyl group having 1 to 12 carbon atoms, Average particle size of 0.03 to
A molded sealing material composition having a thickness of 5.0 μm. 3. The molded sealing material composition according to claim 1, further comprising a fatty acid and / or an aromatic phosphate. 4. A method in which a molded sealing material is disposed on a joint of an outer panel of a vehicle which has been subjected to undercoating or an intermediate coat following the undercoating, and then the entire joint is painted to seal the joint. In, exhibiting the sealing material composition according to any one of claims 1 to 3, followed by preheating,
A step of obtaining a pseudo-curable sheet as a molded sealing material, arranging the molded sealing material on a joint of an outer plate of a vehicle, applying external force, leveling the molded sealing material, and then coating. Characteristic sealing method. 5. The sealing method according to claim 4, wherein, in producing the pseudo-curable sheet, after the molded sealing material composition is spread, a step of further laminating and impregnating a maintenance cloth is provided. How to seal. 6. The sealing method according to claim 4, wherein in producing the pseudo-curable sheet, the preheating is performed at a temperature lower than the reaction temperature of the heat-active curing agent (b) and 70 ° C.
A sealing method characterized in that the sealing is performed at the above temperature. 7. The sealing method according to claim 4, wherein the molded sealing material liquid composition is spread to a thickness of 0.5 to 5.0 mm, and the leveling is 0.1 to 5.0.
A sealing method characterized in that the sealing is performed with an external force of 2.0 kgf / cm ² . 8. The sealing method according to claim 4, wherein the spreading of the molded sealing material composition is performed on release paper, and when the molded sealing material is arranged at the joint portion of the outer plate, A sealing method comprising disposing a pattern paper as an outer surface, peeling off the release paper after leveling, and performing coating.