JPH06116546A - Photocurable sealant for automobile and application method using the same - Google Patents

Abstract

PURPOSE:To provide a photocurable sealant comprising a photocurable resin, a (meth)acrylate monomer, an inorganic or organic filler, a thermoplastic resin, etc., and excellent in workability and adhesion to electrodeposition-coated plates. CONSTITUTION:The composition comprises (A) 10-70 pts.wt. (preferably 20-50 pts.wt.) of a photocurable resin, (B) 10-80 pts.wt. (preferably 30-70 pts.wt.) of a (meth)acrylate monomer having a viscosity of preferably 5-200cps/25 deg.C, (C) 5-40 pts.wt. (preferably 5-30 pts.wt.) of an inorganic or organic filler (e.g. talc or calcium carbonate), (D) 1-20 pts.wt. (preferably 3-15 pts.wt.) of a thermoplastic resin or polyisobutylene, and (E) a photoreaction initiator and/or a thermal reaction initiator [1-7 pts.wt. (preferably 3-5 pts.wt.) of the photoreaction initiator and/or 0.1-3 pts.wt. (preferably 0.5-1 pt.wt.) of the thermal reaction initiator].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealant used for seams of members, for example, seams of steel plates in automobile manufacturing processes, and more specifically, it is cured in a few seconds by adjusting the shape and irradiating with light. The present invention relates to a photo-curing or heat-curing sealing agent that can be further modified in shape on the spot.

[0002]

2. Description of the Related Art At present, in the automobile manufacturing process, there are many parts where a sealing agent is used, but the part that is particularly required to have a good appearance is a part where the owner of the car can see it, for example, the seam of step steel plates. , The rain lip part of the trunk room, the seam part of the steel plate of the engine room, etc. If the finish of these parts is poor, the commercial value of the automobile is significantly reduced, so brazing has been conventionally performed. This brazing is a processing method in which a seam portion of a steel sheet is welded in a heap and the sander is ground until it becomes flat.

However, in this method, when the metal part is scraped off, vibration of the sander, scattering of metal powder, scattering of sparks, etc. are unavoidable, and therefore the worker wears a protective mask, which results in workability. Poorly, it takes 30 to 40 minutes to finish in one place, and at present speed of the automobile manufacturing line, it is not at all incorporated into the line, and furthermore, when a sander is applied, the steel plate part There was a drawback that the rust preventive effect was lost by scraping off the electrodeposition paint applied to the.

Further, conventionally, a method of using a thermosetting type PVC sol sealer is known as a method of constructing a joint portion of a steel sheet. This method does not scatter metal powder, so you can avoid using a protective mask, etc.
There is a drawback that when the PVC is heat-cured, it has sagging and shrinkage, and it requires reworking the construction site. Furthermore, with this construction method, it takes several tens of minutes to pass through the heating furnace installed in the automobile manufacturing line once, so after confirming the quality of the finished product, and then reworking it, heating again. In order to check the finished state through the furnace, it takes several hours to complete the work, which is extremely inefficient.

[0005]

An object of the present invention is to efficiently and quickly confirm the finished state immediately after construction,
(EN) It is possible to provide a sealing agent which can correct a construction site on the spot and can be immediately coated, and a construction method using the sealing agent.

[0006]

The first aspect of the present invention is (A)
Photocurable resin, (B) (meth) acrylate monomer,
(C) An inorganic or organic filler, (D) a thermoplastic resin or polyisobutylene, and (E) a photoreaction and / or heat reaction initiator, which is a photocurable sealing agent for automobiles. A second aspect of the present invention is characterized in that the sealing agent is discharged to an application site, the external shape of the discharged sealing agent is adjusted, and then the external shape is fixed by irradiating with light, and further the resin is heat-cured. It is a construction method.

The present invention will be described in detail below. The photocurable resin used in the present invention is not particularly limited as long as it is a resin that is cured by irradiation with light such as ultraviolet light and electron beam, and examples thereof include acryloyl polybutadiene oligomer at both ends, epoxy acryl oligomer, urethane acryl oligomer, urethane. (Meth) acryloyl oligomer, polyester acryl oligomer, alkyd acryl oligomer, silicone acryl oligomer, (meth) acryl monomer trimethylolpropane tri (meth) acrylate, polyethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, 1.
Examples thereof include 6-hexanediol (meth) acrylate, neopentyl glycol di (meth) acrylate, diacryloxetyl phosphate and the like. Among them, acryloyl polybutadiene oligomer, urethane (meth) acryloyl oligomer, and alkyd acrylic oligomer are preferable.

The photocurable resin imparts the sealing material of the present invention with the same workability as that of vinyl chloride sol, and shortens the curing speed in seconds. The content of the photocurable resin is 10 to 70 parts by weight, preferably 20 to 50 parts by weight.

The (meth) acrylate monomer used in the present invention is a commercially available mono- or di-tri (meth) acrylate monomer.
The acrylate can be appropriately selected and used, and specific examples thereof include butoxyethyl (meth) acrylate.
Butanediol mono (meth) acrylate, 2-ethoxyethyl (mono) acrylate, ethyl carbite
(Mono) acrylate, 2-ethylhexyl (meth)
Acrylate, 2-hydroxyethyl (meth) acrylate, isobornyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate
G, phenoxyhydroxypropyl (meth) acryl-
Mono (meth) acrylates such as phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc.
Acrylate; polyethylene glycol di (meth) acrylate, 1,4-butanediol (meth) acrylate
, Glycerol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethyloltri (meth) acrylate, PO-modified trimethylpropanetri (meth) acrylate, etc. Examples thereof include tri (meth) acrylate.

The viscosity of the (meth) acrylate monomer is
1 to 300 cps / 25 ° C., preferably 5 to 200 c
ps / 25 ° C. The (meth) acrylate monomer can reduce the viscosity of the photocurable resin.
The (meth) acrylate monomer can reduce the viscosity of the photocurable resin. The content of the (meth) acrylate monomer is 10 to 80 parts by weight, preferably 30 to
70 parts by weight.

Examples of the inorganic or organic filler used in the present invention include talc, mica, calcium carbonate, magnesium hydroxide, silicic acid anhydride, inorganic pigments and organic pigments, and bulky fillers are preferred. The inorganic or organic filler can impart stringing prevention and polishing properties to the sealing agent of the present invention. The content of the inorganic or organic filler is 5 to 40 parts by weight, preferably 5 to 30 parts by weight. When the content of the filler is less than 5 parts by weight, the sealing agent may cause stringing or cold flow, and when the content of the filler exceeds 40 parts by weight, the viscosity of the sealing agent becomes too high, so that it may be extruded from a tube or the like. It may disappear, and the surface may be roughened when finishing the surface with a spatula or the like, which is not preferable.

The thermoplastic resin or polyisobutylene used in the present invention is a thermoplastic resin or polyisobutylene having a molecular weight of 10,000 or more which is soluble in the (meth) acrylate monomer and has an elongation after curing of 100% or more and a volume shrinkage ratio. Is preferably 7% or less. By using such a thermoplastic resin or polyisobutylene, it is possible to further strengthen the physical properties of the sealing agent after curing, improve the water resistance and solvent resistance, and improve the adhesion with the electrodeposition coated plate. Can be improved.

Examples of the thermoplastic resin include polybutylene, polybutadiene, polybutene, polyisoprene vinyl butyral, polyphenylene oxide, polysulfone, polycarbonate, polyvinyl acetate, methacrylic resin, polyacrylonitrile, thermoplastic polyesters, polyamides, (derivatives). ), Polyvinyl butyral, a thermoplastic epoxy resin, an ethylene vinyl acetate copolymer, or a copolymer thereof. The amount of thermoplastic resin or polyisobutylene used is 1 to
It is 20 parts by weight and preferably 3 to 15 parts by weight. When the amount used is less than 1 part by weight, the adhesion to the steel sheet may be reduced, and when it exceeds 20 parts by weight, the viscosity of the sealing agent increases, which is not preferable.

Examples of the photoreaction initiator used in the present invention include Darocur 1173 (manufactured by Merck) and Irgacure-651 (manufactured by Ciba). The amount of the photoreaction initiator used is 1 to 7 parts by weight, preferably 3 to 5 parts by weight. Examples of the thermal reaction initiator used in the present invention include benzoyl peroxide, di-2-ethylhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, benzoyl peroxide and cyclohexane peroxide. it can. The amount of the thermal reaction initiator used is 0.1 to 3 parts by weight, preferably 0.1.
5 to 1 part by weight.

According to the construction method of the present invention, a container such as a sealer gun or a tube is filled with the sealing material mixed in the predetermined amount, and from the container, for example, a joint of steel plates,
A desired amount of sealing material is discharged onto the construction site such as a groove or a dent, and then the external shape of the discharge surface is adjusted using a spatula, a brush or the like, and then light is irradiated to remove the sealing material. Fix the external shape.

The light to be applied is not particularly limited as long as it can cure the photocurable resin.
For example, ionizing radiation such as ultraviolet rays and electron beams can be used. Further, in the construction method of the present invention, after the sealing material is further discharged from above the cured sealing material, the external shape is adjusted and light is irradiated to cure the sealing material, and the construction is carried out. Is preferred. If necessary, the hardened part is scraped off with a cutter knife or the like to adjust the external shape. next,
After fixing the external shape of the sealing material, if necessary, after coating the surface, heating is performed to completely cure the sealing material. Generally, the heating temperature may be about the same as the temperature of the coating drying furnace of the automobile manufacturing line.

[0017]

The present invention has the following effects. Since it contains an inorganic or organic filler, threading and cold flow do not occur, and the external shape of the sealing material discharged onto the construction site can be easily corrected with a spatula or the like. Since it can be cured in a few seconds by irradiating with ultraviolet rays, after that, depending on the finished state of the seam, it is possible to repeat the same process from above the construction site immediately after curing, and it is easy and You can get a nice finish in a short time.

Since it contains a thermoplastic resin or polyisobutylene, it has excellent adhesion to the electrodeposition coated plate. Since no plasticizer used in the PVC sol is used, the plasticizer does not emerge when the paint is applied and the paint is not transparent. Compared to the case where a PVC sol sealer is used in an automobile manufacturing line, the number of times of passing through a heating tunnel is reduced by at least two steps, so that the economic effect is extremely large. Compared with brazing, the work is extremely easy, the environment does not deteriorate, and the construction time can be reduced to about 1/10 or less.

[0019]

【Example】

Example 1 Epoxy acrylate resin 3002A (Kyoeisha Yushi Co., Ltd.)
30) Epoxy acrylate resin M-600A (Kyoeisha Yushi Co., Ltd.)
70 parts ethylene vinyl acetate copolymer ESCORENE ULMV02514 (manufactured by Exxon Chemical Co., Ltd.)
..10 parts fine powder of urethane resin (manufactured by Negami Kogyo Co., Ltd.)
・ ・ ・ ・ ・ ・ 10 copies Darocur 1173 (Merck) ・ ・ ・ ・ ・ ・ ・ ・
........ 6 parts Benzoyl peroxide (manufactured by NOF CORPORATION)
..... 1 part The above composition was piled up with a sealer gun on an untreated steel plate having a circular recess with a radius of 7.5 mm and a depth of 1 mm and loosely squeezed with a rubber spatula. When it was irradiated with ultraviolet rays for about 2 seconds with a high-pressure mercury lamp, it cured while slightly rising. # 220
I made it flat with sandpaper and then applied electrodeposition,
The concave portion was indistinguishable. No effect of heating was observed.

Example 2 Urethane acrylate resin (Aronix M-1100, manufactured by Toagosei Kagaku Kogyo Co., Ltd.)
・ ・ ・ ・ 40 parts Butanediol monoacrylate (manufactured by BASE) ・ ・
・ ・ ・ ・ ・ ・ 60 parts Aerosil No.300 (manufactured by Nippon Aerosil Co., Ltd.) ・ ・ ・ ・
..... 15 parts saturated polyester (Byron 300, manufactured by Toyobo Co., Ltd.)
・ ・ ・ ・ ・ ・ 10 copies Darocur 1173 (Merck) ・ ・ ・
........ 6 parts Lauroyl peroxide (manufactured by NOF CORPORATION)
..... 1 part The above composition is applied to the seam (width 3 mm, depth 3) of the electrodeposition coated steel sheet.
mm, groove 100 mm long), lifted it out of the tube and squeezed it with a urethane rubber shigee. And 1KW
Ultraviolet rays were irradiated for about 2 seconds with a high pressure mercury lamp. Since the seam portion was slightly recessed, the composition was placed in the recessed portion and flattened with a squeegee, and then similarly irradiated with ultraviolet rays. Next, when it was painted from above and baked, the seams were almost invisible. Since the above composition also contained a thermal reaction initiator, it was hardened at the depth of the working portion of 3 mm in the baking process.

Example 3 Polybutadiene acrylate (R-45 ACR, manufactured by Idemitsu Petrochemical Industry Co., Ltd.) ...
50 parts polyisobutylene rubber (Vistanex LMMH, manufactured by Exxon) ...
・ ・ ・ ・ ・ ・ 10 parts Tetrahydrofuran acrylate (Kyoeisha Yushi Co., Ltd.)
50 parts calcium carbonate (Maruo Calcium Co., Ltd.)
........ 5 parts silicic acid anhydride (Fluorite R, manufactured by Tokuyama Soda Co., Ltd.)
・ ・ ・ ・ 10 copies Irgacure-184 (manufactured by Ciba) ・ ・ ・
........ 6 parts Lauroyl peroxide (manufactured by NOF CORPORATION)
..... 1 part When tested in the same manner as in Example 2, substantially the same results were obtained. The adhesion of the paint was also good.

Example 4 Urethane acrylate resin (Aronix M-1100, manufactured by Toagosei Chemical Industry Co., Ltd.) ...
・ ・ ・ 40 parts Epoxy acrylate resin M-600A (Kyoeisha Yushi Co., Ltd.)
(Made) ... 60 parts Vistanex LMMS (Made by Exxon) ...
・ ・ ・ ・ ・ ・ 10 parts Urethane resin fine powder (manufactured by Negami Industry Co., Ltd.) ・ ・
・ ・ ・ ・ ・ ・ 10 parts Aerosil No.300 (manufactured by Nippon Aerosil Co., Ltd.) ・ ・ ・
・ ・ ・ ・ ・ ・ ・ ・ ・ Part 3 Darocur 1173 (Merck)
........ 4 parts benzoyl peroxide (manufactured by NOF CORPORATION)
..... 1 part The above composition was piled up on a seam (a groove having a width of 3 mm and a depth of 0.8 mm) of an electrodeposition coated plate having a thickness of 0.8 mm and squeezed with a spatula of silicone rubber. At this time, since the urethane resin fine powder and the silicic acid anhydride fine powder were contained, there was no fluidity at room temperature, and there was no stringing even with a spatula and workability was good. No thread pull was observed when the above composition was screen-printed.

Next, the construction part was irradiated with ultraviolet rays for about 2 seconds with a 1 KW high pressure mercury lamp. Since the seam was slightly recessed, the composition was again placed on the seam, squeezed with a Teflon spatula and irradiated with ultraviolet rays, and the seam was almost flat. Next, when white coating was applied on it and baking was carried out at 140 ° C. for 30 minutes, the joint portion was almost invisible. Since the composition contains a thermoplastic resin, when baked, the adhesion to the electrodeposition coated plate becomes extremely strong, and when the cured product is peeled from the coated plate, cohesive failure may occur. The adhesion was extremely good. Further, after curing, even when immersed in boiling water at 100 ° C. for 1 hour or more, there was no peeling or blistering, and the adhesion to the coated plate after immersion was good.

Comparative Example 1 A vinyl chloride sol sealer was piled up at the seam of an electrodeposition coated steel sheet in the same manner as in Example 2 and wrung with a urethane rubber squeegee. The seams remained slightly recessed. Next, this was put into a paint drying furnace of an automobile manufacturing line and baked. After cooling this, vinyl chloride sol was applied to the recessed portion again with a squeegee, finished with a brush, and similarly baked in a drying furnace. After cooling, the construction portion was painted, but the construction portion was smooth but the paint was transparent, and the construction portion could be visually confirmed. Further, the time required to cure the vinyl chloride sol twice was 1 hour or more.

Comparative Example 2 In order to perform electric welding on the seam of the electrodeposition coated steel sheet of Example 2,
The electro-deposition paint was removed with sandpaper, and the seam was raised with a welding rod to weld. Next, after flattening the welded part with a sander with # 220 sandpaper attached,
Finished with # 220 sandpaper. Next, an undercoat for rust prevention was applied, and an overcoat was applied from above. Although the finish was good, the time required for brazing was about 40 minutes and the working environment was poor, so it was necessary to wear gloves, a protective cap, and a protective mask to perform the work.

Comparative Example 3 Urethane acrylate resin (Aronix M-1100, manufactured by Toagosei Kagaku Kogyo Co., Ltd.)
・ ・ ・ 40 parts Epoxy acrylate resin M-600A (Kyoeisha Yushi Co., Ltd.)
Made) 60 parts Urethane resin fine powder (made by Negami Kogyo Co., Ltd.)
・ ・ ・ ・ ・ ・ 10 parts Aerosil No.300 (manufactured by Nippon Aerosil Co., Ltd.) ・ ・ ・
・ ・ ・ ・ ・ ・ ・ ・ ・ Part 3 Darocur 1173 (Merck)
........ 4 parts benzoyl peroxide (manufactured by NOF CORPORATION)
.... 1 part The above composition was cast in the seam of the electrodeposition coated plate in the same manner as in Example 4 and irradiated with ultraviolet rays to be cured, and then 140
It was baked at 30 ° C. for 30 minutes. As a result, the composition does not contain a thermoplastic resin, so the adhesion is insufficient,
The cured product peeled off easily.

Comparative Example 4 The same compositions as in Examples 1 to 4 were prepared, respectively, except that no inorganic or organic filler was contained. These compositions are
All had strong stringing and cold flow, so they could not be molded with a spatula.

Comparative Example 5 Compositions similar to those of Examples 1 to 4 were prepared, except that the thermoplastic resin and the inorganic or organic filler were not contained.
Since all of these compositions had strong stringiness and cold flow, they could not be molded with a spatula.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoji Maeda 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (2)

[Claims] 1. A photocurable resin (A), a (meth) acrylate monomer (B), an inorganic or organic filler (C),
(D) Thermoplastic resin or polyisobutylene and (E)
A photocurable sealing agent for automobiles, which comprises a photoreaction and / or heat reaction initiator. 2. The sealing agent according to claim 1 is discharged to a construction site, the external shape of the discharged sealing agent is adjusted, and then the external shape is fixed by irradiating with light, and further cured by heating. Sealing construction method.