JPH0228627B2 - JIDOSHA YOSHIIRINGUZAI - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a sealant for automobiles that is applied to the joints of steel plates for use in automobiles to prevent the occurrence of rust due to the intrusion of moisture, salt, etc. into the joints of steel plates. (Prior Art) Conventionally, the above-mentioned sealing agent for automobiles is known which contains a vinyl chloride resin, a plasticizer, and calcium carbonate as main components for forming a coating film. (Problems to be Solved by the Invention) The conventional sealants mentioned above have been made to thicken the film by adding calcium carbonate and to obtain viscosity by adding a plasticizer. The viscosity can only be adjusted to between 700 and 900 poise, and the film thickness is not constant due to insufficient permeability.
The thicker portions give rise to poor appearance, while the thinner portions lack rust prevention. In addition, in order to prevent such inconveniences, brush strokes are performed after applying the sealant, but even if an intermediate coat or top coat is applied after brush strokes, the inconvenience that the handwriting will stand out on the surface and cause sagging defects will occur. have (Means for Solving the Problems) The present invention solves the above-mentioned conventional drawbacks, and solves the above-mentioned conventional problems by applying only extrusion coating using a sealer gun or spray coating.
We provide an automotive sealant that enables process coating, improves coating workability, has improved rust prevention, durability, moisture resistance, etc., and has a good appearance of the paint film, and is made of urethane resin or epoxy resin. , or calcium carbonate per 100 parts by weight of polyester resin
25 to 70 parts by weight, 65 to 200 parts by weight of barium sulfate, and 50 to 150 parts by weight of an aromatic or/and ester solvent having a boiling point of 150°C or higher, and is characterized by not containing a plasticizer. (Example) Next, an example of the present invention will be described in detail. The resins that are the main components for coating film formation include urethane resins, epoxy resins, and epoxy resins that do not require the use of plasticizers.
Use polyester resin. In order to crosslink and cure these resins, various modified polyamines, polyamide resins,
The curing agent may be appropriately selected from conventionally known curing agents such as polyol resins, melamine resins, and urea resins, and may be blended in equivalent amounts with the resin depending on the type of the resin. As an extender pigment, it is especially essential to combine calcium carbonate and barium sulfate. Calcium carbonate contributes to thickening the coating film and improving chemical resistance and impact resistance after application. Its blending amount is
The amount is 25 to 70 parts by weight per 100 parts by weight of urethane resin, epoxy resin, or polyester resin.
If it is less than 25 parts by weight, the above effects cannot be obtained,
If it exceeds 70 parts by weight, the coating film may become brittle. Barium sulfate is necessary to smooth the surface of the thick film of the sealant after painting, and its amount is 65 to 200 parts by weight per 100 parts by weight of urethane resin, epoxy resin, or polyester resin. If it is less than 65 parts by weight, the above-mentioned effects cannot be obtained, and if it exceeds 200 parts by weight, the coating film may become brittle. Incidentally, a small amount of coloring pigment is generally added to the above-mentioned sealant for automobiles of the present invention. For example, an appropriate amount of powder of titanium oxide, carbon black, talc, mica, kaolin, magnesium carbonate, erosil, vermiculite, graphite, alumina, silica, etc., per 100 parts by weight of urethane resin, epoxy resin, or polyester resin. Add 4 to 25 parts by weight. The solvent is an aromatic or/and ester solvent with a boiling point of 150°C or higher, urethane resin, or epoxy, for the purpose of adjusting viscosity, preventing sagging and wrinkles, and improving permeability and leveling. 50 parts per 100 parts by weight of resin or polyester resin
~150 parts by weight is blended. If it is less than 50 parts by weight, it may not be possible to adjust the viscosity to the level required for coating work.
If it exceeds 150 parts by weight, the coating work and rust prevention performance may deteriorate. Examples of aromatic solvents with a boiling point of 150°C or higher include diethylbenzene, isopropylbenzene, triamylbenzene, tetraamylbenzene, didodecylbenzene, amyltoluene, P-cymentetralin, decalin, dipentene, and P-menthane. Use one or more petroleum solvents with a temperature of 150℃ or higher. Ester solvents include acetate, succinate, glutarate, adipate, carboxylate, sulfonate,
Inorganic acid esters, glycerin esters, etc.
Use one species or two or more species. Further, aromatic solvents and ester solvents having a boiling point of 150° C. or higher may be used in combination. As other additives, lead powder, zincated lead, zinc yellow, strontium chromate, red lead, basic chromate, etc. can be mixed as appropriate in order to improve the rust prevention effect, and antifoaming agents and thickeners can be added. Agents, preservatives, dispersants, thixotropic agents, antifreeze agents, PH adjusters, etc. can be added. The automotive sealant of the present invention is usually applied to the joints of steel plates after baking the electrocoated paint on the car body, for example, when it is applied in a band shape using a sealer gun, air spray, airless spray, etc. It is usually preferable to adjust the temperature within the range of 20 to 500 poise (20°C) from the viewpoint of film rideability, sprayability, etc. The application can be carried out at any stage after the baking of the electrodeposition paint and before the top coat is applied; unlike conventional sealants containing plasticizers, it is limited to after the baking and before the intermediate coat. It is possible to freely select the The painted parts are also
Although not particularly limited, it is mainly used under doors, engine room joints, and near tailgates where the seam spacing of automobile body steel plates is 2 m/m or less. Further, it is preferable to adjust the viscosity of the sealant as appropriate depending on the spacing between the steel plates. Next, a more specific embodiment will be described in detail together with a conventional example. Example 1 100 parts by weight of a resin material prepared by blending 100 parts by weight of a urethane resin (trade name Takenate B-830, manufactured by Takeda Pharmaceutical Co., Ltd.) with 20 parts by weight of a polyamide resin (trade name Epoqueure 3080, manufactured by Yuka Ciel Epoxy Co., Ltd.) Calcium carbonate (trade name: Calseeds)
33 parts by weight of barium sulfate (product name: Barite BC, manufactured by Sakai Chemical Industry Co., Ltd.), 100 parts by weight of acetic acid ester as a solvent, antifoaming agent (product name: BYK-0, BITSU) 8 parts by weight of a dispersant (trade name: Disparon #1250, manufactured by Kusumoto Kasei Co., Ltd.) were blended and uniformly kneaded to obtain a sealant for automobiles of the present invention. Example 2 Resin material 100 was prepared by blending 100 parts by weight of an epoxy resin (trade name Epicote 828, manufactured by Yuka Ciel Epoxy Co., Ltd.) with 42 parts by weight of a polyamide resin (trade name Epoqueure 3080, manufactured by Yuka Ciel Epoxy Co., Ltd.).
Based on the weight part, 33 parts by weight of calcium carbonate (trade name: Calseeds PL, manufactured by Kamishima Chemical Industry Co., Ltd.), 100 parts by weight of barium sulfate (trade name: Barite BC, manufactured by Sakai Chemical Industry Co., Ltd.), ethylbenzene and carboxylic acid ester as a solvent. 100 parts by weight of a mixed solvent, 7 parts by weight of an antifoaming agent (product name: BYK-0, manufactured by Bitzkumarinkrodt Co., Ltd.), and 7 parts by weight of a dispersant (product name: Disparon #1250, manufactured by Kusumoto Kasei Co., Ltd.) were mixed uniformly. The mixture was kneaded to obtain an automotive sealant of the present invention. Example 3 Polyester resin (trade name Betsukolite M-
6402-50, manufactured by Dainippon Ink & Chemicals Co., Ltd.)
Calcium carbonate (product name: Calcease PL,
33 parts by weight (manufactured by Kamishima Chemical Industry Co., Ltd.), barium sulfate (trade name Barite BC, Sakai Chemical Industry Co., Ltd.)
100 parts by weight, 100 parts by weight of a mixed solvent of ethylbenzene and carboxylic acid ester as a solvent, antifoaming agent (trade name: BYK-0, manufactured by Bitzkumarinkrodt) 7
and 7 parts by weight of a dispersant (trade name Disparon #1250, manufactured by Kusumoto Kasei Co., Ltd.) were blended and uniformly kneaded to obtain an automotive sealant of the present invention. Conventional example: Polyvinyl chloride resin (product name: Zeon 400×
110A, manufactured by Nippon Zeon Co., Ltd.), 400 parts by weight of calcium carbonate (product name: Calseeds PL, manufactured by Kamishima Chemical Industry Co., Ltd.), 200 parts by weight of phthalate ester as a plasticizer, titanium oxide (product name: Taipeke R) −820, manufactured by Ishihara Sangyo Co., Ltd.)
14 parts by weight, polyamide resin (trade name: Epoqueure)
3080 (manufactured by Yuka Ciel Epoxy Co., Ltd.) was blended with 18 parts by weight and kneaded uniformly to obtain a conventional sealant for automobiles. These sealants were tested for the following seven items, and the test results shown in Table 1 below were obtained.

[Table] The test methods for the following items were performed as follows. 1. Permeability test After applying 20ml of sealant to the joints of the steel plates with a spacing of 100μ, the sheets were stood vertically and baked at 140°C. At this time, the distance that the sealant penetrated was
Those with a velocity of 20 m/m or more are considered to be good and marked with a circle. 2 Appearance test Examples 1, 2,
For each sealant in No. 3, 200μ of each was applied with a sealer gun without brushing, while the conventional sealant
After applying 1000μ with a sealer gun, brush
After that, each of these test boards was further coated with 20μ intermediate coat and top coat.
After painting 40μ, the appearance of the painted surface was examined for unevenness and scratches. Items with no unevenness or scratches on the painted surface were marked with a circle. 3 Rust prevention power test Insert a knife cut into each coated test plate that has been coated with top coat in the same way as in Section 2 until it reaches the metal plate in the center.
240 to the salt spray tester specified in JIS-K-5400
After some time, the rust depth from the cut portion was measured. 4 Durability test Each coated test board prepared in the same manner as in Section 2 was tested on a sunshine weather meter for 600 hours and then for 50 hours.
℃, after 6 cycles of 72 hours in a 98% humidity tester,
Peeling of a 0.2m/m square tape was investigated. Those that did not peel off were marked with a circle. 5 Moisture resistance test Each coated test plate prepared in the same manner as in Section 2 was heated at 50°C and 98°C.
% humidity tester After 240 hours, peeling of the 0.2 m/m square tape and surface blistering were examined. Those with no peeling and no blistering were marked with a circle. 6 Tensile strength test A single coating film of sealant formed on a steel plate was tested according to JIS
- Pulled at 50m/m with dumbbell No. 2 according to K-6300. 7. Shear adhesion test A single coating film similar to that described in Section 6 was stretched at 50 m/m with a spacer of 3 m/m according to JIS-K-6300. As is clear from Table 1 above, the automotive sealants of Examples 1, 2, and 3 have better permeability, appearance, rust prevention, durability, moisture resistance, and better performance than the conventional automotive sealants. It was excellent in both tensile strength and shear adhesive strength. (Effects of the Invention) As described above, when using the automotive sealant of the present invention, 25 to 70 parts by weight of calcium carbonate, 65 to 200 parts by weight of barium sulfate, and a material having a boiling point of 150°C or higher are added to 100 parts by weight of the resin component. By blending 50 to 150 parts by weight of an aromatic or/and ester solvent to avoid plasticizers, it has excellent workability, rust prevention, durability, moisture resistance, etc., and the appearance of the coating film. It has the effect of being good.

Claims (1)

[Claims] 1 Calcium carbonate per 100 parts by weight of urethane resin, epoxy resin, or polyester resin
25 to 70 parts by weight of barium sulfate, 65 to 200 parts by weight of barium sulfate, and 50 to 150 parts by weight of an aromatic or/and ester solvent with a boiling point of 150°C or higher, and does not contain a plasticizer. Sealant for use.