JP2006117140A - Sealing method of roof drip part of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure a space for certain sealing and fitting of a decoration mold at water-proof treatment by a sealer and a rust-proof treatment of a roof drip part of a vehicle. <P>SOLUTION: A value of viscosity of the sealer 5 at coating is set and adjusted to 50-55 Pas/20°C and the TI (thixo coefficient) value is set and adjusted to 5.0-5.3. Coating of the sealer 5 is performed in the state that a temperature difference of a surface temperature of a roof drip groove 4 and a temperature of the sealer 5 itself is 10-40°C. The viscosity is reduced to a range of 5-15 Pas/20°C utilizing the temperature difference and further the TI value is raised to 5.5-5.8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for sealing a roof drip portion of a vehicle.

A roof drip groove formed at a joint between a roof panel and a side panel of a vehicle generally has a simple mating structure in which end portions of both panels are overlapped and spot-welded. Such roof drip grooves need to be waterproofed and rustproofed against rainwater because of spot welding.
Conventionally, for example, after applying a body sealer to the bottom of the roof drip groove and applying the waterproof and rust-proofing treatment, a decorative molding is fitted into the roof drip groove to conceal the body sealer and improve the finished appearance. ing. A specific example is shown in FIG. 1, which is a cross-sectional view of a roof portion of a vehicle 1, in which a body sealer 5 is applied to the bottom of a roof drip groove 4 formed at a joint portion between a roof panel 2 and a side panel 3. A rod-shaped decorative molding 6 having substantially the same length is fitted over the entire length of the roof drip groove 4.

The roof drip groove 4 has a structure in which an end portion 2a of the L-shaped cross section of the roof panel 2 and an end portion 3a of the L-shaped cross section of the side panel 3 are overlapped and spot welded, and is located at the bottom of the roof drip groove 4. An appropriate amount of the body sealer 5 is applied to a portion where the ends of the panels 2 and 3 are overlapped with each other using a sealer application gun (not shown). The body sealer 5 is a waterproofing / rustproofing agent such as polyvinyl chloride and penetrates the mating surfaces of the panels 2 and 3 at the bottom of the roof drip groove 4 to perform waterproofing and rustproofing.
After the body sealer 5 is applied to the roof drip groove 4, a molding 6 having the same length is fitted into the roof drip groove 4 and fixed to the bottom of the roof drip groove 4 with an adhesive.

By the way, as shown in FIG. 1, when waterproofing and rust-proofing are performed by the body sealer 5, after the body sealer 5 is applied with a sealer application gun, a space for secure sealing and fitting of a decorative molding is provided. After securing the body sealer 5, leveling is performed using a leveling jig and hooked from the L-shaped end portion 2 a of the roof panel 2 to the L-shaped end portion 3 a of the side panel 3. Thus, the body sealer 5 is spread, and if the body sealer 5 has a convex portion, the decorative molding 6 cannot be attached, so that the convex portion does not exist.
This leveling work takes 7 to 8 times as long as the coating (painting) work, and does not require the work, and secures a space for secure sealing and fitting of the decorative mall. There was a need to develop technology that could

As the sealing technique, a thermosetting resin is filled in the roof drip groove 4 at the joint between the roof panel 2 and the side panel 3, and the waterproof rust prevention treatment of the bottom of the roof drip groove 4 is performed with the thermosetting resin. There is known a roof structure that is performed and uses the cured thermosetting resin in the roof drip groove 4 as a decorative molding as it is (see Japanese Patent Laid-Open Nos. 1-152049 and 9-207687).
Japanese Patent Application Laid-Open No. 11-170927 describes a sealing method performed by fitting a multilayer tape in which a lower layer is a thermosetting adhesive resin layer and an upper layer is a heat resistant surface layer forming resin layer.
Japanese Unexamined Patent Publication Nos. 1-152049, 9-207687, 11-170927

The object of the present invention is to provide a technique capable of answering the above request.
Other objects and novel features of the present invention will become apparent from the description of the present specification and the drawings.

The claims of the present invention are as follows.
(Claim 1) A method for sealing a roof drip portion of a vehicle with a sealer, wherein the viscosity is 50 to 55 Pa.s. A sealer with s / 20 ° C. and a thixotropic index of 5.0 to 5.3 has a temperature difference between the surface temperature of the roof drip portion and the temperature of the sealer itself of 10 to 10. Coating is performed at 40 ° C., and the viscosity of the sealer is set to 5 to 15 Pa.s. A method for sealing a roof drip portion of a vehicle, wherein the range of s / 20 ° C is lowered and the thixotropic index is increased to 5.5 to 5.8.
(Claim 2) The surface temperature of the roof drip portion is 25 ° C to 70 ° C, and the sealer temperature is 10 ° C to 40 ° C. Sealing method.

In the present invention, in order to seal the roof drip portion of the vehicle with a sealer such as the above body sealer, the initial thixotropic index (TI) value of the sealer is set (adjusted) to 5.0 to 5.3. The viscosity of the coated sealer is set so that the sealer is applied in a state where the temperature difference between the surface temperature of the roof drip portion and the temperature of the sealer itself is 10 to 40 ° C. 5-15 Pa. Using the temperature difference. The range of s / 20 ° C. is reduced, and the TI value of the coated sealer is reduced by using the temperature difference, and then the surface temperature of the roof drip portion is reduced (the temperature difference from the sealer is reduced). Thus, the TI value is increased to 5.5 to 5.8.
With the above configuration, the sealer has a viscosity of 5 to 15 Pa.s. By reducing the range of s / 20 ° C., the sealer moves from the end of the L-shaped section of the roof panel to the end of the L-shaped section of the side panel without using a leveling jig due to the high fluidity immediately after coating. It spreads over and does not produce a convex part on the sealer, and it can secure enough space for mounting the decorative mall, and then raise the TI value to 5.5 to 5.8, so that the sealer hangs down. Does not occur.
This eliminates the need for leveling with a brush or spatula, which was necessary after applying the body sealer, and allows for secure sealing and a space for fitting the decorative molding, significantly reducing the work time. I was able to.

In the present invention, paying attention to the temperature difference between the surface temperature of the roof drip portion, for example, the roof drip groove, and the temperature of the material of the body sealer 5 as shown in FIG. When the state is reached, the body sealer 5 is applied.
For example, after the vehicle is sent into a painting baking furnace in the painting process and the paint is baked while heating the vehicle, the surface of the roof drip portion is relatively not passed through the cooling process that is normally performed. It is possible to apply the body sealer 5 when the temperature is high.
Knowing the surface temperature of the roof drip and the temperature of the body sealer (working temperature), and applying the body sealer 5 when the temperature difference derived from the following equation 1 is 10 to 40 ° C. To implement.

In general, the preferable surface temperature of the roof drip portion in the above case is 25 ° C to 70 ° C, and the sealer temperature is 10 ° C to 40 ° C.
As described above, the temperature difference is in the range of 10 to 40 ° C. When deviating from the range, a leveling operation is required after the body sealer is applied, and a space for fitting the decorative molding is secured. May not be possible, or the fluidity may be too high to ensure reliable sealing.

In the present invention, the body sealer is applied when the temperature difference between the surface temperature of the roof drip portion and the temperature of the material of the body sealer is 10 to 40 ° C. Therefore, the thixotropic index (hereinafter referred to as a thixotropic coefficient, TI) before painting needs to be in an appropriate range.
The thixo coefficient (TI) is derived from Equation 2 below.

  The TI value is 5.0 to 5.3. If the initial TI value is less than 5.0, the decrease in the TI value after painting may be so great that dripping may occur. On the other hand, if the TI value exceeds 5.3, the change in the TI value after painting is not sufficient, and leveling is insufficient, so that there is a possibility that a leveling operation may be required or sealing may be impossible. .

  In the present invention, the thixotropic coefficient (TI) and viscosity behavior after the body sealer is painted are important. Using the temperature difference between the sealer and the roof drip part, the initial viscosity is temporarily 50 to 55 Pa.s. s / 20 ° C. is 5 to 15 Pa.s. By reducing the range of s / 20 ° C., high fluidity can be obtained, so that a high sealing effect and leveling effect can be achieved. Thereafter, the surface temperature of the roof drip portion decreases, so that the temperature difference from the sealer temperature is reduced. As a result, the TI value rapidly increases to 5.5 to 5.8, and the coated sealer is Dripping can be prevented.

Examples of the sealer used in the present invention include, for example, a vinyl chloride plastisol-based automotive sealant used as a body sealer.
Specific examples of the vinyl chloride plastisol-based automotive sealing material include a vinyl chloride resin and a plasticizer as essential components, and an adhesion / tackifier and a filler that are added as necessary. And vinyl chloride plastisol-based automotive sealing material diluted with a diluting solvent.

  The vinyl chloride resin constituting the sealing material may be a vinyl chloride homopolymer or a copolymer of vinyl chloride and other monomers. The blending amount of the vinyl chloride resin is suitably 15 to 25% by weight. When the blending amount of the vinyl chloride resin is less than 15% by weight, the coating film is not sufficiently formed with the sealing material, whereas when it exceeds 25% by weight, the coating film may become too hard.

Examples of the plasticizer constituting the sealing material include a phthalic acid polyester plasticizer, a sebacic acid polyester plasticizer, and an adipic acid polyester plasticizer.
As other plasticizers, plasticizers usually used for vinyl chloride sealants can be used. Examples thereof include phthalic acid ester plasticizers such as dioctyl phthalate (DOP), diisononyl phthalate (DINP), and diisobutyl phthalate (DIBP), and adipic acid plasticizers such as dioctyl adipate (DOA). The blending amount of the plasticizer is suitably 25 to 35% by weight. If the blending amount of the plasticizer is less than 25% by weight, the coating film of the sealing material may become too hard. On the other hand, if it exceeds 35% by weight, the fluidity of the sealing material is too high and the coating film is sufficiently formed. There is a fear that it is not.

  A polyurethane resin, an epoxy resin, a polyamide resin, or the like can be used as an adhesion-imparting agent constituting the sealing material. The adhesion-imparting agent can assist this when heat-sealing. In addition, as a tackifier, a tackifier such as polyamide, polyol, or blocked isocyanate, or a liquid rubber such as polybutadiene or polybutene may be used.

The filler constituting the sealing material includes calcium carbonate, barium sulfate, talc, clay, kaolin, zinc white, titanium oxide, silica, pigments such as alumina, flake filler such as mica, plastic balloon, glass Examples thereof include hollow fillers such as balloons, silica balloons, shirasu balloons, and carbon hollow spheres.
As the calcium carbonate, a surface-treated or non-surface-treated one can be used, and it is preferable to appropriately mix these surface-treated calcium carbonate and non-surface-treated calcium carbonate. By changing the mixing ratio of these surface-treated calcium carbonate and non-surface-treated calcium carbonate, the TI value at the time of coating can be adjusted within the range of 5.0 to 5.3. The TI value of the painted sealer before installation is temporarily reduced to less than 5.0 to obtain a large fluidity to obtain a high sealing effect and a leveling effect, and thereafter, the surface temperature of the roof drip portion By reducing the temperature difference from the sealer temperature due to the decrease, the TI value is rapidly increased to 5.5 or more, and the painted sealer can be made a smooth surface to prevent dripping.

  To constitute the sealing material, other additives can be blended as necessary. Examples of the additive include a vinyl chloride resin stabilizer, an ultraviolet absorber, a hygroscopic agent, and a high boiling point solvent for improving the workability of the coating film. The blending amount of the additive can be 0 to 10% by weight.

  The sealing material is produced by dispersing and kneading components constituting the sealing material such as a vinyl chloride resin by a conventionally known mixing and dispersing machine such as a Banbury mixer, a planetary mixer, an open kneader, or a vacuum kneader. In addition, the sealing material can be painted by a dedicated coating machine called a flow gun by a high-pressure coating machine driven by an airless pump or the like.

(Embodiment of the Invention)
In order to provide an understanding of the present invention, examples are described below. Needless to say, the present invention is not limited to the following examples.
Example 1.

Sealing materials were prepared with the formulations shown in Table 1. The sealing material has a viscosity (Pa.s / 20 ° C.) of 50, and its thixotropy coefficient (TI) is obtained when the number of rotors of a rotational viscometer (for example, BH rotational viscometer) is changed between 2 rpm and 20 rpm. Each of the viscosities was measured and calculated according to Equation 1 above, and it was 5.2.
Sealing was performed using the sealing material at a sealer temperature of 20 ° C. and a roof drip groove surface temperature of 50 ° C. When the viscosity of the sealing material at the time of sealing was measured in the same manner as described above, it was 10 Pa.s. s / 20 ° C. and 40 Pa. s / 20 ° C., and the thixotropic coefficient (TI) was measured in the same manner as described above. As a result, the surface temperature of the roof drip groove decreased and the temperature difference from the sealer temperature decreased. The thixotropic coefficient (TI) increased to 5.7.
The roof molding could be attached without the need for leveling with a brush or spatula during sealing coating, and good sealing was possible. The work time required for sealing coating could be reduced to 1/7 of the conventional time.
Using the above sealing material, the filling method of the step gap due to the coating method and viscosity was examined.
The test method was as shown in FIG. 2, and the performance of the sealing material was examined by changing the angle of the nozzle 7 and changing the offset X of the coating film and examining the value of the ski Y (unit: mm).
Test method:
Nozzle angle 30 ° and 60 °
Gun speed about 400mm / sec
Painting pressure 5-6MPa
(GRACO BULLDOG 30: 1 3 / 8x5mm)
Paint temperature 20 ° C (atmosphere 16 ° C)
The test results are shown in Table 2.
Also, the flowability is (baking 140 ° C. × film thickness after 20 minutes / film thickness after 1 hour of wet standing) × 100
Was found to be 100%, indicating excellent flowability.
Comparative Example 1

Sealing materials were prepared with the formulations shown in Table 1 below. The sealing material had a viscosity (Pa.s / 20 ° C.) of 50 and a thixotropic coefficient (TI) of 6.5.
In the same manner as in Example 1, sealing was performed using the sealing material at a sealer temperature of 20 ° C. and a roof drip groove surface temperature of 50 ° C. When the viscosity of the sealing material during the sealing was measured in the same manner as described above, it was 5.0 Pa.s. Only s / 20 ° C. decreased. Further, when the thixotropic coefficient (TI) of the sealing material at the time of sealing was measured in the same manner as described above, the surface temperature of the roof drip groove was lowered, and the temperature difference from the sealer temperature was reduced. The coefficient (TI) increased to 7.0.
Using the above-mentioned sealing material, in the same manner as in Example 1, the fillability and flowability of the step gap due to the coating method and viscosity were examined.
The test method was as shown in FIG. 2, and the performance of the sealing material was examined by changing the angle of the nozzle 7 and changing the offset X of the coating film and examining the value of the ski Y (unit: mm).
The test results are shown in Table 2.
Further, when the flowability was examined in the same manner as in Example 1, it was 96%, and the sealing effect was insufficient.

  From Table 2, according to the example of the present invention, even if the nozzle angle is changed, the step is 1 mm or 2 mm, and even if the coating film offset is changed, the gap can be reduced to 0. In doing so, it can be seen that it is possible to secure a sufficient space for reliable sealing and fitting of a decorative molding.

  The present invention can be applied to vehicles in addition to automobiles.

It is sectional drawing which shows the seal structure of a roof drip groove. It is explanatory drawing of the test method in the Example of this invention.

Explanation of symbols

1 Vehicle 2 Roof Panel 3 Side Panel 4 Roof Drip Groove 5 Sealer 6 Decoration Mall 7 Nozzle

Claims (2)

A method for sealing a roof drip portion of a vehicle with a sealer, wherein the viscosity is 50 to 55 Pa.s. A sealer with s / 20 ° C. and a thixotropic index of 5.0 to 5.3 has a temperature difference between the surface temperature of the roof drip portion and the temperature of the sealer itself of 10 to 10. Coating is performed at 40 ° C., and the viscosity of the sealer is set to 5 to 15 Pa.s. A method for sealing a roof drip portion of a vehicle, wherein the range of s / 20 ° C is lowered and the thixotropic index is increased to 5.5 to 5.8. The surface temperature of the roof drip portion of the vehicle according to claim 1, wherein the surface temperature of the roof drip portion is 25 ° C to 70 ° C, and the sealer temperature is 10 ° C to 40 ° C. Sealing method.

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