JPS6363775A - Method of assembling and bonding panel for automobile body - Google Patents

Abstract

PURPOSE:To obtain the title panels having excellent fortifying strength and no distortion, by assembling and bonding panels for an automobile body by means of a specified adhesive, heating it to semi-cure it and completely curing it by moisture in air. CONSTITUTION:1-40% (by weight; the same applies hereinbelow) synthetic diene rubber (e.g., butadiene rubber) is mixed with 0.5-50% vulcanizing agent for rubbers (e.g., 1,1-di-tert-butylperoxycyclohexane), 1-40% plasticizer (e.g., a phthalate plasticizer), 5-70% filler having a low water content (e.g., silica powder) and 5-70% room-temperature moisture-curing organosilicon compd. having at least two groups of the formula (wherein X is a hydrolyzable group; R is a group other than X; and n is 0-2) to obtain an adhesive. Panels for an automobile body are assembled by means of said adhesive, washed by means of a warm water shower, subjected to electrodeposition coating and baked at 140-200 deg.C for 20-40min and at the same time, the adhesive is semi-cured. The panels are cooled to room temp. to completely cure the adhesive by moisture in air.

Description

Detailed Description of the Invention (,) Object of the Invention (Field of Industrial Application) The method for assembling and adhering automobile body panels of the present invention provides hoods, trunks,
Panels for automobile bodies such as roofs and doors can be easily manufactured using conventional adhesive painting line equipment.

(Prior Art) Conventionally, panels for automobile bodies, such as hoods, trunks, roofs, doors, etc., have generally been assembled and manufactured at a speed of 0.5 to
1. An outer steel plate (hereinafter referred to as the ``outer plate'') that has been press-cut from a steel plate with a thickness of 0.0 cm, and a steel plate that has been press-cut in the same manner for reinforcement (hereinafter referred to as the ``inner plate'').
from the inside, and fix the edges by caulking, screwing, welding, or gluing, and in order to reinforce the lack of strength in all relatively flat parts of the outer skin, In other parts, the outer panel and inner panel are separated and integrated using adhesive.

Conventionally, the adhesive used in such cases is a rubber adhesive containing synthetic rubber, a rubber vulcanizing agent, a plasticizer, a filler, etc., and the curing of the adhesive is I?
This is done by heating in the panel painting baking process, that is, heating at 140 to 200° C. for 20 to 40 minutes in a paint baking oven.

However, if the above-mentioned conventional adhesives are designed to have high adhesive strength, distortion will occur in the glossy outer panel due to thermal expansion and contraction during heating and cooling during the paint baking process, and the adhesive strength will be low. Although the above-mentioned distortion can be prevented by designing, the adhesive strength is too low and the original purpose of adhesion is defeated.
In other words, it was possible to achieve the purpose of reinforcing glossy flanges.

One possible solution to the above problem is to completely harden the adhesive used for assembly bonding before entering the baking oven. For example, a method of completely curing the used adhesive using radiation such as ultraviolet rays, ultrasonic waves, or high frequency waves, or a method of using urethane/silicone resin as the adhesive and completely curing it with moisture, etc. However, these methods have problems in terms of the price of the adhesive used, curing speed, heat resistance, paint resistance, etc., and they also require new equipment, so they cannot be used in conventional assembly adhesive painting lines. It has not been put to practical use because the equipment cannot be used as is.

(Problems to be Solved by the Invention) The present invention provides an assembly method for easily producing glossy panels for automobile bodies that have sufficient adhesive reinforcing strength and are free from distortion by using conventional adhesive painting line equipment as is. The aim is to provide an adhesive method.

(b) Structure of the Invention (Means for Solving the Problems) As a result of repeated research in order to solve the above problems, the present inventors have found that the present inventors have developed the conventional method for assembling and bonding this kind of flannel. If an adhesive containing a room-temperature moisture-curing organosilicon compound is used in addition to a synthetic rubber adhesive, the adhesive used for assembly will be able to withstand the heating in the baking oven of the conventional paint baking process. It is possible to semi-cure and temporarily bond without causing distortion, and if the obtained panels are taken out of the baking oven and left in the air, the room-temperature moisture-curing organic silicon compounded in the adhesive The present invention was achieved by discovering that the compound can be completely cured by moisture in the air and panels having sufficient adhesive strength can be easily obtained.

That is, the assembly adhesive method of the present invention is an assembly adhesive method using an adhesive for automobile body panels, and the adhesive includes synthetic rubber, a rubber vulcanizing agent, a plasticizer, a filler, and a room temperature moisture-curable organosilicon compound. After using an adhesive containing J? This is a method for assembling and adhering glossy flannel for automobile bodies, which is characterized by completely curing the flannel by the moisture in the air by leaving the flannel in the air.

As the synthetic rubber in the adhesive used in the assembly adhesive method of the present invention, diene-based synthetic rubber is preferable.

For example, butadiene rubber, isoprene rubber, chloroprene rubber, butadiene-acrylonitrile monomer rubber (
NBR), styrene-butadiene copolymer rubber (SB
R) etc. The content of the synthetic rubber is 1 to 40% by weight, preferably 3 to 30% by weight, based on the adhesive composition. If the content of synthetic rubber is too small, sufficient adhesive strength cannot be obtained, and if it is too large, the workability of the adhesive will deteriorate.

Rubber vulcanizing agents in the adhesive used in the present invention include sulfur vulcanizing agents and sulfur-free vulcanizing agents.

The sulfur vulcanizing agent further contains a thiazole compound such as 2-mercaptobenzothiazole or 2-benzothiazoyl disulfide as a vulcanization accelerator: N, N
Thiourea compounds such as '-diphenylthiourea, N,N'-di-o-)lylthiourea; dithioate salt compounds such as copper dimethyldithiocarbamate and ferric dimethyldithiocarbamate; 1,3-diphenylguanidine;
Guanidine compounds such as di-lotryl guanidine;
Thiuram compounds such as tetramethylthiuram disulfide and tetramethylthiuram monosulfide can be used in combination. Moreover, metal oxides such as zinc oxide and magnesium oxide can be used in combination with the sulfur vulcanizing agent as an activation aid. The blending ratio of the sulfur vulcanizing agent is 0.5 to the synthetic rubber, including the vulcanization accelerator and active aid mentioned above.
~50% by weight.

Furthermore, typical examples of the sulfur-free vulcanizing agent include organic peroxides. A specific example is 1,1-
Di-tert-butyl peroxycyclohexane, 4,4-di-tert-butyl peroxyvaleric acid, 4,4-di-tert-butyl peroxyvalerate butyl ester, 1,1-di-tert-butyl (ruoxy-3,3゜5-trimethyl Cyclohexane, di-tert-butyl(ruoxide), 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane, 2
,5-dimethyl-2,5-・no(tert-butylperoxy)-3-hexyne, tert-butylcumenyl(ruoxide), 1,3-bis-(tert-butylyloxy-isopropyl)benzene, dicumenylperoxide, 2 , 2-no-tert-butylperoxy-7-butane, and other dialkyl peroxides.Two or more of these organic peroxides can be used in combination, and the content ratio is 0.5 to 0.5 to 100% of the synthetic rubber. 1Offiff1%.

The plasticizer used in the adhesive used in the present invention is one that is compatible with both the synthetic rubber and the moisture-curable organosilicon compound. Specific examples include phthalate ester plasticizers, dibasic fatty acid ester plasticizers,
Examples include phosphate ester plasticizers, chill plasticizers, petroleum fractionation products, and the like.

The amount of plasticizer used is 1 to 40% by weight based on the adhesive composition.
, preferably 5 to 30% by weight.

The filler in the adhesive used in the present invention is added to improve the physical properties, workability, and price of the adhesive, and there are no particular restrictions on its type, but it is usually an inorganic filler. For example, calcium carbonate, clay, Merck, silica powder, mica powder, etc. are used, and these fillers preferably have a low water content. The content ratio of the filler to the adhesive composition is 5 to 70%, preferably 20 to 6%.
It is 0% by weight.

The moisture-curable organosilicon compound in the adhesive used in the present invention has the general formula (wherein, X is a hydrolyzable group, R is a group other than the hydrolyzable group, and n is O Examples thereof include organosilicon compounds having at least two groups represented by (hereinafter sometimes referred to as "reactive silicon functional groups") in the molecule.

Specific examples of the hydrolyzable group X in the general formula (1) include acyloxy groups such as acetoxy, octanoyloxy, and benzoyloxy groups; dimethylketoxime, methylethylketoxime, and diethylketoxime groups. Ketoxime groups such as; alkoxy groups such as methoxy, ethoxy, and propoxy groups; alkenyloxy groups such as improynyloxy and 1-ethyl-2-methylvinyloxy; trimethylamino, diethylamino, butylamino, Examples include amine groups such as a cyclohexylamino group; aminooxy groups such as a dimethylaminooxy group and a diethylaminooxy group; and amide groups such as an N-methylacetamide group, an N-ethylacetamide group, and an N-methylbenzamide group.

In addition, as the group R other than the hydrolyzable group in the general formula (1), for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; alkenyl groups, such as phenyl, tolyl, and naphthyl groups; aralkyl groups, such as 2-phenylethyl; iminoalkyl groups represented by structural formulas; hydrogen atoms of each of these groups; Examples include groups partially or entirely substituted with halogen atoms such as chlorine atoms.

Examples of the organosilicon compound having in its molecule at least two silicon atoms to which the hydroestrous group is bonded include compounds obtained by the methods described in (a) to (c) below.

(b) Room-temperature curability obtained by reacting various polyisocyanate compounds with compounds f1 having a group capable of reacting with an isocyanate group and a reactive silicone functional group represented by the above general formula (1) in the molecule. Silicon-terminated compound (see Japanese Patent Publication No. 46-30711, etc.): (b) An isocyanate group in the molecule and the above general formula (1)
A compound having a reactive silicon functional group represented by
A room-temperature curable silicon-terminated compound obtained by reacting a Fukufuku-style polyhydrotici compound or various organic polythiol compounds; (c) a polyoxypolyalkylene polyether compound having an allyl group at the molecular end; ) A silicon-modified polyoxyalkylene polyether compound obtained by addition reaction with a compound having a reactive silicone functional group represented by -H8 group or hydrogen directly bonded to silicon: In the adhesive of the present invention The content ratio of the room temperature moisture-curable organosilicon compound is usually 5 to 70% relative to the adhesive composition.
% by weight, preferably 8-60% by weight.

The adhesive used in the present invention may contain an organotin compound or a - grade,
A secondary or tertiary amine compound can be contained, and two or more of these curing accelerators can be used in combination.

In addition to the above-mentioned components, the adhesive used in the present invention includes:
Adhesive agents such as molecular sheep such as silane compounds, dehydrating agents such as calcium oxide, anti-aging agents that impart acid resistance and heat resistance, etc. can be contained as necessary.

Next, in order to assemble and bond automobile body panels using the adhesive described in detail above, for example, 0.
A steel plate with a thickness of 5 to 1.0 m is pressed onto an outer plate that has been press cut into the shape of an automobile hood, trunk, roof, door, etc., and an inner plate that has been press cut in the same way is applied from the inside. In addition to fixing both sides of the board by caulking, screwing, welding, or gluing, etc., in order to reinforce the lack of strength in relatively flat parts of the outer board, fix the parts at the center other than the edges. Also, the outer panel and the inner panel are bonded together by spot bonding or the like using the adhesive described above.

To explain in detail the assembly of the mother flannel and the curing of the adhesive, first, apply the above adhesive to a predetermined location on the inside of the press-cut outer panel using an airless method. A predetermined amount is applied automatically or manually using a coating gun or metering dispenser.

Next, a press-cut reinforcing inner plate is placed on top of it, the edges are caulked, and it is fixed using means such as screwing, welding, or gluing to create panels for trunks, hoods, doors, etc. .

Next, these panels are assembled to the main body of the car body to complete the car body, and then the process of painting the car body begins.

In the painting process, first, the surface is showered with hot water at 50 to 60 degrees Celsius to completely wash away any oils such as press oil, anti-corrosion oil, etc., as well as dirt and grime. Next, after performing a so-called chemical conversion treatment using a phosphate, an electrodeposition paint is applied and baked in a paint baking oven, generally at 140 to 200°C for 20 to 40 minutes.

At this time, the adhesive used in the assembly bonding of the present invention is semi-cured by heating. Next, after cooling to room temperature, an intermediate coat is applied and baked (120~
15-30 minutes at 150℃), cooled, then apply top coat and bake (15-30 minutes at 120-150℃)
to complete the painting.

Generally speaking, it takes about 4 hours at most to paint an automobile body from the first electrodeposition coating to the final coating, but it is left at room temperature until it goes through the finishing process and is delivered to the finished car. During this time, the semi-hardened adhesive used in the assembly bonding of the present invention gradually hardens due to the moisture in the air, and eventually becomes completely hardened.

(Examples, etc.) Next, the present invention will be described in further detail with reference to Examples and Comparative Examples.

"Parts" in these examples mean parts by weight.

Examples 1 to 1g Comparative Examples 1 to 3 Adhesives having a composition ratio of 1 to 1 shown in Table 1 were prepared, and adhesives bonded using each of the obtained adhesives were heated at 170°C.
After heating and curing at a temperature of 30 minutes, the adhesive strength was measured after being left in the air. The results are in Table 1:・
ζIt was as shown. Table 1 shows the results of examining the occurrence of distortion in automobile hoods when assembled and bonded using each of these adhesives. From these test results, it was found that if the adhesives of each example were used to assemble and bond automobile body panels, the adhesive reinforcement strength would be excellent.
It can be seen that distortion-free channels can be easily obtained.

The adhesives shown in Table 1 were prepared as follows. That is, first, synthetic rubber and dioqual phthalate are kneaded using a strong negoo, and then calcium carbonate (preliminarily dried by heating at 100°C for about 4 hours), calcium oxide, and a moisture-curing organic silicon compound (however, the In the case of example only), after blending IQ
The mixture was kneaded for 60 minutes under a reduced pressure of tmHg to defoam, then all the remaining components were added, and the mixture was further defoamed and kneaded for 30 minutes at +'C.

1;7:'4 Notes to Table 1: *1...Nippon Zeon Co., Ltd. product name Zeon 121*
2...Nippon Zeon Co., Ltd. Product name Hiker 1042
*3...Nippon Zeon Co., Ltd. Product name Norica-15
02*4...Tetramethylthiuram disulfide*5
...Tertiary butylcumenilno-oxide*6...
γ-β (aminoethyl)-γ-aminopropyltrimethoxysilane *7...Shōgabuchi Chemical Industry Co., Ltd. Product name MS PolyC
)( Marna 300.(CHO Sho S I-C1(2C112
0-Curtain-terminated propylene oxide polymer *8...The test method is to use two iron plates with a length of 100 cm x width of 25 m x thickness of 0.8 cm, and a wrap area of 25 m x 2.
5 chickens were glued together using adhesive so that the adhesive thickness was 3 mm, and after heating at a temperature of 170°C for 30 minutes, the resulting glue was placed in air at 20°C and 65 cm RH. The tensile shear strength after standing for a period of time was measured using a tensile tester at a tensile rate of 50 W/min.

*9...A car hood with an outer panel thickness of 0.65 m and an inner panel thickness of 0.65 points, the number of adhesive dots is 50, and the amount of adhesive applied is 2.
The hoods were assembled and bonded according to a conventional method using cc 7-point conditions, and the presence or absence of distortion in the hood after baking at 170° C. for 30 minutes was examined.

(c) Effects of the Invention The method of assembling and adhering automobile body panels of the present invention is different from conventional methods of this type. By using the assembly adhesive painting and baking equipment for flannel as it is, 74 flannel which has excellent reinforcing strength and is free from distortion can be easily manufactured.

Patent applicant: Cemedine Co., Ltd. Attorney Moriya Dochutani [・'=:=xII'-p',
'−,': 1−−−−− j

Claims (1)

[Scope of Claims] 1) An assembly bonding method using an adhesive for automobile body panels, wherein the adhesive contains synthetic rubber, a rubber vulcanizing agent, a plasticizer, a filler, and a room temperature moisture-curable organosilicon compound. The adhesive used for assembly and bonding is semi-cured by heating the obtained panels, and then the panels are left in the air to be completely cured by the moisture in the air. An assembly adhesive method for automobile body panels characterized by: 2) The assembly adhesive method according to claim 1, wherein the room temperature curable organosilicon compound is an organosilicon compound having in its molecule at least two silicon atoms to which a hydrolyzable group is bonded.