JPH06158024A - Composition for gasket and sealing method - Google Patents

Abstract

PURPOSE:To obtain a sealing agent excellent in handleability, adaptability to on-line processes, pressure resistance, especially initial pressure resistance, capability tracing the surface profile of a flange, vibration resistance and vibration-damping properties, and to provide a sealing method. CONSTITUTION:A photo-setting and moisture-curing liquid composition which gives a cured material exhibiting rubber-like elasticity is applied to the surface of a flange on one side and irradiated with ultraviolet rays, and other flange is then flange is then fastened thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flange composition and a sealing method using the same, and particularly to an initial sealing property applied as a FIPG to a sealing surface of automobile parts, electric / electronic parts, etc., and movement of the flange surface. The present invention relates to a one-part FIPG composition which is a sealant having excellent followability with respect to and a sealing method using the same.

[0002]

2. Description of the Related Art As a sealing agent mainly applied as FIPG, one-component moisture-curable silicone, modified silicone and the like are known. However, these react with moisture in the air and harden from the surface.
It takes 10 days. Especially when forming a FIPG sealant for an oil pan of an automobile engine, the engine is normally run within 1 hour after the parts are assembled, so only the surface is hardened, which may cause problems such as oil leaks. was there.

Further, in these sealing methods, the thickness of the rubber layer cannot be removed between the two flanges, resulting in a metal touch.
There were inconveniences in the followability to the movement of the flange and in the vibration isolation.

As a means for solving these problems, in order to improve the initial sealing property, a method of making the viscosity extremely high and a method of making the sealing agent into a two-liquid type which is fast-curing at room temperature have been used. If it is used, there is a problem that the discharge device is overloaded and a precise beat cannot be drawn, and if it is a two-liquid type, there is a problem that it takes time to measure and mix, and that the curing time changes depending on the environmental temperature. .

There is also proposed a so-called CIPG method in which a sealant is hardened in advance to assemble the flange in order to prevent the flange from being metal-touched. However, in this method, one surface of the flange is not adhered to the contact surface. The risk of leakage remains.

In recent years, it has been desired to join various parts through a thick rubber member in order to prevent noise, but in the conventional FIPG, since the sealant is joined before being uncured, the rubber floats. I could not take the structure.

An object of the present invention is to solve these problems of the prior art, and in particular, it is excellent in handleability and on-line property, and further, pressure resistance, especially initial pressure resistance, followability to flange surface, vibration resistance, prevention of damage. It is an object of the present invention to provide a sealing agent and a sealing method having excellent vibration properties.

[0008]

The gasket composition of the present invention, that is, the sealing material is characterized by comprising a liquid composition having both photo-curing property and moisture-curing property and the cured product exhibiting rubber-like elasticity. By applying this composition to one flange surface, then irradiating with ultraviolet rays, and then fastening the other flange, the initial pressure resistance can be cleared by the rubber layer cured by ultraviolet rays, and further due to oxygen inhibition. When the uncured portion of the surface is cured by moisture, both flanges are bonded on both sides with the sealing material layer interposed therebetween, whereby excellent pressure resistance, vibration resistance, and soundproofing properties can be obtained.

The composition of the present invention is not particularly limited as long as the cured product has rubber-like elasticity and can be cured by ultraviolet rays and moisture, but a composition comprising the following components is preferable. a. A prepolymer having at least one reactive group composed of a (meth) acrylic group and at least two hydrolyzable silyl groups and / or isocyanate groups in one molecule, b. A reactive monomer optionally having at least one (meth) acrylic group, c. A photopolymerization initiator, d. Moisture curing catalyst

Specific examples of a include polyether diol, polyester diol, polybutadiene diol,
A diisocyanate compound is reacted with a polymer having a hydroxy group such as polycarbonate diol, polycaprolactone diol, and organopolysiloxane modified with carbinol at both ends, and further has a hydrolyzable silyl group, a (meth) acrylic group and a hydroxyl group. A compound such as γ- (meth) acryloxypropylmethyldimethoxysilane is Michael-added to a prepolymer obtained by reacting a compound (for example, S-1 manufactured by Shin-Nakamura Chemical Co., Ltd.) or a compound having amine functional groups at both ends. There is a prepolymer obtained by adding a compound having an isocyanate and a (meth) acrylic group to the remaining secondary amine, for example, methacryloyloxyethyl isocyanate. In addition, γ- (meth) is added to silanol-terminated organopolysiloxane.
A condensation reaction of a hydrolyzable silyl group such as acryloxypropyltrimethoxysilane and a compound having a radically polymerizable group, or condensation of γ-aminopropyltrimethoxysilane with an isocyanate and a (meth) acrylic group A compound to which a compound is polyadded may also be used. The amine-modified organopolysiloxane may be modified and used in the same manner as above. Among these, a prepolymer having a metaacryloyl group as a UV-reactive curable group is preferable because of poor surface curability due to oxygen inhibition.

The reactive monomer having at least one (meth) acrylic group of b is used for various purposes such as decreasing the viscosity of the composition, improving the mechanical strength, and imparting an adhesive upon ultraviolet curing. It is added as needed for various purposes and may be a conventionally known one and is not particularly limited.

The photopolymerization initiator of c may be any known one, and the kind is not particularly limited, but the addition amount is preferably a relatively small amount sufficient to cure the inside, usually 3% by weight or less. It is preferable. Generally, when the concentration of the photopolymerization initiator increases, the surface curability by light becomes good, it becomes difficult to leave an uncured portion on the surface, and the thick film curability also deteriorates. 0.01% or more is desirable. Further, it is because the wettability is deteriorated when the flange is tightened and the double-sided adhesive cannot be adhered. Specific examples include benzophenone, acetophenone, propiophenone, xanthol, fluorein, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3 -Bromoacetophenone, diethoxyacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-allylacetophenone, 4-methylbenzophenone, 4-chloro-4-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro 8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butyl ether, bis (4-dimethylaminophenyl) ketone, benzyl Tokishiketaru,
2-chlorothioxanthone and the like can be mentioned.

The moisture-curing catalyst d is a conventionally used lead-2-ethyl octoate, dibutyltin laurate, dibutyltin acetate, butyltin tri-2-.
Ethylhexoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, zinc-2-ethylhexoate, stannous caprate, tin naphthenate , Tin oleate, tin butyrate, tin naphthenate, zinc naphthenate, cobalt naphthenate, metal salts of organic carboxylic acids such as zinc stearate, tetrabutyl titanate, tetra-2-ethylhexyl titanate, triethanolamine titanate, tetra Organic titanate esters such as (isopropenyloxy) titanate, organotitanium compounds such as organosiloxytitanium and β-carbonyltitanium, alkoxyaluminum compounds, quaternary ammonium salts such as benzyltriethylammonium acetate; potassium acetate, sodium acetate, hydrobromic acid. Richi Alkali metal lower fatty acid such as arm, dimethylhydroxylamine, etc. dialkylhydroxylamine such as diethylhydroxylamine and the like. The addition amount of this condensation catalyst is preferably 0.01 to 10 parts by weight, particularly 0.1 to 5 parts by weight, based on the total weight of the composition.

In addition to the above, various additives may be optionally used in combination with the composition of the present invention. Various inorganic fillers for improving mechanical properties, thixotropic agents such as polyethylene glycol and its derivatives, pigments, dyes, antioxidants, antioxidants, antimony oxide, flame retardants such as paraffin chloride, boron nitride, aluminum oxide Thermal conductivity improver such as rust inhibitor, carbon functional silane having amino group, epoxy group, thiol group, acryl group, etc., known adhesive imparting agent such as metal salt of carboxylic acid, metal alcoholate, etc. It is also optional to do so. Of these, the amino group-containing silane coupling agent is previously reacted with an isocyanate compound and an epoxy compound,
It is more preferable from the viewpoint of storability that the UV-reactive group is in an inactive form so that it does not react during storage.

When the composition of the present invention is applied to an oil pan of an engine of an automobile, a gasket layer on which the composition of the present invention is finally formed is usually used on a peripheral sealing surface of the oil pan by using a robot or the like. To have a thickness of 0.5 mm or more, and the surface is irradiated with ultraviolet rays to cure the inside, but the surface part of the coating layer is substantially uncured, and the irradiation is stopped. A method is used in which the relevant part of the engine block is overlaid and fastened. By doing so, the curing mechanism of the rubber-like cured portion and each adhesive interface can be optimally combined, and thereby a double-sided adhesive rubber float structure having excellent characteristics can be obtained in a short time.

Next, the present invention will be described with reference to examples.

[Preparation of Prepolymer 1] 1.2 g of γ-aminopropyltrimethoxysilane was added to 100 g of dimethylpolysiloxane having a molecular weight of 30,000 and having a molecular chain end blocked with silanol, and the mixture was stirred under nitrogen substitution at 120 ° C. for 2 hours. React. Then, vacuum is pulled to remove excess γ-aminopropyltrimethoxysilane, and the liquid temperature is 50 ° C.
Then, 1.1 g of 2-isocyanatoethylmethacrylate was added and reacted for 1 hour under nitrogen substitution to obtain a prepolymer: P-1 which can be cured by moisture and light.

[Preparation of Prepolymer 2] 2.8 g of isophorone diisocyanate was added to 100 g of a polycarbonate diol having a molecular weight of 12000, the ends of which were blocked with hydroxyl groups, and dibutyltin laurate was added as a polymerization catalyst.
02 g was added and mixed at 80 ° C. for 2 hours to obtain a prepolymer of isocyanate at the molecular chain end. A compound having an acryl group and a hydrolyzable silyl group: CH ₂ ═CHCOOCH
_{2 CHOHCH 2 OC 3 H 6 SiMe} (OCH 3)
₂ (S-1 manufactured by Shin-Nakamura Chemical Co., Ltd.) was added to obtain a prepolymer: P-2 which can be cured by moisture and photo.

[Adjustment of Moisture and Photocurable Resin] Prepolymers P-1 and P-2 are blended as shown in Table 1 below,
A light and moisture curable composition was obtained.

[0020]

[Table 1]

Next, the following three types were prepared as reference examples. Comparative Example 1, 1-liquid moisture-curable silicone TB12
16 ThreeBond Comparative Example 2, 1-liquid moisture-curing modified silicone TB12
08D manufactured by ThreeBond Comparative Example 3, 2-liquid heat addition-curable silicone TB12
70 Three Bond

Shear adhesive strength (iron / iron) of Examples 1 to 4 and Comparative Examples 1 to 3, initial pressure resistance after about 1 hour, pressure resistance after 72 hours, thickness of sealing material layer, movement of flange surface Table 2 shows the test results of the followability.

[0023]

[Table 2]

The shear adhesive strength test was carried out in Examples 1 to 4 after coating the material on one surface, irradiating ultraviolet rays and assembling the other test piece, and leaving it for 168 hours for measurement. Comparative Example 1
2 attach the other test piece immediately after application 1
It was measured after 68 hours. In Comparative Example 3, the material is applied on one side,
After curing at 120 ° C for 10 minutes, assemble the other 16
It measured after 8 hours.

Regarding the pressure resistance test, the JIS flange has 5φ
It was carried out by catching the beat.

[0026]

As described above, in the present invention, the rubber-like elastic gasket can be formed in a short time by irradiating the sealant with ultraviolet rays. Furthermore, this composition has an unhardened portion on the surface after assembly, which is cured by moisture and can completely bond both flanges through the rubber-like gasket layer, so that the final pressure resistance and the like are remarkably excellent. Become.

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[Procedure amendment]

[Submission date] November 5, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Regarding the pressure resistance test, the JIS flange has 5φ
It was carried out by catching the beat. Trackability is set as shown in Fig. 1.
Shear force is applied to the attached test piece to break it in the shear direction.
It is represented by a displacement distance (mm) before breaking.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Added

[Correction content]

[Brief description of drawings]

FIG. 1 is a diagram showing a test method of followability.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Added

[Correction content]

[Figure 1]

Claims (5)

[Claims] 1. A liquid resin composition having both photo-curing property and moisture-curing property and whose cured product exhibits rubber-like elasticity is applied to one flange surface, and then irradiated with ultraviolet rays, and then the other flange is fastened. Sealing method characterized by. 2. Curing of the inside of the applied layer composed of the resin composition and adhesion to one flange surface to which it is applied are mainly carried out by irradiation of ultraviolet rays to cure the surface layer part and adhesion to the other flange surface. The method according to claim 1, wherein the method is performed by humidity. 3. The method according to claim 1, wherein the coating thickness of the resin composition is such that the thickness of the gasket layer adhered on both sides after fastening is 0.5 mm or more. 4. A gasket composition, characterized in that it has both photo-curing property and moisture-curing property and the cured product is a liquid composition exhibiting rubber-like elasticity. 5. At least one reactive group of either an acrylic group or a methacrylic group and at least two hydrolyzable silyl groups and / or isocyanate groups per molecule.
The composition for gaskets according to claim 4, which comprises a prepolymer having at least one, a photopolymerization initiator and a moisture curing catalyst, and a reactive monomer having at least one acrylic group or methacrylic group as an optional component.