JPH0826281B2 - Primer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a primer composition, particularly a primer composition used for firmly adhering and curing a room temperature-curable urethane rubber composition to the surface of an inorganic adherend.

II Conventional technology and its problems Pretreatment of the adherend with a primer in order to bond and cure the room temperature curable polyurethane rubber composition or the room temperature curable silicone rubber composition to the surface of the inorganic adherend such as glass, metal or ceramics The method is adopted.

As such a primer composition, one containing an aminoalkylalkoxysilane has been conventionally used (US Pat. No. 3,246,671). When this is applied to a polyurethane rubber composition, for example, a) it can impart sufficient adhesiveness even with a short air-drying time (within 1 minute), and b) even at extremely low temperatures (-30 ° C to -10 ° C). It is possible to impart excellent adhesiveness, and c) it is possible to impart good adhesiveness to an inorganic adherend contaminated with oil without requiring solvent cleaning or the like. is there.

However, as described above, this product has a drawback that, even if it has excellent adhesiveness in the initial stage, when it is immersed in water, the adhesiveness is impaired in a short time. For example, in warm water of about 40 ° C, it elutes and disappears even after one day.

Therefore, in order to improve such water-resistant adhesiveness, JP-A-51-139831 discloses a primer composition containing a mercapto group-containing organosilane or organosiloxane and a titanate ester. .

Although this product has improved water-resistant adhesiveness, a) it is necessary to set the air-drying time to at least 60 minutes at room temperature or more to obtain good adhesiveness, and b) very low temperature (-30 ° C to-). There are drawbacks such as slow development of adhesion at 10 ° C) and poor adhesion to oil surface.

Further, JP-A-52-129000 discloses a primer composition containing an epoxysilane and a titanate ester.

This one also has improved water resistance, but the above b),
It has the drawback of c).

Therefore, a primer composition satisfying all of the above a) to c) and having excellent water resistance is desired.

III Object of the Invention An object of the present invention is to provide a primer composition which has a short air-drying time, can impart excellent adhesiveness, and can impart low-temperature adhesiveness, oil surface adhesiveness and water resistant adhesiveness. is there.

IV Composition of the Invention The present invention provides a primer composition characterized by containing 10 to 100 parts by weight of a tetraalkyl titanate and 10 to 200 parts by weight of an alkoxy group-containing polysiloxane with respect to 100 parts by weight of an aminoalkylalkoxysilane. It is provided.

 Hereinafter, the present invention will be described in detail.

The aminoalkylalkoxysilane contained in the primer composition of the present invention is an essential component for imparting strong adhesiveness, and particularly, low temperature adhesiveness developability and adhesiveness (oil surface contact) to an adhered surface contaminated with oil. It is the one that imparts a wearability).

Specific examples of such an aminoalkylalkoxysilane include γ-aminopropyltrimethoxysilane and N
-Β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
Examples thereof include N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, and among them, γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane are preferable.

In the present invention, 10 to 100 parts by weight, preferably 20 to 50 parts by weight of a tetraalkyl titanate ester is added to 100 parts by weight of the above aminoalkylalkoxysilane.

The tetraalkyl titanate ester shortens the air drying time of the primer and improves workability.

The above content is used because if it is less than 10 parts by weight, the water-resistant adhesiveness is lowered, and if it exceeds 100 parts by weight, the oil surface adhesiveness is lowered.

Examples of such tetraalkyl titanate ester include tetrabutyl orthotitanate ester, tetramethyl titanate ester, tetraethyl titanate ester,
Examples thereof include tetrapropyl titanate ester, terilaisopropyl titanate ester, buy tetrapentyl titanate ester, tetraoctyl titanate ester, and tetra-2-ethylhexyl titanate ester.

Of these, tetrabutyl orthotitanate and tetraisopropyl titanate are preferable.

In the present invention, the alkoxy group-containing polysiloxane together with the above tetraalkyl titanate ester 10 to 200 parts by weight with respect to 100 parts by weight of aminoalkoxysilane,
It is preferably contained in an amount of 50 to 100 parts by weight.

With the content as described above, the water-resistant adhesive property is reduced when less than 10 parts by weight, and the oil surface adhesiveness when it exceeds 200 parts by weight,
This is because the low temperature adhesion developability is reduced.

Examples of such an alkoxy group-containing polysiloxane include those having a methoxy group or an ethoxy group as an alkoxy group.

The primer composition of the present invention is preferably diluted with a solvent.

As such a solvent, those which are easily volatilized are preferable, and specifically, alcoholic solvents such as methanol, ethanol and isopropanol, benzene, toluene, xylene,
Aromatic hydrocarbons such as trimethylbenzene, tetramethylbenzene, diethylbenzene, trichloroethylene, perchloroethylene, 1,1,1-trichloroethane,
Chlorinated hydrocarbons such as carbon tetrachloride and chloroform, n
-Hexane, cyclohexane, methylcyclohexane,
Examples thereof include aliphatic hydrocarbons such as dimethylcyclohexane, ketones such as acetone and methyl ethyl ketone, and esters such as ethyl acetate.

Of these, methanol, ethanol, isopropanol, n-hexane, ethyl acetate and the like are preferable.

Such solvents may be used alone or in combination of two or more kinds.

The proportion of the solvent in the primer composition is 90 to 99.5.
From the viewpoint of use, it is preferable to set the content to about wt%.

Coating amount of inorganic deposition body surface of the primer composition of the present invention, aminoalkylalkoxysilane, tetraalkyl titanate, and alkoxy group-containing polysiloxane in total 0.5 to 20 g / m ^2, preferably from 1 to 5 g / m ² do it.

The primer composition of the present invention is particularly preferably applied for adhering a room temperature curable urethane rubber composition to an inorganic adherend. In addition, it can be applied to adhesion of room temperature curable silicone rubber compositions, room temperature curable polysulfide rubber compositions and the like.

Examples of the inorganic adherend in this case include glass, metals (iron, aluminum, copper, zinc, stainless steel, brass, etc.), various ceramics, and the like.

When treated with the primer composition of the present invention, it may be used as a pretreatment agent for the urethane-based and silane-based primer compositions containing carbon black disclosed in JP-B-53-5061.

By using it as such a pretreatment agent, it becomes possible to impart weather-resistant adhesiveness.

Specifically, the primer composition of the present invention is used, for example, when imparting adhesiveness to a body and glass when they are bonded to each other using a polyurethane rubber composition in an automobile or the like.

V Example The present invention will be specifically described below with reference to Examples and Comparative Examples.

(Examples 1 to 8 and Comparative Examples 1 to 10) As shown in Table 1, each compounding agent was added and mixed to obtain a primer composition.

 The compounding agents shown in Table 1 are as follows.

Aminosilane… γ-aminopropyltrimethoxysilane [Product name A-1110UCC] Epoxysilane… γ-Glycidoxypropyltrimethoxysilane [Product name A-187 UCC] Mercaptosilane… γ-Mercaptopropyltrimethoxysilane [Product Name A-189 UCC] TBT ... Tetrabutyl orthotitanate [Product name T
BT-100 Nippon Soda Co., Ltd.] DC-3037… Methoxy group-containing polysiloxane [Dow Corning Co.] Glass plate (0.5 cm × 2.5 cm × 15 cm) or SUS shown in Table 1 as an inorganic adherend. The above primer composition was applied to one surface of each of the stainless plates [(0.1 cm × 2.5 cm × 15 cm), trade name: SUS340, manufactured by Nippon Test Panel Co., Ltd.] indicated by.

The coating amount was 1 to ² g / m ² excluding the solvent.

This was air-dried in a room at 20 ° C for 1 or 60 minutes as shown in Table 1 as open time, and then a room temperature curable polyurethane rubber composition [trade name WS-100F manufactured by Yokohama Rubber Co., Ltd.] was used as an adhesive. It was applied to a thickness of 2 mm to obtain each test body.

Then, using these, the adhesiveness under the aging conditions shown in Table 1 was examined.

 The aging conditions shown in Table 1 are as follows.

Initial period… The test piece was left for 7 days at 20 ℃ and 65% RH.

Hot water resistance: The test piece was left at 20 ° C and 65% RH for 7 days and then immersed in hot water at 40 ° C for 7 days.

Low temperature cycle: The test piece was left standing at 20 ° C and 65% RH for 7 days, and then left at -30 ° C and -10 ° C for 12 hours each, which was repeated 7 times.

In addition, the adhesiveness was examined by performing the peel peel test shown below.

<Peel hand peeling test> For the test piece prepared as described above, the adhesive was peeled off from the edge of the glass plate or the stainless steel plate using a knife, and the angle of 90 ° or more (about 150
The adhesion was examined by pulling in the direction of (°). At this time, the knife was placed on the adhesive at an angle of 60 ° with the plate surface.

 Table 1 shows the results.

◯ and × in Table 1 indicate the following evaluations.

○: 100% of cohesive failure of adhesive ×: Interface peeling between adhesive surface and adhesive
over 50 From the results in Table 1, the primer composition of the present invention is water resistant,
It was found to give good adhesion at both low temperatures and oil surfaces.

After the application of the primer composition of the present invention, a commercially available urethane-based and silane-based carbon black-containing primer composition was applied, and then the same treatment as above was performed to prepare a test body. The adhesion of this test piece was similarly examined under the aging condition of 1000 hours of sunshine arc weather meter (black panel temperature 63 ° C.). In this, it was further confirmed that the weather resistance was sufficient.

VI Effect of the Invention According to the present invention, sufficient adhesiveness can be imparted even if the air-drying time is 1 minute or less. In addition, it imparts excellent adhesion developability even at extremely low temperatures of -30 ° C to -10 ° C, and imparts good adhesiveness to oil-contaminated inorganic adherends without the need for solvent cleaning or the like. can do. Furthermore, water-resistant adhesion can be imparted.

Further, when it is used as a pretreatment agent for a urethane-based or silane-based primer composition containing carbon black, weather resistance can be further imparted.

Claims (1)

[Claims] 1. A primer composition comprising 10 to 100 parts by weight of a tetraalkyl titanate ester and 10 to 200 parts by weight of an alkoxy group-containing polysiloxane with respect to 100 parts by weight of an aminoalkylalkoxysilane.