JP2001123092A - Primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primer composition which can ensure excellent adhesion to both a polyester resin and a polydicyclopentadiene resin, exhibits an open time as long as 18 hr or longer after being applied, and hence is excellent in workability. SOLUTION: This primer composition comprises (A) a reaction product of a tolylene diisocyanate trimer with a mercaptosilane or a reaction product of a mixture of a tolylene diisocyanate trimer and hexamethylene diisocyanate with a mercaptosilane, (B) tris-p-isocyanatophenyl thiophosphate, and (C) a polyester urethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition which can ensure excellent adhesiveness to both a polyester resin and a polydicyclopentadiene resin.

[0002]

2. Description of the Related Art Conventionally, various kinds of primers (undercoats) have been used in order to ensure excellent adhesiveness when bonding various materials (adherends). For example, various primers have been studied for polyester resins that are widely used as resins for glass fiber reinforced plastic products such as septic tanks and large water tanks.

As a primer for a polyester resin, for example, JP-A-58-142956 discloses a polyester resin containing an isocyanate having a 1-oxa-3,5-diazine-2,4,6-trione ring. An "adhesive primer" is disclosed, and this primer can surely ensure excellent adhesiveness to a polyester resin.

On the other hand, in recent septic tanks and large water tanks, a polydicyclopentadiene resin which is relatively inexpensive and can be used to obtain a tough product without reinforcing with glass fiber has been used. The number of cases where a resin component and a polydicyclopentadiene resin component are used together is increasing.

However, since the polydicyclopentadiene resin has a low polarity, there is a problem that the conventional polyester resin primer as disclosed in the above disclosure cannot secure sufficient adhesiveness.

Therefore, a primer capable of ensuring excellent adhesiveness to both a polyester resin having a relatively high polarity and a polydicyclopentadiene resin having a relatively low polarity has been studied.

As such a primer, for example,
A "primer composition containing an isocyanate mixture containing tris-p-isocyanatephenylthiophosphate, a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate as essential components, and a polyester-based urethane resin" is disclosed.

However, in the primer disclosed in the above, the time (open time) in which the adhesive can be applied after the primer is applied is as short as about 2 hours, so that the adhesive is applied within about 2 hours after the primer is applied. Therefore, there is a problem that the bonding process is restricted.

[0009]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to ensure excellent adhesiveness to both a polyester resin and a polydicyclopentadiene resin and to improve the adhesion after applying a primer. An object of the present invention is to provide a primer composition having a sufficiently long open time of 18 hours or more, and thus excellent workability.

[0010]

According to the present invention, there is provided a primer composition comprising a reaction product of a trimer of tolylene diisocyanate and a mercaptosilane or a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate. It is characterized by containing a reaction product with silane, tris-p-isocyanatophenylthiophosphate and a polyester-based urethane resin.

[0011] The primer composition according to the second aspect is the primer composition according to the first aspect,
The equivalent ratio of the mercapto group in the mercaptosilane to the isocyanate group in the isomer group in the trimer of tolylene diisocyanate or the mixture of the trimer of tolylene diisocyanate and the trimer of hexamethylene diisocyanate is 0.5 to 1.0. Features.

Further, the primer composition according to claim 3 is characterized in that, in the primer composition according to claim 1 or 2, the polyester-based urethane resin comprises a polyester polyol and tolylene diisocyanate. I do.

The primer composition of the present invention comprises a reaction product of a trimer of tolylene diisocyanate (trimer) alone and mercaptosilane, or a trimer of tolylene diisocyanate (trimer) and a trimer of hexamethylene diisocyanate. (Trimer) and a reaction product of mercaptosilane. In the case of the latter reaction product, a mixture in which a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate are mixed at a predetermined ratio is prepared, and the mixture may be reacted with mercaptosilane. The reaction product of the trimer alone and mercaptosilane and the reaction product of the hexamethylene diisocyanate trimer alone and mercaptosilane are separately prepared in advance, and the two reaction products are mixed at a predetermined ratio and used. Is also good.

By preliminarily reacting a trimer of tolylene diisocyanate or a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate with mercaptosilane, the resulting primer composition can be used for both the polyester resin and the polydicyclopentadiene resin. While maintaining excellent adhesiveness, it has a sufficiently long open time.

The mercaptosilane used for producing the above reaction product includes, for example, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane Examples include silane. These mercaptosilanes may be used alone or in combination of two or more.

In the production of the above reaction product, the isocyanate group (N
CO) or the ratio of mercapto groups (SH) in mercaptosilane to isocyanate groups (NCO) in a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate (SH / NCO) is:
It is preferable that the equivalent ratio be 0.5 to 1.0.

When the SH / NCO (equivalent ratio) is less than 0.5, the open time of the obtained primer composition may not be sufficiently long.
When O (equivalent ratio) exceeds 1.0, the adhesion (adhesion) between the coated surface of the obtained primer composition and the adhesive applied on the coated surface may be insufficient.

The method for producing the above reaction product is not particularly limited. For example, the trimer of tolylene diisocyanate alone or the tolylene diisocyanate under a stream of an inert gas such as nitrogen gas or under reduced pressure. By reacting a predetermined amount of a mixture of a trimer and a trimer of hexamethylene diisocyanate with a predetermined amount of mercaptosilane at a temperature of about 80 to 100 ° C. for about 3 to 6 hours, a desired reaction product can be obtained. .

Further, the primer composition of the present invention contains tris-p-isocyanatephenylthiophosphate.

The tris-p-isocyanate phenyl thiophosphate described above has a relatively low polarity, so that the adhesion of the resulting primer composition, particularly to polydicyclopentadiene resin, can be significantly improved.

The mixing ratio of the trimer of tolylene diisocyanate or the trimer of hexamethylene diisocyanate and the above-mentioned tris-p-isocyanatephenylthiophosphate used in the production of the reaction product in the primer composition is not particularly limited. But not
10 to 85 parts by weight of trimer of tolylene diisocyanate, 0 to 8 trimer of hexamethylene diisocyanate
It is preferably 5 parts by weight and 10 to 80 parts by weight of tris-p-isocyanatophenylthiophosphate.

When the mixing ratio of the above three components is less than the lower limit or exceeds the upper limit, the polyester resin and / or
Alternatively, the adhesiveness to the polydicyclopentadiene resin may be insufficient.

Further, the primer composition of the present invention includes:
A polyester urethane resin is contained.

By containing the above-mentioned polyester-based urethane resin, the adhesiveness of the obtained primer composition to particularly the polyester resin is remarkably improved. Also,
The effect of improving the film forming property of the primer composition as a secondary effect is also obtained.

The polyester-based urethane resin is a polymer compound having a urethane bond in a molecule obtained by reacting a polyester polyol with a polyisocyanate compound.

Examples of the polyester polyol include dicarboxylic acids such as adipic acid, phthalic acid, sebacic acid and dimer acid and ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, and the like.
Examples thereof include a reaction product with a glycol such as 1,3-butanediol and hexanetriol, and a polycaprolactone polyol obtained by ring-opening polymerization of caprolactone. These polyester polyols may be used alone or in combination of two or more.

Examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalenediisocyanate,
Hexamethylene diisocyanate, xylene diisocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. These polyisocyanate compounds may be used alone,
Two or more types may be used in combination.

As the polyester-based urethane resin, those having various characteristics can be obtained by selecting and combining the types of the polyester polyol and the polyisocyanate compound.

In the present invention, any of these polyester-based urethane resins may be used. Among them, polyester-based urethane resins obtained from various polyester polyols and tolylene diisocyanate as a polyisocyanate compound are preferably used. Can be These polyester-based urethane resins may be used alone or in combination of two or more.

The mixing ratio of the polyester-based urethane resin in the primer composition is not particularly limited, but may be a reaction product of the trimer of tolylene diisocyanate and mercaptosilane or a trimer of tolylene diisocyanate and hexamethylene. The amount of the polyester-based urethane resin is preferably 2 to 50 parts by weight based on 100 parts by weight of the reaction product of the mixture of the diisocyanate with the trimer and mercaptosilane.

If the mixing amount of the polyester-based urethane resin is less than 2 parts by weight with respect to 100 parts by weight of the above reaction product, the above-mentioned effect due to the inclusion of the polyester-based urethane resin may not be sufficiently obtained. If the amount of the polyester-based urethane resin is more than 50 parts by weight based on 100 parts by weight of the reaction product, the adhesion to the polydicyclopentadiene resin may be insufficient.

It is preferable that an organic solvent such as ethyl acetate or butyl acetate is added to the primer composition of the present invention in order to dissolve or dilute the above-mentioned essential components to improve coatability. . The amount of the organic solvent to be added may be appropriately set according to the viscosity, solid content, and the like to be imparted to the primer composition, and is not particularly limited.

The primer composition of the present invention may further contain, in addition to the essential components and the organic solvent, an adhesion-imparting agent for further improving the adhesion, if necessary, as long as the object of the present invention is not hindered. Or one or more of various additives such as a coloring agent, an antioxidant (antioxidant), and a heat stabilizer for improving the discriminability of the applied primer composition. May be.

The method for producing the primer composition of the present invention comprises:
It is not special, and using a normal stirring mixer, the respective predetermined amounts of the respective essential components and the organic solvent and the respective predetermined amounts of the various additives to be added as necessary are uniformly mixed at room temperature or under heating. By stirring and mixing, a desired primer composition can be obtained.

An adhesive used for bonding the polyester resin coated with the primer composition of the present invention to the polydicyclopentadiene resin, or a polyester resin or polydicyclopentadiene coated with the primer composition of the present invention. The adhesive used for bonding the resin and another adherend is not particularly limited,
Although any conventionally known adhesives may be used, urethane resin-based adhesives are particularly preferable.

[0036]

The primer composition of the present invention comprises a reaction product of a reaction product of a trimer of tolylene diisocyanate and mercaptosilane or a reaction product of a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate with mercaptosilane and a polyester resin. Since it contains a urethane resin, it exhibits particularly excellent adhesiveness to a polyester resin.

Further, since tris-p-isocyanatophenylthiophosphate is contained together with the above-mentioned components, excellent adhesion to polydicyclopentadiene resin is exhibited. That is, the primer composition of the present invention has excellent adhesiveness to both the polyester resin and the polydicyclopentadiene resin.

Furthermore, since the trimer of tolylene diisocyanate or a mixture of the trimer of tolylene diisocyanate and the trimer of hexamethylene diisocyanate has been reacted with mercaptosilane in advance, the open time after the application of the primer composition is 18 hours. As described above, the length is sufficiently long, and thus the workability is also excellent.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”.

Example 1 30 parts of a mixture consisting of 15 parts of a trimer of tolylene diisocyanate and 15 parts of a trimer of hexamethylene diisocyanate and 30 parts of γ-mercaptopropyltrimethoxysilane as mercaptosilane were previously charged with a nitrogen gas stream. In, at 80 ℃ 3
The reaction was performed for a time to produce a reaction product.

Using a conventional stirring mixer, 15 parts of tris-p-isocyanatophenylthiophosphate and “Pandex T-5205” (trade name) as a polyester-based urethane resin were added to the reaction product obtained above. 3 parts of Dainippon Ink and Chemicals, and 440 parts of ethyl acetate and 10 parts of butyl acetate as organic solvents were added and uniformly stirred and mixed to produce a primer composition.

Comparative Example 1 γ as Mercaptosilane
-Without adding mercaptopropyltrimethoxysilane,
A primer composition was produced in the same manner as in Example 1 except that a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate was not reacted with mercaptosilane.

Comparative Example 2 γ as Mercaptosilane
-A primer composition was produced in the same manner as in Example 1 except that the amount of mercaptopropyltrimethoxysilane was changed to 45 parts.

Comparative Example 3 A primer composition was prepared in the same manner as in Example 1 except that the amount of the hexamethylene diisocyanate trimer was changed to 30 parts and tris-p-isocyanatephenylthiophosphate was not added. Was manufactured.

The performance (tensile shear strength) of the four types of primer compositions obtained in Example 1 and Comparative Examples 1 to 3 was evaluated by the following method. The results were as shown in Table 1.

Measurement of tensile shear strength: 25 mm × 100 m
mx 8mm glass fiber reinforced polyester resin (GFR
P) A primer composition is thinly applied to a plate and a 25 mm × 100 mm × 8 mm polydicyclopentadiene resin (DCPD) plate using a brush, and the primer composition is coated at 20 ° C.-65% RH.
After leaving under the atmosphere (standard state) for 10 minutes (open time after application of primer: 10 minutes) or for 24 hours (open time after application of primer: 24 hours), a two-part mixed type urethane resin adhesive ( Product name "Esdine 5
54 ", manufactured by Sekisui Chemical Co., Ltd.)
An adhesive test specimen was prepared by adhering so as to have a size of 10 mm × 10 mm and a coating thickness of 0.5 mm, and curing for 7 days in a standard state. Then, the adhesive test specimen was placed in warm water at 60 ° C. for 2 hours.
After immersion for a week, leave for 1 hour in standard condition,
Tensile shear strength (kg / cm ² ) was measured at 0 mm / min. In addition, the destruction state was also visually observed.

[0047]

[Table 1]

As is clear from Table 1, the primer composition of Example 1 according to the present invention was obtained by using a GFRP plate and a DCPD.
Excellent adhesion to both plates. In addition, the open time after application of the primer was sufficiently long, and the excellent adhesiveness was exhibited even when the open time was 24 hours.

On the other hand, the primer composition of Comparative Example 1 in which a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate was not reacted with mercaptosilane had a short open time, and when the open time was 24 hours, Adhesion (adhesion) between the primer-coated surface and the adhesive was poor.

The primer composition of Comparative Example 2 in which the SH / NCO (equivalent ratio) at the time of the reaction between the isocyanate trimer mixture and the mercaptosilane exceeded 1.0 had an extremely short open time and an open time of 1%.
Even at 0 minutes, the adhesion (adhesion) between the primer-coated surface and the adhesive was poor.

Furthermore, the primer composition of Comparative Example 3, which did not contain tris-p-isocyanatephenylthiophosphate, had poor adhesion to a DCPD plate.

[0052]

As described above, the primer composition of the present invention exhibits excellent adhesion to both the polyester resin and the polydicyclopentadiene resin.
For example, it is suitably used as an adhesion primer for a septic tank, a large water tank, or the like.

Further, since the open time after the application of the primer is sufficiently long at 18 hours or more, the workability at the time of bonding is excellent.

Claims (3)

[Claims] 1. A reaction product of a reaction product of a trimer of tolylene diisocyanate and a mercaptosilane or a reaction product of a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate with mercaptosilane, tris-p-isocyanatophenylthiophos A primer composition comprising a fate and a polyester urethane resin. 2. An isocyanate group in a trimer of tolylene diisocyanate or a mixture of a trimer of tolylene diisocyanate and a trimer of hexamethylene diisocyanate with an equivalent ratio of mercapto groups in mercaptosilane to isocyanate groups of 0.5 to 1. The primer composition according to claim 1, wherein the primer composition is 0. 3. The primer composition according to claim 1, wherein the polyester urethane resin comprises a polyester polyol and tolylene diisocyanate.