JP3126261B2 - Primer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition used for bonding a sealing material such as an elastic sealant to an adherend such as glass, metal or concrete.

[0002]

2. Description of the Related Art When bonding various sealing materials such as an elastic sealant to an object to be bonded such as glass, metal, or concrete, the surface of the object to be bonded and the surface of the elastic sealant are modified to improve the bonding strength and the bonding durability. A primer treatment is performed for the purpose of causing the reaction. This primer treatment is performed using a primer composition corresponding to each type of the adherend and the elastic sealant. For example, a primer composition comprising a polyisocyanate and a chlorinated rubber is used for concrete which is a porous, alkaline environment adherend. This primer composition is excellent in properties such as permeability to the porous adherend and alkali resistance. However, since it has poor water resistance, there is a problem that the adhesive surface may be peeled off by water immersion. On the other hand, for an adherend such as glass or metal, a primer composition comprising a resin such as a silane compound and a chlorinated rubber is used. This primer composition has excellent adhesion to glass or the like, but cannot be used for a porous adherend because of poor permeability, and also has poor alkali resistance. As described above, the types of the adherend and the sealing material applied to the primer composition are limited depending on the type, and one kind of the primer composition is used in combination with two or more kinds of the adherends and the like. Is virtually impossible. However, with the diversification of building materials and techniques in recent years, movable joints and fixed joints of buildings are
Various materials have come to have a structure that is finely combined. For a joint having such a structure, when applying a primer treatment, it is troublesome to separately apply the primer composition according to the type of the adherend and the sealing material, which causes a significant decrease in workability. Had become. Under such circumstances, development of a versatile primer composition has been strongly desired.

[0003]

In order to solve the above-mentioned problems, a primer composition containing a chlorinated polymer, polyisocyanate and modified pentadiene has been proposed (Japanese Patent Application No. 53-67529). issue). This primer composition can be applied to polyurethane-based and thiochol-based elastic sealants,
And it is excellent in water resistance and alkali resistance characteristics. However, there is a problem that adhesion to an elastic sealant comprising a polymer having a silyl group at a molecular terminal such as a modified silicone sealant is poor. In addition, there is a problem that it is unstable during operation and storage. That is, the isocyanate groups in the polyisocyanate react with moisture in the air or in the primer composition to increase the amount thereof, and the primer composition may be thickened or gelled. For this reason, in the primer composition,
Furthermore, it is necessary to mix a dehydrating agent such as zeolite or the like, which causes disadvantages such as an increase in cost.

On the other hand, at least one of an aromatic polyisocyanate, a thermoplastic polyurethane resin, a chlorinated polyolefin and a vinylidene chloride copolymer, four components of a polyurethane having an alkoxysilane at a molecular terminal, and a solvent dissolving these components. The following primer composition has been proposed (Japanese Patent Application No. 51-97429). This primer composition exhibits excellent performance regardless of the type of the elastic sealant and the adherend. However, similarly to the above primer composition, there is a problem of stability during operation and storage.

[0005] The present invention has been made in view of such circumstances, and provides a primer composition having versatility, excellent stability during storage and use, and excellent water resistance and alkali resistance properties. Its purpose is to provide.

[0006]

In order to achieve the above object, the present invention comprises the following (A) to (E) , and (B)
Is 55 to 75 weight per 100 parts by weight of (A)
Is set in the range of parts by weight, and the blending ratio of (C) is
It is set in the range of 10 to 25 parts by weight with respect to 0 parts by weight,
The mixing ratio of (D) is 45 to 100 parts by weight of (A).
Is set in the range of 100 parts by weight, and the blending ratio of (E) is
(A) 700 to 1000 parts by weight per 100 parts by weight
A configuration that that have been set in the range. (A) With a mercaptosilane having an alkoxy group,
Polyisocyanate in which 66 to 90% of isocyanate groups in the molecule have been reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) at least one of an alkoxysilane and γ-chloropropyltrimethoxysilane. (D) a chlorinated polymer. (E) An inert organic solvent that dissolves the above (A) to (D).

[0007]

That is, the present inventors first studied the stability of the primer composition in order to solve the above problems. As a result, when a polyisocyanate used in the primer composition is used in which isocyanate groups are reacted with a mercaptosilane having an alkoxy group at a predetermined ratio, the reaction between the isocyanate groups and moisture is suppressed, and the primer composition It was found that no thickening, gelling, etc. occurred. In addition, as a polyisocyanate different from the above polyisocyanate, a polyisocyanate having an isocyanurate ring and an isocyanate group in a predetermined ratio is used, and in addition, when a specific silane coupling agent and a chlorinated polymer are used, the polyisocyanate is formed. The present inventors have found that it is possible to obtain a primer composition having high strength, excellent water resistance and alkali resistance properties, and further having general versatility. Thereby, it can be used irrespective of the type of adherend such as vitreous, metallic, or porous and the type of sealing material, and has excellent stability during storage and use, as well as water resistance and alkali resistance. It becomes possible to provide a primer composition having characteristics.

Next, the present invention will be described in detail.

The primer composition of the present invention can be obtained by mixing and dissolving the following components (A) to (D) in an inert organic solvent of the following component (E). (A) With a mercaptosilane having an alkoxy group,
Polyisocyanate in which 66 to 90% of isocyanate groups in the molecule have been reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) at least one of an alkoxysilane and γ-chloropropyltrimethoxysilane. (D) a chlorinated polymer. (E) An inert organic solvent that dissolves the above (A) to (D).

The component (A) is a polyisocyanate in which isocyanate groups are reacted at a predetermined ratio with mercaptosilane having an alkoxy group.

Examples of the polyisocyanate include an aliphatic polyisocyanate, an alicyclic polyisocyanate, and an aromatic polyisocyanate having an aliphatic group. Specific examples include a trimer of hexamethylene diisocyanate, a reaction product of tolylene diisocyanate and hexamethylene diisocyanate, and a reaction product of hexamethylene diisocyanate and tris (2-hydroxyethyl) isocyanate. Among these, it is preferable to use an aliphatic isocyanate from the viewpoint of the gelation stability of the thiourethane compound generated by the reaction of mercaptosilane.

The above polyisocyanate needs to react an isocyanate group in a molecule with a mercaptosilane having an alkoxy group. The mercaptosilane used in this reaction is represented by the following general formula (1), and examples thereof include γ-mercaptopropyltrimethoxysilane and β-mercaptoethyltriethoxysilane.

[0013]

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The above reaction must be carried out so that 66 to 90% of the isocyanate groups in the polyisocyanate molecule react. That is, when the reaction ratio is less than 66%, the number of silyl groups in the polyisocyanate molecule is reduced, and a sealing material mainly containing a polymer having a silyl group substituted by an alkyl group, an alkoxy group, or the like at the molecular terminal is used. This is because there is a tendency that the adhesiveness to a glassy adherend such as glass or bricks treated with a drug is reduced. In addition, unreacted isocyanate groups become excessive,
This is because there is a possibility that the isocyanate group reacts with water during storage or use, resulting in poor stability. Conversely, if it exceeds 90%, the silane content becomes too high, the adhesion to the metal body is reduced, and the water resistance and the alkali resistance tend to be inferior. With the above reaction ratio, the primer composition containing the polyisocyanate has improved adhesion to stone, concrete, glass, metal and the like. In addition, since the reaction activity of the isocyanate group in the molecule decreases, the reaction of moisture and the like in the air is suppressed, and the stability of the primer composition becomes excellent. This is one of the features of the present invention.

The component (B) has at least one isocyanurate ring in one molecule and has two isocyanate groups.
It is a polyisocyanate having at least one polyisocyanate. Examples of such a product include a reaction product of tolylene diisocyanate and hexamethylene diisocyanate represented by the following general formulas (2) and (3).

[0016]

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[0017]

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Further, there may be mentioned a reaction product of hexamethylene diisocyanate and xylene diisocyanate.

Among them, a reaction between tolylene diisocyanate and hexamethylene diisocyanate having moderate reactivity, excellent adhesion to stone, concrete, metal, etc., and excellent in enhancing the structural strength of the formed film. It is preferred to use the product.

The proportion of the component (B) is 55 to 7 parts by weight per 100 parts by weight of the component (A) (hereinafter abbreviated as "part").
It is necessary to set a range of 5 parts . If the amount is less than 55 parts, the adhesiveness to various sealing materials becomes poor, and the adhesive strength during storage tends to decrease. On the other hand, if it exceeds 75 parts, viscosity increases and gelation tends to occur during storage and during operation, and the stability is reduced.

The component (C) is a specific silane coupling agent, and comprises both alkoxysilane and γ-chloropropyltrimethoxysilane, or one of them.

The above alkoxysilane and γ-chloropropyltrimethoxysilane are represented by the following general formula (4), and examples of the alkoxysilane include methyltrimethoxysilane, methyltriethoxysilane and the like.

[0023]

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The specific silane coupling agent, which is the component (C), has high reactivity with water, and thus has a dehydrating effect in the primer composition, contributing to storage stability.
In addition, by containing this specific silane coupling agent, it becomes possible to impart excellent adhesiveness to an object to be adhered such as a sealing material and glass, which have a low affinity for a primer in the past.

It is necessary to set the mixing ratio of the component (C) in a range of 10 to 25 parts with respect to 100 parts of the component (A).
You. That is, if the amount is less than 10 parts, the adhesive strength and the dehydration effect become insufficient, and if it exceeds 25 parts, the weather resistance tends to decrease. In addition, since this silane coupling agent is expensive, adding more than necessary increases the cost.

Examples of the chlorinated polymer as the component (D) include chlorinated natural rubber, chlorinated isoprene-based synthetic rubber, chlorinated homopolymer or copolymer of olefins such as ethylene and propylene, and butadiene. And chlorinated products such as homopolymers and copolymers of styrene, chlorinated paraffin, and chlorinated chloroprene rubber.
Among them, those having a chlorine content of 50 to 70% of the whole are preferable. This chlorinated polymer has an effect of improving the cohesive force of the primer composition, and as a result, the adhesion of the primer composition becomes excellent. The mixing ratio of the component (D) is 45 to 100 with respect to 100 parts of the component (A).
Must be set in the range of parts . That is, if the amount is less than 45 parts, the permeability decreases, and the adhesion to the adherend such as a porous or alkaline environment base material becomes poor. Conversely, when the amount exceeds 100 parts, the viscosity of the primer composition increases, so that the workability tends to deteriorate.

The component (E) is an organic solvent which dissolves the components (A) to (D) and is inactive against isocyanate groups, various alkoxysilanes and γ-chloropropyltrimethoxysilane. Such materials include, for example, toluene, xylene, methyl ethyl ketone, methylene chloride, methyl acetate, butyl acetate, etc., and may be used alone or in combination. This compounding ratio is
It is necessary to set the amount in the range of 700 to 1000 parts with respect to 100 parts of the component (A) . That is, when the amount is less than 700 parts, the concentration of the primer composition becomes too high, and the storage stability tends to be deteriorated. Conversely, when the amount exceeds 1,000 parts, the concentration becomes too low after the primer composition is applied. This is because it takes a long time to dry the varnish, and the workability decreases.

The primer composition of the present invention may contain a modified pentadiene (F) component in addition to the components (A) to (E). By blending this, water resistance and alkali resistance are further improved. Examples of the modified pentadiene include those having an iodine value of 200 to 500 and an average molecular weight of 350 to 10,000.
Examples thereof include a homopolymer of 3-pentadiene or a copolymer obtained by introducing an epoxy group and a hydroxy group into this copolymer. Further, a product obtained by further reacting with a silane coupling agent may be used. The compounding ratio of the component (F) is preferably set in the range of 40 to 100 parts with respect to 100 parts of the component (A). That is, if the amount is less than 40 parts, it becomes impossible to sufficiently impart water resistance and alkali resistance properties to the primer composition, and
If the amount exceeds the part, the weather resistance will decrease and the cost will increase.

The primer composition of the present invention can be prepared using the above-mentioned raw materials, for example, as follows.

The preparation of the component (A) is performed as follows. That is, first, 10 to 90 parts of mercaptosilane having an alkoxy group and 0.1 to 1.2 parts of a catalyst are mixed and dissolved in 70 to 150 parts of an inert organic solvent in a reaction vessel under a nitrogen stream. On the other hand, 10 to 90 parts of a polyisocyanate is mixed and dissolved in 5 to 40 parts of an inert organic solvent. Then, the polyisocyanate mixture was added to the mercaptosilane mixture in the reaction tank for 60 to 90 minutes at a temperature of 20 to 90 minutes.
The mixture is dropped and mixed at 50 ° C., and the isocyanate group and the mercapto group in the polyisocyanate are reacted in a range of 66 to 90%. This reaction rate can be adjusted by the amount of mercaptosilane. Examples of the catalyst include stannous octylate, dibutyltin dilaurate, and the like. The catalyst is appropriately selected and used depending on the type of mercaptosilane and polyisocyanate. The mixing ratio is not particularly limited, and is appropriately selected and determined according to the intended use of the primer composition.

Next, the polyisocyanate (B) component, the silane coupling agent (C) component, the chlorinated polymer (D) component, the inert organic solvent (E) component, and the Accordingly, the modified pentadiene (F) component is blended at a predetermined ratio and mixed and dissolved, whereby a primer composition can be obtained. At this time, the mixed dissolution temperature is set in the range of 20 to 40 ° C.

[0032]

As described above, the present invention relates to a polyisocyanate (A) in which an isocyanate group is reacted at a predetermined ratio with a mercaptosilane having an alkoxy group.
Component, polyisocyanate (B) having isocyanurate ring and isocyanate group at predetermined ratios
This is a primer composition prepared by mixing and dissolving a component, a specific silane coupling agent (C) component, and a chlorinated polymer (D) component in an inert organic solvent (E). Therefore, since the reaction between the isocyanate group and water is suppressed, during storage and during use, the thickening or gelling of the primer composition does not occur, and good brushability can be maintained. Become like Also,
Since the primer composition of the present invention can be used irrespective of the type of the adherend and the sealing material, various materials such as concrete, vitreous and metallic adherends and elastic sealants are finely combined. This eliminates the need to separately apply the primer composition to movable joints and fixed joints having a different structure. That is, use of the primer composition of the present invention improves workability. And since the primer composition of this invention has high strength of the formed film and is excellent in water resistance and alkali resistance, the adherend such as concrete and the elastic sealant can be strongly bonded by using this. In addition, it is possible to make the bonding durability excellent. Therefore, a structure having excellent strength and durability can be obtained by using the primer composition of the present invention.

Next, examples will be described together with comparative examples.

[0034]

Example 1 In a reaction vessel under a nitrogen stream, dehydrated ethyl acetate 95 was used.
Then, 52 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Union Carbide Co., Ltd., AZ-6129) and 0.5 part of stannous octylate were mixed and dissolved. On the other hand, 67 parts of a hexamethylene diisocyanate derivative (Sumitomo Bayer Urethane Co., Ltd., Sumidur N75, solid content 75%) was mixed and dissolved in 13 parts of dehydrated ethyl acetate. Then, the polyisocyanate mixture was dropped and mixed at 30 ° C. for 1 hour and 30 minutes into the mercaptosilane mixture in the reaction tank, and the isocyanate group and the mercapto group of the polyisocyanate were reacted to prepare the component (A). At this time, the reaction rate was 80%. Next, 68 parts of a chlorinated rubber (D) component (manufactured by Asahi Denka Kogyo Co., Ltd., CR-20, chlorine content of 65% or more), a reaction product (B) component of tolylene diisocyanate and hexamethylene diisocyanate (Sumitomo Bayer Urethane Co., Ltd.) (E) component, modified polypentadiene polymer (F) component (Phiol 538, manufactured by Asahi Denka Kogyo KK), 115 parts of Desmodur HL, 60% solid content, 700 parts of dehydrated ethyl acetate and 42 parts of dehydrated butyl acetate. , 70% of solid content) and 11 parts of methyltrimethoxysilane (C) component were mixed and dissolved at 30 ° C. to prepare a target primer composition.

[0035]

Examples 2 to 4 The components (A) were prepared according to the types and amounts of the polyisocyanates shown in Table 1 below. Also, 0.5 parts of stannous octylate (Nestan U28, manufactured by Nitto Kasei) was blended as a catalyst. Otherwise, the same operation as in Example 1 was performed to prepare a primer composition.

[0036]

[Table 1]

[0037]

Examples 5 to 16 The mixing ratios and the reaction rates of the isocyanate groups of the component (A) are shown in Tables 2 and 3 below. Otherwise, the same operation as in Example 1 was performed to prepare a primer composition.

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

Comparative Example In the preparation of the component (A), no isocyanate group was reacted. Otherwise, the same operation as in Example 1 was performed to prepare a primer composition.

Example products 1 to 1 thus obtained
6, Water resistance, alkali resistance, weather resistance and storage stability when various adhesives and elastic sealants were bonded using the primer composition of Comparative Example were examined. The results are shown in Tables 4 to 18 below. Table 4 to Table 7
Is a polyurethane two-part sealant as an elastic sealant. Tables 8 to 11 are polysulfide two-part sealants as elastic sealants.
Shows the respective results when the modified silicone two-pack type sealant was used as the elastic sealant. Further, the above characteristics were examined by the following method.

[Adhesion between adherend and elastic sealant]
According to IS R5201, a mortar plate (porous), an aluminum plate and a glass plate were produced. The surfaces of these plates were coated twice with a primer composition using a brush, air-dried for one hour, and then filled with the above three kinds of sealing materials according to JIS A5758, followed by initial curing. The adhesive thus obtained was used as a test piece for tensile adhesive strength. The initial curing was performed at 20 ° C. for 7 days and then at 50 ° C.
For 7 days.

[Water resistance] Adhesion strength (kg / c) immediately after initial curing of the test piece and after immersion in warm water at 50 ° C. for 7 days
m ² ) and elongation (%) were measured. The state of fracture at that time was examined.
Those having less than 0% were represented by x.

[Alkali Resistance] The adhesive strength (kg / cm ² ) and elongation (%) of the test specimen immediately after initial curing and after immersion in a 3% sodium hydroxide solution for 7 days were measured.
The state of destruction at that time was examined and evaluated in the same manner as in the above-mentioned water resistance.

[Weather Resistance] The adhesive strength (kg / cm ² ) and elongation (%) of the test piece immediately after initial curing and after irradiation for 1000 hours with a sunshine weatherometer tester were measured. The state of destruction at that time was examined and evaluated in the same manner as in the above-mentioned water resistance.

[Storage stability] To the primer composition, water and a 3% sodium hydroxide solution were added at 1000 ppm, 20 ppm.
The mixture was forcibly added at a ratio of 00 ppm and 3000 ppm and stored at 50 ° C. for 4 days. Then, the viscosity [viscosity meter: BH type viscometer (manufactured by Tokimec Co., Ltd., BH type viscometer (10 rpm, rotor: NO1)]) was measured to determine whether or not brushing was possible using the primer composition thus treated. Examined. Then, ◎ indicates that there was no change in viscosity, ○ indicates that a slight change was observed, Δ indicates that the viscosity was increased, and X indicates that the gel was formed and the viscosity could not be measured. In addition, 100
Using the primer composition to which 0 ppm was added, an aluminum plate was used as an adherend, and a modified silicone two-pack type sealant was used as a sealing material to prepare a tensile adhesion test piece according to the above method, and the adhesive force after initial curing was measured. did.

[0047]

[Table 4]

[0048]

[Table 5]

[0049]

[Table 6]

[0050]

[Table 7]

[0051]

[Table 8]

[0052]

[Table 9]

[0053]

[Table 10]

[0054]

[Table 11]

[0055]

[Table 12]

[0056]

[Table 13]

[0057]

[Table 14]

[0058]

[Table 15]

[0059]

[Table 16]

[0060]

[Table 17]

[0061]

[Table 18]

From the above Tables 4 to 18, the primer compositions of the examples have excellent adhesive strength, water resistance, alkali resistance and weather resistance regardless of the type of the adherend and the elastic sealant. It can be seen that there is provided. In addition, the primer compositions of Examples are excellent in storage stability, and do not thicken or gel even when mixed with water or alkaline water, and can be brush-coated. Then, even when 1000 ppm of water was added and stored for 4 days, no change was observed in the adhesive strength.
On the other hand, the primer composition of the comparative example was inferior in adhesive strength and poor in water resistance, alkali resistance and weather resistance. In addition, gel was formed by adding water or alkaline water, and brushing could not be performed. And add 100 water
Those that were added for 0 ppm and stored for 4 days had remarkably poor adhesion.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09J 175/04 C09J 175/04 201/02 201/02 // C09K 3/10 C09K 3/10 D (58) Field surveyed ( Int.Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 C09D 5/00-201/10 C09J 5/00-201/10

Claims (2)

(57) [Claims] (1) It contains the following (A) to (E) , and
The mixing ratio of (B) is 55 to 100 parts by weight of (A).
It is set in the range of 75 parts by weight, and the blending ratio of (C) is
(A) 10 to 25 parts by weight with respect to 100 parts by weight
Is set, and the mixing ratio of (D) is relative to 100 parts by weight of (A).
Is set in the range of 45 to 100 parts by weight, and
The mixing ratio is 700 to 1000 parts per 100 parts by weight of (A).
Primer composition characterized that you have been set in a range of parts by weight. (A) With a mercaptosilane having an alkoxy group,
Polyisocyanate in which 66 to 90% of isocyanate groups in the molecule have been reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) at least one of an alkoxysilane and γ-chloropropyltrimethoxysilane. (D) a chlorinated polymer. (E) An inert organic solvent that dissolves the above (A) to (D). 2. The composition according to claim 1 , further comprising (F):
(A) 40 to 100 weight parts for 100 weight parts
Claim 1 primer composition according to claim parts that have been set. (F) a modified pentadiene polymer.