JPH06329925A - Primer composition - Google Patents

Abstract

PURPOSE:To provide a primer composition which can be used generally, is excellent in stability during storage and use, and also is excellent in such characteristics as water resistance and alkali resistance. CONSTITUTION:The primer composition comprises (A) a polyisocyanate in which 66-90% of the isocyanate groups are reacted with an alkoxylated mercaptosilane, (B) a polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in the molecule, (C) at least one selected from an alkoxysilane and gamma-chloropropyltrimethoxysilane, (D) a chlorinated polymer, and (E) an organic inert solvent which dissolves above (A) to (D).

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 adhering 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 various sealing materials such as an elastic sealant are adhered to an adherend such as glass, metal or concrete, the surface of the adherend and the surface of the elastic sealant are modified to improve the adhesion strength and the adhesion durability. Primer treatment is performed for the purpose of This primer treatment is performed by using a primer composition suitable for each type of the adherend and the elastic sealant. For example, a primer composition composed of polyisocyanate and chlorinated rubber is used for concrete, which is a porous and alkaline environment adherend. This primer composition has excellent properties such as permeability and alkali resistance to porous adherends. However, since it is poor in water resistance, there is a problem that the adhesive surface may peel off due to water immersion. On the other hand, a primer composition made of a resin such as a silane compound and a chlorinated rubber is used for an adherend such as glass or metal. Although this primer composition has excellent adhesiveness to glass or the like, it cannot be used for porous adherends due to poor penetrability, and also has poor alkali resistance. As described above, the types of the adherend and the sealing material to be applied to the primer composition are limited depending on the type, and one kind of the primer composition should be used in combination with two or more kinds of the adherends. Is virtually impossible. However, with the recent diversification of building materials and construction techniques, movable joints and fixed joints of buildings are
It has come to have a structure in which various materials are finely combined. When applying a primer treatment to joints having such a structure, it is complicated to apply different primer compositions according to the types of the adherend and the sealing material, and it is considered that the workability is significantly reduced. Was becoming. Under such circumstances, the development of a versatile primer composition has been strongly desired.

[0003]

In order to solve the above problems, a primer composition characterized by 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 thiocol-based elastic sealants,
It is also excellent in water resistance and alkali resistance. However, it has a problem of poor adhesion to an elastic sealant made of a polymer having a silyl group at its molecular end, such as a modified silicone sealant. There is also a problem of being unstable during working and storage. That is, the isocyanate groups in the polyisocyanate may react with water in the air or the water in the primer composition to increase the amount thereof, and the primer composition may thicken or gel. Therefore, in the primer composition,
Further, it is necessary to add a dehydrating agent such as zeolite, which causes a problem such as an increase in cost.

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

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

[0006]

In order to achieve the above object, the present invention comprises the following (A) to (E). (A) With a mercaptosilane having an alkoxy group,
Polyisocyanate in which 66 to 90% of the isocyanate groups in the molecule are reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) At least one of alkoxysilane and γ-chloropropyltrimethoxysilane. (D) Chlorinated polymer. (E) An inert organic solvent capable of dissolving the above (A) to (D).

[0007]

In other words, the present inventor first examined the stability of the primer composition in order to solve the above problems. As a result, when the polyisocyanate used in the primer composition is one in which an isocyanate group is reacted with a mercaptosilane having an alkoxy group at a predetermined ratio, the reaction between the isocyanate group and water is suppressed, and the primer composition It was found that the increase in viscosity and gelation did not occur. Further, as a polyisocyanate different from the above polyisocyanate, a polyisocyanate having an isocyanurate ring and an isocyanate group at a predetermined ratio is used, and in addition, a specific silane coupling agent and a chlorinated polymer are used to form a polyisocyanate. The inventors have found that it is possible to obtain a primer composition having high strength, excellent water resistance and alkali resistance, and further having versatility, and arrived at the present invention. As a result, it can be used regardless of the type of adherend such as glass, metal, or porous and the type of sealing material, has excellent stability during storage and use, and is water and alkali resistant. It is 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 the isocyanate groups in the molecule are reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) At least one of alkoxysilane and γ-chloropropyltrimethoxysilane. (D) Chlorinated polymer. (E) An inert organic solvent capable of dissolving the above (A) to (D).

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

Examples of the above polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates having an aliphatic group. Specific examples thereof 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. Of these, aliphatic isocyanates are preferably used from the viewpoint of gelation stability of the thiourethane compound produced by the reaction of mercaptosilane.

The above-mentioned polyisocyanate needs to react the isocyanate group in the 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]

[Chemical 1]

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 composed of a polymer having a silyl group substituted with an alkyl group, an alkoxy group or the like at the molecular end, This is because there is a tendency that the adhesiveness to glassy adherends such as glass and bricks treated with a drug is reduced. In addition, the unreacted isocyanate group becomes excessive,
This is because the isocyanate group may react with water during storage or use, resulting in poor stability. On the contrary, if it exceeds 90%, the silane content becomes too high, the adhesion to the metal body is deteriorated, and the water resistance and alkali resistance tend to be poor. With the above reaction ratio, the primer composition containing this polyisocyanate has improved adhesion to stone materials, concrete materials, glass, metals and the like. In addition, since the reaction activity of the isocyanate group in the molecule is reduced, the reaction of water in the air is suppressed, and the stability of the primer composition becomes excellent. This is one of the features of this invention.

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

[0016]

[Chemical 2]

[0017]

[Chemical 3]

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

Among these, a reaction of tolylene diisocyanate and hexamethylene diisocyanate, which has an appropriate reactivity, is excellent in adhesion to stone materials, concrete, metals, etc. and is excellent in enhancing the structural strength of the formed film. Preference is given to using the product.

The mixing ratio of the component (B) is 55 to 7 relative to 100 parts by weight of the component (A) (hereinafter abbreviated as "part").
It is preferable to set the range of 5 parts. If it is less than 55 parts, the adhesiveness with various sealing materials becomes poor,
Furthermore, the adhesive strength tends to decrease during storage. On the other hand, if the amount exceeds 75 parts, thickening and gelation are likely to occur during storage and during work, and the stability tends to decrease.

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

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

[0023]

[Chemical 4]

The specific silane coupling agent, which is the component (C), has a high reactivity with water and therefore exhibits a dehydrating action in the primer composition and contributes to storage stability.
Further, by containing this specific silane coupling agent, it becomes possible to impart excellent adhesiveness to the adherend such as a sealing material and glass, which have a low affinity with a conventional primer, and an adherend.

The blending ratio of the component (C) is preferably set in the range of 10 to 25 parts with respect to 100 parts of the component (A). That is, if it is less than 10 parts, the adhesive force and the dehydrating action will be insufficient, and conversely if it exceeds 25 parts, the weather resistance will tend to deteriorate. Further, this silane coupling agent is expensive, and the compounding more than necessary increases the cost.

Examples of the chlorinated polymer as the component (D) include chlorinated products of natural rubber, chlorinated products of isoprene-based synthetic rubber, chlorinated products of homopolymers or copolymers of olefins such as ethylene and propylene, and butadiene. , Chlorinated products of homopolymers or copolymers of styrene and the like, chlorinated paraffins and chlorinated products of chloroprene rubber.
Among these, those having a chlorine content of 50 to 70% of the total are preferable. This chlorinated polymer has a function of improving the cohesive force of the primer composition, and as a result, the primer composition has excellent adhesiveness. The mixing ratio of the component (D) is 45 to 100 with respect to 100 parts of the component (A).
It is preferable to set within the range of parts. That is, if it is less than 45 parts, the permeability is lowered, and the adhesiveness to the adherend such as a porous or alkaline environment base material is deteriorated. On the other hand, if the amount exceeds 100 parts, the viscosity of the primer composition increases, and the workability tends to deteriorate.

The above-mentioned component (E) is an organic solvent which dissolves the above-mentioned components (A) to (D) and is inert to isocyanate groups, various alkoxysilanes and γ-chloropropyltrimethoxysilane. Examples of such substances include toluene, xylene, methyl ethyl ketone, methylene chloride, methyl acetate, butyl acetate and the like, which may be used alone or in combination. This mixing ratio is
It is preferable to set the range of 700 to 1000 parts with respect to 100 parts of the component (A). That is, if the amount is less than 700 parts, the concentration of the primer composition tends to be too high and the storage stability tends to be poor. On the contrary, if it exceeds 1000 parts, the concentration tends to be too low after the primer composition is applied. This is because it takes a long time to dry and the workability is reduced.

The primer composition of the present invention may contain a modified pentadiene (F) component in addition to the components (A) to (E). By compounding this, water resistance and alkali resistance are further improved. Examples of the modified pentadiene include 1, 1 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 thereof in which an epoxy group and a hydroxy group are introduced. Further, a product obtained by further reacting this with a silane coupling agent may be used. The mixing 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, when the amount is less than 40 parts, it becomes impossible to sufficiently impart the properties of water resistance and alkali resistance to the primer composition, and conversely 100%.
This is because if the amount exceeds the above range, the weather-resistant adhesiveness will decrease and the cost will increase.

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

The component (A) is prepared as follows. That is, first, 10 to 90 parts of an alkoxy group-containing mercaptosilane 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 tank under a nitrogen stream. On the other hand, 10 to 90 parts of polyisocyanate is mixed and dissolved in 5 to 40 parts of an inert organic solvent. Then, the polyisocyanate mixture is 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 added dropwise at 50 ° C. to react the isocyanate group in the polyisocyanate with the mercapto group in the 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, which are appropriately selected and used according to the types of mercaptosilane and polyisocyanate. The mixing ratio of each of the above is not particularly limited, and is appropriately selected and determined according to the intended use of the primer composition.

Next, with respect to the above component (A), a polyisocyanate (B) component, a silane coupling agent (C) component, a chlorinated polymer (D) component, an inert organic solvent (E) component and, if necessary, Accordingly, the modified pentadiene (F) component is mixed in a predetermined ratio and mixed and dissolved to obtain a primer composition. At this time, the mixing and melting temperature is set in the range of 20 to 40 ° C.

[0032]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the polyisocyanate (A) in which the mercaptosilane whose isocyanate group has an alkoxy group is reacted in a predetermined ratio
Component, polyisocyanate (B) having isocyanurate ring and isocyanate group in predetermined proportions
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, the primer composition does not thicken or gel during storage and use, and good brushability can be maintained. Like Also,
Since the primer composition of the present invention can be used regardless of the types of the adherend and the sealing material, various materials such as concrete, glassy and metallic adherends and elastic sealant are finely combined. It becomes unnecessary to separately apply the primer composition to movable joints and fixed joints having the above structure. That is, workability is improved by using the primer composition of the present invention. Since the primer composition of the present invention has a high strength of the formed film and is excellent in water resistance and alkali resistance, it is possible to strongly adhere the adherend such as concrete and the elastic sealant by using this. Also, it is possible to make the adhesion durability excellent. Therefore, by using the primer composition of the present invention, a structure having excellent strength and durability can be obtained.

Next, examples will be described together with comparative examples.

[0034]

Example 1 Dehydrated ethyl acetate 95 in a reaction tank under a nitrogen stream.
52 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Union Carbide Co., 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., Sumidule N75, solid content 75%) was mixed and dissolved in 13 parts of dehydrated ethyl acetate. Then, the polyisocyanate mixture was added dropwise to the mercaptosilane mixture in the reaction tank under the condition of 1 hour and 30 minutes at 30 ° C. to react the isocyanate group and the mercapto group of the polyisocyanate to prepare the component (A). The reaction rate at this time was 80%. Next, 68 parts of chlorinated rubber (D) component (manufactured by Asahi Denka Co., Ltd., CR-20, chlorine content of 65% or more), reaction product (B) component of tolylene diisocyanate and hexamethylene diisocyanate (Sumitomo Bayer Urethane Co., Ltd. Manufactured by Desmodur HL. Solid content 60%) 115 parts, dehydrated ethyl acetate 700 parts and dehydrated butyl acetate 42 parts (E) component, modified polybutadiene polymer (F) component (Asahi Denka Kogyo Co., Ltd., PRIOR 5)
38 parts, solid content 70%) 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 Component (A) was prepared according to the type and amount of polyisocyanate shown in Table 1 below. As a catalyst, 0.5 part of stannous octylate (manufactured by Nitto Kasei Co., Nestan U28) was blended. Other than that, the same operation as in Example 1 was performed to prepare a primer composition.

[0036]

[Table 1]

[0037]

Examples 5 to 16 The composition ratios and the reaction rates of the isocyanate groups of the component (A) shown in Tables 2 to 3 below were followed. Other than that, 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), the reaction of the isocyanate group was not carried out. Other than that, 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 were investigated when various adhesives and elastic sealants were bonded using the primer composition of Comparative Example. The results are shown in Tables 4 to 18 below. In addition, Table 4 to Table 7
Is a polyurethane-based two-component sealant as the elastic sealant, and Tables 8 to 11 are polysulfide-based two-component sealant as the elastic sealant.
Shows respective results when a modified silicone-based two-component sealant was used as the elastic sealant. Further, the above characteristics were examined by the methods described below.

[Adhesion between the adherend and the elastic sealant] J
A mortar plate (porous), an aluminum plate and a glass plate were produced according to ISR5201. The primer composition was applied twice to the surface of these plates with a brush, air-dried for 1 hour, and then the above-mentioned three kinds of sealing materials were filled in accordance with JIS A5758 to carry out initial curing. The adhesive body thus obtained was used as a test piece for tensile adhesion. The above initial curing was performed at 20 ° C for 7 days and then at 50 ° C.
The conditions were 7 days.

[Water resistance] The adhesive strength (kg / c) immediately after the initial curing of the test piece and after 7 days of immersion in warm water of 50 ° C.
m ² ) and elongation (%) were measured. In addition, the state of destruction at that time was examined, and those with a cohesive failure rate of 70% or more were evaluated as ○,
Those less than 0% were expressed as x.

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

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

[Storage stability] Water and 3% sodium hydroxide solution were added to the primer composition at 1000 ppm, 20 ppm.
It was forcibly added at a ratio of 00 ppm and 3000 ppm and stored at 50 ° C. for 4 days. Then, a viscosity [viscosimeter: manufactured by Tokimec, BH type viscometer (10 rpm, rotor: NO1)] was measured to determine whether or not the brush coating using the primer composition thus treated was possible. Examined. Then, those with no change in viscosity are indicated by ⊚, those with a slight change observed are indicated by ∘, those with increased viscosity are indicated by Δ, and those in which gelation is not possible and whose viscosity cannot be measured are indicated by x. Also, water 100
Using the primer composition with 0 ppm added, an aluminum plate was used as the adherend, and a modified silicone two-component sealant was used as the sealing material to prepare tensile adhesion test pieces according to the above method, and the adhesive strength 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 regardless of the adherend and the type of the elastic sealant, and have the characteristics of water resistance, alkali resistance and weather resistance. You can see that In addition, the primer compositions of the examples are excellent in storage stability, and even when water or alkaline water is mixed, thickening and gelation do not occur, and brush coating is possible. Even after adding 1000 ppm of water and storing for 4 days, no change was observed in the adhesive strength.
On the other hand, the primer composition of the comparative example product was inferior in adhesive strength, and was poor in water resistance, alkali resistance and weather resistance. In addition, addition of water or alkaline water caused gelation, which made brushing impossible. And 100 water
The adhesive strength of the product added with 0 ppm and stored for 4 days was significantly inferior.

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Claims (2)

[Claims] 1. A primer composition containing the following (A) to (E): (A) With a mercaptosilane having an alkoxy group,
Polyisocyanate in which 66 to 90% of the isocyanate groups in the molecule are reacted. (B) A polyisocyanate having one or more isocyanurate rings and two or more isocyanate groups in one molecule. (C) At least one of alkoxysilane and γ-chloropropyltrimethoxysilane. (D) Chlorinated polymer. (E) An inert organic solvent capable of dissolving the above (A) to (D). 2. The primer composition according to claim 1, containing the following (F). (F) Modified pentadiene polymer.