JP2005281404A - Moisture curable resin composition and its curing acceleration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that, since a moisture curable adhesive, sealing material, etc. cause the curing to proceed by internal moisture or suction of moisture of an adherend, external moisture, etc., if the adherend is a material non-porous and not containing moisture such as a metal and a tile, the curing time becomes long, and, if the coating thickness is thick, the deep part is not cured, and so forth. <P>SOLUTION: The moisture curable composition incorporates a modified silicone polymer having an alkoxysilyl group in the terminal, a curing catalyst and Zeolite, and can advance the curing rapidly by making the water adsorbed in Zeolite be discharged into the outside by heating. Because this enables the rapid curing even if the adherend is of non-porous nature not containing moisture or the coating thickness is thick, the works of adhesion, sealing, etc. can be done promptly. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a moisture curable resin composition and a method for accelerating the curing thereof, and more particularly to a modified silicone type moisture curable resin composition and a method for accelerating the curing thereof.

Moisture curable resin compositions typified by one-component modified silicone resins and urethane resins react with the moisture contained in the adherend and the surrounding moisture to cure, so that the adherend is, for example, a metal Adherents made of materials that do not contain moisture such as glass, stone, plastic, etc., adherends made of materials that do not transmit moisture, or adherents that absorb moisture but remain at a low moisture content, or are placed under low humidity for a long time. However, there are problems that the adherend is slow to cure, only the vicinity of the contact surface with the adherend is cured, and the deep portion of the adhesive layer is not cured.
In such a case, when various processed products are produced by laminating adherends, the production efficiency is not improved, which hinders mass production.

As a means for solving such problems, a method of adopting a two-component type in which a curing accelerator is blended has been studied, but the work of mixing the two components is necessary at the time of application, so the construction is complicated. Since the work time becomes longer and air is entrained during mixing and taken in as bubbles, the silicone resin has a relatively high gas permeability, and air bubbles escape during or after curing. For processed products, the thickness accuracy of the processed product cannot be obtained, and there is a problem that a depression appears on the coated surface and the finished appearance is deteriorated.

JP-A-4-202563 JP-A-3-236937

  The object of the present invention is that the curing is extremely slow in the case of the above-mentioned problems, that is, an adherend made of a material not containing moisture such as metal, glass, or plastic, or an adherend made of a material having no moisture permeability. In addition to providing a moisture curable composition and a method for accelerating the curing, which solves the problem that the adhesive layer is not thick at the deep part of the adhesive layer, the adhesive processing is possible even when the adherend is used. It is to enable mass production such as lamination processing.

  In order to solve the above-mentioned problems, the present invention provides a moisture curable resin composition comprising a modified silicone polymer having an alkoxysilyl group at the terminal, a curing catalyst, and zeolite, for example, metal, glass, plastic, etc. Curing is extremely slow for adherends made of materials that do not contain moisture, adherends made of materials that do not have moisture permeability, or adherends with low moisture content. If the adhesive layer is thick, the deep part of the adhesive layer A moisture curable composition that solves the problem of not being cured at the same time and a curing accelerating method that is suitable for mass production of various processes are realized.

The moisture-curable composition according to the present invention is present in the formulation because it is heated and depressurized in the preparation process, adjusted to a low level of moisture value, and blended with zeolite having excellent moisture adsorption ability. Moisture is trapped inside the zeolite, and long-term preservation is ensured despite the presence of moisture in spite of curing. For this reason, if the opening of the container is closed with a non-moisture permeable sealing tape after use, the sealing tape can be peeled off when used again.
In addition, according to the method for accelerating the curing of the moisture curable composition according to the present invention, the moisture adsorbed inside the zeolite can be instantaneously released by heating, so that the modified silicone which is originally moisture curable The polymer can be cured in a short time and deep. Therefore, it can be effectively used in the fields of adhesion and sealing of adherends made of non-porous materials such as metal, tile, glass, and plastic that do not contain moisture inside.
In addition, by adopting a method in which a treated product such as a laminate to which the moisture-curable composition is applied is continuously heat-treated in a heating and drying furnace or the like to accelerate the curing, a high efficiency can be achieved in various types of adhesion processing and lamination processing. Production work becomes possible.

The modified silicone polymer according to the present invention is an organic polymer having a molecular weight of 300 to 15000 whose main chain has a structure such as a polyether bond or a polyester bond, and has at least one hydrolyzable alkoxysilyl group per polymer molecule. It is widely used in main agents such as adhesives, sealants, and paints.
In this modified silicone polymer, the alkoxysilyl group is crosslinked by hydrolysis with the surrounding water, but considering that the curing at the deep part is deteriorated as described above, it is preferable that a hydrophilic polyether bond is added to the main chain. Those finished in a molecular structure with are suitable.

As the curing catalyst, an organic tin, a metal complex, a platinum catalyst, a basic substance, an organic phosphorous oxide, or the like is used.
Specific examples of the organic tin include dibutyltin dilaurate, dioctyltin dimaleate, dibutyltin phthalate, stannous octylate, dibutyltin dissate and the like.
Metal complexes include titanate compounds such as tetrabutyl titanate, tetraisopropyl titanate, triethanolamine titanate, carboxylic acid metal salts such as lead octylate, lead naphthenate, nickel naphthenate, cobalt naphthenate, aluminum acetyl acetate complex, Examples thereof include metal acetyl acetate complexes such as vanadium acetylacetonate complex.
Examples of platinum catalysts include platinum metal, platinum compounds such as chloroplatinic acid and chloroplatinic acid hexahydrate, complexes of chloroplatinic acid and alcohols, aldehydes, ketones, and platinum complexes such as platinum-olefin complexes. It is done.
Examples of basic substances include quaternary ammonium salts such as tetramethylammonium chloride and benzalkonium chloride.
Examples of the organic phosphorus compound include monomethyl phosphoric acid, di-n-butyl phosphoric acid, and triphenyl phosphate.
These curing catalysts are suitably blended in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the modified silicone polymer solids. It is not preferable because it becomes too fast and the thickening becomes remarkable.

Zeolite is a hydrous metal salt of alumina and silicates. There are natural products and synthetic products. Adsorption due to physical adsorption by van der Waals force and chemical adsorption by metal cations is excellent for adsorbing water and polar solvents. Have the ability. For this reason, the water | moisture content in a formulation can be confined inside a zeolite.
There are various types and products of zeolite, and a suitable type can be selected. Among them, those having an average pore diameter of 0.3 to 0.8 nm in the pores are preferable.
Examples of commercially available products include “PURMOL” from UETIKON Corporation, for example, “PURMOL3” “PURMOL3ST” with an average pore diameter of 0.3 nm, “PURMOL4” with 0.4 nm, “PURMOL5” with 0.5 nm, and 0.8 nm. "Zeostar" from Nippon Chemical Industry Co., Ltd., such as "PURMOL8", for example, "Zeostar KA-100P" with an average pore diameter of 0.3 nm, "Zeostar NA-100P" with 0.4 nm, "Zeostar CA-1100P with 0.5 nm""ZeostarNX-100P", 0.9nm "Zeostar KA-110P" Tosoh Corporation's average pore diameter of 0.3nm "Zeoram JA-3", Union Showa Corporation's average pore diameter of 0.3nm ""Molecular sieve 3A", "Molecular sieve 4A" with an average pore size of 0.4nm The average pore diameter and the like "molecular sieve 5A" of 0.5 nm.
The blending amount of zeolite is preferably 5% by weight or more with respect to 100 parts by weight of the modified silicone resin. If it is 5 parts by weight or less, the hygroscopic action of the zeolite becomes low, the curing of the modified silicone resin proceeds, and the storage stability is lowered, which is not preferable.

For the purpose of improving the adhesion to the adherend, a coupling agent such as an amino group-substituted alkoxysilane may be appropriately blended with the modified silicone polymer.
Specific examples thereof include those having a primary or secondary amino group. Specific examples include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyl-methyldimethoxysilane, γ- Phenyl-γ-aminopropyl-methyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-amino And propyltriethoxysilane, N-β (aminoethyl) -γ-aminoethyl-aminopropylmethyldiethoxysilane, and the like.
These coupling agents are added in an amount of not more than 10 parts by weight based on 100 parts by weight of the modified silicone polymer. However, vinylsilane has a dehydrating action, which reduces moisture in the system and delays curing. It is preferable that the amount is controlled to 5 parts by weight or less with respect to 100 parts by weight of the modified silicone resin solid content.

  Other compounding materials include inorganic fillers such as calcium carbonate, cinnabar and kaolin for viscosity adjustment, reinforcing materials such as glass fiber for reinforcement of cured resin, shirasu balloon and glass balloon for weight reduction and viscosity adjustment. A hollow body such as may be appropriately blended.

  As a measure of storage stability of a blended preparation, the viscosity when left at 40 ° C. for 1 month is preferably 1.5 times or less of the initial viscosity, and stored when the blend is 1.5 times or more. Stability is deteriorated, which is not preferable for practical use. A composition suitable for such conditions is set.

  Moisture curable composition is pre-heated to 90-120 ° C while the modified silicone polymer is heated to 90-120 ° C in a planetary mixer that can be heated and depressurized. It can be prepared by stirring under reduced pressure at room temperature for 2 hours or more to reach an equilibrium state of adsorption and desorption of water and zeolite, and then adding a curing catalyst and stirring under reduced pressure for a short time. it can.

The moisture-curable composition thus prepared is filled in a hermetic and moisture-proof dedicated container and used in production sites such as bonding and laminating of various products in factories and processing sites.
In the use form of the small mouth, for example, a heat-sealing container processed from a non-moisture permeable sheet material in which a hot-melt adhesive for heat sealing is applied in a film form to an aluminum sheet having a thickness of 50 to 200 μm, or the inside A cylindrical container coated with a moisture-proof coating agent and provided with a discharge port, or a metal container having moisture resistance can be used.
If the moisture-curable composition remains in a special container or other container, seal it with a sealing material such as heat-sealable or adhesive-sealable, or use an adhesive-coated aluminum sheet for the discharge port. It is possible to use it again at a later date by storing it closely so that there is no gap with a sealing tape such as.

Although the moisture-curable composition according to the present invention confines moisture inside the zeolite during storage, it is released from the zeolite by increasing the molecular energy of water and other polar substances by heating from the surroundings. It can promote hardening acceleration.
As a heating method, electric heating, a method of heating between hot plates that can be heated by passing a medium such as water vapor or heated oil, etc., heating air generated through a medium such as water vapor or heated oil is released. (Continuous) A method of heating with a hot stove or the like can be adopted.

  As specific examples of the method for promoting the curing of the moisture curable composition according to the present invention, adhesion promotion of an adherend made of a material not containing moisture such as a metal-based sizing material, tile, stone, glass, metal, or the like having no moisture permeability is possible. Alternatively, it is used for acceleration of hardening when sealed to the connection part of these adherends, filling of recesses, etc., and the heating method adopts the above method in consideration of the shape and size of the adherend. .

Next, the present invention will be described with reference to examples and comparative examples. In addition, this invention is not restrict | limited at all by an Example. Further, the parts by weight are simply referred to as parts with respect to the formulations shown in Tables 1 and 2.
Examples 1-5, Comparative Examples 1-6
As a modified silicone resin, a modified silicone polymer MS303 (manufactured by Kaneka Chemical Co., Ltd., viscosity 20 Pa · s / 23 ° C., having a polyether structure in the main chain structure and a hydrolyzable methyldimethoxysilyl group at the molecular end) Average molecular weight 8000), vinyltrimethoxysilane (hereinafter referred to as VS) as vinylsilane, dibutyltin diacetylacetate (hereinafter referred to as DBTA) as a curing catalyst, and average pore size of 0.
Using PURMOL3 (manufactured by UETIKON), which is a zeolite having a potassium cation species at 3 nm, the formulations shown in Table 1 were prepared by the above preparation method.
Tables 1 and 2 show the evaluation and measurement results of the curability and storage stability of each compound.

Evaluation and measurement method 1. Tensile shear adhesive strength Degreased thickness 1.5 mm, width 10 cm, length 20 cm steel plates are used as adherends, and the thickness is 10 × 8 cm from the end of one steel plate.
After each compound is applied to 00μm, the other steel plate is overlaid only on the applied part, the laminated part is hot-pressed at 100 ° C for 60 seconds, and immediately after that, tensile shear bonding is performed using an Instron type tensile tester. Measure the force (N / mm ² ).
2. Storage stability Viscosity measurement used for the evaluation of storage stability is 1 immediately after compounding and at 40 ° C.
After standing for months, the viscosity at 23 ° C (Pa · s) is measured using a BH viscometer.
Measurements were taken with a No 6 rotor at 20 rpm.

According to the method of promoting the curing of a laminate coated with the moisture curable composition according to the present invention by a heating means such as a hot press or a tunnel type heating furnace, highly efficient production work can be performed in the processing of various products. Become.
In particular, in processing fields such as adhesion of adherends made of materials that do not contain moisture or are not permeable to moisture, such as metals, stones, tiles, glass, plastics, and adhesion, joining, and filling of the adherends. It is valid.
In addition, since moisture in the formulation is confined inside the zeolite, long-term preservation is ensured, and after use, the remaining container of the moisture-curable composition is sealed with an airtight packaging material. Alternatively, if the discharge port is closed with a moisture-impermeable sealing tape or the like, it can be opened and used again.

Claims (4)

  A moisture curable resin composition comprising at least a modified silicone polymer, a curing catalyst, and zeolite. The moisture curable resin composition according to claim 1, wherein 0.1 to 20 parts by weight of a curing catalyst and 5 parts by weight or more of zeolite are blended with respect to 100 parts by weight of the modified silicone polymer solids.   A curing accelerating method comprising: applying a moisture curable resin composition containing at least a modified silicone polymer, a curing catalyst, and zeolite to a surface of an adherend, followed by heating. 4. A moisture-curing resin composition in which 0.1 to 20 parts by weight of a curing catalyst and 5 parts by weight or more of zeolite are blended with respect to 100 parts by weight of a modified silicone polymer solid content. The curing acceleration method as described.