JP2008111006A - Sealant composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealant composition which has a good balance on weather resistance, curability not needing the anxiety of joint breakage from an uncured state to a semi-cured state and capable of being treated through the whole year, low surface adhesiveness, water-based coating coatability, plasticizer migration reduction, corrosion resistance and oil surface adhesiveness improvement. <P>SOLUTION: This sealant composition is characterized by comprising an oligomer having alkoxysilyl groups at terminals and a rubber component as essential components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sealing material composition called a solvent-free one-component curable modified silicone generally used for construction or vehicles, particularly its weather resistance, curability capable of prescription throughout the year, low surface tackiness, The present invention relates to a sealing material composition having improved paintability of water-based paint, reduced migration of plasticizer, rust prevention and oil surface adhesion.

  In the conventional construction industry, a one-component curable sealant composition is used for waterproof parts of joints such as low-rise building siding boards. In particular, the sealant composition called solvent-free one-component curable modified silicone is superior in the stain resistance of the periphery and joints with respect to the silicone sealant, and weather resistance and yellowing resistance compared to the urethane sealant. Excellent paintability compared to polysulfide sealants. In addition, water-based acrylic sealing materials and urethane-based sealing materials, which are said to have good paintability for building exterior water-based paints, are often used because they have features such as less volume shrinkage during curing (Patent Document 1). , 2).

  The solvent-free one-component curable modified silicone sealant composition is mainly composed of an oligomer having a polyoxypropylene structure in the main chain and an alkoxysilyl group structure at the end, and a plasticizer, a curing catalyst, and a filler. However, further improvements have been required in recent years. That is, improvement in weather resistance is required for long-term guarantee of the waterproof function of buildings. However, here, the polyoxypropylene structure as the main chain is easily cut by ultraviolet rays, and light resistance deterioration becomes a problem, and surface cracks occur over time, and the appearance and waterproof function are deteriorated.

  As a countermeasure, the two-component curable type was proposed and put into practical use by a resin manufacturer whose main chain structure was changed to acrylic or polyisobutylene. However, in the case of a one-part curable type by moisture curing, a thick sealant, unlike paint, exchanges substances due to the low moisture permeability of the acrylic or polyisobutylene network structure that is formed when curing is performed from the surface side. There is a problem that the internal curing due to is not sufficiently advanced, and it has not been put into practical use.

  The curing rate of the solventless one-component curable modified silicone sealant composition is mainly adjusted by the type and amount of catalyst such as organic tin and amine. It is advantageous that the curing rate is slow when securing the time from filling the joint to pressing with a spatula or when transferring from a container such as a can to a hand-held device for filling. On the other hand, it should not be washed away by rain after filling the joints, so that dust and dirt should not adhere to the uncured state, or during the time from uncured to semi-cured state due to temperature differences, In order to prevent the surface of the sealing material composition from cracking due to the movement of the width, it is advantageous that the curing speed is high. At present, it is necessary to secure sufficient time until curing in the summer, and it is necessary to cure early in the winter, so there are two or more prescriptions depending on the season and the style of the container such as cartridge or can Although it is often produced, it is colored according to the color of the outer wall paint according to the order, so from the viewpoint of productivity and distribution stock, it will not crack after following joint movement from uncured to semi-cured state A prescription is strongly desired.

It is desirable that the surface has low adhesion with less adhesion of dust after curing.
In recent renovations, solvent-based paints are regulated due to environmental problems. Conventional emulsions and inorganic / organic hybrid water-based paints blended with silica sol are often used as top coatings for sealing materials. Because the adhesion of the sealant composition and the solubility of the plasticizer retained by the sealant composition are close to that of the resin component of the water-based paint, the plasticizer migrates to the water-based paint film that has been dried or once dried, and is softened again Since there is a case where it becomes sticky, improvement is desired.

Furthermore, since metal fittings may be used to fix the siding board, it is desired that rust prevention, oil surface adhesion, and the like be better than at present. Furthermore, it may be used as a sealing material for vehicles, but in this case, there are many cases in which oil for rust prevention is applied to the surface of the metal base, and it is desirable that the oil surface has adhesiveness.
JP 2003-313418 A JP 2003-313419 A

  The present invention is a solvent-free one-component curable modified silicone-based sealant composition for use in buildings or vehicles, which has a year-round formulation that is weather resistant and has no worry about joint breakage from uncured to semi-cured. An object of the present invention is to provide a sealing material composition balanced with respect to possible curability, low surface tackiness, paintability of water-based paints, reduction of plasticizer migration, rust prevention and oil surface adhesion It is.

The present invention is a sealing material composition comprising an oligomer having an alkoxysilyl group at the terminal and a rubber component as essential components.
A preferred example of the oligomer is an oligomer having a polyoxyolefin structure in the main chain and a terminal alkoxysilyl group being a methoxysilyl group or an ethoxysilyl group. A preferred example of the polyoxyolefin of the main chain of the oligomer is polyoxypropylene.

  As such an oligomer, specifically, the number average molecular weight of polyoxypropylene as a main chain is 5000 or more and 50000 or less, and there is no branching or one structure, and a methyldimethoxysilyl group is formed at the terminal. The structure it has can be raised.

  Another preferred example of the oligomer is one in which the main chain is a polymer composed of an acrylic acid alkyl ester monomer and / or a methacrylic acid alkyl ester monomer.

  As the rubber component, butyl rubber, polyisobutylene, polybutadiene, hydrogenated polybutadiene, polyisoprene, styrene butadiene rubber, nitrile rubber, acrylic rubber, natural rubber, and recycled products called these recycled rubbers are also used.

  Of these rubber components, butyl rubber, polyisobutylene, polybutadiene, and recycled polybutadiene rubber are desirable from the viewpoint of weather resistance, hydrophobicity, and economy.

  The rubber component is generally larger in molecular weight than an oligomer having an alkoxysilyl group structure except for what is said to be a liquid rubber. However, since it does not contribute to crosslinking in a chemical reaction, the addition amount of the rubber component is an alkoxysilyl group. It is desirable to use in the range of 3 to 100 parts by weight with respect to 100 parts by weight of the oligomer having a structure. If the amount is less than this, the effect of addition will not be apparent, and if it is more than this, the curing of the sealing composition will be insufficient.

  The present invention is a sealing material composition comprising an oligomer having an alkoxysilyl group structure and a rubber component as essential components. The rubber component, which is one of the essential components, is added to a conventional one-component curable modified silicone-based sealant composition that uses an oligomer having an alkoxysilyl group structure, which is another essential component, thereby improving the weather resistance. Excellent solvent-free one-component curing type that is well-balanced in terms of stability, year-round prescription, low surface tack, water-based paint paintability, plasticizer migration reduction, rust prevention, and oil surface adhesion improvement It is possible to provide a modified silicone-based formulation.

  That is, weather resistance is improved by compensating for ultraviolet degradation of the polyoxyolefin structure of the oligomer main chain by using a rubber component such as butyl rubber or polyisobutylene having ultraviolet resistance. The rubber component contributes to the improvement of the weather resistance by having a chemical structure in which the main chain is difficult to be cleaved by ultraviolet rays or having a sufficient high molecular weight as an auxiliary strength even when cleaved. Furthermore, the weather resistance is further improved by blending a deterioration inhibitor for rubber.

  Since these rubbers are not particularly crosslinked during the curing process of the sealing material of the present invention, mass transfer is not greatly hindered even during curing. Therefore, in the acrylic and polyisobutylene structures having an alkoxysilyl group structure such as a methoxysilyl group or ethoxysilyl group at the terminal, the surface hardening proceeds and the film is applied to prevent the internal hardening from proceeding due to its low moisture permeability. However, in the present invention, the rubber component is blended so that the problem does not occur. Further, in the acrylic or polyisobutylene structure, there is a problem that a crack called “joint breakage” occurs due to lack of followability to joint expansion and contraction in an uncured to semi-cured state. Addition of rubber increases resistance to “joint joints” and enables year-round recipes with a catalyst formulation having a long curing time.

  Moreover, since rubber is generally low in polarity, its surface tackiness is low in a semi-cured state or a cured state. When rubber plasticizers and diluents are used, the tendency to low surface tackiness becomes stronger if the aromatic plasticizer is changed to a partially paraffinic process oil.

  With regard to adhesion to water-based paints, the plasticizer contained in the conventional modified silicone sealant that does not add rubber migrates to soften the paint film, and the same applies to some solvent-type paints. In addition to the phenomenon, there are some that cannot adhere to the crosslinked cured body, but when the rubber component is added according to the present invention, the migration of the plasticizer and oil component is small, and the adhesion is improved. The improvement in adhesion is considered to be a clue that the rubber component is attached to the paint.

Since it becomes hydrophobic as a whole, it prevents the intrusion of moisture that causes rust and improves rust prevention.
In addition, when the rust preventive oil remains on the steel plate surface, the rubber component absorbs and oil surface adhesion is exhibited.

  Heavy calcium carbonate (product “Whiteon 305” manufactured by Toyo Fine Chemical Co., Ltd.) and synthetic calcium carbonate (product manufactured by Shiroishi Kogyo Co., Ltd., “Hakuen Hana CCR”) are used in the weight ratio of 30 to 70 as fillers used in Examples and Comparative Examples. And then dried at 105 ° C. for 24 hours or more. An evaluation test was carried out using what was packed in a sealing material cartridge after degassing under reduced pressure after mixing in an airtight container sufficiently dried with the formulations of Examples 1 to 7 and Comparative Examples 1 to 4 below.

  As for weather resistance, the cured body was observed with a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.), which is an accelerated weather resistance test apparatus, for 1000 hours. , × (5: No crack, ○: There are few cracks of 0.5 mm or less, ○ to Δ: Many cracks of 0.5 mm or less, Δ: 0.5 mm or more There are cracks, x: many cracks are deep, and powder is formed by rubbing with a fingertip.

  The joint cutting test for year-rounding was performed by fixing the end faces of two siding boards 10 mm long and 100 mm wide and 10 mm apart, and fixing the 10 mm × 10 mm × 100 mm joints with the sealing materials of each example and comparative example. Create 5 sets of each of the filled specimens and leave them in a room with a room temperature of 25 ° C and a humidity of 65%. The joint width of each specimen is increased to 20 mm for each hour of the curing process until 5 hours have passed. The surface was observed for cracks. Depending on how many cracks have occurred, ◎, ○, ○ to △, △, × 5 stages (◎: no cracks, ○: one cracks, ○ to △: two cracks, The results are shown in Table 2. Evaluated by Δ: three cracks, x: four or more cracks.

  The surface tackiness of the cured product is defined as ◎, ○, ○ to △ when the surface of the cured product is cured for 7 days and sprinkled with dry soil powder on the surface of the Kanto Loam layer and then lightly wiped with a brush. , △, x (◎: no powder adheres, ○: slight powder adheres, ○ to Δ: some powder adheres, Δ: powder adheres and changes color, X: Powder is attached to the entire surface and cannot be removed.

  Regarding adhesion to water-based paints, after curing for 7 days, the surface is coated with acrylic water-based paint A and silicate-based water-based paint B, and after drying for 3 days, it is paralleled at intervals of 5 mm with a cutter to a length of 15 mm. Cut three tapes in a perpendicular direction and then press the cello tape (registered trademark) and then peel it off in the vertical direction to determine the state of adhesion in five stages: ◎, ○, ○-△, △, × (◎ : Adhesion is good and no peeling is observed, ○: Adhesion is good and there is slight peeling around the notch, ○ to Δ: Adherence is poor and the area is less than ¼ or less, but peeling is present, Δ: Adhesion is poor and less than half The area was peeled off, x: the adhesion was poor and more than half of the area was peeled off, or the coating film was softened due to the migration of the plasticizer.

  The evaluation of the migration of the plasticizer to the water-based paint is as follows. When the above specimen is left at 60 ° C. for 12 hours and then returned to room temperature, the surface is rubbed with a fingertip (◎) and slightly sticky (○ ), Tacky (◯ to Δ), the paint adheres to the hand (Δ), and sticky (×), and evaluated in 5 stages and listed in Table 2.

  For rust prevention, a sealant was applied to one side of a 50 mm × 150 mm × 0.6 mm thick cold rolled steel sheet of SPCC-SD at a thickness of 1 mm, and after curing for 7 days, 500 ml was applied to a salt spray machine. After the time exposure, the sealing material is removed with a knife or the like, and the surface rust is graded in five stages: ◎, ○, ○ to Δ, △, × (◎: No rust is observed, ○: Diameter of 1 mm or less No more than 3 rust, ○ to Δ: There is only rust with a diameter of 1 mm or less, △: There is rust with a diameter of 5 mm or less, but there are 5 or less, x: There is more rust. Described.

  Oil surface adhesion is applied to the surface of the steel sheet surface with a thin coating of rust-preventive oil and lightly wiped with a cloth, and a sealing material is applied in the form of a bead with a height of 5 mm, a width of 10 mm, and a length of 100 mm. Then, after curing for another 7 days, after cutting 10 mm from the end with a knife between the steel plate and the sealing material, the adhesion state when the end is picked and peeled off is ◎, ○, ○ ~ △ , △, × 5 stages (◎: not peeled off at all, cut with sealing material, ○: peeled off slightly but sealing material cut, ○ to △: attached but peeled off at interface, △: slightly attached Is easily peeled off, x: not adhered at all.

(Example 1)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the terminal (“Exexa 2410” manufactured by Asahi Glass Co., Ltd.), 20 parts by weight of butyl rubber (“068” manufactured by JSR Co.) as a rubber component, plasticizer As a catalyst, 150 parts by weight of diisononyl phthalate ("DINP" manufactured by Diaeplus Co., Ltd.), 10 parts by weight of process oil ("Process Oil P-400" manufactured by Nippon Oil Corporation) and 200 parts by weight of filler, 1 part by weight of dibutyltin dilaurate as a catalyst Parts were blended to obtain a sealing material composition.

(Example 2)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the end (“MS Polymer S203” manufactured by Kaneka), polyisobutylene resin (“Tetrax PB6T” manufactured by ExxonMobil) as a rubber component 60 Parts by weight, 150 parts by weight of diisononyl phthalate as plasticizer ("DINP" manufactured by Diaeplus), 10 parts by weight of process oil ("Process Oil P-400" manufactured by Nippon Oil Corporation) and 200 parts by weight of filler, and dibutyl as a catalyst A sealant composition was prepared by blending 1 part by weight of tin dilaurate.

(Example 3)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the terminal (“Exestar 2410” manufactured by Asahi Glass Co., Ltd.), 30 parts by weight of polybutadiene rubber (“Ubepol BR150” manufactured by Ube Industries), UV absorber for rubber (“ANTAGE HP-100” manufactured by Kawaguchi Chemical Co., Ltd.) 0.1 part by weight, diisononyl phthalate (“DINP” manufactured by DIAPLUS) as plasticizer and 165 parts by weight filler, catalyst As a sealing material composition, 1 part by weight of dibutyltin dilaurate was added.

Example 4
A product obtained by adding a reaction equivalent to 100% of 3-hydroxypropyltriethoxysilane (“KBE9007” manufactured by Shin-Etsu Chemical Co., Ltd.) to the number of hydroxyl groups of an aliphatic polycarbonate having hydroxyl groups (“PCDL T5652” manufactured by Asahi Kasei Co., Ltd.) 100 Parts by weight, 30 parts by weight of a polyisobutylene resin (“Tetrax PB6T” manufactured by ExxonMobil) as a rubber component, 130 parts by weight of diisononyl phthalate (“DINP” manufactured by DIAPLUS) as a plasticizer, process oil (manufactured by Nippon Oil Corporation) “Process oil P-400”) and 10 parts by weight of filler and 200 parts by weight of filler were combined with 1 part by weight of dibutyltin dilaurate as a catalyst to obtain a sealant composition.

(Example 5)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the end (“MS polymer S203” manufactured by Kaneka), and recycled rubber (“recycled rubber during operation” manufactured by Ube Industries) 80 Parts by weight, ultraviolet absorber for rubber ("ANTAGE HP-100" manufactured by Kawaguchi Chemical Industry Co., Ltd.) 0.1 parts by weight, diisononyl phthalate ("DINP" manufactured by DIAPLUS) as plasticizer, process oil (new Nippon Oil Co., Ltd. “Process Oil P-400”) and 100 parts by weight of filler and 250 parts by weight of filler were combined with 1 part by weight of dibutyltin dilaurate as a catalyst to form a sealing material composition.

(Example 6)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the terminal ("Exstar 2410" manufactured by Asahi Glass Co., Ltd.), white recycled rubber ("DAINARC-NW" manufactured by Daiei Gokan Co., Ltd.) as a rubber component 30 Parts by weight, 0.1 parts by weight of an ultraviolet absorber for rubber (“ANTAGE HP-100” manufactured by Kawaguchi Chemical Industry Co., Ltd.), 30 parts by weight of diisononyl phthalate (“DINP” manufactured by DIAPLUS) as a plasticizer, process oil (new Nippon Oil Co., Ltd. “Process Oil P-400”) 100 parts by weight and 165 parts by weight of filler were combined with 1 part by weight of dibutyltin dilaurate as a catalyst to obtain a sealing material composition.

(Example 7)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the end (“MS polymer S203” manufactured by Kaneka), 60 parts by weight of butyl rubber (“butyl l365” manufactured by JSR) as a rubber component, plastic 150 parts by weight of diisononyl phthalate ("DINP" manufactured by Diaeplus Co., Ltd.) as an agent, 10 parts by weight of process oil ("Process Oil P-400" manufactured by Nippon Oil Corporation) and 200 parts by weight of a filler, dibutyltin dilaurate 1 as a catalyst A sealing material composition was prepared by blending parts by weight.

(Example 8)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group at the end ("Exstar 2410" manufactured by Asahi Glass Co., Ltd.), 30 parts by weight of polyisoprene rubber ("Nippol R2200L" manufactured by Nippon Zeon Co., Ltd.) Parts, 0.1 parts by weight of an ultraviolet absorber for rubber (“ANTAGE HP-100” manufactured by Kawaguchi Chemical Industry Co., Ltd.), 130 parts by weight of diisononyl phthalate (“DINP” manufactured by DIAPLUS) as a plasticizer, and 165 parts by weight of a filler. As a catalyst, 1 part by weight of dibutyltin dilaurate was blended to prepare a sealing material composition.

Example 9
A polymer consisting of an acrylic acid alkyl ester monomer and / or a methacrylic acid alkyl ester monomer in the main chain, as an oligomer having an alkoxysilyl group at the end, and having an acrylic main chain and a methoxysilyl group at the end 100 parts by weight of oligomer (“MS polymer S943” manufactured by Kaneka), 20 parts by weight of butyl rubber (“068” manufactured by JSR) as a rubber component, 150 parts by weight of diisononyl phthalate (“DINP” manufactured by DIAPLUS) as a plasticizer, process A sealant composition was prepared by blending 10 parts by weight of oil ("Process Oil P-400" manufactured by Nippon Oil Corporation) and 200 parts by weight of a filler with 1 part by weight of dibutyltin dilaurate as a catalyst.

(Comparative Example 1)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the end (MS polymer S203 manufactured by Kaneka), 100 parts by weight of diisononyl phthalate (DINP manufactured by DIAPLUS) as a plasticizer, 150 parts by weight of a filler, As a catalyst, 1 part by weight of dibutyltin dilaurate was blended to prepare a sealing material composition.

(Comparative Example 2)
100 parts by weight of main chain polyoxypropylene and terminal methoxysilyl structure oligomer (“MS Polymer S203” manufactured by Kaneka), 80 parts by weight of diisononyl phthalate (“DINP” manufactured by Diaeplus) as a plasticizer, process oil (Shin Nippon Oil Co., Ltd.) "Process oil P-400" manufactured by the company and 1 part by weight of dibutyltin dilaurate as a catalyst were blended with 20 parts by weight and 150 parts by weight of a filler to obtain a sealing material composition.

(Comparative Example 3)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group at the terminal (“MS Polymer S203” manufactured by Kaneka), and a molecular weight of 3000 as a high molecular weight plasticizer (“Exenol 3020” manufactured by Asahi Glass Co., Ltd.) ) 1 part by weight of dibutyltin dilaurate as a catalyst was blended with 100 parts by weight and 150 parts by weight of filler to obtain a sealing material composition.

(Comparative Example 4)
100 parts by weight of an oligomer having a polyoxypropylene in the main chain and having a methoxysilyl group structure at the terminal (“MS Polymer S203” manufactured by Kaneka), 150 parts by weight of a polybutadiene rubber (“Ubepol BR150” manufactured by Ube Industries) In addition, 100 parts by weight of diisononyl phthalate ("DINP" manufactured by Diaeplus) as a plasticizer, 150 parts by weight of process oil ("Process Oil P-400" manufactured by Nippon Oil Corporation) and 300 parts by weight of a filler, dibutyltin as a catalyst The part which mix | blended 1 weight of dilaurate and was set as the sealing material composition.

  Table 1 summarizes the main compositions of Examples 1 to 7 and Comparative Examples 1 to 4. The unit of numerical values is parts by weight.

(Comparative Example 5)
A polymer consisting of an acrylic acid alkyl ester monomer and / or a methacrylic acid alkyl ester monomer in the main chain, as an oligomer having an alkoxysilyl group at the end, and having an acrylic main chain and a methoxysilyl group at the end 100 parts by weight of an oligomer (“MS Polymer S943” manufactured by Kaneka), 100 parts by weight of diisononyl phthalate (DINP manufactured by DIAPLUS) as a plasticizer, 150 parts by weight of a filler, and 1 part by weight of dibutyltin dilaurate as a catalyst It was set as the composition.

Table 2 shows the evaluation results of Examples 1 to 8 and Comparative Examples 1 to 5.

Comparative Example 1 is a conventional type of modified silicone, which has problems to be improved by the present invention over all items.
Comparative Example 2 shows that even if a part of the plasticizer component is changed without adding a rubber component, the migration and the like cannot be improved.
Comparative Example 3 is a recent improved formulation for migration using high molecular weight plasticizers, but the effect is insufficient.
In Comparative Example 4, the amount of the rubber component added is excessive, so that a sufficient cured product is not obtained.
Comparative Example 5 is a conventional type highly weatherable modified silicone, which is excellent in weather resistance, but other items have problems to be improved.
It can be seen that all of the examples achieve the object of the present invention relative to these comparative examples.

Claims (6)

  A sealing material composition comprising an oligomer having an alkoxysilyl group at a terminal and a rubber component as essential components.   The sealing material composition according to claim 1, wherein the oligomer has a polyoxyolefin structure in a main chain, and the terminal alkoxysilyl group is a methoxysilyl group or an ethoxysilyl group.   The sealing material composition according to claim 2, wherein the polyoxyolefin of the main chain of the oligomer is polyoxypropylene.   2. The sealing material composition according to claim 1, wherein the oligomer is a polymer whose main chain is composed of an alkyl acrylate monomer and / or an alkyl methacrylate monomer. 3.   The sealing according to any one of claims 1 to 4, wherein the rubber component is butyl rubber, polyisobutylene rubber, polybutadiene rubber, polyisoprene rubber, styrene butadiene rubber, nitrile rubber, acrylic rubber, natural rubber, or recycled rubber thereof. Material composition.   The sealing material composition according to claim 5, wherein the rubber component is butyl rubber, polyisobutylene rubber, polybutadiene rubber, polyisoprene rubber, or recycled rubber thereof.