JP4178791B2 - Sealant composition - Google Patents

Description

【００２５】
実施例の配合に使用された本発明の技術的範囲に含まれる可塑剤１〜５（可塑化用重合体）の組成および物性値を表２に示す。
【００２６】
【表２】

【００２７】
比較例１〜４の配合に使用された本発明の技術的範囲に含まれない可塑剤６〜８の組成および物性値を表２に示す。
比較例５〜８では、本発明の技術的範囲に含まれない可塑剤としてジオクチルフタレート（以下、ＤＯＰという。）、重量平均分子量４０００の末端がメトキシ基であるポリプロピレングリコール（以下、末端メトキシＰＰＧという。）、およびＡＲＵＦＯＮ ＵＨ２０００（東亞合成株式会社製、重量平均分子量Ｍｗ＝１３０００の水酸基含有アクリル重合体（メタクリル酸エステル単位を有していない。）、水酸基価は２０、粘度１４０００ｍＰａ・ｓ）が使用された。
【００２８】
＜評価＞
・押し出し性試験
ＪＩＳ・Ａ−１４３９に基づいて、上記配合物の押し出し性試験を行った。所要時間が短いほど作業性が良好であることを意味する。
・タックフリー試験
初期（配合直後）と、５０℃で１ヶ月間貯蔵したものについて、ＪＩＳ・Ａ−１４３９に基づいて、タックフリー試験（指触によりタックフリーと認められるまでに要する時間を測定）を行った。５０℃で１ヶ月間貯蔵後のタックフリーに要する時間が長いものほど貯蔵安定性が悪いことを意味する。
・耐汚染性試験
配合直後の組成物から作成された試験体は１週間の室内の養生の後、名古屋市船見町で６ヶ月の屋外曝露を行い、汚れ具合を目視により次の判定基準で評価した。
○：塵埃の付着がほとんどなかった。
△塵埃が少し付着した。
×：塵埃がかなり付着した。
・促進耐候性試験
促進耐候性試験については、試料をＪＩＳ・１４３９記載のホルダーに取り付け、サンシャインウェザオメータ（スガ試験機製）に１０００時間入れた後の表面状態を観察し、次の判定基準で評価した。
○：クラックがなかった。
△僅かにクラックがあった。
×：はっきりとしたクラックがあった。
これらの結果を表３に示す。
【００２９】
【表３】

【００３０】
【発明の効果】
貯蔵安定性、施工時の作業性に優れ、良好な耐候性、耐汚染性を有する硬化物を与えるシーリング材組成物が得られた。
また、本発明の組成物は、シーリング材以外の用途として、接着剤、塗料などにも好適に利用することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing material composition that can be cured at room temperature, has high weather resistance, and has good adhesion to a top coating.
[0002]
[Prior art]
Sealing materials are indispensable materials in the fields of architecture and civil engineering. In addition to the sealing substrate, a filler, a plasticizer, a curing accelerator, an antiaging agent, a thixotropic agent, and the like are usually added to the components of the sealing material. Among these, a plasticizer is mainly added to improve workability, and phthalic acid esters such as dioctyl phthalate and diisononyl phthalate are usually used. Phthalic acid ester plasticizers have been mainly used so far for sealing materials based on modified silicone, which are now widely used, but they do not have sufficient weather resistance. Also, after years of construction, there was a problem of bleeding on the surface, self-contamination and surrounding contamination. In order to solve such a problem, a curable composition based on a modified silicone in which an acrylic ester polymer having a low glass transition temperature is added as a plasticizer instead of the phthalate ester has been recently proposed. It is known that it can be used as a sealing material (Japanese Patent Laid-Open No. 2001-288374).
However, the composition of the invention specifically described in the above-mentioned known literature may have insufficient plasticizing effect, that is, workability improvement effect using the composition, and usage conditions are limited. . In addition, the composition may have a problem in storage stability. For example, when the composition is stored in a state of being shielded from the atmosphere at room temperature, the curing rate may decrease after a long period of time.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a sealant composition that is excellent in storage stability and workability during construction, and provides a cured product having good weather resistance and stain resistance.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the sealing material composition of the invention according to claim 1 has 100 parts by mass of a sealing substrate having a crosslinkable silyl group, a glass transition temperature of 10 ° C. or less, and a weight average molecular weight of 500 to 10,000. Hereinafter, the viscosity at 25 ° C. is 7000 mPa · s or less, and the alcohol component constituting the ester is a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms (provided that the alkyl group is composed only of carbon and hydrogen. A copolymer of methacrylic acid ester and acrylic acid ester having 1 to 50 parts by weight of a vinyl polymer having 1 to 50% by weight of the methacrylic acid ester unit. . The sealing material composition of the invention described in claim 2 is the modified silicone or / and acrylic silicone polymer in the invention described in claim 1 , wherein the vinyl polymer is methyl methacrylate, n-butyl methacrylate and methacrylic acid. It is a copolymer of at least one methacrylic acid ester selected from 2-ethylhexyl acid and at least one acrylate ester selected from ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate. It is a feature. According to a third aspect of the present invention, there is provided the sealing material composition according to the first or second aspect, wherein the vinyl polymer is a copolymer of a methacrylic acid ester and an acrylic acid ester, and the methacrylic acid ester. The unit ratio is 5 to 40% by mass .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The sealing material composition of the present invention has 100 parts by mass of a sealing substrate having a crosslinkable silyl group, a glass transition temperature of 10 ° C. or less, a weight average molecular weight of 500 or more and 10,000 or less, and a viscosity at 25 ° C. of 7000 mPa · s or less. It contains 1 to 100 parts by weight of a vinyl polymer having 1 to 50% by weight of methacrylic acid ester units.
[0006]
A well-known thing can be used as a sealing base material which has a crosslinkable silyl group. Specific examples of the crosslinkable silyl group include trimethoxysilyl group, dimethoxymethylsilyl group, dimethylmethoxysilyl group, triethoxysilyl group, diethoxymethylsilyl group, dimethylethoxysilyl group and other alkoxysilyl groups, trichlorosilyl group, etc. And a silyl group having a halogen bonded thereto.
Specific examples of the sealing substrate having a crosslinkable silyl group include a modified silicone and an acrylic silicon polymer. The modified silicone is a polymer having a structure having a crosslinkable silyl group at the molecular terminal of polyoxyalkylene. Examples of the polyoxyalkylene that becomes the skeleton of the modified silicone include polyoxyethylene, polyoxypropylene, and polyoxybutylene, and polyoxypropylene is preferable. The acrylic silicon polymer has a structure obtained by copolymerizing a silane coupling agent such as γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyldimethoxymethylsilane, and other acrylate esters. However, the present invention is not limited to these, and the structure of the main skeleton may be used as long as it has a crosslinkable silyl group in the molecule. A mixture of these may also be used.
[0007]
The glass transition temperature is 10 ° C. or less, the weight average molecular weight is 500 or more and 10,000 or less, the viscosity at 25 ° C. is 7000 mPa · s or less , and the alcohol component constituting the ester is linear or branched having 1 to 8 carbon atoms. A copolymer of a methacrylic acid ester and an acrylic acid ester having an alicyclic alkyl group (wherein the alkyl group is composed of only carbon and hydrogen), and a vinyl polymer having 1 to 50% by mass of the methacrylic acid ester unit Is a component that is blended in the sealant composition and does not impair the storage stability of the composition, improves the handling workability of the composition, and improves the weather resistance and stain resistance of the cured product. Hereinafter, the polymer is also referred to as a plasticizing polymer.
[0008]
The plasticizing polymer of the present invention has a glass transition temperature of 10 ° C. or lower, preferably 0 ° C. or lower, more preferably −10 ° C. or lower. The glass transition temperature is measured by the midpoint of the endothermic peak detected in a differential scanning calorimeter. When the glass transition temperature is higher than 10 ° C., workability at low temperatures is deteriorated.
[0009]
The weight average molecular weight of the plasticizing polymer is measured by gel permeation chromatography (GPC) as a value in terms of polystyrene. The value is 500 or more and 10,000 or less, preferably 700 or more and 7,000 or less. When the weight average molecular weight exceeds 10,000, sufficient plasticity cannot be obtained, and workability of the resulting composition is deteriorated. On the other hand, if it is less than 500, the low-molecular polymer bleeds, so that the resulting sealing material is less contaminated.
[0010]
The plasticizing polymer has a viscosity measured at 25 ° C. of 7000 mPa · S or less. Preferably, it is 5000 mPa · S or less. When it is larger than 7000 mPa · S, workability is remarkably deteriorated.
[0011]
The polymer for plasticization is a vinyl polymer having 1 to 50% by mass of methacrylic acid ester units based on all the constituent monomer units of the polymer. When the proportion of the methacrylic acid ester unit is less than 1% by mass, the sealing material composition is insufficient in storage stability, and the sealing material stored for a long period of time is delayed in curing (the time required for curing becomes longer). Is inevitable. When it is larger than 50% by mass, the plasticizing polymer has a high viscosity, and therefore the sealing material composition has a high viscosity, so that workability is poor. A desirable ratio of the methacrylic acid ester unit is 5 to 40% by mass.
[0012]
Examples of the methacrylic acid ester capable of introducing a methacrylic acid ester unit which is an essential constituent monomer unit of a plasticizing polymer include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, methacrylic acid. Acid 2-ethylhexyl etc. are mentioned. One or two or more of these may be used. The alcohol component constituting these methacrylic acid esters does not contain a hydroxyl group, consists only of carbon and hydrogen, and the residue is a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms. When the number of carbon atoms is larger than 8, the compatibility with the sealing substrate is deteriorated. Further, since the ester moiety is an inactive alkyl group, the compatibility is relatively good and does not adversely affect the curing reaction. Among these, more preferred methacrylic acid esters are methyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate.
[0013]
As a constituent monomer unit other than the methacrylic ester unit of the plasticizing polymer, an acrylate unit is essential. Specific examples of acrylate esters include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, secondary butyl acrylate, tertiary butyl acrylate, neopentyl acrylate, acrylic acid Examples include 2-ethylhexyl and cyclohexyl acrylate. One or more of these are used . The alcohol component constituting these acrylate esters does not contain a hydroxyl group, consists only of carbon and hydrogen, and the residue is a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms. When the number of carbon atoms is larger than 8, the compatibility with the sealing substrate is deteriorated. Further, since the ester moiety is an inactive alkyl group, the compatibility is relatively good and does not adversely affect the curing reaction. Among these, more preferable acrylic acid esters are ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate . Other vinyl monomers may also be used, and examples of such monomers include styrene, α-methylstyrene, α-olefins, vinyl esters and vinyl ethers.
[0014]
The plasticizing polymer must be substantially free of hydroxyl groups . When the plasticizing polymer has a hydroxyl group, the resulting sealing material composition may have poor storage stability. Specifically, the sealing material composition that has passed for a long time after the production may have a longer time required to become tack-free after construction, that is, the curability may be deteriorated.
[0015]
The plasticizing polymer can be produced by ordinary radical polymerization.
Depending on the polymerization conditions, a radical polymerization initiator may or may not be used. Examples of radical polymerization initiators that may be used include peroxides such as diisopropyl peroxydicarbonate, tertiary butyl peroxypivalate, benzoyl peroxide, lauroyl peroxide and ditertiary butyl peroxide, or azo Examples thereof include azo compounds such as bisisobutyronitrile and azobisisovaleronitrile, and inorganic peroxides such as ammonium persulfate and potassium persulfate. The amount of the polymerization initiator used is preferably 5 parts by mass or less, and more preferably 2 parts by mass or less, based on 100 parts by mass of the total amount of monomers to be subjected to polymerization. When there is too much usage-amount of a polymerization initiator, a weather resistance will fall. Moreover, it is preferable not to use a chain transfer agent because it leads to a decrease in weather resistance.
[0016]
As the polymerization method, a usual method such as suspension polymerization or emulsion polymerization in an aqueous medium, solution polymerization in an organic solvent, or bulk polymerization can be employed.
In the case of solution polymerization, the organic solvent may be one usually used as a solvent, for example, cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, and esters such as ethyl acetate and butyl acetate. , Ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, etc., and one or more of these can be used.
[0017]
As polymerization conditions, the polymerization temperature is 20 to 300 ° C., the pressure is normal pressure to 10 MPa, and in the case of pressurization, a pressure resistant autoclave is used and the reaction time can be 5 minutes to 20 hours. The polymerization method may be batch polymerization, semi-continuous polymerization, or continuous polymerization.
[0018]
The sealing material composition of the present invention contains 100 parts by mass of the above-mentioned sealing substrate and 1-100 parts by mass of the plasticizing polymer. The ratio of the plasticizing polymer based on 100 parts by mass of the sealing substrate is more preferably 5 to 100 parts by mass, and still more preferably 10 to 100 parts by mass. When the amount is less than 1 part by mass, the effect as a plasticizer is insufficient, and the resulting sealing material composition has insufficient workability. On the other hand, when the amount is more than 100 parts by mass, bleeding occurs on the surface of the applied sealing material, resulting in poor contamination.
[0019]
The sealing material of the present invention may be one in which a curing accelerator and a filler are blended as components other than the above-mentioned sealing substrate and plasticizing polymer.
Examples of the curing accelerator include dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dibutyltin diacetate, dibutyltin diacetylacetonate, tin octylate and dioctyltin dimaleate, and octylic acid. Organic lead compounds such as lead, organic titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, other organic metal compounds such as organic bismuth compounds, organic iron compounds, organic cobalt compounds and organic zirconium compounds, triethylamine, N, N-dimethylcyclohexyl Amine compounds such as amines, N, N, N′N′-tetramethylethylenediamine, N, N′-dimethylpiperazine diazabicyclooctane and diazabicycloundecene, and - the like organic acid compounds such as toluene sulfonic acid are exemplified, organotin compounds are preferable from the surface of the curing rate.
The addition amount is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the sealing substrate. More preferably, it is 0.2-7 mass parts, More preferably, it is 0.5-5 mass parts. When the amount is less than 0.1 parts by mass, curing is not sufficient, and when the amount is more than 10 parts by mass, the weather resistance is lowered, the curing is accelerated, and workability may be deteriorated.
[0020]
Examples of the filler include light calcium carbonate having an average particle size of about 0.02 to 2.0 μm, heavy calcium carbonate having an average particle size of about 1.0 to 5.0 μm, titanium oxide, zinc oxide, carbon black, and synthetic silicic acid. And diatomaceous earth, shirasu balloon, glass fiber, talc, zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide and barium sulfate. The added amount of the filler is preferably 10 to 300 parts by mass based on 100 parts by mass of the sealing substrate. More preferably, it is 20-250 mass parts.
[0021]
Furthermore, if necessary, UV absorbers such as benzophenone compounds, benzotriazole compounds and oxalic acid anilide compounds, light stabilizers such as hindered amine compounds, antioxidants such as hindered phenol compounds, and dripping prevention such as hydrogenated castor oil Agents, dehydrating agents such as vinyltrimethoxysilane, trimethoxymethylsilane, dimethoxydimethylsilane, methyl orthoformate and methyl orthoacetate, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-amino) Ethyl) 3-aminopropyltrimethoxysilane, methylisobutylketoiminopropyltriethoxysilane, 3-gridoxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane and 3-ureidopropylto Adhesion enhancer such as silane, coloring agents and organic solvents may be added.
[0022]
It is also possible to add an anti-tack agent. Specifically, photocurable compounds represented by Aronix M6100, M7100, M8060, M8100 (all of which are polyester acrylates manufactured by Toagosei Co., Ltd.) and trifunctional acrylic oligomers such as trimethylolpropane, tung oil, linseed oil, polybutadiene and Air-curable compounds such as saturated polyesters can be mentioned. These tack prevention agents may be used in combination. A polyfunctional acrylic oligomer is preferable because it has an excellent anti-tacking effect, and when a polyfunctional acrylic oligomer is used, it is more effective to use a photoinitiator in combination.
Hereinafter, an example is given and it demonstrates concretely.
[0023]
【Example】
<Plasticizer type and composition of sealing material composition>
Table 1 shows the composition of the sealing material compositions of Examples and Comparative Examples. The quantity in the table | surface which shows a mixture ratio means a mass part. What was used as a sealing base material is as follows.
1. Base material A (modified silicone sealing base material)
MS polymer S-203 (manufactured by Kaneka Chemical)
2. Base material B (acrylic silicone sealing base material)
Mixture of butyl acrylate / methyl dimethoxysilylpropyl methacrylate = 96/4 (mass ratio) polymer (number average molecular weight 12000) and S-203 mixed at a ratio of 2: 8.
[Table 1]

[0025]
Table 2 shows the composition and physical property values of plasticizers 1 to 5 (plasticizing polymer) included in the technical scope of the present invention used in the blending of the examples.
[0026]
[Table 2]

[0027]
Table 2 shows the compositions and physical property values of the plasticizers 6 to 8 not included in the technical scope of the present invention used in the blending of Comparative Examples 1 to 4.
In Comparative Examples 5 to 8, dioctyl phthalate (hereinafter referred to as DOP) as a plasticizer not included in the technical scope of the present invention, polypropylene glycol having a weight average molecular weight of 4000 and a terminal having a methoxy group (hereinafter referred to as terminal methoxy PPG) ), And ARUFON UH2000 (manufactured by Toagosei Co., Ltd., a hydroxyl group-containing acrylic polymer having a weight average molecular weight Mw = 13000 (having no methacrylic acid ester unit), a hydroxyl value of 20, and a viscosity of 14,000 mPa · s) are used. It was done.
[0028]
<Evaluation>
-Extrudability test The extrudability test of the said formulation was done based on JIS * A-1439. The shorter the required time, the better the workability.
・ Tack free test early (immediately after compounding) and those stored for 1 month at 50 ° C., tack free test based on JIS A-1439 (measure the time required to be recognized as tack free by finger touch) Went. A longer time required for tack-free after storage at 50 ° C. for one month means that the storage stability is worse.
-Specimens made from a composition immediately after mixing with a stain resistance test are exposed for 6 months outdoors in Funami-cho, Nagoya after one-week indoor curing, and the degree of contamination is evaluated visually according to the following criteria. did.
○: There was almost no dust adhesion.
Δ A little dust adhered.
X: Dust adhered considerably.
-Accelerated weather resistance test For the accelerated weather resistance test, the sample was mounted on the holder described in JIS 1439, and the surface condition after 1000 hours in a sunshine weatherometer (manufactured by Suga Test Instruments) was observed. evaluated.
○: There was no crack.
ΔSlightly cracked.
X: There was a clear crack.
These results are shown in Table 3.
[0029]
[Table 3]

[0030]
【The invention's effect】
A sealing material composition was obtained that gave a cured product having excellent storage stability and workability during construction, and good weather resistance and stain resistance.
Moreover, the composition of this invention can be utilized suitably also for an adhesive agent, a coating material, etc. as uses other than a sealing material.

Claims (3)

100 parts by mass of a sealing substrate having a crosslinkable silyl group, a glass transition temperature of 10 ° C. or less, a weight average molecular weight of 500 or more and 10,000 or less, a viscosity at 25 ° C. of 7000 mPa · s or less, and an alcohol component constituting the ester A copolymer of a methacrylic acid ester and an acrylate ester having a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms (wherein the alkyl group comprises only carbon and hydrogen), The sealing material composition containing 1-100 mass parts of vinyl polymers which have 1-50 mass% of acid ester units. The sealing substrate having a crosslinkable silyl group is a modified silicone or / and acrylic silicone polymer, and the vinyl polymer is one or more selected from methyl methacrylate, n-butyl methacrylate and 2-ethylhexyl methacrylate. The sealing material composition according to claim 1, which is a copolymer of methacrylic acid ester and at least one acrylic acid ester selected from ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate. The sealing material composition according to claim 1 or 2, wherein the ratio of the methacrylic acid ester unit of the vinyl polymer is 5 to 40% by mass.