JP2003193033A - Sealing material composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sealing material composition having excellent storage stability and operating efficiency during application and capable of affording a cured product having good weather resistance and stain resistance. <P>SOLUTION: This sealing material composition comprises 100 pts.mass of a sealing base material having crosslinkable silyl groups and 1-100 pts.mass of a vinyl polymer having ≤10°C glass transition temperature, ≥500 and ≤10,000 weight-average molecular weight and ≤7,000 mPas viscosity at 25°C and containing 1-50 mass% of methacrylic ester units. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealant composition which is curable at room temperature, has high weather resistance, and has good adhesion to topcoat paints.

[0002]

2. Description of the Related Art Sealants are essential materials in the fields of construction and civil engineering. The components of the sealing material include
In addition to the sealing base material, a filler, a plasticizer, a curing accelerator, an antiaging agent, a thixotropic agent, etc. are usually added. Among them, the plasticizer is mainly added to improve workability, and phthalic acid esters such as dioctyl phthalate and diisononyl phthalate are usually used. Sealing materials based on modified silicones, which are now widely used, have mainly used phthalate ester plasticizers, but they do not have sufficient weather resistance. Also, there was a problem that the surface bleeds with the passage of time after construction, causing self-contamination and surrounding pollution.
In order to solve such a problem, a curable composition based on a modified silicone containing an acrylic acid ester polymer having a low glass transition temperature added as a plasticizer instead of the phthalic acid ester has recently been proposed. , And can be used as a sealing material (Japanese Patent Laid-Open No. 2001-2).
88374). However, the composition of the invention specifically described in the above-mentioned known documents may have an insufficient plasticizing effect, that is, the effect of improving the workability of using the composition, and the use conditions are limited. . Further, the composition may have a problem in storage stability. For example, when the composition was stored at room temperature in a state of being shielded from the air, the curing rate sometimes decreased after a long period of time.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealant composition which gives a cured product having excellent storage stability, workability during construction, and good weather resistance and stain resistance. is there.

[0004]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the sealing material composition according to the invention of claim 1 has 100 parts by mass of a sealing base material having a crosslinkable silyl group and a glass transition temperature of 10 ° C or less. , The weight average molecular weight is 500
Above 10000, viscosity at 25 ° C is 7,000 mP
a · s or less and 1 to 50 methacrylic acid ester units
It is characterized by containing 1 to 100 parts by mass of a vinyl polymer having a mass%. The sealant composition of the invention described in claim 2 is characterized in that, in the invention described in claim 1, the vinyl polymer is substantially free of a hydroxyl group. In the sealing material composition of the invention described in claim 3, in the invention described in any one of claims 1 to 2, the vinyl polymer is a copolymer of methacrylic acid ester and acrylic acid ester, and the methacrylic acid is The residue containing no hydroxyl group of the alcohol component constituting the ester and the ester of acrylic acid ester is a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The sealant composition of the present invention comprises:
100 parts by weight of a sealing base material having a crosslinkable silyl group, a glass transition temperature of 10 ° C. or lower, and a weight average molecular weight of 5
00 or more and 10000 or less, viscosity at 25 ° C is 700
0 mPa · s or less and 1 to 1 methacrylic acid ester unit
It contains 1 to 100 parts by mass of a vinyl polymer having 50% by mass.

As the sealing base material having a crosslinkable silyl group, known materials can be used. Specific examples of the crosslinkable silyl group include trimethoxysilyl group, dimethoxymethylsilyl group, dimethylmethoxysilyl group, triethoxysilyl group, diethoxymethylsilyl group, alkoxysilyl group such as dimethylethoxysilyl group, trichlorosilyl group and the like. And a silyl group to which the halogen of is bonded. Specific examples of the sealing base material having a crosslinkable silyl group include modified silicone and acryl silicone polymer. Modified silicone is a polymer having a structure having a crosslinkable silyl group at the molecular end of polyoxyalkylene. Examples of the polyoxyalkylene serving as the skeleton of the modified silicone include polyoxyethylene, polyoxypropylene, polyoxybutylene and the like, and polyoxypropylene is preferable. The acrylic silicon polymer has a structure obtained by copolymerizing a silane coupling agent such as γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyldimethoxymethylsilane and another acrylic acid ester. However, the present invention is not limited to these, and the structure of the main skeleton may be any as long as it has a crosslinkable silyl group in the molecule. Also, a mixture of these may be used.

A vinyl polymer having 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 7,000 mPa · s or less and 1 to 50% by mass of a methacrylic acid ester unit is a sealing material composition. Blended with the product, without impairing the storage stability of the composition,
Good workability of the composition, weather resistance of the cured product,
It is a component that makes the stain resistance excellent. Hereinafter, the polymer is also referred to as a plasticizing polymer.

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 by a differential scanning calorimeter. When the glass transition temperature is higher than 10 ° C, workability at low temperatures becomes poor.

The weight average molecular weight of the plasticizing polymer is measured by gel permeation chromatography (GPC) as a polystyrene conversion value. Its value is 50
0 or more and 10000 or less, preferably 700 or more 7
It is 000 or less. When the weight average molecular weight exceeds 10,000, sufficient plasticity cannot be obtained, and the workability of the obtained composition deteriorates. On the other hand, when it is less than 500, the low molecular weight polymer bleeds, so that the contamination of the obtained sealing material is deteriorated.

The plasticizing polymer has a viscosity of 7,000 mPa · S or less measured at 25 ° C. Preferably 5
It is below 000 mPa · S. If it is more than 7,000 mPa · S, the workability is significantly deteriorated.

The plasticizing polymer has 1 to 5 methacrylic acid ester units based on all the constituent monomer units of the polymer.
It is a vinyl polymer having 0% by mass. When the proportion of methacrylic acid ester units is less than 1% by mass, the sealing material composition has insufficient storage stability, and the sealing material stored for a long time has a delayed curing (the time required for curing becomes long). Is inevitable. When it is more than 50% by mass, the plasticizing polymer has a high viscosity, and therefore the sealing material composition has a high viscosity, which results in poor workability. A preferable ratio of the methacrylic acid ester unit is 5 to 40% by mass.
Is.

Examples of the methacrylic acid ester capable of introducing the methacrylic acid ester unit which is an essential constituent monomer unit of the plasticizing polymer include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and methacrylic acid. Cyclohexyl, methacrylic acid 2-
Examples include ethylhexyl and the like. One or more of these may be used. Those in which the residue not containing a hydroxyl group of the alcohol component constituting these methacrylic acid esters is a linear, branched or alicyclic alkyl group having 1 to 8 carbon atoms are preferred methacrylic acid esters. When the carbon number is larger than 8, the compatibility with the sealing base material becomes poor. Further, since the ester moiety is an inactive alkyl group, the compatibility is relatively good and does not adversely affect the curing reaction. Among them, more preferable methacrylic acid esters are methyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate.

Examples of constituent monomer units other than the methacrylic acid ester unit of the plasticizing polymer include an acrylic acid ester unit and other vinyl monomer units. Specific examples of the acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate,
Secondary acrylate acrylate, tertiary butyl acrylate, neopentyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate and the like can be mentioned. One or more of these may be used. The hydroxyl group-free residue of the alcohol component constituting these acrylic acid esters is a straight chain having 1 to 8 carbon atoms,
Those which are branched or alicyclic alkyl groups are preferred acrylic acid esters. When the carbon number is larger than 8, the compatibility with the sealing base material becomes poor. Further, since the ester moiety is an inactive alkyl group, the compatibility is relatively good and does not adversely affect the curing reaction. Among them, more preferable acrylic acid ester is ethyl acrylate, n-butyl acrylate, acrylic acid 2
-Ethylhexyl. Examples of the other vinyl monomer include styrene, α-methylstyrene, α-olefins, vinyl esters and vinyl ethers.

The plasticizing polymer preferably has substantially no hydroxyl group. When the plasticizing polymer has a hydroxyl group, the resulting sealant composition may have poor storage stability. Specifically, the sealing material composition after a long period of time after production,
It may take a long time to become tack-free after construction, that is, the curability may deteriorate.

The plasticizing polymer can be produced by a conventional radical polymerization. The radical polymerization initiator may or may not be used depending on the polymerization conditions. When a radical polymerization initiator is used, examples thereof include peroxides such as diisopropyl peroxydicarbonate, tert-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 1 total amount of the monomers to be used for the polymerization.
It is preferably 5 parts by mass or less, and more preferably 2 parts by mass or less, relative to 00 parts by mass. If the amount of the polymerization initiator used is too large, the weather resistance decreases. Also,
It is preferable not to use the chain transfer agent, because it leads to deterioration of weather resistance.

As the polymerization method, a usual method such as suspension polymerization in an aqueous medium, emulsion polymerization, solution polymerization in an organic solvent, or bulk polymerization can be adopted. 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, esters such as ethyl acetate and butyl acetate. Examples thereof include ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, and one or more of these can be used.

The polymerization conditions are such that the polymerization temperature is 20 to 30.
At 0 ° C., the pressure is normal pressure to 10 MPa, and in the case of pressurization, a pressure resistant autoclave can be 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.

The sealant composition of the present invention comprises 100 parts by weight of the above-mentioned sealing substrate and 1 to 10 polymers for plasticizing.
It contains 0 parts by mass. Sealing substrate 100
The ratio of the plasticizing polymer based on parts by mass is 5 to 100.
A mass part is more preferable, and 10-100 mass parts is still more preferable. When the amount is less than 1 part by mass, the effect as a plasticizer is insufficient, and the obtained sealing material composition has insufficient workability. Further, if the amount is more than 100 parts by mass, bleeding will occur on the surface of the applied sealing material, resulting in poor contamination.

The sealing material of the present invention may contain a curing accelerator and a filler as components other than the sealing base material and the 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 other organic tin compounds, octyl acid. Organic lead compounds such as lead, organic titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, other organic bismuth compounds, organic iron compounds, organic metal compounds such as organic cobalt compounds and organic zirconium compounds, triethylamine, N, N-dimethylcyclohexyl Amines, amine compounds such as 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 parts by mass to 10 parts by mass based on 100 parts by mass of the sealing base material. More preferably 0.2 to 7 parts by mass, still more preferably 0.
5 to 5 parts by mass. If the amount is less than 0.1 parts by mass, the curing will not be sufficient, and if it is more than 10 parts by mass, the weather resistance will be lowered, and the curing will be accelerated and the workability may be deteriorated.

The filler has an average particle size of 0.02 to 2.
Light calcium carbonate of about 0 μm, average particle size 1.0 ~
About 5.0 μm heavy calcium carbonate, titanium oxide, zinc oxide, carbon black, synthetic silicic acid, diatomaceous earth, silas balloon, glass fiber, talc, zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide and Examples include barium sulfate and the like.
The addition amount of the filler is preferably 10 to 300 parts by mass based on 100 parts by mass of the sealing base material. More preferably, it is 20 to 250 parts by mass.

Further, if necessary, an ultraviolet absorber such as a benzophenone compound, a benzotriazole compound and an oxalic acid anilide compound, a light stabilizer such as a hindered amine compound, an antioxidant such as a hindered phenol compound, hydrogenated castor oil, etc. Anti-sagging agent, vinyltrimethoxysilane, trimethoxymethylsilane, dimethoxydimethylsilane, dehydrating agents such as methyl orthoformate and methyl orthoacetate, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N
Such as-(2-aminoethyl) 3-aminopropyltrimethoxysilane, methylisobutylketoiminopropyltriethoxysilane, 3-glydoxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane and 3-ureidopropyltriethoxysilane. An adhesion enhancer, a colorant and an organic solvent may be added.

It is also possible to add anti-tack agents. Specifically, Aronix M6100, M7100,
M8060, M8100 (both are polyester acrylate manufactured by Toagosei Co., Ltd.) and photocurable compounds represented by polyfunctional acrylic oligomers such as trimethylolpropane, and air-curable compounds such as tung oil, linseed oil, polybutadiene and unsaturated polyester. Can be mentioned. These anti-tack agents may be used in combination. A polyfunctional acrylic oligomer is preferable because it has an excellent anti-tack effect, and when a polyfunctional acrylic oligomer is used, it is more effective to use a photoinitiator together. Hereinafter, the present invention will be specifically described with reference to examples.

[0023]

Examples <Types of Plasticizers and Blends of Sealant Compositions> Table 1 shows the blends of the sealant compositions of Examples and Comparative Examples. The quantity in the table showing the mixing ratio means parts by mass. The following were used as the sealing base material. 1. Substrate A (modified silicone-based sealing substrate) MS Polymer S-203 (manufactured by Kanegafuchi Chemical Co., Ltd.) 1. Substrate B (Acrylic silicon-based sealing substrate) A polymer (number average molecular weight 12000) of butyl acrylate / methyldimethoxysilylpropyl methacrylate = 96/4 (mass ratio) and S-203 were mixed at a ratio of 2: 8. Mixture

[0024]

[Table 1]

Table 2 shows the compositions and physical properties of the plasticizers 1 to 5 (polymers for plasticization) used in the formulation of the examples and included in the technical scope of the present invention.

[0026]

[Table 2]

Table 2 shows the composition and physical properties of the plasticizers 6 to 8 used in the formulations of Comparative Examples 1 to 4 and not included in the technical scope of the present invention. In Comparative Examples 5 to 8, dioctyl phthalate (hereinafter referred to as DOP) was used as a plasticizer not included in the technical scope of the present invention, and polypropylene glycol having a weight average molecular weight of 4000 and a methoxy group at the terminal (hereinafter, referred to as
It is called terminal methoxy PPG. ), And ARUFON
UH2000 (manufactured by Toagosei Co., Ltd., weight average molecular weight M
A hydroxyl group-containing acrylic polymer having a w = 13,000 (having no methacrylic acid ester unit) and a hydroxyl value of 2
0, viscosity 14000 mPa · s) was used.

<Evaluation> Extrudability test An extrudability test of the above-mentioned compound was carried out based on JIS A-1439. The shorter the required time, the better the workability.・ Tack-free test initial (immediately after compounding) and one stored at 50 ° C for 1 month, tack-free test based on JIS A-1439 (measurement of time required to be recognized as tack-free by touch) I went. The longer the tack-free time after storage at 50 ° C. for 1 month, the worse the storage stability.・ Stain resistance test A test sample made from a composition immediately after being compounded was subjected to indoor curing for 1 week, and then subjected to outdoor exposure for 6 months in Funami Town, Nagoya City, and the degree of dirt was visually evaluated according to the following criteria. did. ◯: Almost no dust adhered. △ A small amount of dust adhered. X: A lot of dust adhered. -Accelerated weather resistance test For the accelerated weather resistance test, the sample was attached to a holder described in JIS 1439, and the surface condition after being put in a sunshine weatherometer (manufactured by Suga Test Instruments) for 1000 hours was observed, and the following criteria were used. evaluated. ◯: There was no crack. △ There was a slight crack. X: There was a clear crack. The results are shown in Table 3.

[0029]

[Table 3]

[0030]

EFFECT OF THE INVENTION A sealant composition which is excellent in storage stability, workability during construction, and has a weather resistance and a stain resistance, which gives a cured product, is obtained. Further, the composition of the present invention can be suitably used as an adhesive, a paint, etc., as an application other than the sealing material.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Inukai             1 East of Funami-cho, Minato-ku, Nagoya City, Aichi Prefecture             Inside Agosei Co., Ltd. F-term (reference) 4H017 AB01 AB15 AC11 AE03

Claims (3)

[Claims] 1. A methacrylic acid ester unit having 100 parts by mass of a sealing base material having a crosslinkable silyl group, a glass transition temperature of 10 ° C. or less, a weight average molecular weight of 500 to 10,000 and a viscosity at 25 ° C. of 7,000 mPa · s or less. 1 to 10 having 1 to 50 mass% of
A sealing material composition containing 0 part by mass. 2. The sealing material composition according to claim 1, wherein the vinyl polymer is substantially free of hydroxyl groups. 3. The vinyl polymer is a copolymer of methacrylic acid ester and acrylic acid ester, and the residue not containing a hydroxyl group of the alcohol component constituting the methacrylic acid ester and acrylic acid ester has 1 carbon atoms. The sealing material composition according to any one of claims 1 to 2, which is a linear, branched or alicyclic alkyl group of -8.