JP2001354846A - Moisture-curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture-curing composition capable of holding a low modulus and a high extension and improved in weather resistance. SOLUTION: This moisture-curing composition is characterized by compounding a solventless type acrylic polymer which is liquid at normal temperatures and obtained by carrying out continuous bulk polymerization of a modified silicone polymer and an alkoxysilyl group-containing acrylic polymer as principal components at a high temperature under a high pressure and has no functional group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a moisture-curable composition,
More particularly, the present invention relates to a moisture-curable composition having low modulus and high elongation and improved weather resistance, and particularly useful as a building sealing material.

[0002]

2. Description of the Related Art Moisture-curable compositions mainly composed of modified silicone polymers and alkoxysilyl group-containing acrylic polymers are used as various sealing materials, for example, window glass sealing materials in automobile assembly lines. Things are used. When applying this composition to architectural sealing materials, in order to impart low modulus and high elongation, plasticizers generally used frequently in modified silicone-based sealing materials, for example, dioctyl phthalate (DOP), diisononyl phthalate (DIN)
Compounding of P), alkylbenzene, PPG and the like was required. However, in the latter half to one year of the sealing work, the weather resistance is reduced, and a whitening phenomenon occurs particularly in a thin layer portion, which is a fatal defect in design.

[0003]

Means for Solving the Problems Accordingly, the present inventors have:
Upon applying the moisture-curable composition to a building sealing material, the keen study was conducted to improve weather resistance while maintaining low modulus and high elongation.Instead of replacing the above-mentioned plasticizer or a part thereof, It has been found that the incorporation of a specific liquid-temperature acrylic polymer compatible with the above modified silicone polymer significantly improves the intended weather resistance, thereby completing the present invention.

That is, the present invention relates to a moisture-curable composition comprising a modified silicone polymer and an alkoxysilyl group-containing acrylic polymer as main components, which has a functional group which is obtained by continuous bulk polymerization at high temperature and high pressure and is in a liquid state at room temperature. The present invention provides a moisture-curable composition characterized by containing a solventless acrylic polymer.

[0005] The modified silicone polymer used in the present invention is a polyoxyalkylene ether having a main chain skeleton and having a hydrolyzable group (for example, a hydroxyl group,
A liquid polymer having a silyl group or a silanol group having a halogen group, an alkoxy group, a mercapto group, etc. is referred to, and among them, a polymer having a polyoxypropylene ether as a main chain and a molecular weight of 8,000 to 15,000 is preferable.

The alkoxysilyl group-containing acrylic polymer (hereinafter simply referred to as silyl group-containing polymer) used in the present invention includes, for example, (i) Japanese Patent Publication No. 3-80829.
(A) Acrylic acid alkyl ester (preferably having 2 to 4 carbon atoms) (e.g., ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate) , Cyclohexyl acrylate, n-octyl acrylate, etc.) and (b) vinylalkoxysilane (for example, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinyldimethylmethoxysilane, etc.) and (meth) acryloxyalkoxysilane ( For example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, etc.) and one or more mixtures selected from the group consisting of: In the presence of mercaptoalkoxylan (c) (eg, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc.) as a chain transfer agent, radical copolymerization [usually, α, α′-azobisisobutyro] Nitrile (AIB
N), known methods such as bulk polymerization and solution polymerization using a polymerization initiator such as α, α′-azobisisovaleronitrile, benzoyl peroxide, and methyl ethyl ketone peroxide;
Or a redox catalyst, for example, a redox polymerization method in which a transition metal salt, an amine or the like is combined with a peroxide initiator] (usually, an average molecular weight of 3,000 to 100,000, and an average alkoxysilyl in one molecule). (Radix 1.5-3); and (ii) Tokuho 4
-69667, vinyl monomers [e.g., acrylates such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, propyl acrylate, pentyl acrylate, and stearyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate; Methacrylates such as lauryl methacrylate, benzyl methacrylate, cyclohexyl methacrylate; styrene or derivatives thereof (α-methylstyrene, chloromethylstyrene, etc.); fumaric acid diesters such as diethyl fumarate, dibutyl fumarate, dipropyl fumarate; vinyl chloride, vinylidene chloride , Ethylene fluoride, vinylidene fluoride, vinyl halide such as vinylene fluoride Etc.] 100 parts (parts by weight, hereinafter the same)
In addition, an alkoxysilyl group-containing disulfide compound [eg, bis (trimethoxysilylmethyl) disulfide,
Bis (triethoxysilylmethyl) disulfide, bis (trimethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) disulfide, bis (methyldimethoxysilylmethyl) disulfide, bis (methyldiethoxysilylmethyl) disulfide, bis (propyldimethoxy) Silylmethyl) disulfide, bis (propyldiethoxysilylmethyl) disulfide,
Bis (dimethylmethoxysilylpropyl) disulfide, bis (dimethylethoxysilylpropyl) disulfide, etc.] in an amount of 0.05 to 50 parts, and if necessary, in an organic solvent (toluene, xylene, hexane, ethyl acetate, dioctyl phthalate, etc.). Photopolymerization (room temperature to 50-6
(Light irradiation at 0 ° C. for 4 to 30 hours).

[0007] The amount of the silyl group-containing polymer to be used is usually selected so that the weight ratio of the modified silicone polymer to the silyl group-containing polymer is 1/1 to 1/9.
When the ratio of the silyl group-containing polymer is below the lower limit,
When the weather resistance of the thin film decreases, and when the upper limit is exceeded, the modulus tends to be high and the elongation tends to be low. The silyl group-containing polymer is produced by the above-mentioned polymerization methods (i) and (ii), and the polymerization is preferably carried out in a modified silicone polymer, which is advantageous in terms of compatibility.

The non-solvent type acrylic polymer used in the present invention uses an acrylic monomer having no functional group [for example, acrylate or methacrylate as used in the above-mentioned method (ii) for polymerizing a silyl group-containing polymer]. It can be produced in a very short reaction time (about 5 minutes) by continuous bulk polymerization at a high temperature and high pressure of around 400 ° C. (very little or no initiator, no chain transfer agent required), 100% polymer and low Presents a liquid at room temperature of Tg,
And good compatibility with the modified silicone polymer (∵
Composition distribution and molecular weight distribution are narrow), giving excellent weather resistance. On the other hand, an acrylic polymer obtained by general solution polymerization is a 30 to 60% polymer and has a wide composition distribution and molecular weight distribution, so that the compatibility with the modified silicone polymer is poor, and a desired weather resistance may be obtained. Can not. further,
A polymer using an acrylic monomer having a functional group, for example, acrylic acid, methacrylic acid (COOH) or 2-hydroxyethyl acrylate (OH) is not preferable because of poor compatibility.

The amount of the solventless acrylic polymer used is usually such that the weight ratio of the modified silicone polymer to the solventless acrylic polymer is 1/5 to 5/1, preferably 1/5.
What is necessary is just to select so that it may become 1-5 / 1. If the ratio of the solvent-free acrylic polymer is below the above lower limit, high modulus and low elongation will result, and if it exceeds the above upper limit, the compatibility will deteriorate and the thin film weather resistance will tend to decrease.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The moisture-curable composition according to the present invention comprises a modified silicone polymer and a silyl group-containing polymer in the above-mentioned predetermined proportions as main components and a predetermined amount of a solventless acrylic polymer. Are the usual components, such as fillers (heavy calcium carbonate, calcium carbonate treated with fatty acids, fumed silica, precipitated silica, carbon black, talc, titanium oxide, etc.), adhesives (epoxy compounds, silane coupling agents, etc.), Anti-aging agents (hindered phenols, mercaptans, sulfides,
Dithiocarboxylates, thioureas, thiophosphates, thioaldehydes), thixotropic agents, water preservatives (water, inorganic salt hydrates, etc.), solvents, ultraviolet absorbers (hindered amines, benzotriazole) Kind),
An ozone deterioration inhibitor, a light stabilizer, a toner and the like can be blended in an appropriate amount range.

[0011]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Examples 1 to 4 and Comparative Examples 1 and 2 (1) Moisture-curable composition A moisture-curable composition (sealing material) is prepared by blending each component in the number shown in Table 1 below. (2) Performance test (results are shown in Table 2 below) i) Physical properties of dumbbell Curing condition of sealing material: 7 days at 20 ° C and 35 days
JIS K625 using 7 days at 90 ° C and 90% relative humidity
1, No. 3 shape, thickness 2 mm, tensile speed 2
It is performed at 00 mm / min. ii) Weather resistance A sealing material is cast on a flexible board to a thickness of 0.2 mm, and is heated at 20 ° C. for 7 days and at 35 ° C. and 95% relative humidity.
After curing for 7 days in the sunshine weather meter (black panel temperature 63 ° C, rainfall time 18 minutes out of 120 minutes)
, And the whitening of the surface of the sealing material with time (whether the finger is white or not) is examined, and the time (h) until the finger becomes white is defined as the end time.

[0012]

[Table 1]

In Table 1, Note 1) "S-203" manufactured by Kanegafuchi Chemical Industry Co., Ltd. Note 2) "MSX-911" manufactured by Kanegafuchi Chemical Industry Co., Ltd. Note 3) Made by Toa Gosei Co., Ltd. , “UP-1000” (66
0 mPa · s / 25 ° C., molecular weight 3000, Tg-55
° C) Note 4) “Alken 100P” manufactured by Nippon Oil Co., Ltd. Note 5) No. 1: “AO-50” manufactured by Asahi Denka Kogyo Co., Ltd. 2: “LA-62” No. 3: LA-32 Note 6) No. 1: Vinyl triethoxysilane manufactured by Chisso Corporation, “Sila Ace S-220” No. 1 2: Vinyl trimethoxysilane manufactured by the same company,
"Sila Ace S-210" No. 3: Aminoalkoxysilane manufactured by the same company, “Sila Ace S-320” Note 7) Idemitsu Petrochemical Co., Ltd., “Polybutene OH” Note 8) Kusumoto Kasei Co., Ltd.
"Dispalon # 6500"

[0014]

[Table 2]

[0015]

According to the results shown in Table 2, the dumbbell physical properties (low modulus and high modulus) were obtained by using the solvent-free acrylic polymer alone (Examples 1 and 4) or in combination with the plasticizer (Examples 2 and 3). (Elongation) is obtained, and it is recognized that the weathering effect is excellent. The composition of the present invention is mainly used for building sealing materials, but in addition to this, automobiles, electric appliances, civil engineering sealing materials, and other adhesives,
It can be applied to paints, coating materials, potting materials, molded products, and the like.

Continued on the front page F term (reference) 4H017 AA04 AA39 AB01 AB15 AC05 AC17 AD05 AD06 AE03 AE05 4J002 BG03 BG03Y BG04Y BG05Y BG07X BG07Y BQ00X CH05W ED030 FD010 FD050 FD200 GJ02

Claims (3)

[Claims] 1. A moisture-curable composition mainly composed of a modified silicone polymer and an alkoxysilyl group-containing acrylic polymer, which is obtained by continuous bulk polymerization at a high temperature and a high pressure and has no functional group which has no liquid-state functional group at room temperature. A moisture-curable composition characterized by containing a type acrylic polymer. 2. The weight ratio of the modified silicone polymer and the non-solvent acrylic polymer in a liquid state at room temperature is from 1/5 to 5/1.
The moisture-curable composition according to claim 1, which is: 3. The moisture-curable composition according to claim 1, wherein the alkoxysilyl group-containing acrylic polymer is polymerized in a modified silicone polymer.