JP2002201350A - Room temperature curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a room temperature curing composition capable of giving a cured material excellent in weathering resistance when used as a sealing material or the like, e.g. a joint filler for an outer wall. SOLUTION: This room temperature curing composition comprises (A) a polymer of which the main chain consists essentially of a polyalkylene oxide and which has at least one of cross-linkable hydrolyzing silyl group and, preferably, a number-average molecular weight of 4,000-30,000, (B) another polymer of which the main chain consists essentially of an (meth)acrylic ester copolymer and has at least one of the cross-linkable hydrolyzing silyl group and, preferably, a number-average molecular weight of 6,000-30,000, and (C) an (meth)acrylic ester copolymer having a weight-average molecular weight of 500-30,000. Further, the composition preferably contains a polyether having a number-average molecular weight of 500-30,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room temperature curable composition containing a polymer which cures into a rubbery state by reacting with moisture in the atmosphere, and particularly relates to a sealing material having excellent weather resistance. The present invention relates to a room-temperature curable composition used in the above.

[0002]

2. Description of the Related Art As a polymer which reacts with moisture in the atmosphere and cures into a rubbery state, a polymer having at least one hydrolyzable silicon group per molecule has a molecular weight of 300 to 15,000.
Organic polymer. For example, JP-A-55-31
JP-A-874-874 describes a curable composition comprising a polymer having a hydrolyzable silicon group and a polymer plasticizer such as polyester or polypropylene glycol. However, when a sealing material containing a high-molecular plasticizer that is easily decomposed by light irradiation or the like is used for joints of the outer wall, etc., the weather resistance is not necessarily sufficient,
There has been a problem that deterioration occurs with the passage of time, the sealing material is cut, and the waterproof function is impaired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, such as deterioration with the passage of time when used as a sealing material at the joint of an outer wall, and to provide excellent weather resistance. It is an object of the present invention to provide a room temperature curable composition which gives a cured product.

[0004]

According to the present invention, there is provided a room-temperature-curable composition comprising: a polymer (A) having a main chain consisting essentially of a polyalkylene oxide and having at least one crosslinkable hydrolyzable silyl group. Polymer (B): a polymer whose main chain is essentially a (meth) acrylate copolymer and has at least one crosslinkable hydrolyzable silyl group, and a polymer (B) C): a (meth) acrylate copolymer having a weight average molecular weight of 500 to 30,000.

[0005] A room temperature curable composition according to a second aspect is the room temperature curable composition according to the first aspect, wherein the polymer (A) has a number average molecular weight of 4000 to 30,000. The room-temperature-curable composition according to claim 3 is claim 1.
Or the room temperature curable composition according to 2, wherein the polymer (B)
Has a number average molecular weight of 6,000 to 30,000. The room temperature curable composition according to claim 4 is that the room temperature curable composition according to any one of claims 1 to 3, further comprising a polyether having a number average molecular weight of 500 to 30,000. Features.

Hereinafter, the present invention will be described in detail. The polymer (A) used in the present invention is a polymer whose main chain is essentially a polyalkylene oxide and has at least one crosslinkable hydrolyzable silyl group. The polyalkylene oxide is not particularly limited, and includes, for example, polyethylene oxide, polypropylene oxide, and polybutylene oxide, and a cured product obtained by curing the room-temperature curable composition of the present invention (hereinafter, referred to as a cured product).
Is simply referred to as “cured product”).
When the room-temperature-curable composition of the present invention is used as a sealing material, polypropylene oxide is preferred because excellent elasticity can be secured.

The crosslinkable hydrolyzable silyl group is not particularly limited, but, for example, an alkoxysilyl group such as a methoxysilyl group and an ethoxysilyl group does not generate harmful by-products after the reaction. This is preferable. When the number average molecular weight of the polymer (A) is too small, the elongation of the cured product becomes insufficient, and the followability to joints and the like is reduced. When the number average molecular weight is too large, the viscosity before curing becomes too high, and the compounding step Because the workability at
It is preferably 30,000. Furthermore, when the number average molecular weight of the polymer (A) is 10,000 to 30,000 and the molecular weight distribution (Mw / Mn) is 1.6 or less,
It is further preferable that the balance between the workability and the elongation of the cured product is excellent.

As a commercial product of the polymer (A), MS polymers S-203 and S-303, for example, as trade names of MS polymer manufactured by Kanegafuchi Chemical Co., Ltd., and a silyl polymer as trade name, Cyril SAT-200, SA
T-350, SAT-400 and the like. Exestar, a product name of Asahi Glass Co., Ltd., is ESS-36
20, ESS-3430, ESS-2420, ESS-
2410 and the like.

Furthermore, a mixture of the polymer (A) and the polymer (B) in the present invention is also commercially available. For example, MS polymer S-brand manufactured by Kanegafuchi Chemical Co., Ltd.
903, MSX-908, MSX-911, MSX-9
43 and the like, and the silyl polymer (trade name) manufactured by the company includes Silyl MA-430 and MAX-447.

The polymer (B) used in the present invention is not particularly limited as long as it has at least one crosslinkable hydrolyzable silyl group. For example, the following (1) to (4) This is a polymer obtained by the method described in (1). (1) A method in which a (meth) acrylate polymer having an allyl group is reacted with a hydrosilicon compound represented by the following general formula in the presence of a Group VIII metal (Japanese Patent Application Laid-Open No. 54-36395). Described).

[0011]

Embedded image (Wherein, R is a group composed of a monovalent hydrocarbon group and a halogenated monovalent hydrocarbon group, a is an integer of 0, 1 or 2, and X is selected from a halogen atom, an alkoxy group, an acyloxy group and a ketoximate group. Represents an atom or group to be formed.)

(2) An alkyl (meth) acrylate is
A method of copolymerizing in the presence of an alkyl (meth) acrylate containing an alkoxysilyl group and a chain transfer agent containing a mercapto group (described in JP-A-57-179210). (3) A method of copolymerizing an alkyl (meth) acrylate in the presence of a bifunctional radical polymerizable compound and a mercaptan containing an alkoxysilyl group as a chain transfer agent (described in JP-A-59-78222). (4) A method of polymerizing an alkyl (meth) acrylate using an azobisnitrile compound containing an alkoxysilyl group as a polymerization initiator (JP-A-60-23405)
No. Gazette).

Among these polymers, the (meth) acrylate copolymer as the main chain is a copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms. It is preferable that the cured product has excellent flexibility, and it is more preferable that the alkyl group has 2 to 8 carbon atoms. The crosslinkable hydrolyzable silyl group is not particularly limited, but an alkoxysilyl group such as a methoxysilyl group and an ethoxysilyl group is preferable because no harmful by-product is generated after the reaction.

If the number average molecular weight of the polymer (B) is too small, the tackiness (stickiness) of the cured product is deteriorated. If the number average molecular weight is too large, the adhesiveness is poor due to a decrease in miscibility with the polymer (A). Since it is sufficient, it is preferably 6,000 to 30,000. More preferably, it is 8,000 to 20,000. The blending amount of the copolymer (B) with respect to the polymer (A) is as follows:
If the amount is too small, the effect of improving the weather resistance will be insufficient, and if it is too large, the elongation of the cured product will decrease.
It is preferably 0.1 to 100 parts by weight, more preferably 0.5 to 80 parts by weight based on parts by weight.

The compound (C) has a weight average molecular weight of 500
(Meth) acrylic acid ester copolymer having a weight average molecular weight of up to 30,000, which is used for adjusting the modulus of the polymers (A) and (B). Contamination is likely to occur, and if it is too large, a problem arises in workability due to an increase in viscosity, so that the content is limited to 500 to 30,000. The compounding amount of the compound (C) depends on the amount of the polymer (A) or (B).
The total amount is preferably 3 to 60 parts by weight based on 100 parts by weight. Less than 3 parts by weight has little effect,
If the amount is more than 60 parts by weight, there may be a problem in paintability. Preferably, it is 5 to 30 parts by weight.

In order to further reduce the modulus,
A polyether having a number average molecular weight of 500 to 30,000 can be used if necessary. In this case, the polyether is not particularly limited, for example,
Polypropylene glycol, polyethylene glycol,
Polybutylene glycol and the like can be mentioned, and among them, polypropylene glycol is more preferable. The blending amount of the above polyether is determined by adding the total amount of the polymers (A) and (B) to 10
As 0 parts by weight, 80 parts by weight or less is preferable. If the amount is more than 80 parts by weight, there may be a problem in paintability.

The room temperature-curable composition of the present invention may further contain, if necessary, the following compounds in addition to the above compounds. (1) Compound having an amino group and an alkoxysilyl group in one molecule Specific examples of the above compound include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane ,
N, N'-bis- [3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis- [3- (triethoxysilyl) propyl] ethylenediamine,
N′-bis- [3- (methyldimethoxysilyl) propyl] ethylenediamine, N, N′-bis- [3- (trimethoxysilyl) propyl] hexamethylenediamine,
N, N'-bis- [3- (triethoxysilyl) propyl] hexamethylenediamine, N, N'-bis- [3-
(Methyldimethoxysilyl) propyl] hexamethylenediamine, N, N-bis- [3- (trimethoxysilyl) propyl] ethylenediamine, N, N-bis- [3
-(Methyldimethoxysilyl) propyl] ethylenediamine, N, N-bis- [3- (triethoxysilyl) propyl] ethylenediamine, N, N-bis- [3- (trimethoxysilyl) propyl] hexamethylenediamine, N-bis- [3- (methyldimethoxysilyl)
Propyl] hexamethylenediamine, N, N-bis-
[3- (triethoxysilyl) propyl] hexamethylenediamine, N, N-bis- [3- (trimethoxysilyl) propyl] amine, N, N-bis- [3- (triethoxysilyl) propyl] amine, N, N-bis- [3
-(Methyldimethoxysilyl) propyl] amine and the like, and these can be used alone or in combination of two or more.

(2) Silanol condensation catalyst For example, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate,
Tin compounds such as bis (dibutyltin laurate) oxide, dibutyltin bisacetylacetonate, dibutyltin bis (monoester malate), tin octylate, dibutyltin octoate, dioctyltin oxide, tetra-n
-Butoxytitanate, titanate compounds such as tetraisopropoxytitanate, amine salts such as dibutylamine-2-ethylhexoate, and other acidic catalysts and basic catalysts, and the like, alone or in combination of two or more. It can be used in combination.

(3) Dehydrating agent For example, vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethylsilane, diphenyldimethoxysilane, etc. Silane compounds,
Examples include hydrolyzable ester compounds such as methyl orthoformate, ethyl orthoformate, methyl orthoacetate, and ethyl orthoacetate, and these can be used alone or in combination of two or more.

(4) Anti-sagging agent For example, an anti-sagging agent such as hydrogenated castor oil, fatty acid bisamide and fumed silica may be added.

(5) Various additives For example, calcium carbonate, magnesium carbonate, hydrated silicic acid, anhydrous silicic acid, calcium silicate, silica, titanium dioxide, clay, talc, carbon black, glass balloon and the like can be mentioned. They can be used alone or in combination of two or more. Further, if necessary, an antioxidant, an antioxidant, an ultraviolet absorber, a light stabilizer, a pigment, a solvent, a fragrance and the like can be used.

(Function) In the room temperature curable composition of the present invention, the polymer (A) having a polyalkylene oxide skeleton and necessary for ensuring elongation of the cured product, and
The polymer (B), whose main chain is essentially a (meth) acrylic acid ester copolymer and has at least one crosslinkable hydrolyzable silyl group, is used as a main component, and further has a plasticizing effect (low modulus). Effect), a (meth) acrylate copolymer (C) having a weight average molecular weight of 500 to 30,000 and having excellent weather resistance is used. That is, instead of using a plasticizer that is easily decomposed by light irradiation or the like, such as polypropylene glycol, as in the conventional technology, a polymer (C) having a similar molecular structure to the polymer (B) is used. For the first time, the present invention exerts effects such as excellent weather resistance in the present invention. Further, in the present invention, on the premise that the polymer (C) is blended, a plasticizer such as polyether may be further added, if necessary, in order to adjust the modulus of the cured product. It can be suitably used without impairing the properties.

[0023]

EXAMPLES The present invention will be described in detail with reference to examples and comparative examples. Note that the present invention is not limited to only the following examples. (1) Preparation of room temperature curable composition Each composition shown in Table 1 was uniformly mixed under reduced pressure using a mixing stirrer sealed so as to prevent moisture from entering from the outside. I got In addition, about calcium carbonate and titanium oxide, what was previously decompressed at 110 degreeC was used.

The following polymers and the like shown in the composition of Table 1 were used. "MS Polymer S-203" (trade name): manufactured by Kanegafuchi Chemical Industry Co., Ltd., number average molecular weight 8,000, (main chain is essentially polyalkylene oxide, and has at least one crosslinkable hydrolyzable silyl group. (Polymer) “MS Polymer MSX-943” (trade name): manufactured by Kaneka Chemical Co., Ltd. ((Meth) acrylate copolymer having at least one crosslinkable hydrolyzable silyl group and crosslinked A mixture in which propylene glycol having a terminal end of a possible hydrolyzable silyl group is uniformly dispersed) "Alphon UP-1000" (trade name): manufactured by Toagosei Co., Ltd., having a weight average molecular weight of 3000 (meth) acrylic acid ester copolymer Combined “Diol 3000” (trade name): polypropylene glycol with a number average molecular weight of 3000 manufactured by Mitsui Chemicals, Inc. “KBM603” (trade name): Shin-Etsu Chemical Manufactured by Gaku Kogyo, N-
(2-aminoethyl) -3-aminopropyltrimethoxysilane “Sanol LS770” (trade name): manufactured by Sankyo, hindered amine light stabilizer “Tinuvin 327” (trade name): Ciba Specialty Chemicals, benzotriazole UV absorber

(2) Evaluation The obtained room temperature curable composition was evaluated as follows. Table 1 shows the evaluation results. [Type I physical properties] Using the obtained room temperature curable composition,
An I-type test piece conforming to SA1415 was prepared and subjected to a tensile test to determine elongation (%). [Weather Resistance] The above-prepared I-type test piece was irradiated with light under the following conditions, and after a predetermined time, a tensile test was performed to determine elongation (%). The following elongation retention was determined. Elongation retention = (Elongation after irradiation for 300 hours) / (Initial elongation) <Light irradiation conditions> Type: Eye super UV tester Test equipment: Eye super UV tester (SUV-F11)
UV intensity: 100 mW / cm ² Limited wavelength: 295-450 nm Black panel temperature: 63 ° C. Irradiation distance: 235 mm (between light source and sample)

[0026]

[Table 1] In the room temperature curable composition of the present invention, as shown in Examples 1 to 5, the elongation was maintained at 400% or more even after light irradiation, and the retention was 60% or more.

[0027]

As described above, the present invention is to obtain a room temperature curable composition which gives a cured product having excellent weather resistance,
For example, when the sealing material is used at the joint of the outer wall or the like, the deterioration hardly occurs with the passage of time, and the sealing material can be prevented from being cut. Therefore, by using the room temperature-curable composition of the present invention, it is possible to obtain a product excellent in weather resistance without impairing the waterproof function or the like for a long period of time.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09K 3/10 C09K 3/10 G E04B 1/682 E04B 1/68 L

Claims (4)

[Claims] 1. Polymer (A): a polymer whose main chain is essentially a polyalkylene oxide and has at least one crosslinkable hydrolyzable silyl group; Polymer (B): a main chain essentially A polymer having at least one crosslinkable hydrolyzable silyl group, and a polymer (C) having a weight average molecular weight of 500 to 30,000 A room temperature curable composition comprising an acid ester copolymer. 2. The number average molecular weight of the polymer (A) is 4000.
The room temperature-curable composition according to claim 1, wherein the composition has a molecular weight of up to 30,000. 3. The polymer (B) has a number average molecular weight of 6,000.
The room-temperature-curable composition according to claim 1 or 2, wherein the composition has a molecular weight of up to 30,000. 4. The room temperature curable composition according to claim 1, further comprising a number average molecular weight of 500 to 300.
A room temperature curable composition comprising a polyether of No. 00.