JPH0995609A - Room temperature curable composition and method for producing the same - Google Patents

Abstract

(57) [PROBLEMS] To provide a curable composition having a low viscosity and giving a cured product having sufficient flexibility. SOLUTION: The total molecular end groups are based on 100 parts by weight of a high molecular weight polymer (I) and a high molecular weight polymer (I) having a molecular weight of 8000 to 30,000 in which 50% or more of all molecular end groups are hydrolyzable silicon groups. Of less than 50% of which is a hydrolyzable silicon group having a molecular weight of 4000 to 30,000 (I
A room temperature curable composition obtained by mixing 1 to 200 parts by weight of I).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a room temperature curable composition which cures in the presence of moisture.

[0002]

2. Description of the Related Art A method of curing various polymers having a hydrolyzable silicon group and using them as a sealing material, an adhesive or the like is well known and industrially useful.

Of these compounds, a polymer whose main chain is a polyether is a liquid at room temperature, and the cured product retains its flexibility even at a relatively low temperature, and is used as a sealing material, an adhesive or the like. If it does, it has desirable characteristics.

As such a moisture-curable polymer,
Examples thereof include moisture-curable polymers having a hydrolyzable silicon group at the terminal, which are described in JP-A-3-72527, JP-A-3-47825 and the like. In such a polymer having a hydrolyzable silicon group at the terminal, generally, the larger the molecular weight is, the more flexibility the cured product is, but the higher the viscosity of the polymer is, and the workability is remarkably deteriorated.

If the molecular weight of such a polymer is small, the viscosity will be low, but the cured product will be inferior in flexibility. Until now, various plasticizers have been used in order to reduce the viscosity of the polymer while maintaining the flexibility of the cured product.

Examples of such plasticizers include aromatic carboxylic acid esters, aliphatic carboxylic acid esters, glycol esters, phosphoric acid esters, epoxy plasticizers,
Chlorinated paraffin is used. However, since these plasticizers are migrating, when used as a sealing material or the like, they have a drawback that the surroundings of the sealing part, the surface after coating, and the adhesiveness are adversely affected.

[0007] For the purpose of eliminating these drawbacks, a reactive plasticizer which does not lower the flexibility of the cured product and has a very low migration property with respect to a moisture-curable polymer having a hydrolyzable silicon group. A curable composition to which is added is disclosed in JP-A-5-5926.
Proposed in 7. However, for use as a sealing material or the like, there is a demand for a curable composition having higher flexibility and good elongation, and having improved surface stain resistance when coated on the surface. In addition, usually, various inorganic fillers are used in the compounding of actual sealing materials and adhesives, but the use of fillers makes the physical properties of the cured product harder, so the flexibility of the polymer itself is further required. is there.

From such a point of view, JP-A-1-27995
No. 8 describes a composition obtained by mixing a polyether compound containing a terminal unsaturated group having a narrow molecular weight distribution with a hydrolyzable silicon group-containing polyether polymer and containing no plasticizer such as dioctyl phthalate. However, in the case of a cured product of such a composition, when the amount of the terminal unsaturated group-containing polyether compound added is particularly large, after curing, the polyether having no cross-linking group gradually exudes on the surface, and the cured product surface is It had the drawback of being sticky.

Further, JP-A-5-65403 describes a composition in which a hydrolyzable silicon group-containing polyether polymer having a narrow molecular weight distribution is blended without a plasticizer, but without using a plasticizer. In the case where the cured product has a practical viscosity and the cured product is flexible, there is a drawback that the curing is very slow.

Further, JP-A-5-65405 discloses an example in which two or more kinds of hydrolyzable silicon group-containing polyether polymers having different numbers of branches are mixed and used.
06 shows an example in which two or more kinds of hydrolyzable silicon group-containing polyether polymers having different molecular weight distributions are mixed and used. However, since the proportion of hydrolyzable silicon groups in all molecular end groups of the polyether polymer mixed in both cases is more than 80%, the cured product is obtained without a plasticizer, especially when an inorganic filler such as calcium carbonate is used. There is a drawback to flexibility.

[0011]

Therefore, the viscosity of the composition is practically satisfactory, the cured product is flexible even when an inorganic filler is used, the cured product has good elongation characteristics, and the surface coating film is excellent. As a result of examining a composition which does not contaminate the present invention, the present invention has been completed.

[0012]

That is, the present invention is the following inventions. Less than 50% of all molecular end groups based on 100 parts by weight of a high molecular weight polymer (I) having a molecular weight of 8000 to 30,000 and a high molecular weight polymer (I) in which 50% or more of all molecular end groups are hydrolyzable silicon groups. Is a hydrolyzable silicon group and has a molecular weight of 4000 to 30000 (I
I) A room temperature curable composition containing 1 to 200 parts by weight, and 1 to 200 parts by weight of the polymer (II) are mixed with 100 parts by weight of the polymer (I). A method for producing a room temperature curable composition.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In both the high molecular polymer (I) and the high molecular polymer (II) used in the present invention, the main chain of the molecule preferably consists essentially of polyether.

Such a polymer is preferably one obtained by introducing a hydrolyzable silicon group into a hydroxyl group-containing polyether by a suitable method.

Such a polymer is disclosed, for example, in JP-A-3-
47825, JP-A-3-72527, JP-A-3-796
27, JP-B-46-30711, JP-B-45-3631
9, proposed in Japanese Examined Patent Publication No. 46-17553.

The hydroxyl group-containing polyether can be obtained by polymerizing a monoepoxide such as alkylene oxide in the presence of an initiator and a catalyst.

As the initiator, compounds having 2 to 10 active hydrogens are preferable. A polyhydroxy compound is preferable, and a polyhydroxy compound having 2 to 8, especially 2 to 4 hydroxyl groups is preferable. Specifically, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,
There are 4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, sucrose, and polyols having a lower molecular weight than the target product obtained by reacting these with monoepoxide. These may be used alone or in combination of two or more. Further, an unsaturated group-containing monohydroxy compound such as allyl alcohol can also be used.

Examples of monoepoxides include propylene oxide, butylene oxide, ethylene oxide and allyl glycidyl ether. Propylene oxide is particularly preferred. Examples of the catalyst include alkali metal catalysts, complex metal cyanide complex catalysts, and metal porphyrin catalysts.

Particularly preferred hydroxyl group-containing polyethers are polyoxypropylene diol, polyoxypropylene triol, polyoxypropylene tetraol and polyoxypropylene hexaol. When used in the following methods (1) and (4), olefin-terminated polyethers such as polyoxypropylene glycol monoallyl ether can also be used.

The hydrolyzable silicon group may be any silicon group which undergoes hydrolysis and crosslinking reaction in moisture. Silicon-containing groups having hydrolyzable groups directly bonded to silicon atoms can be used. For example, the group represented by formula (A) is preferable.

-R ² -SiX _a R ¹ _3-a (A)

In the formula, R ¹ is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms, R ² is a divalent organic group, X is a hydroxyl group or a hydrolyzable group, a is 1 to 3
Is an integer.

R ¹ in the formula (A) is preferably an alkyl group having 8 or less carbon atoms, a phenyl group or a fluoroalkyl group, and a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group or a phenyl group. A group and the like are particularly preferable.

X is a hydroxyl group or a hydrolyzable group, and examples of the hydrolyzable group include a halogen atom, an alkoxy group, an acyloxy group, an amide group, an amino group, an aminooxy group, a ketoximate group and a hydride group. Of these, the hydrolyzable group having a carbon atom preferably has 6 or less carbon atoms, and particularly preferably 4 or less carbon atoms. Examples of preferable X include a lower alkoxy group having 4 or less carbon atoms, particularly a methoxy group, an ethoxy group and a propoxy group. a is 2 or 3
Is preferred.

Next, a method for producing the high molecular weight polymers (I) and (II) will be described. These polymers are produced by introducing a hydrolyzable silicon group to the terminal of the hydroxyl group-containing polyether by the methods described in (1) to (4) below.

(1) A method of reacting a hydroxyl group-terminated polyether having an unsaturated group at the terminal and a silicon hydride compound represented by the formula (B) in the presence of a catalyst.

HSiX _a R ¹ _3-a (B)

However, in the formula, R ¹ , X and a are the same as described above.

The term "unsaturated group introduced at the end of the hydroxyl group-terminated polyether" means that an unsaturated group is introduced at one or more terminals of the hydroxyl group terminated polyether. As this method, the terminal hydroxyl group O of the hydroxyl group-terminated polyether is used.
After H is OM (M is an alkali metal), a method of reacting with an unsaturated group-containing halogenated hydrocarbon such as allyl chloride or a compound having an unsaturated group and a functional group capable of reacting with a hydroxyl group is used as a hydroxyl group-terminated polyether. There is a method of reacting and binding with an ester bond, a urethane bond, a carbonate bond or the like.

Further, when polymerizing a monoepoxide in the production of a hydroxyl-terminated polyether, a method or an initiator for introducing an unsaturated group into a side chain by copolymerizing an unsaturated group-containing monoepoxide such as allyl glycidyl ether It can also be obtained by using a monohydroxy compound having a terminal unsaturated group as.

(2) A method in which a compound having an isocyanate group and a hydrolyzable silicon group represented by the formula (A) is reacted with a hydroxyl group-terminated polyether.

(3) After reacting a hydroxyl group terminated polyether with a polyisocyanate compound such as tolylene diisocyanate to form an isocyanate group terminal, the isocyanate group is reacted with the W group of the silicon compound represented by the formula (C). Method.

R ¹ _3-a -SiX _a -R ³ W ... (C)

However, in the formula, R ¹ , X and a are the same as described above, R ³ is a divalent organic group, W is a hydroxyl group, a carboxyl group, a mercapto group and an amino group (primary or secondary).
It is an active hydrogen-containing group selected from the group).

(4) A method of reacting an unsaturated group obtained by introducing an unsaturated group at the end of a hydroxyl group-terminated polyether with the mercapto group of the silicon compound represented by the formula (C) in which W is a mercapto group.

The number of hydrolyzable silicon groups of the polymer (I) of the present invention is 50% or more and 100% or less, preferably 60% or more and 100% or less, of the total molecular end groups. The number of molecular terminal groups per molecule is preferably 2-8, particularly preferably 2-4.

The hydrolyzable silicon group of the polymer (II) of the present invention is less than 50% of the total molecular end groups, and is 25%.
It is preferably at least 50%. The number of molecular terminal groups per molecule is preferably 2-8, particularly preferably 3-8,
3-6 are more preferable.

As the high molecular weight polymer (I) of the present invention, a polymer having a molecular weight of 8,000 to 30,000 can be used. Especially,
When the molecular weight of the polymer is lower than 8,000, the proportion of hydrolyzable silicon groups in the total molecular end groups must be reduced as compared with the higher molecular weight in order to make the cured product flexible. However, there is a drawback that the curability is deteriorated. When the molecular weight exceeds 30,000, the workability is remarkably deteriorated due to the high viscosity even after mixing with the high molecular polymer (II). Preferred molecular weight is 10,000 to 2000
0.

As the high molecular weight polymer (II) of the present invention, a polymer having a molecular weight of 4,000 to 30,000 can be used. In particular, even if it is mixed with the high molecular weight polymer (I), if the molecular weight of the polymer is lower than 4000, the curability becomes poor, and if it exceeds 30,000, the workability becomes remarkably poor because of high viscosity. Preferred molecular weight is 8000-2
0000.

The molecular weights of the high molecular weight polymer (I) and the high molecular weight polymer (II) are calculated based on the hydroxyl group equivalent valence molecular weight of the raw material hydroxyl group terminated polyether.

In the present invention, 1 to 200 parts by weight of the polymer (II) is used with respect to 100 parts by weight of the polymer (I). Preferably, the high molecular weight polymer (II) is 10 to 15
0 parts by weight, particularly preferably 20 to 100 parts by weight are used.

The room-temperature curable composition in the present invention is a polymer (I) based on 100 parts by weight of the polymer (I).
I) It can be produced by mixing 1 to 200 parts by weight.

The advantage of mixing and using two or more kinds of high molecular weight polymers is that the physical properties of the cured product obtained by curing the curable composition can be controlled by the mixing ratio. By using this method, many cured product properties can be freely expressed with a small number of polymer types. That is, a hard cured product can be obtained by increasing the amount of the high molecular polymer (I), and a more flexible cured product can be obtained by increasing the amount of the high molecular polymer (II). Can be arbitrarily selected.

The composition of the present invention may contain various known curing catalysts, fillers, additives, and if necessary, solvents, plasticizers and the like.

The following compounds can be used as the curing catalyst. Alkyl titanates, organosilicon titanates, metal salts such as bismuth tris-2-ethylhexoate, phosphoric acid, p-toluenesulfonic acid, acidic compounds such as phthalic acid, butylamine, hexylamine, octylamine,
Aliphatic monoamines such as decylamine and laurylamine,
Aliphatic diamines such as ethylenediamine and hexanediamine, diethylenetriamine, triethylenetetramine,
Aliphatic polyamines such as tetraethylenepentamine, heterocyclic amines such as piperidine and piperazine, aromatic amines such as metaphenylenediamine, ethanolamines, triethylamine, various modified amines used as curing agents for epoxy resins, etc. Amine compounds.

Mixtures of divalent tin such as tin dioctylate, tin dinaphthenate and tin distearate with the above amines.

Dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate and the following carboxylic acid type organotin compounds and mixtures of these carboxylic acid type organotin compounds with the above amines. (nC ₄ H ₉ ) ₂ Sn (OC
OCH = CHCOOCH ₃ ) ₂ , (nC ₄ H ₉ ) ₂ Sn (OCOCH = CHCOOC ₄ H ₉ -n) ₂ ,
(nC ₈ H ₁₇ ) ₂ Sn (OCOCH = CHCOOCH ₃ ) ₂ , (nC ₈ H ₁₇ ) ₂ Sn (OCOCH
= CHCOOC ₄ H ₉ -n) ₂ , (nC ₈ H ₁₇ ) ₂ Sn (OCOCH = CHCOOC ₈ H ₁₇ -iso)
₂ .

The following sulfur-containing organotin compounds: (nC ₄ H ₉ ) ₂ S
n (SCH ₂ COO), (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ COO), (nC ₈ H ₁₇ ) ₂ Sn (S
CH ₂ CH ₂ COO), (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOCH ₂ CH ₂ OCOCH ₂ S), (n
-C ₄ H ₉ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -iso) ₂ , (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ COO
C ₈ H ₁₇ -iso) ₂ , (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -n) ₂ , (nC
₄ H ₉ ) ₂ SnS.

Organotin oxides such as (nC ₄ H ₉ ) ₂ SnO and (nC ₈ H ₁₇ ) ₂ SnO, and these organotin oxides and ethyl silicates, dimethyl maleate, diethyl maleate, dioctyl maleate, phthalic acid. Reaction products with ester compounds such as dimethyl, diethyl phthalate and dioctyl phthalate.

The following chelate tin compounds and reaction products of these tin compounds with alkoxysilanes (provided that
acac is an acetylacetonate ligand). (nC ₄ H ₉ ) ₂ Sn
(acac) ₂ , (nC ₈ H ₁₇ ) ₂ Sn (acac) ₂ , (nC ₄ H ₉ ) ₂ (C ₈ H ₁₇ O) S
n (acac).

The following tin compounds. (nC ₄ H ₉ ) ₂ (CH ₃ COO) SnOSn
(OCOCH ₃ ) (nC ₄ H ₉ ) ₂ , (nC ₄ H ₉ ) ₂ (CH ₃ O) SnOSn (OCH ₃ ) (nC
₄ H ₉ ) ₂ .

As the filler, for example, the following known fillers can be used. Calcium carbonate whose surface is surface-treated with a fatty acid or a resin acid organic compound, and further finely powdered, colloidal calcium carbonate having an average particle size of 1 μm or less, light calcium carbonate having an average particle size of 1 to 3 μm produced by a precipitation method, average particles Calcium carbonate such as ground calcium carbonate having a diameter of 1 to 20 μm, fumed silica, precipitated silica, silicic acid anhydride, hydrous silicic acid and carbon black, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, Powdered fillers such as organic bentonite, ferric oxide, zinc oxide, activated zinc oxide, shirasu balloon, wood flour, pulp, cotton chips, mica, walnut flour, rice flour, graphite, fine aluminum powder, and flint powder. Asbestos, glass fiber, glass filament,
Fibrous fillers such as carbon fiber, Kevlar fiber and polyethylene fiber.

The amount of the filler used is preferably 1 to 1000% by weight, more preferably 50 to 250% by weight, based on the total amount of the high molecular polymer (I) and the high molecular polymer (II). These fillers may be used alone or in combination of two or more.

The room temperature curable composition in the present invention has a sufficiently low viscosity by itself, and it is preferable that a plasticizer is not substantially used, but a plasticizer may be used. Examples of the plasticizer include dioctyl phthalate, dibutyl phthalate, butylbenzyl phthalate, and other phthalic acid alkyl esters; dioctyl adipate, diisodecyl succinate, dibutyl sebacate, butyl oleate, and other aliphatic carboxylic acid alkyl esters. Glycol esters such as pentaerythritol ester; Phosphoric acid esters such as trioctyl phosphate, tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil and benzyl epoxystearate; chlorinated paraffin; It can be used in the above mixture.

However, among such plasticizers, the low molecular weight plasticizer has a problem that it tends to bleed out after curing the room temperature curable composition of the present invention, and therefore it is preferable not to use it. That is, it is preferable that the room temperature curable composition of the present invention further contains a plasticizer and does not contain a low molecular weight plasticizer as the plasticizer. The low molecular weight plasticizer refers to a plasticizer in which the compound itself has a low molecular weight and does not have a reactive group. For example, phthalic acid alkyl esters.

A hydrolyzable silicon compound may be optionally added to the composition of the present invention for the purpose of controlling the physical properties and curability of the cured product. Specific examples of such a compound include tetramethyl silicate, vinyltrimethoxysilane,
Examples thereof include, but are not limited to, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and compounds in which these methoxy groups are substituted with ethoxy groups.

The additives are intended to be a thixotropic agent, an adhesion imparting agent such as phenol resin, epoxy resin and various silane coupling agents, pigments, various stabilizers, and surface modification such as oligoester acrylate. The photocurable compound etc. which were mentioned are mentioned. Also, a solvent may be used for the purpose of adjusting the viscosity.

The room temperature curable composition of the present invention can be used as a sealing material, particularly as an elastic sealing material or an adhesive.

[0059]

EXAMPLES The present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to these. Synthesis Examples 1 to 6 are high molecular polymers (I), Synthesis Examples 7 to 12 are high molecular polymers (II), and Synthesis Example 13 is a comparative polymer.

[Synthesis Example 1] Polyoxypropylene diol obtained by reacting propylene oxide with ethylene glycol as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group for purification. Furthermore, chloroplatinic acid was used as a catalyst to react with methyldimethoxysilane, and a methyldimethoxysilylpropyl group was introduced into 60% of all molecular end groups.
7,000 polymer a was synthesized. Viscosity at 25 ℃ is 15
000 cP.

[Synthesis Example 2] In the same manner as in Synthesis Example 1, a polymer b having a molecular weight of about 17,000 in which a methyldimethoxysilylpropyl group was introduced into 75% of all molecular terminal groups was synthesized.
The viscosity at 25 ° C. was 15200 cP.

Synthesis Example 3 Polyoxypropylene triol obtained by reacting propylene oxide with glycerin as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group for purification. Furthermore, a molecular weight of about 1800 was obtained by reacting with methyldimethoxysilane using chloroplatinic acid as a catalyst to introduce methyldimethoxysilylpropyl groups into 60% of all molecular end groups.
0 polymer c was synthesized. Viscosity at 25 ° C is 10500
It was cP.

[Synthesis Example 4] By the same method as in Synthesis Example 3, a polymer d having a molecular weight of about 10,000 and having a methyldimethoxysilylpropyl group introduced into 84% of all molecular terminal groups was synthesized.
The viscosity at 25 ° C. was 3000 cP.

[Synthesis Example 5] In the same manner as in Synthesis Example 3, a polymer e having a molecular weight of about 15,000 in which a methyldimethoxysilylpropyl group was introduced into 91% of all molecular terminal groups was synthesized.
The viscosity at 25 ° C. was 8800 cP.

Synthesis Example 6 Polyoxypropylene diol obtained by reacting propylene oxide with ethylene glycol as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group for purification. Furthermore, 120% of methyldimethoxysilane was reacted with all molecular end groups using chloroplatinic acid as a catalyst, and then unreacted substances were distilled off under reduced pressure to introduce a methyldimethoxysilylpropyl group at the end. 9,000 polymer f was synthesized. Viscosity at 25 ° C is 54
It was 00 cP.

[Synthesis Example 7] In the same manner as in Synthesis Example 3, a polymer g having a molecular weight of about 18,000 in which a methyldimethoxysilylpropyl group was introduced into 35% of all molecular terminal groups was synthesized.
The viscosity at 25 ° C was 10500 cP.

[Synthesis Example 8] In the same manner as in Synthesis Example 3, a polymer h having a molecular weight of about 9000 and having a methyldimethoxysilylpropyl group introduced into 35% of all molecular terminal groups was synthesized. Two
The viscosity at 5 ° C. was 2800 cP.

Synthesis Example 9 Polyoxypropylene triol obtained by reacting propylene oxide with glycerin as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group for purification. Furthermore, a molecular weight of about 9000 was obtained by reacting with methyldiethoxysilane using chloroplatinic acid as a catalyst to introduce methyldiethoxysilylpropyl groups into 45% of all molecular end groups.
Polymer i was synthesized. Viscosity at 25 ℃ is 2800cP
Met.

Synthesis Example 10 Polyoxypropylene tetraol obtained by reacting propylene oxide with pentaerythritol as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group and then purified. . Further, methyldimethoxysilane was reacted with chloroplatinic acid as a catalyst to give 3
A polymer j having a molecular weight of about 17,000 in which 5% of methyldimethoxysilylpropyl group was introduced was synthesized. The viscosity at 25 ° C. was 6000 cP.

[Synthesis Example 11] In the same manner as in Synthesis Example 10, a polymer k having a molecular weight of about 8000 in which a methyldimethoxysilylpropyl group was introduced into 25% of all molecular terminal groups was synthesized. The viscosity at 25 ° C. was 2000 cP.

[Synthesis Example 12] Polyoxypropylene hexaol obtained by reacting propylene oxide with sorbitol as an initiator in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group for purification. Furthermore, chloroplatinic acid was used as a catalyst to react with methyldimethoxysilane, and 20% of all molecular end groups were reacted.
A polymer 1 having a molecular weight of about 12000 in which a methyldimethoxysilylpropyl group was introduced was synthesized. The viscosity at 25 ° C. was 2200 cP.

[Synthesis Example 13] Using glycerin as an initiator,
Polyoxypropylene triol obtained by reacting propylene oxide in the presence of a zinc hexacyanocobaltate complex catalyst was converted to an allyloxy group at the terminal hydroxyl group and then purified to obtain a polymer m having a molecular weight of about 9000. 25 ° C
The viscosity was 2500 cP.

Examples 1 to 6 and Comparative Examples 1 to 6 Polymer (I) and polymer (II) (or polymer for comparison) or dioctyl phthalate (D)
OP) are mixed in the ratios shown in Tables 1 and 2 to obtain a mixed solution,
The viscosity (unit: cP) at 25 ° C. was measured.

Next, with respect to 160 parts by weight (hereinafter referred to as "parts") of a mixed solution of a high molecular polymer (or a high molecular polymer and DOP), calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd.,
75 parts of white luster flower CCR), 75 parts of calcium carbonate (white stone SB manufactured by Shiraishi Calcium Co., Ltd.), titanium dioxide 30
Part, stabilizer (mixture of antioxidant, UV absorber, light stabilizer, Ciba Geigy, Tinuvin B75) 2 parts, photocurable resin (Toagosei Kagaku Kogyo, Aronix M602)
0) 5 parts, silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.,
KBM603) 2 parts, Disparon 6500 (Kusumoto Kasei Co., fatty acid amide thixotropic agent) 1 part, and dibutyltin bisacetylacetonate (Nippon Kagaku Sangyo Co., Ltd.,
2 parts of Nasem tin) was added and kneaded under the condition that water was not mixed to obtain a uniform mixture. Then (1)-
The evaluation of (5) was performed and the results are shown in Tables 1 and 2.

(1) 50% modulus (unit: kg / c
m ² ), breaking strength (unit: kg / cm ² ) and elongation (unit:%): After making the mixture into a sheet having a thickness of about 2 mm, after curing at 20 ° C. for 7 days and then at 50 ° C. for 7 days , JIS No. 3 dumbbell punched out was measured.

(2) Curability: Mixture at 20 ° C., 65% R
The curability after standing for 6 hours under the condition of H was evaluated by touch with a finger.
In the evaluation, ◯ means that it is tack-free, and × means that it is not tack-free.

(3) Flexibility of cured product: The flexibility of a cured product obtained by curing the mixture by curing was also evaluated. ◯ means that the material has a preferable flexibility as a sealing material for construction, and x means that it is too hard or too soft as a sealing material for construction.

(4) Change with time: The surface of the uncoated cured product was 5
After standing at 0 ° C. for 2 weeks, the surface was examined for bleed-out of unreacted substances and the like by finger touch. O indicates that no bleed-out was observed, and X indicates that bleed-out was observed.

(5) Contamination of the coating surface: A solvent-type alkyd paint (House Paint, manufactured by Rock Paint Co., Ltd.) was applied to a cured product of a 1 cm thick sheet, and then at 1 ° C at 70 ° C.
After heating for a week, the coating surface was exposed to the outdoors and one month later, the state of stains on the coated surface was observed. O indicates that it is clean with a small amount of dirt attached, and X indicates that it is dirty due to marked adhesion of dust and the like.

As can be seen from the table, the high molecular weight polymer (I
When I) is not used (Comparative Examples 2 and 4), the cured product is too hard to exhibit the desired flexibility as a sealing material. Further, when the surface coating is applied, the composition using dioctyl phthalate undesirably contaminates the coating film surface. Further, when a polymer having no hydrolyzable silicon group is used, an uncrosslinked polymer bleeds out from the cured product to the surface of the cured product, which is not preferable.

[0081]

[Table 1]

[0082]

[Table 2]

[0083]

The room temperature curable composition of the present invention has a sufficiently low viscosity and has the effect of not lowering the flexibility of the cured product even when an inorganic filler is used. When the composition of the present invention is used as a sealing material or the like, it does not adversely affect the contamination or adhesiveness around the sealing part or the coating surface.

Claims (6)

[Claims] 1. A high molecular weight polymer (I) having a molecular weight of 8000 to 30,000 in which 50% or more of all molecular end groups are hydrolyzable silicon groups, and 100 parts by weight of the high molecular weight polymer (I), all molecules are added. High molecular weight polymer having a molecular weight of 4000 to 30000 (I of which less than 50% of terminal groups are hydrolyzable silicon groups (I
I) A room temperature curable composition containing 1 to 200 parts by weight. 2. The room temperature curable composition according to claim 1, wherein both the main chain of the high molecular polymer (I) and the main chain of the high molecular polymer (II) are essentially polyether. 3. The room temperature curable composition according to claim 1, wherein the hydrolyzable silicon group of the polymer (I) and the hydrolyzable silicon group of the polymer (II) are both represented by the following formula (A). Stuff. -R ² -SiX _a R ¹ in _3-a ··· (A) formula, R ¹ is a monovalent organic group, substituted or unsubstituted 1 to 20 carbon atoms, R ² is a divalent organic group X is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3. 4. The room temperature curable composition of claim 1, 2 or 3 wherein the room temperature curable composition is substantially free of plasticizer. 5. The room temperature curable composition further contains a plasticizer and does not contain a low molecular weight plasticizer as the plasticizer.
The room temperature curable composition according to claim 1, 2 or 3. 6. Less than 50% of all molecular end groups are hydrolyzed with respect to 100 parts by weight of a high molecular weight polymer (I) having a molecular weight of 8000 to 30,000 in which 50% or more of all molecular end groups are hydrolyzable silicon groups. Molecular weight of volatile silicon group 4000-300
1 to 200 parts by weight of the high molecular weight polymer (II) of No. 00 are mixed, and the method for producing a room temperature curable composition, comprising