JP3145022B2 - Curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Several examples of polyethers having a hydrolyzable silicon group capable of forming a siloxane bond by hydrolysis to increase the molecular weight or being crosslinkable are known in the art (for example, see Japanese Patent Application Laid-Open No. 47825, JP-A-3-72527, JP-A-3-79627, Japanese Patent Publication No. Sho 4
6-30711, JP-B-45-36319, JP-B-46
-17553).

[0003] Since these polyethers undergo a step of reacting with an organic halogen compound or the like under alkaline conditions as production conditions, salts are by-produced and need to be removed.
It is known that the residual salt increases the water absorption of a cured product obtained by curing a polyether having a hydrolyzable silicon group, and deteriorates water resistance. In addition, as the alkali in the above reaction, for example, when an alkali metal compound such as an alkali metal, an alkali metal hydroxide, or an alkali metal hydride is used, a polyether having a hydrolyzable silicon group produced depending on the case may be used. In some cases, the storage stability of a curable composition produced by adding a filler, a catalyst, and the like is significantly deteriorated.

A method for removing ionic components derived from these salts or alkalis has been proposed (for example, Japanese Patent Publication No. 61-29371).

[0005]

On the other hand, polyoxyalkylenes having a terminal hydroxyl group, which are the raw materials of polyethers having a hydrolyzable silicon group, are generally prepared by adding an alkylene oxide to an initiator in the presence of a catalyst. Although produced by polymerization, in recent years, it has become industrially possible to use a metal compound other than an alkali metal compound as a polymerization catalyst for this alkylene oxide.

The polyether having a hydrolyzable silicon group has a high average molecular weight and a narrow molecular weight distribution, and is therefore excellent in curability. However, when a hydrolyzable silicon group is introduced into a terminal hydroxyl group, the raw material polyoxyalkylene is produced. Decomposition products of the metal catalyst at the time remain, and the storage stability of the curable composition produced by adding a polymer plasticizer, a catalyst, and the like may be significantly deteriorated.

A composition obtained by adding a filler, a catalyst, and the like to a polyether having a hydrolyzable silicon group is used as a sealing agent, an adhesive, and the like. This was a problem to be solved by causing a decrease in workability such as a decrease in thixotropy.

[0008]

DISCLOSURE OF THE INVENTION The present invention is intended to improve such problems, particularly the storage stability of a curable composition, and includes the following organic polymer (A) having a molecular weight of 1,000.
A curable composition containing the above-mentioned polymer plasticizer (E) and curing catalyst (F) is provided. (Organic Polymer) Hydroxyl represented by the formula (1) derived from a hydroxyl group-containing polyoxyalkylene polymer (C) obtained by polymerizing an alkylene oxide with an initiator using a double metal cyanide complex (B) as a catalyst. Having a decomposable silicon group,
And an organic polymer (A) having a total amount of ionic impurities of 50 ppm or less. —R—SiX _a R ¹³ _-a (1) In the formula (1), R is a divalent organic group, and R ¹ is a carbon number of 1 to 20.
Is a substituted or unsubstituted monovalent hydrocarbon group, X is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The organic polymer (A) is derived from a hydroxyl group-containing polyoxyalkylene polymer (C) obtained by polymerizing an alkylene oxide with an initiator using a double metal cyanide complex (B) as a catalyst. You.

The use of the double metal cyanide complex (B) results in a M
It is possible to obtain a hydroxyl group-containing polyoxyalkylene polymer (C) having a low _w / _Mn , a higher molecular weight and a lower viscosity.

As the double metal cyanide complex (B), a complex containing zinc hexacyanocobaltate as a main component is preferable, and an ether and / or alcohol complex thereof is particularly preferable. Its composition is essentially JP-B-46-2725.
No. 0 can be used. As ethers, ethylene glycol dimethyl ether (glyme),
Diethylene glycol dimethyl ether (diglyme)
Are preferred, and glyme is particularly preferred from the handling during the production of the complex. As the alcohol, t-butanol is preferable.

As the initiator, a compound having 2 to 10 active hydrogens is 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 them with alkylene oxide. These may be used alone or in combination of two or more. Also, unsaturated group-containing monohydroxy compounds such as allyl alcohol can be used.

The organic polymer (A) of the present invention has a total amount of ionic impurities of 50 ppm or less. In particular, the present invention is suitable when the ionic impurities include (a) a metal compound derived from the double metal cyanide complex (B) and / or (b) an alkali metal compound. 3 ionic impurities
It is preferably at most 0 ppm, more preferably at most 20 ppm.

By reducing the amount of these metallic impurities, the storage stability of the organic polymer (A) and the curable composition of the present invention can be further improved. Property is obtained.

[0015] The reduction method is as follows:
(III). When removing the metal compound originating from the double metal cyanide complex (B), (II)
The method I) is particularly preferred. The method (I) is particularly preferable because ionic impurities can be effectively and economically reduced.

(I) A method in which ionic impurities contained in a polymer are converted into a salt essentially insoluble in the polymer, and the salt is removed from the polymer. Specifically, after adding a compound capable of reacting with ionic impurities to form a salt essentially insoluble in the polymer, water and, if necessary, a nonionic surfactant,
There is a method of precipitating a salt by dehydration and then removing the salt. As the compound capable of forming a salt, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, pyrophosphoric acid, sodium acid pyrophosphate and the like are preferable. The precipitated salt can be removed by a filtration operation, an adsorption operation, or the like.

(II) A method of removing a ionic impurity by adding a solvent to a polymer and then bringing the polymer into contact with an anion exchange resin and / or a cation exchange resin.

(III) A method of removing a metal compound caused by a double metal cyanide complex (B) after treatment with a pH buffer and optionally ammonia and a chelating agent, adding an aliphatic alcohol and a chelating agent, A method of removing a metal compound caused by the double metal cyanide complex (B), and a method of removing a metal compound caused by the double metal cyanide complex (B) after treatment with an oxidizing agent.

The ionic impurities referred to in the present invention are:
Cations and anions, such as zinc ions, cobalt ions, cyan ions, and chloride ions, caused by the double metal cyanide complex (B); sodium ions and potassium ions mixed as impurities in the step of producing the organic polymer (A) Alkali metal ions, halogen ions, etc .; carboxylate ions generated by oxidation of polyoxyalkylene in the step of producing the organic polymer (A); ester bonds in the step of producing the organic polymer (A),
Includes all anions and cations such as catalytic metal salts added when forming carbonate bonds and the like.

The organic polymer (A) has a hydrogen atom in the hydroxyl group of the hydroxyl group-containing polyoxyalkylene polymer (C),
What substituted by the group represented by Formula (1) is preferable.

The number of hydroxyl groups per molecule of the polyoxyalkylene polymer (C) used in the present invention is preferably 2 to 10. From the balance of physical properties such as viscosity, strength and elongation, it is particularly preferable that the number is 2 to 8, especially 2 to 4.

Preferred polymers (C) are polyoxypropylene diol, polyoxypropylene triol and polyoxypropylene tetraol. Further, when used in the following methods (a) and (d), unsaturated group-terminated polyoxyalkylene monols such as polyoxypropylene glycol monoallyl ether can also be used.

The polyoxyalkylene polymer (C) preferably has a molecular weight in terms of hydroxyl value of 5,000 to 30,000, more preferably 8,000 to 30,000.

In the present invention, the hydroxyl value-equivalent molecular weight means the number of functional groups of the initiator used for producing the polyoxyalkylene polymer (C) having a terminal hydroxyl group, and the molecular weight per hydroxyl group of the polyoxyalkylene of the polymer. Refers to the molecular weight calculated by the product of

The organic polymer (A) has a hydrolyzable silicon group represented by the formula (1). —R—SiX _a R ¹³ _-a (1) In the formula (1), R is a divalent organic group, and R ¹ is a carbon number of 1 to 20.
Is a substituted or unsubstituted monovalent hydrocarbon group, X is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3.

R in the formula (1) is a divalent organic group. R
¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably an alkyl group having 8 or less carbon atoms, a phenyl group or a fluoroalkyl group. Particularly preferred are a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, a phenyl group and the like.

X is a hydroxyl group or a hydrolyzable group. 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. Among these, the number of carbon atoms of the hydrolyzable group having a carbon atom is preferably 6 or less, particularly preferably 4 or less. Preferred X includes a lower alkoxy group having 4 or less carbon atoms, particularly a methoxy group, an ethoxy group, a propoxy group, and the like. a is an integer of 1 to 3, preferably 2 or 3.

Next, a method for producing the organic polymer (A) will be described. In the organic polymer (A) in the present invention, a hydrolyzable silicon group can be introduced into the terminal of the hydroxyl group-containing polyoxyalkylene polymer (C) by the method described in the following (A) to (D). Such compounds are liquid at room temperature, and the cured product retains flexibility even at relatively low temperatures,
When used as a sealing material, an adhesive or the like, it has preferable characteristics.

(A) A method of reacting the terminal unsaturated group-introduced product (D) of the polymer (C) with a silicon hydride compound represented by the formula (4). ^{_{HSiX a R 1 3-a ···}} (4) where Equation (4) was R ^1, X, a is as defined above.

The terminal unsaturated group-introduced product (D) of the polymer (C)
Can be obtained by converting the terminal hydroxyl group OH of the polymer (C) to OM (M is an alkali metal) and then reacting the polymer with an unsaturated group-containing halogenated hydrocarbon such as allyl chloride or the like. There is a method in which a compound having a functional group capable of reacting is reacted with the polymer (C) and bound by an ester bond, a urethane bond, a carbonate bond, or the like.

Further, when polymerizing an alkylene oxide in the production of the polymer (C), a method for introducing an unsaturated group into a side chain by copolymerizing an alkylene oxide containing an unsaturated group such as allyl glycidyl ether or the like, It can also be obtained by using a monohydroxy compound having a terminal unsaturated group as an agent.

(B) Compound having isocyanate group and hydrolyzable silicon group represented by formula (1) and polymer (C)
How to react.

(C) After the polymer (C) is reacted with a polyisocyanate compound such as tolylene diisocyanate to give an isocyanate group terminal, the W group of the silicon compound represented by the formula (5) is reacted with the isocyanate group. How to let. ^{_{R 1 3-a -SiX a -R}} 5 W ··· (5) However, Equation (5) Medium R ^1, X, a are as defined above, R ⁵ is a divalent organic radical, W is a hydroxyl group, a carboxyl An active hydrogen-containing group selected from a group, a mercapto group and an amino group (primary or secondary).

(D) The unsaturated group of the terminal unsaturated group-introduced product (D) of the polymer (C) and the formula (5) wherein W is a mercapto group
And reacting the mercapto group of the silicon compound represented by

The removal of the ionic impurities is carried out in the above (a) to
In each method of (d), it is preferable to carry out at an appropriate stage such as before the reaction of each silicon compound, and the total amount is 50 ppm or less. The following method (e) or (f) is preferred.

(E) After the ionic impurities contained in the polymer (C) are converted into salts essentially insoluble in the polymer (C),
After removing the salt from the polymer (C) to reduce the ionic impurities contained in the polymer (C) to 50 ppm or less, a hydrolyzable silicon group is introduced into the polymer (C),
Organic polymer (A).

(F) The ionic impurities contained in the terminal unsaturated group-introduced product (D) of the polymer (C) are converted into salts essentially insoluble in the terminal unsaturated group-introduced product (D). By removing the salt from the terminal unsaturated group-introduced product (D), ionic impurities contained in the terminal unsaturated group-introduced product (D) are reduced to 50 pp.
m or less, the terminal unsaturated group-introduced product (D) and the formula (2)
To produce an organic polymer (A).

In the present invention, the molecular weight of the organic polymer (A) is calculated based on the hydroxyl value-converted molecular weight of the polymer (C) as a raw material. The molecular weight is 5,000 to 30,000
Is preferred. If it is lower than 5,000, the cured product is hard and the elongation is low. If it exceeds 30,000, the flexibility and elongation of the cured product are not problematic, but the viscosity of the polymer itself becomes extremely high and the practicality is lowered. Especially 8000-30
000 is preferred.

The polymer plasticizer (E) in the present invention is selected from polyoxyalkylene ether, polyester, poly-α-methylstyrene, polystyrene, polybutadiene, alkyd resin, polychloroprene and butadiene-acrylonitrile copolymer. More than species are preferred. The molecular weight is 1000 or more, preferably 10
00 to 30,000.

The polymer plasticizer (E) preferably has good compatibility with the organic polymer (A). In particular, an organic polymer in which the high molecular weight plasticizer (E) is a polyoxyalkylene having a molecular weight of 1,000 to 30,000 obtained by polymerizing an alkylene oxide and has no hydrolyzable silicon group is preferable.

Such a polyoxyalkylene is preferably produced by a method similar to that for the organic polymer (A). Particularly preferred is a polymer derived from a hydroxyl group-containing polyoxyalkylene or a polymer thereof. A polymer obtained by converting 80% or more of terminal hydroxyl groups into another organic group is particularly preferred.

Specifically, a polymer in which a terminal hydroxyl group is sealed with a hydrocarbon group such as an alkyl group or an alkenyl group via a bond such as an ether bond, an ester bond, or a urethane bond is particularly preferable. Most preferably, it is a polymer sealed with an allyl group via an ether bond.

The amount of the polymer plasticizer (E) used is preferably from 1 to 150 parts by weight based on 100 parts by weight of the organic polymer (A).

In the present invention, a curing catalyst (F) is essential for curing the organic polymer. When the curing catalyst (F) is not used, a significant reaction rate cannot be obtained in the crosslinking reaction of the hydrolyzable silicon group.

As the curing catalyst (F), a compound known as a catalyst for hydrolysis and condensation of a hydrolyzable silicon group can be used. Metal salts of carboxylic acids such as alkyl titanates, organosilicon titanates, tin octylate and dibutyltin dilaurate; amine salts such as dibutylamine-2-ethylhexoate; and other acidic catalysts and Basic catalysts can be used.

The amount of the curing catalyst (F) used is preferably from 0.001 to 10 parts by weight, particularly preferably from 0.01 to 5 parts by weight, based on 100 parts by weight of the organic polymer (A).

The composition of the present invention may contain fillers, reinforcing agents, anti-sagging agents, adhesives and the like. The amount of the filler used is 0 to 1000% by weight, especially 5% by weight, based on the organic polymer (A).
0 to 250% by weight is preferred. The following are specific examples of the filler. These fillers may be used alone or in combination of two or more.

Calcium carbonate, fumed silica, precipitated silica, silicic anhydride, hydrous silicic acid and carbon black, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, Powdered fillers such as zinc oxide, activated zinc flower, shirasu balloon, wood flour, pulp, cotton chips, mica, walnut flour, fir flour, graphite, aluminum fine powder, flint powder, asbestos, glass fiber, glass filament, Fibrous fillers such as carbon fiber, Kevlar fiber and polyethylene fiber.

Pigments include inorganic pigments such as iron oxide, chromium oxide, and titanium oxide; and organic pigments such as phthalocyanine blue and phthalocyanine green. , Fine powder silica, etc .; Examples of the adhesive include aminosilane, epoxysilane and the like.

In the present invention, a low-molecular plasticizer having a molecular weight of less than 1,000 can be used in combination. As a low-molecular plasticizer,
Known plasticizers can be used, and specifically, phthalic esters such as dioctyl phthalate, dibutyl phthalate and butyl phthalate; aliphatic carboxylic acids such as dioctyl adipate, isodecyl succinate, dibutyl sebacate and butyl oleate Acid esters; glycol esters such as pentaerythritol ester; phosphoric esters such as trioctyl phosphate and tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil and epoxy benzyl stearate; and chlorinated paraffins alone or two kinds It can be used in a mixture of the above.

The composition of the present invention can further contain various known additives. As the additive, an adhesion imparting agent such as a phenol resin and an epoxy resin, various antioxidants, an ultraviolet absorber and the like can be used.

The room temperature curable composition of the present invention cures at room temperature in the presence of moisture, and can be used especially for elastic sealants and adhesives.

[0053]

【Example】

(Synthesis of polymer) Hydroxyl value using a glycerin-propylene oxide adduct having a molecular weight of 1,000 as an initiator and a zinc hexacyanocobaltate glyme complex as a catalyst.
0 mg KOH / g of polyoxypropylene triol was obtained. This was reacted with allyl chloride in the presence of an alkali to convert the terminal hydroxyl group to an allyloxy group, thereby obtaining a polymer containing impurities such as metal ions.

(Purification of polymer) To 1 kg of a polymer containing impurities such as metal ions, 5 g of polyoxypropylene having a molecular weight of 10,000 obtained by block-polymerizing ethylene oxide to 10% of terminals, 50 g of water and 10 g of sodium acid pyrophosphate were added. Stirred at 90 ° C. for 1 hour. Subsequently, water was distilled off at 90 ° C. under reduced pressure.
00 (synthetic magnesia silicate, Kyowa Chemical)
g, and then dehydrated under reduced pressure at 90 ° C. for 1 hour. Then, 2 liters of hexane was added to dissolve the polymer, and impurities were removed by filtration using filter paper. Thereafter, hexane was distilled off under reduced pressure to obtain a purified polymer A1.

(Purification of polymer a) Except that 1 g of sodium acid pyrophosphate was added,
A purified polymer A2 was obtained in exactly the same manner as described above.

(Preparation Example 1 of Polymer) Methyldimethoxysilane was added to the polymer A1 obtained by (purification of polymer a) using chloroplatinic acid as a catalyst to give 0.17.
Thus, a polymer P1 having mmol / g of a hydrolyzable silicon group at the terminal was obtained. Table 1 shows the content of the ionic impurities contained in the composition.

(Production Example 2 of Polymer) The polymer A2 obtained by (Purification of Polymer A) was subjected to an addition reaction with methyldimethoxysilane using chloroplatinic acid as a catalyst to give 0.16.
A polymer P2 having mmol / g of a hydrolyzable silicon group at a terminal was obtained. Table 1 shows the content of the ionic impurities contained in the composition.

(Production Example 1 of Polymer Plasticizer) Glycerin-initiated polyoxypropylene having a molecular weight of 4000, which was synthesized using a KOH catalyst, was reacted with allyl chloride in the presence of an alkali to convert a terminal hydroxyl group to an allyloxy group. Was obtained as an impurity. This one 1k
g of hexane, 1 kg of hexane was added to dissolve uniformly, and p
800 g of a dilute hydrochloric acid aqueous solution of H3 was added, and the mixture was stirred at room temperature for 30 minutes, and allowed to stand for 2 hours to separate phases.

The hexane phase was taken out and Kyoward 50
30 g of synthetic magnesia silicate (Kyowa Chemical)
In addition, after dehydration under reduced pressure at 110 ° C. for 2 hours, insolubles were removed by filtration under pressure using a filter paper to obtain a polyoxyalkylene in which 96% of the terminals were capped with an allyl group. This was used as the polymer plasticizer PL1.

(Production Example 2 of Polymer Plasticizer) In the same manner as described in (Synthesis of Polymer), the molecular weight was 1000
Was used as an initiator and a zinc hexacyanocobaltate glyme complex as a catalyst to obtain a polyoxypropylene having a hydroxyl value of 37.1 mgKOH / g. This was reacted with allyl chloride in the presence of an alkali to convert the terminal hydroxyl group to an allyloxy group, thereby obtaining a polymer containing impurities such as metal ions.

In the same manner as in (a) of polymer purification, 5 g of polyoxypropylene having a molecular weight of 10,000 obtained by block-polymerizing ethylene oxide to 10% of terminals and 5 g of water were added to 1 kg of the polymer containing impurities such as metal ions.
0 g and 10 g of sodium acid pyrophosphate are added, and 9
Stirred at 0 ° C. for 1 hour.

Subsequently, water was distilled off at 90 ° C. under reduced pressure.
10 g of Kyoward 600 (synthetic magnesia silicate, manufactured by Kyowa Chemical Industry Co., Ltd.) was added, and the mixture was dehydrated under reduced pressure at 90 ° C. for 1 hour. Then, 2 liters of hexane was added to dissolve the polymer, and impurities were removed by filtration using filter paper. Thereafter, hexane was distilled off under reduced pressure to obtain a polyoxyalkylene in which 93% of the terminal was allylated. This is a polymer plasticizer PL
Used as 2.

(Examples and Comparative Examples) 100 parts by weight of the organic polymer P1 or P2 was added to calcium carbonate 1
20 parts by weight, 20 parts by weight of heavy calcium carbonate, 55 parts by weight of polymer plasticizer PL1 or PL2, 5 parts by weight of dioctyl phthalate, 3 parts by weight of hydrogenated castor oil, 5 parts by weight of titanium oxide, and phenolic antioxidant Add 1 part by weight and add 3
The composition was obtained by kneading using the paint roll. The viscosity of this composition was measured at 10 rpm and 2.5 rpm with a B8R viscometer (20 ° C., No. 6 rotor), and the thixotropy ratio (the ratio of the numerical value at 10 rpm / the numerical value at 2.5 rpm) was examined.

Further, 3 parts by weight of tin dioctylate, 0.5 part by weight of laurylamine, 6.5 parts by weight of dioctyl phthalate and 20 parts by weight of heavy calcium carbonate were previously mixed with this composition, and the mixture was mixed with three paint rolls. Was added as a curing agent, and the time-dependent change in viscosity at 20 ° C. and 65% humidity was measured using a B8R viscometer (No. 6 rotor).
At 5 rpm, and the time required for the viscosity to reach 800,000 cP was taken as the pot life. Further, after the obtained composition was sealed and stored in a gear oven at 60 ° C. for 2 weeks (storage stability test), the thixotropic property was examined in the same manner. The same curing agent as described above was added, and the pot life was examined. Table 2 shows the results.

As shown in Examples 1 and 2 in Table 2, in the combination of the low ionic impurity P1 and the high molecular weight plasticizer,
While the initial viscosity, thixotropy and pot life are kept almost constant after the storage stability test at 60 ° C. for 2 weeks, the P containing ionic impurities shown in Comparative Examples 1 and 2
The composition comprising the same combination using No. 2 shows a significant increase in viscosity and a decrease in thixotropy after the storage stability test, and a remarkable reduction in the pot life.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

According to the present invention, a curable composition having excellent storage stability can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-113049 (JP, A) JP-A-5-339490 (JP, A) JP-A 8-231707 (JP, A) JP-A-6-231707 200013 (JP, A) Table 6 6-502438 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08G 65/00-65/48

Claims (6)

(57) [Claims] 1. The following organic polymer (A) having a molecular weight of 1,000
A curable composition containing the above polymer plasticizer (E) and curing catalyst (F). (Organic Polymer) Hydroxyl represented by the formula (1) derived from a hydroxyl group-containing polyoxyalkylene polymer (C) obtained by polymerizing an alkylene oxide with an initiator using a double metal cyanide complex (B) as a catalyst. Having a decomposable silicon group,
And an organic polymer (A) having a total amount of ionic impurities of 50 ppm or less. —R—SiX _a R ¹³ _-a (1) In the formula (1), R is a divalent organic group, and R ¹ is a carbon number of 1 to 20.
Is a substituted or unsubstituted monovalent hydrocarbon group, X is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3. 2. The polymer plasticizer (E) is a polyoxyalkylene polymer having a molecular weight of 1,000 to 30,000 obtained by polymerizing an alkylene oxide, and is an organic polymer having no hydrolyzable silicon group. Item 1. The curable composition according to Item 1. 3. The ionic impurity according to claim 1, wherein the ionic impurity is (a) a metal compound derived from the double metal cyanide complex (B) and / or (b) an alkali metal compound. 2. The curable composition of 2. 4. The organic polymer (A) converts ionic impurities contained in the polymer (C) into a salt essentially insoluble in the polymer (C), and then converts the salt into the polymer (C). ), The ionic impurities contained in the polymer (C) are reduced to 50 p.
4. The curable composition according to claim 1, which is an organic polymer obtained by introducing a hydrolyzable silicon group into the polymer (C) after the pm or less. 5. The organic polymer (A) comprises an ionic impurity contained in the terminal unsaturated group-introduced product (D) of the polymer (C),
After forming a salt essentially insoluble in the terminal unsaturated group-introduced product (D), the salt is removed from the terminal unsaturated group-introduced product (D) to be contained in the terminal unsaturated group-introduced product (D). The organic polymer obtained by reducing the ionic impurity to 50 ppm or less and then reacting the terminal unsaturated group-introduced product (D) with the silicon hydride compound represented by the formula (4). Or the curable composition of 3. ^{_{HSiX a R 1 3-a ···}} (4) Equation (4), R ¹ is a monovalent hydrocarbon group having a substituted or unsubstituted 1 to 20 carbon atoms, X is a hydroxyl group or a hydrolyzable group,
a is an integer of 1 to 3. 6. A polymer (C) having a hydroxyl value-converted molecular weight of 50.
The curable composition according to claim 1, 2, 3, 4, or 5, which has a molecular weight of from 00 to 30,000.