JP2019156998A - Curable composition - Google Patents

Abstract

To provide a curable composition containing a polymer having a hydrolyzable silyl group, which realizes improved physical properties of the composition after curing, such as depth curability and weather resistance, by using a polyether-based plasticizer represented by the general formula (2) defined by R(OCHCH)OCHO(CHCHO)Rand/or general formula (3) defined by RC(=O)O-(CHCH-O)-C(=O)Rinstead of a conventional phthalic acid-based plasticizer.SOLUTION: The problem is solved by adding a specific polyether-based plasticizer to a curable composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a moisture-curable curable composition containing a polymer having a hydrolyzable silyl group.

  An organic polymer containing at least one reactive silicon group in the molecule is crosslinked at room temperature by forming a siloxane bond accompanied by a hydrolysis reaction of the reactive silicon group due to moisture, etc. It is known to have the property of being obtained. Among these polymers having reactive silicon groups, polyoxyalkylene polymers and (meth) acrylic acid ester polymers having a main chain skeleton are disclosed in Patent Document 1, Patent Document 2, and the like. Already industrially produced, it is widely used for applications such as sealing materials, adhesives and paints.

  A curable composition containing an organic polymer having a reactive silicon group generally uses a plasticizer for the purpose of improving workability or adjusting the mechanical properties of a cured product. Viscosity and inexpensive phthalate ester plasticizers have been used. In a one-pack type composition using a reactive silicon group-containing polymer, curing proceeds from the surface due to moisture in the air, but for applications that require strength and adhesion at an early stage, deep curing is required. There was a demand to speed up.

  When a phthalate ester plasticizer is used, it is more difficult to improve the deep curability than at present, and there is a concern about a delay in curing due to an ester exchange reaction with an organic polymer containing a reactive silicon group during a storage stability test.

  Patent Document 1 describes a stain resistance and a curing delay-inhibiting cure by adding a polyether monool plasticizer having a molecular weight range of 1000 to 4000.

  However, studies on polyether compounds as plasticizers have been conducted before, but the terminal hydroxyl groups may react with reactive silyl groups in silyl group-containing polyoxyalkylene polymers. Depending on the composition, there is a problem in practical use due to thickening and curing delay. This is particularly remarkable in a one-component composition in which a curing catalyst coexists.

  Therefore, in Patent Document 2, the curing delay inhibition of the main chain-containing adhesive composition having a trialkoxysilyl group-containing oxyalkylene group repeating unit by addition of a polyether plasticizer having a molecular weight of 500 to 5,000 and having a terminal hydroxyl group blocked. The effect of improving storage stability has been found. However, the same effect was not examined for a polyether plasticizer having a lower molecular weight than that. Moreover, examination about the deep part sclerosis | hardenability improvement of a curable composition is not implemented. Curing delay is caused by a decrease in catalyst activity when stored, and it is important to suppress a decrease in the activity of the catalyst for improvement. It is important to make it happen, and the mechanisms of both are different.

  In Patent Documents 3 and 4, etc., 5,8,11,13,16,19-hexaoxatricosane, which is a relatively low molecular weight compound, is used as a plasticizer having a polyether group in the molecule. Yes. However, in Patent Documents 3 and 4, etc., there was no precedent used in combination with a curable composition containing an organic polymer having a reactive silicon group.

JP-A-5-339490 JP 2010-261010 A Special table 2011-511851 gazette JP-A-2015-227405

The present invention relates to a curable composition containing a polymer having a hydrolyzable silyl group, and a general formula R ² (OCH ₂ CH ₂ ) _n OCH ₂ O (CH ₂ ) instead of the conventional phthalic acid plasticizer. By using a polyether-based plasticizer represented by CH ₂ O) _n R ² and / or R ³ C (═O) O— (CH ₂ CH ₂ —O) _m —C (═O) R ³ , It is an object of the present invention to provide a curable composition having improved physical properties after curing, such as deep part curability and weather resistance.

  As a result of studies conducted by the present inventor to solve such problems, the use of a polyether plasticizer improves the deep-part curability and reduces the degree of curability after storage and can be used for a long time. It has been found that a composition can be obtained. Furthermore, it discovered that it was effective in the weather resistance improvement of hardened | cured material by using the said plasticizer.

That is, the present invention
(1). A curable composition comprising 100 parts by weight of an organic polymer (A) having a reactive silicon group represented by the following general formula (1) in the molecule and a polyether plasticizer (B). There,
-SiR ¹ _3-a X ¹ _a (1)
(In the formula, R 1 is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. X ¹ is Each independently is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3, and the polyether plasticizer (B) is represented by the following general formula (2) and / or (3 A curable composition characterized by having
_{^{R 2 (OCH 2 CH 2)}} n OCH 2 O (CH 2 CH 2 O) n R 2 (2)
_{^{R 3 C (= O) O-}} (CH 2 CH 2 -O) m -C (= O) R 3 (3)
(In the formula, each R ² is independently a linear or branched alkyl group having 4 to 12 carbon atoms, and each R ³ is independently a group having 6 to 12 carbon atoms. A linear or branched alkyl group, each n is independently an integer of 1 to 5, and each m is an integer of 2 to 10.)
(2). The curable composition according to (1), which contains the polyether plasticizer (B) of the general formula (2),
(3). The curable composition according to (1) or (2), wherein the organic polymer (A) is a polyoxyalkylene polymer,
(4). The curable composition according to any one of (1) to (3), wherein the polyether-based plasticizer (B) is 5,8,11,13,16,19-hexaoxatricosane,
(5). Any one of (1) to (4), wherein the polyether plasticizer (B) is contained in an amount of 15 to 100 parts by weight with respect to 100 parts by weight of the organic polymer (A). A curable composition of
(6). The present invention relates to a cured product obtained by curing the curable composition according to any one of (1) to (5).

  The present invention is a thermosetting composition containing a polymer having a hydrolyzable silyl group, and the physical properties after curing of the composition, for example, deep curability, little physical property change after storage test, and improvement in weather resistance. A composition having an effect is provided.

It is explanatory drawing which showed the time-dependent change of hardened | cured material surface crack generation when the weather resistance test of hardened | cured material was implemented.

The present invention will be described in detail below.
The present invention relates to 100 parts by weight of an organic polymer (A) having at least one reactive silicon group in one molecule represented by the general formula (1),
-SiR ¹ _3-a X ¹ _a (1)
(In the formula, R 1 is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. X ¹ is Each independently is either a hydroxyl group or a hydrolyzable group, and a is an integer from 1 to 3), and
15 to 100 parts by weight of the polyether-based plasticizer (B) represented by the general formula (2) and / or (3) R ² (OCH ₂ CH ₂ ) _n OCH ₂ O (CH ₂ CH ₂ O) _n R ² ( 2)
And / or R ³ C (═O) O— (CH ₂ CH ₂ —O) _m —C (═O) R ³ (3)
(In the formula, each R ² is independently a linear or branched alkyl group having 4 to 12 carbon atoms, and each R ³ is independently a group having 6 to 12 carbon atoms. A linear or branched alkylene group, each n is independently an integer of 1 to 5, and each m is independently an integer of 2 to 10). It relates to a curable composition.

<Organic polymer having hydrolyzable silyl group (A)>
The main chain skeleton of the organic polymer (A) is not particularly limited, and those having various main chain skeletons can be used.

  Specifically, polyoxyalkylene heavy polymers such as polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene-polyoxybutylene copolymer, etc. Copolymer; ethylene-propylene copolymer, polyisobutylene, copolymer of isobutylene and isoprene, polychloroprene, polyisoprene, isoprene or copolymer of butadiene and acrylonitrile and / or styrene, polybutadiene, isoprene or butadiene And a copolymer of acrylonitrile and / or styrene, etc., hydrocarbon polymers such as hydrogenated polyolefin polymers obtained by hydrogenating these polyolefin polymers; dibasic acids such as adipic acid; Polyester polymers obtained by condensation with recall or ring-opening polymerization of lactones; polyacrylic acid esters obtained by radical polymerization of monomers such as ethyl acrylate and butyl acrylate, acrylic acids such as ethyl acrylate and butyl acrylate Acrylate ester polymers such as acrylate copolymers of esters with vinyl acetate, acrylonitrile, methyl methacrylate, styrene, etc .; graft polymers obtained by polymerizing vinyl monomers in the organic polymers; polysulfides Polymer: Nylon 6 by ring-opening polymerization of ε-caprolactam, Nylon 6.6 by condensation polymerization of hexamethylenediamine and adipic acid, Nylon 6.10 by condensation polymerization of hexamethylenediamine and sebacic acid, ε-aminoundecanoic acid Condensation polymerization Nylon 11, nylon 12 by ring-opening polymerization of ε-aminolaurolactam, polyamide-based polymer such as copolymer nylon having two or more components among the above nylons; for example, polycondensation from bisphenol A and carbonyl chloride Examples thereof include polycarbonate polymers and diallyl phthalate polymers to be produced.

  Saturated hydrocarbon polymers such as polyisobutylene, hydrogenated polyisoprene and hydrogenated polybutadiene, polyoxyalkylene polymers, and (meth) acrylic acid ester polymers have a relatively low glass transition temperature, and the resulting cured product Is more preferable because of its excellent cold resistance.

  The glass transition temperature of the organic polymer as component (A) is not particularly limited, but is preferably 20 ° C. or lower, more preferably 0 ° C. or lower, and particularly preferably −20 ° C. or lower. . If the glass transition temperature exceeds 20 ° C., the viscosity in winter or in a cold region may increase and workability may deteriorate, and the flexibility of the cured product may decrease and elongation may decrease. The glass transition temperature is a value obtained by DSC measurement.

  In addition, polyoxyalkylene polymers and (meth) acrylic acid ester polymers are particularly preferable because they have high moisture permeability and are excellent in deep-part curability when made into a one-component composition, and also in excellent adhesiveness. A polyoxyalkylene polymer is most preferred. Among the polyoxyalkylene polymers, polyoxypropylene polymers are particularly preferable.

The reactive silicon group contained in the organic polymer of the present invention has a hydroxy group or hydrolyzable group bonded to a silicon atom, and is crosslinked by forming a siloxane bond by a reaction accelerated by a silanol condensation catalyst. Is a possible group. As the reactive silicon group, the general formula (1):
-SiR ¹ _3-a X _a (1)
(In the formula, each R ¹ independently represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or —OSi (R ′) _3. (Wherein R ′ is each independently a hydrocarbon group having 1 to 20 carbon atoms), and X is each independently a hydroxy group or a hydrolyzable group. , A is an integer of 1 to 3).

  It does not specifically limit as a hydrolysable group, What is necessary is just a conventionally well-known hydrolysable group. Specific examples include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group are preferable. From the viewpoint that hydrolysis is mild and easy to handle. The group is particularly preferred.

Hydrolyzable groups and hydroxy groups can be bonded to one silicon atom in the range of 1 to 3. When two or more hydrolyzable groups or hydroxy groups are bonded to the reactive silicon group, they may be the same or different.
In the general formula (1), n is preferably 2 or 3 from the viewpoint of curability, and is particularly preferably 3 when quick curability is required, and when stability during storage is required. Is preferably 2.

Specific examples of R ¹ in the general formula (1) include, for example, an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, And a triorganosiloxy group represented by —OSi (R ′) _{3 in} which R ′ is a methyl group, a phenyl group, or the like. Of these, a methyl group is particularly preferred.

  More specific examples of the reactive silicon group include a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, and a diisopropoxymethylsilyl group. A trimethoxysilyl group, a triethoxysilyl group, and a dimethoxymethylsilyl group are more preferable, and a trimethoxysilyl group is particularly preferable because of high activity and good curability. Further, from the viewpoint of storage stability, a dimethoxymethylsilyl group and a triethoxysilyl group are particularly preferable. Further, triethoxysilyl group and diethoxymethylsilyl group are particularly preferable because the alcohol produced by the hydrolysis reaction of the reactive silicon group is ethanol and has higher safety.

  Introduction of the reactive silicon group may be performed by a known method. That is, for example, the following method can be mentioned.

  (I) An organic polymer having an unsaturated group by reacting an organic polymer having a functional group such as a hydroxy group in the molecule with an organic compound having an active group and an unsaturated group that are reactive with the functional group. A polymer is obtained. Alternatively, an unsaturated group-containing organic polymer is obtained by copolymerization with an unsaturated group-containing epoxy compound. Next, the resulting reaction product is hydrosilylated by the action of a hydrosilane having a reactive silicon group.

  (II) An organic polymer containing an unsaturated group obtained in the same manner as in the method (I) is reacted with a compound having a mercapto group and a reactive silicon group.

  (III) An organic polymer having a functional group such as a hydroxy group, an epoxy group or an isocyanate group in the molecule is reacted with a compound having a reactive functional group and a reactive silicon group.

  Among the above methods, the method (I) or the method (III) in which the polymer having a hydroxyl group at the terminal is reacted with the compound having an isocyanate group and a reactive silicon group has a relatively short reaction time. It is preferable because a high conversion rate can be obtained. Furthermore, the organic polymer having a reactive silicon group obtained by the method (I) becomes a curable composition having a lower viscosity and better workability than the organic polymer obtained by the method (III). The organic polymer obtained by the method (II) has a strong odor based on mercaptosilane, and therefore the method (I) is particularly preferred.

  Specific examples of the hydrosilane compound used in the method (I) include halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and phenyldichlorosilane; trimethoxysilane, triethoxysilane, and methyldiethoxysilane. , Methyldimethoxysilane, phenyldimethoxysilane, alkoxysilanes such as 1- [2- (trimethoxysilyl) ethyl] -1,1,3,3-tetramethyldisiloxane; methyldiacetoxysilane, phenyldiacetoxysilane Examples thereof include, but are not limited to, acyloxysilanes such as: ketoximate silanes such as bis (dimethylketoximate) methylsilane and bis (cyclohexylketoximate) methylsilane. Of these, halogenated silanes and alkoxysilanes are particularly preferable, and alkoxysilanes are particularly preferable because the hydrolyzability of the resulting curable composition is gentle and easy to handle. Among the alkoxysilanes, methyldimethoxysilane is preferred because it is easily available and the curable composition containing the resulting organic polymer has high curability, storage stability, elongation characteristics, and tensile strength. Trimethoxysilane is particularly preferable from the viewpoints of curability and restorability of the resulting curable composition.

  As a synthesis method of (II), for example, a compound having a mercapto group and a reactive silicon group is converted into an unsaturated bond site of an organic polymer by a radical addition reaction in the presence of a radical initiator and / or a radical generation source. Although the method of introduce | transducing etc. is mentioned, it does not specifically limit. Specific examples of the compound having a mercapto group and a reactive silicon group include, for example, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldiethoxy. Examples include, but are not limited to, silane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, and the like.

  As a method of reacting a polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group in the synthesis method of (III), for example, the method described in JP-A-3-47825 can be mentioned. However, it is not particularly limited. Specific examples of the compound having an isocyanate group and a reactive silicon group include, for example, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropyltriethoxysilane, and γ-isocyanatepropylmethyldiethoxy. Examples include, but are not limited to, silane, isocyanate methyltrimethoxysilane, isocyanatemethyltriethoxysilane, isocyanatemethyldimethoxymethylsilane, and isocyanatemethyldiethoxymethylsilane.

  A silane compound in which three hydrolyzable groups are bonded to one silicon atom such as trimethoxysilane may undergo a disproportionation reaction. As the disproportionation reaction proceeds, an unstable compound such as dimethoxysilane is produced, which may make handling difficult. However, such disproportionation reaction does not proceed with γ-mercaptopropyltrimethoxysilane or γ-isocyanatopropyltrimethoxysilane. For this reason, when a group in which three hydrolyzable groups such as trimethoxysilyl group are bonded to one silicon atom is used as the silicon-containing group, the synthesis method (II) or (III) may be used. preferable.

On the other hand, general formula (4):
H- (SiR ⁴ ₂ O) _b SiR ⁴ ₂ -R ⁵ -SiX ₃ (4)
(In the formula, X is the same as above. 2m + 2 R ^{2 s} are each independently a hydrocarbon group, and from the viewpoint of availability and cost, a hydrocarbon group having 1 to 20 carbon atoms is preferable. A hydrocarbon group having 1 to 8 carbon atoms is more preferable, and a hydrocarbon group having 1 to 4 carbon atoms is particularly preferable, and R ⁵ is a divalent organic group, and has 1 to 12 carbon atoms in view of availability and cost. The divalent hydrocarbon group is preferably a divalent hydrocarbon group having 2 to 8 carbon atoms, more preferably a divalent hydrocarbon group having 2 carbon atoms, and b is 0 to 19. The silane compound represented by the formula (1 is preferable from the viewpoint of availability and cost) does not proceed with the disproportionation reaction.

Therefore, when introducing a group in which three hydrolyzable groups are bonded to one silicon atom in the synthesis method (I), use the silane compound represented by the general formula (2). Is preferred. Specific examples of the silane compound represented by the general formula (2) include 1- [2- (trimethoxysilyl) ethyl] -1,1,3,3-tetramethyldisiloxane, 1- [2- (trimethoxy Silyl) propyl] -1,1,3,3-tetramethyldisiloxane, 1- [2- (trimethoxysilyl) hexyl] -1,1,3,3-tetramethyldisiloxane.
The organic polymer having a reactive silicon group may be linear or branched, and its number average molecular weight is about 500 to 100,000 in terms of polystyrene in GPC, more preferably 1,000 to 50,000. And particularly preferably from 3,000 to 30,000. If the number average molecular weight is less than 500, the cured product tends to be disadvantageous in terms of elongation characteristics, and if it exceeds 100,000, the viscosity tends to be inconvenient because of high viscosity.
In order to obtain a rubber-like cured product having high strength, high elongation and low elastic modulus, the average number of reactive silicon groups contained in the organic polymer is at least 1, preferably 1, .1 to 5 should be present. When the number of reactive silicon groups contained in the molecule is less than 1 on average, curability becomes insufficient and it becomes difficult to exhibit good rubber elastic behavior. The reactive silicon group may be at the end of the main chain or the side chain of the organic polymer molecular chain, or at both ends. In particular, when the reactive silicon group is only at the end of the main chain of the molecular chain, the effective network length of the organic polymer component contained in the finally formed cured product is increased, so that the strength and elongation are high. It becomes easy to obtain a rubber-like cured product exhibiting a low elastic modulus.

The polyoxyalkylene polymer essentially has the general formula (5):
—R ⁶ —O— (5)
(Wherein R ⁶ is a linear or branched alkylene group having 1 to 14 carbon atoms), and R ⁶ in the general formula (5) is the number of carbon atoms. 1 to 14, more preferably 2 to 4, linear or branched alkylene groups are preferred. Specific examples of the repeating unit represented by the general formula (5) include
_{-CH 2 O -, - CH 2} CH 2 O -, - CH 2 CH (CH 3) O -, - CH 2 CH (C 2 H 5) O -, - CH 2 C (CH 3) (CH 3) _{O -, - CH 2 CH 2} CH 2 CH 2 O- and the like. The main chain skeleton of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units. In particular, when used in a sealant or the like, a polymer comprising a propylene oxide polymer as a main component is preferred because it is amorphous or has a relatively low viscosity.

  Examples of the method for synthesizing the polyoxyalkylene polymer include a polymerization method using an alkali catalyst such as KOH, and a complex obtained by reacting an organoaluminum compound and porphyrin as disclosed in JP-A-61-215623. Polymerization method using transition metal compound-porphyrin complex catalyst, Japanese Patent Publication No. 46-27250, Japanese Patent Publication No. 59-15336, US Pat. No. 3,278,457, US Pat. No. 3,278,458, US Pat. No. 3,278,459, US Pat. No. 3,427,256, US Pat. Polymerization method using double metal cyanide complex catalyst as shown in U.S. Pat. No. 3,427,335, polymerization method using catalyst comprising polyphosphazene salt exemplified in JP-A-10-273512, phosphazene exemplified in JP-A-11-060722 Using a compound catalyst Polymerization method, and the like, but not particularly limited.

  A method for producing a polyoxyalkylene polymer having a reactive silicon group is disclosed in JP-B Nos. 45-36319, 46-12154, JP-A Nos. 50-156599, 54-6096, and 55-13767. JP-A-55-13468, JP-A-57-16123, JP-B-3-2450, US Pat. No. 3,632,557, US Pat. No. 4,345,053, US Pat. No. 4,366,307, US Pat. No. 4,960,844, etc. -197631, 61-215622, 61-215623, 61-218632, JP-A-3-72527, JP-A-3-47825, and JP-A-8-231707. Polyoxya with a narrow molecular weight distribution with a high molecular weight with a number average molecular weight of 6,000 or more and Mw / Mn of 1.6 or less Killen polymer can be exemplified, but not particularly limited thereto.

  Examples of the organic polymer having an active hydrogen-containing group at the terminal include an oxyalkylene polymer having a hydroxy group at the terminal (polyether polyol), a polyacryl polyol, a polyester polyol, and a saturated hydrocarbon polymer having a hydroxy group at the terminal ( Polyolefin polyol), polythiol compounds, polyamine compounds and the like. Among these, polyether polyol, polyacryl polyol, and polyolefin polyol are preferable because the obtained organic polymer has a relatively low glass transition temperature and the resulting cured product is excellent in cold resistance. In particular, polyether polyols are particularly preferred because the resulting organic polymer has a low viscosity, good workability, and good deep part curability and adhesiveness. Polyacryl polyols and saturated hydrocarbon polymers are more preferred because the resulting cured organic polymer has good weather resistance and heat resistance.

  As the polyether polyol, those produced by any production method can be used, but those having at least 0.7 hydroxy groups per molecular terminal in the average of all molecules are preferable. Specifically, an oxyalkylene polymer produced using a conventional alkali metal catalyst, an initiator such as a polyhydroxy compound having at least two hydroxy groups in the presence of a double metal cyanide complex or cesium, an alkylene Examples include oxyalkylene polymers produced by reacting oxides.

  Among the above polymerization methods, a polymerization method using a double metal cyanide complex has a lower degree of unsaturation, a smaller Mw / Mn, a lower viscosity, a high acid resistance, and a high weather resistance oxyalkylene heavy. It is preferable because a coalescence can be obtained.

<Polyether plasticizer (B)>
As the plasticizer of the present invention, the general formula (2) and / or (3)
^{_{R 2 (OCH 2 CH 2)}} n OCH 2 O (CH 2 CH 2 O) n R 2 (2)
_{^{R 3 C (= O) O-}} (CH 2 CH 2 -O) m -C (= O) R 3 (3)
(In the formula, each R ² is independently a linear or branched alkyl group having 4 to 12 carbon atoms, and each R ³ is independently a group having 6 to 12 carbon atoms. A linear or branched alkyl group, each n is independently an integer of 1 to 5, and each m is an integer of 2 to 10).

Specific examples of the plasticizer include the above general formula (2) such as 5,8,11,13,16,19-hexaoxatricosane and / or the above such as polyethylene glycol bis (2-ethylhexanoic acid). Examples include ether plasticizers represented by general formula (3).
In addition, aliphatic dibasic acid esters such as dibutyl adipate, acetic acid esters such as glycerin triacetate, aromatic esters such as dibutyl phthalate, normal phosphoric acid esters such as trimethyl phosphate, sulfonamides such as N-butylbenzenesulfonamide, And / or mono or polyethylene glycol 400 di-2-ethylhexonoate (currently commercially available as TegMe® 809 glycol ester (CAS No. 9004-93-7) from The CP. Hall Company, Chicago, Illinois) Possible), triethylene glycol di-2-ethylhexonoate (currently commercially available as TegMe® 803 glycol ester (CAS No. 94-28-0) from The CP. Hall Company, Chicago, Illinois) And tetraethylene glycol di-2-ethylhexonoate (currently from The CP. Hall Company, Chicago, Illinois TegMeR® 804 glycol ester (available commercially as CAS No. 18268-70-7)), but is not limited thereto.

The said plasticizer can be used individually by 1 type or in combination of 2 or more types.
R ³ may be linear or branched, and preferably has 6 to 12 carbon atoms. A specific example of R ³ is preferably a 2-ethylhexyl group.

  Among these, 5,8,11,13,16,19-hexaoxatricosane represented by the general formula (2) is particularly preferable.

  The amount of the plasticizer used is preferably 15 to 300 parts by weight, more preferably 15 to 100 parts by weight, and particularly preferably 15 to 60 parts by weight with respect to 100 parts by weight of the polymer (A) having a hydrolyzable silyl group. preferable.

<Other additives>
In addition to the organic polymer (A) having a hydrolyzable silyl group, a filler, an adhesion imparting agent, an antioxidant, a light stabilizer, and an ultraviolet absorber are added as additives to the composition of the present invention. May be. Moreover, you may add the polymer which has hydrolysable silyl groups other than a polyoxyalkylene type. Examples of the polymer include acrylic polymers and saturated hydrocarbon polymers. Furthermore, you may add various additives to the curable composition of this invention as needed. Examples of such additives include, for example, silanol condensation catalysts, solvents, diluents, sagging inhibitors, physical property modifiers, tackifier resins, photocurable materials, oxygen curable materials, surface property improvers, epoxy resins. , Other resins, flame retardants, curability modifiers, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus peroxide decomposers, lubricants, pigments, fungicides, and the like.

<Filler>
Various fillers can be mix | blended with the composition of this invention. Fillers include heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, clay, talc, titanium oxide, fumed silica, precipitated silica, crystalline silica, fused silica, anhydrous silicic acid, hydrous silicic acid, Examples thereof include carbon black, ferric oxide, aluminum fine powder, zinc oxide, activated zinc white, PVC powder, PMMA powder, glass fiber, filament, organic balloon, and inorganic balloon.

  The amount of the filler used is preferably 1 to 300 parts by weight, particularly preferably 10 to 250 parts by weight, based on 100 parts by weight of the polymer (A) having a hydrolyzable silyl group.

<Adhesive agent>
An adhesiveness imparting agent can be added to the composition of the present invention.

  As an adhesiveness imparting agent, a silane coupling agent or a reaction product of a silane coupling agent can be added.

  Specific examples of the silane coupling agent include γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-. Amino group-containing silanes such as aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, (2-aminoethyl) aminomethyltrimethoxysilane; γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltri Isocyanate group-containing silanes such as ethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, α-isocyanatemethyltrimethoxysilane, α-isocyanatemethyldimethoxymethylsilane; γ-mercaptopropyltrimethoxysilane , Γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane and other mercapto group-containing silanes; γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. And epoxy group-containing silanes.

  The adhesiveness-imparting agent may be used alone or in combination of two or more. Moreover, the reaction material of various silane coupling agents can also be used.

  0.1-20 weight part is preferable with respect to 100 weight part of polymers (A) which have a hydrolyzable silyl group, and, as for the usage-amount of a silane coupling agent, 0.5-10 weight part is especially preferable.

<Antioxidant>
An antioxidant (antiaging agent) can be used in the composition of the present invention. If an antioxidant is used, the weather resistance of the cured product can be increased. Examples of the antioxidant include hindered phenols, monophenols, bisphenols, and polyphenols. Specific examples of the antioxidant are also described in JP-A-4-283259 and JP-A-9-194731.

  0.1-15 weight part is preferable with respect to 100 weight part of polymers (A) which have a hydrolysable silyl group, and, as for the usage-amount of antioxidant, 1-10 weight part is more preferable.

<Light stabilizer>
A light stabilizer can be used in the composition of the present invention. Use of a light stabilizer can prevent photooxidation degradation of the cured product. Examples of the light stabilizer include benzotriazole, hindered amine, and benzoate compounds, with hindered amines being particularly preferred.

  0.1-10 weight part is preferable with respect to 100 weight part of polymers (A) which have a hydrolysable silyl group, and, as for the usage-amount of a light stabilizer, 0.2-5 weight part is especially preferable.

<Ultraviolet absorber>
An ultraviolet absorber can be used in the composition of the present invention. When the ultraviolet absorber is used, the surface weather resistance of the cured product can be enhanced. Examples of UV absorbers include benzophenone, benzotriazole, salicylate, substituted tolyl, and metal chelate compounds, but benzotriazole is particularly preferable, and commercially available names are Tinuvin P, Tinuvin 213, Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, Tinuvin 571 (above, manufactured by BASF) can be mentioned.

  0.1-10 weight part is preferable with respect to 100 weight part of polymers (A) which have a hydrolyzable silyl group, and, as for the usage-amount of a ultraviolet absorber, 0.2-5 weight part is especially preferable.

<Preparation of curable composition>
When the curable composition of the present invention is a one-component type, since all of the blending components are blended in advance, if moisture is present in the blend, curing may proceed during storage. Therefore, it is preferable to add the moisture-containing blending component after dehydrating and drying in advance, or dehydrating it during decompression or the like during blending kneading.

As the dehydration and drying method, use heat drying method or vacuum dehydration method when the compound is a solid such as powder, and use vacuum zeolite dehydration method or synthetic zeolite, activated alumina, silica gel, quick lime, magnesium oxide, etc. The dehydration method is preferred. Further, n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, methylsilicate, ethylsilicate, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxy An alkoxysilane compound such as silane; an oxazolidine compound such as 3-ethyl-2-methyl-2- (3-methylbutyl) -1,3-oxazolidine; or an isocyanate compound added to the curable composition, A dehydration method performed by reacting with water contained therein is also preferable. Thus, the storage stability of a curable composition improves by addition of an alkoxysilane compound, an oxazolidine compound, and an isocyanate compound.
As an addition amount when using an alkoxysilane compound that can react with water such as vinyltrimethoxysilane for the purpose of drying, 0.1 to 20 parts by weight is preferable with respect to 100 parts by weight of the organic polymer (A). 0.5-10 weight part is more preferable.

  The method for preparing the curable composition of the present invention is not particularly limited. For example, the above-described compounding components are prepared and kneaded using a mixer, roll, kneader, or the like at room temperature or under heating, and a suitable solvent. A known method such as a method in which a small amount is used and the compounding components are dissolved and then mixed can be employed.

  When exposed to the atmosphere, the curable composition of the present invention forms a three-dimensional network structure by the action of moisture, and cures to a solid having rubbery elasticity.

<Application>
The curable composition of the present invention comprises: an adhesive; a sealing material for buildings, ships, automobiles, roads, etc .; an adhesive; a mold taking agent; a vibration-proofing material; a vibration-damping material; Among these uses, the obtained cured product is more excellent in flexibility and adhesiveness, so that it is more preferably used as a sealing material or an adhesive.

  Examples of the method of the present invention will be specifically described below, but the present invention is not limited to these examples.

  The number average molecular weight and molecular weight distribution in the examples are GPC molecular weight and molecular weight distribution measured under the following conditions.

Liquid feeding system: Tosoh HLC-8220GPC
Column: Tosoh TSK-GEL H type Solvent: THF
Molecular weight: Polystyrene conversion Measurement temperature: 40 ° C

  The molecular weight in terms of end groups in the examples is determined by measuring the hydroxyl value by the measuring method of JIS K 1557 and the iodine value by the measuring method of JIS K 0070, and calculating the structure of the organic polymer (the degree of branching determined by the polymerization initiator used). This is the molecular weight determined in consideration.

(Synthesis Example 1)
Polymerization of propylene oxide with a zinc hexacyanocobaltate glyme complex catalyst using a 1/1 (weight ratio) mixture of polyoxypropylene diol having a molecular weight of about 2,000 and polyoxypropylene triol having a molecular weight of about 3,000 as an initiator. A polypropylene oxide having a number average molecular weight of about 19,000 (polystyrene equivalent molecular weight measured using Tosoh's HLC-8120GPC as the liquid feeding system, TOS-GEL H type as the column, and THF as the solvent). It was. Subsequently, a methanol solution of NaOMe 1.2 times equivalent to the hydroxyl group of the hydroxyl group-terminated polypropylene oxide was added to distill off the methanol, and 1.7 times equivalent of allyl chloride to the hydroxyl group was added. The terminal hydroxyl group was converted to an allyl group.

  After mixing and stirring 300 parts by weight of n-hexane and 300 parts by weight of water with respect to 100 parts by weight of the obtained unpurified allyl-terminated polypropylene oxide, water was removed by centrifugation, and water was further added to the resulting hexane solution. After 300 parts by weight of the mixture were mixed and stirred, water was removed again by centrifugation, and then hexane was removed by devolatilization under reduced pressure. As a result, a polypropylene oxide having a number average molecular weight of about 19,000 having an allyl group at the end was obtained. 100 parts by weight of the allyl group-terminated polypropylene oxide was reacted with 1.35 parts by weight of methyldimethoxysilane at 90 ° C. for 2 hours using 150 ppm of an isopropanol solution having a platinum content of 3 wt% of a platinum vinylsiloxane complex as a catalyst. Obtained a polyoxypropylene polymer (A-1) having 7 methyldimethoxysilyl groups.

Example 1
100 parts by weight of the reactive silicon group-containing polyoxypropylene polymer (A-1) obtained in Synthesis Example 1, and 5,8,11,13,16,19-hexaoxatricosane (made by Hallstar) as a plasticizer , Trade name: TP-90B) 55 parts by weight, surface-treated colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., trade name: Shirahika Hana CCR), 120 parts by weight, rutile titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., trade name: Typaque R-820) 20 parts by weight, thixotropic agent (manufactured by Enomoto Kasei Kogyo Co., Ltd., trade name: Disparon 6500), 2 parts by weight, hindered amine light stabilizer (manufactured by BASF Japan Ltd., trade name: TINUVIN 770) 1 part by weight and 1 part by weight of a benzotriazole-based UV absorber (BASF Japan Ltd., trade name: TINUVIN 326) were mixed and sufficiently kneaded. After that, it was dispersed by passing three times through three paint rolls. Thereafter, dehydration under reduced pressure at 120 ° C. for 2 hours, cooling to 50 ° C. or less, and 2 parts by weight of vinyltrimethoxysilane (manufactured by EVONIK, trade name: Dynasylan VTMO) as a dehydrating agent, γ- ( 2-aminoethyl) aminopropyltrimethoxysilane (manufactured by EVONIK, trade name: Dynasylan DAMO) 3 parts by weight, and finally dibutyltin bisacetylacetonate (manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-) as a curing catalyst 220H) 2 parts by weight was added and kneaded, and sealed in a moisture-proof cartridge in the absence of moisture to obtain a one-component curable composition.

(Example 2)
Instead of using 5,8,11,13,16,19-hexaoxatricosane in Example 1, polyethylene glycol 400 di-2-ethylhexanoate (Hallstar, trade name: TegMeR 809) 55 weight A curable composition was obtained in the same manner as in Example 1 except that the parts were used.

(Comparative Example 1)
Instead of using 5,8,11,13,16,19-hexaoxatricosane in Example 1, diisodecyl phthalate which is a phthalate ester plasticizer (trade name: DIDP, manufactured by J. Plus) A curable composition was obtained in the same manner as in Example 1 except that 55 parts by weight was used.

  Using the curable composition obtained above, the skinning time of the surface and the deep curability were measured. A moisture-proof paper / aluminum cartridge (Showa Marutsu, 330 ml) is filled with the curable composition, placed in a 50 ° C. dryer for 4 weeks, and then placed at 23 ° C. and 50% RH for 1 day. The surface skinning time was measured. In addition, a weather resistance test evaluation using a sunshine super long life weather meter was performed on the cured product. Each physical property was evaluated by the following methods. The results are shown in Table 1 and FIG.

(Surface skinning time)
The above curable composition was stretched with a spatula to a thickness of about 3 mm under conditions of 23 ° C. and 50% RH, and the surface of the curable composition was lightly touched over time using a microspatula. The time until the micro spatula was not reached was measured.

(Deep part curability)
The above curable composition was filled in a polyethylene tube having a diameter of 12 mm under conditions of 23 ° C. and 50% RH so as not to cause bubbles, and was scraped with a spatula so that the surface was horizontal to obtain a test specimen. After standing for 7 days under the same conditions, the cured portion of the surface layer was peeled off, the uncured portion was removed cleanly, and the thickness of the cured portion was measured using calipers.
(Storage stability) The state (cured or uncured) of the composition after the obtained cartridge was stored at 50 ° C. for 4 weeks was confirmed by skinning time measurement.

(Evaluation of weather resistance of cured product)
Cut a few cured sheets (3mm thickness) obtained under conditions of 23 ° C, 50% RH, 3 days + 50 ° C, 4 days into squares of about 2cm x 2cm, and fix one side using double-sided tape on an aluminum plate I let you. An aluminum sheet to which the cured product sheet was attached was placed on a mold, and weather resistance evaluation was started in a sunshine super long life weather meter (WEL-SUN-HC-B type). The evaluation start time was set to 0 h, and one sample was taken out every about 1000 hours from the initial stage, and the state evaluation was performed visually. A sample with almost no deterioration of the sample (no crack) was described as “◯”, and the sample at the time of taking out the crack was described as “x”.

  As can be seen from Table 1 and FIG. 1, the curable composition using 5,8,11,13,16,19-hexaoxatricosane as a plasticizer is a phthalate ester plasticizer (diisodecyl phthalate; DIDP). The initial curability is fast compared to the above, and the degree to which the curability decreases (becomes slower) after 4 weeks at 50 ° C. is small, and can be suitably used for a long time. This composition is good with almost no cure rate delay as compared to the use of phthalate plasticizers that have been used conventionally. Further, the deep-part curability was remarkably improved, and deterioration of the cured product (crack generation) was not observed after 5000 hours even in the evaluation of the weather resistance test.

  In addition, polyethylene glycol 400 di-2-ethylhexanoate is a diester compound obtained from diethylene glycol and 2-ethylhexanoic acid. As shown in Example 2, although deep curing is excellent, the curing rate decreases after storage. Following 5,8,11,13,16,19-hexaoxatricosane, it is superior in terms of deep part curability and weather resistance compared to phthalate plasticizers.

On the other hand, the composition using diisodecyl phthalate as a plasticizer has a deep curability of 5,8,11,13,16,19-hexaoxatricosane and polyethylene glycol 400 di-2-ethylhexanoate at the initial evaluation. It was lower than that, and it was 10 mm or less after 7 days. Furthermore, in comparison with 5,8,11,13,16,19-hexaoxatricosane, the composition using diisodecyl phthalate as a plasticizer has a slower curing time after storage stability evaluation than in the initial evaluation. became. It can be seen from FIG. 1 that the occurrence of surface cracks in the composition using diisodecyl phthalate as the plasticizer was the earliest and more frequent than the weather resistance test evaluation.
Among the many polyether group-containing compounds, it has been found in this evaluation that a compound having no ester group is particularly suitable as a plasticizer for a one-component curable composition using the component (A).

  The present invention is a curable composition containing a polymer having a hydrolyzable silyl group. Physical properties after curing of the composition, for example, deep curability, little change in physical properties after storage test, and effect on improving weather resistance Is provided.

The present invention will be described in detail below.
The present invention relates to 100 parts by weight of an organic polymer (A) having at least one reactive silicon group in one molecule represented by the general formula (1),
-SiR ¹ _3-a X ¹ _a (1)
(In the formula, R 1 is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. X ¹ is Each independently is either a hydroxyl group or a hydrolyzable group, and a is an integer from 1 to 3), and
15 to 100 parts by weight of the polyether-based plasticizer (B) represented by the general formula (2) and / or (3) R ² (OCH ₂ CH ₂ ) _n OCH ₂ O (CH ₂ CH ₂ O) _n R ² ( 2)
And / or R ³ C (═O) O— (CH ₂ CH ₂ —O) _m —C (═O) R ³ (3)
(In the formula, each R ² is independently a linear or branched alkyl group having 4 to 12 carbon atoms, and each R ³ is independently a group having 6 to 12 carbon atoms. A linear or branched alkylene group, each n is independently an integer of 1 to 5, and each m is independently an integer of 2 to 10). The present invention relates to a curable composition.

Claims (6)

A curable composition comprising 100 parts by weight of an organic polymer (A) having a reactive silicon group represented by the following general formula (1) in the molecule and a polyether plasticizer (B). There,
-SiR ¹ _3-a X ¹ _a (1)
(In the formula, R 1 is at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. X ¹ is Each independently is a hydroxyl group or a hydrolyzable group, and a is an integer of 1 to 3, and the polyether plasticizer (B) is represented by the following general formula (2) and / or (3 The curable composition characterized by having.
_{^{R 2 (OCH 2 CH 2)}} n OCH 2 O (CH 2 CH 2 O) n R 2 (2)
_{^{R 3 C (= O) O-}} (CH 2 CH 2 -O) m -C (= O) R 3 (3)
(In the formula, each R ² is independently a linear or branched alkyl group having 4 to 12 carbon atoms, and each R ³ is independently a group having 6 to 12 carbon atoms. A linear or branched alkyl group, each n is independently an integer of 1 to 5, and each m is an integer of 2 to 10.) 2. The curable composition according to claim 1, comprising the polyether plasticizer (B) of the general formula (2). The curable composition according to claim 1 or 2, wherein the organic polymer (A) is a polyoxyalkylene polymer. The curable composition according to any one of claims 1 to 3, wherein the polyether plasticizer (B) is 5,8,11,13,16,19-hexaoxatricosane. The polyether-based plasticizer (B) is contained in 15 to 100 parts by weight with respect to 100 parts by weight of the organic polymer (A), according to any one of claims 1 to 4. Curable composition. Hardened | cured material obtained by hardening the curable composition of any one of Claim 1 to 5.