JP5188698B2 - Curable composition - Google Patents

Description

  The present invention relates to a curable composition excellent in weather resistance and suitable as a sealing material, and in particular, contains a triazine compound excellent in ultraviolet absorption, and provides a cured product excellent in surface weather resistance. About.

  In recent years, an organic polymer containing a reactive silicon group, that is, a silicon atom-containing group containing a silicon atom bonded with a hydroxyl group or a hydrolyzable group, which can form a siloxane bond, is used as a base component of a sealing material. It is made to use. Such a modified silicone sealant is excellent in weather resistance and durability, so that the demand is steadily growing.

  Various synthetic methods have been proposed for organic polymers having a reactive silicon group and at least one urethane bond in the molecule, and have excellent properties as a sealing material in terms of mechanical properties and water resistance. It has been known. (See Patent Document 1 and Patent Document 2)

However, such a reactive silicon group-containing polymer has a problem that the weather resistance of the cured product surface is poor due to a urethane bond contained in the molecule. For this reason, it has not been put into practical use as a sealing material for buildings where the weather resistance of the surface is regarded as important.
JP-A-5-287186 JP 2001-19842 A

  The present invention has been made to solve these problems, and a cured product having a reactive silicon group-containing oxyalkylene polymer as a main component, good weather resistance, and particularly excellent surface weather resistance is obtained. An object of the present invention is to provide a curable composition suitable as a sealing material for an automobile.

  As a result of intensive investigations to achieve the above object, the present inventor has found that an ultraviolet absorber having a specific chemical structure is extremely effective in improving the surface weather resistance, and is further unique by combining an antioxidant. The present invention was completed by finding that a sealing material exhibiting a natural effect, having good weather resistance and having excellent surface weather resistance can be obtained.

That is, the curable composition of the present invention mainly comprises (A) a reactive silicon group-containing oxyalkylene polymer having a urethane bond having a number average molecular weight (Mn) of 4,000 or more, and (B) a triazine-based ultraviolet ray. An absorbent, at least one curing catalyst selected from dibutyltin dilaurate, dibutyltin maleate, dibutyltin acetate, tin octylate, tin naphthenate, dibutyltin oxide and phthalate, and dibutyltin acetylacetonate; It contains 1 type chosen from the condensation product of aminopropyltrimethoxysilane , 3- (2-aminoethyl) aminopropyltrimethoxysilane, and ( gamma ) -aminopropylmethyldiethoxysilane.

  According to the curable composition of the present invention, a triazine-based ultraviolet absorber is added to a composition mainly composed of an oxyalkylene polymer having a urethane bond and a reactive silicon group (for example, an oxypropylene polymer). By mix | blending, the hardened | cured material which has the outstanding surface weather resistance can be provided, and the curable composition which can be used also as a sealing material for construction can be obtained.

  Further, by using a hindered phenol antioxidant together with a triazine ultraviolet absorber, a curable composition having better weather resistance and excellent surface weather resistance can be obtained.

  Embodiments of the present invention will be described below. The curable composition of the embodiment is mainly composed of (A) a reactive silicon group-containing oxyalkylene polymer having a number average molecular weight (Mn) of 4,000 or more and having a urethane bond in the molecule. Contains an ultraviolet absorber as an essential component.

In the reactive silicon group-containing oxyalkylene polymer having a urethane bond as the component (A), the reactive silicon group is not particularly limited, and examples thereof include a group represented by the following general formula (2).

In the formula, each of R ¹ and R ² is represented by 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 a formula: (R ³ ) ₃ SiO—. When a triorganosiloxy group is represented and two or more R ¹ or R ² are present, they may be the same as or different from each other. R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ³ may be the same or different. Specific examples of R ¹ and R ² include alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group, aralkyl groups such as benzyl group, and R ³ as methyl group and Examples thereof include a triorganosiloxy group represented by the formula: (R ³ ) ₃ SiO—, which is a phenyl group. R ¹ , R ² and R ³ are all preferably methyl groups.

X represents a hydroxyl group or a hydrolyzable group, and when two or more X exist, they may be the same or different. a represents 0, 1, 2 or 3; b represents 0, 1 or 2; Furthermore, b in m groups represented by the following general formula (3) may be different. m shows the integer of 0-19. However, it is assumed that a + Σb ≧ 1 is satisfied.

  The hydrolyzable group represented by X is not particularly limited as long as it is a known hydrolyzable group. Specific examples include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximato 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 ketoximato group, an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group are preferable. An alkoxy group such as a methoxy group is particularly preferred from the viewpoint of mild hydrolysis and easy handling.

  One to three of these hydrolyzable groups and hydroxyl groups can be bonded to one silicon atom, and (a + Σb) is preferably 1 to 5. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon group, they may be the same or different. There may be one silicon atom or two or more silicon atoms in the reactive silicon group. In the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like, about 20 may be present.

なお、式中、Ｒ^２、Ｘおよびａは、前記一般式（２）におけるものと同じである。 In view of easy availability, a reactive silicon group represented by the following general formula (4) is particularly preferable.

In the formula, R ² , X and a are the same as those in the general formula (2).

  There are at least one reactive silicon group, more preferably 1.1 to 5 in one molecule of the oxyalkylene polymer. When the number of reactive silicon groups contained in one molecule of the polymer is less than one, the curability becomes insufficient and it is difficult to express good rubber elasticity. The reactive silicon group may be present at the end or in the middle of the molecular chain of the oxyalkylene polymer, but when present at the end, the oxyalkylene polymer has an oxy group contained in the finally formed cured product. Since the network structure of the alkylene polymer component increases, it is easy to obtain a rubber-like cured product having high strength, large elongation, and low elasticity.

  In the embodiment of the present invention, the reactive silicon group-containing oxyalkylene polymer as the component (A) can be obtained by introducing a reactive silicon group into the oxyalkylene polymer having a functional group by a known method. . That is, the method shown below is mentioned.

  (1) An oxyalkylene polymer having a functional group such as a hydroxyl group at the terminal is reacted with an organic compound having an active group and an unsaturated group reactive to the functional group, or an unsaturated group-containing epoxy compound and By copolymerization, an unsaturated group-containing oxyalkylene polymer is obtained. Next, hydrosilane having a reactive silicon group is allowed to act on the obtained reaction product for hydrosilylation.

  (2) An unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1) is reacted with a compound having a mercapto group and a reactive silicon group.

  (3) An oxyalkylene polymer having a functional group (hereinafter referred to as Y1 functional group) such as a hydroxyl group, an epoxy group or an isocyanate group (hereinafter referred to as Y1 functional group) at the terminal is reactive toward the Y1 functional group. A silicon compound having a functional group (hereinafter referred to as Y2 functional group) and a reactive silicon group is reacted.

  Here, examples of the silicon compound having a Y2 functional group include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxysilane. Such amino group-containing silanes; mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and the like; γ-glycidoxypropyltrimethoxysilane, β- (3,4- Epoxy cyclohexyl) Epoxy silanes such as ethyltrimethoxysilane; Vinyl-type unsaturated group-containing silane groups such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; γ- Chlorine atom-containing silanes such as rolopropyltrimethoxysilane; Isocyanate-containing silanes such as γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane; methyldimethoxysilane And hydrosilanes such as trimethoxysilane and methyldiethoxysilane.

  The reactive silicon group-containing polyoxyalkylene (oxyalkylene polymer) is not particularly limited, but representative examples thereof include, for example, JP-A-50-156599 and 54-6096. No. 57-126823, No. 59-78223, No. 55-82123, No. 55-130122, No. 55-137129, No. 62-230822, No. 63-83131, JP-A-3-47825 3-72527, 3-122152, U.S. Pat. Nos. 3,632,557, 4,345,053, 4,366,307, 4,960,844, etc. Can be illustrated.

  In the embodiment of the present invention, it is preferable to adopt the method (1) or the method (3) among the above methods, and among the methods (3), an oxyalkylene polymer having a hydroxyl group at the terminal. It is particularly preferable to employ a method of reacting (polyoxyalkylene) with a compound having an isocyanate group and a reactive silicon group (for example, isocyanate alkoxysilanes).

  That is, in the methods (1) and (2), not only the reaction efficiency for converting a hydroxyl group to an unsaturated group (allyl group) is bad, but also a reactive silicon group by a subsequent hydrosilylation reaction or addition reaction of a mercapto group. Since the introduction efficiency is low, the reactivity may be lowered.

  In contrast, in the method (3), in the method of reacting an oxyalkylene polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group, the resulting polymer containing a urethane bond is used. The effect of improving curability is obtained. In addition, from the viewpoint of the weather resistance of the obtained cured product, particularly the surface weather resistance, the presence of a reactive residue such as an unreacted hydroxyl group at the terminal becomes a factor causing deterioration of the cured product. In addition, when a diisocyanate compound is used in the introduction of a reactive silicon group, there is a possibility that a carbamic acid which is a hydrolyzate of the isocyanate group, and a urea group or an allophanate group resulting therefrom may be generated. It is difficult to obtain, it is difficult to control the reaction, it is easy to cause thickening, and a process of extending the chain length is required. Furthermore, in order to reduce the surface weatherability failure caused by the contained urethane bond as much as possible, the terminal hydroxyl group of the polyoxyalkylene polymer having a large molecular weight (for example, Mn is 4,000 or more) is substituted with an alkyl group containing an isocyanate group. It is preferable to take a method of directly blocking with silane (for example, γ-isocyanatopropyltrimethoxysilane). According to such a method, a reactive silicon group-containing oxyalkylene polymer having Mn as a component (A) of 4,000 or more can be obtained in one step without requiring complicated steps.

  In the embodiment of the present invention, the number average molecular weight (Mn) of the reactive silicon group-containing oxyalkylene polymer as the component (A) is preferably 4,000 or more, particularly when it is 6,000 or more. The effect of the present invention is remarkably achieved.

  The reactive silicon group-containing polyoxyalkylene (oxyalkylene polymer) is not particularly limited, but representative examples thereof include, for example, JP-A-50-156599 and 54-6096. No. 57-126823, No. 59-78223, No. 55-82123, No. 55-130122, No. 55-137129, No. 62-230822, No. 63-83131, JP-A-3-47825 3-72527, 3-122152, U.S. Pat. Nos. 3,632,557, 4,345,053, 4,366,307, 4,960,844, etc. Can be illustrated.

In the (A) reactive silicon group-containing oxyalkylene polymer of the embodiment, the oxyalkylene polymer constituting the main chain of the molecule is represented by the general formula: — (R—O) _n — (R represents 1 to 4 carbon atoms). Represents a divalent alkylene group.). From the viewpoint of easy availability, use of an oxypropylene polymer having a repeating unit represented by the following formula (1) is preferred.

  The oxypropylene polymer may be linear or branched, or a mixture thereof. Although other monomers may be contained, the unit represented by the above formula (1) is present in the polymer at 50% by weight or more, preferably 80% by weight or more.

  As the number average molecular weight (Mn) of this oxypropylene polymer, those having a molecular weight of 6,000 or more can be used effectively, but those having a Mn of 6,000 to 30,000 are preferred. Further, this oxypropylene polymer has a weight average molecular weight (Mw) to Mn ratio (Mw / Mn) of 1.6 or less, and has a very narrow molecular weight distribution (high monodispersity). preferable. The value of Mw / Mn is more preferably 1.5 or less, and even more preferably 1.4 or less. The molecular weight distribution can be measured by various methods, but is usually measured by a gel permeation chromatography (GPC) method. Since the molecular weight distribution is narrow in spite of such a large Mn, the viscosity is low before the curing and the handling is easy, and the rubbery elasticity is good after the curing.

  As described above, the reactive silicon group-containing oxypropylene polymer having the repeating unit represented by the formula (1) introduces a reactive silicon group into the functional oxypropylene polymer (1). It can obtain by the method of (3). When a reactive silicon group is introduced, the molecular weight distribution tends to be broader than that of the polymer before introduction, so that the molecular weight distribution of the polymer before introduction is preferably as narrow as possible. Also in the production of a reactive silicon group-containing oxypropylene polymer, it is possible to adopt the method (3) of reacting an oxypropylene polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group. preferable.

  In the embodiment of the present invention, (B) a triazine-based ultraviolet absorber is contained as an essential component together with the above-described component (A). (B) As the triazine-based ultraviolet absorber, it is preferable to use a compound having a chemical structure in which at least one (more preferably three) benzene rings are bonded to the triazine ring. Commercially available products of such triazine-based ultraviolet absorbers include TINUVIN 1577, TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 479, IRGANOX 565, MELAPUR MC 25, MELAPUR 200/70, ILGUARD ( IRGAGUARD) D1071 (all are trade names of Ciba Specialty Chemicals Co., Ltd.).

  Among these, the use of TINUVIN 1577, TINUVIN 400, TINUVIN 405, TINUVIN 460, and TINUVIN 479, which are hydroxyphenyl-based triazine compounds that do not contain a primary amino group and a secondary amino group in the molecular structure is preferable.

で表される２−（４，６−ジフェニル−１，３，５−トリアジン−２−イル）−５―［（ヘキシル）オキシ］−フェノールであり、トリアジン環に３個のベンゼン環が結合した分子構造を有し、かつ１級および２級のアミノ基を含まないヒドロキシフェニル系のトリアジン化合物である。チヌビン４００、チヌビン４０５、チヌビン４６０、チヌビン４７９も同様に、トリアジン環に３個のベンゼン環が結合した分子構造を有し、かつ１級および２級のアミノ基を含まないヒドロキシフェニル系のトリアジン化合物である。 Incidentally, Tinuvin 1577 has the following chemical formula:

2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol represented by the formula, and three benzene rings bonded to the triazine ring It is a hydroxyphenyl triazine compound having a molecular structure and not containing primary and secondary amino groups. Similarly, Tinuvin 400, Tinuvin 405, Tinuvin 460, and Tinuvin 479 have hydroxyphenyl triazine compounds having a molecular structure in which three benzene rings are bonded to the triazine ring and containing no primary and secondary amino groups. It is.

  Such a triazine-based ultraviolet absorber as the component (B) is 0.01 to 10 parts by weight, preferably 0.8 parts per 100 parts by weight of the reactive silicon group-containing oxyalkylene polymer as the component (A). It mix | blends in the ratio of 3-5 weight part.

  In the embodiment of the present invention, a benzotriazole ultraviolet absorber can be used in combination with these triazine ultraviolet absorbers. When a benzotriazole-based ultraviolet absorber is used in combination, not only the absorption of ultraviolet rays on the short wavelength side but also the absorption of ultraviolet rays on the long wavelength side is enhanced, so that there is an effect that deterioration due to ultraviolet rays on the long wavelength side is prevented.

  Commercially available products of benzotriazole-based UV absorbers used include Tinuvin P, Tinuvin 213, Tinuvin 234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, Tinuvin 360, Tinuvin 571, Tinuvin 99-2, Examples are Tinuvin 109, Tinuvin 384-2, and Tinuvin 1130 (all are trade names of Ciba Specialty Chemicals Co., Ltd.). In particular, it is preferable to use a compound having a relatively large molecular weight such as tinuvin 213, tinuvin 234, tinuvin 571, tinuvin 99-2, tinuvin 109, tinuvin 384-2, and tinuvin 1130.

  Furthermore, a hindered phenolic antioxidant can be contained with (B) triazine type ultraviolet absorber. Commercially available hindered phenolic antioxidants include Nocrack 200 (BHT), Nocrack M-17, Nocrack SP, Nocrack SP-N, Nocrack NS-5, Nocrack NS-6, Nocrack NS-30, Nocrack PBK, NOCRACK NS-7, NOCRACK DAH (all are trade names of Ouchi Shinsei Chemical Co., Ltd.), ADK STAB AO-20, AO-30, AO-40, AO-50 (same as Irganox-1076), AO. -60 (same as Irganox 1010), AO-70 (same as Irganox 245), AO-80, AO-330 (same as Irganox 1330), AO-611, AO-612, AO-613 AO-616, AO-635, AO-658, A-15, AO-15, AO-18, AO 328, AO-37, AO-51 (all are trade names of Adeka Co., Ltd.), Irganox 245, Irganox 259, Irganox 1010, Irganox 1076, Irganox 1081, Irganox 1135, Irganox 1222, Irganox Examples include Knox 1330, Irganox 3114, and Irganox 3790 (all manufactured by Ciba Specialty Chemicals Co., Ltd.).

  In particular, Nocrack NS-5, Nocrack NS-6, Nocrack NS-30, Nocrack PBK, Nocrack SP-N, Adekastab AO-20, AO-30, AO-50, AO-60, AO-70, AO-80, The use of AO-330, Irganox 245, Irganox 259, Irganox 1010, Irganox 1330, Irganox 3114, Irganox 3790 is preferred.

  These hindered phenolic antioxidants do not contain primary amino groups and secondary amino groups in the molecular structure, as with the above-described triazine ultraviolet absorbers, and hindered phenols having such a structure. Phenol antioxidants are preferred. Moreover, what does not contain a thiol group and a thioether group in a molecular structure is preferable. Furthermore, those having a relatively large molecular weight are more preferable so that they are difficult to be extracted by rainwater and have a long-lasting antioxidant effect. From such a viewpoint, Nocrack NS-5, Nocrack NS-6, Nocrack NS-30, Nocrack PBK, Nocrack SP-N, Adekastab AO-20, AO-30, AO-50, AO-60, AO-70, The use of AO-80, AO-330, Irganox 245, Irganox 259, Irganox 1010, Irganox 1330, Irganox 3114, Irganox 3790 is preferred.

  Further, from the viewpoint of compatibility with the reactive silicon group-containing oxyalkylene polymer as the component (A) of the present invention, Irganox 245, Irganox 259, Irganox 1010, Irganox 3114, Irganox 3790, Nocrack NS -30, Nocrack PBK, Adekastab A-60, AO-70, AO-80, AO-330 are preferably used. Furthermore, the use of Irganox 245, Irganox 259, Irganox 1010, Irganox 1330, Irganox 3114 having a low vapor pressure is particularly preferred.

  In the embodiment, by using these hindered phenol-based antioxidants together with the triazine-based ultraviolet absorber as the component (B), the reactive silicon group-containing oxyalkylene polymer as the component (A) is used. This brings about a specific effect of improving the surface weather resistance of the cured product. The triazine-based ultraviolet absorber and the hindered phenol-based antioxidant are each 0.01 to 10 parts by weight, preferably 0.3 to 5 parts per 100 parts by weight of the (A) reactive silicon group-containing oxyalkylene polymer. It mix | blends in the ratio of a weight part.

  In the embodiment of the present invention, a curing catalyst, a filler, a plasticizer, and other various additives can be blended with the (A) reactive silicon group-containing oxyalkylene polymer as necessary.

  Specific examples of the curing catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin acetate, tin octylate and tin naphthenate; dibutyltin oxide and phthalic acid Reaction products with esters, dibutyltin acetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetylacetonate, etc. Chelate compounds; lead octylate, lead naphthenate; zinc octylate, lead naphthenate; bismuth compound; butylamine, o Tylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6 -Amine compounds such as tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5,4,0) undecene-7 (DBU), or Salts of these amine compounds with carboxylic acids, etc .; low molecular weight polyamide resins obtained from excess polyamines and polybasic acids; reaction products of excess polyamines and epoxy compounds Silanol condensation catalysts such as silane coupling agents having amino groups such as γ-aminopropyltrimethoxysilane and N- (β-aminoethyl) aminopropylmethyldimethoxysilane; and other acidic catalysts and basic catalysts Known silanol condensation catalysts such as In the embodiment, an organometallic salt catalyst that is effective in a small amount and has little influence of coloring, yellowing and the like, such as an amine compound, is preferable. These catalysts may be used alone or in combination of two or more.

  Fillers include reinforcing fillers such as fumed silica, precipitated silica, anhydrous silicic acid, hydrous silicic acid and carbon black; calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite And fillers such as organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloon; and fibrous fillers such as asbestos, glass fibers and filaments. These fillers may be used alone or in combination of two or more.

  Plasticizers include phthalates such as dioctyl phthalate, dibutyl phthalate and butyl benzyl phthalate; aliphatic dibasic esters such as dioctyl adipate, isodecyl succinate and dibutyl sebacate; diethylene glycol dibenzoate, pentaerythritol ester, etc. Glycol esters; aliphatic esters such as butyl oleate and methyl acetylricinoleate; phosphate esters such as tricresyl phosphate, trioctyl phosphate and octyl diphenyl phosphate; epoxidized soybean oil, epoxidized linseed oil, epoxy Epoxy plasticizers such as benzyl stearate; polyester plasticizers such as polyesters of dibasic acids and dihydric alcohols; polyethers such as polypropylene glycol and its derivatives; Li -α- methyl styrene, polystyrenes such as polystyrene; polybutadiene, butadiene - acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, and chlorinated paraffins are exemplified. These plasticizers can be optionally used alone or in the form of a mixture of two or more.

  Other additives include adhesion improvers, physical property modifiers, storage stability improvers, metal deactivators, ozone degradation inhibitors, light stabilizers, amine radical chain inhibitors, phosphorus peroxides. Additives such as a decomposing agent, a lubricant, a pigment, and a foaming agent can be exemplified.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to an Example. In the examples, “parts” means “parts by weight” and “%” means “% by weight”. All physical property values such as viscosity are measured values at 23 ° C. and relative humidity (RH) 50%.

Synthesis example 1
A 3 liter four-necked separable flask equipped with a stirrer, a dropping funnel, a reflux tube, a thermometer, a nitrogen gas flow apparatus, and a pressure reducing apparatus was added to a polyoxypropylene diol having a Mn of 16,000 (trade name: Preminol 4016: Asahi Glass Co., Ltd.) The resulting product was dehydrated by vacuum distillation at 100 ° C. and 10-20 mmHg for 1 hour. Next, this was cooled to 50 ° C. or lower, and 50.2 parts of γ-isocyanatopropyltrimethoxysilane (trade name Silquest A-link35: manufactured by GE Toshiba Silicone) was added so that the NCO / OH ratio was 0.98. Then, the temperature was raised under a nitrogen stream, and stirring was continued at a temperature of 60 to 70 ° C. for 8 hours. When the NCO content was measured, it decreased to 0.05% (theoretical value: 0%), so it was taken out after cooling. A reactive silicon group-containing oxypropylene polymer was thus obtained. The viscosity of this polymer was 21,000 mPa · s. Moreover, Mn was 18,300 and Mw / Mn was 1.34.

Synthesis example 2
Instead of the polyoxypropylene diol having Mn of 16,000 used in Synthesis Example 1, polyoxypropylene diol having a Mn of 10,000 (trade name: Preminol 4010: manufactured by Asahi Glass Co., Ltd.) is used, and the NCO / OH ratio is 0.00. The reaction was conducted in the same manner as in Synthesis Example 1 by adding 82.4 parts of γ-isocyanatopropyltrimethoxysilane (trade name Silquest A-link35) so that the NCO content was 98. S reactive silicon group-containing oxypropylene polymer was obtained. This polymer had Mn of 12,900 and Mw / Mn of 1.25.

Synthesis example 3
Γ-isocyanatopropyltrimethoxysilane prepared by adjusting 400 parts (0.1 mol) of polyoxypropylene diol having a Mn of 4,000 (trade name: Preminol 4002: manufactured by Asahi Glass Co., Ltd.) so that the NCO / OH ratio is 0.98. 40.2 parts of (trade name Silquest A-link35) and 60 ppm of dibutyltin dilaurate were added as reaction catalysts, respectively, and the mixture was stirred at 60 to 70 ° C. for about 8 hours to reduce the NCO content to about 0.8%. . Thus, a reactive silicon group-containing oxypropylene polymer having a viscosity of 1230 mPa · s was obtained. This polymer had Mn of 4,690 and Mw / Mn of 1.19.

Synthesis example 4
400 parts (0.1 mol) of polyoxypropylene diol having a Mn of 4,000 (trade name: Preminol 4002) and 36 parts of 4,4′-diphenylmethane diisocyanate adjusted to an NCO / OH ratio of 1.4 (0 In addition, 60 ppm of dibutyltin dilaurate as a reaction catalyst and 20 ppm of benzoyl chloride as a retarder are added to the mixture with each other and stirred at 60 to 70 ° C. for about 4 hours, and the NCO content is reduced to about 0.8%. Reduced.

  Next, 21.4 parts (0.084 mol) of N-phenyl-γ-aminopropyltrimethoxysilane (trade name Silquest Y-9669: manufactured by GE Toshiba Silicone) was added to the isocyanate group-terminated polyurethane prepolymer, and the NCO content was The reaction was carried out at 70 to 75 ° C. until the value became zero. Thus, a reactive silicon group-containing oxypropylene polymer was obtained. This polymer had Mn of 11,400 and Mw / Mn of 1.46.

Synthesis example 5
After replacing the air in a 2 liter four-necked separable flask equipped with a stirrer, dropping funnel, reflux tube, thermometer, nitrogen flow apparatus and decompression apparatus with nitrogen, γ-aminopropylmethyl was added to the flask. Diethoxysilane (trade name Silquest A-2100: manufactured by GE Toshiba Silicones) 764 parts was added and stirred. Next, 74 parts of ion-exchanged water was gradually added from the dropping funnel into the flask while flowing a small amount of nitrogen into the flask. Since the exothermic reaction occurred, the temperature of the flask contents was adjusted to be kept at 60 ° C. or lower while cooling.

  After the dropping of ion-exchanged water was completed, the temperature in the flask was raised to 80 ° C., and ethanol as a reaction by-product was distilled off in the receiving tank. At this time, pressure reduction was performed as necessary while confirming the amount of ethanol distilled off (346 parts). After completion of the reaction, the reaction product was cooled to 40 ° C. or lower, and the reaction product was taken out from the flask. Thus, 432 parts of a slightly yellow transparent amino-functional polyorganosiloxane were obtained. This amino-functional polyorganosiloxane had a viscosity of 223 mPa · s, and a loss on heating at 150 ° C. × 1 hour was 0.6%.

Example 1
To 100 parts of the reactive silicon group-containing oxypropylene polymer obtained in Synthesis Example 1, 1.5 parts of TINUVIN 1577, which is a triazine-based UV absorber, and TYPAKE R-820 (titanium oxide for making surface cracks easily visible) 1 part of Ishihara Sangyo Co., Ltd.) was added and mixed uniformly. Thereafter, 1 part of vinyltrimethoxysilane (trade name Silquest A-171: manufactured by GE Toshiba Silicone), 3- (2-aminoethyl) aminopropyltrimethoxysilane (trade name Silquest A-1130: manufactured by GE Toshiba Silicone) 1 part and 0.5 part of dibutyltin dilaurate as a curing catalyst were added and kneaded uniformly to obtain a curable composition.

Examples 2-4
Instead of the reactive silicon group-containing oxypropylene polymer obtained in Synthesis Example 1, the same operation as in Example 1 was carried out except that the reactive silicon group-containing oxypropylene polymer obtained in Synthesis Examples 2 to 4 was used. Each was performed to obtain a curable composition.

Comparative Example 1
A curable composition was obtained in the same manner as in Example 1 except that tinuvin 1577, which is a triazine ultraviolet absorber, was not added.

Comparative Example 2
A curable composition was obtained in the same manner as in Example 4 except that tinuvin 1577, which is a triazine ultraviolet absorber, was not added.

Comparative Example 3
A curable composition was obtained in the same manner as in Example 1 except that tinuvin 326, a benzotriazole ultraviolet absorber, was used instead of tinuvin 1577, a triazine ultraviolet absorber. It was.

Comparative Example 4
A curable composition was obtained in the same manner as in Example 1 except that tinuvin 329 as a benzotriazole ultraviolet absorber was used instead of tinuvin 1577 as a triazine ultraviolet absorber. It was.

Comparative Example 5
Instead of blending 1.5 parts of TINUVIN 1577 which is a triazine UV absorber, 0.75 parts of TINUVIN 326 which is a benzotriazole UV absorber and NOCRACK NS-6 which is a hindered phenol antioxidant 0 .75 parts each. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Comparative Example 6
Instead of blending 1.5 parts of TINUVIN 1577, a triazine UV absorber, 0.75 parts of TINUVIN 326, a benzotriazole UV absorber, and 0.75 parts of TINUVIN 770DF, a hindered amine antioxidant, respectively. Blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Examples 5-8
Tinuvin 400 (Example 5), Tinuvin 405 (Example 6), Tinuvin 460 (Example 7), Tinuvin 479 (Example), which are also triazine ultraviolet absorbers, are used instead of Tinuvin 1577 which is a triazine ultraviolet absorber. Each of 8) was used. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain curable compositions.

Example 9
3- (2-aminoethyl) aminopropyl trimethoxysilane, instead of blending (trade name Silquest A-1130) 1 part, and the amino-functional polyorganosiloxanes 1 part obtained in case Narurei 5, 3-glycidoxypropyltrimethoxysilane Sidoxypropyltrimethoxysilane (trade name: Silquest A-187: manufactured by GE Toshiba Silicones) 0.3 parts was blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Example 10
Instead of blending 1 part of 3- (2-aminoethyl) aminopropyltrimethoxysilane (trade name Silquest A-1130), 1 part of the aminofunctional polyorganosiloxane obtained in Synthesis Example 5 and 3-glycidide 0.3 parts of xylpropyltrimethoxysilane (trade name Silquest A-187) was blended. Otherwise, the same operation was carried out with the same components as in Example 5 to obtain a curable composition.

Example 11
Instead of blending 1 part of 3- (2-aminoethyl) aminopropyltrimethoxysilane (trade name Silquest A-1130), 1 part of 3-aminopropyltrimethoxysilane was blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Example 12
Instead of blending 1 part of 3- (2-aminoethyl) aminopropyltrimethoxysilane (trade name Silquest A-1130), 1 part of 3-aminopropyltrimethoxysilane was blended. Otherwise, the same operation was carried out with the same components as in Example 5 to obtain a curable composition.

Example 13
Instead of blending 1.5 parts of tinuvin 1577 which is a triazine-based ultraviolet absorber, 0.75 parts of tinuvin 1577 and 0.75 parts of Irganox 245 which is a hindered phenol antioxidant were blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Example 14
Instead of blending 1.5 parts of tinuvin 1577 which is a triazine ultraviolet absorber, 0.75 parts of tinuvin 1577 and 0.75 parts of irganox 1010 which is a hindered phenol antioxidant were blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Comparative Example 7
Instead of blending 1.5 parts of TINUVIN 1577, a triazine UV absorber, 0.75 parts of TINUVIN 326, a benzotriazole UV absorber, and Irganox 245, a hindered phenol antioxidant, were added in an amount of 0.001. 75 parts of each were blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

Comparative Example 8
Instead of blending 1.5 parts of TINUVIN 1577 which is a triazine UV absorber, 0.75 parts of TINUVIN 326 which is a benzotriazole UV absorber and Irganox 1010 which is a hindered phenol antioxidant are added in an amount of 0.001. 75 parts of each were blended. Otherwise, the same operation was carried out with the same components as in Example 1 to obtain a curable composition.

  Next, for the curable compositions obtained in Examples 1 to 14 and Comparative Examples 1 to 8, the weather resistance of the cured product surface was measured and evaluated according to the following method. These measurement results are shown in Tables 1 to 6, respectively.

[Ease of surface cracks]
The composition was molded into a sheet having a thickness of 2 mm, cured for 7 days under the conditions of 23 ° C. and 50% RH, and further cured at 50 ° C. for 3 days. This sheet was irradiated with sunshine weather ometa (WOM) for 500 hours, 1000 hours, 1500 hours, 2000 hours and 2500 hours, and the state of the sheet surface after irradiation was observed. And the deterioration state of the surface was determined in accordance with the following criteria based on ISO TC35DS.

(Surface condition)
○: No abnormality ○-△: Slightly sticky △: Sticky △ -X: Dissolved from the irradiation side surface ×: No shape (amount of cracks)
0: None (no detection)
1: Very little 2: few (some important cracks)
3: Medium 4: Large amount 5: Densely present (crack size)
0: Invisible at 10x magnification 1: Slightly visible (10x magnification)
2: Visually confirmable 3: Clearly visible cracks up to 4: 1 mm 5 Large cracks exceeding 1 mm

[H-type tensile adhesion]
In accordance with JIS A5758, an H-type test specimen was prepared using aluminum sulfate as an adherend, and this specimen was irradiated with sunshine WOM for 500 hours, 1000 hours, 1500 hours, 2000 hours and 2500 hours, respectively. The adhesion state (cohesive failure rate CF) after irradiation was examined. Moreover, the maximum tensile strength (Tmax) and the elongation at the maximum load (Emax), which are characteristics of the cured product, were measured.

  As can be seen from Tables 1 to 6, since the curable compositions obtained in Examples 1 to 14 are blended with a triazine-based ultraviolet absorber, the curable compositions obtained in Comparative Examples 1 to 8 are used. Compared with the weather resistance, the surface weather resistance is greatly improved.

  According to the curable composition of the present invention, a cured product having excellent surface weather resistance can be obtained. Therefore, this silicon group-containing polymer composition is particularly suitable as a sealing material for construction.

Claims (6)

(A) Mainly a reactive silicon group-containing oxyalkylene polymer having a urethane bond having a number average molecular weight (Mn) of 4,000 or more,
(B) a triazine ultraviolet absorber;
At least one curing catalyst selected from dibutyltin dilaurate, dibutyltin maleate, dibutyltin acetate, tin octylate, tin naphthenate, a reaction product of dibutyltin oxide and phthalate, and dibutyltin acetylacetonate;
A curable composition comprising: one selected from 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and γ-aminopropylmethyldiethoxysilane condensate object. The reactive silicon group-containing oxyalkylene polymer as the component (A) has a polymer main chain.

2. The curable composition according to claim 1, which is an oxypropylene polymer having at least one reactive silicon group comprising a silicon atom having a hydroxyl group or a hydrolyzable group bonded thereto. .   The curable composition according to claim 2, wherein the oxypropylene polymer has a Mw (weight average molecular weight) / Mn (number average molecular weight) value of 1.6 or less.   4. The curable composition according to claim 2, wherein the oxypropylene polymer has a number average molecular weight (Mn) of 6,000 to 30,000.   2. The curable composition according to claim 1, wherein the reactive silicon group is present at a molecular chain terminal in the reactive silicon group-containing oxyalkylene polymer as the component (A).   The curable composition according to any one of claims 1 to 5, further comprising a hindered phenol-based antioxidant.