JP2787348B2 - Curable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a curable resin composition containing a novel curable resin, and more specifically, to provide excellent mechanical properties, weather resistance, heat resistance and the like after curing. The present invention relates to a curable resin composition containing a curable resin that can be exhibited.

[Problems to be Solved by the Related Art and the Invention] A room-temperature-curable resin is a resin that can be cross-linked and hardened by moisture or the like in the air even at room temperature to give a rubber-like elastic body or the like. Examples of the group that can be crosslinked by moisture in the air include a silicon atom-containing group that has a hydroxyl group or a hydrolyzable group bonded to a silicon atom and can be crosslinked by forming a siloxane bond (hereinafter referred to as a “reactive silicon group”). ") Is known. Room temperature-curable polysiloxane is well known as a room temperature-curable resin that can be cross-linked and cured by the action of such a group. Further, room-temperature-curable polyethers containing reactive silicon groups using inexpensive polyethers without using expensive polysiloxanes in the main chain are also known. Cured products of these resins can have very low tensile modulus and very high elongation often required as rubber elastomers. For example, when these rubber elastic bodies are used for building sealants, 3kgf / c
m ² or less 100% modulus and elongation at break of about 1000% of the degree is often required, but the cured product of the resin can satisfy these requirements.

On the other hand, JP-B-46-30711 and JP-B-49-32673
Patent Document discloses a room temperature curable resin having a reactive silicon group using polycaprolactone as a main chain. Polycaprolactone is inexpensive, has excellent weather resistance,
Although it has heat resistance, reactive silicon group-containing polycaprolactone is often inconvenient to use as a rubber elastic body because the cured product has crystallinity, the tensile modulus is large and the elongation is small. . In particular, as described above, the properties were too poor for use in building sealants.

An object of the present invention is to provide a state composition containing a polycaprolactone having a reactive silicon group, which gives a rubber elastic body having a small tensile modulus and a large elongation.

[Means and Actions for Solving the Problems] The curable resin composition of the present invention comprises: (A) at least one silicon atom-containing group (reactive silicon group) containing a silicon atom having a hydroxyl group or a hydrolyzable group bonded thereto; A polymer of ε-caprolactone which can be cross-linked by forming a siloxane bond, (R is an alkyl group having 1 to 5 carbon atoms) having at least one bonding unit represented by the following formula and having a number average molecular weight of 8,000 or more; and (B) a silanol condensation catalyst. .

The tensile properties of the cured product obtained from the curable resin composition of the present invention are shown in FIGS. 1 to 3, and as can be seen from the figures, especially when the molecular weight is around 8,000 or more and less than 8,000. It is clear that they show very excellent characteristics. When it is more than 8,000, it is a property that is enough to be used as a building sealant. Also, Japanese Patent Publication No. 49-3267
No. 3 discloses a polycaprolactone having a molecular weight of 8,000 or more having a reactive silicon group, but the tensile properties of the cured product are inferior to the properties as a rubber compared to the tensile properties of the cured product obtained from the present invention. Things.

The reactive silicon group in the component (A) of the composition of the present invention is not particularly limited.
For example, a group represented by the following general formula (1) can be mentioned.

Wherein R ¹ and R ² are each 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 (R ′) ₃ SiO— It represents a triorganosiloxy group, and when two or more R ¹ or R ² are present, they may be the same or different. Here, R 'is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and the three R's may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more Xs are present, they may be the same or different. a represents 0, 1, 2 or 3, b represents 0,
1 or 2 is shown, respectively. In addition, m B in may be different. m is 0 or 1 to 19
Indicates an integer. However, it is assumed that a + Σb ≧ 1 is satisfied. The hydrolyzable group represented by X is not particularly limited, and may be any conventionally known hydrolyzable 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. Of 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 preferred, but an alkoxy group is preferred from the viewpoint of gentle hydrolysis and easy handling. Is particularly preferred.

This hydrolyzable group or hydroxyl group is one to one silicon atom.
Three can be bonded, and (a + Δb) 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.

The reactive silicon group may have one silicon atom or two or more silicon atoms. In the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like,
There may be about one.

Note that a reactive silicon group represented by the following general formula (2) is preferable from the viewpoint of easy availability.

(In the formula, R ² , X, and a are the same as described above.) Further, specific examples of R ¹ and R ² in the general formula (1) include, for example, an alkyl group such as a methyl group and an ethyl group, and a cyclohexyl group. Such as a cycloalkyl group, an aryl group such as a phenyl group, an aralkyl group such as a benzyl group, and R ′ being a methyl group or a phenyl group (R ′) ₃ S
and a triorganosiloxy group represented by iO-. R ² is particularly preferably a methyl group.

At least one reactive silicon group per molecule of the polymer;
Preferably, 1.1 to 5 are present. When the number of reactive silicon groups contained in one polymer molecule is less than one,
The curability becomes insufficient, and it becomes difficult to exhibit good rubber elasticity behavior.

The reactive silicon group may be present at the terminal of the polymer molecular chain, may be present internally, or may be present at both. In particular, when the reactive silicon group is present at the terminal of the molecular chain, the amount of the effective network chain of the polymer component contained in the finally formed cured product increases, so that a rubber having high strength and high elongation is obtained. This is preferable because it has advantages such as easy formation of a cured state.

The polymer of ε-caprolactone used in the present invention has, in its polymerization main chain, (R is an alkyl group having 1 to 5 carbon atoms). The crystallinity of the polymer can be suppressed by including this bonding unit, but the number can be arbitrarily selected as needed. The preferred content of the linking unit is 1 to 2 to 100 ε-caprolactone monomer units. In order to increase the molecular weight when the content of the binding unit is large, it is necessary to devise a measure such as using a monomer unit other than ε-caprolactone (for example, a dicarboxylic acid such as adipic acid or a derivative thereof). is there. Commercially available such polymers include those wherein R is --CH ₃
(Daicel Chemical Industry Co., Ltd., trade name) and the like are known.

The number average molecular weight of the polymer of ε-caprolactone (before curing) used in the present invention needs to be 8,000 or more in order to obtain a cured product with sufficient mechanical strength. If it is less than 8,000, the cured product cannot obtain sufficient elongation and breaks before sufficient strength is developed. There is no particular upper limit on the molecular weight of the polymer, but those up to 20,000 are preferred.

As described above, the polymer in the resin composition of the present invention has, in its polymerization main chain, (R represents an alkyl group having 1 to 5 carbon atoms) and has a number average molecular weight of 8,000 or more. A cured product having flexibility can be obtained.

In order to obtain a polymer in which the main chain is a polyester obtained by polymerizing ε-caprolactone and the number average molecular weight is 8,000 or more, the number average molecular weight is easily available at about 1,000 to 4,000, A polymer consisting of ε-caprolactone having a functional group such as a hydroxyl group is added to an organic compound having two or more active groups reactive to the functional group (for example, isophthaloyl chloride, terephthaloyl chloride, malonic acid dichloride). And a polyvalent halogen compound such as succinic dichloride, glutaric dichloride or adipic dichloride, preferably a compound having two or more acid halide groups) to make the molecular weight 8,000 or more.

The introduction of the reactive silicon group into the polymer may be performed by a known method. That is, for example, a polymer composed of ε-caprolactone having a functional group such as a hydroxyl group at a terminal or a main chain is reacted with an organic compound having an active group and an unsaturated group that are reactive with respect to this functional group. Next, a hydrosilane having a hydrolyzable group is allowed to act on the obtained reaction product to perform hydrosilylation.

Such a hydrosilane is represented by the following general formula (3).

(Wherein R ³ is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms,
When two or more are present, they may be the same,
It may be different. X is a hydroxyl group or a hydrolyzable group, and when two or more are present, they may be the same or different. a is 1, 2 or 3. As a catalyst for the hydrosilylation reaction, for example, H ₂ PtCl
₆ · 6H ₂ O, Pt _{metal, RhCl (PRh 3) 3,} RhCl 3, Rh / Al
₂ O ₃ , RuCl ₃ , IrCl ₃ , FeCl ₃ , AlCl ₃ , PdCl ₂・ 2H ₂ O, NiCl
₂ , compounds such as TiCl ₄ can be used.

The hydrosilylation reaction is usually performed at 0 to 150 ° C., but a solvent such as benzene, toluene, xylene, or tetrahydrofuran may be used as necessary for adjusting the reaction temperature or adjusting the viscosity of the reaction system.

In order to obtain a cured product using the above polymer, it is necessary to condense a hydrolyzable group with a silanol condensation catalyst (curing catalyst). Examples of such silanol condensation catalysts include titanates such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylate salts such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate, tin naphthenate; dibutyltin Reaction products of oxide and phthalic acid ester; dibutyltin diacetylacetonate; organic aluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetyl Chelating compounds such as acetonate; lead octylate; butylamine, octylamine, dibutylamine, Noruamin, diethanolamine, triethanolamine,
Diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine,
Diethylaminopropylamine, xylylenediamine,
Triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5.
4.0) amine compounds such as undecene-7 (DBU), or salts of these amine compounds with carboxylic acids and the like;
Low molecular weight polyamide resin obtained from excess polyamine and polybasic acid; reaction product of excess polyamine and epoxy compound; γ-aminopropyltrimethoxysilane;
Silanol condensation catalysts such as silane coupling agents having an amino group such as N- (β-aminoethyl) aminopropylmethyldimethoxysilane; and other known silanol condensation catalysts such as other acidic catalysts and basic catalysts. Can be These catalysts may be used alone or in combination of two or more.

The compounding amount of such a curing catalyst in the resin composition of the present invention is preferably 0.1 to 20 parts with respect to 100 parts by weight of a polymer having a reactive silicon group (hereinafter, simply referred to as “parts”), 10 parts is more preferred. If the amount of the curing catalyst is too small, the curing speed becomes slow and the curing reaction does not proceed sufficiently, which is not preferable. On the other hand, if the blending amount of the curing catalyst is too large, local heat generation or foaming occurs during curing, and it becomes difficult to obtain a favorable cured product, which is not preferable.

The composition of the present invention further comprises, if necessary, an adhesion improver, a physical property modifier, a storage stability improver, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a metal deactivator, Various additives such as an ozone deterioration inhibitor, a light stabilizer, an amine-based radical chain inhibitor, a phosphorus-based peroxide decomposer, a lubricant, a pigment, and a foaming agent can be appropriately added.

[Effect of the Invention] A cured product obtained by curing the curable resin composition of the present invention can exhibit excellent mechanical properties, weather resistance, heat resistance, and the like, and has sufficient elasticity.

[Examples] In order to further clarify the present invention, examples will be given below.

Example 1 Praxel 220AL (average molecular weight: 2,000, manufactured by Daicel Chemical Industries, Ltd.), a polyester whose main chain is mainly a ring-opened polymer of ε-caprolactone and has hydroxyl groups at both ends
0 g was weighed in a four-necked flask, and azeotropically dehydrated with a small amount of toluene to remove water in the system. To this, 400 ml of toluene dried using molecular sieve, and 30 m of pyridine
l was added. Next, 22.8 g of isophthaloyl chloride was dissolved in toluene and added to the system by a dropping funnel. After completion of the dropwise addition, the reaction temperature was raised to 60 ° C., and the reaction was carried out for 1 hour. This was cooled to around room temperature, 16.0 ml of allyl chloroformate was added, and the reaction was carried out again at 60 ° C. for 1 hour. After completion of the reaction, the precipitated salt and pyridine were removed by washing with water, dried,
By desolvation, a polyester having a number average molecular weight of about 8,000 and allyl groups introduced at both ends was obtained.

200 ml of toluene dried using molecular sieve was added to the obtained polyester to lower the viscosity of the system, and 0.1 ml of a 10% ethanol solution of chloroplatinic acid was added. next,
30 ml of methyldimethoxysilane was added with a dropping funnel,
By reacting at 80 ° C. for 1 hour, the desired polyester having a reactive silicon group at the terminal and having a number average molecular weight of about 8,000 was obtained.

A resin composition was prepared by adding 3 parts of tin octylate and 0.75 part of laurylamine to 100 parts of the polyester.
The composition was cured to obtain a cured product.

Example 2 In the same manner as in Example 1, Plaxel 220AL (average molecular weight 2,0
(300 g, manufactured by Daicel Chemical Industries, Ltd.) was weighed into a four-necked flask and azeotropically dehydrated with a small amount of toluene to remove water in the system. To this, 400 ml of toluene dried using a molecular sieve and 30 ml of pyridine were added. Next, 25.4 g of isophthaloyl chloride was dissolved in toluene and added to the system by a dropping funnel. After completion of the dropwise addition, the reaction temperature
C. and reacted for 1 hour. This was cooled to near room temperature, 10.0 ml of allyl chloroformate was added, and the reaction was performed again at 60 ° C. for 1 hour. After completion of the reaction, the precipitated salt and pyridine were removed by washing with water, followed by drying and desolvation to obtain a polyester having a number average molecular weight of about 12,000 and having allyl groups introduced at both ends.

200 ml of toluene dried using molecular sieve was added to the obtained polyester to lower the viscosity of the system, and 0.1 ml of a 10% ethanol solution of chloroplatinic acid was added. next,
20 ml of methyldimethoxysilane was added with a dropping funnel,
By reacting at 80 ° C. for 1 hour, the desired polyester having a reactive silicon group at the terminal and having a number average molecular weight of about 12,000 was obtained.

A resin composition was prepared by adding 3 parts of tin octylate and 0.75 part of laurylamine to 100 parts of the polyester.
The composition was cured to obtain a cured product.

Comparative Example 1 In the same manner as in Example 1, Plaxel 220AL (average molecular weight 2,0
(300 g, manufactured by Daicel Chemical Industries, Ltd.) was weighed into a four-necked flask and azeotropically dehydrated with a small amount of toluene to remove water in the system. To this, 400 ml of toluene dried using a molecular sieve and 30 ml of pyridine were added. Next, 50.0 ml of allyl chloroformate was added and reacted at 60 ° C. for 1 hour.
After completion of the reaction, the precipitated salt and pyridine were removed by washing with water, dried and desolvated to obtain a polyester having a number average molecular weight of about 2,000 and allyl groups introduced into both terminals at both ends.

To the obtained polyester was added 200 ml of toluene dried using molecular sieve to lower the viscosity of the system, and 0.1 ml of a 10% ethanol solution of chloroplatinic acid was added. Next, 50 ml of methyldimethoxysilane was added by a dropping funnel, and 80
By reacting at 1 ° C. for 1 hour, the desired polyester having a reactive silicon group at the terminal and having a number average molecular weight of about 2,000 was obtained.

A resin composition was prepared by adding 3 parts of tin octylate and 0.75 part of laurylamine to 100 parts of the polyester.
The composition was cured to obtain a cured product.

Comparative Example 2 In the same manner as in Example 1, Plaxel 220AL (average molecular weight 2,0
(300 g, manufactured by Daicel Chemical Industries, Ltd.) was weighed into a four-necked flask and azeotropically dehydrated with a small amount of toluene to remove water in the system. To this, 400 ml of toluene dried using a molecular sieve and 30 ml of pyridine were added. Next, 20.3 g of isophthaloyl chloride was dissolved in toluene and added to the system by a dropping funnel. After completion of the dropwise addition, the reaction temperature
C. and reacted for 1 hour. This was cooled to around room temperature, 20.0 ml of allyl chloroformate was added, and the reaction was performed again at 60 ° C. for 1 hour. After completion of the reaction, the precipitated salt and pyridine were removed by washing with water, followed by drying and desolvation to obtain a polyester having a number average molecular weight of about 6,000 and allyl groups introduced at both ends.

To the obtained polyester, 200 ml of toluene dried using a molecular sieve was added to lower the viscosity of the system, and 0.1 ml of a 10% ethanol solution of platinum chloride was added. By adding 40 ml of methyldimethoxysilane through a dropping funnel and reacting at 80 ° C. for 1 hour, a polyester having a desired reactive silicon group at the terminal and having a number average molecular weight of about 6,000 was obtained.

A resin composition was prepared by adding 3 parts of tin octylate and 0.75 part of laurylamine to 100 parts of the polyester.
The composition was cured to obtain a cured product.

The results of measuring the tensile properties of the cured products obtained in Example 1, Example 2, Comparative Example 1, and Comparative Example 2
This is shown in FIGS. 2, 2 and 3. As is clear from the figure, the cured product obtained from the resin composition containing a polymer having a number average molecular weight of 8,000 or more exhibited extremely excellent tensile properties.

When the cured products of the above Examples and Comparative Examples were placed in an oven at 130 ° C. and subjected to a heat resistance test,
After the lapse of time, no change such as dissolution of the surface was observed in any of the samples. In a weather resistance test using a sunshine weather meter, no remarkable change was observed on the surface even after 5,000 hours.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the molecular weight of the polymer and the breaking strength of the cured product, FIG. 2 is a diagram showing the relationship between the molecular weight of the polymer and the breaking elongation of the cured product, and FIG. It is a relation figure with the tensile modulus of a hardened material.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-125528 (JP, A) JP-A-2-133459 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 67/00-67/08 C08L 83/00-83/16 C08K 3/00-13/08 C08G 63/00-63/91 C08G 77/00-77/62

Claims (2)

(57) [Claims] (A) A polymer of ε-caprolactone which has at least one silicon atom-containing group containing a silicon atom bonded to a hydroxyl group or a hydrolyzable group and can be crosslinked by forming a siloxane bond. And in the polymerization main chain, (R is an alkyl group having 1 to 5 carbon atoms) A curable resin comprising at least one bonding unit represented by the following formula and having a number average molecular weight of 8,000 or more; and (B) a silanol condensation catalyst. Composition. 2. The curable resin composition according to claim 1, wherein said silicon atom-containing group is present at an end of a polymerization main chain of said polymer.