JP2687038B2 - Room temperature curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field The present invention relates to room temperature curable compositions comprising polyethers having hydrolyzable silicon functional groups.

(Prior Art) A polyether having a hydrolyzable silicon functional group has a property of being cured into a rubber-like substance when exposed to moisture in the atmosphere, and is used for applications such as adhesives and sealing agents. .

This polyether is generally used for various purposes in the form of a composition containing a plasticizer, a filler and the like. For example, when it is used as a sealant for construction, it is required to have a low modulus and a high elongation rate, and thus it has been used as a composition containing a plasticizer such as a non-functional polyether.

(Problems to be Solved by the Invention) However, in order to obtain a cured product with a low modulus and a high elongation from the above polyether, it is necessary to add a large amount of a plasticizer.

However, in a cured product obtained from a polyether composition containing a large amount of a plasticizer, the plasticizer bleeds over the surface of the cured product over time, causing problems such as stickiness. Further, since the plasticizer bleeds onto the surface of the cured product, there is a problem that the physical properties such as hardness and elongation of the cured product change.

Therefore, an object of the present invention is to provide a polyether composition in which bleeding of a plasticizer on the surface of a cured product is effectively eliminated and a cured product having a low modulus and a high elongation rate can be obtained.

(Means for Solving Problems) According to the present invention, (A) the following general formula [I], In the formula, a and b are each an integer of 0 to 2, m is an integer of 0 to 18, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ² is , A substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or an organosiloxy group, R ³ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, X is a hydrolyzable functional group, Y is a polyoxyalkylene polymer chain, Z is -R-, -ROR-, -ROC (= O)-, -RC (=
O)-, -RNHC (= O)-and -C (= O)-[wherein
R is the same or different type of divalent hydrocarbon group having 1 to 20 carbon atoms], which is any group selected from the group consisting of: 10-90% by weight of a polyether having a functional group, (B) the following general formula [II], In the formula, a, b, m and R ^{1 to} R ³ are as described above, and R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. A room temperature-curable composition comprising: a polyether compound having 90 to 10% by weight of a polyether having a hydrolyzable silicon functional group at one end of a molecular chain; and (C) a curing catalyst.

The present invention is directed to an end-modified polyether [component (A)] having a hydrolyzable silicon functional group at both ends of the polyether polymer chain as described above, and a hydrolyzable silicon at one end of the polyether polymer chain. By combining with a terminal-modified polyether [component (B)] having a functional group, it was possible to obtain a cured product having a low modulus and a high elongation without adding a plasticizer. That is, in the curable composition of the present invention, since it is not necessary to add a plasticizer in particular, it is possible to effectively avoid the problem of bleeding of the plasticizer onto the surface of the cured product.

Component (A) The polyether used as the component (A) in the present invention is represented by the above general formula [I], that is, (In the formula, a, b, m, R ^{1 to} R ³ , X, Y and Z are as described above). As is apparent from the general formula [I], the polyether polymer chain is an end-modified polyether having hydrolyzable silicon functional groups at both ends.

In the general formula [I], a and b are integers of 0 to 2 and m is an integer of 0 to 18. As can be understood from this value of a, the silicon atoms at both ends of the molecular chain have the groups X respectively.
Is essential, and the group R ¹ does not necessarily have to be bonded to the silicon atom.

The group X is a hydrolyzable group, and examples of such a hydrolyzable group include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group and an ethoxyethoxy group; an acetoxy group and a propionoxy group. , Acyloxy groups such as butyroxy group; alkenyloxy groups such as propenyloxy group and isobutenyloxy group; iminoxy groups such as dimethylketoxime group, diethylketoxime group, methylethylketoxime group, cyclopentanoxime group and cyclohexanoxime group Group; amino group, N
-Amino group such as methylamino group, N-ethylamino group, N-propylamino group, N-butylamino group, N, N-dimethylamino group, N, N-diethylamino group; N-methylacetamide group, N- Amido groups such as ethylacetamide group and N-methylpropionamide group; N, N-dimethylaminooxy group, N-methyl-N-ethylaminooxy group, N,
An aminooxy group such as an N-diethylaminooxy group can be mentioned. Due to the presence of such a group, the polyether of this component (A) exhibits condensation curability.

The group R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, for example, methyl group, ethyl group, propyl group, butyl group, octyl group. Alkyl group such as, cyclopentyl group, cyclohexyl group, cycloalkyl group such as cyclobutyl group, phenyl group, tolyl group, xylyl group, aryl group such as naphthyl group, benzyl group, phenylethyl group, aralkyl group such as phenylpropyl group, Further, a chloromethyl group, a 3,3,3-trifluoropropyl group and the like in which a part or all of hydrogen atoms bonded to these hydrocarbon groups are substituted with a halogen atom are exemplified.

The radical R ² has from 1 to 20 carbon atoms, preferably 1 carbon atom
To 10 substituted or unsubstituted monovalent hydrocarbon groups or organosiloxy groups. Examples of such a monovalent hydrocarbon group include the groups exemplified for R ¹ above. Examples of the organosiloxy group include trimethylsiloxy group and the like.

In the present invention, a hydrolyzable silicon functional group at the molecular end composed of each group described above, that is, Particularly suitable as, for example, An alkoxysilyl group such as —Si (OC ₂ H ₅ ) ₃ Alkenyloxysilyl groups such as An acyloxysilyl group such as Aminosilyl groups such as Aminooxysilyl groups such as Iminooxysilyl groups such as Amidosilyl groups and the like can be exemplified.

In the general formula [I], Y is a polyoxyalkylene polymer chain and constitutes the main chain of the polyether modified at both ends of the component (A). Specifically, the Y
Is a polyether having a repeating unit represented by the following formula: R ⁵ O (wherein R ⁵ is a divalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms) It is a polymer chain. As the repeating unit, in _{particular, -CH 2 O -, - CH} 2 CH 2 O-, Is preferably -CH ₂ CH ₂ CH ₂ CH ₂ O-like, it may be used in the form of a mixture also of two or more as a singly, most preferably, - (C
H ₃₎ CHCH ₂ is O-. The molecular weight of the polyether with respect to the group Y is in the range of 300 to 15,000, particularly 3,000 to 1
It is desirable to be in the range of 2,000.

Z is -R-, -ROR-, -ROC (= O)-, -RC (=
O)-, -RNHC (= O)-and -C (= O)-[wherein
R is a divalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms]. Here, specific examples of the group R include alkylene groups such as methylene, ethylene, propylene and butylene, And an aralkylene group such as
Examples of _{ROR- -CH 2 OCH 2 -, -} CH 2 CH 2 OCH 2 -, And the like. In the present invention, a particularly preferred group Z is a methylene group.

In the general formula [I], R ³ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which is the same as R ¹ described above. Specific examples of the monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, butyl group and octyl group, cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cyclobutyl group, phenyl group and tolyl group. A group, an xylyl group, an aryl group such as a naphthyl group, a benzyl group, a phenylethyl group, an aralkyl group such as a phenylpropyl group, and a part or all of the hydrogen atoms bonded to these hydrocarbon groups are substituted with a halogen atom, Examples thereof include a chloromethyl group and a 3,3,3-trifluoropropyl group. Of these, a hydrogen atom and a methyl group are preferable, and a hydrogen atom is particularly preferable.

The both-end modified polyether represented by the above general formula [I] has the following formula [Ia] at both ends of the molecular chain. (In the formula, Z and R ² are as described above), and a polyether having an olefin group (the main chain of which is composed of the repeating unit described above), and the following formula [Ib]: (In the formula, a, b, m, R ¹ , R ² and X are as described above) in the presence of a hydrosilylation catalyst known per se such as chloroplatinic acid. It can be easily produced by an addition reaction at room temperature to 200 ° C.

Component (B) In the present invention, the polyether used as the component (B) is represented by the general formula [II], that is, (In the formula, a, b, m and R ^{1 to} R ² , Y, Z are as described above), and as is clear from the general formula [II], this polyether is It has a hydrolyzable silicon functional group at one end of the molecular chain.

In the present invention, by using the above-mentioned one-end modified polyether in combination with the above-mentioned both-end modified polyether [component (A)], a low modulus and a high elongation rate can be obtained without compounding a plasticizer. It is possible to form a cured product of Therefore, bleeding of the plasticizer from the surface of the cured product (hereinafter simply referred to as "oil bleed") can be effectively avoided.

In the above general formula [II], a, b, m and R ^{1 to} R ³ , Y, Z
Are the same as those described for the general formula [I], and the same can be exemplified as specific examples of each group.

R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and specific examples thereof include those exemplified for R ^1. can do.

The one-terminal polyether of the component (B) is incorporated and fixed in the cured product via the hydrolyzable silicon functional group formed at one end.

The above-mentioned one-end-modified polyether of the component (B) can be basically produced by the same method as the production method of the both-end-modified polyether of the component [A]. That is, one end of the molecular chain is blocked with a group R ⁴ such as an alkyl group,
And the other one end is a polyether blocked with an olefin group represented by the formula [Ia], and a silicon hydride compound represented by the formula [Ib], in the presence of the hydrosilylation catalyst described above. It can be produced by addition reaction.

The one-end modified polyether of the component (B) is used in an amount of 10 to 90% by weight, preferably 25 to 85% by weight, based on the total amount of the above-mentioned both-end-modified polyether of the component [A]. To be taken. When the amount of this component (B) used is less than the above range, a large amount of a plasticizer needs to be blended in order to obtain a cured product having a low modulus and a high elongation rate, and as a result, the surface of the resulting cured product is obtained. This causes oil bleeding, which causes contamination of the surface of the cured product and deterioration of the physical properties of the cured product.
Further, when used in a larger amount than the above range, the obtained cured product tends to be unsatisfactory in mechanical strength.

Component (C) In the present invention, the curing agent used as the component (C) is compounded to condense and cure the polyether modified at both ends of the component (A).

As such a curing agent, the one used in condensed silicone RTV can be used. In particular,
Metal salts of organic acids such as dibutyltin dilaurate, dibutyltin dibenzyl maleate, dibutyltin dioctoate, iron stearate, lead octylate, tin octylate, tin compounds such as dibutyltin oxide, dioctyltin oxide, tetrabutyl titanate, Examples thereof include titanic acid esters such as tetraisopropyl titanate, titanium chelate compounds such as titanium acetylacetonate, and mixtures thereof. In particular, in the case where the hydrolyzable group X is an alkoxy group as the polyether modified with component (A) at both ends, it is preferable to use a tin carboxylate or a titanium chelate compound as a curing catalyst. Is.

In the composition of the present invention, the above curing agent is used in an amount of 0.01 to 10 parts by weight per 100 parts by weight of a total of 100 parts by weight of both-end modified polyether [component (A)] and one-end modified polyether [component (B)]. In particular, it is desirable that the amount is 0.1 to 5 parts by weight. If the blending amount is less than the above range, there is a tendency that the function as a curing catalyst is not sufficiently exhibited, the curing time becomes long, and the curing to a deep portion is not sufficiently performed. Further, if it is blended in a larger amount than the above range, the storage stability of this composition tends to decrease.

Other components In addition to the components (A) to (C) described above, various components may be added to the composition of the present invention within a range that does not impair the object of the present invention. For example, fumed silica,
Precipitable silica and hydrophobized products thereof, silicic acid anhydride, silicic acid hydrate, carbon black, calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, oxidation Fillers such as zinc, activated zinc white, hydrogenated castor oil, shirasu balloon, asbestos, glass fiber, and filaments may be used alone or in combination of two or more. Further, a coloring agent such as an inorganic pigment or an organic dye, an adhesion-imparting agent such as a phenol resin or an epoxy resin, an antiaging agent, an ultraviolet absorber or the like can be added. In particular, when obtaining a cured product having low hardness and large elongation, titanium oxide, calcium carbonate, magnesium carbonate,
It is preferable to add a filler such as talc, ferric oxide, zinc oxide, and shirasu balloon in a ratio of 5 to 200 parts by weight per 100 parts by weight of the total amount of the components (A) and (B). . Further, when tackiness appears on the surface of the cured product, various silanes such as trimethoxysilane, triethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and their partial hydrolysates are appropriately blended. You can also

Curable composition The curable composition of the present invention can be easily prepared by uniformly mixing the above-mentioned components.

The curable composition is condensation-cured at room temperature to form a cured product. At the time of curing, water and alcohols such as methanol, ethanol, propanol, and methyl cellosolve can be added in order to accelerate the curing or to improve the deep curing.

The curable composition of the present invention is particularly useful as a one-pack type and two-pack type elastic sealant, and is preferably used as a sealing agent for buildings, ships, automobiles, roads and the like.
In addition, by using an internal additive such as aminosilane or epoxysilane or a primer together, glass, porcelain,
Since it can be adhered to substrates such as wood, metal and resin moldings, it can be used as various types of sealing compositions and adhesive compositions. Further, it is also useful as a food packaging material, cast rubber material, paint and tampo printing material.

Example 1 Example 1 At both ends of the molecular chain 50 parts by weight of an oxylopylene polymer having an average molecular weight of 8,000 And an oxypropylene polymer having an average molecular weight of 8,000 in which the other molecular chain end is blocked with a butoxy group 50 parts by weight Calcium carbonate 140 parts by weight Titanium oxide 25 parts by weight Styrenated phenol (anti-aging agent) 1 part by weight, After kneading in a substantially water-free state, 1 part by weight of dibutyltin dilaurate was added and uniformly kneaded to obtain a curable composition.

Using this composition, an H-shaped test piece was prepared in accordance with JIS K-5758 and cured at 23 ° C. and 60% humidity for 14 days.
A rubber-like elastic body that was completely cured to the inside was obtained. When this rubber-like elastic body is subjected to a tensile test at a speed of 50 mm / min,
It showed tensile properties with a% modulus of 2.8 kg / cm ² , a strength at break of 8.1 kg / cm ² , and an elongation at break of 600%.

A sheet-like sample having a thickness of 3 mm was prepared from the above curable composition, and after curing at 90 ° C. and 60% humidity for 14 days, the surface condition was observed and no oil bleeding was observed.

Example 2 At both ends of the molecular chain An oxypropylene polymer having an average molecular weight of 9000 having an average molecular weight of 9000 and an oxypropylene polymer having an average molecular weight of 3000 and having the same group at one end of the molecular chain and the other end being blocked with a butoxy group. A curable composition was prepared in the same manner as in Example 1, except that a part was used instead of the oxypropylene polymer used in Example 1.

The tensile properties of the H-shaped test piece prepared by using this curable composition in the same manner as in Example 1 have a 50% modulus of 2.5 kg / cm ² , after being cured at 23 ° C. and 60% humidity for 14 days. The strength at break was 6.5 kg / cm ² , and the elongation at break was 550%. A sheet-like sample similar to that of Example 1 was prepared and the surface condition was observed under the same conditions, but no oil bleeding was observed.

Example 3 At both ends of the molecular chain Oxypropylene polymer having an average molecular weight of 8,400
Parts by weight and at one end of the molecular chain Example 1 except that 50 parts by weight of an oxypropylene polymer having an average molecular weight of 8,400 in which the other end of the molecular chain was blocked with a butoxy group was used instead of the oxypropylene polymer used in Example 1. A curable composition was prepared according to the same formulation.

The tensile properties of the H-shaped test piece prepared by using this curable composition in the same manner as in Example 1 have a 50% modulus of 2.5 kg / cm ² , after being cured at 23 ° C. and 60% humidity for 14 days. The strength at break was 8.0 kg / cm ² and the elongation at break was 650%. Further, a sheet-like sample similar to that of Example 1 was prepared and the surface condition was observed under the same conditions, but no oil bleeding was observed.

(Effect of the Invention) According to the present invention, a curable composition having no oil bleed and capable of forming a cured product having a low modulus and a high elongation ratio was obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-142850 (JP, A) JP-A-4-15251 (JP, A) JP-A-2-117956 (JP, A) JP-A-1- 279958 (JP, A) JP-A-8-176429 (JP, A) JP-A-8-143660 (JP, A) JP-A-63-108058 (JP, A)

Claims (2)

(57) [Claims] (A) The following general formula [I], In the formula, a and b are each an integer of 0 to 2, m is an integer of 0 to 18, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ² is , A substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or an organosiloxy group, R ³ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, X is a hydrolyzable functional group, Y is a polyoxyalkylene polymer chain, Z is -R-, -ROR-, -ROC (= O)-, -RC (=
O)-, -RNHC (= O)-and -C (= O)-[wherein
R is the same or different type of divalent hydrocarbon group having 1 to 20 carbon atoms], which is any group selected from the group consisting of: 10-90% by weight of a polyether having a functional group, (B) the following general formula [II], In the formula, a, b, m and R ^{1 to} R ³ are as described above, and R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. A room temperature-curable composition comprising: a polyether compound having 90 to 10% by weight of a polyether having a hydrolyzable silicon functional group at one end of a molecular chain; and (C) a curing catalyst. 2. A cured product obtained by curing the composition according to claim 1.