JP2718962B2 - Polybutadiene having a molecular chain terminal blocked by a hydrolyzable silyl group, a method for producing the same, and a room temperature curable composition containing the same - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a polybutadiene having a molecular chain terminal blocked by a hydrolyzable silyl group, and particularly to room temperature curing which can provide a rubbery cured product having a high strength and a high elongation. Liquid polybutadiene useful as a base polymer of the reactive composition and a method for producing the same,
Furthermore, a composition which uses the polybutadiene as a base polymer and is suitable as a sealing material composition and which can be cured to a rubber-like elastic body at room temperature when exposed to moisture, especially has a high strength, a high elongation and an essentially adhesive property. The present invention relates to a room-temperature curable composition having a good rubber-like cured product and good workability.

[Technical background of the invention and its problems]

As a liquid organic polymer having a hydrolyzable silyl group at a terminal, a polymer having a main chain of polyether is known (Japanese Patent Laid-Open No. 50-156599, etc.), In recent years, the composition has begun to be used as a sealing material for joints of buildings and joints of transportation machines (Japanese Patent Laid-Open No. 52-73998). However, this type has a drawback that it has essentially no adhesive property and has a low strength after curing, so that it cannot be used for a portion to which a large force is applied.

[Object of the invention]

The present invention is intended to solve these problems, and has adhesiveness in nature, and has a high strength and a high elongation rate. An object of the present invention is to provide a useful polybutadiene, a method for producing the same, and the room-temperature-curable composition.

[Configuration of the invention]

That is, the present invention has a general formula: (Wherein, R ¹ is a monovalent hydrocarbon group, R ² , R ³ , and R ⁴ are divalent hydrocarbon groups, and A is a compound or a secondary amine containing one or more primary amines in one molecule.) The residue of a compound containing two or more or a compound containing two or more thiol groups, Y represents a hydrolyzable group, a represents a number of 1 to 3, m represents a number of 10 to 100, and n represents a number of 1 or more. The present invention relates to polybutadiene having a molecular weight of 500 to 50,000, the molecular chain end of which is blocked with a hydrolyzable silyl group, and (a) a general formula; (Wherein R ⁴ , m is as defined above), a polybutadiene having a molecular chain terminal capped with an epoxy group, and (b) a compound containing at least one primary amino group in one molecule or a secondary amino group. A method for producing the above polybutadiene, comprising reacting a compound containing two or more groups or a compound containing two or more thiol groups, and (c) an organosilicon compound having an epoxy group and a hydrolyzable group; and The present invention relates to a room temperature curable composition containing at least one of the above polybutadienes as a main component.

In the polybutadiene of the present invention, in which the molecular chain end is blocked by the hydrolyzable silyl group represented by the general formula, the polybutadiene may be any of a cis-form, a trans-form and a 1,2-adduct, and may be a copolymer. It may be a thing. The degree of polymerization m of the butadiene unit is selected in the range of 10 to 100. When m is less than 10, it is difficult to obtain a rubber-like cured product having a high elongation rate, which is a feature of the present invention. Conversely, when m is greater than 100, the workability as a sealing material is reduced.

The monovalent hydrocarbon group represented by R ¹ is selected from an alkyl group such as a methyl group, an ethyl group, and a propyl group, an aryl group such as a phenyl group, and an aralkyl group such as a β-phenylethyl group and a β-phenylpropyl group. However, a methyl group or a phenyl group is preferable, and a methyl group is particularly preferable, because of ease of synthesis and availability of raw materials. Examples of the divalent hydrocarbon of R ² include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a phenylene group, a cyclohexylene group, and the like. Therefore, a trimethylene group is preferable.
Examples of the divalent hydrocarbon group of R ³ and R ⁴ are the same as those of R ² , but a methylene group is preferable in view of availability of raw materials and ease of synthesis.

Examples of the hydrolyzable group for Y include an alkoxy group, an alkoxyalkoxy group, an acyloxy group, an N, N-dialkylalkoxy group, an N-alkylamide group, an N, N-dialkylaminoxy group, a ketoxime group, and an alkenoxy group. However, since it is easily available, has no reactivity, and has no corrosiveness to the metal of the hydrolysis product, it has 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a hexyloxy group. And a methoxy group and an ethoxy group are particularly preferable from the viewpoint of the curing reactivity and the like. The number of the hydrolyzable groups a is selected in the range of 1 to 3, but a is preferably 2 in order to obtain a composition that gives a rubber-like cured product having a high elongation.

A is a residue obtained by reacting a compound containing one or more primary amines, a compound containing two or more secondary amines, or a compound containing two or more thiol groups.

Further, n is a number of 1 or more, and it is necessary to select the polybutadiene of the present invention within a range where the molecular weight is 500 to 50,000. If the molecular weight is less than 500, a cured rubber product having a high elongation rate, which is a feature of the present invention, cannot be obtained. Conversely, if the molecular weight is more than 50,000, the viscosity will increase and the workability will deteriorate.

The polybutadiene of the present invention includes, for example, (a) a general formula; (Wherein R ⁴ and m are as described above), a polybutadiene having a molecular chain terminal capped with an epoxy group, (b) a compound containing one or more primary amino groups in one molecule or a secondary compound The compound can be synthesized by reacting a compound containing two or more amino groups or a compound containing two or more thiol groups, and (c) an organosilicon compound having an epoxy group and a hydrolyzable group.

A typical example of the component (a) is one obtained by condensing epichlorohydrin with polybutadiene whose both ends are blocked by a hydroxyl group.

The compound (b) is a compound having an amino group or a thiol group that reacts with the epoxy group of (a) and (c). For the purpose of obtaining a high-elongation rubber cured product which is a feature of the present invention, one compound is used. It must be a compound containing one or more primary amines, a compound containing two or more secondary amines, or a compound containing two or more thiol groups.

As such a component (b), butylamine, allylamine, pentylamine, hexylamine, aniline, aminophenol, ethylenediamine, hexamethylenediamine, diaminobenzene, P, P ′ -Diaminodiphenylmethane, P,
P'-diaminodiphenylsulfone, piperazine, 1,3
-Di-4-piperidylpropane, hexamethylenedithiol, phenylenedithiol, 2,5-dimercapto-1,
3,4-Thiadiazole is preferred, and piperazine and 2,5-dimercapto-1,3,4-thiadiazole are particularly preferred in view of high reactivity and easy control of the reaction.

The organosilicon compound (c) has an epoxy group and a hydrolyzable group in one molecule. Preferred examples of the component (c) include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxybutyltriethoxysilane. Methyl (γ-glycidoxypropyl) dimethoxysilane, methyl (γ-glycidoxypropyl) dimethoxysilane, methyl (γ-glycidoxypropyl) diethoxysilane,
Methyl (γ-glycidoxybutyl) diethoxysilane,
Phenyl (γ-glycidoxypropyl) dimethoxysilane, phenyl (γ-glycidoxybutyl) dimethoxysilane, dimethyl (γ-glycidoxypropyl) methoxysilane, dimethyl (γ-glycidoxybutyl) methoxysilane, and these Alkoxy groups are alkylalkoxy groups, acyloxy groups, N, N-dialkylamino groups, N-
Compounds substituted with an alkylamide group, an N, N-dialkylaminooxy group, a ketoxime group, an alkenoxy group, and the like can be given.

The polybutadiene of the present invention has been described so far (A)
And (c) an epoxy group and (b) an amino group or a thiol group.

The reactions (a), (b) and (c) are preferably carried out at a temperature higher than the ambient temperature, for example, at 50 to 150 ° C. At that time, it is preferable to use a compound such as methanol, ethanol, phenol, salicylic acid and tris (dimethylaminomethyl) phenol as a reaction accelerator. Methanol is one of the preferred ones.
It is not necessary to use a solvent when performing this reaction,
Solvents such as hydrocarbons, ethers, and esters may be used.

The mixing ratio of (a), (b) and (c) is theoretically a molar ratio of (a) :( b) :( c) = n: (n + 1): 2. However, in practice, (b) and (c) may be used in amounts slightly greater than the theoretical amount.

As a procedure for the reaction, (a), (b) and (c) may be added simultaneously to carry out the reaction.
And after elongating the chain by reacting (b) in an amount exceeding the equivalent amount and suitable for obtaining polybutadiene having the above-mentioned molecular weight range, the required amount or an amount slightly exceeding (c) is obtained. In addition, the reaction is easier to control the degree of polymerization,
In addition, a hydrolyzable group can be reliably introduced into the molecular chain terminal.

The present invention further relates to a room temperature curable composition containing at least one of the above polybutadienes as a main component.

 As a typical example of this composition, a composition comprising (A) at least one kind of the above polybutadiene, 100 parts by weight, (B) an inorganic filler, 3 to 300 parts by weight, and (C) a curing catalyst, 0.001 to 20 parts by weight is exemplified.

 Hereinafter, each component will be described.

The component (B) is a component for imparting a suitable non-fluidity or reinforcing property to the composition. As these (B) components,
Fumed silica, precipitated silica, ground silica, diatomaceous earth,
Examples thereof include calcium carbonate, titanium oxide, alumina, aluminum hydroxide, iron oxide, talc, and clay. The amount of the component (B) used is in the range of 3 to 300 parts by weight, preferably 5 to 200 parts by weight, based on 100 parts by weight of the component (A). If the amount of the component (B) is less than 3 parts by weight, non-fluidity and reinforcing property cannot be obtained, and if it is more than 300 parts by weight, the viscosity of the composition becomes high and the workability decreases.

Examples of the curing catalyst (C) used in the present invention include tin carboxylate such as tin octylate; organic tin carboxylate such as dibutyltin dilaurate, dibutyltin dimaleate and dibutyltin phthalate; and organic tin oxide and its ester. Reactants; organic titanates such as tetrabutyl titanate; amines; amine salts; quaternary ammonium salts; guanidine compounds and the like. These curing catalysts are used in an amount of 0.001 to 100 parts by weight of the component (A).
Preferably, it is used in the range of 20 parts by weight. If the amount of the component (C) is less than this, the curing speed is too slow to be suitable for use. Conversely, if the amount is more than this, it is not only meaningless but also may cause leaching or precipitation, which is not preferable.

Because the composition of the present invention is inherently adhesive,
It is not necessary to use silane coupling agents that are commonly used to impart adhesiveness, but to use them to further enhance adhesiveness, or to allow long-term storage in one package Alternatively, a hydrolyzable silane including them may be added. These hydrolyzable silanes include H ₂ N (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , H ₂ N (CH ₂ ) ₃ Si (OCH ₂ CH ₃ ) ₃ , H ₂ N (CH ₂ ) ₃ NH ( CH ₂ ) ₃ Si (OCH ₃ ) ₃ , CH ₂ = CHSi (OCH ₂ CH ₃ ) ₃ , (CH ₃ ) ₂ Si (OCH ₃ ) ₂ , CH ₃ Si (OCH ₃ ) ₃ , CH ₃ Si (OCH ₂ CH ₃ ) ₃ , Si (OCH ₂ CH ₃ ) ₄ , etc. are exemplified.

To obtain long-term storage stability in one package,
It is also effective to add a monohydric primary alcohol such as methanol or ethanol.

In the composition of the present invention, a thixotropic agent such as hydrogenated castor oil and a plasticizer such as dioctyl phthalate, butylbenzyl phthalate and chlorinated paraffin can be used.

The composition of the present invention can be used in the form of a single package as described above, and can be stored separately in two components, for example, a component consisting of the components (A) and (B) and a component (C). It is also possible to prepare a two-package type in which both are mixed before use.

〔The invention's effect〕

A sealing material can be obtained by adding a curing catalyst such as an organotin compound, a filler and the like to the polybutadiene of the present invention. By using the polybutadiene of the present invention as a base polymer, it is possible to obtain a sealing material having a high elongation and a high strength and capable of exhibiting adhesiveness.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples. In the Examples and Comparative Examples, “parts” means “parts by weight” and “%” means “% by weight”.

Example 1 Polybutadiene having a glycidyl group at both ends and having an average degree of polymerization of 20, a molecular weight of about 1,100 and a viscosity at 25 ° C. of 2,400 cSt 6
Moles of 7 moles of n-butylamine and polybutadiene
Add methanol equivalent to 10%, and under nitrogen atmosphere,
Heating and stirring was started at 60 ° C. Samples were taken at 2 hour intervals after the start of heating and stirring, the total amount of epoxy and amino groups in the sample was determined by potentiometric titration, and the peak due to the epoxide methylene protons by NMR (2.67 pp based on TMS)
m) and the viscosity at 25 ° C. were measured. After 16 hours from the heating and stirring, the titer of the epoxy group and the amino group decreased by almost the theoretical amount, the peak due to the epoxide methylene proton disappeared, and the viscosity at 25 ° C became constant at 5,830 cSt, Methyl (γ-
2.2 mol of (glycidoxypropyl) dimethoxysilane was added, and heating and stirring were continued under the same conditions. A portion was removed at intervals of 2 hours after the addition of the above silane, and the total amount of epoxy groups and amino groups in the sample was determined by potentiometric titration and the peak due to the epoxide methylene proton was observed by NMR. Twelve hours later, they almost disappeared, so the completion of the reaction was recognized, and methanol was distilled off. The resulting reaction product has a viscosity of 4 at 25 ° C.
5,600 cSt, a light yellow viscous liquid having a specific gravity of 1.02 at the same temperature and a number average molecular weight measured by GPC of 7,300, which was capped with a hydrolyzable silyl group represented by the following formula It was confirmed that it was polybutadiene (P-1).

Example 2 Two moles of polybutadiene having both ends of glycidyl group having an average degree of polymerization of 56, a molecular weight of about 3,000, and a viscosity at 25 ° C. of 12,000 cSt were mixed with 3 moles of piperazine and 10 moles of polybutadiene.
% Of methanol, and add
Heat stirring was started at ℃. A portion was extracted at 2 hour intervals in the same manner as in the synthesis of P-1 and subjected to potentiometric titration, NMR and viscosity measurement. After 8 hours from the start of heating and stirring, the titer of the epoxy group and imino group was almost the theoretical amount. As the peak decreased, the peak due to the epoxide methylene proton disappeared, and the viscosity at 25 ° C. became constant at 6,400 cSt. Therefore, 2.2 mol of methyl (γ-glycidylpropyl) dimethoxysilane was added, and the reaction was continued. After adding silane,
Determination of total amount of epoxy group and imino group in 6 hours and NMR
The termination of the reaction was confirmed by observing the disappearance of the epoxide methylene by the observation of the proton peak of the epoxide methylene, and methanol was distilled off to terminate the reaction. The resulting reaction product has a viscosity at 25 ° C. of 47,300 cSt, a specific gravity at the same temperature of 1.02, and a number average molecular weight of 7,1 measured by GPC.
It was confirmed that this was polybutadiene (P-2) whose terminal was blocked by a hydrolyzable silyl group represented by the following formula.

Example 3 5 mol of 2,5-dimercapto-1,3,4-thiadiazole and 10 mol of polybutadiene were added to 4 mol of polybutadiene having both ends of glycidyl group having an average degree of polymerization of 56, a molecular weight of about 3,000, and a viscosity at 25 ° C. of 12,000 cSt. % Of ethanol was added, and heating and stirring were started at 80 ° C. under a nitrogen atmosphere. A part was extracted at an interval of 2 hours in the same manner as in the synthesis of P-1.
Eight hours after the start of the heating and stirring, the titration amounts of the mercapto group and the epoxy group decreased by almost the theoretical amount, the peak of the epoxide methylene proton disappeared, and the viscosity at 25 ° C. became constant at 15,200 cSt. -Glycidylpropyl) diethoxysilane 2.2 mol,
The reaction was continued. Six hours after the addition of the silane, titration of the total amount of the mercapto group and the epoxy group and observation of the peak of the epoxide methylene by NMR measurement confirmed the disappearance of these, and the end of the reaction was confirmed. Finished. This gives a viscosity at 25 ° C of 49,300 cS
t, specific gravity 1.02, number average molecular weight measured by GPC is 1
3,400 pale yellow viscous liquids were obtained. This was confirmed to be polybutadiene (P-3) whose terminal was blocked by a hydrolyzable silyl group represented by the following formula.

Example 4 Polybutadiene having a glycidyl-group-terminal-terminated polybutadiene 3 having an average degree of polymerization of 35, a molecular weight of about 1,900 and a viscosity at 25 ° C. of 7,500 cSt.
In moles, 5 moles of P, P'-diaminodiphenylmethane and 10% of polybutadiene in ethanol;
% Of phenol was added, and heating and stirring at 80 ° C. was started. A portion was sampled at 2 hour intervals in the same manner as in the synthesis of P-1. Potentiometric titration, NMR measurement, and viscosity measurement were performed. After 14 hours, the total amount of amino groups and epoxy groups was reduced by almost the theoretical amount, and NMR The peak of the proton due to the epoxide methylene disappeared, and the viscosity at 25 ° C was 1
Since it became almost constant at 0,500 cSt, 2.2 mol of phenyl (γ-glycidoxypropyl) diethoxysilane was added,
The reaction was continued. Twelve hours after silane addition, titration of total amino and epoxy groups by potentiometric titration and NMR
As a result of the observation of the peak of epoxide methylene, the end of the reaction was recognized, and ethanol was distilled off to terminate the reaction. This gives a viscosity at 25 ° C of 61,300 cSt, a specific gravity of 1.03, and G
A pale yellow viscous liquid having a number average molecular weight of 3,100 by PC was obtained. This was confirmed to be polybutadiene (P-4) whose terminal was blocked with a hydrolyzable silyl group represented by the following formula.

Examples 5 to 8 With respect to 100 parts of polybutadiene (P-1 to 4) whose molecular chain ends were blocked by the hydrolyzable silyl groups obtained in Examples 1 to 4, the fillers shown in Table 1 and the inorganics were used. Samples 1 to 4 were prepared by adding a pigment and a thixotropic agent, uniformly dispersing the mixture using a three-roll mill, and further adding and mixing a tin compound shown in Table 1. Each of these samples was cured into a sheet having a thickness of 2 mm, cured at room temperature for 14 days, punched out with a JIS No. 2 dumbbell, and subjected to a tensile test. These samples 1
4 was used to prepare a shear adhesion test body shown in FIG. 1, and after being cured at room temperature for 8 days, a tensile test was performed. These results are also shown in Table 1.

Comparative Example 1 Molecular weight of about 8,000, as terminal group The filler, inorganic pigment and thixotropic agent shown in Table 1 were added to 100 parts of the polyoxypropylene having the above, and the mixture was uniformly dispersed with a three-roll mill. The compounds were added and mixed, and sample-5
I got The same tests as in Examples 5 to 8 were performed using Sample-5. The results are also shown in Table 1.

Comparative Example 2 The sample-5 prepared in Comparative Example 1 was added with a silane coupling agent shown in Table 1 as an adhesiveness-imparting agent to obtain Sample-6. The same tests as in Examples 5 to 8 were performed using this sample, and the results are also shown in Table 1.

As shown from the above results, the polybutadiene of the present invention is useful as a base polymer of a room temperature curable composition, and particularly, a cured product of the composition has a high strength and a high elongation, and a silane coupling agent is used. It is evident that even in the system not containing, it has good adhesiveness.

[Brief description of the drawings]

FIG. 1 is a perspective view of a test piece subjected to a shear adhesion test.
The unit in the figure is mm. 1 ... Sample 2 ... Adherend (glass, aluminum or PVC steel plate)

Claims (5)

(57) [Claims] (1) a general formula; (Wherein, R ¹ is a monovalent hydrocarbon group, R ² , R ³ , and R ⁴ are divalent hydrocarbon groups, and A is a compound or a secondary amine containing one or more primary amines in one molecule.) The residue of a compound containing two or more or a compound containing two or more thiol groups, Y represents a hydrolyzable group, a represents a number of 1 to 3, m represents a number of 10 to 100, and n represents a number of 1 or more. A) polybutadiene having a molecular weight of 500 to 50,000, the molecular chain end of which is blocked with a hydrolyzable silyl group. (2) a general formula: (Wherein R ⁴ and m are as described above), a polybutadiene having a molecular chain terminal capped with an epoxy group, (b) a compound containing one or more primary amino groups in one molecule or a secondary compound 2. The polybutadiene according to claim 1, wherein a compound containing two or more amino groups or a compound containing two or more thiol groups, and (c) an organosilicon compound having an epoxy group and a hydrolyzable group are reacted. Manufacturing method. 3. The component (b) is butylamine, allylamine, pentylamine, hexylamine, aniline, aminophenol, ethylenediamine, hexamethylenediamine, diaminobenzene, P, P'-diaminodiphenylmethane, P, P'-diaminodiphenyl. The method according to claim 2, which is a compound selected from sulfone, piperazine, 1,3-di-4-piperidylpropane, hexamethylenedithiol, phenylenedithiol, and 2,5-dimercapto-1,3,4-thiadiazole. 4. The component (c) has a general formula: 3. The method according to claim 2, wherein the compound is an organosilicon compound represented by the formula: wherein R ¹ , Y, and a are as described above. 5. A room temperature curable composition comprising (A) 100 parts by weight of the polybutadiene according to claim 1, (B) 3 to 300 parts by weight of an inorganic filler, and (C) 0.001 to 20 parts by weight of a curing catalyst.