JP3012876B2 - Polymer having a molecular chain terminal blocked by a hydrolyzable silyl group, method for producing the same, and room temperature curable composition containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a polymer containing a hydrogenated polybutadiene unit whose molecular chain end is blocked by a hydrolyzable silyl group,
In particular, the present invention relates to a polymer useful as a base polymer of a room-temperature-curable composition from which a rubber cured product having high strength, high elongation, and excellent weather resistance can be obtained, and a method for producing the polymer. Suitable as an agent composition,
A composition that can cure to a rubber-like elastic material at room temperature when exposed to moisture, especially high-strength, high-elongation, inherently adhesive, and has excellent weatherability and excellent workability at room temperature Composition.

[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 (JP-A-50-156599, etc.), and a room-temperature curable composition based on this is used. Products (JP-A-52-73998, etc.)
It has begun to be used as a sealing material for joints of buildings and joints of transportation equipment. 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 inventors have previously found a method for producing polybutadiene in which the molecular chain ends are blocked with a hydrolyzable silyl group, the polymer obtained by this method has adhesive properties, and It has been found that a rubber-like cured product having a higher strength than that of the base polymer can be obtained (Japanese Patent Application No. 63-28).
No. 5432).

The present inventors have further studied to impart heat resistance and weather resistance in addition to adhesiveness and high strength, and as a result, have completed the present invention.

[Configuration of the invention]

That is, the present invention relates to a polymer having a number average molecular weight of 500 to 50,000 represented by the following general formula (I) and having a molecular chain terminal blocked by a hydrolyzable silyl group. (Wherein R ¹ is a monovalent hydrocarbon group, R ² , R ³ , and R ⁴ are divalent hydrocarbon groups, and A is a compound containing one or more primary amino groups in the molecule or a secondary amino group) A unit of a compound containing two or more groups or a compound containing two or more thiol groups, Y is a hydrolyzable group, a is an integer of 1 to 3, m is an integer of 10 to 100, n
Represents a number of 1 or more, B represents a general formula, (Where p, q, and r are not simultaneously 0), and are hydrogenated polybutadiene units obtained by hydrogenating at least one polybutadiene unit. ), A production method thereof and a room temperature curable composition containing the same.

The polybutadiene which is a precursor of the hydrogenated polybutadiene unit of B constituting the polymer of the present invention in which the molecular chain end is blocked by the hydrolyzable silyl group represented by the general formula (I) is a cis-form, a trans-form, It may be an isomer or a 1,2 adduct, or a copolymer obtained by mixing them. The degree of polymerization m of the hydrogenated butadiene unit is 10 to
Selected in the range of 100. When m is less than 10, it is difficult to obtain a rubber-like cured product having a high elongation rate. Conversely, when m is greater than 100, the workability of the composition is reduced, which is not preferable.

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 in terms of synthesis and availability. Examples of the divalent hydrocarbon group for R ² include a methylene group, an ethylene group, a trimethylene group,
Examples thereof include a tetramethylene group, a phenylene group, and a cyclohexylene group. Of these, a trimethylene group is preferable because of easy 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 readily available, reactive, and has no corrosiveness to the metal of the hydrolysis product, it has 1 to 1 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a hexyloxy group. 6 alkoxy groups are suitable,
A methoxy group and an ethoxy group are particularly preferred from the viewpoint of the curing reactivity. The number a of the hydrolyzable groups is selected in the range of 1-3, but in order to obtain a rubber-like cured product having a high elongation, a is 2
It is preferred that

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

In addition, n is a number of 1 or more, and it is necessary to select n in a range where the polymer of the present invention has a molecular weight of 500 to 50,000. Molecular weight 5
If it is smaller than 00, a rubber-like cured product having a high elongation rate cannot be obtained, while if it is larger than 50,000, the viscosity becomes high and the workability is reduced.

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

Representative examples of component (a) include those obtained by condensing epichlorohydrin with hydrogenated polybutadiene having both ends blocked by a hydroxyl group using boron trifluoride, tin tetrachloride or the like as a catalyst.

The compound (b) is a compound having an amino group or a thiol group which reacts with the epoxy group in (a) and (c), and is used for the purpose of obtaining a rubber-like cured product having a high elongation and for obtaining the adhesiveness. The compound must be a compound containing one or more primary amino groups, a compound containing two or more secondary amino groups, or a compound containing two or more thiol groups in one molecule.

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, Hexamethylene dithiol, phenylenedithiol, and 2,5-dimercapto-1,3,4-thiadiazole are preferred.From the viewpoint of high reactivity and ease of control of the reaction, piperazine, 2,
5-dimercapto-1,3,4-thiadiazole is particularly preferred.

The organosilicon compound (c) has an epoxy group and a hydrolyzable group in the same molecule. These (c)
Preferred components are γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxybutyltriethoxysilane,
Methyl (γ-glycidoxypropyl) dimethoxysilane, methyl (δ-glycidoxypropyl) dimethoxysilane, methyl (γ-glycidoxypropyl) diethoxysilane, methyl (δ-glycidoxybutyl) diethoxysilane, Phenyl (γ-glycidoxypropyl) dimethoxysilane, dimethyl (γ-glycidoxypropyl) methoxysilane, dimethyl (δ-glycidoxybutyl) methoxysilane, and these alkoxy groups are replaced with alkoxyalkoxy, acyloxy, N, Compounds substituted with an N-dialkylamino group, an N-alkylamide group, an N, N-dialkylaminoxy group, a ketoxime group, an alkenoxy group, and the like can be given.

The polymer of the present invention can be obtained by the reaction between the epoxy groups (a) and (c) described above and the amino group or thiol group (b). The reactions (a), (b) and (c) are preferably carried out at 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. It is not necessary to use a solvent when performing this reaction, but a hydrocarbon-based, ether-based, or ester-based solvent 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.
After elongating the chain by reacting (b) in an amount exceeding its equivalent and suitable for obtaining a polymer having the above-mentioned molecular weight range, the theoretical amount or a slightly larger amount (c) is obtained. When the reaction is carried out in a stepwise manner, the degree of polymerization can be easily controlled, and a hydrolyzable group can be reliably introduced into the terminal of the molecular chain.

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

 As a typical example of this composition, a composition comprising (A) at least one kind of the above polymer, 100 parts by weight, (B) 3 to 300 parts by weight of an inorganic filler, and (C) 0.001 to 20 parts by weight of a curing catalyst 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). When the amount of the component (B) is less than 3 parts by weight, non-flowability and reinforcing property cannot be obtained, and when 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 octylic acid; organic tin carboxylate such as dibutyltin dilaurate, dibutyltin dimaleate, and dibutyltin diphthalate; 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 20 parts by weight per 100 parts by weight of the component (A).
It is preferred to use in the range of parts by weight. If the amount of the component (C) is less than this, the curing rate is too slow to be suitable for use. Conversely, if the amount is more than this, it is not only meaningless, but there is a risk of exudation and 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 enable long-term storage in one package As such, 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 ) and the like.

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 component (A) and component (B) and a component (C). It is also possible to use a two-component 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 polymer of the present invention. By using the polymer of the present invention as a base polymer, it is possible to obtain a sealing material having high elongation and strength, having adhesiveness, and further having weather resistance and heat resistance.

〔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 The average degree of polymerization was 20 and the molecular weight was about 1100.
100 cSt, and the hydrogenated polybutadiene unit is N-glycidyl group-terminated hydrogenated polybutadiene obtained by hydrogenating a liquid polybutadiene of the formula
7 mol of butylamine and an amount of methanol corresponding to 10% thereof were added, and heating and stirring were started at 60 ° C. under a nitrogen atmosphere. A portion was withdrawn at intervals of 2 hours after the start of heating and stirring, the total amount of epoxy groups and amino groups in the sample was determined by potentiometric titration, the peak due to epoxide methylene protons (2.67 ppm based on TMS) was observed by NMR, and 25%. The viscosity was measured at ° C. Sixteen hours after heating and stirring, the titer of the epoxy group and the amino group decreased by almost the theoretical value, the peak due to the proton of epoxide methylene disappeared, and the viscosity at 25 ° C became constant at 5920 cSt. (Γ-glycidoxypropyl)
2.2 mol of 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 obtained reaction product is a light yellow viscous liquid having a viscosity at 25 ° C. of 45,800 cSt and a number average molecular weight of 7,500 as measured by GPC, which is a hydrolyzable silyl group represented by the following formula. It was confirmed that the polymer was a polymer (P-1) having a terminal capped. (B ¹ is the above hydrogenated polybutadiene unit) Example 2 Average degree of polymerization: 56, molecular weight: about 3000, viscosity at 25 ° C.
12000 cSt, and the hydrogenated polybutadiene unit is To 2 moles of hydrogenated polybutadiene having glycidyl groups at both ends, which was obtained by hydrogenating liquid polybutadiene, 3 moles of piperazine and an amount of methanol equivalent to 10% thereof were added, and heating and stirring were started at 60 ° C. under a nitrogen atmosphere. .
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 reduced by almost the theoretical value. At the same time, the peak due to the epoxide methylene proton disappears, and the viscosity at 25 ° C becomes 6450 cS.
Since it became constant at t, 2.2 mol of methyl (γ-glycidoxypropyl) dimethoxysilane was added, and heating and stirring were continued under the same conditions.

Six hours after the addition of the silane, the termination of the reaction was confirmed by quantifying the total amount of the epoxy group and the imino group and observing the peak of the epoxide methylene proton by NMR and confirming the completion of the reaction. Finished. The resulting reaction composition has a viscosity at 25 ° C. of 48500 c.
It is a pale yellow viscous liquid having a number average molecular weight of about 7200 as measured by St and GPC, and is a polymer (P-2) whose terminal is blocked by a hydrolyzable silyl group represented by the following formula: (B ² is the above hydrogenated polybutadiene unit) Example 3 Average degree of polymerization: 56, molecular weight: about 3000, viscosity at 25 ° C .: 1
2000 cSt, and the hydrogenated polybutadiene unit is Glycidyl-group-end-capped hydrogenated polybutadiene obtained by hydrogenating liquid polybutadiene of
3-mol of 5-dimercapto-1,3,4-thiadiazole and methanol corresponding to 10% thereof were added, and heating and stirring were started at 80 ° C. under a nitrogen atmosphere. As in the synthesis of P-1, 2
At time intervals, a portion was extracted and potentiometric titration, NMR measurement, and viscosity measurement were performed. Eight hours after the start of heating and stirring, the titer of mercapto and epoxy groups decreased by almost the theoretical value, and the peak of the proton of epoxide methylene was observed. Disappeared and the viscosity at 25 ° C. became constant at 6100 cSt, and 2.2 mol of methyl (γ-glycidoxypropyl) dimethoxysilane was added, and the reaction was continued. Six hours after the addition of the silane, titration of the total amount of mercapto groups and epoxy groups and observation of the peak of epoxide methylene by NMR measurement confirmed that these had disappeared, and the end of the reaction was confirmed. finished. This
The viscosity at 25 ° C is 48200 cSt, and the molecular weight measured by GPC is about
8100 pale yellow viscous liquids were obtained. This it was confirmed that a polymer terminally blocked with hydrolyzable silyl groups represented by the following formula ^(P-3) (B 3 are the hydrogenated polybutadiene units) Example 4 Average degree of polymerization 35, molecular weight of about 1900, viscosity at 25 ° C. 77
00cSt, and the hydrogenated polybutadiene unit is Of glycidyl group-terminated hydrogenated polybutadiene obtained by hydrogenating liquid polybutadiene of
5 mol of P'-diaminodiphenylmethane and its 10%
Of methanol and an amount of phenol equivalent to 2% were added, and heating and stirring were started at 80 ° C. A portion was extracted at 2 hour intervals in the same manner as in the synthesis of P-1, and potentiometric titration, NMR measurement, and viscosity measurement were performed. After 14 hours, the total amount of amino groups and epoxy groups decreased by almost the theoretical value, and NMR was measured. Since the peak of the proton due to epoxide methylene disappeared and the viscosity at 25 ° C. became almost constant at 10200 cSt, 2.2 mol of phenyl (γ-glycidoxypropyl) dimethoxysilane was added and the reaction was continued. Twelve hours after the addition of the silane, titration of the total amount of amino groups and epoxy groups by potentiometric titration and observation of the peak of epoxide methylene by NMR revealed that the reaction was complete. Ethanol was distilled off to terminate the reaction. This has a viscosity at 25 ° C of 64500 cSt and a number average molecular weight of 550 by GPC.
A pale yellow viscous liquid of 0 was obtained. It was confirmed that this was a polymer whose terminal was blocked by a hydrolyzable silyl group represented by the following formula. (B ⁴ are the hydrogenated polybutadiene units) Examples 5 to 8 With respect to 100 parts of the polymer (P-1 to 4) in which the molecular chain end was blocked by the hydrolyzable silyl group obtained in Examples 1 to 4, the filler shown in Table 1 was used. Add inorganic pigment and thixotropic agent and uniformly disperse with three rolls,
Further, tin compounds shown in Table 1 were added and mixed.
4 was prepared. 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. Next, the dumbbell-shaped test piece obtained in the same manner was placed in a dryer at 150 ° C. and a weatherometer, and given the deterioration conditions (heating and ultraviolet irradiation) for the period shown in Table 1, and then the state of the test piece was observed. And a tensile test. Further, a shear adhesion test body shown in FIG. 1 was prepared using these samples 1 to 4, 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 8000, as terminal group Is added to 100 parts of polyoxypropylene having the above, a filler, an inorganic pigment and a thixotropic agent shown in Table 1 are added and uniformly dispersed by a three-roll mill.
Sample 5 was prepared by adding and mixing the tin compounds shown in the table.
The same tests as in Examples 5 to 8 were performed using Sample 5. The results are also shown in Table 1.

As shown from the above results, the polymer of the present invention is useful as a base polymer of a room temperature curable composition, and particularly, a cured product of the composition exhibits high strength and high elongation, and also has weather resistance and It is clear that the heat resistance is excellent.

[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)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 65/00-65/48 C08L 1/00-101/14

Claims (5)

(57) [Claims] 1. A polymer represented by the following general formula (I) and having a number average molecular weight of 500 to 50,000 and having a molecular chain terminal blocked by a hydrolyzable silyl group. (Wherein R ¹ is a monovalent hydrocarbon group, R ² , R ³ , and R ⁴ are divalent hydrocarbon groups, and A is a compound containing one or more primary amino groups in the molecule or a secondary amino group) A unit of a compound containing two or more groups or a compound containing two or more thiol groups, Y is a hydrolyzable group, a is an integer of 1 to 3, m is an integer of 10 to 100, n
Represents a number of 1 or more, B represents a general formula, (Where p, q, and r are not simultaneously 0), and are hydrogenated polybutadiene units obtained by hydrogenating at least one polybutadiene unit. ) (2) a general formula: (Wherein R ⁴ , B, and m are as described above), and hydrogenated polybutadiene having a molecular chain terminal capped with an epoxy group, and (b) one primary amino group in one molecule. Reacting a compound containing the above or a compound containing two or more secondary amino groups or a compound containing two or more thiol groups, and (c) an organosilicon compound having an epoxy group and a hydrolyzable group. The method for producing a polymer according to claim 1. 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 at least one kind of the polymer according to claim 1 as a main component.