JPH0477525A - Polyether copolymer, its production and composition containing the same copolymer - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer capable of forming a cured rubber- like elastomer, excellent in adhesion properties, etc., and suitable for a sealing material composition, etc., by reacting a polyether having a terminal epoxy group with a compound having plural mercapto groups. CONSTITUTION:(A) A polyether obtained by reacting a polyoxyethylene with epichlorohydrin and having its molecular terminals blocked with an epoxy group is made to react with (B) a compound such as dimercaptobenzene having >=2 mercapto groups, e.g. at 50-150 deg.C to obtain the objective copolymer represented by the formula (X is aromatic, etc.; Q<1> and Q<2> are divalent hydrocarbon; (m) is 10-500; (n) is >=1).

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a polyether copolymer whose molecular terminals are blocked with mercapto groups and a method for producing the same, and further relates to a sealing material composition using the polymer as a base polymer. The present invention relates to a composition that can be cured into a rubber-like elastic body at room temperature and is suitable for commercial use, and particularly relates to a composition that has excellent adhesive properties and does not cause curing failure in the surface layer even in a humid atmosphere.

[Technical background of the invention and its problems]

Urethane-based and polysulfide-based sealants are known as sealants whose base polymer is a polymer whose main chain is polyether.

However, since these sealants have urethane bonds or sulfide bonds, they have the problem of being easily degraded by heat or ultraviolet rays, that is, having poor weather resistance. Also,
A polymer whose main chain is polyether and has a hydrolyzable silicon group at the end of the molecular chain (Japanese Unexamined Patent Publication No. 156599/1989, etc.)
In recent years, room-temperature curable compositions based on the following have begun to be used as sealants (Japanese Patent Application Laid-Open No. 73998/1984, etc.). Cured products of this type of polymer have excellent weather resistance because they do not contain urethane bonds or sulfide bonds, but they do not have adhesive properties, and if cured in a humid atmosphere, the surface layer may fail to cure. There was a problem.

[Purpose of the invention]

The present invention is intended to solve these problems, and provides a sealant composition and its base that have excellent weather resistance and adhesive properties and do not cause curing defects in the surface layer even when cured in a humid atmosphere. The purpose of this invention is to provide a novel polyether copolymer that can be used as a polymer.

[Structure of the invention]

That is, the present invention relates to a polyether copolymer represented by general formula (1), a method for producing the same, and a composition containing the same.

(I) (wherein, QISQ2 is a divalent hydrocarbon group, m is 10-5
00, n is an integer of 1 or more, and X represents a divalent aromatic ring or a heterocyclic group. ) In the polyether copolymer represented by the general formula (I) of the present invention, the oxyalkylene unit represented by Q10 is an oxyethylene unit, an oxypropylene unit, or a combination system of oxyethylene units and oxypropylene units. Oxypropylene units are particularly preferred because they are easy to obtain raw materials, are easy to polymerize, and can easily maintain a liquid state even at a high degree of polymerization. The degree of polymerization m of oxyalkylene units is lO~50
Selected from a range of 0. m, if smaller than 410,
It becomes difficult to obtain a copolymer that provides a rubber-like cured product with a viscosity that provides practical workability and a sufficient elongation rate. On the other hand, if m is larger than 500, the adhesiveness, which is a feature of the present invention, decreases.

The divalent hydrocarbon group for Q2 includes a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. Among these groups, a methylene group is preferred from the viewpoint of easy availability of raw materials.

n is an integer of 1 or more, and is not particularly limited, but as a base polymer for a sealant, the number average molecular weight is 1
The number is preferably from 000 to 50,000. Further, X is a divalent aromatic ring or a heterocyclic ring, and examples of such a group include. The polyether copolymer represented by the general formula (I) can be obtained, for example, by copolymerizing the following components (A) and (B) through a heating reaction.

Component (A) has the general formula (n) (wherein, Ql and Q2 are divalent hydrocarbon groups, and m is 10 to 5
Indicates the number of 00. ) is a polyether whose molecular chain ends are blocked with epoxy groups.A typical example of (A) is polyoxyethylene or polyoxypropylene, which has both ends blocked with hydroxyl groups, and epichlorohydrin. Examples include those obtained by condensing in the presence of a basic catalyst.

In addition, the compound (B) is a compound in which two mercapto groups are bonded to a carbon atom constituting an aromatic ring or a heterocycle. From the viewpoint of balance etc., 2,5-dimercapto-1,3,4-thiazodiazole, dimercaptobenzene, dimercaptotoluene, dimercaptoxylene, dimercaptonaphthalene, etc. are recommended. Among these, 2,5-dimercapto-1,3,4-thiadiazole is particularly preferred for the above reasons.

The polymer (I) of the present invention can be obtained by reacting the epoxy group (A) described above with the mercapto group (B). The reaction between (A) and (B) is preferably carried out at a temperature higher than the ambient temperature, for example at 50 to 150°C. In this case, methanonopethanonopephenonovesalicylic acid, tris(dimethylaminomethyl)phenonopebenzylmethylamine, tributylamine and 2
- Preference is given to using compounds such as methylimidazole as reaction accelerator. Methanol is one of the preferred ones. Although it is not necessary to use a solvent when carrying out this reaction, a hydrocarbon-based, ether-based, or ester-based solvent may be used. (A) and (B)
Theoretically, the molar ratio of the blending amount is (A):(B)=P:
(P+1) (wherein P represents a natural number starting from 1).

However, in reality, (B) may be used in an amount slightly exceeding the theoretical amount.

The present invention further relates to the following curable composition using this polymer (I) as a pace polymer.

(1) Polyether copolymer represented by general formula (I) (2) Compound having an average number of epoxy groups exceeding two in the molecule (3) Inorganic filler (4) Epoxy group and mercapto group This base polymer (1) can be produced by the method described above, but when used in the present composition, the number average molecular weight is 10
It is preferable that it is 00-50000.

The compound (2) having an average number of more than two epoxy groups in the molecule is a component for reacting with the terminal mercapto group of the polymer (1) to form a rubber-like elastic body.

The number of epoxy groups in the molecule (2) must exceed two on average for the purpose of crosslinking to form a three-dimensional structure. In addition, the amount of (2) relative to (1) is such that the number of moles of mercapto groups in (1) is equal to the number of moles of epoxy groups in (2), in order to obtain a rubber-like cured product with excellent physical properties. It is preferable to choose as follows. These (2) components include: H H The (3) component of the present invention is a component for imparting appropriate non-flowability and reinforcing properties to the composition of the present invention.

Examples of these components (3) include fumed silica, precipitated silica, ground quartz, diatomaceous earth, calcium carbonate, titanium oxide, alumina, aluminum hydroxide, iron oxide, talc, clay, and carbon black. Note that these inorganic fillers include fatty acids or organosilicon compounds such as trimethylchlorosilane, hexamethyldisilazane,
It can also be used after surface treatment with hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, silicone oil, etc. The amount of component [3] to be used is 3 to 2 parts by weight per 100 parts by weight of components (1) + (2).
00 parts by weight. (3) If the amount of the component is less than 3 parts by weight, non-flowability and reinforcing properties cannot be obtained, and if it is more than 300 parts by weight, the viscosity of the composition increases and workability decreases.

Component (4) of the present invention is a catalyst component for promoting the reaction between the mercapto groups of the polymer (1) and the epoxy groups of (2) to quickly form a rubber-like cured product at room temperature. be. These (4) components include alcohols such as methanol and ethanol; compounds containing phenolic hydroxyl groups such as phenol and salicylic acid; tertiary amines such as benzyldimethylamine, tributylamine, and tris(dimethylamino)methylphenol; Examples include quaternary ammonium salts such as triethylbenzylammonium chloride and tetramethylammonium chloride, and imidazoles such as 2-methyl-4-ethylimidazotope 2-methylimidazole. These (4)
The amount of the catalyst is arbitrarily selected depending on how fast curing is desired and is not particularly limited, but a particularly large amount, for example, 30 parts by weight for 100 parts by weight of [1] + (2). If more than 1 part is used, precipitation or oozing will occur, which is undesirable.

Compositions of the invention typically include (1), (3) or (3)
It is stored separately into two components: a component consisting of part of and (4), and a component consisting of the remaining amount of (2) or (2) and (3), and these two components are mixed before use. It takes the form of a two-component package.

〔Effect of the invention〕

A composition using the novel polyether copolymer of the present invention quickly forms a rubber-like cured product at room temperature and has excellent adhesive properties. Furthermore, it does not cause curing failure in the surface layer even in humid male enclosure air, and has excellent weather resistance. Therefore, it is suitable as a sealing material for buildings and other applications.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, parts in Examples indicate parts by weight.

Example 1 Polyoxypropylene with average degree of polymerization of 15, molecular weight of 1000.25°C, viscosity at 270 cSt, glycidyl group end-blocked polyoxypropylene (5 moles, 00 (epoxy) equivalent), 6 moles of dimercapto to 1.3.4-thiadiazole and polyoxy Methanol in an amount equivalent to 10% of propylene was added, and heating and stirring was started at 60° C. under a nitrogen atmosphere. A portion was taken out at 4-hour intervals from the start of heating and stirring, and the peak due to protons of epoxide methylene (2.67 ppm based on tetramethylsilane) was observed by NMR, and the viscosity at 25° C. was measured.

12 hours after heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity of the mixture, which was 100 cSt before heating and stirring, decreased to 111,100 cS.
The methanol was distilled off, and the viscosity at 25°C was 19,000 cSt. The SSH value was 0.28 eq/k.
Number average molecular weight measured by gSGPC is 6,500
The polymer (P) represented by the following formula is a pale yellow viscous liquid of
-1) was obtained.

Example 2 For 5 moles of glycidyl group-end-blocked polyoxypropylene [IO (epoxy) equivalent] having an average degree of polymerization of 32 and a molecular weight of 2000.25°C and a viscosity of 550 cSt, 2
, 5-dimercapto-1,3,4-thiadiazole 6
Ethanol in an amount equivalent to 10% of the mole and polyoxypropylene was added, and heating and stirring was started at 60° C. under a nitrogen atmosphere. A portion was taken out at 4-hour intervals from the start of heating and stirring, and the peak due to protons of epoxide methylene was observed using NMH, and the viscosity at 25° C. was measured. 12 hours after the start of heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity was 4.4, which was 270 cSt 12 hours before the start of heating and stirring.
Since the temperature reached 00 cSt, the ethanol was distilled off and the
The viscosity at °C is 29.0OOcSt.

A polymer (P-2) represented by the following formula, which is a pale yellow viscous liquid with an S8 value of 0.17 eq/kg and a number average molecular weight measured by GPC of 11.00 (l), was obtained.

Leaf Example 3 2,
4 moles of 5-dimercapto-1,3,4-thiadiazole and methanol in an amount equivalent to 10% of polyoxypropylene were added, and heating and stirring at 60° C. under a nitrogen atmosphere was started. A portion was taken out at 4-hour intervals from the start of heating and stirring, and the peak due to protons of epoxide methylene was observed by NMR, and the viscosity at 25° C. was measured. 16 hours after the start of heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity, which was 420 cSt before the start of heating and stirring, decreased to 5.600 cSt.
The methanol was distilled off to reduce the viscosity at 25°C to 27,000 cSt and the SSH value to 0.20 eq/k.
Number average molecular weight measured by gSGPC is 9,500
The polymer (P) represented by the following formula is a pale yellow viscous liquid of
-3) was obtained.

Leaf Example 4 Polyoxypropylene with average polymerization degree of 50 and molecular weight of about 3000 as used in Example 3 and viscosity of 970 cSt at 25° C., glycidyl group end-blocked polyoxypropylene. A portion was extracted at 3-way intervals and epoxide was analyzed by NMR. A peak due to methylene protons was observed and the viscosity at 25°C was measured. 12 hours after the start of heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity, which was 400 cSt before the start of heating and stirring, decreased to 5.20 cSt.
Since it reached 0 cSt, methanol was distilled off and the viscosity at 25°C was 25.000 cst and the SH number was 0.1.
A polymer (P-4) represented by the following formula was obtained as a pale yellow viscous liquid with a number average molecular weight of 700 as measured by GPC.

4 moles of p-dimercaptobenzene represented by the formula and methanol in an amount equivalent to 10% of polyoxypropylene were added, and heating and stirring at 60°C under a nitrogen atmosphere was started. 4 hours after the start of heating and stirring Example 5 3 moles of glycidyl group-end-blocked polyoxypropylene [6 (
epoxy) equivalent], 4 mol of SH SH phthalin and 10% of polyoxypropylene
Add an amount of methanol equivalent to
Heating and stirring was started at 0°C. A portion was taken out at 4-hour intervals from the start of heating and stirring, and the peak due to protons of epoxide methylene was observed by NMR, and the viscosity at 25° C. was measured. 12 hours after the start of heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity force 5, which was 430 cSt before the start of heating and stirring, decreased.
．． Since it reached 500cst, methanol was distilled off and 2
A polymer represented by the following formula (P ~5) was obtained.

Preparation Examples 1 to 8 Polymers P-1 to 5 obtained in Examples 1 to 5, CH5 at the molecular chain end (CH30)2SI CLCLCL=O-
Polyoxypropylene, HS (CH, CH2-OCH, 0CH2
CH2-3S)? (H, CH, 0-CH, 0CH2C)
Polyoxypropylene having a urethane bond in the molecule and a hydroxyl group at the end of the molecular chain obtained by reacting 2 moles of hexamethylene diisocyanate with a polysulfide polymer represented by I2SH and 3 moles of polypropylene glycol with a molecular weight of about 3000, each containing 100% per part, 50 parts of fatty acid-treated colloidal calcium carbonate, 20 parts of fatty acid-treated light calcium carbonate, 20 parts of heavy calcium carbonate,
5 parts of titanium oxide was added and rolled uniformly with three rolls to obtain base comparan)' (B-1 to B-8).

Examples 6 to 10 and Comparative Examples 1 to 3 Samples 1 to 8 were prepared by mixing 100 parts of the pace compound prepared in Preparation Examples 1 to 8 with the epoxy group-containing compound and curing catalyst shown in Table 1. Obtained. These samples were stored at 20°C, 50% RH for 7 days and at 35°C, 80% RH.
It was cured into a 2m thick sheet. After observing the surface condition of these sheets, a JI No. 32 dumbbell was punched and subjected to a tensile test. The dumbbells obtained by curing at 20° C. and 50% RH were placed in a weatherometer, and after 1000 hours of ultraviolet irradiation, the appearance was observed and a tensile test was performed.

These results are shown in Table 1.

In addition, H-type test specimens shown in Figure 1 were prepared using Samples 1 to 8, and cured at 20°C and 50% RH for 14 days, and then
A tensile test was conducted after immersion in 0°C warm water for 7 days. The results are also shown in Table 1.゛Sample 6 is a comparative example using polyoxypropylene having a hydrolyzable silicon group at the end of the molecule, Sample 7 is a comparative example using polysulfide polymer, and Sample 8 is a comparative example using urethane polymer. be.

4,

[Brief explanation of drawings]

FIG. 1 shows a perspective view of the test specimen used in Examples 6 to 10. The unit in the figure is mm. Sample adherend

Claims (1)

[Claims] 1. A polyether copolymer represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, Q^1 and Q^2 are divalent hydrocarbon groups, m is 10
-500, n is an integer of 1 or more, and X represents a divalent aromatic ring or a heterocyclic group. ) 2 (A) General formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, Q^1 and Q^2 are divalent hydrocarbon groups, m is 10
Indicates a number of ~500. ) and (B) an aromatic compound or a heterocyclic compound in which two mercapto groups are bonded to the carbon atoms constituting the aromatic ring or heterocycle. 2. A method for producing a polyether copolymer represented by general formula (I) according to claim 1, which comprises reacting. 3 (1) Polyether copolymer represented by general formula (I) according to claim 1 (2) Compound having an average number of epoxy groups exceeding 2 in the molecule (3) Inorganic filler (4) A sealing material composition comprising a catalyst that promotes the reaction between an epoxy group and a mercapto group.