JPH05132616A - Curable composition - Google Patents

Abstract

PURPOSE:To obtain subject composition useful for a sealing material, excellent in durability, having specific physical properties, composed of polyoxyalkylene polymer containing reactive silicon groups. CONSTITUTION:The objective composition comprises polyoxyalkylene polymer containing reactive silicon groups, which is a fluorine containing polymer having polyoxyalklene polymer as the side chains, and has >=10000 molecular weight and <= 1.5 Mw/Mn of a parameter expressing a molecular distribution, and has >=30% recovery rate after hot compression of cured material, 0.5-2.5kg/cm<2> stress at 50% stretching and >=400% elongation at maximum tensile strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition which provides a sealing material having excellent durability.

[0002]

2. Description of the Related Art A modified silicone-based sealing material has excellent durability as compared with a polysulfide-based or polyurethane-based sealing material, but it is still insufficient as compared with a silicone-based sealing material.

The present invention was achieved by finding that a curable composition having excellent durability can be obtained by controlling the three parameters of the heat compression compression recovery rate of the cured product, the stress at 50% tension and the elongation at maximum tensile strength. did.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a curable composition which produces a cured product having excellent durability using a reactive silicon group-containing polyoxyalkylene polymer as a base polymer. .

[0005]

[Means for Solving the Problems] The above-mentioned problems are as follows: the cured product has a heat compression recovery rate of 30% or more, a stress at 50% tension of 0.5 to 2.5 kg / cm ² , and a maximum tensile strength. It is achieved by a reactive silicon group-containing polyoxyalkylene polymer-based curable composition characterized by an elongation of 400% or more.

In particular, the reactive silicon group-containing polyoxyalkylene polymer as the base polymer has a molecular weight of 10,
000 or more and the parameter (M _w / M _n ) indicating the molecular weight distribution measured by gel permeation chromatography is 1.5 or less, and it is achieved particularly effectively, and the base polymer is a polyoxyalkylene polymer. A fluorine-containing polymer having a side chain is particularly preferable for achieving the object.

The reactive silicon group-containing polyoxyalkylene polymer that can be used in the present invention is not particularly limited, but representative ones include, for example, the following general formula (1):

[0008]

[Chemical 1] [In the formula, R ¹ and R ² are each an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 7 to ² carbon atoms.
0 represents an aralkyl group or a triorganosiloxy group represented by (R ³ ) ₃ SiO—, and when two or more R ¹ or R ² are present, they may be the same or different. Here, R ³ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and the three R ³ may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a is 0, 1, 2 or 3
And b represents 0, 1, or 2, respectively. In addition, b in the following m [Chemical Formula 2] groups may be different. m
Represents an integer of 0 to 19. However, it is assumed that a + Σb ≧ 1 is satisfied. ]

[0009]

[Chemical 2] The hydrolyzable group represented by X is not particularly limited as long as it is a 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. Among 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 preferable, but a methoxy group is preferable from the viewpoint of easy hydrolysis and easy handling. Particularly preferred are alkoxy groups such as

1 to 3 of these hydrolyzable groups and hydroxyl groups can be bonded to one silicon atom, and (a + Σb) is 1
It is preferably -5. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon, they may be the same or different.

There may be one silicon atom or two or more silicon atoms in the reactive silicon, but in the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like, about 20 silicon atoms are included. It may be.

The reactive silicon group represented by the following general formula (2) [Chemical Formula 3] is preferable from the viewpoint of easy availability.

[0013]

[Chemical 3] [In formula, R < ² >, X, a is the same as the above. Specific examples of R ¹ and R ² in the general formula (1) include, for example, alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group, and benzyl group. And the triorganosiloxy group represented by (R ³ ) ₃ SiO— in which R ³ is a methyl group or a phenyl group. R ¹ ,
A methyl group is particularly preferable as R ² and R ³ .

At least one reactive silicon group is preferably present in one molecule of the oxyalkylene polymer, and preferably 1.1 to 5 is present. When the number of reactive silicon groups contained in one molecule of the polymer is less than 1, the curability becomes insufficient,
It becomes difficult to exhibit good rubber elasticity behavior.

The reactive silicon group may be present at the terminal of the molecular chain of the oxyalkylene polymer or may be present inside thereof. When the reactive silicon group is present at the terminal of the molecular chain, the amount of effective network chains of the oxyalkylene polymer component contained in the finally formed cured product increases, so that high strength, high elongation, and low elastic modulus are achieved. The rubber-like cured product shown is easily obtained.

As the oxyalkylene polymer constituting the polymer chain in the polymer of the present invention, those represented by the following general formula (3) can be used. General formula (3)-(R-O) _n- : (R is a divalent alkylene group having 1 to 4 carbon atoms) However, from the viewpoint of easy availability, the repeating formula represented by the following general formula (4) is used. Oxyalkylene polymers having units are preferred.

General Formula (4) --CH (CH ₃ ) CH ₂ O-- The oxyalkylene polymer may be linear or branched, or may be a mixture thereof. Good. Further, other monomers and the like may be contained, but the monomer unit represented by the above general formula (4) is contained in the polymer in an amount of 50 or more.
It is preferably present in an amount of not less than 80% by weight, preferably not less than 80% by weight.

The oxyalkylene polymer having a reactive silicon group of the present invention is preferably obtained by introducing a reactive silicon group into an oxyalkylene polymer having a functional group.

The reactive silicon group may be introduced by a known method. That is, for example, the following method can be used. (1) An oxyalkylene polymer having a functional group such as a hydroxyl group at the terminal is reacted with an organic compound having an active group and an unsaturated group reactive with the functional group, or with an unsaturated group-containing epoxy compound An unsaturated group-containing oxyalkylene polymer obtained by the copolymerization of is obtained. Then, the obtained reaction product is hydrosilylated by reacting hydrosilane having a reactive silicon group.

(2) The unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1) is reacted with a compound having a mercapto group and a reactive silicon group. (3) An oxypropylene polymer having a functional group such as a hydroxyl group, an epoxy group or an isocyanate group (hereinafter referred to as Y ¹ functional group) at the above-mentioned terminal has a functional group (hereinafter referred to as a functional group reactive with the Y ¹ functional group). , Y ² functional group) and a compound having a reactive silicon group.

Examples of the silicon compound having the Y ² functional group include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxysilane. Amino group-containing silanes such as; γ-
Mercapto group-containing silanes such as mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane; such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Epoxy silanes; vinyl-type unsaturated group-containing silane groups such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; γ-chloropropyltrimethoxysilane, etc. Chlorine atom-containing silanes;
γ-isocyanatopropyltriethoxysilane, γ-
Isocyanate-containing silanes such as isocyanate propylmethyldimethoxysilane; hydrosilanes such as methyldiethoxysilane can be specifically exemplified, but not limited thereto.

Among the above methods, the method (1) or the method (3) of reacting a polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group is preferable.

The above-mentioned reactive silicon group-containing polyoxyalkylene polymer is not particularly limited, but representative ones include, for example, JP-A-50-15659.
No. 9, No. 54-6096, No. 57-126823,
59-78223, 55-82123, 55
-113022, 55-137129, 62-
No. 230822, No. 63-83131, JP-A-3-4
No. 7825, No. 3-72527, No. 3-122152
U.S. Pat. Nos. 3,632,557 and 4,345.
No. 053, No. 4,366, 307, No. 4,960,8
Those disclosed in No. 44 and the like can be exemplified.

Here, the parameters (M _w / M _n ) indicating the above-mentioned molecular weight and molecular weight distribution are measured by gel permeation chromatography. When the above polymer is used as a sealing material, various additives and curing catalysts such as the following fillers and plasticizers can be used.

As the filler, reinforcing fillers such as fumed silica, precipitated silica, silicic acid anhydride, hydrous silicic acid and carbon black; calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide. Fillers such as bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and silas balloons; fibrous fillers such as asbestos, glass fibers and filaments. Of course, these fillers may be used alone or in combination of two or more.

As the plasticizer, phthalic acid esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate; aliphatic dibasic acid esters such as dioctyl adipate, isodecyl succinate and dibutyl sebacate; diethylene glycol. Glycol esters such as dibenzoate and pentaerythritol ester; Aliphatic esters such as butyl oleate and methyl acetylricinoleate; Phosphate esters such as tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate; epoxy Soybean oil, epoxidized linseed oil, epoxy plasticizers such as benzyl epoxystearate; polyester plasticizers such as polyesters of dibasic acids and dihydric alcohols; polypropylene polypropylene Polyethers such as calls and derivatives thereof; poly -α- methyl styrene, polystyrenes such as polystyrene; polybutadiene, butadiene -
Plasticizers such as acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, and chlorinated paraffins may be optionally used alone or in the form of a mixture of two or more kinds.

Further, as other additives, curing catalyst, adhesion improver, physical property adjuster, storage stability improver, ultraviolet absorber, metal deactivator, ozone deterioration inhibitor, light stabilizer, amine radical. Various additives such as a chain inhibitor, a phosphorus-based peroxide decomposing agent, a lubricant, a pigment and a foaming agent can be appropriately added.

Specific examples of the curing catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin acetate, tin octylate and tin naphthenate; dibutyltin. Reaction products of oxides and phthalates, dibutyltin acetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminumethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetyl Chelate compounds such as acetonate; lead octylate; butylamine, octylamine, dibutylamine,
Monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylamino) Methyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8 diazabicyclo (5.4.0) undecene-7 (DBU), and other amine compounds, or carboxylic acids of these amine compounds Low molecular weight polyamide resin obtained from excess polyamine and polybasic acid; reaction product of excess polyamine and epoxy compound; γ-aminopropyltrimethoxysilane, N- (β-aminoe Le) a silane coupling agent having an amino group such as aminopropyl methyl dimethoxy silane; silanol condensation catalyst such as news other acidic catalysts, such as well-known silanol condensation catalysts such as basic catalyst. These catalysts may be used alone or in combination of two or more.

The term "heat compression recovery rate" as used in the present invention means JIS.
Based on the durability evaluation item of A-5758, at 90 ° C, 1
After carrying out the cycle, it is determined by the following formula (1) based on the number measured after being left at room temperature for 1 day.

Heating compression recovery rate base = (L ₂ −L ₁ / L ₀
-L ₁₎ × 100 where, L _0: the thickness L of the compression direction of the sealing material before heating and compression _1: heat compression during sealing material in the compressing direction of the thickness L _2: JISA-5758 endurance 9030 test 1 cycle The thickness in the compression direction of the sealing material after being left at room temperature for 1 day after the execution, the heat compression recovery rate is expressed in%. If this value is less than 30%, the durability is poor. Regarding the stress at 50% tension and the elongation at maximum tensile strength, the same as in JIS A-5758 II.
It was measured with a mold and an H-shaped test piece.

Based on the measured numbers, the stress at 50% tension must be 0.5 to 2.5 kg / cm ² , and the elongation at maximum tensile strength must be 400% or more. It is necessary for the effects of the present invention to be exhibited that the above three characteristics (heat compression recovery rate, stress at 50% tension and elongation at maximum tensile strength) are simultaneously within the above range.

Such a composition can be obtained by the method described in the Japanese Patent Application No. 3-160 filed by the present inventors. Durability is particularly good when a reactive silicon group-containing polyoxyalkylene polymer having a molecular weight of 10,000 or more and a parameter (M _w / M _n ) indicating the molecular weight distribution of 1.5 or less is used. .

[0033]

【Example】

Polymer A: 85% of all terminals are (CH ₃ O) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH
Polyoxypropylene polymer containing ₂ -groups and having a number average molecular weight of 10,000 as measured by gel permeation chromatography Polymer B: (CH ₃ O) ₂ Si (CH ₃ ) CH at 85% of all terminals ₂ CH ₂ CH
_A polyoxypropylene polymer containing a ₂ -group and having a number average molecular weight of 17,000 and a parameter (M _w / M _n ) indicating the molecular weight distribution of 1.3 Polymer C: 90% of all terminals (CH ₃ O) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH
₂ NHC (O) O- group, having a number average molecular weight of 20,000,
The parameter (M _w / M _n ) indicating the molecular weight distribution is 1.3.
Polyoxypropylene polymer of (Polymer A, B, C) Using the three types of reactive silicon group-containing polyoxyalkylene polymers described above, a curable composition having the composition shown in Table A is produced and cured. Then, the characteristics of the cured product were evaluated. The evaluation results are also shown in Table A.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

According to the present invention, a curable composition which gives a cured product having excellent durability can be obtained.

Claims (3)

[Claims] 1. The cured product has a heat compression recovery rate of 30% or more and a stress at 50% tension of 0.5 to 2.5 kg / cm.sup.2.
^2. Reactive silicon group-containing polyoxyalkylene polymer-based curable composition having an elongation at maximum tensile strength of 400% or more. 2. The reactive silicon group-containing polyoxyalkylene polymer has a molecular weight of 10,000 or more and a parameter (M _w / M _n ) indicating the molecular weight distribution is 1.5 or less. Item 1. The curable composition according to Item 1. 3. The curable composition according to claim 1, wherein the reactive silicon group-containing polyoxyalkylene polymer is a fluorine-containing polymer having a polyoxyalkylene polymer in a side chain.