JP3317676B2 - Cured composition cured product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cured product of a curable composition which provides a sealing material having excellent durability.

[0002]

2. Description of the Related Art Modified silicone-based sealing materials exhibit excellent durability as compared with polysulfide-based and polyurethane-based sealing materials, but are still insufficient in comparison with silicone-based sealing materials. The inventors have found that a curable composition having excellent durability can be obtained by controlling three parameters of the heat-compression restoration ratio of the cured product, the stress at the time of 50% tension, and the elongation at the maximum tensile strength.

[0003]

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

[0004]

The object of the present invention is to provide (a) a reactive silicon group-containing oxy group having a molecular weight of 10,000 or more and a parameter ( _Mw / _Mn ) indicating a molecular weight distribution of 1.5 or less. A cured product of a curable composition containing an alkylene polymer and (b) a colloidal calcium carbonate as a filler, an epoxy plasticizer as a plasticizer, and an additive containing tin octylate and an amine compound as a curing catalyst. According to the durability evaluation item of (c) JIS A-5758, the product was subjected to one cycle at 90 ° C., and after heating and restoring for one day at room temperature, the recovery rate by heating and compression was 30%. The reactive silicon group-containing oxyalkylene having (d) a stress at 50% tensile strength of 0.5 to 1.8 kg / cm ² , and (e) an elongation at maximum tensile strength of 400% or more. Heavy Reactive silicon groups of the body, the curable composition characterized by being represented by the following general formula (1)
Achieved by cured products .

Embedded image [Wherein, R ¹ and R ² each represent 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. Wherein 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 (however, excluding a mercapto group). a represents 0, 1, 2, or 3, and b represents 0, 1, or 2. Also,
b in the following m groups may be different. m is 0
Represents an integer of ~ 19. However, it is assumed that a + Σb ≧ 1 is satisfied. ]

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[0005]

[0006]

[0007]

[0008]

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The hydrolyzable group represented by X is not particularly limited, and may be any 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 , and an alkenyloxy group. Among these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, amido group, aminoxy Moto及 beauty alkenyloxy group are preferable, from the viewpoint of hydrolyzability and easy handling at moderate such a methoxy group Alkoxy groups are particularly preferred.

This hydrolyzable group and hydroxyl group can be bonded to one to three silicon atoms, and (a + Δb) is 1
-5 is preferred. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon, they may be the same or different. In the reactive silicon group, there may be one silicon atom or two or more silicon atoms. 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 present. Is also good.

[0011] Incidentally, the reactive silicon group represented by the following Symbol one general formula (2), preferred in terms of easy availability.

[0012]

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Wherein R ² , X and a are the same as above. Specific examples of R ¹ and R ² in the general formula (1) include, for example, an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, and a benzyl group. An aralkyl group such as (R ³ ) ₃ S wherein R ³ is a methyl group or a phenyl group;
and a triorganosiloxy group represented by iO-. As R ¹ , R ² and R ³ , a methyl group is particularly preferred.

It is preferable that at least one, preferably 1.1 to 5 reactive silicon groups be present in one molecule of the oxyalkylene polymer. 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 therein. When the reactive silicon group is present at the terminal of the molecular chain, the effective network chain amount of the oxyalkylene polymer component contained in the finally formed cured product increases, so that high strength, high elongation, and low elastic modulus are obtained. The resulting rubber-like cured product 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)-(RO) _n- : (R is a divalent alkylene group having 1 to 4 carbon atoms) However, from the viewpoint of availability, a repeating unit represented by the following general formula (4) Oxyalkylene polymers having units are preferred.

Formula (4) -CH (CH ₃ ) CH ₂ O- The oxyalkylene polymer may be linear or branched, or 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 by 50%.
It is preferably present in an amount of at least 80% by weight, preferably at least 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 introduction of the reactive silicon group into the oxyalkylene polymer may be performed by a known method. That is, for example, the following method is 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 having reactivity with the functional group, or containing an unsaturated group-containing compound. An unsaturated group-containing oxyalkylene polymer obtained by copolymerization with an epoxy compound is obtained. Next, the obtained reaction product is reacted with hydrosilane having a reactive silicon group to effect hydrosilylation.

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

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

Of the above methods, the method (1) or the method (3) of reacting a polymer having a terminal hydroxyl group with a compound having an isocyanate group and a reactive silicon group is preferable. As the reactive silicon group-containing oxyalkylene polymer, although not particularly limited,
A typical example is described in, for example, Japanese Patent Application Laid-Open No. 50-1565.
No. 99, No. 54-6096, No. 57-126823
Nos. 59-78223, 55-82123, 55-13022, 55-137129, and 6
2-230822 and 63-83131, JP-A-Hei 3
-47825, 3-72527, 3-1221
No. 52, U.S. Pat. Nos. 3,632,557 and 4,34.
5,053, 4,366,307, 4,96
No. 0,844, for example.

Here, the molecular weight and the parameter (M _w / M _n ) indicating the molecular weight distribution are measured by gel permeation chromatography. When the above polymer is used as a sealing material, various additives including a filler and a plasticizer shown below can be used. Fillers include reinforcing fillers such as fumed silica, precipitated silica, silicic anhydride, hydrous silicic acid and carbon black; calcium carbonate,
Magnesium carbonate, diatomaceous earth, calcined clay, clay,
Fillers such as talc, titanium oxide, bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloon; fibrous fillers such as asbestos, glass fibers and filaments. You. Of course, these fillers may be used alone or in combination of two or more.

Examples of the plasticizer include phthalic esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate; aliphatic dibasic 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 acetyl ricinoleate; phosphate esters such as tricresyl phosphate, trioctyl phosphate and octyl diphenyl phosphate; epoxy Plasticizers such as oxidized soybean oil, epoxidized linseed oil, and benzyl epoxy stearate; polyester-based plasticizers such as polyesters of dibasic acid and dihydric alcohol; 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 can be optionally used alone or in a mixture of two or more.

Further, other additives include a curing catalyst, an adhesion improver, a physical property modifier, a storage stability improver, an ultraviolet absorber, a metal deactivator, an ozone deterioration inhibitor, a light stabilizer, and an amine radical. Various additives such as a chain inhibitor, a phosphorus-based peroxide decomposer, a lubricant, a pigment, and a foaming agent can be appropriately added. Specific examples of the curing catalyst include titanates such as tetrabutyl titanate and tetrapropyl titanate; dibutyltin dilaurate;
Tin carboxylate salts such as dibutyltin maleate, dibutyltin acetate, tin octylate, tin naphthenate; reaction products of dibutyltin oxide and phthalic acid ester; dibutyltin acetylacetonate; aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diiso Organoaluminum compounds such as propoxyaluminum ethyl acetoacetate; Chelate compounds such as zirconium tetraacetylacetonate and titanium tetraacetylacetonate;
Lead octylate; butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenyl Guanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8
Amine compounds such as diazabicyclo (5.4.0) undecene-7 (DBU), or salts of these amine compounds with carboxylic acids, etc .; low molecular weight polyamide resins obtained from excess polyamines and polybasic acids; A silanol condensation catalyst such as a reaction product of a polyamine and an epoxy compound; a silane coupling agent having an amino group such as γ-aminopropyltrimethoxysilane and N- (β-aminoethyl) aminopropylmethyldimethoxysilane;
Further, other known silanol condensation catalysts such as other acidic catalysts and basic catalysts may be mentioned. These catalysts may be used alone or in combination of two or more.

[0025] The heating / compression restoration ratio in the present invention is defined by JIS.
According to the durability evaluation section of A-5758, at 90 ° C, 1
After performing the cycle, it is determined by the following equation (1) based on the value measured after standing at room temperature for one day. Heat compression restoration rate = (L ₂ −L ₁ / L ₀ −L ₁ ) × 100 where L ₀ : thickness of the sealing material in the compression direction before heat compression L ₁ : thickness of the sealing material in the compression direction during heat compression Thickness L ₂ : Thickness in the compression direction of the sealing material after one cycle of the JIS-5758 durability 9030 test and left at room temperature for one day. If this value is less than 30%, the durability is poor, and the stress at the time of 50% tension and the elongation at the maximum tensile strength are also the same as those of JISA-5758 II.
And H type test pieces.

Based on the measured numbers, 50% tensile
The stress at the time is 0.5 to 2.5 kg / cm^Two, Maximum tensile strength
The elongation at the time must be 400% or more. The above three characteristics (addition
Thermal compression recovery rate, 50% tensile stress and maximum tensile strength
Of the present invention that the elongation of
It is necessary for the expression of the effect. Molecular weight of 10,000 or more
And a parameter (M_w/ M _n)
A reactive silicon group-containing oxyalkylene having a value of 1.5 or less
The durability is particularly good when a polymer is used.

[0027]

EXAMPLES Polymer A: (CH ₃ O) ₂ Si (CH
₃ ) An oxypropylene polymer containing a CH ₂ CH ₂ CH ₂ -group and having a number average molecular weight of 10,000 as measured by gel permeation chromatography Polymer B: (CH ₃ O) ₂ accounts for 85% of all terminals Si (CH ₃ ) CH ₂ CH ₂ CH
An oxypropylene polymer containing a _2- group, having a number average molecular weight of 17,000 and a molecular weight distribution parameter ( _Mw / _Mn ) of 1.3 Polymer C: (CH ₃ O 90% of all terminals) ) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH
₂ Contains NHC (O) O- group, has a number average molecular weight of 20,000,
The parameter ( _Mw / _Mn ) indicating the molecular weight distribution is 1.3.
Using the above three types of reactive silicon group-containing oxyalkylene polymers (polymers A, B, and C), a curable composition having the formulation shown in Table A was produced and cured. The properties of the cured product were evaluated. The evaluation results are also shown in Table A.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

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

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-298525 (JP, A) JP-A-5-39428 (JP, A) JP-A-5-132616 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 71/02 C09K 3/10

Claims (1)

(57) [Claims] 1. A reactive silicon group-containing oxyalkylene polymer having a molecular weight of 10,000 or more and a parameter ( _Mw / _Mn ) indicating a molecular weight distribution of 1.5 or less, and (b) a filler. Curable composition containing colloidal calcium carbonate as material, epoxy plasticizer as plasticizer, and additives containing tin octylate and amine compound as curing catalyst
A cured product of (c) JISA-5
According to the durability evaluation item of No. 758, the heating and compression recovery rate obtained by performing one cycle at 90 ° C. and then standing at room temperature for one day and then measuring the value after heating is 30% or more;
(D) The stress at the time of 50% tension is 0.5 to 1.8 kg / cm.
² and (e) the elongation at the maximum tensile strength is 400% or more, and the reactive silicon group of the reactive silicon group-containing oxyalkylene polymer is represented by the following general formula (1): Cured product of the curable composition. Embedded image [Wherein, R ¹ and R ² each represent 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. Wherein 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 (however, excluding a mercapto group). a represents 0, 1, 2, or 3, and b represents 0, 1, or 2. Also,
b in the following m groups may be different. m is 0
Represents an integer of ~ 19. However, it is assumed that a + Σb ≧ 1 is satisfied. [Chemical formula 2]