JPH01271476A - Moisture-curable sealant - Google Patents

Abstract

PURPOSE:To obtain the title one-pack, substantially unplasticized sealant for construction, excellent in an ability to be pressed out, water resistance, heat resistance, etc., by mixing a reaction product of a specified polyol with specified aromatic and aliphatic polyisocyanates with a specified curing agent and a specified filler. CONSTITUTION:100 pts.wt. reaction product of a polyol (A) which is preferably selected from among a polyoxyalkylene polyol, a polymer polyol and a polybutadienepolyol with an aromatic polyisocyanate (B) which is preferably toluene diisocyanate and/or 4,4'-diphenylmethane diisocyanate and an aliphatic type polyisocyanate (C) which is preferably aliphatic and/or alicyclic polyisocyanates [wherein the B/C molar ratio is preferably 10/90-60/40, and the (B+C)/A equivalent ratio is preferably 1.2-3.0] is mixed with preferably, 0.0001-3.0 pts.wt. curing catalyst of, for example, a metallic type and/or an amine type and preferably, 0.5-500 pts.wt. pigment, solvent and filler such as an extender to obtain a sealant having an NCO content of, preferably, 0.2-0.8wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field] The present invention relates to a one-component moisture-curing architectural sealant.

[Prior Art] Conventionally, there are liquid-type moisture-curable architectural sealants that consist of a polymer containing terminal isocyanate groups from a polyoxyalkylene polyol and 4,4ξ diphenylmethane diisocyanate, a filler, and a curing catalyst.

[Problems to be solved by the invention]However, polyoxyalkylene polyol and 4,
Since the viscosity of the terminal isocyanate group-containing polymer made from 4ζ diphenylmethane diisocyanate is very high, extrudability, which is one of the minimum requirements for a construction sealant, is insufficient.

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive studies aimed at obtaining a liquid-type moisture-curable architectural sealant with excellent extrudability.

That is, the present invention comprises a polyol (a), an aromatic polyisocyanate (b), and an aliphatic polyisocyanate (c).
reaction product (A), curing catalyst (B), and filler (C)
This is a one-component moisture-curable architectural sealant characterized by containing substantially no plasticizer.

Examples of the polyol (a) include polyoxyalkylene polyols, polyester polyols, polysiloxane polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, and polymer polyols.

Examples of polyoxyalkylene polyols include low-molecular polyols such as low-molecular glycols (ethylene glycol, propylene glycol, 1,4-butanediol, etc.), low-molecular triols (glycerin, trimethylolpropane, hexanetriol, etc.), and tetrafunctional or higher-functional polyols. active hydrogen compounds such as low-molecular polyols (sorbitol, sucrose, etc.), amines (alkanolamines, aliphatic polyamines, etc.), phenols (hydroquinone, bisphenol-8, etc.), phosphoric acid, and alkylene oxides (2 carbon atoms). to 4 alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide (combined combinations of these) (in the case of combined use, block,
(random addition) or ring-opening polymers of alkylene oxides. Addition reactions and ring-opening polymerizations of alkylene oxides can be carried out in a conventional manner, either without a catalyst or in the presence of a catalyst (alkali catalyst, amine catalyst, acidic catalyst), in one step or in multiple steps under normal pressure or increased pressure. It will be done. Specific compounds include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

Polyester polyols include polycarboxylic acids (aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, and dimer acid; aromatic polycarboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid); and polyols (such as the above-mentioned low-molecular polyols), and lactones (ε
Examples include those produced by ring-opening polymerization of (-caprolactone, etc.).

Examples of polysiloxane polyols include hydroxy-modified polysiloxanes. Specifically, the following can be mentioned.

[1] Hydroxy-modified polysiloxane (wherein At and A2 are alkylene groups having 2 to 4 carbon atoms, (
(ethylene group, propylene group, etc.), R1 and R2 are alkyl groups having 1 to 4 carbon atoms (methyl group, ethyl group, etc.) or phenyl groups, k and n are integers of 1 or more, and +n is 1 to 450
m is an integer from 2 to 265. ), a compound represented by the general formula (wherein A1 is an alkylene group having 2 to 4 carbon atoms, (ethylene group, propylene group, etc.), R1, R2R3 is a carbon number 1
~4 alkyl groups (methyl group, ethyl group, etc.) or phenyl group, n is an integer of 1 to 450, and m is an integer of 2 to 265. ), a compound represented by the general formula (wherein Am and A2 are alkylene groups having 2 to 8 carbon atoms, (
(ethylene group, propylene group, etc.), R1-R6 are alkyl groups having 1 to 4 carbon atoms (methyl group, ethyl group, etc.) or phenyl group, and n is an integer of 1 to 265. ), (wherein A1 is an alkylene group having 2 to 4 carbon atoms, (ethylene group, propylene group, etc.), R1-R7 is a compound having 1 to 4 carbon atoms
is an alkyl group (such as a methyl group or an ethyl group) or a phenyl group, m and n are integers of 1 to 265, and q is an integer of 1 to 5. )
Examples include compounds shown in

Examples of polybutadiene polyols include hydroxyl-terminated polybutadiene oligomers (hydroxyl-terminated liquid polymers of polybutadiene). Specific examples of polybutadiene polyols include Po1y-Bd manufactured by ARCO of the United States and Nl5SO-PBG series manufactured by Nippon Soda. P
o1y-Bd includes butadiene homopolymer types and copolymer types (styrene butadiene copolymer, acrylonitrile butadiene copolymer, etc.).

Its chemical structure is as follows.

Homopolymer type C)(-C)12). , 6 pieces. OH n: 55 (for R-45M) 50 (for R-45) IT) Copolymer type X: Cjllsu (C5-15) a=0.75. b=0.25. n=54X: C
N(CN-15) a=0.85. b=0.15. n=78-87 Molecular weight is usually 500-5,000, preferably 1,000-
It is 5.000.

The number of functional groups is usually 2 to 3.

Further, the chemical structure of the Nl5SO-PBG series is as follows.

Specifically, G-1000, G-2000, G-300
There is 0.

Its molecular weight is usually 500 to 5,000, preferably 1,
000 to 5,000.

Polybutadiene polyol is disclosed in Japanese Patent Application Laid-open No. 55-98220, Japanese Rubber Association Journal No. 45 (1972), 449-450.
Page, Searants (by Damsis, Reinhold Publishing, 19
(published in 1967). Also, JP-A-56-8
Those described in Japanese Patent No. 4715 can also be used.

As the hydrogenated polybutadiene polyol, the above R-45
) Hydrogenated IT can be mentioned.

Examples of the polymer polyol include those produced by using a polyol and an ethylenically unsaturated monomer in a conventional polymer polyol manufacturing method.

Examples of the polyol include the above-mentioned polyols.

Ethylenically unsaturated monomers include α-olefins (hexene, octene, decene, dodecene, tetradecene,
hexadecene, octadecene, icosene, hexadecene, tococene, tricosene, tetradecyl, bentacocene, hexadecyl, etc.), aromatic hydrocarbon monomers (
styrene, α-methylstyrene, etc.), unsaturated nitriles ((meth)acrylonitrile, etc.), (meth)acrylic acid esters [(meth)acrylic acid alkyl esters (alkyl group has 1 to 30 carbon atoms) (methyl meth)acrylate, butyl(meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, undecyl(meth)acrylate, dodecyl(meth)acrylate, tridecyl(meth)acrylate, tetradecyl(meth)acrylate, pentadecyl(meth)acrylate acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, tocosyl (meth)acrylate, etc.), (meth)acrylic acid hydroxyalkyl ester (hydroxyethyl (meth)acrylate, etc.)], ethylenically Saturated carboxylic acids and their derivatives ((meth)acrylic acid,
(meth)acrylamide), aliphatic hydrocarbon monomers (ethylene, propylene, etc.), fluorine-containing vinyl monomers (perfluorooctylethyl methacrylate, perfluorooctylethyl acrylate, etc.), nitrogen-containing vinyl monomers (diaminoethyl methacrylate, morpholinoethyl methacrylate, etc.) and vinyl-terminated silicone.

The production method includes, for example, a method of polymerizing ethylenically unsaturated monomer (ii) in polypropylene glycol (i) in the presence of a polymerization initiator (radical generator, etc.) (U.S. Pat. No. 3,383,351, Japanese Patent Publication No. No. 39-24737,
JP-B-47-47999, JP-A-50-15894, etc.) and a polymer obtained by pre-polymerizing (ii).
A method of graft polymerizing i) in the presence of a radical generator is mentioned.

A polymerization initiator is usually used in these polymerizations.

The polymerization initiator is one that generates free radicals to initiate polymerization, such as 2. γ-azobisisobutyronitrile (AIBN), 2.2'-azobis-(2
, 4-dimethylvaleronitrile) (AVN); peroxides such as dibenzoyl peroxide, dicumyl peroxide, bis(4-1-butylcyclohexyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, etc. Articles and patent applications 1977
Peroxides other than those described in No. 9-199160,
Or persulfates, perborates.

Persuccinic acid etc. can be used. Among these, preferably A
IBN and bis(4-t-butylcyclohexyl) peroxydicarbonate.

The amount of polymerization initiator used is usually 0.1 to 15%, preferably 0.2 to 10%, based on the weight of the ethylenically unsaturated monomer.
%.

The above polymerization reaction can be carried out without a solvent, but it can also be carried out in the presence of an organic solvent (especially when the polymer concentration is high). Examples of organic solvents include benzene, toluene, xylene, acetonitrile, ethyl acetate, hexane, heptane, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, isopropyl alcohol, and n-butanol.

If necessary, chain transfer agents such as alkyl mercaptans (dodecyl mercaptan, mercaptoethanol, etc.), alcohols (isopropyl alcohol, methanol, 2-butanol, allyl alcohol, etc.), halogenated hydrocarbons (carbon tetrachloride, etc.).

carbon tetrabromide, chloroform, etc.), JP-A-55-318
Polymerization can be carried out in the presence of enol ethers such as those described in Japanese Patent No. 80.

Polymerization can be carried out either batchwise or continuously. The polymerization reaction is carried out at a temperature higher than the decomposition temperature of the polymerization initiator, usually 60 to 180°C.
Preferably 90-160°C, particularly preferably 100-1
It can be carried out at 50°C, and it can also be carried out under atmospheric pressure, increased pressure, or even reduced pressure.

The content of ethylenically unsaturated monomer is usually 0.1 to 50%
The content is preferably 0.2 to 30%.

Among the polyols (a), preferred are polyoxyalkylene polyols, polymer polyols, polysiloxane polyols and polybutadiene polyols, and particularly preferred are polyoxyalkylene polyols, polymer polyols and polybutadiene polyols.

The equivalent weight (molecular weight per active hydrogen-containing group) of (a) is usually 100 to 15,000, preferably 200 to 10,000.
0, particularly preferably 1,000 to s, ooo. 1
Flexibility is insufficient without 00 groove. If it exceeds 15,000, the resin strength will be insufficient.

As the aromatic polyisocyanate (b), those conventionally used in the production of polyurethane can be used. Such polyisocyanates include aromatic polyisocyanates having 6 to 20 carbon atoms (excluding the carbon in the NCO group) [e.g. 2,4 and/or 2,6-] lylene diisocyanate (TDI), crude TDI, 4 , 4'-diphenylmethane diisocyanate (MDI), phenylene diisocyanate, naphthalene diisocyanate, crude MD
I [crude diaminophenylmethane (condensation product of formaldehyde and an aromatic amine (aniline) or a mixture thereof diaminophenylmethane and a small amount of ff1 (e.g. 5 to
20% by weight) of trifunctional or higher functional polyamine) phosgenated product: polyfuryl polyisocyanate (PAP
I) etc.]: and modified products of these isocyanates (
Examples include modified products containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretonimine group, an isocyanurate group, and an oxazolidone group. Preferred among these are TDI and MDI.

As the aliphatic polyisocyanate (C), aliphatic,
Mention may be made of cycloaliphatic and aromatic cycloaliphatic polyisocyanates. Specifically, aliphatic polyisocyanates having 2 to 18 carbon atoms [for example, hexamethylene isocyanate (HDI
), lysine diisocyanate, alicyclic polyisocyanate having 4 to 15 carbon atoms [e.g. isophorone isocyanate (IPDI), 4,4'-dicyclohexylmethane isocyanate (hydrogenated MD) 1, aromatic fat having 8 to 15 carbon atoms Examples include polyisocyanates of the group polyisocyanate [for example, xylylene diisocyanate-1-(XDI)]. Preferred among these are HDI, IPDI, hydrogenated MDI and XDI.

(b) when reacting (a), (b) and (c);
The equivalent ratio of +(C) and (a) is usually 1.1 to 4.0, preferably 1.2 to 3.0. When the equivalent ratio is less than 1.1, the surface tack of the cured product will be poor. If it exceeds 4.0, the cured product will lack elasticity.

The molar ratio of (b) and (c) is usually 5:95 to 95:5,
This results in poor workability.

The above reaction can be carried out in the presence or absence of a solvent inert to isocyanate groups.

Examples of this solvent include ester solvents (ethyl acetate, butyl acetate, etc.), ether solvents (dioxane, tetrahydrofuran, etc.), ketone solvents (cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, etc.), aromatic hydrocarbon solvents (toluene, xylene, etc.) and mixed solvents of two or more of these.

The reaction method is to charge (a), (b) and (c) together into a reaction vessel and react;
Examples include a method of dividing C) and performing a multistage reaction.

The reaction temperature is usually 30 to 150°C, preferably 50 to 13°C.
It is 0°C.

(A) usually has a number average molecular weight of 1.000 to 200,00
0, NCO content is usually 0.1 to 5% by weight, and nitrogen (nitrogen contained in polyisocyanate) content is usually 0.1 to 4.
It is 5% by weight. Preferably, the nitrogen content is between 0.3 and 3.
0% by weight, particularly preferably 0.4-2.0% by weight.

As the curing catalyst (B), metal-based and amine-based catalysts conventionally used in urethane sealants can be used. As a metal catalyst, dibutyltin dilaurate (DTD
), alkyl titanates, organosilicon titanates, stanasoff I ate, lead octylate, zinc octylate, bismuth octylate, dibutyltin diorthophenyl phenoxide, tin oxide and ester compounds (dioctyl phthalate, etc.) Examples include reaction products. Among these, preferred are tin and bismuth catalysts.

Examples of amine catalysts include monoamines [triethylamine, etc.], diamines [N, N, Nゝ, N'-tetramethylethylenediamine, etc.], triamines [N, N,
N', N'', N''-pentamethyldiethylenetriamine, etc.], cyclic amines (triethylenediamine, etc.). As the curing catalyst, a metal type and an amine type may be used alone or a combination of a metal type and an amine type may be used.

Examples of the filler (C) include pigments, solvents, extenders, antiaging agents, thixotropic agents, thixotropic auxiliaries, and the like.

Examples of the pigment include inorganic pigments (carbon black, titanium oxide, red iron, etc.) and organic pigments (phthalocyanine, quinoline, etc.).

Examples of the solvent include toluene and methyl ethyl ketone.

Extending agents include fillers (grained calcium carbonate, precipitated calcium carbonate, carbon black, talc, mica, etc.), resins (vinyl chloride, polyethylene, etc.), and the like.

As anti-aging agents, hindered amine type [4-benzoyloxy-2,2,6,6-titramethylpiperidine (Sankyo Seisaku Nord LS-744) etc.], hindered phenol type [octadecyl-3-(3,5 -di-t-butyl-4-hydroxyphenyl) filobionate (Irganox 1076, manufactured by Ciba Geigy Japan), benzophenone type (2-hydroxy-4-methoxybenzophenone etc.), benzotriazole type [2-(5-methyl-2- hydroxyphenyl) benzotriazole, etc.].

Examples of the thixotropic agent include ultrafine powdered silica and hydrogenated castor oil.

Examples of thixotropy aids include DMSO (dimethyl sulfoxide) and polyethylene propylene polyol.

The amount of (B) used is usually 0.00001 to 5 parts, preferably 0.00 parts per 100 parts of (A), on a weight basis.
01 to 3 parts.

The amount of (C) used is usually 0.1 to 1,000 parts, preferably 0.5 to 1,000 parts, based on weight, per 100 parts of (A).
500 copies.

The NCO content of sealants is usually 0.1-1.0% by weight
The amount is preferably 0.2 to 0.8% by weight.

Architectural sealants are used to caulk various joints in private residences, apartment complexes, and buildings to stop water.

There are various performance items as stipulated in JIS A-5758, but in recent years, there has been a desire to develop sealants that have good performance, particularly those related to workability (e.g. extrudability) and stain resistance. .

The sealant of the present invention can be used as a construction sealant for joints between PC and C joints of PC curtain walls, RC joints, RC trigger joints, joints between concrete frames and sashes, and various interior and exterior joints such as ALC boards and slate boards. It can be applied to the joints of stone or tiling, seals on various building hardware, etc.

Application methods include the usual method, such as kneading (A), (B) and (C), filling a cartridge, and caulking using a cartridge gun, or applying the kneaded material with a spatula, coating, spraying, etc. Examples include methods of coating.

The sealant of the present invention typically has a temperature of -50°C to +150°C.
C. and a humidity of 1 to 100% to obtain a sealant with satisfactory physical properties.

[Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. Hereinafter, parts refer to parts by weight. The abbreviations used in the examples are as follows.

Indicates the meaning of

1. Polyol (a) CP-5000: Polyoxypropylene ether of glycerin, MW = 5000 PP-3000: Polypropylene glycol MW = 30
00 PS-3000: Terminal alcohol polydimethylsiloxane diol, MW = 3000 PB-2400: Polybutadiene polyol MW = 2000 Examples 1 to 3 (a), (b) of Table 1, and (c) was charged and reacted at a reaction temperature of 130°C for 16 hours,
Compound (a) was obtained.

500 parts of the compound, 2 parts of DTDo, 250 parts of dried calcium carbonate, 40 parts of titanium oxide, 25 parts of ultrafine powdered silica, 10 parts of thixotropic agent Nyubol 80-4000 (manufactured by Sanyo Chemical Industries), 80 parts of toluene. and 3 parts of Irganox 1076 into a planetary mixer,
The sealant of the present invention was obtained by kneading at 60° C. for 1 hour.

The sealant was evaluated using the following dyeability test method, H-type test, and extrusion test. The results are shown in Table-1.

(Staining test method) The sealants of Examples and Comparative Examples were placed on a mortar board for 1 hour.
It was coated to a thickness of 0 mm and cured at 20° C. and 65% RH.

After curing for 7 days, acrylic elastic paint is sprayed to a thickness of 300μ.

The spraying is then cured for two days, and left in a constant temperature and humidity chamber at 70°C and 80% RH for 10 days.

Afterwards, it was exposed outdoors for 7 days to examine its contamination properties.

Judgment criteria O: No contamination Partial contamination is seen in ΔD. X: Significantly contaminated (H-type test method) Approved as JIS A-5758.

(Extrudability test) Compliant with JISA-5758.

Comparative Example 1 250 parts of GP-5000 and PP were placed in a reactor purged with nitrogen.
300 parts of -3000 and 85 parts of MDI were charged, and the reaction was carried out at a reaction temperature of 100°C for 7 hours.

350 parts of the compound, 2 parts of DTDo, 250 parts of dried calcium carbonate, 40 parts of titanium oxide, 25 parts of ultrafine powder silica, 10 parts of thixotropic agent Nyubol 80-4000 (manufactured by Sanyo Chemical Industries), 10 parts of dioctyl phthalate 150
80 parts of toluene and 10,763 parts of Irganox were placed in a planetary mixer and kneaded at 60°C for 1 hour to obtain a sealant of Comparative Example 1.

Comparative Example 2 250 parts of CP-5000 and PP were added to a reactor purged with nitrogen.
300 parts of -3000 and 85 parts of MDI were charged, and the reaction was carried out at an anti-brittle temperature of 100°C for 7 hours.

500 parts of the compound, 2 parts of DTDo, 250 parts of dried calcium suboxide, 40 parts of titanium oxide, 25 parts of ultrafine powder silica, 10 parts of thixotropic agent Nyubol 80-4000 (manufactured by Sanyo Chemical Industries), toluene Put 80 parts and 3 parts of Irganox 1076 into a planetary mixer,
The sealant of Comparative Example 2 was obtained by kneading at 60° C. for 1 hour.

The sealants of Comparative Examples 1 and 2 were evaluated by the dyeability test method, H-type test, and extrudability test in the same manner as in the examples. The results are shown in Table-2. As shown in Table 2, it does not meet the minimum requirements for non-staining architectural sealants, both stainability and extrudability (workability).

[Effects of the Invention] The moisture-curable sealant of the present invention uses a low-viscosity urethane prepolymer [reactant (A)] containing terminal isocyanate groups that can ensure sufficient extrudability;
Workability) is excellent. ■Polluting. ■Excellent softness, water resistance, heat resistance, weather resistance, etc. required for architectural sealants.

Therefore, the use of a urethane prepolymer containing terminal isocyanate groups [reactant (A)] with low viscosity not only improves extrudability, but also improves the finishing process required for architectural sealants, such as ``cutting'' and ``stringing''. Problems such as ``waving'' and materials used in the construction field (mortar, ALC1 resin steel plates, etc.) and exterior wall paint sprayed after Sealand construction are contaminated, causing problems such as ``lifting of joints'' and ``poor color.'' I won't wake you up.

The moisture-curable sealant of the present invention is useful for construction because it exhibits the above-mentioned effects.

Claims (1)

[Claims] 1. Polyol (a) and aromatic polyisocyanate (
b), a reaction product (A) with an aliphatic polyisocyanate (c), a curing catalyst (B), and a filler (C),
A one-component moisture-curing architectural sealant characterized in that it contains substantially no plasticizer. 2. The sealant according to claim 1, wherein (c) is an aliphatic and/or cycloaliphatic polyisocyanate. 3. The molar ratio of (b) and (c) is 10:90 to 60:40
The sealant according to claim 1 or 2. 4. The sealant according to claim 1, 2 or 3, wherein (a) is a polyol selected from the group consisting of polyoxyalkylene polyols, polymer polyols and polybutadiene polyols. 5, (b) is toluene diisocyanate and/or 4,
5. The sealant according to claim 1, 2, 3 or 4, which is 4'-diphenylmetallidiisicyanate.