JP2000178334A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition which, even when applied to an area not exposed to sun light, can give a cured product free from residual surface tack and gloss and is suited as a sealing material by mixing a polymer containing at least two thiol groups with a compound containing at least two isocyanate groups and an air-oxidizable unsaturation-containing compound. SOLUTION: The polymer (A) containing at least two thiol groups is especially desirably a polysulfide polyether polymer or a polysulfide polymer. The compound (B) containing at least two isocyanate groups is desirably at least either of an organic polyisocyanate and/or a urethane prepolymer. The air- oxidizable unsaturation-containing compound (C) is exemplified by a drying oil, a diene compound or a modified drying oil. The amount of component C added is desirably 0.1-50 pts.wt. per 100 pts.wt. total of components A, B, and C. It is desirable to add a small amount of an oxidation aid to the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition, and more particularly to a curable composition suitable for use as a sealing material, which can provide a good cured product with little residual tack and gloss on the surface of the cured product.

[0002]

2. Description of the Related Art A curable composition comprising a polymer containing two or more thiol groups in one molecule and a compound containing two or more isocyanate groups in one molecule includes a thiol group-containing polysulfide polymer and a polyisocyanate compound. Is used as a polysulfide-based sealant, has excellent weather resistance, and has excellent non-staining properties without causing the cured product surface to be stained outdoors. However, the surface tackiness (residual tack) at the early stage of curing is slowly lost in a state where the solar radiation is not applied, particularly in an indoor construction, and the surface may be contaminated by dust and the like in the air. In recent years, there has been an increasing demand for a matte sealing material from the viewpoint of aesthetics, but sufficient matting properties have not always been obtained with a conventional formulation using a filler such as an inorganic or organic balloon.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hardening type suitable for use as a sealing material with reduced glossiness, which reduces residual tack on the surface of a hardened material when applying a portion not exposed to sunlight. It is to provide a composition.

[0004]

As a result of intensive studies in view of the above-mentioned objects, the present inventors have found that a polymer containing two or more thiol groups in a molecule and a polymer containing two or more isocyanate groups in a molecule. It has been found that the addition of a compound containing an air-oxidizable unsaturated group to the compound eliminates surface tackiness and luster after curing even in a state where sunlight does not shine, especially in indoor installation.

That is, the present invention has the following configuration.

[1] (a) a polymer containing two or more thiol groups in one molecule; (b) a compound containing two or more isocyanate groups in one molecule; A curable composition comprising a compound having a saturated group.

[2] The curable composition according to the above [1], further comprising an oxidation aid.

[3] (a) The curable composition according to the above [1], wherein the polymer containing two or more thiol groups in one molecule is a polysulfide polymer and / or a polysulfide polyether polymer. .

[4] (1) The compound as described in [1] above, wherein the compound containing an air-oxidizable unsaturated group is a drying oil.
The curable composition according to the above.

[5] The curable composition according to the above [4], wherein the drying oil is tung oil.

[6] With respect to 100 parts by weight of (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule, c) The curable composition according to the above [1], which contains 0.1 to 50 parts by weight of a compound containing an air-oxidizable unsaturated group.

[7] Based on 100 parts by weight of the total of (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule. d) The curable composition according to the above [1], which contains 0.001 to 2 parts by weight of an oxidation aid.

[8] (b) the compound containing two or more isocyanate groups in one molecule contains (C) a compound containing an air-oxidizable unsaturated group. 1] The curable composition according to [1].

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the curable composition of the present invention, the polymer containing two or more thiol groups in one molecule and the compound containing two or more isocyanate groups in one molecule are reacted with thiourethane and isocyanate to form thiourethane. It is a composition that cures at room temperature by forming a bond, and each polymer and compound will be described below. (a) A polymer having two or more thiol groups in one molecule: a polymer having two or more thiol groups in one molecule is an ether bond, a thioether bond, a disulfide bond, a urethane bond or an ester bond in a main chain. May be included.

A preferred example of such a polymer having two or more thiol groups in one molecule is described in JP-B-47-4970.
Examples include polyoxyalkylene polyols described in US Pat. No. 8,279, and polymercaptans described in US Pat. No. 4,092,293 and JP-B-46-3389. Other known compounds include thiol-terminated liquid polymers described in U.S. Pat. No. 3,923,748 and U.S. Pat. No. 4,366,630.
Among the liquid thioethers described in the specification of JP-A-7, those having a thiol group terminal are exemplified. Furthermore, particularly preferred are the polysulfide polyether polymers and polysulfide polymers described below.

The number average molecular weight of such a polymer having two or more thiol groups in one molecule is 100 to 200,0.
00, preferably 400 to 100,000.

Polysulfide polyether polymer As a polysulfide polyether polymer, (a)-(R ₁ O) n-(where R ₁ is an alkylene group having 2 to 4 carbon atoms, and n is 6 to 6) A polyether moiety represented by (a)-(C ₂ H ₄ OCH ₂ OC ₂ H ₄ -S _X -)-
And a structural unit represented by-(CH ₂ CH (OH) CH ₂ -S _X )-(where X is an integer of 1 to 5), and (C) -C ₂ H ₄ OCH ₂ OC ₂ H ₄ -SH and / or -CH ₂ CH
It has a thiol group represented by (OH) CH ₂ —SH.

In this polysulfide polyether polymer, the polyether portion of (a) and the structural unit shown in (a) may be bonded in an arbitrary sequence. Also the proportion of _{(A) - (R 1 O) n} - component 2 to 95 _{wt%, (C 2 H 4 OCH} 2 OC 2 H 4 -S X) component of (b) is from 3 to 70 weight % And the (CH ₂ CH (OH) CH ₂ —S _X ) component is preferably 1 to 50% by weight. The number average molecular weight of the polysulfide polyether polymer is usually from 600 to 200,000, preferably from 800 to 50,000. Such a polysulfide polyether polymer can be produced, for example, by a method described in JP-A-4-363325. · Polysulfide Polymer - polysulfide polymer, in the main chain (d) - (C ₂ H ₄ O
CH ₂ OC ₂ H ₄ -S _X ) − (where x is an integer of 1 to 5)
And (E) -C ₂ H
_It has a thiol group represented by ₄ OCH ₂ OC ₂ H ₄ -SH. This polysulfide polymer has fluidity at room temperature, and has a number average molecular weight of 100 to 200,000, preferably 400 to 50,000.

Preferred examples of such polysulfide polymers are described in US Pat. No. 2,466,963. (b) Compound containing two or more isocyanate groups in one molecule: The compound containing two or more isocyanate groups in one molecule is obtained by reacting an organic polyisocyanate compound and / or an active hydrogen-containing compound with an organic polyisocyanate compound. The resulting urethane prepolymer is preferred.

As the organic polyisocyanate compound,
Specific examples include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (crude MDI), xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and the like.

Examples of active hydrogen-containing compounds include hydroxyl-terminated polyesters, polyvalent polyalkylene ethers, hydroxyl-terminated polyurethane polymers, acrylic polyols having hydroxyl groups introduced into acrylic copolymers, hydroxyl-terminated polybutadienes, polyvalent polythioethers, polyacetals, and the like. Aliphatic polyols, and alkanes including alkylene thiols having two or more SH groups, alkenes and aliphatic thiols, polysulfide polymers having terminal SH groups,
Diamines, including aromatic, aliphatic and heterocyclic diamines, and the like, and mixtures thereof.

As the urethane prepolymer, the active hydrogen-containing compound and the organic polyisocyanate compound described above are used.
It is obtained by reacting under conditions of an excess of isocyanate compound.

In the composition of the present invention, (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule are preliminarily reacted. By using only the urethane prepolymer described above, the composition can be used as a one-part curable composition.

In addition, a catalyst for reaction between a polymer containing a thiol group and a compound containing an isocyanate group and an acidic substance as a curing retarder can be added in order to quickly and surely cure the composition after application. .

Specifically, a tertiary amine and an organometallic compound are used as a reaction catalyst.

As the tertiary amine, monoamines, diamines, triamines, polyamines, cyclic amines,
There are alcohol amines, ether amines and the like, and specific examples are triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-. Tetramethylpropane-1,3-diamine, N, N, N ′, N′-tetramethylhexane-1,6-diamine, N, N,
N ', N ", N" -pentamethyldiethylenetriamine, N, N, N', N ", N" -pentamethyldipropylenetriamine, tetramethylguanidine, N, N-dipolyoxyethylenestearylamine, N, N -Dipolyoxyethylene tallow alkylamine, triethylenediamine, N, N'-dimethylpiperazine, N-methyl-
N '-(2 dimethylamino) -ethylpiperazine, N-
Methylmorpholine, N-ethylmorpholine, N-
(N ′, N′-dimethylaminoethyl) -morpholine,
1,2-dimethylimidazole, dimethylaminoethanol, dimethylaminoethoxyethanol, N, N,
N'-trimethylaminoethylethanolamine, N-
Methyl-N ′-(2-hydroxyethyl) -piperazine,
N- (2hydroxyethyl) -morpholine, bis- (2
Dimethylaminoethyl) ether, ethylene glycol bis- (3dimethyl) -aminopropyl ether, and the like. Among them, an N, N-dipolyoxyethylene alkylamine compound is preferable because the residual tack of the cured product is small. Specific examples include N, N-dipolyoxyethylene stearylamine, N, N-dipolyoxyethylene tallow alkylamine, and the like. Further, a hindered amine type light stabilizer is also preferable because the residual tack is small. These three
Two or more secondary amines may be used.

Examples of the organometallic compound include an organic tin compound, an organic mercury compound, and an organic lead compound. Specific examples include tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, and dibutyltin thiocarboxylate. Rates, dibutyltin dimaleate, dioctyltin mercaptide, dioctyltin thiocarboxylate, phenylmercuric propionate, lead octenoate and the like. Among them, an organic tin compound which is less affected by discoloration and the like is preferable, and more preferable are dialkyltin mercaptide, dialkyltin dicarboxylate, dialkyltin bis (dicarboxylic acid monoalkyl ester) salt, dialkyltin (dicarboxylic acid) salt and the like. .

As the acidic substance, organic acids such as citric acid, stearic acid, 2-ethylhexanoic acid and dodecylbenzenesulfonic acid are preferred. (c) a compound containing an air-oxidizable unsaturated group: as the compound containing an air-oxidizable unsaturated group of the present invention,
Dry oils, diene compounds, and various modified products of dry oils may be mentioned. Specifically, fats and oils (drying oil and fish oil) having an iodine value of 130 or more as mixed triglycerides of unsaturated fatty acids can be used. Unsaturated fatty acids include succinic acid, lindelic acid, tunic acid, maccoic acid, myristooleic acid, zomalic acid, petroselic acid, oleic acid, vaccenic acid, gadolinic acid, whale oil acid, erucic acid, shark oil acid, and linoleic acid , Hiragoic acid, eleostearic acid, bunnic acid,
Trichosanoic acid, linolenic acid, moloctic acid, parinaric acid, arachidonic acid, succinic acid, hiragashiric acid and nisic acid. Specifically, linseed oil as vegetable oil,
Eno oil, paulownia oil, Japanese paulownia oil, deer oil, hempseed oil, kaya oil, Inugaya oil, walnut oil, onigurimi oil, poppy oil, sunflower oil, soybean oil, safflower oil, etc. Fish oils include sardine oil, herring oil, menhaden oil and the like. Other examples include isomerized oil obtained by alkali isomerization of fish oil, dehydrated castor oil obtained by dehydration of castor oil, and the like. Particularly preferred examples are tung oil and oitichika oil which contain a large amount of unsaturated fatty acids of the conjugate acid type such as eleostearic acid.

In the present invention, the drying oil is added in an amount of 100 parts by weight of the total of the polymer containing two or more thiol groups per molecule and the compound containing two or more isocyanate groups per molecule. It is desirable that the amount be 0.1 to 50 parts by weight. If the amount is less than 0.1 part by weight, the effect of improving the residual tack and the matting effect on the surface becomes poor, and if the amount exceeds 50 parts by weight, there is a possibility that problems may arise in terms of economy and odor.

The compound (c) of the present invention containing an air-oxidizable unsaturated group can be reacted with the polymer containing a thiol group for a long time if the thiol group and the unsaturated group react gradually, Unsaturated groups may react with air in the air, and air is oxidized at the time of curing to reduce the residual tackiness on the surface and reduce the matting effect, which is not preferable. However, when reacting an active hydrogen-containing compound and an organic polyisocyanate compound under the condition of an excess of an isocyanate compound, (c) by synthesizing the compound containing an air-oxidizable unsaturated group, the compound (b) It is possible to stably present (c) a compound containing an air-oxidizable unsaturated group in a compound containing two or more isocyanate groups in one molecule, and also to improve the surface residual tack during curing. The matte effect is also excellent, which is particularly preferable.

The composition of the present invention comprises (a) a polymer containing two or more thiol groups in one molecule, (b) a compound containing two or more isocyanate groups in one molecule, and (c) air oxidation. The compound containing a possible unsaturated group eliminates the surface residual tack and luster after curing.
(d) By adding a small amount of an oxidizing aid, the effect can be expressed more quickly.

As the oxidizing aid, sulfur, ZnO, ZnO
₂ , FeO ₂ , FeO ₂ , Fe ₂ O ₃ , PbO _2, MgO ₂ , M
gO, CoO, CaO ₂ , CaO, CuO, BaO ₂ , B
aO, MnO ₂ , TeO ₂ , SeO ₂ , Pb ₃ O ₄ , Pb
Inorganic oxides such as O, SrO ₂ , LiO ₂ , Sb ₂ O ₃ , N
a ₂ CrO ₄ , K ₂ CrO ₄ , K ₂ Cr ₂ O ₇ , NaClO ₄ ,
_{NaBO 2 · H 2 O 2,} K 2 C 2 O 6, KMnO 4, inorganic oxidizing agents such as sodium percarbonate _{(2Na 2 CO 3 + 3H 2} O 2), benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide , T-butyl hydroperoxide, t-butyl perbenzoate, organic peroxides such as sodium peracetate, urea peroxide, nitrobenzene,
Organic oxidizing agents such as dinitrobenzene and paraquinone dioxime are exemplified. The sulfur is not particularly limited, but is preferably in the form of powder for rubber compounding. Also, iron 2-ethylhexanoate, lead 2-ethylhexanoate, cobalt 2-ethylhexanoate, zinc 2-ethylhexanoate,
-Various metal soaps such as tin ethylhexanoate, lead naphthenate, cobalt naphthenate, zinc naphthenate, manganese naphthenate, copper naphthenate, iron naphthenate, calcium stearate, and barium stearate can be used.

In the present invention, the amount of the oxidizing aid added is
0.001 to 2 parts by weight based on 100 parts by weight of (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule Desirably. If the amount is less than 0.001 part by weight, the effect of improving the residual tack becomes poor, and if it exceeds 2 parts by weight, there may be a problem in physical properties, weather resistance and economical efficiency of the cured product.

Further, (a) the polymer containing two or more thiol groups in one molecule is disclosed in JP-A-63-1453.
The thiol group may be protected as a trialkylsilylthio group by a silylating reagent as described in JP-A-21. Such a polymer containing two or more trialkylsilylthio groups in one molecule and a compound containing two or more isocyanate groups in one molecule can be made into a one-part curable composition, By adding the air-oxidizable unsaturated group-containing compound of the present invention and further an oxidizing aid, the trialkylsilylthio group returns to a thiol group upon curing, and contains two or more isocyanate groups in the molecule. When cured with a compound to be cured, an effect of eliminating tackiness and gloss remaining on the surface after curing is exhibited.

The composition of the present invention contains fillers such as calcium carbonate, talc, clay, titanium oxide and silica for the purpose of improving economy, workability in applying the composition, and physical properties after curing. Plasticizers can be added.

According to the present invention, a predetermined amount of an air-oxidizable composition can be obtained by using a polymer containing two or more thiol groups in one molecule and a compound containing two or more isocyanate groups in one molecule. By adding a compound containing an unsaturated group, and by further adding an oxidizing aid, the surface remaining tack and gloss after curing are lost even in a state where sunlight does not shine, especially indoor installation, and dust after curing. A cured product having no matting and having good matting properties can be obtained.

[0038]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

[Synthesis Example 1] Bifunctional polypropylene glycol (OH value: 55.3 mgKOH / g) obtained by adding propylene oxide to propylene glycol 800
g, 87.7 g of epichlorohydrin, and 1.0 g of stannic chloride pentahydrate were charged into a reaction vessel, and heated at 80 to 90 ° C.
For 3 hours. Furthermore, polysulfide polymers
(Trade name “Tiocoll LP5” manufactured by Toray Thiokol Co., Ltd.)
5 ″) 887.7 g was added and mixed, 76 g of sodium hydrosulfide (purity 70%) was added, and the mixture was stirred at 80 ° C. for 2 hours. Then, 7.1 g of a 50% aqueous solution of citric acid was added, and the mixture was added for 15 minutes. After stirring, the mixture was dehydrated and the salts were removed to obtain a pale yellow transparent polymer having a mercaptan content of 2.0% by weight and a viscosity of 80 poise (25 ° C.).

[Synthesis Example 2] 900 g of a bifunctional polypropylene glycol having a molecular weight of 1,000 (OH value 112) and a trifunctional polypropylene glycol having a molecular weight of 1,000 (O
100 g of H value 162) and 60 g of tung oil were charged into a reaction vessel, dehydrated under reduced pressure at 80 ° C. for 3 hours, replaced with nitrogen, charged with 334 g of xylene diisocyanate, and stirred at 80 ° C. for 3 hours. The obtained isocyanate group-containing polymer had an isocyanate content of 4.1%.

[Synthesis Example 3] 700 g of a bifunctional polypropylene glycol having a molecular weight of 1000 (OH value 112) and a trifunctional polypropylene glycol having a molecular weight of 1,000 (O
300 g of H value 162) and 60 g of tung oil were placed in a reaction vessel, dehydrated under reduced pressure at 80 ° C. for 3 hours, replaced with nitrogen, and charged with 298 g of hexamethylene diisocyanate.
The mixture was stirred for 3 hours. The obtained isocyanate group-containing polymer had an isocyanate content of 3.8%.

Examples 1 to 9 Plasticizers, fillers, and additives were added to the polymer of Synthesis Example 1 in the proportions shown in Table 1 to obtain main ingredients. 400 parts by weight of the main agent, 67 parts by weight of a urethane prepolymer (isocyanate content: 4.2% by weight) obtained by adding xylene diisocyanate to polypropylene glycol, tung oil and an oxidation aid in amounts (parts by weight) shown in Table 2 Mixed. The obtained mixture was poured into a container having an inner diameter of 30 mm and a depth of 5 mm, and the weight (a
g), immediately sprinkle 50-80 mesh silica sand (Chemical Pure Chemicals Co., Ltd.) on the exposed surface, tap the bottom lightly with this surface down to drop the silica sand, and determine the sample weight (bg). I weighed. On the other hand, the sealant mixture was poured into a container and cured under the conditions shown in Table 5, and the weight (cg) before silica sand adhesion and the weight (dg) of silica sand adhesion were measured in the same manner as described above, and the residual tack ratio was determined by the equation (1). (%) Was calculated. At this time, the presence or absence of gloss on the surface of the cured sealant was visually evaluated. Table 3 shows the results.

[Example 10] and [Example 11] 400 parts by weight of the same main ingredient as in Example 1 and 67 parts by weight of a urethane prepolymer synthesized by adding tung oil obtained in Synthesis Examples 2 and 3 were mixed. The same test as in Example 1 was performed to measure the residual tack ratio. Table 3 shows the results.

Comparative Example 1 As a comparative example, when tung oil was not added, a plasticizer and a filler were added to the polymer of Synthesis Example 1 in the proportions shown in Table 1 to obtain a base material. The test was performed. Table 3 shows the results.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

As described in detail above, the present invention relates to (a) a polymer containing two or more thiol groups in one molecule;
A curable composition comprising a compound containing two or more isocyanate groups in one molecule and (c) a compound containing an air-oxidizable unsaturated group, in a state where it is not exposed to sunlight, In particular, the surface remaining tack and gloss after hardening are eliminated even in indoor installation, and it is suitable for use as a sealing material. By further adding an oxidation aid, tack disappears,
It is possible to promote the matting effect.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) C09K 3/10 C09K 3/10 DF term (reference) 4H017 AA04 AA35 AB03 AB14 AC11 AC16 AD05 AD06 AE03 4J002 AE052 CK051 DA046 DE036 DE056 DE066 DE076 DE086 DE096 DE106 DE116 DE126 DE156 DE186 DE196 DK006 EG016 EG046 EG086 EK006 EK016 EK026 EK046 EK056 ES006 ES016 FD010 GJ02 4J034 CA03 CA15 CA32 CB02 CB03 CB07 DN02 03 EA11 GA06 GA33 HA01 HA02 HA06 HA07 HC03 HC12 HC17 HC22 HC46 HC52 HC61 HC63 HC64 HC67 HC71 HC73 JA42 KA01 KB02 KC08 KC17 KC18 KD02 KD12 KD21 KE02 MA02 MA03 MA12 MA14 QB12 RA08

Claims (8)

[Claims] (1) a polymer containing two or more thiol groups in one molecule; (b) a compound containing two or more isocyanate groups in one molecule; and (c) an air-oxidizable unsaturated compound. A curable composition comprising a group-containing compound. 2. The curable composition according to claim 1, further comprising an oxidation aid. 3. The curable composition according to claim 1, wherein (a) the polymer containing two or more thiol groups in one molecule is a polysulfide polymer and / or a polysulfide polyether polymer. 4. The curable composition according to claim 1, wherein (c) the compound containing an air-oxidizable unsaturated group is a drying oil. 5. The curable composition according to claim 4, wherein the drying oil is tung oil. 6. A total of 100 parts by weight of (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule.
(c) 0.1% of a compound containing an air-oxidizable unsaturated group
2. The curable composition according to claim 1, wherein the curable composition is contained in an amount of from 50 to 50 parts by weight. 7. A total of 100 parts by weight of (a) a polymer containing two or more thiol groups in one molecule and (b) a compound containing two or more isocyanate groups in one molecule.
2. The curable composition according to claim 1, wherein (d) contains 0.001 to 2 parts by weight of an oxidation aid. 8. The method according to claim 1, wherein (b) the compound containing two or more isocyanate groups in one molecule contains (C) a compound containing an air-oxidizable unsaturated group.
The curable composition according to the above.