JP2504222B2 - Room temperature curable composition and sealant - Google Patents

Description

TECHNICAL FIELD The present invention relates to a room temperature curable composition and a sealant.

[Prior Art] Conventional curable compositions such as sealing materials having stretchability have self-contaminating property due to weather resistance and surface tackiness due to their flexible molecular structure, and are included in them. Defects such as peripheral contamination due to migration of low molecular weight components have been pointed out and improvements have been required.

For example, taking an elastic sealing material as an example, a polysulfide system having low surface tackiness has a good restoring property upon compression and has a problem in stretchability itself. Polyurethane type has a problem in weather resistance, and modified silicone type also has insufficient improvement in self-contamination property based on weather resistance and surface tackiness. Further, a silicone-based material having excellent weather resistance is self-polluting due to its lipophilicity, and at the same time fatal contamination of the surroundings occurs due to migration of low molecular weight silicone oil contained in the component.

Therefore, the present situation is that none of them have sufficiently overcome the stretchability, the weather resistance, and the non-staining property with respect to themselves and their surroundings.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art.

That is, it is an object of the present invention to provide a composition that gives a cured product having both stretch resistance and weather resistance and stain resistance.

[Means for Solving the Problems] The present invention has been made to solve the above-described problems, and (a) a polymerized unit having a polyether side chain whose repeating unit is 10 to 50 and a carbon number of 2 to 3 Of the fluoroolefin having a number average molecular weight of 1,000 to 50,000 and having a curable site, and a functional group and carbon number capable of co-crosslinking with the fluorine-containing copolymer of (b) and (a). And a copolymer having three or more polyfluoroalkyl groups as an active ingredient.

The fluorine-containing copolymer (a) in the present invention has a polymer unit whose repeating unit has a polyether side chain of 10 to 50, and preferably a polymer unit containing a side chain having a polyether bond of 10 to 50. In a proportion of 1 to 80 mol%.

Since this specific side chain is contained, it can be an elastic body having good elasticity. In particular, it is preferable that the end of this side chain is a curable site. It is considered that a cured product having a crosslinked bond formed on the basis of the curable site at the end of the side chain exhibits particularly excellent elasticity due to the specific crosslinked structure.

If the number of ether bonds in the side chain is less than 10, an elastic body having preferable elasticity cannot be obtained, and thus it is not adopted. An elastic body having good elasticity can be obtained as the number of ether bonds in the side chain is large, but if it is too long, weather resistance and stain resistance are deteriorated, which is not preferable. Usually, the number of ether bonds is 50 or less, more preferably 40 or less. In addition, the space between ether bonds is usually composed of alkylene groups such as methylene group, ethylene group, propylene group and butylene group. The water resistance of the coalesced product or the crosslinked product thereof may decrease, which is not preferable. Further, those having a large number of carbon atoms between ether bonds have problems such as difficulty in synthesis and are not usually preferably used. Preferably, an alkylene group having about 2 to 6 carbon atoms such as ethylene group and propylene group is adopted. The alkylene chain may be one in which a part or all of the hydrogen bonded to carbon is substituted with a substituent such as a halogen group such as fluorine and chlorine, an alkyl group, an aryl group or the like. In particular, in order to obtain a good elastic body, the number of side chain ether bonds is
In order to obtain 10 or more and those suitable for applications such as sealants, those having 20 or more ether bonds are preferably adopted. Further, as described above, it is preferable that the specific side chain end is a curable site. Examples of such a curable site include a hydroxyl group, an amino group, an acid amide group, an active hydrogen-containing group such as a mercapto group, an epoxy group, an active halogen-containing group, and a hydrolyzable silyl group.

Moreover, the polymerized unit containing this specific side chain is contained in a ratio of 1 to 80 mol%. If the content ratio of the polymerized units containing the specific side chain is too small, a good elastic body cannot be obtained or an elastic body cannot be obtained, which is not preferable. On the other hand, if the amount is too large, the weather resistance may be deteriorated or it may be difficult to obtain an elastic body, which is not preferable.
In particular, a fluorinated copolymer containing 5 to 30 mol% of polymerized units containing a specific side chain is preferable.

Further, the fluorine-containing copolymer (a) of the present invention contains a polymer unit based on a fluoroolefin, and preferably 20 to
Contains 70 mol%. As the fluoroolefin, a fluoroolefin having 2 to 3 carbon atoms such as tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene and pentafluoropropylene is adopted. Of these, perhaloolefins in which hydrogen is completely replaced by halogen are most preferable. Further, when the polymerized unit based on fluoroolefin is less than 20 mol%,
Sufficient weather resistance is not exhibited, and stains may become remarkable during long-term use, which is not preferable. When the amount of the fluoroolefin is more than 70 mol%, good elasticity cannot be obtained or adhesion with other materials cannot be obtained, which is not preferable. Particularly, those containing 30 to 60 mol% of polymerized units based on fluoroolefin are preferable.

Further, the fluorine-containing copolymer of the present invention may contain another polymerized unit in addition to the polymerized unit based on the fluoroolefin and the polymerized unit containing a specific side chain. In this case, the total of the polymerized units based on the fluoroolefin and the polymerized units containing a specific side chain is contained in a proportion of 30 mol% or more based on the total polymerized units. If the proportion of these two types of polymerized units is too small, sufficient weather resistance, stain resistance and elasticity will not be exhibited. Another polymerized unit is a polymerized unit based on a monomer that can be copolymerized with a fluoroolefin, and examples thereof include a polymerized unit based on an ethylenically unsaturated compound such as a vinyl type, an allyl type, an acryloyl type, or a methacryloyl type. By appropriately copolymerizing these monomers, a large number of polymer units are contained between the polymer units having a specific side chain, and elasticity is more effectively exhibited, which is preferable.

Further, such a fluorinated copolymer has a number average molecular weight of 5
It is preferably about 000 or less. Those having an excessively large molecular weight are not preferable because they are not excellent in coating workability when used as an elastic paint. Especially when used without a solvent, such as for a sealant, those having a large molecular weight have extremely poor workability. Molecular weight of 15,0 when used without solvent
It is preferable to employ one of 00 or less, particularly 10,000 or less. The lower limit of the molecular weight is not particularly limited, but usually 1,000 or more, preferably 2,000 or more is adopted to obtain a sufficient cured state.

The fluorine-containing copolymer of the present invention can be produced by the method described below.

First, a method of copolymerizing a fluoroolefin and a monomer which is copolymerizable with the fluoroolefin and has 10 to 50 ether bonds.

Second, polymerized units (1) based on fluoroolefins
20 to 70 mol% and 1 to 1 of the polymer unit (4) having a hydroxyl group.
Addition reaction of alkylene oxide to the fluorine-containing copolymer which is contained at a ratio of 80 mol% and the total amount of the polymerized units (1) and the polymerized units (4) is 30 mol% or more with respect to all polymerized units. A method etc. are illustrated.

In the first method, the monomer copolymerizable with fluoroolefin and having 10 to 50 ether bonds is composed of an ethylenically unsaturated group such as vinyl group, allyl group, acryloyl group, and methacryloyl group. A monomer having a polymerizable site is adopted. As such a monomer, one having 10 to 50 ether bonds is adopted. The monomer having such an ether bond can be synthesized by the method shown below. Hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether, reaction product of acrylic acid and polyhydric alcohol, reaction product of glycidyl allyl ether and alkanolamine or phenolic compound, addition of alkylene oxide to hydroxyl group-containing monomer such as allyl alcohol How to react. A polyether compound having a monomer having a reactive group such as a hydroxyl group, an alkoxysilyl group, an epoxy group and an amino group, and a group capable of reacting with the above reactive group such as an isocyanate group, an alkoxysilyl group and a carboxylic acid group. And the like can be exemplified. Further, in the first method, when one kind of each of a monomer having a fluoroolefin and 10 to 50 ether bonds is polymerized, there is a high possibility that alternating copolymerization will occur. This possibility becomes extremely high when the monomers having 50 monomers are vinyl or allyl compounds. In the case of alternating copolymerization, ether bond
Other polymer units existing between 10 to 50 polymer units are 1
Since the number of individual polymers is small, it is difficult for the polymer to exhibit good flexibility or elasticity. Preferably, two or more compounds of different types are employed for either or both of the fluoroolefin and the monomer having 10 to 50 ether bonds.

Alternatively, a fluoroolefin or ether bond with 10 to
In addition to the monomers having 50, a method of copolymerizing a comonomer that can be copolymerized with these is adopted,
It is operated such that a large number of other polymerized units are present between polymerized units having ˜50 ether bonds. Usually, a method of copolymerizing the latter comonomer is adopted. Here, as the comonomer, a compound having a polymerizable site such as a vinyl group, an allyl group, an acryloyl group or a methacryloyl group is adopted. Specific examples include olefins, vinyl ethers, vinyl esters, allyl ethers, allyl esters, acrylic acid esters, and methacrylic acid esters. A compound having a linear, branched or alicyclic alkyl group having about 1 to 15 carbon atoms is particularly preferable. As such a comonomer, a part or all of hydrogen bonded to carbon may be replaced with fluorine. In the first method, the polymerization ratio of each polymerizable monomer is such that the fluoroolefin is 20 to 70 mol% and the monomer having 10 to 50 ether bonds is 1 to 80 mol%. It is preferable to control such that a monomer having 10 to 50 fluoroolefins and ether bonds is copolymerized in a proportion of 30 mol% or more based on the polymerized units. Such polymerization may be carried out by any of solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization, and the polymerization can be carried out by causing a predetermined amount of a monomer to act on a polymerization initiation source such as a polymerization initiator or ionizing radiation. Done. Other various conditions can be generally the same as those used for solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization and the like.

In the second method, 20 to 70 mol% of polymerized units (1) based on fluoroolefin and polymerized units (4) having a hydroxyl group are used.
Addition of alkylene oxide to a fluorine-based copolymer that is contained in a proportion of 1 to 80 mol% and the total of polymerized units (1) and polymerized units (4) is 30 mol% or more based on all polymerized units. This is a reaction method.

However, it is important that the fluorine-based copolymer has a hydroxyl group. When a hydroxyl group-containing monomer such as hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether or allyl alcohol is copolymerized, the hydroxyl group can be easily introduced into the fluorine-based copolymer. On the other hand, when a monomer having reactivity other than a hydroxyl group such as glycidyl allyl ether and acrylic acid is copolymerized, it is necessary to convert the reactive group into a hydroxyl group. The conversion of a reactive group into a hydroxyl group can be easily achieved by reacting a compound such as an alkanolamine or a polyhydric alcohol. The addition reaction of the fluorinated copolymer healkylene oxide can be carried out in the same manner as in the production of a usual polyether compound. In addition, in the third method, after the addition reaction of alkylene oxide is performed, the hydroxyl group generated at the side chain terminal may be converted into another reactive group such as a carboxylic acid group or a hydrolyzable silyl group. Good.

The composition comprising the fluorocopolymer (a) in the present invention, particularly the fluorocopolymer having a curable site at the end of a specific side chain, and a curing agent provides a cured product having good elasticity. It can be preferably used as a base for, for example, sealants and elastic paints. Here, the curing agent includes a compound that reacts with the curable site of the fluorocopolymer to form a crosslink, a compound that promotes the reaction between the curable sites of the fluorocopolymer, and the like. Be done. Of these, a polyol-modified isocyanate compound is preferable because it gives a cured product having good elasticity. This compound is a reaction product of a polyhydroxyl compound and a polyisocyanate compound, and has an isocyanate group at the terminal.

Examples of the polyhydroxyl compound include various polyether polyols or polyester polyols generally used for the production of urethane compounds, and further polymer polyols.

The polyether polyol is, for example, one or two or more selected from alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide, and cyclic ethers such as tetrahydrofuran, is addition-polymerized with a compound having two or more active hydrogens. Product.

Examples of the polyisocyanate compound include various compounds used in the production of ordinary polyurethane resins.
Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, xylene diisocyanate, diphenylmethane-4,
4'-diisocyanate, naphthylene-1,5-diisocyanate, and hydrogenated compounds thereof, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1-methyl-2,4
-Diisocyanate cyclohexane, 1-methyl-2,6
-Diisocyanate cyclohexane, dicyclohexylmethane diisocyanate, triphenylmethane triisocyanate and the like can be mentioned. These polyisocyanate compounds may be used alone or in combination of two or more. Further, it is preferable to select a polyisocyanate compound which does not cause yellowing because it causes less discoloration. Here, it is preferable that the curing-reactive site of the fluorine-containing copolymer is a hydrolyzable silyl group or a polyvalent isocyanate group, since it can be cured by moisture and the workability is excellent. When a polyvalent isocyanate compound is used as the curing agent, the curable site of the fluorinated copolymer is preferably an active hydrogen-containing group, particularly a hydroxyl group, which is excellent in reactivity.

Further, as the copolymer having a functional group capable of co-crosslinking with the fluorine-containing copolymer (a) of (b) in the present invention and a polyfluoroalkyl group, those having the following properties are preferably adopted.

That is, when mixed with the fluorinated copolymer of (a), while having mixability within a range that does not hinder workability,
After application, it should move to the surface until it cures, and if possible it should cure at the same level as the interior or a little faster than the interior, making it difficult for moisture-inhibiting factors such as moisture to enter the interior. After curing, it has low surface tackiness so that it does not cause self-contamination due to dust, etc., and has sufficient weather resistance and stretchability, and it does not cause itself to flow out and cause contamination of the surrounding area. It is possible to obtain a cured product which is hardened and fixed to the above and can exhibit a sufficient barrier property to prevent migration of a plasticizer and other substances that cause contamination from the inside.

That is, as a molecular structure for exhibiting these properties, a polyfluoroalkyl group having 3 or more carbon atoms is contained in order to have surface migration. Polyfluoroalkyl group is a perfluoroalkyl group having 3 to 20 carbon atoms, especially 5 carbon atoms
It is preferable that the number is 20 to 20 perfluoroalkyl groups.

Further, it preferably has a functional group capable of co-crosslinking with the fluorine-containing copolymer (a) or, if possible, is a functional group having the same or higher reactivity as the fluorine-containing copolymer (a).
For example, when the crosslinking functional group of the fluorine-containing copolymer (a) is a secondary hydroxyl group with respect to an isocyanate curing agent, a primary hydroxyl group is selected or crosslinking of the fluorine-containing copolymer (a) is performed. When the functional group is a hydrolyzable ethoxysilyl group, it is preferable to select a methoxysilyl group. One or more such functional groups are required in the molecule in order to be reliably fixed in the cured product, and preferably 30 or less in order not to impair sufficient stretchability. The molecular weight is preferably 400 to 40,000. This is because the molecular weight of 400 or more is required to exhibit sufficient barrier properties, and the molecular weight of 40,000 or less is required to obtain good surface migration.

As the polyfluoroalkyl group-containing monomer having 3 or more carbon atoms, a monomer containing a perfluoroalkyl group having usually 3 to 20 carbon atoms, particularly preferably 5 to 20 carbon atoms can be preferably used. It is not particularly limited as long as it has a polyfluoroalkyl group,
For example, unsaturated esters having an addition-polymerizable unsaturated group are exemplified, and normally, acrylate or methacrylate is mentioned as a preferable example. A specific example is as follows.

CF ₃ (CF ₂ ) ₄ CH ₂ OCOC (CH ₃ ) = CH ₂ CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ CF ₃ (CF ₂ ) ₆ COOCH = CH ₂ CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ OCOCH = CH ₂ CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ ) ₂ OCOCH = CH ₂ CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₄ OCOCH = CH ₂ CF ₃ (CF ₂ ) ₇ SO _{2 N (CH 3) (CH 2} ) 2 OCOC (CH 3) = CH 2 CF 3 (CF 2) 7 SO 2 N (C 2 H 5) (CH 2) 2 OCOCH = CH 2 CF 3 (CF 2) 7 CONH (CH ₂ ) ₄ OCOCH ＝ CH ₂ CF ₃ (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH = CH ₂ CF ₃ (CF ₂ ) ₈ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ CF ₃ (CF ₂ ) ₈ CONH (CH ₂ ) ₂ OCOC (CH ₃ ) ＝ CH ₂ H (CF ₂ ) ₁₀ CH ₂ OCOCH = CH ₂ CF ₂ Cl (CF ₂ ) ₁₀ CH ₂ OCOC (CH ₃ ) = CH ₂ The monomer having a high refractive index functional group preferably used for copolymerization in the present invention may basically be a monomer having a molecular refractive index of 1.48 or more, but the following ones are particularly preferable.

Cyclohexyl methacrylate, benzyl methacrylate, styrene, vinyl chloride, vinylidene chloride, cyclohexyl acrylate, benzyl acrylate, α-chlorostyrene, dichlorostyrene, vinyl alcohol,
Acrylonitrile, methyl acrylate, ethyl acrylate, t-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, methyl methacrylate, ethyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate.

Dodecyl acrylate, stearyl acrylate, 2
Examples thereof include ethylhexyl acrylate, dodecyl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, polyoxyethylene methacrylate, polyoxypropylene methacrylate, 2-hydroxyethyl methacrylate, polyoxyethylene / polyoxypropylene methacrylate, and methacrylic acid.

In the present invention, the polyfluoroalkyl group-containing monomer having a carbon number of 3 or more and the high refractive index functional group-containing monomer may each be used one type, but either one or both types are used in two or more types. You may.

In the present invention, the copolymerized oligomer as described above, which is a preferred embodiment of the specific fluorine-containing compound, is prepared by appropriately polymerizing each of the monomers as described above by a conventionally known or well-known polymerization means. It can be obtained synthetically by copolymerizing under addition. Depending on the combination of each monomer, it is possible to prepare a copolymerized oligomer having a predetermined molecular weight by selecting the polymerization conditions without using a molecular weight modifier, but it is usually HSC ₂ H ₄ OH, HSCH ₂ CO
OH, HSC ₈ H ₁₇ ,, HSC ₁₂ H ₂₅ , HSC ₂ H ₄ C ₈ F ₁₇ , HSC ₂ H ₄ COOC ₂ H ₄ C ₈ F ₁₇
It is desirable to employ a chain transfer agent such as the above as the molecular weight modifier. The polymerization method and polymerization conditions for preparing the copolymer oligomer are not particularly limited as long as the specific molecular weight in the present invention can be obtained.

Further, the mixing ratio of the fluorine-containing copolymer of (a) to the copolymer of (b) having a polyfluoroalkyl group having 3 or more carbon atoms in the present invention is (b) with respect to 100 parts of (a).
Is more than 0.5 part, it is effective in improving adhesion, but if 100 parts or more is added, the stretchability inherent in the fluorocopolymer (a) is affected, so 0.5 to 100 parts is preferable.

In addition to the above-mentioned two components, such a composition includes a curing agent, a filler, a plasticizer, a solvent, a light stabilizer, an ultraviolet absorber,
A heat stabilizer, a leveling agent, etc. may be added and blended.

Examples of the filler include 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, bentonite, Organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloon,
Fillers such as; and fibrous fillers such as asbestos, glass fibers and filaments can be used.

When it is desired to obtain a high-strength curable composition with these fillers, mainly fumed silica, precipitated silica, silicic anhydride, hydrous silicic acid, carbon black, surface-treated fine calcium carbonate, calcined clay, clay, and If a filler selected from activated zinc white is used in the range of 1 to 200 parts by weight based on 100 parts by weight of the total of the fluorine-containing copolymer (a) and the copolymer (b), preferable results are obtained. can get. Further, when it is desired to obtain a curable composition having low strength and large elongation, filling mainly selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, shirasu balloon and the like. 1 to 2 with respect to 100 parts by weight of the total of the fluorine-containing copolymer (a) and the copolymer (b).
When used in the range of 00 parts by weight, favorable results are obtained.
Of course, these fillers may be used alone or in combination of two or more.

[Examples] Synthesis example 1 312 g of hydroxybutyl vinyl ether (HBVE) and 15 g of potassium hydroxide (concentration 95%) were charged into a stainless steel pressure-resistant reactor equipped with a stirrer with an internal volume of 5.5 l, and 4690 g of propylene oxide (PO) was gradually added. It was added, 3kg / cm ^2, 110 ℃ in 18 hours,
The reaction was performed. The obtained liquid was purified by synthetic magnesia to obtain a vinyl ether having a polyoxyalkylene chain. The number of moles of vinyl ether added with PO was 30 moles.

Next, a pressure-resistant reactor with a stirrer made of stainless steel with an internal volume of 550 ml was charged with 112 g of xylene, 112 g of ethanol, 1.6 g of potassium carbonate and 0.5 g of azoisobutyronitrile, 36 g of ethyl vinyl ether, 162 g of PO-added HBVE polymerized previously, and liquid. The residual air due to nitrogen was removed, then 80 g of chlorotrifluoroethylene (CTFE) was introduced, and the temperature was gradually raised to 65
Polymerization was carried out while maintaining the temperature at ℃. After continuing the polymerization reaction for 10 hours under stirring, the reactor was cooled with water to stop the polymerization. After cooling the reactor to room temperature, unreacted monomers were extracted and the reactor was opened. After filtering the polymer solution, the solvent was removed by an evaporator to obtain a fluorinated copolymer. The resulting fluorine-containing copolymer had a hydroxyl value (KOHmg / g) of 20, a number average molecular weight of 6000 and a glass transition temperature of -68 ° C.

Synthesis Example 2 In an autoclave having an internal volume of 1, Then, 5 parts by weight of C ₈ H ₁₇ SH was charged as a chain transfer agent, 100 parts by weight of ethyl acetate was used as a solvent, and 1 part by weight of α, α′-azobisisobutyronitrile was used as a polymerization initiator. The polymerization reaction was carried out for 10 hours. As a result, a polyfluoroalkyl group-containing copolymer having a molecular weight of 4,000 was obtained.

Synthetic Example 3 200 g of the fluorocopolymer of Synthetic Example 1 and 14.6 g of γ-isocyanatopropylmethyldimethoxysilane and 0.02 g of dibutyltin dilaurate as a curing catalyst were added to a glass container having an inner volume of 300 ml, at room temperature under a nitrogen atmosphere. After stirring for 4 hours, a fluorocopolymer having an alkoxysilyl group at the end was obtained.

Synthesis Example 4 To a glass container having an inner volume of 300 ml, 50 g of the polyfluoroalkyl group-containing copolymer of Synthesis Example 2, 150 g of toluene, 14.6 g of γ-isocyanatopropyldimethoxysilane and 0.02 g of dibutyltin dilaurate as a curing catalyst were added, After stirring at room temperature under a nitrogen atmosphere for 4 hours, the solvent was removed by distillation under reduced pressure to obtain a copolymer having a polyfluoroalkyl group having an alkoxysilyl group at the terminal.

Examples 1 to 5 and Comparative Examples 1 to 9 (a) obtained in Synthesis Examples 1 to 4 at the ratios shown in Table 1.
(B) Polyfluoroalkyl group-containing copolymer and curing catalyst titanium oxide calcium carbonate and, if necessary, as a curing agent, a polyol-modified diisocyanate compound (trade name, Duranate D101 Asahi Kasei Co., Ltd.) The following shows the results obtained by kneading and curing. Tensile test and durability test are performed according to JIS A 5758 (sealing material for construction) and its 9030 grade (heat resistance at 90 ° C and
30% stretchability combination). Surface adhesiveness is
The resistance value when the aluminum ring was pressed for 60 seconds with a load of 500 g for 60 seconds and then pulled up at a speed of 30 cm / sec using a Pictumack (manufactured by Toyo Seiki) was shown in kg. (The lower the number, the less sticky). The accelerated weather resistance was evaluated by observing the surface condition after irradiating a 2 mm-thick film for 3000 hours with a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.) (◎ indicates no change, ○ indicates slight decrease in gloss. Is no problem,
In the case of Δ, cracks and the like are not recognized, but discoloration and large changes such as surface peeling are recognized. × is marked with cracks, × ×
Indicates that cracking will occur within 1000 hours).

Next, the elongation retention rate (elongation at break after weathering test / initial elongation at break × 100 (%)) was evaluated.

In the outdoor exposure test, four crystallized glass pieces (20 cm x 20 cm) were used to fill and harden the test piece into a cross-shaped joint with a joint width of 2 cm.
The sample was exposed outdoors for 6 months, and the dust adhering to the glass substrate was observed and evaluated as the peripheral contamination, and the dust adhering to the test body was observed as the self-contaminating property. (○ shows almost no dust, △
Indicates that a small amount of dust is attached, and x indicates that a large amount of dust is attached. ) As Comparative Example 1, only the fluorine-containing copolymer of (a) of Synthesis Example 1 is used, as Comparative Example 2 is used only of the fluorine-containing copolymer of (a) of Synthesis Example 6, and as a Comparative Example 3, a commercially available two-component system is used. Modified Silicone (Yokohama Rubber, trade name HamaTite Super II), as Comparative Example 4, commercially available two-component modified silicone adhesive improved type (Sunstar Giken, trade name Penguin Seal 2500 Dry), commercially available as Comparative Example 5. 1-component modified silicone (made by Cemedine, trade name POS seal), commercially available 2-component urethane as Comparative Example 6 (Yokohama Rubber, trade name Hama Tight UH-30), commercially available 2-component system as Comparative Example 7. Polysulfide (Yokohama Rubber, trade name Hama Tight SC-500), as Comparative Example 8, using a commercially available two-component silicone (Shin-Etsu Silicone trade name Sealant 70), the same test results were obtained. The results are shown in Table 1.

[Effects of the Invention] As shown in Table 1, the fluorine-containing copolymer (a) of the present invention is superior in stretchability, durability, weather resistance, and non-contamination property to Comparative Examples 1-2 and 3-. It is clear by comparison with 8. In other words, there is no fateful peripheral contamination of silicone type,
It is extremely superior to modified silicone, polysulfide, and polyurethane in durability and weather resistance. The only problem was that it had surface tackiness and self-contamination due to the adhesion of dust. In addition, (b) of the present invention
By blending the copolymer having a polyfluoroalkyl group having 3 or more carbon atoms, the effect of improving self-polluting property was recognized without impairing stretchability, durability and weather resistance.

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Claims (2)

(57) [Claims] 1. A number-average molecular weight of 1,000 to 50,000, wherein the repeating unit (a) includes a polymer unit having a polyether side chain of 10 to 50 and a polymer unit based on a fluoroolefin having 2 to 3 carbon atoms and having a curable site. And (b) a copolymer having a functional group capable of co-crosslinking with the fluorine-containing copolymer (a) and a polyfluoroalkyl group having 3 or more carbon atoms as an active ingredient. A room temperature curable composition characterized by the above. 2. A number-average molecular weight of 1,000 to 50,000, wherein (a) the repeating unit includes a polymer unit having a polyether side chain of 10 to 50 and a polymer unit based on a fluoroolefin having 2 to 3 carbon atoms, and having a curable site. (B) a copolymer having a functional group capable of co-crosslinking with the fluorine-containing copolymer (a) and a polyfluoroalkyl group having 3 or more carbon atoms, and (c) a filler. Sealant consisting of.