JP2725280B2 - Curable composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a curable composition containing a fluorine-containing copolymer and a curing agent.

[Prior Art] Conventionally, in the field of sealing materials and coating materials, it has been necessary to develop resins which are excellent in elasticity, excellent in weather resistance and can be cured at room temperature. In recent years, in addition to this, even if the above conditions are satisfied, for example, silicone resin, there is a problem of occurrence of contamination due to migration of a low molecular weight silicone oil or a plasticizer contained therein, and a demand for recoatability. Is also happening.

For example, taking a sealing material as an example, a non-stretchable oil-based caulking material has evolved into an elastic urethane-based or polysulfide-based material, and a more weather-resistant silicone has been developed. There is a drawback that the properties are remarkable. Accordingly, modified silicones having a skeleton of polyalkylene oxide having only a siloxane bond only at a cross-linking site have been developed. However, in some cases, the weather resistance and the like are insufficient, and it cannot be said that this is a satisfactory solution.

On the other hand, as a resin having high weather resistance and curability at room temperature, a fluoroolefin-vinyl ether copolymer is known and used as a coating composition or the like. The coating composition of the resin is excellent in weather resistance and has been recognized as having industrial benefits such as enhancing the durability of buildings.

However, resins having higher flexibility are desired for applications such as sealing materials, elastomers, waterproofing materials, adhesives, paints for PCM, elastic paints and the like which require higher stretchability as well as weather resistance as in the present invention. .

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and has the following polymerized units (1), (2) and (3),
A fluorine-containing copolymer having a number average molecular weight of 1,000 to 50,000, containing 20 to 70 mol% of the polymerized unit (1) and 1 to 30 mol% of the polymerized unit (2) based on all the polymerized units. And
Polymerized unit (1) and polymerized unit (2) for all polymerized units
Is a curable composition containing a fluorinated copolymer and a curing agent, wherein the curable composition is contained in a proportion of 30 mol% or more.

(1) Polymerized units based on fluoroolefin.

(2) a polymerized unit based on an ethylenically unsaturated compound copolymerizable with a fluoroolefin, and the polymerized unit is a polymerized unit having 5 or more ether bonds and containing a side chain having a curable site at the end, A polymerized unit whose curable site is selected from an active hydrogen-containing group, an epoxy group, an active halogen-containing group and a hydrolyzable silyl group.

(3) A polymerization unit other than the polymerization units (1) and (2) and based on an ethylenically unsaturated compound copolymerizable with a fluoroolefin.

The fluorinated copolymer in the present invention contains 20 to 70 mol% of a polymerized unit based on a fluoroolefin. Examples of the fluoroolefin include tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene, pentafluoropropylene, and the like having 2 to 6 carbon atoms, especially fluorocarbons having about 2 to 4 carbon atoms. Olefins are preferred.

Among them, perhaloolefins in which hydrogen is completely replaced by halogen are most preferred. On the other hand, if the amount of the polymerized units based on fluoroolefin is less than 20 mol%, sufficient weather resistance is not exhibited, and stains and the like may become remarkable in long-term use, which is not preferable. If the amount of the fluoroolefin is more than 70 mol%, good elasticity cannot be obtained, and adhesion to other materials cannot be obtained, which is not preferable. In particular, those containing 30 to 60 mol% of polymerized units based on fluoroolefin are preferred.

Further, the fluorinated copolymer in the present invention has one polymerized unit containing a side chain having at least five ether bonds.
It is contained at a ratio of 3030 mol%. Since this specific side chain is contained, an elastic body having good elasticity can be obtained. In particular, it is preferable that the terminal of this side chain is a curable site. It is considered that a cured product having a crosslinked bond formed based on the curable site at the side chain terminal exhibits particularly excellent elasticity due to the specific crosslinked structure.

Examples of the side chain having at least five ether bonds of the fluorinated copolymer in the present invention include polypropylene glycol chains, polyethylene glycol chains, and the like.
A side chain consisting only of an ether bond and a carbon-carbon bond,
Alternatively, it may contain another bond such as a urethane bond, an ester bond, or an amino bond. When the number of ether bonds in the side chain is smaller than 5, an elastic body having preferable elasticity cannot be obtained, and is not adopted. An elastic body having good elasticity can be obtained as the number of ether bonds in the side chain increases, but if the length is too long, weather resistance and stain resistance deteriorate, which is not preferable. Usually, the number of ether bonds,
40 or less, more preferably 30 or less is employed.

In addition, the space between the ether bonds is usually composed of an alkylene group such as a methylene group, an ethylene group, a propylene group, and a butylene group. It is not preferred because the water resistance of the coalesced product or the crosslinked product thereof may decrease. Those having a large number of carbon atoms between ether bonds have problems such as difficulty in synthesis, and are not usually preferably employed. Preferably, an alkylene group having about 2 to 6 carbon atoms such as an ethylene group or a propylene group is employed.

The alkylene chain may be one in which part or all of the hydrogen bonded to carbon is substituted with a substituent such as a halogen group such as fluorine or chlorine, an alkyl group, or an aryl group. In particular, in order to obtain a good elastic body, the number of ether bonds in the side chain is preferably 5 or more, and in order to obtain a material suitable for applications such as sealants, the number of ether bonds is preferably 10 or more. Adopted.

As described above, the specific side chain terminal is preferably 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.

Further, the polymerized unit containing the specific side chain is contained at a ratio of 1 to 30 mol%. When the content ratio of the polymerized unit containing the specific side chain is too small, it is not preferable because a good elastic body is not obtained or an elastic body cannot be obtained. On the other hand, if the amount is too large, the weather resistance may deteriorate or an elastic body may not be easily obtained, which is not preferable.
In particular, a fluoropolymer in which a weight unit containing a specific side chain is contained at a ratio of 5 to 30 mol% is preferable.

Further, the fluorine-containing copolymer in the present invention contains another polymerization unit in addition to the polymerization value based on the above-mentioned fluoroolefin and the polymerization 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 all the 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. The other polymerization unit is a polymerization unit based on a monomer copolymerizable with a fluoroolefin, and is a polymerization unit based on an ethylenically unsaturated compound such as a vinyl-based, allyl-based, acryloyl-based, and methacryloyl-based compound. By appropriately copolymerizing these monomers, a large number of polymerized units are included between polymerized units having a specific side chain, and elasticity is more effectively exhibited.

Further, such a fluorine-containing copolymer preferably has a molecular weight of about 50,000 or less. If the molecular weight is too large, the coating workability is not excellent when used as an elastic paint, which is not preferable. Particularly when used without a solvent, such as for sealants, those having a large molecular weight have extremely poor workability. When used without solvent, molecular weight 15,000 or less,
In particular, it is preferable to use one of 10,000 or less. The lower limit of the molecular weight is not particularly limited, but is usually 1,000 or more, preferably 2,000 or more.

The fluorine-containing copolymer in the present invention can be produced by the following method or the like.

First, 1) a fluoroolefin, 2) a monomer copolymerizable with a fluoroolefin and having at least 5 ether bonds, and 3) a monomer other than the above 1) and 2), which is copolymerizable with the fluoroolefin. A method of copolymerizing the obtained ethylenically unsaturated compound.

Second, ethylene other than (1) a polymerized unit based on a fluoroolefin, (4) a polymerized unit having a reactive group, and (3) a polymerized unit other than (1) and (4), which can be copolymerized with the fluoroolefin A fluorine-containing copolymer having a polymerized unit based on the unsaturated unsaturated compound is reacted with a compound having at least one ether bond and capable of reacting with a reactive group of the fluorine-containing copolymer. 1) ", a method of obtaining a fluorine-containing copolymer having" polymerized unit (2) obtained by reaction of polymerized unit (4) "and" (3) polymerized unit ".

In the second method, the number of ether bonds in the polymerized unit (2) is determined by comparing the “compound having at least one ether bond and capable of reacting with the reactive group of the fluorine-containing copolymer” with the “ The reaction with the "fluorine-containing copolymer" may result in 5 or more. The number of ether bonds in the “compound capable of reacting with the reactive group of the fluorine-containing copolymer” is preferably 5 or more.

Third, (1) a polymerized unit based on a fluoroolefin, (5) a polymerized unit having a hydroxyl group, and (3) a polymerized unit other than the polymerized units (1) and (5), and an ethylenically unsaturated polymerizable with the fluoroolefin. It has a polymerized unit based on a saturated compound, contains a polymerized unit (1) in a proportion of 20 to 70 mol%, a polymerized unit (5) in a ratio of 1 to 30 mol%, and has a polymerized unit (1) and Examples include a method in which an alkylene oxide is subjected to an addition reaction with a fluorine-containing copolymer containing a total of the polymerized units (5) in a proportion of 30 mol% or more.

In the first method, the monomer copolymerizable with the fluoroolefin and having at least five ether bonds is a polymerizable monomer having an ethylenically unsaturated group such as a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group. A monomer having an appropriate site (ethylenically unsaturated compound) is employed.

As such a monomer, one having at least five ether bonds is employed. Such a monomer having an ether bond can be synthesized by the following method. 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 reaction of alkylene oxide to hydroxyl group-containing monomer such as allyl alcohol How to make it. Monomers having a reactive group such as a hydroxyl group, an alkoxysilyl group, an epoxy group, or an amino group, and a polyether compound having a group capable of reacting with the above-mentioned reactive group such as an isocyanate group, an alkoxysilyl group, or a carboxylic acid group Can be exemplified.

In the first method, a monomer having at least 5 fluoroolefins and at least 5 ether bonds is added to each of the monomers.
When polymerized one by one, the possibility of alternate copolymerization is high, especially when the monomer having at least 5 ether bonds is a vinyl or allyl compound. In the case of alternating copolymerization, the number of other polymerization units existing between the polymerization units having at least five ether bonds becomes about one, and it becomes difficult for the polymer to exhibit good flexibility or elasticity.

Preferably, two or more different types of compounds are employed for either or both the fluoroolefin and the monomer having at least five ether bonds. Alternatively, a method of copolymerizing a comonomer copolymerizable with a fluoroolefin or a monomer having at least five ether bonds in addition to a monomer having at least five ether bonds may be employed. It is operated so that a large number of other polymerization units exist between the polymerization units having Usually, a method of copolymerizing the latter comonomer is employed.

Here, as the comonomer, a compound having a polymerizable site such as a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group is employed. Specifically, olefins,
Examples include vinyl ethers, vinyl esters, allyl ethers, allyl esters, acrylic esters, methacrylic esters, and the like. Especially 1 to 15 carbon atoms
Compounds having a degree of linear, branched or alicyclic alkyl groups are preferred. As such a comonomer, one in which part or all of the hydrogen bonded to carbon is replaced by fluorine may be used.

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 at least 5 ether bonds is 1 to 30 mol%.
It is preferable to control so that a monomer having at least 5 fluoroolefins and at least 5 ether bonds is copolymerized at a ratio of 30 mol% or more with respect to all polymerizable monomers.

Such polymerization may be performed by any of solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization.The polymerization is carried out by reacting a predetermined amount of monomer with a polymerization initiator such as a polymerization initiator or ionizing radiation. Done. Other conditions can be generally carried out under the same conditions as those for performing solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization and the like.

In the second method, the fluorine-containing copolymer is obtained by copolymerizing a fluoroolefin, a monomer containing a reactive group or a group-containing monomer capable of being converted into a reactive group and, if necessary, another comonomer. Can be synthesized. As the reactive group, a hydroxyl group, a carboxylic acid group, an amino group, a mercapto group,
Examples thereof include an active hydrogen-containing group such as an acid amide group, an epoxy group, an unsaturated group, a hydrolyzable silyl group, and an active halogen-containing group.

Here, as the reactive group-containing monomer, hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether, hydroxyalkyl vinyl ester, hydroxyalkyl allyl ester, glycidyl vinyl ether,
Glycidyl allyl ether, aminoalkyl vinyl ether, aminoalkyl allyl ether, aminoalkyl vinyl ester, aminoalkyl allyl ether, acrylic acid, methacrylic acid, allyl vinyl ether, etc. vinyl group, allyl group, acryloyl group, ethylenically unsaturated such as methacryloyl group A monomer having a polymerizable site consisting of a group (ethylenically unsaturated compound) is exemplified.

Examples of the group that can be converted into a reactive group include an ester group that can be hydrolyzed after polymerization. Further, the reactive group may be converted to another reactive group after polymerization, if necessary. For example, a hydroxyl group is reacted with a polycarboxylic acid or an anhydride thereof to convert to a carboxylic acid group, a hydroxyl group is reacted with silyl isocyanate to convert to a hydrolyzable silyl group, and an epoxy group is alkanolamine or phenol. Examples thereof include a method of reacting an acidic compound to convert it to a hydroxyl group, and a method of reacting an isocyanate alkyl methacrylic acid to a hydroxyl group to convert it to an unsaturated group.

Further, in synthesizing the fluorine-containing copolymer, a monomer similar to the comonomer described in the first method may be copolymerized. Further, the fluorine-containing copolymer has a polymerization unit (1) based on a fluoroolefin of 20 to 70 mol%, and a polymerization unit (2) obtained by changing the polymerization unit (4) by a reaction in an amount of 1 to 30 mol%. And the total of “polymerized unit (1)” and “polymerized unit (2) obtained by changing polymerization unit (4) by reaction” is 30 with respect to all polymerized units.
It is contained in a proportion of at least mol%. In the fluorine-containing copolymer, when each polymerized unit is not contained in the above ratio,
Production of the desired fluorinated copolymer becomes difficult.

Further, in the second method, by reacting "a compound having at least one ether bond and capable of reacting with a reactive group of a fluorine-containing copolymer" with "a fluorine-containing copolymer", A fluorinated copolymer having 5 or more ether bonds in the side chain can be produced.

In particular, when the polymerized unit having a reactive group of the fluorine-containing copolymer has an ether bond such as vinyl ether or allyl ether, or the ether bond is formed by a reaction between the fluorine-containing copolymer and a compound having an ether bond. When formed, even if the compound to be reacted is a compound having, for example, four ether bonds, a fluorine-containing copolymer having a polymerized unit containing a side chain having five ether bonds (that is, the above-mentioned present invention) Fluorinated copolymer). Further, when the polymerized unit having a reactive group does not have an ether bond, or when an ether bond is not generated by the reaction, the compound to be reacted is a compound having at least five ether bonds. The fluorinated copolymer of the present invention having a polymerized unit containing a side chain having at least 5 ether bonds can be produced.

As the compound to be reacted, it is preferable to react a compound having 5 or more ether bonds, particularly a compound having 10 or more ether bonds. Further, the group capable of reacting with the reactive group of the fluorine-containing copolymer can be appropriately selected depending on the type of the reactive group of the fluorine-containing copolymer.

Specific examples include an isocyanate group, a hydroxyl group, a carboxylic acid group, an epoxy group, an amino group, and a hydrolyzable silyl group. Such a compound can be usually synthesized by a method of reacting an addition polymer of an alkylene oxide with a terminal hydroxyl group, if necessary, with silyl isocyanate, a polycarboxylic acid or an anhydride thereof according to a conventional method. The reaction between the fluorine-containing copolymer and the compound having at least one ether bond and having a group capable of reacting with the reactive group of the fluorine-containing copolymer is performed per one reactive group of the fluorine-containing copolymer. It is desirable that the compound be reacted under more than one condition.

When the amount of the compound to be reacted is small, a cross-linked structure may be formed between the fluorine-containing polymers,
It is not preferable because subsequent handling may be complicated.

Examples of the compound having a group capable of reacting with the reactive group of the fluorine-containing copolymer include vinyl ethers, allyl ethers, alkylene oxide addition polymers, alkylene oxide addition polymers, alkanolamines, polyvalent isocyanate compounds, Isocyanate alkyl acrylate,
A reaction product with a compound such as silyl isocyanate or polycarboxylic anhydride is exemplified.

In the third method, the fluorinated copolymer is used in the second method.
It can be manufactured by a method similar to the method described in the above method. However, the fluorine-based copolymer preferably 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, glycidyl allyl ether, acrylic acid, etc.
When a monomer having a reactivity other than a hydroxyl group is copolymerized, it is necessary to convert the reactive group into a hydroxyl group. Conversion of a reactive group to a hydroxyl group can be easily achieved by reacting a compound such as an alkanolamine or a polyhydric alcohol.

The addition reaction of the alkylene oxide to the fluorine-based copolymer can be carried out in the same manner as in the production of ordinary polyether compounds. Further, in the third method, after performing the addition reaction of the alkylene oxide,
The hydroxyl group generated at the terminal of the side chain may be converted into another reactive group such as a carboxylic acid group or a hydrolyzable silyl group.

The fluorine-containing copolymer in the present invention, particularly a fluorine-containing copolymer having a curable site at a specific side chain terminal, and a composition containing a curing agent, to give a cured product having good elasticity, a sealant, It can be preferably used as a base for an elastic paint or the like.

Here, examples of the curing agent include a compound that reacts with the curable site of the fluorinated copolymer to form a crosslinking bond and a compound that promotes the reaction between the curable sites of the fluorinated copolymer. It is. Among them, a polyol-modified isocyanate compound is preferable because it gives a cured product having good elasticity. This compound has a terminal isocyanate group among the reaction products of the polyhydroxyl compound and the polyisocyanate compound.

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

The polyether polyol is, for example, one or two or more kinds selected from alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide, and cyclic ethers such as tetrahydrofuran, subjected to addition polymerization of 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-train 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 Nath, 1-methyl-2,4
-Diisocyanatocyclohexane, 1-methyl-2,6
-Diisocyanate cyclohexane, dicyclohexylmethane diisocyanate, triphenylmethane triisocyanate and the like.

These polyisocyanate compounds may be used alone or in combination of two or more. In addition, it is preferable to select a non-yellowing polyisocyanate compound because the discoloration is small.

Here, when the curing reactive site of the fluorinated copolymer is a hydrolyzable silyl group or a polyvalent isocyanate group, curing can be performed with moisture and the workability is excellent, so that it is preferable. When a polyvalent isocyanate compound is employed as the curing agent, the curable site of the fluorinated copolymer is preferably an active hydrogen-containing group, particularly a hydroxyl group, because of its excellent reactivity.

Further, in addition to the above two components, a filler, a solvent, a light stabilizer, an ultraviolet absorber, a heat stabilizer, a leveling agent, and the like may be added to the composition.

As fillers, 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, talc, titanium oxide, bentonite, Organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and shirasu balloon,
Fillers such as and the like; fibrous fillers such as asbestos, glass fibers and filaments can be used.

When it is desired to obtain a high-strength cured composition with these fillers, mainly fumed silica, precipitated silica, silicic anhydride,
Fillers selected from hydrous silicic acid, carbon black, surface-treated fine calcium carbonate, calcined clay, clay, activated zinc white, etc. are used in an amount of 1 to 200 parts by weight, based on 100 parts by weight of the fluorinated copolymer. If so, favorable results can be obtained.

In addition, when it is desired to obtain a cured composition having low strength and large elongation, a filler selected mainly from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, and shirasu balloon, etc. A fluorine-containing copolymer 10
If the amount is used in the range of 5 to 200 parts by weight relative to 0 parts by weight, preferable results can be obtained. Of course, these fillers may be used alone or in combination of two or more.

[Examples] In the following synthesis examples, Synthesis Examples 1 to 3 are synthesis examples of vinyl ether, Synthesis Examples 4 to 8 are synthesis examples of fluorine-containing copolymers,
Comparative Synthesis Examples 1 and 2 show Comparative Synthesis Examples of the fluorine-containing copolymer.

"Synthesis Examples 1 to 3" The amount of hydroxybutyl vinyl ether (HB
VE), were charged potassium hydroxide (concentration 95%) in inner volume 5 L stainless steel stirrer with pressure-resistant reactor was gradually added propylene oxide (PO), the predetermined time 3kg / cm ^2, 110 ℃, The reaction was performed. The obtained liquid was purified with synthetic magnesia to obtain a vinyl ether having a polyoxyalkylene chain. Table 1 shows the number of moles of PO added to each vinyl ether.

[Synthesis Examples 4 to 8, Comparative Synthesis Examples 1 and 2] A stainless steel pressure-resistant reactor with a stirrer having an inner volume of 550 ml was prepared.
112 g of xylene, 112 g of ethanol, 1.6 g of potassium carbonate and 0.5 g of azoisobutyronitrile were charged, and monomers having the compositions shown in Table 2 were polymerized.

In the polymerization, after charging monomers other than chlorotrifluoroethylene (CTFE) or tetrafluoroethylene (TFE), the residual air due to liquid nitrogen is removed, and then CTFE
Alternatively, TFE was introduced, the temperature was gradually raised to maintain the temperature at 65 ° C., and the reaction was continued under stirring for 10 hours, and then the polymerization was stopped by cooling the reactor with water. After the reactor was cooled to room temperature, unreacted monomers were withdrawn and opened from the reactor. After filtering the polymer solution, the solvent was removed with an evaporator to obtain a fluorinated copolymer.

The hydroxyl value (mgKOH / g) of the obtained fluorinated copolymer,
Tables 2 and 3 show the number average molecular weight and the glass transition temperature.

In addition, in the molecular weight measurement (using GPC) of the fluorine-containing copolymer in each of the synthesis examples, almost no peak was observed in the portion corresponding to the vinyl ether obtained in synthesis examples 1, 2, and 3. Is presumed to be copolymerized.

In Tables 2 and 3, CTFE is chlorotrifluoroethylene,
TFE is tetrafluoroethylene, EVE is ethyl vinyl ether, CHVE is cyclohexyl vinyl ether, HBVE is hydroxybutyl vinyl ether, VE2 is the vinyl ether of Synthesis Example 2, and VE3 is the vinyl ether of Synthesis Example 3.

The molar ratio of each polymerized unit in the fluorinated copolymer obtained in Synthesis Example 5 was: polymerized unit based on CTFE / polymerized unit based on EVE / polymerized unit based on VE2 = 50.0 / 49.0 / 1.0 mol%
The molar ratio of each polymerized unit in the fluorinated copolymer obtained in Synthesis Example 7 is as follows: polymerized unit based on CTFE / polymerized unit based on CHVE / polymerized unit based on VE2 = 50.0 / 49.0 / 1.0 mol% Met.

"Synthesis Example 9" 145 g of xylene, 145 g of ethanol, 33 g of EVE (ethyl vinyl ether), and HBVE (hydroxybutyl vinyl ether) were placed in a 550 ml stainless steel pressure-resistant reactor equipped with a stirrer.
5.5 g, 1 g of potassium carbonate, and 0.5 g of AIBN (azoisobutyronitrile) are charged, and dissolved air is removed by solidifying and degassing with liquid nitrogen.

After a while, 58 g of CTFE (chlorotrifluoroethylene)
And gradually raise the temperature. The reaction was continued under stirring at a temperature of 65 ° C., and after 10 hours, the reaction was stopped by cooling the reactor with water. After cooling to room temperature, unreacted monomer is withdrawn and the reactor is opened. After filtering the reaction solution, the solvent was removed with an evaporator to obtain a fluorinated copolymer.

Further, 1000 g of this fluorinated copolymer and 6 g of 95% strength potassium hydroxide were charged into a 5 liter stainless steel pressure-resistant reactor equipped with a stirrer, and PO (propylene oxide) 81
Add 6g gradually. The transparent bicolor liquid obtained by reacting at 3 kg / cm ² and 110 ° C. for 10 hours was purified with synthetic magnesia, whereby the number of moles of PO added was 20 moles per mole of hydroxyl groups in the fluorocopolymer. The desired fluoroolefin copolymer was obtained. The hydroxyl value of the obtained resin was 15 (mgKOH / g), the number average molecular weight by GPC was 10,000, and the glass transition temperature was -25 ° C.

"Synthesis Example 10" 100 g of polyoxypropylene diol having a molecular weight of 1,000
And dimethylsilyl diisocyanate (15 g) were mixed and reacted to obtain polyoxypropylene having a terminal isocyanate group. With respect to 100 g of the fluorine-containing copolymer obtained in Comparative Synthesis Example 1, the polyoxypropylene having the terminal isocyanate group was used.
By reacting 30 g, a fluorinated copolymer having a polyoxyalkylene chain was obtained.

"Examples 1 to 6, Comparative Examples 1 and 2" The fluorine-containing copolymers obtained in Synthesis Examples 4 to 9 and Comparative Synthesis Examples 1 and 2 were combined with a polyol-modified diisocyanate compound (trade name: DURAT D101; Asahi Kasei Corporation). Was added in an amount corresponding to NCO / OH = 1, and dibutyltin dilaurate 50 was used as a catalyst.
0 ppm was added and allowed to cure. The results of each test for breaking elongation, breaking strength, elastic modulus, surface tackiness and weather resistance of the cured product
Tables 1 to 5 show the results.

"Example 7" The fluorine-containing copolymer obtained in Synthesis Example 10 was cured with moisture. Table 4 shows the test results of the elongation at break, breaking strength, elastic modulus, surface tackiness, and weather resistance of the cured product.

"Comparative Example 3" A cured product was obtained in the same manner as in Example 1 except that polyoxypropylene triol having a molecular weight of 5,000 (hydroxyl value: 33.7 KOHmg / g) was used instead of the fluorinated copolymer. Table 5 shows the test results of the elongation at break, breaking strength, elastic modulus, surface tackiness, and weather resistance of the cured product.

"Comparative Example 4" was the same as Synthesis Example 4 except that the fluorine-containing copolymer obtained by adding 3 moles of ε-caprolactone per mole of hydroxyl group of the fluorine-containing copolymer of Comparative Synthesis Example 1 was used instead of the fluorine-containing copolymer. Similarly, a cured product was obtained. Table 5 shows the test results of the cured product.

"Comparative Example 5" Table 5 shows the results of tests of a commercially available modified silicone-based sealing material, which were tested for elongation at break, strength at break, elastic modulus, surface tackiness, and weather resistance.

In Examples and Comparative Examples, elongation at break, strength at break,
The elastic modulus was measured in accordance with JIS K-6301, and the surface tackiness was measured with a load of 100 g using Pictamac (Toyo Refinery). The weather resistance is the surface state after 1000 hours of sunshine weather o-meter (◎ indicates no change, ○ indicates slight decrease in gloss, but others indicate no problem, × indicates significant surface deterioration), elongation retention (Elongation at break after weathering test / Elongation at initial fracture × 100 (%)) was evaluated.

[Effect of the Invention] The fluorinated copolymer of the present invention has excellent weather resistance, and
Sealant, to give a cured product with excellent elongation
Very useful as an elastic paint base.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09D 127/12 C09D 127/12 175/04 175/04

Claims (1)

(57) [Claims] 1. The following polymerized units (1), (2) and (3)
Is a fluorine-containing copolymer having a number average molecular weight of 1,000 to 50,000, wherein a polymerization unit (1) is
20 to 70 mol%, containing 1 to 30 mol% of the polymerized unit (2), and the total of the polymerized unit (1) and the polymerized unit (2) is contained at a ratio of 30 mol% or more to all the polymerized units. A curable composition comprising a fluorine copolymer and a curing agent. (1) Polymerized units based on fluoroolefin. (2) a polymerized unit based on an ethylenically unsaturated compound copolymerizable with a fluoroolefin, and the polymerized unit is a polymerized unit having 5 or more ether bonds and containing a side chain whose terminal is a curable site; A polymerized unit whose curable site is selected from an active hydrogen-containing group, an epoxy group, an active halogen-containing group and a hydrolyzable silyl group. (3) A polymerization unit other than the polymerization units (1) and (2) and based on an ethylenically unsaturated compound copolymerizable with a fluoroolefin.