JPS6331487B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a crosslinkable fluorine-containing copolymer with excellent solvent solubility. Conventional fluorine-containing polymers have been used for various purposes that take advantage of their excellent properties such as chemical resistance, weather resistance, stain resistance, and heat resistance. However, when using this fluorine-containing polymer in a room-temperature curing paint, for example, this fluorine-containing polymer has poor solubility in ordinary solvents, and even if it is soluble, the types of solvents that can be used are limited. and
Furthermore, since these solvents have high boiling points, they have the disadvantage that heat treatment at high temperatures is required to remove the solvent after coating. In order to solve the above-mentioned drawbacks, various fluorine-containing copolymers have been studied, and copolymers consisting of fluoroolefin, cyclohexyl vinyl ether, and other copolymerizable monomer components have been developed for the purpose of room-temperature-curing coatings. Combination has been proposed (Unexamined Japanese Patent Publication No. 1983-
No. 25414, JP-A-57-34107 and JP-A-57-
Publication No. 34108). However, all of the above-mentioned copolymers had insufficient heat resistance and stain resistance, and their solvent solubility was improved at the expense of the properties of fluorine-containing polymers. Therefore, the present inventors have developed a method that has sufficient heat resistance, weather resistance,
As a result of intensive research on fluorine-containing copolymers that have stain resistance, chemical resistance, good solvent solubility, and can be easily cured at room temperature when mixed with a curing agent, we have developed a fluorine-containing copolymer that has a specific structural unit. The inventors have discovered that an elementary copolymer satisfies the above-mentioned properties, and have completed the present invention. In other words, the gist of the present invention is the structural unit: (a) -CFX-CF ₂ - (X represents F or Cl) (b) (X ₁ and X ₂ are the same or different F or
CF ₃ , Y is H, Cl or F, n is 1-3m is 0
Indicates an integer of ~6. ) and (c) (Z is -OH or

[Formula] P represents an integer of 2 to 5. ) (excluding 2,2,3,3-tetrafluoropropyl vinyl ether in component (b)). The fluorine-containing copolymer according to the present invention usually contains 40 to 60 mol% of the component (a), and the monomer forming the basis of the component (a) is usually tetrafluoroethylene or chlorotrifluoroethylene. It is fluoroethylene. When the copolymer contains component (a) in an amount of 40 to 60 mol % as described above, the copolymer has good heat resistance and weather resistance. Specific examples of monomers that are usually the basis of component (b) are CH ₂ = CHOCH ₂ CF ₃ , CH ₂ =
CHOCH ₂ CF ₂ CF ₃ , CH ₂ = CHOCH ₂ (CF ₂ ) ₂ CF ₃ ,
CH ₂ = CHOCH ₂ (CF ₂ ) ₃ CF ₃ , CH ₂ = CHOCH ₂
(CF ₂ ) ₄ CF ₃ , CH ₂ = CHOCH ₂ (CF ₂ ) ₅ CF ₃ , CH ₂ =
CHOCH ₂ (CF ₂ ) ₆ CF ₃ , CH ₂ =
CHOCH ₂ CF ₂ CF ₂ H, CH ₂ = CHOCH ₂
(CF ₂ CF ₂ ) ₂ H, CH ₂ =CHOCH ₂ (CF ₂ CF ₂ ) ₃ H,

[Formula] CH ₂ = CHOCH ₂ CF ₂ CFHCF ₃ ,

[Formula] CH ₂ = CHOCH ₂ CF ₂ CF ₂ Cl, CH ₂ = CHOCH ₂ (CF ₂ ) ₄ Cl,
CH ₂ = CHOCH ₂ CH ₂ CF ₃ , CH ₂ =
CHOCH ₂ CH ₂ CF ₂ CF ₃ , CH ₂ = CHOCH ₂ CH ₂
(CF ₂ ) ₂ CF ₃ , CH ₂ =CHOCH ₂ CH ₂ (CF ₂ ) ₃ CF ₃ ,
CH ₂ = CHOCH ₂ CH ₂ (CF ₂ ) ₄ CF ₃ , CH ₂ =
CHOCH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ , CH ₂ = CHOCH ₂ CH ₂
(CF ₂ ) ₆ CF ₃ , CH ₂ =CHOCH ₂ CH ₂ CF ₂ CF ₂ H,
CH ₂ = CHOCH ₂ CH ₂ (CF ₂ CF ₂ ) ₂ H, CH ₂ =
CHOCH ₂ CH ₂ (CF ₂ CF ₂ ) ₃ H,

【formula】

CH ₂ = CHOCH ₂ CH ₂ CH ₂ CF ₂ CF ₃ , etc., and one or more of these may be used. In the general formula of component (b), cases where m is 4 or more and n is 7 or more are not advantageous in terms of physical properties or synthesis, and are therefore excluded, but it is of course possible to use these vinyl ethers. The amount of component (b) contained in the copolymer is 20
A range of 50 mol % is preferable in order to obtain good solvent solubility, heat resistance, and stain resistance. Specific examples of monomers that are the source of component (c) include CH ₂ = CHOCH ₂ CH ₂ OH, CH ₂ =
CHOCH ₂ CH ₂ CH ₂ OH, CH ₂ = CHO(CH ₂ ) ₄ OH,
_CH2 =CHO( _CH2 ) _5OH ,

【formula】

【formula】

【formula】

[Formula] etc., and one or more of these may be used. Since component (c) has the effect of crosslinking with the curing agent and curing the cured composition described below, the copolymer content of component (c) is determined as appropriate to satisfy the desired physical properties of the cured product. However, the range is usually preferably from 0.5 to 30 mol%, and more preferably from 2 to 20 mol%. In addition to the constituent components of the copolymer of the present invention, within a range (0.5 to 10 mol%) that does not deteriorate the physical properties of the copolymer,
CH ₂ = CF ₂ , CHF = CF ₂ , CH ₂ = CHF, CF ₂ =
CFCF ₃ , CF ₂ = CFOCF ₃ , CF ₂ = CFOCF ₂ CF ₃ ,
Fluorine-containing monomers such as CF ₂ = CFOC ₃ F ₇ and CH ₂ =
_{CHOCH3 , CH2} = _CHOC2H5 , _CH2 = _{CHOC3H7 ,}
It is also possible to copolymerize hydrocarbon monomers such as CH ₂ =CHOC ₄ H ₉ . The solvent solubility of the copolymer of the present invention is particularly influenced by the fluorine content of the fluoroalkyl group of component (b) among the constituent components. When the fluorine content of the fluoroalkyl group is low, the polymer of the present invention may be an ester solvent such as ethyl acetate, butyl acetate, isobutyl acetate, cellosolve acetate, acetone,
It dissolves well in ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbon solvents such as toluene and xylene can be used as diluents for these good solvents in a range of 0 to 80% by weight based on the good solvent. can. If the fluoroalkyl group has a high fluorine content, cyclic ethers such as tetrahydrofuran, which are more polar than the ester or ketone solvents, amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and methyl Easily dissolved in alcohols such as alcohol, ethyl alcohol, butyl alcohol. The solubility in a solvent is also influenced by the amount of component (c), and as the amount of component (c) increases, it becomes easier to dissolve in a polar solvent. The method for producing the copolymer of the present invention includes solution polymerization,
Any method such as suspension polymerization or emulsion polymerization can be used, and as a polymerization initiator, a persulfate such as ammonium persulfate or potassium persulfate, or a combination of the above persulfate and a sulfite such as potassium sulfite or sodium sulfite, and ( or) redox polymerization initiators using acidic sulfites such as acidic potassium and sodium sulfites, peroxide polymerization initiators such as di-i-propyl peroxydicarbonate, t-butyl peroxybutyrate, or benzoyl peroxide. , azo polymerization initiators such as azobisisobutyronitrile and the like are preferably used. The amount of polymerization initiator used is usually based on the total amount of the monomers mentioned above.
It is 0.01 to 5% by weight, preferably 0.05 to 1.0% by weight. The polymerization temperature is -20~150℃, preferably 5~
95℃, polymerization pressure 0-30Kg/cm ² G, preferably 10
Kg/cm ² G or less. The solvent used for solution polymerization is trichlorotrifluoroethane, 1,1,1,2-tetrachloro-
2,2-difluoroethane, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, propyl acetate, etc. are used depending on the solubility of the above-mentioned copolymer. Examples of emulsifiers in emulsion polymerization include ammonium salts and sodium salts of perfluorocarboxylic acid, ω-hydroperfluorocarboxylic acid, and the like. A cured composition can be prepared by combining the copolymer of the present invention and a curing agent. The curing agent added to such a curing composition reacts with hydroxyl groups and epoxy groups in the temperature range of -20°C to 200°C, and any curing agent can be used as long as it has a crosslinked structure, and the reaction temperature is not specified. A temperature range of 5 to 150°C is preferably used, except in certain cases. As examples of curing agents that react with hydroxyl groups and epoxy groups, the following curing agents can be used, but the curing agents are not limited thereto. Example of curing agent A compound having the following structural formula. (In the formula, MX _n+o represents BF ₄ , PF ₆ , SbF ₆ , m is an integer, and A represents an organic substituent.) AlCl ₃ , SbCl ₃ , BF ₃ , BCl ₃ , BeCl ₃ , FeCl ₃ ,
FeBr ₃ , TiCl ₄ , NnCl ₂ , PF ₅ , etc. Melamine resin, hexamethylol melamine obtained by methylolizing melamine, compounds obtained by etherifying methylol melamine with alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, etc. Urea resin, a compound formed by condensing urea and formaldehyde, and a compound having an epoxy group and an isocyanate group having the structural formula shown below. Product name “EPE-1359” (manufactured by Ciba Geigy) “QT-3476” (manufactured by Dow Chemical) Product name “Ebon 1031” “ERRA-0153” (manufactured by UCC) Product name “DEN438” (n=1.3) “DEN439” “Epicote 152” (n=0-1) “Epicote 154” (n=1.5 or more) Above (manufactured by Ciel Chemical Co., Ltd.) Tolylene diisocyanate (TDI) 3,3″-tolylene-4,4′-diisocyanate Diphenylmethane-4,4'-diisocyanate (MDI) Triphenylmethane-P,P′,P″-triisocyanate (TM) 2,4-trilene timer (TT) Naphthalene-1,5-diisocyanate Tris(4-phenyl isocyanate) thiophosphate Product name “Desmodur RF” (manufactured by Bayer) Crude (MDI) TDI trimer Dicyclohexamethane 4,4'-diisocyanate (HMDI) Hydrogenated TDI (HTDI) Meta-xylene diisocyanate (XDI) Hexahydrometa-xylene diisocyanate (HXDI) Hexamethylene diisocyanate (HMDI) OCN-CH ₂ CH 2 CH ₂ CH ₂ CH ₂ CH ₂ -NCO Trimethylpropane-1-methyl- ₂ -isocyano-4-kababamate Product name “Desmodur L” (manufactured by Bayer AG) Polymethylene polyphenyl isocyanate Product name "PAPI"3,3'-dimethoxy-4,4'-diphenyl diisocyanate Product name "DADI" Diphenyl ether-2,4,4'-triisocyanate Product name: “Desmodur TH” (manufactured by Vial) Product name: “Desmodur HH” (manufactured by Bayer AG) Additionally, maleic anhydride phthalic anhydride isophthalic acid Terephthalic acid Hexahydrophthalic anhydride (HHPA) Tetrahydrophthalic anhydride 3,6-endomethylenetetrahydrophthalic anhydride Tetrachlorophthalic anhydride 3,6-endodichloromethylenetetrachlorophthalic acid Adipic acid HOOC (CH ₂ ) ₄ COOH Sebacic acid HOOC (CH ₂ ) ₃ COOH Ethyleneamine group H ₂ N (CH ₂ CH ₂ NH) _o H N-Aminoethylpuperazine metaxylylenediamine 1,3-bis(aminomethyl)cyclohexane Paramethane diamine Metsphorone diamine Bis(4-amino-3-methylcyclohexital)methane Metaphenylenediamine 4,4'-diaminodiphenylmethane 4,4′-diaminodiphenyl sulfone Diaminodiphenyl ether melamine Pyromethic acid etc. The above curing agent can be used in an amount of 0.5 to 2 equivalents per functional group of the copolymer. At this time, it is also possible to use curing accelerators such as amine compounds and organometallic compounds. Pigments, viscosity modifiers, leveling agents, anti-gelling agents, ultraviolet absorbers, anti-scald agents, etc. can also be added to the copolymer of the present invention as a curing composition.
These can be mixed using equipment commonly used for mixing paints, such as a ball mill, sand mill, paint shaker, or triple roll. This curing composition can be cured in several minutes to several days by appropriately selecting the content of hydroxyl groups or epoxy groups, the type of curing agent, the curing temperature, etc. When using this composition as a coating material, It is possible to form a coating film with good heat resistance, stain resistance, chemical resistance, and weather resistance. This cured composition is used as an outdoor or indoor paint on metal, wood, concrete, glass, plastic, etc., and is used in fields that take advantage of the chemical resistance, weather resistance, stain resistance, heat resistance, etc. of the paint film. It will be done. Furthermore, since this cured composition has high transparency and a refractive index in the range of 1.35 to 1.45, it can also be used as a sheath material for optical fibers. In addition, this cured composition has a volume resistivity of 10 ¹³ to 10 ¹⁷ Ω・cm,
Since it has high triboelectric charging properties and good stain resistance, it is also useful as a carrier coating material for electronic copying machines. Next, the copolymer of the present invention and the composition using the same will be explained with reference to Examples and Comparative Examples. Example 1 A 1000 ml glass autoclave was charged with 350 g of ion-exchanged water and 1 g of sodium carbonate, and after the space was sufficiently replaced with nitrogen gas to remove oxygen, 180 ml of trichlorotrifluoroethane was charged.
Next, 25.5 g of 2,2,2-trifluoroether vinyl ether, hydroxybutyl vinyl ether
5.8g and 30g of fluorotrifluoroethylene were charged. The mixture was heated to 45° C. with stirring, and 0.35 g of diisopropyl peroxydicarbonate was added as a polymerization initiator, followed by polymerization at the same temperature for 8 hours. Pressure at the start of polymerization is 2.1Kg/m ² G, after completion of polymerization
It was 0.2Kg/m ² G. The polymer was dissolved in trichlorotrifluoroethane, and this was added to petroleum ether with stirring to reprecipitate it. After that, the polymer was dried under reduced pressure to obtain 48 g of polymer (polymerization rate
80%). The intrinsic viscosity [η] of the obtained polymer at 35°C in methyl ether ketone is 0.33 (dl/g), and the thermal decomposition temperature (temperature at which weight loss is 5% in air at a heating rate of 10°C/min)
is 370℃, and the glass transition temperature measured using a differential scanning calorimeter (hereinafter referred to as DSC) (heating rate 10℃/
minute) was 53°C. In addition, the obtained polymer was subjected to infrared absorption analysis and the presence of hydroxyl groups was confirmed.The hydroxyl groups were quantitatively determined using the acetic anhydride-pyridine method (JIS K0070), and it was found that 10 hydroxybutyl vinyl ethers were present in the copolymer. Hydroxyl groups were present corresponding to the mole % content. The overall composition of the copolymer was analyzed by elemental analysis and found to be 31.7% carbon, 42.9% fluorine,
The chlorine content was 15.0%, and the resulting copolymer was found to be a copolymer of approximately chlorotrifluoroethylene/trifluoroethyl vinyl ether/hydroxybutyl vinyl ether = 5/4/1 (mol). Examples 2 to 15 Each monomer shown in Table 1 was copolymerized in the same manner as in Example 1. Table 1 shows the composition, intrinsic viscosity, thermal decomposition temperature and glass transition temperature of the obtained copolymer.
Shown below.

【table】

[Table] Comparative Examples 1 to 11 In the same manner as in Example 1, each monomer shown in Table 2 was copolymerized. Table 2 is the same as the composition, intrinsic viscosity, thermal decomposition temperature and glass transition temperature of the obtained copolymer.
Shown below.

【table】

[Table] The constituent monomers of each copolymer in Tables 1 and 2 are abbreviated as follows. CTFE=chlorotrifluoroethylene 3FVE=2,2,2-trifluoroethyl vinyl ether 4FVE=2,2,3,3-tetrafluoropropyl vinyl ether 5FVE=2,2,3,3,3-pentafluoropropyl vinyl ether 6FVE= 2,2,3,4,4,4-hexafluorobutyl vinyl ether 7FVE=2-trifluoromethyl-2,3,
3,3-tetrafluoropropyl vinyl ether 8FVE=2,2,3,3,4,4,5,5-
Octafluoropentyl vinyl ether 13FVE=2,2,3,3,4,4,5,5,
6,6,7,7,7-tridecafluorononyl vinyl ether TFE = Tetrafluoroethylene HBVE = Hydroxybutyl vinyl ether GVE = Glycidyl vinyl ether MVE = Methyl vinyl ether EVE = Ethyl vinyl ether PrVE = Propyl vinyl ether BVE = Butyl vinyl ether iBVE = Isobutyl vinyl ether Implementation As is clear from comparing the glass transition temperature and thermal decomposition temperature of the copolymers shown in the examples and the copolymers shown in the comparative examples, the fluorine-containing copolymers of the present invention have excellent heat resistance properties. Next, Examples of cured compositions will be shown to explain the features of the copolymer of the present invention. Example 16 The copolymer obtained in Example 1 was dissolved in a mixed solvent of methyl ether ketone and butyl acetate (weight 1/1) so that the copolymer content was 20% by weight. Dismodule, which is a hexamethylene diisocyanate trimer, per 100 parts by weight of the solution.
After adding 7 parts by weight of TP-KL5-2444 (manufactured by Sumitomo Bayer) and 1 part by weight of triethylamine and mixing thoroughly, spray painting was performed on a 0.5 mm steel plate treated with zinc phosphate (Nippon Tent Panel Co., Ltd.), and the mixture was heated at room temperature for 3 minutes. Allowed to harden for days. The resulting cured coating has a thickness of
It was a hard, glossy 33μ film. Table 5 shows the chemical resistance, solvent resistance, boiling water resistance, and stain resistance of the paint films obtained in Examples 16 to 29 and Comparative Examples 12 to 19. Examples 17-29 Paint films were obtained in the same manner as in Example 16 using the curing agents and copolymers shown in Table 3.

【table】

[Table] Comparative Examples 12 to 19 The following coating film samples were prepared in the same manner as in Example 16.

【table】

[Table] ◎ Excellent ○ Good △ Bad × Significantly poor.
The results show that it has excellent chemical resistance, solvent resistance, and stain resistance.

Claims (1)

[Claims] 1 Structural unit: (a) -CFX -CF ₂ - (X represents F or Cl) (b) (X ¹ and X ² are the same or different F or
CF ₃ , Y represents H, Cl or F, n represents an integer of 1 to 3, and m represents an integer of 0 to 6. ) and (c) (Z is -OH or [Formula] p represents an integer of 2 to 5.) (However, component (b) excludes 2,2,3,3-tetrafluoropropyl vinyl ether), and ( a) unit, (b) unit and (c) unit are 40 to 60 mol%, 20 to 50 mol% and
A fluorine-containing copolymer having a content of 0.5 to 30 mol%.