JPH05194668A - Vinylidene fluoride-fluorine-containing (meth)acrylic acid ester copolymer, its production and coating composition using the same - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer, good in water dispersibility and having excellent film-forming properties, etc., by copolymerizing vinylidene fluoride with a fluorine-containing (meth)acrylic acid ester and a specific ethylenically unsaturated compound in the presence of a radical polymerization initiator. CONSTITUTION:The objective copolymer is obtained by copolymerizing a mixture of (A) 5-90wt.% vinylidene fluoride with (B) 10-95wt.% fluorine-containing (meth)acrylic acid ester such as 2,2,2-trifluoroethyl (meth)acrylate expressed by the formula [X is 1-4C (fluoro)alkylene; R1 is H or methyl; Rf is 1-18C perfluoroalkyl or hydrofluoroalkyl] and (C) 0-60wt.% ethylenically unsaturated compound such as methyl meth)acrylate other than the component (A) or (B) in the presence of a radical polymerization initiator such as acetyl peroxide. This copolymer is excellent in gasoline resistance such as gasoline permeation resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer and a method for producing the same, more specifically, it is produced in an extremely high yield during synthesis and is water dispersible. Good film forming property,
The present invention relates to a vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer having mechanical strength such as transparency and tensile strength and excellent in gasoline resistance such as gasoline permeation resistance, and a method for producing the same.

Further, the present invention relates to a fluorine-containing coating composition containing a vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer, more specifically, weather resistance, durability, stain resistance and chemical stability. TECHNICAL FIELD The present invention relates to a fluorine-containing coating composition which has excellent properties such as properties and surface smoothness, has good adhesion to a substrate, and forms an excellent coating film.

[0003]

2. Description of the Related Art In recent years, gasoline-resistant rubber used as automobile parts tends to be used at higher and higher temperatures as a result of measures such as exhaust emission control measures and improvements aimed at improving engine performance. Excellent heat resistance and ozone resistance are required. Further, sour gasoline is oxidized due to an increase in engine operating temperature (referred to as gasoline containing peroxide that is generated by oxidation of gasoline. For details, refer to A. Nersasia.
n: Rubber and PlasticsNew
s, June 26 (1978). )
Occurs, and the problem of degrading rubber occurs, and sour gasoline resistance is required. Further, from the viewpoint of measures for preventing environmental pollution, regulations on hydrocarbon compounds evaporated from automobiles are becoming more strict, and it is required that the gasoline permeation resistance (difficult to permeate gasoline) is excellent.

Conventionally, as a rubber having gasoline resistance,
Butadiene-acrylonitrile rubber is known and widely used for applications such as hoses, gaskets, O-rings, packings and oil seals.

However, butadiene-acrylonitrile rubber is inferior in ozone resistance and inadequate in heat resistance and sour gasoline resistance, so that it cannot be used in an environment where it comes into contact with gasoline at high temperatures.

Fluorine rubber is also excellent in sour gasoline resistance, ozone resistance, heat resistance and gasoline permeation resistance (materials presented at the Tokai Branch of the Japan Rubber Association (Recent automobile for fluororubber "Viton") Demand from the industry "Showa Neoprene Co., Ltd. Tsuyoshi Sugimoto), is attracting attention as a gasoline-resistant rubber material.However, this fluororubber has poor flexibility at low temperatures and poor physical properties in normal state, making it difficult to handle. Since it is also very expensive, it is not versatile as a gasoline resistant rubber material.

Further, acrylic rubber is used as a rubber material having excellent oil resistance, heat resistance and ozone resistance, but such rubber is inferior in gasoline resistance, particularly gasoline permeation resistance, and is used around the engine of automobiles. It is unsuitable as a material to be used.

As a means for improving the physical properties of these rubber materials, for example, a vulcanized rubber composition composed of a mixture of acrylic multi-component copolymer rubber and vinylidene fluoride resin has been proposed (Japanese Patent Laid-Open No. 61-17665). Publication). This rubber composition is not only excellent in sour gasoline resistance, ozone resistance and heat resistance, but also has good normal state physical properties, good processability, and a gasoline resistance excellent in balance between gasoline resistance and cold resistance. It is attracting attention as a rubber material. However, the gasoline permeation resistance is insufficient to comply with the regulations on the evaporation of hydrocarbon compounds in automobiles, which are expected to become more severe in the future.

More recently, a copolymer composition of vinylidene fluoride and an acrylic ester has been proposed (Japanese Patent Laid-Open No. 63-182310). However, in the synthesis of such a copolymer, since the copolymerization reactivity of vinylidene fluoride and an acrylic ester is low, a sufficient polymer yield cannot be expected, which is a major obstacle to industrialization.

On the other hand, the fluorine-based paint is widely used not only for building materials but also for furniture, vehicles, etc. by utilizing its excellent weather resistance, corrosion resistance, chemical resistance and water repellency. However, most of the fluorine-based paints are solvent-based, and water-based fluorine-based paints that are convenient for environmental pollution prevention measures are desired.

As the water-based fluorine coating composition, for example, an aqueous dispersion of a homo- or copolymer of fluoro-olefin such as vinylidene fluoride, tetrafluoroethylene or hexafluoropropylene is commercially available. However, such a water-dispersible fluororesin has poor processability, for example, film formability,
Since a baking process at a high temperature is required, film defects such as pinholes are likely to occur. Further, there is a drawback that the adhesion to the substrate, the transparency, and the mechanical strength such as tensile strength are poor. For this reason, the fluororesin is used only for a limited number of purposes and is not yet widely used.

Under these circumstances, the vinylidene fluoride copolymer is widely used as a coating material, a lining material or a molding material because it has excellent properties such as weather resistance, stain resistance and corrosion resistance. .. However, since the vinylidene fluoride copolymer is thermally and chemically stable, it is insoluble or sparingly soluble in a solvent at room temperature, and it is necessary to perform baking coating under heating at 200 ° C. or higher in the coating process. .. For this reason, such a coating cannot be used for room temperature coating at a construction site, and line coating needs to be performed, and the range of use is limited. Also, 200 when painting
Heating above ℃ has a great influence on the coating substrate, and there is a problem that the substrate such as an aluminum building material is deformed. Further, there are drawbacks such that the dispersibility of the pigment and the adhesion to the base material are poor, and many of them are difficult to produce gloss.

In order to make up for such drawbacks, a copolymer prepared by copolymerizing four components of fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether and hydroxyalkyl vinyl ether has been proposed (Japanese Patent Publication No. 60-21686). .. This copolymer is characterized in that it is soluble in an organic solvent at room temperature and can be cured at room temperature by mixing a curing component. However, this paint is solvent-based and has problems such as odor and environmental pollution during painting.

[0014]

The object of the present invention is to produce a very high yield at the time of synthesis, to have good water dispersibility, to have excellent film formability, transparency and mechanical strength such as tensile strength. Further, it is to provide a vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer excellent in gasoline resistance such as gasoline permeation resistance and a method for producing the same. Further, another object of the present invention is that the aqueous dispersion is rich in film forming property at room temperature, can be dissolved and cured at room temperature even in an organic solvent, without impairing the original properties of the fluororesin, and has weather resistance, An object of the present invention is to provide a composition for a fluorine-containing coating material that has excellent properties such as durability, stain resistance, chemical stability, and surface smoothness, and has good adhesion to a substrate and forms an excellent coating film. ..

[0015]

Means for Solving the Problems The present inventors have produced an extremely high yield during synthesis, have good water dispersibility, and have excellent film forming properties, transparency, and mechanical properties such as tensile strength. In addition, as a result of diligent studies to obtain a copolymer excellent in gasoline resistance such as gasoline permeation resistance, a new vinylidene fluoride containing vinylidene fluoride and a fluorine-containing (meth) acrylic acid ester as essential constituents. The fluorine-containing (meth) acrylic acid ester copolymer has a particularly excellent gasoline permeation resistance as compared with a composition comprising a mixture of an acrylic multi-component copolymer rubber and vinylidene fluoride resin, Compared with vinylidene chloride / acrylic acid ester copolymer,
It was discovered that they are produced in an extremely high yield during synthesis, have good water dispersibility, and have excellent film-forming properties, transparency and mechanical strength. Furthermore, as a result of repeated studies of the composition containing the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer, the present inventors have found that, according to this composition, the film-forming property at room temperature as an aqueous dispersion is obtained. Rich in
It can be dissolved and cured at room temperature even in organic solvents. Furthermore, it does not impair the original characteristics of fluororesin and is weather resistant,
It has been found that excellent characteristics such as durability, stain resistance, chemical stability, and surface smoothness are obtained, and that the adhesiveness to a substrate is excellent, thereby forming an excellent coating film.

That is, the present invention comprises (A) a vinylidene fluoride unit of 5 to 90% by weight, (B) the following general formula (I):

[Chemical 4] The fluorine-containing (meth) acrylic acid ester unit represented by 10 to 95% by weight, and (C) the ethylenically unsaturated monomer other than the above (A) or (B) component 0 to 60% by weight, and the intrinsic viscosity (In N, N-dimethylacetamide at 25 ° C.) is 0.01 to 10 dl / g, and the bond of each unit is substantially random, and vinylidene fluoride / fluorine-containing (meth) acrylic acid is characterized. Ester copolymer; (A) Vinylidene fluoride 5 to 90% by weight,
(B) The following general formula (II):

[Chemical 5] Fluorine-containing (meth) acrylic acid ester 10
To 95% by weight and (C) a mixture of 0 to 60% by weight of an ethylenically unsaturated compound other than the component (A) or (B) described above are copolymerized in the presence of a radical polymerization initiator. Vinylidene fluoride / Fluorine content (meta)
Method for producing acrylic acid ester copolymer; (A) vinylidene fluoride unit 5 to 90% by weight, (B) the following general formula (I):

[Chemical 6] Vinylidene fluoride comprising 10 to 95% by weight of a fluorine-containing (meth) acrylic acid ester unit represented by and (C) 0 to 60% by weight of an ethylenically unsaturated monomer other than the component (A) or (B). A fluorine-containing coating composition containing a fluorine-containing (meth) acrylic acid ester copolymer is provided.

As described above, the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention is mainly composed of a vinylidene fluoride unit which is the component (A) and a fluorine-containing (which is the component (B) ( (C) as an optional component, though it is composed of a (meth) acrylic acid ester unit.
It can contain ethylenically unsaturated monomers.

The component (A) of the present invention has the following formula:

[Chemical 7] And vinylidene fluoride unit which is a repeating unit thereof in the copolymer of the present invention:

[Chemical 8] It is contained in the form of.

The component (B) of the present invention has the general formula (II) above.
And is contained in the copolymer of the present invention in the form of the fluorine-containing (meth) acrylic acid ester unit represented by the general formula (I).

The hydrofluoroalkyl group R _f in the above general formula (I) or (II) is represented by the following structural formula.

[Chemical 9]

Examples of the fluorine-containing (meth) acrylic acid ester represented by the above general formula (II) include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3.
3,3-pentafluoropropyl (meth) acrylate, 2,2,3,3,4,4,4-heptafluorobutyl (meth) acrylate, 2,2-difluoroethyl (meth) acrylate, 2,2,3 , 3-tetrafluoropropyl (meth) acrylate, 2,2,3,3
4,4-hexafluorobutyl (meth) acrylate,
Hexafluoroisopropyl (meth) acrylate,
3,3,3-trifluoropropyl (meth) acrylate and the like can be mentioned.

The component (C) of the present invention is an ethylenically unsaturated compound which is optionally used and is contained in the copolymer of the present invention in the form of a monomer. Examples of the ethylenically unsaturated compound include (i) methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-. Pentyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-methylpentyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-decyl (meth) ) Acrylate, n-dodecyl (meth) acrylate, (meth) acrylic acid alkyl ester such as n-octadecyl (meth) acrylate,
(Ii) 2-methoxyethyl (meth) acrylate, 2-
Ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, 2- (n-butoxy) ethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate (Meth) acrylic acid alkoxy-substituted alkyl esters such as 2- (n-propoxy) propyl (meth) acrylate and 2- (n-butoxy) propyl (meth) acrylate, (iii) alkylidene norbornene, alkenyl norbornene, dicyclopentadiene. , Non-conjugated dienes such as methylcyclopentadiene and its dimer, (iv) conjugated dienes such as butadiene and isoprene, (v) dihydrodicyclopentadienyl (meth) acrylate, dihydrodicyclopentadienyloxyethyl (meth). ) Dihydrodicyclopentadienyl group-containing (meth) acrylic acid ester compounds such as acrylates, (vi) vinyl benzyl chloride, vinyl benzyl bromide, 2-chloroethyl vinyl ether, 2
An active halogen-containing ethylenically unsaturated compound such as chloroethyl acrylate, vinyl chloroacetate, vinyl chloropropionate, allyl chloroacetate, allyl chloropropionate, chloromethyl vinyl ketone, 2-chloroacetoxymethyl-5-norbornene,
(Vii) Acrylic acid, methacrylic acid, crotonic acid, 2-
Carboxyl group-containing ethylenically unsaturated compounds such as pentenoic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, (viii) allyl glycidyl ether, epoxy group-containing ethylenically unsaturated compounds such as glycidyl (meth) acrylate, ( ix) The following formula:

[Chemical 10] A vinyl group-containing organosilicon-containing unsaturated compound represented by: (x) alkyl vinyl ketone such as methyl vinyl ketone, (xi) vinyl ethyl ether, alkyl vinyl and alkyl allyl ether such as allyl methyl ether, (xii) Vinyl aromatic compounds such as styrene, α-methylstyrene, chlorostyrene and vinyltoluene, (xiii) vinyl nitrile such as acrylonitrile and methacrylonitrile, (xiv) vinylamide such as acrylamide, methacrylamide and N-methylolacrylamide, (xv) Vinyl chloride, vinylidene chloride, alkyl fumarate, hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro (methyl Vinyl ether), perfluoro (propyl vinyl ether), vinyl acetate, unsaturated compounds such as ethylene and propylene, and the like.

The component (C) is copolymerized in the copolymer of the present invention in a small amount to introduce a crosslinkable functional group into the copolymer and modify the copolymer of the present invention to be crosslinkable. be able to. Further, the type and amount of the ethylenically unsaturated compound in the component (C) can be variously selected according to the purpose. In particular, in order to introduce a crosslinkable functional group, the compounds (iii) to (ix) are preferably used.

(A) and (B) in the copolymer of the present invention
The composition ratio of the component (C) is 5 to 90% by weight of the component (A), 10 to 95% by weight of the component (B) and 0 of the component (C).
To 60% by weight, and preferably (A) component 5 to 85
% By weight, 10 to 80% by weight of component (B) and 0.01 to 50% by weight of component (C).

If the amount of the component (A) is less than 5% by weight, the chemical resistance, weather resistance and the like are deteriorated. In the synthesis of the copolymer of the present invention, by using the component (B) as an essential component, the components (A), (B) and (C) can be copolymerized in an extremely high yield. At this time, (B)
When the component is present in a molar ratio of 2 times or more of the component (C), the conversion of vinylidene fluoride by polymerization is improved, and a high molecular weight polymer can be obtained in high yield.

The composition ratios of the above (A), (B) and (C) can be appropriately determined within the above range according to the properties of the intended fluoropolymer. For example,
When the component (C) is the crosslinkable monomer of the above (iii) to (ix), its content is preferably within the range of 0.1 to 10% by weight.

The vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention has a molecular weight of N,
It is usually 0.01 to 10 dl / g, preferably about 0.05 to 5 dl / g in terms of the intrinsic viscosity measured in N-dimethylacetamide at 25 ° C. Furthermore, when the copolymer of the present invention is used as a rubber elastomer, the Mooney viscosity (ML _{1 + 4} , 100 ° C.) is preferably 20 to 150.

In the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention, the vinylidene fluoride unit and the fluorine-containing (meth) acrylic acid ester unit are bonded substantially randomly, and generally, The glass transition temperature is 0 ° C or lower. The form of the copolymer of the present invention is not particularly limited, and it can be used as a solid, liquid or aqueous dispersion or solution depending on its application.

The vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention has a monomer composition of 5 to 90% by weight of the component (A), 10 to 95% by weight of the component (B) and (C). ) Ingredient 0-60% by weight, preferably 0-5
0% by weight of the mixture in the presence of a radical polymerization initiator,
It can be produced by a known method such as emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization, which is copolymerized by a batch, semi-continuous or continuous operation. Of the above polymerization methods, the preferred method for obtaining the copolymer of the present invention is emulsion polymerization.

Examples of the above-mentioned radical polymerization initiator used in producing the copolymer of the present invention include dialkyl peroxides such as acetyl peroxide and benzoyl peroxide, ketone peroxides such as methyl ethyl ketone peroxide and cyclohexane peroxide. , Hydrogen peroxide, t-butyl hydroperoxide,
Hydroperoxides such as cumene hydroperoxide, di-alkyl peroxides such as di-t-butylperoxide and dicumyl peroxide, t-
Butyl peracetate, alkyl peresters such as t-butyl perpivalate, azo compounds such as azobisinbutyronitrile and azobisvaleronitrile, ammonium persulfate, persulfates such as potassium persulfate, and the like.
If necessary, an inorganic reducing agent such as sodium hydrogen sulfite or sodium pyrosulfite, or an organic reducing agent such as cobalt naphthenate or dimethylaniline may also be used.

Copolymer reaction in producing the copolymer of the present invention
The response is generally -20 ° C to 120 ° C, preferably 0-12.
The temperature at the start of polymerization is generally 1 to 150 kg.
/cm ²G, preferably 10-100 kg / cm²G.
From the reaction mixture obtained by the above copolymerization reaction, chloride
Ordinary coagulation method using metal salts such as calcium,
Is usually a non-solvent such as ethanol or methanol
It is possible to recover the produced copolymer by the coagulation method of
It

In the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention, a cross-linking agent, a cross-linking accelerator, a reinforcing agent, a filler, a plasticizer, a softening agent, an anti-aging agent may be added, if necessary. Ordinary compounding agents such as a stabilizer, a foaming agent, a pigment, and a pigment dispersant can be appropriately mixed.

When the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention produced as described above is used as an elastomer, gasoline permeation resistance, heat resistance, ozone resistance and sour gasoline resistance are obtained. Since it is excellent, it can be used as various hoses that come into contact with fuel oil, hydraulic oil, lubricating oil, etc., such as automobile fuel system hoses, diaphragms, gaskets, O-rings, various seals such as oil seals. .. Further, it can also be used as various rolls or transmission belts, conveyor belts and the like which require oil resistance and solvent resistance for iron making, spinning, printing, paper making, dyeing and the like.

In addition, as a coating material for various paints, coating materials, etc., it can be used as a coating material for various paints and coating materials by taking advantage of the fact that it provides a tough sheet and a film-shaped molded product having excellent solvent resistance, weather resistance, transparency, flexibility and cold resistance. It can also be preferably used. For example, the aqueous dispersion of the copolymer of the present invention has excellent film-forming properties,
As it forms a film with excellent weather resistance, transparency, chemical resistance, adhesion to substrates, mechanical strength, etc., it can be used as a baking or normally dry coating, and also as a cationic electrodeposition coating, fiber treatment agent, paper processing. It can also be used as an agent, a floor coating agent, a carpet backing agent, a packing agent, a non-adhesive treatment agent, a sealant, a laminating agent, a water / oil repellent treatment agent and the like.

The coating composition of the present invention is obtained by subjecting the copolymer of the present invention to emulsion polymerization or suspension polymerization, and then discharging unreacted monomers to obtain vinylidene fluoride / fluorine-containing (meth) acrylic acid ester. In the aqueous dispersion of the copolymer, if necessary, pigments such as titanium oxide, iron oxide and zinc oxide, fillers such as calcium carbonate and silica, dispersants such as sodium polycarboxylate and sodium tripolyphosphate, hydroxyethyl cellulose , Thickeners such as polyether urethane, polysiloxane, antifoaming agents such as mineral oil, antifreezing agents such as ethylene glycol and propylene glycol, pH adjusting agents such as 2-amino-2-methyl-1-propanol, etc. It is obtained by blending a preservative and the like.

1 to 100 parts of the pigment is added to 100 parts of the aqueous dispersion of the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention.
Filler 0-100 parts, dispersant 0-10 parts, defoamer 0-5
Parts, antifreeze agent 0 to 10 parts, pH adjuster 0 to 10 parts and preservative 0 to 5 parts are preferably blended.

The coating composition of the present invention is prepared by polymerizing the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention, recovering it in solid form, and dissolving it in a solvent. , Pigments such as titanium oxide, if necessary
It can also be obtained by adding a wetting dispersant such as polyester, an anti-sagging agent such as silica, and a compounding agent such as a conventionally known defoaming agent. These compounding agents are 1 to 100 parts of pigment, 0 to 10 parts of wetting and dispersing agent, 0 to 10 parts of anti-sagging agent, and 100 parts of solution of vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer. Defoamer 0
It is preferable to mix it in a ratio of 5 parts.

The organic solvent for dissolving the coating composition of the present invention includes ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; methyl cellosolve, 1,4
Ethers such as dioxane and propylene glycol methyl ether are preferred.

In addition to the above-mentioned compounding agents, various additives such as a leveling agent and a curing agent may be added to the coating composition of the present invention. Further, a polymer other than the fluoroolefin copolymer, for example, acrylic, epoxy, urethane, or phenol-based polymer may be blended. These polymers can be blended within a range that does not impair the performance of the composition of the present invention, preferably 5 to 90 parts by weight, particularly preferably 10 parts by weight, per 100 parts by weight of the composition of the present invention.
-50 parts by weight are blended.

[0040]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Unless otherwise specified, parts and% in the examples mean parts by weight and% by weight, respectively.

Examples 1 to 10 and Comparative Examples 1 to 4 In a stainless steel autoclave with an internal capacity of 500 ml equipped with an electromagnetic stirrer, 250 g of deionized deoxygenated water and F-top EF-204 (trade name: manufactured by Shin-Akita Kasei Co., Ltd. 2.5 g of fluoroalkylcarboxylic acid salt-based surfactant) and 1.25 g of ammonium persulfate were charged, and the system was sufficiently replaced with nitrogen. Next, the monomers shown in Table 1 were charged into this autoclave, and copolymerized at 90 ° C. for 4 hours with stirring. Table 1 shows the polymerization pressures at the start of copolymerization and after 4 hours (at the end of copolymerization).

After the reaction was completed, the contents were cooled to room temperature, unreacted monomer gas was discharged, and then the latex contents were taken out. Then, the amount of solid content was measured, the latex was coagulated with an aqueous solution of calcium chloride, the obtained polymer was washed with water, and then dried at 50 ° C. under reduced pressure. The analysis results of the obtained polymer are shown in Table 1 and Table 2.

[0043]

[Table 1]

[Table 2]

The glass transition point (Tg) and melting point (Tm) shown in Table 2 were measured at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter (DSC). In Table 2, polystyrene is 100 ° C and SBR15 is
00 to -64 ° C and Tm of benzoic acid of 12
The correction values based on the values at 7.4 ° C and chloroform at -63.5 ° C are shown. Further, the intrinsic viscosity ([η]) is N, N-dimethylacetamide (DM
In A), it was measured under the condition of 25 ° C. Further, the solubility was determined by dissolving 1 g of the polymer in 100 ml of a solvent (methyl isobutyl ketone) and then filtering through a 200-mesh wire net, and determining whether or not the polymer remained on the wire net.

From the results shown in Table 2, the copolymers of the present invention each showed a single Tg, and a homopolymer of vinylidene fluoride having a Tm and solubility (Comparative Example 1) or a homopolymer of trifluoroethyl acrylate. It can be seen that it is completely different from the polymer (Comparative Example 3).

The infrared absorption spectrum of the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer produced in Example 2 is shown in FIG. This infrared absorption spectrum shows C of vinylidene fluoride near 1080 cm ^-1.
-Characteristic absorption due to stretching vibration of F bond, 1760 cm
Characteristic absorption due to stretching vibration of the C = 0 bond of the ester is shown near ^-1 . That is, from the infrared absorption spectrum, it can be confirmed that both the C—F bond of vinylidene fluoride and the C = 0 bond of ester are present in the copolymer of Example 2.

Further, DSC of the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of Example 2
The results of the measurement by are shown in FIG. In FIG. 2, (a) is DSC
The chart is shown, and (b) shows the differential chart. These charts show that there is a single and sharp glass transition peak at -2.0 ° C (after correction),
It can be seen that the copolymer of Example 2 is a single copolymer. Further, from the comparison between Examples 1 to 10 and Comparative Example 2, it is understood that the vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer is produced in an extremely high yield.

Examples 11 to 15 and Comparative Example 5 The minimum film forming temperature (MFT) of the latex of the copolymers of Examples 1 to 4 and 6 and the homopolymer of Comparative Example 1 was measured by a thermal gradient tester (Rigaku Kogyo). Table 11 as Examples 11 to 15 and Comparative Example 5, respectively. The lower the minimum film forming temperature (MFT), the better the film forming property.

Furthermore, the above-mentioned latex was added to a sample of 15 cm × 10.
It was poured into a container with a glass frame having a size of cm and a depth of 0.2 cm so that the film thickness after drying would be 0.06 cm, and dried at 50 ° C. for 24 hours. For the obtained film, transparency, visually evaluated for the presence of cracks,
Further, physical properties (tensile strength, breaking elongation, 100% modulus) were measured, and the results are also shown in Table 3.

[0050]

[Table 3]

From the results shown in Table 3, vinylidene fluoride
It can be seen that the fluorine-containing (meth) acrylic acid ester copolymer exhibits a much lower MFT than the vinylidene fluoride homopolymer and gives a film having excellent transparency. Copolymers of Examples 16 to 17 and Comparative Examples 6 to 8 and Examples 9 and 10 (hereinafter abbreviated as F / A copolymers), and an acrylic polymer of Comparative Example 4 (hereinafter AR).
Is abbreviated. ), Butadiene / acrylonitrile rubber (JSR N220S, manufactured by Japan Synthetic Rubber Co., Ltd., acrylonitrile content 41%: hereinafter abbreviated as NBR) and hydrogenated butadiene / acrylonitrile rubber (Zet).
pol 1020, manufactured by Nippon Zeon Co., Ltd., acrylonitrile content 45%, iodine value 25: hereinafter abbreviated as H-NBR. Each of the polymers was blended according to the formulation shown in Table 4 and crosslinked under the conditions shown in Table 4 to obtain a crosslinked rubber sheet. The gasoline permeation resistance of the obtained crosslinked rubber sheet was measured by the following method. Fuel C (toluene and isooctane 1:
After putting 100 ml of 1 (volume ratio) mixture, the lid was covered with a crosslinked rubber sheet. Next, the periphery was tightened with a stainless steel ring, and after confirming that FuelC did not leak, the cup was turned over so that FuelC could directly contact the crosslinked rubber sheet. In this state, the cup was allowed to stand, and the transpiration amount of Fuel C passing through the crosslinked rubber sheet was determined by measuring the weight of the cup. The measurement is performed at 20 ° C for 7 days,
The gasoline permeation coefficient per unit area, unit thickness and unit time was calculated from the weight loss values during the period in which a linear weight loss was observed from the 4th day to the 7th day. The results are shown in Table 4.

[0052]

[Table 4]

From the results shown in Table 4, it can be seen that the copolymer of the present invention has excellent gasoline permeation resistance.

Example 18 An autoclave made of stainless steel equipped with a stirrer was charged with 500 parts of deionized deoxygenated water, 1.25 parts of ammonium persulfate and 2.5 parts of ammonium perfluorooctanoate, and the system was thoroughly replaced with nitrogen. After that, 2, 2, 2-
15 parts of trifluoroethyl acrylate and 85 parts of vinylidene fluoride were charged, and copolymerized at 90 ° C. for 4 hours with stirring. After the reaction was completed, the content was cooled to room temperature and the unreacted monomer gas was discharged to obtain a fluoropolymer aqueous dispersion. This aqueous dispersion was coagulated, and the compositional ratio (% by weight) of the obtained polymer was measured by ¹⁹ F-NMR and ¹³ C-NMR. As a result, vinylidene fluoride / 2,2,2-
Trifluoroethyl acrylate was 85/15. Next, to 100 parts (solid content) of the obtained aqueous dispersion,
50 parts of titanium oxide as a filler, 2 parts of polycarboxylic acid sodium salt as a dispersant, 1 part of ethylene glycol as an antifreezing agent, 0.05 part of a preservative, 0.5 part of a defoaming agent and 2-amino-2-methyl. After adding 2 parts of -1-propanol and adjusting with water so that the solid content becomes 50%,
Using hydroxyethyl cellulose as a thickener, the viscosity of the coating was adjusted to 2000 cps. After thoroughly mixing with a mixing disper stirrer, the mixture was transferred to a vacuum degasser and degassed. Minimum film forming temperature (MF) of the obtained paint
When T) was measured using a thermal gradient tester (Rigaku Kogyo Co., Ltd.), the MFT was 35 ° C. An iron plate (JIS-G3141, SPCCD plate, 0.8 × 70 ×, degreased with xylene and an alkaline detergent)
150mm), the coating film after drying with an air spray gun is 1
It was applied so that the thickness would be 00 μm. The iron plate coated with the paint was dried at 150 ° C. for 15 minutes.

The following tests were carried out on the above coated iron plate. (A) Weather resistance test After being put in a fade meter for 100 hours, the initial value of gloss / gloss [gloss retention (%)] was determined, and the weather resistance was evaluated from this gloss retention (%) according to the following criteria. Gloss retention rate ◯: 100 to 80% △: 79 to 40% ×: 39% or less (B) Adhesion test After cross-cutting the coating film surface (2 mm square 10 × 10 pieces), a peeling test with an adhesive tape is performed. Carried out. Adhesion was evaluated according to the following criteria. Remaining number on cut surface ○: 100 to 80 △: 79 to 40 ×: 39 or less (C) Alkali resistance test According to JIS-K5400, a 5% sodium carbonate solution was used to test (40 ± 2 ° C). , 24 hours). (D) Volatile oil resistance According to JIS-K5400, it was tested using No. 2 volatile oil. (E) Acid resistance According to JIS-K5400, a test was conducted using 1% sulfuric acid (20 ± 1 ° C., 8 hours). Table 5 shows the test results of the above (a) to (e).

Examples 19 to 21 The amount of the charged monomers was 80 parts vinylidene fluoride and 20 parts 2,2,2-trifluoroethyl acrylate (Example 19), 50 parts vinylidene fluoride and 2,
50 parts of 2,2-trifluoroethyl acrylate (Example 20), 30 parts of vinylidene fluoride and 2,2,2-
70 parts of trifluoroethyl acrylate (Example 21)
A coating material was prepared in the same manner as in Example 18 except that the above was changed to and tested in the same manner as in Example 18. The composition ratio (% by weight) of the polymer was measured by ¹⁹ F-NMR and ¹³ C-NMR to find that vinylidene fluoride / 2,2,2-trifluoroethyl acrylate was 79/21 (Example 19), It was 46/54 (Example 20) and 22/78 (Example 21). The MFTs of the obtained coating materials were 27 ° C. (Example 19), 12 ° C. (Example 20), and 3 ° C., respectively.
C (Example 21). The test results are shown in Table 5.

Comparative Examples 9 and 10, except that the charged amount of the monomer was changed to 100 parts of vinylidene fluoride (Comparative Example 9) and 100 parts of 2,2,2-trifluoroethyl acrylate (Comparative Example 10). A paint was prepared in the same manner and tested in the same manner as in Example 18. The MFT of the obtained paint is 220 ° C, respectively.
(Comparative Example 9) and 0 ° C. (Comparative Example 10). The test results are shown in Table 5.

[0058]

[Table 5]

As is clear from the results shown in Table 5, the vinylidene fluoride homopolymer (Comparative Example 9) was inferior in adhesion, and the 2,2,2-trifluoroethyl acrylate homopolymer (Comparative Example 10) was poor. The weather resistance is poor. On the other hand, in the copolymers of Examples 18 to 21, the composition was controlled, and coatings excellent in weather resistance and adhesion were obtained. Further, MFT also shows an extremely low value as compared with the homopolymer of vinylidene fluoride, and it can be seen that the film forming property is excellent.

Examples 22 to 25 2,2,2-trifluoroethyl acrylate
A coating material was prepared in the same manner as in Examples 18 to 21 except that 2,2-trifluoroethyl methacrylate was used, and the coating material was tested in the same manner as in Example 18. The test results are shown in Table 6.

[0061]

[Table 6]

As is clear from the results shown in Table 6, the weather resistance is further improved by changing acrylate to methacrylate.

Examples 26 to 33 The fluoropolymer aqueous dispersions synthesized in Examples 18 to 25 were coagulated, the polymer was filtered off, washed with water and then 5
It was dried under reduced pressure at 0 ° C. Obtained fluoropolymer 10
0 part was dissolved in a mixed solvent consisting of 92.5 parts of cyclohexanone, 46.25 parts of methyl isobutyl ketone and 46.25 parts of n-butyl acetate at 65 ° C. to obtain a composition in solution. In this solution composition, titanium dioxide as a pigment,
A volume fraction of 20% was added to the solid content, and the mixture was stirred and dispersed by a ball mill to prepare a coating composition. This coating composition was applied to a steel sheet with a doctor blade having a gap of 150 μm, dried at room temperature and then cured for 1 week to obtain a coating film for coating. The obtained coating film was subjected to the above (b) adhesion test and the following (f) weather resistance test. (F) Weather resistance test A dew cycle tester is used to accelerate the deterioration of the coating film.
The gloss retention (%) after 00 hours was measured by a gloss meter. Gloss retention rate ◯: 100 to 80% Δ: 79 to 40% ×: 39% or less Table 7 shows the test results of the above (b) and (f).

Comparative Examples 11 and 12 The coatings containing the fluoropolymers obtained in Comparative Examples 9 and 10 were tested in the same manner as in Examples 26 to 33.
The test results are shown in Table 7.

[0065]

[Table 7]

As is clear from the results in Table 7, Example 2
The vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymers used in 6 to 33 were vinylidene fluoride homopolymers (Comparative Example 11) and fluorine-containing (meth) acrylic acid ester homopolymers (Comparative It can be seen that, as compared with Example 12), the weather resistance and the adhesion are excellent.

Example 34 A stainless autoclave with an internal volume of 5 liters equipped with a magnetic stirrer was charged with 2500 g of deionized deoxygenated water, 25.0 g of ammonium perfluorooctanoate, and 12.5 g of ammonium persulfate, and the system was sufficiently replaced with nitrogen. .. Next, 32.0 g of 2,2,2-trifluoroethyl acrylate and 64.0 g of vinylidene fluoride were charged into this autoclave, and the temperature was raised to 90 ° C with stirring. Thereafter, as the pressure decreased, 2,2,2-trifluoroethyl acrylate was continuously added at 120.0 g / hr while maintaining the pressure at 15 kg / cm ² · G, and the reaction was continued. After 5 hours, the feed of each monomer was stopped and 1.0 kg /
After continuing the reaction to cm ² · G, after cooling the autoclave to room temperature and discharging unreacted monomer gas,
A latex having a solid content concentration of 23.8% was obtained. Next, the latex was coagulated with an aqueous solution of calcium chloride, the obtained polymer was washed with water, then washed with ethanol, and dried at 50 ° C. under reduced pressure. The intrinsic viscosity ([η]) of the obtained polymer was 1.34 dl / g in N, N-dimethylacetamide (DMA) at 25 ° C. In addition, the composition ratio (% by weight) of the polymer is ¹⁹ F-NM
When measured by R and ¹³ C-NMR, vinylidene fluoride / 2,2,2-trifluoroethyl acrylate was 20/80. ¹³ C-NMR of the obtained polymer
The spectra are shown in Figures 3 and 4. Table 8 shows the attribution
Shown in.

[0068]

[Table 8]

Based on the ¹³ C-NMR spectra shown in FIGS. 3 and 4 and the attribution according to Table 8, the following formula was obtained in the obtained polymer.

[Chemical 11] It is clear that the structure represented by is randomly present.

[0070]

The vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of the present invention is produced in an extremely high yield during synthesis, has good water dispersibility, and has excellent film-forming properties.
It has transparency and mechanical strength such as tensile strength, and is excellent in gasoline resistance such as gasoline permeation resistance. Further, the copolymer of the present invention is a coating material such as various coating materials and coating materials, in order to provide a tough sheet or film-like molded article having excellent transparency, flexibility, solvent resistance, weather resistance and cold resistance. Can be suitably used as. Furthermore, since the copolymer of the present invention is excellent in gasoline permeation resistance, heat resistance, ozone resistance, and sour gasoline resistance, it has various oil resistance and solvent resistance, including automobile fuel parts such as hoses and diaphragms. It is also suitable as a rubber component. The copolymer of the present invention can also be used as a contact lens material by taking advantage of its excellent transparency, low refractive index and flexibility.

Further, the composition for fluorine-containing coating material of the present invention is an aqueous dispersion which has a good film-forming property at room temperature, can be dissolved and cured in an organic solvent at room temperature, and has the original characteristics of a fluororesin. Excellent properties such as weather resistance, durability, stain resistance, chemical stability, surface smoothness, etc.
In addition, the adhesiveness to the substrate is good, and an excellent coating film can be formed.

[Brief description of drawings]

FIG. 1 Vinylidene fluoride prepared in Example 2
It is a graph showing the infrared absorption spectrum of a fluorine-containing (meth) acrylic acid ester copolymer.

FIG. 2 is a graph showing a DSC chart of a vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer of Example 2 and a differential chart thereof.

FIG. 3 ¹³ C-of the polymer obtained in Example 34
It is a graph showing an NMR spectrum.

FIG. 4 ¹³ C-of the polymer obtained in Example 34
It is a graph showing an NMR spectrum.

Front page continuation (72) Inventor Hozumi Sato 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (3)

[Claims] 1. (A) a vinylidene fluoride unit of 5 to 90% by weight; (B) the following general formula (I): 10 to 95% by weight of a fluorine-containing (meth) acrylic acid ester unit represented by, and (C) 0 to 60% by weight of an ethylenically unsaturated monomer other than the above (A) or (B) component, Intrinsic viscosity (N,
In N-dimethylacetamide, 25 ° C) is 0.01 to 1
A vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer, wherein the bond of each unit is substantially random at 0 dl / g. 2. (A) 5 to 90% by weight of vinylidene fluoride, (B) the following general formula (II): Fluorine-containing (meth) acrylic acid ester 10
To 95% by weight, and (C) the above (A) or (B)
Of a vinylidene fluoride / fluorine-containing (meth) acrylic acid ester copolymer characterized by copolymerizing a mixture of an ethylenically unsaturated compound other than the components in an amount of 0 to 60% by weight in the presence of a radical polymerization initiator. Production method. 3. A vinylidene fluoride unit of 5 to 90% by weight, (B) the following general formula (I): A fluorine-containing (meth) acrylic acid ester unit of 10 to 95% by weight and (C) an ethylenically unsaturated monomer other than the component (A) or (B) of 0 to 60% by weight. A fluorine-containing coating composition comprising a vinylidene chloride / fluorine-containing (meth) acrylic acid ester copolymer.