JPH08283654A - Formation of stain-resistant coating membrane - Google Patents

Abstract

PURPOSE: To form an stain-resistant coating layer on a not-heat-resistant substrate by drying an aqueous dispersion of a fluororesin prepared by using a self-dispersible polyurethane resin under certain conditions. CONSTITUTION: In the presence of (A) a self-dispersible polyurethane resin and (B) (i) an ethylenically unsaturated monomer bearing a perfluoroalkyl and (ii) an ethylenically unsaturated monomer copolymerizable with the component (i) are polymerized in an aqueous medium to give an aqueous dispersion of a fluorine resin. This aqueous dispersion is applied to (C) a not-heat-resistant material. preferably paper, nenwoven fabric or polyvinyl chloride an dried at 50-100 deg.C. The component A is preferably a polyurethane resin having 0.03-0.1 equivalent, per 100 pts.wt. of the polyurethane resin on the solid basis, of hydrophilic groups, preferably carboxylic acid or sulfonic acid groups. The component i is preferably a compound of the formula [Rf is a 4-20C perfluoroalkyl; R1 is H, methyl; A is -Q- (Q is a 1-10C alkylene)].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluororesin antifouling coating on a non-heat resistant substrate. More specifically, it relates to a method for forming an antifouling coating film on a non-heat resistant substrate, which comprises drying an aqueous dispersion of a fluororesin obtained by using a self-dispersing polyurethane resin under certain conditions.

[0002]

2. Description of the Related Art Conventionally, an aqueous dispersion of a fluororesin containing a perfluoroalkyl group-containing ethylenically unsaturated monomer as a polymerized structural unit has been used for a substrate such as a textile product to have water repellency, oil repellency, stain resistance, etc. Has been used for the purpose of giving.

However, when a base material is coated with an aqueous dispersion of a fluororesin containing the above-mentioned perfluoroalkyl group-containing monomer, the strength of the formed film becomes low and the surface of the film-shaped base material must be coated. Was difficult.

For the purpose of overcoming this problem, a technique has been proposed in which an aqueous fluororesin dispersion is added to an aqueous resin having a high film-forming property to apply it to a substrate. However, in the above technique, the water-repellent and oil-repellent performance is usually insufficiently expressed, and when the amount of the fluororesin aqueous dispersion used to increase the water- and oil-repellent performance is increased, the film strength is lowered. there were.
Further, in this case, it is necessary to raise the temperature when drying the coated product, and it is difficult to apply the substrate when the substrate is non-heat resistant.

Therefore, there has been a demand for a method of forming an antifouling film which can be applied to non-heat resistant substrates.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for forming an antifouling coating on a non-heat resistant substrate which exhibits a high fluorine function even at a low drying temperature and is excellent in coating strength. The purpose is to do.

[0007]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above-mentioned circumstances, and as a result, by using an aqueous fluororesin dispersion obtained by a specific method, excellent antifouling property is obtained even at a low drying temperature. The inventors have found that a film can be formed and completed the present invention.

That is, the present invention provides a perfluoroalkyl group-containing ethylenically unsaturated monomer or a perfluoroalkyl group-containing ethylenically unsaturated monomer and the monomer in the presence of a self-dispersing polyurethane resin. A fluororesin aqueous dispersion obtained by polymerizing a copolymerizable ethylenically unsaturated monomer in an aqueous medium is applied to a non-heat resistant substrate and dried at a temperature of 50 to 100 ° C. Is a method for forming an antifouling coating on a non-heat resistant substrate, wherein the self-dispersing polyurethane resin preferably has a hydrophilic group of 0.03 to 0.00 per 100 parts by weight of the polyurethane resin solid content.
The present invention provides a method for forming an antifouling coating on a non-heat resistant substrate, which is a polyurethane resin containing 1 equivalent.

As the self-dispersing polyurethane resin used in the present invention, any conventionally known one can be used as long as it is a polyurethane resin having self-dispersibility in an aqueous medium. However, it is hydrophilic per 100 parts by weight of the solid content of the polyurethane resin. Those having 0.03 to 0.1 equivalents of groups are preferable. 0.
When a polyurethane resin having less than 03 equivalents of hydrophilic groups is used, a stable fluororesin dispersion cannot be obtained, and a polyurethane resin having more than 0.1 equivalents of hydrophilic groups cannot exist as a polyurethane resin. .

Examples of the hydrophilic group in this case include a carboxylic acid group, a sulfonic acid group and the like and salts thereof, a polyethylene oxide group and the like. The following anionic groups are preferred, and carboxylic acid groups and salts thereof are more preferred.

The raw material used for introducing a hydrophilic group into the polyurethane resin or the urethane prepolymer having a terminal isocyanate group according to the present invention has at least one active hydrogen atom in the molecule and has the above hydrophilic property. Examples thereof include compounds having a functional group.

Examples of the hydrophilic group-containing compound include 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid,
Sulfanilic acid, 1,3-phenylenediamine-4,6
-Sulfonic acid-containing compounds such as disulfonic acid and 2,4-diaminotoluene-5-sulfonic acid, and their derivatives or polyester polyols obtained by copolymerizing these; 2,2-dimethylolpropionic acid and 2,2 -Dimethylol butyric acid, 2,2-dimethylol valeric acid, dioxymaleic acid, 2,6-dioxybenzoic acid, 3,4-diaminobenzoic acid and other carboxylic acid-containing compounds, and derivatives or copolymers thereof. Examples thereof include polyester polyols, which may be used alone or in combination.

The self-dispersing polyurethane resin of the present invention is
It can be obtained by reacting an active hydrogen compound, a hydrophilic group-containing compound and polyisocyanate. The polyisocyanate is not particularly limited, but, for example, 2,4-tolylene diisocyanate, 2,
6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,
4'-diphenylmethane diisocyanate, 2,4'-
Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-
4,4'-biphenylene diisocyanate, 3,3'-
Dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate,
1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,
3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 3,3′- Dimethyl-4,4'-dicyclohexylmethane diisocyanate and the like can be mentioned.

As the active hydrogen-containing compound, a high molecular weight substance and a low molecular weight substance are usually used in combination. The high molecular weight product has an average molecular weight of 300 to 10,000, preferably 500 to 5,000.
And a low molecular weight compound refers to a compound having a molecular weight of 300 or less.

Examples of the high molecular weight compound include polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol, polyacrylate polyol, polyester amide polyol, polythioether polyol and the like.

As the polyester polyol, for example, ethylene glycol, propylene glycol, 1,3-
Propanediol, 1,4-butanediol, 1,5-
Pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (molecular weight 300 to 6,000), dipropylene glycol, Tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,
4-cyclohexanedimethanol, bisphenol A,
Glycol components such as hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3
-Cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid,
Naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid and anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p- (2-hydroxyethoxy) ) A polyester obtained by a dehydration condensation reaction with an acid component such as benzoic acid or an ester-forming derivative of these hydryloxycarboxylic acids. In addition, ε
-A polyester obtained by a ring-opening polymerization reaction of a cyclic ester compound such as caprolactone and a copolyester thereof can also be used.

Examples of the polyether include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, Glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconit sugar, trimellitic acid, hemimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, 1,2, With one or more compounds having at least two active hydrogen atoms such as 3-propanetrithiol as an initiator, ethylene oxide, propylene oxide, butyric acid, etc. Emissions oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and the like obtained by addition polymerization in a conventional manner one or more monomers such as cyclohexylene.

Examples of the polycarbonate polyol include compounds obtained by reacting glycols such as 1,4-butanediol, 1,6-hexanediol and diethylene glycol with diphenyl carbonate and phosgene.

The above-mentioned low molecular weight compound is a compound containing at least two or more active hydrogens in the molecule. Specifically, for example, a glycol component used as a raw material of polyester polyol; glycerin, trimethylolethane, trimethylol. Polyhydroxy compounds such as propane, sorbitol, pentaerythritol; ethylenediamine, 1,6-hexamethylenediamine, piperazine,
2,5-dimethylpiperazine, isophoronediamine,
4,4'-dicyclohexylmethanediamine, 3,3 '
Examples include amine compounds such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, 1,2-propanediamine, hydrazine, diethylenetriamine and triethylenetetramine.

The above polyisocyanates, active hydrogen-containing compounds and hydrophilic group-containing compounds may be used alone or in admixture of two or more. The content of hydrophilic group is
It is 0.03 to 0.1 equivalent per 100 parts by weight of the solid content of the polyurethane resin finally obtained, and if it is less than this, a stable fluororesin aqueous dispersion cannot be obtained, and if it is more than this, the polyurethane resin is Cannot exist as.

The method for producing the self-dispersing polyurethane resin aqueous dispersion according to the present invention may be any of the methods well known in the art, such as the following method.

An organic solvent solution or an organic solvent dispersion of a hydrophilic group-containing polyurethane resin obtained by reacting an active hydrogen-containing compound and a hydrophilic group-containing compound with polyisocyanate is added with an aqueous solution containing a neutralizing agent if necessary. A method of mixing to obtain an aqueous dispersion.

The hydrophilic group-containing terminal isocyanate group-containing urethane prepolymer obtained by reacting an active hydrogen-containing compound and a hydrophilic group-containing compound with a polyisocyanate is mixed with an aqueous solution containing a neutralizing agent, or in advance, the prepolymer. A method in which a neutralizing agent is added, water is mixed, dispersed in water, and then reacted with polyamine to obtain an aqueous dispersion.

The hydrophilic group-containing terminal isocyanate group-containing urethane prepolymer obtained by reacting an active hydrogen-containing compound and a hydrophilic group-containing compound with a polyisocyanate is mixed with an aqueous solution containing a neutralizing agent and a polyamine, or in advance. A method in which a neutralizing agent is added to a prepolymer and then mixed with an aqueous solution containing polyamine to obtain an aqueous dispersion.

The polyurethane resin and urethane prepolymer having terminal isocyanate groups according to the present invention are produced by the conventionally known method using the above raw materials. For example, the polyisocyanate and the active hydrogen-containing compound (including the hydrophilic group-containing compound) and the equivalent ratio of the isocyanate group and the active hydrogen group are 0.8: 1 in the case of the polyurethane resin, respectively.
˜1.2: 1, preferably 0.9: 1 to 1.1: 1, and in the case of terminal isocyanate group containing urethane prepolymers 1.1: 1 to 3: 1, preferably 1.
The reaction is carried out at a ratio of 2: 1 to 2: 1 at a temperature of 20 to 120 ° C, preferably 30 to 100 ° C.

These reactions can be carried out in the absence of a solvent, but an organic solvent can be used for the purpose of controlling the reaction of the reaction system or reducing the viscosity. The organic solvent is not particularly limited, but examples thereof include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetic acid esters such as ethyl acetate and butyl acetate; dimethylformamide, N- Examples include amides such as methylpyrrolidone. When such an organic solvent is distilled off from the finally obtained polyurethane resin aqueous dispersion, it is preferable to use an organic solvent having a relatively low boiling point, which is easily removed by distillation. Even when it is necessary to use an organic solvent having a boiling point of 100 ° C. or higher, it is preferable to keep the amount used to the minimum necessary.

In order to impart self-dispersibility to the hydrophilic group-containing polyurethane resin obtained by the above method, the hydrophilic group is neutralized with a neutralizing agent. Examples of the neutralizing agent include non-volatile bases such as sodium hydroxide and potassium hydroxide; tertiary amines such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine and triethanolamine, and volatile bases such as ammonia. To be The time for neutralizing the anionic group may be either during or after the urethanization reaction.

Examples of the chain extender that can be used in the production of the aqueous polyurethane dispersion of the present invention include polyamine and the like. Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, 3,
3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, aminopropylethanolamine, aminohexylethanolamine, aminoethylpropanolamine,
Examples thereof include diamines such as aminopropylpropanolamine and aminohexylpropanolamine; polyamines such as diethylenetriamine, dipropylenetriamine and triethylenetetramine; hydrazines; acid hydrazides, which may be used alone or in combination.

The aqueous polyurethane resin thus obtained may be used as it is, but it is also possible to use it by removing the organic solvent by distillation, if necessary. Various types of distillation apparatuses can be used for removing the organic solvent by distillation, but a distillation apparatus that does not release the distilled solvent and the organic solvent that has been distilled off to the atmosphere is preferable, and a thin-film evaporation apparatus is particularly preferable.

The perfluoroalkyl group-containing ethylenically unsaturated monomer used in the present invention is not particularly limited, and any known and conventional one can be used. For example, the general formula (I)

[0031]

Embedded image [Wherein R _f is a perfluoroalkyl group having 4 to 20 carbon atoms, R ₁ is —H or —CH ₃ , A is —Q—, —
_{CON (R 2) -Q -,} - SO 2 N (R 2) -Q -, ( where, -Q- is an alkylene group having 1 to 10 carbon atoms, R ₂
Is an alkyl group having 1 to 4 carbon atoms. Represents a perfluoroalkyl group-containing (meth) acrylate.

Specific examples of the perfluoroalkyl group-containing (meth) acrylate include the following compounds. That is, B-1: CF ₃ (CF ₂ ) _n CH ₂ CH ₂ OCOCH = CH ₂ (n = 5-11, average of n = 9) B-2: CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ OCOC ( CH ₃ ) = CH ₂ B-3: CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ B-4: (CF ₃ ) ₂ CF (CF ₂ ) ₆ (CH ₂ ) ₃ OCOCH = CH ₂ B-5: (CF ₃ ) ₂ CF (CF ₂ ) ₁₀ (CH ₂ ) ₃ OCOCH = CH ₂ B-6: CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOCH = CH ₂ B-7: CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ B-8: CF ₃ (CF ₂ ) ₇ SO ₂ N ( CH ₃ ) CH ₂ CH ₂ OCOCH = CH ₂ B-9: CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₄ OCOCH = CH ₂ B-10: CF ₃ (CF ₂ ) ₆ COOCH = CH ₂ B-11: CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₄ H ₉ ) (CH ₂ ) ₄ OCOCH = CH ₂ B-12: CF ₃ (CF ₂ ) ₇ CH ₂ CH (OH) CH ₂ OCOCH = CH ₂ B- 13: CF ₃ (CF ₂ ) ₅ CON (C ₃ H ₇ ) CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ B-14: CF ₃ (CF ₂ ) ₇ CON (C ₂ H ₅ ) CH ₂ CH ₂ Examples are monomers such as OCOCH = CH ₂ .

Other ethylenic monomers copolymerizable with the perfluoroalkyl group-containing ethylenically unsaturated monomer include, for example, ethylene, propylene, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene, vinyl acetate, Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-
Butyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, n
-Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate,
Dodecyl (meth) acrylate, hexadecyl (meth)
Acrylate, stearyl (meth) acrylate, is
o-stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, methyl vinyl ether, propyl vinyl ether, octyl Vinyl ether, butadiene,
Examples of the monomer include isoprene, chloroprene, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, and 3-chloro-2-hydroxy (meth) acrylate.

Further, a crosslinkable ethylenically unsaturated monomer can be used. Examples of the crosslinkable ethylenically unsaturated monomer include N-methylol (meth) acrylamide,
Glycidyl (meth) acrylate, diacetone acrylamide, or acetoacetoxyethyl acrylate, acetoacetoxyethyl methacrylate, acetoacetoxyethyl crotonate, acetoacetoxypropyl acrylate, acetoacetoxypropyl methacrylate, acetoacetoxypropyl crotonate, 2-cyanoacetoacetoxyethyl methacrylate , N- (2
-Acetoacetoxyethyl) acrylamide, N- (2
-Acetoacetoxyethyl) methacrylamide, allyl acetoacetate, vinyl acetoacetate and the like, acetoacetyl group-containing ethylenically unsaturated monomers, blocked isocyanate group-containing ethylenically unsaturated monomers represented by the general formula (II)

[0035]

Embedded image [In the formula, R ₃ is a hydrogen atom or a methyl group, and X is -OBO.
-(However, B is an alkylene group having 2 to 10 carbon atoms which may be substituted with a halogen atom or an alkyl group) or -NH-, Y is an isocyanate residue of an aromatic diisocyanate, Z is a hydrogen residue of a ketoxime. Is represented] and the like.

The perfluoroalkyl group-containing ethylenically unsaturated monomer can be used alone, but it is 40 to 40 parts by weight based on 100 parts by weight of the total amount of the ethylenically unsaturated monomers.
It is preferably 95 parts by weight. When the amount of the perfluoroalkyl group-containing ethylenically unsaturated monomer is less than 40 parts by weight, the fluororesin aqueous dispersion does not sufficiently exhibit the function as a fluororesin such as oil repellency, and when it is more than 95 parts by weight. However, it is not preferable because a stable fluororesin aqueous dispersion cannot be produced.

The amount of the polyurethane resin of the present invention to be used is not particularly limited, but it is not limited to the perfluoroalkyl group-containing ethylenically unsaturated monomer or the perfluoroalkyl group-containing ethylenically unsaturated monomer and the other copolymerizable therewith. It is usually 20 to 300% with respect to the total amount of ethylenically unsaturated monomers such as ethylenically unsaturated monomers, and in order to obtain a stable aqueous dispersion, 30% or more is preferable, and 40% or more should be used. Is particularly preferable. The amount of polyurethane resin used is 3
When the content is 00% or more, the functions of the fluororesin such as water repellency and oil repellency are not sufficiently exhibited, which is not preferable.

In the present invention, in addition to the polyurethane resin having self-dispersibility in the aqueous medium, various surfactants may be used supplementarily within the range such as low foaming property.

Examples of such surfactants include nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene sorbitol tetraoleate; sodium oleate. Fatty acid salts such as, alkyl sulfate ester salts, alkyl benzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, sodium alkane sulfonates, sodium alkyl diphenyl ether sulfonates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyls Anionic surfactants such as phenylsulfate; alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, alkyldimes Triethanolamine and the like cationic surface active agents.

As the method for polymerizing the fluororesin aqueous dispersion used in the present invention, known and conventional methods can be employed. For example, a method of dropping all or part of the ethylenically unsaturated monomer mixture into water containing a polyurethane resin having self-dispersing property in an aqueous medium and polymerizing the mixture by a polymerization initiation source, polyurethane having self-dispersing property in an aqueous medium. A method of dropping an aqueous dispersion of an ethylenically unsaturated monomer mixture preliminarily adjusted with a resin into water and polymerizing it with a polymerization initiator, in the presence of a polyurethane resin having self-dispersibility in an aqueous medium, an ethylenically unsaturated monomer Examples of the method include a method in which the body mixture is dispersed in water by a stirrer having a high shearing force, a mixer and polymerized by a polymerization initiation source.

Among these, in order to obtain a stable aqueous dispersion, it is preferable to prepare an aqueous dispersion of the monomer in advance with an emulsifying device having a high shearing force and polymerize it with a polymerization initiation source. As the emulsifying device in this case, a homogenizer having high shearing force, manufactured by Gorin Co., Microfluidizer, Nanomizer and the like are preferable.

Of course, an organic solvent may be added and used in order to improve the dispersibility of these monomers in water, and a polar solvent such as a ketone or glycol ether may be used as the organic solvent.

The polymerization initiation source is not particularly limited, but various polymerization initiators such as azo compounds and organic peroxides, and ionizing radiation such as ultraviolet rays or γ-rays may be employed.

As a method for coating the fluororesin aqueous dispersion according to the present invention on the substrate, any known method can be used. For example, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, cast coater, spray coater, curtain coater, calendar coater, extrusion coater, A rotary screen coater etc. are mentioned.

The present invention is characterized in that the above fluororesin aqueous dispersion is applied to a substrate and dried at a temperature of 50 to 100 ° C. If the drying temperature is less than 50 ° C., a sufficient fluororesin function will not be exhibited and the antifouling property of the film will not reach a useful level. On the other hand, if the temperature exceeds 100 ° C., the non-heat-resistant substrate cannot withstand heat, causing deformation, discoloration, etc., and there is no point in forming a practical antifouling film.

A thickener is added to the fluororesin aqueous dispersion in order to improve the workability when the fluororesin aqueous dispersion is applied to the base material, control the coating amount, and improve the adhesion of the resin to the base material. Is preferred.

As the thickener, any one having no problem in compatibility with the fluororesin aqueous dispersion such as anionic or nonionic can be used. For example, water-soluble polymers such as carboxymethyl cellulose and hydroxyethyl cellulose, acrylic emulsions and latexes containing a carboxyl group (usually called an alkali thickener), polyoxyethylene group-containing water-soluble resins and the like can be mentioned.

The base material for coating the fluororesin aqueous dispersion according to the present invention is not particularly limited, but paper,
Non-heat resistant base materials such as non-woven fabric, polyvinyl chloride (medium or soft), polypropylene, artificial leather, synthetic leather, and cloth made of ultrafine fibers can be mentioned. The present invention is an extremely effective method for these non-heat resistant substrates.

[0049]

EXAMPLES Next, the present invention will be described in detail with reference to Examples and Comparative Examples. All parts and% are based on weight unless otherwise specified. The names of the monomers used in the above detailed description of the invention were used as they were.

Synthesis Example 1 (Synthesis of Self-Dispersing Polyurethane Resin) In a 4-necked flask equipped with a thermometer, a stirrer and a reflux condenser, a polyester of 1,4-butanediol / adipic acid (OH value 56) was prepared. ) Is added under reduced pressure to 120-
Dehydrate at 130 ℃, then cool to 50 ℃ 1
3.6 parts of 1,4-butanediol, 65.6 parts of dimethylolpropionic acid and 733 parts of methyl ethyl ketone were added, and after sufficiently stirring and mixing, 300 parts of isophorone diisocyanate were added and heated to 70 ° C., 6 at this temperature
The reaction was carried out for a time to obtain a prepolymer solution having a terminal isocyanate group. Next, this prepolymer was cooled to 40 ° C. or lower, 49.5 parts of triethylamine was added, and the mixture was rapidly stirred and mixed, and subsequently 3805 parts of water was added to emulsify. Five minutes after the addition of water, 36.5 parts of hexamethylene diane were added to obtain an aqueous dispersion. The aqueous dispersion thus obtained was distilled under reduced pressure at 55 ° C. to obtain a semitransparent polyurethane aqueous dispersion having a solid content of 25%. (Hydrophilic group content polyurethane resin solid content 10
(0.04 equivalents per 0 parts by weight)

Synthesis Example 2 (Synthesis of Self-Dispersing Polyurethane Resin) In the same manner as in Synthesis Example 1, 713.8 parts of polytetramethylene glycol (OH value 112), 262 parts of 4,
An isocyanate terminated prepolymer was obtained from 4'-dicyclohexylmethane diisocyanate and 976 parts of acetone. This prepolymer is then added to 21
After adding 7.6 parts of a 25% aqueous solution of ethylenediamine and sodium vinyl sulfonate, 3957 parts of water was gradually added to obtain an aqueous dispersion. The aqueous dispersion thus obtained was distilled under reduced pressure at 55 ° C. to obtain a translucent polyurethane aqueous dispersion having a solid content of 20%. (0.03 per 100 parts by weight of hydrophilic group polyurethane resin solids)
Equivalent)

Synthesis Example 3 (Synthesis of Fluororesin Aqueous Dispersion Liquid) The following formulation liquid 1 and formulation liquid 2 were each heated to 50 ° C.,
Disperse evenly. After that, mix liquid 1 and mix liquid 2,
300 Kgf / cm ² with a homogenizer manufactured by Gorin Co.
It emulsified by the pressure of and obtained the monomer emulsion. This monomer emulsion was placed in a nitrogen-substituted four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, heated to 70 ° C., and 1.5 parts of ammonium persulfate was added with stirring. Polymerization reaction was carried out for 8 hours to obtain a stable dispersion without solid content sedimentation.
The average particle diameter of the fluororesin was 150 nm (light scattering method). (Polyurethane resin 43% based on perfluoroalkyl group-containing ethylenically unsaturated monomer or perfluoroalkyl group-containing ethylenically unsaturated monomer and ethylenically unsaturated monomer copolymerizable therewith)

<Blended liquid 1> B-1 190 parts Methyl methacrylate 15 parts 2-Hydroxyethyl methacrylate 3 parts N-methylol acrylate amide 2 parts Lauryl mercaptan 2 parts Acetone 100 parts <Blended liquid 2> Polyurethane aqueous solution of Synthesis Example 1 Dispersion 360 parts Water 328 parts

Synthesis Example 4 (Synthesis of Fluororesin Aqueous Dispersion Liquid) The following compounding liquid 3 and compounding liquid 4 were subjected to a polymerization reaction in the same manner as in Synthesis example 3 to obtain a stable dispersion without solid content sedimentation. .
The average particle diameter of the fluororesin was 400 nm (light scattering method). (Polyurethane resin 25% relative to perfluoroalkyl group-containing ethylenically unsaturated monomer or perfluoroalkyl group-containing ethylenically unsaturated monomer and ethylenically unsaturated monomer copolymerizable therewith) <Compound liquid 3> Said B-2 150 parts Stearyl methacrylate 90 parts Lauryl mercaptan 2 parts Dipropylene glycol monomethyl ether 100 parts <Formulation liquid 4> Polyurethane aqueous dispersion of Synthesis Example 2 300 parts Water 358 parts

Synthesis Example 5 (Synthesis of Fluororesin Aqueous Dispersion Liquid) Each of the above-mentioned blended liquid 1 and the following blended liquid 5 is heated to 50 ° C. and uniformly dispersed. Then, the compounding liquid 1 and the compounding liquid 5 are mixed, and 300 Kgf / c is obtained with a homogenizer manufactured by Gorlin Co.
The emulsion was emulsified at a pressure of m ² to obtain a monomer emulsion. This monomer emulsion was charged into a nitrogen-substituted four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, heated to 70 ° C., and 1.5 parts of ammonium persulfate was added with stirring. 8
The polymerization reaction was carried out for a period of time to obtain a stable dispersion without solid content sedimentation. Fluororesin average particle size 100 nm (light scattering method)
Met.

<Formulation Liquid 5> Sodium lauryl sulfate 4.2 parts Polyethylene glycol nonyl phenyl ether 8.4 parts Water 675 parts

Synthesis Example 6 (Synthesis of Fluororesin Aqueous Dispersion) Each of the above-mentioned blended liquid 3 and blended liquid 5 was heated to 50 ° C.,
Disperse evenly. After that, mix solution 3 and mix solution 5,
300 Kgf / cm ² with a homogenizer manufactured by Gorin Co.
It emulsified by the pressure of and obtained the monomer emulsion. This monomer emulsion was charged into a nitrogen-substituted four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, heated to 70 ° C., and 1.5 parts of ammonium persulfate was added with stirring. Polymerization reaction was carried out for 8 hours to obtain a stable dispersion without solid content sedimentation. The average particle size of the fluororesin was 120 nm (light scattering method).

Synthesis Example 7 (Synthesis of Fluorine Resin Aqueous Dispersion) The fluororesin aqueous dispersion synthesized in Synthesis Example 3 was adjusted to a solid concentration of 20% with water, and the viscosity was adjusted with a carboxyl group-containing acrylic emulsion and aqueous ammonia. To 5000 cps
Adjusted to.

Synthetic Example 8 (Synthesis of Fluororesin Aqueous Dispersion) The fluororesin aqueous dispersion synthesized in Synthetic Example 4 was adjusted to a solid concentration of 20% with water, and the viscosity was adjusted with a carboxyl group-containing acrylic emulsion and aqueous ammonia. To 3000 cps
Adjusted to.

Synthesis Example 9 (mixing of polyurethane resin and fluororesin emulsion) Polyurethane aqueous dispersion 24 synthesized in Synthesis Example 1 above
0 part, fluororesin emulsion 6 synthesized in Synthesis Example 5
After mixing 67 parts and 93 parts of water, the viscosity is 5000 cps with carboxyl group-containing acrylic emulsion and ammonia water.
Adjusted to.

Synthesis Example 10 (mixing of polyurethane resin and fluororesin emulsion) Aqueous polyurethane dispersion 20 synthesized in Synthesis Example 2
0 parts, fluororesin emulsion 8 synthesized in Synthesis Example 6
After mixing 00 parts, the viscosity was adjusted to 3000 cps with a carboxyl group-containing acrylic emulsion and aqueous ammonia.

Example 1 The fluororesin aqueous dispersion prepared in Synthesis Example 7 was coated on a soft vinyl chloride film with a bar coater, and the coating was carried out at 60 ° C. for 5 hours.
After drying for a minute, a film was formed. Resin adhesion amount is 3g / m ²
Met. The water contact angle of the resulting coating was 115 °. When Tabasco droplets were placed on the film surface and left at room temperature for 3 hours and then wiped off with a tissue paper, Tabasco could be completely removed without leaving behind.

Example 2 The fluororesin aqueous dispersion prepared in Synthesis Example 8 was coated on cardboard with a knife coater and dried at 80 ° C. for 3 minutes,
A film was formed. The resin adhesion amount was 5 g / m ² . Water and soybean oil were placed on the resulting film, but droplets of the water and soybean oil respectively rolled on the film and were not adsorbed on the film at all.

Example 3 The fluororesin aqueous dispersion prepared in Synthesis Example 8 was coated on a rayon nonwoven fabric with a rotary screen coater and dried at 100 ° C. for 5 minutes to form a film. The resin adhesion amount was 6 g / m ² . Water droplets placed on the formed film were not adsorbed on the film at all.

Comparative Example 1 The fluororesin aqueous dispersion prepared in Synthesis Example 9 was coated on a soft vinyl chloride film with a bar coater, and the coating was carried out at 60 ° C. for 5 hours.
After drying for a minute, a film was formed. Resin adhesion amount is 3g / m ²
Met. The water contact angle of the resulting film was 95 °. Also, when Tabasco droplets were placed on the coated surface and allowed to stand at room temperature for 3 hours and then wiped off with tissue paper, Tabasco could not be completely removed, leaving behind.

Comparative Example 2 The fluororesin aqueous dispersion prepared in Synthesis Example 10 was coated on cardboard with a knife coater and dried at 80 ° C. for 3 minutes to form a film. Resin adhesion amount is 5g / m2. Water and soybean oil were placed on the resulting film, but in both cases, droplets were adsorbed on the film and the surface was contaminated.

Comparative Example 3 The fluororesin aqueous dispersion prepared in Synthesis Example 9 was coated on a soft vinyl chloride film with a bar coater and dried at 120 ° C. for 5 minutes to form a film. The vinyl chloride film was resistant to heat treatment. It was transformed.

Comparative Example 4 The fluororesin aqueous dispersion prepared in Synthesis Example 7 was coated on a soft vinyl chloride film with a bar coater, and the coating was performed at 40 ° C. for 5 hours.
After drying for a minute, a film was formed. Resin adhesion amount is 3g / m ²
Met. The water contact angle of the resulting film was 50 °. Also, when Tabasco droplets were placed on the coated surface and allowed to stand at room temperature for 3 hours and then wiped off with tissue paper, Tabasco could not be completely removed, leaving behind.

[0069]

The method of the present invention can form a film exhibiting high antifouling property on a non-heat resistant substrate by using a specific aqueous fluororesin dispersion.

Claims (6)

[Claims] 1. In the presence of a self-dispersing polyurethane resin,
Perfluoroalkyl group-containing ethylenically unsaturated monomer,
Or, a fluororesin aqueous dispersion obtained by polymerizing a perfluoroalkyl group-containing ethylenically unsaturated monomer and an ethylenically unsaturated monomer copolymerizable with the monomer in an aqueous medium, Apply to non-heat resistant substrate, 50-1
A method for forming an antifouling coating on a non-heat resistant substrate, which comprises drying at a temperature of 00 ° C. 2. The self-dispersing polyurethane resin has a hydrophilic group of 0.03 per 100 parts by weight of the solid content of the polyurethane resin.
The method according to claim 1, wherein the polyurethane resin is contained in an amount of 0.1 equivalent. 3. The non-heat-resistant base material is one selected from the group consisting of paper, non-woven fabric, polyvinyl chloride, polypropylene, artificial leather, synthetic leather, and cloth made of ultrafine fibers. The method according to 1 or 2. 4. The method according to claim 1, wherein a thickener is used in combination with the fluororesin aqueous dispersion. 5. The method according to any one of claims 1 to 4, wherein the hydrophilic group is a carboxylic acid group or a sulfonic acid group. 6. A perfluoroalkyl group-containing ethylenically unsaturated monomer has the general formula (I): [However, R _f is a perfluoroalkyl group having 4 to 20 carbon atoms, R ₁ is —H or —CH ₃ , and A is —Q—, —C.
ON (R ₂ ) -Q-, -SO ₂ N (R ₂ ) -Q- (however-
Q- represents an alkylene group having 1 to 10 carbon atoms, and R ₂ represents an alkyl group having 1 to 4 carbon atoms]]. The method according to item 1.