JPH1060058A - Fluororesin for coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin, excellent in solubility in solvents, weather resistance, cross-linking characteristics and further adhesion to various substrates and usable as a vehicle for a curable type fluororesin coating material by efficiently grafting an acrylic or a methacrylic resin onto a fluororesin. SOLUTION: This fluororesin for a coating material is obtained by carrying the grafting reaction of (A) 100 pts.wt. fluorine-based copolymer prepared by copolymerizing a fluoroolefin with a monomer having a peroxy group with (B) 1-200 pts.wt. hydrocarbon-based monomer using the peroxy group of the component A as a starting point. The resultant resin is soluble in organic solvents having hydroxyl group, carboxyl group or an alkoxysilyl group. Thereby, a coating film formed of a coating material prepared from the resin has a high surface hardness and is hardly damaged due to good adhesion to various coating films and capable of producing remarkable effects such as excellent weather and fouling resistances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororesin for a paint which is soluble in an organic solvent.

[0002]

2. Description of the Related Art Conventionally, fluororesin coatings utilizing the excellent weather resistance of a fluorocopolymer have been industrialized. Particularly recently, a solvent-soluble fluorine-based copolymer having a cured site has been synthesized (for example, JP-A-57-34107, JP-A-61-57609, etc.), and is used for construction, automobile, and chemical. It is widely used as a weather-resistant paint in fields such as industry. The main components of these coating resins are chlorotrifluoroethylene, tetrafluoroethylene, vinylidene fluoride, etc., as a fluorine-based raw material, and a hydrocarbon-based monomer such as vinyl carboxylate or vinyl ether as a copolymer component. It has increased solubility.

On the other hand, from the viewpoints of industrial economy, adhesion to a substrate, and hardness of a coating film, research and development of graft reaction to a fluororesin (for example, JP-A-59-41315, JP-A-61- 247717, JP-A-62-2
No. 95914), but the reactive double bond contained in the fluororesin is often copolymerized with a graft monomer, so that many low-molecular-weight non-grafted substances are formed or the reaction is multi-staged. There are still problems to be solved, such as insufficient economic merit. Examples of grafts of fluorine-containing acrylic resins (Japanese Patent Application Laid-Open No. 61-436)
No. 67, Japanese Unexamined Patent Publication No. 02-58513) have also been reported, but have the disadvantage that the raw materials are expensive and the weather resistance is not sufficient. Further, Japanese Patent Application Laid-Open No. 58-206615 reports graft polymerization in which a peroxy group is contained in a fluororesin, but the graft monomer is also a fluororesin, which has disadvantages in solubility and economic merit as a paint resin. Was left.

[0004] Japanese Patent Application Laid-Open No. 6-25595 discloses that
Graft resin obtained by graft copolymerization of methyl methacrylate, ethyl acrylate and hydroxyethyl methacrylate on a vinylidene fluoride polymer having a peroxy group obtained by copolymerizing vinylidene fluoride and t-butyl peroxyallyl carbonate Discloses a coating composition comprising polyvinylidene fluoride, an acrylic resin and a solvent.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a fluororesin used as a vehicle for a curable fluororesin paint, which has excellent solvent solubility, weather resistance, crosslinking properties, and adhesion to various substrates. Provide highly efficient fluororesin.

[0006]

Means for Solving the Problems The present inventors have studied a method for producing a solvent-soluble fluororesin by copolymerizing a hydrocarbon monomer with a fluoroolefin,
When a hydrocarbon monomer is further copolymerized with a solvent-soluble fluororesin in which a peroxy group has been introduced into a fluorine-based copolymer in advance by graft polymerization using the peroxy group as a starting point, solvent solubility and weather resistance can be improved. The present inventors have found that a fluororesin for coatings having excellent production properties, excellent cross-linking properties, and excellent adhesion to various substrates can be obtained, and the present invention has been completed.

That is, according to the present invention, 100 parts by weight of a fluorine-based copolymer [A] obtained by copolymerizing a fluoroolefin and a monomer having a peroxy group, and a hydrocarbon-based monomer [B]
An organic solvent having a hydroxy group, a carboxyl group, or an alkoxysilyl group, which is obtained by subjecting 1 to 200 parts by weight to a graft reaction using a peroxy group of a fluorine-based copolymer [A] as a starting point. It is a fluorine resin for paint that is soluble in water.

Hereinafter, the present invention will be described in detail. In the structural unit based on the fluoroolefin of the fluorine-based copolymer [A] according to the present invention, at least one of the hydrogen atoms of ethylene is substituted with a fluorine atom, and the other one to three hydrogen atoms are optionally halogen (fluorine). , Chlorine, bromine), fluoromethyl groups, difluoromethyl groups, trifluoromethyl groups, and other substituted fluoroolefins, such as chlorotrifluoroethylene, tetrafluoroethylene, vinylidene fluoride, fluoride Examples thereof include vinyl, trifluoroethylene, hexafluoropropene, and hexafluoroisobutene, and chlorotrifluoroethylene is particularly preferable. These may be used in combination of two or more. The copolymerization ratio of the fluoroolefin in the fluorine-based copolymer [A] is not necessarily limited, but is not preferably 20 mol% or more, preferably 40 mol%, of the total amount of the monomers, since a decrease in weather resistance is not preferred.
Mol% or more, preferably 70 mol% or less, more preferably 60 mol% or less, in order to maintain solvent solubility.

Examples of the monomer having a peroxy group used for the fluorine-based copolymer [A] include various unsaturated peroxyesters or peroxycarbonates. Specifically, t-butylperoxymethacrylate, Di (t-butylperoxy) fumarate, t-
Butylperoxycrotonate, t-butylperoxyallylcarbonate, t-hexylperoxyallylcarbonate, 1,1,3,3-tetramethylbutylperoxyallylcarbonate, t-butylperoxymethallylcarbonate, 1,1,3,3- Examples thereof include tetramethylbutyl peroxymethallyl carbonate, p-menthane peroxyallyl carbonate, p-menthane peroxymethallyl carbonate and the like. The copolymerization ratio of these peroxy group-containing monomers in the fluorine-based copolymer [A] is not particularly limited, but is preferably used in the range of 0.01 to 15 mol%. When the amount is less than 0.01 mol%, the amount of the graft starting point is insufficient, so that not only the graft reactivity is low but also the solubility becomes poor due to the increase in the molecular weight. On the other hand, if it exceeds 15 mol%, the amount of the graft starting point is too large, which may unfavorably impair the weather resistance.

The other polymerizable monomer used in the fluorine-based copolymer [A] according to the present invention is not particularly limited as long as it is copolymerized for the purpose of solubilizing a fluorine resin in a solvent. , Vinyl carboxylate, vinyl ether, olefin, allyl ether, etc. are preferably used, and vinyl carboxylate is particularly preferable in order to maintain compatibility with the graft portion. As the carboxylic acid vinyl ester, specifically, a vinyl ester of an alicyclic or aromatic carboxylic acid which may have a branched chain of a fatty acid or a substituent having 2 to 22 carbon atoms, for example, acetic acid Vinyl, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl myristate,
Examples include vinyl palmitate, vinyl stearate, versatic vinyl 9-acid, versatic vinyl 10-acid, and vinyl benzoate. The carboxylic acid vinyl ester is a monomer which polymerizes the fluorine-based copolymer [A], and is preferably 20 to 7%.
It is preferably 0 mol%, more preferably 30 to 60 mol%. If it is less than 20 mol%, the solubility of the fluorine-based copolymer [A] in the graft polymerization solvent may be low. If it exceeds 70 mol%, the weather resistance of the coating film prepared from the fluorine-based copolymer [A] may be reduced. It is not preferable because the property is lowered. Examples of the vinyl ether include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether. Examples of the allyl ether include ethyl allyl ether, butyl allyl ether, benzyl allyl ether, and cyclohexyl allyl ether.

Further, a monomer having a hydroxy group, a carboxyl group, an alkoxysilyl group or another functional group can be used for the purpose of introducing a crosslinking site into the fluorine-based copolymer [A]. Examples of the hydroxy group-containing monomer copolymerized in the fluorine-based copolymer [A] include hydroxy having 2 to 8 carbon atoms such as allyl alcohol, ethylene glycol monoallyl ether, propylene glycol monoallyl ether, and hydroxybutyl allyl ether. Hydroxyalkyl allyl ethers having an alkyl group, diethylene glycol monoallyl ether, alkylene glycol monoallyl ethers having an alkylene glycol group having 4 to 40 carbon atoms such as polyethylene glycol monoallyl ether, hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl Hydroxyalkyl vinyl ethers such as vinyl ether, hydroxypentyl vinyl ether and hydroxyhexyl vinyl ether, diethylene Polyethylene glycol monovinyl ether such as recall monovinyl ether, and the like crotonic acid-modified compound such as crotonic acid hydroxyethyl. Among these, the above-mentioned allyl alcohol, hydroxyalkyl allyl ethers, alkylene glycol monoallyl ethers and the like are particularly preferable. These hydroxy group-containing allyl ethers are not necessarily essential as monomers for polymerizing the fluorine-based copolymer [A], but 1 to 30 mol% of monomers for polymerizing the fluorine-based copolymer [A]. And more preferably 5 to 25 mol%. Also,
If the amount is less than 1 mol%, the coating prepared from the fluorine-based copolymer [A] may be insufficiently cured and the weather resistance may be reduced. If it exceeds 30 mol%, the fluorine-based copolymer [A] may be used. The water resistance and the weather resistance of the coating film prepared from the above are undesirably low.

Further, as the carboxyl group-containing monomer,
Unsaturated aliphatic carboxylic acids having 2 to 12 carbon atoms, for example, unsaturated carboxylic acids such as vinyl acetic acid, undecylenic acid, crotonic acid, acrylic acid and methacrylic acid can be used. These unsaturated carboxylic acids are preferably from 0.1 to 10 mol%, more preferably from 0.2 to 5 mol%, of the monomers polymerizing the fluorine-based copolymer [A]. preferable. On the other hand, if it is less than 0.1 mol%, the pigment dispersibility of the coating material may be deteriorated.

Further, a monomer having an alkoxysilyl group can be used in the fluorine-based copolymer [A]. Specifically, vinylalkoxysilane such as vinyltrimethoxysilane and vinyltriethoxysilane and vinylmono ( Or di) alkoxysilane. Further, a monomer having an epoxy group can also be used, and examples thereof include allyl glycidyl ether.

The hydroxy group, carboxyl group or alkoxysilyl group may be contained in at least one of the fluorine-based copolymer [A] and the hydrocarbon-based monomer [B]. In order to exhibit the property, it is preferable that both the fluorine-based copolymer [A] and the hydrocarbon-based monomer [B] contain a hydroxy group or a carboxyl group.

Furthermore, in the present invention, the fluorine-based copolymer [A]
In at least a part of the above, ε-caprolactone-modified vinyl ether or allyl ether, or a vinyl or allyl compound containing a β-ketoester group is preferably used for the purpose of improving the compatibility with the graft portion. Specific examples include ε-caprolactone-modified vinyl ether or allyl ether having a -C (ＯO) (CH ₂ ) ₅ O— group obtained by ring-opening addition of ε-caprolactone to a hydroxyalkyl group. Daicel Chemical's Praxel and the like. As the vinyl or allyl compound containing a β-ketoester group, allyl acetoacetate having an acetoacetoxy group [—OC (＝ O) CH ₂ C (＝ O) CH ₃ ] as a side chain is preferably used. By introducing these polar monomers, the fluorine-based copolymer [A]
Has improved compatibility with the graft portion, and a coating film having high gloss and weather resistance can be obtained even if the fluorine content is high. Further, by using a monomer having a β-ketoester group, a metal alkoxide, a chelate-based curing agent, or a hydrazine-based compound can be used as a curing agent in addition to a polyisocyanate or a melamine-based curing agent.

Further, glycerin monoallyl ether having a secondary hydroxyl group in the molecule can be used in a small amount and can introduce a high OH value. The secondary hydroxyl group has low reactivity at the time of curing and has a low hydroxyl group. It is preferably used because it remains in the film and is effective in improving the stain resistance by making the coating film surface hydrophilic.

In a preferred embodiment of the fluororesin for a coating material of the present invention, if the fluorocopolymer [A] is a fluoroolefin, a peroxy group-containing allyl compound, a carboxylic acid vinyl ester, a hydroxy group-containing allyl compound, A copolymer obtained by copolymerizing a saturated carboxylic acid, comprising 20 to 70 mol% of a fluoroolefin, 0.01 to 15 mol% of a peroxy group-containing allyl compound, 20 to 70 mol% of a vinyl carboxylate, Group-containing allyl compound 1 to 30 mol%, unsaturated carboxylic acid 0.1 to 10 mol%, hydrocarbon monomer [B] is (meth) acrylate, hydroxy group-containing (meth) acrylate or alkoxy One or more monomers selected from silyl group-containing (meth) acrylates and optionally 0 to 50 mol% Can be exemplified a fluorine resin consisting of copolymerizable monomers, not of course limited thereto.

The method for producing the fluorine-based copolymer [A] copolymerized with these monomers is preferably solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization. For this purpose, solution polymerization is particularly preferable because it is necessary to solubilize the solvent. Examples of the solvent include water and alcohol compounds, saturated hydrocarbons such as n-hexane and n-heptane, aromatic hydrocarbons such as toluene and xylene, trichlorotrifluoroethane, and dichlorotetrafluoroethane. For example, a fluorine-based solvent, a ketone-based solvent such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; an ester-based solvent such as ethyl acetate and butyl acetate; and a mineral spirit and a terpene-based solvent that are petroleum-based solvents can be used. These can be used alone or in combination.

Examples of the radical initiator that can be used here include diisopropyl peroxydicarbonate, di-n-propylperoxydicarbonate,
Dicarbonates such as 2-ethylhexylperoxydicarbonate, or n-heptafluorobutylic peroxide, lauroyl peroxypivalate, t-
Diacyl peroxides such as butyloxy neodecanoate; alkyl peroxides such as di-t-butyl peroxide and t-butyl cumyl peroxide; t-butyl peroxy pivalate; t-butyl peroxy neodecanoate Specific examples thereof include peroxyesters and the like, and it is necessary to select a radical initiator that decomposes at a lower temperature than the peroxy group copolymerized in the fluorine-based copolymer [A].

On the other hand, the grafting reaction according to the present invention proceeds with the polymerization of the hydrocarbon monomer [B] starting from the radical originating from the decomposition of the peroxy group copolymerized in the fluorine copolymer [A]. The reaction mode is solution polymerization in the presence of a solvent-solubilized copolymer (fluorine-based copolymer [A]) and a monomer (hydrocarbon-based monomer [B]). Therefore, when the fluorine-based copolymer [A] is produced by solution polymerization, the hydrocarbon-based monomer [B] can be introduced into the reactor immediately after the polymerization and grafted, so that the production can be simplified and economical. Big merit. Another major feature is that it is not necessary to newly coexist a polymerization initiator.

The hydrocarbon monomer [B] according to the present invention
Is not particularly limited as long as it is a (meth) acrylate ester usually used for the production of an acrylic resin for paint, but may have an alkyl group or a substituent that may have a branch having 1 to 22 carbon atoms. Specific examples of suitable (meth) acrylic acid esters comprising a cycloalkyl group or an aromatic group and a (meth) acryloyl group include methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, and acrylic acid. -Tert-butyl, cyclohexyl acrylate, ethylhexyl acrylate, -n-octyl acrylate, isooctyl acrylate, nonyl acrylate, tridecyl acrylate, lauryl acrylate, benzyl acrylate (meth) acrylate, isobornyl, methyl methacrylate , Ethyl methacrylate, methacryl Butyl, isobutyl methacrylate, -tert-butyl methacrylate, cyclohexyl methacrylate, ethylhexyl methacrylate, -n-octyl methacrylate, isooctyl methacrylate, nonyl methacrylate, tridecyl methacrylate, lauryl methacrylate, benzyl methacrylate, methacrylic acid Isobornyl and the like.

In addition, the general formula Rf-CH_Two-OH (Rf is
Represents a perfluoroalkyl group having 1 to 30 carbon atoms. )so
Of fluorinated alcohol and (meth) acrylic acid
Stell, for example, nC₈F₁₇CH_Two-OC (= O) C
H = CH_Two, N-C₈F₁₇CH _Two-OC (= O) C (-
CH_Three) = CH_Two, CF_ThreeC (-CF_Three) H-O-C (=
O) CH = CH_Two, CF_ThreeC (-CF_Three) H-O-C (=
O) C (-CH_Three) = CH _TwoOr the general formula (CH_Three)_ThreeSi-
(O-Si (CH_Two)_Two)_n-OH (n represents an integer)
Ester of alcohol and (meth) acrylic acid represented,
For example, (CH_Three)_ThreeSi- (O-Si (CH_Three)_Two)_m-O
-C (= O) CH = CH_Two(M is about 10 on average.
Same below. ), (CH_Three)_ThreeSi- (O-Si (CH_Three)_Two)
_m-OC (= O) C (CH_Three) = CH_Twoto use
Can be used, but the fluorine for paint obtained by using these
The characteristic that the coating formed from resin is excellent in water repellency
Show.

In the hydrocarbon monomer [B] according to the present invention, the (meth) acrylate may be a hydroxy group-containing (meth) acrylate, and may have 1 to 1 carbon atoms.
A hydroxyalkyl group which may have 22 branches,
It consists of a cycloalkyl group or an aromatic group having a hydroxy group and sometimes having another substituent and a (meth) acryloyl group, specifically, hydroxymethyl (meth)
Acrylate, hydroxyethyl (meth) acrylate,
Examples thereof include hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate.

Further, those having an alkoxysilyl group such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, methacryloxymethyltrimethoxysilane, those having an epoxy group such as glycidyl (meth) acrylate Can also be used.

Other copolymerizable monomers include acrylonitrile, aromatic vinyl compounds such as styrene, and olefins such as ethylene, propylene and butene. In addition, general-purpose monomers such as vinyl carboxylate and vinyl ether exemplified as monomers usable in the fluorine-based copolymer [A] can also be used.

The other copolymerizable monomer may be a monomer containing a hydroxy group or a carboxyl group, and the hydroxy group exemplified as the polymerizable monomer usable for the fluorine-based copolymer [A] may be used. Allyl ether and vinyl ether contained therein can also be used.

As the hydrocarbon monomer [B], a (meth) acrylate, a hydroxy group-containing (meth) acrylate or an alkoxysilyl group-containing (meth) acrylate is used in an amount of 50 mol% or more. Is preferred, and any other copolymerizable monomer described above may be used in combination.

The amount of grafting of these hydrocarbon monomers [B] is 1 to 100 parts by weight of the fluorine-based copolymer [A].
２００200 parts by weight. If the amount is less than 1 part by weight, the grafting effect such as economy, coating film hardness, adhesion and the like is difficult to be obtained.
If the amount exceeds 00 parts by weight, the fluorine content is decreased, and the weather resistance is undesirably reduced.

In the fluororesin for a coating material of the present invention, a hydrocarbon monomer [B] is added to a polymerization vessel in which a fluorocopolymer [A] is previously charged, and the fluorocopolymer [A] is added to the polymer. The reaction proceeds simply by raising the temperature to the temperature required for the decomposition of the contained peroxy group. At this time, the organic solvent exemplified in the case of producing the fluorine-based copolymer [A] can be further added.

Desirable hydroxy value of the fluorine-based graft resin thus produced having no other crosslinking site is 10 to 180 mgKOH / g. 10mg KO
If it is less than H / g, the number of crosslinked sites is small and the weather resistance of the coating film is poor,
If it exceeds 180 mgKOH / g, too much curing agent is required, so that the weather resistance is still insufficient. The acid value is preferably in the range of 0.1 to 80 mgKOH / g.
If it is less than 0.1 mgKOH / g, the pigment dispersibility and crosslinkability will be low, and if it exceeds 80 mgKOH / g, the water resistance will decrease. These hydroxy groups or carboxyl groups may be contained in at least one of the fluorine-based copolymer [A] and the hydrocarbon-based monomer [B], and may be contained in both. When an alkoxysilyl group or the like is introduced as a crosslinking site, the above range is not necessarily required.

The molecular weight of the fluorinated copolymer [A] according to the present invention is 1,000 to 30,000 (number average molecular weight;
(Styrene equivalent) is preferred, and 3,000 to 15,000
Is more preferred. If it is less than 1,000, the weather resistance and flexibility of the coating film decrease, and if it exceeds 30,000, the solubility decreases and graft polymerization becomes difficult. Although the molecular weight of the fluorine-based graft copolymer of the present invention is not particularly limited, it is preferable to use the fluorine-based graft copolymer in the range of 2,000 to 50,000 depending on the required strength and flexibility of the coating film. Here, when it is 2,000 or less, the weather resistance and flexibility of the coating film are reduced, and when it is 50,000 or more, the coating composition becomes high in viscosity, the solubility is reduced, and there is a disadvantage that it is difficult to handle.

The fluororesin for paint of the present invention is used together with a solvent. As a solvent, toluene, xylene, ethylbenzene, benzene, methyl isobutyl ketone, butyl acetate, cyclohexanone, diacetone alcohol, diisobutyl ketone, butyrolactone, tetraethylurea, isophorone, triethyl phosphate, carbitol acetate, propylene carbonate, dimethyl phthalate, acetone, acetone, It can be used as a mixed solvent together with tetrahydrofuran, methyl ethyl ketone, dimethylformamide, dimethylacetamide, tetramethylurea, trimethylphosphate, pentane, methanol, hexane, isopropyl alcohol, ethanol, decane and the like.

The fluororesin of the present invention can be used as a curable fluororesin paint using a polyisocyanate, a blocked isocyanate, a melamine resin, a silanol condensation catalyst or the like as a curing agent.

The polyisocyanate is not particularly restricted but includes ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (H
DI), dodecamethylene diisocyanate, 1,6,1
1-undecane triisocyanate, 2,2,4-trimethylhexane diisocyanate, 2,6-diisocyanate methyl caproate (LDI), bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanate Ethyl-2,6-diisocyanate hexanoate, isophorone diisocyanate (IPDI), 4,4'-diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI) , Bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, xylylenediisocyanate (XD1), diethylbenzenediyl Socyanate, toluene diisocyanate (TDI), and urethane adducts, burettes, isocyanurates, blocked isocyanates, urethane prepolymers and the like prepared therefrom, for example, water-modified HDI, TDI dimer, TDI trimethylolpropane adduct ( L), HMDI-biuret, L-phenol block, IPDI trimer and the like, and a crude product thereof or a mixture of two or more thereof.

In the fluororesin coating composition of the present invention, the above-mentioned polyisocyanate may be selected and used. However, in general, discoloration is not preferred, and isocyanate groups called non-yellowing type or hardly yellowing type are usually used. Non-adjacent to benzene nucleus, for example, aliphatic diisocyanate such as HDI, XDI, LDI or IPDI, hydrogenated MD
I, alicyclic isocyanates such as hydrogenated XDI are preferable, and urethane adducts, burettes, isocyanurates, blocked isocyanates, urethane prepolymers and the like prepared from these polyisocyanates can also be preferably used.

Specific examples of the polyisocyanate include TP-100 and TP-703 of Nippon Polyurethane Industry, TPLS2071 of Sumitomo Bayer Urethane, and Duranate TSA-100 and TPA-100 of Asahi Kasei Corporation, but are not limited thereto. Not something.

As the melamine resin, melamine, urea,
A condensate obtained by reacting an amino group-containing compound such as acetoguanamine, benzoguanamine, sterognamin or spiroganamin with an aldehyde such as formaldehyde, paraformaldehyde, acetaldehyde or glyoxazole by a conventional method, or a condensate thereof with alcohols Examples thereof include those in which at least a portion is etherified, but are not limited thereto.

Specific examples of the amino resin include hexamethyletherified methylolmelamine, hexabutyletherified methylolmelamine, methylbutyletherified methylolmelamine, methyletherified methylolmelamine, butyletherified methylolmelamine or isobutyletherified methylolmelamine, or a mixture thereof. Can be mentioned.

Examples of the silanol condensation catalyst having an alkoxysilyl group include carboxylic acid tin compounds such as dibutyltin dilaurate, tin dioctylate and dibutyltin maleate; sulfide type and mercaptide type such as dibutyltin sulfide and dibutyltin dioctyl mercaptide. Sulfur-containing organic tin compounds, acid phosphates such as monomethyl acid phosphate, carboxylic acids such as adipic acid, maleic acid and citric acid, γ
-Amino group-containing compounds such as -aminopropyltriethoxysilane and triethylamine, and organic titanate compounds such as isopropyltriisostearoyl titanate.

A coating film coated with these curing agents becomes a tough and crosslinked coating film having excellent weather resistance.

The fluororesin for a coating material of the present invention can be made into a coating material in the same manner as a usual resin, and a pigment or a dye can be appropriately added. In that case, an ultraviolet absorber, a light stabilizer,
Rust inhibitors, dispersants, anti-dripping agents, fungicides, leveling agents and the like can also be added.

Further, when forming a coating material, another resin, for example, a fluorine-based polyol, another fluorine-containing resin having an alkoxysilane, acrylic silicone, an acrylic-based polyol,
Polyvinyl esters, silicone compounds, polyalkylene glycols, alkyd resins and the like can also be added as appropriate.

Hereinafter, the present invention will be described specifically with reference to examples, but embodiments of the present invention are not limited thereto. In the examples, “parts” means “parts by weight” unless otherwise noted.

[0044]

Example 1 In a 3.5-liter SUS autoclave equipped with a magnetic stirrer, 193 g of vinyl pivalate (25 mol% of the fluorine-based copolymer [A] component), 88 g of vinyl versatate (fluorine-based) 8 mol% of the copolymer [A] component),
92 g of ethylene glycol monoallyl ether (15 mol% of the fluorine-based copolymer [A] component), 10 g of t-butylperoxyallyl carbonate (1 mol% of the fluorine-based copolymer [A] component), 11 g of undecylenic acid (fluorine The copolymer (1 mol% of the component [A]), 5 g of t-butyl peroxypivalate, and 10 g of celite were charged, and degassing was repeated three times with nitrogen gas, followed by degassing, followed by 350 g of chlorotrifluoroethylene (fluorine). (50 mol% of the system copolymer [A] component) and polymerized at 55 ° C. for 18 hours.

Next, unreacted monomers were degassed, and 225 g of methyl methacrylate, 33 g of hydroxyethyl methacrylate and 400 g of xylene were added under reduced pressure.
Graft polymerization was performed for hours. After the polymerization, the content was taken out and filtered, and the concentration was adjusted to obtain a transparent fluorine-based graft resin varnish having a solid content of 55%. Table 1 shows the hydroxy value and acid value of the obtained resin.

[0046]

[Table 1]

Examples 2 to 5 In the same manner as in Example 1, polymerization was carried out using the monomer compositions shown in Table 1. In each case, after the polymerization was completed, the content was taken out and filtered, and the concentration was adjusted to obtain a 55% transparent fluorine-based graft resin varnish. Table 1 shows the hydroxy value and acid value of the obtained resin.

COMPARATIVE EXAMPLE 1 In the same manner as in Example 1, the internal capacity was 3.5 with an electromagnetic stirrer.
As shown in Table 2, 193 g (26 mol%) of vinyl pivalate, 88 g (8 mol%) of vinyl versatate, 92 g (15 mol%) of ethylene glycol monoallyl ether, and 11 g (1 mol) of undecylenic acid were placed in a liter autoclave made of SUS. Mol%), 5 g of t-butyl peroxypivalate, and 10 g of celite. Degassing and replacement were repeated three times with nitrogen gas, followed by 350 g (50 mol%) of chlorotrifluoroethylene. Polymerization was carried out for hours. No peroxy group-containing monomer was used in this polymerization.

Next, unreacted monomers were degassed, 225 g of methyl methacrylate, 33 g of hydroxyethyl methacrylate and 400 g of xylene were added under reduced pressure.
Graft polymerization was performed for hours. After the polymerization, the content was taken out and filtered, and the concentration was adjusted to obtain an opaque fluororesin varnish having a solid content of 55%.

Comparative Examples 2 to 4 In the same manner as in Example 1, a fluorine-based copolymer [A] was polymerized with the monomer composition shown in Table 2, and then a fluorine-based graft resin was polymerized. In Comparative Example 2, the hydroxy group-containing monomer and the carboxyl group-containing monomer were not used. In Comparative Example 3, graft polymerization was performed such that the amount of the hydrocarbon monomer [B] was about 210 parts with respect to 100 parts of the fluorine-based copolymer [A]. In Comparative Example 4, no peroxy group-containing monomer was used for the polymerization of the fluorine-based copolymer [A], and no graft reaction was performed.

Application Example 1 Solid content conversion 1 of graft resin varnish obtained in Example 1
100 parts of titanium oxide CR-90 is dispersed in 100 parts by mill, and TPA100 (hexamethylene diisocyanate trimer manufactured by Asahi Kasei Kogyo Co., Ltd.) is added to 18 parts, and an aluminum plate and various bases, that is, a fluororesin coating film (Sefural Coat A202B), Acrylic urethane coating (A801),
It was spray-coated on an acrylic silicon coating film (ares silicon), a polyvinylidene fluoride-based baking coating film (Kyner), and an alkyd resin coating film, and was cured at room temperature for 7 days.
The film thickness was about 43 microns. The accelerated weather resistance of the coating film on the aluminum plate, the pencil hardness, the stain resistance test (color difference) due to outdoor exposure, and the boiling adhesion test of the coating film on various bases were performed. Table 3 shows the results.

[0052]

[Table 2]

Application Examples 2 to 4 Using the fluorinated graft resin varnish obtained in Examples 2 to 4, white enamel was obtained in the same manner as in Application Example 1, and the amount of TPA100 shown in Table 3 was added. Various bases, ie, fluororesin coatings (Sefural Coat A2
02B), an acrylic urethane coating film (A801), an acrylic silicon coating film (Ales Silicone), a polyvinylidene fluoride-based baked coating film (Kyner), and an alkyd resin coating film, and the coating was cured at room temperature for 7 days. The film thicknesses were about 41, about 40, and about 42 microns, respectively. The accelerated weather resistance of the coating film on the aluminum plate, the pencil hardness, the stain resistance test (color difference) due to outdoor exposure, and the boiling adhesion test of the coating film on various bases were performed. Table 3 shows the results.

Application Example 5 Using the fluorinated graft resin varnish obtained in Example 5, white enamel was obtained in the same manner as in Application Example 1, and as shown in Table 3, 1 part of dibutyltin dilaurate was added to the aluminum plate and various substrates. That is, a fluororesin coating film (Sefural Coat A202B), an acrylic urethane coating film (A80
1) Spray coating on an acrylic silicon coating film (Ales Silicone), a polyvinylidene fluoride-based baking coating film (Kyner), and an alkyd resin coating film, and cured at room temperature for 7 days. The film thickness was about 41 microns. The accelerated weather resistance of the coating film on the aluminum plate, the pencil hardness, the stain resistance test (color difference) due to outdoor exposure, and the boiling adhesion test of the coating film on various bases were performed. Table 3 shows the results. In this application example, PVD
Although the adhesion to the F coating film was not sufficient, other evaluations were excellent.

Comparative Application Example 1 The fluorine-based graft resin obtained in Comparative Example 1 was enamelled in white in the same manner as in Application Example 1, and the amount of TPA100 shown in Table 3 was used.
To the aluminum plate and various bases,
Spray coating on fluororesin coating film (Sefural Coat A202B), acrylic urethane coating film (A801), acrylic silicon coating film (ares silicon), polyvinylidene fluoride-based baked coating film (Kainer), and alkyd resin coating film Cured for days. The film thickness was about 44 microns. The accelerated weather resistance of the coating film on the aluminum plate, the pencil hardness, the stain resistance test (color difference) due to outdoor exposure, and the boiling adhesion test of the coating film on various bases were performed. Table 3 shows the results.

Comparative Application Examples 2 to 4 The fluorinated (graft) resin obtained in Comparative Examples 2 to 4 was enamelled in the same manner as in Application Example 1, and TPA100 was added. Spray coating on coating film (Sefural Coat A202B), acrylic urethane coating film (A801), acrylic silicon coating film (ares silicon), polyvinylidene fluoride-based baking coating film (Kainer), and alkyd resin coating film, and curing at room temperature for 7 days I let it. The film thickness is about 40 and about 4 respectively.
1, about 44 microns. The accelerated weather resistance of the coating film on the aluminum plate, the pencil hardness, the stain resistance test (color difference) due to outdoor exposure, and the boiling adhesion test of the coating film on various bases were performed. Table 3 shows the results.

[0057]

[Table 3]

<Evaluation method> Weatherability: Accelerated test (5000 degree gloss retention before and after the test) by 5000 hours of sunshine weatherometer. -Pencil hardness: Tested according to JIS K5400. -Color difference: Stain resistance test (ΔE measurement). After 6 months of outdoor exposure, color difference before and after exposure (JIS-8730) was measured.
Exposure location: Kawagoe City, Saitama Prefecture. -Boiling adhesion test: Prepare a coating film in which various coating films are undercoated, and boil them in boiling water for 5 hours. After that, adhesion was judged by a coin scratch test.

○ Peeling off at the interface of top coat / undercoat at all, △ peeling off at the interface due to coin scratch, × peeling off due to generation of blister or boiling.

[0060]

According to the fluororesin for paints of the present invention, since the (meth) acrylic resin is efficiently grafted to the fluororesin, the paint films prepared therefrom have a high surface hardness and various paint films. It has a remarkable effect of being excellent in weather resistance and stain resistance because it has good adhesion to the surface and is hardly damaged.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08F 220: 26)

Claims (6)

[Claims] 1. A fluorine-based copolymer [A] 10 obtained by copolymerizing a fluoroolefin and a monomer having a peroxy group.
A fluorine-based graft resin obtained by subjecting 0 part by weight and 1 to 200 parts by weight of a hydrocarbon-based monomer [B] to a graft reaction starting from a peroxy group of a fluorine-based copolymer [A]; A fluorocarbon resin for coatings having a group, carboxyl group or alkoxysilyl group and soluble in organic solvents. 2. A copolymer obtained by copolymerizing a fluoroolefin, a peroxy group-containing allyl compound, a carboxylic acid vinyl ester, a hydroxy group-containing allyl compound, and an unsaturated carboxylic acid. 20 to 70 mol% of a fluoroolefin, 0.01 to 15 mol% of a peroxy group-containing allyl compound, 20 to 70 mol% of a carboxylic acid vinyl ester, 1 to 30 mol% of a hydroxy group-containing allyl compound, 0 unsaturated carboxylic acid 2. The fluororesin for paints according to claim 1, wherein the amount is from 1 to 10 mol%. 3. The monomer of claim 1, wherein the hydrocarbon monomer [B] is at least one monomer selected from the group consisting of (meth) acrylate, hydroxy group-containing (meth) acrylate and alkoxysilyl group-containing (meth) acrylate. Mers and optionally 0
3. The fluororesin for a coating material according to claim 1, comprising 50 mol% of another copolymerizable monomer. 4. The fluororesin for paints according to claim 1, wherein either the fluorocopolymer [A] or the hydrocarbon monomer [B] has a β-ketoester group. 5. The method according to claim 1, wherein either the fluorine-based copolymer [A] or the hydrocarbon-based monomer [B] has a —C (＝ O) (CH ₂ ) ₅ O— group derived from ε-caprolactone. The fluororesin for paint according to claim 1, wherein: 6. The fluororesin for paints according to claim 1, wherein the fluorocopolymer [A] has a structural unit derived from an allyl ether containing a secondary hydroxy group.