JPS5850269B2 - Thermosetting resin composition for paints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a fluorinated acrylic resin in combination to improve the coated surface of a thermosetting resin composition for paints, especially powder paints.

It is well known that powder coating is used to coat metal surfaces with thermosetting resin compositions such as polyester, acrylic resin, and epoxy resin. Widely used for painting, etc.

However, coating films obtained from powder coatings that do not use solvents tend to be inferior to solution-type coatings in terms of smoothness and appearance.

In particular, polyester and vinyl polymer systems, which have been in the spotlight in recent years due to their excellent weather resistance, have relatively high molecular weights, high molten clay, and the crosslinking reaction occurs before sufficient melting and smoothing. It has poor smoothness, gloss, and sharpness, and its uses are severely limited.

For this reason, various additives have been researched, and ketone resins, petroleum resins, acrylic polymers with low glass transition points, etc. have been evaluated to some extent.

However, these additives do not necessarily have a sufficient smoothing effect, and they also have various disadvantages such as yellowing of the cured paint film, deterioration of the physical properties of the paint film, and deterioration of weather resistance. It's not a thing.

In view of these points, the present inventors conducted extensive research and found that by blending a specific amount of fluorinated acrylic resin into a thermosetting resin, it is possible to create a film without impairing the excellent coating properties inherent to the thermosetting resin. It has been found that a coating film that is extremely smooth, glossy, and has excellent image clarity can be obtained.

Furthermore, it has been found that such an effect is effective not only for powder coatings but also for ordinary organic solvent solution-based, aqueous solution-based and dispersion-based coatings.

Therefore, the present invention includes ioo parts by weight of a thermosetting resin (hereinafter referred to as parts) and 0.001 to 10 parts of a fluorinated acrylic resin represented by the general formula (1) described below, preferably 0.01 parts by weight.
-1 part, more preferably 0.1 to 1 part, of a thermosetting resin composition for coatings.

In this case, the blending ratio of the fluorinated acrylic resin of the present invention is o
If the amount is less than , ooi parts, these effects will be insufficient, and if it exceeds 10 parts, there will be a disadvantage that the physical properties, weather resistance, etc. of the coating film will deteriorate.

Thermosetting resins are already known, and include, for example, polyester resins, vinyl polymer resins, epoxy resins, and the like.

Polyester type refers to polyester made of polyhydric alcohol and polycarboxylic acid mixed with a curing agent, or self-crosslinking and curing polyester, and vinyl polymer type refers to polyester containing hydroxyl groups, carboxyl groups, glycidyl groups, A vinyl monomer containing a functional group such as an oxazoline group and another vinyl monomer may be mixed with a curing agent, or a vinyl polymer containing a self-crosslinking functional group such as a butoxymethylamide group. A combination thereof, or a vinyl polymer modified with an epoxy resin, polyester, etc. is used.

In this case, if the functional group of each polymer is a hydroxyl group, the curing agent is
Examples include amino resins such as hexamethoxymethylmelamine and tetrabutoxybenzoguanamine, block polyisocyanates, etc. In the case of carboxyl groups, examples include epoxy resins and polyoxazolines; and in the case of glycidyl groups, examples include polyhydric carboxylic acids, These include polyhydric phenols.

An epoxy resin system is a combination of a polyhydric epoxy compound such as a bisphenol type or an ester type and a curing agent such as an amine or an acid.

The fluorinated acrylic resin in the present invention has the general formula [wherein, Rf is a perfluoroalkyl group containing 3 to 18 carbon atoms, and Z is a divalent group bonded to the carbon atom of Rf and the carbon atom of +CH2+]. R1 is a hydrogen atom or an alkyl group having up to 3 carbon atoms, R2 is an alkylene group having 2 to 6 carbon atoms, and R3 is a hydrogen atom or an alkyl group having up to 5 carbon atoms. an alkyl group having a carbon atom or an alkyl group-substituted aryl group having 30 or less carbon atoms,
p is an integer from 1 to 12, q is an integer from 3 to 100, l is O or l, n and m are integers representing the repeating unit of each acrylic monomer, and m/n+m is 0. It is assumed that the number is a rational number between .95 and 0.05, and n+m is an integer between 2 and 100.

].

Incidentally, Rf represents a perfluoroalkyl group containing a carbon atom as described above, but this also includes structures such as linear, branched, cyclic (e.g. perfluorocyclohexyl), or combinations thereof. , and furthermore, they are those in which oxygen atoms intervene between carbon atoms (for example, (CF3)
2CFOCF2CF2...) may also be used.

Z also represents a crosslinking group as described above, and examples of such a crosslinking group include ester (-CO2- or -8
03-) ether (-〇-CH2CH20- or -5
-) Amino (-(CH2')4 y-N-: y is an integer from 1 to 6, R4 is hydrogen or an alkyl group having 4 or less carbon atoms), Amide OR4 1 (-C-N- or -8O2N- :R4 is as described above).

A specific example of R2 is -CH2CH2CH2CH2
--CH2-CHH3 CH2CH2 is the first class.

The method for producing such a fluorinated acrylic resin is expressed by the general formula (
A common method is to copolymerize the fluorinated acrylic ester monomer represented by II) and the polyoxyalkylene acrylic ester monomer represented by general formula (I) at a molar ratio of 5/95 to 9515.

In this case, preferred specific examples of the fluorinated acrylic ester monomer (n) include the following fluorinated alcohols (na).
acrylic acid or methacrylic acid ester.

11a-11,1-Cibide Roba-Fluorobutanol 11a-21,1-Cibide Roba-Fluorohexanol IIa-31,1-Cibide Roba-Fluoctanol IIa-41,1,2,2-Tetrahydroperfluorohexanol 11a-51,1 ,2,2-tetrahydroperfluorodecanol 11a-6N-ethylperfluorooctanesulfonamide ethanol 11a-7N-propylperfluorooctanesulfonamide ethanol 11a-8N-ethylperfluorocyclohexane sulfonamide ethanol 11a-9N-methylper Fluorooctanesulfonamide ethanol IIa-105-(perfluorooctyl)pentanol-1 11a-116-(perfluorooctyl)hexanol-1 11a-128-(perfluorooctyl)octano-
Ru-1 1I a-1311-(perfluorooctyl)undecanol-1 11a-143-(perfluorooctyl)propene-
2-ol-1 1I a-1511-(perfluorooctyl)undecen-10-ol-1 11a-165-(heptafluoroisopropoxy)pentanol II a-1711-(heptafluoroisopropoxy)undecanol On the other hand, polyoxy Preferred specific examples of the alkylene acrylic ester monomer (I) are the following acrylic or methacrylic esters of polyoxyalkylene monoalkyl ether polyoxyalkylene glycol or polyoxyalkylene monoalkyl ester (l[a).

Ha-1 polyoxyethylene monobutyl ether (molecular weight 700) Na-2 polyoxyethylene monobutyl ether (molecular weight 2000) 1 [a-3 polyoxypropylene monomethyl ether (
molecular weight 2000) 1[a-4 polyoxypropylene monobutyl ether (
Molecular weight 750) 1[a-5 polyoxypropylene monobutyl ether (
Molecular weight 2000) 1 [a-6 polyoxypropylene seven methyl ester (
Molecular weight 500) 1[a-7 Polyoxyethylene oxypropylene monomethyl ether (molecular weight 1000, ethylene/propylene (mole ratio) = 40/60) 1[a-8 Polyoxyethylene monononyl phenyl ether (molecular weight 2000) IIa- 9 polyoxypropylene glycol (molecular weight 2
000) ■a-10 me 10 polyoxyethylene glycol 40
0) (Note) Molecular weight refers to number average molecular weight.

Of course, when producing a fluorinated acrylic resin from these fluorinated acrylic ester monomers (II) and polyoxyalkylene acrylic ester monomers (I), these monomers can be used not only alone but also as a mixture of two or more. good.

The resin composition of the present invention can be easily produced by uniformly mixing a thermosetting resin and a fluorinated acrylic resin using a conventional method, but there are no particular restrictions on the method of blending the fluorinated acrylic resin, and They may be blended together, or may be blended simultaneously when pigments and other fillers are blended into the thermosetting resin.

This resin composition can be particularly preferably used as a powder coating.

To prepare a powder coating from the resin composition of the present invention, ingredients such as pigments, fillers, additives, etc. are added to the resin composition which has been melt-kneaded in advance, the mixture is melt-kneaded, and the mixture is cooled and then pulverized. Alternatively, a method of melt-kneading the mixture of the resin composition and the compounded components, cooling and pulverizing the mixture, or a method of mixing the resin composition and the compounded components in a solvent and treating the mixture with a spray dryer is possible. be.

As a method for applying the powder coating, any known method such as electrostatic coating, fluidized dipping coating, etc. can be employed.

Of course, as mentioned above, the present resin composition can also be made into ordinary organic solvent solution-based, aqueous solution-based, or dispersion-based paints.

The present invention will be explained below with reference to Examples, in which "饅" means "% by weight".

Example 1 70 parts of xylene and 30 parts of n-butyl alcohol were added to a reactor equipped with a thermometer, a stirrer, and a reflux condenser at 100°C.
33 parts of methyl methacrylate, 30 parts of styrene, 20 parts of butyl methacrylate, 15 parts of β-hydroxyethyl methacrylate, 2 parts of methacrylic acid, 1 part of thioglycolic acid, 3 parts of azobisisobutyronitrile, and cumene. Gradually add 2 parts of hydroperoxide,
The solution obtained by keeping at the same temperature for 10 hours was vacuumed (50~
200 parts mHg) while continuously removing the solvent.
The temperature was raised to .degree. C. to obtain a resin with a softening point of 114.degree.

15 parts of a blocked product obtained by blocking 85 parts of this resin with an adduct of 3 moles of xylene diisocyanate and 1 mole of trimethylolpropane with methanol, 50 parts of titanium oxide, 1 part of dibutyltin oxide, and a fluorinated acrylic resin such as "the above-mentioned l1a7 acrylic resin". Acid ester and l1a-
2 parts of a copolymer (molecular weight 8,000) Jo having a molar ratio of 7:3 with the methacrylic ester of No. 7 was added, mixed in a super mixer, mixed in an extruder at 12,000, and then cooled and pulverized.

The obtained powder coating was applied to a steel plate by electrostatic coating, and
The baking was cured at 0°C for 30 minutes.

The resulting coating film has no pinholes or craters, has excellent smoothness and sharpness, and has a gloss ((600 reflection): the same applies hereinafter) of 90 and an Erichsen rating of 6mvt.

Impact resistance 500gX 30crn, pencil hardness 3-4H
Physical and chemical tests (both excellent) showed no abnormality after 100 times of 1-torr rubbing.

Example 2 As a fluorinated acrylic resin, a copolymer (molecular weight 11.000) of the above-mentioned na-6 methacrylic ester and Na-4 acrylic ester with a molar ratio of 3 is used.
A coating film was obtained in exactly the same manner as in Example 1, except that (by straining)

The coating film has no craters or pinholes, has excellent smoothness and sharpness, has a gloss of 86, an Erichsen rating of 6 mm, an impact resistance of 500 g x 30 cm, and a pencil hardness of 3 to 4 H1. No abnormality after 100 toluene rubbings. It also had excellent chemical properties.

Example 3 35 parts of styrene, 10 parts of glycidyl methacrylate, β
-10 parts of methylglycidyl methacrylate, 45 parts of isobutyl methacrylate, 70 parts of xylene, 30 parts of n-butanol, 3 parts of azobisisobutyronitrile, tert
- Mixture prepared from 1 part of butyl perbenzoate at 80°C.
After keeping the temperature at 100°C for 30 minutes and keeping at the same temperature for 7 hours, the solvent was removed to obtain a resin with a softening point of 100'C and a molecular weight of 7000.

85 parts of the resin, 15 parts of 10-decanedicarboxylic acid,
As a fluorinated acrylic resin, "a copolymer (molecular weight 6000) of the above-mentioned Ua-12 acrylic ester and Na-7 acrylic ester in a molar ratio of 1.5:8.5 (molecular weight 6000) J
5 parts of titanium oxide and 50 parts of titanium oxide were heated with three rolls.
After kneading for 3 minutes at oo'c, the mixture was separated using a 150-mesh wire mesh to obtain a powder coating with a mesh size of 150 mesh or less.

This powder coating was applied to a mild steel plate using electrostatic spray coating.
It was baked at ℃ for 20 minutes to obtain a coating film.

The coating film had no pinholes or craters, had excellent smoothness and sharpness, and had a gloss level of 86 and an Erichsen level of 7.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the fluorinated acrylic resin was not used, but the coating film had craters and
The skin was noticeably wavy.

Example 4 69.59 parts of dimethyl terephthalate (40,39φ)
, ■, 3-butylene glycol 32.28 parts (40,4
0φ), 0.03 part of cadmium acetate was heated to 150°C over 5 hours while continuously removing the generated methanol from the system.
After raising the temperature from 0C to 210C, terephthalic acid 13.
41 parts (9,10%), 1°6-hexanediol 10
．． Add 58 parts (10,11f0), 0.05 part of dibutyltin oxide, and a small amount of xylene, and heat to 220°C for about 18 hours while removing water from the yarn by azeotropy to obtain a softening point of 98°C and a number average molecular weight. 7000. Hydroxyl value 13 (KO
A polyester having an acid value of 3 (KOH/g) and an acid value of 3 (KOH/g) was obtained.

To 95 parts of this polyester, 5 parts of hexamethoxymethyl melamine, 50 parts of titanium oxide, and a fluorinated acrylic resin were added.
12 parts of JO, a copolymer (molecular weight 7000) having a molar ratio of 3 with a methacrylic acid ester of -7, was added, and the mixture was melt-kneaded at 120° C. for 15 minutes using a heated triple roll, and then cooled and pulverized.

The obtained powder coating was applied to a steel plate by electrostatic coating.
Bake for 30 minutes at °C to cure.

The resulting coating film has no craters or pinholes, has excellent smoothness and sharpness, has a gloss of 90, and has an Erichsen rating of 5m.
H impact resistance 500 j; l x 20 cm, pencil hardness 3~
4H1 toluene rubbing was performed 100 times without any abnormality, indicating excellent physical and chemical properties.

Example 5 194 parts of dimethyl terephthalate, 220 parts of neopentyl glycol, and 0.1 part of zinc acetate were produced at 150° while continuously removing the methanol from the system for 5 hours.
After raising the temperature from ℃ to 210℃, isophthalic acid 204
1 part and 0.05 part of dibutyltin oxide were added, and the mixture was reacted at 240° C. for about 5 hours while removing water from the system to obtain an intermediate polyester (I) having an acid value of 75, a hydroxyl value of 24, and a molecular weight of 1100.

To 1000 parts of this intermediate polyester (I) was added Epiclon 850 (an epoxy compound manufactured by Inu Nippon Ink Chemical Co., Ltd.):
After adding 260 parts of epoxy equivalent (190) and 100 parts of xylene and reacting at 120°C for 12 hours, 180'C2
The solvent was removed at 0 mmHg to a solid mass of approximately 100 fO.

The obtained polyester (u) t o o . 171 parts of trimellitic anhydride was added to the mixture and reacted at 200°C for 2 hours to obtain polyester (I) having an acid value of 85, a molecular weight of 5000°, and a softening point of 108°C.

Polyester (I) 100 parts, triglycidyl isocyanurate 15 parts, titanium oxide R-820 (Ishiya Sangyo ■
After kneading 40 parts of the fluorinated acrylic resin used in Example 1 with an extruder at 80°C, the mixture was ground to 200 mesh, electrostatically sprayed onto a mild steel plate, and kneaded at 180°C.
Baked for 0 minutes.

The resulting coating film was free of craters and pinholes, had excellent smoothness and sharpness, had a gloss of 98, and an Erichsen rating of 7.

Comparative Example 2 A coating film was obtained in exactly the same manner as in Example 5 except that the fluorinated acrylic resin was not used.

Craters were generated over the entire surface of the coating film, and its smoothness and sharpness were extremely poor.

Example 6 A mixture consisting of 26 parts of phthalic anhydride, 7 parts of adipic acid, 13 parts of trimethylolpropane, 50 parts of neopentyl glycol, and 16 parts of benzoic acid was reacted by heating at 200°C for 16 hours, and then diluted with xylene to remove the nonvolatile content. Section 70, clay ■-
An oil-free alkyd resin having a J1 acid value of 90 was obtained.

To 70 parts of this oil-free alkyd resin, 42 parts of Super Beckamine J-820 (trade name, butyl etherified melamine resin manufactured by Inu Nippon Ink Chemical Co., Ltd.), 0.005 part of the fluorinated acrylic resin used in Example 4, and oxidized 60 parts of titanium was kneaded using three rolls.

The resulting paint was applied to a steel plate and baked at 140° C. for 20 minutes to harden it.

The resulting coating film had good gloss and sharpness, and had no craters or pinholes.

Example 7 70 parts of butyl cellosolve, 30 parts of styrene, 51 parts of ethyl acrylate, 9 parts of β-hydroxyethyl methacrylate
1 part, 10 parts of acrylic acid and azobisisobutyroni) I
Gradually add 2 parts of Jul dropwise, react at 120°C for 10 hours, then neutralize by adding 16 parts of triethylamine, and then add 30 parts of water to obtain a water-soluble acrylic resin with a non-volatile content of 50% and a viscosity of ST. I got it.

To 80 parts of this water-soluble acrylic resin, 18 parts of Watersol S-695 (trade name, water-soluble methyl etherified melamine resin manufactured by Inu Nippon Ink Chemical Co., Ltd.) and 50 parts of titanium oxide.
Add the ingredients and mix well.

100 parts of the resulting water-soluble paint were added with the acrylic ester of l1a-11 and II as a fluorinated acrylic resin.
After mixing 0.005 parts of a copolymer (molecular weight: 31,000) with an acrylic acid ester of Ia-4 at a molar ratio of 3, it was coated on a steel plate and baked at 140°C for 30 minutes.

The resulting coating film was smooth and free of wrinkles, repellents, and pinholes.

Example 8 A coating film was obtained in the same manner as in Example 1, except that the fluorinated acrylic resin having a molecular weight of 2,000 and having the above-mentioned general formula % of 2.7 was used.

The resulting coating film has no craters or pinholes, has excellent smoothness and sharpness, and has a gloss of 85, an Erichsen rating of 6, and an impact resistance of 500 g x 30.
cm, the pencil hardness was 3H to 4H, and toluene rubbing showed no abnormality 100 times, indicating excellent physical and chemical properties.

Example 9 As a fluorinated acrylic resin, n is 67.3 and m is 29
．． 7, therefore n+m is 99.0, molecular weight 76.0
Example 1 except that 00 was used.
A coating film was obtained in the same manner as above.

The resulting coating film has no craters or pinholes, has excellent smoothness and sharpness, and has a gloss of 87, an Erichsen rating of 6, and an impact resistance of 500J9X30.
It was excellent both physically and chemically, with CrrL, pencil hardness of 3H to 4H, and no abnormalities after 100 times rubbing with toluene.

Example 10 As a fluorinated acrylic resin, n is 0.3 and m is 1.7
, Therefore, a coating film was obtained in the same manner as in Example 3 except that a material having a molecular weight of 2,000 and n+m of 2.0 was used.

The coating film obtained here has no thickness or pinholes, has excellent smoothness and sharpness, and has a gloss of 85.
And Eriksen was 7 months.

Example 11 As a fluorinated acrylic resin, n is 13.7 and m is 77
．． 6, therefore n+m is 91.3, molecular weight 90.0
Example 3, except that 00 was used.
A coating film was obtained in the same manner as above.

The coating film obtained in this way has no pinholes or craters, has excellent smoothness and sharpness, and has a gloss of 87.
So, Eriksen had 7 tears.

Claims (1)

[Scope of Claims] 1 Thermosetting resin ioo parts by weight and general formula [wherein, Rf
is a perfluoroalkyl group containing 3 to 18 carbon atoms, Z is a carbon atom of Rf and (-CH2
÷ is a divalent bridging group bonded to a carbon atom, R1 is a hydrogen atom or an alkyl group having 3 or less carbon atoms, R2 is an alkylene group having 2 to 6 carbon atoms, R3 is a hydrogen atom or an alkyl group having 5 or less carbon atoms or an alkyl group-substituted aryl group having 30 or less carbon atoms, p is an integer from 1 to 12, and q is an integer from 3 to 100. can be,
l is O or 1, n and m are integers representing the repeating unit of each acrylic monomer, and m/
n + m is a rational number of 0.95 to 0.05,
And n+m shall be an integer from 2 to 100. ] A thermosetting resin composition for paints comprising ~10 parts by weight of a fluorinated acrylic resin o, oot.