JPS5986665A - Oil-modified alkyd resin paint composition - Google Patents

Abstract

PURPOSE:To provide a solventless paint compsn. which gives a coating film having excellent wheather resistance, gloss, hardness, adhesion to metal, etc., by blending a specified oil-modified alkyd resin, a polymerizable monomer which can dissolve the resin and is a liquid at room temp. and a curing catalyst. CONSTITUTION:The titled compsn. is obtd. by blending 100pts.wt. oil-modified alkyd resin (A) obtd. by reacting a drying oil and/or a semidrying oil e.g. soybean oil, safflower oil or linolic acid separated therefrom), a polyhydric alcohol such as glycerol, an organosilicon compd. of the formula (wherein R1 is CH3, C6H5; R2 is CH3, C6H5, OCH3, OH; X is H, CH3; n is 1-3) such as diphenyldiphenyldimethoxysilane and optionally a polybasic acid such as phthalic anhydride, 50-200pts.wt. polymerizable monomer (B) which is liquid at 20 deg.C and can dissolve component A, such as 2-hydroxypropyl (meth)acrylate, and a proper quantity of a curing catalyst (C) such as cobalt naphthenate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solvent-free coating composition that provides a coating film excellent in weather resistance, adhesion to metals, gloss, hardness, etc.

Oil-modified alkyd resins are generally prepared from polybasic acids, polyhydric alcohols, and fatty acids (including fatty acids separated from drying oils and semi-drying oils), and the double bonds of the fatty acids in the ingredients are crosslinked with oxygen and hardened. It is used in various types of paints such as air-drying paints and baking paints due to its properties.

Conventionally, oil-modified alkyd resins with an oil length of between 30% and 80% are generally diluted with solvents such as turpentine oil and toluene and used in air-drying and baking paints; Oil-modified alkyd resin paints have problems such as requiring a long time to dry and the solvent that evaporates during drying worsens the working environment.

We have considered oil-modified alkyd resin paints that do not use solvents, that is, non-polluting paints in which all the paint components react, but conventional paints not only have poor adhesion to metals but also have problems with coating properties. The current situation is that it has not been put into practical use.

For the purpose of practical application of such a solvent-free oil-modified alkyd resin coating, we first prepared (a) an oil with a length of 40 to 60% modified with a fatty acid having a linoleic acid and/or lylunic acid content of 65% by weight or more; oil-modified alkyd resin 50 to sob amount% (b) having at least 2 hydroxyl groups and having 2 to 2 carbon atoms
50 to 20% by weight of acrylate and/or methacrylate, which is a monoester of 0 alcohol (c) Curing catalyst An oil-modified alkyd resin coating composition containing appropriate amounts of the above components (a), C#3) and (c) is proposed. It has been put into practical use (Japanese Patent Publication No. 54-32650).

This solvent-free coating composition can be dried at room temperature and cured by baking, and provides a coating film with excellent surface smoothness, hardness, and adhesion to metal, so it can be used for steel stationery products such as steel furniture, shelves, desks, etc. It is useful as a paint for

This solvent-free oil-modified alkyd resin paint is also useful as a heavy-duty anti-corrosion paint for oil plants, oil storage tanks, etc., and after four and a half years, the weatherability of the paint film has been confirmed in practical tests at a plant in the Yokkaichi Industrial Complex. Gender is not an issue.

Conventionally, solvent-based heavy-duty anticorrosive paints have been reapplied every two to three years for weather resistance reasons. This repainting requires the removal of the old paint film and the construction of scaffolding to apply the new paint, which together with the cost of the new paint will account for the majority of the cost. Therefore, it is important for a heavy-duty anticorrosion paint to have a long period of time before repainting, that is, to have good weather resistance of the paint film.

The present invention was made with the aim of further improving the weather resistance of this solvent-free oil-modified alkyd resin paint. The method consists in using a resin obtained by replacing the organic silicon derivative with the determined organosilicon derivative.

That is, the present invention provides the following components: (4) Components: Drying oil and/or semi-drying oil, polyhydric alcohol, organosilicon visiting conductor represented by the following formula (1), and optionally a polybasic acid, which are reacted as raw materials. Oil-modified alkyd resin obtained by 100 parts by weight ω) Component: 50 to 200 parts by weight of a polymerizable monomer that is liquid at 20°C that can dissolve the above component (4) Component 6-0: The above component (■), An oil-modified alkyd resin coating composition 1' characterized in that component (B) and component 0 are blended in the above proportions.

(wherein R1 is CHa or C6H5; R2 is C
Ha, CaHs, OCH3 or OH; X is H or CH3. In addition, n is a number from 1 to 3).

In the present invention, the oil-modified alkyd resin as a captive component is a drying oil or a semi-drying oil (including fatty acids derived from these), a polyhydric alcohol, and an organosilicon derivative represented by the above formula (1), if necessary. It is obtained by condensing saturated polybasic acids as raw materials, and has an oil length of 30 to 70%, more preferably 40 to 60%.

When considering that fatty acids in the resin react with glycerin to form fatty acid triglycerides in oil-modified alkyd resins, the weight percentage of the triglycerides in the resin is called the oil length, and this is determined by the physical properties of the paint. It is an important index for determining properties such as solubility, hardness, gloss, color retention, weather resistance, curing time, and storage stability. For example, increasing oil length helps increase coating flexibility and solubility in organic solvents, as well as coating curing speed;
It tends to reduce the hardness of the paint film.Also, a decrease in oil length tends to improve the gloss and color retention of the paint film, but conversely it also tends to reduce the spreadability of the paint.

The oil or fatty acid used to synthesize the oil-modified alkyd resin of component (2) is a drying oil, a semi-drying oil, or an oil fatty acid separated from them, such as soybean oil, tall oil, safflower oil, These include dehydrated castor oil and linseed oil, and fatty acids separated from them, such as linoleic acid and linuric acid.

Polyhydric alcohol components include ethylene glycol, diethylene glycol, fluoropylene gellicol, dipropylene glycol, 1.4-7" tanediol, neopentyl glycol, glycerin, trimethylolpropane, tris(2-hydroxyethyl)isocyanurate, and pentaeryth. IJ)-ru and the like can be used alone or in combination of two or more.

Examples of organosilicon derivatives include dimethylmethoxysilane,
Methylphenyldimethoxysilane, diphenyldimethoxysilane, phenyltrimethoxy, silane, and condensates derived from these, such as Shin-Etsu Silicone Varnish KR-212 and KR-213, which are commercially available as modified silicone varnishes. , KR-214
, KR-215, KR-216, KR-218 [Shin-Etsu Chemical Product Name], Toshiba Silicone Varnish TSR
-160゜TSR-165, YR-316s (product names manufactured by Toshiba Silicone ■), Toray Silicone Oil B
YI 6-817, BX16-801, SF-9- 8427, 5F-8417C and above Toray silicone ■
product name] etc.

Examples of polybasic acids include saturated polybasic acids such as phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, adipic acid, cepadino acid, azelaic acid, trimellitic anhydride, alloocimene maleic acid adduct, myrcene maleic acid adduct, etc. can be used. A part of it may be replaced with an unsaturated polybasic acid such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc., as long as gelation does not occur.

Furthermore, in addition to the drying oil, semi-drying oil, and fatty acids, α,β-unsaturated acid-base acids sorbic acid, crotonic acid, and β-(2-furfuryl)acrylic acid or the like may also be used. The content of these acids is preferably 30% by weight or less in the raw material of the oil-modified alkyd resin.

The amount of each raw material used is determined to be 10 so that the oil length of the oil-modified alkyd resin is 30 to 70% of the above value and that the alkyd resin does not undergo gelation during production. In addition, the organosilicon compound represented by formula (1), which is a polyfunctional acid, accounts for 20 to 100 mol%, preferably 30 to 90 mol% of the total of the polyfunctional acids of the polybasic acid and the organosilicon derivative. Use within a range of %. If it is less than 20 mol%, no further improvement in weather resistance can be expected.

Various conventionally employed methods can be used to produce the oil-modified alkyd resin. For example, the above-mentioned oils and fats or oil fatty acids, polybasic acids, organosilicon derivatives, and polyhydric alcohols are heated at 180 °C in an inert gas. It can be produced by heating at ~250°C. Preferably, a low condensate is prepared in advance from other components except the organosilicon derivative under the same conditions, and then the low condensate and the organosilicon derivative are condensed.

The reaction is terminated when the acid value of the oil-modified alkyd resin obtained is 20 or less, preferably 5 to 10.

Oil-modified alkyd resins with an acid value exceeding 20 have slow drying properties and the resulting coating film is too soft, making them impractical.

Next, the radically polymerizable monomer of component (8) will be described. This polymerizable monomer of component (B) can dissolve the oil-modified alkyd resin of component (4), and always! 'It is liquid at 2oC. Although any monomer can be used as such a polymerizable monomer, the purpose is to suppress volatilization as much as possible until the coating composition of the present invention is cured at room temperature or heated. Because it is a substance, its boiling point is 20% higher than that of low-boiling monomers such as styrene, methyl methacrylate, and divinylbenzene.
Monomers with a high boiling point of 0° C. or higher are preferred.

Specifically, acrylates or methacrylates of the following groups (a) to (c) are preferred.

(a) Monoacrylate or monomethacrylate which is an esterified product of a monohydric or polyhydric alcohol having 2 to 20 carbon atoms and acrylic acid or methacrylic acid.

Some specific examples of such monoacrylates and monomethacrylates are as follows. In the following, the expression "(meth)acrylate" means acrylate and methacrylate.

2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyethoxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, neopentyl glycol mono(meth)
Acrylate, 3-butoxy-2-hydroxypropyl (meth)acrylate, 2-hydroxy-1 or 2-
Phenylethyl (meth)acrylate, polypropylene glycol monomethacrylate, glycerin mono(meth)acrylate monohalf maleate, diethylene glycol mono(meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-
Ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, tetrahydrofurfuryl (
Meta) acrylate.

13-), di(meth) which is an esterified product of a polyhydric alcohol having 2 to 20 carbon atoms and acrylic acid or methacrylic acid
Acrylate, tri(meth)acrylate or tetra(meth)acrylate.

Specifically, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,
3-butanediol di(meth)acrylate, 1,4-
butanediol di(meth)acrylate), 1,6-hexanethiol di(meth)acrylate, neobentyl glycol di(meth)acrylate, glycerin monoacrylate monomethacrylate, trimethylol gulon(
Examples include tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetramethacrylate.

These may be used alone or in a mixture of two or more. A preferred embodiment is di(meth)acrylate 50 to 90
Weight% and mono(meth) having at least one hydroxyl group
When using a mixture with 50-10% acrylate,
It is possible to obtain a coating film that is well-balanced in water resistance, flexibility, adhesion to gold 14-coat, smoothness, and gloss. Tri(meth)acrylate and tetra(meth)acrylate have the effect of increasing the hardness of the paint film, but they themselves have high viscosity and impair the coating properties of the paint, so they are preferably used in an amount of 20% by weight or less of component (6). should be used at less than 5% by weight.

The polymerizable monomer of component (2) is used in an amount of 50 to 200 parts by weight, preferably 80 to 120 parts by weight, based on 100 parts by weight of component (2). If the amount of the polymerizable monomer is less than 50 parts by weight, the paint will have a significantly high viscosity and will be difficult to apply, and the curability of the inside of the paint film will be insufficient.
Ru. '. On the other hand, if it exceeds 200 parts by weight, physical properties such as drying properties of the paint and water resistance of the paint film will deteriorate.

This mixed resin composition (with component (4)) is cured by using a redox catalyst consisting of an organic peroxide or an organic peroxide and a reducing agent, and a metal drying agent such as a manganese or cobalt compound. be able to. Among these, the following combinations are available as preferred examples.

(a) Methyl ethyl ketone peroxide and cobalt naphthenate (b) Cyclohexanone peroxide, cobalt naphthenate and mankane naphthenate (c) Methyl ethyl ketone peroxide, dimethylaniline and cobalt naphthenate) t-butyl peroxide and dimethylaniline, especially accelerators When cobalt naphthenate is used as a cobalt naphthenate, it is necessary to add another type of metal desiccant because it not only participates in radical generation as a reducing agent but also as a metal desiccant and participates in the oxidative hardening of double bonds in oil fatty acid residues. There is no
suitable.

These catalysts have a total of 1
0.00 parts by weight, the organic peroxide is 0.5 to 5.0 parts by weight, the reducing agent is 0.01 to 5.0 parts by weight, and the metal desiccant is 0.01 to 5.0 parts by weight. In the coating composition of the present invention, pigments such as titanium oxide, zinc white, ultramarine blue, carbon black, talc, calcium carbonate, barium sulfate, various resins or additives for modification, stabilizers, and polymerization inhibitors are added to the paint composition of the present invention. agents, surface property improvers such as polyethylene glycol,
Pigment dispersion and the like can be added within a range that does not impair coating film performance or storage stability of the paint.

The coating composition of the present invention can be applied by brush, roller, spray gun, or other methods. Furthermore, in order to facilitate painting, a solvent such as mineral spirit, xylene, ethyl acetate, methyl isobutyl ketone, etc. may be added within a range that does not harm the environment.

The coating composition of the present invention can be dried and cured at room temperature.
It is also possible to harden the baking by heating to 0° C. or higher.

Particularly when used as an air-drying paint, the curing time is short, making it ideal for painting aerial structures.Examples and comparative examples are shown below. Note that all parts in the examples mean parts by weight.

A. Production of oil-modified alkyd resin 17- Production Example 1 In a reactor equipped with a stirrer, thermometer, cooler, water separator, and nitrogen inlet tube, 50.0 parts of dehydrated castor oil fatty acid and 14.0 parts of phthalic anhydride were placed. 2 parts of glycerin, 21.4 parts of neopentyl glycol, and 1.2 parts of neopentyl glycol, and further added 5 rnl of xylene, and the acid value was 20 at 220°C under a nitrogen stream.
The reaction was carried out until reaching .

The reactor was then cooled to 180'C, 35.1 parts of diphenyldimethoxysilane was added, and the reactor was cooled again to 200'C.
℃, the acid value of the oil-modified alkyd obtained is 10
The reaction was carried out until .

After the reaction was completed, it was cooled, and then water, xylene, etc. were removed to obtain a yellow-brown dehydrated castor oil-modified alkyd resin powder with an oil length of 48.4%.Production Examples 2 to 5 The raw materials are shown in Table 1. Oil-modified alkyd resin ω)~■ with the oil length shown in the same table was prepared in the same manner as in Production Example 1 except that
I got it.

Production Example 6 50 parts of linoleic acid, 34.8 parts of phthalic anhydride, 21.4 parts of glycerin, and 1.0 parts of neopentyl glycol were placed in a reactor equipped with a stirrer, a thermometer, a cooler, a water separator, and a nitrogen inlet tube. Add 2 parts and add 5 ra of xylene.
After adding t, the reaction was carried out at 220°C in a nitrogen stream until the acid value became 20 or less, and then water, xylene, etc. were removed to obtain a yellow-brown linoleic acid-modified alkyd resin with an oil length of 52.3% ( Resin-F) was obtained.

(Margin below) Examples 1 to 5, Comparative Example 1 [Paint evaluation] Touch drying time and pencil hardness of coating film: Oil-modified alkyd resin resins A to F obtained in the above examples 5
A resin composition for coating was prepared by dissolving 0 M in a mixture of 16 parts of 2-hydroxypropyl methacrylate and 34 parts of 1,3-butanediol dimethacrylate.

For every 100 parts of this composition, 1.0 part of cobalt naphthenate (cobalt content 6% by weight) and 1 part of methyl ethyl ketone peroxide (55% by weight dimethyl phthalate solution) are added.
．． A paint was prepared by adding 5 parts. The viscosity of this paint at 25°C was measured using an Emiller rotational viscometer.

Apply this paint to a polished mild steel plate (length 7 crn, width 15 cy++
, thickness 8 + mn) using an applicator so that the film thickness is 45 μm, and then
It was left to stand in an air bath at ℃ for 7 days and dried to obtain a coating film.

The pencil hardness of the obtained coating film was measured according to JIS K-5652.

Furthermore, when the paint film was touched with a finger in the same air bath, the time when the paint film no longer felt sticky was defined as the dry-to-touch time.

Non-volatile content: The coating material obtained above was placed in a Petri dish with an inner diameter of 6 crn to form a uniform film, and was allowed to stand in an air bath at 30° C. for 24 hours to dry. The nonvolatile content was determined using the following formula.

Water resistance: 42.7 parts of rutile titanium oxide and 25.6 parts of barium sulfate were mixed with 102.5 parts of the above paint, and the mixture was kneaded with three rolls to obtain a paint. Apply oil-based anti-rust paint (JIS) in advance.
A test piece obtained by applying and curing the paint in the same manner as above on a mild steel plate coated with K-56232 and dried was immersed at room temperature for 7 days in accordance with JISK-5400.

Those with abnormalities such as blisters and cracks in the coating film were marked as ×, and those without were marked as ○.

Weather resistance: The test piece obtained above was tested using a Suga Test Instruments Due Cycle Super Long Life Weatherometer WEL-8U.
Rainfall cycle in N-DC for 12 minutes out of 60 minutes, temperature 43℃
The coating film was observed after being stored under the following operating conditions. The retention rate (%) of surface gloss (60'-600) was determined.

Table 2 shows the results of paint evaluation.

Example 6 50 parts of oil-modified alkyd resin-C obtained in Production Example 3 was added to 2
-Hydroxypropyl methacrylate 15 parts, 1.3-
A coating material was prepared and evaluated in exactly the same manner as in Example 1, except that a solution diluted with a mixture of 25 parts of butanediol dimethacrylate and parts of trimethylolpropane triac+)V-)tO was used.

The results are shown in Table 2.

Comparative Example 2 Silicone alkyd varnish KP-206 (Gr. Etsu Kagaku Kogyo product, 50% by weight xylene solution) 25.0 parts of rutile titanium oxide, 15.0 parts of barium sulfate, cobalt naphthenate ( Cobalt content 6
% by weight) were mixed and a paint was obtained in the same manner as above. Evaluation was performed in the same manner as in Example 1 except for using this paint.

The results are shown in Table 2.

Comparative Example 3 Evaluation was carried out in the same manner as in Comparative Example 2 except that silicone alkyd varnish TSR-184 (Toshiba Silicone ■ product, 50% by weight turpentine solution) was used. The results are shown in Table 2.

(Margin below) 25-

Claims (1)

[Claims] 1), Components: Drying oil and/or semi-drying oil, polyhydric alcohol, organosilicon visiting conductor represented by the following formula (1), and if necessary polybasic acid are used as raw materials, and these are reacted. Oil-modified alkyd tree P3 obtained by An oil-modified alkyd resin coating composition characterized in that the above-mentioned active ingredient, Φ) ingredient and 0 ingredient are blended in the above-mentioned proportions (wherein, R1 is CH3 or C5Hs; R2 is CHs, Cs, Hs, UCHs or OH;
is H or CH3. Also, the number is n1dt~3. 2) In the raw material for the oil-modified alkyd as a prison component, the organosilicon derivative is used in a proportion of 20 to 100 mol% of the molar sum of the organosilicon derivative and the polybasic acid. A coating composition according to scope 1. 3), (131 component polymerizable monomers are (bl):
A monoacrylate obtained by reacting a carbon a2-2o alcohol with acrylic acid or methacrylic acid, and containing 10 to 50% by weight of a monomer having at least one hydroxyl group (b+): Carbon 't- Diacrylate 90 to 50% by weight (ba) obtained by reacting a polyhydric alcohol having a number of 2 to 20 carbon atoms with acrylic acid or methacrylic acid: Reacting a polyhydric alcohol having 3 to 6 carbon atoms with acrylic acid or methacrylic acid 2. The coating composition according to claim 1, which is a mixture of 0 to 20% by weight of triacrylate or tetraacrylate.