JPS5927917A - Coating alkyd resin - Google Patents

Abstract

PURPOSE:A coating alkyd resin excellent in adhesion of dried films, low-temperature processability, etc., obtained by using a liquid carboxyl group-terminated acrylonitrile/butadiene copolymer as part of a polybasic acid component. CONSTITUTION:As part of a polybasic acid component is used 2-20wt%, based on the total weight of an alkyd resin, liquid carboxyl group-terminated acrylonitrile/butadiene copolymer having an acrylonitrile content of about 5-40wt% and a MW of, preferably, about 2,500-5,000. Then, this copolymer is mixed with an animal or vegetable oil (e.g., soybean oil, or fish oil) or a fatty acid, and a polybasic acid (e.g., phthalic anhydride, or maleic anhydride), and the resulting mixed acid component together with a polyalcohol (e.g., ethylene glycol, or glycerin) is heated to effect transesterification and esterification to form the purpose coating alkyd resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The novel alkyd resin used as a vehicle for RT and A materials of the present invention is: 1- It is small in size, and has a lower cured coating film resistance than conventional paint alkyd resins. Attachability.

The present invention provides an alkyd resin for paints that has excellent low-temperature processability.

Alkyd resins are widely used for materials such as gold ducks, wood, concrete, and plastics due to their pigment dispersibility, painting workability, finish quality, and economic efficiency, but in cases where high adhesion to the object being coated is required. For example, it is not necessarily suitable for primary rust prevention such as coil coating, heavy anti-corrosion undercoating, and steel pipes.
Currently, some expensive epoxy resins and urethane resins are unavoidably used.

In order to overcome these drawbacks of alkyd resins, the inventors conducted various studies and found that a liquid acrylonitrile-butadiene copolymer having a terminal carboxyl group was used as a polybasic acid component in an amount of 2 to 20% by weight of the total amount of alkyd resins. %, it was discovered that the adhesion to the painted object was greatly improved and the low-temperature processability was excellent, and the invention was completed.

Alkyd resin for paints is a polyester resin produced through transesterification and esterification reactions from animal and vegetable oils, fatty acids, or both, polybasic acids, and polyhydric alcohols. As part of the alkyd resin, a liquid acrylonitrile-butadiene copolymer containing a carboxyl group at the terminal is added to the total amount of alkyd resin.
It was used in an amount of 20% by weight. The alkyd resin for coatings of the present invention contains, as its constituent components, animal and vegetable oils, fatty acids, or both, common polybasic acids, liquid acrylonitrile-butadiene copolymers with terminal carboxy groups, and polyhydric alcohols. Contains^0 Animal and vegetable oils are conventionally used to modify alkyd resins for paints.
Drying oils, semi-drying oils, non-drying oils such as soybean oil, linseed oil, castor oil, dehydrated castor oil, tall oil, coconut oil, safflower oil, fish oil, rice bran oil, etc. can be used; You can also modify one piece of it by modifying it as necessary.

Further, one type of fatty acid may be used, or two or more types may be mixed. It is also possible to use animal and vegetable oils and fatty acids in combination.

For polybase #11, select an appropriate one from among those conventionally used as components of alkyd resins for paints. For example, dibasic acids such as phthalic anhydride and maleic anhydride. , isophthalic acid, terephthalic acid, tetonhydrophthalic anhydride, adipine rR+ 7-r ruic acid,
Examples include dimer acids obtained from polymerization of sebacic acid and linoleic acid, and examples of tribasic acids include trimellitic anhydride.

Liquid acrylonitrile (having a carboxyl group at the end) I
The butadiene copolymer preferably has molecules it2&
00 to 5,000, and the acrylonitrile content is 5 to 40 weight: 1%, and has carboxyl groups at both ends of the molecule, and is commercially available, and is appropriately selected from On et al. and use it. There are 601 and so on.

Liquid acrylonitrile with a carboxyl group at the end
The amount of butadiene copolymer is 2-2 of the total amount of alkyd resin.
It is appropriate to use 0% by weight. If it is less than 2% by weight, the μ adhesion and low-temperature processability will not be the same as above, and if it is 200% by weight, the coating will become too soft and drying will be delayed! : Not only that, but liquid acrylonitrile-butadiene copolymers with M terminal carboxyl groups are more expensive than animal and vegetable oils, polybasic acids, and polyhydric alcohols.
It is uneconomical.

Polyhydric alcohols are also the same as the alcohol components of conventional alkyd resins, such as ethylene glycol, diethylene glycol, glycerin, pentaerythritol, mannitol 11"J methylolpropane, and trimethylol. Ethane, neopentyl glycol, etc. used alone or in combination of two or more
L.

Uninvented alkyd resin for paint is basically alkyd resin +
It has excellent performance as a fat, and on top of that, it contains a liquid acrylonitrile-butadiene copolymer with a carboxyl group at the end as the fourth component. The rubber-like properties of the co-combination are expressed, and compared to the conventional three-component one,
+M has good adhesion and the coating film is rich in low-temperature loe properties.

General alkyd resins can be varied in properties depending on the type and combination of animal and vegetable oils or fatty acids, polybasic acids, and polyhydric alcohols, but it is possible to change the properties of alkyd resins in various ways, but uninvented alkyd resins for paints The same goes for the resin, and by changing the value of the 4fL oil or fatty acid, it is possible to obtain alkyd resins of Z, 6, long oil, medium oil, and short oil.
In addition, in order to raise the glass transition point and adjust the molecular weight,
If necessary, a more basic acid such as benzoic acid or paratertiary butylbenzoic acid can also be used.

It is also possible to bake the resin for use in painting, or to use a drying oil and/or semi-drying oil as the LU4M oil or fatty acid to create an alkyd resin for paints that cures at room temperature.

Transesterification and esterification of the alkyd resin for paint according to the present invention, animal and vegetable oils or fatty acids, polybasic acids, polyhydric alcohols, and a liquid acrylonitrile-butadiene copolymer having a terminal carboxyl group are carried out in a conventional manner by heating L dino 10. You can easily get it by doing it.

Examples and comparative examples of non-invention are shown below.

(1) Synthesis of alkyd resin a) Transesterification reaction For formulation 1 shown in Table 1, containing animal and vegetable oils in the raw materials (Examples 6 and 7 and Comparative Examples 4 and 5), the ester was first prepared by the following procedure. Perform an exchange reaction.

Reactor 1/C1 is equipped with a stirrer, a temperature of 4 tons, a cooler, a water separator, and a nitrogen gas collector. Raw materials for animal and vegetable oil components and polyhydric alcohol components are charged, and lithium naphthenate is added as a catalyst to about 0.0% of the charged amount. 18% of the solution was added, and the mixture was reacted for 1 hour at 250° C. in a nitrogen gas flow. After the reaction, the mixture was cooled.

b) Esterification reaction The raw materials are charged into the above-mentioned reactor according to the mixing ratio shown in Table 1. If the raw materials contain animal or vegetable oil, add the remaining raw materials to the ones after the transesterification reaction described in the previous section]
Get 1. Next, the mixture is heated to 220° C. in a nitrogen gas stream to react until the acid value reaches 20 or less, and after cooling, the mixture is diluted with a varnish diluent to a solid concentration of 50% to obtain a modified alkyd resin varnish.

Go 1 (2) Preparation of test pieces Melamine alkyd resin paints were used as melamine alkyd resin paints for the actual flow sides 1 to 5 and Comparative Examples 1 to B of the baking paint formulations shown in Table 1, and the baked coating films were evaluated.

The composition of the paint is as follows.

Alkyd resin varnish 100 Vansemin 12
5-60 (Taneya Kasei 85.7 Butylated melamine resin titanium white (rutile) manufactured by Egyo Co., Ltd.
47.6 With the above formulation, the particle size is 10 by three rolls.
The mixture was kneaded until it was less than μ and diluted with xylene to prepare a paint for 18 to 20 seconds in a Ford cup 1+4. This paint was degreased with xylene and the thickness of one film on the steel plate was 80~8.
It was spray coated to a thickness of 5μ, baked in a hot air dryer at 150°C for 20 minutes, and the test piece was used as a test piece to measure the value of one paint needle.

b) Room-temperature-drying paint Regarding the actual flow side 6 to 8 and Comparative Examples 4 to 6 of the formulations in Table 1, the formulations of the paints that were evaluated in the room-temperature drying film are as follows.

Alkyd resin varnish io.

Titanium white (rutile) 88.56% Cobalt naphthenate 042524% Lead naphthenate 0.884% Calcium naphthenate 0.13 The above composition was kneaded with three rolls until the particle size was below loμ, and a varnish diluent was added. A paint having a viscosity of 751 U (25° C.) was prepared using the above.

Apply this paint to a polished steel plate degreased with xylene with a film thickness of 80~
It was coated with a percoater to a thickness of 35 μm, dried at 20° C. and 65% relative humidity for 7 days, and used as a test piece for paint evaluation.

(8) @Membrane test method Pencil hardness was conducted according to JIS K-5400, and judgment was made based on the occurrence of scratches and heat.

b) Impact resistance Using a DuPont impact tester, 172 inches.

Tested under the conditions of 1 kg + 80 (1'll +), the percent n of the coating film
Judgment was made based on the presence or absence of

C) Flexibility: Compliant with JIS K-5400. The bar diameter is 8 degrees shoulder,
Judgment was made based on the presence or absence of %n in the coating film.

d) Wf adhesion J119 According to K-5400, after the cross-cut test, Erichsen was applied and the tape was combed, and the number of cross-cuts remaining on the coating film was evaluated.

0) Low-temperature workability The test piece was left in a thermostat at -5°C, and its bending resistance was determined at 0°C.

f) Drying property According to JIS K-5400, 20°C, relative humidity 65%
The curing and drying time was measured under the following conditions.

(4) Test results The test results are shown in Table 2.

According to the present invention, the polybasic acid component of the alkyd resin is a liquid acrylonitrile having a carboxylic group at the terminal.
Contains a butadiene copolymer, so it has excellent impact resistance, bending resistance, adhesion to coated objects, and low-temperature resistance, as shown in Table 2. The effect is particularly noticeable when using mesimine alkyd resin paint and ray.

Claims (1)

[Claims] The alkyd resin for paints is characterized by using a liquid acrylonitrile/getadiene copolymer having a carboxyl group at the terminal as a polybasic acid component in an amount of 2 to 20 i of the total amount of alkyd resin.