JPH021775A - Resin composition for coating - Google Patents

Abstract

PURPOSE:To obtain the subject composition having balanced corrosion resistance of the coating film and adhesivity to untreated metal by cooking a specific amount of a metal oxide to an alkyd resin modified with a rosin phenolic resin. CONSTITUTION:The objective composition having an acid value (solid component) of 10-40 can be produced by compounding and reacting (A) 15-40 pts.wt. of an oil having an iodine value of >=100 or its fatty acid, (B) 10-50 pts.wt. of a polyhydric alcohol having 2-6 hydroxyl groups in one molecule, (C) 10-50 pts.wt. of a polybasic acid having 1-4 carboxyl groups in one molecule or its acid anhydride, (D) 5-25 pts.wt. of a rosin-modified phenolic resin having a softening point of 100-150 deg.C and (E) a metal oxide. The sum of the components A-D is 100 pts.wt., the amount of the component E is 0.5-5 pts.wt. per 100 pts.wt. of A-D and the molar ratio of OH/COOH in the components A-D is (1.0-1.6)/1.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a resin composition for paint.

[Conventional technology]

Drying oil/semi-drying oil-modified alkyd resins are generally used as oxidative polymerization type paints for the purpose of preventing rust and corrosion of general-purpose metal products, but their adhesion to iron or corrosion resistance is insufficient, and there is a strong demand for improvement.

In order to improve adhesion and corrosion resistance, modification with short oil type alkyd resins, phenolic resins, or epoxy resins has been carried out since the 1950s.

[Problem to be solved by the invention]

However, modification with short oil type alkyd resins, phenolic resins, or epoxy resins has the problem that corrosion resistance and adhesion cannot be balanced.

The present invention provides a resin composition for paint that has an excellent balance of adhesion to iron and corrosion resistance.

[Means to solve the problem]

The present invention has been completed by discovering and completing a resin composition for coatings with an excellent balance between corrosion resistance and adhesion by cooking a certain amount of metal oxide into an alkyd resin modified with a rosin phenol resin having excellent corrosion resistance. be.

That is, the present invention provides (A) 15 to 40 parts by weight of oil or its fatty acid having an iodine value of 100 or more, (B) 2 parts by weight per molecule.
10 to 50 parts by weight of a polyhydric alcohol having ~6 hydroxyl groups, (C) 10 to 50 parts by weight of a polybasic acid or its acid anhydride having 1 to 4 carboxyl groups in one molecule, (D)
5 to 25 parts by weight of a rosin-modified phenolic resin having a softening point of 100 to 150°C and (E) metal oxide, (A) to
The total amount of component (D) is 100 parts by weight, the component (E) is 0.5 to 5 parts by weight based on 100 parts by weight of components (A) to (D), and the components (A) to (D) are The number of hydroxyl groups is 1.
It is obtained by blending and reacting so that the ratio is 0 / 1 ~ 1.6 / 1, and the 4 reed value (solid content) is 10 ~ 4
0.

The component (A) that can be used in the present invention has an iodine value of 1.
00 or higher, such as soybean oil, dehydrated castor oil, linseed oil, tung oil, etc., and their fatty acids.

One or more of these components (A) can be selected and used as appropriate. If the iodine value of the oil or fatty acid is less than 100 months, it will be difficult to oxidize and crosslink, resulting in poor drying properties.
If it is less than 40 parts by weight, curing and drying properties will be poor, and if it exceeds 40 parts by weight, hardness, initial drying properties and corrosion resistance will be poor. Therefore, (A)
The ingredients are mixed in an amount of 15 to 40 parts by weight, preferably 25 to 30 parts by weight.

Component (B) includes ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1.4-butanediol, 1.6-hexanediol, cyclohexane dimetatool, trimethylbentanediol, trimethylolpropane, trimethylolethane, If dipropylene glycol, glycerin, tripropylene glycol, pentaerythritol, dipentaerythritol, etc. are selected alone or in combination of two or more and exceed parts by weight, the reaction will not proceed smoothly.

Also, the water resistance and corrosion resistance of the paint are poor. Therefore, the amount of component (B) is 10 to 50 parts by weight, preferably 15 to 30 parts by weight.

Component (C) includes phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid, p-tert-butylbenzoic acid, hemic acid, maleic acid, fumaric acid, adipic acid, and sebacic acid. , dimer acid, trimellitic acid, or their acid anhydrides, etc., alone or in excess of two or more parts by weight, it is difficult for the reaction to proceed smoothly.

Also, the water resistance and corrosion resistance of the paint are poor. Therefore, the amount of component (C) is 10 to 50 parts by weight, preferably 30 to 40 parts by weight.

Component (D) is obtained by reacting rosin, phenols, and aldehydes by a known method, and the rosin includes gum rosin, tall oil rosin, wood rosin, etc.
0 parts by weight, phenols such as phenol, O-cresol, m-cresol, p-cresol, 2,3-xylenol, 2゜4-xylenol, p-phenylphenol, p-tert-butylphenol, etc., and aldehydes such as formaldehyde , paraformaldehyde,
Hexamethylenetetramine and the like can be used, and the molar ratio of phenols to aldehydes is preferably 1/2 to 1/3. The softening point of rosin modified phenolic resin is 100℃~15
0°C 1 preferably 110 to 130°C, and the softening point is 1
If it is less than 00°C, the initial drying properties will be poor, and if it exceeds 150°C, it will become brittle and the physical properties of the coating will deteriorate. The amount of rosin-modified phenolic resin is 5 to 25 parts by weight, preferably 10 parts by weight.
If the amount is less than 5 parts by weight, the corrosion resistance will be poor, and if it exceeds 25 parts by weight, the physical properties and adhesion will deteriorate.

As component (E), magnesium oxide, zinc oxide, calcium oxide, etc. can be used, and the amount thereof is 0.5 to 5 parts by weight, preferably 1 to 3 parts by weight, per 100 parts by weight of components (A) to (D). If it is less than 0.5 parts by weight, the adhesion to iron will not be improved, and if it exceeds 5 parts by weight, gelation will occur during the reaction or the resin will become cloudy.

In addition, metal oxides are simply defined as components (A) to (D).
The above components (A) to (D) have a hydroxyl group/carboxyl group ratio of 1.0/1 to 1.6/l, preferably 1
．． Blend so that the ratio is 1/1 to 1.4/1, perform a condensation reaction according to the usual alkyd resin synthesis method, and preferably when the reaction rate reaches 60 to 90% of the target acid value (E) It is obtained by adding the ingredients and further proceeding with the reaction until the desired viscosity is reached.

The acid value (solid content) of the resin composition for coating is 10 to 40, preferably 20 to 30. If the acid value is less than 10, the adhesion to iron will be poor, and if it exceeds 40, the corrosion resistance will be reduced. Further, the hydroxyl value of the alkyd resin is preferably 80 to
150, more preferably 100 to 120. If the hydroxyl value is less than 80, water resistance tends to be poor, and if it exceeds 150, solvent solubility tends to be poor. The paint resin composition thus obtained can contain alcohols such as methanol, ethanol, isopropyl alcohol, triol, pheasantol, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monobutyl ether or ester, terpene, aromatic hydrocarbons, One or more solvents can be appropriately selected from ketone, ether, ester, and aliphatic hydrocarbon solvents and diluted to an appropriate solid content before use.

In addition, the above diluted alkyd resin is prepared by dispersing inorganic pigments such as titanium oxide and iron oxide, rust preventive pigments such as zinc chromate, barium metaborate, and calcium tripolyphosphate, or organic pigments such as carbon black, and then dispersing the diluted alkyd resin with naphthenic acid. , Co, Mn, Pb, Z of aliphatic carboxylic acids such as octenoic acid
Metal salts such as n, Zr, etc. are added in an amount of about 0.0 O1 to 0.5% by weight based on the solid content of the alkyd resin (as a metal dryer).
By adding it, it exhibits excellent properties as an oxidative polymerization type paint. This coating resin composition can be applied by dipping, brushing, spraying, etc., and exhibits excellent properties especially when applied to untreated metal (iron) materials.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Below, parts and % refer to parts by weight and % by weight, respectively.
means.

Example 1 (Synthesis of rosin-modified phenolic resin) 180 g of Chinese rosin was charged into 11 glass flasks equipped with a stirrer, a thermometer, a reflux dehydrator, and an inert gas introduction tube, and after melting at 150 to 170 "C, p-tert-
100-11 while adding 200g of butylphenol.
The temperature is lowered to 0° C., 120 g of rose formaldehyde is added, and after keeping the temperature for 3 to 4 hours, the temperature is raised to 230° C. over 6 to 8 hours, and after keeping at 230° C. for 1 hour, it is taken out from the flask and solidified by cooling. The softening point of the obtained rosin-modified phenol resin was 125°C.

(Manufacture of resin composition for paint) 125 parts of linseed oil, 50 parts of glycerin, and 0.13 parts of 12% lithium naphthenate were placed in 11 glass flasks equipped with a stirrer, thermometer, reflux dehydrator, and inert gas inlet tube.
25 parts of tung oil, 47.5 parts of glycerin, and 12.6 parts of ethylene glycol. parts, phthalic acid 187.4
1, 75 parts of the rosin-modified phenol resin obtained above and 70 parts of refluxing pheasant roll were charged, heated to 180°C, kept warm for 2 hours, and then raised to 220°C. Gardner foam viscosity with an acid value (solid content) of 20 and a solid content of 50% in Kijiroll/
When 25℃ becomes S-T, add 5 parts of zinc oxide,
The reaction was further continued at 220°C, and when the Gardner foam viscosity reached W-X, it was cooled and diluted with Kijiroll to a solid content of about 50% to obtain a resin composition for paint.

Example 2 Based on the raw material composition shown in Table 1, the amount of zinc oxide was changed from 5 parts to 1 part.
A resin composition for paint was obtained in the same manner as in Example 1 except that the amount was changed to 5 parts.

Example 3 A coating resin composition was obtained in the same manner as in Example 1, except that 15 parts of magnesium oxide was used instead of zinc oxide based on the raw material composition shown in Table 1.

Comparative Example 1 Based on the raw material composition shown in Table 1, zinc oxide was added from 5 parts to 40 parts.
A resin composition for paint was obtained in the same manner as in Example 1, except that the resin composition was made into a resin composition.

Comparative Examples 2 and 3 Paint resin compositions were obtained in the same manner as in Example 1, except that no metal oxide was added based on the raw material composition shown in Table 1.

Comparative Example 4 A coating resin composition was obtained in the same manner as in Example 1, except that the amount of rosin-modified phenol resin was changed from 75 parts to 150 parts based on the raw material composition shown in Table 1.

Comparative Example 5 A resin composition for paint in which the oil length was increased from 30% to 50% in the same manner as in Example 1, except that the amount of linseed oil was changed from 125 parts to 225 parts based on the raw material composition shown in Table 1. I got it.

Comparative Example 6 A coating resin composition was obtained in the same manner as in Example 1, except that the rosin-modified phenol was removed based on the raw material composition shown in Table 1.

Method for producing paints The alkyd resin solutions of Examples 1 to 3 and Comparative Examples 1 to 2.4 to 6 were made into paints in the following manner.

A paint was produced by dispersing the dispersed paint of paint formulation (1) in Table 2 for 120 minutes in a paint shaker, and then mixing the post-added paint uniformly.

The alkyd resin solution of Comparative Example 3 was made into a paint in the following manner.

A dispersion paint made by cold blending zinc oxide, a metal oxide, according to paint formulation (II) in Table 2 was dispersed in a paint shaker for 120 minutes, and then the post-added paint was mixed uniformly to form the paint. Manufactured.

Paint film test Preparation conditions of test plate Base material: Untreated satin steel plate (5PCC manufactured by Nippon Test Panel Co., Ltd.)
-SD O, 8tX70X150) Painting: Percoater #60 (manufactured by Barcoater) Film thickness: 25-3 in dry film thickness
5 μ Drying: 5 days at 22 to 24°C Application of paints Examples 1 to 3, which are within the scope of the present invention, were excellent in all aspects such as appearance, pencil hardness, water resistance, moisture resistance, corrosion resistance, and adhesion. It shows excellent performance.

Comparative Example 1 is an example in which (E) there is too much metal oxide, and the outer shape and appearance of the face are poor. Comparative Example 2 is an example in which (E) metal oxide is not added, and the adhesion to metals is extremely poor. Comparative Example 3 is an example in which (E) metal oxide is cold-blended when forming a paint, and the adhesion to metals is poor. Comparative Example 4 is an example in which (D) the rosin-modified phenol resin is used in too much amount, and it can be seen that the physical properties deteriorate due to too much amount.

Comparative Example 5 is an example in which (A) there is too much oil, and the hardness and corrosion resistance are poor. Comparative Example 6 is an example in which (D) rosin phenol resin was excluded, and the corrosion resistance was significantly inferior.

Claims (1)

[Claims] 1. (A) 15 to 40 parts by weight of oil or its fatty acid having an iodine value of 100 or more, (B) 10 to 50 parts by weight of polyhydric alcohol having 2 to 6 hydroxyl groups in one molecule, (C) 1.
10 to 50 parts by weight of a polybasic acid or its acid anhydride having 1 to 4 carboxyl groups in the molecule, (D) a softening point of 10
Rosin-modified phenolic resin 5-25 with a temperature of 0-150°C
The total amount of components (A) to (D) is 100 parts by weight, and the component (E) is (A) to (D).
) 0.5 to 5 parts by weight per 100 parts by weight of the component,
And components (A) to (D) are blended so that the number of hydroxyl groups/number of carboxyl groups is 1.0/1 to 1.6/1, and the acid value (solid content) obtained by reacting is 10 to 1. 40
A resin composition for paint.