JPH07133405A - Phenolic water-based resin composition - Google Patents

Abstract

PURPOSE:To obtain the composition suitable for a coating without using any organic solvent, capable of forming a colorless transparent coating film having good water resistance, chemical resistance and adhesion, by combining a specific molecular weight formaldehyde condensation product as a part of its components. CONSTITUTION:A water-based resin composition contains as a part of its components, a condensation product of formaldehyde with 1 mole of a phenolic compound and 0.5-0.05 mole of an aromatic aminosulfonic acid, having an average molecular weight of 2000-500000. Also the composition contains the condensation product with one mole of a bisphenol and 0.75-0.05 mole of the aromatic amino acid, having an average molecular weight of 2000-50000. The bisphenol is expressed by the formula (wherein, X is CH2, SO2, O, etc.). The formaldehyde condensation product of 100wt.pt. is used by combining with 5-200wt.pt. of a component containing a functional group capable of reacting with amino group, methylol group, etc., a water-based melamine resin, a water-based epoxide resin, a water-based urethane resin or a water-based blocked isocyanate. This composition is used for an ink, a coating material, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel aqueous phenolic resin composition, which can be used in the fields of coating materials such as paints, inks and coating agents, sealing agents, adhesives and binders for fibers. .

[0002]

2. Description of the Related Art In recent years, it has been desired to reduce the amount of organic solvents emitted into the atmosphere from the viewpoint of environmental protection. Attempts to reduce the amount of organic solvents used have also been tried in the paint industry. Among them, water-based phenolic resins provide paints and adhesives with excellent chemical resistance, corrosion resistance, and adhesion that are well-balanced. However, the cured product containing a phenol resin has a drawback that flexibility is insufficient and cracks and cracks are likely to occur due to impact.

Conventionally, water-soluble phenolic resins have a phenolic hydroxyl group in the aromatic nucleus, and a water-soluble resol resin obtained by condensing phenols with formalin under alkaline conditions is used as an adhesive, paint or paper phenol laminate. It is used for boards. However, the aqueous resin used here is colored from reddish brown to light brown, and the cured product and cured film formed using them are similarly hard and colored. For this reason, conventional aqueous phenolic resins have been limited to fields in which the color of the resin is not a problem, such as a dark-colored chemical-resistant special paint, structural plywood-like adhesive, and paper phenolic laminate.

On the other hand, the formalin condensate of phenols and aromatic aminosulfonic acid has been actively developed in recent years as a surfactant, and is used as a concrete admixture, a water reducing agent for cement compositions, a dispersant for dyes and gypsum. Patent application as a dispersant (Japanese Patent Application No. 63-238521, Japanese Patent Application No. 1-227082, Japanese Patent Application No. 1-279229, Japanese Patent Application No. 1-279230, Japanese Patent Application No. 1-344656)
And Japanese Patent Application No. 2-63525).

However, conventional formalin condensates of phenols and aromatic aminosulfonic acids are colored reddish brown and have almost no film-forming property. Also,
Even if a film could be formed, the film was soluble in water in a short time.

[0006]

The object of the present invention is to provide a paint, ink or coating capable of forming a colorless and transparent film excellent in water resistance, chemical resistance and adhesion without using any organic solvent. To provide a novel aqueous phenolic resin composition which can be used in the fields of adhesives, sealing agents and adhesives.

[0007]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors have conducted extensive studies on an aqueous phenolic resin capable of forming a colorless and transparent film, and as a result, phenols,
When condensing bisphenols and aromatic amino sulfonic acids with formaldehyde, the amount of aromatic amino sulfonic acids and formaldehyde used for phenols and bisphenols should be adjusted within the proper range to achieve water solubility and water dispersibility in the condensate. It has been found that the coloring can be reduced without impairing the coating property and the film forming ability can be imparted, and that the film has low coloring property, water resistance, chemical resistance and adhesion to a metal surface. Furthermore, they have found that a more colorless coating can be formed by adding a component capable of crosslinking with the aqueous phenolic resin, and a coating having improved water resistance and chemical resistance can be formed.

That is, the present invention is characterized in that it is a formaldehyde condensate of 1 mol of a phenol and 0.5 to 0.05 mol of an aromatic aminosulfonic acid, and contains a condensate having an average molecular weight of 2000 to 500000 as a part of the constituents. It is an aqueous resin composition.

An aqueous resin composition characterized by containing a formaldehyde condensate of 1 mol of bisphenols and 0.75 to 0.05 mol of aromatic aminosulfonic acid and having an average molecular weight of 2000 to 500000 as a part of its constituent components. It is a thing.

Further, the above bisphenol is an aqueous resin composition represented by the following general formula (1). General formula (1)

Further, a functional group which reacts with the formaldehyde condensate of the above-mentioned phenols or bisphenols and aromatic aminosulfonic acid with one or more of an amino group, a methylol group, a hydroxyl group and a secondary amine. An aqueous resin composition characterized by containing a crosslinkable component having two or more of these is effective.

Further, the above-mentioned phenols or bisphenols are blended with 5 to 200 parts by weight of an aqueous melamine resin as a crosslinkable component with respect to 100 parts by weight of a formaldehyde condensate of an aromatic aminosulfonic acid. The aqueous resin composition is more effective.

Further, the above-mentioned phenols or bisphenols are mixed with 5 to 200 parts by weight of an aqueous epoxy resin as a crosslinkable component with respect to 100 parts by weight of a solid content of a formaldehyde condensate of aromatic aminosulfonic acid. The aqueous resin composition is effective.

Further, based on 100 parts by weight of the above phenols or bisphenols and the solid content of the aromatic aminosulfonic acid formaldehyde condensate, 5 to 20 parts by weight of the aqueous urethane resin is added.
An aqueous resin composition characterized by being blended in an amount of 0 part by weight is effective.

Further, the above-mentioned phenols or bisphenols and 100 parts by weight of the aromatic aminosulfonic acid formaldehyde condensate contain 5 to 5 parts by weight of an aqueous blocked isocyanate.
An aqueous resin composition characterized by containing 200 parts by weight is effective.

Further, there are coatings, inks, film-forming products such as coating agents, sealing agents, adhesives, and binders for fibers, which form the above-mentioned aqueous resin composition as a part of the constituents.

The present invention will be described in detail below. The phenols used in the present invention mean mononuclear and polynuclear aromatics having a phenolic hydroxyl group. Here, for example, phenol, para-cresol and its isomers, resorcinol and its isomers, lower alkoxyphenol,
Lower alkylphenols and bisphenols are considered here as a part of phenols, but specifically, 4,4'-dihydroxydiphenyl sulfone, 2,2-
Bis (4-hydroxyphenyl) propane, 4,4'-
Dihydroxybenzophenone, 4,4 '-(perfluoroisopropylidene) diphenol, 4,4'-dihydroxydiphenylmethane, 2,2-bis (4-hydroxyphenyl) butane, 4,4'-dihydroxydiphenyl ether, 4,4' -Dihydroxydiphenylsulfite, 4,4'-dihydroxybiphenyl, and isomers thereof.

The aromatic aminosulfonic acid has, for example, 4-aminobenzenesulfonic acid and its isomer, naphthylaminesulfonic acid and its isomer, and a methyl group such as 2-amino-5-methylbenzenesulfonic acid. Things can also be used.

The formaldehyde used is an aqueous solution. The reaction is preferably carried out in the presence of a basic substance, and as the basic substance used at that time, sodium hydroxide, calcium hydroxide, metal hydroxide such as potassium hydroxide, ammonia and an aqueous solution thereof are preferable. . 1 mol of aromatic aminosulfonic acid existing in the reaction system
On the other hand, it is preferable to use 1.0 to 2.0 mol equivalent of the basic substance. If these mol ratios and mol equivalent ratios deviate from the ranges, the amount of unreacted aromatic aminosulfonic acid and the amount of unreacted phenols are likely to increase. These mols
Ratio, under aqueous conditions, normal concentration 20-50%, reaction temperature 60-11
The condensate of the present invention can be obtained at 0 ° C for a reaction time of 3 to 20 hours.

The above object of the present invention can be achieved by an aqueous resin containing a formaldehyde condensate as a main component, wherein 0.75 to 0.05 mol of aminobenzene sulfonic acid is used per 1 mol of phenol. The formaldehyde condensate preferably has a weight average molecular weight of 2000 or more and 500000 or less, and more preferably 3000 or more and 200000 or less. If the molecular weight is smaller than this range, the chemical resistance, corrosion resistance, flexibility and adhesion of the coating will be insufficient, and if it is larger than this range, the viscosity will be too large and handling will be difficult. The average molecular weight is GPC
The method can measure polystyrene as a standard sample.

Since the aqueous resin of the present invention has a phenolic hydroxyl group, an amino group, a methylol group, and a secondary amine in its structure, it is capable of reacting with those functional groups, for example, an aqueous epoxy resin, an aqueous melamine resin. The physical properties can be further improved by blending a water-based blocked isocyanate and a water-based urethane resin.

The resin composition of the present invention thus obtained has excellent adhesion to a metal surface and is not only excellent as a primer for coating and adhesion, but also a vehicle resin for water-based paints and a binder for water-based inks. It can also be applied as a resin. Further, it can be applied not only as the above film-forming material but also as an aqueous adhesive for plywood, an aqueous adhesive for various plastics, a binder for pulp and glass fiber.

Further, the aqueous resin composition of the present invention is used by adding 0.01 to 15 parts by weight of a drying promoting component such as alcohol in order to improve the evaporation rate of water during drying, if necessary.

In addition, pigments such as rust preventive pigments, coloring pigments, extender pigments, thixotropic agents, viscosity adjusting agents, flow aids, surface modifiers, primary rust preventives, antifoaming agents, preservatives, fungicides, etc. The various additives of (1) are added and mixed in the required amounts.

[0025]

The aqueous resin composition of the present invention exhibits good flexibility, good adhesion, chemical resistance, acid resistance, alkali resistance and water resistance. Aqueous resol resin, which is a general aqueous phenol resin, has one or more methylol groups for one phenol nucleus in order to make itself aqueous, whereas the novel phenol resin of the present invention hydrophilizes the resin with sulfanilic acid to a suitable degree. The amount of methylol group can be controlled. With this, the density of crosslinks in the film formed during drying and baking can be freely controlled, and flexibility can be imparted to the film by decreasing the crosslink density.

Further, the use of bisphenols can suppress the formation of a quinone structure which is a chromophore, so that the color number of the condensate can be further reduced.
In addition, by reducing the compounding ratio of aminobenzene sulfonic acid, it was possible to further suppress the formation of chromophore and increase the water resistance of the film.

Further, the aqueous resin composition of the present invention is blended with a crosslinkable component such as an aqueous epoxy resin, an aqueous melamine resin, an aqueous blocked isocyanate, an aqueous urethane resin or the like to give the coating film a metal adhesion property, a chemical resistance and a water resistance. The inventors have found that the weather resistance can be further improved.

[0028]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In addition, "part" which shows a compounding quantity shows a weight part.

(Example 1) 260 parts of ion-exchanged water and 4-aminobenzenesulfonic acid 2 were placed in a reactor equipped with a stirrer, a reflux device, a thermometer, and a formaldehyde aqueous solution dropping device.
Add 1.6 parts and 5.5 parts of sodium hydroxide and dissolve with stirring.
To this aqueous solution was added 94 parts of phenol. The temperature of the reaction solution is 80.
37% formaldehyde aqueous solution with stirring at 1 ℃
50 parts was added dropwise over 1 hour, and the mixture was further reacted at a temperature of 90 ° C. for 8 hours, and then water was added to adjust the solid content to 30%. The obtained aqueous condensate has an average molecular weight of 64,000 and a viscosity of 38 cps (solid content 30%
Aqueous solution, 25 ° C).

Example 2 A reactor similar to that of Example 1 was charged with 593 parts of ion-exchanged water and 4-aminobenzenesulfonic acid 43.
And 11 parts of sodium hydroxide are added and dissolved by stirring. To this aqueous solution was added 228 parts of 2,2-bis (4-hydroxyphenyl) propane. The reaction solution was heated to a temperature of 80 ° C., 162 parts of a 37% aqueous formaldehyde solution was added dropwise over 1 hour with stirring, and the mixture was further reacted at a temperature of 80 ° C. for 2 hours. Water was added to adjust the solid content to 30% to obtain an aqueous condensed resin solution. The obtained aqueous condensate has an average molecular weight of 55,000 and a viscosity of 65 cps (solid content of 30
% Aqueous solution, 25 ° C.).

Example 3 A reactor similar to that of Example 1 was charged with 750 parts of deionized water and 4-aminobenzenesulfonic acid 43.
And 24 parts of sodium hydroxide are added and dissolved by stirring. To this aqueous solution, 250 parts of 2,2-bis (4-hydroxyphenyl) sulfone was added. The reaction solution was heated to a temperature of 90 ° C, 162 parts of a 37% aqueous formaldehyde solution was added dropwise over 1 hour with stirring, and the mixture was further reacted at a temperature of 90 ° C for 5 hours to give an average molecular weight of 320
An aqueous solution of a condensate having a viscosity of 00 and a viscosity of 23 cps (solid content 30% aqueous solution, 25 ° C.) was obtained.

(Examples 4 to 12) Using the condensates synthesized in Examples 1, 2 and 3, the crosslinkable components were blended at the blending ratio (solid content weight ratio) shown in Table 1, and then the solid content was changed. Adjusted to 30%. However, the parts by weight indicate the weight of the solid content.

Comparative Example 2 4-aminobenzenesulfonic acid 173 was added to 800 parts of ion-exchanged water in the same reactor as in Example 1.
And 40 parts of sodium hydroxide are added and dissolved by stirring. To this aqueous solution, 114 parts of 2,2-bis (4-hydroxyphenyl) propane was added. The reaction solution was heated to a temperature of 80 ° C., 162 parts of a 37% aqueous formaldehyde solution was added dropwise over 1 hour, and further reacted at a temperature of 90 ° C. for 20 hours. Water was added to adjust the solid content to 30% to obtain an aqueous condensed resin solution. The obtained aqueous condensate had an average molecular weight of 55,000, a color number of 13, and a viscosity of 25 cps (solid content 30% aqueous solution, 25 ° C.).

(Comparative Examples 1, 3, 4) Commercially available water-based resole resin, BRL-105 (manufactured by Showa High Polymer) and Oshika Resindinol No. 17 (manufactured by Oshika Shinko Co., Ltd.) were used, and the compounding ratios shown in Table 1 ( After blending the crosslinkable component in solid content weight ratio),
The solid content was adjusted to 30%.

[0035]

[Table 1]

The following compounding crosslinkable components in Table 1 were used. Water-based melamine resin; Watersol S-695 (manufactured by Dainippon Ink) Water-based epoxy resin; Aquatote 8535 (manufactured by Toto Kasei) and Epicurure 3255 (manufactured by Yuka Shell) 1: 1
Used as a mixture. Aqueous blocked isocyanate; Elastron BN-69
(Daiichi Kogyo Seiyaku Co., Ltd.) Water-based urethane resin; Superflex E-2000
(Daiichi Kogyo Seiyaku Co., Ltd.) Aqueous Resol Resin; Aqueous Resol Resin A: BRL-10
5 (Showa High Polymer) Aqueous Resol Resin B: Oshika Resin Dinanol No. 17 (Oshika Promotion Co., Ltd.)

[Test Method] Examples 1 to 12 and Comparative Examples 1 to 1
The water-soluble resin composition prepared in 4 was diluted with water to a solid content of 10%, spray-coated on a base material (polishing mild steel plate or glass plate), and the following wettability test was performed, then at room temperature or 60 ° C. It was pre-dried and baked at 180 ° C for 20 minutes. The film thickness is 10 ~
It was adjusted to 15 μm. The following pencil hardness test, adhesion test, impact resistance test, acid resistance test, and alkali resistance test were performed on the obtained coated plate. The results of these tests are shown in Table 2.

Wettability test A 10% diluted aqueous resin is spray-coated on a degreased polished mild steel sheet (based on JIS-G3141) to visually check whether the coating material spreads uniformly or unevenly on the steel sheet. Evaluated by

Next, the following test was carried out using a test plate having a coating formed on a polished mild steel plate.

Pencil hardness test According to JIS K5400, pencil scratch test method. Only the wood part of a pencil (Mitsubishi Uni, manufactured by Mitsubishi Pencil, trade name) is scraped off, the core is rubbed against the coated steel plate surface at an angle of 45 degrees, and the pencil hardness just before the painted surface is scratched is displayed.

Adhesion test A test was carried out based on JIS K5400, the eye contact test method. Make a cut on the coated surface with a cutter to make 100 cuts at 2 mm intervals, adhere cellophane adhesive tape on it, peel it off 5 times at 180 ° C, and count the number of remaining cuts .

Impact resistance test A test was conducted according to JIS K5400, DuPont test method. The changes occurring in the coating when a 500 g weight was dropped from a height of 50 cm were evaluated.

Acid resistance test A test was conducted based on JIS K5400, acid resistance test. After being immersed in a 5% aqueous solution of sulfuric acid for 24 hours, washed gently with running water, shaken off the water, and visually inspected the state of the coating film. Furthermore, the test piece is left in the standard state for 2 hours, and the state of the coating film is examined again.

Alkali resistance test A test was conducted based on JIS K5400, an alkali resistance test. After immersing in a 5% sodium carbonate aqueous solution for 24 hours, gently washing with running water, shaking off the water, and visually observing the state of the coating film. In addition, put the test piece in the standard condition 2
After leaving for a while, the state of the coating film was examined again.

Color Number Measurement The color number of a 30% aqueous solution of the prepared aqueous resin and blended composition was measured by the Gardner method.

Evaluation of color tone of coating A water-based resin was cast on a glass plate having a thickness of 2 mm, preliminarily dried at room temperature or 60 ° C., and then baked at 180 ° C. for 20 minutes to form a coating of 20 μm. This was visually evaluated.

[0047]

[Table 2]

From the results shown in Table 2, not only the phenolic aqueous resin composition of the present invention forms a coating film having low coloring property,
It can be seen that it exhibits excellent physical properties in pencil hardness, adhesion, impact resistance, acid resistance and alkali resistance.

[0049]

EFFECT OF THE INVENTION By using the phenolic water-soluble resin composition of the present invention, a coating material, ink, coating agent, etc. having a low organic solvent content and excellent chemical resistance, corrosion resistance, flexibility and adhesion can be obtained. A film forming product, a sealing agent, an adhesive, a binder for fibers, and the like can be provided.

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[Procedure amendment]

[Submission date] February 3, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

Adhesion test A test was carried out based on JIS K5400, the eye contact test method. Make a cut on the painted surface with a cutter
100 pieces of eyes were made at intervals of 1 mm , a cellophane adhesive tape was adhered on the pieces, and the pieces were peeled off in the 180 ° direction 5 times to count the number of remaining eyes.

Claims (9)

[Claims] 1. An aqueous resin composition comprising a formaldehyde condensate containing 1 mol of a phenol and 0.5 to 0.05 mol of an aromatic aminosulfonic acid and having a mean molecular weight of 2000 to 500000 as a part of its constituent components. object. 2. A water-based resin composition comprising 1 mol of bisphenols and 0.75 to 0.05 mol of aromatic aminosulfonic acid, which is a formaldehyde condensate, and which contains a condensate having an average molecular weight of 2000 to 500000 as a part of constituent components. object. 3. The aqueous resin composition according to claim 2, wherein the bisphenol is represented by the following general formula (1). General formula (1) 4. An amino group based on 100 parts by weight of a formaldehyde condensate of the phenol or bisphenol according to claim 1, 2 or 3 and an aromatic aminosulfonic acid,
An aqueous resin composition comprising 5 to 200 parts by weight of a crosslinkable component having two or more functional groups that react with one or more of a methylol group, a hydroxyl group and a secondary amine. 5. A phenolic or bisphenol compound according to claim 1, 2 or 3 and 5 to 200 parts by weight of an aqueous melamine resin as a crosslinkable component are added to 100 parts by weight of a formaldehyde condensate of an aromatic aminosulfonic acid. The aqueous resin composition according to claim 4, wherein 6. A phenolic or bisphenol compound according to claim 1, 2 or 3 and 5 to 200 parts by weight of an aqueous epoxy resin as a crosslinkable component with respect to 100 parts by weight of a formaldehyde condensate of an aromatic aminosulfonic acid. The aqueous resin composition according to claim 4, wherein 7. The phenol or bisphenol according to claim 1, 2 or 3 and 5 to 200 parts by weight of an aqueous urethane resin as a crosslinkable component are blended with 100 parts by weight of a formaldehyde condensate of an aromatic aminosulfonic acid. The aqueous resin composition according to claim 4, wherein 8. The aqueous block isocyanate as a crosslinkable component is blended in an amount of 5 to 200 parts by weight with respect to 100 parts by weight of the formaldehyde condensate of the aromatic aminosulfonic acid and the phenol or bisphenol according to claim 1, 2 or 3. The aqueous resin composition according to claim 4, wherein 9. A coating film-forming material such as a paint, an ink, a coating agent, a sealing agent, an adhesive and a binder for fibers, which comprises the aqueous resin composition according to any one of claims 1 to 8 as a part of its constituent components.