JP2603172B2 - Aqueous resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin composition and can be used mainly as a paint, a primer, an ink, an adhesive, and a sealing agent. Further, the resin composition of the present invention can be used in combination with other water-based resins such as water-based acryl, polyester, epoxy, and the like, depending on the use.

[0002]

2. Description of the Related Art Conventionally, polypropylene, polyethylene,
And propylene, a modified polyolefin composition obtained by modifying a polyolefin such as a copolymer of ethylene and an α-olefin with an unsaturated carboxylic acid and / or an acid anhydride, and an acid-modified chlorinated polyolefin obtained by chlorinating the composition.
Used for primers, inks, etc. However, at present, since these resins are dissolved only in aromatic organic solvents such as toluene and xylene, a large amount of aromatic solvents must be used, and there is a problem in terms of safety and health and environmental pollution.

[0003] Attempts have been made to produce aqueous dispersions of chlorinated polyolefins.
153778 JP, JP-A-1-256556, JP-A-2-284973
However, they use an aromatic organic solvent at the time of production, and it has been difficult to completely eliminate the aromatic organic solvent. Attempts have also been made to produce aqueous dispersions of modified polyolefins, which are disclosed, for example, in JP-A-59-47244 and JP-A-2-286724. However, when the object to be coated and the object to be bonded are polyolefin resin in coating, bonding, etc., there are drawbacks such as poor adhesion and poor water resistance or poor paintability, and such an aqueous composition is still in practical use. Has not been reached. In Japanese Patent Application Laid-Open No. H3-182534, the performance of a coating film is improved by converting a modified chlorinated polyolefin into an aqueous solution using a surfactant and further adding an aqueous polyurethane resin. However, since the surfactant is not reactive, the surfactant component is eluted from the coating film by water, which causes a phenomenon that the water resistance is lowered due to a defect of the coating film which is considered to be caused by the elution.

[0004]

As described above, since the conventional acid-modified polyolefin composition is used as an organic solvent solution, there have been problems such as solvent toxicity and environmental problems. In addition, an aqueous resin composition using a surfactant devised to solve them has conventionally had a problem of water resistance. An object of the present invention is to provide an aqueous resin composition that simultaneously solves these toxicity, environmental problems, and poor water resistance.

[0005]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies on an aqueous resin composition which is free from problems such as toxicity and pollution, and which is excellent in safety and water resistance. Invented the invention.

[0006] In order to solve the drawbacks of the aqueous resin composition using a non-reactive surfactant which has hitherto been carried out, an attempt was made to immobilize a hydrophilic structure on the aqueous starting material resin using a reactive surfactant. Was. In the study, it is possible to react in the process of film formation by applying the composition before the reaction as it is and heat-treating it without immobilizing a substance having surface activity before coating by copolymerization method etc. Progressed, and as a result, the physical properties of the film could be improved.

That is, the present invention relates to a polyolefin modified with an unsaturated carboxylic acid and / or an acid anhydride, a reactive surfactant and a reaction initiator, and if necessary, a basic substance, a reactive monomer and a non-reactive surfactant. And dispersing in water. Another aspect of the present invention relates to a polyolefin modified with an unsaturated carboxylic acid and / or an acid anhydride, a reactive surfactant and a reaction initiator, and if necessary, a basic substance, a reactive monomer, and a non-reactive surfactant. An aqueous resin composition comprising an aqueous resin composition and an aqueous polyurethane, wherein the aqueous resin composition is characterized by adding an agent and dispersing in water. Still another aspect of the present invention is a film-forming product such as a coating agent, a primer, or an ink, and an adhesive containing the resin composition.

Hereinafter, the present invention will be described in detail. The polyolefin used in the present invention is a homopolymer of ethylene or propylene, or ethylene or propylene and other comonomers having 2 carbon atoms such as butene-1, pentene-1, hexene-1, heptene-1, octene-1, and the like.
As described above, it is preferably a random copolymer or a block copolymer with 2 to 6 α-olefin comonomers, and a random copolymer is more preferable than a block copolymer. Further, these comonomers may be copolymerized with two or more kinds. Among these, ethylene or 1-butene is preferred in view of the physical properties of the resin. The ratio of the propylene component is
It is preferably at least 55 mol%, and if it is less than 55 mol%, the adhesion to polypropylene is poor, which is not preferable.

Α, β used for modification of polyolefin
-Examples of unsaturated carboxylic acids or acid anhydrides thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, allylsuccinic acid, mesaconic acid, aconitic acid, and acid anhydrides thereof. The amount of graft copolymerizing the α, β-unsaturated carboxylic acid or anhydride thereof is 1 to 2
0% by weight is preferable, and when it is 1% by weight or less, stability when dispersed in water is deteriorated, and when it is 20% by weight or more, graft efficiency is deteriorated, which is uneconomical. Particularly preferably, it is 2 to 15% by weight.

The number average molecular weight of a resin obtained by graft copolymerizing an α, β-unsaturated carboxylic acid or an acid anhydride thereof is 3
If it is 3,000 to 35,000, the cohesion is insufficient and the adhesion to the polyolefin resin is poor, and if it is more than 35,000, the operability when dispersing in water is poor, which is not preferable. In order to make the molecular weight fall within this range, it is possible to select the molecular weight of the raw material and the conditions for performing the graft reaction, and it is also possible to perform the graft reaction after the molecular weight of the raw material is reduced. The number average molecular weight can be measured by GPC (gel permeation chromatography).

The method of graft copolymerizing an α, β-unsaturated carboxylic acid or an acid anhydride thereof with a polyolefin may be carried out by a known method. Is preferably carried out by a method of graft copolymerization. In this method, a reaction vessel equipped with a powerful stirrer, a Banbury mixer, a kneader, an extruder, or the like is used, and at a temperature of about 150 ° C. or more and about 300 ° C. or less, α, β-unsaturated carboxylic acid or its acid anhydride is used. The product and the radical generator are added and reacted, and the product is pelletized by a known method. As another method, it is also possible to carry out the method of heating and dissolving the polyolefin in an organic solvent such as xylene and reacting it in the presence of a radical generator, but it takes time and effort to remove the organic solvent and the organic solvent remains. Is not preferred.

The radical generator used in the reaction can be appropriately selected from known ones, but an organic peroxide is particularly preferred. Examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, 2,5-dimethyl-2,5-di (t
-Butylperoxy) -hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide,
Examples thereof include t-butyl peroxybenzoate, cumene hydroperoxide and the like, which are selected and used depending on the reaction temperature.

In the present invention, the basic substance is added to ionize a hydrophilic group such as a carboxyl group or a sulfone group so as to improve the dispersion in water. In some cases, it is not necessary to use the reactive surfactant when it is already neutralized with a base. As a base, sodium hydroxide, potassium hydroxide,
Ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, dimethylamine, diethylamine, triethylamine, N, N-
Dimethylethanolamine, 2-dimethylamino-2-
Methyl-1-propanol, 2-amino-2-methyl-
Examples thereof include 1-propanol and morpholine. The degree of hydrophilicity of the resin also varies depending on the type of base used, so it is necessary to select it appropriately depending on the conditions. The amount of the basic substance used is suitably in the range of 0.3 to 1.5 times the equivalent of the carboxyl group of the acid-modified polyolefin, and preferably 0.5 to 1.2 times.

The reactive surfactant used in the present invention may be any of those generally used as a reactive surfactant or a reactive emulsifier, but is preferably disclosed in JP-A-4-53.
Examples thereof include alkyl propenyl phenol polyethylene oxide adducts, alkyl dipropenyl phenol polyethylene oxide adducts, and salts of sulfates thereof, which are disclosed in JP-A-802-802 and JP-A-4-50204. Among them, alkyl propenyl phenol ethylene oxide
20 mol adduct, 30 mol adduct, 50 mol adduct (Aqualon RN-20, RN-30, RN-50, manufactured by Daiichi Kogyo Seiyaku) and ammonium sulfate ester of alkylpropenylphenol polyethylene oxide 10 mol adduct Salts and ammonium sulfate salts of the same 20-mol adduct (Aqualon HS-10, HS-20, manufactured by Daiichi Kogyo Seiyaku) are preferred.

The non-reactive surfactants that can be used as required include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyhydric alcohol fatty acid esters, and polyoxyethylene propylene polyol. (Pluronic type), nonionic surfactants such as alkylolamide, sorbitan alkyl ester, polyglycerin ester, alkyl sulfate ester salt, alkyl phenol sulfonate salt, sulfosuccinate ester salt, and other carboxylate and phosphate ester salts Anionic surfactants that can also be exemplified, amphoteric surfactants such as alkyl betaines and alkyl imidazolines, and the like and mixtures of two or more thereof can be used.

The reactive monomer which can be used in the present invention includes acrylic acid, methacrylic acid, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylonitrile, acrylamide, hydroxyethyl acrylate and the like. Acrylic monomers, conjugated diene monomers such as butadiene, isoprene and chloroprene; halogenated olefin monomers such as vinyl chloride and vinylidene chloride; aromatic monomers such as styrene and divinylbenzene; vinyl ester monomers such as vinyl acetate; methyl maleate , Maleic anhydride and the like.

The reaction initiator may be a known one, and examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, 2,5-dimethyl-2,5-di (t-butyl). Peroxy) -hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, cumene hydroperoxide and the like. Select and use by. A water-soluble initiator or an oil-soluble initiator such as azobisisobutyronitrile, hydrogen peroxide, potassium persulfate can be used. They may be used in combination.

The water resistance and adhesion of the coating film can be improved by mixing the aqueous polyurethane with the aqueous modified polyolefin resin composition. As the aqueous polyurethane, a commercially available aqueous polyurethane resin can be used. In selecting the aqueous polyurethane resin, a film is formed only with the aqueous urethane resin, and the film is subjected to a hot water resistance test (treatment condition: 80 ° C., 2 hours, pH with acetic acid, After immersion in water prepared at 4.0, dry at 130 ° C for 1 hour), moisture resistance test (70
It is desirable to use a material which has a change in tensile strength and elongation before and after the test of 25% or less and has no visual whitening phenomenon of the coating film after being left in a moist heat oven at 95 ° C. and 95% RH for 200 hours.

The resin composition of the present invention dispersed in water in this way has excellent adhesion to polyolefins, and is excellent not only as a primer for painting and bonding, but also as a vehicle resin for aqueous coatings, aqueous adhesives. And a binder resin for aqueous inks. Further, the aqueous resin composition of the present invention may be mixed with a pigment as it is, or may be blended with another aqueous resin.

When a film is formed using the aqueous resin composition of the present invention, the reaction proceeds at the time of film formation at 80 to 200 ° C.
For 10 minutes to 2 hours. Regarding the treatment conditions, it is necessary to set an optimum value depending on the activities of the reactive surfactant and the reactive monomer, and the kind and amount of the reaction initiator.

[0021]

The aqueous resin composition of the present invention has a polyolefin modified with an unsaturated carboxylic acid and / or an acid anhydride as one of its components. Since the surfactant used for the reaction is reactive, it is fixed to the film on which the surfactant component is formed by the reaction, and the effect of remarkably improving the water resistance after the film is formed has been found.

[0022]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Trial Production Example-1) In a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, a propylene-α-olefin copolymer (propylene component 75 mol%, ethylene component 20 mol% 5 mol% of 1-butene component,
(Number average molecular weight 25000) 300 g of toluene was dissolved by heating in 700 g of toluene, and then 13 g of maleic anhydride and 12 g of di-t-butyl peroxide as a radical generator were each added for 2 hours while stirring while maintaining the temperature of the system at 115 ° C. And aged for 3 hours. After the reaction, the reaction product was cooled to room temperature, and then poured into 20 L of acetone for purification.
A 2.1% by weight maleic anhydride graft copolymer was obtained.

(Trial Production Example 2) In a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, a propylene-butene-ethylene copolymer (propylene component 68 mol%, butene component 24 mol%) 300 g of ethylene component, 8 mol% of ethylene component and number average molecular weight of 68000) After heating and melting 300 g of the system, 40 g of maleic anhydride and 5 g of dicumyl peroxide as a radical generator were added for 3 hours while stirring while maintaining the temperature of the system at 180 ° C. Then, the reaction was carried out for 3 hours.
After cooling to room temperature after the reaction, the reaction product was poured into 20 L of acetone and purified to obtain a maleic anhydride graft copolymer having a graft amount of 9.2% by weight. The number average molecular weight measured by GPC was 26,000.

In the measurement of the number average molecular weight, Tosoh H
A column TSK-GEL was attached to PLC-8020, the sample was dissolved in THF (tetrahydrofuran), and measured at 40 ° C., and the molecular weight was determined from a calibration curve prepared using a polystyrene standard sample.

Example 1 In a four-necked flask similar to that of Trial Production Example 1, 100 g of the maleic anhydride graft copolymer obtained in Trial Production Example 1 was heated and dissolved at 110 ° C. Isopropyl carbonate 15 g, morpholine 4.6
g, and 60 g of a 20 mol adduct of alkylpropenylphenol ethylene oxide was added.
While maintaining the temperature at 90 ° C, water at 90 ° C was added little by little to obtain an aqueous resin composition (solid content: 45%).

(Examples 2 to 5) The same operation as in Example 1 was performed to disperse the resin of the trial production example in water with the composition shown in Table 1.

Example 6 The same operation as in Example 1 was carried out, and after adding HS-10 shown in Table 1, acrylic acid 10 was further added.
g was added. While maintaining the liquid at 100 ° C., water at 90 ° C. was added to obtain an aqueous resin composition.

(Examples 7 and 8) Using the graft polymer prepared in Prototype Example 2, the same operation as in Example 1 was performed to obtain an aqueous resin composition having the composition shown in Table 1. .

(Examples 9 to 13) Using the graft polymer prepared in Prototype Example 2, the same operation as in Example 6 was performed to obtain an aqueous resin composition having the composition shown in Table 1. .

(Examples -14 to 17)
Nonionic ester-based aqueous urethane resin Superflex E based on 100 g of the aqueous resin solid content prepared in 7 and 8
(Daiichi Kogyo Seiyaku) was added, and water was added with stirring to obtain an aqueous resin composition having a solid content of 45%.

Comparative Examples 1-4 An aqueous resin composition having the composition shown in Table 1 was obtained in the same manner as in Example.

The numerical values of the compounds in Table 1 indicate the compounding weight (g), and the abbreviations of the compounds indicate the following compounds. RN-20; alkylpropenylphenol ethylene oxide 20 mol adduct (Daiichi Kogyo Seiyaku, Aqualon RN-
20) RN-30; an alkylpropenylphenol ethylene oxide 30 mol adduct (Daiichi Kogyo Seiyaku, Aqualon RN-
30) HS-10; Ammonium salt of alkylpropenyl phenol ethylene oxide 10 mol adduct sulfate (Daiichi Kogyo Seiyaku, Aqualon HS-10) HS-20; Alkyl propenyl phenol ethylene oxide 20 mol adduct sulfate ester of ammonium salt Industrial Pharmaceutical, Aqualon HS-20) Perbutyl I; t-butylperoxyisopropyl carbonate (Perbutyl I, manufactured by NOF Corporation) 2HEMA; 2-hydroxyethyl methacrylate 2HEA; 2-hydroxyethyl acrylate NS-212; polyethylene glycol nonyl phenyl ether ( Nippon Yushi, NS-212)

[0034]

[Table 1]

Table 2 shows the stability test results, adhesion test results, and gasoline resistance test results of the aqueous dispersions of Examples 1-1 to -17 and Comparative Examples -1 to -4 after standing for one month. . The test method is as follows.

The aqueous resin compositions prepared in Examples 1 to 17 and Comparative Examples 1 to 4 were spray-coated on a polypropylene plate and heat-treated at 140 ° C. for 30 minutes to 2 hours. The film thickness is
The thickness was adjusted to 10 to 15 μm. Next, a two-pack type urethane top coat was applied, left at room temperature for 10 minutes, and then forcibly dried at 80 ° C. for 30 minutes using a hot air drier. After leaving the obtained coated plate at room temperature for one day, the coating film was tested.

Adhesion test A cut was made on the surface of the coating film to reach the substrate with a cutter, and 100 goban eyes were made at 1 mm intervals, and a cellophane adhesive tape was adhered thereon and peeled off at 180 ° direction five times. The number of remaining goban eyes was counted.

Gasoline resistance test A cut was made on the surface of the coating film to reach the substrate with a cutter, and the coating film was immersed in gasoline (Nisseki, high-octane gasoline) for 4 hours, and the state of the coating film was visually observed.

Water resistance test The coated plate was immersed in warm water of 40 ° C. for 48 hours to examine the state of the coating film.

Bending resistance test A coated plate was bent 180 ° with a 1φ inch mandrel, and the state of the coating film was examined.

Storage stability test A prepared aqueous resin composition sample (solid content: 25%) was placed in a glass container having a capacity of 250 ml, and at room temperature, the degree of separation of the aqueous phase from the emulsion phase to the upper portion, and the formation of resin aggregates The changes over time were compared.

[0042]

[Table 2]

[0043]

The aqueous resin composition of the present invention has excellent adhesion to polyolefin, good storage stability, and good flexibility of the coating film. Moreover, a water-resistant coating film can be formed as compared with a conventional polyolefin-based aqueous resin composition using a surfactant. Furthermore, since it can be made water-based without using any aromatic organic solvent, it is excellent in terms of safety and health and environmental pollution.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 75/04 NGG C08L 75/04 NGG C09D 123/26 PFA C09D 123/26 PFA 151/06 PGX 151 / 06 PGX 175/04 PHR 175/04 PHR C09J 5/02 JGP C09J 5/02 JGP 123/26 JCL 123/26 JCL 151/06 JDH 151/06 JDH 175/04 JFC 175/04 JFC C09K 3/10 C09K 3/10 D

Claims (8)

(57) [Claims] 1. A polyolefin modified with an unsaturated carboxylic acid and / or acid anhydride (100 parts), a reactive surfactant (40 to 60 parts), a basic substance (4.6 to 5 parts) and a required amount of a reaction initiator. Aqueous resin composition. 2. 100 parts of polyolefin modified with unsaturated carboxylic acid and / or anhydride, 40 to 60 parts of reactive surfactant, 4.6 to 5 parts of basic substance, 10 to 20 parts of reactive monomer And an aqueous resin composition comprising a required amount of a reaction initiator. 3. Polyolefin modified with unsaturated carboxylic acid and / or acid anhydride (100 parts), reactive surfactant (40-60 parts), basic substance (4.6-5 parts), reactive monomer (10-20 parts) , An aqueous resin composition comprising 10 parts of a surfactant and a required amount of a reaction initiator. 4. An aqueous resin composition obtained by blending 50 parts by weight of an aqueous urethane resin with respect to 100 parts by weight of the aqueous resin composition for forming a film according to claim 1. 5. A film-forming agent comprising the aqueous resin composition according to claim 1. 6. A sealing agent comprising the aqueous resin composition according to any one of claims 1 to 4. 7. An adhesive comprising the aqueous resin composition according to any one of claims 1 to 4. 8. A method for forming a film, comprising applying the aqueous resin composition according to claim 1 to heat after coating.