JPH03152168A - Water-based resin dispersion liquid - Google Patents

Abstract

PURPOSE:To obtain the subject dispersion having excellent adhesivity, water- resistance, solvent resistance and weather resistance by compounding a specific emulsion and a synthetic emulsion at a specific ratio. CONSTITUTION:The objective dispersion is produced by compounding (A) an emulsion produced by emulsifying (i) 100 pts.wt. (in terms of solid) of a solution- type resin having a weight-average molecular weight of 10,000-100,000 [preferably alkyl (meth)acrylate resin] and (ii) 1-20 pts.wt. of an acrylic oligomer having 3-5 acryloyl unsaturated double bonds and a weight-average molecular weight of 180-800 in water in the presence of a surfactant and (B) an emulsion of a synthetic resin containing an amino group-containing ethylenic unsaturated monomer (preferably aminoethyl acrylate or aminomethyl acrylate) and copolymerized with other unsaturated monomer. The equivalent ratio of the acryloyl unsaturated double bond of the component A to the active hydrogen of the monomer of the component B is 0.5-2.5.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an aqueous resin dispersion with excellent adhesion and film properties that can be applied to adhesives or paint binders that utilize synthetic resin emulsilane. be.

(Prior Art) Synthetic resin emulsilane has conventionally been used as a binder for water-based adhesives, pressure-sensitive adhesives, or paints.

These water-based adhesives, pressure-sensitive adhesives, or paint binders are required to have film properties such as adhesion, water resistance, solvent resistance, and weather resistance due to their intended use.

However, no synthetic resin emulsilane has been found that satisfies all of these film properties.

For example, a common synthetic resin emulsilane has a particle size of 0.1 to 0.5p. In the case of such a particle size, depending on the type of substrate, the particles have difficulty in penetrating (as a result, the casting effect of the coating is reduced, making it difficult to obtain good adhesion.

In addition, the formation mechanism of the synthetic resin emulsilane film is based on the fusion of emulsion particles, and the formed film has better water resistance, solvent resistance, and water resistance than a film made of solution-type resin.
The physical properties of the coating, such as weather resistance, were insufficient.

On the other hand, Japanese Patent Publication No. 63-14023 describes a method for improving the adhesion to substrates by using ultrafine synthetic resin emulsilane with an average particle diameter of 10 to 70 n-, which can be synthesized by combining a reactive emulsifier and a transition metal. has been done.

In addition, JP-A No. 62-27747 discloses a method in which a solvent-based resin is emulsified into an aqueous phase by phase inversion, thereby allowing better penetration into a substrate and ensuring adhesion to the substrate compared to emulsion particles formed by emulsion polymerization. It is shown.

On the other hand, in order to improve film properties such as water resistance, solvent resistance, and weather resistance, methods other than fusion bonding, which is a film formation mechanism, have been proposed.

For example, JP-A No. 62-62851, JP-A No. 62-6
No. 2852 states that interparticle crosslinking can occur at room temperature by reaction between hydrazine and carbonyl groups during film formation.

Furthermore, in JP-A-63-223018, a core-shell type synthetic resin emulsion was synthesized, in which a water-insoluble epoxy resin was present in the core part, and an unsaturated monomer containing an amino group was added to the shell part. It is said that by copolymerizing, the synthetic resin emulsilanes can be crosslinked with each other when forming a film at room temperature.

(Problems to be Solved by the Invention) However, as mentioned above, according to the conventional method, the emulsion particles are made into fine particles in order to improve the adhesion of the coating, that is, the anchoring effect due to the penetration of the resin into the base material. However, because the polymer chains in the emulsion particles are partially internally crosslinked by the polyfunctional monomer used during the polymerization reaction, even though the solvent resistance of the coating is good, when the synthesized emulsion particles are fused, the emulsion The compatibility between the particles at the particle interface may deteriorate, and the water resistance and weather resistance of the formed film may decrease.

In addition, in order to improve the poor water resistance, solvent resistance, and weather resistance caused by the film formation mechanism called fusion, if the emulsion particles are crosslinked during film formation, the penetration of the resin into the base will be poor, and the adhesion will be improved. level decreases. Furthermore, in order to satisfy both of these physical properties of the film, it is possible to mix emulsion particles made into fine particles with emulsilane that crosslinks between particles during film formation, but due to poor compatibility, it is difficult to mix additives etc. In some cases, gelation occurred and it was difficult to store stably.

Therefore, a stable one-component aqueous resin dispersion that forms a film that satisfies both adhesion, water resistance, solvent resistance, and weather resistance has been desired.

(Means for Solving the Problems) In view of the above problems, the present inventors have made a synthetic resin emulsion with amino groups compatible with a specific acrylic oligomer that easily reacts with amino groups at room temperature. The storage stability of the aqueous resin dispersion is improved by mixing an emulsion obtained by emulsifying the aqueous phase with a phase-converted emulsion together with a solution-type resin having good properties.When forming a film, the emulsion particles are cross-linked at room temperature, increasing the strength of the film. We have completed a technology that allows for better adhesion to substrates.

That is, when forming a film, the specific acrylic oligomer in the emulsified solution-type resin and the amino group in the synthetic resin emulsilane gradually react, and the film crosslinks at room temperature, and the solution-type resin adheres to the base material. This is to improve the quality of the product.

Regarding the crosslinking reaction between acrylic oligomers and amino group-containing monomers with active hydrogen at room temperature, see Michael.
This is known as the el addition reaction, but in order to ensure stability during storage in the aqueous resin dispersion of the present invention, an acrylic oligomer that exhibits a crosslinking reaction is mixed and dispersed in a solution type resin at a specific ratio. Protected by emulsifying it in the aqueous phase through conversion, and protected in a synthetic resin emulsilane by copolymerizing an amino group-containing unsaturated monomer that undergoes an addition reaction with this acrylic oligomer at a specific ratio by emulsion polymerization. It is.

The aqueous resin dispersion in the present invention consists of an emulsion of a solution-type resin as the A component and a synthetic resin emulsilane as the B component.

Component A is an emulsion consisting of a solution type resin, an acrylic oligomer, a surfactant, and water.

The solution type resin (a) needs to have a weight average molecular weight (hereinafter referred to as Mw) of 10,000 to 100,000. If the MW is less than 10,000, the film strength and weather resistance will decrease. Also, Mw
If it is larger than 10,000, the anchoring effect will be reduced and the adhesion will be reduced.

As monomers constituting such a solution-type resin, the following monomers having one or more unsaturated double bonds in the molecule can be used alone or in any combination.

■ Alkyl acrylate or alkyl methacrylate such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, etc. ■ Carboxylic acid-containing monomers such as acrylic acid, methacrylic acid, Itaconic acid, maleic acid, fumaric acid, crotonic acid, etc. Polymerizable aromatic compounds such as styrene, α-styrene, vinyltoluene, t
- Butylstyrene, etc. ■ Vinyl compounds For example, vinyl acetate, vinyl propionate, etc. ■ Polymerizable nitriles For example, acrylonitrile, methacrylonitrile, etc. Of these, alkyl acrylates are selected in consideration of the water resistance of the coating and the ease of copolymerization. Alternatively, an alkyl methacrylate type is preferable.

Note that the solution type resin can be synthesized by known radical polymerization.

Next, the acrylic oligomer (b) will be explained.

The acrylic oligomer (b) has a weight average molecular weight of 18
If the number of unsaturated double bonds is 0 to 800 and 3 to 5, and the number of unsaturated double bonds is 2 or less, the crosslinking density decreases and the water resistance, solvent resistance, and weather resistance of the coating decrease.

On the other hand, if the number of unsaturated double bonds is 6 or more, the crosslinking density becomes too high and the coating becomes too hard.

Furthermore, if the molecular weight is greater than 800, the reaction with the amino group in component B will not proceed smoothly during film formation.

The acrylic oligomer (b) can be produced by any conventional method. For example, in the case of tri(acryloylmethyl-propane), a mixture of trimethylolpropane and acrylic acid is heated under an acidic catalyst to undergo an esterification reaction. It can be synthesized by Since the acrylic oligomer (b) has good compatibility with the solution type resin (a), by emulsifying the mixture with the resin (a) in water with a surfactant, the aqueous resin dispersion of the present invention Storage stability can be maintained in liquid.

Examples of surfactants include the following.

■Alkyl ether type nonions, such as polyoxyethylene nonylphenyl ether, polysaccharide diethylene lauryl ether, polyoxyethylene stearyl ether, etc. ■Alkyl ester type nonions, such as polyoxyethylene laurate, polyoxyethylene stearate, etc. ■Sorbitan derivative type Examples of nonions include sodium dodecylbenzenesulfonate and polyoxyethylene alkylphenyl ether sulfate salts.

In particular, among these, the combination of polyoxyethylene nonylphenyl ether with HLB 10 to 15 and polyoxyethylene nonylphenyl ether sulfate salt is A.
Excellent in stabilizing ingredients.

If the amount of surfactant used is too small, the emulsified micelles will become unstable and the storage stability of component A will deteriorate, while if it is too large, the water resistance of the film will be reduced.

The amount of water used is not particularly limited as long as an emulsion of component A can be formed.

On the other hand, as the main monomer constituting the resin of component B, monomers having one or more unsaturated bonds in the molecule or any combination thereof can be used as shown below.

■ Alkyl acrylate or alkyl methacrylate such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, etc. ■ Polymerizable aromatic compounds such as styrene, α-styrene, vinyl toluene, t
- Vinyl compounds such as butylstyrene Examples include vinyl acetate, vinyl propionate, etc. Polymerizable nitriles Examples include acrylonitrile, methacrylonitrile, and the like.

Examples of the amino group-containing ethylenically unsaturated monomer include aminomethyl acrylate, aminomethyl methacrylate, aminoethyl acrylate, aminoethyl methacrylate,
Alkylamino esters of acrylic acid or methacrylic acid such as N-methylaminoethyl acrylate and N-methylaminoethyl methacrylate, monovinylpyridines such as vinylpyridine, vinyl ethers having an alkylamino group such as aminoethyl vinyl ether, Examples include unsaturated amides having an alkylamino group such as N-(2-dimethylaminoethyl)acrylamide or N-(2-dimethylaminoethyl)methacrylamide, and allylamines such as monoallylamine diallylamine and triallylamine. Among these, especially
Aminoethyl acrylate or aminomethyl acrylate are particularly useful.

Here, the amount of component B used relative to component A is determined by the ratio of the equivalent of the acryloyl unsaturated double bond in component A to the active hydrogen equivalent of the amino group-containing ethylenically unsaturated monomer in component B, that is, the formula ( Mix at a ratio such that the value of 1) is 0.5 to 2.5.

(Equivalent amount of acryloyl unsaturated double bonds) If this blending ratio is larger than 2.5, the crosslinking reaction at room temperature will not proceed sufficiently and the water resistance, solvent resistance, and weather resistance of the coating will not improve. If it is less than 0.5, the water resistance of the coating will decrease due to the influence of the amino group-containing monomer.

As a method for preparing an aqueous resin dispersion in the present invention, for example, a surfactant is mixed into a resin solution of (a) tlFl sap and (b) acrylic oligomer in component A. Thereafter, water is injected at a constant rate while stirring to form an emulsion of the present invention, component A.Next, component B is added to component A while stirring to form an aqueous resin dispersion.

While the aqueous resin dispersion of the present invention is dispersed in water, the A component is protected by a surfactant, and the amino group is copolymerized with an ethylenically unsaturated monomer containing an amino group by emulsion polymerization. It is protected in a synthetic resin emulsion silane.

However, when forming a film, the acrylic oligomer and the amino groups in the synthetic resin emulsilane react to form a crosslinked structure, which improves the film strength and water resistance, and has good solvent resistance. By penetrating the material, a coating with excellent adhesion can be obtained.

Therefore, when this water-based resin dispersion is used as a coating material for inorganic building materials, wood, and plastics, it exhibits very good properties such as adhesion to the base material, water resistance, solvent resistance, and weather resistance. .

In addition, when the aqueous resin dispersion of the present invention is used as a binder for nonwoven fabric interlining for various fiber treatments, it exhibits excellent properties in water resistance, washing resistance, weather resistance, and adhesion to substrates. It also has excellent adhesion and holding power to various base materials as an adhesive for packaging tapes, double-sided tapes, paper labels, etc.

In addition, when the aqueous resin dispersion of the present invention is used as a paint binder for interior and exterior paints of buildings, it has good adhesion to the substrate, and since a crosslinking reaction occurs during film formation, the water resistance of the film is improved. It is possible to create a coating composition with good adhesion to the base and good weather resistance in one step without the need for a primer or topcoat.

The present invention will be described below with reference to Reference Examples, Examples, and Comparative Examples.

[Reference Example 1] (Synthesis method of (a) solution-type resin in component A) Toluene (50 weight portion) was charged in advance to a polymerization apparatus equipped with a three-loaf flask equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a dropping funnel. , maintain the temperature inside the flask at 110°C, then,
Methyl methacrylate (75.6 parts by weight), n-butyl acrylate (23.4 parts by weight), acrylic acid (1 part by weight), lauryl mercaptan as a chain transfer agent (1,
0 parts by weight), L-butylperoxy-3 as an initiator,
A mixture of 5,5-)limethylhexoate (0.8 parts by weight) is added dropwise over a period of 3 hours. Thereafter, the reaction system was aged for 1 hour, and then 50 parts by weight of toluene was added and cooled.

The weight average molecular weight of the obtained solution type resin was 18,000 as determined by GPC (gel permylene silane chromatography), the viscosity was 1.2 ps/25°C, and the solid content was 50.0%.

[Reference Examples 2 to 5] The raw materials shown in Table 1 were used for the synthesis of solution type resins, and the synthesis method was in accordance with Reference Example 1.

[Reference Example 6] (Method for synthesizing synthetic resin emulsion of component B) Water (60 parts by weight) was charged in advance into a polymerization apparatus equipped with a four-loaf flask equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a dropping funnel, and the reaction vessel was placed in a polymerization apparatus. While maintaining the temperature inside the reactor at 75°C, nitrogen substitution is carried out, and nitrogen substitution and stirring are continued during the polymerization reaction.

Subsequently, methyl methacrylate (64.9 parts by weight),
n-butyl methacrylate (31.1 parts by weight), aminoethyl methacrylate (6.1 parts by weight), water (42 parts by weight), surfactant (polyoxyethylene nonylphenyl ether (5.0 parts by weight), polyoxy 5% of a mixed emulsion (emulsified mixture) of ethylene nonyl phenyl ether ammonium salt (2.0 parts by weight) was dissolved and mixed with ammonium persulfate (0.5 parts by weight) in water (5.0 parts by weight). The remaining emulsified monomer mixture and initiator solution were simultaneously added dropwise over 30 minutes together with 10% of the initiator solution prepared, and then the temperature of the reaction system was kept at 80° C. to proceed with ripening.

After cooling the reaction vessel, ammonia water was added to the reaction system to adjust the pH to 8.0 to 9.0.

The resulting synthetic resin emulsilane had a solid content of 49.1%.

[Reference Examples 7 to 12] For the synthesis of synthetic resin emulsilane, the raw materials shown in Table 2 were used, and the synthesis method was in accordance with Reference Example 6.

(Example 1) 200 parts by weight of the solution-type resin of Reference Example 1, acrylic oligomer 1 (Aroex M-309 (Toagosei Chemical Co., Ltd.)
10 parts by weight (manufactured by Manufacturer) into a tank, and the circumferential speed was 12 m/see.
The surfactant (polyoxyethylene nonylphenyl ether (HLB14)
After adding 5 parts by weight of a mixture of 4 parts by weight of ) and 1 part by weight of ammonium polyoxyethylene nonylphenyl ether sulfate, 60 parts by weight of water was added little by little and stirred for about 15 minutes to produce component A.

Thereafter, synthetic resin Emulsin 2 of Reference Example 6 was used as the B component.
00 parts by weight were added little by little to produce an aqueous resin dispersion of the present invention. The aqueous dispersion produced has a viscosity of 4800 c
ps/25°C.

[Examples 2 to 4, Comparative Examples 1 to 6] Manufactured according to the manufacturing method of Example 1 (however, the formulations are listed in Table-3 and Table-4) [Test method] (Physical properties of aqueous resin dispersion) ( 1) Viscosity (c p s/25°C) The prepared sample was measured using a B-type viscometer (BH type). However, all samples were measured at 25°C.

e) Storage stability After storing the prepared sample at 50°C for one month, check whether abnormal thickening or layer separation has occurred.

(3) Low temperature stability JIS 56004.4 Check whether the sample prepared according to the test method for low temperature stability does not change in quality.

The results are shown in Table-5.

(Physical properties of water-based resin dispersion film) (1) Alkali-resistant samples were prepared on a glass plate with a gap of 0.150±0.004-B according to JIS 54003.5 (3)
The specimen was applied using a type film applicator, placed horizontally, and dried for 48 hours.
) was immersed in an aqueous solution-3% NaOH aqueous solution for 12 hours, and the level of whitening of the film was visually confirmed.

(2) Adhesion (standard) The aqueous resin dispersion of the present invention was applied to a flexible board at 60°C.
The specimen was coated with g/rrf and dried for 48 hours. The coating of this test specimen was cut into 5×5 substrates at 2 m intervals using a cutter knife, and a taping test was performed using Nichi/<Nencero tape, and the remaining state of the coating was examined and evaluated as follows.

O-...The coating did not peel off at all.

Δ: Part of the film peeled off.

×...The film was completely peeled off.

The results are shown in Table-5.

(3) Adhesion (warm water) The aqueous resin dispersion of the present invention was applied to a flexible board at 60°C.
A test specimen was prepared by applying a coating of g/po and drying it for 48 hours, then immersing it in warm water at 50°C for 3 days, and then drying it in a thermostat at 20°C for 2 hours.

The test method is the same as the standard condition.

(Performance test for non-woven fabric interlining) (1) Washing resistance The aqueous resin dispersion of the present invention was diluted with water to reduce the non-volatile content by 2
Add polyester non-woven interlining (fabric weight 16) to the solution adjusted to 0%.
0 g/nf) and squeezed at a squeezing rate of 80%.
The sample was dried at ℃ for 5 minutes.

The washing resistance test was carried out according to JIS L 1085 r Non-woven fabric interlining test method” 45° cantilever method.
Table 6 shows the results of evaluation based on the percentage of texture retained after washing.

(Test for Adhesive) (1) Tack Tack was measured by the ball rolling method specified in JIS Z 0237. The results are shown in Table-7.

(2) Adhesive force Peeling adhesive force of 180@peel adhesion specified in JIS Z 0237 (adherent: stainless steel plate g f / 25 mm) was measured. In addition, the adhesive force when the adherend was a polyethylene plate was also measured using the same method.

The results are shown in Table-7.

(3) Holding force: According to JIS Z 0237, the area for pasting is 20X.
A load of 1 kg was applied at 40°C at 20 degrees Celsius, and the holding time or shear radius after a certain period of time was measured. The results are shown in Table-7.

(Test for paint) 130 parts of titanium oxide, SMA fractional dispersant Nnopco Co., Ltd.)
2 parts by weight, ) IEC (Daicel Chemical Industry ■) 4 parts by weight,
63 parts by weight of water and 1.0 parts by weight of aqueous ammonia were mixed and dispersed in a disper to obtain 200 parts by weight of a pigment paste. To 200 parts by weight of this pigment paste, 468 parts by weight of the aqueous resin dispersion used in Example 1, and 5 parts by weight of an antifoaming agent (Sannopco).
parts by weight, 0.3 parts by weight of the thickener, and 30 parts by weight of the plasticizer were mixed and stirred to obtain a coating composition.

Similarly, paints were prepared using the aqueous resin dispersions of Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

(1) Repeat heating and cooling.Apply one coat of paint to a flexible board specified in JIS^5403.
．． After coating at 3 kg/nf, it was cured at room temperature for 7 days.

After that, the sample was heated to -20±3℃ for 3 hours and then to 50±3℃ for 3 hours, and after 10 cycles, the coated surface was visually inspected to see if there was any flaking or peeling. Confirmed with 1〒(Evaluated as 1 or less.

0...No abnormality Δ−・・・Some cranks occur ×−・・−Full surface cracks The results are shown in Table-8.

(2) Adhesion Strength A sample was prepared by applying 1.3 kg/% of the paint onto a mortar prepared according to the method specified in JIS R52019.4 and curing it at room temperature for 7 days. After that, JIS^6
Adhesion was measured according to the Adhesion Strength Test of 9155.8. The results are shown in Table-8.

(3) Accelerated Weather Resistance A sample was prepared by applying a paint of 1.3 kg/rrf to a flexible board specified in JIS A 5403 and curing for 7 days. Then JIS K 56604.14
According to the accelerated weather resistance test, irradiation was performed for 1000 hours using a sunshine carbon arc lamp type weather resistance tester specified in JIS B 7753, and chalking and gloss retention were confirmed. However, the results are shown in Table 8.

(Effects) From the results in Tables 3, 4, 5, 6, 7, and 8, the physical properties of the paints or coatings in the comparative examples are inferior to the examples of the present invention. The reason for this is that in Comparative Example 1, the molecular weight of the solution type resin in component A is smaller than the range of the present invention, so the adhesion after hot water immersion in the physical properties of the film is poor.
Comparative Example 2 is larger than the range of the present invention, so it cannot gel and form a film. Comparative Example 3 has a small amount of acrylic oligomer in component A, and the physical properties of the film are poor in terms of adhesion after immersion in hot water. Since No. 4 contains a large amount of acrylic oligomer, it falls outside the equivalence ratio range of the present invention, and as a result, the physical properties of the film are poor in adhesion after immersion in hot water, and whitening also occurs. Furthermore, both Comparative Examples 5 and 6 do not contain acrylic oligomers, so Comparative Example 5 has poor washing resistance, and Comparative Example 6 has poor tack, adhesive strength, and holding power.

Therefore, within the scope of the specific formulation in the present invention,
It can be seen that it exhibits excellent physical properties both as a paint and as a film, particularly in adhesion, water resistance, solvent resistance, and weather resistance, which are contradictory properties of a film. Moreover, a stable one-component aqueous resin dispersion having such excellent performance can be used in many applications that were previously impossible.

(that's all) Procedural amendment 1. Display of incident 1999 Patent Office No. 290 2. Name of the invention direction No. 34 Two 3. Person who makes corrections Relationship to the incident: Patent applicant phone 0726-43-6245

Claims (1)

[Claims] (1) As component A, (a) a solution-type resin with a weight average molecular weight of 10,000 to 100,000 per 100 parts by weight as a solid content; (b) an acryloyl-based unsaturated double resin with a weight average molecular weight of 180 to 800; An emulsion obtained by emulsifying 1 to 20 parts by weight of an acrylic oligomer having 3 to 5 bonds in water with a surfactant, containing an amino group-containing ethylenically unsaturated monomer as the B component, and other unsaturated monomers. A synthetic resin emulsion copolymerized with a saturated monomer is prepared such that the ratio of the equivalent of the acryloyl unsaturated double bond of the component A to the active hydrogen equivalent of the amino group-containing ethylenically unsaturated monomer of the component B is 0.5 to 0.5. An aqueous resin dispersion blended at a ratio of 2.5.