JP2003342523A - Stain-reducing agent for coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stain-reducing agent which has an excellent initial stain- reducing effect and its excellent durability, does not deteriorate water resistance, and has profitability. <P>SOLUTION: This stain-reducing agent for coatings comprises a compound (A) prepared by polymerizing a 2 to 4C alkylene oxide on a non-reducing di- or tri-saccharide. The stain-reducing agent is added to water-based coatings. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful stain-reducing agent for paints, which is particularly useful for reducing the stains on a coating film by an aqueous paint.

[0002]

2. Description of the Related Art In recent years, paints are becoming water-based due to problems such as environmental pollution, and at the same time, the repainting cycle is prolonged as an economical demand, and the stain on the paint surface has become a problem. Therefore, as a technique to reduce the pollution of paint,
A method of modifying the coating film, for example, a method of washing away contaminants by rainfall or the like has been proposed. However, the method of modifying the resin forming the coating film is liable to cause deterioration of water resistance and durability, and therefore, improvement by additives has come to be carried out. For example, JP-A-2-123176 using a water-swellable polymer
JP-A-8-337754 and glycerin using a silicone modified product containing a high polymer of ethylene oxide.
JP-A-11-279 using an ethylene oxide / propylene oxide polymer for pentaerythritol and the like
No. 454 and the like are known.

[0003]

The conventional technique and the method using the silicone modified product are disadvantageous in terms of cost, and other techniques mainly use the ethylene oxide high polymer, and are satisfactory in the sustainability of the effect. There is a defect that there is nothing and the water resistance of the coating film is lowered. It is an object of the present invention to provide a stain-reducing agent for coatings, which is improved in the drawbacks of the above-mentioned conventional techniques and which is excellent in the initial stain-reducing effect and its sustainability even when added in a small amount, and which is economical.

[0004]

Means for Solving the Problems The present invention has been achieved as a result of intensive studies to solve the above problems. That is, it is a stain reducing agent for paints, which is composed of a compound [A] obtained by polymerizing a non-reducing di-, tri-saccharide with an alkylene oxide having 2 to 4 carbon atoms.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The non-reducing di- and trisaccharide according to the present invention is a saccharide in which two or three monosaccharides are bound together by a hemiacetal hydroxyl group, and sucrose, trehalose, raffinose, gentianose, etc. Is mentioned. Of these, sucrose is particularly preferable, and examples thereof include finely powdered purified salame sugar or granulated sugar.
Further, examples of the alkylene oxide having 2 to 4 carbon atoms which is subjected to the addition polymerization with the saccharide include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO) and butylene oxide. Among these alkylene oxides, PO and 1,2-butylene oxide (hereinafter abbreviated as BO) are preferable.

In the present invention, the number of moles of alkylene oxide polymerized to the saccharide is 15 to 100, preferably 2
0 to 90. If it is less than 15 mol, the ability to reduce pollution will be reduced. If it exceeds 100 moles, the water resistance of the coating film decreases. The order of addition polymerization of the alkylene oxide is not particularly limited, and the polymerization method may be either block or random.

In the present invention, examples of the polymerization method used for addition of alkylene oxide include anionic polymerization, cationic polymerization and coordinated anionic polymerization. These polymerization methods may be used alone or in combination depending on the degree of polymerization. As a catalyst,
Alkali or alkaline earth metal hydroxides, alcoholates or carbonates, and trialkylamines,
Lewis acid catalysts such as stannic chloride and boron trifluoride, mineral acids, and the like, complex metal cyano complexes found in JP-A-63-277236 or organic aluminum porphyrins found in JP-B-5-14734. A complex or the like is used. Of these, potassium hydroxide, cesium hydroxide, trimethylamine and the like are preferable. The amount of catalyst used is 0.05 with respect to the mass of the compound at the end of the polymerization.
To 2.0% by mass, preferably 0.1 to 1.
It is 0 mass%.

In the present invention, the addition polymerization reaction may be carried out under usual conditions, for example, at a temperature of 80 to 130 ° C.,
It is preferably 90 to 110 ° C. The maximum pressure (gauge pressure) during polymerization is 0.8 MPa, preferably 0.5 M.
Pa. The time required for the reaction is usually 4 to 12 hours.

In the present invention, the method for removing the catalyst from the polymer obtained by the polymerization is, for example, Japanese Patent Publication No. 47.
As described in JP-A-3745, a method of neutralizing an alkaline catalyst with an acidic component and removing a salt formed by filtration, a method of using an alkaline adsorbent described in JP-A-53-123499, and JP-B-49-14359. A method of dissolving in a solvent described in JP-A No. 51-23211 and washing with water, a method of using an ion exchange resin described in JP-A No. 51-23211, and a carbonate formed by neutralizing an alkaline catalyst of JP-B No. 52-33000 with carbon dioxide gas. There is a method of filtering and neutralizing with various organic acids and inorganic acids, or in the case of an acidic catalyst, it may be removed by the above method after once made weakly alkaline with an alkali component. It doesn't matter.

In the present invention, the cloud point is a measure of the hydrophilicity of the nonionic surfactant, and a compound having a higher cloud point has a greater hydrophilicity. The measuring method in the present invention is in accordance with “Measuring method B” in “ISO 1065-1975 (E)”, “Ethylene oxide nonionic surfactant-cloud point measuring method”. That is, first, a sample is dissolved in a 25% by mass butyldiglycol (butanol / EO2 mol addition product) aqueous solution so as to have a concentration of 10% by mass. Next, about 5 cc of this sample solution is put into a test tube, and a thermometer is put in the test tube and gradually heated with stirring, and finally the sample solution becomes cloudy. The temperature at which the sample solution becomes completely cloudy is read and used as the cloud point. The cloud point of the composition of the present invention is 3
The temperature is 0 to 60 ° C, preferably 35 to 55 ° C. Cloud point is 6
Even if the temperature exceeds 0 ° C or lower than 30 ° C, the hydrophilic / hydrophobic balance is lost, and sufficient stain reducing property and its sustainability cannot be obtained.

The paint stain reducing agent obtained by the present invention exhibits its effect in an aqueous emulsion paint. Examples of emulsions used in the water-based emulsion paint include vinyl acetate-based, acrylic-based, styrene-based, halogenated olefin-based, urethane-based, silicone-based, and fluorine-based emulsions.

As a method of adding the stain reducing agent for paints of the present invention to an aqueous emulsion paint, (1) it is added at the time of dispersing the pigment. (2) There is a method such as post-addition after the paint is prepared, and any addition method does not affect the pollution reduction effect.

The amount of the stain reducing agent for paint of the present invention added to the water-based emulsion paint is usually 0.05 to 10.0% by mass, preferably 0.1 to 0.1% by mass based on the final finished paint.
It is 5.0 mass%.

The thus obtained stain reducing agent for paint is diluted with water to a viscosity suitable for coating, if necessary. Further, in the coating material, an ultraviolet absorber, a pigment dispersant, an anti-repellent agent, a thickener, and the like which are usually used, if necessary.
A paint additive such as an antifoaming agent can also be included at appropriate times. The coating method can be carried out by means of brush coating, roller coating, air spray coating, airless coating, roll coater coating, flow coater coating or the like according to a conventional method.

[0015]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The hydrophilicity, low stain resistance and water resistance evaluation results are shown in Table 1. In addition, the part in an Example means a mass part.

[Water-based emulsion coating composition for evaluation] Grinding process water 8.1 * 1 SN Dispersant 5027 1.1 * 2 SN thickener 636 0.5 Ammonia aqueous solution (25%) 0.2 Ethylene glycol 3.4 * 3 SN deformer 399 0.2 * 4 Taipaque R-930 27.8 Letdown process * 5 Boncoat EC-819 55.3 * 6 Nopcoside SN-215 0.9 * 3 SN deformer 399 0.3 Texanol 2.0 * 2 SN thickener 623N 0.2 ────────────────────────── * 1 Sannopco Ltd. dispersant * 2 Sannopco Ltd. Thickener * 3 Defoamer manufactured by San Nopco Ltd. * 4 Titanium dioxide manufactured by Ishihara Sangyo Co., Ltd. * 5 Manufactured by Dainippon Ink and Chemicals, Inc. Lil based emulsion ※ 6 San Nopco Ltd. preservatives aqueous emulsion paints obtained in this manner was diluted to standard paint so as to be 77KU (25 ℃) stormer viscometer with water. The blank is a test plate coated with only the standard paint (wet thickness 1 mm, the same applies below), Example,
Comparative example is standard paint / contamination reducing agent = 100/2 (mass ratio)
The paint mixed with the above was applied to prepare a test coated plate. The curing was at room temperature for 10 days.

[Evaluation Items] 1. Hydrophilicity evaluation 0.03 on the surface of the coating film of the test coated plate prepared above.
Add mL of ion-exchanged water dropwise. After 3 minutes, the contact angle of the water droplet was measured and used as the contact angle with water. The measurement was performed at 25 ° C. using a contact angle meter CAA manufactured by Kyowa Chemical Co., Ltd. The smaller the value, the more hydrophilic it is.

2. The coated plate for the stain resistance evaluation test was exposed outdoors for 6 months, and the degree of contamination was evaluated by the difference in lightness (ΔL) 1, 3 and 6 months after the start. After lightly washing the exposed test coated plate with water, Minolta Co., Ltd.
The lightness was measured with CR-200 manufactured by CR-200, and the value obtained by subtracting the lightness measured before the start of the test from the value was defined as ΔL. Although the value is negative, the closer it is to 0, the better the stain resistance is. The exposure location was 31 Takaracho, Tokai City, on the premises of our factory, with a slope of 30 degrees northward, and the period was May to October.

3. Water resistance evaluation The coating film was immersed in water at 25 ° C, and the surface of the coating film after 1 day was visually observed. The evaluation was ⊚ (no blisters were generated on the surface of the coating film), Δ (slightly blisters were generated on the surface of the coating film), and × (blisters were generated on the entire surface of the coating film).

Production Example 1 In a pressure vessel capable of stirring, heating up to 250 ° C., cooling, dropping and degassing, Sannix Polyol RP-410A [manufactured by Sanyo Kasei Co., Ltd., sucrose / PO13 mol adduct, average] Hydroxyl value of 410, average molecular weight of 1095] 1095 parts of potassium hydroxide 2.0 parts [reagent special grade, the same below] was added, and after dehydration under reduced pressure at 130 ° C., 3 mol of BO, 21
6 parts were dropped while keeping the pressure at 0.2 MPa or less, and 100-
Addition polymerization was carried out at 120 ° C. The required reaction time was about 5 hours. Next, after adding 2.5 parts of ion-exchanged water at 90 ° C., 50 parts of KYOWARD 600 (manufactured by Kyowa Chemical Co., Ltd.), which is an alkaline adsorbent, was added, and the mixture was stirred at the same temperature for 1 hour. Next, at the same temperature, No. 2 Filter paper [Toyo Roshi Kaisha, Ltd.]
Manufactured] to remove the catalyst by adsorption and further under reduced pressure 1
It was dehydrated at 20 ° C to obtain [A-1] having a sucrose / PO13 / BO3 mol adduct and a cloud point of 58.2 ° C.

Production Example 2 In a pressure resistant container similar to that of Production Example 1, 1095 parts of Sannix polyol RP-410A was added to potassium hydroxide 10.0.
Parts were added, and after dehydration under reduced pressure at 130 ° C., 82 mol of PO and 4756 parts were added dropwise while maintaining 0.2 MPa or less, and addition polymerization was carried out at 100 to 120 ° C. The reaction time required was about 15 hours. Next, after adding 12.0 parts of ion-exchanged water at 90 ° C., Kyoward 600 250
Parts were added, and the mixture was stirred at the same temperature for 1 hour. Next, at the same temperature, No. 2 Filtered with filter paper and dehydrated at 120 ° C. under reduced pressure to give 95 mol of sucrose / PO adduct, cloud point 3
[A-2] having a temperature of 2.6 ° C. was obtained.

Production Example 3 In the same manner as in Production Examples 1 and 2, sucrose / PO13 mol / E
O3 mol / PO50 mol adduct, cloud point 43.2 ° C. [A
-3] was obtained.

Production Example 4 Similarly, sucrose / PO35 mol adduct, cloud point 48.0 ° C.
[A-4] of was obtained.

Production Example 5 A pressure resistant reaction vessel similar to that of Production Example 1 was charged with 504 parts of 1 mol of raffinose (special grade reagent) and 1.0 part of an aqueous solution of 85% triethylenediamine, and the air was replaced with nitrogen. Then, while stirring at 100 ° C., 30 mol of PO 174
0 part was added dropwise while maintaining 0.4 MPa or less, and further B
216 parts of 3 moles of O are added dropwise while maintaining the pressure at 0.2 MPa or less. When the mixture was stirred at the same temperature for 15 hours, the pressure in the system did not decrease. Then, an adsorbent treatment was carried out in the same manner as in Production Example 1 to obtain a sample [A-5] having a raffinose / 30 mol PO / 3 mol BO polymer and a cloud point of 38 ° C. and used for the test.

Production Example 6 After adding 2.0 parts of ion-exchanged water at 90 ° C. to 1095 parts of Sannix Polyol RP-410A, 25 parts of Kyoward 600 was added and stirred at the same temperature for 1 hour. Next, at the same temperature, No. 2 Filtered with filter paper and dehydrated under reduced pressure at 120 ° C to give sucrose / PO13
A molar adduct and a cloud point of 80.2 ° C. [a-1] were obtained.

Production Example 7 Similarly, sucrose / PO110 mol adduct, cloud point 27.0
C. [a-2] was obtained.

MANUFACTURING EXAMPLE 8 Sannicks GP-1 was placed in a pressure-resistant reaction vessel similar to that in Manufacturing Example 1.
000 [Glycerin / PO16 manufactured by Sanyo Chemical Industry Co., Ltd.
1 mol of 1000 mol and 1000 parts of potassium hydroxide were charged, and dehydration under reduced pressure was carried out at 120 ° C., then 100 ° C.
Then, 24 mol of 1392 parts of PO is added dropwise at 0.4 MPa or less and 40 mol of 1760 parts of EO is added dropwise at 0.5 MPa or less. When the mixture was stirred at the same temperature for 18 hours, the pressure in the system did not decrease. Then, the same adsorbent treatment as in Production Example 1 and the like was performed to give glycerin / PO4.
0 mol / 40 mol of EO polymer [a-3] was obtained.

Example 1 A coating material for standard test / [A-1] = 100/2 (mass ratio) was applied to prepare a test coated plate. (Hereafter, the name of the sample of the pollution reducing agent to be added is used to create the test coated plate,
(List only the product name)

Example 2 [A-2] was used.

Example 3 [A-3] was used.

Example 4 [A-5] was used.

Example 5 [A-2] / [A-4] = 1/1 (mass ratio, the same applies hereinafter)
Was used.

Example 6 A mixture of [A-1] / [A-2] / [A-5] = 1/1/1 was used.

COMPARATIVE EXAMPLE 1 A test coated plate was prepared using only the standard paint without adding a stain reducing agent.

Comparative Example 2 [A-1] was used.

Comparative Example 3 [A-2] was used.

Comparative Example 4 [A-3] was used.

Comparative Example 5 Ethylene oxide modified silicone, KF-351 [produced by Shin-Etsu Silicone Co., Ltd.] was used.

Comparative Example 6 An anionic activator, SN Wet 123 (manufactured by San Nopco Ltd.) was used.

[0040]

[Table 1]

From Table 1, the stain reducing agent according to the present invention has a smaller contact angle than the conventional ones, and the exposure test result shows Δ.
It can be seen that L shows a value closer to zero, imparts low stain resistance, and does not reduce water resistance.

[0042]

Industrial Applicability The stain reducing agent according to the present invention and the coating material containing the stain reducing agent according to the present invention are useful for reducing stain resistance without lowering water resistance when applied outdoors such as for external walls. .

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J038 BA012 CB171 CC031 CD091                       CF021 CG141 DF022 DG001                       DL031 EA011 KA02 MA08                       MA10 MA14 NA05 NA27

Claims (4)

[Claims] 1. A stain-reducing agent for paints, which comprises a compound [A] obtained by polymerizing a non-reducing di- or trisaccharide with an alkylene oxide having 2 to 4 carbon atoms. 2. A non-reducing di- or trisaccharide [A] is polymerized with 15 to 100 mol of an alkylene oxide having 2 to 4 carbon atoms, and has a cloud point of 30 to 60 in a 25% by mass aqueous butyldiglycol solution method. The stain-reducing agent for paint according to claim 1, which has a temperature of ° C. 3. The stain-reducing agent for coating composition according to claim 1, wherein the non-reducing di-, tri-saccharide constituting [A] is sucrose. 4. The stain-reducing agent for coating composition according to claim 1, wherein the alkylene oxide forming [A] is propylene oxide and / or butylene oxide.