JP7623021B2 - Roller coating improver for water-based emulsion paint and water-based emulsion paint containing same - Google Patents

Description

The present invention relates to a roller coating property improver for water-based emulsion paints and water-based emulsion paints containing the same.

（式中、Ｒ^１～Ｒ^４はそれぞれ炭素数１～１３の直鎖アルキル基を表し、Ｒ^５及びＲ^６は下記の式（２）又は（３）で表されるいずれかの基を表し、ｍ及びｎはそれぞれ３～１５の数を表し、ｘは４０～８００の数を表し、ｙは１以上の数を表す。ただし、Ｒ^１とＲ^２の炭素数の和及びＲ^３とＲ^４の炭素数の和はいずれも１０～１４でなければならない。）

」が知られている（特許文献１）。 A viscosity modifier represented by the following general formula (1) is used as an agent for improving the roller coating properties of water-based emulsion paints.

(In the formula, R ¹ to R ⁴ each represent a linear alkyl group having 1 to 13 carbon atoms, R ⁵ and R ⁶ each represent a group represented by the following formula (2) or (3), m and n each represent a number from 3 to 15, x represents a number from 40 to 800, and y represents a number of 1 or more. However, the sum of the carbon numbers of R ¹ and R ² and the sum of the carbon numbers of R ³ and R ⁴ must each be 10 to 14.)

" is known (Patent Document 1).

JP 2013-122011 A

Conventional viscosity modifiers have a problem of poor roller applicability of aqueous emulsion paints. That is, when applying a conventional viscosity modifier to an aqueous emulsion paint for roller application, if the viscosity modifier is added to the paint to increase its viscosity in order to prevent the paint from scattering, the paint becomes difficult to spread on the paint, while if the viscosity modifier is reduced or a dilution solvent is added to reduce the viscosity of the paint, the amount of the paint impregnated into the roller is small and the paint scatters.
An object of the present invention is to provide a roller coatability improver which is excellent in roller coatability.

The roller coatability improver for aqueous emulsion paints of the present invention is characterized in that it contains a polyoxyalkylene compound (X) represented by formula (1).

RN{-(AO) _n- H} ₂ (1)

R represents an alkyl or alkenyl group having 8 to 22 carbon atoms, N represents a nitrogen atom, H represents a hydrogen atom, AO represents an oxyalkylene group having 2 to 4 carbon atoms, and n represents an integer from 2 to 20.

The water-based emulsion paint of the present invention is characterized in that it is a water-based emulsion paint comprising water, an emulsion resin, and the above-mentioned roller coatability improver,
The gist of the invention is that the content of the roller coatability improver is 0.5 to 5% by weight based on the weight of water, emulsion resin and roller coatability improver.

The roller coatability improver for aqueous emulsion paint of the present invention exhibits excellent suitability for roller coating. Therefore, aqueous emulsion paints exhibiting excellent suitability for roller coating can be easily prepared. In other words, when the roller coatability improver for aqueous emulsion paint of the present invention is applied to aqueous emulsion paint and roller coating is performed, the paint has excellent anti-scattering properties, paint spreadability, and roller impregnation properties.

The aqueous emulsion paint of the present invention contains the roller coatability improver described above, and therefore exhibits excellent roller coatability, and when this aqueous emulsion paint is roller coated, it has excellent anti-scattering properties, paint spreadability, and roller impregnation properties.

Photographs of the state of the coated surface immediately after evaluating the emulsion paint (1) for evaluation prepared using the roller coatability improver for aqueous emulsion paint (1) of Example 1, 3. paint spreadability, (1) amount of transfer to the slate board, and the presence or absence of smearing. Photographs of the condition of the coated surface immediately after evaluating the spreadability of the coating material (H1) prepared using the comparative viscosity modifier (H1) of Comparative Example 1, and (1) the amount of transfer to the slate board and the presence or absence of smearing. In the column of Examples, for the emulsion paint for evaluation (blank), 3. Paint spreadability, (1) the amount of transfer to the slate board and the presence or absence of smearing were evaluated. The photographs show the state of the coated surface immediately after the evaluation. In the section of Examples, 3. Coating spreadability, (2) A schematic diagram showing the locations (parts marked with circles) where film thickness was measured to calculate the average film thickness and standard deviation (numbers indicate the distance between each circle (unit: cm)).

<Polyoxyalkylene Compound (X)>
Examples of the alkyl or alkenyl group (R) having 8 to 22 carbon atoms (preferably 10 to 20, and more preferably 12 to 18) include n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, isodecyl, n-undecyl, n-dodecyl, n-tridecyl, isotridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, isooctadecyl, n-docosyl, n-decenyl, 2-dodecenyl, isotridecenyl, and n-octadecenyl.

The oxyalkylene group (AO) having 2 to 4 carbon atoms includes oxyethylene, oxypropylene and oxybutylene.
When (AO) _n contains a plurality of types of oxyalkylene groups, the bonding form may be any of block, random, and a mixture thereof.

The polyoxyalkylene compound (X) represented by formula (1) includes polyoxyalkylene compounds having a structure produced by a chemical reaction between an alkylamine (a1) or alkenylamine (a2) having 8 to 22 carbon atoms and ethylene oxide, propylene oxide, and/or butylene oxide (a3) {preferably, 4 to 40 moles of (a3) are used per mole of (a1) or (a2).}.

Examples of alkylamines (a1) or alkenylamines (a2) having 8 to 22 carbon atoms include n-octylamine, 2-ethylhexylamine, n-nonylamine, n-decylamine, isodecylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, isotridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, isooctadecylamine, n-docosylamine, n-decenylamine, 2-dodecenylamine, isotridecenylamine, and n-octadecenylamine.

<Polyoxyalkylene Compound Y>
The roller coatability improver for aqueous emulsion paint of the present invention preferably contains a polyoxyalkylene compound (Y) represented by formula (2).

Q{-(AO) _m -H} _t (2)

In the above, Q represents a residue obtained by removing hydrogen atoms from t primary hydroxyl groups of a non-reducing di- or trisaccharide, AO represents an oxyalkylene group having 2 to 4 carbon atoms, m represents an integer of 5 to 30, t represents an integer of 2 to 4, and H represents a hydrogen atom. The total number of AO is 20 to 80 per residue (Q), and the t (AO) _m's may be the same or different.

Examples of non-reducing di- or trisaccharides that can constitute the residue (Q) obtained by removing hydrogen atoms from t primary hydroxyl groups of a non-reducing di- or trisaccharide include sucrose (saccharose), trehalose, isotrehalose, isosaccharose, gentianose, raffinose, melezitose, and planteose. Among these, from the viewpoint of roller coating properties, sucrose, trehalose, gentianose, raffinose, and planteose are preferred, more preferably sucrose, trehalose, and raffinose, and particularly preferably sucrose from the viewpoints of supplyability and cost.

Examples of oxyalkylene groups (AO) having 2 to 4 carbon atoms include oxyethylene, oxypropylene, and oxybutylene. Of these, from the viewpoint of roller coating properties, when the total number of oxyalkylene groups (AO) per residue (Q) is 25 to 59, oxypropylene alone is preferred, when this total number is 15 to 24, a mixture of oxybutylene and oxypropylene is preferred, and when this total number is 60 to 80, a mixture of oxyethylene and oxypropylene is preferred.

When a mixture of oxypropylene and/or oxybutylene with oxyethylene is included, the content (mol%) of oxyethylene is preferably 2 to 10, more preferably 2 to 8, and particularly preferably 4 to 6, based on the total number of moles of oxyalkylene groups. In this case, it is preferable that oxypropylene and/or oxybutylene is located at an end away from the reactive residue (Q). That is, in this case, it is preferable that the oxyethylene group is directly bonded to the reactive residue (Q). In addition, when multiple types of oxyalkylene groups (AO) are included, the bonding pattern may be block-like, random-like, or a mixture of these, but it is preferable that at least the bonding pattern is included.

m is preferably an integer from 5 to 30, more preferably an integer from 7 to 28, and particularly preferably an integer from 10 to 25. Within this range, roller coating properties will be even better.

t is preferably an integer between 2 and 4, and more preferably 3. Within this range, roller coating properties will be even better.

When polyoxyalkylene compound (Y) is contained, the content weight ratio of polyoxyalkylene compound (X) to polyoxyalkylene compound (Y) {(X):(Y)} is preferably 50-95:50-5, more preferably 55-90:45-10, from the viewpoint of roller coating properties.

The roller coating property improver for aqueous emulsion paints of the present invention can contain known additives (defoamers, wetting agents, etc.) as necessary.

Examples of defoamers include SN Defoamer 180 and 184 (manufactured by San Nopco Ltd.), and examples of wetting agents include SN Wet 125 and 126 (manufactured by San Nopco Ltd.). When known additives are included, the content of these is preferably about 0.01 to 10% by weight based on the weight of the polyoxyalkylene compound (X).

The method for producing the roller coatability improver for aqueous emulsion paint of the present invention is not particularly limited and any known method can be applied. Polyoxyalkylene compound (X) can be prepared by known alkylene oxide addition reaction or the like. When polyoxyalkylene compound (Y) is contained, polyoxyalkylene compound (Y) can be prepared by known alkylene oxide addition reaction or the like, and can be obtained by uniformly mixing polyoxyalkylene compound (X) and polyoxyalkylene compound (Y). There is no limit to the uniform mixing temperature, but from the viewpoint of mixing efficiency, about 10 to 70°C is preferable.

The roller coatability improver for water-based emulsion paints of the present invention is particularly suitable for water-based emulsion paints, but can also be widely applied to paints that contain water.

<Water-based emulsion paint>
The aqueous emulsion paint of the present invention contains water, an emulsion resin, and the above-mentioned roller coatability improver for aqueous emulsion paints, and may contain, if necessary, a pigment, a dispersant, a wetting agent, a viscoelasticity modifier, an antifoaming agent, a preservative, and/or a film-forming aid.

The amount (wt%) of the roller coatability improver for water-based emulsion paint used is preferably 0.5 to 5, and more preferably 1 to 4, based on the weight of the water, emulsion resin, and roller coatability improver for water-based emulsion paint. Within this range, the roller coatability will be even better.

The aqueous emulsion paint of the present invention can be obtained by known methods, and the roller coatability improver for aqueous emulsion paint can be mixed in at any step, but it is preferable to mix it in at the dissolution step (let-down step).

The aqueous emulsion paint of the present invention can be used for various purposes, including architectural paints or paints for structures such as tanks and bridges, coating liquids for coated paper, paints for electronic materials such as electromagnetic and optical components, paints for structural materials using ceramics, and coating compositions such as functional slurry paints for application to various molded bodies.

<Examples 1 to 7>
As the polyoxyalkylene compound (X) represented by the formula (1), an adduct of 20 moles of n-octadecylamine and ethylene oxide (X1), an adduct of 7 moles of isodecylamine and ethylene oxide (X2), an adduct of 4 moles of n-decenylamine and ethylene oxide (X3), and an adduct of 40 moles of 2-dodecenylamine and ethylene oxide (X4) were used. As the polyoxyalkylene compound (Y) represented by the formula (2), an adduct of 3 moles of sucrose and propylene oxide was used. The roller coatability improvers for aqueous emulsion paints (1) to (7) of Examples 1 to 7 were prepared by uniformly mixing the amounts (parts by weight) shown in Table 1 of each of the following: trehalose. propylene oxide. 72 mole block adduct (Y1), trehalose. propylene oxide. 12 moles. butylene oxide. 8 mole random adduct (Y2), sucrose. ethylene oxide. 63 mole block adduct (Y3), and sucrose. propylene oxide. 59 mole adduct (Y4).

<Comparative Example 1>
The product 3 of the present invention described in the column of Examples of Patent Document 1 was prepared in accordance with the description in the column of Examples from 800 g (0.1 mol) of polyoxyethylene glycol having a weight average molecular weight of 8,000, 40.2 g (0.2 mol) of a secondary alcohol 12EO having 12 to 14 carbon atoms {obtained by adding 9 mol of ethylene oxide to 1 mol of alcohol 1 (a secondary alcohol 3EO having 12 to 14 carbon atoms (SOFTANOL M30, Nippon Shokubai Co., Ltd., "SOFTANOL" is a registered trademark of the company)} (alcohol 3), and 34 g (0.2 mol) of hexamethylene diisocyanate, and this was used as a comparative viscosity modifier (H1).

<Evaluation 1>
1. Preparation of emulsion paint for evaluation The raw material composition shown in Table 2 was ground with a tabletop sand mill equipped with a disk-type blade (Kanpe Home Paint Co., Ltd., Kanpe Sand Mill), and then let down with a mixer equipped with an anchor-type blade (Tokyo Rikakikai Co., Ltd., MAZELLA ZZ-1100, "MAZELLA" is a registered trademark of the company) to prepare an emulsion base paint. 98 parts by weight of this emulsion base paint and any of the roller coating improvers (1) to (7) obtained in the examples or any of 2 parts by weight of the viscosity adjuster (H1) for comparison were mixed and stirred at 25°C, 2000 rpm, and 5 minutes in an Excel Auto Homogenizer (Nippon Seiki Co., Ltd., Model ED) equipped with a Coles-type blade to obtain emulsion paints (1) to (7) and (H1) for evaluation. Also, 98 parts by weight of the emulsion base paint and 2 parts by weight of water were mixed by stirring in the same manner as above to obtain an emulsion paint for evaluation (blank).

*1 Dispersant: San Nopco Limited, and "Nopcol" is a registered trademark of the company.
*2 Thickener, Daicel FineChem Ltd. *3 Wetting agent, San Nopco Ltd. *4 Wetting agent, San Nopco Ltd. *5 Barium sulfate, Sakai Chemical Industry Co., Ltd. "Variace" is a registered trademark of the company.
*6 Titanium dioxide, Ishihara Sangyo Kaisha, Ltd., and “Tipaque” are registered trademarks of the company.
*7 Acrylic emulsion, DIC Corporation; "Boncoat" is a registered trademark of the company.
*8 Film forming regulator, JNC Corporation

2. Roller impregnation 100 g of each emulsion paint for evaluation was placed in a 140 ml glass bottle, sealed, and left at 25° C. for 18 hours, then 80 g of the emulsion paint for evaluation was transferred to a roller tray (width 240 mm x depth 76 mm x height 385 mm, product name: Roller tray 4 inches, Otsuka Brush Manufacturing Co., Ltd.) in a room adjusted to 25° C., and the paint was impregnated by rolling it back and forth 10 times with a weighed 4-inch small roller (hair length 13 mm, product name: Maron for interior and exterior use, Otsuka Brush Manufacturing Co., Ltd.), and the weight of the 4-inch small roller was measured, and the amount of paint impregnation (g) was calculated from the weight before and after impregnation, and is shown in the table below. The greater the amount of impregnation, the better the roller impregnation.

3. Paint spreadability (1) Amount transferred to slate board and presence or absence of smearing 100 g of each emulsion paint for evaluation was placed in a 140 ml glass bottle, sealed, and left at 25° C. for 18 hours, and then in a room adjusted to 25° C., a 20 cm x 13.5 cm slate board that had been surface treated with a sealer (product name: water-based silicone undercoat sealer, Nippe Home Products Co., Ltd.) was covered with masking tape outside the painted area, and the slate board was then held against a vertical wall with the short sides facing up and down and the long sides facing left and right. Next, 80 g of the emulsion paint for evaluation was transferred to a roller tray (width 240 mm x depth 76 mm x height 385 mm, product name: Roller tray 4 inches, Otsuka Brush Manufacturing Co., Ltd.), and the paint was impregnated by 10 reciprocations with a weighed 4-inch small roller (hair length 13 mm, product name: Maron for interior and exterior use, Otsuka Brush Manufacturing Co., Ltd.), and the paint was then adjusted by reciprocating or squeezing the roller so that the paint impregnation amount was 40 g. The roller was then reciprocated three times to paint a slate board held against a vertical wall, and the weight of the small roller immediately after painting was measured, and the amount of paint transferred (g) to the slate board out of 40 g of paint was calculated. Furthermore, the masking tape was peeled off from the slate board, and the presence or absence of smearing on the painted surface was visually confirmed, and these are shown in the table below. The greater the "amount of transfer (g) to the slate board," the better the paint spreadability, and further, the absence of "smearing" indicates good paint spreadability.

(2) Average value and standard deviation of film thickness The average value and standard deviation of film thickness were measured in the same manner as in "(1) Amount of transfer to slate board and presence or absence of smearing", except that "20 cm x 13.5 cm slate board surface-treated with a sealer (product name: water-based silicone undercoat sealer, Nippe Home Products Co., Ltd.)" was changed to "one piece (15 cm x 10 cm) of a tin plate (30 cm x 20 cm x 0.3 mm thick, JIS G3303, TP Giken Co., Ltd.) divided into two." The masking tape was removed from the tin plate and the plate was dried at 25°C for 24 hours. The average value and standard deviation of film thickness were measured using an electromagnetic film thickness meter (DELTASCOPE FMP-10, Fischer Instruments Co., Ltd., "DELTASCOPE" is a measurement device manufactured by Helmut Fischer GmbH Institut fur Elektronik und The coating thickness (μm) was measured at a total of 10 points indicated by circles in Figure 4 in accordance with JIS K 5600-1-7:2014, 5.5.6, Measurement Method 7C, using a magnetic induction coating thickness gauge (registered trademark of Messtechnik Co., Ltd.), and the arithmetic mean value (μm) and standard deviation were calculated, which are shown in the table below. If the "average coating thickness" is 22 μm or more, the paint spreadability is good, and the smaller the "standard deviation value", the better the paint spreadability.

4. Anti-scattering property of paint Each emulsion paint for evaluation was left at 25°C for 18 hours, and then in a room adjusted to 25°C, the entire cup part of a Zahn cup (No. 3, orifice diameter: 3.85 mm, volume: 44 mL, All Good Co., Ltd., ASTM D4212-16) was immersed in each emulsion paint for evaluation, and then the Zahn cup was lifted and the emulsion paint for evaluation was dropped from the orifice, and the time (seconds: viscosity) until the entire amount had finished dropping was measured, and the number of times that the emulsion paint for evaluation dripped was measured within 15 seconds from the time when the dripping was completed. This operation was repeated five times, and the average value of the five times was calculated. The average number of drips (times) was taken as anti-scattering property and is shown in the table below. The smaller the number of times, the more stringy the paint is, and the less likely it is to scatter.

As described above, the water-based emulsion paint using the roller coatability improver of the present invention had superior paint splash prevention, paint spreadability, and roller impregnation properties compared to the water-based emulsion paint using the comparative viscosity modifier and the blank.

As shown in Figures 1 to 3, the surface painted with the water-based emulsion paint using the comparative viscosity modifier (Figure 2) showed "fading," and this "fading" also affected the standard deviation of the film thickness. Also, the surface painted with the evaluation water-based emulsion paint (blank) (Figure 3) showed no "fading," but in addition to the absence of roller marks (roller painting traces), the paint film was thin near the top edge and thick near the bottom edge, with sagging observed near the bottom edge (near where the masking tape was removed), and this difference in paint film thickness also affected the standard deviation of the film thickness.

Claims (5)

A roller coatability improver for aqueous emulsion paints, comprising a polyoxyalkylene compound (X) represented by formula (1):

RN{-(AO) _n- H} ₂ (1)

R represents an alkyl or alkenyl group having 8 to 22 carbon atoms, N represents a nitrogen atom, H represents a hydrogen atom, AO represents an oxyalkylene group having 2 to 4 carbon atoms, and n represents an integer of 2 to 20. The roller coatability improver according to claim 1 , further comprising a polyoxyalkylene compound (Y) represented by formula (2):
Q{-(AO) _m -H} _t (2)
In the above, Q represents a residue obtained by removing hydrogen atoms from t primary hydroxyl groups of a non-reducing di- or trisaccharide, AO represents an oxyalkylene group having 2 to 4 carbon atoms, m represents an integer of 5 to 30, t represents an integer of 2 to 4, and H represents a hydrogen atom. The total number of AO is 20 to 80 per residue (Q), and the t (AO) _m's may be the same or different. The roller coating property improver according to claim 2, wherein the reaction residue (Q) of a non-reducing di- or trisaccharide is a reaction residue of sucrose. The roller coatability improver according to claim 2, in which the weight ratio of the polyoxyalkylene compound (X) to the polyoxyalkylene compound (Y) {(X):(Y)} is 50-95:50-5. An aqueous emulsion paint comprising water, an emulsion resin, and a roller coatability improver according to any one of claims 1 to 4, characterized in that the content of the roller coatability improver is 0.5 to 5% by weight based on the weight of the water, emulsion resin, and roller coatability improver.

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