Aqueous emulsion stabilizer

Abstract

To provide an aqueous emulsion stabilizer which can easily impart excellent freezing and melting stability to aqueous emulsion.SOLUTION: An aqueous emulsion stabilizer for preventing separation and / or thickening after aqueous emulsion has been frozen and melted contains a polyoxyalkylene compound X1 represented by formula (1) and / or a polyoxyalkylene compound X2 represented by formula (2). Formula (1): Q{-(AO)p-H}t. Formula (2): H-(EO)n1-(PO)m-(EO)n2-OH. Q represents a residue obtained by removing hydrogen atoms from t pieces of primary hydroxyl groups of non-reductive disaccharides or trisaccharides, AO represents an oxyalkylene group, p represents 5 to 30, t represents 2 to 4, the total number of AO is 20 to 80 pieces per one residue Q1, EO represents an oxyethylene group, PO represents an oxypropylene group, m represents 10 to 80, and a sum (n1+n2) of n1 and n2 represents 10 to 300.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an aqueous emulsion stabilizer and an aqueous emulsion containing the same. [Background technology]

[0002] As a "freeze-thaw stabilizer additive composition," the following definition is provided: "A freeze-thaw stabilizer additive composition comprising: (a) at least one antifreeze compound; and (b) at least one emulsifier, wherein the freeze-thaw stabilizer additive composition provides a paint formulation having stability, and wherein a change in viscosity of the paint formulation after the formulation is subjected to a freeze-thaw stability test as described in GB / T-91 68-2008 is less than or equal to 10% when the viscosity of the paint formulation is measured at 23°C using a Stormer viscometer before and after the freeze-thaw stability test. is 0 to less than 10 percent." (Claim 1 of Patent Document 1), in which "the antifreeze compound is selected from the group consisting of glycerin alkoxylates, pentaerythritol alkoxylates, sorbitol alkoxylates, and mixtures thereof" (Claim 2 of Patent Document 1), and "the at least one emulsifier comprises a C12 to C14 primary or secondary alkoxylate, castor oil ethoxylate, ethylene oxide / propylene oxide copolymer, butylene oxide, or a mixture thereof" (Claim 3 of Patent Document 1) are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-535652 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional compositions have been insufficient in terms of freeze-thaw stability (the property of being less susceptible to separation and / or thickening after being frozen and then thawed). An object of the present invention is to provide an aqueous emulsion stabilizer which can easily impart excellent freeze-thaw stability to an aqueous emulsion. [Means for solving the problem]

[0005] The aqueous emulsion stabilizer of the present invention is characterized in that it is a stabilizer for preventing separation and / or thickening of an aqueous emulsion after freezing and then thawing, The gist of the present invention is that it contains a polyoxyalkylene compound (X1) represented by formula (1) and / or a polyoxyalkylene compound (X2) represented by formula (2).

[0006] Q{-(AO) p -H} t (1)

[0007] H-(EO) n1 -(PO) m -(EO) n2 -OH (2)

[0008] Q is a residue obtained by removing hydrogen atoms from t primary hydroxyl groups of a non-reducing di- or trisaccharide, AO is an oxyalkylene group having 2 to 4 carbon atoms, p is an integer of 5 to 30, t is an integer of 2 to 4, the total number of AO is 20 to 80 per residue (Q), and t {-(AO) p —H} may be the same or different, EO represents an oxyethylene group, PO represents an oxypropylene group, m represents an integer of 10 to 80, the sum of n1 and n2 (n1+n2) represents an integer of 10 to 300, H represents a hydrogen atom, and OH represents a hydroxyl group.

[0009] The aqueous emulsion of the present invention is characterized in that it comprises water, an emulsion resin, and the aqueous emulsion stabilizer described above, The content of the aqueous emulsion stabilizer is 0.5 to 20% by weight based on the weight of water, emulsion resin and aqueous emulsion stabilizer. Effect of the Invention

[0010] The aqueous emulsion stabilizer of the present invention can easily impart excellent freeze-thaw stability (the property of being less susceptible to separation and / or thickening after freezing and thawing) to an aqueous emulsion.

[0011] The aqueous emulsion of the present invention contains the above-mentioned aqueous emulsion stabilizer, and therefore exhibits excellent freeze-thaw stability (the property of being less susceptible to separation and / or thickening after freezing and thawing). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Polyoxyalkylene compound (X1) represented by formula (1)> Examples of non-reducing di- or trisaccharides capable of constituting 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, planteose, etc. Among these, from the viewpoint of the freeze-thaw stability of an aqueous emulsion, sucrose, trehalose, gentianose, raffinose, and planteose are preferred, more preferably sucrose, trehalose, and raffinose, and from the viewpoints of supplyability, cost, etc., sucrose is particularly preferred.

[0013] Examples of the oxyalkylene group (AO) having 2 to 4 carbon atoms include oxyethylene, oxypropylene, and oxybutylene.

[0014] The polyoxyalkylene compound (X1) may contain multiple types of oxyalkylene groups or may contain only a single type of oxyalkylene group. When multiple types of oxyalkylene groups (OA) are contained, the bonding pattern may be block-like, random-like, or a mixture thereof, but from the viewpoint of the freeze-thaw stability of the aqueous emulsion, it is preferable to contain at least block-like.

[0015] From the viewpoint of the freeze-thaw stability of the aqueous emulsion, p is preferably an integer of 5 to 30, more preferably an integer of 7 to 28, and particularly preferably an integer of 8 to 25.

[0016] From the viewpoint of the freeze-thaw stability of the aqueous emulsion, t is preferably an integer of 2 to 4, and more preferably 3.

[0017] The total number of AOs per residue (Q) is preferably 20 to 80, more preferably 21 to 78, and particularly preferably 24 to 75, from the viewpoint of the freeze-thaw stability of the aqueous emulsion.

[0018] The polyoxyalkylene compound (X1) represented by formula (1) can be prepared by a known alkylene oxide addition reaction.

[0019] <Polyoxyalkylene compound (X2) represented by formula (2)> The polyoxyalkylene compound (X2) represented by the formula (2) is a so-called Pluronic type surfactant. From the viewpoint of the freeze-thaw stability of the aqueous emulsion, m is preferably an integer of 10 to 80, more preferably 12 to 78, and particularly preferably 14 to 75.

[0020] The sum of n1 and n2 (n1+n2) is preferably an integer from 10 to 300, more preferably an integer from 14 to 290, and particularly preferably 20 to 280, from the viewpoint of the freeze-thaw stability of the aqueous emulsion.

[0021] The polyoxyalkylene compound (X2) represented by the formula (2) can be prepared by a known alkylene oxide addition reaction.

[0022] The aqueous emulsion stabilizer of the present invention may contain known additives (antifoaming agents, wetting agents, etc.) if necessary.

[0023] The aqueous emulsion stabilizer of the present invention can be prepared by uniformly mixing a polyoxyalkylene compound (X1) represented by formula (1), a polyoxyalkylene compound (X2) represented by formula (2), and, if necessary, known additives.

[0024] The aqueous emulsion stabilizer of the present invention can be widely applied to aqueous emulsions, for example, aqueous emulsion paints and aqueous emulsion adhesives, etc. Among these, it is particularly suitable for aqueous emulsion paints.

[0025] <Water-based emulsion> The aqueous emulsion of the present invention comprises water, an emulsion resin, an emulsifier, and the above-mentioned aqueous emulsion stabilizer, and may contain other additives (antifoaming agents, preservatives, etc.) as necessary.

[0026] Examples of the emulsion resin include acrylic resin, vinyl acetate resin, vinyl chloride resin, acrylic styrene resin, silicone resin, urethane resin, and epoxy resin. Of these, acrylic resin is preferred.

[0027] As the emulsifier, anionic emulsifiers (such as alkylbenzene sulfates and polyoxyethylene alkyl ether sulfates) and nonionic emulsifiers (such as polyoxyethylene alkyl ethers and polyoxyethylene fatty acid esters) can be used.

[0028] The content (wt %) of the aqueous emulsion stabilizer is preferably 0.5 to 20, and more preferably 1 to 17, based on the weight of the emulsion resin.

[0029] The aqueous emulsion can be prepared by a known method. For example, the aqueous emulsion can be obtained by preparing a resin emulsion by emulsion polymerization using water, monomers constituting the emulsion resin, and an emulsifier, and then uniformly mixing the resin emulsion with the aqueous emulsion stabilizer described above and, if necessary, other additives. Alternatively, the aqueous emulsion can be obtained by uniformly mixing a commercially available resin emulsion with the aqueous emulsion stabilizer described above.

[0030] Resin emulsions available on the market include the ACRONAL series (BASF Japan Ltd., "ACRONAL" is a registered trademark of BASF Societas Europea), the ACRYSET series (Nippon Shokubai Co., Ltd., "ACRYSET" is a registered trademark of the company), and the ECOVAE series (Celanse Corporation, "ECOVAE" (a graphic trademark with the American continent inside an O) is a registered trademark of Celanese International Corporation). EXAMPLES

[0031] <Example 1> An aqueous emulsion stabilizer of the present invention (1; 15 mol ethylene oxide-35 mol propylene oxide-15 mol ethylene oxide block adduct) was prepared by subjecting 1 mol of propylene glycol, 30 mol of ethylene oxide, and 34 mol of propylene oxide to an alkylene oxide addition reaction (block addition).

[0032] <Example 2> An aqueous emulsion stabilizer of the present invention (2; 140 mol ethylene oxide-75 mol propylene oxide-140 mol ethylene oxide block adduct) was prepared by subjecting 1 mol of propylene glycol, 280 mol of ethylene oxide, and 74 mol of propylene oxide to an alkylene oxide addition reaction (block addition).

[0033] <Example 3> An aqueous emulsion stabilizer of the present invention (3; 10 mol ethylene oxide-14 mol propylene oxide-10 mol ethylene oxide block adduct) was prepared by alkylene oxide addition reaction (block addition) of 1 mol propylene glycol, 20 mol ethylene oxide, and 13 mol propylene oxide.

[0034] <Example 4> An aqueous emulsion stabilizer of the present invention (4; sucrose-propylene oxide 75 mol adduct) was prepared by subjecting 1 mol part of sucrose and 75 mol parts of propylene oxide to an alkylene oxide addition reaction. In addition, since the alkylene oxide addition reaction proceeds selectively to the primary hydroxyl groups of sucrose (due to steric hindrance and the difference between primary and secondary hydroxyl groups), t in formula (2) is 3 and p is 25.

[0035] <Example 5> An aqueous emulsion stabilizer of the present invention (5; sucrose propylene oxide 15 moles / butylene oxide 15 moles random adduct) was prepared by subjecting 1 mole of sucrose, 15 moles of propylene oxide, and 15 parts of butylene oxide to an alkylene oxide addition reaction (random addition). In addition, since the alkylene oxide addition reaction proceeds selectively to the primary hydroxyl groups of sucrose (due to steric hindrance and the difference between primary and secondary hydroxyl groups), t in formula (2) is 3 and p is 10.

[0036] <Example 6> An aqueous emulsion stabilizer of the present invention (6; sucrose-propylene oxide 24 mol adduct) was prepared by subjecting 1 mol part of sucrose and 24 mol parts of propylene oxide to an alkylene oxide addition reaction. In addition, since the alkylene oxide addition reaction proceeds selectively to the primary hydroxyl groups of sucrose (due to steric hindrance and the difference between primary and secondary hydroxyl groups), t in formula (2) is 3 and p is 8.

[0037] <Example 7> The aqueous emulsion stabilizer of the present invention (7; sucrose 6 mol ethylene oxide-60 mol propylene oxide block adduct) was prepared by alkylene oxide addition reaction (block addition) of 1 mol part of sucrose, 6 mol of ethylene oxide, and 60 mol of propylene oxide. In addition, since the alkylene oxide addition reaction proceeds selectively to the primary hydroxyl groups of sucrose (due to steric hindrance and the difference between primary and secondary hydroxyl groups), t in formula (2) is 3 and p is 22.

[0038] <Example 8> An aqueous emulsion stabilizer of the present invention (8; trehalose propylene oxide 20 moles / butylene oxide 6 moles random adduct) was prepared by subjecting 1 mole of trehalose, 20 moles of propylene oxide, and 6 moles of butylene oxide to an alkylene oxide addition reaction (random addition). In addition, since the alkylene oxide addition reaction proceeds selectively to the primary hydroxyl groups of trehalose (due to steric hindrance and the difference between primary and secondary hydroxyl groups), t in formula (2) is 2 and p is 13.

[0039] <Example 9> 50 parts by weight of the aqueous emulsion stabilizer (1) prepared in Example 1 and 50 parts by weight of the aqueous emulsion stabilizer (4) prepared in Example 4 were uniformly mixed to prepare an aqueous emulsion stabilizer (9) of the present invention.

[0040] <Example 10> 50 parts by weight of the aqueous emulsion stabilizer (2) prepared in Example 2 and 50 parts by weight of the aqueous emulsion stabilizer (7) prepared in Example 7 were uniformly mixed to prepare an aqueous emulsion stabilizer (10) of the present invention.

[0041] <Example 11> An aqueous emulsion stabilizer (11) of the present invention was prepared by uniformly mixing 40 parts by weight of the aqueous emulsion stabilizer (3) prepared in Example 3 and 60 parts by weight of the aqueous emulsion stabilizer (4) prepared in Example 4.

[0042] <Example 12> An aqueous emulsion stabilizer (12) of the present invention was prepared by uniformly mixing 60 parts by weight of the aqueous emulsion stabilizer (1) prepared in Example 1 and 40 parts by weight of the aqueous emulsion stabilizer (6) prepared in Example 6.

[0043] <Comparative Example 1> In accordance with Inv.Ex.1 (Example 1) of Patent Document 1 (JP Patent Publication 2022-535652), 80 parts by weight of Voranol CP300 (glycerin-PO, theoretical Mw=300, The Dow Chemical Company, "VORANOL" is a registered trademark of The Dow Chemical Company) and 20 parts by weight of Tergitol 15-S-9 (C12-14 secondary alcohol ethoxylate, HLB=12, The Dow Chemical Company, "TERGITOL" is a registered trademark of Union Carbide Corporation) were uniformly mixed to prepare a comparative freeze-thaw additive.

[0044] <Evaluation of freeze-thaw stability 1> 100 parts by weight of Acronal 295DN (acrylic emulsion, acrylic resin concentration 50%, BASF Japan Ltd.) and any of the aqueous emulsion stabilizers (1) to (12) obtained in the Examples or 0.5 parts by weight of the comparative aqueous emulsion stabilizer (H1) were uniformly mixed to prepare aqueous emulsions (1) to (12) and (H1). 100 g of each of these aqueous emulsions (1) to (12) and (H1) was placed in a 140 cc glass bottle, sealed, and left at -15°C for 18 hours and then allowed to stand at 25°C for 6 hours. After the glass bottle was turned sideways, the condition after 5 minutes was evaluated according to the following criteria, and the results are shown in the table below.

[0045] <Evaluation of freeze-thaw stability 2> 100 parts by weight of EcoVAE 401 Emulsion (ethylene vinyl acetate emulsion, ethylene vinyl acetate resin concentration 55%, Celanse) and any of the aqueous emulsion stabilizers (1) to (12) obtained in the Examples or 9.35 parts by weight of the comparative aqueous emulsion stabilizer (H1) were uniformly mixed to prepare aqueous emulsions (1) to (12) and (H1). 100 g of each of these aqueous emulsions (1) to (12) and (H1) was placed in a 140 cc glass bottle, sealed, and left at -15°C for 18 hours and then left to stand at 25°C for 6 hours. The glass bottle was then turned sideways, and the state after 5 minutes was evaluated according to the following criteria, as shown in the table below.

[0046] ○: The aqueous emulsion flowed and the liquid level became horizontal. ×: The aqueous emulsion did not flow and the liquid surface remained vertical.

[0047] [Table 1]

[0048] The aqueous emulsion stabilizer of the present invention was able to readily impart superior freeze-thaw stability to the aqueous emulsion as compared to the comparative freeze-thaw additive.

Claims

1. A stabilizer for preventing separation and / or thickening of an aqueous emulsion after freezing and thawing, An aqueous emulsion stabilizer comprising a polyoxyalkylene compound (X1) represented by formula (1) and / or a polyoxyalkylene compound (X2) represented by formula (2). Q{-(AO) ｐ -H} ｔ (1) 80(59) ｎ１ -(0) ｍ -(59) ｎ２ -O((2) Q is a residue obtained by removing hydrogen atoms from t primary hydroxyl groups of a non-reducing di- or trisaccharide, AO is an oxyalkylene group having 2 to 4 carbon atoms, p is an integer of 5 to 30, t is an integer of 2 to 4, the total number of AO is 20 to 80 per residue (Q), and t {-(AO) ｐ —H} may be the same or different, EO represents an oxyethylene group, PO represents an oxypropylene group, m represents an integer of 10 to 80, the sum of n1 and n2 (n1+n2) represents an integer of 10 to 300, H represents a hydrogen atom, and OH represents a hydroxyl group.

2. 2. The aqueous emulsion stabilizer according to claim 1, wherein the reactive residue (Q) of the non-reducing di- or trisaccharide is the reactive residue of sucrose.

3. An aqueous emulsion comprising water, an emulsion resin, and the aqueous emulsion stabilizer according to claim 1 or 2, The aqueous emulsion is characterized in that the content of the aqueous emulsion stabilizer is 0.5 to 20% by weight based on the weight of water, emulsion resin and aqueous emulsion stabilizer.

Images