JP2022045837A - Novel emulsion - Google Patents

Abstract

To provide a novel emulsion.SOLUTION: An O/W type (oil-in-water type) emulsion includes a polymer (A) having a structural unit (A1) derived from an amide group-containing monomer. The polymer (A) contains the structural unit (A1) in an amount of 0.1-35 mass%.SELECTED DRAWING: None

Description

The present invention relates to novel emulsions and the like.

Conventionally, various components have been developed as coagulants. For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-188731), as a sludge coagulant, an inorganic coagulant such as aluminum sulfate and an organic synthetic polymer coagulant such as polyacrylamide are known. Is described.

Japanese Unexamined Patent Publication No. 2013-188731 (paragraph number [0003])

An object of the present invention is to provide a novel emulsion or the like.

As mentioned above, polyacrylamide is known as a polymer-type flocculant (coagulant). If such a polymer-type cohesive agent is used as a powder as it is, it may become difficult to exert an efficient cohesive force in a compounding (additional) target, such as a stepchild shape.

Therefore, the polymer-type flocculant may be used as a liquid dissolved / dispersed (diluted) in an appropriate solvent (water or the like) depending on the intended use.

However, even if it is used in such a liquid state, the coagulant becomes highly viscous in the solvent, and it may not be sufficient in terms of usability. In particular, such a tendency often becomes more remarkable as the concentration of the flocculant increases.

On the other hand, the reduction of high viscosity often leads to the reduction of the cohesive function of the coagulant, and it is difficult to achieve both usability (low viscosity liquid) and sufficient cohesiveness.

Under such circumstances, the present inventor can obtain a new emulsion by selecting a specific polymer composition and emulsion type, and according to such an emulsion, sufficient cohesiveness and excellent use. It has been found that both properties (providing a low-viscosity liquid) can be achieved (exhibited).

In addition to the above, the present inventors have obtained various new findings as described below, and have made further diligent studies to complete the present invention.

That is, the present invention includes the following inventions and the like.
[1]
An O / W type (oil-in-water type) emulsion containing a polymer (A) having a structural unit (A1) derived from an amide group-containing monomer, wherein the polymer (A) has a structural unit (A1) of 0.1 to 35. Emulsion containing in% by weight.
[2]
The emulsion according to [1], wherein the amide group-containing monomer contains (meth) acrylamide.

[3]
The emulsion according to [1] or [2], wherein the ratio of the structural unit (A1) in the polymer (A) is 0.5 to 25% by mass.
[4]
The emulsion according to any one of [1] to [3], wherein the polymer (A) has a structural unit (A2) derived from a (meth) acrylic acid ester.
[5]
The emulsion according to [4], wherein the structural unit (A2) has a structural unit derived from (meth) acrylic acid C _1-3 alkyl ester.
[6]
The emulsion according to [4] or [5], wherein the ratio of the structural unit (A2) in the polymer is 20% by mass or more.
[7]
The emulsion according to any one of [4] to [6], which contains 2 parts by mass or more of the structural unit (A2) with respect to 1 part by mass of the structural unit (A1).
[8]
The emulsion according to any one of [1 to [7], wherein the polymer (A) has a structural unit (A3) derived from an acid group-containing monomer.
[9]
The emulsion according to [8], wherein the proportion of the structural unit (A3) in the polymer is 5% by mass or more.
[10]
The emulsion according to [8] or [9], which contains 0.5 part by mass or more of the structural unit (A3) with respect to 1 part by mass of the structural unit (A1).
[11]
The polymer (A) has a structural unit (A2) derived from a (meth) acrylic acid ester and a structural unit (A3) derived from an acid group-containing monomer, and the structural unit (A2) has a structural unit (A1) with respect to 1 part by mass of the structural unit (A2). ) And the emulsion according to any one of [1] to [10], which contains 3 parts by mass or more of the structural unit (A3).
[12]
The polymer (A) has a structural unit (A1) derived from an amide group-containing monomer, a structural unit (A2) derived from a (meth) acrylic acid ester, and a structural unit (A3) derived from an acid group-containing monomer.
The structural unit (A2) has a structural unit derived from (meth) acrylic acid C _1-3 alkyl ester, and has.
The structural unit (A3) has a structural unit derived from (meth) acrylic acid and has.
The ratio of the structural unit (A1) in the polymer (A) is 1 to 20% by mass.
The ratio of the structural unit (A2) in the polymer is 30% by mass or more, and the ratio is 30% by mass or more.
The emulsion according to any one of [1] to [11], wherein the ratio of the structural unit (A3) in the polymer is 10% by mass or more.
[13]
The emulsion according to any one of [1] to [12], wherein the polymer (A) has a weight average molecular weight of 1 million or more.
[14]
The emulsion according to any one of [1] to [13], wherein the polymer (A) (or the particles constituting the emulsion) has an average particle diameter of 1000 nm or less.
[15]
The emulsion according to any one of [1] to [14], which has a pH of 5 or less.
[16]
The viscosity at 20% by mass of solid content (25 ° C., BM type viscometer, 30 rpm) is 1000 mPa · s or less, and the viscosity at 1% by mass of solid content (25 ° C., BM type viscometer, 30 rpm) is 100 mPa · s or less. The emulsion according to any one of [1] to [15].
[17]
The viscosity of the emulsion at a solid content concentration of 20% by mass is V ₂₀ (mPa · s), the viscosity of the emulsion at a solid content concentration of 1% by mass is V ₁ (mPa · s), and the viscosity of the emulsion at a solid content concentration of 0.1% by mass. When V _0.1 (mPa · s), the value of V ₂₀ -V ₁ is 100 mPa · s or less, and the value of V ₂₀ -V _0.1 is 300 mPa · s or less, [1] to [16]. ] The emulsion according to any one of.

In the present invention, a novel emulsion or the like can be provided.
Surprisingly, such an emulsion can achieve both sufficient cohesive force and excellent usability (providing a low-viscosity liquid).
Moreover, according to such an emulsion, a low-viscosity liquid can be obtained even at a relatively high concentration. Therefore, it is also possible to provide an emulsion having a high concentration and a low viscosity.
Further, since the emulsion of the present invention is an emulsion type (further, a low-viscosity solution), unlike the powder type, the equipment for dissolving can be omitted in the use of a coagulant or the like.

The emulsion of the present invention is an O / W type (oil-in-water type) emulsion containing a polymer (A) having a structural unit (A1) derived from an amide group-containing monomer.

[Polymer (A)]
The polymer (A) has at least a structural unit (A1) derived from an amide group-containing monomer (or has an amide group-containing monomer as a polymerization component).

(Amide group-containing monomer unit (A1))
Examples of the amide group-containing monomer include (meth) acrylamide-based monomers {for example, (meth) acrylamide, N-substituted (meth) acrylamide [for example, N-alkyl (meth) acrylamide (for example, N-monomethyl (meth) acrylamide). , N-monoC _1-4 alkyl (meth) acrylamide such as N-monoethyl (meth) acrylamide), N, N-dialkyl (meth) acrylamide (eg, N, N such as N, N-dimethyl (meth) acrylamide) -Di C _1-4 alkyl (meth) acrylamide), etc.], etc.}, cyclic amide-based monomers (for example, N-vinylpyrrolidone, etc.) and the like can be mentioned.

The amide group-containing monomer usually does not have to have an acid group.

The amide group-containing monomer may be used alone or in combination of two or more (may be derived from the structural unit (A1)).

Among the amide group-containing monomers, a chain amide-based monomer such as a (meth) acrylamide-based monomer, particularly (meth) acrylamide, is advantageous in terms of cohesive force (higher molecular weight of the polymer (A)) and the like.

Therefore, the amide group-containing monomer may contain at least a (meth) acrylamide-based monomer [particularly (meth) acrylamide] [or a structural unit (A1) (hereinafter, an amide-containing monomer unit (A1)) or the like. The same) may contain at least (meth) acrylamide-based monomers [particularly, containing (meth) acrylamide] units].

When the amide group-containing monomer contains (meth) acrylamide, the ratio of the (meth) acrylamide unit to the amide group-containing monomer unit [or the ratio of (meth) acrylamide to the amide-containing monomer] is, for example, 30% by mass or more. It may be preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass or more (for example, 85% by mass or more, 90% by mass or more, 95% by mass or more, 100% by mass, etc.). There may be.

In the polymer (A), the ratio of the amide group-containing monomer unit (the ratio of the amide group-containing monomer unit to the structural unit constituting the polymer (A) or the ratio of the amide group-containing monomer to the polymer component of the polymer (A)) is For example, it may be 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, 35% by mass or less, preferably 30% by mass or less, still more preferably 25% by mass. It may be about the following (for example, 20% by mass or less).
The range may be a combination of a lower limit value and an upper limit value as appropriate (for example, 0.1 to 35% by mass, 0.5 to 25% by mass, etc.). The same applies to the description of the range below.

By including the structural unit (A1) in such a ratio, it is easy to efficiently obtain an O / W emulsion having sufficient cohesive force.

((Meta) acrylic acid ester unit (A2))
The polymer (A) has a structural unit (A2) derived from a (meth) acrylic acid ester (or a polymer (or a polymer)) from the viewpoint of polymerizability with a (meth) acrylic monomer, formability of an O / W emulsion, and the like. A) may be (with (meth) acrylic acid ester as a polymerization component).
By combining the (meth) acrylic monomer with the amide group-containing monomer, it is easy to obtain an O / W type emulsion having sufficient cohesive force (and a sufficient high molecular weight).

Examples of the (meth) acrylic acid ester include chain aliphatic (meth) acrylate {linear or branched chain aliphatic (meth) acrylate, for example, alkyl (meth) acrylate [for example, methyl (meth) acrylate, ethyl (for example). Meta) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, amyl ( Meta) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, n-lauryl (meth) C _1-20 alkyl (meth) acrylates such as acrylates, tridecyl (meth) acrylates, stearyl (meth) acrylates (eg, C _1-18 alkyl (meth) acrylates)], alkoxyalkyl (meth) acrylates [eg, alkoxyalkyls] (Meta) Acrylate (eg, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, (meth) C _1-12 alkoxy C _1-12 alkyl methacrylate, etc. such as 3-methoxypropyl acrylate, 4-methoxybutyl (meth) acrylate, etc.], etc.}, alicyclic (meth) acrylate [eg, cycloalkyl (meth) ) Acrylate (eg, C _4-20 cycloalkyl (meth) acrylate such as cyclohexyl (meth) acrylate, preferably C _4-10 cycloalkyl (meth) acrylate), cycloalkylalkyl (meth) acrylate (eg, cyclohexylmethyl (eg, cyclohexylmethyl). C _4-10 cycloalkyl C _1-4 alkyl (meth) acrylates such as meth) acrylates, cyclohexylethyl (meth) acrylates, cyclohexylpropyl (meth) acrylates, 4-methylcyclohexylmethyl (meth) acrylates), crosslinked cyclic (meth) acrylates. Meta) acrylates (eg, isobornyl (meth) acrylates, adamantyl (meth) acrylates, etc.), aromatic (meth) acrylates ((meth) acrylic acid esters having an aromatic ring) [eg, aryl (meth) acrylates (eg, eg) , Fe C _6-10 aryl (meth) acrylates such as nyl (meth) acrylates), C _6-10 aryl C _1-4 alkyls such as aralkyl (meth) acrylates (eg, benzyl (meth) acrylates, phenethyl (meth) acrylates) Meta) acrylate), aryloxyalkyl methacrylate (for example, C _6-10 aryloxy C _1-4 alkyl methacrylate such as phenoxyethyl methacrylate), etc.] and the like.

The (meth) acrylic acid ester usually does not have to have a functional group (for example, a hydroxy group, a mercapto group, an acid group, an epoxy group, an amino group, etc.).
Further, the (meth) acrylic acid ester may be a monofunctional [(meth) acrylic acid ester having one polymerizable group ((meth) acryloyloxy group)].

Of these, aliphatic (meth) acrylates [eg, alkyl acrylates (eg, C _1-18 alkyl acrylates such as ethyl acrylate and butyl acrylate), alkyl methacrylates (eg, C _1-18 alkyl such as methyl methacrylate) (Methyl), alkoxyalkyl (meth) acrylate, etc.], in particular, (meth) acrylic acid C _1-3 alkyl ester from the viewpoint of polymerizability with amide group-containing monomers and formability (stability) of O / W emulsion. (In particular, methyl acrylate, ethyl acrylate, especially ethyl acrylate and the like) are preferable.

Therefore, the polymer (A) may have at least an aliphatic (meth) acrylate unit (particularly, a (meth) acrylic acid C _1-3 alkyl ester unit such as an ethyl (meth) acrylate unit).

When the (meth) acrylic acid ester contains an aliphatic (meth) acrylate, the ratio of the aliphatic (meth) acrylate unit to the (meth) acrylic acid ester unit [or the aliphatic (meth) in the (meth) acrylic acid ester. ) Acrylate ratio] may be, for example, 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass or more (for example, 85% by mass or more, 90% by mass or more). , 95% by mass or more, 100% by mass, etc.).

When the (meth) acrylic acid ester contains (meth) acrylic acid C _1-3 alkyl ester, the ratio of (meth) acrylic acid C _1-3 alkyl ester unit to the (meth) acrylic acid ester unit [or (meth). ) Ratio of (meth) acrylic acid C _1-3 alkyl ester to acrylic acid ester] may be, for example, 20% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and 70. It may be mass% or more (for example, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, 100% by mass, etc.).

When the (meth) acrylate ester contains ethyl (meth) acrylate, the ratio of the (meth) ethyl acrylate unit to the (meth) acrylate unit [or the (meth) acrylic in the (meth) acrylate ester. The proportion of ethyl acrylate] may be, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, and 30% by mass or more (for example, 40% by mass or more, 50% by mass or more). , 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 100% by mass, etc.).

When the polymer (A) has (meth) acrylic acid ester units, the ratio of (meth) acrylic acid ester units (the ratio of (meth) acrylic acid ester units to the structural units constituting the polymer (A) or the polymer (A). The ratio of the (meth) acrylic acid ester to the polymer component of) is, for example, 1% by mass or more (for example, 5% by mass or more), preferably 10% by mass or more (for example, 15% by mass or more), and more preferably. It may be 20% by mass or more (for example, 25% by mass or more), particularly 30% by mass or more (for example, 35% by mass or more, 40% by mass or more, 45% by mass or more, 50% by mass or more, etc.).
The upper limit of the ratio of the (meth) acrylic acid ester unit may be, for example, 95% by mass, 90% by mass, 85% by mass, 80% by mass, 75% by mass, or the like.

When the polymer (A) has a (meth) acrylic acid ester unit (A2), the ratio of the structural unit (A2) is, for example, 1 part by mass or more (for example, 1 part) with respect to 1 part by mass of the structural unit (A1). .5 parts by mass or more), more preferably 2 parts by mass or more (for example, 2.5 parts by mass or more), particularly 3 parts by mass or more (for example, 3.5 parts by mass or more and 4 parts by mass or more). ..

By including the structural unit (A2) in such a ratio, it is easy to obtain an O / W emulsion having sufficient cohesive force more efficiently.

(Acid group-containing monomer unit (A3))
The polymer (A) may have a structural unit (A3) derived from an acid group-containing monomer from the viewpoints of cohesive force, alkali solubility (solubilized from a particle structure with a base to become a uniform polymer), and the like. When it is alkali-soluble, for example, when used under basic conditions, it is easy to solubilize the particulate polymer (emulsion particles) to homogenize the polymer, and the function of the polymer (A) is efficient depending on the application. It becomes easier to exert (condensation power, etc.).

Examples of such an acid group-containing monomer (acid group-containing monomer) include a carboxyl group- or acid anhydride group-containing monomer [for example, unsaturated monocarboxylic acid (for example, acrylic acid, methacrylic acid, crotonic acid, etc.). An aliphatic unsaturated monocarboxylic acid), an unsaturated polycarboxylic acid (eg, an aliphatic unsaturated dicarboxylic acid such as maleic acid, fumaric acid, or itaconic acid) or a partial ester thereof (for example, a monoester of dicarboxylic acid (half ester)). Etc.), these acid anhydrides (eg, maleic anhydride, etc.), etc.], sulfonic acid group-containing monomers [eg, styrene-based monomers (eg, styrene sulfonic acid, etc.), (meth) acrylic acid sulfonic acid. Alkyl esters (eg, ethyl (meth) acrylic acid 2-sulfonic acid), alkenyl sulfonic acid (eg, vinyl sulfonic acid), (meth) acryloylaminoalkyl sulfonic acid (eg, 2-acrylamide-2-methyl sulfonic acid), etc. ] Etc. can be mentioned.

Typical acid group-containing monomers include carboxyl groups or acid anhydride group-containing monomers, and among them, (meth) acrylic acid (acrylic acid, methacrylic acid) and the like are preferable, and methacrylic acid is particularly preferable from the viewpoint of low viscosity. Acids may be used more preferably.

The acid group-containing monomer does not have to contain (meth) acryloylaminoalkylsulfonic acid.

The acid group-containing monomer may be used alone or in combination of two or more.

The acid group-containing monomer unit may be neutralized in the polymer (A) (may form a salt), but may be usually neutralized or may be a partial unit. , The polymer (A) preferably has an acid group-containing monomer unit in at least a free form.

When the acid group-containing monomer contains a (meth) acrylic acid unit, the ratio of the (meth) acrylic acid unit to the acid group-containing monomer unit [or the ratio of the (meth) acrylic acid to the acid group-containing monomer] is, for example, , 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and 75% by mass or more (for example, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass). % Or more, 100% by mass, etc.).

When the polymer (A) has an acid group-containing monomer unit, the ratio of the acid group-containing monomer unit (the ratio of the acid group-containing monomer unit to the structural unit constituting the polymer (A) or the ratio of the polymer (A) to the polymer component. The ratio of the acid group-containing monomer) is, for example, 0.1% by mass or more (for example, 1% by mass or more), preferably 3% by mass or more (for example, 5% by mass or more), and more preferably 8% by mass or more (for example). It may be 10% by mass or more), particularly 12% by mass or more (for example, 15% by mass or more, 18% by mass or more, 20% by mass or more, etc.).
The upper limit of the ratio of the acid group-containing monomer unit is, for example, 90% by mass, 80% by mass, 75% by mass, 70% by mass, 65% by mass, 60% by mass, 55% by mass, 50% by mass, 45% by mass. It may be% or the like.

When the polymer (A) has an acid group-containing monomer unit (A3), the ratio of the structural unit (A3) is, for example, 0.1 part by mass or more (for example, 0) with respect to 1 part by mass of the structural unit (A1). .3 parts by mass or more), more preferably 0.5 parts by mass or more (for example, 0.8 parts by mass or more), particularly 1 part by mass or more (for example, 1.2 parts by mass or more, 1.5 parts by mass or more, 1) It may be 0.8 parts by mass or more, 2 parts by mass or more, 2.5 parts by mass or more).

When the polymer (A) has a structural unit (A2) and an acid group-containing monomer unit (A3), the ratio of the structural unit (A3) is, for example, 0. 05 parts by mass or more (for example, 0.08 parts by mass or more), more preferably 0.1 parts by mass or more (for example, 0.12 parts by mass or more), particularly 0.15 parts by mass or more (for example, 0.18 parts by mass). As mentioned above, 0.2 parts by mass or more, 0.25 parts by mass or more) may be used.

When the polymer (A) has a structural unit (A2) and an acid group-containing monomer unit (A3), the ratio of the total amount of the structural unit (A1) and the structural unit (A3) is 1 part by mass of the structural unit (A2). On the other hand, for example, 1 part by mass or more (for example, 2 parts by mass or more), more preferably 3 parts by mass or more (for example, 3.5 parts by mass or more), particularly 4 parts by mass or more (for example, 4.5 parts by mass or more). 5, 5 parts by mass or more, 5.5 parts by mass or more, 6 parts by mass or more, 6.5 parts by mass or more, 7 parts by mass or more).

By including the structural unit (A3) (furthermore, the structural unit (A2)) in such a ratio, it is easy to obtain an O / W type emulsion having sufficient cohesive force (further, sufficient high molecular weight).

(Other units)
The polymer (A) may have a structural unit (other monomer unit) derived from another monomer (or another monomer as a polymerization component), if necessary.

Examples of other monomers include a monomer having a functional group (a functional group other than an acid group) (functional group-containing monomer), a polyfunctional monomer, a styrene-based monomer [or an aromatic vinyl-based monomer, for example, styrene, α-. Alkyl styrene (eg α-C _1-4 alkyl styrene such as α-methyl styrene), alkyl styrene (eg C _1-4 alkyl styrene such as vinyl toluene), halo styrene (eg chloro styrene etc.), halo alkyl styrene (eg chloro styrene) For example, chloromethylstylene), etc.], vinyl ester-based monomers [for example, fatty acid vinyl esters such as vinyl acetate and vinyl propionate (for example, C _1-10 fatty acid vinyl ester, C _2-6 fatty acid vinyl ester, etc.)], etc.] , Vinyl ether-based monomers (eg, alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether), olefin-based monomers [eg, alkene (eg, C _2-10 alkene such as ethylene, propylene, 1-butene, isobutylene, 1-octene) and the like. ], Halogen-containing monomers [eg, halo C _2-10 alkene such as vinyl chloride, vinylidene chloride, vinyl fluoride; haloalkyl vinyl ether such as chloroethyl vinyl ether (halo C _1-10 alkyl vinyl ether, etc.)], unsaturated nitrile ( For example, (meth) acrylonitrile, etc.) and the like.

Examples of the functional group-containing monomer include a hydroxy group-containing monomer {for example, hydroxyalkyl (meth) acrylate [for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth)). Acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxy C _2-10 alkyl (meth) acrylate such as 2-hydroxy-3-phenoxypropyl (meth) acrylate], polyalkylene glycol Mono (meth) acrylate [for example, poly-C _2-4 alkanediol (mono) methacrylate such as diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate], 3 or more. A hydroxy group-containing (meth) acrylate such as a mono (meth) acrylate of a polyol having a hydroxy group [for example, a tri to a mono (meth) acrylate of a hexahydroxy C _3-10 polyol such as a glycerin mono (meth) acrylate]}, Epoxy group-containing monomers [eg, glycidyl (meth) acrylate, glycidyloxyalkyl (meth) acrylate (eg, glycidyloxy C _2-4 alkyl (meth) acrylate such as 2-glycidyloxyethyl (meth) acrylate)], oxazoline Group-containing monomers [eg, alkenyl oxazoline (eg, C _2-6 alkenyl oxazoline such as 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline), alkenyl-alkyl oxazoline (eg, 2-vinyl-4-). C _2-6 such as methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, etc. Alkenyl-C _1-10 alkyl oxazoline), etc.] and the like.

Examples of the polyfunctional monomer include polyfunctional (meth) acrylate {for example, polyol [or polyhydric alcohol, for example, diol (eg, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexane). Poly (meth) acrylates of diols, alcoholic diols such as neopentyl glycol, polyethylene glycols, polypropylene glycols, etc.), polyols having 3 or more hydroxy groups (eg, glycerin, trimethyllolpropane, diglycerin, pentaerythritol, etc.) }, Alkenyl (meth) acrylate (eg, allyl (meth) acrylate), divinylbenzene, diallyl phthalate and the like.

When the polymer (A) has other units, the ratio of the other units in the polymer (A) [or the ratio of other monomers to the polymerized components of the polymer (A)] is, for example, 0.01% by mass or more. (For example, 0.05% by mass or more), preferably 0.1% by mass or more (for example, 0.2% by mass or more), more preferably 0.3% by mass or more (for example, 0.5% by mass or more, 0). It may be 0.8% by mass or more, 1% by mass or more, 1.2% by mass or more, 1.5% by mass or more, 1.8% by mass or more, 2% by mass or more) and the like.

When the polymer (A) has other units, the ratio of the other units in the polymer (A) [or the ratio of other monomers to the polymerized components of the polymer (A)] is, for example, 50% by mass or less (for example). , 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less), preferably 25% by mass or less (for example, 20% by mass or less), and more preferably 15% by mass or less (for example, 12% by mass). Hereinafter, it may be 10% by mass or less, 5% by mass or less) and the like.

In particular, when the polymer (A) has a polyfunctional monomer unit, the ratio of the polyfunctional monomer unit in the polymer (A) [or the ratio of the polyfunctional monomer in the polymerization component of the polymer (A)] is, for example, , 15% by mass or less (for example, 12% by mass or less), preferably 10% by mass or less (for example, 8% by mass or less), more preferably 5% by mass or less (for example, 3% by mass or less), particularly 2% by mass or less. (For example, 1.5% by mass or less) may be used.

The polyfunctional monomer can use the polymer (A) as a cross-linking component, but from the viewpoint of workability and the like, even when the polyfunctional monomer is used, the degree of cross-linking is not too high, and it is about the above ratio. preferable.

The polymer (A) (emulsion particles) may be either a single-layer (single-layer, single-layer, single-layer structure) polymer or a multi-layer (multilayer structure) polymer (for example, a core-shell type polymer), and is easy. From the viewpoint of being able to produce the polymer, a single-layer polymer may be used.

(Physical characteristics, etc.)
The weight average molecular weight of the polymer (A) (emulsion particles) may be, for example, 1 million or more, preferably 3 million or more, and more preferably 5 million or more from the viewpoint of cohesive force and the like. The upper limit of the weight average molecular weight of the polymer (A) may be, for example, 50 million, 100 million, 300 million, 500 million, 1 billion or the like from the viewpoint of cohesive force or the like.

Such a polymer (A) tends to retain sufficient cohesive force and the like.

The weight average molecular weight can be measured by, for example, measurement using gel permeation chromatography (for example, in terms of polystyrene) or measurement with a molecular weight measuring device (for example, DLS-8000 manufactured by Otsuka Electronics) by a static light scattering method. , May have been decided.

The glass transition temperature of the polymer (A) may be, for example, 80 ° C. or lower, preferably 75 ° C. or lower (for example, 65 ° C. or lower), more preferably 50 ° C. or lower, and −40 ° C. or higher, preferably −. It may be 30 ° C. or higher (for example, −20 ° C. or higher), more preferably −10 ° C. or higher.

The glass transition temperature may be determined by differential scanning calorimetry (for example, measurement based on JIS-K7121), differential calorimetry (DTA), thermomechanical analysis (TMA), or the like.
Alternatively, the glass transition temperature is determined by using the glass transition temperature of the homopolymer of the monomer used as the monomer component constituting the polymer.
Equation (I): 1 / Tg = Σ (Wm / Tgm) / 100 (I)
[In the formula, Wm indicates the content (% by mass) of the monomer m in the monomer component constituting the polymer, and Tgm indicates the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m].
It may be determined based on the Fox formula represented by.
To give an example of the glass transition temperature, for example, 105 ° C. for a homopolymer of methyl methacrylate, -70 ° C. for a homopolymer of 2-ethylhexyl acrylate, -56 ° C. for a homopolymer of n-butyl acrylate, and cyclohexyl methacrylate. 83 ° C for homopolymer, 107 ° C for tert-butyl methacrylate homopolymer, 55 ° C for 2-hydroxyethyl methacrylate homopolymer, 95 ° C for acrylic acid homopolymer, 130 ° C for methacrylic acid homopolymer. ° C., 100 ° C. for styrene homopolymers and the like.
For monomers such as special monomers and polyfunctional monomers whose glass transition temperature is unknown, the total amount of the monomers whose glass transition temperature is unknown in the monomer component is the mass fraction. When the temperature is 10% by mass or less, the glass transition temperature may be determined using only the monomer whose glass transition temperature is known. On the other hand, if the total amount of monomers whose glass transition temperature is unknown in the monomer component exceeds 10% by mass in terms of mass fraction, other methods (differential scanning calorimetry, differential calorimetry, thermomechanical analysis, etc.) It may be measured by the above-mentioned method).

[Emulsion and its manufacturing method]
The emulsion of the present invention is an O / W type (oil-in-water type) emulsion containing the polymer (A).

Such an emulsion can be obtained, for example, by polymerizing the polymerization component of the polymer (A) in water (in an aqueous solvent) in the presence of an emulsifier (emulsion polymerization), so that the emulsifier can be used to obtain the polymer (A). It often has a coating structure (composed of a polymer (A) (particles) and an emulsifier present on its surface (surface layer)).

In other words, the emulsion of the present invention is usually an emulsion in which the polymer (A) is dispersed (dissolved) in water (in an aqueous solvent) in the form of particles (emulsion particles, particles constituting the emulsion) together with an emulsifier present on the surface thereof. (O / W type emulsion) may be used.

The emulsifier usually covers the surface of the polymer (A), but may penetrate into the polymer (A) (particles).

The polymer (A) may be a polymer contained in an O / W type emulsion but having a relatively large degree of hydrophilicity. Therefore, in order to obtain a stable O / W type emulsion containing such a polymer having a high degree of hydrophilicity, a relatively large amount of emulsifier may be used, and in such a case, the inside of the polymer (A). The emulsifier may invade.

The emulsifier is not particularly limited as long as it can form an O / W type emulsion, and examples thereof include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, and amphoteric emulsifiers.

Each of these emulsifiers may be used alone or in combination of two or more.

Examples of the anionic emulsifier include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; alkyl aryl sulfonate salts such as ammonium dodecylbenzene sulfonate and sodium dodecyl naphthalene sulfonate; Polyoxyethylene alkyl sulfate salt; polyoxyethylene alkyl aryl sulfate salt; polyoxyethylene alkyl ether sulfate (for example, Hytenol series manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); dialkyl sulfosuccinate; aryl sulfonic acid-formalin condensate; Examples thereof include fatty acid salts such as ammonium laurylate and sodium stealylate.

Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic. Examples thereof include a condensate with amine.

Examples of the cationic emulsifier include alkylammonium salts such as dodecylammonium chloride.

Examples of the amphoteric emulsifier include betaine ester type emulsifiers.

The emulsifier may be a polymer emulsifier (polymer type emulsifier). Examples of the polymer emulsifier include anionic emulsifiers (for example, poly (meth) acrylates such as sodium polyacrylate) and nonionic emulsifiers (for example, polyvinyl alcohol, polyvinylpyrrolidone, polyhydroxyethyl acrylate and the like). (Meta) acrylate), a polymer having one or more kinds of monomers constituting these polymers as a copolymerization component, and the like can be mentioned.

The emulsifier may be a reactive emulsifier (an emulsifier having a reactive group).

Examples of the reactive emulsifier include propenyl-alkylsulfosuccinate ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, and polyoxyethylene alkylpropenylphenyl ether ammonium sulfate [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10, Aqualon BC-10, etc.], Alkoxymethylalkyloxypolyoxyethylene sulfonate salt [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10, etc.], Allyloxymethylnonylphenoxy Ethyl hydroxypolyoxyethylene sulfonate salt [for example, manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SE-10, etc.], allyloxymethylalkoxy ethyl hydroxypolyoxyethylene sulfate ester salt [for example, manufactured by ADEKA Co., Ltd., Product name: Adecaria soap SR-10, SR-30, etc.], Bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salt [For example, manufactured by Nippon Embroidery Co., Ltd., product name: Antox MS-60, etc.] , Allyloxymethylalkoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap ER-20, etc.], polyoxyethylene alkylpropenylphenyl ether [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Product name: Aqualon RN-20, etc.], Allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., product name: Adecaria Soap NE-10, etc.] and the like.

The HLB of the emulsifier can be selected within the range in which an O / W type emulsion can be obtained depending on the composition of the polymer (A) and the like, and may be, for example, about 7 to 17, preferably about 8 to 16.

As described above, the polymer (A) often has a relatively high degree of hydrophilicity, and from the viewpoint of including (stablely dispersing) such a polymer (A) in an O / W emulsion, etc. At least an emulsifier with a relatively high HLB value may be used.
Specific examples of the use of such an emulsifier include, for example, a form in which an emulsifier having a relatively high HLB value (for example, an anionic emulsifier and a nonionic emulsifier) is used alone, and an emulsifier having a relatively high HLB value. Examples thereof include a form in which an anionic emulsifier is used in combination.

The ratio of the emulsifier (usage ratio) is, for example, 1 part by mass or more (for example, 1 to 5 parts by mass, 1.5 parts by mass or more) with respect to 100 parts by mass of the polymer (A) (or its polymerized component). It may be preferably 2 parts by mass or more (for example, 2.5 parts by mass or more), and more preferably 3 parts by mass or more.

The average particle size of the emulsion particles (particles constituting the emulsion) may be, for example, 3000 nm or less, preferably 1000 nm or less, more preferably 500 nm or less, or 30 nm or more (for example, 50 nm or more). good.
Emulsion particles having such a relatively small particle size are suitable in terms of usability, such as permeability and cohesive force, as well as easy suppression or prevention of clogging.

The average particle size of the emulsion particles may be measured according to JISZ8828-2019 using a multi-specimen nanoparticle size measuring device (nanoSAQLA manufactured by Otsuka Electronics) by a dynamic light scattering method.

When the emulsion particles (polymer (A)) have an acid group (at least an acid group in an unneutralized form), the acid value is, for example, 5 mgKOH / g or more (for example, 10 mgKOH / g or more), preferably 20 mgKOH. / G or more (for example, 25 mgKOH / g or more), more preferably 30 mgKOH / g or more (for example, 40 mgKOH / g or more), particularly 50 mgKOH / g or more (for example, 80 mgKOH / g or more, 100 mgKOH / g or more), etc. It may be 500 mgKOH / g or less (for example, 400 mgKOH / g or less, 300 mgKOH / g or less) or the like.

For the acid value of the emulsion (A), for example, the acid value (mgKOH / g) per 1 g of the resin solid content was measured according to JIS K0070: 1992 using an automatic titrator (trade name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.). May be.

The solvent constituting the emulsion is usually water, but a water mixture containing water and another solvent [for example, a solvent containing water [for example, water and alcohol (for example, methanol, ethanol, etc.) C _{1- 4} An aqueous solvent such as a mixed solvent of alcohol)] may be used.

In such an aqueous mixture, the ratio of the other solvent to the total solvent is, for example, 50% by mass or less (for example, 30% by mass or less), preferably 20% by mass or less (for example, 15% by mass or less). , More preferably, it may be 10% by mass or less (for example, 5% by mass or less).

In the emulsion, the ratio of the solid content (nonvolatile content) can be appropriately selected depending on the application, handleability, etc., and is, for example, 0.1% by mass or more (for example, 1% by mass or more), preferably 2% by mass or more (for example). 3% by mass or more), more preferably 5% by mass or more (for example, 8% by mass or more, 10% by mass or more, 15% by mass or more), and 60% by mass or less, preferably 50% by mass or less. May be.

The concentration of the inorganic salt dissolved in the solvent constituting the emulsion is, for example, 10% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, based on the total amount of the solvent (total amount of the solvent and the inorganic salt). .. The lower limit of the concentration of the inorganic salt may be 0% by mass, 0.5% by mass, or 1% by mass.

The inorganic salt is intended to be an inorganic salt having no organic chain and does not contain an emulsifier. Specific examples of the inorganic salt include salts containing chloride ions and polyvalent anions. Examples of the salt containing chloride ion include sodium chloride, potassium chloride, calcium chloride, ammonium chloride salt and the like. Examples of the salt containing a polyvalent anion include sodium sulfate, magnesium sulfate, ammonium sulfate and the like.

The emulsion may be diluted before use.

The viscosity of the emulsion depends on the solid content concentration, but even in a relatively high concentration emulsion, the viscosity is often relatively low.

For example, the viscosity of the emulsion may be, for example, 1000 mPa · s or less (for example, 800 mPa · s or less, 500 mPa · s or less, 300 mPa · s or less, 200 mPa · s or less) at a solid content concentration of 20% by mass. It may be about 100 mPa · s or less (for example, 80 mPa · s or less, 50 mPa · s or less, 30 mPa · s or less, 20 mPa · or less), or about 10 mPa · s or less.

The viscosity of the emulsion can be selected from the range of, for example, 1000 mPa · s or less (for example, 800 mPa · s or less, 500 mPa · s or less, 300 mPa · s or less, 200 mPa · s or less) at a solid content concentration of 1% by mass, and is usually used. , 100 mPa · s or less (for example, 80 mPa · s or less, 50 mPa · s or less, 30 mPa · s or less, 20 mPa · or less), and typically 10 mPa · s or less.

The viscosity of the emulsion can be selected from the range of, for example, 100 mPa · s or less (for example, 80 mPa · s or less, 50 mPa · s or less, 30 mPa · s or less, 20 mPa · or less) at a solid content concentration of 0.1% by mass. Typically, it may be 10 mPa · s or less.

As mentioned above, the viscosity of an emulsion is usually relatively low at a wide range of concentrations (especially at high concentrations), but with increasing (variation) in solid content concentration (variation in viscosity). The degree is also relatively small.

For example, when the viscosity of the emulsion at a solid content concentration of 20% by mass is V ₂₀ (mPa · s) and the viscosity of the emulsion at a solid content concentration of 1% by mass is V ₁ (mPa · s), the value is V ₂₀ −V ₁ . May be, for example, 1000 mPa · s or less (for example, 800 mPa · s or less, 500 mPa · s or less, 300 mPa · s or less, 200 mPa · s or less), and 100 mPa · s or less (for example, 80 mPa · s or less, 50 mPa or less). -S or less, 30 mPa · s or less, 20 mPa · or less), 10 mPa · s or less.

When the viscosity of the emulsion at a solid content concentration of 20% by mass is V ₂₀ (mPa · s) and the viscosity of the emulsion at a solid content concentration of 0.1% by mass is V _0.1 (mPa · s), V ₂₀ −V ₀ . The value of _.1 may be, for example, 1000 mPa · s or less (for example, 800 mPa · s or less, 500 mPa · s or less, 300 mPa · s or less, 200 mPa · s or less), and 100 mPa · s or less (for example, 80 mPa · s ·). s or less, 50 mPa · s or less, 30 mPa · s or less, 20 mPa · or less), and 10 mPa · s or less.

When the viscosity of the emulsion at a solid content concentration of 1% by mass is V ₁ (mPa · s) and the viscosity of the emulsion at a solid content concentration of 0.1% by mass is V _0.1 (mPa · s), V ₁ − V ₀ . The value of _.1 may be, for example, 100 mPa · s or less (for example, 80 mPa · s or less, 50 mPa · s or less, 30 mPa · s or less, 20 mPa · s or less), and 10 mPa · s or less (for example, 8 mPa · s ·). It can also be about s or less, 5 mPa · s or less, 3 mPa · s or less, 2 mPa · or less, 1 mPa · s or less).

As the viscosity of the emulsion, for example, a BM viscometer (for example, manufactured by Toki Sangyo Co., Ltd., product number: TVB-10M) may be used to measure the viscosity at 25 ° C. at a rotation speed of 30 rpm.

The emulsion may be acidic from the viewpoint of cohesive force and the like. In such an acidic emulsion, the pH can be selected from, for example, in the range of about 6 or less, 5.5 or less, preferably 5 or less (for example, 1 to 4.5), and more preferably 4 or less (for example, 1). It may be .5-4) or the like.
The pH of the emulsion can be measured, for example, at 25 ° C. using a pH meter (LAQUA manufactured by HORIBA, Ltd.) in accordance with JIS Z8802.

As described above, the emulsion (O / W type emulsion) of the present invention can be produced, for example, by emulsion polymerization of the polymerization component of the polymer (A) in water (aqueous solvent).

The method for emulsifying and polymerizing the polymerization component is not particularly limited, but for example, a method of dropping the polymerization component into a solvent containing an emulsifier to polymerize, a method of dropping the polymerization component previously emulsified with an emulsifier into the solvent, or the like. And the method of polymerizing.

The amount of the solvent may be appropriately set in consideration of the amount of non-volatile content contained in the obtained emulsion and the like.

In the emulsion polymerization, the polymerization initiator is not particularly limited and conventional components can be used, for example, azobisisobutyronitrile, 2,2-azobis (2-methylbutyronitrile), 2,2-azobis (2,). 4-Dimethylvaleronitrile), 2,2-azobis (2-diaminopropane) hydrochloride, 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-methylpropionamidine) and other azo compounds Persulfates such as potassium persulfate; peroxides such as hydrogen peroxide, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, ammonium peroxide and the like can be mentioned.

The polymerization initiator may be used alone or in combination of two or more.

Further, the emulsion polymerization may be carried out in the presence of a chain transfer agent or the like. In addition, the emulsion polymerization conditions (temperature, time, etc.) can be appropriately selected.

The emulsion particles obtained by emulsion polymerization are obtained in a state of being dispersed in water (aqueous solvent). The non-volatile content (solid content) of the emulsion can be adjusted by removing (diluting) a part of such a solvent or adding (diluting) a part thereof.
The emulsion of the present invention tends to maintain a relatively high viscosity (particularly low viscosity) even when water (aqueous solvent) is newly added.

[Use, etc.]
The emulsion of the present invention can be used for various purposes. For example, the emulsion of the present invention can be used as a coagulant (coagulant), a granulator, a thickener (a thickener for paints, etc.) and the like.

In particular, the emulsion of the present invention is used as a coagulant or a granulator (for example, a dust inhibitor) in consideration of its cohesive force, handleability or usability (for example, a point that it has a relatively low viscosity even at a high concentration). Alternatively, it may be suitably used for dust prevention applications) and the like.

In such applications, the compounding (application) target is not particularly limited, but for example, soil, sand, earth and sand, minerals (for example, iron ore, slag, limestone, etc.), carbonaceous substances (for example, coal, coke, etc.). ), Paint, etc.

The present invention is not limited to the above-described embodiments, and various modifications can be made, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the present invention. ..

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.
Unless otherwise specified, "parts" and "%" mean "mass (weight) parts" and "% by mass", respectively.
In addition, various analyzes and evaluations were conducted as follows.

<Particle diameter>
The average particle size of the emulsion particles was measured according to JISZ8828: 2019 using a multi-sample nanoparticle size measuring device (nanoSAQLA manufactured by Otsuka Electronics) by a dynamic light scattering method.

<Glass transition temperature (Tg)>
It was obtained based on the above-mentioned Fox formula.
However, the emulsion particles obtained in Reference Example 2 were measured by DSC (differential scanning calorimetry).

<Molecular weight>
The differential refractive index dn of the parameters required for calculating the weight average molecular weight Mw using a molecular weight measuring instrument (DLS-8000 manufactured by Otsuka Electronics) and a high-sensitivity differential refractometer (DRM-3000 manufactured by Otsuka Electronics) by the static light scattering method. / Dc was obtained, and the weight average molecular weight Mw was obtained from the following formula.

_{Is /} I ₀ = [4π ² _n ² Mw × c (dn / dc) ² ] × (1 + cos ² θ) ÷ (λ ₀ ⁴ r ² NA)

Incident light wavelength: λ ₀ , Incident light intensity: I ₀ )
Scattered light intensity: _Is
Refractive index of solvent: n
Weight average molecular weight: Mw
Solute concentration: c
Increased concentration of refractive index difference: dn / dc
Distance from scattered material to detection device: r
Avogadro's number: _NA

The sample preparation conditions and measurement conditions are shown below.
Sample preparation conditions
Each sample is dried at 110 ° C. for 1 hour to obtain a solid sample. Next, it was diluted with a 1 mol / L NaCl aqueous solution to the following four concentrations.
Concentration 1 0.100 mg / mL
Concentration 2 0.200 mg / mL
Concentration 3 0.300 mg / mL
Concentration 4 0.400 mg / mL
Measurement condition
After each concentration sample after dilution is sufficiently stirred, the sample is placed in a φ21 cylindrical cell, and the sample is placed.
Measurements were carried out at DLS-8000 at an angle of 40 ° to 120 ° at 10 ° intervals.
The measurement temperature was 25 ° C., and the number of integrations was 100 times.
As the solvent condition, the value of water at 25 ° C. (refractive index 1.3328) was used.

<Acid value>
The acid value (mgKOH / g) per 1 g of resin solid content was measured according to JIS K0070: 1992 using an automatic titrator (trade name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.).

<pH>
The pH was measured at 25 ° C. using a pH meter (LAQUA manufactured by HORIBA, Ltd.) in accordance with JIS Z8802.

<Solid content (non-volatile content)>
For the amount of solid content in the emulsion, 1 g of the emulsion was weighed and dried in a hot air dryer at a temperature of 110 ° C. for 1 hour, and the obtained residue was used as a non-volatile content.
[Non-volatile content in resin emulsion (% by mass)]
= ([Mass of residue] ÷ [Resin emulsion 1 g]) × 100
Obtained based on.

<Cohesion evaluation>
Add 25 parts of water to 75 parts of iron (III) oxide (purchased from Fuji Film Wako Pure Chemical Industries, Ltd.) to prepare a slurry of iron (III) oxide with a water content of 25%, and add 30 parts from it. I took it out. Each sample (emulsion or powder) was added so as to have a solid content of 0.02 part, and the mixture was well stirred.
Cohesive strength The obtained mixture was evaluated according to the following criteria.
(Evaluation criteria)
⊚: The slurry was dried and became a fine powder.
◯: The slurry aggregated into a dumpling-like mass.
Δ: The slurry showed some water floating, but thickened and aggregated.
X: The slurry does not aggregate and remains a low-viscosity solution.

<Aqueous solution viscosity>
Measurements were performed under the following conditions in accordance with JIS-7117-1: 1999.
Each sample (emulsion, powder) is diluted or dissolved with deionized water to prepare a 20% aqueous solution, a 1% aqueous solution, and a 0.1% aqueous solution, placed in a closed container, and cured at room temperature for 1 day. , BM viscosity meter (manufactured by Toki Sangyo Co., Ltd., product number: TVB-10M) was used to measure the viscosity at 25 ° C. at a rotation speed of 30 rpm, and the viscosity was evaluated based on the following evaluation criteria.

(Evaluation criteria)
⊚: Viscosity is 10 mPa · s or less.
◯: The viscosity exceeds 10 mPa · s and is 100 mPa · s or less.
Δ: Viscosity exceeds 100 mPa · s and is 1,000 mPa · s or less ×: Viscosity exceeds 1,000 mPa · s. Or it does not dissolve.

(Example 1)
660 parts of deionized water was placed in a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser.

From 570 parts of deionized water, 30 parts of 20% aqueous solution of emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Hytenol LA-10], 371 parts of ethyl acrylate, 256 parts of methacrylic acid and 13 parts of acrylamide in the dropping funnel. By preparing a pre-emulsion, 62 parts of which is added into the flask, the temperature is raised to 67 ° C. while gently blowing nitrogen gas, and 8 parts of a 0.5% aqueous solution of ammonium persulfate is added into the flask. , Polymerization was started.

Next, the rest of the preemulsion for dropping was uniformly dropped into the flask over 120 minutes. After completion of the dropping, the contents of the flask were maintained at 60 ° C. for 100 minutes and cooled to complete the polymerization reaction.

The obtained reaction solution was cooled to room temperature and then filtered through a wire mesh of 300 mesh (JIS mesh, the same applies hereinafter) to obtain an emulsion having a non-volatile content of 30% by mass. The emulsion particles contained in the emulsion had an average particle diameter of 150 nm and a glass transition temperature of the entire emulsion particles was 26 ° C. In addition, Table 1 shows the emulsions described including their properties.

(Examples 2 to 4)
An emulsion was obtained in the same manner as in Example 1 except that the monomer component (polymerization component) used in Example 1 was changed to the monomer component shown in Table 1. Table 1 shows the composition of the monomer components used in the emulsion, the properties of the emulsion, and the like.

(Reference example 1)
In a flask equipped with a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser, 140 parts of a hydrocarbon solvent [Isoper M manufactured by ExxonMobil Co., Ltd.] and 9 parts of sorbitan monostearate were charged.

Next, a monomer solution consisting of 200 parts of deionized water, 12 parts of acrylic acid and 170 parts of acrylamide was prepared, and 11.5 parts of sodium hydroxide was added to the monomer solution to adjust the pH to 8.5. The monomeric solution was added to the organic phase with rapid stirring. The temperature was raised to 60 ° C. while gently blowing nitrogen gas, and 0.35 parts of 2,2'-azobis (isobutyronitrile) was added into the flask to initiate polymerization.

Next, the contents of the flask were maintained at 60 ° C. for 150 minutes and cooled to complete the polymerization reaction.

The obtained reaction solution was cooled to room temperature and then filtered through a wire mesh of 300 mesh to obtain an emulsion having a non-volatile content of 40% by mass. The emulsion particles contained in the resin emulsion had an average particle diameter of 3 μm and a glass transition temperature of the entire emulsion particles was 140 ° C. In addition, Table 1 shows the emulsions described including their properties.

(Reference example 2)
150 parts of deionized water and 140 parts of ammonium sulfate were placed in a flask equipped with a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser.

Next, 22 parts of a 50% aqueous solution of 2-acrylamide 2-methylpropanesulfonic acid (hereinafter abbreviated as AMPS) neutralized product, 8.4 parts of acrylic acid, 2.7 parts of sodium hydroxide and 106 parts of acrylamide were prepared. Further, 58 parts of a 15% homopolymer aqueous solution of AMPS having a polymerization average molecular weight of 400,000 that was neutralized by 100 mol% was added, and the temperature was adjusted to 30 ° C. while gently blowing nitrogen gas to obtain a 0.5% aqueous solution of ammonium persulfate. Polymerization was initiated by adding 5 parts and 0.5 part of a 0.5% aqueous solution of ammonium hydrogensulfate into the flask.

After 7 hours from the start of the polymerization, 0.5 part of a 0.5% aqueous solution of ammonium persulfate and 0.5 part of a 0.5% aqueous solution of ammonium hydrogen sulfite were added, and the mixture was further maintained at 30 ° C. for 8 hours to complete the polymerization reaction.

The obtained reaction solution was filtered through a wire mesh of 300 mesh to obtain an emulsion having a non-volatile content of 45% by mass. The emulsion particles contained in the resin emulsion had an average particle diameter of 5 μm and a glass transition temperature of the entire emulsion particles was 140 ° C. In addition, Table 1 shows the emulsions described including their properties.

(Reference example 3)
Powdered polyacrylamide (100 mol% acrylamide homopolymer, Mw 5-6 million, obtained from Polyscience, Inc) was used. Table 1 shows a description of this powder polymer including its properties.

(Reference example 4)
A powdered sodium acrylate / acrylamide copolymer [soda acrylate / acrylamide = 70/30 (mol%) = 66/34 (wt%), Mw 18 million, obtained from Polyscience, Inc) was used. Table 1 shows a description of this powder polymer including its properties.

The results are shown in Table 1. In Table 1, EA is ethyl acrylate, MAA is methacrylic acid, AA is acrylic acid, and Aam is acrylamide.

According to the present invention, a novel emulsion or the like can be provided.

Claims (17)

An O / W type emulsion containing a polymer (A) having a structural unit (A1) derived from an amide group-containing monomer, wherein the polymer (A) contains the structural unit (A1) in a proportion of 0.1 to 35% by mass. Emulsion containing. The emulsion according to claim 1, wherein the amide group-containing monomer contains (meth) acrylamide. The emulsion according to claim 1 or 2, wherein the ratio of the structural unit (A1) in the polymer (A) is 0.5 to 25% by mass. The emulsion according to any one of claims 1 to 3, wherein the polymer (A) has a structural unit (A2) derived from a (meth) acrylic acid ester. The emulsion according to claim 4, wherein the structural unit (A2) has a structural unit derived from (meth) acrylic acid C _1-3 alkyl ester. The emulsion according to claim 4 or 5, wherein the ratio of the structural unit (A2) in the polymer is 20% by mass or more. The emulsion according to any one of claims 4 to 6, wherein the structural unit (A1) contains 2 parts by mass or more of the structural unit (A2) with respect to 1 part by mass. The emulsion according to any one of claims 1 to 7, wherein the polymer (A) has a structural unit (A3) derived from an acid group-containing monomer. The emulsion according to claim 8, wherein the ratio of the structural unit (A3) in the polymer is 5% by mass or more. The emulsion according to claim 8 or 9, which contains 0.5 part by mass or more of the structural unit (A3) with respect to 1 part by mass of the structural unit (A1). The polymer (A) has a structural unit (A2) derived from a (meth) acrylic acid ester and a structural unit (A3) derived from an acid group-containing monomer, and the structural unit (A2) has a structural unit (A1) with respect to 1 part by mass of the structural unit (A2). ) And the emulsion according to any one of claims 1 to 10, which contains 3 parts by mass or more of the structural unit (A3). The polymer (A) has a structural unit (A1) derived from an amide group-containing monomer, a structural unit (A2) derived from a (meth) acrylic acid ester, and a structural unit (A3) derived from an acid group-containing monomer.
The structural unit (A2) has a structural unit derived from (meth) acrylic acid C _1-3 alkyl ester, and has.
The structural unit (A3) has a structural unit derived from (meth) acrylic acid and has.
The ratio of the structural unit (A1) in the polymer (A) is 1 to 20% by mass.
The ratio of the structural unit (A2) in the polymer is 30% by mass or more, and the ratio is 30% by mass or more.
The emulsion according to any one of claims 1 to 11, wherein the ratio of the structural unit (A3) in the polymer is 10% by mass or more. The emulsion according to any one of claims 1 to 12, wherein the polymer (A) has a weight average molecular weight of 1 million or more. The emulsion according to any one of claims 1 to 13, wherein the polymer (A) has an average particle size of 1000 nm or less. The emulsion according to any one of claims 1 to 14, wherein the pH is 5 or less. The viscosity at 20% by mass of solid content (25 ° C., BM type viscometer, 30 rpm) is 1000 mPa · s or less, and the viscosity at 1% by mass of solid content (25 ° C., BM type viscometer, 30 rpm) is 100 mPa · s or less. The emulsion according to any one of claims 1 to 15. The viscosity of the emulsion at a solid content concentration of 20% by mass is V ₂₀ (mPa · s), the viscosity of the emulsion at a solid content concentration of 1% by mass is V ₁ (mPa · s), and the viscosity of the emulsion at a solid content concentration of 0.1% by mass. 1. Is V _0.1 (mPa · s), the value of V ₂₀ -V ₁ is 100 mPa · s or less, and the value of V ₂₀ -V _0.1 is 300 mPa · s or less, according to claims 1 to 16. Emulsion according to any.