JPWO2020085123A1 - Composition for aqueous coating liquid containing a polymer of N-vinylcarboxylic acid amide - Google Patents

Abstract

We propose a structure that can be efficiently dried when producing a coated product from an aqueous composition containing a polymer of N-vinylcarboxylic acid amide. A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide and water.

Description

The present invention relates to a composition containing a polymer of N-vinylcarboxylic acid amide as a water-soluble polymer, and mainly comprises a paint, an ink, an adhesive containing a water-soluble polymer, a positive electrode, a negative electrode, and a separator of a lithium ion battery. The present invention relates to a composition capable of forming an easily dry coating product on a construction surface in a water-based coating liquid such as.

Coating and printing technologies using water-soluble polymers have begun to be widely used in the entire industrial field from the viewpoints of environment and safety and efficiency. Especially in the case of thinning, a water-based coating liquid using a water-soluble polymer is very excellent, and has a great industrial advantage.

Among them, poly N-vinylacetamide (hereinafter, sometimes referred to as PNVA (registered trademark)), which is one of the polymers of N-vinylcarboxylic acid amide, is also amphipathic, and has high molecular weight and high viscosity. Because it is easy to use, it is used for various purposes such as water-based inks and paints, thickening of various water-based compound coating liquids, film formation, and adhesives. In particular, it is used as an adhesive, a paint, a building material, and a binder resin for a secondary battery in the personal care field such as pharmaceuticals and cosmetics, and the construction field and industrial field such as building materials.

However, when a water-soluble polymer such as a polymer of N-vinylcarboxylic acid amide is dissolved in water as a solvent and used, the case where an organic solvent is used except for some high boiling point organic solvents is used. In many cases, the drying efficiency is significantly inferior in comparison.

In addition, non-hydrophilic polymer emulsions and rubber latex may be used as water-based coating liquids in applications where filming properties are not expected, but the drying speed differs greatly when these are compared with water-soluble polymers. With water-soluble polymers, it has been a problem that it takes a long time to dry. Polymer emulsions and rubber latex cannot be expected to thicken as binders for coating, and there are many problems in that the coated surface is brittle.

In general, improving the drying efficiency is often dealt with by improving the equipment and optimizing the drying conditions.

The cost of equipment improvement is often enormous, and increasing the hot air temperature and air volume has a considerable effect on the object to be dried, so there is a natural limit.

From the viewpoint of energy saving, it is necessary to avoid unnecessarily increasing energy consumption due to an increase in drying temperature or air volume.

In particular, in the manufacture of secondary batteries such as lithium ion batteries, it is required to reduce the thickness of the coated material from the viewpoint of weight reduction and high density. For this reason, the direction in which energy consumption in the manufacturing process increases is extremely unfavorable in consideration of the environment, and therefore, improving the drying speed of coated materials containing water-soluble polymers is recognized as a necessary technology. ..

The following are conventional techniques for improving the drying method of water-based coating liquids.

For example, in Patent Document 1, a drying method is used in which the coating liquid is irradiated with near infrared rays from a short distance of 10 to 35 cm and blown to cure the coated product. This is an improvement of the drying conditions and the binder itself is dried. It is not a sex improvement.

Further, as a method for improving the drying property of the aqueous medium substance, it is conceivable to add inorganic fillers or non-hydrophilic resins to the emulsion, but it is not always applicable to a coating liquid containing a water-soluble polymer. No.

For example, Patent Document 2 describes a composition in which talc is added to water-dispersion emulsions as a base adjusting material for a cement-based base material, but it is intended to be naturally dried or air-dried, and has high water solubility. The range of application as a method for improving the dryness of a coating liquid containing molecules is quite limited.

Further, Patent Document 3 discloses an adhesive composition containing a thermoplastic resin powder such as an acrylic resin in an aqueous resin dispersion containing a styrene-butadiene copolymer latex and a chloroprene rubber latex. However, when a water-soluble polymer is used, it is often difficult to add a water-insoluble substance, and the amount of addition is limited, so the scope of application is extremely narrow.

Patent Document 4 discloses a thickening dispersant for a slurry for a positive electrode of a lithium ion secondary battery containing one or more of water-soluble polymers such as carboxylmethyl cellulose and poly N-vinylacetamide. However, the binding property between the positive electrode active materials and the positive electrode active material and the current collector is enhanced, the concentration of the thickening dispersant in the positive electrode slurry is low, and the problem of drying is neither disclosed nor suggested.

Japanese Unexamined Patent Publication No. 6-170327 Japanese Patent No. 5433149 JP-A-2009-102606 WO2015 / 146649A

Generally, when improving the drying property of a coating liquid containing a water-soluble polymer, it is rare that a non-hydrophilic resin or the like can be added to the composition in the first place, and even if it can be added, the amount is limited. There are many cases, and there are not many cases where the effectiveness can be utilized.

In reality, no configuration has been proposed that can efficiently dry a coated product from an aqueous composition in which a polymer of N-vinylcarboxylic acid amide is dissolved.

Under such circumstances, the present inventors have diligently studied and found that the drying property is remarkably improved by mixing the polymer of N-vinylcarboxylic acid amide, which is a water-soluble polymer, with a polysaccharide. Has been completed.

That is, the configuration of the present invention is as follows.
[1] A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide and water.
[2] The composition for an aqueous coating liquid according to [1], wherein the N-vinylcarboxylic acid amide is N-vinylacetamide.
[3] The composition for an aqueous coating liquid according to [1], wherein the polysaccharide is a cellulose derivative.
[4] The composition for an aqueous coating liquid according to [3], wherein the cellulose derivative is an alkaline (earth) metal salt of carboxylmethyl cellulose.
[5] The compositions for aqueous coating liquids of [1] to [4], wherein the composition ratio of the polymer of the N-vinylcarboxylic acid amide to the polysaccharide is 95: 5 to 50:50 by mass ratio. ..
[6] The compositions for aqueous coating liquids of [1] to [5], which further contain inorganic fillers.
[7] The composition for an aqueous coating liquid according to [6], wherein the inorganic fillers are alumina.
[8] The composition for an aqueous coating liquid according to [1] to [7], wherein the content of the polymer of the N-vinylcarboxylic acid amide in the composition is in the range of 0.05 to 20% by mass.
[9] A method for producing an aqueous polymer coated product, wherein the compositions for the aqueous coating liquids of [1] to [8] are applied to the surface of the base material and dried.

According to the present invention, since the polysaccharide is contained in the composition containing the polymer of water and N-vinylcarboxylic acid amide, the drying property is remarkably improved when the composition is applied.

The composition of the present invention has a structure derived from N-vinylcarboxylic acid amide, has high hydrophilicity because it retains polarity, and has moistening, dispersing, and thickening effects on various aqueous solutions, and at the same time, various materials. Has adhesiveness to. Above all, it has an extremely high affinity for metals, glass, polypropylene, polyethylene, polyethylene terephthalate film, etc., and has high adhesion to these materials.

Such compositions are suitably used in fields where wetting, dispersing and thickening effects, adhesive effects and the like are required. In particular, it can be used as an adhesive, a paint, a building material, and a coating liquid for a secondary battery in the personal care field such as pharmaceuticals and cosmetics, and the construction field and industrial field such as building materials.

Hereinafter, the present invention will be specifically described. The configuration of the present invention is, of course, not limited to these.

Composition for Aqueous Coating Liquid The composition for an aqueous coating liquid of the present invention contains at least water, a polymer of N-vinylcarboxylic acid amide, and a polysaccharide as essential compositions. Examples of the coating liquid include adhesives, paints, inks, positive electrodes, negative electrodes, and separators of lithium ion batteries. Hereinafter, each component will be described.

The polymer present invention N- vinylcarboxamides, polymers of N- vinyl carboxylic acid amide is used as the water-soluble polymer.

The N-vinylcarboxylic acid amide is represented by the following formula (1).

（一般式（１）中、Ｒ¹は水素原子および炭素数１〜６の炭化水素基からなる群より選ばれるいずれか１種である。Ｒ²は水素原子または炭素数1〜６の炭化水素基を示す。Ｒ¹は、ＮＲ²と環構造を形成してもよい。）

(In the general formula (1), R ¹ is any one selected from the group consisting of a hydrogen atom and a hydrocarbon group ^{having 1 to 6 carbon atoms. R 2} is a hydrogen atom or a hydrocarbon having 1 to 6 carbon atoms. Indicates a group. R ¹ may form a ring structure with NR ^2.)

Specific examples of the N-vinylcarboxylic acid amide include N-vinylformamide, N-vinylacetamide, N-vinylpropionamide, N-vinylbenzamide, N-vinyl-N-methylformamide, and N-vinyl-N-. Ethylformamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinylpyrrolidone and the like can be mentioned. Of these, N-vinylacetamide is particularly preferable. The N-vinylcarboxylic acid amide may be used alone or in combination of two or more.

The polymer used in the present invention may be a homopolymer of N-vinylcarboxylic acid amide, but may be a copolymer containing another monomer unit in the structure.

The other monomer unit is not particularly limited as long as it can be copolymerized with N-vinylcarboxylic acid amide, and is, for example, methacrylic acid, itanconic acid, maleic acid, maleic anhydride, crotonic acid, and derivatives thereof. Maleic anhydride monomers such as salts and esters;
Acryloyl morpholine, isopropyl acrylamide;
Unsaturated nitrile monomers such as metachloronitrile and α-chloroacrylonitrile;
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate. , Nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, etc. Acrylate;
Alicyclic alkyl group-containing ethylenically unsaturated monomers such as cyclohexyl (meth) acrylate and isobonyl (meth) acrylate;
Fluorinated alkyl group-containing ethylenically unsaturated monomers such as trifluoroethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate; (meth) acrylamide, N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl -(Meta) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl- (meth) acrylamide, N, N-di (methoxymethyl) acrylamide, N- Ethoxymethyl-N-methoxymethylmethacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N -(Propoxymethyl) metaacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) metaacrylamide, N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl- Amid group-containing ethylenically unsaturated mono-acrylamides such as N- (pentoxymethyl) metaacrylamide, N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide. Acrylamide;
2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, allyl Hydroxyl group-containing ethylenically unsaturated monomers such as alcohol; styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxy Ethyl methacrylate, phenoxydiethylene glycol acrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol acrylate, phenoxytetraethylene glycol methacrylate, phenoxyhexaethylene glycol acrylate, phenoxyhexaethylene glycol methacrylate, phenylacrylate, phenylmethacrylate, etc.
If cross-linking is required, 2-[(O-1'-methylpropylideneamino) carboxyamino] ethyl methacrylate (Showa Denko KK Karens MOI-BM (registered trademark)), and 2-[(3, 5-Dimethylpyrazolyl) carbonylamino] ethyl methacrylate (Showa Denko KK Karens MOI-BP (registered trademark)), dihydroxypropyl (meth) acrylate, trade name Light Ester HO, HOP, HOB manufactured by Kyoeisha Chemical Co., Ltd. , HOA, HOPA, Kyoeisha Chemical Co., Ltd., trade name: Light acrylate (registered trademark) HOBA-derived monomer units can be mentioned.

The content of the monomer unit derived from N-vinylcarboxylic acid amide in the copolymer is preferably 60 mol% or more and 100 mol% or less.

Among them, the homopolymer of N-vinylacetamide is excellent in thinning when applying an aqueous solution compounding agent to various base materials, and is used for a secondary battery having a high level of safety requirement from the viewpoint of heat resistance. Most preferable as a coating material.

The weight average molecular weight of the polymer of N-vinylcarboxylic acid amide used in the present invention is preferably 10,000 to 4 million, more preferably 100,000 to 3 million, still more preferably 500,000 to 2 million. Is in the range of. The weight average molecular weight here is determined by the method by the GPC measurement method described later.

The viscosity of the aqueous solution obtained by dissolving the polymer in water so as to be 5% by mass is preferably 1,000 to 30,000 mPa · s, more preferably 3,000 to 20,000 mPa · s, and further. It is preferably 6,000 to 15,000 mPa · s. The viscosity was determined by the Brookfield viscometer described below.

An aqueous solution of a polymer having such properties becomes a viscous liquid having thixotropy and slipperiness.

The method for producing the polymer is not particularly limited, and the polymer can be produced by polymerizing various monomers of N-vinylcarboxylic acid amide by a known polymerization method using a radical polymerization initiator. Examples of the polymerization method include a solution polymerization method, an aqueous solution polymerization method, a precipitation precipitation polymerization method, and a reverse layer suspension polymerization method. Upon completion of the polymerization, a viscous liquid, agar-like, or powder-like product is obtained. Furthermore, the viscous liquid and agar-like products can be pulverized by dehydration drying.

When used for coating purposes, it is essential to increase the molecular weight, so the radical polymerization method using an aqueous solution is preferable.

When the polymerization reaction is carried out by an aqueous solution polymerization method, a monomer aqueous solution is placed in a reaction vessel equipped with a stirrer, a thermometer and a nitrogen gas vent tube, and the monomer aqueous solution is aerated with nitrogen gas. Then, when the radical polymerization initiator is added and mixed, the polymerization is started. This monomer aqueous solution is prepared by dissolving various monomers such as N-vinylcarboxylic acid amide and unsaturated carboxylic acid monomer in ion-exchanged water in advance and adjusting the polymerization start temperature. The input temperature of the radical polymerization initiator is preferably 45 to 70 ° C., and the radical polymerization initiator may be produced by sequential polymerization in which an aqueous monomer solution or an aqueous polymerization initiator is added dropwise.

In the case of the polymerization method in which all the monomers are charged in advance, the internal temperature of the polymerization tank rises to the peak temperature about 0.5 to 3 hours after the initiator is charged.

The concentration of the N-vinylcarboxylic acid amide monomer in the aqueous monomer solution is usually preferably 3 to 20% by mass, more preferably 5 to 15% by mass, still more preferably 7 to 12% by mass, and a single amount. When the monomer concentration in the aqueous solution of the body is in this range, the polymerization rate and the degree of heat generation are suitable, and a product having a target viscosity can be obtained and easily taken out from the reaction vessel.

As the polymerization initiator used for the polymerization of N-vinylcarboxylic acid amide, those generally used for radical polymerization of vinyl compounds can be used without limitation. Examples thereof include a redox-based polymerization initiator, an azo compound-based polymerization initiator, and a peroxide-based polymerization initiator.

These may be used alone or in combination of two or more. In some cases, a chain transfer agent may be used to adjust the molecular weight.

Examples of redox-based polymerization initiators include ammonium persulfate in combination with sodium thiosulfate, sodium thiosulfate, trimethylamine, or tetramethylethylenediamine, or t-butyl hydroperoxide with sodium thiosulfate or sodium thiosulfate. There are combinations.

Examples of peroxide-based polymerization initiators include persulfates such as sodium, potassium and ammonium, benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-butyl peroxide, and organic peroxides such as diacetyl peroxide. Can be mentioned.

As azo-based initiators, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis (isobutyrate), etc. Dimethyl-2,2'-azobis (2-methylbutyrate) and dimethyl-2,2'-azobis (2,4-dimethylpentanoate), 2,2'-azobis (2-amidinopropane) dihydrochloride , 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] n hydrate, 2,2'-azobis {2- [N- (2-carboxyethyl) amidino] propane} Examples thereof include n-hydrate and azo compounds such as 2,2'-azobis (2-methylpropionic acid) dimethyl.

Among the above-mentioned polymerization initiators, in the polymerization method using water as a solvent, considering the influence of the residue on the polymer, 2,2'-azobis [N- (carboxyethyl) -2-methyl, which does not contain halogen. Propion amidine] Tetrahydrate (trade name: azo-based polymerization initiator VA-057 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) is most preferably used.

This VA-057 is dissolved in nitrogen gas degassed water before use.

These radical polymerization initiators may be used in combination, or a redox-based polymerization initiator and a water-soluble azo compound-based polymerization initiator may be used in combination.

In that case, it is preferable to use a combination of ammonium persulfate and sodium thiosulfate as the redox-based polymerization initiator, and 2,2'-azobis (2-amidinopropane) dihydrochloride as the water-soluble azo compound-based polymerization initiator.

The amount of the radical polymerization initiator used is preferably 100 to 10000% by mass, more preferably 500 to 5000% by mass in the case of the azo compound-based polymerization initiator with respect to the total amount of all the monomers. In the case of the system polymerization initiator, it is preferably 10 to 300 mass ppm, more preferably 30 to 100 mass ppm. When the amount of the radical polymerization initiator used is within the above range, both the polymerization rate and the molecular weight of the copolymer tend to be suitable.

As long as the object of the present invention is not impaired, a chain transfer agent may be used at the time of polymerization for the purpose of adjusting the degree of polymerization of the polymer and for introducing a modifying group at the end of the polymer. Examples of the chain transfer agent include aldehyde compounds such as propionaldehyde, ketone compounds such as acetone and methyl ethyl ketone, thiol compounds such as 2-hydroxyethanethiol, 3-mercaptopropionic acid, dodecanethiol and thioacetic acid, and carbon tetrachloride. Examples thereof include halogenated hydrocarbon compounds such as trichloroethylene and tetrachloroethylene, and phosphinates such as sodium phosphinate monohydrate. Of these, thiol compounds, aldehyde compounds, and ketone compounds are preferably used. The amount of the chain transfer agent added is preferably 0.1% by mass or more and 2.0% by mass or less with respect to the total amount of all the monomers. Within this range, the objectives of adjusting the degree of polymerization and introducing a modifying group at the end of the polymer can be sufficiently achieved.

Polysaccharide The polysaccharide is not particularly limited as long as it is hydrophilic, and xanthan gum, gellan gum, pectin, carrageenan, guar gum, karaya gum, dextrin, cellulose derivative and the like can be used. Among these, cellulose derivatives are preferable in terms of high heat resistance.

The following cellulose derivatives can be used without particular limitation. Specifically, methyl cellulose, hydroxypropyl methyl cellulose, alkali (earth) metal salt of carboxyl methyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose and the like can be used. As the alkali (earth) metal salt, sodium salt, potassium salt, lithium salt, magnesium salt, calcium salt and the like are used.

The water water is not particularly limited, and distilled water, ion-exchanged water, tap water and the like can be used, but ion-exchanged water is preferable.

Composition for Aqueous Coating Liquid The composition for an aqueous coating liquid of the present invention is a composition in which the polymer of the above N-vinylcarboxylic acid amide and a polysaccharide are dissolved in a solvent containing at least water. ..

The method for mixing the N-vinylcarboxylic acid amide polymer and the polysaccharide is not particularly limited, but in order to obtain a more uniform mixed state, the N-vinylcarboxylic acid amide polymer and the polysaccharide are used. Is preferably dissolved in a solvent containing at least water, and then mixed with other compounding agents, if necessary. More preferably, both the polymer of N-vinylcarboxylic acid amide and the polysaccharide are dissolved in a solvent containing at least water, and then mixed and homogenized. This makes it possible to take an ideal mixed form. Water is used as the solvent, but a mixed solvent in which water and alcohols are mixed may be used. When alcohols are mixed, they are preferably contained in the solvent in an amount of 50% by mass or less. It is preferable to use only water in terms of cost, production control and waste treatment.

The ideal mixed form is a state in which polysaccharides such as cellulose derivatives are finely dispersed in a water-soluble polymer which is a polymer of N-vinylcarboxylic acid amide, and is combined with a polymer of N-vinylcarboxylic acid amide. As a result of presuming that it inhibits a part of hydrogen bonds with water, it is considered that water is easily separated and dried easily.

In order to obtain the effect, the effect can be expected when the blending amount of one is smaller than that in the mixed state at the same ratio, and in the present invention, it is effective when the amount of polysaccharide is smaller than that of the polymer of N-vinylcarboxylic acid amide. Is easy to express.

Regarding the ratio of the polymer of N-vinylcarboxylic acid amide to the polysaccharide, it is not always better as the ratio of the polysaccharide increases due to the above-mentioned reasons, and the mixing ratio of the water-soluble polymer and the polysaccharide is the mass. The ratio (polymer of N-vinylcarboxylic acid amide: polysaccharide) is preferably 95: 5 to 30:70, more preferably 95: 5 to 50:50, and even more preferably 90: 10 to 80:20. .. The mixing ratio corresponds to the composition ratio.

Within this range, a composition excellent in easy drying can be obtained. The term "easy to dry" means, for example, one that can be dried in a shorter time than the drying time of the polymer of N-vinylcarboxylic acid amide when the same amount of heat is applied. The shorter the drying time, the less time it takes to heat and the shorter the time it takes to cool down. Therefore, the heat history of the base material and the like can be reduced.

The concentration of the polymer of N-vinylcarboxylic acid amide in the composition is appropriately selected depending on the intended use of the composition, the coating method, the viscosity of the coating liquid, and the like, but usually contains at least water. It is preferably in the range of 1 to 30% by mass, more preferably 2 to 20% by mass, still more preferably 4 to 15% by mass, based on the total weight of the composition containing the solvent. Within this range, coating can be performed by a known printing means, and drying can be performed quickly.

The content of the polysaccharide in the composition is appropriately selected depending on the intended use of the composition, the coating method, the viscosity of the coating liquid, and the like, but usually, the composition containing at least a solvent containing water. It is preferably in the range of 0.05% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 5% by mass or less, and further preferably 0.2% by mass or more and 3% by mass or less with respect to the total weight. Is desirable. Within this range, it can be effective in promoting the drying of the composition.

Further, the composition according to the present invention may contain inorganic fillers. When an inorganic filler is contained, the surface area is increased and at the same time, the filler itself has heat dissipation properties, so that the drying property can be further improved. Regarding the composition to which the inorganic fillers are added, the coated product itself has high heat dissipation, heat resistance, and toughness, which has a great industrial advantage.

Examples of the inorganic fillers include at least one selected from the group consisting of boron nitride, aluminum nitride, silicon carbide, silica, alumina, boehmite, talc, zinc oxide, titanium oxide, titanium black and graphite. Of these, alumina is preferable in terms of heat dissipation and easy availability.

The content of the inorganic fillers is preferably in the range of 70% by mass or less, more preferably 20 to 60% by mass, and further preferably 30 to 55% by mass with respect to the total weight of the composition. Within this range, it can be effective in promoting the drying of the composition.

In the method for producing an aqueous polymer coated product according to the present invention, the composition for an aqueous coating liquid is applied to the surface of a base material and dried to form a coating film to produce the coated product. The composition is as described above.

In other words, in the present invention, by mixing a predetermined amount of polysaccharide with the composition containing at least water of the polymer of N-vinylcarboxylic acid amide, the composition is significantly dried as compared with the composition containing no polysaccharide. It is possible to provide a coating / drying method that shortens the time.

The method of applying the composition to the substrate is not particularly limited, but in addition to spray coating, roll coating, bar coating, gravure coating, die coating, knife coating, inkjet coating, brush coating, dip coating, etc., roll to It is also possible to apply continuously using a roll pattern coating device.

Further, the composition may contain a known material to be added to the coating material in addition to the above, and for example, an emulsion binder, a thixotropic agent, a dispersant, a surface conditioner, a defoaming agent, and a leveling agent. May include.

As the base material, a film, a non-woven fabric, a porous body, a plate-shaped body, or the like can be used without particular limitation.

Materials constituting the base material include homopolypropylene, copolymers of propylene and other olefins, polyethylene terephthalate, polyethylene naphthalate, polyamide ether ketone, polyimide, polyamide, polyphenylene sulfone, polyphenylene ether, polyethylene, polyether sulfone, and the like. Organic resin materials such as polyether ether ketone, polybenzoimidazole, polyetherimide, polyamideimide, poly (p-phenylene 2,6-benzobisoxazole), fluororesin, epoxy resin, aluminum, copper, silver, iron, etc. Examples thereof include metal materials, glass (silicon oxide), alumina, magnesia, aluminum nitride, aluminum carbide, silicon nitride, barium titanate and the like. As the base material, one type may be used alone, or two or more types may be used in combination.

The drying method is not particularly limited, and is not particularly limited such as spin drying, vacuum drying, warm air drying, and infrared drying.

The drying time is also not particularly limited, but according to the present invention, the drying time is 95% by mass, which will be described later, at a rate of 1/3 to 1/10 as compared with the case where the polymer of N-vinylacetamide is dried alone. The drying time can be shortened.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not construed as being limited thereto.
[Manufacturing example]
Polymerization of N-vinylacetamide A nitrogen gas vent tube, a stirrer, a solvent dropping device, and a thermometer are attached to a 4-port 1-liter capacity separable flask, and 550 g of ion-exchanged water is charged into the separable flask, and then N − 50 g of vinylacetamide (manufactured by Showa Denko KK) was added. In that state, the mixture was stirred and heated while substituting nitrogen gas in the solution, and the polymerization initiation temperature was raised to 51 ° C., the initiator 2,2'-azobis [N- (carboxyethyl) -2-methylpropion amidine]. Tetrahydrate (hereinafter referred to as VA-057) was added in a state of being dissolved in 10 g of ion-exchanged water degassed with nitrogen gas in an amount of 0.04 g (total monomer ratio: 0.08% by mass). In that state, the polymerization reaction was carried out for 4 hours, and then the internal temperature was raised to 80 ° C. and held for 1 hour, and then sampling was performed to measure the residual monomer by the HPLC method, and the monomer became 1000 mass ppm or less. The reaction was terminated with time, and then 400 g of ion-exchanged water was added, diluted, stirred for 1 hour, and then cooled.

The weight average molecular weight of the obtained N-vinylacetamide polymer was 2,000,000. The viscosity of the 5% by mass aqueous solution was 11,500 mPa · s.

Measurement of Weight Average Molecular Weight The polymer was dissolved in distilled water at a concentration of 1% by mass, and the weight average molecular weight was measured by the GPC (gel permeation chromatography) method under the following conditions.

For the calculation of the weight average molecular weight in this measurement, a calibration curve prepared from the absolute molecular weight measurement results of the N-vinylacetamide polymer in each molecular weight band was used.

Detector (RI): Showa Denko Corporation SHODEX (registered trademark) RI-201H Pump: Shimadzu Corporation LC-20AD
Column oven: Showa Denko SHODEX (registered trademark) AO-30C
Analytical device: SIC 480II Data Station manufactured by System Instruments Co., Ltd.
Column: Showa Denko Corporation SHODEX (registered trademark) SB806 x 2 Eluent: Distilled water / 2-propanol = 8/2 (mass ratio)
Flow rate: 0.7 ml / min

Viscosity measurement method Place the test piece in a 300 ml tall beaker and leave it in a constant temperature bath at 20 ° C. for 12 hours or more so that there are no air bubbles inside. After that, a beaker was placed in a constant temperature water tank whose temperature was adjusted to 20 ° C., and it was confirmed with a thermometer that the temperature of the specimen was 20 ± 0.5 ° C., and a B-type viscometer shown in JIS K-7117-1-1999. The viscosity is measured under the following conditions using. Record the viscosity 10 minutes after the value settles.

Viscometer: DVE (Brookfield) Viscometer HA type Spindle: No. 6 Spindle rotation speed: 50 rpm
Temperature: 20 ° C

Measurement of the amount of residual monomer The polymer sample was dissolved in an aqueous solution of _{sodium sulfate (Na 2} SO ₄ ) having a concentration of 0.05 mol / L to obtain a polymer solution. The concentration of the polymer in this polymer solution is 0.1% by mass. Then, this polymer solution was analyzed by the GPC method, and the total amount (residual monomer amount) of various monomers remaining in the polymer sample was calculated. From this amount of residual monomer, it can be confirmed whether or not the polymerization reaction is completed.

Detector (RI): Showa Denko Corporation SHODEX (registered trademark) UV-41
Pump: Showa Denko Corporation SHODEX (registered trademark) DS-4
Column oven: Sugai U-620 40 ° C
Analytical device: Shimadzu Corporation C-R7A Plus
Column: Showa Denko Corporation SHODEX (registered trademark) SB802.5HQ x 1 Eluent: 0.05 mol / L Na ₂ SO ₄ aqueous solution Flow rate 1.0 ml / min
The concentration was determined by the calibration curve method (sample concentration: 1, 5, 10, 100 mass ppm).

[Examples 1 to 16]
The 5% by mass N-vinylacetamide polymer aqueous solution obtained in the production example and the 5% by mass aqueous solution of the polysaccharide shown in Table 1 were placed in the same container at 25 ° C. according to the mixing ratio in Table 1. The mixture was stirred and homogenized to prepare a composition for an aqueous coating solution. Further, in Example 16, after homogenization, alumina was mixed at the ratio shown in Table 1.

[Comparative Examples 1 to 7]
A composition for an aqueous coating liquid having the composition shown in Table 1 was prepared. In Comparative Example 7, alumina was mixed with the aqueous solution of Comparative Example 1 at the ratio shown in Table 1.

The materials other than the N-vinylacetamide polymer (PNVA) used in Examples and Comparative Examples are as follows.

Sodium salt of carboxylmethyl cellulose (CMC): MAC-350-HC Nippon Paper Industries, Ltd.
Acrylic emulsion: Viniblanc (registered trademark) 2685 Nisshin Kagaku Kogyo Co., Ltd.
Styrene-butadiene latex: BM-400B ZEON CORPORATION
Guagam: Reagent Made by Junsei Chemical Co., Ltd. Hydroxyethyl cellulose (HEC): AW-15F Made by Sumitomo Seika Chemical Co., Ltd. Alumina: AL-160SG Showa Denko KK

The drying rate was measured by the following method.
Evaluation (95% by mass drying time and 47.5% by mass drying time)
Collect 1.5 g of the sample aqueous coating liquid composition on an aluminum cup, place it on the aluminum cup, and spread it smoothly and evenly on the bottom surface of the aluminum cup with a spatula. For the samples of Examples 1 to 15 and Comparative Examples 1 to 6, on a heat balance (manufactured by METTLER TOLEDO Co., Ltd .: PM460), the mass was reduced by 95% by mass from the initial mass at 85 ° C., that is, until the water was almost evaporated. Evaporation time is measured at 1 minute intervals.

For Examples 1 to 15, the evaporation time difference (shortening time) from Comparative Example 1 to which the polysaccharide was not added was determined.

Example 16 and Comparative Example 7 were evaluated at 85 ° C. by the evaporation time from the initial mass to a decrease of 47.5 mass%. In Example 16, the difference in evaporation time from Comparative Example 7 was set as the shortened time.

The results are shown in Table 1.

From the results in Table 1, even when compared with acrylic emulsions and styrene-butadiene latex, which have a high drying rate, the drying time is comparable to that of N-vinylacetamide polymers by adding and mixing polysaccharides such as CMC. became. Further, it can be seen that the drying property is most improved when the ratio of the polysaccharide to the polymer of N-vinylacetamide is about 10 to 20% by mass.

Furthermore, depending on the ratio, the drying rate may be faster when the N-vinylacetamide polymer and the polysaccharide are mixed than when the polysaccharide containing the polymer of N-vinylcarboxylic acid amide is contained alone. Even in the system to which the inorganic filler is added, the drying rate is faster in the system to which the polysaccharide is added. Therefore, the mixing of the N-vinylacetamide polymer and the polysaccharide should increase the drying rate. It can be said that it is a useful means in.

As described above, the drying rate can be increased by adding and mixing a polysaccharide such as CMC at a constant ratio to the polymer of N-vinylcarboxylic acid amide.

In the production of a product having a step of applying and drying an aqueous coating solution containing a polymer of N-vinylcarboxylic acid amide, according to the present invention, it is possible to dry at a higher speed, and the production of the entire industry. It is expected to contribute significantly to improving productivity.

Claims (9)

A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide and water. The composition for an aqueous coating liquid according to claim 1, wherein the N-vinylcarboxylic acid amide is N-vinylacetamide. The composition for an aqueous coating liquid according to claim 1, wherein the polysaccharide is a cellulose derivative. The composition for an aqueous coating liquid according to claim 3, wherein the cellulose derivative is an alkaline (earth) metal salt of carboxylmethyl cellulose. The aqueous coating liquid according to any one of claims 1 to 4, wherein the composition ratio of the polymer of the N-vinylcarboxylic acid amide to the polysaccharide is 95: 5 to 50:50 by mass ratio. Composition. The composition for an aqueous coating liquid according to any one of claims 1 to 5, further comprising an inorganic filler. The composition for an aqueous coating liquid according to claim 6, wherein the inorganic fillers are alumina. The composition for an aqueous coating liquid according to any one of claims 1 to 7, wherein the content of the polymer of N-vinylcarboxylic acid amide in the composition is in the range of 0.05 to 20% by mass. thing. The composition for an aqueous coating liquid according to any one of claims 1 to 8 is applied to the surface of the base material and dried.
A method for manufacturing an aqueous polymer coated product.